Single-stage and cascade cycle free conversion multi-connection variable temperature cold storage refrigeration system

Abstract

The present invention provides a multi-connected variable temperature cold storage refrigeration system with single-stage and cascade cycles freely convertible, including a first single-stage circulation system, a second single-stage circulation system and an intermediate heat exchanger system, wherein the first single-stage circulation system includes a first compression condensing unit module and at least one first cold air machine module; the second single-stage circulation system includes a second compression condensing unit module and at least one second cold air machine module; the first single-stage circulation system and the second single-stage circulation system are both connected to the intermediate heat exchanger system; wherein the first single-stage circulation system and the second single-stage circulation system can be operated separately, and can also be connected to the intermediate heat exchanger system to form a cascade circulation system, and in the cascade circulation system, the first single-stage circulation system or the second single-stage circulation system can be used as a low temperature stage. The system can adapt to changes in high and low temperature storage temperatures and ensure that the unit operates efficiently at different storage temperatures.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration technology, and in particular to a single-stage, cascade cycle free-conversion multi-connected variable temperature cold storage refrigeration system. Background Art

[0002] Prefabricated cold storage usually uses a refrigerant system, such as a multi-connected refrigeration system. Compared with a refrigerant system, the refrigerant and air directly transfer heat through phase change, and the energy carried by the unit mass of refrigerant is higher. The refrigerant system has the advantages of fewer heat transfer links and reduced energy consumption. However, when the storage temperature required for prefabricated cold storage is low, such as the storage temperature of the tuna cold storage room is -40 to -60℃, the storage temperature of ice cream products is -30℃, or the outdoor temperature is high, the ordinary single-stage compression cycle system is often difficult to adapt to the large pressure ratio; and the use of a multi-stage compression system will be limited by aspects such as the performance of the refrigerant itself and the pressure bearing capacity of the unit.

[0003] The cascade refrigeration cycle divides the large total temperature difference into two or several sections, selects the appropriate refrigerant cycle according to the temperature zone of each section, and then stacks them up. It usually uses two or more independent refrigeration cycles with medium-temperature refrigerants and low-temperature refrigerants. Therefore, the cascade refrigeration cycle can be used as the refrigeration system cycle of the cold storage, which can improve the economic performance of the refrigeration cycle, and also improve its low-temperature performance to obtain a lower temperature.

[0004] Since the goods stored in the prefabricated cold storage often change, the storage temperature requirements also have different requirements, and the use of a single-stage compression system and a cascade system alone cannot meet the requirements of a variable temperature cold storage at the same time. In addition, the defrosting problem of the refrigeration system in the cold storage has always been a hot topic in the field of low temperature and refrigeration. The defrosting temperature fluctuation has an important impact on the safety of the goods stored in the cold storage. Therefore, it is urgent to develop a variable temperature cold storage refrigeration system that can adapt to the changes in high and low temperature storage temperatures. Summary of the invention

[0005] The embodiment of the present invention provides a single-stage, cascade cycle freely switchable multi-connected variable temperature cold storage refrigeration system, which is used to solve the technical problem that the refrigeration system in the prior art cannot adapt to the changes in high and low temperature storage temperatures.

[0006] The embodiment of the present invention provides a single-stage, cascade cycle free-conversion multi-connected variable temperature cold storage refrigeration system, comprising:

[0007] A first single-stage circulation system includes a first compression condensing unit module and at least one first air cooler module;

[0008] A second single-stage circulation system, comprising a second compression condensing unit module and at least one second air cooler module;

[0009] The intermediate heat exchanger system, the first single-stage circulation system and the second single-stage circulation system are both connected to the intermediate heat exchanger system; wherein,

[0010] The first single-stage circulation system and the second single-stage circulation system can be operated independently, or can be connected to the intermediate heat exchanger system to form a cascade circulation system. In the cascade circulation system, the first single-stage circulation system or the second single-stage circulation system can serve as the low-temperature stage.

[0011] According to a single-stage, cascade cycle free conversion multi-connected variable temperature cold storage refrigeration system of one embodiment of the present invention,

[0012] The intermediate heat exchanger system comprises an evaporative condenser, and a first tube body, a second tube body, a third tube body and a fourth tube body connected to the evaporative condenser;

[0013] The first cooling fan module and the first compression condensing unit module have opposite sides connected to the first tube body and the third tube body;

[0014] The second air cooler module and the second compression condensing unit module have opposite sides connected to the second tube body and the fourth tube body.

