High-temperature heat pump capable of being flexibly adjusted

Abstract

The invention provides a flexibly-adjusted high-temperature heat pump. The flexibly-adjusted high-temperature heat pump comprises an evaporator, a low-pressure compressor, a low-pressure expansion valve, an intermediate heat exchanger, a first one-way valve, a high-pressure compressor, a high-pressure expansion valve, a second one-way valve, a refrigerant pump and a condenser. A refrigerant flowing out of the evaporator is compressed by the low-pressure compressor, enters the high-temperature side of the intermediate heat exchanger for heat exchange and condensation and then flows through the low-pressure expansion valve to return to the evaporator to complete low-pressure refrigerant circulation. When the temperature of incoming water of a heat source is low, a refrigerant flowing out of the low-temperature side of the intermediate heat exchanger enters the high-pressure compressor, enters the condenser for condensation and heat release after being compressed and then returns to the intermediate heat exchanger through the high-pressure expansion valve, and high-pressure refrigerant circulation is completed. When the temperature of incoming water of a heat source is high, a refrigerant flowing out of the low-temperature side of the intermediate heat exchanger enters the condenser after passing through the first one-way valve, sequentially flows through the second one-way valve and the refrigerant pump to return to the intermediate heat exchanger after releasing heat and cooling in the condenser, and high-pressure refrigerant circulation is completed. High-temperature heat energy output is achieved, meanwhile, large-range variable working condition efficient and flexible adjustment of the heat pump at the high heat source temperature is achieved, heat supply energy consumption is reduced, and the system operation economical efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of heating, and in particular relates to a flexibly adjustable high-temperature heat pump. Background Art

[0002] With the development of urban construction, heat pump technology has been increasingly used in urban building heating and industrial fields, and high-temperature heat pumps are an important direction for the development of heat pump technology. High-temperature heat pumps are often designed according to large pressure ratio conditions. However, in actual operation, the range of variation of water supply temperature and heat source temperature is usually large, and the corresponding heat pump condensing pressure and evaporation pressure also vary greatly. Due to the limited operating range of the compressor's pressure ratio, for high-temperature heat pumps designed according to a large pressure ratio, their variable operating performance in response to changes in water supply temperature and heat source temperature is poor, and the adjustment lacks flexibility, which leads to low efficiency of high-temperature heat pumps in full-condition operation.

[0003] The invention patent with the publication number CN113932470A discloses a high-temperature heat pump circulation system, which realizes the output of high-temperature heat energy through two-stage compression devices connected in series. However, the compressors of the two-stage compression devices connected in series are coupled to each other, and the high-temperature heat pump has poor adjustability. At the same time, due to the operation limitation of the minimum pressure ratio of the compressor, when the heat source temperature is high, the evaporation pressure of the corresponding high-temperature heat pump increases, the heat pump operation pressure ratio decreases, and the operation efficiency of the high-temperature heat pump decreases significantly. The invention patent with the publication number CN115451610A discloses a heat recovery water medium multi-stage compression ultra-high temperature heat pump system. The high-temperature heat pump system uses water as a medium and realizes the output of ultra-high temperature heat energy through the series connection of high-pressure compressors and low-pressure compressors. Similarly, the high-temperature heat pump system is still subject to the operation limitation of the minimum pressure ratio of the compressor. When the water supply temperature and the heat source temperature change over a large range, the adjustability is poor, especially when the heat source temperature is high, the operation efficiency is low.

[0004] It can be seen that it is of great significance to propose a high-temperature heat pump that can overcome the minimum pressure ratio limitation of the compressor and improve the flexibility of regulation under a wide range of variable operating conditions. Summary of the invention

[0005] (I) Purpose of the invention

[0006] The object of the present invention is to provide a flexibly adjustable high-temperature heat pump, which realizes the output of high-temperature thermal energy through a high-pressure compressor and a low-pressure compressor. At the same time, by setting a first one-way valve, a second one-way valve, and a refrigerant pump, the high-pressure compressor can be cut out while ensuring the normal circulation of the refrigerant, thereby realizing efficient and flexible adjustment of the heat pump over a wide range of operating conditions at high heat source temperatures, reducing heating energy consumption, and improving the economy of system operation.

[0007] (II) Technical solution

[0008] In order to solve the above problems, the first aspect of the present invention provides a flexibly adjustable high-temperature heat pump, comprising:

[0009] Evaporator, low-pressure compressor, low-pressure expansion valve, intermediate heat exchanger, first check valve, high-pressure compressor, high-pressure expansion valve, second check valve, refrigerant pump, condenser.

[0010] The evaporator has a heat source water inlet, a heat source water outlet, a refrigerant inlet, and a refrigerant outlet.

