A cooling expansion valve adjustment method and device based on variable frequency drive

Abstract

The present application provides a cooling expansion valve adjustment method and device based on variable frequency drive; applied to a variable frequency module, the variable frequency module is provided with an auxiliary refrigerant pipeline, the auxiliary refrigerant pipeline is provided with a radiator and an expansion valve, and the expansion valve is connected to the radiator; by obtaining the temperature of the variable frequency module; when the temperature of the variable frequency module is within a preset temperature range, lowering the temperature of the variable frequency module; when the temperature of the variable frequency module is outside the preset temperature range, adjusting the opening of the expansion valve to adjust the temperature of the variable frequency module to a target temperature; making the preset temperature range related to the normal operating temperature of the variable frequency module and the allowable operating deviation temperature; being able to improve the cooling effect of the variable frequency heat pump system.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of expansion valves, and in particular to a method and device for regulating a cooling expansion valve based on variable frequency drive. Background Art

[0002] The current variable frequency heat pump system usually installs the heat sink of the variable frequency drive in the air duct, and uses the air flow in the air duct to remove the heat from the heat sink to cool the variable frequency drive. The cooling effect is affected by many factors, such as ambient temperature, air duct design, and dust accumulated on the heat sink, which will affect the cooling of the variable frequency drive and cause the variable frequency drive module to not be cooled in time. Summary of the invention

[0003] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0004] The purpose of the present application is to solve one of the technical problems existing in the related art to at least a certain extent. The embodiment of the present application provides a cooling expansion valve adjustment method and device based on variable frequency drive, which can improve the cooling effect.

[0005] An embodiment of the first aspect of the present application is a cooling expansion valve adjustment method based on variable frequency drive, comprising:

[0006] Get the temperature of the frequency conversion module;

[0007] When the temperature of the frequency conversion module is within a preset temperature range, lowering the temperature of the frequency conversion module;

[0008] When the temperature of the frequency conversion module is outside the preset temperature range, adjusting the opening of the expansion valve to adjust the temperature of the frequency conversion module to the target temperature;

[0009] The preset temperature range is related to the normal operating temperature and the allowable operating deviation temperature of the frequency conversion module.

[0010] According to certain embodiments of the first aspect of the present application, the opening degree of the expansion valve is related to the actual operating temperature, the normal operating temperature, the allowable operating deviation temperature and the allowable operating temperature proportionality coefficient of the frequency conversion module.

[0011] According to certain embodiments of the first aspect of the present application, when the difference between the actual operating temperature and the normal operating temperature is a positive number, the opening of the expansion valve is equal to [(actual operating temperature-normal operating temperature)+allowable operating deviation temperature]*allowable operating temperature proportional coefficient÷10.

[0012] According to certain embodiments of the first aspect of the present application, when the difference between the actual operating temperature and the normal operating temperature is a negative number, the opening of the expansion valve is equal to [(actual operating temperature-normal operating temperature)-allowable operating deviation temperature]*allowable operating temperature proportional coefficient ÷ 10.

[0013] According to certain embodiments of the first aspect of the present application, the cooling expansion valve adjustment method based on variable frequency drive further includes:

[0014] When the unit is powered on and the compressor is not in operation, the opening of the expansion valve is reset to zero.

[0015] According to certain embodiments of the first aspect of the present application, the cooling expansion valve adjustment method based on variable frequency drive further includes:

[0016] When the compressor is powered on and the actual operating temperature of the frequency conversion module reaches the normal operating temperature, the temperature of the frequency conversion module is reduced.

[0017] According to certain embodiments of the first aspect of the present application, the cooling expansion valve adjustment method based on variable frequency drive further includes:

[0018] When the compressor is powered on and the actual operating temperature of the frequency conversion module reaches the normal operating temperature, the opening of the expansion valve is adjusted to a preset initial opening.

[0019] An embodiment of the second aspect of the present application is a cooling expansion valve regulating device based on variable frequency drive, which applies the cooling expansion valve regulating method based on variable frequency drive as described in the embodiment of the first aspect of the present application; the device includes a compressor, a gas-liquid separator, a condenser, a liquid reservoir, an economizer and an evaporator; an auxiliary refrigerant pipeline is arranged between the compressor and the liquid reservoir, and the auxiliary refrigerant pipeline is provided with a radiator and an expansion valve, and the expansion valve is connected to the radiator.

[0020] According to certain embodiments of the second aspect of the present application, the inlet of the auxiliary refrigerant pipeline is connected to the outlet of the liquid reservoir, and the outlet of the auxiliary refrigerant pipeline is connected to the outlet of the gas-liquid separator and the inlet of the compressor.

