Refrigeration system capable of refrigerating multiple temperature zones

Abstract

The present invention belongs to the field of refrigeration technology, and in particular, relates to a refrigeration system that can provide refrigeration for multiple temperature zones, including a compressor, an oil separator, a condenser, a dryer, a precooler and a second plate heat exchanger connected to the inlet flow path, a first gas-liquid separator and a second gas-liquid separator are respectively connected between the precooler and the second plate heat exchanger, and a first plate heat exchanger is connected between the first gas-liquid separator and the second gas-liquid separator; a first evaporator is connected to the first gas-liquid separator, and the other end of the first evaporator is connected to the precooler; a second evaporator is connected to the second gas-liquid separator, and the other end of the second evaporator is connected to the first plate heat exchanger; and the second plate heat exchanger is respectively connected to the two ends of a third evaporator. The beneficial technical effects of the present application are: a set of refrigeration systems can be used in different temperature zones, saving costs and making the operation simpler and more convenient.

Description

Technical Field

[0001] The invention belongs to the technical field of refrigeration, and in particular relates to a refrigeration system capable of refrigerating multiple temperature zones. Background Art

[0002] In the prior art, a refrigeration system can usually only work on one refrigeration area. However, in large-scale sub-areas such as cold storage, the temperature requirements of different areas are often different. Therefore, it is impossible to perform sub-area refrigeration. Summary of the invention

[0003] The invention provides a refrigeration system capable of refrigerating in multiple temperature zones, and the refrigeration system has a simple structure.

[0004] The technical problem solved by the present invention is achieved by adopting the following technical solutions:

[0005] A refrigeration system capable of providing refrigeration in multiple temperature zones, comprising a refrigeration circuit, wherein the refrigeration circuit comprises an inlet flow path, a return flow path and a defrost flow path;

[0006] The inlet flow path is connected with a compressor, an oil separator, a condenser, a dryer, a precooler and a second plate heat exchanger, the precooler and the second plate heat exchanger are respectively connected with a first gas-liquid separator and a second gas-liquid separator, and the first plate heat exchanger is connected with the first gas-liquid separator and the second gas-liquid separator;

[0007] The first gas-liquid separator is connected to a first evaporator, and the other end of the first evaporator is connected to a precooler; the second gas-liquid separator is connected to a second evaporator, and the other end of the second evaporator is connected to the first plate heat exchanger;

[0008] The second plate heat exchanger is respectively connected to two ends of the third evaporator;

[0009] A first stop valve, a first solenoid valve and a first capillary tube are sequentially connected between the first gas-liquid separator and the first evaporator, and a first return air stop valve is connected between the first evaporator and the precooler;

[0010] A second stop valve, a second solenoid valve and a second capillary tube are connected between the second gas-liquid separator and the second evaporator, and a second return air stop valve is connected between the second evaporator and the first plate heat exchanger;

[0011] A third stop valve, a third solenoid valve and a third capillary tube are connected between the liquid outlet of the second plate heat exchanger and the third evaporator, and a third return air stop valve is connected between the other end of the third evaporator and the air inlet of the second plate heat exchanger;

[0012] The return path is sequentially connected with the second plate heat exchanger, the first plate heat exchanger, the precooler and the compressor;

[0013] The defrost flow path includes a first defrost flow path provided on the first refrigeration circuit, a second defrost flow path provided on the second refrigeration circuit, and a third defrost flow path provided on the third refrigeration circuit;

[0014] The first defrost flow path is sequentially connected to the oil separator, the first defrost stop valve, the first defrost solenoid valve and the first evaporator; the second defrost flow path is sequentially connected to the oil separator, the second defrost stop valve, the second defrost solenoid valve and the second evaporator; the third defrost flow path is sequentially connected to the oil separator, the third defrost stop valve, the third defrost solenoid valve and the third evaporator;

[0015] The refrigeration system further comprises a protection flow path, wherein the protection flow path is sequentially connected with the first plate heat exchanger, the bypass solenoid valve, the expansion container, the bypass capillary tube and the compressor;

[0016] The oil separator is provided with an oil return pipe, and the oil return pipe is connected to the air intake port of the compressor.