[0015] According to a single-stage, cascade cycle free conversion multi-connected variable temperature cold storage refrigeration system of one embodiment of the present invention,

[0016] The first cooling air machine module includes a first evaporator, a first fan arranged at one side of the first evaporator, and a first throttling device connected to the third tube body and the first evaporator;

[0017] The second cooling air machine module includes a second evaporator, a second fan arranged at one side of the second evaporator, and a second throttling device connected to the fourth tube body and the second evaporator.

[0018] According to a single-stage, cascade cycle free conversion multi-connected variable temperature cold storage refrigeration system of one embodiment of the present invention,

[0019] The first compression condensing unit module includes a first gas-liquid separator, a first compressor, a first four-way reversing valve, a first outdoor heat exchanger and a third throttling device;

[0020] The second compression condensing unit module includes a second gas-liquid separator, a second compressor, a second four-way reversing valve, a second outdoor heat exchanger and a fourth throttling device.

[0021] According to a single-stage, cascade cycle free conversion multi-connected variable temperature cold storage refrigeration system of one embodiment of the present invention,

[0022] The first pipe body includes a first flow pipe, a second flow pipe and a third flow pipe, the gas in the first flow pipe flows from the first air cooler module to the intermediate heat exchanger system, the gas in the second flow pipe flows sequentially through the first gas-liquid separator and the first compressor to the intermediate heat exchanger system, the third flow pipe is connected to the second flow pipe, the third flow pipe flows sequentially through the first four-way reversing valve, the first outdoor heat exchanger and the first throttling device to the third pipe body and then flows to the intermediate heat exchanger system;

[0023] The second pipe body includes a fourth flow pipe, a fifth flow pipe and a sixth flow pipe. The gas in the fourth flow pipe flows from the second air cooler module to the intermediate heat exchanger system. The gas in the fifth flow pipe flows through the second gas-liquid separator and the second compressor in sequence and flows to the intermediate heat exchanger system. The sixth flow pipe is connected to the fifth flow pipe. The sixth flow pipe flows through the second four-way reversing valve, the second outdoor heat exchanger and the second throttling device in sequence to the fourth pipe body and then flows to the intermediate heat exchanger system.

[0024] According to a single-stage, cascade cycle free conversion multi-connected variable temperature cold storage refrigeration system of one embodiment of the present invention,

[0025] The intermediate heat exchanger system further includes a fifth throttling device, a sixth throttling device, a third four-way reversing valve and a fourth four-way reversing valve;

[0026] The fifth throttling device is arranged on the third pipe body, and the third four-way reversing valve is connected to the first flow pipe and the second flow pipe respectively;

[0027] The sixth throttling device is arranged on the fourth pipe body, and the fourth four-way reversing valve is connected to the fourth flow pipe and the fifth flow pipe respectively.

[0028] According to a single-stage, cascade cycle free conversion multi-connected variable temperature cold storage refrigeration system of one embodiment of the present invention,

[0029] The first single-stage circulation system further includes a first defrost channel, the first defrost channel being respectively connected to the outlet side of the first compressor in the second circulation pipe and the first air cooler module;

[0030] The second single-stage circulation system further includes a second defrost passage, which is respectively connected to the outlet side of the second compressor in the fifth circulation pipe and the second air cooler module.

[0031] According to a single-stage, cascade cycle free conversion multi-connected variable temperature cold storage refrigeration system of one embodiment of the present invention,

[0032] The first single-stage circulation system further includes a fifth four-way reversing valve, and the fifth four-way reversing valve is respectively connected to the first defrost channel, the first air cooler module and the first flow pipe;

[0033] The second single-stage circulation system also includes a sixth four-way reversing valve, which is respectively connected to the second defrost channel, the second air cooler module and the fourth flow pipe.

[0034] According to a multi-connected variable temperature cold storage refrigeration system with free conversion between single-stage and cascade cycles according to one embodiment of the present invention, in the cascade cycle system, the low temperature stage is used to maintain an evaporation temperature lower than that reached when the first single-stage cycle system or the second single-stage cycle system operates alone.

[0035] According to a multi-connected variable temperature cold storage refrigeration system with free conversion between single-stage and cascade cycles according to one embodiment of the present invention, in the cascade cycle system, the evaporative condenser includes an evaporation side and a condensation side, and the evaporation side or the condensation side corresponds to the evaporation end and the condensation end in the first single-stage cycle system or the second single-stage cycle system, respectively.

