Control method for a compression refrigeration system and compression refrigeration system

Abstract

The application relates to a control method and device of a compression refrigeration system, the compression refrigeration system, a computer readable storage medium and a computer program product. The method comprises the following steps: determining whether the compression refrigeration system meets the double-stage low-pressure air supplement mode operation condition based on the actual water outlet temperature of the compression refrigeration system; when the compression refrigeration system meets the double-stage low-pressure air supplement mode operation condition, controlling the compression refrigeration system to operate in the double-stage low-pressure air supplement mode; in the double-stage low-pressure air supplement mode, the refrigerant flowing out of the first end of the compressor in the compression refrigeration system is subjected to temperature and pressure reduction treatment through at least two low-pressure air supplement circuits, and the refrigerant passing through the at least two low-pressure air supplement circuits is mixed at the second end of the compressor. The method can improve the stability of the system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, and in particular to a control method of a compression refrigeration system, a device of the compression refrigeration system, the compression refrigeration system, a computer readable storage medium, and a computer program product. BACKGROUND

[0002] With the development of air conditioning technology, a compression refrigeration system appears, in the operation process of the compression refrigeration system,

[0003] If the ambient temperature is too high, the exhaust temperature of the system is relatively high, and in severe cases, it may even exceed the normal operation range of the compressor, so that the system operation stability is not high. SUMMARY

[0004] Therefore, it is necessary to provide a control method, device, compression refrigeration system, computer readable storage medium, and computer program product of the compression refrigeration system, which can improve the system stability.

[0005] In a first aspect, the present application provides a control method of a compression refrigeration system, the method comprising:

[0006] determining whether the compression refrigeration system meets a double-stage low-pressure gas supplement mode operation condition based on an actual outlet water temperature of the compression refrigeration system;

[0007] controlling the compression refrigeration system to operate in a double-stage low-pressure gas supplement mode when the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition; in the double-stage low-pressure gas supplement mode, refrigerant from a first end of a compressor in the compression refrigeration system is subjected to cooling and pressure reduction processing through at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at a second end of the compressor.

[0008] In one embodiment, the determining whether the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition based on the actual outlet water temperature of the compression refrigeration system comprises: when a difference between the actual outlet water temperature and a target outlet water temperature is within a preset range, increasing a rotation speed of a compressor of the compression refrigeration system, and obtaining an actual exhaust temperature of the compression refrigeration system after the rotation speed of the compressor is increased.

[0009] determining that the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition when the actual exhaust temperature of the compression refrigeration system after the rotation speed of the compressor is increased is greater than or equal to a target exhaust temperature.

[0010] In one embodiment, the actual outlet water temperature is obtained in the following manner:

[0011] obtaining an actual exhaust temperature of the compression refrigeration system and an actual ambient temperature of the compression refrigeration system;

[0012] When the actual ambient temperature is greater than or equal to the target ambient temperature, and the actual exhaust temperature is less than the target water outlet temperature, an actual water outlet temperature of the compression refrigeration system is obtained.

[0013] In one embodiment, the compression refrigeration system comprises a condenser, the at least two low-pressure supplemental gas circuits comprise a first low-pressure supplemental gas circuit and a second low-pressure supplemental gas circuit, and the control of the compression refrigeration system to run the two-stage low-pressure supplemental gas mode comprises:

[0014] controlling a first control valve of the first low-pressure supplemental gas circuit to open; wherein a first end of the first low-pressure supplemental gas circuit is connected to a second end of the condenser, and a second end of the first low-pressure supplemental gas circuit is connected to a second end of the compressor; the first low-pressure supplemental gas circuit comprises the first control valve, a supplemental gas circuit electronic expansion valve, a first end and a third end of an intermediate heat exchanger;

[0015] controlling a second control valve of the second low-pressure supplemental gas circuit to open; wherein a first end of the second low-pressure supplemental gas circuit is connected to the second end of the condenser, a first end of the second low-pressure supplemental gas circuit is connected to the second end of the condenser, and a second end of the second low-pressure supplemental gas circuit is connected to the second end of the compressor through a main circuit electronic expansion valve and an evaporator; the second low-pressure supplemental gas circuit comprises the second control valve, a second end and a fourth end of the intermediate heat exchanger;

[0016] controlling a main circuit control valve to close; wherein a first end of the main circuit control valve is connected to the second end of the condenser, a second end of the main circuit control valve is connected to a first end of the main circuit electronic expansion valve, a second end of the main circuit electronic expansion valve is connected to a first end of the evaporator, and a second end of the evaporator is connected to the second end of the compressor.

[0017] In one embodiment, after the control of the compression refrigeration system to run the two-stage low-pressure supplemental gas mode, the method further comprises:

[0018] controlling an opening degree of the supplemental gas circuit electronic expansion valve according to the re-obtained actual exhaust temperature of the compression refrigeration system; wherein the opening degree of the supplemental gas circuit electronic expansion valve and the exhaust temperature of the compression refrigeration system have a mapping relationship.

[0019] In one embodiment, the control of the opening degree of the supplemental gas circuit electronic expansion valve according to the re-obtained actual exhaust temperature of the compression refrigeration system comprises:

[0020] obtaining a corresponding relationship between the opening degree of the supplemental gas circuit electronic expansion valve of the compression refrigeration system and the exhaust temperature of the compression refrigeration system;

[0021] According to the correspondence and the re-acquired actual exhaust temperature of the compression refrigeration system, the opening of the supplemental route electronic expansion valve is controlled.

[0022] In one embodiment, the method further comprises:

[0023] When the compression refrigeration system does not satisfy the double-stage low-pressure gas supplement mode operation condition, the compression refrigeration system is controlled to operate in a single-stage low-pressure gas supplement mode; in the single-stage low-pressure gas supplement mode, the refrigerant from the first end of the compressor is subjected to temperature and pressure reduction treatment through the main route electronic expansion valve and the evaporator.

[0024] In one embodiment, the control of the compression refrigeration system to operate in the single-stage low-pressure gas supplement mode comprises:

[0025] The first control valve of the first low-pressure gas supplement circuit is controlled to be closed, the second control valve of the second low-pressure gas supplement circuit is controlled to be closed, and the main route control valve is controlled to be opened.

[0026] In a second aspect, the application provides a compression refrigeration system, comprising: a controller, a temperature sensor,

[0027] The temperature sensor is configured to acquire an actual outlet water temperature of the compression refrigeration system.

[0028] The controller is configured to determine, based on the actual outlet water temperature of the compression refrigeration system, whether the compression refrigeration system satisfies a double-stage low-pressure gas supplement mode operation condition; when the compression refrigeration system satisfies the double-stage low-pressure gas supplement mode operation condition, the compression refrigeration system is controlled to operate in a double-stage low-pressure gas supplement mode; in the double-stage low-pressure gas supplement mode, the refrigerant from the first end of the compressor in the compression refrigeration system is subjected to temperature and pressure reduction treatment through at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at the second end of the compressor.

[0029] In one embodiment, the compression refrigeration system further comprises: a condenser and an intermediate heat exchanger; the first end of the condenser is connected to the first end of the compressor; the intermediate heat exchanger comprises a first end and a second end, a third end and a fourth end, the first end is in communication with the third end, and the second end is in communication with the fourth end; the at least two low-pressure gas supplement circuits comprise a first low-pressure gas supplement circuit and a second low-pressure gas supplement circuit,

[0030] The first end of the first low-pressure gas supplement circuit is connected to the second end of the condenser, and the second end of the first low-pressure gas supplement circuit is connected to the second end of the compressor; the first low-pressure gas supplement circuit comprises a first control valve, a supplemental route electronic expansion valve, the first end and the third end of the intermediate heat exchanger;

[0031] The first end of the second low-pressure gas supplementing circuit is connected with the second end of the condenser, and the second end of the second low-pressure gas supplementing circuit is connected with the second end of the compressor through the main circuit electronic expansion valve and the evaporator; the second low-pressure gas supplementing circuit comprises a second control valve, a second end and a fourth end of the intermediate heat exchanger.

[0032] In one embodiment, the controller is further configured to: control the first control valve of the first low-pressure gas supplementing circuit to open; control the second control valve of the second low-pressure gas supplementing circuit to open; and control the main circuit control valve to close; the first end of the main circuit control valve is connected with the second end of the condenser, the second end of the main circuit control valve is connected with the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected with the first end of the evaporator, and the second end of the evaporator is connected with the second end of the compressor.

