A multi-purpose heat pump system for cooling, heating and electricity

Abstract

The present invention relates to the fields of engines, refrigerators, and heat pumps. The present invention relates to a multipurpose heat pump system for cooling, heating, and power generation, comprising a first heat exchanger, a compressor, a second heat exchanger, an expansion device, and a motor connected in sequence. The expansion devices include first-type expansion devices and second-type expansion devices. The first-type expansion device is an expander that recovers expansion work during the expansion of a working fluid and outputs mechanical work. The number of first-type expansion devices (X ≥ 1) is greater than or equal to one. The second-type expansion device is an expansion device other than an expander. The number of second-type expansion devices (Y ≥ 1) is greater than or equal to one. The second-type expansion device includes an electronic expansion valve, etc. The multipurpose heat pump system for cooling, heating, and power generation has two operating modes. The first operating mode is a refrigeration cycle, in which the multipurpose heat pump system consumes electricity and generates cooling and heat. The second operating mode is a power cycle, in which the multipurpose heat pump system consumes cooling and heat and generates electricity. The system has the advantages of multiple functions, high efficiency, good economy, and high reliability.

Description

Technical Field

[0001] The present invention relates to the fields of engines, refrigerators and heat pumps, and in particular to a multi-purpose heat pump system for cooling, heating and electricity. Background Art

[0002] Heat pump systems are typically used to provide cooling or heat. To improve overall energy efficiency and reduce operating costs, the industry has proposed generating cooling or heat during the nighttime off-peak period when electricity load is very low, storing the heat and releasing it during the daytime peak period when electricity load is higher, to meet cooling or heat needs. However, since cooling is primarily stored through ice making and heat is primarily stored through phase change media or sensible heat materials, the small operating temperature difference makes it difficult to balance both operating efficiency and heat storage density. Furthermore, since cooling or heat demand is affected by seasonality, energy storage methods based on cooling or heat storage and directly used for cooling or heating needs have limited year-round operation time, resulting in poor economic efficiency.

[0003] In recent years, heat pump systems have gained increasing attention for their application in energy storage. These systems use a reverse cycle to convert nighttime electricity during low-demand periods into high-temperature heat and low-temperature heat, storing them separately. Then, through a forward cycle, the stored high-temperature heat and low-temperature cooling are converted back into electricity during peak demand periods. These heat pumps, designed for energy storage, differ significantly from existing heat pumps designed for cooling or heating in terms of operating temperature differential, cycle, working fluid, and device design. For example, the average temperature difference between the high-temperature and low-temperature heat in heat pumps designed for energy storage typically ranges from 100°C to 600°C, while that in heat pumps designed for cold or heat storage typically ranges from 20°C to 80°C. Therefore, efficiently meeting both cooling or heating needs and energy storage requirements with a single heat pump system is extremely difficult. This is why current heat pump systems designed to meet both cooling / heating needs and energy storage are primarily based on cold / heat storage and directly utilize cold / heat energy storage. In addition, the industry has also proposed some heat pump systems that meet the needs of electricity storage while taking into account cooling / heating needs, such as patent CN106224040B and patent CN110206599B. These systems mainly use stored heat and cold for heating, cooling and power generation. Since the cold and heat for their cooling / heating needs are obtained from the cold and heat storage used for power generation needs, and the cold and heat storage used for power generation needs usually have a large operating temperature difference, the cold and heat used for power generation needs are generated under a large temperature difference. When they are used for cooling / heating needs, the cold / heat temperature difference is usually low, resulting in low efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a multi-purpose heat pump system for cooling, heating and electricity. The system includes a mass regulating device, which regulates the pressure in the heat pump system, so that the heat pump system can switch between different operating cycles under different application requirements. At the same time, in order to solve the damage of the liquid to the expander in the vapor compression cycle, the system also includes two types of expansion devices. When facing cooling or heating needs, the pressure in the heat pump system is regulated by the mass regulating device, so that the system cycle can achieve or approach the vapor compression cycle, and expansion devices other than the expander are fully or mainly used for working fluid expansion, achieving high performance, high reliability and low cost in the process of facing cooling or heating needs; when facing power storage needs, the pressure in the heat pump system is regulated by the mass regulating device, so that the system cycle can achieve or approach the Brayton cycle or the reverse Brayton cycle, and the expander is fully or mainly used to recover expansion work, achieving high performance in the process of facing power storage needs. Therefore, a set of heat pump systems can efficiently meet different application needs, thereby having the advantages of multiple functions, high efficiency, good economy and high reliability.

[0005] To solve the above technical problems, the present invention adopts the following technical solution: a multi-purpose heat pump system for cooling, heating and electricity, comprising a first heat exchanger, a compressor, a second heat exchanger, an expansion device connected in sequence, and a motor, characterized in that the expansion device comprises a first type expansion device and a second type expansion device;

[0006] The first type of expansion device is an expander that recovers the expansion work of the working medium during expansion and outputs mechanical work. The number of the first type of expansion devices X is ≥ 1;

[0007] The second type of expansion device is an expansion device other than an expander, and the number of the second type of expansion devices Y is ≥ 1;

[0008] The multi-purpose heat pump system for cooling, heating and power has at least two working fluid circuits, the first working fluid circuit being composed of a first-type expansion device and a compressor, and the second working fluid circuit being composed of a second-type expansion device and a compressor and / or a first-type expansion device, wherein: in the first working fluid circuit, the inlet of the compressor is connected to the outlet end of the second heat exchanger, and the outlet of the compressor is connected to the inlet end of the first heat exchanger, the inlet of the first-type expansion device is connected to the outlet end of the first heat exchanger, and the outlet of the first-type expansion device is connected to the inlet end of the second heat exchanger, and two pipelines are formed between the compressor and the first-type expansion device, the first pipeline comprising a connecting pipeline between the outlet of the compressor and the inlet of the first-type expansion device, and the second pipeline comprising a connecting pipeline between the inlet of the compressor and the outlet of the first-type expansion device; in the second working fluid circuit, one interface of the second-type expansion device is connected to the first pipeline, and the other interface of the second-type expansion device is connected to the second pipeline;

[0009] The system further includes a mass regulating device, which includes a working fluid storage tank and a control valve. The control valve has the function of controlling the connection and disconnection between the working fluid storage tank and the working fluid in the multi-purpose heat pump system, pumping the working fluid in the multi-purpose heat pump system into the working fluid storage tank for storage or releasing the working fluid stored in the working fluid storage tank into the working fluid in the multi-purpose heat pump system, so as to regulate the total mass of the working fluid in the multi-purpose heat pump system.

[0010] The multi-purpose heat pump system for cooling, heating and electricity contains at least one working fluid with a critical temperature higher than 300K;

[0011] The multi-purpose heat pump system for cooling, heating and electricity has two operating modes;

[0012] The first operating mode is a refrigeration cycle, wherein the multi-purpose heat pump system consumes electricity and generates cooling and heat;

[0013] The second operation mode is a power cycle, in which the cold, heat and electric multi-purpose heat pump system consumes cold energy and heat energy to generate electricity.

[0014] Furthermore, the multi-purpose heat pump system for cooling, heating and power also includes a working fluid with a critical temperature lower than 300K;

[0015] When operating in the first operating mode and when the operating working medium working temperature difference is less than 60°C, the mass regulating device is used to control the proportion of the mass flow of the working medium with a critical temperature higher than 300K in the total working medium mass flow in the circulating working medium flow of the multi-purpose heat pump system to be greater than 50%, and the proportion of the mass flow of the working medium with a critical temperature lower than 300K in the total working medium mass flow to be less than 50%;

[0016] When operating in the first operating mode and when the operating working medium operating temperature difference is greater than 100°C, the mass regulating device is used to control the proportion of the mass flow of the working medium with a critical temperature higher than 300K in the total mass flow of the working medium in the cooling, heating and power multi-purpose heat pump system to be less than 50% and the proportion of the mass flow of the working medium with a critical temperature lower than 300K to be greater than 50% of the total mass flow of the working medium;

[0017] When operating in the second operating mode and when the operating working fluid operating temperature difference is greater than 100°C, the mass regulating device is used to control the proportion of the mass flow of the working fluid with a critical temperature higher than 300K in the circulating working fluid flow of the multi-purpose heat pump system to be less than 50% of the total working fluid mass flow, and the proportion of the mass flow of the working fluid with a critical temperature lower than 300K to be greater than 50% of the total working fluid mass flow.

[0018] Furthermore, a multi-purpose heat pump system for cooling, heating and electricity comprises a first heat exchanger, a compressor, a second heat exchanger, an expansion device connected in sequence, and a motor, wherein the expansion device comprises a first type expansion device and a second type expansion device;

[0019] The first type of expansion device is an expander that recovers the expansion work of the working medium during expansion and outputs mechanical work. The number of the first type of expansion devices X is ≥ 1;

[0020] The second type of expansion device is an expansion device other than an expander, and the number of the second type of expansion devices Y is ≥ 1;

[0021] The multi-purpose heat pump system for cooling, heating and power has at least two working fluid circuits, the first working fluid circuit being composed of a first-type expansion device and a compressor, and the second working fluid circuit being composed of a second-type expansion device and a compressor and / or a first-type expansion device, wherein: in the first working fluid circuit, the inlet of the compressor is connected to the outlet end of the second heat exchanger, and the outlet of the compressor is connected to the inlet end of the first heat exchanger, the inlet of the first-type expansion device is connected to the outlet end of the first heat exchanger, and the outlet of the first-type expansion device is connected to the inlet end of the second heat exchanger, and two pipelines are formed between the compressor and the first-type expansion device, the first pipeline comprising a connecting pipeline between the outlet of the compressor and the inlet of the first-type expansion device, and the second pipeline comprising a connecting pipeline between the inlet of the compressor and the outlet of the first-type expansion device; in the second working fluid circuit, one interface of the second-type expansion device is connected to the first pipeline, and the other interface of the second-type expansion device is connected to the second pipeline;

[0022] The system further includes a mass regulating device, which includes a working fluid storage tank and a control valve. The control valve has the function of controlling the connection and disconnection between the working fluid storage tank and the working fluid in the multi-purpose heat pump system, pumping the working fluid in the multi-purpose heat pump system into the working fluid storage tank for storage or releasing the working fluid stored in the working fluid storage tank into the working fluid in the multi-purpose heat pump system, so as to regulate the total mass of the working fluid in the multi-purpose heat pump system.

[0023] The multi-purpose heat pump system for cooling, heating and electricity contains at least one working fluid with a critical temperature higher than 300K;

[0024] The multi-purpose heat pump system for cooling, heating and electricity contains at least one working fluid with a critical temperature lower than 300K;

[0025] The multi-purpose heat pump system for cooling, heating and electricity has two operating modes;

[0026] The first operating mode is a refrigeration cycle, wherein the multi-purpose heat pump system consumes electricity and generates cooling and heat;

[0027] The second operation mode is a power cycle, in which the cold, heat and electric multi-purpose heat pump system consumes cold energy and heat energy to generate electricity.

[0028] Furthermore, the connection point between an interface of the second type expansion device and the first pipeline includes the outlet of the compressor, the inlet of the first type expansion device, and the connecting pipeline between the outlet of the compressor and the inlet of the first type expansion device;

[0029] The connection point between the other interface of the second type expansion device and the second pipeline includes the inlet of the compressor, the outlet of the second type expansion device, and the connecting pipeline between the inlet of the compressor and the outlet of the first type expansion device.

[0030] Furthermore, when operating in the first operating mode and when the operating temperature difference of the operating working fluid is less than 60°C, the proportion of the mass flow of the liquid working fluid at the inlet and / or outlet of at least one expansion device to the total mass flow of the working fluid is controlled to be greater than 10%; the proportion of the mass flow of the working fluid in the cooling, heating and power multi-purpose heat pump system passing through the second type of expansion device to the total mass flow of the working fluid is controlled to be greater than 90%; and the proportion of the mass flow of the working fluid in the cooling, heating and power multi-purpose heat pump system passing through the first type of expansion device to the total mass flow of the working fluid is controlled to be less than 10%;

[0031] When operating in the first operating mode and when the operating temperature difference of the operating working fluid is greater than 100°C, the proportion of the liquid working fluid mass flow at the inlet of at least one expansion device to the total working fluid mass flow is controlled to be ≤10%; the proportion of the working fluid mass flow of the operating working fluid in the cooling, heating and power multi-purpose heat pump system passing through the second type expansion device to the total working fluid mass flow is controlled to be less than 10%, and the proportion of the working fluid mass flow of the operating working fluid in the cooling, heating and power multi-purpose heat pump system passing through the first type expansion device to the total working fluid mass flow is controlled to be greater than 90%;

[0032] When operating in the second operating mode and when the operating temperature difference of the operating working fluid is greater than 100°C, the proportion of the liquid working fluid mass flow at the inlet of at least one expansion device to the total working fluid mass flow is controlled to be ≤10%; the proportion of the working fluid mass flow of the operating working fluid in the cooling, heating and power multi-purpose heat pump system passing through the second type of expansion device to the total working fluid mass flow is controlled to be less than 10%, and the proportion of the working fluid mass flow of the operating working fluid in the cooling, heating and power multi-purpose heat pump system passing through the first type of expansion device to the total working fluid mass flow is controlled to be greater than 90%.

[0033] Furthermore, when operating in the first operating mode and the operating working fluid operating temperature difference is less than 60°C, the operating working fluid is controlled to operate according to the second working fluid circuit; when operating in the first operating mode and the operating working fluid operating temperature difference is greater than 100°C, the operating working fluid is controlled to operate according to the first working fluid circuit; when operating in the second operating mode and the operating working fluid operating temperature difference is greater than 100°C, the operating working fluid is controlled to operate according to the first working fluid circuit.

[0034] Furthermore, when operating in the first operating mode and the operating working fluid operating temperature difference is less than 60°C, X≥1 first-type expansion devices are controlled to stop being used for working fluid expansion; when operating in the first operating mode and the operating working fluid operating temperature difference is greater than 100°C, Y≥1 second-type expansion devices are controlled to stop being used for working fluid expansion; when operating in the second operating mode and the operating working fluid operating temperature difference is greater than 100°C, Y≥1 second-type expansion devices are controlled to stop being used for working fluid expansion.

[0035] Furthermore, it also includes a first heat storage device and a second heat storage device;

[0036] The heat exchange between the heat storage device and the working medium can be achieved under any of the following conditions:

[0037] The heat transfer medium from the heat storage device flows into the heat storage device after completing heat exchange with the working medium in the first heat exchanger and / or the second heat exchanger;

[0038] And / or, the heat storage device is connected in parallel with the heat exchanger, and the working fluid directly exchanges heat with the heat storage device.

[0039] Furthermore, the expansion device has an unloading operation mechanism, which is used to reduce additional losses generated when the first type expansion device and / or the second type expansion device are not used for working medium expansion during the operation of the heat pump.

[0040] Furthermore, the unloading operation mechanism includes a clutch and a valve;

[0041] When the unloading operation mechanism is a valve, the valve is arranged on the inlet or outlet pipeline of the expansion device.

[0042] Furthermore, when the first-type expansion device can be used for working fluid compression, the first-type expansion device is used to compress the working fluid in the second working fluid circuit, including any of the following situations:

[0043] The working fluid is completely compressed in the first type of expansion device, and the working fluid is expanded through the second type of expansion device;

[0044] and / or, a portion of the working fluid from the second heat exchanger is compressed in the first type expansion device, another portion is compressed in the compressor, and the working fluid is expanded through the second type expansion device;

[0045] and / or, a first type expansion device is connected in series with a compressor, the working fluid flows into the first type expansion device for pre-compression and flows into the compressor for secondary compression, and the working fluid is expanded through the second type expansion device;

[0046] And / or, the first type expansion device is connected in series with the compressor, the working medium flows into the compressor for pre-compression and flows into the first type expansion device for secondary compression, and the working medium expands through the second type expansion device.

[0047] Furthermore, the compressor is composed of a compression module control valve and N≥2 compression modules.

[0048] Furthermore, under the action of the compression module control valve, the first type of expansion device is ≥1 compression module of the compressor, that is, ≥1 compression module is used to recover the expansion work of the working medium expansion process and output mechanical work;

[0049] When operating in the first operating mode and the working temperature difference of the operating working fluid is greater than 100°C, under the action of the compression module control valve, K ≥ 1 compression module is used for working fluid compression, J ≥ 1 compression module is used for working fluid expansion, and K + J ≤ N;

[0050] When operating in the second operating mode, K≥1 compression modules are used for working fluid compression, J≥1 compression modules are used for working fluid expansion, and K+J≤N.

[0051] Furthermore, the compressor is a positive displacement compressor having ≥1 air valve, the air valve being an intake valve and / or an exhaust valve, at least one of the air valves being an actively controlled valve, and the opening and closing of the actively controlled valve is controlled by electromagnetic force, hydraulic pressure or mechanical force;

[0052] And / or, the first type of expansion device is a volumetric expander having ≥1 air valve, which is an intake valve and / or an exhaust valve, at least one of which is actively controlled, and the opening and closing of the actively controlled valve is controlled by electromagnetic force, hydraulic pressure or mechanical force.

[0053] Furthermore, it also includes ≥2 mass adjustment devices, wherein: at least one mass adjustment device is used to adjust the mass of at least one working fluid with a critical temperature higher than 300K; at least one mass adjustment device is used to adjust the mass of a working fluid with a critical temperature lower than 300K.

[0054] Furthermore, it also includes a regenerator, which has a first flow channel and a second flow channel. One end of the first flow channel of the regenerator is connected to the outlet end of the first heat exchanger, and the other end is connected to the inlet end of the first type of expansion device. One end of the second flow channel of the regenerator is connected to the outlet end of the second heat exchanger, and the other end is connected to the compressor.