[0036] The multi-connected variable temperature cold storage refrigeration system with free conversion between single-stage and cascade cycles provided in an embodiment of the present invention comprises a first single-stage circulation system, a second single-stage circulation system and an intermediate heat exchanger system, and the first single-stage circulation system, the second single-stage circulation system and the intermediate heat exchanger system can be combined to form a cascade circulation system, so that the compression condensing unit module in the first single-stage circulation system or the second single-stage circulation system can generate a temperature lower than that of the compression condensing unit module in the single-stage circulation system, and the first single-stage circulation system and the second single-stage circulation system can work alone or together with the intermediate heat exchanger system to form a cascade circulation system to provide a lower temperature, so that the system can adapt to changes in high and low temperature storage temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 It is a structural view of an embodiment of a multi-connected variable temperature cold storage refrigeration system with single-stage and cascade cycle free conversion according to the present invention;

[0039] Figure 2 It is a structural view of another embodiment of the multi-connected variable temperature cold storage refrigeration system with single-stage and cascade cycle free conversion of the present invention;

[0040] Reference numerals:

[0041] 10: first single-stage circulation system 110: first compression condenser 1110: first gas-liquid separation system; group module; device;

[0042] 1130: first four-way reversing 1140: first outdoor heat exchange 1120: first compressor; valve; device;

[0043] 1150: The third throttle device 120: The first cooling air machine module

[0044] 1210: first evaporator; 1220: first fan; 1230: first throttling device; 130: first defrosting channel; 140: fifth four-way reversing 20: second single-stage circulation system 210: second compression condensing valve; system; unit module;

[0045] 2110: second gas-liquid separator; 2130: second four-way reversing device; 2120: second compressor; valve;

[0046] 2140: second outdoor heat exchange 220: second cooling air machine module; 2150: fourth throttling device; block;

[0047] 2230: second throttling device; 2210: second evaporator; 2220: second fan; device;

[0048] 240: sixth four-way reversing 30: intermediate heat exchanger system 230: second defrost channel; valve; system;

[0049] 310: evaporative condenser; 320: first tube body; 3210: first flow tube;

[0050] 3220: second flow pipe; 3230: third flow pipe; 3240: evaporation side;

[0051] 3250: condensation side; 330: second tube body; 3310: fourth flow tube;

[0052] 3320: fifth flow tube; 3330: sixth flow tube; 340: third tube body;

[0053] 350: fourth tube body; 360: fifth throttling device; 370: sixth throttling device;

[0054] 380: Third four-way reversing 390: Fourth four-way reversing

[0055] Valve; valve; 40: throttle valve. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] Please refer to Figure 1 and Figure 2 , Figure 1 It is a structural view of an embodiment of a multi-connected variable temperature cold storage refrigeration system with single-stage and cascade cycle free conversion according to the present invention; Figure 2 This is a structural view of another embodiment of the multi-connected variable temperature cold storage refrigeration system with single-stage and cascade cycle free conversion according to the present invention.

[0058] Please refer to the following Figure 2The present invention provides a multi-connected variable temperature cold storage refrigeration system with free conversion between single-stage and cascade cycles, comprising a first single-stage circulation system 10, a second single-stage circulation system 20 and an intermediate heat exchanger system 30, wherein the first single-stage circulation system 10 comprises a first compression condensing unit module 110 and at least one first cold air machine module 120; the second single-stage circulation system 20 comprises a second compression condensing unit module 210 and at least one second cold air machine module 220; the intermediate heat exchanger system 30, wherein the first single-stage circulation system 10 and the second single-stage circulation system 20 are both connected to the intermediate heat exchanger system 30; wherein the first single-stage circulation system 10 and the second single-stage circulation system 20 can be operated independently, and can also be connected to the intermediate heat exchanger system 30 to form a cascade circulation system, and in the cascade circulation system, the first single-stage circulation system 10 or the second single-stage circulation system 20 can be used as the low-temperature stage side. That is, in the cascade circulation system, the storage temperature maintained by the first air cooler module 120 in the first single-stage circulation system 10 or the second air cooler module 220 in the second single-stage circulation system 20 is lower than the storage temperature maintained by the first air cooler module 120 or the second air cooler module 220 when the first single-stage circulation system 10 or the second single-stage circulation system 20 is operated alone. Therefore, whether one side of the first single-stage circulation system 10 or one side of the second single-stage circulation system 20 can be used as the low-temperature side, so that the first single-stage circulation system 10 and the second single-stage circulation system 20 can adapt to the changes of high and low temperature cold storages, ensuring that the unit operates efficiently at different storage temperatures. It should be noted that the first single-stage circulation system 10 and the second single-stage circulation system 20 can both work alone, and the first single-stage circulation system 10, the second single-stage circulation system 20 and the intermediate heat exchanger system 30 work together to form a cascade circulation system. And in the cascade circulation system, the first single-stage circulation system 10 or the second single-stage circulation system 20 can both be used as the low-temperature side, and the other side is relatively used as the high-temperature side. For example, when the first single-stage circulation system 10 serves as the low-temperature side, the first air cooler module 120 in the first single-stage circulation system 10 can generate a storage temperature lower than the storage temperature maintained by the first air cooler module 120 when the first single-stage circulation system 10 works alone, or the storage temperature maintained by the second air cooler module 220 when the second single-stage circulation system 20 works alone, so that the system can adapt to cold storage with high and low temperature changes.