[0021] According to certain embodiments of the second aspect of the present application, the compressor is connected to the condenser and the gas-liquid separator, the condenser is connected to the liquid reservoir, the gas-liquid separator is connected to the evaporator, and the economizer is connected to the radiator, the liquid reservoir and the compressor.

[0022] The above scheme has at least the following beneficial effects: by adding a refrigerant pipeline for the variable frequency drive and installing an expansion valve in the pipeline to control the refrigerant flow; by obtaining the temperature of the frequency conversion module; when the temperature of the frequency conversion module is within the preset temperature range, lowering the temperature of the frequency conversion module; when the temperature of the frequency conversion module is outside the preset temperature range, adjusting the opening of the expansion valve to adjust the temperature of the frequency conversion module to the target temperature; making the preset temperature range related to the normal operating temperature of the frequency conversion module and the allowable operating deviation temperature; being able to improve the cooling effect of the variable frequency heat pump system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application. The reinforcement layer is filled with multiple sand bags.

[0024] Figure 1 is a step diagram of a cooling expansion valve adjustment method based on variable frequency drive provided in an embodiment of the present application;

[0025] Figure 2 is a step diagram of step S100 provided in an embodiment of the present application;

[0026] Figure 3 is a step diagram of step S210 and step S220 provided in an embodiment of the present application;

[0027] Figure 4 is a structural diagram of a cooling expansion valve regulating device provided in an embodiment of the present application;

[0028] Figure 5 is the circuit diagram of the controller;

[0029] Figure 6 is the circuit diagram of a multiplexer;

[0030] Figure 7 It is the circuit diagram of the high and low pressure sensor interface;

[0031] Figure 8 It is the circuit diagram of the circuit diagram of the dip switch;

[0032] Fig. 9 This is the circuit diagram of the water level switch;

[0033] Fig.10 This is the circuit diagram of the RS485 communication interface;

[0034] Fig.11 This is the circuit diagram of the relay electronic expansion valve;

[0035] Fig.12 It is another circuit diagram of the relay electronic expansion valve;

[0036] Fig.13 This is the circuit diagram of the PWM signal output circuit;

[0037] Fig.14 It is another circuit diagram of PWM signal output circuit. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] It should be noted that, although the functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first", "second", etc. in the specification, claims or the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0040] The embodiments of the present application are further described below in conjunction with the accompanying drawings.

[0041] The current variable frequency heat pump system usually installs the heat sink of the variable frequency drive in the air duct, and uses the air flow in the air duct to remove the heat from the heat sink to cool the variable frequency drive. The cooling effect is affected by many factors, such as ambient temperature, air duct design, and dust accumulated on the heat sink, which will affect the cooling of the variable frequency drive and cause the variable frequency drive module to not be cooled in time.

[0042] The embodiment of the present application provides a cooling expansion valve adjustment method based on variable frequency drive, which can improve the cooling effect. The method is applied to a variable frequency module, the variable frequency module is provided with an auxiliary refrigerant pipeline, the auxiliary refrigerant pipeline is provided with a radiator and an expansion valve, and the expansion valve is connected to the radiator. The radiator is connected between the compressor and the condenser.

[0043] The embodiments of the present application are further described below in conjunction with the accompanying drawings.

[0044] Reference Figure 1 , the cooling expansion valve adjustment method includes but is not limited to the following steps:

[0045] Step S300, obtaining the temperature of the frequency conversion module;

[0046] Step S410, when the temperature of the frequency conversion module is within a preset temperature range, lowering the temperature of the frequency conversion module;

[0047] Step S420: When the temperature of the frequency conversion module is outside the preset temperature range, the opening of the expansion valve is adjusted to adjust the temperature of the frequency conversion module to the target temperature.

[0048] The preset temperature range is related to the normal operating temperature and the allowable operating deviation temperature of the frequency conversion module.

[0049] Reference Figure 2 The cooling expansion valve adjustment method further comprises the following steps:

[0050] Step S100, when the unit is powered on and the compressor is not in operation, the opening of the expansion valve is reset to zero.

[0051] It can be understood that step S300 , step S410 and step S420 are performed after step S100 .

[0052] Reference Figure 3 The cooling expansion valve adjustment method further comprises the following steps:

[0053] Step S210, when the compressor is powered on and the actual operating temperature of the frequency conversion module reaches the normal operating temperature, lowering the temperature of the frequency conversion module;

[0054] Step S220, when the compressor is powered on and the actual operating temperature of the frequency conversion module reaches the normal operating temperature, the opening of the expansion valve is adjusted to a preset initial opening.

