A refrigeration / heat pump system based on multi-dimensional construction approximating the lorentz cycle

Abstract

The application discloses a refrigeration / heat pump system based on a multi-dimensional constructed approximation Lorentz cycle, which is constructed in four aspects of driving stage number, heating stage number, different configurations and refrigerants, and is a multi-stage compression gradient coupling heating configuration, a multi-stage cascade gradient coupling heating cycle configuration or a single compressor intermediate exhaust gradient coupling 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 a high-temperature heat source, when the temperature rise of the heat source is large, the driving stage number is increased and the heating stage number is 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 rise of the heat source with the temperature glide characteristics. Through the collaborative matching of the working medium characteristics and the cycle structure, the working medium and the high-temperature heat source are gradually approximated in the temperature and enthalpy characteristics, so that the energy efficiency is higher under the working condition of large temperature rise and large temperature span, and the energy consumption is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of heat pumps, and particularly relates to a heat pump system approximating to a Lorentz cycle based on multi-dimensional construction. BACKGROUND

[0002] With the increasing demand for energy and the increasingly serious environmental problems, the development of energy-saving and environment-friendly methods has become mainstream. Heat pumps are widely researched and applied due to their energy-saving, environment-friendly and high-efficiency characteristics, and especially under the promotion of relevant policies in China, the research on heat pump systems has become a hot topic.

[0003] Compared with traditional single-stage compression heat pump systems, existing two-stage compression or cascade heat pump systems have higher efficiency and wider working range. However, the temperature-enthalpy characteristics of the refrigerant are basically the same at high pressure (condenser) and low pressure (evaporator), while in actual industries, the high-temperature and low-temperature heat sources are often not the same medium. Therefore, there is a different heat exchange temperature difference between the refrigerant and the heat source, which causes large energy efficiency differences of the system under different working conditions. In some cold regions and industrial processes with high temperature requirements, the system is still difficult to apply. Therefore, improving the energy efficiency and stability of the heat pump system under low ambient temperature, different heat sources and industrial large temperature rise conditions has become a key topic. SUMMARY

[0004] In order to overcome the low energy efficiency and large energy consumption of the existing heat pump system under low ambient temperature, large temperature rise, large temperature span and different heat source conditions, the present application provides a refrigeration / heat pump system approximating to a Lorentz cycle based on multi-dimensional construction. The temperature slip characteristics of the mixed working medium two-phase region are matched with the cycle structure to make the heat source and the working medium closer to the heat exchange without temperature difference, i.e. closer to the Lorentz cycle, thereby improving the energy efficiency of the system.

[0005] The technical scheme adopted by the present application to solve its technical problems is:

[0006] A refrigeration / heat pump system approximating to a Lorentz cycle based on multi-dimensional construction, different driving stage numbers d, heating stage numbers h, cooling stage numbers c and configuration forms f are set according to the temperature conditions of the heated and cooled media and the temperature changes thereof in the heat exchange process, i.e. the refrigeration / heat pump cycle is constructed from four structural dimensions, and the following requirements need to be met.

[0007] d≥h≥1 and d≥c≥1 and d≥1 and h+c≤d+1

[0008] In the driving dimension, the number d represents the number of times the refrigerant is pressurized by the compressor, and one pure driving module, one heating module, and one cooling module can provide one level of driving; in the heating dimension, the number h represents the number of times the heated medium is heated by the condenser, and one heating module can provide one level of heating; in the cooling dimension, the number c represents the number of times the cooled medium is cooled by the evaporator, and one cooling module can provide one level of cooling; the configuration form f includes a multi-stage compression configuration, a multi-stage cascade configuration, and a single-stage compression intermediate suction and exhaust configuration, the serial numbers of the modules are sequentially numbered from 1 according to the temperature position of the module from low to high, and the c cooling modules, the r pure driving modules, and the h heating modules are sequentially connected according to the set rule, so as to obtain a d-level driving c-level cooling h-level heating refrigeration / heat pump cycle.

[0009] Further, when h+c>d, the first cooling module and the first heating module partially overlap, and the repeated driving links and throttling devices are deleted.

[0010] Further, the pure driving modules of the multi-stage compression configuration and the multi-stage cascade configuration each include a compressor and a throttling device, the compressor inlet is the low-pressure refrigerant inlet of the driving module, the compressor outlet is the high-pressure refrigerant outlet of the driving module, the throttling device inlet is the high-pressure refrigerant inlet of the driving module, and the throttling device outlet is the low-pressure refrigerant outlet of the driving module; in the pure driving module of the single-stage compression intermediate suction and exhaust configuration, the compressor is replaced by a compression interval, the compression interval is artificially divided into several segments, and the original compressor outlet becomes the end point of the compression interval, and the original compressor inlet becomes the starting point of the compression interval.

[0011] Further, the heating module under the multi-stage compression configuration comprises a compressor, a condenser, an auxiliary heating heat exchanger, a throttling device and a flow regulating valve. The outlet of the compressor is divided into two paths. One path passes through the flow regulating valve as the high-temperature refrigerant outlet of the heating module, and the other path enters the refrigerant inlet of the condenser. The refrigerant outlet of the condenser is divided into two paths. One path is the high-temperature refrigerant inlet, and the other path is connected with the refrigerant inlet of the auxiliary heating heat exchanger. The refrigerant outlet of the auxiliary heating heat exchanger is connected with the inlet of the throttling device. The outlet of the throttling device is the low-temperature refrigerant outlet of the heating module. The inlet of the compressor is the low-temperature refrigerant inlet of the heating module. The heating medium inlet of the auxiliary heating heat exchanger is the first heating medium inlet of the heating module. The heating medium outlet of the auxiliary heating heat exchanger is combined with the second heating medium inlet of the heating module, and then divided into two paths. One path is the first heating medium outlet of the heating module, and the other path is connected with the heating medium inlet of the condenser. The heating medium outlet of the condenser is the second heating medium outlet of the heating module. The hth heating module, i.e., the highest heating module, has no first heating medium outlet of the heating module, high-temperature refrigerant inlet of the heating module, high-temperature refrigerant outlet of the heating module and refrigerant flow regulating valve compared with the ordinary heating module. The 1st heating module has no auxiliary heating heat exchanger and first heating medium inlet of the heating module compared with the ordinary heating module. The second heating medium inlet of the heating module is divided into two paths by a pump or a fan.

[0012] The heating module under the multi-stage cascade configuration adds a cascade heat exchanger to the heating module under the multi-stage compression configuration. The changes in the pipeline are as follows: the outlet of the throttling device is connected with the first inlet of the cascade heat exchanger. The first outlet of the cascade heat exchanger is connected with the inlet of the compressor. The second inlet of the cascade heat exchanger is the low-temperature refrigerant inlet of the module. The second outlet of the cascade heat exchanger is the low-temperature refrigerant outlet of the module. The 1st heating module and the highest heating module also have the same changes.

[0013] The heating module under the single-stage compression intermediate suction and exhaust configuration replaces the compressor with a compression interval on the basis of the multi-stage compression configuration. Correspondingly, the original compressor outlet becomes the end point of the compression interval, and the original compressor inlet becomes the starting point of the compression interval. The 1st heating module and the highest heating module also have the same changes.

[0014] The cooling module under the multi-stage compression configuration comprises a compressor, an evaporator, an auxiliary cooling heat exchanger, a throttling device, a refrigerant flow regulating valve and a cooling medium flow regulating valve. The high-temperature refrigerant inlet of the cooling module is divided into two paths by the throttling device. One path is the low-temperature refrigerant outlet of the cooling module, and the other path is connected with the refrigerant inlet of the evaporator. The refrigerant outlet of the evaporator is divided into two paths by the refrigerant flow regulating valve. One path is the low-temperature refrigerant inlet, and the other path is connected with the refrigerant inlet of the auxiliary cooling heat exchanger. The refrigerant outlet of the auxiliary cooling heat exchanger is connected with the compressor inlet. The compressor outlet is the high-temperature refrigerant outlet of the heating module. The cooling medium first inlet of the cooling module is connected with the cooling medium inlet of the auxiliary cooling heat exchanger through the cooling medium flow regulating valve. The cooling medium outlet of the auxiliary cooling heat exchanger is combined with the cooling medium second inlet of the cooling module, and is divided into two paths again. One path is the cooling medium first outlet of the cooling module, and the other path is connected with the cooling medium second outlet of the cooling module through the evaporator. The first-stage cooling module is the lowest cooling stage, and does not have the cooling medium first outlet of the cooling module, the low-temperature refrigerant inlet of the cooling module, the low-temperature refrigerant outlet of the cooling module and the refrigerant flow regulating valve compared with the ordinary cooling module. The c-stage cooling module is the highest temperature stage cooling module, and does not have the auxiliary cooling heat exchanger and the cooling medium first inlet of the cooling module compared with the ordinary cooling module. The refrigerant outlet of the evaporator is directly connected with the compressor inlet. The cooling medium second inlet of the cooling module is divided into two paths again through a pump or a fan.