[0059] The specific structures of the first single-stage circulation system 10 and the second single-stage circulation system 20 are as follows:

[0060] In the first single-stage circulation system 10, the intermediate heat exchanger system 30 includes an evaporative condenser 310, and a first tube body 320, a second tube body 330, a third tube body 340 and a fourth tube body 350 connected to the evaporative condenser 310; the first air cooler module 120 and the first compression condensing unit module 110 are connected to the first tube body 320 and the third tube body 340 on opposite sides; the first air cooler module 120 includes a first evaporator 1210, a first fan 1220 arranged on one side of the first evaporator 1210, and a first throttling device 1230 connected to the third tube body 340 and the first evaporator 1210; the first compression condensing unit module includes a first gas-liquid separator 1110, a first compressor 1120, a first four-way reversing valve 1130, a first outdoor heat exchanger 1140 and a third throttling device 1150. The first pipe body 320 includes a first flow pipe 3210, a second flow pipe 3220 and a third flow pipe 3230. The gas in the first flow pipe 3210 flows from the first air cooler module 120 to the intermediate heat exchanger system 30. The gas in the second flow pipe 3220 flows through the first gas-liquid separator 1110 and the first compressor 1120 in sequence to the intermediate heat exchanger system 30. The third flow pipe 3230 is connected to the second flow pipe 3220. The third flow pipe 3230 flows through the first four-way reversing valve 1130, the first outdoor heat exchanger 1140 and the first throttling device 1230 in sequence to the third pipe body 340 and then flows to the intermediate heat exchanger system 30. The first single-stage circulation system 10 also includes a first defrost channel 130, which is respectively connected to the outlet side of the first compressor 1120 in the second flow pipe 3220 and the first air cooler module 120.

[0061] In the second single-stage circulation system 20: the second air cooler module 220 and the second compression condensing unit module 210 are connected to the second tube body 330 and the fourth tube body 350 on opposite sides; the second air cooler module 220 includes a second evaporator 2210, a second fan 2220 arranged on one side of the second evaporator 2210, and a second throttling device 2230 connected to the fourth tube body 350 and the second evaporator 2210; the second compression condensing unit module includes a second gas-liquid separator 2110, a second compressor 2120, a second four-way reversing valve 2130, a second outdoor heat exchanger 2140 and a fourth throttling device 2150; the second tube The body 330 includes a fourth flow pipe 3310, a fifth flow pipe 3320 and a sixth flow pipe 3330. The gas in the fourth flow pipe 3310 flows from the second air cooler module 220 to the intermediate heat exchanger system 30. The gas in the fifth flow pipe 3320 flows through the second gas-liquid separator 2110 and the second compressor 2120 in sequence to the intermediate heat exchanger system 30. The sixth flow pipe 3330 is connected to the fifth flow pipe 3320. The sixth flow pipe 3330 flows through the second four-way reversing valve 2130, the second outdoor heat exchanger 2140 and the second throttling device 2230 in sequence to the fourth pipe body 350 and then flows to the intermediate heat exchanger system 30. The second single-stage circulation system 20 also includes a second defrost channel 230, which is respectively connected to the outlet side of the second compressor 2120 in the fifth flow pipe 3320 and the second air cooler module 220.

[0062] In the intermediate heat exchanger system 30: the intermediate heat exchanger system 30 also includes a fifth throttling device 360, a sixth throttling device 370, a third four-way reversing valve 380 and a fourth four-way reversing valve 390; the fifth throttling device 360 ​​is arranged on the third pipe body 340, and the third four-way reversing valve 380 is respectively connected to the first flow pipe 3210 and the second flow pipe 3220; the sixth throttling device 370 is arranged on the fourth pipe body 350, and the fourth four-way reversing valve 390 is respectively connected to the fourth flow pipe 3310 and the fifth flow pipe 3320.