[0055] It can be understood that step S210 and step S220 are executed in parallel, that is, when the compressor is powered on and the actual operating temperature of the frequency conversion module reaches the normal operating temperature, the temperature of the frequency conversion module is lowered and the opening of the expansion valve is adjusted to a preset initial opening.

[0056] Step S210 and step S220 are performed after step S100. Step S300, step S410 and step S420 are performed after step S210 and step S220.

[0057] Then, when the unit is powered on and the compressor is not working, the opening of the expansion valve is reset to zero. When the compressor is powered on and the actual operating temperature of the frequency conversion module reaches the normal operating temperature, the temperature of the frequency conversion module is lowered, and the opening of the expansion valve is adjusted to the preset initial opening. The temperature of the frequency conversion module is obtained; when the temperature of the frequency conversion module is within the preset temperature range, the temperature of the frequency conversion module is lowered; when the temperature of the frequency conversion module is outside the preset temperature range, the opening of the expansion valve is adjusted to adjust the temperature of the frequency conversion module to the target temperature.

[0058] In one embodiment, the normal operating temperature is set to 55 degrees Celsius and the initial opening is set to 20 steps. Then, when the compressor is powered on and the actual operating temperature of the frequency conversion module reaches 55 degrees Celsius, the temperature of the frequency conversion module is lowered and the opening of the expansion valve is adjusted to 20 steps.

[0059] Of course, in other embodiments, the normal operating temperature can be set to other values, and the initial opening degree can be set to other values ​​according to actual needs.

[0060] In step S300 , the frequency conversion module is monitored in real time to obtain the temperature of the frequency conversion module, and it is determined whether the temperature of the frequency conversion module is greater than a set normal operating temperature.

[0061] For step S410, when the temperature of the frequency conversion module is within a preset temperature range, the temperature of the frequency conversion module is lowered and the electronic expansion valve is not adjusted.

[0062] The preset temperature range is: [normal operating temperature - allowable operating deviation temperature, normal operating temperature + allowable operating deviation temperature].

[0063] In some embodiments, the normal operating temperature is set to 55 degrees Celsius, and the allowable operating deviation temperature is set to 5 degrees Celsius. Then, the preset temperature range is 50 degrees Celsius to 60 degrees Celsius.

[0064] It is understandable that when the temperature of the frequency conversion module is between 50 degrees Celsius and 60 degrees Celsius, the temperature of the frequency conversion module is lowered and the electronic expansion valve is not adjusted.

[0065] Regarding step S420, when the temperature of the frequency conversion module is outside the preset temperature range, the opening of the expansion valve is adjusted according to the PID algorithm to adjust the temperature of the frequency conversion module to the target temperature.

[0066] In some embodiments, the normal operating temperature is set to 55 degrees Celsius, and the allowable operating deviation temperature is set to 5 degrees Celsius. Then, the preset temperature range is 50 degrees Celsius to 60 degrees Celsius.

[0067] It can be understood that when the temperature of the frequency conversion module is between 50 degrees Celsius and 60 degrees Celsius, the opening of the expansion valve is adjusted according to the PID algorithm to adjust the temperature of the frequency conversion module to the target temperature.

[0068] In other embodiments, the allowable operating deviation temperature ranges from 3 degrees Celsius to 7 degrees Celsius.

[0069] In some embodiments, the opening degree of the expansion valve is related to the actual operating temperature, the normal operating temperature, the allowable operating deviation temperature and the allowable operating temperature proportionality coefficient of the frequency conversion module.

[0070] Specifically, when the difference between the actual operating temperature and the normal operating temperature is a positive number, the opening of the expansion valve is equal to [(actual operating temperature - normal operating temperature) + allowable operating deviation temperature] * allowable operating temperature proportionality coefficient ÷ 10. When the difference between the actual operating temperature and the normal operating temperature is a negative number, the opening of the expansion valve is equal to [(actual operating temperature - normal operating temperature) - allowable operating deviation temperature] * allowable operating temperature proportionality coefficient ÷ 10.

[0071] In some embodiments, the allowable operating temperature proportional coefficient is set to 6. Of course, in other embodiments, the allowable operating temperature proportional coefficient can be set to other values ​​according to actual needs.

[0072] In some embodiments, the allowable operating deviation temperature is set to be less than or equal to the normal operating temperature.

[0073] The cooling expansion valve regulation method upgrades the mainboard electronic expansion valve function program by adjusting the electronic expansion valve control logic.