[0055] Furthermore, when the first type of expansion device cannot be used for working fluid compression, the number of compressors is ≥ 2, wherein: when operating in the first operating mode and when the working fluid operating temperature difference is greater than 100°C, the compressor used for working fluid compression is the first compressor; when operating in the second operating mode and when the working fluid operating temperature difference is greater than 100°C, the compressor used for working fluid compression is the second compressor;

[0056] When operating in the first operating mode and when the operating working medium operating temperature difference is less than 60° C., the second compressor is used to compress the working medium in the second working medium circuit, including any of the following situations:

[0057] The working medium is entirely compressed in the second compressor and then expanded through the second type expansion device;

[0058] and / or, a portion of the working fluid is compressed in the second compressor and another portion is compressed in the first compressor, and the working fluid is expanded through a second type expansion device;

[0059] and / or, the first compressor and the second compressor are connected in series, the working medium flows into the second compressor for pre-compression and flows into the first compressor for secondary compression, and the working medium is expanded through the second type expansion device;

[0060] And / or, the first compressor and the second compressor are connected in series, the working medium flows into the first compressor for pre-compression and flows into the second compressor for secondary compression, and the working medium is expanded through the second type expansion device.

[0061] Furthermore, it further comprises a third heat exchanger, wherein the third heat exchanger is located in the connecting pipeline between the compressor outlet and the inlet of the second type expansion device;

[0062] And / or, it further includes a fourth heat exchanger, which is located in the connecting pipeline between the outlet of the second type expansion device and the inlet of the compressor.

[0063] Furthermore, the second type of expansion device is an expansion device that cannot recover the expansion work of the working medium expansion process and outputs mechanical work;

[0064] The second type of expansion device includes electronic expansion valves, thermal expansion valves, capillary tubes, ejectors or orifice plates.

[0065] Furthermore, when operating in the first operating mode and when the operating working fluid operating temperature difference is less than 60°C, the mass flow rate of the working fluid with a critical temperature higher than 300K in the multi-purpose heat pump system accounts for more than 50% of the total working fluid mass flow rate, and the mass flow rate of the working fluid with a critical temperature lower than 300K accounts for less than 50% of the total working fluid mass flow rate;

[0066] When operating in the first operating mode and when the operating working fluid operating temperature difference is greater than 100°C, the proportion of the mass flow of the working fluid with a critical temperature higher than 300K in the multi-purpose heat pump system to the total mass flow of the working fluid is less than 50%, and the proportion of the mass flow of the working fluid with a critical temperature lower than 300K to the total mass flow of the working fluid is greater than 50%;

[0067] When operating in the second operating mode and when the operating working fluid operating temperature difference is greater than 100°C, the proportion of the mass flow of the working fluid with a critical temperature higher than 300K in the multi-purpose heat pump system to the total working fluid mass flow is less than 50%, and the proportion of the mass flow of the working fluid with a critical temperature lower than 300K to the total working fluid mass flow is greater than 50%.

[0068] Furthermore, it also includes at least one gas separator, wherein the gas separator has a cavity inside and at least one interface communicating with the closed cavity;

[0069] The gas separator can achieve the following functions:

[0070] When operating in the first operating mode and the operating working fluid temperature difference is less than 60°C, the gas separator is used to reduce the proportion of working fluid with a critical temperature below 300K in the total working fluid mass flow;

[0071] and / or, when operating in the first operating mode and the operating working fluid operating temperature difference is greater than 100° C., the gas separator is used to reduce the proportion of working fluid with a critical temperature higher than 300K in the total working fluid mass flow;

[0072] And / or, when operating in the second operating mode and the operating temperature difference of the operating working fluid is greater than 100° C., the gas separator is used to reduce the proportion of the working fluid with a critical temperature higher than 300K in the total working fluid mass flow.

[0073] Furthermore, the gas separator can be connected in any of the following ways:

[0074] The first gas separator is connected to a connecting pipe between an interface of the second type expansion device and the compressor outlet;

[0075] And / or, the second gas separator is connected to the first pipeline, or the second gas separator is connected to the second pipeline, or the second gas separator is connected to the connecting pipeline between the compressor outlet and the second type of expansion device, or the second gas separator is connected to the connecting pipeline between the compressor inlet and the second type of expansion device.

[0076] Furthermore, when operating in the first operating mode and the operating working medium operating temperature difference is greater than 100°C, the liquid temperature in the first gas separator and / or the second gas separator is controlled to be ≤273K, so that a portion of the working medium with a critical temperature higher than 300K is stored in the first gas separator and / or the second gas separator in a liquid state; when operating in the second operating mode and the operating working medium operating temperature difference is greater than 100°C, the liquid temperature in the first gas separator and / or the second gas separator is controlled to be ≤273K, so that a portion of the working medium with a critical temperature higher than 300K is stored in the second gas separator in a liquid state;

[0077] When operating in the first operating mode or the second operating mode and the operating working medium temperature difference is greater than 100°C, the first gas separator or the second gas separator stores a portion of liquid working medium with a critical temperature higher than 300K. The liquid working medium may be generated in any of the following situations:

[0078] The working fluid with a critical temperature higher than 300K entering the first gas separator or the second gas separator is in liquid phase or gas-liquid two-phase;

[0079] The working fluid with a critical temperature higher than 300K entering the first gas separator or the second gas separator is in gas phase, and the gas phase working fluid is condensed into liquid in the first gas separator or the second gas separator.

[0080] Furthermore, the gas separator includes a storage tank and a bent pipe.

[0081] Furthermore, it also includes a switching valve, a first switching valve is located at the compressor outlet, and is used to control the connection and disconnection between the compressor outlet and the first heat exchanger or the third heat exchanger; the second switching valve is located at the compressor inlet, and is used to control the connection between the compressor inlet and the second heat exchanger or the fourth heat exchanger.

[0082] Furthermore, when operating in the first operating mode or the second operating mode and the operating temperature difference of the operating working fluid is greater than 100°C, part of the working fluid with a critical temperature higher than 300K is stored in liquid form in the third heat exchanger or the fourth heat exchanger, and the liquid temperature in the third heat exchanger or the fourth heat exchanger is controlled to be ≤273K.

[0083] Furthermore, when operating in the first operating mode and when the operating working medium operating temperature difference is greater than 100°C, in the first working medium circuit, the pressure in the first heat exchanger and the second heat exchanger is greater than or equal to 0.5 MPa;

[0084] When operating in the second operating mode and when the operating temperature difference of the operating working medium is greater than 100° C., in the first working medium circuit, the pressure in the first heat exchanger and the second heat exchanger is greater than or equal to 0.5 MPa.

[0085] Compared with the prior art, the advantages of the present invention are:

[0086] The multi-purpose heat pump system for cooling, heating and power disclosed in the present invention adjusts the pressure in the heat pump system through a mass regulating device, and through two types of expansion devices, can achieve a set of equipment to meet the high efficiency requirements of different application needs. It can also solve the reliability problems existing in the use of expanders in vapor compression cycles. Therefore, the multi-purpose heat pump system for cooling, heating and power has the advantages of multiple functions, high efficiency, good economy and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 It is a structural schematic diagram of the multi-purpose heat pump system of cooling, heating and electricity of the present invention.

[0088] Figure 2 a is a schematic diagram of the first structure of the multi-purpose heat pump system for cooling, heating and electricity with different working fluid circuits based on four heat exchangers of the present invention.

[0089] Figure 2 b is a first structural diagram of the present invention's multi-purpose heat pump system for cooling, heating and electricity with different working fluid circuits based on three heat exchangers.

[0090] Figure 2 c is a first structural diagram of the multi-purpose heat pump system for cooling, heating and electricity based on two heat exchangers with different working fluid circuits according to the present invention.

[0091] Figure 2 d is a second structural schematic diagram of the present invention's multi-purpose heat pump system with three heat exchangers and different working fluid circuits for cooling, heating and electricity.

[0092] Figure 2 e is a second structural diagram of the multi-purpose heat pump system for cooling, heating and electricity based on two heat exchangers with different working fluid circuits according to the present invention.

[0093] Figure 2 f is a second structural diagram of the multi-purpose heat pump system for cooling, heating and electricity with different working fluid circuits based on four heat exchangers of the present invention.

[0094] Figure 2 g is a third structural diagram of the present invention's multi-purpose heat pump system for cooling, heating and electricity with different working fluid circuits based on two heat exchangers.

[0095] Figure 2 h is a structural schematic diagram of the present invention's multi-purpose heat pump system for cooling, heating and electricity based on different working fluid circuits with connection positions located on the heat exchanger.

[0096] Figure 3 It is a schematic diagram of the operation mode of the multi-purpose heat pump system of cooling, heating and electricity of the present invention.

[0097] Figure 4a is a schematic structural diagram of a multi-purpose heat pump system for cooling, heating and power generation in which an expander and a compressor are connected in parallel for working medium compression.

[0098] Figure 4 b is a structural diagram of a multi-purpose heat pump system for cooling, heating and power, in which the expander and the compressor are connected in series and the expander serves as the front-stage compression.

[0099] Figure 4 c is a structural diagram of a multi-purpose heat pump system for cooling, heating and power, in which the expander and the compressor are connected in series and the expander is the latter stage compression.

[0100] Figure 5 The diagram is a schematic structural diagram of a multi-purpose heat pump system for cooling, heating and power generation in which the compression module of the present invention is used for working medium expansion.

[0101] Figure 6 The present invention is a schematic structural diagram of a multi-purpose heat pump system for cooling, heating and electricity, which includes a working fluid with a critical temperature lower than 300K.

[0102] Figure 7 It is a schematic structural diagram of the multi-purpose heat pump system of cooling, heating and electricity with a heat regenerator of the present invention.

[0103] Figure 8 a is a schematic structural diagram of a multi-purpose heat pump system for cooling, heating and power, in which a first compressor and a second compressor are connected in parallel for working medium compression.

[0104] Figure 8 b is a structural diagram of a multi-purpose heat pump system for cooling, heating and electricity, in which the first compressor and the second compressor are connected in series and the second compressor serves as the front-stage compressor.

[0105] Figure 8 c is a structural diagram of a multi-purpose heat pump system for cooling, heating and power, in which the first compressor and the second compressor are connected in series and the second compressor is a subsequent stage compressor.

[0106] Figure 8 d is a schematic structural diagram of the multifunctional cooling, heating and power multipurpose heat pump system of the present invention with the first compressor and the second compressor connected in parallel and in series.

[0107] Figure 9 It is a schematic structural diagram of the multi-purpose heat pump system for cooling, heating and electricity based on turbine machinery of the present invention.

[0108] Figure 10 It is a structural schematic diagram of the multi-purpose heat pump system for cooling, heating and electricity based on a switching valve and a working fluid pump of the present invention.

[0109] Figure 11 a is a first structural schematic diagram of the multi-purpose heat pump system for cooling, heating and electricity based on a gas separator of the present invention.

[0110] Figure 11b is a second structural schematic diagram of the multi-purpose heat pump system of cooling, heating and electricity based on a gas separator of the present invention.

[0111] Figure 11 c is a third structural schematic diagram of the multi-purpose heat pump system for cooling, heating and power generation based on a gas separator of the present invention.

[0112] Figure 11 d is a fourth structural schematic diagram of the multi-purpose heat pump system for cooling, heating and power generation based on a gas separator of the present invention.

[0113] Wherein: 101, first heat exchanger; 102, second heat exchanger; 103, third heat exchanger; 104, fourth heat exchanger; 105, fifth heat exchanger; 106, sixth heat exchanger; 2, compressor; 201, first compressor; 202, second compressor; 2001, first compression module; 2002, second compression module; 3, expansion device; 301, first type expansion device; 302, second type expansion device; 3010, first first type expansion device; 3011, second first type expansion device; 5, working fluid storage tank; 6, control valve; 7, working fluid pump; 801, first heat storage device; 802, second heat storage device; 901, first valve; 902, second valve; 903, third valve; 904, fourth valve; 905, fifth valve; 906, sixth valve; 907, seventh valve; 908, eighth valve; 909, ninth valve; 10, regenerator; 12, motor; 13, clutch; 1401, first compression module control valve; 1402, second compression module control valve; 1403, third compression module control valve; 1404, fourth compression module control valve; 15, gas separator; 1601, first gas separation control valve; 1602, second gas separation control valve; 1701, first switching valve; 1702, second switching valve. DETAILED DESCRIPTION

[0114] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0115] First, heat pumps targeting cooling or heating requirements are typically based on a vapor compression cycle. This is highly efficient, and the working fluid in a vapor compression cycle absorbs or releases heat through phase change, resulting in low flow rates and low compressor costs. Heat pumps based on the reverse Brayton cycle are typically less efficient in applications targeting cooling or heating requirements, and the sensible heat absorption or release results in high flow rates and high compressor costs. Therefore, heat pumps based on the reverse Brayton cycle are relatively rare in applications targeting cooling or heating requirements. Furthermore, cooling or heating requirements refer to evaporation temperatures greater than -70°C and condensing temperatures less than 120°C.

[0116] Secondly, the working fluid undergoes a phase change during the vapor compression cycle. However, the droplets produced during this phase change can cause cavitation or liquid hammer in the expander, damaging it. Furthermore, due to the small operating temperature differential during cooling or heating demand, the recoverable expansion work is low. Therefore, non-expander expansion devices, such as electronic expansion valves, thermal expansion valves, capillary tubes, ejectors, or orifice plates, are more suitable. This is why expanders are rarely used in heat pump systems currently designed for cooling or heating needs. Heat pumps designed for power storage operate with large operating temperature differentials and require a large amount of recoverable expansion work. Failure to recover this expansion work results in very low electricity-to-electricity conversion efficiency, leading to loss of economic viability. Therefore, expanders that recover expansion work are suitable, and Brayton or reverse Brayton cycles are suitable.

[0117] Finally, electricity storage is achieved through the conversion of heat storage and cold storage. Heat pumps based on vapor compression cycles will produce phase change, so the heat storage material needs to be precisely matched with its phase change temperature, which makes it difficult to obtain such phase change materials. Heat pumps based on reverse Brayton cycles do not undergo phase change and can use large temperature glide heat exchange, therefore, it is easy to achieve high energy density heat and cold storage.

[0118] In addition, non-expander expansion devices are low-cost and can be used to replace the expansion function of the expander in applications with cooling or heating requirements. The expander can also be used for compression. Therefore, heat pump systems have three types of compressors with different capacities: for small-scale cooling / heating, only the expander performs the compression function; for medium-scale cooling / heating, only the compressor performs the compression function; and for large-scale cooling / heating, the expander and compressor jointly perform the compression function. This improves the performance of the heat pump system under different loads and reduces the demand for and cost of compressors. Moreover, the expander can be connected in series with the compressor, acting as the first or last stage of compression in the compressor, improving compressor performance. In addition, the multi-purpose heat pump system for cooling and heating electric heat pumps can also utilize the waste heat generated during the power storage process to provide relevant heat for related heat needs, thereby improving energy utilization.

[0119] In summary, the multi-purpose heat pump system for cooling, heating and electricity uses different expansion devices, different working fluids and mass regulating devices to control the operating pressure or the gas separation method based on gas-liquid separation to adjust the proportion of different working fluids in the total working fluid mass flow under different applications. According to application requirements, the heat pump system can realize (or approach) the vapor compression cycle, realize (or approach) the reverse Brayton cycle during operation, and select the most suitable "compressor" according to the load. It can also utilize the waste heat in the storage and power conversion process, thus having the advantages of multiple functions, high efficiency, high reliability and low cost.

