A heat pump system oriented to heat capacity characteristics of high temperature heat sources

Abstract

A heat pump system for high-temperature heat source heat capacity characteristics, from driving level, heating level, different configuration and refrigerant four aspects to carry out compound construction multistage compression gradient coupling heating configuration, multistage cascade gradient coupling heating cycle configuration or single compressor intermediate exhaust gradient coupling heating cycle configuration, the heating level is less than or equal to the driving level, and the heating level is at least one;The driving level changes according to the temperature rise of the high-temperature heat source, when the heat source temperature rises, the driving level is increased and the heating level is increased to reduce the heat transfer temperature difference between each level, when the temperature rise is small, the driving level and the heating level are reduced, at this time, the mixed working medium is also changed, so that its temperature glide characteristics match the temperature rise of the heat source.The working medium and the high-temperature heat source enthalpy characteristics gradually approach through the collaborative matching of working medium characteristics and cycle structure, so that the energy efficiency is higher under the condition of large temperature rise and large temperature span, and the energy consumption is greatly reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of heat pumps and water heaters, and relates to a heat pump system oriented to the heat capacity characteristics of high-temperature heat sources. BACKGROUND

[0002] With the increasingly serious energy and environmental problems, research on energy-saving, environment-friendly and high-efficiency energy equipment and technology has become mainstream, and heat pumps have been widely concerned due to their energy-saving, environment-friendly and low-carbon emission characteristics, and research on heat pump systems has become a hot topic. However, the energy efficiency of existing heat pump systems will be greatly reduced as the temperature of the low-temperature heat source decreases or the temperature of the high-temperature heat source increases, thereby limiting the energy-saving effect and application range of the heat pump system. Therefore, improving the efficiency and stability of the heat pump system under large temperature span and large temperature rise conditions has become an important topic for improvement. SUMMARY

[0003] In order to overcome the low energy efficiency and large energy consumption of the existing heat pump system under large temperature span and large temperature rise conditions, the application proposes a heat pump system oriented to the heat capacity characteristics of high-temperature heat sources and a composite construction method thereof, which reduces the heat exchange temperature difference by the temperature-enthalpy characteristics (temperature glide) of the mixed working medium and the step-by-step coupled heating of the high-temperature heat source, so as to gradually approach the temperature-enthalpy characteristics of the high-temperature heat source to improve the system energy efficiency.

[0004] The technical scheme adopted by the application to solve the technical problems is:

[0005] A heat pump system oriented to the heat capacity characteristics of high-temperature heat sources, which is constructed in a composite manner from four aspects of driving stage number, heating stage number, different configurations and refrigerants, to construct a multi-stage compression step-by-step coupled heating configuration, a multi-stage cascade step-by-step coupled heating cycle configuration or a single compressor intermediate exhaust step-by-step coupled heating cycle configuration, wherein the heating stage number is less than or equal to the driving stage number, and the heating stage number is at least one; the driving stage number is changed according to the temperature rise of the high-temperature heat source, when the heat source temperature rise is large, the driving stage number and the heating stage number are increased to reduce the heat exchange temperature difference between each stage, and when the temperature rise is small, the driving stage number and the heating stage number are reduced, and at this time, the mixed working medium is also changed to match the temperature glide characteristics with the heat source temperature rise.

[0006] Further, the temperature rise process of the high-temperature heat source is first dispersed to each stage by step heating, that is, the temperature rise of the heat source in each stage is reduced; then the temperature rise of each stage heat source is matched by mixed refrigerant with two-phase region temperature glide of different components and different concentrations, that is, the heat capacity characteristics of the high-temperature heat source are adapted, so as to reduce the heat exchange temperature difference between the refrigerant and the heat source; when the components and concentrations of the mixed refrigerant are adjusted to realize the matching of the temperature glide and the heat source temperature rise, reduce the heat exchange temperature difference, and at the same time, the cycle performance of the mixed working medium may be reduced, so that the total energy efficiency is not necessarily improved; taking the total energy efficiency of the cycle as the target, considering the matching of the temperature glide and the cycle performance of the mixed working medium, and at the same time, the heating stage number and the mixed refrigerant component are optimized; the form of step heating reduces the temperature rise of the heat source in each stage, thereby reducing the requirement for the temperature glide characteristics of the refrigerant; and the matching by the temperature glide of the refrigerant also increases the flexibility of the selection of the heating stage number, so that the range of the optimization parameters is increased, and higher comprehensive energy efficiency is possible; the pure refrigerant and zero temperature rise can be regarded as a special case of the above process.

[0007] Further, the multi-stage compression cascade heating configuration is a three-stage compression three-stage cascade heating heat pump system, comprising a first-stage compressor, a second-stage compressor, a third-stage compressor, a first-stage condenser, a second-stage condenser, a third-stage condenser, a stop valve, a first auxiliary heat exchanger, a second auxiliary heat exchanger, a first-stage throttle valve, a second-stage throttle valve, a third-stage throttle valve, an evaporator, a pump or a fan, the outlet of the first-stage compressor is connected to the refrigerant inlet of the first-stage condenser, the refrigerant first outlet of the first-stage condenser is connected to the refrigerant inlet of the evaporator through the first-stage throttle valve, and the refrigerant outlet of the evaporator is connected to the inlet of the first-stage compressor; the refrigerant second outlet of the first-stage condenser is connected to the inlet of the second-stage compressor through the stop valve, the outlet of the second-stage compressor is connected to the refrigerant inlet of the second-stage condenser, the refrigerant first outlet of the second-stage condenser is connected to the refrigerant inlet of the first auxiliary heat exchanger, and the refrigerant outlet of the auxiliary heat exchanger is connected to the refrigerant first outlet of the first-stage condenser through the second-stage throttle valve; the inlet of the heated medium is connected to the inlet of the pump or the fan, the outlet of the pump or the fan is connected to the heated medium inlet of the first-stage condenser and the heated medium inlet of the first auxiliary heat exchanger respectively, the heated medium outlet of the first-stage condenser is connected to the heated medium outlet of the first auxiliary heat exchanger, and then connected to the heated medium inlet of the second-stage condenser and the heated medium inlet of the second auxiliary heat exchanger respectively, the heated medium outlet of the second-stage condenser and the heated medium outlet of the second auxiliary heat exchanger are connected to the heated medium inlet of the third-stage condenser, and the heated medium outlet of the third-stage condenser is the total outlet.