[0015] The cooling module under the multi-stage cascade configuration is based on the multi-stage compression configuration cooling module and adds a cascade heat exchanger. The changes in the pipeline are as follows: the throttling device outlet is divided into two paths. One path is connected with the evaporator refrigerant inlet, and the other path is connected with the cascade heat exchanger first inlet. The evaporator refrigerant outlet is combined with the cascade heat exchanger first outlet through the refrigerant flow regulating valve and is connected with the refrigerant inlet of the auxiliary cooling heat exchanger. The cascade heat exchanger second inlet is connected with the low-temperature refrigerant inlet of the module. The cascade heat exchanger second outlet is connected with the low-temperature refrigerant outlet of the module. The first-stage cooling module and the highest-stage cooling module also have the same changes.

[0016] The cooling module under the single-stage compression intermediate suction and exhaust configuration is based on the multi-stage compression configuration cooling module and replaces the compressor with a compression interval. The corresponding original compressor outlet becomes the end point of the compression interval, the original compressor inlet becomes the starting point of the compression interval, the evaporator refrigerant outlet is connected with the refrigerant inlet of the auxiliary cooling heat exchanger, the refrigerant outlet of the auxiliary cooling heat exchanger is connected with the starting point of the compression interval, and the first-stage cooling module and the highest-stage cooling module also have the same changes.

[0017] In the preferred pure drive module of the multi-stage compression configuration, an economizer and an auxiliary throttling device are added, the high-temperature refrigerant inlet of the module is divided into two paths, one path is connected to the first inlet of the economizer, and the other path passes through the auxiliary throttling device and is connected to the second inlet of the economizer, the first outlet of the economizer passes through the throttling device to become the low-temperature refrigerant outlet of the module, and the second outlet of the economizer is connected to the inlet of the compressor;

[0018] In the preferred pure drive module of the single-stage compression intermediate suction and exhaust configuration, the same method as the preferred pure drive module of the multi-stage compression configuration is used, except that the compressor is replaced by a compression interval, and the original outlet of the compressor becomes the end point of the compression interval, and the original inlet of the compressor becomes the starting point of the compression interval.

[0019] In the preferred heating module of the multi-stage compression configuration, the outlet of the compressor is not divided into two paths, but is directly connected to the refrigerant inlet of the condenser, and the condenser adds an exhaust cooling outlet, which passes through a refrigerant flow regulating valve to become the high-temperature refrigerant outlet of the module. This preferred scheme is applicable to all heating modules except the highest stage heating module. In the preferred first-stage heating module of the multi-stage compression configuration, an economizer and an auxiliary throttling device are added, the high-temperature refrigerant inlet of the module is divided into two paths after converging with the refrigerant outlet of the condenser, one path is connected to the first inlet of the economizer, and the other path passes through the auxiliary throttling device and is connected to the second inlet of the economizer, the first outlet of the economizer passes through the throttling device to become the low-temperature refrigerant outlet of the module, and the second outlet of the economizer is connected to the inlet of the compressor.

[0020] In the preferred first-stage heating module of the single-stage compression intermediate suction and exhaust configuration, the same method as the preferred first-stage heating module of the multi-stage compression configuration is used, except that the compressor is replaced by a compression interval, and the original outlet of the compressor becomes the end point of the compression interval, and the original inlet of the compressor becomes the starting point of the compression interval. In the preferred liquid injection cooling heating module of the single-stage compression intermediate suction and exhaust configuration, a liquid injection throttling valve is added based on the heating module of the single-stage compression intermediate suction and exhaust configuration, the inlet of the liquid injection throttling valve is connected to the refrigerant outlet of the auxiliary heating heat exchanger, and the outlet of the liquid injection throttling valve is connected to the starting point of the compression interval.

[0021] In the same configuration, when the c cooling modules, the r pure drive modules and the h heating modules are connected, the high-temperature refrigerant outlet of the lower-level module and the high-temperature refrigerant inlet are connected with the low-temperature refrigerant inlet of the higher-level module and the low-temperature refrigerant outlet, respectively, starting from the first-level cooling module; the cooling medium first inlet and the second inlet of the lower-level cooling module are connected with the cooling medium first outlet and the second outlet of the higher-level cooling module, respectively; the heating medium first outlet and the second outlet of the lower-level heating module are connected with the heating medium first inlet and the second inlet of the higher-level heating module, respectively; all the cooling modules are connected first, then the pure drive modules are connected, and finally the heating modules are connected, until the connection of the hth-level heating module is completed.

[0022] The step-by-step heating is that the heated medium is heated to the final high temperature in the condenser of each heating module, and the step-by-step cooling is that the cooled medium is cooled to the final low temperature in the evaporator of each cooling module, so that the total temperature rise dT h of the heated medium and the total temperature drop dT c of the cooled medium are achieved through the step-by-step heating and the step-by-step cooling, respectively. r The heat source is distributed to each level, i.e., the temperature rise or drop of the heat source between each level is reduced; and then the mixed working medium with different components and concentrations and having a two-phase region temperature slip dT r is further matched with the temperature rise or drop of each heating or cooling, i.e., approximately satisfies:

[0023] dTr×h=dT h and dTr×c=dT c

[0024] Since the temperature slip dT r of the mixed working medium is not completely the same at different temperature positions, the above formula is only an approximate relationship, which approximately enables the heating side and the cooling side to approach the Lorentz cycle and reduces the heat exchange temperature difference between each working medium and the heating medium and the cooling medium; and the number of heating and cooling stages and the components and concentrations of the mixed working medium are optimized simultaneously to achieve the total energy efficiency of the system.

[0025] The beneficial effects of the present application mainly include:

[0026] 1. Compared with single-stage compression, two-stage compression or cascade refrigeration / heat pump, the working temperature range and the types of heat sources are further expanded.

[0027] 2. For different working conditions, the number of drive stages, the number of heating stages and the number of cooling stages of the system can be changed by different module combinations to maximize the energy efficiency of the system.

[0028] 3. The three cycle configurations of multi-stage compression, multi-stage cascade and single-stage compression with intermediate suction and exhaust are used to improve the energy efficiency while increasing the diversity and selectivity of the refrigeration / heat pump system.

[0029] 4. Ingeniously utilizing the temperature glide characteristics of non-azeotropic mixed refrigerants and matching with three kinds of cycle configurations, the temperature difference between each stage of working medium and the heated medium and the cooled medium is reduced, and the system efficiency is improved.

[0030] 5. When the high-temperature heat source temperature is relatively high, the three kinds of cycle configurations can effectively prevent the exhaust temperature of the compressor from being too high, and further improve the energy efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Figure 1 is a schematic diagram of a pure drive module under a multi-stage compression configuration, wherein (a) is a pure drive module under a multi-stage compression configuration and a multi-stage cascade configuration, and (b) is a preferred pure drive module under a multi-stage compression configuration.

[0032] Figure 2 Figure 2 is a schematic diagram of a heating module under a multi-stage compression configuration, wherein (a) is a heating module under a multi-stage compression configuration, (b) is an exhaust cooling type heating module under a preferred multi-stage compression configuration, (c) is a highest stage heating module under a multi-stage compression configuration, (d) is a first stage heating module under a multi-stage compression configuration, and (e) is a preferred economic first stage heating module under a multi-stage compression configuration.

[0033] Figure 3 Figure 3 is a schematic diagram of a cooling module under a multi-stage compression configuration, wherein (a) is a cooling module under a multi-stage compression configuration, (b) is a first stage cooling module under a multi-stage compression configuration, and (c) is a highest stage cooling module under a multi-stage compression configuration.

[0034] Figure 4 Figure 4 is a schematic diagram of a heating module under a multi-stage cascade configuration, wherein (a) is a heating module under a multi-stage cascade configuration, (b) is a first stage heating module under a multi-stage cascade configuration, and (c) is a highest stage heating module under a multi-stage cascade configuration.