[0120] Example 1:

[0121] like Figure 1As shown, this embodiment provides a multi-purpose heat pump system for cooling, heating, and electricity, including a first heat exchanger 101, a compressor 201, a second heat exchanger 102, an expansion device, and a motor 12. Motor 12 can be a motor and / or a generator. A motor consumes electricity to generate mechanical work, while a generator consumes mechanical work to generate electricity. Preferably, the motor is an integrated motor-generator. Motor 12 is connected to compressor 2. The number of expansion devices 3 is ≥2, and the types of expansion devices include first-class expansion devices and second-class expansion devices, wherein: the first-class expansion device is an expander that recovers the expansion work of the working fluid expansion process and outputs mechanical work. The expander can be a turbine expander or a volumetric expander. The volumetric expander includes a piston expander, a rotor expander, a scroll expander, a screw expander, etc. The first-class expansion device is connected to the compressor, and the mechanical work output by the first-class expansion device is used to drive the compressor. The number of first-class expansion devices is ≥1; the second-class expansion device is an expansion device other than an expander, that is, the second-class expansion device cannot recover the expansion work and output mechanical work to the motor, including a thermal expansion valve, an electronic expansion valve, a capillary tube, an ejector, an orifice plate, etc. The number of second-class expansion devices is ≥1, among which the ejector can recover the expansion work but cannot output mechanical work. Therefore, the ejector is classified as a second-class expansion device. In some cases, such as when multiple modules are connected in parallel and share a common motor, the number of first-type expansion devices and the number of second-type expansion devices depend on the number of parallel modules, typically less than 100. Preferably, the number of first-type expansion devices is ≤ 16, and the number of second-type expansion devices is ≤ 16. The multi-purpose heat pump system for cooling, heating, and power has at least two working fluid circuits. The first working fluid circuit consists of the first-type expansion device and compressor 2, and the second working fluid circuit consists of the second-type expansion device, compressor 2, and / or the first-type expansion device.Compressors and expanders are usually very easy to distinguish in heat pump systems. In the present invention, since some types of compression or expansion devices, such as piston compressors or piston expanders, have a set of devices that can serve as both working fluid compression devices and working fluid expansion devices, and when the multi-purpose heat pump system for heat and cold electricity is facing the needs of power storage applications, the same set of devices may be used for working fluid compression during power storage, that is, to play the role of a compressor, but may be used for working fluid expansion during discharge, that is, to play the role of an expander, or the same set of devices may be used for working fluid compression during discharge, that is, to play the role of a compressor, but may be used for working fluid expansion during power storage, that is, to play the role of an expander. Function, therefore, in order to clarify the compressor and the expander, the compressor and the expander in the multi-purpose heat pump system of cold, hot and electric power of the present invention refer to the multi-purpose heat pump system of cold, hot and electric power working in the refrigeration cycle mode, that is, the charging process for power storage needs, wherein: the compressor is a device for compressing the working fluid in the first working fluid circuit when running in the first operating mode, and the expander, that is, the first type of expansion device, is a device for expanding the working fluid in the first working fluid circuit when running in the first operating mode. It is further emphasized that it refers to the compressor and expander in the first working fluid circuit under rated working conditions or maximum cooling and heating capacity, that is, maximum charging power conditions when the heat pump system operates in the first operating mode. In the first working fluid circuit, the inlet of compressor 2 is connected to the outlet of the second heat exchanger 102, and the outlet of compressor 2 is connected to the inlet of the first heat exchanger 101. The inlet of the first-type expansion device is connected to the outlet of the first heat exchanger 101, and the outlet of the first-type expansion device is connected to the inlet of the second heat exchanger 102. Two pipelines are formed between compressor 2 and the first-type expansion device: the first pipeline comprises a connecting pipeline between the outlet of compressor 2 and the inlet of the first-type expansion device 301, and the second pipeline comprises a connecting pipeline between the inlet of compressor 2 and the outlet of the first-type expansion device 301. In the second working fluid circuit, one port of the second-type expansion device 302 is connected to the first pipeline, and the other port of the second-type expansion device 302 is connected to the second pipeline. The inlet and outlet of compressor 2, the inlet and outlet of the first-type expansion device, the inlet and outlet of the first heat exchanger 101, and the inlet and outlet of the second heat exchanger 102 are defined based on the working fluid inflow and outflow conditions when the first working fluid circuit operates in the first operating mode. Furthermore, one interface of the second type of expansion device and the connection point position of the first pipeline include the outlet of the compressor 2, the inlet of the first type of expansion device, and the connecting pipeline between the outlet of the compressor 2 and the inlet of the first type of expansion device; another interface of the second type of expansion device and the second connection point position include the inlet of the compressor 2, the outlet of the second type of expansion device, and the connecting pipeline between the inlet of the compressor 2 and the outlet of the first type of expansion device. Therefore, the connection position point includes the two ports of the first pipeline or the second pipeline and the connecting pipeline between the ports. The following situations are schematic diagrams of the connection forms of connection points at different positions:.

[0122] (1) The connection point between one interface of the second type expansion device and the first pipeline is located at the inlet of the first type expansion device or on the connecting pipeline between the inlet of the first type expansion device and the outlet of the first heat exchanger 101, and the connection point between the other interface of the second type expansion device and the second pipeline is located at the outlet of the first type expansion device or on the connecting pipeline between the outlet of the first type expansion device and the inlet of the second heat exchanger 102. Figure 1 As shown, the second working medium circuit is composed of the compressor 2, the first heat exchanger 101, the second type expansion device 302, and the second heat exchanger 102. Figure 2 (a) shows another connection form, in which the interface of the second-type expansion device 302 is connected to the first pipeline or the second pipeline through a heat exchanger, a third heat exchanger 103 is provided between one interface of the second-type expansion device and the connection point of the first pipeline, and a fourth heat exchanger 104 is provided between the other interface of the second-type expansion device and the connection point of the second pipeline. The second working fluid circuit is composed of the compressor 2, the first heat exchanger 101, the third heat exchanger 103, the second-type expansion device 302, the fourth heat exchanger 104, and the second heat exchanger 102. Although the third heat exchanger and the fourth heat exchanger are provided on the connecting pipelines between the interface of the second-type expansion device and the first pipeline and the second pipeline, in this case, one interface of the second-type expansion device is connected to the first pipeline and the other interface is connected to the second pipeline. See Figure 2 In (a), the second working fluid circuit can also be composed of the third heat exchanger 103, the first type expansion device 301, the second type expansion device 302, and the fourth heat exchanger 104. In this case, the first type expansion device 301 replaces the compressor for working fluid compression. When the first heat exchanger 101 and the second heat exchanger 102 are provided with a parallel bypass pipe, the second working fluid circuit can also be composed of the compressor 2, the first type expansion device 301, the third heat exchanger 103, the second type expansion device 302, and the fourth heat exchanger 104. The compressor 2 and the first type expansion device 301 are used for working fluid compression simultaneously. When the inlet and outlet of the first type expansion device 301 have a direction, when the compressor 2 and the first type expansion device 301 are used for working fluid compression simultaneously, a four-way valve or multiple valves are required to connect the inlet of the first type expansion device 301 and the inlet of the compressor 2 to the outlet of the fourth heat exchanger 104, and the outlet of the first type expansion device 301 and the outlet of the compressor 2 to the inlet of the third heat exchanger 103.

[0123] (2) The connection point between one interface of the second type expansion device and the first pipeline is located at the inlet of the first type expansion device or the connecting pipeline between the inlet of the first type expansion device and the outlet of the first heat exchanger 101, and the connection point between the other interface of the second type expansion device and the second pipeline is located at the inlet of the compressor or the connecting pipeline between the inlet of the compressor and the outlet of the second heat exchanger 102. Figure 2As shown in (b) in the figure, a fifth heat exchanger 105 is further included. One end of the fifth heat exchanger 105 is connected to the second type expansion device 302, and the other end is connected to the compressor 2. The second working medium circuit is composed of the compressor 2, the first heat exchanger 101, the second type expansion device 302, and the fifth heat exchanger 105. As mentioned above, although the fifth heat exchanger 105 is provided on the connecting pipeline between the interface of the second type expansion device and the second pipeline, in this case, one interface of the second type expansion device is connected to the first pipeline, and the other interface is connected to the second pipeline. Figure 2 (c) in the figure shows another connection form. In the first working fluid circuit, the first valve 901 is opened and the second valve 902 is closed. The first working fluid circuit is composed of the compressor 2, the first heat exchanger 101, the first type expansion device 301, the second heat exchanger 102, and the first valve 901. In the second working fluid circuit, the second valve 902 is opened and the first valve 901 is closed. The second working fluid circuit is composed of the compressor 2, the first heat exchanger 101, the second type expansion device 302, the second heat exchanger 102, and the second valve 902. In this case, although the first valve 901 is provided between the inlet of the compressor 2 and the outlet of the second heat exchanger 102 and is closed in the second working fluid circuit, the inlet of the compressor 2 and the outlet of the second heat exchanger 102 are connected in the first working fluid circuit, and the connection point between the other interface of the second type expansion device and the second pipeline can be located at the compressor inlet or on the connecting pipeline between the compressor inlet and the second heat exchanger 102, still satisfying the requirement that one interface of the second type expansion device is connected to the first pipeline and the other interface is connected to the second pipeline.

[0124] (3) The connection point between one interface of the second type expansion device and the first pipeline is located at the outlet of the compressor 2 or on the connecting pipeline between the outlet of the compressor 2 and the inlet of the first heat exchanger 101, and the connection point between the other interface of the second type expansion device and the second pipeline is located at the outlet of the first type expansion device or on the connecting pipeline between the outlet of the first type expansion device and the inlet of the second heat exchanger 102. Figure 2 As shown in (d), it also includes a fifth heat exchanger 105. One end of the fifth heat exchanger 105 is connected to the connecting pipeline between the outlet of compressor 2 or the outlet of compressor 2 and the first heat exchanger 101, and the other end is connected to the inlet of the second type expansion device 302. The second working medium circuit is composed of the compressor 2, the fifth heat exchanger 105, the second type expansion device 302, and the second heat exchanger 102. In this case, although one end of the second type expansion device 302 is connected to the first pipeline through the fifth heat exchanger 105, as mentioned above, it still meets the requirement that one interface of the second type expansion device is connected to the first pipeline and the other interface is connected to the second pipeline. Figure 2 (e) in FIG. 1 shows another connection form, such as Figure 2As shown in (e), in the first working fluid circuit, the third valve 903 is opened and the fourth valve 904 is closed. The first working fluid circuit is composed of the compressor 2, the third valve 903, the first heat exchanger 101, the first type expansion device 301, and the second heat exchanger 102. In the second working fluid circuit, the third valve 903 is closed and the fourth valve 904 is opened. The second working fluid circuit is composed of the compressor 2, the fourth valve 904, the first heat exchanger 101, the second type expansion device 302, and the second heat exchanger 102. In this case, as described above, although the third valve 903 is provided between the outlet of the compressor 2 and the inlet of the first heat exchanger 101 in the first working fluid circuit and is closed in the second working fluid circuit, the outlet of the compressor 2 and the inlet of the first heat exchanger 101 are connected in the first working fluid circuit, and one interface of the second type expansion device is connected to the connecting pipeline between the outlet of the compressor 2 and the inlet of the first heat exchanger 101, which still satisfies the requirement that one interface of the second type expansion device is connected to the first pipeline and the other interface is connected to the second pipeline.

[0125] The connection point between one interface of the second type expansion device and the first pipeline is located at the outlet of the compressor 2 or on the connecting pipeline between the outlet of the compressor 2 and the inlet of the first heat exchanger 101. The connection point between the other interface of the second type expansion device and the second pipeline is located at the inlet of the compressor or on the connecting pipeline between the inlet of the compressor and the outlet of the second heat exchanger 102. Figure 2 As shown in (f), it also includes a third heat exchanger 103 and a fourth heat exchanger 104. The second working medium circuit is composed of the compressor 2, the third heat exchanger 103, the second type expansion device 302, and the fourth heat exchanger 104. Figure 2(g) in the figure shows another connection form, in which the fourth valve 904 and the first valve 901 are closed, and the third valve 903 and the second valve 902 are opened. The first working fluid circuit is composed of the compressor 2, the third valve 903, the first heat exchanger 101, the first type expansion device 301, the second heat exchanger 102, and the second valve 902; the fourth valve 904 and the first valve 901 are opened, and the third valve 903 and the second valve 902 are closed. The second working fluid circuit is composed of the compressor 2, the fourth valve 904, the first heat exchanger 101, the second type expansion device 302, the second heat exchanger 102, and the first valve 901; when the first type expansion device 301 is also used for working fluid compression, the second working fluid circuit can also be composed of the first heat exchanger 101, the first type expansion device 301, the second type expansion device 302, and the second heat exchanger 102; when the compressor 2 and the first type expansion device 301 are used for working fluid compression at the same time, the second working fluid circuit can also be composed of the compressor 2, the first type expansion device 301 , a fourth valve 904, a first heat exchanger 101, a second type of expansion device 302, a second heat exchanger 102, and a first valve 901. In this case, similarly, when there is a direction between the first type of expansion device 301 and the inlet and outlet of the compressor 2, when the compressor 2 and the first type of expansion device 301 are used for working fluid compression at the same time, it is necessary to use a four-way valve or multiple valves to connect the inlet of the first type of expansion 301 and the inlet of the compressor 2 to the outlet of the second heat exchanger 102, and the outlet of the first type of expansion 301 and the outlet of the compressor 2 to the inlet of the first heat exchanger 101. On the other hand, similarly, a valve is provided on the relevant connecting pipeline, and is closed in the second working fluid circuit, but in the first working fluid circuit, the outlet of the compressor 2 and the inlet of the first heat exchanger 101 are connected, and one interface of the second type of expansion device is connected to the connecting pipeline between the outlet of the compressor 2 and the inlet of the first heat exchanger 101, which still satisfies the requirement that one interface of the second type of expansion device is connected to the first pipeline and the other interface is connected to the second pipeline.

[0126] It is important to emphasize that: Figure 2 In the embodiment, the first type expansion device 301 is a first type expansion device, and the second type expansion device 302 is a second type expansion device; the valve 9 can have the function of opening or closing the connection between the working medium at both ends of the valve. It should be further pointed out that, if Figure 2As shown in (h), the first heat exchanger 101 has other interfaces in addition to the inlet and outlet, and these interfaces are not located at the inlet and outlet. When one interface of the second-type expansion device is connected to the other interface of the first heat exchanger 101, since the first heat exchanger 101 is still located on the first pipeline of the first working fluid circuit, the requirement that one interface of the second-type expansion device is connected to the first pipeline and the other interface is connected to the second pipeline is still met. Similarly, when the other interface of the second-type expansion device is connected to the other interface of the second heat exchanger 102, the requirement that one interface of the second-type expansion device is connected to the first pipeline and the other interface is connected to the second pipeline is also met.

[0127] The heat pump system also includes a mass regulating device. The function of the mass regulating device is to switch the heat pump system operation cycle between a vapor compression cycle approaching or a complete Brayton cycle and a Brayton cycle approaching or a complete Brayton cycle by regulating the mass of the working fluid. The mass regulating device includes a working fluid storage tank 5 and a control valve 6. The control valve 6 has the function of controlling the connection and disconnection between the working fluid storage tank 5 and the working fluid in the heat pump system. The working fluid in the heat pump system includes the working fluid inside the heat exchanger, the compressor, and the expansion device. More specifically, the working fluid in the heat pump system refers to the working fluid inside the space connected by the running compressor, the expansion device, and the heat exchanger that is exchanging heat. The total mass of the working fluid in the heat pump system can be adjusted by pumping the working fluid in the heat pump system into the working fluid storage tank 5 for storage or releasing the working fluid stored in the working fluid storage tank 5 into the working fluid in the heat pump system. Figure 1 As shown, under the action of the control valve 6, the connection and disconnection between the working medium in the working medium storage tank 5 and the working medium in the heat pump system can be connected or disconnected. The working medium in the heat pump system can be pumped into the working medium storage tank 5 by using the compressor 2 of the heat pump system, for example: the mass regulating device is arranged on the outlet side of the compressor 2; the working medium in the heat pump system can also be pumped into the working medium storage tank 5 by the mass regulating device including a working medium pump 7, for example: Figure 1 A mass regulating device with a working fluid pump 7 is shown. When the control valve 6 connects the working fluid storage tank 5 with the working fluid in the heat pump system, the working fluid in the heat pump system is pumped into the working fluid storage tank 5 under the action of the working fluid pump 7, thereby reducing the total mass of the working fluid in the heat pump system.

[0128] The heat pump system contains at least one working fluid with a critical temperature higher than 300K, such as CO2, Freon, alkanes, and mixtures thereof. Freon is a general term for chlorofluorocarbons, hydrofluoroolefins, and hydrofluorocarbons. This is because in order to achieve or approach a vapor compression cycle when meeting cooling or heating needs, the working fluid critical temperature needs to be higher than 300K.

[0129] The heat pump system has two operating modes; the first operating mode is the refrigeration cycle, in which the heat pump system consumes electricity and generates cold and heat.

[0130] When the heat pump system operates in the first operating mode, and when the operating temperature difference of the operating working medium is less than 60°C, the mass regulating device is controlled to regulate the total mass of the operating working medium in the heat pump system, and the pressure in the first heat exchanger 101 and the second heat exchanger 102 is regulated, so that the proportion of the mass flow of the liquid working medium at the inlet and / or outlet of at least one expansion device to the total mass flow of the working medium is greater than 10%. Since the heat pump system has X ≥ 1 first-class expansion devices and Y ≥ 1 second-class expansion devices, preferably, for non-CO2 working medium, the inlet and / or outlet of the expansion device is the inlet of the second-class expansion device, and the liquid at the inlet of the second-class expansion device is greater than 10%. The proportion of the mass flow of the solid working fluid to the total mass flow of the working fluid is 100%. In view of the possible existence of non-condensable gases, the proportion of the mass flow of the liquid working fluid to the total mass flow of the working fluid is greater than 90%. For CO2 working fluid, the inlet and / or outlet of the expansion device is the outlet of the second type of expansion device, and the proportion of the mass flow of the liquid working fluid to the total mass flow of the working fluid is greater than 50%. The proportion of the mass flow of the working fluid in the heat pump system passing through the second type of expansion device to the total mass flow of the working fluid is greater than 90%, and the proportion of the mass flow of the working fluid in the heat pump system passing through the first type of expansion device to the total mass flow of the working fluid is less than 10%. Therefore, liquid will be generated in the first heat exchanger 101 and / or the second heat exchanger 102. In order to reduce the damage of the generated liquid droplets to the first type expansion device 301, the proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the first type expansion device 301 to the total working fluid mass flow is controlled to be less than 10%. Preferably, the proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the second type expansion device to the total working fluid mass flow is controlled to be 100%, and the proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the first type expansion device to the total working fluid mass flow is controlled to be 0%, thereby eliminating the damage of the liquid to the first type expansion device. Among them: the operating temperature difference of the operating working fluid refers to the difference between the average temperature of the heat exchange between the working fluid and the external high-temperature heat source and the average temperature of the heat exchange between the working fluid and the external low-temperature heat source. The average temperature of the heat exchange with the external heat source is theoretically obtained based on the average of the heat absorption or release at each temperature. For the case where there is a phase change process in the heat exchanger for heat exchange with the external heat source, since the heat release or heat absorption mainly occurs in the phase change process, for simplicity, the phase change temperature will change due to flow resistance, but the phase change temperature slip is generally small, and it can be calculated using any phase change temperature from the beginning stage to the end stage of the phase change, preferably, the phase change temperature corresponding to the midpoint between the beginning stage and the end stage of the phase change; for the case where there is no phase change process in the heat exchanger for heat exchange with the external heat source, it can be calculated by taking the arithmetic average of the working fluid inlet temperature and the outlet temperature of the heat exchanger, that is, (working fluid inlet temperature + working fluid outlet temperature) / 2. In addition, the selection of relevant parameters: <60℃ is mainly for cooling or heating needs. For example, for cooling in summer, the evaporation temperature is 5℃, and the ambient temperature is generally within 50℃; for heating in winter, the heating temperature of the terminal equipment can reach 35~45℃, and the heating temperature difference of <60℃ can meet the heating needs of the environment of -15~-10℃.It should be noted that when meeting cooling or heating requirements, the operating temperature difference of the operating working fluid may be greater than 60°C. Preferably, in this case, the proportion of the liquid working fluid mass flow rate at the inlet of at least one expansion device to the total working fluid mass flow rate can still be controlled to be greater than 10%; the proportion of the working fluid mass flow rate passing through the second-type expansion device in the heat pump system to the total working fluid mass flow rate can be controlled to be greater than 90%, and the proportion of the working fluid mass flow rate passing through the first-type expansion device in the heat pump system to the total working fluid mass flow rate can be controlled to be less than 10%. Furthermore, it should be emphasized that the total working fluid mass flow rate in the proportion of the liquid working fluid mass flow rate at the inlet of the expansion device to the total working fluid mass flow rate refers to the total working fluid mass passing through the expansion device. When multiple expansion devices are operating simultaneously, the proportion of the liquid working fluid mass flow rate at the inlet of at least one expansion device to the total working fluid mass flow rate passing through the expansion device must meet the above requirements.