[0074] An embodiment of the present application also provides a cooling expansion valve regulating device based on variable frequency drive.

[0075] The cooling expansion valve regulating device based on variable frequency drive applies the above cooling expansion valve regulating method based on variable frequency drive.

[0076] Based on the original refrigerant pipeline, the device adds a new refrigerant pipeline dedicated to variable frequency drive cooling, and an expansion valve is installed in the pipeline to control the refrigerant flow.

[0077] The refrigerant pipeline is an auxiliary refrigerant pipeline, and the auxiliary refrigerant pipeline is provided with a radiator 25 and an auxiliary cooling electronic expansion valve 24 .

[0078] Reference Figure 4 , the structure of the cooling expansion valve regulating device is as follows.

[0079] The outlet of the compressor 1 is connected to an inlet of the four-way valve 2. A high-pressure switch 15, a needle valve 17 and an exhaust temperature sensor 19 are provided between the outlet of the compressor 1 and an inlet of the four-way valve 2. One inlet of the compressor 1 is connected to the economizer 9, and the other inlet of the compressor 1 is connected to the outlet of the radiator 25. An intake temperature sensor 18, a low-pressure switch 16 and an intake pressure sensor 23 are provided between the other inlet of the compressor 1 and the outlet of the radiator 25.

[0080] The inlet of the radiator 25 is connected to the auxiliary cooling electronic expansion valve 24. The inlet of the radiator 25 is connected to the economizer 9 via the auxiliary circuit electronic expansion valve 12. A liquid injection solenoid valve 11 is provided between the auxiliary circuit electronic expansion valve 12 and the auxiliary cooling electronic expansion valve 24.

[0081] The outlet of the economizer 9 is connected to the inlet of the fin-tube evaporator 5 through the main electronic expansion valve 10. The main electronic expansion valve 10 is connected in parallel with an unloading valve 14.

[0082] The outlet of the fin-tube evaporator 5 is connected to the four-way valve 2 .

[0083] The outlet of the four-way valve 2 is connected to the inlet of the pot condenser 3, and the outlet of the pot condenser 3 is connected to the liquid storage 8. A drying filter 7 is arranged between the pot condenser 3 and the liquid storage 8.

[0084] The inlet of the gas-liquid separator 4 is connected to the four-way valve 2 , and the outlet of the gas-liquid separator 4 is connected to an inlet of the compressor 1 .

[0085] The economizer 9 is provided with a spray liquid inlet temperature sensor 21 and a spray liquid outlet temperature sensor 22 .

[0086] exist Figure 4 In the figure, the red arrow indicates the flow direction of the high-pressure refrigerant, the blue arrow indicates the flow direction of the low-pressure refrigerant, the red line indicates the refrigerant pipeline through which the high-pressure refrigerant flows, and the blue line indicates the refrigerant pipeline through which the low-pressure refrigerant flows.

[0087] The refrigerant leaving the compressor 1 flows through the four-way valve 2 and enters the tank condenser 3. After leaving the tank condenser 3, it flows through the drying filter 7 and enters the liquid reservoir 8. After leaving the liquid reservoir 8, part of it flows to the economizer 9 and the other part flows to the radiator 25. The amount of refrigerant flowing to the radiator 25 is adjusted by the auxiliary cooling electronic expansion valve 21. The amount of refrigerant flowing to the economizer 9 is adjusted by the auxiliary circuit electronic expansion valve 12.

[0088] The refrigerant leaving one outlet of the economizer 9 flows to the fin-tube evaporator 5 after passing through the drying filter, and the amount of refrigerant flowing to the fin-tube evaporator 5 is adjusted by the main electronic expansion valve 10. The refrigerant leaving the fin-tube evaporator 5 flows to the gas-liquid separator 4 through the four-way valve, and the refrigerant leaving the gas-liquid separator 4 merges with the refrigerant leaving the radiator 25 and flows to the compressor 1.

[0089] The refrigerant leaving from the other outlet of the economizer 9 flows directly to the compressor 1 .

[0090] The cooling expansion valve regulating device based on variable frequency drive controls the overall operation through the control circuit. Figures 5 to 14 This is a partial circuit diagram of the control circuit.