[0008] According to different requirements, a fourth-stage compressor and a fourth-stage condenser, as well as corresponding auxiliary heat exchangers, stop valves, throttle valves, etc., can be added to form a four-stage compression four-stage heating cycle, and so on, which can be increased to an infinite number of stages of compression and an infinite number of stages of heating; similarly, the third-stage compressor and the third-stage condenser, as well as corresponding auxiliary heat exchangers, stop valves, throttle valves, etc., can be removed to form a two-stage compression two-stage heating cycle, and so on, which can be reduced to a single-stage compression single-stage heating cycle.

[0009] Or: the multi-stage cascade step coupling heating cycle configuration is a three-stage cascade three-stage coupling heating system, comprising a first-stage compressor, a second-stage compressor, a third-stage compressor, a first-stage condenser, a second-stage condenser, a third-stage condenser, a stop valve, a first intermediate heat exchanger, a second intermediate heat exchanger, a first auxiliary heat exchanger, a second auxiliary heat exchanger, a first-stage throttle valve, a second-stage throttle valve, a third-stage throttle valve, an evaporator, a pump or a fan, the first-stage compressor outlet is divided into two paths, one path is connected with the first-stage condenser refrigerant inlet, and the other path is connected with the first inlet of the first intermediate heat exchanger through the stop valve, the first outlet of the first intermediate heat exchanger is combined with the refrigerant outlet of the first-stage condenser, and then connected with the evaporator inlet through the first-stage throttle valve, and the evaporator outlet is connected with the inlet of the first-stage compressor; the second outlet of the first intermediate heat exchanger is connected with the inlet of the second-stage compressor, the outlet of the second-stage compressor is divided into two paths, one path is connected with the second-stage condenser refrigerant inlet, and the other path is connected with the first inlet of the second intermediate heat exchanger through the stop valve, the first outlet of the second intermediate heat exchanger is combined with the refrigerant outlet of the second-stage condenser, and then connected with the refrigerant inlet of the first auxiliary heat exchanger, and the refrigerant outlet of the first auxiliary heat exchanger is connected with the second inlet of the first intermediate heat exchanger through the second-stage throttle valve; the second outlet of the second intermediate heat exchanger is connected with the inlet of the third-stage compressor, the outlet of the third-stage compressor is connected with the refrigerant inlet and outlet of the third-stage condenser, the refrigerant outlet of the third-stage condenser is connected with the refrigerant inlet of the second auxiliary heat exchanger, and the refrigerant outlet of the second auxiliary heat exchanger is connected with the second inlet of the second intermediate heat exchanger through the third-stage throttle valve; the heated medium inlet is connected with the inlet of the pump or the fan, the pump or the fan outlet is connected with the heated medium inlet of the first-stage condenser and the heated medium inlet of the first auxiliary heat exchanger respectively, the heated medium outlet of the first-stage condenser is combined with the heated medium outlet of the first auxiliary heat exchanger, and then connected with the heated medium inlet of the second-stage condenser and the heated medium inlet of the second auxiliary heat exchanger respectively, the heated medium outlet of the second-stage condenser is combined with the heated medium outlet of the second auxiliary heat exchanger, and then connected with the heated medium inlet of the third-stage condenser, and the heated medium outlet of the third-stage condenser is the total outlet.

[0010] According to different requirements, a fourth-stage compressor and a fourth-stage condenser, and corresponding intermediate heat exchangers, auxiliary heat exchangers, condensers, stop valves, throttle valves and the like can be added to form a four-stage cascade four-stage heating cycle, and so on, which can be increased to an infinite number of stages; similarly, the third-stage compressor and the third-stage condenser, and corresponding intermediate heat exchangers, auxiliary heat exchangers, condensers, stop valves, throttle valves and the like can be removed to form a two-stage cascade two-stage heating cycle, and so on, which can be reduced to a single-stage heating cycle.

[0011] Alternatively, the single-press intermediate exhaust step coupling heating cycle configuration is a single-press intermediate exhaust three-stage coupling heating system, which comprises a staged efficiency compressor, a first-stage condenser, a second-stage condenser, a third-stage condenser, a stop valve, a first auxiliary heat exchanger, a second auxiliary heat exchanger, a first-stage throttle valve, a second-stage throttle valve, a third-stage throttle valve, a first auxiliary throttle valve, a second auxiliary throttle valve, an evaporator, a pump or a fan, the first exhaust port of the staged efficiency compressor is connected with the refrigerant inlet of the first-stage condenser, the refrigerant outlet of the first-stage condenser is connected with the refrigerant inlet of the evaporator through the first-stage throttle valve, and the refrigerant outlet of the evaporator is connected with the first suction port of the staged efficiency compressor; the second exhaust port of the staged efficiency compressor is connected with the refrigerant inlet of the second-stage condenser, the refrigerant outlet of the second-stage condenser is connected with the refrigerant inlet of the first auxiliary heat exchanger, and the refrigerant outlet of the first auxiliary heat exchanger is connected with the refrigerant outlet of the first-stage condenser through the second-stage throttle valve and connected with the second suction port of the staged efficiency compressor through the first auxiliary throttle valve; the third exhaust port of the staged efficiency compressor is connected with the refrigerant inlet of the third-stage condenser, the refrigerant outlet of the third-stage condenser is connected with the refrigerant inlet of the second auxiliary heat exchanger, the refrigerant outlet of the second auxiliary heat exchanger is connected with the refrigerant outlet of the second-stage condenser through the third-stage throttle valve and connected with the third suction port of the staged efficiency compressor through the second auxiliary throttle valve; the heated medium inlet is connected with the pump or fan inlet, the pump or fan outlet is connected with the heated medium inlet of the first-stage condenser and the heated medium inlet of the first auxiliary heat exchanger respectively, the heated medium outlet of the first-stage condenser and the heated medium outlet of the first auxiliary heat exchanger are connected with the heated medium inlet of the second-stage condenser and the heated medium inlet of the second auxiliary heat exchanger respectively after being merged, the heated medium outlet of the second-stage condenser and the heated medium outlet of the second auxiliary heat exchanger are connected with the heated medium inlet of the third-stage condenser after being merged, and the heated medium outlet of the third-stage condenser is the total heat outlet.