[0131] The second operating mode is a power cycle, in which the heat pump system consumes cold and heat to generate electricity. When the heat pump system operates in the second operating mode and the operating temperature difference of the operating working fluid is greater than 100°C, the control mass regulating device adjusts the total mass of the operating working fluid in the heat pump system and adjusts the pressure in the first heat exchanger 101 and the second heat exchanger 102 to achieve a liquid working fluid mass flow rate at at least one expansion device inlet of the total working fluid mass flow rate of ≤10%. This is because if liquid is generated in the second operating mode, it will cause irreversible losses in the heat transfer process or increase the difficulty of storing cold and heat. Preferably, the expansion device inlet is a first-type expansion device inlet, and the proportion of the liquid working fluid mass flow rate at the first-type expansion device inlet to the total working fluid mass flow rate is 0 The proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the second type of expansion device to the total working fluid mass flow is controlled to be less than 10%, and the proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the first type of expansion device to the total working fluid mass flow is controlled to be greater than 90%. This is because the second type of expansion device cannot recover the expansion work and output mechanical work, which causes the power production of the heat pump system to decrease when operating in the second operating mode. Preferably, the proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the second type of expansion device to the total working fluid mass flow is controlled to be 0, and the proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the first type of expansion device to the total working fluid mass flow is controlled to be 100%. The above process can be achieved by controlling the total mass of the working fluid in the heat pump system by controlling the mass regulating device. When the mass of the working fluid in the system is less than the mass corresponding to saturated steam at the average temperature of the system, there is no liquid in the system. On the contrary, when the mass of the working fluid in the system is greater than the mass corresponding to saturated steam at the average temperature of the system, the excess working fluid exists in the form of liquid.

[0132] Since the second operation mode uses cold and heat to produce electricity, and the cold and heat used to produce electricity come from the first operation mode, Figure 3As shown, when the heat pump system operates in the first operating mode and when facing the power storage demand, the operating working fluid operating temperature difference is basically the same as the operating working fluid operating temperature difference in the second operating mode, that is, when the operating working fluid operating temperature difference is greater than 100°C, the control mass regulating device regulates the total mass of the operating working fluid in the heat pump system and regulates the pressure in the first heat exchanger 101 and the second heat exchanger 102 to achieve a proportion of the liquid working fluid mass flow rate in the total working fluid mass flow rate of less than or equal to 10% at the inlet of at least one expansion device. Preferably, the inlet of the expansion device is a first-type expansion device inlet, and the first-type expansion device inlet The proportion of the liquid working fluid mass flow rate at the outlet of the heat pump system to the total working fluid mass flow rate is 0; the proportion of the working fluid mass flow rate passing through the second type expansion device in the heat pump system to the total working fluid mass flow rate is controlled to be less than 10%, and the proportion of the working fluid mass flow rate passing through the first type expansion device in the heat pump system to the total working fluid mass flow rate is controlled to be greater than 90%. Preferably, the proportion of the working fluid mass flow rate passing through the second type expansion device in the heat pump system to the total working fluid mass flow rate is controlled to be 0, and the proportion of the working fluid mass flow rate passing through the first type expansion device in the heat pump system to the total working fluid mass flow rate is controlled to be 100%. In addition, the selection of relevant parameters: >100°C is mainly based on energy storage needs. For a certain heat and cold storage volume, a larger temperature difference between hot and cold can achieve a higher energy storage density. Preferably, the temperature difference between the average temperature in the first heat exchanger and the average temperature in the second heat exchanger is suitable between 150 and 550°C.

[0133] When operating in the first operating mode and the operating working fluid temperature difference is less than 60°C, the operating working fluid is controlled to operate according to the second working fluid circuit. When operating in the first operating mode and the operating working fluid temperature difference is greater than 100°C, the operating working fluid is controlled to operate according to the first working fluid circuit. When operating in the second operating mode and the operating working fluid temperature difference is greater than 100°C, the operating working fluid is controlled to operate according to the first working fluid circuit. When the operating working fluid operates in both the second working fluid circuit and the first working fluid circuit simultaneously, if the mass flow through the second type expansion device in the second working fluid circuit accounts for less than 20% of the total mass flow, it is still considered to be operating according to the first working fluid circuit. Otherwise, it is considered to be operating according to the second working fluid circuit, and the total working fluid mass flow is equal to the sum of the mass flow through the second type expansion device in the second working fluid circuit and the mass flow through the first type expansion device in the first working fluid circuit.

[0134] When operating in the first operating mode and the working fluid temperature difference is less than 60°C, the first-type expansion device (X≥1) is controlled to stop expanding the working fluid. In this case, the first-type expansion device can still be used for compressing the working fluid. This is because the working fluid entering the first-type expansion device may contain liquid. To prevent liquid damage to the first-type expansion device, at least one first-type expansion device is controlled to stop expanding the working fluid, and preferably, all first-type expansion devices are controlled to stop expanding the working fluid. When operating in the first operating mode and the working fluid temperature difference is greater than 100°C, the second-type expansion device (Y≥1) is controlled to stop expanding the working fluid. When operating in the second operating mode and the working fluid temperature difference is greater than 100°C, the second-type expansion device (Y≥1) is controlled to stop expanding the working fluid. In this case, the heat pump is mainly used for power storage, and the working fluid temperature difference is large. To improve efficiency, it is necessary to avoid using expansion devices that cannot recover expansion work. Therefore, at least one second-type expansion device is controlled to stop expanding the working fluid, and preferably, all second-type expansion devices are controlled to stop expanding the working fluid. When the expansion device has an unloading operating mechanism, it can be judged based on the status of the unloading operating mechanism; when there is no unloading operating mechanism and a working fluid flow passes through the expansion device in addition to leakage, the first-class expansion device stops being used for working fluid expansion, which can be judged based on whether the expansion device is running and whether working fluid passes through the expansion device. For example, the speed of the first-class expansion device is less than the speed of the compressor or 20% of the rated speed of the first-class expansion device, which should be considered to be stopped; the second-class expansion device stops being used for working fluid expansion, which can be judged based on the opening of the second-class expansion device. The second-class expansion device is considered to have stopped being used for working fluid expansion if the opening is less than 10% of its maximum opening.

[0135] The expansion device of the heat pump system has an unloading operation mechanism, which is used to reduce or eliminate additional leakage losses or friction losses when the expansion device is not used for working fluid expansion. The unloading operation mechanism is a valve and / or a clutch, etc. The valve can be a solenoid valve or a hydraulic valve, etc. When the expansion device is not used for working fluid expansion, for example: when the heat pump system is operating in the second mode, it is necessary to control the proportion of the working fluid mass flow through the second type of expansion device to less than 10% of the total working fluid mass flow, preferably 0. However, the second type of expansion device may have its own leakage in the closed operating state, thereby generating leakage losses. A valve can be set at the inlet or outlet of the expansion device. When the expansion device is not operating, the valve at the inlet or outlet of the expansion device is closed to avoid leakage losses when the relevant expansion device is not used for working fluid expansion during the operation of the heat pump. In addition, for the first type of expansion device, since it can directly output mechanical work, the output shaft of the first type of expansion device is connected to the motor to eliminate the additional friction losses generated by idling during the period when the first type of expansion device is not used for working fluid expansion. As Figure 1As shown, a clutch 13 can be provided between the first-type expansion device 301 and the motor 12. When the heat pump system adopts the second-type expansion device 302 for working fluid expansion and the first-type expansion device 301 is not used for working fluid expansion or compression, the clutch 13 disconnects the first-type expansion device 301 from the motor 12. When the motor is running, the first-type expansion device 301 is in a stationary state to avoid friction loss. When the heat pump system adopts the first-type expansion device 301 for working fluid expansion or compression, the clutch 13 creates an axial connection between the first-type expansion device 301 and the motor 12.

[0136] The heat pump system also includes a first heat storage device 801 and a second heat storage device 802. The heat exchange between the heat storage device and the working medium can be any of the following: the heat transfer medium from the heat storage device flows into the heat storage device after the heat exchange with the working medium in the first heat exchanger 101 or the second heat exchanger 102 is completed; and / or, the heat storage device and the heat exchanger are connected in parallel, and the working medium directly exchanges heat with the heat storage material inside the heat storage device. Figure 1 As shown, the heat transfer medium from the first heat storage device 801 exchanges heat with the working medium in the first heat exchanger 101, and then the heat transfer medium flows into the first heat storage device 801. In order to meet the cooling and heating needs, a sixth heat exchanger 106 is also included. The heat transfer medium transfers heat to the heating object through the sixth heat exchanger 106. Under this structure, when meeting the cooling or heating needs, the heat exchange between the heat transfer medium and the first heat storage device 801 is closed by setting a relevant valve on the pipeline, and the heat transfer medium exchanges heat between the first heat exchanger 101 and the sixth heat exchanger 106; when meeting the power storage needs, the heat exchange between the heat transfer medium and the sixth heat exchanger 106 is closed by setting a relevant valve on the pipeline, and the heat transfer medium exchanges heat between the first heat exchanger 101 and the first heat storage device 801; similarly, the second heat storage device 802 can also adopt a similar structure for heat exchange. Figure 1 A parallel structure of a heat storage device and a heat exchanger is also shown. A second heat storage device 802 is connected in parallel with a second heat exchanger 102. The second heat storage device 102 contains a heat storage material, which is a solid medium such as rock or steel balls. When the heat or cooling demand is met, a valve is installed in the pipeline to close the heat exchange between the working medium and the second heat storage device 802, and the working medium transfers the cold energy to the cooled object through the second heat exchanger 802. When the heat storage demand is met, a valve is installed in the pipeline to close the heat exchange between the working medium and the second heat exchanger 102, and the working medium exchanges heat with the heat storage material in the second heat storage device 802. Similarly, the first heat storage device 801 can also adopt a similar heat exchange structure. In addition, a hybrid combination of the above schemes is also possible. Preferably, the heat transfer medium is a liquid such as an aqueous solution or thermal oil.

[0137] Certain types of expanders, such as positive displacement expanders, are not only highly efficient for working fluid expansion but also for working fluid compression. Therefore, when the heat pump system operates in the first operating mode, when the heat pump system is serving cooling / heating demands, or when the operating working fluid temperature difference is less than 60°C, the working fluid expansion of the heat pump system is performed by the second-type expansion device. Since the first-type expansion device is not suitable for working fluid expansion in this application, in this case, the first-type expansion device can be used for working fluid compression in the second working fluid circuit through the operation of a valve, thereby reducing the size and cost of the compressor when serving cooling or heating demands. When the first-type expansion device is used for working fluid compression, the following scenarios are possible: the working fluid is entirely compressed within the first-type expansion device; part of the working fluid is compressed within the first-type expansion device and the rest is compressed within compressor 2; the first-type expansion device is connected in series with compressor 2, with the working fluid flowing into the first-type expansion device for pre-compression and then into compressor 2 for secondary compression; the first-type expansion device is connected in series with the compressor, with the working fluid flowing into compressor 2 for pre-compression and then into the first-type expansion device for secondary compression. All of these functions can be implemented within the same heat pump system. Figure 4 The following diagram shows the working diagram of several expanders used for compressing working fluid under the action of valves. Figure 4 (a) shows the parallel operation of the expander and the compressor. The first type expansion device 301 is a first type expansion device, i.e., an expander. When used for expansion, the first type expansion device 301 is an expander. When used for expansion, the first valve 901 and the second valve 902 are closed, the third valve 903 and the fourth valve 904 are opened, and the working medium passes through the second heat exchanger 102, the compressor 2, the first heat exchanger 101, and the first type expansion device 301 in sequence; when the first type expansion device 301 is used for compression, the third valve 904 and the fourth valve 904 are closed, the first valve 901 and the second valve 903 are opened, and the working medium passes through the second heat exchanger 102, the compressor 2, the first heat exchanger 101, and the first type expansion device 301 in sequence. 902 is opened, and part of the working fluid flowing out of the second heat exchanger 102 flows into the first heat exchanger 101 through the compressor 2, and part flows into the first heat exchanger 101 through the second valve 902, the first type expansion device 301, and the first valve 901. After heat exchange in the first heat exchanger 101, the working fluid flows into the second heat exchanger 102 through the second type expansion device 302. Therefore, at this time, the expander and the compressor are connected in parallel to play a compression function. When the compressor 2 is closed, only the first type expansion device 301 is used for compression, and the working fluid flowing out of the second heat exchanger 102 all flows into the first type expansion device 301. Figure 4(b) shows the serial operation. The first-type expansion device 301 is an expander. When used for expansion, the second valve 902 and the sixth valve 906 are closed, and the third valve 903, the fourth valve 904, and the fifth valve 905 are opened. The working medium passes through the second heat exchanger 102, the fifth valve 905, the compressor 2, the first heat exchanger 101, the fourth valve 904, the first-type expansion device 301, and the third valve 903 in sequence. When the first-type expansion device 301 is used for compression, the second valve 902 and the sixth valve 906 are opened, and the third valve 903, the fourth valve 904, and the fifth valve 905 are closed. The working medium flowing out of the second heat exchanger 102 flows through the second valve 902, the first-type expansion device 301, and the sixth valve 906 into the compressor 2. After heat exchange in the first heat exchanger 101, the working medium flows through the second-type expansion device 302 into the second heat exchanger 102. Therefore, the expander and the compressor are connected in series at this time, serving as the pre-stage compression of the compressor. Figure 4 (c) in the figure shows another series operation situation. The first type expansion device 301 is an expander. When it is used for expansion, the ninth valve 909 and the seventh valve 907 are closed, and the third valve 903, the fourth valve 904, and the eighth valve 908 are opened. The working medium passes through the second heat exchanger 102, the compressor 2, the eighth valve 908, the first heat exchanger 101, the fourth valve 904, the first type expansion device 301, and the third valve 903 in sequence. When the first type expansion device 301 is used for second-stage compression, the ninth valve 909 and the seventh valve 907 are opened, and the third valve 903, the fourth valve 904, and the eighth valve 908 are closed. The working medium flowing out of the second heat exchanger 102 flows into the compressor 2. After being compressed in the compressor, the working medium passes through the seventh valve 907, the first type expansion device 301, and the ninth valve 909 in sequence. After heat exchange in the first heat exchanger 101, the working medium flows into the second heat exchanger 102 through the second type expansion device 302. Therefore, the expander and the compressor are connected in series at this time, serving as the subsequent stage of compression of the compressor. In addition, the first to ninth valves are installed on a system according to the above diagram, such as Figure 8 As shown in (d) in the figure, the above-mentioned operation of the expander and compressor can be realized on a heat pump system. Figure 4 All the functions shown in (a), (b) and (c) are parallel, series and other functions, which will not be repeated here. Preferably, the structural scheme of the expander for compressing the working medium under the action of the valve is a parallel scheme of the expander and the compressor.

[0138] The heat pump system compressor consists of N ≥ 2 compression modules and a compression module control valve 14. The number of compression modules can be configured according to the cooling or heating capacity of the unit. The number is usually less than 100, preferably 8 or 16. Under the action of the compression module control valve 14, the first type of expansion device is ≥ 1 compression module of the compressor 2, that is, ≥ 1 compression module is used to recover the expansion work of the working fluid expansion process and output mechanical work. When operating in the first operating mode and the working fluid operating temperature difference is greater than 100°C, under the action of the compression module control valve, K ≥ 1 compression modules are used for working fluid compression and J ≥ 1 compression modules are used for working fluid expansion, and K + J ≤ N; when operating in the second operating mode and the working fluid operating temperature difference is greater than 100°C, K ≥ 1 compression module is used for working fluid compression and J ≥ 1 compression module is used for working fluid expansion, and K + J ≤ N.

[0139] Figure 5 A heat pump system is shown in which the first-type expansion device is a compression module. The heat pump system consists of two compression modules and a compression module control valve 14. When the first compression module 2001 and the second compression module 2002 are used for working fluid compression, the third compression module control valve 1403 and the fourth compression module control valve 1404 are opened, and the first compression module control valve 1401 and the second compression module control valve 1402 are closed. The working fluid from the second heat exchanger 102 is compressed in the first compression module 2001 and the second compression module 2002, and then flows into the first heat exchanger 101. After expanding in the first-type expansion device 301 or the second-type expansion device 302, it flows into the second heat exchanger 102. When the second compression module 2002 is used for working fluid expansion, the third compression module control valve 1403 and the fourth compression module control valve 1404 are closed, and the first compression module control valve 1401 and the second compression module control valve 1402 are opened. The working fluid from the second heat exchanger 102 is compressed in the first compression module 2001, then flows into the first heat exchanger 101, flows into the second compression module 2002 through the first compression module control valve 1401 and expands in the second compression module 2002, and then flows into the second heat exchanger 102 through the second compression module control valve 1402.

