A temperature control device and a control method and a control device for an electronic expansion valve thereof

Abstract

The present invention discloses a temperature control device and a control method and a control device for an electronic expansion valve thereof. The control method for the electronic expansion valve in the temperature control device includes obtaining the actual temperature of the liquid in the liquid supply pipeline, the set temperature, the preset temperature deviations corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline; according to the actual temperature and the set temperature, determining the working mode of the temperature control device and controlling the temperature control device to be in the working mode; the working mode at least includes the cooling mode; according to the working mode, the actual temperature, and the preset temperature deviations corresponding to each temperature range segment, determining the theoretical temperature in the refrigerant pipeline; according to the theoretical temperature and the actual pressure, determining the theoretical opening of the electronic expansion valve and controlling the current opening of the electronic expansion valve to be the theoretical opening. The technical solution provided by the present invention can improve the heat exchange efficiency and working reliability of the temperature control device.

Description

Technical Field

[0001] The present invention relates to the field of control technology, and in particular to a temperature control device and a control method and a control device for an electronic expansion valve thereof. Background Art

[0002] At present, the refrigeration and heating system uses an electronic expansion valve as a throttling element, and the flow rate of the refrigerant circulating in the refrigeration and heating system is adjusted by adjusting the opening of the electronic expansion valve. When the temperature needs to be lowered, the refrigeration and heating system is in the cooling mode, and when the temperature needs to be raised, the refrigeration and heating system is in the heating mode.

[0003] The existing method for adjusting the opening of the electronic expansion valve in the refrigeration and heating system is as follows: the opening of the electronic expansion valve is adjusted according to the difference between the actual temperature of the target liquid to be adjusted and the set temperature. In this method, when the difference between the actual temperature and the set temperature is small, the opening of the electronic expansion valve is small, resulting in less refrigerant circulating in the temperature control system, reduced heat exchange efficiency, and affecting the normal operation of the temperature control equipment. Summary of the invention

[0004] The present invention provides a temperature control device and a control method and a control device for an electronic expansion valve thereof, so as to improve the heat exchange efficiency and working reliability of the temperature control device.

[0005] In a first aspect, the present invention provides a control method for an electronic expansion valve in a temperature control device, wherein the temperature control device comprises at least an evaporator, an electronic expansion valve, a liquid supply pipeline, a temperature sensor and a pressure sensor; the evaporator comprises a portion of the liquid supply pipeline and a refrigerant pipeline, and the outlet of the electronic expansion valve is connected to the refrigerant inlet of the evaporator; the temperature sensor is used to detect the actual temperature of the liquid in the liquid supply pipeline, and the pressure sensor is used to detect the actual pressure in the refrigerant pipeline;

[0006] The control method of the electronic expansion valve in the temperature control device comprises:

[0007] Obtaining the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline;

[0008] According to the actual temperature and the set temperature, determining the working mode of the temperature control device and controlling the temperature control device to be in the working mode; the working mode at least includes a cooling mode;

[0009] Determining a theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each of the preset temperature deviations corresponding to each of the temperature range segments;

[0010] According to the theoretical temperature and the actual pressure, the theoretical opening of the electronic expansion valve is determined and the current opening of the electronic expansion valve is controlled to be the theoretical opening.

[0011] Optionally, the working mode of the temperature control device is determined according to the actual temperature and the set temperature; the working mode at least includes a cooling mode, including:

[0012] Determining whether the actual temperature is greater than the set temperature;

[0013] If so, it is determined that the working mode of the temperature control device is the cooling mode, and the temperature control device is controlled to be in the cooling mode.

[0014] Optionally, controlling the temperature control device to be in the cooling mode includes:

[0015] The duration for which the current opening of the electronic expansion valve is controlled to be a preset opening is a preset holding duration.

[0016] Optionally, determining the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each of the preset temperature deviations corresponding to each of the temperature range segments includes:

[0017] When the working mode is the cooling mode, according to the actual temperature and each of the temperature range segments, the temperature range segment including the actual temperature is used as a reference temperature range segment;

[0018] The theoretical temperature in the refrigerant pipeline is determined according to the preset temperature deviation and the actual temperature corresponding to the reference temperature range.