[0035] Figure 5 Figure 5 is a schematic diagram of a cooling module under a multi-stage cascade configuration, wherein (a) is a cooling module under a multi-stage cascade configuration, (b) is a first stage cooling module under a multi-stage cascade configuration, and (c) is a highest stage cooling module under a multi-stage cascade configuration.

[0036] Figure 6 Figure 6 is a schematic diagram of a pure drive module under a single-stage compression intermediate suction and exhaust configuration, wherein (a) is a pure drive module under a single-stage compression intermediate suction and exhaust configuration, and (b) is a preferred economizer pure drive module under a single-stage compression intermediate suction and exhaust configuration.

[0037] Figure 7Schematic diagram of heating module under single-stage compression intermediate suction and exhaust configuration, wherein (a) is a heating module under single-stage compression intermediate suction and exhaust configuration, (b) is a preferred liquid injection cooling heating module under single-stage compression intermediate suction and exhaust configuration, (c) is the highest stage heating module under single-stage compression intermediate suction and exhaust configuration, (d) is the first stage heating module under single-stage compression intermediate suction and exhaust configuration, (e) is a preferred economical first stage heating module under single-stage compression intermediate suction and exhaust configuration.

[0038] Figure 8 Schematic diagram of cooling module under single-stage compression intermediate suction and exhaust configuration, wherein (a) is a cooling module under single-stage compression intermediate suction and exhaust configuration, (b) is a first stage cooling module under single-stage compression intermediate suction and exhaust configuration, (c) is the highest stage cooling module under single-stage compression intermediate suction and exhaust configuration.

[0039] Figure 9 Schematic diagram of refrigeration / heat pump system constructed when the driving stage number of multi-stage compression configuration is 2, wherein (a) has a heating stage number of 1 and a cooling stage number of 1; (b) has a heating stage number of 2 and a cooling stage number of 1; (c) has a heating stage number of 1 and a cooling stage number of 2.

[0040] Figure 10 Schematic diagram of refrigeration / heat pump system constructed when the driving stage number of multi-stage compression configuration is 3, wherein (a) has a heating stage number of 1 and a cooling stage number of 1; (b) has a heating stage number of 2 and a cooling stage number of 1; (c) has a heating stage number of 1 and a cooling stage number of 2; (d) has a heating stage number of 3 and a cooling stage number of 1; (e) has a heating stage number of 2 and a cooling stage number of 2; (f) has a heating stage number of 1 and a cooling stage number of 3.

[0041] Figure 11 Schematic diagram of refrigeration / heat pump system constructed when the driving stage number of multi-stage compression configuration is 2, wherein (a) has a heating stage number of 1 and a cooling stage number of 1, (b) has a heating stage number of 2 and a cooling stage number of 1, (c) has a heating stage number of 1 and a cooling stage number of 2.

[0042] Figure 12 Schematic diagram of refrigeration / heat pump system constructed when the driving stage number of multi-stage compression configuration is 3, wherein (a) has a heating stage number of 1 and a cooling stage number of 1; (b) has a heating stage number of 2 and a cooling stage number of 1; (c) has a heating stage number of 1 and a cooling stage number of 2; (d) has a heating stage number of 3 and a cooling stage number of 1; (e) has a heating stage number of 2 and a cooling stage number of 2; (f) has a heating stage number of 1 and a cooling stage number of 3.

[0043] Figure 13The refrigeration / heat pump system schematic diagram constructed for single-stage compression intermediate suction and exhaust configuration driving stage number is 2, wherein the heating stage number of (a) is 1, and the cooling stage number is 1; the heating stage number of (b) is 2, and the cooling stage number is 1; the heating stage number of (c) is 1, and the cooling stage number is 2.

[0044] Figure 14 The refrigeration / heat pump system schematic diagram constructed for single-stage compression intermediate suction and exhaust configuration driving stage number is 3, wherein the heating stage number of (a) is 1, and the cooling stage number is 1; the heating stage number of (b) is 2, and the cooling stage number is 1; the heating stage number of (c) is 1, and the cooling stage number is 2; the heating stage number of (d) is 3, and the cooling stage number is 1; the heating stage number of (e) is 2, and the cooling stage number is 2; the heating stage number of (f) is 1, and the cooling stage number is 3.

[0045] Figure 15 The refrigeration / heat pump system schematic diagram of different heating and cooling stage number combinations under three-stage driving.

[0046] Figure 16 The refrigeration / heat pump system schematic diagram of combination relationship under three dimensions of driving, cooling and heating stage number

[0047] Figure 17 The refrigeration / heat pump system temperature-entropy diagram of different heating stage numbers under single-stage cooling.

[0048] Figure 18 The refrigeration / heat pump system temperature-entropy diagram of different cooling stage numbers under single-stage heating. DETAILED DESCRIPTION

[0049] The application will be further described below with reference to the drawings.

[0050] Reference Figures 1-18 A refrigeration / heat pump system based on multi-dimensional construction approximating the Lorentz cycle, according to the temperature conditions of the heated and cooled medium and the temperature change conditions thereof in the heat exchange process, different driving stage numbers d, heating stage numbers h, cooling stage numbers c and configuration forms f are set, that is, the refrigeration / heat pump cycle is constructed from four structural dimensions, which needs to meet the following requirements.

[0051] d≥h≥1 and d≥c≥1 and d≥1 and h+c≤d+1

[0052] In the driving dimension, the number d represents the number of times the refrigerant is pressurized by the compressor, and one pure driving module, one heating module, and one cooling module can provide one level of driving; in the heating dimension, the number h represents the number of times the heated medium is heated by the condenser, and one heating module can provide one level of heating; in the cooling dimension, the number c represents the number of times the cooled medium is cooled by the evaporator, and one cooling module can provide one level of cooling; the configuration form f is divided into multi-stage compression configuration, multi-stage cascade configuration, and single-stage compression intermediate suction and exhaust configuration, the serial numbers of the modules are numbered from 1 in the order of the temperature position of the modules from low to high, and the c cooling modules, r pure driving modules, and h heating modules are connected in a set rule, so that a refrigeration / heat pump cycle with d levels of driving, c levels of cooling, and h levels of heating is obtained.

[0053] Further, when h+c>d, the first cooling module and the first heating module partially overlap, and the repeated driving links and throttling devices are deleted.

[0054] Under the same configuration, when the c cooling modules, r pure driving modules, and h heating modules are connected, starting from the first cooling module, the high-temperature refrigerant outlet of the lower-level module and the high-temperature refrigerant inlet are connected to the low-temperature refrigerant inlet of the higher-level module and the low-temperature refrigerant outlet, respectively; the first inlet and the second inlet of the cooling medium of the lower-level cooling module are connected to the first outlet and the second outlet of the cooling medium of the higher-level cooling module, respectively; the first outlet and the second outlet of the heating medium of the lower-level heating module are connected to the first inlet and the second inlet of the heating medium of the higher-level heating module, respectively; all the cooling modules are connected first, then the pure driving modules, and finally the heating modules, until the connection of the hth heating module is completed.

[0055] Through step-by-step heating and step-by-step cooling, the total temperature rise dT h of the heated medium and the total temperature drop dT c of the cooled medium are distributed to each level, i.e., the temperature rise or drop of the heat source between each level is reduced; then, the mixed working medium with different components and concentrations and the temperature slip dT r of the two-phase region are further matched with the temperature rise or drop of each level of heating or cooling, i.e., approximately satisfy:

[0056] dTr×h=dT h and dTr×c=dT c

[0057] Due to the temperature slip dT rThe temperature glide at different temperature levels is not exactly the same, so the above formula is only an approximate relationship, which can approximate the Lorentz cycle on both the heating side and the cooling side, reduce the heat transfer temperature difference of each stage working fluid and heating medium and cooling medium, and improve the energy efficiency. Of course, using different components and concentrations of mixed working fluids to achieve temperature glide and heat source temperature matching to reduce the heat transfer temperature difference may reduce the cycle performance of the mixed working fluid, and the total energy efficiency may not be improved. Therefore, the total energy efficiency of the system should be taken as the target, and the heating and cooling stages, mixed working fluid components and concentrations (temperature glide) should be optimized. In addition, the form of cascade coupling heating and cooling reduces the heat transfer temperature difference of each stage, thereby reducing the requirements for the temperature glide characteristics of the working fluid; and the matching through the temperature glide of the working fluid also increases the flexibility of the selection of the heating and cooling stages, which increases the range of optimization parameters and provides the possibility for higher overall energy efficiency. In addition, pure refrigerant and zero temperature change can be regarded as a special case of the above process.