[0140] Since turbine machinery has poor efficiency under low power and variable operating conditions, while positive displacement compressors and expanders have better efficiency under low power and variable operating conditions, it is preferred that the compressor and expander of a multi-purpose heat pump system for cooling or heating and electricity storage needs are positive displacement compression or expansion devices, and the compressor of the heat pump system is a positive displacement compressor with ≥1 air valve, which can be an intake valve or an exhaust valve, at least one of which is actively controlled, and the opening and closing of the active control valve is controlled by electromagnetic force, hydraulic pressure or mechanical force, etc. Preferably, the compressor has both an intake valve and an exhaust valve, and both the intake valve and the exhaust valve are actively controlled valves; and / or, the first type of expansion device has ≥1 air valve, which can be an intake valve or an exhaust valve, at least one of which is actively controlled, and the opening and closing of the active control valve is controlled by electromagnetic force, hydraulic pressure or mechanical force, etc. Preferably, the first type of expansion device has both an intake valve and an exhaust valve, and both the intake valve and the exhaust valve are actively controlled valves. The reason why the number of valves is ≥ 1 is that for some types of compressors, the number of valves is 1, such as scroll compressors, which usually only have an exhaust valve; for some types of compressors, the number of valves is 2, such as piston compressors. Similarly, the same situation exists for the first type of expansion device.

[0141] When the heat pump system operates in the second mode, the mass regulating device is controlled to regulate the total mass of the working fluid in the heat pump system, and the minimum operating pressure in the heat pump system is controlled to be less than the saturation pressure of the working fluid at 0°C. Since the heat pump system operates in the second mode, in order to achieve a larger amount of heat absorption, the minimum temperature in the second heat exchanger may reach about 200K. Therefore, it is preferred to control the minimum operating pressure in the heat pump system to be less than the saturation pressure of the working fluid at 230K. For example, for CO2 working fluid, its saturation pressure at 230K is 0.89291MPa, and the heat is controlled to be less than the saturation pressure of the working fluid at 230K. The minimum operating pressure in the pump system is <0.89291MPa. For example, when the minimum pressure is 0.5MPa, when the minimum temperature is 230K, CO2 will not be liquefied; and / or, when the heat pump system operates in the second operating mode, the mass adjustment device is controlled to adjust the total mass of the working fluid operating in the heat pump system, and the minimum operating pressure in the heat pump system is controlled to achieve a proportion of the liquid working fluid mass flow in the first heat exchanger and / or the second heat exchanger to the total working fluid mass flow of ≤1%, preferably 0, thereby reducing the impact of liquid phase change on the efficiency during the second mode operation.

[0142] Due to the different requirements for working fluids for cooling or heating and electricity storage needs, for example: cooling or heating needs require the working fluid to have phase change in the room temperature range, so that the cooling efficiency is high and the cooling capacity is large; the electricity storage needs require the working fluid to have a large adiabatic index, so that the unit heat release or heat absorption of the working fluid is large and the unit volume electricity storage density is high. Therefore, when working fluids with a critical temperature higher than 300K are used for electricity storage, there are problems such as low efficiency and electricity storage density. The heat pump system further includes a working fluid with a critical temperature lower than 300K. When operating in the first operating mode and when the operating temperature difference of the operating working fluid is less than 60°C, the mass regulating device is used to control the mass flow of the working fluid with a critical temperature higher than 300K in the circulating working fluid flow of the multi-purpose heat pump system to account for more than 50% of the total working fluid mass flow, and the mass flow of the working fluid with a critical temperature lower than 300K to account for less than 50% of the total working fluid mass flow. Preferably, the mass flow of the working fluid with a critical temperature higher than 300K accounts for ≥99% of the total working fluid mass flow, and the mass flow of the working fluid with a critical temperature lower than 300K accounts for less than 1% of the total working fluid mass flow. When operating in the first operating mode and when the operating working fluid operating temperature difference is greater than 100°C, the mass regulating device is used to control the proportion of the mass flow of the working fluid with a critical temperature higher than 300K in the circulating working fluid flow of the multi-purpose heat pump system to be less than 50% of the total working fluid mass flow, and the proportion of the mass flow of the working fluid with a critical temperature lower than 300K to be greater than 50% of the total working fluid mass flow. Preferably, the proportion of the mass flow of the working fluid with a critical temperature higher than 300K to the total working fluid mass flow is less than 1%, and the proportion of the mass flow of the working fluid with a critical temperature lower than 300K to the total working fluid mass flow is ≥99%. When operating in the second operating mode and when the operating working fluid temperature difference is greater than 100°C, the mass regulating device is used to control the mass flow of the circulating working fluid in the cooling, heating, and power multi-purpose heat pump system to ensure that the proportion of the mass flow of working fluid with a critical temperature above 300K in the total working fluid mass flow is less than 50%, and the proportion of the mass flow of working fluid with a critical temperature below 300K in the total working fluid mass flow is greater than 50%. Preferably, the proportion of the mass flow of working fluid with a critical temperature above 300K in the total working fluid mass flow is less than 1%, and the proportion of the mass flow of working fluid with a critical temperature below 300K in the total working fluid mass flow is ≥99%. This is because in the first mode and when the temperature difference is small, working fluid with a critical temperature below 300K may not undergo phase change. Therefore, the presence of a large amount of working fluid with a critical temperature below 300K in the heat pump system will increase the thermal resistance and reduce the performance of the heat pump system. In the first mode and when the temperature difference is large, this operating condition is aimed at energy storage. Working fluid with a critical temperature above 300K may undergo phase change, thereby reducing the efficiency of heat and cold storage, and thus the energy storage efficiency. Preferably, the working fluid with a critical temperature lower than 300K may be helium, hydrogen, argon, nitrogen, oxygen, air, etc.The number of mass regulating devices is ≥ 2, of which at least one mass regulating device is used for mass regulation, including storage and release, of at least one working fluid with a critical temperature higher than 300K; and at least one mass regulating device is used for mass regulation, including storage and release, of a working fluid with a critical temperature lower than 300K. When the working fluid with a critical temperature lower than 300K is a gas that can be obtained from the environment, such as air, nitrogen, or oxygen, the number of mass regulating devices can be one, which is mainly used for storing and regulating working fluids with a critical temperature higher than 300K. In addition, when there is a cold source inside the mass regulating device, the number of mass regulating devices can also be one, that is, using an external cold source to condense a fluid with a critical temperature higher than 300K into a liquid, gas separation can be achieved inside the mass regulating device. In this case, the mass regulating device is a gas separator with a valve.

[0143] Figure 6A multi-purpose heat pump system for heating, cooling and electricity with a critical temperature lower than 300K and a working fluid higher than 300K is shown. The heat pump system has a first mass regulating device 401 and a second mass regulating device 402. Under the action of the first mass regulating device 401, the working fluid with a critical temperature higher than 300K in the heat pump system is pumped into the working fluid storage tank 5, and then, under the action of the second mass regulating device 402, the working fluid with a critical temperature lower than 300K stored in the working fluid storage tank of the second mass regulating device 402 is released into the heat pump system. Similarly, under the action of the second mass regulating device 402, the working fluid with a critical temperature lower than 300K can be pumped into the working fluid storage tank 5, and then, under the action of the first mass regulating device 401, the working fluid with a critical temperature higher than 300K stored in the working fluid storage tank of the first mass regulating device 401 is released into the heat pump system, thereby realizing automatic switching of the operating working fluid in the heat pump system. When the working fluid with a critical temperature lower than 300K can be obtained from the atmosphere, it can also be as follows: under the action of the first mass regulating device 401, the heat pump system pumps the working fluid with a critical temperature higher than 300K in the heat pump system into the working fluid storage tank 5, and then pumps the ambient atmosphere into the heat pump system. Similarly, the ambient atmosphere is pumped out of the heat pump system, and the working fluid with a critical temperature higher than 300K stored in the working fluid storage tank 5 of the first mass regulating device 401 is pumped into the heat pump system. Since it may be difficult for the heat pump system to completely pump the working fluids of different critical temperatures into the working fluid storage tank during the above-mentioned working fluid switching process, which leads to mixing of the working fluids and makes it very difficult to completely operate the second working fluid or the first working fluid, the heat pump system also includes a gas separator 15. The gas separator can be arranged at the heat exchanger outlet or in the working fluid storage tank. For example, when the critical temperature is higher than 300K, the working fluid undergoes a phase change, the first working fluid in the first heat exchanger 101 is liquid, and the working fluid with a critical temperature below 300K is still in a gaseous state. The working fluid separator 15 can be used to separate the two working fluids with different critical temperatures under the action of gravity, and then in the first heat exchanger 101, the working fluid can be separated. A gas separation control valve 1601 and a working fluid pump 7 operate to pump a working fluid with a critical temperature below 300K into the working fluid storage tank 5 of the second mass regulating device 402. Once the working fluid with a critical temperature above 300K enters the working fluid storage tank 5 of the second mass regulating device 402, it can be condensed into a liquid by, for example, using an independent refrigeration device or heat pump system. Gravity can also be utilized to condense the working fluid with a critical temperature above 300K into a liquid. The liquid working fluid with a critical temperature above 300K is then fed into the working fluid storage tank 5 of the first mass regulating device 402 through a connecting pipe at the bottom of the working fluid 5 and the second gas separation control valve 1602. Furthermore, an adsorption separation device can be installed at the outlet of the working fluid storage tank 5 to further purify the working fluid entering the heat pump system.

[0144] The heat pump system also includes a regenerator having a first flow channel and a second flow channel. One end of the first flow channel of the regenerator is connected to the outlet end of the first heat exchanger and the other end is connected to the inlet end of the first type expansion device. One end of the second flow channel of the regenerator is connected to the outlet end of the second heat exchanger and the other end is connected to the compressor. Figure 7 As shown, the heat pump system has a regenerator 10. When the heat pump system operates in the first working medium circuit, the working medium passes through the compressor 2, the first heat exchanger 101, the first flow channel of the regenerator 10, the first type expansion device 301, the second heat exchanger 102, and the second flow channel of the regenerator 10. The heat pump system can be used for cooling or heating needs. The heat pump system can use a regenerator or not. Since the use of a regenerator for some working mediums will reduce performance, Figure 7 It shows the case where no regenerator is used when meeting cooling or heating requirements, and the working medium passes through the compressor 2 , the third heat exchanger 103 , the second type expansion device 302 , and the fourth heat exchanger 104 .

[0145] When the first type of expansion device cannot be used for working fluid compression, such as when the first type of expansion device is a turbine expander, due to the low efficiency of turbine expanders when used for compression, a compressor is required for working fluid compression during charging, i.e., when operating in the first operating mode, and when the working fluid operating temperature difference is greater than 100°C; a compressor is also required for working fluid compression during discharging, i.e., when operating in the second operating mode, and when the working fluid operating temperature difference is greater than 100°C. However, the requirements for compressors under the two operating conditions are different, so the number of compressors required is ≥ 2, where: when operating in the first operating mode, and when the working fluid operating temperature difference is greater than 100°C, the compressor used for working fluid compression is first compressor 201, and when operating in the second operating mode, and when the working fluid operating temperature difference is greater than 100°C, the compressor used for working fluid compression is second compressor 202. Preferably, the second compressor 202 has a smaller gas output than the first compressor 201 under the same frequency and intake parameters. Therefore, when the heat pump system is facing cooling / heating demand, since the working fluid expansion of the heat pump system is completed based on the second type of expansion device, at this time, the second compressor 202 can be used for the working fluid compression function in the second working fluid circuit under the action of the valve, thereby reducing the volume and cost of the compressor when facing cooling or heating demand. Therefore, when operating in the first operating mode, and when the operating working fluid operating temperature difference is less than 60°C, the second compressor 202 is used for compressing the working fluid in the second working fluid circuit, including any of the following situations: the working fluid is all compressed in the second compressor 202, and the working fluid is expanded through the second type of expansion device; and / or, one of the working fluids Part of the working fluid is compressed in the second compressor 202, and the other part is compressed in the first compressor 201, and the working fluid is expanded through the second type of expansion device; and / or, the first compressor 201 and the second compressor 202 are connected in series, and the working fluid flows into the second compressor 202 for pre-compression and then flows into the first compressor 201 for a second compression, and the working fluid is expanded through the second type of expansion device; and / or, the first compressor 201 and the second compressor 202 are connected in series, and the working fluid flows into the first compressor 201 for pre-compression and then flows into the second compressor 202 for a second compression, and the working fluid is expanded through the second type of expansion device. All of the above functions can be implemented in the same heat pump system. Figure 8 Several schematic diagrams of the second compressor 202 operating under the action of valves for compressing the working medium in the second working medium circuit are shown. Figure 8(a) in the figure shows the parallel operation of the first compressor 201 and the second compressor 202. The first compressor 201 can be used as a compressor for compressing the working fluid or as an expander for expanding the working fluid. During charging, the working fluid passes through the first compressor 201, the first heat exchanger 101, the first type of expansion device 301 and the second heat exchanger 102 in sequence. During discharging, since the first type of expansion device 301 cannot be used for working fluid compression, the second compressor 202 is equipped, the third valve 904 and the fourth valve 904 are opened, the first valve 901 and the second valve 902 are closed, and the working fluid is compressed in the second compressor 202 and expanded in the first compressor 201. In the second working fluid circuit, the third valve 904 and the fourth valve 904 are opened, and the first valve 901 and the second valve 902 are closed. The door 904 and the fourth valve 904 are closed, and the first valve 901 and the second valve 902 are opened. Part of the working fluid flowing out of the second heat exchanger 102 is compressed by the first compressor 201 and then flows into the first heat exchanger 101, and part of it is compressed by the second valve 902 and the second compressor 202 and then flows into the first heat exchanger 101 through the first valve 901. After heat exchange in the first heat exchanger 101, the working fluid flows into the second heat exchanger 102 through the second type expansion device 302. Therefore, at this time, the expander and the compressor are connected in parallel to perform the compression function. When the first compressor 201 is closed, only the second compressor 202 is used for compression, and all the working fluid flowing out of the second heat exchanger 102 flows into the second compressor 202. Figure 8 (b) shows the series operation. During discharge, since the first type expansion device 301 cannot be used for working medium compression, a second compressor 202 is equipped, the second valve 902 and the sixth valve 906 are closed, and the third valve 903, the fourth valve 904, and the fifth valve 905 are opened. The working medium is compressed in the second compressor 202 and expanded in the first compressor 201. In the second working medium circuit, the second valve 902 and the sixth valve 906 are opened, and the third valve 903, the fourth valve 904, and the fifth valve 905 are closed. The working medium flowing out of the second heat exchanger 102 flows into the first compressor 201 through the second valve 902, the second compressor 202, and the sixth valve 906. After heat exchange in the first heat exchanger 101, the working medium flows into the second heat exchanger 102 through the second type expansion device 302. Therefore, at this time, the second compressor 202 is connected in series with the second compressor 202, serving as the front-stage compression of the compressor. Figure 8(c) in the figure shows another series operation situation. During discharge, since the first type expansion device 301 cannot be used for working medium compression, a second compressor 202 is equipped, the ninth valve 909 and the seventh valve 907 are closed, the third valve 903, the fourth valve 904, and the eighth valve 908 are opened, and the working medium is compressed in the second compressor 202 and expanded in the first compressor 201. When the second compressor 202 is used for second-stage compression, the ninth valve 909 and the seventh valve 907 are opened, the third valve 903, the fourth valve 904, and the eighth valve 908 are closed, and the working medium flowing out of the second heat exchanger 102 flows into the first compressor 201. After being compressed in the first compressor 201, the working medium passes through the seventh valve 907, the second compressor 202, and the ninth valve 909 in sequence. After heat exchange in the first heat exchanger 101, the working medium flows into the second heat exchanger 102 through the second type expansion device 302. Therefore, at this time, the expander and the compressor are connected in series as the second-stage compression of the compressor. In addition, the first to ninth valves are installed on a system according to the above schematic diagram, as shown in FIG. Figure 8 As shown in (d), the heat pump system can realize the above-mentioned operation of the second compressor 202 and the first compressor 201 in one heat pump system. Figure 8 The functions shown in (a), (b) and (c) are preferably such that the second compressor 202 is used for compressing the working medium under the action of the valve, and the second compressor 202 is connected in parallel with the first compressor 201. Figure 8 In the second operating mode, when the working medium temperature difference is greater than 100°C, the compressor used for working medium compression is the second compressor 202, and the first compressor 201 is used for working medium expansion and recovery of expansion work. In fact, when the first compressor 201 is a turbine machine, the problem of low expansion efficiency also exists. Therefore, it is necessary to configure an additional first-class expansion device. In this case, Figure 9 As shown, two compressors and two expanders are required. The two compressors can also realize the parallel and series functions as described above by setting relevant valves, which will not be repeated here. In addition, Figure 9 In the figure, the second compressor 202 is connected in parallel with the first first-class expansion device 3010. In fact, the second compressor 202 can also be connected in parallel with the first compressor 201. At this time, the second first-class expansion device 3011 is connected in parallel with the first first-class expansion device 3010. Similarly, the two compressors can also achieve the parallel and series functions as described above by setting relevant valves, which will not be repeated here.