[0091] in, Figure 5 It is the circuit diagram of the controller; the controller is the core of the control circuit, and the controller processes various input signals to obtain the output signal of the control device operation. Figure 6 This is the circuit diagram of a multiplexer; multiple input signals are combined and output through the multiplexer. Figure 7It is a circuit diagram of a high and low pressure sensor interface; it is connected to the high and low pressure sensors through the high and low pressure sensor interface. Figure 8 It is a circuit diagram of the circuit diagram of the dip switch; parameters are set through the dip switch. Fig. 9 This is the circuit diagram of the water level switch; the water level parameters are set through the water level switch. Fig.10 It is the circuit diagram of RS485 communication interface; communication is achieved by connecting RS485 communication interface with RS485 communication module. Fig.11 This is the circuit diagram of the relay electronic expansion valve; Fig.12 Another circuit diagram of the relay electronic expansion valve realizes the control of the main electronic expansion valve 10, the auxiliary electronic expansion valve 12 and the auxiliary cooling electronic expansion valve 21 through the relay electronic expansion valve. Fig.13 This is the circuit diagram of the PWM signal output circuit; Fig.14 It is another circuit diagram of a PWM signal output circuit; a PWM signal is provided to a controller through the PWM signal output circuit.

[0092] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the embodiments. Technical personnel familiar with the field can make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A cooling expansion valve adjustment method based on variable frequency drive, characterized in that: Applied to a frequency conversion module, the frequency conversion module is provided with an auxiliary refrigerant pipeline, the auxiliary refrigerant pipeline is provided with a radiator and an expansion valve, and the expansion valve is connected to the radiator; the method comprises: Get the temperature of the frequency conversion module; When the temperature of the frequency conversion module is within a preset temperature range, lowering the temperature of the frequency conversion module; When the temperature of the frequency conversion module is outside the preset temperature range, adjusting the opening of the expansion valve to adjust the temperature of the frequency conversion module to the target temperature; The preset temperature range is related to the normal operating temperature and the allowable operating deviation temperature of the frequency conversion module.

2. The cooling expansion valve adjustment method based on variable frequency drive according to claim 1 is characterized in that: The opening degree of the expansion valve is related to the actual operating temperature, the normal operating temperature, the allowable operating deviation temperature and the allowable operating temperature proportionality coefficient of the frequency conversion module.

3. The cooling expansion valve adjustment method based on variable frequency drive according to claim 2 is characterized in that: When the difference between the actual operating temperature and the normal operating temperature is a positive number, the opening degree of the expansion valve is equal to [(actual operating temperature-normal operating temperature)+allowable operating deviation temperature]*allowable operating temperature proportionality coefficient÷10.

4. The cooling expansion valve adjustment method based on variable frequency drive according to claim 2 is characterized in that: When the difference between the actual operating temperature and the normal operating temperature is a negative number, the opening degree of the expansion valve is equal to [(actual operating temperature-normal operating temperature)-allowable operating deviation temperature]*allowable operating temperature proportionality coefficient÷10.

5. The cooling expansion valve adjustment method based on variable frequency drive according to claim 1, characterized in that: Also includes: When the unit is powered on and the compressor is not in operation, the opening of the expansion valve is reset to zero.

6. The cooling expansion valve adjustment method based on variable frequency drive according to claim 1, characterized in that: Also includes: When the compressor is powered on and the actual operating temperature of the frequency conversion module reaches the normal operating temperature, the temperature of the frequency conversion module is reduced.

7. The cooling expansion valve adjustment method based on variable frequency drive according to claim 1, characterized in that: Also includes: When the compressor is powered on and the actual operating temperature of the frequency conversion module reaches the normal operating temperature, the opening of the expansion valve is adjusted to a preset initial opening.

8. A cooling expansion valve regulating device based on variable frequency drive, characterized in that: A cooling expansion valve regulation method based on variable frequency drive as described in any one of claims 1 to 7 is applied; the device includes a compressor, a gas-liquid separator, a condenser, a liquid reservoir, an economizer and an evaporator; an auxiliary refrigerant pipeline is arranged between the compressor and the liquid reservoir, the auxiliary refrigerant pipeline is provided with a radiator and an expansion valve, and the expansion valve is connected to the radiator.

9. The cooling expansion valve regulating device based on variable frequency drive according to claim 8, characterized in that: The inlet of the auxiliary refrigerant pipeline is connected to the outlet of the liquid accumulator, and the outlet of the auxiliary refrigerant pipeline is connected to the outlet of the gas-liquid separator and the inlet of the compressor.

10. The cooling expansion valve regulating device based on variable frequency drive according to claim 8, characterized in that: The compressor is connected to the condenser and the gas-liquid separator, the condenser is connected to the liquid reservoir, the gas-liquid separator is connected to the evaporator, and the economizer is connected to the radiator, the liquid reservoir, and the compressor.

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