[0058] wherein, Figure 1 In (a), the pure driving module under the multi-stage compression configuration and the multi-stage cascade configuration includes a compressor 1 and a throttling device 2, the inlet of the compressor 1 is the low-temperature refrigerant inlet of the driving module, the outlet of the compressor 1 is the high-temperature refrigerant outlet of the driving module, the inlet of the throttling device 2 is the high-temperature refrigerant inlet of the driving module, and the outlet of the throttling device 2 is the low-temperature refrigerant outlet of the driving module.

[0059] Figure 1 In (b), the pure driving module under the preferred multi-stage compression configuration is added with an economizer 3 and an auxiliary throttling device 2, the high-temperature refrigerant inlet of the module is divided into two paths, one path is connected with the first inlet of the economizer 3, and the other path passes through the auxiliary throttling device 2 and is connected with the second inlet of the economizer 3, the first outlet of the economizer 3 passes through a throttling device 4 to become the low-temperature refrigerant outlet of the module, and the second outlet of the economizer 3 is connected with the inlet of the compressor 1.

[0060] Figure 2In (a), the heating module under the multi-stage compression configuration comprises a compressor 1, a condenser 3, an auxiliary heating heat exchanger 4, a throttling device and a flow regulating valve 2. The outlet of the compressor 1 is divided into two paths. One path passes through the flow regulating valve 2 to serve as the high-temperature refrigerant outlet of the heating module, and the other path enters the refrigerant inlet of the condenser 3. The refrigerant outlet of the condenser 3 is divided into two paths. One path is the high-temperature refrigerant inlet, and the other path is connected to the refrigerant inlet of the auxiliary heating heat exchanger 4. The refrigerant outlet of the auxiliary heating heat exchanger 4 is connected to the inlet of the throttling device 5. The outlet of the throttling device 5 is the low-temperature refrigerant outlet of the heating module. The inlet of the compressor 1 is the low-temperature refrigerant inlet of the heating module. The heating medium inlet of the auxiliary heating heat exchanger 4 is the first heating medium inlet of the heating module. The heating medium outlet of the auxiliary heating heat exchanger 4 is combined with the second heating medium inlet of the heating module, and then divided into two paths. One path is the first heating medium outlet of the heating module, and the other path is connected to the heating medium inlet of the condenser 3. The heating medium outlet of the condenser 3 is the second heating medium outlet of the heating module.

[0061] Figure 2 In (b), the heating module under the preferred multi-stage compression configuration is preferably used. The outlet of the compressor 1 is not divided into two paths, but is directly connected to the refrigerant inlet of the condenser 3. The condenser 3 has an exhaust cooling outlet. The exhaust cooling outlet passes through the refrigerant flow regulating valve 2 to become the high-temperature refrigerant outlet of the module. This preferred scheme is applicable to all heating modules except the highest heating module.

[0062] Figure 2 In (c), the highest heating module under the multi-stage compression configuration is the highest heating module. Compared with the ordinary heating module, the heating module has no heating medium first outlet, high-temperature refrigerant inlet, high-temperature refrigerant outlet and refrigerant flow regulating valve of the heating module. The second heating medium outlet is the total outlet of the heating medium of the refrigeration / heat pump system.

[0063] Figure 2 In (d), the first-stage heating module under the multi-stage compression configuration has no auxiliary heating heat exchanger and first heating medium inlet of the heating module compared with the ordinary heating module. The second heating medium inlet of the heating module passes through a pump or a fan and is then divided into two paths. The second heating medium inlet is the total inlet of the heating medium of the refrigeration / heat pump system.

[0064] Figure 2The middle (e) is the preferred economical first stage heating module under the multi-stage compression configuration, an economizer 5 and an auxiliary throttling device 4 are added, the high temperature refrigerant inlet of the module is divided into two ways after being combined with the refrigerant outlet of the condenser 3, one way is connected with the first inlet of the economizer 5, the other way is connected with the second inlet of the economizer 5 through the auxiliary throttling device 4, the first outlet of the economizer 5 becomes the low temperature refrigerant outlet of the module through the throttling device 6, and the second outlet of the economizer 5 is connected with the inlet of the compressor 1.

[0065] Referring to Figure 3 The middle (a) is a cooling module under the multi-stage compression configuration, including a compressor 1, an evaporator 3, an auxiliary cooling heat exchanger 5, a throttling device 2, a refrigerant flow regulating valve 4, and a cooling medium flow regulating valve 6, the high temperature refrigerant inlet of the cooling module is divided into two ways through the throttling device 2, one way is the low temperature refrigerant outlet of the cooling module, the other way is connected with the refrigerant inlet of the evaporator 3, the refrigerant outlet of the evaporator 3 is divided into two ways through the refrigerant flow regulating valve 4, one way is the low temperature refrigerant inlet, the other way is connected with the refrigerant inlet of the auxiliary cooling heat exchanger 5, the refrigerant outlet of the auxiliary cooling heat exchanger 5 is connected with the inlet of the compressor, the outlet of the compressor 1 is the high temperature refrigerant outlet of the heating module, the first inlet of the cooling medium of the cooling module is connected with the cooling medium inlet of the auxiliary cooling heat exchanger 5 through the cooling medium flow regulating valve 6, the cooling medium outlet of the auxiliary cooling heat exchanger 5 is combined with the second inlet of the cooling medium of the cooling module, and is divided into two ways again, one way is the first outlet of the cooling medium of the cooling module, and the other way is connected with the second outlet of the cooling medium of the cooling module through the evaporator 3.

[0066] Figure 3 The middle (b) is the first stage cooling module under the multi-stage compression configuration, since it is the lowest cooling stage, compared with the ordinary cooling module, the first outlet of the cooling medium of the cooling module, the low temperature refrigerant inlet of the cooling module, the low temperature refrigerant outlet of the cooling module, and the refrigerant flow regulating valve are not provided, and the second outlet of the cooling medium is the total outlet of the cooling medium of the refrigeration / heat pump system.

[0067] Figure 3 The middle (c) is the highest stage cooling module under the multi-stage compression configuration, compared with the ordinary cooling module, the auxiliary cooling heat exchanger and the first inlet of the cooling medium of the cooling module are not provided, the refrigerant outlet of the evaporator 3 is directly connected with the inlet of the compressor 5, and the second inlet of the cooling medium of the cooling module is divided into two ways again through a pump or a fan, and the two ways are the total inlets of the cooling medium of the refrigeration / heat pump system.

[0068] Referring to Figure 4In (a), the heating module is in a multi-stage cascade configuration. One cascade heat exchanger 7 is added to the multi-stage compression configuration heating module. The changes in the pipeline are as follows: the outlet of the throttling device 6 is connected to the first inlet of the cascade heat exchanger 7, the first outlet of the cascade heat exchanger 7 is connected to the inlet of the compressor 1, the second inlet of the cascade heat exchanger 7 is the low-temperature refrigerant inlet of the module, and the second outlet of the cascade heat exchanger 7 is the low-temperature refrigerant outlet of the module. Figure 4 In (b) and (c), the first-stage heating module and the highest-stage heating module in a multi-stage cascade configuration are respectively provided, and the same changes are made.

[0069] Referring to Figure 5 In (a), the cooling module is in a multi-stage cascade configuration. One cascade heat exchanger 6 is added to the multi-stage compression configuration cooling module. The changes in the pipeline are as follows: the outlet of the throttling device 2 is divided into two paths, one of which is connected to the refrigerant inlet of the evaporator 3, and the other is connected to the first inlet of the cascade heat exchanger 6; the refrigerant outlet of the evaporator 3 is connected to the refrigerant inlet of the auxiliary cooling heat exchanger 5 through the refrigerant flow regulating valve 4 and the first outlet of the cascade heat exchanger 6; the second inlet of the cascade heat exchanger 6 is connected to the low-temperature refrigerant inlet of the module, and the second outlet of the cascade heat exchanger 6 is connected to the low-temperature refrigerant outlet of the module. Figure 5 In (b) and (c), the first-stage cooling module and the highest-stage cooling module in a multi-stage cascade configuration are respectively provided, and the same changes are made.