[0033] In one embodiment, the controller is further configured to: control the first control valve of the first low-pressure gas supplementing circuit to close, control the second control valve of the second low-pressure gas supplementing circuit to close, and control the main circuit control valve to open, so that the compression refrigeration system operates in a single-stage low-pressure gas supplementing mode; in the single-stage low-pressure gas supplementing mode, the refrigerant from the first end of the compressor is subjected to temperature and pressure reduction treatment through the main circuit electronic expansion valve and the evaporator.

[0034] In a third aspect, the present application provides a compression refrigeration system, which comprises:

[0035] a compressor;

[0036] a condenser, a first end of the condenser being connected with a first end of the compressor;

[0037] an intermediate heat exchanger; the intermediate heat exchanger comprises a first end and a second end, a third end and a fourth end, the first end being in communication with the third end, and the second end being in communication with the fourth end;

[0038] at least two low-pressure gas supplementing circuits; the at least two low-pressure gas supplementing circuits comprise the first low-pressure gas supplementing circuit and the second low-pressure gas supplementing circuit;

[0039] a first end of the first low-pressure gas supplementing circuit is connected with a second end of the condenser, and a second end of the first low-pressure gas supplementing circuit is connected with a second end of the compressor; the first low-pressure gas supplementing circuit comprises a first control valve, a supplement circuit electronic expansion valve, the first end and the third end of the intermediate heat exchanger;

[0040] The first end of the second low-pressure supplementing circuit is connected with the second end of the condenser, the second end of the second low-pressure supplementing circuit is connected with the second end of the compressor through the main circuit electronic expansion valve and the evaporator; the second low-pressure supplementing circuit comprises a second control valve, a second end and a fourth end of the intermediate heat exchanger.

[0041] In one embodiment, the compression refrigeration system further comprises a main circuit control valve; the first end of the main circuit control valve is connected with the second end of the condenser, the second end of the main circuit control valve is connected with the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected with the first end of the evaporator, and the second end of the evaporator is connected with the second end of the compressor.

[0042] In one embodiment, the first end of the supplement circuit electronic expansion valve is connected with the second end of the condenser, the second end of the supplement circuit electronic expansion valve is connected with the first end of the intermediate heat exchanger, the third end of the intermediate heat exchanger is connected with the first end of the first control valve, and the second end of the first control valve is connected with the second end of the compressor.

[0043] In one embodiment, the first end of the supplement circuit electronic expansion valve is connected with the third end of the intermediate heat exchanger, the second end of the supplement circuit electronic expansion valve is connected with the first end of the first control valve, the second end of the first control valve is connected with the second end of the compressor, and the first end of the intermediate heat exchanger is connected with the second end of the condenser.

[0044] In one embodiment, the first end of the supplement circuit electronic expansion valve is connected with the second end of the first control valve, the second end of the supplement circuit electronic expansion valve is connected with the second end of the compressor, the first end of the first control valve is connected with the third end of the intermediate heat exchanger, and the first end of the intermediate heat exchanger is connected with the second end of the condenser.

[0045] In one embodiment, the first end of the first control valve is connected with the second end of the condenser, the second end of the first control valve is connected with the first end of the supplement circuit electronic expansion valve, the second end of the supplement circuit electronic expansion valve is connected with the first end of the intermediate heat exchanger, and the third end of the intermediate heat exchanger is connected with the second end of the compressor.

[0046] In one embodiment, the first end of the first control valve is connected with the second end of the supplement circuit electronic expansion valve, the second end of the first control valve is connected with the first end of the intermediate heat exchanger, the first end of the supplement circuit electronic expansion valve is connected with the second end of the condenser, and the third end of the intermediate heat exchanger is connected with the second end of the compressor.

[0047] In one embodiment, the first end of the second control valve is connected to the second end of the condenser, the second end of the second control valve is connected to the second end of the intermediate heat exchanger, and the fourth end of the intermediate heat exchanger is connected to the second end of the compressor through the main electronic expansion valve, the evaporator.

[0048] In one embodiment, the first end of the main electronic expansion valve is connected to the fourth end of the intermediate heat exchanger, the second end of the main electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor.

[0049] In one embodiment, the first end of the second control valve is connected to the fourth end of the intermediate heat exchanger, the second end of the second control valve is connected to the second end of the compressor through the main electronic expansion valve and the evaporator, and the second end of the intermediate heat exchanger is connected to the second end of the condenser.

[0050] In a fourth aspect, the present application further provides a control device of a compression refrigeration system. The device comprises:

[0051] A determination module is configured to determine whether the compression refrigeration system meets a double-stage low-pressure gas supplement mode operation condition based on an actual outlet water temperature of the compression refrigeration system.

[0052] A control module is configured to control the compression refrigeration system to operate in a double-stage low-pressure gas supplement mode when the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition. In the double-stage low-pressure gas supplement mode, the refrigerant from the first end of the compressor in the compression refrigeration system is subjected to cooling and pressure reduction through at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at the second end of the compressor.

[0053] In a fifth aspect, the present application further provides a computer readable storage medium. The computer readable storage medium has a computer program stored thereon, and the computer program is executed by a processor to implement the following steps:

[0054] Determine whether the compression refrigeration system meets a double-stage low-pressure gas supplement mode operation condition based on an actual outlet water temperature of the compression refrigeration system.

[0055] Control the compression refrigeration system to operate in a double-stage low-pressure gas supplement mode when the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition. In the double-stage low-pressure gas supplement mode, the refrigerant from the first end of the compressor in the compression refrigeration system is subjected to cooling and pressure reduction through at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at the second end of the compressor.

[0056] In a sixth aspect, the present application also provides a computer program product. The computer program product comprises a computer program which, when executed by a processor, implements the following steps:

[0057] determining whether the compression refrigeration system meets a two-stage low-pressure gas supplement mode operation condition based on the actual outlet water temperature of the compression refrigeration system;

[0058] controlling the compression refrigeration system to operate in the two-stage low-pressure gas supplement mode when the compression refrigeration system meets the two-stage low-pressure gas supplement mode operation condition; in the two-stage low-pressure gas supplement mode, the refrigerant coming out of the first end of the compressor in the compression refrigeration system is subjected to temperature and pressure reduction treatment through at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at the second end of the compressor.

[0059] The control method and device of the compression refrigeration system, the compression refrigeration system, the storage medium and the computer program product described above, by determining whether the compression refrigeration system meets a two-stage low-pressure gas supplement mode operation condition based on the actual outlet water temperature of the compression refrigeration system, and controlling the compression refrigeration system to operate in the two-stage low-pressure gas supplement mode when the compression refrigeration system meets the two-stage low-pressure gas supplement mode operation condition, so that the refrigerant coming out of the first end of the compressor in the compression refrigeration system can be subjected to temperature and pressure reduction treatment through at least two low-pressure gas supplement circuits, thereby reducing the exhaust temperature of the compression refrigeration system and improving the stability of the refrigeration system. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1 FIG. 1 is a structural schematic diagram of a compression refrigeration system in one embodiment;

[0061] Figure 2 FIG. 2 is a flowchart of a control method of a compression refrigeration system in one embodiment;

[0062] Figure 3 FIG. 3 is a flowchart of controlling the opening degree of a supplement electronic expansion valve according to the actual exhaust temperature of a compression refrigeration system reacquired in one embodiment;

[0063] Figure 4 FIG. 4 is a flowchart of determining whether a compression refrigeration system meets a two-stage low-pressure gas supplement mode operation condition based on the actual outlet water temperature of the compression refrigeration system in one embodiment;

[0064] Figure 5 FIG. 5 is a flowchart of the acquisition method of the actual outlet water temperature in one embodiment;

[0065] Figure 6 FIG. 6 is a flowchart of a control method of a compression refrigeration system in one embodiment;

[0066] Figure 7A structural block diagram of a control device for a compression refrigeration system in one embodiment. DETAILED DESCRIPTION

[0067] For the purpose, technical solutions and advantages of the present application to be clearer, the present application will be further described in details below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0068] The control method of the compression refrigeration system provided by the embodiments of the present application can be applied to the compression refrigeration system. The compression refrigeration system comprises a compressor, a condenser, an intermediate heat exchanger, a first low-pressure supplement circuit and a second low-pressure supplement circuit.

