Generator-condenser heat exchange coupled automatic cascade absorption refrigeration cycle system

Abstract

The invention discloses a generator-condenser heat exchange coupled automatic cascade absorption type refrigeration cycle system. On the basis of an automatic cascade absorption refrigeration cycle, a non-azeotropic mixed refrigerant and an absorbent are adopted as working media. In the condenser, the mixed refrigerant can release a large amount of temperature slippage heat, the heat is effectively recycled by establishing a coupling heat exchange process between the generator and the condenser, the heating capacity of the generator in the system is reduced, and therefore the COP of circulation is improved. In addition, the system can adjust the refrigeration temperature by replacing the mixed refrigerant, the refrigeration temperature range can be from the room temperature to-100 DEG C or below, and the system has the advantage of being flexible in refrigeration temperature adjustment. Through reasonable arrangement of the generator-condenser coupling heat exchanger, the self-cascade absorption type refrigeration cycle configuration is optimized, the refrigeration efficiency is remarkably improved, the advantages of energy conservation and environmental protection are achieved, the wide refrigeration temperature adjusting range is provided, and the self-cascade absorption type refrigeration cycle system is suitable for various application scenes.

Description

Technical Field

[0001] The invention relates to the technical field of absorption refrigeration, and in particular to a self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling. Background Art

[0002] The widespread existence of low-grade waste heat and waste heat below 350°C that has not been effectively utilized is one of the main reasons for high energy consumption. Medium and low-grade thermal energy exists in a wide range of forms, mainly including industrial waste heat, ocean thermal energy, geothermal energy and solar thermal energy. At present, these low-grade thermal energies are usually directly discarded. The effective recycling of these low-grade thermal energies can significantly improve energy utilization efficiency and greatly reduce thermal pollution to the environment.

[0003] The absorption refrigeration cycle can effectively utilize low-grade heat and produce a cooling effect. The self-cascade absorption refrigeration cycle applies the self-cascade principle to the traditional single-stage absorption refrigeration cycle. Compared with the single-stage absorption refrigeration cycle, at the same heat source driving temperature and cooling temperature, the self-cascade absorption refrigeration cycle can achieve a lower refrigeration temperature and a wider temperature adjustment range, so the application scenarios and applicability to low-grade heat sources are significantly improved. For example, it provides a low-temperature pre-cooling temperature for the liquefaction of clean energy gases - hydrogen and natural gas, thereby reducing the specific power consumption of the liquefaction process and promoting the development of clean energy.

[0004] However, although the self-cascade process can achieve a lower refrigeration temperature, since part of the refrigerant's cold capacity is used for self-precooling inside the cycle, the refrigeration coefficient of performance (COP) is significantly reduced. Therefore, the self-cascade absorption refrigeration cycle urgently needs to break through the performance bottleneck of low COP.

[0005] For absorption refrigeration cycles, since the heat emitted by the absorption process overlaps with the solution heating temperature zone, an effective way to improve COP is to establish a heat coupling process between the generator and the absorber, namely Generator-Absorber Heat Exchange (GAX for short). However, although the GAX process can recover the waste heat in the absorption process, reduce the heat dissipation of the system to the environment and reduce the heat generated in the cycle, in order to achieve this process, the absorption temperature needs to be increased, resulting in a decrease in the absorbent's ability to absorb the refrigerant, thereby causing the absorption process to deteriorate. When the absorption temperature is high, GAX will significantly increase the cycle rate, which will have a negative impact on the actual operation of the system.

[0006] Since the self-cascade absorption refrigeration cycle must use non-azeotropic mixed refrigerants, there is a significant temperature glide phenomenon in the condenser. During the condensation process, each component in the high-temperature mixed refrigerant vapor (composed of a small amount of absorbent and mixed refrigerant components) is condensed step by step at different temperatures, which will discharge a large amount of temperature glide heat. The condensation heat generally accounts for 40-65% of the input heat of the absorption refrigeration system (heat input from the generator and heat input from the evaporator), and this heat temperature zone overlaps with the heating temperature zone of the circulating solution. Therefore, drawing on the GAX idea, the present invention proposes to establish a generator-condenser heat exchange coupling in the self-cascade absorption refrigeration cycle, namely Generator-Condenser Heat Exchange (GCX), effectively recovering the temperature glide heat discharged by the non-azeotropic mixed refrigerant in the condenser, thereby significantly reducing the heat consumption of the generator and improving the COP.