[0012] According to different requirements, a fourth-stage condenser and corresponding auxiliary heat exchangers, stop valves, throttle valves, etc. can be added to form a single-press intermediate exhaust four-stage coupling heating cycle, and so on, which can be increased to a single-press intermediate exhaust infinite-stage heating; similarly, the third-stage condenser and corresponding auxiliary heat exchangers, stop valves, throttle valves, etc. can be removed to form a single-press intermediate exhaust two-stage heating cycle, and so on, which can be reduced to a single-stage heating cycle.

[0013] Further, in the single-press intermediate exhaust step coupling heating cycle configuration, the staged efficiency compressor shell is provided with multiple suction ports and exhaust ports, and the refrigerant is sucked in or discharged at different pressures. When the number of heating stages is increased, the pipeline can be directly connected with the intermediate suction and exhaust ports based on the staged efficiency compressor, or the number of staged efficiency compressors can be increased.

[0014] In the present application, the process includes the step of heating the medium by cascade heating and the step of multi-stage compression cycle (or multi-stage cascade cycle, single compressor intermediate exhaust cycle) of the refrigerant.

[0015] In the step of cascade heating of the medium, the heated medium is divided into two paths after being accelerated by a pump or a fan, one path is heated by the first stage condenser, and the other path is preliminarily heated by the first auxiliary heat exchanger and then mixed with the heated medium from the first stage condenser; after mixing, the medium is again divided into two paths, one path is heated by the second stage condenser, and the other path is heated by the second auxiliary heat exchanger and then mixed with the medium from the second stage condenser; and so on, the medium heated by the N-1 stage condenser is mixed with the medium heated by the N-1 stage auxiliary heat exchanger, and then enters the N stage condenser to be heated to the final temperature.

[0016] In the step of multi-stage compression cycle of the refrigerant, the refrigerant compressed by the first stage compressor is first cooled to the first condensing temperature by releasing part of the heat in the first stage condenser, and then divided into two parts, one part of the refrigerant continues to release heat in the first stage condenser, and the other part of the gaseous refrigerant enters the second stage compressor for further compression to prevent the exhaust temperature of the compressor from being too high; the compressed refrigerant is first cooled to the second condensing temperature by releasing part of the heat in the second stage condenser, and then divided into two parts again, one part of the refrigerant continues to release heat in the second stage condenser, and the other part of the refrigerant enters the third stage compressor for further compression to prevent the exhaust temperature of the compressor from being too high; the compressed refrigerant is first cooled to the third condensing temperature by releasing part of the heat in the third stage condenser, and then divided into two parts, one part of the refrigerant continues to release heat in the third stage condenser, and the other part of the refrigerant enters the fourth stage compressor for compression; and so on, the refrigerant compressed by the N stage compressor enters the N stage condenser to release heat, and the refrigerant coming out of the N stage condenser enters the N-1 auxiliary heat exchanger to heat part of the water to a certain temperature, and then the refrigerant coming out of the N-1 auxiliary heat exchanger is throttled to the N-1 condensing pressure by the N stage throttle valve, and then mixed with the refrigerant from the N-1 stage condenser to enter the N-2 auxiliary heat exchanger to release heat, and then enters the N-1 stage throttle valve to be throttled to the N-2 condensing pressure; the refrigerant throttled to the first condensing pressure by the second stage throttle valve is mixed with part of the refrigerant from the first stage condenser, and then the mixed refrigerant is throttled to the evaporation pressure by the first stage throttle valve and then enters the evaporator to absorb the heat of the low temperature heat source to become gaseous refrigerant, and then enters the first stage compressor for compression.

[0017] The multi-stage compression cascade heating process can also be implemented by a multi-stage cascade heating process with intermediate heat exchangers, which is different from the multi-stage compression cascade heating process in that heat is transferred between stages through intermediate heat exchangers, and the same or different refrigerants can be used in each stage, and part of the refrigerant discharged from the first, second, …, N-stage condenser enters the second, third, …, N-1 intermediate heat exchanger instead of the compressor, and the refrigerant in the second stage cycle absorbs heat from part of the refrigerant in the first stage condenser in the first intermediate heat exchanger to become gaseous refrigerant, which is then compressed by the second stage compressor, and so on.

[0018] The multi-stage compression cascade heating process can also be implemented by a single-compressor intermediate exhaust cascade heating process, which is different from the multi-stage compression cascade heating process in that the single-compressor cascade heating process uses a staged efficiency compressor, and the number of compressors can be one or more, and the compressor shell has multiple exhaust ports and suction ports, each of which inhales or exhausts refrigerant at different pressures and temperatures. Another difference is that the refrigerant after heat exchange by the auxiliary heat exchanger is not throttled by the same throttle valve, but a part of it is throttled by an auxiliary throttle valve, which has a lower throttling degree. The throttled refrigerant enters the intermediate suction port of the compressor for further compression, and the remaining cycle process is the same as that of the multi-stage compression cascade heating process.

[0019] The beneficial effects of the present application mainly include:

[0020] 1. Compared with traditional single-stage compression, two-stage compression or cascade heat pump, the application further expands the application range.

[0021] 2. For different temperature requirements and working conditions, the number of driving stages and heating stages of the system can be changed to maximize the energy efficiency.

[0022] 3. The multi-stage compression cascade heating, multi-stage cascade heating with intermediate heat exchangers, or single-compressor intermediate exhaust cascade heating cycle configuration can be applied to more different heat scenarios.

[0023] 4. The temperature glide characteristics of the non-azeotropic mixed refrigerant are ingeniously utilized and matched with the three cycle configurations to reduce the temperature difference of the working medium and the heated medium at each stage, and the enthalpy characteristics are gradually approached to improve the system efficiency.