[0019] Optionally, determining the theoretical temperature in the refrigerant pipeline according to the preset temperature deviation corresponding to the reference temperature range and the actual temperature includes:

[0020] A temperature difference between the actual temperature and the preset temperature deviation corresponding to the reference temperature range is calculated, and the temperature difference is used as the theoretical temperature in the refrigerant pipeline.

[0021] Optionally, determining the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure includes:

[0022] Acquire a mapping relationship between the temperature and pressure of the refrigerant in the refrigerant pipeline;

[0023] According to the mapping relationship, determining the pressure corresponding to the theoretical temperature as the theoretical pressure;

[0024] The theoretical opening of the electronic expansion valve is determined according to the theoretical pressure and the actual pressure.

[0025] Optionally, determining the theoretical opening of the electronic expansion valve according to the theoretical pressure and the actual pressure includes:

[0026] According to the theoretical pressure and the actual pressure, based on a PID control algorithm, the theoretical opening of the electronic expansion valve is determined.

[0027] Optionally, after determining the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure and controlling the current opening of the electronic expansion valve to be the theoretical opening, the method further includes:

[0028] The current opening of the electronic expansion valve is controlled to be maintained at the theoretical opening for a period of T, and the process returns to the steps of obtaining the actual temperature of the liquid in the liquid supply pipeline and determining the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure, and controlling the current opening of the electronic expansion valve to be the theoretical opening, until the temperature control device is powered off; wherein, 1s≤T≤5s.

[0029] In a second aspect, the present invention provides a control device for an electronic expansion valve in a temperature control device, wherein the temperature control device comprises at least an evaporator, an electronic expansion valve and a liquid supply pipeline; the evaporator comprises part of the liquid supply pipeline and the refrigerant pipeline, and the outlet of the electronic expansion valve is connected to the refrigerant inlet of the evaporator;

[0030] The control device comprises:

[0031] A parameter acquisition module, used to acquire the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline;

[0032] A working mode determination module, used to determine the working mode of the temperature control device according to the actual temperature and the set temperature and control the temperature control device to be in the working mode; the working mode at least includes a cooling mode;

[0033] a theoretical temperature determination module, configured to determine a theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each of the preset temperature deviations corresponding to each of the temperature range segments;

[0034] The opening degree determination control module is used to determine the theoretical opening degree of the electronic expansion valve according to the theoretical temperature and the actual pressure and control the current opening degree of the electronic expansion valve to be the theoretical opening degree.

[0035] In a third aspect, the present invention provides a temperature control device, comprising: an evaporator, an electronic expansion valve, a liquid supply pipeline, a temperature sensor, a pressure sensor and a controller;

[0036] The evaporator includes part of the liquid supply pipeline and the refrigerant pipeline, and the outlet of the electronic expansion valve is connected to the refrigerant inlet of the evaporator; the temperature sensor is used to detect the actual temperature of the liquid in the liquid supply pipeline, and the pressure sensor is used to detect the actual pressure in the refrigerant pipeline;

[0037] The controller is electrically connected to the control end of the electronic expansion valve, the temperature sensor, and the pressure sensor respectively, and the controller is used to execute the control method of the electronic expansion valve in the temperature control device described in the first aspect.

[0038] The technical solution provided by the present invention obtains the actual temperature of the liquid in the liquid supply pipeline, the set temperature, the preset temperature deviations corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline, so as to determine the working mode of the temperature control device and control the temperature control device to be in the working mode according to the size relationship between the actual temperature and the set temperature, so that in this working mode, the theoretical temperature in the refrigerant pipeline is determined according to the preset temperature deviation of the temperature range segment corresponding to the actual temperature, and then the theoretical opening of the electronic expansion valve is determined according to the theoretical temperature and the actual pressure, and the current opening of the electronic expansion valve is controlled to be the theoretical opening. In this way, by setting the corresponding preset temperature deviation for each temperature range segment, the refrigerant in the refrigerant pipeline in the evaporator and the liquid in the liquid supply pipeline have a higher heat exchange efficiency, while ensuring the refrigerant flow in the refrigeration pipeline, preventing the small opening of the electronic expansion valve from affecting the normal operation of the temperature control device, and improving the working reliability and stability of the temperature control device. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the structure of a temperature control device provided by an embodiment of the present invention;