[0007] After searching, in the field of absorption refrigeration technology, no prior art related to the self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling conceived by the present invention has been found. Summary of the invention

[0008] The purpose of the present invention is to address the deficiencies of the prior art and propose a self-cascade absorption refrigeration cycle system with heat exchange coupling between a generator and a condenser. The present invention constructs a heat exchange coupling process between a generator and a condenser in a self-cascade absorption refrigeration cycle, recovers the temperature glide heat of the non-azeotropic high-temperature mixed refrigerant vapor at the gas phase outlet of the generator, thereby significantly reducing the heating heat required by the generator and improving the cycle COP.

[0009] The object of the present invention is achieved through the following technical solution: a self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling, the system comprising:

[0010] Generator, its gas phase enters the gas-liquid separator through the generator-condenser heat exchanger GCX; the liquid dilute solution enters the absorber through the solution heat exchanger and solution expansion valve;

[0011] Gas-liquid separator, the liquid phase passes through the first throttle valve and the low temperature side of a regenerator and then enters the absorber, the gas phase passes through the high temperature sides of two regenerators and passes through the second throttle valve and evaporator, and then passes through the low temperature sides of two regenerators and then enters the absorber;

[0012] In the absorber, the concentrated liquid solution is divided into two streams after passing through the solution pump and enters the generator through the solution heat exchanger and the GCX heat exchanger respectively.

[0013] Furthermore, both the liquid phase concentrated solution and the liquid phase dilute solution include a non-azeotropic mixed refrigerant and an absorbent, and the molar proportion of the non-azeotropic mixed refrigerant in the liquid phase concentrated solution is higher than the molar proportion of the mixed refrigerant in the liquid phase dilute solution.

[0014] Furthermore, the non-azeotropic mixed refrigerant is selected from at least two of hydrofluoroalkanes, alkanes, olefins and hydrofluoroolefins.

[0015] Furthermore, the non-azeotropic mixed refrigerant is tetrafluoromethane and difluoroethane.

[0016] Furthermore, the heat source of the generator adopts low-grade thermal energy, and its source includes at least one of industrial waste heat, industrial residual heat, ocean thermal energy, geothermal energy or solar energy.

[0017] Furthermore, the liquid phase outlet of the absorber is connected to a solution pump, which raises the solution from a low pressure to a high pressure state and then separates the solution into two streams.

[0018] Furthermore, a distillation device is installed between the generator and the generator-condenser heat exchanger GCX.

[0019] Furthermore, a condenser is installed between the generator-condenser heat exchanger GCX and the gas-liquid separator.

[0020] Furthermore, the absorbent content in the non-azeotropic mixed refrigerant vapor and the mass flow rate ratio of the hot and cold side streams of the GCX heat exchanger are regulated to maximize the refrigeration coefficient of performance (COP) of the generator-condenser coupled heat exchange cascade absorption refrigeration (GCX-ACAR) cycle.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) By recovering the temperature glide condensation heat of the non-azeotropic mixed refrigerant components, the refrigeration performance coefficient (COP) of the cycle is improved. The self-cascade absorption refrigeration (ACAR) cycle must use non-azeotropic mixed refrigerants. The high-temperature mixed refrigerant vapor in the condensation process is composed of a small amount of absorbent and mixed refrigerant. Due to the different dew point temperatures of different components, a large temperature glide heat will be discharged, and the heat temperature zone overlaps with the heating temperature of the concentrated solution. This heat is directly discharged to the environment through the condenser in the ACAR cycle and is not utilized. Therefore, the present invention proposes to establish a generator-condenser heat exchange coupling (GCX) process in the ACAR cycle to effectively utilize the temperature glide condensation heat discharged by the non-azeotropic mixed refrigerant, thereby significantly reducing the heat consumption of the generator and improving the cycle COP. A simulation model of the GCX-ACAR system was built, and the calculation results showed that after establishing the generator-condenser heat exchange coupling process in the ACAR cycle, the cycle COP can be effectively improved, and the COP improvement rate is up to 190%.