[0069] Specifically, the first end of the condenser is connected with the first end of the compressor; the intermediate heat exchanger comprises a first end and a second end, a third end and a fourth end, the first end of the intermediate heat exchanger is communicated with the third end of the intermediate heat exchanger, and the second end of the intermediate heat exchanger is communicated with the fourth end of the intermediate heat exchanger; the first low-pressure supplement circuit comprises a first control valve, a supplement circuit electronic expansion valve, the first end and the third end of the intermediate heat exchanger, the first end of the first low-pressure supplement circuit is connected with the second end of the condenser, and the second end of the first low-pressure supplement circuit is connected with the second end of the compressor; the second low-pressure supplement circuit comprises a second control valve, the second end and the fourth end of the intermediate heat exchanger, the first end of the second low-pressure supplement circuit is connected with the second end of the condenser, and the second end of the second low-pressure supplement circuit is connected with the second end of the compressor through the main circuit electronic expansion valve and the evaporator.

[0070] In one embodiment, the compression refrigeration system further comprises a main circuit control valve; the first end of the main circuit control valve is connected with the second end of the condenser, the second end of the main circuit control valve is connected with the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected with the first end of the evaporator, and the second end of the evaporator is connected with the second end of the compressor.

[0071] In one embodiment, the first end of the supplement circuit electronic expansion valve is connected with the second end of the condenser, the second end of the supplement circuit electronic expansion valve is connected with the first end of the intermediate heat exchanger, the third end of the intermediate heat exchanger is connected with the first end of the first control valve, and the second end of the first control valve is connected with the second end of the compressor.

[0072] In one embodiment, the first end of the supplement circuit electronic expansion valve is connected with the third end of the intermediate heat exchanger, the second end of the supplement circuit electronic expansion valve is connected with the first end of the first control valve, the second end of the first control valve is connected with the second end of the compressor, and the first end of the intermediate heat exchanger is connected with the second end of the condenser.

[0073] In one embodiment, the first end of the supplemental electronic expansion valve is connected to the second end of the first control valve, the second end of the supplemental electronic expansion valve is connected to the second end of the compressor, the first end of the first control valve is connected to the third end of the intermediate heat exchanger, and the first end of the intermediate heat exchanger is connected to the second end of the condenser.

[0074] In one embodiment, the first end of the first control valve is connected to the second end of the condenser, the second end of the first control valve is connected to the first end of the supplemental electronic expansion valve, the second end of the supplemental electronic expansion valve is connected to the first end of the intermediate heat exchanger, and the third end of the intermediate heat exchanger is connected to the second end of the compressor.

[0075] In one embodiment, the first end of the first control valve is connected to the second end of the condenser, the second end of the first control valve is connected to the first end of the supplemental electronic expansion valve, the second end of the supplemental electronic expansion valve is connected to the first end of the intermediate heat exchanger, and the third end of the intermediate heat exchanger is connected to the second end of the compressor.

[0076] In one embodiment, the first end of the first control valve is connected to the second end of the condenser, the second end of the first control valve is connected to the first end of the supplemental electronic expansion valve, the second end of the supplemental electronic expansion valve is connected to the first end of the intermediate heat exchanger, and the third end of the intermediate heat exchanger is connected to the second end of the compressor.

[0077] In one embodiment, the first end of the first control valve is connected to the second end of the condenser, the second end of the first control valve is connected to the first end of the supplemental electronic expansion valve, the second end of the supplemental electronic expansion valve is connected to the first end of the intermediate heat exchanger, and the third end of the intermediate heat exchanger is connected to the second end of the compressor.

[0078] In one embodiment, the first end of the first control valve is connected to the second end of the condenser, the second end of the first control valve is connected to the first end of the supplemental electronic expansion valve, the second end of the supplemental electronic expansion valve is connected to the first end of the intermediate heat exchanger, and the third end of the intermediate heat exchanger is connected to the second end of the compressor.

[0079] Further, in one embodiment, the controller is further configured to control the first control valve of the first low-pressure supplemental gas circuit to open, control the second control valve of the second low-pressure supplemental gas circuit to open, and control the main circuit control valve to close, so as to operate the two-stage low-pressure supplemental gas mode; wherein the first end of the main circuit control valve is connected with the second end of the condenser, the second end of the main circuit control valve is connected with the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected with the first end of the evaporator, and the second end of the evaporator is connected with the second end of the compressor.

[0080] In one embodiment, the controller is further configured to control the first control valve of the first low-pressure supplemental gas circuit to close, control the second control valve of the second low-pressure supplemental gas circuit to close, and control the main circuit control valve to open, so as to operate the single-stage low-pressure supplemental gas mode; in the single-stage low-pressure supplemental gas mode, the refrigerant from the first end of the compressor is subjected to temperature and pressure reduction treatment through the main circuit electronic expansion valve and the evaporator.

[0081] In combination with the above, specifically, as shown in Figure 1 FIG. 1, a structural schematic diagram of a compression refrigeration system is provided. The compression refrigeration system includes a first low-pressure supplemental gas circuit, a second low-pressure supplemental gas circuit, and a single-stage low-pressure supplemental gas circuit, and the first low-pressure supplemental gas circuit and the second low-pressure supplemental gas circuit form a two-stage low-pressure supplemental gas circuit.

[0082] The first low-pressure supplemental gas circuit includes a compressor 102, a condenser 104, a supplemental circuit electronic expansion valve 106, an intermediate heat exchanger 108, and a first control valve 110. In the first low-pressure supplemental gas circuit, the first end of the compressor is connected with the first end of the condenser, the second end of the condenser is connected with the first end of the supplemental circuit electronic expansion valve, the second end of the supplemental circuit electronic expansion valve is connected with the first end of the intermediate heat exchanger, the first end of the intermediate heat exchanger is in communication with the third end of the intermediate heat exchanger, the third end of the intermediate heat exchanger is connected with the first end of the first control valve, and the second end of the first control valve is connected with the second end of the compressor.

[0083] The second low-pressure supplemental gas circuit includes the compressor 102, the condenser 104, a second control valve 112, the intermediate heat exchanger 108, a main circuit electronic expansion valve 114, and an evaporator 116. In the second low-pressure supplemental gas circuit, the first end of the compressor is connected with the first end of the condenser, the second end of the condenser is connected with the first end of the second control valve, the second end of the second control valve is connected with the second end of the intermediate heat exchanger, the second end of the intermediate heat exchanger is in communication with the fourth end of the intermediate heat exchanger, the fourth end of the intermediate heat exchanger is connected with the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected with the first end of the evaporator, and the second end of the evaporator is connected with the second end of the compressor.

[0084] The single-stage low-pressure gas supplement circuit comprises a compressor 102, a condenser 104, a main circuit control valve 118, a main circuit electronic expansion valve 114, and an evaporator 116. In the single-stage low-pressure gas supplement circuit, the first end of the compressor is connected to the first end of the condenser, the second end of the condenser is connected to the first end of the main circuit control valve, the second end of the main circuit control valve is connected to the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor. The second end of the compressor is the suction port end of the compressor.

[0085] In combination with the above, in one embodiment, as shown in Figure 2 a control method of a compression refrigeration system is provided. The control method is applied to a controller in the compression refrigeration system, and comprises the following steps:

[0086] S202, determining whether the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition based on the actual outlet water temperature of the compression refrigeration system.

[0087] In combination with Figure 1 , in the compression refrigeration system, a temperature sensor can be arranged at the third end and the fourth end of the intermediate heat exchanger, and the temperature sensor can obtain the actual outlet water temperature of the compression refrigeration system. After obtaining the actual outlet water temperature based on the temperature sensor, whether the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition is determined according to the actual outlet water temperature.

[0088] S204, when the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition, controlling the compression refrigeration system to operate in the double-stage low-pressure gas supplement mode.

[0089] In the double-stage low-pressure gas supplement mode, the refrigerant discharged from the first end of the compressor in the compression refrigeration system is subjected to cooling and pressure reduction through at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at the second end of the compressor.

[0090] In one embodiment, the compression refrigeration system comprises a condenser, the at least two low-pressure gas supplement circuits comprise a first low-pressure gas supplement circuit and a second low-pressure gas supplement circuit, the first end of the first low-pressure gas supplement circuit is connected to the second end of the condenser, and the second end of the first low-pressure gas supplement circuit is connected to the second end of the compressor; the first low-pressure gas supplement circuit comprises a first control valve, a supplement circuit electronic expansion valve, a first end of an intermediate heat exchanger, and a third end of the intermediate heat exchanger; the first end of the second low-pressure gas supplement circuit is connected to the second end of the condenser, the first end of the second low-pressure gas supplement circuit is connected to the second end of the condenser, and the second end of the second low-pressure gas supplement circuit is connected to the second end of the compressor through a main circuit electronic expansion valve and an evaporator; the second low-pressure gas supplement circuit comprises a second control valve, a second end of the intermediate heat exchanger, and a fourth end of the intermediate heat exchanger.