[0040] Figure 2 A flow chart of a method for controlling an electronic expansion valve in a temperature control device provided by an embodiment of the present invention;

[0041] Figure 3 A flow chart of another method for controlling an electronic expansion valve in a temperature control device provided by an embodiment of the present invention;

[0042] Figure 4 A flow chart of a method for controlling an electronic expansion valve in a temperature control device provided by another embodiment of the present invention;

[0043] Figure 5 A flow chart of a method for controlling an electronic expansion valve in a temperature control device provided by another embodiment of the present invention;

[0044] Figure 6 Flow chart of a method for controlling an electronic expansion valve in a temperature control device provided by an embodiment of the present invention

[0045] Figure 7 A schematic structural diagram of a control device for an electronic expansion valve in a temperature control device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0047] Embodiment 1

[0048] Figure 1 A schematic diagram of a temperature control device provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the temperature control device at least includes an evaporator 10, an electronic expansion valve 20, a liquid supply pipeline 30, a temperature sensor 41, a pressure sensor 42 and a controller 50; the evaporator 10 includes a portion of the liquid supply pipeline 30 and the refrigerant pipeline 11, and the outlet of the electronic expansion valve 20 is connected to the refrigerant inlet of the evaporator 10; the temperature sensor 41 is used to detect the actual temperature of the liquid in the liquid supply pipeline 30, and the pressure sensor 42 is used to detect the actual pressure in the refrigerant pipeline.

[0049] Among them, the electronic expansion valve 20 includes an electromagnetic electronic expansion valve or an electric electronic expansion valve, etc., the temperature sensor 41 includes a thermistor sensor or a thermocouple sensor, etc., and the pressure sensor 42 includes a ceramic pressure sensor or a capacitive pressure sensor, etc., which can be set according to actual needs and are not specifically limited here.

[0050] Specifically, the refrigerant in the refrigerant pipeline 11 of the evaporator 10 exchanges heat with the liquid in the liquid supply pipeline 30 in the evaporator 10 to reduce the temperature of the liquid in the liquid supply pipeline 30. The electronic expansion valve 20 is connected to the refrigerant inlet of the evaporator 10 to adjust the refrigerant flow entering the evaporator 10. The temperature sensor 41 is located in the liquid supply pipeline 30 to detect the actual temperature of the liquid in the liquid supply pipeline 30. The pressure sensor 42 is located at the refrigerant outlet of the evaporator 10 to detect the refrigerant pressure in the refrigerant pipeline 11.

[0051] The temperature control device also includes a condenser 60, a compressor 70, a regenerator 80, a load 31 and a circulation pump 32. The circulation pump 32 and the load 31 are located in the liquid supply pipeline 30. The liquid in the liquid supply pipeline 30 can exchange heat with the device or space to be cooled in the load 31 to adjust the working state of the load 31. The load 31 includes a device that can heat or cool the liquid in the liquid supply pipeline 30, etc., which can be set according to actual needs. The circulation pump 32 is used to provide the liquid after heat exchange in the evaporator 40 to the load 31 at a large flow rate to meet the working requirements of the load 31. The operation of the load 31 causes the temperature of the liquid in the liquid supply pipeline 30 to fluctuate all the time, so it is necessary to adjust the opening of the electronic expansion valve 20, and then control the refrigerant flow in the evaporator 10, so as to reduce the temperature fluctuation of the liquid in the liquid supply pipeline 30 as much as possible.

[0052] When the temperature control device is in the cooling mode, the low-pressure and low-temperature refrigerant gas output by the evaporator 10 enters the compressor 70 after heat exchange through the regenerator 80. The compressor 70 compresses the refrigerant gas into a high-temperature and high-pressure refrigerant gas. The high-temperature and high-pressure refrigerant gas enters the condenser 60. After condensation, a medium-temperature and medium-pressure refrigerant liquid is output. After throttling and pressure reduction by the electronic expansion valve 20 and heat exchange by the regenerator 80, it becomes a low-temperature and low-pressure refrigerant liquid. The low-temperature and low-pressure refrigerant liquid is absorbed and evaporated in the evaporator 10 and then outputs a low-temperature and low-pressure refrigerant gas. The low-temperature and low-pressure refrigerant gas enters the compressor 70 through the regenerator 80. The above process is circulated, so that the refrigerant liquid in the evaporator 10 can continuously exchange heat with the liquid in the liquid supply pipeline 30, thereby reducing the liquid temperature in the liquid supply pipeline 30.