[0070] Referring to Figure 6 In (a), the pure drive module is in a single-stage compression intermediate suction and exhaust configuration. The difference between the pure drive module in the single-stage compression intermediate suction and exhaust configuration and the pure drive module in the multi-stage compression and multi-stage cascade configurations is that the compressor is replaced by a compression interval 1. The original compressor outlet becomes the end point of the compression interval 1, and the original compressor inlet becomes the starting point of the compression interval 1.

[0071] Figure 6 In (b), the preferred economizer pure drive module is in a single-stage compression intermediate suction and exhaust configuration. The preferred economizer pure drive module in the single-stage compression intermediate suction and exhaust configuration is similar to the preferred economizer pure drive module in the multi-stage compression configuration, except that the compressor is replaced by a compression interval 1. The original compressor outlet becomes the end point of the compression interval 1, and the original compressor inlet becomes the starting point of the compression interval 1.

[0072] Referring to Figure 7 In (a), the heating module is in a single-stage compression intermediate suction and exhaust configuration. The compressor in the multi-stage compression configuration is replaced by a compression interval 1. The original compressor outlet becomes the end point of the compression interval 1, and the original compressor inlet becomes the starting point of the compression interval 1.

[0073] Figure 7(b) is the preferred liquid injection cooling heating module under the single-stage compression intermediate suction and exhaust configuration. Based on the heating module of the single-stage compression intermediate suction and exhaust configuration, a liquid injection throttle valve 4 is added. The inlet of the liquid injection throttle valve 4 is connected to the refrigerant outlet of the auxiliary heating heat exchanger 3, and the outlet of the liquid injection throttle valve 4 is connected to the starting point of the compression section 1.

[0074] Figure 7 (c) and (d) are the highest stage heating module and the first stage heating module under the single-stage compression intermediate suction and exhaust configuration, respectively, which are the same changes as Figure 7 (a).

[0075] Figure 7 (e) is the preferred economical first stage heating module under the single-stage compression intermediate suction and exhaust configuration, which is similar to the preferred economical first stage heating module under the corresponding preferred multi-stage compression configuration, except that the compressor is replaced by the compression section 1, and the original compressor outlet becomes the end point of the compression section 1, and the original compressor inlet becomes the starting point of the compression section 1.

[0076] Referring to Figure 8 (a) is the cooling module under the single-stage compression intermediate suction and exhaust configuration. Based on the cooling module of the multi-stage compression configuration, the compressor is replaced by the compression section 1, and the original compressor outlet becomes the end point of the compression section 1, and the original compressor inlet becomes the starting point of the compression section 1. The evaporator 3 refrigerant outlet is connected to the refrigerant inlet of the auxiliary cooling heat exchanger 4, and the refrigerant outlet of the auxiliary cooling heat exchanger 4 is connected to the starting point of the compression section 1. Figure 8 (b) and (c) are the first stage cooling module and the highest stage cooling module under the single-stage compression intermediate suction and exhaust configuration, respectively, which are the same changes.

[0077] Figures 6-8 In the modules under the single-stage compression intermediate suction and exhaust configuration shown, the compression section is represented by a dashed box, and the dashed box only represents the artificial division of the compression section inside the compressor, which has no actual meaning and does not represent the compression degree, which is determined according to the actual situation.

[0078] According to Figures 1-8 Different modules under different configurations are shown in Figures 9-14 The specific construction method, connection scheme and implementation are as follows:

[0079] Referring to Figure 9 The refrigeration / heat pump system shown is of the multi-stage compression configuration, and the drive stage number is 2, Figure 9 (a) (b) (c) heating stage number is 1, 2, 1, respectively, and cooling stage number is 1, 1, 2, respectively, which is all different combinations of heating and cooling stage numbers under the drive stage number of 2, from Figures 1-3The different modules in (e) are constructed according to the foregoing rules.

[0080] Referring to Figure 10 , the refrigeration / heat pump system is of a multi-stage compression configuration, and the number of driving stages is 3. The refrigeration / heat pump system is configured according to the following rules. Figure 10 The 3-stage driving, 2-stage heating, and 2-stage cooling in (e) is taken as an example, which is composed of a first-stage cooling module, a highest-stage cooling module, a first-stage heating module, and a highest-stage heating module. The high-temperature refrigerant inlet and the high-temperature refrigerant outlet of the first-stage cooling module are connected to the low-temperature refrigerant outlet and the low-temperature refrigerant inlet of the highest-stage cooling module, respectively. After removing the compressor and the throttling device of the highest-stage cooling module, the high-temperature refrigerant outlet and the high-temperature refrigerant inlet of the highest-stage cooling module are connected to the low-temperature refrigerant inlet and the low-temperature refrigerant outlet of the first-stage heating module, respectively. The high-temperature refrigerant outlet and the high-temperature refrigerant inlet of the first-stage heating module are connected to the low-temperature refrigerant inlet and the low-temperature refrigerant outlet of the highest-stage heating module, respectively. The cooling medium first inlet and the cooling medium second inlet of the first-stage cooling module are connected to the cooling medium first outlet and the cooling medium second outlet of the highest-stage cooling module, respectively. The heating medium first outlet and the heating medium second outlet of the first-stage heating module are connected to the heating medium first outlet and the heating medium second inlet of the highest-stage heating module, respectively, so that the circulation structure shown in (e) is obtained. Figure 10 The circulation structure shown in (e). Figure 10 The refrigeration / heat pump system structure shown in (e) is all the different combinations of the number of heating stages and the number of cooling stages when the number of driving stages is 3, which is composed of different modules in (e), and the construction method is similar to that of the circulation structure shown in (e). Figures 1-3 The different modules in (e) are constructed according to the foregoing rules.

[0081] Figure 10The working process of the scheme shown in (e) is as follows: the refrigerant, after absorbing heat from the low-temperature heat source in the evaporator 3213 of the first-stage cooling module, enters the auxiliary cooling heat exchanger 3212 to further absorb heat from the low-temperature heat source and becomes a superheated gas, and then enters the compressor 3211 of the first-stage cooling module, is compressed to the second evaporation pressure, and is combined with the gaseous refrigerant from the evaporator 324 of the highest-stage cooling module to enter the compressor 321 of the first-stage heating module, is compressed to the first condensation pressure, and then enters the condenser 322 of the first-stage heating module to release part of the heat to the high-temperature heat source, and the temperature is lowered, and then part of the refrigerant enters the highest-stage heating module through the flow regulating valve 326 to prevent the exhaust temperature of the compressor of the next module from being too high, and the other part continues to release heat in the condenser 322, the refrigerant entering the highest-stage heating module first enters the compressor 327 of the module, is compressed to the second condensation pressure, and then enters the condenser 328 of the module to release heat to the high-temperature heat source and becomes a subcooled liquid, and then enters the auxiliary heating heat exchanger 329 of the module to exchange heat with the high-temperature heat source again, becomes a supercooled liquid, and then is throttled by the throttling device 3210 of the module to become the refrigerant of the first condensation pressure, enters the first-stage heating module, and is combined with the refrigerant released from the condenser 322 of the first-stage heating module, and then is throttled by the throttling device 323 of the module to become the refrigerant of the first evaporation pressure, and then enters the highest-stage cooling module, and is divided into two parts, one part enters the evaporator 324 of the highest-stage cooling module to absorb heat from the low-temperature heat source and becomes a gas, and then is combined with the refrigerant from the high-temperature refrigerant outlet of the first-stage cooling module through the flow regulating valve 325; the other part enters the first-stage cooling module from the high-temperature refrigerant inlet of the first-stage cooling module, is throttled by the throttling device 3214 of the module to become the refrigerant of the first evaporation pressure, enters the evaporator 3213 of the module to absorb heat from the low-temperature heat source and becomes a gas, and then enters the auxiliary cooling heat exchanger 3212, and so on. The cooling medium first enters the highest-stage cooling module from the cooling medium inlet, is accelerated by the pump or fan 3216, and is divided into two parts, one part enters the evaporator 324 of the module to be cooled by the refrigerant, and then enters the second cooling medium inlet of the first-stage cooling module, and the other part directly enters the first cooling medium inlet of the first-stage cooling module, is cooled by the refrigerant in the auxiliary cooling heat exchanger 3212 of the first-stage cooling module after passing through the flow regulating valve 3217, and then the two parts of the cooling medium are combined and enter the evaporator 3213 of the first-stage cooling module to be cooled again, and finally are discharged from the cooling medium outlet at the final cooling temperature.The heating medium first enters the first stage heating module through the first heating medium inlet, is accelerated by the pump or fan 3215, and is then divided into two parts. One part enters the condenser 322 below the module and is heated by the refrigerant, and then enters through the second heating medium inlet of the highest stage heating module. The other part directly enters through the first heating medium inlet of the highest stage heating module, and the auxiliary heating heat exchanger 329 of the highest stage heating module absorbs the heat of the refrigerant to be heated. Then the two parts of the heating medium are combined and enter the condenser 328 of the highest stage heating module to be heated again. Finally, the heating medium is discharged at the final heating temperature through the heating medium outlet. Figure 10 The working processes of the remaining schemes are similar to that of scheme (e).