[0023] 2) The self-cascade absorption refrigeration system with generator-condenser heat exchange coupling can achieve efficient refrigeration at different refrigeration temperatures. Since the self-cascade absorption refrigeration system has the characteristics of flexible refrigeration temperature adjustment, the generator-condenser heat exchange coupling technology is applied to the system. By replacing the mixed refrigerant components, efficient refrigeration at different refrigeration temperatures can be achieved. For example, when the R1234zeE+R32 / DMF working fluid pair is used, efficient refrigeration can be achieved in the range of -30 to -50℃; when the R134a+R23 / DMF working fluid pair is used, efficient refrigeration can be achieved in the range of -50 to -80℃; and when the R152a+R14 / DMF working fluid pair is used, efficient refrigeration can be achieved in the range of -90 to -115℃.

[0024] 3) The generator-condenser heat exchange coupling process will not adversely affect other processes in the cycle. Compared with the typical generator-absorber heat exchange coupling (GAX) process, although the GAX process can recover the waste heat in the absorption process, thereby reducing the heat dissipation of the system to the environment and reducing the heat generated, in order to achieve this process, it is necessary to increase the absorption temperature, resulting in a decrease in the absorbent's absorption capacity for the refrigerant, thereby causing the absorption process to deteriorate. In the generator-condenser heat exchange coupling process, the recovered heat comes from the condensation heat of the high-temperature refrigerant vapor, and this process will not have a negative impact on other links in the cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling of Example 1.

[0026] Figure 2 This is a schematic diagram of the self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling of Example 2.

[0027] Figure 3 This is a schematic diagram of the self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling of Example 3.

[0028] Figure 4 This is a schematic diagram of the generator-condenser heat exchange coupled self-cascade absorption refrigeration cycle system of Example 4.

[0029] Figure 5 The effect of the absorbent ratio (zDMF) in the high-temperature refrigerant vapor of Example 1 on the COP of the GCX-ACAR cycle (zDMF=0.03 / 0.1 / 0.2 / 0.3).

[0030] Figure 6The effect of the GCX heat exchanger flow ratio (β) of Example 1 on the COP of the GCX-ACAR cycle.

[0031] Figure 7 The COP comparison between the GCX-ACAR cycle and the ACAR cycle in Example 2 is shown in FIG.

[0032] Figure 8 Comparison of the cooling curves of refrigerant vapor in different cycles for the condensation process. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0034] Example 1. See Figure 1 The present invention provides a self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling, comprising a generator 1. The top gas phase outlet of the generator is connected to the inlet of the gas-liquid separator 5 through the distillation device 2, the generator-condenser heat exchanger GCX3 and the condenser 4 in sequence, and the bottom liquid phase outlet of the gas-liquid separator is connected to the low temperature side inlet of the first regenerator 7 through the first throttle valve 6; the top gas phase outlet of the gas-liquid separator 5 is connected to the low temperature side inlet of the first regenerator 7 through the high temperature side of the first regenerator 7, the high temperature side of the second regenerator 8, the second throttle valve 9, the evaporator 10 and the low temperature side of the second regenerator 8. The low temperature side outlet of the first regenerator 7 is connected to the gas phase inlet end of the absorber 11. The bottom liquid phase outlet of the generator 1 is connected to the liquid phase inlet of the absorber 11 through the solution heat exchanger 12 and the solution expansion valve 13. The bottom liquid phase outlet of the absorber is divided into two streams after passing through the solution pump 14, one of which is connected to the inlet of the generator 1 through the low temperature side of the solution heat exchanger 12; the other is connected to the inlet of the generator 1 through the low temperature side of the GCX heat exchanger 3.

[0035] The inlet of the generator 1 is a concentrated solution;

[0036] The bottom liquid phase outlet of the generator 1 is a dilute solution;

[0037] The concentrated solution and the dilute solution both include a mixed refrigerant and an absorbent, and the molar proportion of the mixed refrigerant in the concentrated solution is higher than the molar proportion of the mixed refrigerant in the dilute solution.

[0038] The absorbent may be selected from at least one of an organic solvent, an ionic liquid, a low eutectic solvent and a refrigeration oil, including N,N-dimethylformamide (DMF), N,N-dimethylacetamide, triethylene glycol dimethyl ether, α-pyrrolidone, etc.;

[0039] The non-azeotropic mixed refrigerant may be selected from at least two of hydrofluoroalkanes, alkanes, olefins and hydrofluoroolefins;

[0040] The generator-condenser heat exchange coupled self-cascade absorption refrigeration cycle system, the heat source of the generator can adopt low-grade thermal energy, and its source may include at least one of industrial waste heat, industrial residual heat, ocean thermal energy, geothermal energy, solar energy, etc., or other forms of low-grade thermal energy.