[0091] Further, when the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition, the compression refrigeration system is controlled to operate in the double-stage low-pressure gas supplement mode, including: controlling the first control valve of the first low-pressure gas supplement circuit to open, controlling the second control valve of the second low-pressure gas supplement circuit to open, and controlling the main circuit control valve to close. The first end of the main circuit control valve is connected with the second end of the condenser, the second end of the main circuit control valve is connected with the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected with the first end of the evaporator, and the second end of the evaporator is connected with the second end of the compressor.

[0092] In summary, in the embodiments shown in the embodiments, whether the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition is determined based on the actual outlet water temperature of the compression refrigeration system, and when the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition, the compression refrigeration system is controlled to operate in the double-stage low-pressure gas supplement mode, so that the refrigerant from the first end of the compressor can be cooled and decompressed through at least two low-pressure gas supplement circuits, thereby reducing the exhaust temperature of the compression refrigeration system and improving the stability of the compression refrigeration system. Figure 2 In the embodiments shown in the embodiments, whether the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition is determined based on the actual outlet water temperature of the compression refrigeration system, and when the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition, the compression refrigeration system is controlled to operate in the double-stage low-pressure gas supplement mode, so that the refrigerant from the first end of the compressor can be cooled and decompressed through at least two low-pressure gas supplement circuits, thereby reducing the exhaust temperature of the compression refrigeration system and improving the stability of the compression refrigeration system.

[0093] In one embodiment, after the compression refrigeration system is controlled to operate in the double-stage low-pressure gas supplement mode, the method further includes: controlling the opening degree of the supplement circuit electronic expansion valve according to the re-acquired actual exhaust temperature of the compression refrigeration system; and the opening degree of the supplement circuit electronic expansion valve and the exhaust temperature of the compression refrigeration system have a mapping relationship.

[0094] Specifically, in one embodiment, as shown in the embodiments, a flowchart for controlling the opening degree of the supplement circuit electronic expansion valve according to the re-acquired actual exhaust temperature of the compression refrigeration system is provided, including the following steps: Figure 3

[0095] S302, obtaining the corresponding relationship between the opening degree of the supplement circuit electronic expansion valve of the compression refrigeration system and the exhaust temperature of the compression refrigeration system.

[0096] S304, controlling the opening degree of the supplement circuit electronic expansion valve according to the corresponding relationship and the re-acquired actual exhaust temperature of the compression refrigeration system.

[0097] It can be understood that in the case where the refrigerant passing through at least two low-pressure gas supplement circuits is mixed at the second end of the compressor to reduce the exhaust temperature, the exhaust temperature may be too low, and therefore, according to the method shown in the embodiments, the opening degree of the supplement circuit electronic expansion valve is adjusted according to the mapping relationship and the actual exhaust temperature, which can avoid the exhaust temperature being too low to affect the energy efficiency of the compression refrigeration system, so that the exhaust temperature can be controlled within a reasonable range, thereby improving the stability of the system. Figure 3

[0098] ​​In one embodiment, when the compression refrigeration system does not meet the double-stage low-pressure gas supplement mode operation condition, the compression refrigeration system is controlled to operate in a single-stage low-pressure gas supplement mode; in the single-stage low-pressure gas supplement mode, the refrigerant from the first end of the compressor is subjected to temperature and pressure reduction treatment through the main circuit electronic expansion valve and the evaporator.

[0099] Specifically, in one embodiment, the control of the compression refrigeration system operating in the single-stage low-pressure gas supplement mode comprises: controlling the first control valve of the first low-pressure gas supplement circuit to be closed, controlling the second control valve of the second low-pressure gas supplement circuit to be closed, and controlling the main circuit control valve of the single-stage low-pressure gas supplement circuit to be opened. In the single-stage low-pressure gas supplement circuit, the first end of the compressor is connected to the first end of the condenser, the second end of the condenser is connected to the first end of the main circuit control valve, the second end of the main circuit control valve is connected to the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor.

[0100] In one embodiment, as shown in Figure 4 , a flowchart for determining whether the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition based on the actual outlet water temperature of the compression refrigeration system is provided, comprising the following steps:

[0101] S402, when the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range, increasing the rotation speed of the compressor of the compression refrigeration system, and obtaining the actual exhaust temperature of the compression refrigeration system after increasing the rotation speed of the compressor.

[0102] In combination Figure 1 , in the compression refrigeration system, a temperature sensor can be arranged at the first end of the compressor, and the temperature sensor can obtain the actual exhaust temperature of the compression refrigeration system after increasing the rotation speed of the compressor.

[0103] In one embodiment, when the difference between the actual outlet water temperature and the target outlet water temperature is less than or equal to a threshold value, it can be determined that the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range; when the difference between the actual outlet water temperature and the target outlet water temperature is greater than the threshold value, it can be determined that the difference between the actual outlet water temperature and the target outlet water temperature is outside the preset range.

[0104] S404, when the actual exhaust temperature after increasing the rotation speed of the compressor is greater than or equal to the target exhaust temperature, it is determined that the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition.

[0105] In summary, in Figure 4In the embodiment shown, when the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range, the compressor speed of the compression refrigeration system is increased, and the actual exhaust temperature of the compression refrigeration system after increasing the compressor speed is obtained; and when the actual exhaust temperature after increasing the compressor speed is greater than or equal to the target exhaust temperature, it is determined that the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode.

[0106] It is understandable that when it is determined that the compression refrigeration system meets the operating conditions for the two-stage low-pressure gas supply mode, the system is controlled to operate in the two-stage low-pressure gas supply mode; or when it is determined that the compression refrigeration system does not meet the operating conditions for the two-stage low-pressure gas supply mode, the system is controlled to operate in the single-stage low-pressure gas supply mode. The judgment can be based on the ambient temperature. When the ambient temperature is low, the system is controlled to operate in the single-stage low-pressure gas supply mode; when the ambient temperature is high, the system is controlled to operate in the two-stage low-pressure gas supply mode.

[0107] In one embodiment, such as Figure 5 The diagram illustrates a process for obtaining the actual outlet water temperature, including the following steps:

[0108] S502 obtains the actual exhaust temperature and actual ambient temperature of the compression refrigeration system.

[0109] S504: When the actual ambient temperature is greater than or equal to the target ambient temperature and the actual exhaust temperature is less than the target exhaust temperature, obtain the actual outlet water temperature of the compression refrigeration system.

[0110] Among them, combined Figure 4 , Figure 5 The actual exhaust temperature refers to the exhaust temperature of the compressor before the compressor speed is increased. In one embodiment, this exhaust temperature can be the compressor's exhaust temperature when it starts running, or it can be the exhaust temperature corresponding to the compressor when it is adjusted to a preset speed after running for a period of time. The actual ambient temperature refers to the temperature of the environment in which the compression refrigeration system is currently located. In one embodiment, the actual ambient temperature can be obtained by a temperature sensor installed in the environment.

[0111] In summary, Figure 5In the embodiment shown, the actual exhaust temperature and the actual ambient temperature of the compression refrigeration system are obtained, and when the actual ambient temperature is greater than or equal to the target ambient temperature and the actual exhaust temperature is less than the target exhaust temperature, the actual outlet water temperature of the compression refrigeration system is obtained, and then based on the actual outlet water temperature of the compression refrigeration system, it is determined whether the compression refrigeration system meets the two-stage low-pressure gas supplement mode operation condition; when it is determined that the compression refrigeration system meets the two-stage low-pressure gas supplement mode operation condition, the compression refrigeration system is controlled to run in the two-stage low-pressure gas supplement mode, so that the refrigerant from the first end of the compressor is cooled and depressurized through at least two low-pressure gas supplement circuits, and then the exhaust temperature of the compression refrigeration system is reduced, thereby improving the stability of the refrigeration system.

[0112] In combination with the above, in one embodiment, as shown in Figure 6 A flowchart of a control method of a compression refrigeration system is provided, and the method is applied to a controller in the compression refrigeration system. The specific content is described as follows:

[0113] S602, obtaining the actual exhaust temperature and the actual ambient temperature of the compression refrigeration system.

[0114] S604, determining whether the actual ambient temperature is greater than or equal to the target ambient temperature, and whether the actual exhaust temperature is less than the target exhaust temperature.