[0017] The beneficial effects of the present invention are:

[0018] (1) In this application, a set of refrigeration systems can be used in different temperature zones, saving costs and making the operation simpler and more convenient;

[0019] (2) The present application is provided with a defrost flow path to extend the service life of the evaporator and improve the efficiency of the evaporator;

[0020] (3) In this application, a protective flow path is provided to prevent the system pressure from exceeding the set required maximum value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the refrigeration system in this application;

[0022] Figure 2 is a schematic diagram of the inlet flow path of the refrigeration system in this application;

[0023] Figure 3 It is a schematic diagram of the flow direction of the inlet flow path of the refrigeration system in this application;

[0024] Figure 4 It is a schematic diagram of the flow direction of the return circuit of the refrigeration system in this application;

[0025] 1-compressor, 2-oil separator, 21-return oil pipe, 31-condenser, 32-dryer, 4-precooler, 51-first gas-liquid separator, 52-second gas-liquid separator, 61-first evaporator, 62-second evaporator, 63-third evaporator, 71-first plate heat exchanger, 72-second plate heat exchanger, 811-first stop valve, 812-second stop valve, 813-third stop valve, 821-first solenoid valve, 822-second solenoid valve, 823-third Solenoid valve, 831-first capillary, 832-second capillary, 833-third capillary, 841-first return air stop valve, 842-second return air stop valve, 843-third return air stop valve, 851-first defrost solenoid valve, 852-second defrost solenoid valve, 853-third defrost solenoid valve, 861-first defrost stop valve, 862-second defrost stop valve, 863-third defrost stop valve, 91-bypass solenoid valve, 92-expansion container, 93-bypass capillary. DETAILED DESCRIPTION

[0026] like Figure 1-4 As shown, a refrigeration system capable of providing refrigeration in multiple temperature zones can be used to apply a set of the system to multiple zones requiring refrigeration, including a refrigeration circuit, wherein the refrigeration circuit includes an inlet flow path, a return flow path, and a defrost flow path;

[0027] The inlet flow path is sequentially connected to the compressor 1, the oil separator 2, the condenser 31, the dryer 32, the precooler 4 and the second plate heat exchanger 72 through a one-way pipeline, the first gas-liquid separator 51 and the second gas-liquid separator 52 are respectively connected between the precooler 4 and the second plate heat exchanger 72, and the first plate heat exchanger 71 is connected between the first gas-liquid separator 51 and the second gas-liquid separator 52;

[0028] Preferably, the oil separator 2 is provided with an oil return pipe 21, which is connected to the air intake port of the compressor 1, and the refrigeration oil is returned from the return pipe 21 into the compressor 1, thereby playing a role in lubricating the compressor;

[0029] Since the refrigeration system in this embodiment is suitable for refrigeration in multiple different temperature zones, refrigeration circuits of three temperature zones are arranged on the inlet flow path, including a first refrigeration circuit, a second refrigeration circuit and a third refrigeration circuit;

[0030] The first refrigeration circuit is connected to a first evaporator 61, one end of the first evaporator 61 is connected to the liquid inlet of the first gas-liquid separator 51 through a pipeline, and the other end of the first evaporator 61 is connected to the air inlet of the precooler 4;

[0031] Preferably, a first stop valve 811, a first solenoid valve 821 and a first capillary tube 831 are sequentially connected between the first gas-liquid separator 51 and the first evaporator 61, and a first return air stop valve 841 is connected between the first evaporator 61 and the precooler 4;

[0032] The second refrigeration circuit is connected to a second evaporator 62, one end of the second evaporator 62 is connected to the liquid inlet of the second gas-liquid separator 52 through a pipeline, and the other end of the second evaporator 62 is connected to the air inlet of the first plate heat exchanger 71;

[0033] Preferably, a second stop valve 812, a second solenoid valve 822 and a second capillary tube 832 are sequentially connected between the second gas-liquid separator 52 and the second evaporator 62, and a second return air stop valve 842 is connected between the other end of the second evaporator 62 and the first plate heat exchanger 71;

[0034] The third refrigeration circuit is connected to a third evaporator 63, and both ends of the third evaporator 63 are respectively connected to the liquid outlet and the air inlet of the second plate heat exchanger 72;

[0035] Preferably, a third stop valve 813, a third solenoid valve 823 and a third capillary tube 833 are connected in sequence between the liquid outlet of the second plate heat exchanger 72 and the third evaporator 63, and a third return air stop valve 843 is connected between the other end of the third evaporator 63 and the air inlet of the second plate heat exchanger 72.