[0024] 5. When the hot water temperature rise is large, the refrigerant is cooled by different structural methods to prevent the compressor exhaust temperature from being too high, and to further improve the system energy efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic diagram of a heat pump system with a multi-stage compression cascade heating cycle configuration.

[0026] Figure 2Fig. 1 is a schematic diagram of a heat pump system with a multi-stage cascade coupled heating cycle configuration.

[0027] Figure 3 Fig. 2 is a schematic diagram of a heat pump system with a single-pressure machine intermediate exhaust cascade coupled heating cycle configuration. DETAILED DESCRIPTION

[0028] The application will be further described below with reference to the accompanying drawings.

[0029] Reference Figure 1 A heat pump system and its composite construction method for high-temperature heat source heat capacity characteristics, the heat pump system cycle configuration is a multi-stage compression cascade coupled heating type, from left to right, the number of driving (compression) stages increases in turn, such as (a) is a single-stage driving, (b) (d) is a two-stage driving (c) (e) (f) is a three-stage driving, …, until N-stage driving, from bottom to top, the number of heating stages increases in turn, such as (a) (b) (c) is a single-stage heating, (d) (e) is a two-stage heating, (f) is a three-stage heating, …, until N-stage heating. The number of heating stages in each cycle is less than or equal to the number of driving (compression) stages, and so on, which can be infinitely many driving (compression) and infinitely many heating.

[0030] For example, the three-stage compression three-stage coupling heating type (f) includes a first-stage compressor 331, a second-stage compressor 336, a third-stage compressor 3311, a first-stage condenser 332, a second-stage condenser 337, a third-stage condenser 3312, a stop valve, a first auxiliary heat exchanger 3315, a second auxiliary heat exchanger 3313, a first-stage throttle valve 333, a second-stage throttle valve 3316, a third-stage throttle valve 3314, an evaporator 334, a pump or fan 3317, an outlet of the first-stage compressor 331 is connected to a refrigerant inlet of the first-stage condenser 332, a refrigerant first outlet of the first-stage condenser 332 is connected to a refrigerant inlet of the evaporator 334 through the first-stage throttle valve 333, a refrigerant outlet of the evaporator 334 is connected to an inlet of the first-stage compressor 331; a refrigerant second outlet of the first-stage condenser 332 is connected to an inlet of the second-stage compressor 336 through the stop valve 335, an outlet of the second-stage compressor 336 is connected to a refrigerant inlet of the second-stage condenser 337, a refrigerant first outlet of the second-stage condenser 337 is connected to a refrigerant inlet of the first auxiliary heat exchanger 3315, a refrigerant outlet of the first auxiliary heat exchanger 3315 is connected to the refrigerant first outlet of the first-stage condenser 332 through the second-stage throttle valve 3316; a refrigerant second outlet of the second-stage condenser 337 is connected to an inlet of the third-stage compressor 3311 through the stop valve 3310, an outlet of the third-stage compressor 3311 is connected to a refrigerant inlet of the third-stage condenser 3312, a refrigerant outlet of the third-stage condenser 3312 is connected to a refrigerant inlet of the second auxiliary heat exchanger 3313, a refrigerant outlet of the second auxiliary heat exchanger 3313 is connected to the refrigerant first outlet of the second-stage condenser 337 through the third-stage throttle valve 3314; a heated medium inlet is connected to an inlet of the pump or fan 3317, an outlet of the pump or fan 3317 is connected to a heated medium inlet of the first-stage condenser 332 and a heated medium inlet of the first auxiliary heat exchanger 3315 respectively, the heated medium outlet of the first-stage condenser 332 is connected to the heated medium outlet of the first auxiliary heat exchanger 3315, and then connected to a heated medium inlet of the second-stage condenser 337 and a heated medium inlet of the second auxiliary heat exchanger 3313 respectively, the heated medium outlet of the second-stage condenser 337 and the heated medium outlet of the second auxiliary heat exchanger 3313 are connected to a heated medium inlet of the third-stage condenser 3312, and a heated medium outlet of the third-stage condenser 3312 is a total outlet.

[0031] Figure 1(f) The working process of the scheme shown is as follows: the stop valves 335 and 3310 are opened, the refrigerant after absorbing the low-temperature heat source heat from the evaporator 334 is compressed by the first-stage compressor 331 and first enters the first-stage condenser 332 to release part of the heat, is cooled to a first condensing temperature, and is prevented from being too high in temperature when entering the second-stage compressor 336; the refrigerant releasing heat in the first-stage condenser 332 is divided into two parts, one part of the refrigerant continues to release heat in the first-stage condenser 332, and the other part of the gaseous refrigerant enters the second-stage compressor 336 to continue to be compressed; the compressed refrigerant first enters the second-stage condenser 337 to release part of the heat and is cooled to a second condensing temperature, and then is again divided into two parts in the second-stage condenser 337, one part of the refrigerant continues to release heat in the second-stage condenser 337, and the other part of the refrigerant enters the third-stage compressor 3311 to continue to be compressed; the compressed refrigerant enters the third-stage condenser 3312 to release heat, the refrigerant after coming out of the third-stage condenser 3312 continues to release heat in the second auxiliary heat exchanger 3313, and then is throttled to the second condensing pressure by the third-stage throttling valve 3314, is combined with the refrigerant from the second-stage condenser 337, enters the first auxiliary heat exchanger 3315 to release heat at the second condensing temperature, is throttled to the first condensing pressure by the second-stage throttling valve 3316, is combined with the refrigerant from the first-stage condenser 332, is throttled to low-temperature and low-pressure liquid refrigerant by the first-stage throttling valve 333, absorbs heat from the low-temperature heat source in the evaporator 334 to become gaseous refrigerant, and then enters the first-stage compressor 331 to be compressed, and the cycle is repeated. The heated medium is accelerated by the pump or fan 3317 and is divided into two paths, one path is heated by the first-stage condenser 332, and the other path is preliminarily heated by the first auxiliary heat exchanger 3315 and is mixed with the medium from the first-stage condenser 332; after mixing, the medium is again divided into two paths, one path is heated by the second-stage condenser 337, and the other path is heated by the second auxiliary heat exchanger 3314 and is mixed with the medium from the second-stage condenser 337; after mixing, the medium enters the third-stage condenser 3312 to be heated to the required temperature.