[0115] Specifically, when the actual ambient temperature is less than the target ambient temperature, and / or, the actual exhaust temperature is greater than or equal to the target exhaust temperature, S606 is executed. When the actual ambient temperature is greater than or equal to the target ambient temperature, and the actual exhaust temperature is less than the target exhaust temperature, S608-S610 are executed.

[0116] S606, controlling the compression refrigeration system to run in a single-stage low-pressure gas supplement mode.

[0117] S608, obtaining the actual outlet water temperature of the compression refrigeration system.

[0118] S610, determining whether the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range.

[0119] Specifically, when it is determined that the difference between the actual outlet water temperature and the target outlet water temperature is outside the preset range, S606 is executed. When it is determined that the difference between the actual outlet water temperature and the target outlet water temperature is within the preset range, S612-S614 are executed.

[0120] S612, increasing the speed of the compressor.

[0121] S614, determining whether the actual exhaust temperature after increasing the speed of the compressor is greater than or equal to the target exhaust temperature.

[0122] Specifically, when the actual discharge temperature after increasing the compressor speed is determined to be less than the target discharge temperature, S606 is performed. When the actual discharge temperature after increasing the compressor speed is determined to be greater than or equal to the target discharge temperature, S616-S618 are performed.

[0123] S616, controlling the compression refrigeration system to operate in a two-stage low-pressure subcooled mode, in which the first control valve of the first low-pressure subcooled circuit of the compression refrigeration system is controlled to open, the second control valve of the second low-pressure subcooled circuit of the compression refrigeration system is controlled to open, and the main control valve of the single-stage low-pressure subcooled circuit of the compression refrigeration system is controlled to close.

[0124] S618, adjusting the opening degree of the control valve of the bypass electronic expansion valve of the first low-pressure subcooled circuit according to the actual discharge temperature after increasing the compressor speed.

[0125] In the first low-pressure subcooled circuit, the first end of the compressor is connected to the first end of the condenser, the second end of the condenser is connected to the first end of the bypass electronic expansion valve, the second end of the bypass electronic expansion valve is connected to the first end of the intermediate heat exchanger, the first end of the intermediate heat exchanger is communicated with the third end of the intermediate heat exchanger, the third end of the intermediate heat exchanger is connected to the first end of the first control valve, and the second end of the first control valve is connected to the second end of the compressor. In the second low-pressure subcooled circuit, the first end of the compressor is connected to the first end of the condenser, the second end of the condenser is connected to the first end of the second control valve, the second end of the second control valve is connected to the second end of the intermediate heat exchanger, the second end of the intermediate heat exchanger is communicated with the fourth end of the intermediate heat exchanger, the fourth end of the intermediate heat exchanger is connected to the first end of the main electronic expansion valve, the second end of the main electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor. In the single-stage low-pressure subcooled circuit, the first end of the compressor is connected to the first end of the condenser, the second end of the condenser is connected to the first end of the main control valve, the second end of the main control valve is connected to the first end of the main electronic expansion valve, the second end of the main electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor. The second end of the compressor is the suction port end of the compressor.

[0126] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0127] Based on the same inventive concept, this application also provides a control device for a compression refrigeration system for implementing the control method of the compression refrigeration system described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the control device for the compression refrigeration system provided below can be found in the limitations of the control method for the compression refrigeration system described above, and will not be repeated here.

[0128] In one embodiment, such as Figure 7 As shown, a control device for a compression refrigeration system is provided, including a determining module 702 and a control module 704. The determining module 702 is used to determine whether the compression refrigeration system meets the operating conditions for a two-stage low-pressure gas replenishment mode based on the actual outlet water temperature of the compression refrigeration system. The control module 704 is used to control the compression refrigeration system to operate in a two-stage low-pressure gas replenishment mode when the operating conditions are met. In the two-stage low-pressure gas replenishment mode, the refrigerant exiting from the first end of the compressor in the compression refrigeration system undergoes cooling and depressurization treatment through at least two low-pressure gas replenishment circuits, and the refrigerant passing through the at least two low-pressure gas replenishment circuits mixes at the second end of the compressor.

[0129] In one embodiment, the determining module 702 is further configured to increase the compressor speed of the compression refrigeration system when the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range, and obtain the actual exhaust temperature of the compression refrigeration system after increasing the compressor speed; when the actual exhaust temperature after increasing the compressor speed is greater than or equal to the target exhaust temperature, determine that the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode.

[0130] In one embodiment, the determining module 702 is further configured to obtain the actual exhaust temperature and the actual ambient temperature of the compression refrigeration system; when the actual ambient temperature is greater than or equal to the target ambient temperature and the actual exhaust temperature is less than the target outlet water temperature, the actual outlet water temperature of the compression refrigeration system is obtained.

[0131] In one embodiment, the control module 704 is further configured to control the first control valve of the first low-pressure supplement circuit to open, wherein the first end of the first low-pressure supplement circuit is connected to the second end of the condenser, and the second end of the first low-pressure supplement circuit is connected to the second end of the compressor; the first low-pressure supplement circuit comprises the first control valve, the supplement electronic expansion valve, the first end of the intermediate heat exchanger, and the third end of the intermediate heat exchanger; the second control valve of the second low-pressure supplement circuit is controlled to open, wherein the first end of the second low-pressure supplement circuit is connected to the second end of the condenser, the first end of the second low-pressure supplement circuit is connected to the second end of the condenser, and the second end of the second low-pressure supplement circuit is connected to the second end of the compressor through the main electronic expansion valve and the evaporator; the second low-pressure supplement circuit comprises the second control valve, the second end of the intermediate heat exchanger, and the fourth end of the intermediate heat exchanger; the main control valve is controlled to close, wherein the first end of the main control valve is connected to the second end of the condenser, the second end of the main control valve is connected to the first end of the main electronic expansion valve, the second end of the main electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor.

[0132] In one embodiment, the control module 704 is further configured to control the opening degree of the supplement electronic expansion valve according to the re-acquired actual discharge temperature of the compression refrigeration system, wherein the opening degree of the supplement electronic expansion valve and the discharge temperature of the compression refrigeration system have a mapping relationship.

[0133] In one embodiment, the control module 704 is further configured to acquire the corresponding relationship between the opening degree of the supplement electronic expansion valve of the compression refrigeration system and the discharge temperature of the compression refrigeration system, and control the opening degree of the supplement electronic expansion valve according to the corresponding relationship and the re-acquired actual discharge temperature of the compression refrigeration system.

[0134] In one embodiment, the control module 704 is further configured to control the compression refrigeration system to run in a single-stage low-pressure supplement mode when the compression refrigeration system does not meet the double-stage low-pressure supplement mode running condition, and in the single-stage low-pressure supplement mode, the refrigerant from the first end of the compressor is subjected to temperature and pressure reduction treatment through the main electronic expansion valve and the evaporator.

[0135] In one embodiment, the control module 704 is further configured to control the first control valve of the first low-pressure supplement circuit to close, control the second control valve of the second low-pressure supplement circuit to close, and control the main control valve to open.

[0136] The above-mentioned modules in the control device of the compression refrigeration system can be realized by software, hardware, or a combination thereof, in whole or in part. The above-mentioned modules can be embedded in or independent of the processor in the compression refrigeration system in hardware form, or stored in the memory in the compression refrigeration system in software form, so as to be called and executed by the processor to perform the operations corresponding to the above-mentioned modules.

[0137] In one embodiment, a compression refrigeration system is also provided, the compression refrigeration system comprising: a controller, a temperature sensor; the temperature sensor is configured to obtain an actual outlet water temperature of the compression refrigeration system; the controller is configured to determine whether the compression refrigeration system satisfies a two-stage low-pressure gas supplement mode operation condition based on the actual outlet water temperature of the compression refrigeration system; control the compression refrigeration system to operate in the two-stage low-pressure gas supplement mode when the compression refrigeration system satisfies the two-stage low-pressure gas supplement mode operation condition; in the two-stage low-pressure gas supplement mode, the refrigerant from the first end of the compressor is subjected to cooling and pressure reduction treatment through at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at the second end of the compressor.