[0036] Specifically, after the mixed gas refrigerant is compressed by the compressor 1, it changes from a low-temperature and low-pressure mixed gas state to a high-temperature and high-pressure mixed gas state, and then is discharged from the exhaust port of the compressor 1 into the oil separator 2. The oil separator 2 can separate the refrigeration oil in the mixed gas refrigerant;

[0037] After condensation and drying by the condenser 31 and the dryer 32, the mixed gas refrigerant changes from a high-temperature and high-pressure mixed gas state to a liquid-gas mixed state at room temperature and high pressure, and the residual moisture and impurities in the mixed refrigerant and the system are removed, and then the liquid-gas mixed refrigerant flows into the liquid inlet 41 of the precooler. The function of the precooler is to supercool the mixed refrigerant, and the temperature of the liquid-gas mixed refrigerant is further reduced. The mixed refrigerant enters the first gas-liquid separator 51 for gas-liquid separation. The gaseous refrigerant is discharged from the gas outlet 511 of the first gas-liquid separator 51 and enters the first plate heat exchanger 71; after the liquid refrigerant is discharged from the liquid outlet 512 of the first gas-liquid separator 51, a part of it enters the first plate heat exchanger 71 through the primary capillary tube, and the other part of the liquid refrigerant enters the first evaporator 61. In this process, the refrigerant changes from a low-temperature and high-pressure liquid state to a lower-temperature and low-pressure gas state, and evaporates and absorbs heat in this process. After completing this process, it enters the air inlet 42 of the precooler, thereby completing the first refrigeration circuit;

[0038] After the gaseous mixed refrigerant enters the air inlet of the first plate heat exchanger 71 from the air outlet of the first gas-liquid separator 51, it is cooled to become a low-temperature and high-pressure liquid-gas mixed refrigerant, and enters the second gas-liquid separator 52 for gas-liquid separation. The gaseous refrigerant enters the second plate heat exchanger 72 from the air outlet 521 of the second gas-liquid separator 52. After the liquid refrigerant is discharged from the liquid outlet 522 of the second gas-liquid separator 52, a part of it enters the second plate heat exchanger 72 through the secondary capillary tube, and the other part of the liquid refrigerant enters the second evaporator 62. In this process, the refrigerant changes from a low-temperature and high-pressure liquid state to an ultra-low-temperature and low-pressure gas state, evaporates and absorbs heat in this process, and enters the air inlet of the first plate heat exchanger 71 after completing this process, thereby completing the second refrigeration circuit;

[0039] The gaseous refrigerant entering the second plate heat exchanger 72 from the second gas-liquid separator 52 is cooled into a low-temperature and high-pressure liquid after passing through the second plate heat exchanger 72, and then enters the third evaporator 63 to evaporate and absorb heat. After completing this process, the state of the refrigerant changes to an ultra-low-temperature and low-pressure gas, and then enters the air inlet of the second plate heat exchanger 72, thereby completing the third refrigeration circuit.

[0040] Preferably, in this embodiment, the first refrigeration circuit, the second refrigeration circuit and the third refrigeration circuit can perform refrigeration operations independently, and the temperatures of the refrigeration completed are not the same, and are set according to the actual situation required.

[0041] After completing the refrigeration of different temperature zones, a return path is provided in this embodiment to allow the refrigerant to return to the compressor 1. Specifically, the return path is sequentially connected to the second plate heat exchanger 72, the first plate heat exchanger 71, the precooler 4 and the compressor 1 through a one-way pipe, and the gaseous mixed refrigerant enters the suction port of the compressor to complete the refrigeration cycle.

[0042] Preferably, in order to better extend the service life of the first evaporator 61, the second evaporator 62 and the third evaporator 63 and improve their use efficiency, the refrigeration system is further provided with a defrost flow path, and the defrost flow path includes a first defrost flow path, a second defrost flow path and a third defrost flow path;

[0043] Wherein, the first defrost flow path is arranged on the first refrigeration circuit; preferably, the first defrost flow path is connected to the oil separator 2, the first defrost stop valve 861, the first defrost solenoid valve 851 and the first evaporator 61 in sequence through a one-way pipeline;

[0044] The second defrost flow path is provided on the second refrigeration circuit; preferably, the second defrost flow path is connected to the oil separator 2, the second defrost stop valve 862, the second defrost solenoid valve 852 and the second evaporator 62 in sequence through a one-way pipeline;

[0045] The third defrost flow path is provided on the third refrigeration circuit; preferably, the third defrost flow path is sequentially connected to the oil separator 2, the third defrost stop valve 863, the third defrost solenoid valve 853 and the third evaporator 63 through a one-way pipeline;

[0046] When refrigeration is performed for multiple temperature zones, the first, second and third defrost solenoid valves are closed; when defrosting is required for the first, second and third evaporators, the corresponding first, second and third refrigeration solenoid valves are closed, and refrigeration is stopped; the corresponding defrost solenoid valve is opened, and the high-temperature and high-pressure refrigerant enters the corresponding evaporator from the outlet of the oil separator, and then returns to the precooler inlet pipe through the corresponding return air check valve, and then returns to the suction port of the compressor 1, so as to perform daily defrosting work;

[0047] Preferably, in this embodiment, the first defrost flow path, the second defrost flow path and the third defrost flow path can be operated simultaneously or independently according to actual needs.