[0032] According to different requirements, a fourth-stage compressor and a fourth-stage condenser, and corresponding auxiliary heat exchangers, stop valves, throttling valves, etc. can be added to form a four-stage compression and four-stage heating cycle, and so on, to an infinite number of stages of compression and infinite number of stages of heating; similarly, the third-stage compressor and the third-stage condenser, and corresponding auxiliary heat exchangers, stop valves, throttling valves, etc. can be removed to form a two-stage compression and two-stage coupled heating (b), a single-stage heating cycle (d), and so on, to a single-stage compression and single-stage heating cycle (a). At the same time, only part of the condensers and corresponding auxiliary heat exchangers, stop valves, etc. can be removed to form a three-stage compression and two-stage or single-stage heating cycle (e) (c), and an N-stage compression and N-stage heating cycle can also be formed in this way.

[0033] Referring toFigure 2 A heat pump system and its composite construction method for high-temperature heat source heat capacity characteristics, the circulation configuration of the heat pump system is a multi-stage cascade ladder coupling heating type, and the driving (cascade) stage number increases successively from left to right, such as (a) for single-stage driving, (b) (d) for two-stage driving (c) (e) (f) for three-stage driving, …, and N-stage driving. The heating stage number increases successively from bottom to top, such as (a) (b) (c) for single-stage heating, (d) (e) for two-stage heating, (f) for three-stage heating, …, and N-stage heating. The heating stage number in each cycle is less than or equal to the driving (cascade) stage number, and the same applies to infinitely many driving (cascade) stages and infinitely many heating stages.

[0034] Taking a three-stage cascade three-stage heating type (f) as an example, it comprises a first-stage compressor 331, a second-stage compressor 337, a third-stage compressor 3313, a first-stage condenser 332, a second-stage condenser 338, a third-stage condenser 3314, a stop valve, a first intermediate heat exchanger 336, a second intermediate heat exchanger 3312, a first auxiliary heat exchanger 339, a second auxiliary heat exchanger 3315, a first-stage throttle valve 333, a second-stage throttle valve 3310, a third-stage throttle valve 3316, an evaporator 334, and a pump or fan 3317. The outlet of the first-stage compressor 331 is divided into two paths, one of which is connected to the refrigerant inlet of the first-stage condenser 332, and the other is connected to the first inlet of the first intermediate heat exchanger 336 through the stop valve 335. The first outlet of the first intermediate heat exchanger 336 is connected to the refrigerant outlet of the first-stage condenser 332, and the two are combined and then connected to the inlet of the evaporator 334 through the first-stage throttle valve 333. The second outlet of the first intermediate heat exchanger 336 is connected to the inlet of the second-stage compressor 337. The outlet of the second-stage compressor 337 is divided into two paths, one of which is connected to the refrigerant inlet of the second-stage condenser 338, and the other is connected to the first inlet of the second intermediate heat exchanger 3312 through the stop valve 3311. The first outlet of the second intermediate heat exchanger 3312 is connected to the refrigerant inlet of the first auxiliary heat exchanger 339, and the two are combined and then connected to the second inlet of the first intermediate heat exchanger 336 through the first auxiliary heat exchanger 339 and the second-stage throttle valve 3310. The second outlet of the second intermediate heat exchanger 3312 is connected to the inlet of the third-stage compressor 3313. The outlet of the third-stage compressor 3313 is connected to the refrigerant inlet of the third-stage condenser 3314. The refrigerant outlet of the third-stage condenser 3314 is connected to the refrigerant inlet of the second auxiliary heat exchanger 3315. The refrigerant outlet of the second auxiliary heat exchanger 3315 is connected to the second inlet of the second intermediate heat exchanger 3312 through the third-stage throttle valve 3316. The inlet of the heated medium is connected to the inlet of the pump or fan 3317. The outlet of the pump or fan 3317 is connected to the heated medium inlets of the first-stage condenser 332 and the first auxiliary heat exchanger 339. The heated medium outlets of the first-stage condenser 332 and the first auxiliary heat exchanger 339 are combined and then connected to the heated medium inlets of the second-stage condenser 338 and the second auxiliary heat exchanger 3315, respectively. The heated medium outlets of the second-stage condenser 338 and the second auxiliary heat exchanger 3315 are combined and then connected to the heated medium inlet of the third-stage condenser 3314. The heated medium outlet of the third-stage condenser 3314 is the total outlet.

[0035] Figure 2(f) The working process of the scheme is as follows: the refrigerant coming out of the evaporator 334 after absorbing heat is compressed into high-temperature and high-pressure gas by the first-stage compressor 331, and then divided into two parts, one part enters the first-stage condenser 332 to release heat to the first condensing temperature to become liquid refrigerant, and the other part enters the first intermediate heat exchanger 336 through the stop valve 335 to release heat, and then merges with the refrigerant coming out of the first-stage condenser 332, after merging, it is throttled into low-temperature and low-pressure liquid refrigerant by the first-stage throttling valve 333, enters the evaporator 334 to absorb the heat of the low-temperature heat source to become gaseous, and then enters the first-stage compressor 331 to be compressed. The other part of the refrigerant in the first intermediate heat exchanger 336 absorbs heat from the refrigerant in the first-stage cycle to become gaseous, and then enters the second-stage compressor 337 to be compressed, and then divided into two parts, one part releases heat in the second-stage condenser 338 to the second condensing temperature, and the other part enters the second intermediate heat exchanger 3312 through the stop valve 3311 to release heat, and then merges with the refrigerant coming out of the second-stage condenser 338, and then enters the first auxiliary heat exchanger 339 to continue releasing heat, and then throttled to the first intermediate pressure by the second-stage throttling valve 3310, and then enters the first intermediate heat exchanger 336. The other part of the refrigerant in the second intermediate heat exchanger 3312 absorbs heat from the refrigerant in the second-stage cycle to become gaseous, and then enters the third-stage compressor 3313 to be compressed into high-temperature and high-pressure gaseous refrigerant, enters the third-stage condenser 3314 to release heat to the third condensing temperature to become liquid, and then enters the second auxiliary heat exchanger 3315 to continue releasing heat, and then throttled to the second intermediate pressure by the third-stage throttling valve 3316, and then enters the second intermediate heat exchanger 3312. The heated medium accelerated by the pump or fan 3317 is divided into two parts, one part is heated by the first-stage condenser 332, and the other part is preliminarily heated by the first auxiliary heat exchanger 339 and then mixed with the medium from the first-stage condenser; after mixing, it is again divided into two parts, one part is heated by the second-stage condenser 338, and the other part is heated by the second auxiliary heat exchanger 3315 and then mixed with the medium from the second-stage condenser; after mixing, it enters the third-stage condenser 3314 to be heated to the required temperature.