[0138] In one embodiment, the compression refrigeration system further comprises: a condenser and an intermediate heat exchanger; the first end of the condenser is connected to the first end of the compressor; the intermediate heat exchanger comprises a first end and a second end, a third end and a fourth end, the first end is in communication with the third end, and the second end is in communication with the fourth end; the at least two low-pressure gas supplement circuits comprise a first low-pressure gas supplement circuit and a second low-pressure gas supplement circuit, the first end of the first low-pressure gas supplement circuit is connected to the second end of the condenser, and the second end of the first low-pressure gas supplement circuit is connected to the second end of the compressor; the first low-pressure gas supplement circuit comprises a first control valve, a low-pressure gas supplement electronic expansion valve, the first end and the third end of the intermediate heat exchanger; the first end of the second low-pressure gas supplement circuit is connected to the second end of the condenser, and the second end of the second low-pressure gas supplement circuit is connected to the second end of the compressor through a main circuit electronic expansion valve and an evaporator; the second low-pressure gas supplement circuit comprises a second control valve, the second end and the fourth end of the intermediate heat exchanger.

[0139] In one embodiment, the controller is further configured to: control the first control valve of the first low-pressure gas supplement circuit to open; control the second control valve of the second low-pressure gas supplement circuit to open; control the main circuit control valve to close; the first end of the main circuit control valve is connected to the second end of the condenser, the second end of the main circuit control valve is connected to the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor.

[0140] In one embodiment, the controller is further configured to: control the first control valve of the first low-pressure gas supplement circuit to close, control the second control valve of the second low-pressure gas supplement circuit to close, and control the main circuit control valve to open, so that the compression refrigeration system operates in a single-stage low-pressure gas supplement mode; in the single-stage low-pressure gas supplement mode, the refrigerant from the first end of the compressor is subjected to cooling and pressure reduction treatment through the main circuit electronic expansion valve and the evaporator.

[0141] In one embodiment, a compression refrigeration system is provided, the system comprising: a compressor; a condenser connected to a first end of the compressor; an intermediate heat exchanger comprising a first end and a second end, a third end and a fourth end, the first end in communication with the third end, the second end in communication with the fourth end; at least a low pressure suction circuit; at least two low pressure suction circuits comprising a first low pressure suction circuit and a second low pressure suction circuit; a first end of the first low pressure suction circuit connected to a second end of the condenser, a second end of the first low pressure suction circuit connected to a second end of the compressor; the first low pressure suction circuit comprising a first control valve, a suction electronic expansion valve, the first end and the third end of the intermediate heat exchanger; a first end of the second low pressure suction circuit connected to the second end of the condenser, a second end of the second low pressure suction circuit connected to the second end of the compressor through a main circuit electronic expansion valve, an evaporator; the second low pressure suction circuit comprising a second control valve, the second end and the fourth end of the intermediate heat exchanger.

[0142] In one embodiment, the compression refrigeration system further comprises a main circuit control valve; a first end of the main circuit control valve connected to the second end of the condenser, a second end of the main circuit control valve connected to a first end of the main circuit electronic expansion valve, a second end of the main circuit electronic expansion valve connected to a first end of the evaporator, a second end of the evaporator connected to the second end of the compressor.

[0143] In one embodiment, a first end of the suction electronic expansion valve is connected to the second end of the condenser, a second end of the suction electronic expansion valve is connected to the first end of the intermediate heat exchanger, a third end of the intermediate heat exchanger is connected to a first end of the first control valve, a second end of the first control valve is connected to the second end of the compressor.

[0144] In one embodiment, a first end of the suction electronic expansion valve is connected to the third end of the intermediate heat exchanger, a second end of the suction electronic expansion valve is connected to a first end of the first control valve, a second end of the first control valve is connected to the second end of the compressor, a first end of the intermediate heat exchanger is connected to the second end of the condenser.

[0145] In one embodiment, a first end of the suction electronic expansion valve is connected to the second end of the first control valve, a second end of the suction electronic expansion valve is connected to the second end of the compressor, a first end of the first control valve is connected to the third end of the intermediate heat exchanger, a first end of the intermediate heat exchanger is connected to the second end of the condenser.

[0146] In one embodiment, a first end of the first control valve is connected to a second end of the condenser, a second end of the first control valve is connected to a first end of the bypass electronic expansion valve, a second end of the bypass electronic expansion valve is connected to a first end of the intermediate heat exchanger, and a third end of the intermediate heat exchanger is connected to a second end of the compressor.

[0147] In one embodiment, a first end of the first control valve is connected to a second end of the condenser, a second end of the first control valve is connected to a first end of the bypass electronic expansion valve, a second end of the bypass electronic expansion valve is connected to a first end of the intermediate heat exchanger, and a third end of the intermediate heat exchanger is connected to a second end of the compressor.

[0148] In one embodiment, a first end of the second control valve is connected to a second end of the condenser, a second end of the second control valve is connected to a second end of the intermediate heat exchanger, and a fourth end of the intermediate heat exchanger is connected to the main electronic expansion valve, the evaporator and the second end of the compressor.

[0149] In one embodiment, a first end of the main electronic expansion valve is connected to a fourth end of the intermediate heat exchanger, a second end of the main electronic expansion valve is connected to a first end of the evaporator, and a second end of the evaporator is connected to a second end of the compressor.

[0150] In one embodiment, a first end of the second control valve is connected to a fourth end of the intermediate heat exchanger, a second end of the second control valve is connected to the main electronic expansion valve, the evaporator and the second end of the compressor, and a second end of the intermediate heat exchanger is connected to a second end of the condenser.

[0151] In one embodiment, a computer readable storage medium is provided, and a computer program is stored on the computer readable storage medium, and the computer program is executed by a processor to implement the following steps: determining whether a compression refrigeration system meets a double-stage low-pressure gas supplement mode operation condition based on an actual outlet water temperature of the compression refrigeration system; controlling the compression refrigeration system to operate in the double-stage low-pressure gas supplement mode when the compression refrigeration system meets the double-stage low-pressure gas supplement mode operation condition; and in the double-stage low-pressure gas supplement mode, refrigerant coming out of a first end of a compressor in the compression refrigeration system is cooled and depressurized by at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at a second end of the compressor.

[0152] In one embodiment, when the computer program is executed by the processor, it further implements the following steps: when the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range, the compressor speed of the compression refrigeration system is increased, and the actual exhaust temperature of the compression refrigeration system after increasing the compressor speed is obtained; when the actual exhaust temperature after increasing the compressor speed is greater than or equal to the target exhaust temperature, it is determined that the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode.

[0153] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the actual exhaust temperature and the actual ambient temperature of the compression refrigeration system; when the actual ambient temperature is greater than or equal to the target ambient temperature and the actual exhaust temperature is less than the target outlet water temperature, obtaining the actual outlet water temperature of the compression refrigeration system.

[0154] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: controlling the opening of a first control valve of a first low-pressure gas supply circuit; wherein, a first end of the first low-pressure gas supply circuit is connected to a second end of the condenser, and a second end of the first low-pressure gas supply circuit is connected to a second end of the compressor; the first low-pressure gas supply circuit includes a first control valve, a gas supply electronic expansion valve, and a first end and a third end of an intermediate heat exchanger; controlling the opening of a second control valve of a second low-pressure gas supply circuit; wherein, a first end of the second low-pressure gas supply circuit is connected to a second end of the condenser, and a second end of the second low-pressure gas supply circuit is connected to a second end of the compressor via a main circuit electronic expansion valve and an evaporator; the second low-pressure gas supply circuit includes a second control valve, and a second end and a fourth end of an intermediate heat exchanger; controlling the closing of a main circuit control valve; wherein, a first end of the main circuit control valve is connected to a second end of the condenser, a second end of the main circuit control valve is connected to a first end of the main circuit electronic expansion valve, a second end of the main circuit electronic expansion valve is connected to a first end of the evaporator, and a second end of the evaporator is connected to a second end of the compressor.

[0155] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: controlling the opening degree of the supplementary electronic expansion valve according to the reacquired actual exhaust temperature of the compression refrigeration system; wherein the opening degree of the supplementary electronic expansion valve has a mapping relationship with the exhaust temperature of the compression refrigeration system.

[0156] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the correspondence between the opening degree of the supplementary electronic expansion valve of the compression refrigeration system and the exhaust temperature of the compression refrigeration system; and controlling the opening degree of the supplementary electronic expansion valve according to the correspondence and the actual exhaust temperature of the compression refrigeration system obtained again.

[0157] In one embodiment, the computer program, when executed by the processor, further implements the following steps: controlling the compression refrigeration system to operate in a single-stage low-pressure gas supplement mode when the compression refrigeration system does not satisfy the double-stage low-pressure gas supplement mode operating condition; and in the single-stage low-pressure gas supplement mode, the refrigerant out of the first end of the compressor is subjected to temperature and pressure reduction treatment by the main circuit electronic expansion valve and the evaporator.