[0146] In the above process, in order to achieve that the mass flow rate of the liquid working fluid in the first heat exchanger 101 and / or the second heat exchanger 102 accounts for more than 10% of the total working fluid mass flow rate, there are several schemes through the mass regulating device: (1) The heat pump system only has a single working fluid with a critical temperature higher than 300K, such as CO2, R32, etc. Due to the demand for cooling or heating, the lowest temperature in the first heat exchanger 101 and / or the second heat exchanger 102 is lower than the critical temperature of 300K, and the quality of the working fluid in the heat pump system is improved, so that the mass flow rate of the liquid working fluid in the first heat exchanger 101 and / or the second heat exchanger 102 accounts for more than 10% of the total working fluid mass flow rate; (2) The heat pump system has multiple working fluids with a critical temperature higher than 300K, such as CO2+R32, and the heat pump system can be controlled by the mass regulating device. The CO2 working fluid is pumped out of the heat pump system and the R32 working fluid is pumped into the heat pump system, and the quality of the R32 working fluid in the heat pump system can achieve a ratio of the mass flow of the liquid working fluid in the first heat exchanger 101 and / or the second heat exchanger 102 to the total mass flow of the working fluid greater than 10%; (3) the heat pump system has a working fluid with a critical temperature higher than 300K and a working fluid with a critical temperature lower than 300K, such as R32+argon, and the working fluid with a critical temperature lower than 300K, such as argon, can be controlled by a mass regulating device to pump the working fluid with a critical temperature higher than 300K, such as R32, out of the heat pump system and the working fluid with a critical temperature higher than 300K, such as R32, into the heat pump system, and the quality of the R32 working fluid in the heat pump system can achieve a ratio of the mass flow of the liquid working fluid in the first heat exchanger 101 and / or the second heat exchanger 102 to the total mass flow of the working fluid greater than 10%.

[0147] In the above process, in order to achieve that the proportion of the mass flow of the liquid working fluid in the first heat exchanger 101 and / or the second heat exchanger 102 to the total mass flow of the working fluid is less than 10%, the following schemes are available through the mass regulating device: (1) The heat pump system only has a single working fluid with a critical temperature higher than 300K, such as CO2, R32, etc. Due to the need for power storage, the lowest temperature in the first heat exchanger 101 and / or the second heat exchanger 102 is lower than the critical temperature of 300K. Therefore, in order to reduce the liquid specific gravity or eliminate the liquid, it is necessary to reduce the working fluid mass in the heat pump system. For example: for CO2, the parameters before expansion are 1.5MPa and 300K. After isentropic expansion to 0.6MPa, the working fluid temperature is 240.66K. Since the saturation temperature corresponding to 0.6MPa is 220.03K, no liquid will be produced after expansion; (2) The heat pump system has multiple working fluids with a critical temperature higher than 300K, such as CO2+R32. The mass regulating device can be used to control the R32 working fluid in the heat pump system to be pumped out of the heat pump system and the CO2 working fluid to be pumped into the heat pump system. The mass of the CO2 working fluid in the heat pump system can achieve a ratio of the mass flow of the liquid working fluid in the first heat exchanger 101 and / or the second heat exchanger 102 to the total mass flow of the working fluid less than 10%; (3) The heat pump system has a working fluid with a critical temperature higher than 300K and a working fluid with a critical temperature lower than 300K, such as R32+argon. The mass regulating device can be used to control the working fluid with a critical temperature higher than 300K, such as R32, to be pumped out of the heat pump system and the working fluid with a critical temperature lower than 300K, such as argon, to be pumped into the heat pump system. Argon has a low critical temperature and will not be liquefied under specific operating parameters.

[0148] The heat pump system further includes a third heat exchanger 103 and / or a fourth heat exchanger 104. Figure 2 (a) Figure 2 (f) shows a heat pump system including both a third heat exchanger 103 and a fourth heat exchanger 104. The third heat exchanger 103 is located in the connecting pipeline between the outlet of the compressor 2 and the inlet of the second type expansion device 302; the fourth heat exchanger 104 is located in the connecting pipeline between the outlet of the second type expansion device and the inlet of the compressor 2. Figure 2 (b) Figure 2 (d) in the figure shows schematic diagrams of the connecting pipeline of the fifth heat exchanger 105 between the outlet of the compressor 2 and the inlet of the second type expansion device 302, and the connecting pipeline between the outlet of the second type expansion device and the inlet of the compressor 2.

[0149] In addition, it should be emphasized that: according to Carnot's theorem, for the working fluid circuit of the refrigeration cycle and the power cycle, there must be at least two heat exchangers, one of which exchanges heat with an external high-temperature heat source, and the other exchanges heat with an external low-temperature heat source. Moreover, one of the heat exchangers absorbs heat from the outside, and the other absorbs heat from the outside. Therefore, in this embodiment, the first heat exchanger 101 and the second heat exchanger 102 respectively represent the heat exchangers in the first working fluid circuit that exchange heat with the external high-temperature heat source and the external low-temperature heat source when the heat pump operates in the first operating mode. It is further emphasized that it refers to the heat pump system operation. When operating in the first operating mode, the heat exchanger in the first working fluid circuit is under rated working conditions or under conditions where the cooling and heating capacities are maximum, that is, the charging power is maximum. In one working fluid circuit, the heat exchanger that exchanges heat with an external high-temperature heat source should be regarded as the first heat exchanger 101, and the heat exchanger that exchanges heat with an external low-temperature heat source should be regarded as the second heat exchanger 102. When there are multiple heat exchangers, in this working fluid circuit, the heat exchanger that exchanges heat with an external high-temperature heat source can be regarded as part or all of the first heat exchanger 101, and the heat exchanger that exchanges heat with an external low-temperature heat source can be regarded as part or all of the second heat exchanger 102.

[0150] Example 2:

[0151] When the heat pump system is facing cooling or heating demand, that is, when the heat pump system is running in the first operating mode, and when the working temperature difference of the operating medium is less than 60℃, Figure 1 As shown, the working medium passes through the second heat exchanger 102, the compressor 2, the first heat exchanger 101, and the expansion device 3 in sequence, releasing heat in the first heat exchanger 101 and absorbing heat in the second heat exchanger 102. Preferably, the first-type expansion device 301 stops operating, and the working medium expands and flows entirely through the second-type expansion device 302. To avoid losses, the clutch 13 disconnects the expander from the motor 12, and a valve is provided on the connecting pipeline between the first-type expansion device 301 and the first heat exchanger 101 or the second heat exchanger 102 to disconnect the first-type expansion device 301 from the first heat exchanger 101 and the second heat exchanger 102. It should be noted that the first-type expansion device 301 is a first-type expansion device, and the second-type expansion device 302 is a second-type expansion device.

[0152] When the heat pump system is aimed at power storage needs, the positive displacement compressor and expander can have the dual functions of working fluid compression and working fluid expansion. Figure 1As shown, the charging process is as follows: the working fluid passes through the second heat exchanger 102, the compressor 2, the first heat exchanger 101 and the first type expansion device 301 in sequence, the working fluid releases heat in the first heat exchanger 101 and absorbs heat in the second heat exchanger 102, and stores heat and cold in the first heat storage device 801 and the second heat storage device 802 respectively. In the process of producing cold and heat, electricity is consumed to achieve charging. The temperature difference between the average temperature of the working fluid in the first heat exchanger 101 and the average temperature in the second heat exchanger 102 is greater than 100°C. Discharge process: For a compressor and a first-class expansion device that share the same inlet and outlet, or a compressor and a first-class expansion device that use a four-way valve or other valves to switch the inlet and outlet and the heat exchanger interface, the working medium passes through the second heat exchanger 102, the first-class expansion device 301, the first heat exchanger 101, and the compressor 2 in sequence. The working medium absorbs the cold stored in the second heat storage device 802 in the second heat exchanger 102, is compressed in the first-class expansion device 301, and then absorbs the heat stored in the first heat storage device 801 in the first heat exchanger 101. For a compressor and a first-type expansion device that cannot share a common inlet and outlet, and that do not use a four-way valve or other valve to switch the inlet and outlet and heat exchanger interface, the working fluid passes through the first heat exchanger 101, the first-type expansion device 301, the second heat exchanger 102, and the compressor 2 in sequence. The working fluid absorbs the cold energy stored in the second heat storage device 802 within the first heat exchanger 101, is compressed within the first-type expansion device 301, and then absorbs the heat stored in the first heat storage device 801 within the second heat exchanger 102. Therefore, during the discharge process, the first-type expansion device 301 performs the working fluid compression function, while the compressor 2 performs the working fluid expansion function. By absorbing the heat and cold energy stored in the first and second heat storage devices 801 and 802, the heat pump system outputs electricity.

[0153] When the heat pump system is aimed at power storage needs, for a single turbine machine, the efficiency is low when used for both compression and expansion. Therefore, when the compressor and expander of the heat pump system are both turbine machines, the heat pump system needs to be equipped with two compressors and two expanders, or when the heat pump system uses multiple positive displacement devices, such as Figure 9As shown, the charging process: the working medium passes through the second heat exchanger 102, the first compressor 201, the first heat exchanger 101 and the first first-type expansion device 3010 in sequence, the working medium releases heat in the first heat exchanger 101 and absorbs heat in the second heat exchanger 102, and stores heat and cold in the first heat storage device 801 and the second heat storage device 802 respectively. In the process of producing cold and heat, electricity is consumed to achieve charging. The temperature difference between the average temperature of the working medium in the first heat exchanger 101 and the average temperature in the second heat exchanger 102 is greater than 100°C; the discharging process: the working medium The working medium passes through the second heat exchanger 102, the second compressor 202, the first heat exchanger 101, and the second first-class expansion device 3011 in sequence. The working medium absorbs the cold energy stored in the second heat storage device 802 in the second heat exchanger 102 and is compressed in the second compressor 202. Then, the working medium absorbs the heat stored in the first heat storage device 801 in the first heat exchanger 101 and expands in the second first-class expansion device 3011. By absorbing the heat and cold energy stored in the first heat storage device 801 and the second heat storage device 802, the heat pump system outputs electricity.

[0154] In the operation facing cooling or heating demand, the total mass of the working fluid in the heat pump system is adjusted by the mass regulating device to achieve that the proportion of the mass flow of the liquid working fluid in the first heat exchanger 101 and / or the second heat exchanger 102 to the total mass flow of the working fluid is greater than 10%, and at the same time, the proportion of the mass flow of the working fluid in the heat pump system passing through the second type of expansion device to the total mass flow of the working fluid is controlled to be greater than 90%, and the proportion of the mass flow of the working fluid in the heat pump system passing through the first type of expansion device to the total mass flow of the working fluid is controlled to be less than 10%.

[0155] In the operation oriented towards the demand for electricity storage, the total mass of the working fluid in the heat pump system is regulated by the mass regulating device to achieve a proportion of the liquid working fluid mass flow in the first heat exchanger 101 and / or the second heat exchanger 102 to the total working fluid mass flow of less than 10%. At the same time, the proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the second type of expansion device to the total working fluid mass flow is controlled to be less than 10%, and the proportion of the working fluid mass flow of the working fluid in the heat pump system passing through the first type of expansion device to the total working fluid mass flow is controlled to be greater than 90%.

[0156] Example 3:

[0157] This embodiment provides a multi-purpose heat pump system for cooling, heating, and power generation, comprising a first heat exchanger 101, a compressor 2, a second heat exchanger 102, and an expansion device, all connected in sequence. Furthermore, the system further comprises a motor 12, which is connected to the compressor 2. The number of expansion devices 3 is ≥2, and the expansion devices include first-type expansion devices and second-type expansion devices. The first-type expansion device is an expander that recovers expansion work from the expansion process of a working fluid and outputs mechanical work, and the number of first-type expansion devices is ≥1. The second-type expansion device is an expansion device other than an expander, and the number of second-type expansion devices is ≥1. The multi-purpose heat pump system for cooling, heating and power has at least two working fluid circuits. In the first working fluid circuit, the inlet of the compressor 2 is connected to the outlet end of the second heat exchanger 102, and the outlet of the compressor 2 is connected to the inlet end of the first heat exchanger 101. The inlet of the first type of expansion device is connected to the outlet end of the first heat exchanger 101, and the outlet of the first type of expansion device is connected to the inlet end of the second heat exchanger 102. Two pipelines are formed between the compressor 2 and the first type of expansion device. The first pipeline includes a connecting pipeline between the outlet of the compressor 2 and the inlet of the first type of expansion device 301, and the second pipeline includes a connecting pipeline between the inlet of the compressor 2 and the outlet of the first type of expansion device 301; in the second working fluid circuit, one interface of the second type of expansion device 302 is connected to the first pipeline, and the other interface of the second type of expansion device 302 is connected to the second pipeline. The multipurpose heat pump system for cooling, heating and electricity has two operating modes; the first operating mode is the refrigeration cycle, in which the multipurpose heat pump system for cooling, heating and electricity consumes electricity and generates cooling and heat; the second operating mode is the power cycle, in which the multipurpose heat pump system for cooling, heating and electricity consumes cooling and heat and generates electricity.

[0158] A multi-purpose heat pump system for heating, cooling, and power generation contains at least one refrigerant with a critical temperature above 300K and at least one refrigerant with a critical temperature below 300K. For energy storage, its energy storage efficiency is related to the refrigerant's physical properties. Suitable refrigerants are those with critical temperatures below 300K, such as helium, hydrogen, argon, nitrogen, oxygen, and air. For cooling or heating, its cooling / heating efficiency is also related to the refrigerant's physical properties. Suitable refrigerants are those with critical temperatures above 300K, such as R290, R410A, and R32. Therefore, when storing energy, a heat pump system with a high concentration of refrigerants with critical temperatures above 300K will reduce energy storage efficiency. Similarly, a heat pump system with a high concentration of refrigerants with critical temperatures below 300K will reduce cooling / heating efficiency. When storing energy, a system with a high concentration of refrigerants with critical temperatures above 300K will have a greater impact. The primary requirement for energy storage is economic efficiency. Therefore, when the multi-purpose heat pump system for heating, cooling and electricity includes a working fluid with a critical temperature higher than 300K and a working fluid with a critical temperature lower than 300K, in order to reduce the impact of the working fluid with a critical temperature higher than 300K on the energy storage efficiency, when operating in the first operating mode and when the operating working fluid working temperature difference is greater than 100°C, in the first working fluid circuit, the pressure in the first heat exchanger 101 and the second heat exchanger 102 is greater than or equal to 0.5MPa; when operating in the second operating mode and when the operating working fluid working temperature difference is greater than 100°C, in the first working fluid circuit, the pressure in the first heat exchanger 101 and the second heat exchanger 102 is greater than or equal to 0.5MPa. Preferably, under the above working conditions, the pressure in the first heat exchanger 101 and the second heat exchanger 102 is greater than or equal to 1MPa. The reason for choosing 0.5 MPa is that, when the temperature in the second heat exchanger 102 is as low as 200 K or below for power storage, taking R290 as an example, its corresponding saturation pressure at 200 K is approximately 0.02 MPa. Therefore, when the pressure in the first heat exchanger 101 and the second heat exchanger 102 is ≥ 0.5 MPa, the proportion of working fluids with a critical temperature higher than 300 K to all working fluids is less than 5%. Therefore, the influence of working fluids with a critical temperature higher than 300 K on the power storage efficiency can be almost ignored. Moreover, since the demand for cooling or heating is based on the phase change of the working fluid, and the demand for electricity storage is based on sensible heat release or heat absorption, in order to achieve the best match between cooling / heating capacity and electricity storage power, when operating in the first operating mode and when the operating working fluid working temperature difference is greater than 100°C, in the first working fluid circuit, the pressure in the first heat exchanger 101 and the second heat exchanger 102 is ≥0.5MPa; when operating in the second operating mode and when the operating working fluid working temperature difference is greater than 100°C, in the first working fluid circuit, the pressure in the first heat exchanger 101 and the second heat exchanger 102 is ≥0.5MPa.

[0159] Since there are working fluids with a critical temperature higher than 300K and working fluids with a critical temperature lower than 300K in a system, and the requirements for working fluids for power storage and cooling / heating are different, in order to achieve better performance, when operating in the first operating mode and when the operating working fluid working temperature difference is less than 60°C, the proportion of the mass flow of the working fluid with a critical temperature higher than 300K in the cooling, heating and power multi-purpose heat pump system to the total working fluid mass flow is greater than 50%, and the proportion of the mass flow of the working fluid with a critical temperature lower than 300K to the total working fluid mass flow is less than 50%. Preferably, the proportion of the mass flow of the working fluid with a critical temperature higher than 300K to the total working fluid mass flow is ≥99%, and the proportion of the mass flow of the working fluid with a critical temperature lower than 300K to the total working fluid mass flow is less than 1%; when operating in the first operating mode and when the operating working fluid working temperature difference is greater than 100°C, the proportion of the mass flow of the working fluid with a critical temperature higher than 300K in the cooling, heating and power multi-purpose heat pump system to the total working fluid mass flow is greater than 50%. The proportion of the flow rate to the total working fluid mass flow rate is less than 50%, and the proportion of the working fluid mass flow rate with a critical temperature below 300K to the total working fluid mass flow rate is greater than 50%. Preferably, the proportion of the working fluid mass flow rate with a critical temperature above 300K to the total working fluid mass flow rate is less than 1%, and the proportion of the working fluid mass flow rate with a critical temperature below 300K to the total working fluid mass flow rate is ≥99%; when operating in the second operating mode and when the operating working fluid working temperature difference is greater than 100°C, in the cooling, heating and power multi-purpose heat pump system, the proportion of the working fluid mass flow rate with a critical temperature above 300K to the total working fluid mass flow rate is less than 50%, and the proportion of the working fluid mass flow rate with a critical temperature below 300K to the total working fluid mass flow rate is greater than 50%. Preferably, the proportion of the working fluid mass flow rate with a critical temperature above 300K to the total working fluid mass flow rate is less than 1%, and the proportion of the working fluid mass flow rate with a critical temperature below 300K to the total working fluid mass flow rate is ≥99%.