[0041] Each throttle valve in the present invention can be a capillary, a manual throttle valve, an automatic throttle valve, or other forms of throttle valves.

[0042] The internal structure of the condenser can be a floating head type, a fixed tube sheet type, a U-shaped tube sheet type, a plate type, a sleeve type or a tube shell type.

[0043] The absorber may be a spray type, a packing type, a falling film type, or other forms of absorbers.

[0044] The solution pump can raise the solution from a low pressure to a high pressure state, which is similar to the solution pump used in a traditional absorption refrigeration system.

[0045] The distillation device may be composed of three parts, namely, a stripping section, a distillation section and a distillation condenser, or may be a distillation device in other forms.

[0046] Each of the heat regenerators may be a plate-fin multi-channel heat exchanger or other forms of heat exchangers.

[0047] In this embodiment, the mixed refrigerant is a non-azeotropic mixed refrigerant, which is composed of R14 (tetrafluoromethane) and R152a (difluoroethane), and the absorbent is N,N-dimethylformamide (DMF). The basic cycle parameters given in the analysis process are: the generation temperature is 200°C, the condensation temperature is 30°C, the absorption temperature is 30°C, the refrigeration temperature is -105°C, and the generation pressure is 800kPa. The molar proportion of DMF in the circulating concentrated solution is 95%.

[0048] For the generator-condenser coupled heat exchange cascade absorption refrigeration (GCX-ACAR) cycle, there are two main variables that significantly affect the condenser-generator coupled heat exchange process and thus the COP of the cycle. They are the absorbent DMF content in the high-temperature mixed refrigerant vapor at the generator gas phase outlet and the mass flow rate ratio of the hot and cold side streams of the GCX heat exchanger.

[0049] See also Figure 5, which shows the variation trend of GCX-ACAR cycle COP with the molar ratio of R14 in the refrigerant component when the molar content of DMF (zDMF) in the high-temperature mixed refrigerant vapor at the gas phase outlet of the generator in Example 1 is 0.03, 0.1, 0.2 and 0.3, as well as the COP improvement rate compared with the ACAR cycle. By adjusting the number of distillation plates and the cooling water flow rate of the distillation device in Example 1, the DMF molar content (zDMF) in the high-temperature mixed refrigerant vapor can be adjusted. By Figure 5 It can be seen that within the research operating range, compared with the ACAR cycle, the COP improvement rate of the GCX-ACAR cycle is about 10-105%. As zDMF increases, the COP improvement rate of the GCX-ACAR cycle continues to increase. For example, when zDMF is 0.03, the COP improvement rate is about 10-14%; when zDMF is 0.3, the COP improvement rate is about 70-110%. For the refrigeration performance coefficient COP of the GCX-ACAR cycle, as zDMF increases from 0.03 to 0.3, the peak COP of the GCX-ACAR cycle continues to increase from 0.0262 to 0.0290.

[0050] In order to analyze the effect of the flow ratio of the cold side and hot side streams of the GCX heat exchanger on the cycle performance, the mass flow ratio of the cold side stream and the hot side stream of the GCX heat exchanger is defined as β, and its definition is as follows. The COP variation trend of the GCX-ACAR cycle when the GCX flow ratio is 0.5, 1, 1.5 and 2 is studied.

[0051]

[0052] Where: β is the mass flow ratio of the GCX cold side to the hot side stream; m 20 is the mass flow rate at the cold side inlet of the GCX heat exchanger, kg / h; m 1 is the mass flow rate at the hot side inlet of the GCX heat exchanger, kg / h.

[0053] See also Figure 6 , which shows the effect of flow ratio β on the COP of the GCX-ACAR cycle at different zDMF contents in Example 1, and compares it with the COP of the ACAR cycle. As can be seen from the figure, compared with the ACAR cycle, the COP of the GCX-ACAR cycle at different flow ratios is improved, which verifies the effectiveness of the generator-condenser coupled heat exchange in improving the cycle COP. In addition, under different zDMF content conditions, there is an optimal flow ratio of about 1.5, at which the COP of the GCX-ACAR cycle reaches its maximum value.