[0048] Preferably, in this embodiment, a protection flow path is also provided, and the refrigeration system also includes a protection flow path, and the protection flow path is connected to the first plate heat exchanger 71, the bypass solenoid valve 91, the expansion container 92, the bypass capillary 93 and the compressor 1 in sequence through a one-way pipe; when the system pressure exceeds the set maximum pressure, the bypass solenoid valve 91 is energized and the high-pressure refrigerant enters the expansion container 92, and then returns to the compressor 1 through the bypass capillary 93, thereby protecting the system.

[0049] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of application of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A refrigeration system capable of providing refrigeration in multiple temperature zones, characterized in that: A refrigeration circuit is included, wherein the refrigeration circuit includes an inlet flow path and a return flow path; The inlet flow path is connected with a compressor (1), an oil separator (2), a condenser (31), a dryer (32), a precooler (4) and a second plate heat exchanger (72); a first gas-liquid separator (51) and a second gas-liquid separator (52) are respectively connected between the precooler (4) and the second plate heat exchanger (72); and the first plate heat exchanger (71) is connected between the first gas-liquid separator (51) and the second gas-liquid separator (52); The inlet flow path is provided with a refrigeration circuit with three temperature zones, including a first refrigeration circuit, a second refrigeration circuit and a third refrigeration circuit, the first refrigeration circuit is connected to a first evaporator (61), the second refrigeration circuit is connected to a second evaporator (62), and the third refrigeration circuit is connected to a third evaporator (63); The first gas-liquid separator (51) is connected to a first evaporator (61), and the other end of the first evaporator (61) is connected to a precooler (4); The second gas-liquid separator (52) is connected to a second evaporator (62), and the other end of the second evaporator (62) is connected to the first plate heat exchanger (71); The second plate heat exchanger (72) is respectively connected to two ends of the third evaporator (63); The return line is connected in sequence to the second plate heat exchanger (72), the first plate heat exchanger (71), the precooler (4) and the compressor (1).

2. A refrigeration system capable of providing refrigeration in multiple temperature zones according to claim 1, characterized in that: A first stop valve (811), a first solenoid valve (821) and a first capillary tube (831) are connected in sequence between the first gas-liquid separator (51) and the first evaporator (61); and a first return air stop valve (841) is connected between the first evaporator (61) and the precooler (4).

3. The refrigeration system capable of providing refrigeration in multiple temperature zones according to claim 1, characterized in that: A second stop valve (812), a second solenoid valve (822) and a second capillary tube (832) are connected between the second gas-liquid separator (52) and the second evaporator (62), and a second return air stop valve (842) is connected between the second evaporator (62) and the first plate heat exchanger (71).

4. The refrigeration system capable of providing refrigeration in multiple temperature zones according to claim 1, characterized in that: A third stop valve (813), a third solenoid valve (823) and a third capillary tube (833) are connected between the liquid outlet of the second plate heat exchanger (72) and the third evaporator (63), and a third return air stop valve (843) is connected between the other end of the third evaporator (63) and the air inlet of the second plate heat exchanger (72).

5. The refrigeration system capable of providing refrigeration in multiple temperature zones according to claim 1, characterized in that: The refrigeration system further includes a defrost flow path, which includes a first defrost flow path provided on the first refrigeration circuit, a second defrost flow path provided on the second refrigeration circuit, and a third defrost flow path provided on the third refrigeration circuit.

6. A refrigeration system capable of providing refrigeration in multiple temperature zones according to claim 5, characterized in that: The first defrost circuit is connected in sequence to the oil separator (2), the first defrost stop valve (861), the first defrost solenoid valve (851) and the first evaporator (61); the second defrost circuit is connected in sequence to the oil separator (2), the second defrost stop valve (862), the second defrost solenoid valve (852) and the second evaporator (62); the third defrost circuit is connected in sequence to the oil separator (2), the third defrost stop valve (863), the third defrost solenoid valve (853) and the third evaporator (63).

7. The refrigeration system capable of providing refrigeration in multiple temperature zones according to claim 1, characterized in that: The refrigeration system further comprises a protection flow path, which is sequentially connected to the first plate heat exchanger (71), a bypass solenoid valve (91), an expansion container (92), a bypass capillary tube (93) and the compressor (1).

8. The refrigeration system capable of providing refrigeration in multiple temperature zones according to claim 1, characterized in that: The oil separator (2) is provided with an oil return pipe (21), and the oil return pipe (21) is connected to the air intake port of the compressor (1).

Images