[0160] In order to realize the operation of the multi-purpose heat pump system for cooling, heating and power according to the above-mentioned working fluid flow ratio, the following methods can be adopted: (1) a mass regulating device, when facing the cooling or heating demand, pumps the working fluid with a critical temperature lower than 300K into the working fluid storage tank and releases the working fluid with a critical temperature higher than 300K into the heat pump system; when facing the power storage demand, pumps the working fluid with a critical temperature higher than 300K into the working fluid storage tank and releases the working fluid with a critical temperature lower than 300K into the heat pump system. This scheme has been described in detail in the first embodiment and will not be repeated here; (2) no heat exchanger is shared, and the first working fluid circuit heat exchanger for power storage demand uses the working fluid with a critical temperature lower than 300K, and the second working fluid circuit heat exchanger for cooling or heating demand uses the working fluid with a critical temperature higher than 300K; (3) taking advantage of the fact that the working fluid with a critical temperature higher than 300K is liquefied and the working fluid with a critical temperature lower than 300K is not liquefied, the mass flow ratio of the working fluid with a critical temperature higher than 300K in the total mass flow is adjusted based on gas-liquid separation.

[0161] Figure 10A heat pump system solution that does not share a heat exchanger is shown. The first working fluid circuit is composed of a compressor 2, a first heat exchanger 101, a first type of expansion device 301, and a second heat exchanger 102. The second working fluid circuit is composed of a compressor 2, a third heat exchanger 103, a second type of expansion device 302, and a fourth heat exchanger 104. The working fluid in the first working fluid circuit is a working fluid with a critical temperature below 300K, and the working fluid in the second working fluid circuit is a working fluid with a critical temperature above 300K. Since the two working fluid circuits do not share a heat exchanger, a switching valve 17 is further included. The first switching valve 1701 is located at the outlet of the compressor 2, and is used to control the connection and disconnection between the outlet of the compressor 2 and the first heat exchanger 101 or the third heat exchanger 103; the second switching valve 1702 is located at the inlet of the compressor 2, and is used to control the connection between the inlet of the compressor 2 and the second heat exchanger 102 or the fourth heat exchanger 104. When the heat pump system faces cooling or heating demand, the outlet of the compressor 2 is connected to the third heat exchanger 103 and disconnected from the first heat exchanger 101 under the action of the first switching valve 1701, and the inlet of the compressor 2 is connected to the third heat exchanger 103. The outlet of compressor 2 is connected to the fourth heat exchanger 104 and disconnected from the second heat exchanger 102 at the second switching valve 1702. When the heat pump system is facing the power storage demand, the outlet of compressor 2 is disconnected from the third heat exchanger 103 and connected to the first heat exchanger 101 under the action of the first switching valve 1701. The inlet of compressor 2 is disconnected from the fourth heat exchanger 104 and connected to the second heat exchanger 102 at the second switching valve 1702. Therefore, the working fluid in the first working fluid circuit can be a working fluid with a critical temperature lower than 300K, and the working fluid in the second working fluid circuit can be a working fluid with a critical temperature higher than 300K, thereby realizing the working fluid flow ratio operation as described above. Since there is a shared working fluid between the two working fluid circuits and there may be a mixture of working fluids, a working fluid pump 7 is also included. The inlet of the working fluid pump 7 is connected to the inlet or outlet of the compressor 2. The working fluid pump 7 can pump the working fluid in the compressor 2 into the first heat exchanger 101 or the second heat exchanger 102, or can pump the working fluid in the compressor 2 into the third heat exchanger 103 or the fourth heat exchanger 104. For example: in the process of switching from cooling or heating demand to power storage demand, the working fluid pump 7 can be used to pump the working fluid in the compressor 2 into the third heat exchanger 103 or the fourth heat exchanger 104; in the process of switching from power storage demand to cooling or heating demand, the working fluid pump 7 can be used to pump the working fluid in the compressor 2 into the first heat exchanger 101 or the second heat exchanger 102. Similarly, in the first working fluid circuit, the following is installed: Figure 4 The valve shown can be used to compress the working fluid in the second working fluid circuit. Figure 10The figure shows a case where the first type expansion device 301 and the compressor 2 are connected in parallel. Depending on the situation, when facing the cooling or heating demand, the third valve 903 and the fourth valve 904 are closed, and the first valve 901 and the second valve 902 are opened. The second working medium circuit compressor can be compressed by only the first type expansion device 301, only the compressor 2, or by both the first type expansion device 301 and the compressor 2. Other series connection forms can be as follows Figure 4 The valves and pipelines shown will not be described in detail.

[0162] Figure 11 A schematic diagram of a gas-liquid separation regulation of the proportion of the mass flow rate of the working fluid with a critical temperature higher than 300K in the total mass flow rate is shown. The heat pump system includes at least one gas separator 15, which has a cavity inside and at least one interface connected to the closed cavity. When the working fluid of the heat pump system is mainly a working fluid with a critical temperature higher than 300K, the internal cavity of the gas separator 15 is used to store some or all of the working fluid with a critical temperature lower than 300K; when the working fluid of the heat pump system is mainly a working fluid with a critical temperature lower than 300K, the internal cavity of the gas separator 15 is used to store some or all of the working fluid with a critical temperature higher than 300K. Furthermore, the gas separator 15 can realize any one or all of the following functions in the heat pump system: when operating in the first operating mode and the operating working fluid operating temperature difference is less than 60°C, the gas separator 15 is used to reduce the proportion of working fluids with a critical temperature lower than 300K in the total working fluid mass flow; and, or, when operating in the first operating mode and the operating working fluid operating temperature difference is greater than 100°C, the gas separator 15 is used to reduce the proportion of working fluids with a critical temperature higher than 300K in the total working fluid mass flow; and, or, when operating in the second operating mode and the operating working fluid operating temperature difference is greater than 100°C, the gas separator 15 is used to reduce the proportion of working fluids with a critical temperature higher than 300K in the total working fluid mass flow. In order to realize the above functions, the gas separator 15 can be any of the following connection conditions:

[0163] (1) The first gas separator 151 is connected to a connecting pipeline between an interface of the second type expansion device and the outlet of the compressor 2. Specifically, the first gas separator 151 is located on the connecting pipeline between an interface of the second type expansion device in the second working fluid circuit and the outlet of the compressor 2 and is located on the connecting pipeline between the outlet of the heat exchanger closest to the second type expansion device in the second working fluid circuit and the second type expansion device. When the heat pump system operates to meet cooling or heating requirements, the working fluid is expanded through the second type expansion device 302. At this time, the most suitable working fluid for the heat pump system is the working fluid with a critical temperature higher than 300K. For working fluids with a critical temperature higher than 300K, such as R290 and R32, the working fluid is compressed by the compressor 2 and then condensed into liquid after releasing heat through the heat exchanger. At this time, the working fluid with a critical temperature lower than 300K is still in gaseous state. Therefore, the working fluid with a critical temperature higher than 300K and the working fluid with a critical temperature lower than 300K are separated into gas and liquid in the first gas separator 151. The liquid is at the bottom of the first gas separator 151, and the outlet can be set inside the liquid to achieve storage of part or all of the working fluid with a critical temperature lower than 300K inside the first gas separator 151. Therefore, the first gas separator 151 is set at the working fluid inlet of the second type expansion device in the second working fluid circuit to adjust the flow ratio of different working fluids, such as Figure 11 As shown in (a), the first gas separator 151 is located on the pipeline between an interface of the second type expansion device in the second working fluid circuit and the outlet of the third heat exchanger 103. Figure 1 、 Figure 2 (e) in Figure 2 (g) in Figure 2 (d) Figure 2 In the heat pump system shown in (h), the first gas separator 151 is located on the connecting pipeline between the outlet of the compressor 2 and the second type expansion device 302, and further, on the pipeline between the heat exchanger near the inlet end of the second type expansion device 302 and the inlet of the second type expansion device 302;

[0164] (2) and or, the second gas separator 152 is connected to the first pipeline, or, the second gas separator 152 is connected to the second pipeline, or, the second gas separator 152 is connected to the connecting pipeline between the outlet of the compressor 2 and the second type of expansion device, or, the second gas separator 152 is connected to the connecting pipeline between the inlet of the compressor 2 and the second type of expansion device. When the heat pump system operates to meet cooling or heating requirements, the working fluid expands through the first type of expansion device 301. At this time, the working fluid most suitable for the heat pump system is the working fluid with a critical temperature below 300K. Therefore, in order to reduce the impact of the working fluid with a critical temperature above 300K on the energy storage efficiency, it is necessary to reduce the proportion of the working fluid with a critical temperature above 300K in the total working fluid flow. Figure 11 (a) and (b) show the connection between the second gas separator 152 and the second pipeline. Figure 11In (a), the second gas separator 152 is connected to the connecting pipeline between the outlet of the first type expansion device and the inlet of the second heat exchanger 102, Figure 11 In (b), the connecting pipeline between the second gas separator 152 and the inlet of the compressor 2 and the outlet of the second heat exchanger 102 is connected. The temperature of the working fluid is controlled to be low after expansion through the first-type expansion device 301. The working fluid with a critical temperature above 300K becomes a gas-liquid two-phase state. The liquid phase, due to its higher density, flows into the second gas separator 152. The gas phase of the working fluid with a critical temperature above 300K and the working fluid with a critical temperature below 300K mix and enter the compressor 2. To reduce the damage caused by the gas-liquid two-phase state to the first-type expansion device 301, a second-type expansion device can be connected in parallel at both ends of the first-type expansion device 301. In the initial stage of the heat pump system for power storage applications, the first-type expansion device 301 is stopped for expansion, and the second-type expansion device connected in parallel with the first-type expansion device 301 is activated for working fluid expansion. When the critical temperature within the heat pump system exceeds 300K and the working fluid is mostly stored in the second gas separator 152 after liquefaction, the second-type expansion device is stopped and the first-type expansion device 301 is activated. Figure 11 (c) shows the connection between the second gas separator 152 and the connecting pipeline between the compressor 2 inlet and the second type expansion device, and the connection between the second gas separator 151 and the second type expansion device 302 and the fourth heat exchanger 104 . Figure 11 (d) shows the connection between the second gas separator 152 and the connecting pipeline between the compressor 2 outlet and the second type expansion device. Figure 11 (d) also shows the connection between the second gas separator 152 and the first pipeline. The second gas separator 151 is located on the outlet pipeline of compressor 2. In this case, the working fluid with a critical temperature above 300K entering the second gas separator 152 is in the gas phase. The second gas separator 152 requires an external cooling source to cool the working fluid in the second gas separator and condense the working fluid with a critical temperature above 300K within the second gas separator 152. The second gas separator 151 can also be located in the pipeline between the first heat exchanger 101 and the first-type expansion device 301. In this case, an external cooling source is also required to condense the working fluid with a critical temperature above 300K within the second gas separator 152. It should be noted that the heat pump system can only have the first gas separator 151. When used for energy storage, the working fluid with a critical temperature above 300K can be condensed within the first gas separator 151 through an external cooling source, thereby reducing the impact of the working fluid with a critical temperature above 300K on the energy storage efficiency.

[0165] In order to reduce the impact of working fluids with a critical temperature higher than 300K on power storage requirements, when operating in the first operating mode and the operating working fluid operating temperature difference is greater than 100°C, the liquid temperature in the first gas separator 151 and / or the second gas separator 152 is controlled to be ≤273K, so as to achieve the storage of part of the working fluid with a critical temperature higher than 300K in liquid form in the first gas separator 151 and / or the second gas separator 152. When operating in the second operating mode and the operating working fluid operating temperature difference is greater than 100°C, the liquid temperature in the first gas separator 151 and / or the second gas separator 152 is controlled to be ≤273K, so as to achieve the storage of part of the working fluid with a critical temperature higher than 300K in liquid form in the second gas separator 152. The reason for selecting 273K is that the saturation pressure of some working fluids with a critical temperature higher than 300K is very low at 273K, such as R245fa, which has a saturation pressure of approximately 0.05MPa at 273K. When the minimum pressure in the first heat exchanger 101 and the second heat exchanger 102 is 0.5MPa, the proportion of working fluids with a critical temperature higher than 300K in the total working fluid flow rate is approximately 10% when meeting power storage requirements, so the impact is relatively small. Since the lower the temperature, the lower the saturation pressure of working fluids with a critical temperature higher than 300K, the smaller their proportion in the total working fluid flow rate, and the smaller the impact on power storage requirements when mixed with working fluids with a critical temperature lower than 300K. Therefore, it is preferred to control the liquid temperature in the first gas separator 151 and / or the second gas separator 152 to ≤220K.

[0166] The shape of the gas separator 15 includes a storage tank, a bend pipe. Figure 11 As shown in (c), the second gas separator 152 is a bent pipe.

[0167] In addition, the gas separation method based on gas-liquid separation can also be implemented by using the third heat exchanger 103 and / or the fourth heat exchanger 104, for example Figure 2As shown in (f) in FIG, when the heat pump system is used for electricity storage, since the third heat exchanger 103 and the fourth heat exchanger 104 are not used for heat exchange, they can be used to store working fluids with a critical temperature higher than 300K. For example, an external cold source is used to condense the working fluids with a critical temperature higher than 300K in the third heat exchanger. Alternatively, when the heat pump system is used for electricity storage, the working fluid is first expanded using the second-type expansion device, and the gas-liquid two-phase formed after the working fluid expansion is used to retain the liquid in the fourth heat exchanger 104. In addition, an external cold source can also be used to store most of the working fluids with a critical temperature higher than 300K in the fourth heat exchanger 104. Moreover, during the charging and discharging process, the liquid temperature in the third heat exchanger 103 or the fourth heat exchanger 104 is controlled to be ≤273K. Therefore, most of the working fluids with a critical temperature higher than 300K are stored in the third heat exchanger 103 or the fourth heat exchanger 104 in liquid form, thereby reducing their proportion in the total working fluid flow rate. When facing cold or hot, since the first heat exchanger 101 or the second heat exchanger 102 is not used for heat exchange, it can be used to store working fluid with a critical temperature lower than 300K, for example Figure 2 As shown in (f) in the figure, since the working fluid with a critical temperature lower than 300K is in a gaseous state, when the height of the third heat exchanger 103 is smaller than that of the first heat exchanger 101, part or all of the working fluid with a critical temperature lower than 300K is concentrated in the first heat exchanger 101 due to its lighter density, thereby reducing the proportion of the working fluid with a critical temperature lower than 300K in the total working fluid flow when facing cold or hot.

[0168] Although the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, utilize the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A multi-purpose heat pump system for cooling, heating and power, comprising a first heat exchanger (101), a compressor (2), a second heat exchanger (102), and an expansion device (3) connected in sequence, and further comprising a motor (12), the motor (12) being connected to the compressor (2), characterized in that: The expansion device (3) includes a first type of expansion device and a second type of expansion device; The first type of expansion device is an expander that recovers the expansion work of the working medium during expansion and outputs mechanical work. The number of the first type of expansion devices X is ≥ 1; The second type of expansion device is an expansion device other than an expander, and the number of the second type of expansion devices Y is ≥ 1; The multi-purpose heat pump system for cooling, heating and power has at least two working fluid circuits, the first working fluid circuit being composed of a first-type expansion device and a compressor (2), and the second working fluid circuit being composed of a second-type expansion device and a compressor (2) and / or a first-type expansion device, wherein: in the first working fluid circuit, the inlet of the compressor (2) is connected to the outlet end of the second heat exchanger (102), and the outlet of the compressor (2) is connected to the inlet end of the first heat exchanger (101), the inlet of the first-type expansion device is connected to the outlet end of the first heat exchanger (101), and the outlet of the first-type expansion device is connected to the inlet end of the second heat exchanger (102), and two pipelines are formed between the compressor (2) and the first-type expansion device, the first pipeline comprising a connecting pipeline between the outlet of the compressor (2) and the inlet of the first-type expansion device, and the second pipeline comprising a connecting pipeline between the inlet of the compressor (2) and the outlet of the first-type expansion device; in the second working fluid circuit, one interface of the second-type expansion device is connected to the first pipeline, and the other interface of the second-type expansion device is connected to the second pipeline; The system further comprises a mass regulating device, the mass regulating device comprising a working fluid storage tank (5) and a control valve (6), the control valve (6) having the function of controlling the connection and disconnection between the working fluid storage tank (5) and the working fluid in the cooling, heating and power multipurpose heat pump system, pumping the working fluid in the cooling, heating and power multipurpose heat pump system into the working fluid storage tank (5) for storage or releasing the working fluid stored in the working fluid storage tank (5) into the working fluid in the cooling, heating and power multipurpose heat pump system, and being used to regulate the total mass of the working fluid in the cooling, heating and power multipurpose heat pump system; The multi-purpose heat pump system for cooling, heating and electricity contains at least one working fluid with a critical temperature higher than 300K; The multi-purpose heat pump system for cooling, heating and electricity has two operating modes; The first operating mode is a refrigeration cycle, wherein the multi-purpose heat pump system consumes electricity and generates cooling and heat; The second operation mode is a power cycle, in which the cold, heat and electric multi-purpose heat pump system consumes cold energy and heat energy to generate electricity.