[0054] Example 2, see Figure 2. The self-cascade absorption refrigeration system with generator-condenser heat exchange coupling can also be installed without the distillation device that must be used in the traditional self-cascade absorption refrigeration cycle. The above analysis shows that although the distillation device can reduce the DMF content (i.e., zDMF) in the high-temperature mixed refrigerant vapor, theoretically, less DMF in the ACAR cycle refrigerant can achieve a greater throttling effect. However, for the GCX-ACAR cycle, the reduction in the DMF content in the high-temperature mixed refrigerant vapor also causes the hot side stream flow and inlet temperature of the GCX heat exchanger to decrease, and the heat recovery of the GCX heat exchanger is reduced, which has a negative impact on COP. Therefore, the GCX-ACAR cycle can remove the distillation device and still achieve efficient operation.

[0055] See also Figure 7 , which is the calculation result of the COP of the GCX-ACAR system without a distillation device in Example 2 as the molar ratio of R14 in the mixed refrigerant changes. The basic cycle parameters given in the calculation process are: generation temperature of 200°C, condensation temperature of 30°C, absorption temperature of 30°C, refrigeration temperature of -105°C, and generation pressure of 800kPa. It can be seen from the figure that within the research scope, the maximum COP of the GCX-ACAR system without a distillation device is 0.029. At this time, the molar ratio of refrigerants R14 and R152a in the concentrated solution at the outlet of the absorber is 36:64, which is 185% higher than the COP of the ACAR cycle without a distillation device.

[0056] Example 3, see Figure 3 . The self-cascade absorption refrigeration system with generator-condenser heat exchange coupling can also be installed without the condenser that must be used in the traditional self-cascade absorption refrigeration cycle. In the GCX heat exchanger, the flow ratio of the hot and cold side fluids is within a reasonable range. Since the temperature of the high-temperature refrigerant vapor is close to the temperature of the concentrated solution at the outlet of the solution pump after passing through the GCX heat exchanger, and the temperature of the concentrated solution at the outlet of the solution pump is close to the temperature of the cooling water in the absorber, that is, the hot side outlet temperature of the GCX heat exchanger is close to the temperature of the cooling water. Therefore, after the condenser is removed from the GCX-ACAR cycle, the high-temperature mixed refrigerant stream can still be effectively condensed in the GCX heat exchanger, so the cycle can still operate efficiently.

[0057] Example 4, see Figure 4 The generator-condenser heat exchange coupled self-cascade absorption refrigeration system can also be installed without the distillation device and condenser that must be used in the traditional self-cascade absorption refrigeration cycle.

[0058] See also Figure 8 The figure shows the cooling curves of three refrigerant vapors during the condensation process, namely R152a+R14 (containing 3% DMF, the molar ratio of R152a to R14 is 7:3), NH 3 (Contains 1% H2 O) and H 2 O, which represent GCX-ACAR cycle, ammonia water cycle and lithium bromide water cycle respectively. The inlet temperature of the three refrigerant vapors is 100°C and the outlet temperature is 30°C. As can be seen from the figure, when the refrigerant is water, since the phase change process of the single component is a constant temperature process, the entire condensation process is basically at 40°C, and the solution heating process is basically a single-phase temperature change heating process, so it is difficult to effectively utilize the constant temperature condensation heat. 3 Refrigerant, because there is usually a small amount of H 2 O, so there is a certain amount of variable temperature heat dissipation in the initial stage of condensation. However, due to H 2 O content is low (to prevent H 2 O evaporates below 0℃ and solidifies to block the pipeline). 2 After O condenses, the remaining NH 3 The steam enters the constant temperature condensation stage at about 35°C. For the R152a+R14 mixed refrigerant of the GCX-ACAR cycle, since the proportion of both refrigerants is high, the temperature of the condensation process is smoothly reduced from 100°C to 30°C as the heat is discharged, which can achieve a good temperature match with the variable temperature heating process of the solution. This figure reveals the fundamental reason why the generator-condenser coupled heat exchange can be established in a typical ACAR cycle.

[0059] Table 1 shows the freezing points of the absorbent and refrigerant in the GCX-ACAR cycle and compares them with the ammonia cycle, which explains why the GCX-ACAR cycle has a larger temperature glide heat.