[0011] The intermediate heat exchanger has a first inlet, a first outlet, a second inlet, and a second outlet;

[0012] The condenser has a refrigerant inlet, a refrigerant outlet, a water inlet and a water outlet.

[0013] The refrigerant outlet of the evaporator is connected to the inlet of the low-pressure compressor, the outlet of the low-pressure compressor is connected to the first inlet of the intermediate heat exchanger, the first outlet of the intermediate heat exchanger is connected to the inlet of the low-pressure expansion valve, and the outlet of the low-pressure expansion valve is connected to the refrigerant inlet of the evaporator.

[0014] The second outlet of the intermediate heat exchanger is connected to the inlet of the high-pressure compressor, the outlet of the high-pressure compressor is connected to the refrigerant inlet of the condenser, the refrigerant outlet of the condenser is connected to the inlet of the high-pressure expansion valve, and the outlet of the high-pressure expansion valve is connected to the second inlet of the intermediate heat exchanger.

[0015] The second outlet of the intermediate heat exchanger is connected to the inlet of the first one-way valve, the outlet of the first one-way valve is connected to the refrigerant inlet of the condenser, the refrigerant outlet of the condenser is connected to the inlet of the second one-way valve, the outlet of the second one-way valve is connected to the refrigerant inlet of the refrigerant pump, and the refrigerant outlet of the refrigerant pump is connected to the second inlet of the intermediate heat exchanger.

[0016] The water inlet of the condenser is connected to the return water, and the water outlet of the condenser is connected to the supply water.

[0017] The incoming water from the heat source is connected to the heat source water inlet of the evaporator, and the outgoing water from the heat source is connected to the heat source water outlet of the evaporator.

[0018] Furthermore, the intermediate heat exchanger also includes a water inlet and a water outlet. The water inlet of the intermediate heat exchanger is connected to the heat source water, the water outlet of the intermediate heat exchanger is connected to the heat source water inlet of the evaporator, and the heat source water outlet is connected to the heat source water outlet of the evaporator.

[0019] (III) Beneficial effects

[0020] The above technical solution of the present invention has the following beneficial technical effects:

[0021] The present invention utilizes a high-pressure compressor and a low-pressure compressor to achieve the output of high-temperature thermal energy. At the same time, by arranging a first one-way valve, a second one-way valve, and a refrigerant pump, the high-pressure compressor can be cut out while ensuring the normal circulation of the refrigerant, thereby avoiding the operating restrictions of the compressor on the heat pump, improving the operating condition range of the heat pump, and achieving efficient and flexible adjustment of the heat pump over a wide range of operating conditions at high heat source temperatures, significantly improving the operating efficiency of all operating conditions, and reducing the system operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the structure of the device of Embodiment 1 of the present invention;

[0023] Figure 2 is a schematic diagram of the device structure of embodiment 2 of the present invention;

[0024] Figure Tag:

[0025] 1: Evaporator; 101: Evaporator heat source water inlet; 102: Evaporator heat source water outlet; 103: Evaporator refrigerant inlet; 104: Evaporator refrigerant outlet; 2: Low-pressure compressor; 201: Low-pressure compressor inlet; 202: Low-pressure compressor outlet; 3: Low-pressure expansion valve; 301: Low-pressure expansion valve inlet; 302: Low-pressure expansion valve outlet; 4: Intermediate heat exchanger; 401: Intermediate heat exchanger first inlet; 402: Intermediate heat exchanger first outlet; 403: Intermediate heat exchanger second inlet; 404: Intermediate heat exchanger second outlet; 405: Intermediate heat exchanger water inlet; 406: Intermediate heat exchanger water outlet; 5: First one-way valve; 501: first one-way valve inlet; 502: first one-way valve outlet; 6: high-pressure compressor; 601: high-pressure compressor inlet; 602: high-pressure compressor outlet; 7: high-pressure expansion valve; 701: high-pressure expansion valve inlet; 702: high-pressure expansion valve outlet; 8 Second one-way valve; 801: second one-way valve inlet; 802: second one-way valve outlet; 9: refrigerant pump; 901: refrigerant inlet of refrigerant pump; 902: refrigerant outlet of refrigerant pump; 10: condenser; 1001: refrigerant inlet of condenser; 1002: refrigerant outlet of condenser; 1003: water inlet of condenser; 1004: water outlet of condenser. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0027] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. The present invention will be described in more detail below with reference to the accompanying drawings. In each of the drawings, the same elements are represented by similar figure numerals. For the sake of clarity, the various parts in the drawings are not drawn to scale.

[0030] Specifically, as described in the following specific embodiments:

[0031] Embodiment 1:

[0032] Figure 1 It is a schematic diagram of the device structure of the first embodiment of the present invention.