2. The multi-purpose heat pump system for cooling, heating and electricity according to claim 1, characterized in that: The multi-purpose heat pump system for cooling, heating and electricity further comprises a working fluid with a critical temperature lower than 300K; When operating in the first operating mode and when the operating working medium working temperature difference is less than 60°C, the mass regulating device is used to control the proportion of the mass flow of the working medium with a critical temperature higher than 300K in the circulating working medium flow of the multi-purpose heat pump system to be greater than 50% of the total working medium mass flow, and the proportion of the mass flow of the working medium with a critical temperature lower than 300K to be less than 50% of the total working medium mass flow; When operating in the first operating mode and when the operating working medium operating temperature difference is greater than 100°C, the mass regulating device is used to control the proportion of the mass flow of the working medium with a critical temperature higher than 300K in the circulating working medium flow of the multi-purpose heat pump system to be less than 50% of the total working medium mass flow, and the proportion of the mass flow of the working medium with a critical temperature lower than 300K to be greater than 50% of the total working medium mass flow; When operating in the second operating mode and when the operating working fluid operating temperature difference is greater than 100°C, the mass regulating device is used to control the proportion of the mass flow of the working fluid with a critical temperature higher than 300K in the circulating working fluid flow of the multi-purpose heat pump system to be less than 50% of the total working fluid mass flow, and the proportion of the mass flow of the working fluid with a critical temperature lower than 300K to be greater than 50% of the total working fluid mass flow.

3. A multi-purpose heat pump system for cooling, heating and power, comprising a first heat exchanger (101), a compressor (2), a second heat exchanger (102), and an expansion device (3) connected in sequence, and further comprising a motor (12), the motor (12) being connected to the compressor (2), characterized in that: The expansion device (3) includes a first type of expansion device and a second type of expansion device; The first type of expansion device is an expander that recovers the expansion work of the working medium during expansion and outputs mechanical work. The number of the first type of expansion devices X is ≥ 1; The second type of expansion device is an expansion device other than an expander, and the number of the second type of expansion devices Y is ≥ 1; The multi-purpose heat pump system for cooling, heating and power has at least two working fluid circuits, the first working fluid circuit being composed of a first-type expansion device and a compressor (2), and the second working fluid circuit being composed of a second-type expansion device and a compressor (2) and / or a first-type expansion device, wherein: in the first working fluid circuit, the inlet of the compressor (2) is connected to the outlet end of the second heat exchanger (102), and the outlet of the compressor (2) is connected to the inlet end of the first heat exchanger (101), the inlet of the first-type expansion device is connected to the outlet end of the first heat exchanger (101), and the outlet of the first-type expansion device is connected to the inlet end of the second heat exchanger (102), and two pipelines are formed between the compressor (2) and the first-type expansion device, the first pipeline comprising a connecting pipeline between the outlet of the compressor (2) and the inlet of the first-type expansion device, and the second pipeline comprising a connecting pipeline between the inlet of the compressor (2) and the outlet of the first-type expansion device; in the second working fluid circuit, one interface of the second-type expansion device is connected to the first pipeline, and the other interface of the second-type expansion device is connected to the second pipeline; The multi-purpose heat pump system for cooling, heating and electricity contains at least one working fluid with a critical temperature higher than 300K; The multi-purpose heat pump system for cooling, heating and electricity contains at least one working fluid with a critical temperature lower than 300K; The multi-purpose heat pump system for cooling, heating and electricity has two operating modes; The first operating mode is a refrigeration cycle, wherein the multi-purpose heat pump system consumes electricity and generates cooling and heat; The second operation mode is a power cycle, in which the cold, heat and electric multi-purpose heat pump system consumes cold energy and heat energy to generate electricity.

4. The cooling, heating, and electricity multi-purpose heat pump system according to any one of claims 1 to 3, characterized in that: The connection point between an interface of the second type expansion device and the first pipeline includes the outlet of the compressor (2), the inlet of the first type expansion device, and the connecting pipeline between the outlet of the compressor (2) and the inlet of the first type expansion device; The connection point between the other interface of the second type expansion device and the second pipeline includes the inlet of the compressor (2), the outlet of the second type expansion device, and the connecting pipeline between the inlet of the compressor (2) and the outlet of the first type expansion device.

5. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: When operating in the first operating mode and when the operating working medium operating temperature difference is less than 60° C., controlling the proportion of the liquid working medium mass flow at the inlet and / or outlet of at least one expansion device to the total working medium mass flow to be greater than 10%; controlling the proportion of the working medium mass flow of the operating working medium in the cooling, heating and power multi-purpose heat pump system passing through the second type of expansion device to the total working medium mass flow to be greater than 90%, and controlling the proportion of the working medium mass flow of the operating working medium in the cooling, heating and power multi-purpose heat pump system passing through the first type of expansion device to the total working medium mass flow to be less than 10%; When operating in the first operating mode and the operating working fluid operating temperature difference is greater than 100°C, the proportion of the liquid working fluid mass flow at the inlet of at least one expansion device to the total working fluid mass flow is controlled to be ≤10%; the proportion of the working fluid mass flow of the working fluid in the cooling, heating and power multi-purpose heat pump system passing through the second type of expansion device to the total working fluid mass flow is controlled to be less than 10%, and the proportion of the working fluid mass flow of the working fluid in the cooling, heating and power multi-purpose heat pump system passing through the first type of expansion device to the total working fluid mass flow is controlled to be greater than 90%; When operating in the second operating mode and the operating temperature difference of the operating working fluid is greater than 100°C, the proportion of the liquid working fluid mass flow at the inlet of at least one expansion device to the total working fluid mass flow is controlled to be ≤10%; the proportion of the working fluid mass flow of the operating working fluid in the cooling, heating and power multi-purpose heat pump system passing through the second type of expansion device to the total working fluid mass flow is controlled to be less than 10%, and the proportion of the working fluid mass flow of the operating working fluid in the cooling, heating and power multi-purpose heat pump system passing through the first type of expansion device to the total working fluid mass flow is controlled to be greater than 90%.

6. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: When operating in the first operating mode and the operating temperature difference of the operating working fluid is less than 60°C, the operating working fluid is controlled to operate according to the second working fluid circuit; When running in the first operating mode and the operating temperature difference of the operating working fluid is greater than 100°C, the operating working fluid is controlled to operate according to the first working fluid circuit; When operating in the second operating mode and the operating temperature difference of the operating working fluid is greater than 100° C., the operating working fluid is controlled to operate according to the first working fluid loop.

7. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: When operating in the first operating mode and the working temperature difference of the operating working medium is less than 60°C, controlling X≥1 first-type expansion devices to stop being used for working medium expansion; When operating in the first operating mode and the working temperature difference of the operating working medium is greater than 100°C, Y ≥ 1 second-type expansion devices are controlled to stop being used for working medium expansion; When operating in the second operating mode and the operating temperature difference of the operating working medium is greater than 100° C., Y ≥ 1 second-type expansion devices are controlled to stop being used for working medium expansion.

8. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: It also includes a first heat storage device (801) and a second heat storage device (802); Heat exchange between the heat storage device (8) and the working medium can be achieved under any of the following conditions: The heat transfer medium from the heat storage device (8) flows into the heat storage device (8) after completing heat exchange with the working medium in the first heat exchanger (101) and / or the second heat exchanger (102); And / or, the heat storage device (8) is connected in parallel with the heat exchanger, and the working medium directly exchanges heat with the heat storage device (8).

9. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: The expansion device has an unloading operation mechanism, which is used to reduce additional losses generated when the first type expansion device and / or the second type expansion device are not used for working medium expansion during the operation of the heat pump.

10. The multi-purpose heat pump system for cooling, heating and electricity according to claim 9, characterized in that: The unloading operation mechanism includes a clutch and a valve; When the unloading operation mechanism is a valve, the valve is arranged on the inlet or outlet pipeline of the expansion device.

11. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: When the first-type expansion device can be used for working fluid compression, the first-type expansion device is used for compressing the working fluid in the second working fluid circuit, including any of the following situations: The working fluid is completely compressed in the first type of expansion device, and the working fluid is expanded through the second type of expansion device; and / or, a portion of the working fluid is compressed in a first type expansion device, another portion is compressed in a compressor (2), and the working fluid is expanded through a second type expansion device; and / or, the first type expansion device is connected in series with the compressor (2), the working medium flows into the first type expansion device for pre-compression and flows into the compressor (2) for secondary compression, and the working medium is expanded through the second type expansion device; And / or, the first type expansion device is connected in series with the compressor (2), the working medium flows into the compressor (2) for pre-compression and is compressed a second time in the first type expansion device, and the working medium is expanded through the second type expansion device.

12. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: The compressor is composed of a compression module control valve and N≥2 compression modules.

13. The multi-purpose heat pump system for cooling, heating and electricity according to claim 12, characterized in that: Under the action of the compression module control valve, the first type of expansion device is ≥1 compression module of the compressor, that is, ≥1 compression module is used to recover the expansion work of the working medium expansion process and output mechanical work; When operating in the first operating mode and the working temperature difference of the operating working fluid is greater than 100°C, under the action of the compression module control valve, K ≥ 1 compression module is used for working fluid compression, J ≥ 1 compression module is used for working fluid expansion, and K + J ≤ N; When operating in the second operating mode and the operating temperature difference of the working fluid is greater than 100°C, K≥1 compression modules are used for working fluid compression, J≥1 compression modules are used for working fluid expansion, and K+J≤N.

14. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: The compressor is a positive displacement compressor having ≥1 air valve, which is an intake valve and / or an exhaust valve, at least one of which is an actively controlled valve, and the opening and closing of the actively controlled valve is controlled by electromagnetic force, hydraulic pressure or mechanical force; And / or, the first type of expansion device is a volumetric expander having ≥1 air valve, which is an intake valve and / or an exhaust valve, at least one of which is actively controlled, and the opening and closing of the actively controlled valve is controlled by electromagnetic force, hydraulic pressure or mechanical force.

15. The multi-purpose heat pump system for cooling, heating and electricity according to claim 2, characterized in that: It also includes ≥2 mass regulating devices, wherein: at least one of the mass regulating devices is used to regulate the mass of at least one working fluid with a critical temperature higher than 300K; and at least one of the mass regulating devices is used to regulate the mass of a working fluid with a critical temperature lower than 300K.

16. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: The invention also includes a regenerator (10), wherein the regenerator has a first flow channel and a second flow channel, wherein one end of the first flow channel of the regenerator (10) is connected to the outlet end of the first heat exchanger (101), and the other end is connected to the inlet end of the first type expansion device, and one end of the second flow channel of the regenerator (10) is connected to the outlet end of the second heat exchanger (102), and the other end is connected to the compressor (2).

17. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: When the first type of expansion device cannot be used for working fluid compression, the number of the compressors (2) is ≥2, wherein: when operating in the first operating mode and when the operating working fluid operating temperature difference is greater than 100° C., the compressor used for working fluid compression is the first compressor (201); when operating in the second operating mode and when the operating working fluid operating temperature difference is greater than 100° C., the compressor used for working fluid compression is the second compressor (202); When operating in the first operating mode and when the operating working medium operating temperature difference is less than 60° C., the second compressor (202) is used to compress the working medium in the second working medium circuit, including any of the following situations: The working medium is entirely compressed in the second compressor (202), and the working medium is expanded through a second type expansion device; and / or, a portion of the working medium is compressed in the second compressor (202), and another portion is compressed in the first compressor (201), and the working medium is expanded through a second type expansion device; and / or, the first compressor (201) and the second compressor (202) are connected in series, the working medium flows into the second compressor (202) for pre-compression and flows into the first compressor (201) for secondary compression, and the working medium is expanded through the second type expansion device; And / or, the first compressor (201) and the second compressor (202) are connected in series, the working medium flows into the first compressor (201) for pre-compression and flows into the second compressor (202) for secondary compression, and the working medium is expanded through the second type expansion device.

18. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: It also includes a third heat exchanger (103), the third heat exchanger (103) being located on the connecting pipeline between the outlet of the compressor (2) and the inlet of the second type expansion device; And / or, it further comprises a fourth heat exchanger (104), wherein the fourth heat exchanger (104) is located on the connecting pipeline between the outlet of the second type expansion device and the inlet of the compressor (2).

19. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 1 to 3, characterized in that: The second type of expansion device is an expansion device that cannot recover the expansion work of the working medium expansion process and outputs mechanical work; The second type of expansion device includes an electronic expansion valve, a thermal expansion valve, a capillary tube, an ejector or an orifice plate.

20. The multi-purpose heat pump system for cooling, heating and electricity according to claim 3, characterized in that: When operating in the first operating mode and when the operating working fluid operating temperature difference is less than 60°C, the mass flow rate of the working fluid with a critical temperature higher than 300K in the multi-purpose heat pump system accounts for more than 50% of the total working fluid mass flow rate, and the mass flow rate of the working fluid with a critical temperature lower than 300K accounts for less than 50% of the total working fluid mass flow rate; When operating in the first operating mode and when the operating working fluid operating temperature difference is greater than 100°C, the mass flow rate of the working fluid with a critical temperature higher than 300K in the multi-purpose heat pump system accounts for less than 50% of the total mass flow rate of the working fluid, and the mass flow rate of the working fluid with a critical temperature lower than 300K accounts for more than 50% of the total mass flow rate of the working fluid; When operating in the second operating mode and when the operating working fluid operating temperature difference is greater than 100°C, the proportion of the working fluid mass flow with a critical temperature higher than 300K in the multi-purpose heat pump system to the total working fluid mass flow is less than 50%, and the proportion of the working fluid mass flow with a critical temperature lower than 300K to the total working fluid mass flow is greater than 50%.

21. The cooling, heating, and electricity multi-purpose heat pump system according to any one of claims 2 to 3, characterized in that: It also includes at least one gas separator (15), wherein the gas separator (15) has a cavity inside and at least one interface communicating with the closed cavity; The gas separator (15) can achieve the following functions: When operating in the first operating mode and the operating working fluid temperature difference is less than 60° C., the gas separator (15) is used to reduce the proportion of working fluid with a critical temperature below 300K in the total working fluid mass flow; and / or, when operating in the first operating mode and the operating working fluid temperature difference is greater than 100° C., the gas separator (15) is used to reduce the proportion of working fluid with a critical temperature higher than 300K in the total working fluid mass flow; And / or, when operating in the second operating mode and the operating working medium temperature difference is greater than 100° C., the gas separator (15) is used to reduce the proportion of working medium with a critical temperature higher than 300K in the total working medium mass flow.

22. The multi-purpose heat pump system for cooling, heating and electricity according to claim 21, characterized in that: The gas separator (15) can be connected in any of the following ways: The first gas separator (151) is connected to a connecting pipeline between an interface of the second type expansion device and an outlet of the compressor (2); And / or, the second gas separator (152) is connected to the first pipeline, or the second gas separator (152) is connected to the second pipeline, or the second gas separator (152) is connected to the connecting pipeline between the outlet of the compressor (2) and the second type of expansion device, or the second gas separator (152) is connected to the connecting pipeline between the inlet of the compressor (2) and the second type of expansion device.

23. The multi-purpose heat pump system for cooling, heating and electricity according to claim 22, characterized in that: When operating in the first operating mode and the operating working medium operating temperature difference is greater than 100°C, the liquid temperature in the first gas separator (151) and / or the second gas separator (152) is controlled to be ≤273K, so as to achieve that part of the working medium with a critical temperature higher than 300K is stored in the first gas separator (151) and / or the second gas separator (152) in a liquid state; when operating in the second operating mode and the operating working medium operating temperature difference is greater than 100°C, the liquid temperature in the first gas separator (151) and / or the second gas separator (152) is controlled to be ≤273K, so as to achieve that part of the working medium with a critical temperature higher than 300K is stored in the second gas separator (152); When operating in the first operating mode or the second operating mode, and the operating working medium temperature difference is greater than 100° C., a portion of liquid working medium with a critical temperature higher than 300K is stored in the first gas separator (151) or the second gas separator (152), and the liquid working medium may be generated in any of the following situations: The working fluid with a critical temperature higher than 300K entering the first gas separator (151) or the second gas separator (152) is in liquid phase or gas-liquid two-phase; The working fluid with a critical temperature higher than 300K entering the first gas separator (151) or the second gas separator (152) is in the gas phase, and the gas phase working fluid is condensed into liquid in the first gas separator (151) or the second gas separator (152).

24. The multi-purpose heat pump system for cooling, heating and electricity according to claim 21, characterized in that: The gas separator (15) comprises a storage tank and a bent pipe.

25. The multi-purpose heat pump system for cooling, heating and electricity according to claim 18, characterized in that: The invention also includes a switching valve (17), wherein a first switching valve (1701) is located at the outlet of the compressor (2) and is used to control the connection and disconnection between the outlet of the compressor (2) and the first heat exchanger (101) or the third heat exchanger (103); and a second switching valve (1702) is located at the inlet of the compressor (2) and is used to control the connection between the inlet of the compressor (2) and the second heat exchanger (102) or the fourth heat exchanger (104).

26. The multi-purpose heat pump system for cooling, heating and electricity according to claim 18, characterized in that: When operating in the first operating mode or the second operating mode and the operating temperature difference of the operating working fluid is greater than 100°C, part of the working fluid with a critical temperature higher than 300K is stored in the third heat exchanger (103) or the fourth heat exchanger (104) in a liquid state, and the liquid temperature in the third heat exchanger (103) or the fourth heat exchanger (104) is controlled to be ≤273K.

27. The multi-purpose heat pump system for cooling, heating and electricity according to any one of claims 2 to 3, characterized in that: When operating in the first operating mode and when the operating working medium temperature difference is greater than 100° C., in the first working medium circuit, the pressure in the first heat exchanger (101) and the second heat exchanger (102) is greater than or equal to 0.5 MPa; When operating in the second operating mode and when the operating working medium temperature difference is greater than 100° C., in the first working medium circuit, the pressure in the first heat exchanger (101) and the second heat exchanger (102) is greater than or equal to 0.5 MPa.

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