[0082] Referring to Figure 11 , the refrigeration / heat pump system is of a multi-stage cascade configuration, and the driving stage number is 2, Figure 11 , the heating stage number is 1, 2, and 1, and the cooling stage number is 1, 1, and 2, which is a combination of all different heating and cooling stage numbers when the driving stage number is 2, and is composed of Figure 1 , (a), Figure 4 , and Figure 5 are constructed according to the foregoing rules.

[0083] Referring to Figure 12 , the refrigeration / heat pump system is of a multi-stage cascade configuration, and the driving stage number is 3, Figure 12 , for example, the 3-stage driving, 2-stage heating, and 2-stage cooling, which is composed of the first stage cooling module, the highest stage cooling module, the first stage heating module, and the highest stage heating module. The high-temperature refrigerant inlet and the high-temperature refrigerant outlet of the first stage cooling module are connected with the low-temperature refrigerant outlet and the low-temperature refrigerant inlet of the highest stage cooling module, respectively. After removing the compressor and the throttling device of the highest stage cooling module, the high-temperature refrigerant outlet and the high-temperature refrigerant inlet of the highest stage cooling module are connected with the low-temperature refrigerant inlet and the low-temperature refrigerant outlet of the first stage heating module, respectively. The high-temperature refrigerant outlet and the high-temperature refrigerant inlet of the first stage heating module are connected with the low-temperature refrigerant inlet and the low-temperature refrigerant outlet of the highest stage heating module, respectively. The first heating medium outlet and the second heating medium outlet of the first stage heating module are connected with the first heating medium outlet and the second heating medium inlet of the highest stage heating module, respectively, so as to obtain the circulation structure shown in (e). Figure 12 The refrigeration / heat pump system structure shown is all different combinations of heating and cooling stage numbers when the driving stage number is 3, which is composed of Figure 1 , (a), Figure 4 , and Figure 5The modules are different from each other, and some modules are removed from the relevant components, but the construction method is similar to the loop structure shown in (e).

[0084] Figure 12The working process of the scheme shown in (e) is as follows: the refrigerant absorbs heat of the low-temperature heat source in the evaporator 3216 of the first cooling module, enters the auxiliary cooling heat exchanger 3215 to further absorb heat of the low-temperature heat source and becomes a superheated gas, then enters the compressor 3214 of the first cooling module, is compressed to the second evaporation pressure, enters the highest cooling module from the low-temperature refrigerant inlet, enters the cascade heat exchanger 3213 under the highest cooling module to release heat, enters the first cooling module from the high-temperature refrigerant inlet after the heat release is completed, is throttled to the first evaporation pressure by the throttling device 3217 of the first cooling module, and enters the evaporator 3216 to absorb heat; the other path of the refrigerant in the cascade heat exchanger 3213 of the highest cooling module becomes gaseous after absorbing heat and is combined with the gaseous refrigerant from the evaporator 325 of the highest cooling module, enters the compressor 321 of the first heating module from the low-temperature refrigerant inlet and is compressed to the first condensation pressure, then is divided into two parts, one part enters the condenser 323 of the first heating module and releases heat to the high-temperature heat source to become a saturated liquid, then is combined with the low-temperature refrigerant from the highest heating module and is throttled to the second evaporation pressure by the throttling device 324 of the first heating module, and then is divided into two parts again, one part enters the cascade heat exchanger 3213 of the first heating module to absorb heat, and the other part enters the evaporator 325 of the first heating module to absorb heat of the low-temperature heat source; the other part of the refrigerant discharged from the compressor 321 of the first heating module enters the cascade heat exchanger 328 of the highest heating module from the low-temperature refrigerant inlet through the flow regulating valve 327 of the first heating module, enters the highest heating module from the high-temperature refrigerant inlet after releasing heat to the other path of the refrigerant in the cascade heat exchanger 328, the other path of the refrigerant in the cascade heat exchanger 328 of the highest heating module becomes gaseous after absorbing heat, enters the compressor 329 of the highest heating module and is compressed to the second condensation pressure, then enters the condenser 3210 to release heat to the high-temperature heat source to become a saturated liquid, then enters the auxiliary heating heat exchanger 3211 under the highest heating module to exchange heat with the high-temperature heat source again, becomes a supercooled liquid, then is throttled by the throttling device 3212 of the highest heating module and enters the cascade heat exchanger 328 to absorb heat, and so on. The cooling medium first enters the highest cooling module from the cooling medium inlet, is accelerated by the pump or fan 3219, is divided into two parts, one part enters the evaporator 325 under the highest cooling module and is cooled by the refrigerant, then enters the second cooling medium inlet of the first cooling module, and the other part directly enters the first cooling medium inlet of the first cooling module, is cooled by the refrigerant after entering the auxiliary cooling heat exchanger 3215 of the first cooling module through the flow regulating valve 3220, then the two parts of the cooling medium are combined and enter the evaporator 3216 of the first cooling module to be cooled again, and finally are discharged from the cooling medium outlet at the final cooling temperature.The heating medium first enters the first stage heating module through the first heating medium inlet, is accelerated by the pump or fan 3218, and is then divided into two parts. One part enters the condenser 323 below the module and is heated by the refrigerant, and then enters through the second heating medium inlet of the highest stage heating module. The other part directly enters through the first heating medium inlet of the highest stage heating module, and the auxiliary heating heat exchanger 3211 of the highest stage heating module absorbs the heat of the refrigerant to be heated. Then the two parts of the heating medium are combined and enter the condenser 3210 of the highest stage heating module to be heated again. Finally, the heating medium is discharged at the final heating temperature through the heating medium outlet. Figure 12 The working processes of the remaining schemes are similar to that of scheme Figure 12 The working process of scheme (e) is similar.

[0085] Referring to Figure 13 , the refrigeration / heat pump system is a single-stage compression intermediate suction and exhaust configuration, and the driving stage number is 2, Figure 13 , the heating stage number is 1, 2, and 1, respectively, and the cooling stage number is 1, 1, and 2, respectively. It is a combination of all different heating and cooling stage numbers under the condition that the driving stage number is 2, which is constructed by different modules in Figures 6-8 .

[0086] Referring to Figure 14 , the refrigeration / heat pump system is a single-stage compression intermediate suction and exhaust configuration, and the driving stage number is 3. Taking Figure 14 (e) as an example, the 3-stage driving, 2-stage heating, and 2-stage cooling are composed of the first stage cooling module, the highest stage cooling module, the first stage heating module, and the highest stage heating module. The high-temperature refrigerant inlet of the first stage cooling module and the end point of the compression interval are connected with the low-temperature refrigerant outlet of the highest stage cooling module and the start point of the compression interval, respectively. After removing the compression interval and the throttling device of the highest stage cooling module, the start point of the compression interval and the high-temperature refrigerant inlet of the highest stage cooling module are connected with the start point of the compression interval and the low-temperature refrigerant outlet of the first stage heating module, respectively. The end point of the compression interval and the high-temperature refrigerant inlet of the first stage heating module are connected with the start point of the compression interval and the low-temperature refrigerant outlet of the highest stage heating module, respectively. The first heating medium outlet and the second heating medium outlet of the first stage heating module are connected with the first heating medium outlet and the second heating medium inlet of the highest stage heating module, respectively. Thus, the cycle structure shown in Figure 14 (e) can be obtained. Figure 12 The refrigeration / heat pump system structure shown is all different combinations of heating and cooling stage numbers when the driving stage number is 3, which is composed of different modules in Figures 6-8 , and the construction method is similar to that of the cycle structure shown in (e).