[0036] According to different requirements, a fourth-stage compressor and a fourth-stage condenser, as well as corresponding auxiliary heat exchangers, intermediate heat exchangers, stop valves, throttling valves, etc. can be added to form a four-stage cascade four-stage heating cycle, and so on, which can be increased to an infinite number of stages. Similarly, the third-stage compressor and the third-stage condenser, as well as corresponding auxiliary heat exchangers, intermediate heat exchangers, stop valves, throttling valves, etc. can be removed to form a two-stage cascade two-stage coupled (d), single-stage heating cycle (b), and so on, which can be reduced to a single-stage compression single-stage heating cycle (a). At the same time, only part of the condensers and corresponding auxiliary heat exchangers, stop valves, etc. can be removed to form a three-stage cascade two-stage or single-stage heating cycle (e) (c), and an N-stage cascade N-stage heating cycle can also be done in this way.

[0037] Referring to Figure 3 A heat pump system and its composite construction method for high-temperature heat source heat capacity characteristics, the heat pump system configuration is single compressor intermediate exhaust cascade coupling heating type, from left to right driving (exhaust) and heating series increases in turn, such as (a) is single stage driving single stage heating, (b) is two stage driving two stage coupling heating (c) is three stage driving three stage coupling heating, …, until N stage driving N stage coupling heating. The heating series in each cycle is equal to the driving (exhaust) series, and so on to infinitely many levels of driving (exhaust) infinitely many levels of heating.

[0038] Taking the single compressor intermediate exhaust three stage coupling heating type (c) as an example, it includes a staged efficiency compressor 31, a first stage condenser 32, a second stage condenser 35, a third stage condenser 39, a first auxiliary heat exchanger 36, a second auxiliary heat exchanger 40, a first stage throttle valve 33, a second stage throttle valve 38, a third stage throttle valve 42, a first auxiliary throttle valve 37, a second auxiliary throttle valve 41, an evaporator 34, a pump or fan 43, the first exhaust port of the staged efficiency compressor 31 is connected with the refrigerant inlet of the first stage condenser 32, the refrigerant outlet of the first stage condenser 32 is connected with the refrigerant inlet of the evaporator 34 through the first stage throttle valve 33, and the refrigerant outlet of the evaporator 34 is connected with the first suction port of the staged efficiency compressor 31; the second exhaust port of the staged efficiency compressor 31 is connected with the refrigerant inlet of the second stage condenser 35, the refrigerant outlet of the second stage condenser 35 is connected with the refrigerant inlet of the first auxiliary heat exchanger 36, and the refrigerant outlet of the first auxiliary heat exchanger 36 is connected with the second suction port of the staged efficiency compressor 31 through the first auxiliary throttle valve 37 and the second stage throttle valve 38; the third exhaust port of the staged efficiency compressor 31 is connected with the refrigerant inlet of the third stage condenser 39, the refrigerant outlet of the third stage condenser 39 is connected with the refrigerant inlet of the second auxiliary heat exchanger 40, and the refrigerant outlet of the second auxiliary heat exchanger 40 is connected with the third suction port of the staged efficiency compressor 31 through the second auxiliary throttle valve 41 and the third stage throttle valve 42; the inlet of the heated medium is connected with the inlet of the pump or fan 43, the outlet of the pump or fan 43 is connected with the heated medium inlet of the first stage condenser 32 and the heated medium inlet of the first auxiliary heat exchanger 36 respectively, the heated medium outlet of the first stage condenser 32 and the heated medium outlet of the first auxiliary heat exchanger 36 are connected with the heated medium inlet of the second stage condenser 35 and the heated medium inlet of the second auxiliary heat exchanger 40 respectively after being converged, the heated medium outlet of the second stage condenser 35 and the heated medium outlet of the second auxiliary heat exchanger 40 are connected with the heated medium inlet of the third stage condenser 39 after being converged, and the heated medium outlet of the third stage condenser 39 is the total outlet.

[0039] Figure 3 (c) The working process of the scheme is as follows: the refrigerant from the evaporator 34 is compressed by the step-by-step efficiency compressor 31, and a part of the refrigerant enters the first stage condenser 32 from the first exhaust port to release heat, and the temperature and pressure of this part of the refrigerant are both low, another part of the refrigerant continues to be compressed, and then a part is discharged from the second exhaust port of the compressor 31 and enters the second stage condenser 35 to release heat, another part of the refrigerant continues to be compressed, and finally is discharged from the third exhaust port and enters the third stage condenser 39 to release heat, the refrigerant from the third stage condenser 39 continues to release heat in the second auxiliary heat exchanger 40, and then is divided into two parts, one part is throttled by the auxiliary throttle valve 41 and is sucked into the compressor 31 through the third suction port to continue to be compressed, and the other part is throttled to the second condensing pressure by the third stage throttle valve 42, and then is mixed with the refrigerant from the second stage condenser 35 and enters the first auxiliary heat exchanger 36 to release heat, and then is divided into two parts, one part is throttled by the auxiliary throttle valve 37 and is sucked into the compressor 31 through the second suction port to continue to be compressed, and the other part is throttled to the first condensing pressure by the second stage throttle valve 38 and is mixed with the refrigerant from the first stage condenser 32, the mixed refrigerant is throttled to low-temperature and low-pressure liquid refrigerant by the first stage throttle valve 33, and then absorbs heat from the low-temperature heat source in the evaporator 34 to become gaseous refrigerant, and then enters the compressor 31 from the first suction port, and the cycle continues. The heated medium is accelerated by the pump or fan 43 and divided into two paths, one path is heated by the first stage condenser 32, and the other path is preliminarily heated by the first auxiliary heat exchanger 36 and mixed with the medium from the first stage condenser 32; after mixing, the medium is again divided into two paths, one path is heated by the second stage condenser 35, and the other path is heated by the second auxiliary heat exchanger 40 and mixed with the medium from the second stage condenser 35; after mixing, the medium enters the third stage condenser 39 and is heated to the final temperature.