[0033] like Figure 1 As shown, in this embodiment, a flexibly adjustable high-temperature heat pump includes:

[0034] Evaporator 1, low-pressure compressor 2, low-pressure expansion valve 3, intermediate heat exchanger 4, first non-return valve 5, high-pressure compressor 6, high-pressure expansion valve 7, second non-return valve 8, refrigerant pump 9, condenser 10.

[0035] The evaporator 1 has a heat source water inlet 101 , a heat source water outlet 102 , a refrigerant inlet 103 , and a refrigerant outlet 104 .

[0036] The intermediate heat exchanger 4 has a first inlet 401 , a first outlet 402 , a second inlet 403 , and a second outlet 404 .

[0037] The condenser 10 has a refrigerant inlet 1001 , a refrigerant outlet 1002 , a water inlet 1003 , and a water outlet 1004 .

[0038] The heat source water enters the evaporator 1 through the heat source water inlet 101 of the evaporator 1, flows out after heat exchange and cooling, and the refrigerant flowing out of the refrigerant outlet 104 of the evaporator 1 enters the low-pressure compressor 2, enters the intermediate heat exchanger 4 through the first inlet 401 of the intermediate heat exchanger 4 after compression, flows out after heat exchange and cooling, and returns to the evaporator 1 after flowing through the low-pressure expansion valve 3.

[0039] The second outlet 404 of the intermediate heat exchanger 4 is connected to the inlet 601 of the high-pressure compressor 6, the outlet 602 of the high-pressure compressor 6 is connected to the inlet 1001 of the condenser 10, the refrigerant outlet 1002 of the condenser 10 is connected to the inlet 701 of the high-pressure expansion valve 7, and the outlet 702 of the high-pressure expansion valve 7 is connected to the second inlet 403 of the intermediate heat exchanger 4.

[0040] The second outlet 404 of the intermediate heat exchanger 4 is connected to the inlet 501 of the first one-way valve 5, the outlet 502 of the first one-way valve 5 is connected to the refrigerant inlet 1001 of the condenser 10, the refrigerant outlet 1002 of the condenser 10 is connected to the inlet 801 of the second one-way valve 8, the outlet 802 of the second one-way valve 8 is connected to the refrigerant inlet 901 of the refrigerant pump 9, and the refrigerant outlet 902 of the refrigerant pump 9 is connected to the second inlet 403 of the intermediate heat exchanger 4.

[0041] The return water enters the condenser 10 and flows out as supply water after being heated.

[0042] In this embodiment, by setting the first one-way valve, the second one-way valve, and the refrigerant pump, the switching of the Freon circuit can be achieved. When the heat source temperature is high and the water supply temperature is low, the high-pressure compressor can be cut out, thereby improving the operating range of the system and reducing the system operating cost.

[0043] The specific operation and adjustment methods of this embodiment are as follows:

[0044] When the temperature of the heat source water is low, it needs to go through the low-pressure refrigerant circulation and the high-pressure refrigerant circulation to achieve the required water supply temperature. At this time, the high-pressure compressor 6 is running and the refrigerant pump 9 is stopped. The heat source water enters the evaporator 1, exchanges heat with the refrigerant in the evaporator 1 and flows out after cooling. The refrigerant in the evaporator 1 absorbs heat and evaporates, and the refrigerant vapor generated enters the low-pressure compressor 2, enters the intermediate heat exchanger 4 after compression, condenses and releases heat in the intermediate heat exchanger 4, and then returns to the evaporator 1 through the low-pressure expansion valve 3, completing the low-pressure refrigerant cycle. The refrigerant in the intermediate heat exchanger 4 absorbs heat and evaporates, and the refrigerant vapor generated enters the high-pressure compressor 6, enters the condenser 10 after compression, condenses and releases heat in the condenser 10, and transfers heat to the water supply. The refrigerant flowing out of the condenser 10 returns to the intermediate heat exchanger 4 after passing through the high-pressure expansion valve 7, completing the high-pressure refrigerant cycle.

[0045] When the temperature of the water from the heat source is high, the temperature required for water supply can be achieved by relying only on the low-pressure refrigerant circulation. At this time, the high-pressure compressor 6 stops, the high-pressure expansion valve 7 is closed, and the refrigerant pump 9 is running. The low-pressure refrigerant circulation operates normally, and the refrigerant flowing out of the second outlet 404 of the intermediate heat exchanger 4 enters the condenser after passing through the first one-way valve 5, releases heat and cools down in the condenser. The cooled refrigerant flows through the second one-way valve 8 and the refrigerant pump 9 in turn and returns to the intermediate heat exchanger 4, completing the high-pressure refrigerant circulation.

[0046] Embodiment 2:

[0047] Figure 2 It is a schematic diagram of the device structure of the second embodiment of the present invention.