[0087] Figure 14The working process of the scheme shown in (e) is as follows: the refrigerant absorbs heat of the low-temperature heat source in the evaporator 3210 of the first-stage cooling module, enters the auxiliary cooling heat exchanger 329 to further absorb heat of the low-temperature heat source and becomes a superheated gas, then enters the compression section 321-1 of the first-stage cooling module, is compressed to the second evaporation pressure, and enters the compression section 321-2 of the first-stage heating module together with the gaseous refrigerant from the evaporator 324 of the highest-stage cooling module, is compressed to the first condensation pressure, and at the end point of the compression section 321-2 of the first-stage heating module, part of the refrigerant enters the condenser 322 below the module to release heat to the high-temperature heat source, and the other part of the refrigerant mixes with part of the refrigerant from the highest-stage heating module, enters the compression section 321-3 of the highest-stage heating module, is compressed to the second condensation pressure, then enters the condenser 325 of the module to release heat to the high-temperature heat source and becomes a subcooled liquid, then enters the auxiliary heating heat exchanger 326 below the module to exchange heat with the high-temperature heat source again and becomes a supercooled liquid, then is divided into two parts again, one part is throttled by the liquid injection throttling valve 327, mixes with the refrigerant at the end point of the compression section 321-1 of the first-stage heating module, is instantaneously vaporized, is cooled together with the refrigerant from the highest-stage heating module, and enters the compression section 321-3 of the highest-stage heating module; the other part of the supercooled liquid is throttled by the throttling device 328 of the highest-stage heating module, enters the first-stage heating module as the refrigerant at the first condensation pressure, merges with the refrigerant that has completed heat release in the condenser 322 of the first-stage heating module, is throttled by the throttling device 323 below the module to become the refrigerant at the first evaporation pressure, and then enters the highest-stage cooling module, is divided into two parts again, one part enters the evaporator 324 of the highest-stage cooling module to absorb heat of the low-temperature heat source and becomes a gas, and then mixes with the refrigerant from the end point of the compression section 321-1 of the first-stage cooling module; the other part enters the first-stage cooling module from the high-temperature refrigerant inlet of the first-stage cooling module, is throttled by the throttling device 3211 below the module to become the refrigerant at the first evaporation pressure, enters the evaporator 3210 of the module to absorb heat of the low-temperature heat source and becomes a gas, then enters the auxiliary cooling heat exchanger 329, and the cycle continues. The cooling medium first enters the highest-stage cooling module from the cooling medium inlet, is accelerated by the pump or fan 3213, is divided into two parts, one part enters the evaporator 324 below the module to be cooled by the refrigerant, then enters the first-stage cooling module from the second cooling medium inlet of the first-stage cooling module, and the other part directly enters the first-stage cooling module from the first cooling medium inlet of the first-stage cooling module, is cooled by the refrigerant in the auxiliary cooling heat exchanger 329 of the first-stage cooling module after passing through the flow regulating valve 3214, then the two parts of the cooling medium are combined and enter the evaporator 3210 of the first-stage cooling module to be cooled again, and finally are discharged from the cooling medium outlet at the final cooling temperature.The heating medium first enters the first stage heating module through the first heating medium inlet, is accelerated by the pump or fan 3212, and is then divided into two parts. One part enters the condenser 322 below the module and is heated by the refrigerant, and then enters through the second heating medium inlet of the highest stage heating module. The other part directly enters through the first heating medium inlet of the highest stage heating module, the auxiliary heating heat exchanger 326 of the highest stage heating module absorbs the heat of the refrigerant to be heated, and then the two parts of the heating medium are combined and enter the condenser 325 of the highest stage heating module to be heated again, and finally are discharged at the final heating temperature through the heating medium outlet. Figure 14 The working process of the remaining schemes is as shown in the scheme Figure 12 The working process of (e) is similar.

[0088] Figure 13 And 14 The compression interval of the single-stage compression intermediate suction and exhaust configuration is represented by a dashed box, and the dashed box only represents an artificial division of the compression section, and the size has no actual meaning. The compression degree is determined according to the actual situation.

[0089] Figure 15 The refrigeration / heat pump system is a combination of heating stage number h and cooling stage number c in two dimensions when the driving stage number d is 3 (red dot in the figure), and the relationship satisfies 3≥h≥1 and 3≥c≥1 and h+c≤4.

[0090] Figure 16 It is a combination of driving stage number d, heating stage number h and cooling stage number c in three different dimensions (red dot in the figure), and the relationship satisfies d≥h≥1 and d≥c≥1 and d≥1 and h+c≤d+1.

[0091] Figure 17 And 18 The temperature-entropy diagrams of the refrigeration / heat pump system under different heating stages and different cooling stages are shown in the figures, respectively. The dashed line in the figure represents the temperature glide of the two-phase region of the mixed working medium. By further matching the temperature glide of the refrigerant with the temperature rise or temperature drop of each stage of heating or cooling, i.e., combining the temperature glide of the refrigerant with the effects of staged heating or staged cooling, the hot side and the cooling side can be approximately approximated to the Lenz cycle, the heat transfer temperature difference between the working medium and the heating medium and the cooling medium of each stage can be reduced, and the energy efficiency can be improved.

[0092] The content described in the embodiments of the present specification is only a list of implementation forms of the inventive concept, and is 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 refrigeration / heat pump system based on a multidimensionally constructed approximation of the Lorentz cycle, characterized in that, Based on the different temperatures of the heated and cooled media and their temperature changes during the heat exchange process, different numbers of drive stages (d), heating stages (h), cooling stages (c), and configuration forms (f) are set, that is, the refrigeration / heat pump cycle is constructed from four structural dimensions, and the following requirements must be met: d≥h≥1 and d≥c≥1 and d≥1 and h+c≤d+1 In terms of the driving dimension, the number of stages d represents the number of times the refrigerant is pressurized by the compressor. One pure driving module, one heating module, and one cooling module can all provide one stage of driving. In terms of the heating dimension, the number of stages h represents the number of times the heated medium is heated by the condenser. One heating module can provide one stage of heating. In terms of the cooling dimension, the number of stages c represents the number of times the cooled medium is cooled by the evaporator. One cooling module can provide one stage of cooling. The configuration type f includes multi-stage compression configuration, multi-stage cascade configuration, and single-stage compression intermediate suction and exhaust configuration. The serial numbers of each module are numbered sequentially from 1 according to the temperature position of the module type from low to high. By connecting c cooling modules, r pure driving modules, and h heating modules in sequence according to the set rules, a refrigeration / heat pump cycle with d-stage driving, c-stage cooling, and h-stage heating can be obtained. When h+c>d, the c-th stage cooling module partially overlaps with the 1-th stage heating module, and the redundant drive links and throttling devices are removed; the pure drive modules of the multi-stage compression configuration and the multi-stage cascade configuration both include a compressor and a throttling device. The compressor inlet is the low-temperature refrigerant inlet of the drive module, the compressor outlet is the high-temperature refrigerant outlet of the drive module, the throttling device inlet is the high-temperature refrigerant inlet of the drive module, and the throttling device outlet is the low-temperature refrigerant outlet of the drive module. In a single-stage compression intermediate intake / exhaust configuration pure drive module, the compressor is replaced by a compression zone, which is an artificially divided segment of the compression process. The original compressor outlet becomes the end point of the compression zone, and the original compressor inlet becomes the beginning point. In a multi-stage compression configuration, the heating module includes a compressor, condenser, auxiliary heating heat exchanger, throttling device, and flow control valve. The compressor outlet is divided into two paths: one passes through the flow control valve to serve as the high-temperature refrigerant outlet for the heating module, and the other enters the refrigerant inlet of the condenser. The condenser's refrigerant outlet is also divided into two paths: one is the high-temperature refrigerant inlet, and the other connects to the refrigerant inlet of the auxiliary heating heat exchanger. The refrigerant outlet of the auxiliary heating heat exchanger is connected to the inlet of the throttling device, which serves as the low-temperature refrigerant outlet for the heating module. The compressor inlet is the heating module's... The low-temperature refrigerant inlet of the module and the heating medium inlet of the auxiliary heating heat exchanger are the first heating medium inlet of the heating module. The heating medium outlet of the auxiliary heating heat exchanger merges with the second heating medium inlet of the heating module and then splits into two paths. One path is the first heating medium outlet of the heating module, and the other path is connected to the heating medium inlet of the condenser. The heating medium outlet of the condenser is the second heating medium outlet of the heating module. The h-level heating module, which is the highest level heating module, has no first heating medium outlet, high-temperature refrigerant inlet, high-temperature refrigerant outlet, and refrigerant flow regulating valve compared to ordinary heating modules. The 1-level heating module has no auxiliary heating heat exchanger and no first heating medium inlet compared to ordinary heating modules. The second heating medium inlet of the heating module is split into two paths after passing through a pump or fan. The heating module in the multi-stage cascade configuration adds a cascade heat exchanger to the multi-stage compression configuration heating module. The changes in the pipeline are as follows: the outlet of the throttling device is connected to the first inlet of the cascade heat exchanger, the first outlet of the cascade heat exchanger is connected to the compressor inlet, the second inlet of the cascade heat exchanger is the low-temperature refrigerant inlet of the module, and the second outlet of the cascade heat exchanger is the low-temperature refrigerant outlet of the module. The same changes are made to the first-stage heating module and the highest-stage heating module. The heating module in the single-stage compression intermediate intake and exhaust configuration replaces the compressor with the compression zone in the multi-stage compression configuration. The original compressor outlet becomes the end point of the compression zone, and the original compressor inlet becomes the beginning point of the compression zone. The first-stage heating module and the highest-stage heating module also undergo the same changes. Cascade heating refers to the process where the heated medium is heated to a final high temperature step by step in the condenser of each heating module, while cascade cooling refers to the process where the cooled medium is cooled to a final low temperature step by step in the evaporator of each cooling module. Cascade heating and cascade cooling respectively increase the total temperature rise dT of the heated medium. h and the total temperature drop dT of the cooled medium c Distribute the heat to each stage, thus reducing the temperature rise or fall of the heat source between each stage; then, through the temperature glide dT of the two-phase region with different components and concentrations... r The mixed working fluid is further matched with the temperature rise or drop of each stage of heating or cooling, that is, approximately satisfying: dTr×h=dT h And dTr×c=dT c Due to the temperature slip dT of the mixed working fluid r The temperature glide is not exactly the same at different temperature positions, so the above formula is only an approximation. The approximation allows both the heating and cooling sides to approximate the Lorentz cycle, reducing the heat exchange temperature difference between each stage of the working fluid and the heating and cooling media. With the overall system energy efficiency as the target, the number of heating and cooling stages and the composition and concentration of the mixed working fluid are optimized.