[0040] According to different needs, a fourth stage condenser and corresponding auxiliary heat exchangers, stop valves, throttle valves, etc. can be added to form a single-compressor intermediate-exhaust four-stage coupled heat cycle, and similarly, a single-compressor intermediate-exhaust infinite-stage heat cycle can be formed by increasing the number of stages; similarly, a single-compressor intermediate-exhaust two-stage coupled heat cycle (b) can be formed by removing the third stage condenser and corresponding auxiliary heat exchangers, stop valves, throttle valves, etc., and a single-compressor single-stage heat cycle (c) can be formed by further reducing the number of stages.

[0041] The embodiments described in the specification are only a list of implementation forms of the inventive concept, and are only for illustrative purposes. The protection scope of the present application should not be regarded as being limited to the specific forms described in the embodiments, and the protection scope of the present application also extends to equivalent technical means that can be thought of by those skilled in the art according to the inventive concept.

Claims

1. A heat pump system oriented to the heat capacity characteristics of a high-temperature heat source, characterized by, This paper describes a composite construction approach based on four aspects: the number of driving stages, the number of heating stages, different configurations, and refrigerants. This involves constructing multi-stage compression ladder-coupled heating configurations, multi-stage cascade ladder-coupled heating cycle configurations, or single-compressor intermediate exhaust ladder-coupled heating cycle configurations. The number of heating stages is less than or equal to the number of driving stages, and there is at least one heating stage. The number of driving stages changes according to the temperature rise of the high-temperature heat source. When the heat source temperature rise is large, the number of driving stages and heating stages is increased to reduce the heat exchange temperature difference between each stage. When the temperature rise is small, the number of driving stages and heating stages is reduced. The working fluid mixture is also changed accordingly to match its temperature glide characteristics with the heat source temperature rise. The multi-stage compression ladder-coupled heating configuration is a three-stage compression three-stage coupled heating heat pump system, including a first-stage compressor, a second-stage compressor, a third-stage compressor, a first-stage condenser, and a second-stage... The system includes a condenser, a third-stage condenser, a shut-off valve, a first auxiliary heat exchanger, a second auxiliary heat exchanger, a first-stage throttling valve, a second-stage throttling valve, a third-stage throttling valve, an evaporator, and a pump or fan. The outlet of the first-stage compressor is connected to the refrigerant inlet of the first-stage condenser. The first refrigerant outlet of the first-stage condenser is connected to the refrigerant inlet of the evaporator via the first-stage throttling valve. The refrigerant outlet of the evaporator is connected to the inlet of the first-stage compressor. The second refrigerant outlet of the first-stage condenser is connected to the inlet of the second-stage compressor via the shut-off valve. The outlet of the second-stage compressor is connected to the refrigerant inlet of the second-stage condenser. The first refrigerant outlet of the second-stage condenser is connected to the refrigerant inlet of the first auxiliary heat exchanger. The refrigerant outlet of the first auxiliary heat exchanger merges with the first refrigerant outlet of the first-stage condenser via the second-stage throttling valve. The second refrigerant outlet of the second-stage condenser is connected to the inlet of the third-stage compressor via a shut-off valve. The outlet of the third-stage compressor is connected to the refrigerant inlet of the third-stage condenser. The refrigerant outlet of the third-stage condenser is connected to the refrigerant inlet of the second auxiliary heat exchanger. The refrigerant outlet of the second auxiliary heat exchanger is connected to the first refrigerant outlet of the second-stage condenser via a third-stage throttling valve. The inlet of the heated medium is connected to the inlet of the pump or fan. The outlet of the pump or fan is connected to the inlet of the heated medium of the first-stage condenser and the inlet of the heated medium of the first auxiliary heat exchanger, respectively. The outlet of the heated medium of the first-stage condenser and the outlet of the heated medium of the first auxiliary heat exchanger are combined and then connected to the inlet of the heated medium of the second-stage condenser and the inlet of the heated medium of the second auxiliary heat exchanger, respectively. The outlet of the heated medium of the second-stage condenser and the outlet of the heated medium of the second auxiliary heat exchanger are combined and then connected to the inlet of the heated medium of the third-stage condenser. The outlet of the heated medium of the third-stage condenser is the total outlet.