[0048] The difference from the first embodiment is that, in this embodiment, the intermediate heat exchanger 4 further includes a water inlet 405 and a water outlet 406 .

[0049] The heat source water first enters the intermediate heat exchanger 4 through the water inlet 405 of the intermediate heat exchanger 4, flows out through the water outlet 406 of the intermediate heat exchanger 4 after being cooled, and then enters the evaporator 1 for cooling.

[0050] Compared with the first embodiment, in this embodiment, the heat source water passes through the intermediate heat exchanger 4 and the evaporator 1 in series, thereby realizing the cascade utilization of the high-temperature heat source and improving the utilization efficiency of the heat source.

[0051] The specific operation and adjustment methods of this embodiment are as follows:

[0052] On the basis of the first embodiment, when the temperature of the heat source water is high, the heat source water first enters the intermediate heat exchanger 4, is initially cooled in the intermediate heat exchanger 4, and then enters the evaporator 1, is further cooled, and then flows out.

[0053] The present invention has been described above with reference to the embodiments of the present invention. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, a person skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A flexibly adjustable high temperature heat pump, characterized in that: include: Evaporator (1), low-pressure compressor (2), low-pressure expansion valve (3), intermediate heat exchanger (4), first check valve (5), high-pressure compressor (6), high-pressure expansion valve (7), second check valve (8), refrigerant pump (9), condenser (10); The evaporator (1) has a heat source water inlet (101), a heat source water outlet (102), an evaporator refrigerant inlet (103), and an evaporator refrigerant outlet (104); The intermediate heat exchanger (4) has a first inlet (401) of the intermediate heat exchanger, a first outlet (402) of the intermediate heat exchanger, a second inlet (403) of the intermediate heat exchanger, and a second outlet (404) of the intermediate heat exchanger; The condenser (10) has a condenser refrigerant inlet (1001), a condenser refrigerant outlet (1002), a condenser water inlet (1003), and a condenser water outlet (1004); The evaporator refrigerant outlet (104) of the evaporator (1) is connected to the low-pressure compressor inlet (201) of the low-pressure compressor (2), the low-pressure compressor outlet (202) of the low-pressure compressor (2) is connected to the first intermediate heat exchanger inlet (401) of the intermediate heat exchanger (4), the first intermediate heat exchanger outlet (402) of the intermediate heat exchanger (4) is connected to the low-pressure expansion valve inlet (301) of the low-pressure expansion valve (3), and the low-pressure expansion valve outlet (302) of the low-pressure expansion valve (3) is connected to the evaporator refrigerant inlet (103) of the evaporator (1); The intermediate heat exchanger second outlet (404) of the intermediate heat exchanger (4) is connected to the high-pressure compressor inlet (601) of the high-pressure compressor (6), the high-pressure compressor outlet (602) of the high-pressure compressor (6) is connected to the condenser refrigerant inlet (1001) of the condenser (10), the condenser refrigerant outlet (1002) of the condenser (10) is connected to the high-pressure expansion valve inlet (701) of the high-pressure expansion valve (7), and the high-pressure expansion valve outlet (702) of the high-pressure expansion valve (7) is connected to the intermediate heat exchanger second inlet (403) of the intermediate heat exchanger (4); The second outlet (404) of the intermediate heat exchanger (4) is connected to the first one-way valve inlet (501) of the first one-way valve (5), the first one-way valve outlet (502) of the first one-way valve (5) is connected to the condenser refrigerant inlet (1001) of the condenser (10), the condenser refrigerant outlet (1002) of the condenser (10) is connected to the second one-way valve inlet (801) of the second one-way valve (8), the second one-way valve outlet (802) of the second one-way valve (8) is connected to the refrigerant pump refrigerant inlet (901) of the refrigerant pump (9), and the refrigerant pump refrigerant outlet (902) of the refrigerant pump (9) is connected to the second inlet (403) of the intermediate heat exchanger (4); The condenser water inlet (1003) of the condenser (10) is connected to the return water, and the condenser water outlet (1004) of the condenser (10) is connected to the supply water; The incoming water from the heat source is connected to the heat source water inlet (101) of the evaporator (1), and the outgoing water from the heat source is connected to the heat source water outlet (102) of the evaporator (1).

2. A flexibly adjustable high temperature heat pump according to claim 1, characterized in that: The intermediate heat exchanger (4) further comprises an intermediate heat exchanger water inlet (405) and an intermediate heat exchanger water outlet (406); The intermediate heat exchanger water inlet (405) of the intermediate heat exchanger (4) is connected to the heat source water, the intermediate heat exchanger water outlet (406) of the intermediate heat exchanger (4) is connected to the heat source water inlet (101) of the evaporator (1), and the heat source water outlet is connected to the heat source water outlet (102) of the evaporator (1).

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