[0063] Furthermore, the first single-stage circulation system 10 also includes a fifth four-way reversing valve 140, which is respectively connected to the first defrost channel 130, the first air cooler module 120 and the first flow pipe 3210; the second single-stage circulation system 20 also includes a sixth four-way reversing valve 240, which is respectively connected to the second defrost channel 230, the second air cooler module 220 and the fourth flow pipe 3310.

[0064] Please refer to Figure 2The first outlet side of the first four-way reversing valve 1130, that is, the first four-way reversing valve 1130E side, is closed, the second outlet side of the first four-way reversing valve 1130, that is, the first four-way reversing valve 1130D side, is connected to the first compressor 1120, the third outlet side of the first four-way reversing valve 1130, that is, the first four-way reversing valve 1130S side, is connected to the first flow pipe 3210, and the fourth outlet side of the first four-way reversing valve 1130, that is, the first four-way reversing valve 1130C side, is connected to the first outdoor heat exchanger 1140.

[0065] The first outlet side of the second four-way reversing valve 2130, i.e., the second four-way reversing valve 2130E side, is closed, the second outlet side of the second four-way reversing valve 2130, i.e., the second four-way reversing valve 2130D side, is connected to the second compressor 2120, the third outlet side of the second four-way reversing valve 2130, i.e., the second four-way reversing valve 2130S side, is connected to the fourth flow pipe 3310, and the fourth outlet side of the second four-way reversing valve 2130, i.e., the second four-way reversing valve 2130C side, is connected to the second outdoor heat exchanger 2140.

[0066] The first outlet side of the third four-way reversing valve 380, i.e., the third four-way reversing valve 380E side, is connected to the evaporative condenser 310, the second outlet side of the third four-way reversing valve 380, i.e., the third four-way reversing valve 380D side, is connected to the second flow pipe 3220, the third outlet side of the third four-way reversing valve 380, i.e., the third four-way reversing valve 380S side, is connected to the first flow pipe 3210, and the fourth outlet side of the second four-way reversing valve 2130, i.e., the third four-way reversing valve 380C side, is closed.

[0067] The first outlet side of the fourth four-way reversing valve 390, i.e., the fourth four-way reversing valve 390E side, is connected to the evaporative condenser 310, the second outlet side of the fourth four-way reversing valve 390, i.e., the fourth four-way reversing valve 390D side, is connected to the fifth flow pipe 3320, the third outlet side of the fourth four-way reversing valve 390, i.e., the fourth four-way reversing valve 390S side, is connected to the fourth flow pipe 3310, and the fourth outlet side of the fourth four-way reversing valve 390, i.e., the fourth four-way reversing valve 390C side, is closed.

[0068] The first outlet side of the fifth four-way reversing valve 140, i.e., the fifth four-way reversing valve 140E side, is connected to the first evaporator 1210, the second outlet side of the fifth four-way reversing valve 140, i.e., the fifth four-way reversing valve 140D side, is connected to the first defrost channel 130, the third outlet of the fifth four-way reversing valve 140, i.e., the fifth four-way reversing valve 140S side, is connected to the first flow pipe 3210, and the fourth outlet of the fifth four-way reversing valve 140, i.e., the C side, is closed.

[0069] When the first single-stage circulation system 10 works alone, the fifth four-way reversing valve 140E side is connected with the fifth four-way reversing valve 140S side, and the fifth four-way reversing valve 140C side is connected with the fifth four-way reversing valve 140D side; the first four-way reversing valve 1130D side is connected with the first four-way reversing valve 1130C side, and the first four-way reversing valve 1130E side is connected with the first four-way reversing valve 1130S side, the third throttling device 1150 is fully opened, and the first fan 1220 is turned on and is in operation. At this time, the third four-way reversing valve 380C side of the intermediate heat exchanger system 30 is connected to the third four-way reversing valve 380D side, and the third four-way reversing valve 380E side is connected to the third four-way reversing valve 380S side; the fourth four-way reversing valve 390C side is connected to the fourth four-way reversing valve 390D side, and the fourth four-way reversing valve 390E side is connected to the fourth four-way reversing valve 390S side. The fifth throttling device 360 ​​and the sixth throttling device 370 are closed. The refrigerator completes the first single-stage circulation system 10 through the first compressor 1120, the first four-way reversing valve 1130, the first outdoor heat exchanger 1140, the third throttling device 1150, the first throttling device 1230, the first evaporator 1210, the fifth four-way reversing valve 140, and the first gas-liquid separator 1110. In the first single-stage circulation system 10, the first air cooler module 120 provides cooling capacity to the cold room where it is placed to meet the storage temperature requirements of the corresponding cold room. It is understandable that the refrigerator will become a high-temperature and high-pressure gaseous refrigerant after passing through the first compressor 1120. When passing through the first outdoor heat exchanger 1140, the refrigerator undergoes phase change and releases heat. At this time, the first outdoor heat exchanger 1140 is equivalent to a condenser. Then, the refrigerator after passing through the first outdoor heat exchanger 1140 becomes a pure liquid refrigerant. The pure liquid refrigerant flows to the first air cooler module 120 through the third pipe body 340. The first evaporator 1210 absorbs heat outside the cold storage to keep the cold storage at a low temperature. At the same time, the liquid refrigerant will become a gaseous state and flow to the first gas-liquid separator 1110. The gas separated by the first gas-liquid separator 1110 flows to the first compressor 1120 to form a cycle. It is understandable that the unused liquid of the first evaporator 1210 can flow to other first evaporators 1210 to form an internal circulation between multiple first air cooler modules 120. In addition, the temperature difference of the evaporation and condensation side 3250 of the first single-stage circulation system 10 is generally 30 degrees Celsius to 40 degrees Celsius. For example, when the corresponding temperature of the first outdoor heat exchanger 1140 as a condenser is 20 degrees Celsius, the first evaporator 1210 side can produce a low temperature of minus 10 degrees to 20 degrees.