2. A refrigeration / heat pump system based on a multi-dimensional construction approximating the Lorentz cycle as described in claim 1, characterized in that, The cooling module in a multi-stage compression configuration includes a compressor, evaporator, auxiliary cooling heat exchanger, throttling device, refrigerant flow regulating valve, and cooling medium flow regulating valve. The high-temperature refrigerant inlet of the cooling module is divided into two paths by the throttling device: one path becomes the low-temperature refrigerant outlet of the cooling module, and the other path connects to the refrigerant inlet of the evaporator. The refrigerant outlet of the evaporator is also divided into two paths by the refrigerant flow regulating valve: one path becomes the low-temperature refrigerant inlet, and the other path connects to the refrigerant inlet of the auxiliary cooling heat exchanger. The refrigerant outlet of the auxiliary heating heat exchanger is connected to the compressor inlet, and the compressor outlet becomes the high-temperature refrigerant outlet of the heating module. The first cooling medium inlet of the cooling module is connected to the cooling medium inlet of the auxiliary cooling heat exchanger via the cooling medium flow regulating valve. The cooling medium outlet of the auxiliary heat exchanger merges with the second cooling medium inlet of the cooling module, and then splits into two paths: one is the first cooling medium outlet of the cooling module, and the other is connected to the second cooling medium outlet of the cooling module via the evaporator. The first-stage cooling module, being the lowest cooling stage, lacks the first cooling medium outlet, the low-temperature refrigerant inlet, the low-temperature refrigerant outlet, and the refrigerant flow regulating valve compared to ordinary cooling modules. The c-stage cooling module, i.e., the highest temperature cooling module, lacks the auxiliary cooling heat exchanger and the first cooling medium inlet of the cooling module compared to ordinary cooling modules. The refrigerant outlet of the evaporator is directly connected to the compressor inlet, and the second cooling medium inlet of the cooling module is split into two paths via a pump or fan. The cooling module in the multi-stage cascade configuration adds a cascade heat exchanger to the multi-stage compression configuration cooling module. The pipeline changes are as follows: the outlet of the throttling device is divided into two paths, one connected to the refrigerant inlet of the evaporator and the other connected to the first inlet of the cascade heat exchanger. The refrigerant outlet of the evaporator merges with the first outlet of the cascade heat exchanger via the refrigerant flow regulating valve and is connected to the refrigerant inlet of the auxiliary cooling heat exchanger. The second inlet of the cascade heat exchanger is connected to the low-temperature refrigerant inlet of the module, and the second outlet of the cascade heat exchanger is connected to the low-temperature refrigerant outlet of the module. The same changes are made to the first-stage cooling module and the highest-stage cooling module. The cooling module in the single-stage compression intermediate intake and exhaust configuration is based on the multi-stage compression configuration cooling module by replacing the compressor with the compression zone. Accordingly, the original compressor outlet becomes the end point of the compression zone, the original compressor inlet becomes the start point of the compression zone, and the evaporator refrigerant outlet is connected to the refrigerant inlet of the auxiliary cooling heat exchanger, and the refrigerant outlet of the auxiliary cooling heat exchanger is connected to the start point of the compression zone. The first-stage cooling module and the highest-stage cooling module also undergo the same changes.

3. A refrigeration / heat pump system based on a multi-dimensional construction approximating the Lorentz cycle as described in claim 1, characterized in that, In a pure drive module with a multi-stage compression configuration, an economizer and an auxiliary throttling device are added. The high-temperature refrigerant inlet of the module is divided into two paths. One path is connected to the first inlet of the economizer, and the other path is connected to the second inlet of the economizer through the auxiliary throttling device. The first outlet of the economizer becomes the low-temperature refrigerant outlet of the module through the throttling device, and the second outlet of the economizer is connected to the compressor inlet. The pure drive module with single-stage compression intermediate intake and exhaust configuration adopts the same approach as the pure drive module with multi-stage compression configuration. The difference is that the compressor is replaced by the compression zone, and the original compressor outlet becomes the end point of the compression zone, while the original compressor inlet becomes the beginning point of the compression zone.

4. A refrigeration / heat pump system based on a multi-dimensional construction approximating the Lorentz cycle as described in claim 1, characterized in that, In the multi-stage compression heating module, the compressor outlet is not divided into two paths, but is directly connected to the refrigerant inlet of the condenser. The condensate gas has an additional exhaust cooling outlet, which becomes the high-temperature refrigerant outlet of the module after passing through the refrigerant flow regulating valve. This scheme is applicable to all heating modules except the highest-stage heating module. The first-stage heating module of the multi-stage compression configuration adds an economizer and an auxiliary throttling device. The high-temperature refrigerant inlet of the module merges with the refrigerant outlet of the condenser and then splits into two paths. One path is connected to the first inlet of the economizer, and the other path is connected to the second inlet of the economizer after passing through the auxiliary throttling device. The first outlet of the economizer becomes the low-temperature refrigerant outlet of the module after passing through the throttling device, and the second outlet of the economizer is connected to the compressor inlet.

5. A refrigeration / heat pump system based on a multidimensional construction approximating the Lorentz cycle as described in claim 4, characterized in that, The first-stage heating module of the single-stage compression intermediate suction and discharge configuration adopts the same method as the first-stage heating module. The difference is that the compressor is replaced by the compression zone. Accordingly, the original compressor outlet becomes the end point of the compression zone, and the original compressor inlet becomes the beginning point of the compression zone. The heating module of the single-stage compression intermediate suction and discharge configuration adds a liquid injection throttle valve. The inlet of the liquid injection throttle valve is connected to the refrigerant outlet of the auxiliary heating heat exchanger, and the outlet of the liquid injection throttle valve is connected to the beginning point of the compression zone.

6. A refrigeration / heat pump system based on a multi-dimensional construction approximating the Lorentz cycle as described in claim 1, characterized in that, In the same configuration, when connecting c cooling modules, r pure drive modules, and h heating modules, starting from the first-level cooling module, the high-temperature refrigerant outlet and high-temperature refrigerant inlet of the lower-level module are connected to the low-temperature refrigerant inlet and low-temperature refrigerant outlet of the higher-level module, respectively; the first and second inlets of the cooling medium of the lower-level cooling module are connected to the first and second outlets of the cooling medium of the higher-level cooling module, respectively; the first and second outlets of the heating medium of the lower-level heating module are connected to the first and second inlets of the heating medium of the higher-level heating module, respectively; all cooling modules are connected first, then the pure drive modules are connected, and finally the heating modules are connected, until the connection of the h-level heating modules is completed.

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