2. A heat pump system designed for the heat capacity characteristics of high-temperature heat sources, characterized in that, This paper proposes a composite construction approach based on four aspects: the number of driving stages, the number of heating stages, different configurations, and refrigerants. This involves constructing multi-stage compression ladder-coupled heating configurations, multi-stage cascade ladder-coupled heating cycle configurations, or single-compressor intermediate exhaust ladder-coupled heating cycle configurations. The number of heating stages is less than or equal to the number of driving stages, and there must be at least one heating stage. The number of driving stages varies according to the temperature rise of the high-temperature heat source. When the temperature rise is large, both the number of driving and heating stages are increased to reduce the heat exchange temperature difference between each stage. Conversely, when the temperature rise is small, both the number of driving and heating stages are reduced. The working fluid mixture is also modified accordingly to ensure its temperature glide characteristics are in line with the temperature rise of the heat source. Matching; the multi-stage cascaded coupled heating cycle configuration is a three-stage cascaded three-stage coupled heating system, including a first-stage compressor, a second-stage compressor, a third-stage compressor, a first-stage condenser, a second-stage condenser, a third-stage condenser, a shut-off valve, a first intermediate heat exchanger, a second intermediate heat exchanger, a first auxiliary heat exchanger, a second auxiliary heat exchanger, a first-stage throttling valve, a second-stage throttling valve, a third-stage throttling valve, an evaporator, and a pump or fan. The outlet of the first-stage compressor is divided into two paths: one path is connected to the refrigerant inlet of the first-stage condenser, and the other path is connected to the first inlet of the first intermediate heat exchanger via the shut-off valve. The first outlet of the first intermediate heat exchanger merges with the refrigerant outlet of the first-stage condenser and is connected to the evaporator inlet via a first-stage throttling valve. The evaporator outlet is connected to the inlet of the first-stage compressor. The second outlet of the first intermediate heat exchanger is connected to the inlet of the second-stage compressor. The outlet of the second-stage compressor is split into two paths: one path connects to the refrigerant inlet of the second-stage condenser, and the other path connects to the first inlet of the second intermediate heat exchanger via a shut-off valve. The first outlet of the second intermediate heat exchanger merges with the refrigerant outlet of the second-stage condenser and is connected to the refrigerant inlet of the first auxiliary heat exchanger. The refrigerant outlet of the first auxiliary heat exchanger is connected to the second inlet of the first intermediate heat exchanger via a second-stage throttling valve. The second outlet of the second intermediate heat exchanger is connected to the inlet of the third-stage compressor, and the outlet of the third-stage compressor is connected to the inlet of the third-stage condenser. The refrigerant inlet of the first stage condenser is connected to the refrigerant inlet of the second auxiliary heat exchanger. The refrigerant outlet of the second auxiliary heat exchanger is connected to the second inlet of the second intermediate heat exchanger via a third-stage throttling valve. The inlet of the heated medium is connected to the pump or fan inlet. The pump or fan outlet is connected to the heated medium inlet of the first stage condenser and the heated medium inlet of the first auxiliary heat exchanger, respectively. The heated medium outlet of the first stage condenser and the heated medium outlet of the first auxiliary heat exchanger merge and are then connected to the heated medium inlets of the second stage condenser and the second auxiliary heat exchanger, respectively. The heated medium outlet of the second stage condenser and the heated medium outlet of the second auxiliary heat exchanger merge and are then connected to the heated medium inlet of the third stage condenser. The heated medium outlet of the third stage condenser is the total outlet.

3. A heat pump system designed for the heat capacity characteristics of high-temperature heat sources, characterized in that, This paper describes a composite construction approach involving four aspects: the number of driving stages, the number of heating stages, different configurations, and refrigerants. This involves constructing multi-stage compression ladder-coupled heating configurations, multi-stage cascade ladder-coupled heating cycle configurations, or single-compressor intermediate exhaust ladder-coupled heating cycle configurations. The number of heating stages is less than or equal to the number of driving stages, and there is at least one heating stage. The number of driving stages varies according to the temperature rise of the high-temperature heat source. When the temperature rise is large, both the number of driving and heating stages are increased to reduce the heat exchange temperature difference between each stage. Conversely, when the temperature rise is small, both the number of driving and heating stages are reduced. The working fluid mixture is also modified accordingly to match its temperature glide characteristics with the heat source temperature rise. The single-compressor intermediate exhaust ladder-coupled heating cycle configuration... The heating cycle configuration is a single-compressor intermediate discharge three-stage coupled heating system, including a staged efficiency compressor, a first-stage condenser, a second-stage condenser, a third-stage condenser, a first auxiliary heat exchanger, a second auxiliary heat exchanger, a first-stage throttling valve, a second-stage throttling valve, a third-stage throttling valve, a first auxiliary throttling valve, a second auxiliary throttling valve, an evaporator, and a pump or fan. The first discharge port of the staged efficiency compressor is connected to the refrigerant inlet of the first-stage condenser, the refrigerant outlet of the first-stage condenser is connected to the refrigerant inlet of the evaporator via the first-stage throttling valve, and the refrigerant outlet of the evaporator is connected to the first suction port of the staged efficiency compressor; the second discharge port of the staged efficiency compressor... The exhaust port is connected to the refrigerant inlet of the second-stage condenser, and the refrigerant outlet of the second-stage condenser is connected to the refrigerant inlet of the first auxiliary heat exchanger. One path of the refrigerant outlet of the first auxiliary heat exchanger connects to the refrigerant outlet of the first-stage condenser via a second-stage throttling valve, while the other path connects to the second suction port of the staged efficiency compressor via the first auxiliary throttling valve. The third exhaust port of the staged efficiency compressor is connected to the refrigerant inlet of the third-stage condenser, and the refrigerant outlet of the third-stage condenser is connected to the refrigerant inlet of the second auxiliary heat exchanger. One path of the refrigerant outlet of the second auxiliary heat exchanger connects to the refrigerant outlet of the second-stage condenser via a third-stage throttling valve, while the other path connects to the second suction port of the staged efficiency compressor via a second-stage throttling valve. The second auxiliary throttling valve is connected to the third suction port of the staged efficiency compressor; the inlet of the heated medium is connected to the inlet of the pump or fan; the outlet of the pump or fan is connected to the inlet of the heated medium of the first stage condenser and the inlet of the heated medium of the first auxiliary heat exchanger, respectively; the outlet of the heated medium of the first stage condenser and the outlet of the heated medium of the first auxiliary heat exchanger are combined and then connected to the inlet of the heated medium of the second stage condenser and the inlet of the heated medium of the second auxiliary heat exchanger, respectively; the outlet of the heated medium of the second stage condenser and the outlet of the heated medium of the second auxiliary heat exchanger are combined and then connected to the inlet of the heated medium of the third stage condenser; the outlet of the heated medium of the third stage condenser is the total outlet.

4. A heat pump system for high-temperature heat source heat capacity characteristics as described in claim 3, characterized in that, The single-compressor intermediate exhaust stage-coupled heating heat pump system has multiple suction and exhaust ports on the casing of the staged efficiency compressor, and the refrigerant is drawn in or discharged at different pressures. When the number of heating stages is increased, the pipeline can be directly connected to the intermediate suction and exhaust ports on the basis of the staged efficiency compressor, or the number of staged efficiency compressors can be increased.

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