[0158] In one embodiment, the computer program, when executed by the processor, further implements the following steps: controlling the first control valve of the first low-pressure gas supplement circuit to be closed, controlling the second control valve of the second low-pressure gas supplement circuit to be closed, and controlling the main circuit control valve to be opened.

[0159] In one embodiment, a computer program product is provided, comprising a computer program which, when executed by the processor, implements the following steps:

[0160] Based on the actual outlet water temperature of the compression refrigeration system, it is determined whether the compression refrigeration system satisfies the double-stage low-pressure gas supplement mode operating condition.

[0161] When the compression refrigeration system satisfies the double-stage low-pressure gas supplement mode operating condition, the compression refrigeration system is controlled to operate in a double-stage low-pressure gas supplement mode; and in the double-stage low-pressure gas supplement mode, the refrigerant out of the first end of the compressor in the compression refrigeration system is subjected to temperature and pressure reduction treatment by at least two low-pressure gas supplement circuits, and the refrigerant passing through the at least two low-pressure gas supplement circuits is mixed at the second end of the compressor.

[0162] In one embodiment, the computer program, when executed by the processor, further implements the following steps: when the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range, increasing the rotation speed of the compressor of the compression refrigeration system, and obtaining the actual exhaust temperature of the compression refrigeration system after the rotation speed of the compressor is increased; and when the actual exhaust temperature after the rotation speed of the compressor is increased is greater than or equal to the target exhaust temperature, it is determined that the compression refrigeration system satisfies the double-stage low-pressure gas supplement mode operating condition.

[0163] In one embodiment, the computer program, when executed by the processor, further implements the following steps: obtaining the actual exhaust temperature and the actual environment temperature of the compression refrigeration system; and when the actual environment temperature is greater than or equal to the target environment temperature, and the actual exhaust temperature is less than the target outlet water temperature, obtaining the actual outlet water temperature of the compression refrigeration system.

[0164] In one embodiment, the computer program, when executed by the processor, further implements the following steps: controlling the first control valve of the first low-pressure supplement circuit to open; wherein the first end of the first low-pressure supplement circuit is connected with the second end of the condenser, and the second end of the first low-pressure supplement circuit is connected with the second end of the compressor; the first low-pressure supplement circuit comprises the first control valve, the supplement circuit electronic expansion valve, the first end and the third end of the intermediate heat exchanger; controlling the second control valve of the second low-pressure supplement circuit to open; wherein the first end of the second low-pressure supplement circuit is connected with the second end of the condenser, the first end of the second low-pressure supplement circuit is connected with the second end of the condenser, and the second end of the second low-pressure supplement circuit is connected with the second end of the compressor through the main circuit electronic expansion valve and the evaporator; the second low-pressure supplement circuit comprises the second control valve, the second end and the fourth end of the intermediate heat exchanger; controlling the main circuit control valve to close; wherein the first end of the main circuit control valve is connected with the second end of the condenser, the second end of the main circuit control valve is connected with the first end of the main circuit electronic expansion valve, the second end of the main circuit electronic expansion valve is connected with the first end of the evaporator, and the second end of the evaporator is connected with the second end of the compressor.

[0165] In one embodiment, the computer program, when executed by the processor, further implements the following steps: controlling the opening degree of the supplement circuit electronic expansion valve according to the re-acquired actual exhaust temperature of the compression refrigeration system; wherein the opening degree of the supplement circuit electronic expansion valve has a mapping relationship with the exhaust temperature of the compression refrigeration system.

[0166] In one embodiment, the computer program, when executed by the processor, further implements the following steps: acquiring the corresponding relationship between the opening degree of the supplement circuit electronic expansion valve of the compression refrigeration system and the exhaust temperature of the compression refrigeration system; and controlling the opening degree of the supplement circuit electronic expansion valve according to the corresponding relationship and the re-acquired actual exhaust temperature of the compression refrigeration system.

[0167] In one embodiment, the computer program, when executed by the processor, further implements the following steps: when the compression refrigeration system does not meet the double-stage low-pressure supplement mode operation condition, controlling the compression refrigeration system to operate in a single-stage low-pressure supplement mode; in the single-stage low-pressure supplement mode, the refrigerant from the first end of the compressor is subjected to temperature and pressure reduction treatment through the main circuit electronic expansion valve and the evaporator.

[0168] In one embodiment, the computer program, when executed by the processor, further implements the following steps: controlling the first control valve of the first low-pressure supplement circuit to close, controlling the second control valve of the second low-pressure supplement circuit to close, and controlling the main circuit control valve to open.

[0169] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (Read-Only Memory, ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric memory (Ferroelectric Random Access Memory, FRAM), phase change memory (Phase Change Memory, PCM), graphene memory, etc. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0170] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0171] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A control method for a compression refrigeration system, characterized in that, The method includes: Based on the actual outlet water temperature of the compression refrigeration system, determine whether the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode. When the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode, the compression refrigeration system is controlled to operate in the two-stage low-pressure gas replenishment mode. In the two-stage low-pressure gas replenishment mode, the refrigerant from the first end of the compressor in the compression refrigeration system is cooled and depressurized through at least two low-pressure gas replenishment circuits, and the refrigerant that has passed through at least the two low-pressure gas replenishment circuits is mixed at the second end of the compressor. The determination of whether the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas supply mode based on the actual outlet water temperature of the compression refrigeration system includes: When the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range, the compressor speed of the compression refrigeration system is increased, and the actual exhaust temperature of the compression refrigeration system after increasing the compressor speed is obtained. When the actual exhaust temperature after increasing the compressor speed is greater than or equal to the target exhaust temperature, it is determined that the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode.

2. The method according to claim 1, characterized in that, The methods for obtaining the actual outlet water temperature include: Obtain the actual exhaust temperature and actual ambient temperature of the compression refrigeration system; When the actual ambient temperature is greater than or equal to the target ambient temperature, and the actual exhaust temperature is less than the target outlet water temperature, the actual outlet water temperature of the compression refrigeration system is obtained.

3. The method according to claim 1, characterized in that, The compression refrigeration system includes a condenser, and the at least two low-pressure gas supply circuits include a first low-pressure gas supply circuit and a second low-pressure gas supply circuit. Controlling the compression refrigeration system to operate in a two-stage low-pressure gas supply mode includes: The first control valve of the first low-pressure gas supply circuit is opened; wherein, the first end of the first low-pressure gas supply circuit is connected to the second end of the condenser, and the second end of the first low-pressure gas supply circuit is connected to the second end of the compressor; the first low-pressure gas supply circuit includes a first control valve, a gas supply electronic expansion valve, and the first and third ends of an intermediate heat exchanger; The second control valve of the second low-pressure gas supply circuit is opened; wherein, the first end of the second low-pressure gas supply circuit is connected to the second end of the condenser, and the second end of the second low-pressure gas supply circuit is connected to the second end of the compressor through the main electronic expansion valve and the evaporator; the second low-pressure gas supply circuit includes the second control valve, the second end of the intermediate heat exchanger, and the fourth end; The main control valve is closed; wherein, the first end of the main control valve is connected to the second end of the condenser, the second end of the main control valve is connected to the first end of the main electronic expansion valve, the second end of the main electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor.

4. The method according to claim 3, characterized in that, After controlling the compression refrigeration system to operate in a two-stage low-pressure gas supply mode, the method further includes: The opening degree of the supplementary electronic expansion valve is controlled based on the re-acquired actual exhaust temperature of the compression refrigeration system; wherein the opening degree of the supplementary electronic expansion valve has a mapping relationship with the exhaust temperature of the compression refrigeration system.

5. The method according to claim 4, characterized in that, The step of controlling the opening of the supplementary electronic expansion valve based on the re-acquired actual exhaust temperature of the compression refrigeration system includes: Obtain the relationship between the opening degree of the electronic expansion valve of the compression refrigeration system and the exhaust temperature of the compression refrigeration system; Based on the aforementioned correspondence and the actual exhaust temperature of the re-acquired compression refrigeration system, the opening degree of the supplementary electronic expansion valve is controlled.

6. The method according to claim 3, characterized in that, The method further includes: When the compression refrigeration system does not meet the operating conditions of the two-stage low-pressure gas replenishment mode, the compression refrigeration system is controlled to operate in the single-stage low-pressure gas replenishment mode. In the single-stage low-pressure gas replenishment mode, the refrigerant coming out of the first end of the compressor is cooled and depressurized through the main electronic expansion valve and the evaporator.