[0070] It should be noted that the second single-stage circulation system 20 is consistent with the first single-stage circulation system 10 in principle, and will not be elaborated on herein.

[0071] When the cascade circulation system is in operation, the first single-stage circulation system 10 or the second single-stage circulation system 20 can be used as the low-temperature side. Here, the first single-stage circulation system 10 is used as the low-temperature side for explanation. For the first single-stage circulation system 10, the fifth four-way reversing valve 140D side is connected to the fifth four-way reversing valve 140 E side, the fifth four-way reversing valve 140 C side is connected to the fifth four-way reversing valve 140S side, the third throttling device 1150 is closed, the first four-way reversing valve 1130C side is connected to the third four-way reversing valve 380D side, the first four-way reversing valve 1130E side is connected to the third four-way reversing valve 380S side, and the first fan 1220 is in an open state. In the intermediate heat exchanger system 30, the third four-way reversing valve 380D side is connected to the third four-way reversing valve 380E side, and the third four-way reversing valve 380S side is connected to the third four-way reversing valve 380C side. The fourth four-way reversing valve 390D side is connected to the fourth four-way reversing valve 390C, and the fourth four-way reversing valve 390E side is connected to the fourth reversing valve S side. In the second single-stage circulation system 20, the second four-way reversing valve 2130D side is connected to the second four-way reversing valve 2130C side, the second four-way reversing valve 2130E side is connected to the second four-way reversing valve 2130S side, the fourth throttling device 2150 is fully opened, the second air cooler module 220 in the second single-stage circulation system 20 is fully closed, the sixth four-way reversing valve 240D side is connected to the sixth four-way reversing valve 240C side, and the sixth four-way reversing valve 240E side is connected to the sixth four-way reversing valve 240S side. In the cascade circulation system, the first air cooler module 120 absorbs heat from the low-temperature cold storage to maintain the temperature in the low-temperature cold storage, and the evaporative condenser 310 serves as the condenser in the first single-stage circulation system 10. At this time, the second single-stage circulation system 20 is in high-temperature operation, the evaporative condenser 310 serves as the evaporator in the second single-stage circulation system 20, and the second outdoor heat exchanger 2140 serves as the condenser in the second single-stage circulation system 20. Then, in the second single-stage circulation system 20, the high-temperature and high-pressure refrigerator flowing out of the second compressor 2120 becomes a medium-temperature and low-pressure liquid refrigerant after passing through the second outdoor heat exchanger 2140, and then the evaporative condenser 310 serves as an evaporator in the second single-stage circulation system 20 to absorb the heat released by the evaporative condenser 310 as a condenser in the first single-stage circulation system 10, and the low-pressure and low-temperature gas produced flows to the second gas-liquid separator 2110 and the second compressor 2120 for recycling. In the first single-stage circulation system 10, the low-temperature liquid produced by the evaporative condenser 310 flows to the first air cooler module 120 for circulating refrigeration. Compared with operating the first single-stage circulation system 10 or the second single-stage circulation system 20 alone, the cascade circulation system can obtain a lower temperature. In the cascade cycle system, the evaporative condenser 310 includes an evaporation side 3240 and a condensation side 3250. That is, please refer to Figure 2, when the first single-stage circulation system 10 is at the low temperature side, the side of the evaporative condenser 310 close to the first single-stage circulation system 10 is the condensation side 3250, which also corresponds to the evaporative condenser 310 being a condenser in the first single-stage circulation system 10 and being an evaporator in the second single-stage circulation system 20. Therefore, the side of the evaporative condenser 310 close to the second single-stage circulation system 20 is the evaporation side 3240. It should be noted that, similarly, when the second single-stage circulation system 20 is at the low temperature side, the evaporation side 3240 and the condensation side 3250 are arranged in the opposite position to that when the first single-stage circulation system 10 is at the low temperature side, which will not be described in detail here.