[0060] Table 1

[0061]

[0062] The data in Table 1 show that the freezing point temperature of the absorbent (DMF) in the GCX-ACAR cycle is relatively low, only -61°C. In this cycle, most of the absorbent (more than 99.5%) at the outlet of the gas-liquid separator enters the first regenerator to provide pre-cooling above -50°C, and does not enter the evaporator. Therefore, this part of the absorbent will not affect the throttling and cooling effect of the refrigerant stream before the evaporator, and there is no risk of clogging the pipeline due to solidification. As a result, the high-temperature refrigerant vapor in the GCX-ACAR cycle can contain a higher proportion of absorbent, thereby increasing the heat rejection of the mixed refrigerant vapor in the GCX heat exchanger. In contrast, the freezing point temperature of the absorbent (water) in the ammonia cycle is 0°C, and there is no gas-liquid separator at the outlet of the condenser. Therefore, in the ammonia cycle, if the water content in the high-temperature refrigerant vapor is high, it will affect the throttling and cooling effect before the evaporator, and there is a risk of clogging the pipeline due to water solidification. Therefore, the water content in the high-temperature refrigerant vapor in the ammonia cycle must be controlled at a low level, usually not exceeding 2%. This makes the temperature range of available temperature glide heat in the ammonia cycle relatively small.

[0063] The above embodiments are used to illustrate the present invention rather than to limit the present invention. Any modification and change made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling, characterized in that: The system includes: Generator, its gas phase enters the gas-liquid separator through the generator-condenser heat exchanger GCX; the liquid dilute solution enters the absorber through the solution heat exchanger and solution expansion valve; Gas-liquid separator, the liquid phase passes through the first throttle valve and the low temperature side of a regenerator and then enters the absorber, the gas phase passes through the high temperature sides of two regenerators and passes through the second throttle valve and evaporator, and then passes through the low temperature sides of two regenerators and then enters the absorber; In the absorber, the concentrated liquid solution is divided into two streams after passing through the solution pump and enters the generator through the solution heat exchanger and the GCX heat exchanger respectively.

2. A generator-condenser heat exchange coupled self-cascade absorption refrigeration cycle system according to claim 1, characterized in that: The liquid phase concentrated solution and the liquid phase dilute solution both include a non-azeotropic mixed refrigerant and an absorbent, and the molar proportion of the non-azeotropic mixed refrigerant in the liquid phase concentrated solution is higher than the molar proportion of the mixed refrigerant in the liquid phase dilute solution.

3. A generator-condenser heat exchange coupled self-cascade absorption refrigeration cycle system according to claim 2, characterized in that: The non-azeotropic mixed refrigerant is selected from at least two of hydrofluoroalkanes, alkanes, olefins and hydrofluoroolefins.

4. A generator-condenser heat exchange coupled self-cascade absorption refrigeration cycle system according to claim 3, characterized in that: The non-azeotropic mixed refrigerant is tetrafluoromethane and difluoroethane.

5. The self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling according to claim 1, characterized in that: The heat source of the generator adopts low-grade thermal energy, and its source includes at least one of industrial waste heat, industrial residual heat, ocean thermal energy, geothermal energy or solar energy.

6. The self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling according to claim 1, characterized in that: The liquid phase outlet of the absorber is connected to a solution pump, which raises the solution from a low pressure to a high pressure state and then separates it into two fluids.

7. The self-cascade absorption refrigeration cycle system with generator-condenser heat exchange coupling according to claim 1, characterized in that: A distillation device is installed between the generator and the generator-condenser heat exchanger GCX.

8. The self-cascade absorption refrigeration cycle system with heat exchange coupling between a generator and a condenser according to claim 1, characterized in that: A condenser is installed between the generator-condenser heat exchanger GCX and the gas-liquid separator.

9. The self-cascade absorption refrigeration cycle system with heat exchange coupling between a generator and a condenser according to claim 2, characterized in that: The absorbent content in the non-azeotropic mixed refrigerant vapor and the mass flow rate ratio of the hot and cold side streams of the GCX heat exchanger are regulated to maximize the refrigeration coefficient of performance (COP) of the self-cascade absorption refrigeration GCX-ACAR cycle with generator-condenser coupled heat exchange.

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