7. The method according to claim 6, characterized in that, The control of the compression refrigeration system to operate in single-stage low-pressure gas supply mode includes: The first control valve of the first low-pressure gas supply circuit is closed, the second control valve of the second low-pressure gas supply circuit is closed, and the main control valve is opened.

8. A compression refrigeration system, characterized in that, The compression refrigeration system includes: a controller and a temperature sensor; The temperature sensor is used to obtain the actual outlet water temperature of the compression refrigeration system; The controller is used to determine whether the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode based on the actual outlet water temperature of the compression refrigeration system; when the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode, the controller controls the compression refrigeration system to operate in the two-stage low-pressure gas replenishment mode; in the two-stage low-pressure gas replenishment mode, the refrigerant from the first end of the compressor in the compression refrigeration system is cooled and depressurized through at least two low-pressure gas replenishment circuits, and the refrigerant that has passed through at least the two low-pressure gas replenishment circuits is mixed at the second end of the compressor; The controller is further configured to increase the compressor speed of the compression refrigeration system when the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range, and to obtain the actual exhaust temperature of the compression refrigeration system after increasing the compressor speed; and to determine that the compression refrigeration system meets the operating conditions of the two-stage low-pressure gas replenishment mode when the actual exhaust temperature after increasing the compressor speed is greater than or equal to the target exhaust temperature.

9. The compression refrigeration system according to claim 8, characterized in that, The compression refrigeration system further includes: a condenser and an intermediate heat exchanger; the first end of the condenser is connected to the first end of the compressor; the intermediate heat exchanger includes a first end, a second end, a third end, and a fourth end, the first end being connected to the third end, and the second end being connected to the fourth end; the at least two low-pressure gas supply circuits include a first low-pressure gas supply circuit and a second low-pressure gas supply circuit. The first end of the first low-pressure gas supply circuit is connected to the second end of the condenser, and the second end of the first low-pressure gas supply circuit is connected to the second end of the compressor; the first low-pressure gas supply circuit includes a first control valve, a gas supply electronic expansion valve, and the first and third ends of the intermediate heat exchanger. The first end of the second low-pressure gas supply circuit is connected to the second end of the condenser, and the second end of the second low-pressure gas supply circuit is connected to the second end of the compressor through the main electronic expansion valve and the evaporator; the second low-pressure gas supply circuit includes a second control valve, the second end and the fourth end of the intermediate heat exchanger.

10. The compression refrigeration system according to claim 9, characterized in that, The controller is further configured to: control the opening of the first control valve of the first low-pressure gas supply circuit; control the opening of the second control valve of the second low-pressure gas supply circuit; control the closing of the main control valve; wherein the first end of the main control valve is connected to the second end of the condenser, the second end of the main control valve is connected to the first end of the main electronic expansion valve, the second end of the main electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor.

11. The compression refrigeration system according to claim 10, characterized in that, The controller is further configured to: control the first control valve of the first low-pressure gas supply circuit to close, control the second control valve of the second low-pressure gas supply circuit to close, and control the main control valve to open, so that the compression refrigeration system operates in a single-stage low-pressure gas supply mode; in the single-stage low-pressure gas supply mode, the refrigerant coming out of the first end of the compressor is cooled and depressurized through the main electronic expansion valve and the evaporator.

12. A compression refrigeration system, characterized in that, The system includes: compressor; A condenser, the first end of which is connected to the first end of the compressor; An intermediate heat exchanger; the intermediate heat exchanger includes a first end, a second end, a third end, and a fourth end, wherein the first end is connected to the third end, and the second end is connected to the fourth end; At least two low-pressure gas supply circuits are provided; the at least two low-pressure gas supply circuits include a first low-pressure gas supply circuit and a second low-pressure gas supply circuit; a first end of the first low-pressure gas supply circuit is connected to a second end of the condenser, and a second end of the first low-pressure gas supply circuit is connected to a second end of the compressor; the first low-pressure gas supply circuit includes a first control valve, a gas supply electronic expansion valve, a first end and a third end of the intermediate heat exchanger; a first end of the second low-pressure gas supply circuit is connected to a second end of the condenser, and a second end of the second low-pressure gas supply circuit is connected to a second end of the compressor via a main circuit electronic expansion valve and an evaporator; the second low-pressure gas supply circuit includes a second control valve, a second end and a fourth end of the intermediate heat exchanger. The controller is configured to determine whether the compression refrigeration system meets the operating conditions for a two-stage low-pressure gas replenishment mode based on the actual outlet water temperature of the compression refrigeration system; when the compression refrigeration system meets the operating conditions for a two-stage low-pressure gas replenishment mode, the controller controls the compression refrigeration system to operate in the two-stage low-pressure gas replenishment mode; in the two-stage low-pressure gas replenishment mode, the refrigerant exiting from the first end of the compressor in the compression refrigeration system undergoes cooling and depressurization treatment through at least two low-pressure gas replenishment circuits, and the refrigerant passing through at least the two low-pressure gas replenishment circuits mixes at the second end of the compressor; wherein, the controller is further configured to increase the compressor speed of the compression refrigeration system when the difference between the actual outlet water temperature and the target outlet water temperature is within a preset range, and obtain the actual exhaust temperature of the compression refrigeration system after increasing the compressor speed; when the actual exhaust temperature after increasing the compressor speed is greater than or equal to the target exhaust temperature, the controller determines that the compression refrigeration system meets the operating conditions for a two-stage low-pressure gas replenishment mode; The main control valve has a first end connected to the second end of the condenser, a second end connected to the first end of the main electronic expansion valve, a second end connected to the first end of the evaporator, and a second end connected to the second end of the compressor.

13. The compression refrigeration system according to claim 12, characterized in that, The first end of the supplementary electronic expansion valve is connected to the second end of the condenser, the second end of the supplementary electronic expansion valve is connected to the first end of the intermediate heat exchanger, the third end of the intermediate heat exchanger is connected to the first end of the first control valve, and the second end of the first control valve is connected to the second end of the compressor.

14. The compression refrigeration system according to claim 12, characterized in that, The first end of the supplementary electronic expansion valve is connected to the third end of the intermediate heat exchanger, the second end of the supplementary electronic expansion valve is connected to the first end of the first control valve, the second end of the first control valve is connected to the second end of the compressor, and the first end of the intermediate heat exchanger is connected to the second end of the condenser.

15. The compression refrigeration system according to claim 12, characterized in that, The first end of the supplementary electronic expansion valve is connected to the second end of the first control valve, the second end of the supplementary electronic expansion valve is connected to the second end of the compressor, the first end of the first control valve is connected to the third end of the intermediate heat exchanger, and the first end of the intermediate heat exchanger is connected to the second end of the condenser.

16. The compression refrigeration system according to claim 12, characterized in that, The first end of the first control valve is connected to the second end of the condenser, the second end of the first control valve is connected to the first end of the supplementary electronic expansion valve, the second end of the supplementary electronic expansion valve is connected to the first end of the intermediate heat exchanger, and the third end of the intermediate heat exchanger is connected to the second end of the compressor.

17. The compression refrigeration system according to claim 12, characterized in that, The first end of the first control valve is connected to the second end of the supplementary electronic expansion valve, the second end of the first control valve is connected to the first end of the intermediate heat exchanger, the first end of the supplementary electronic expansion valve is connected to the second end of the condenser, and the third end of the intermediate heat exchanger is connected to the second end of the compressor.

18. The compression refrigeration system according to claim 12, characterized in that, The first end of the second control valve is connected to the second end of the condenser, the second end of the second control valve is connected to the second end of the intermediate heat exchanger, and the fourth end of the intermediate heat exchanger is connected to the second end of the compressor through the main electronic expansion valve and the evaporator.

19. The compression refrigeration system according to claim 18, characterized in that, The first end of the main circuit electronic expansion valve is connected to the fourth end of the intermediate heat exchanger, the second end of the main circuit electronic expansion valve is connected to the first end of the evaporator, and the second end of the evaporator is connected to the second end of the compressor.

20. The compression refrigeration system according to claim 12, characterized in that, The first end of the second control valve is connected to the fourth end of the intermediate heat exchanger, the second end of the second control valve is connected to the second end of the compressor through the main electronic expansion valve, the evaporator, and the second end of the intermediate heat exchanger is connected to the second end of the condenser.

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