[0072] Please continue to refer to Figure 2 In addition, Figure 2 In the embodiment of the present invention, the cascade cycle system can also realize the heat recovery bypass defrosting function and the reverse cycle defrosting function. The following takes the first single-stage cycle system 10 as an example: wherein, for the heat recovery bypass defrosting function: in the first air cooler module 120 that needs to be defrosted, the first fan 1220 stops, the first throttling device 1230 is fully opened, the fifth four-way reversing valve 140E side is connected to the fifth four-way reversing valve 140D side, and the fifth four-way reversing valve 140C side is connected to the fifth four-way reversing valve 140S side. At this time, the high-temperature and high-pressure refrigeration fluid discharged from the first compressor 1120 enters the first air cooler module 120 that needs to be defrosted through the first defrost channel 130, and the liquid refrigerant after condensation and heat release enters the third pipe body 340 through the first throttling device 1230. With such a configuration, one or two of the multiple first air cooler modules 120 that need to be defrosted can be defrosted accordingly.

[0073] If multiple or all of the multiple first air cooler modules 120 need to be defrosted, a reverse cycle defrosting function can be used. As follows: Taking the first single-stage circulation system 10 as an example, the first fans 1220 in each first air cooler module 120 are all stopped, and the first four-way reversing valve 1130E side is connected to the first four-way reversing valve 1130D side, and the first four-way reversing valve 1130C side is connected to the first four-way reversing valve 1130S side. The first throttling device 1230 is fully opened. The fifth four-way reversing valve 140E side is connected to the fifth four-way reversing valve 140D side, the fifth four-way reversing valve 140C side is connected to the fifth four-way reversing valve 140S side, and the third four-way reversing valve 380C side in the intermediate heat exchanger system 30 is connected to the third four-way reversing valve 380D side, and the third four-way reversing valve 380E side is connected to the third four-way reversing valve 380S side. The fourth four-way reversing valve 390C side is connected to the fourth four-way reversing valve 390D side, the fourth four-way reversing valve 390E side is connected to the fourth four-way reversing valve 390S side, and the fifth throttling device 360 ​​and the sixth throttling device 370 are closed. At this time, the high-temperature and high-pressure gaseous refrigerant at the outlet of the first compressor 1120 all enters the first evaporator 1210 in each first air cooler module 120 through the first defrost channel 130 for condensation, and then passes through the first throttling device 1230, throttles at the third throttling device 1150, and then enters the first outdoor heat exchanger 1140 to absorb heat, and then passes through the first four-way reversing valve 1130 to return to the first gas-liquid separator 1110 and the first compressor 1120.

[0074] It should be noted that Figure 1 It is a structural view of an embodiment of a multi-connected variable temperature cold storage refrigeration system with single-stage and cascade cycle free conversion according to the present invention; Figure 2 This is a structural view of another embodiment of the multi-connected variable temperature cold storage refrigeration system with single-stage and cascade cycle free conversion according to the present invention. Figure 2 for Figure 1 An improvement based on Figure 2 exist Figure 1 On the basis of adding multiple four-way reversing valves, and adding heat recovery bypass defrosting function and reverse cycle defrosting function, so that Figure 2 The medium cascade cycle system can adapt to cold storage with different high and low temperature changes, ensuring the efficient operation of the unit under different storage temperatures, and can also achieve two defrosting modes at the same time. Figure 1 In the embodiment of the present invention, when reverse cycle defrosting is not required, the first four-way reversing valve 1130 can be replaced with a throttle valve, and then Figure 1 In the embodiment, the first single-stage circulation system 10 and the second single-stage circulation system 20 can be operated independently. Or the first single-stage circulation system 10 and the second single-stage circulation system 20 and the intermediate heat exchanger system 30 form a cascade circulation system. That is, for those that do not need defrosting, you can refer to Figure 1 The embodiment shown in the figure is sufficient, and when regular defrosting is required, you can refer to Figure 2 The embodiment shown can just perform corresponding defrosting operation, and is not limited here.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A single-stage, cascade cycle free conversion multi-connected variable temperature cold storage refrigeration system, characterized in that: include: A first single-stage circulation system includes a first compression condensing unit module and at least one first air cooler module; A second single-stage circulation system, comprising a second compression condensing unit module and at least one second air cooler module; The intermediate heat exchanger system, the first single-stage circulation system and the second single-stage circulation system are both connected to the intermediate heat exchanger system; wherein, The first single-stage circulation system and the second single-stage circulation system can be operated independently, or can be connected to the intermediate heat exchanger system to form a cascade circulation system, and in the cascade circulation system, the first single-stage circulation system or the second single-stage circulation system can serve as the low-temperature stage; The intermediate heat exchanger system includes an evaporative condenser, and a first tube body, a second tube body, a third tube body and a fourth tube body connected to the evaporative condenser; opposite sides of the first air cooler module and the first compression condensing unit module are connected to the first tube body and the third tube body; opposite sides of the second air cooler module and the second compression condensing unit module are connected to the second tube body and the fourth tube body; The first air cooler module includes a first evaporator, a first fan disposed on one side of the first evaporator, and a first throttling device connected to the third tube body and the first evaporator; the second air cooler module includes a second evaporator, a second fan disposed on one side of the second evaporator, and a second throttling device connected to the fourth tube body and the second evaporator; In the cascade cycle system, the low temperature stage is used to maintain an evaporation temperature lower than that achieved when the first single-stage cycle system or the second single-stage cycle system is operated alone; The first compression condensing unit module includes a first gas-liquid separator, a first compressor, a first four-way reversing valve, a first outdoor heat exchanger and a third throttling device; The second compression condensing unit module includes a second gas-liquid separator, a second compressor, a second four-way reversing valve, a second outdoor heat exchanger and a fourth throttling device; The first pipe body includes a first flow pipe, a second flow pipe and a third flow pipe, the gas in the first flow pipe flows from the first air cooler module to the intermediate heat exchanger system, the gas in the second flow pipe flows sequentially through the first gas-liquid separator and the first compressor to the intermediate heat exchanger system, the third flow pipe is connected to the second flow pipe, the third flow pipe flows sequentially through the first four-way reversing valve, the first outdoor heat exchanger and the first throttling device to the third pipe body and then flows to the intermediate heat exchanger system; The second pipe body includes a fourth flow pipe, a fifth flow pipe and a sixth flow pipe, the gas of the fourth flow pipe flows from the second air cooler module to the intermediate heat exchanger system, the gas of the fifth flow pipe flows through the second gas-liquid separator and the second compressor in sequence to the intermediate heat exchanger system, the sixth flow pipe is connected to the fifth flow pipe, the sixth flow pipe flows through the second four-way reversing valve, the second outdoor heat exchanger and the second throttling device in sequence to the fourth pipe body and then flows to the intermediate heat exchanger system; The intermediate heat exchanger system further includes a fifth throttling device, a sixth throttling device, a third four-way reversing valve and a fourth four-way reversing valve; The fifth throttling device is arranged on the third pipe body, and the third four-way reversing valve is connected to the first flow pipe and the second flow pipe respectively; The sixth throttling device is arranged on the fourth pipe body, and the fourth four-way reversing valve is connected to the fourth flow pipe and the fifth flow pipe respectively.

2. The single-stage and cascade cycle free-conversion multi-connected variable temperature cold storage refrigeration system according to claim 1 is characterized in that: The first single-stage circulation system further includes a first defrost channel, the first defrost channel being respectively connected to the outlet side of the first compressor in the second circulation pipe and the first air cooler module; The second single-stage circulation system further includes a second defrost passage, which is respectively connected to the outlet side of the second compressor in the fifth circulation pipe and the second air cooler module.

3. The single-stage and cascade cycle free-conversion multi-connected variable temperature cold storage refrigeration system according to claim 2 is characterized in that: The first single-stage circulation system further includes a fifth four-way reversing valve, and the fifth four-way reversing valve is respectively connected to the first defrost channel, the first air cooler module and the first flow pipe; The second single-stage circulation system also includes a sixth four-way reversing valve, which is respectively connected to the second defrost channel, the second air cooler module and the fourth flow pipe.

4. The single-stage, cascade cycle free-conversion multi-connected variable temperature cold storage refrigeration system according to claim 1 is characterized in that: In the cascade circulation system, the evaporative condenser includes an evaporation side and a condensation side, and the evaporation side or the condensation side corresponds to the evaporation end and the condensation end in the first single-stage circulation system or the second single-stage circulation system, respectively.

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