[0053] The controller in the temperature control device provided in an embodiment of the present invention is used to execute the control method of the electronic expansion valve in the temperature control device provided in any embodiment of the present invention, control the opening of the electronic expansion valve to control the refrigerant flow in the refrigerant pipeline in the temperature control device, and has the same beneficial effect as the method, that is, by controlling the opening of the electronic expansion valve to improve the heat exchange efficiency between the liquid in the liquid supply pipeline and the refrigerant pipeline in the evaporator.

[0054] Embodiment 2

[0055] An embodiment of the present invention provides a control method for an electronic expansion valve in a temperature control device, which is suitable for situations where the temperature of a liquid in a temperature control device is adjusted. The method can be executed by a control device for an electronic expansion valve in a temperature control device provided by an embodiment of the present invention. The control device can be implemented in the form of hardware and / or software, and the control device can be integrated in the temperature control device. Figure 2 A flow chart of a method for controlling an electronic expansion valve in a temperature control device provided by an embodiment of the present invention, such as Figure 2 As shown, the control method includes:

[0056] S101, obtaining the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline.

[0057] Among them, the actual temperature reflects the current temperature of the liquid in the liquid supply pipeline, the set temperature is the preset temperature of the liquid in the liquid supply pipeline, the preset temperature deviation represents the preset difference between the temperature of the liquid in the liquid supply pipeline and the temperature of the refrigerant in the refrigerant pipeline in the evaporator, and the actual pressure of the refrigerant represents the current pressure value of the refrigerant. The liquid in the liquid supply pipeline includes a refrigerant such as ethylene glycol or fluorinated liquid, which can be set according to actual needs and is not specifically limited here.

[0058] Specifically, the actual temperature of the liquid in the liquid supply pipeline can be obtained through a temperature sensor located in the liquid supply pipeline, the preset temperature can be set according to actual needs, and the preset temperature deviations corresponding to each temperature range segment can be obtained according to experimental tests. A pressure sensor can be set in the refrigerant pipeline to obtain the actual pressure of the refrigerant in the refrigerant pipeline through the pressure sensor, so as to subsequently adjust the electronic expansion valve.

[0059] S102: Determine the working mode of the temperature control device according to the actual temperature and the set temperature and control the temperature control device to be in the working mode.

[0060] The working mode at least includes a cooling mode.

[0061] Specifically, when the actual temperature is greater than the set temperature, it means that the temperature of the liquid in the liquid supply pipeline is high and the liquid in the liquid supply pipeline needs to be cooled. At this time, the temperature control device can be controlled to be in the refrigeration working mode, so that the refrigerant in the refrigerant pipeline in the evaporator has a lower temperature, and the refrigerant and the liquid in the liquid supply pipeline are heat exchanged to reduce the temperature of the liquid in the liquid supply pipeline.

[0062] S103, determining a theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each preset temperature deviation corresponding to each temperature range segment.

[0063] The theoretical temperature in the refrigerant pipeline is related to the working mode of the temperature control device, the actual temperature in the liquid supply pipeline, and the preset temperature deviations corresponding to each temperature range segment.

[0064] Specifically, since the efficiency of heat exchange or cold exchange between the refrigerant in the refrigerant pipeline and the liquid in the liquid supply pipeline is different, the preset temperature deviations corresponding to each temperature range segment may be different when the working mode is different. In order to improve the heat exchange efficiency, it is necessary to determine each temperature range segment and each preset temperature deviation corresponding to the working mode according to the working mode, and then according to each preset temperature deviation corresponding to each temperature range segment, the preset temperature deviation corresponding to the actual temperature is used as the theoretical temperature in the refrigerant pipeline, so as to adjust the electronic expansion valve according to the theoretical temperature so that the refrigerant temperature in the refrigerant pipeline reaches the theoretical temperature, thereby improving the heat exchange efficiency between the refrigerant in the refrigerant pipeline and the liquid in the liquid supply pipeline under the working mode.

[0065] S104: Determine the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure, and control the current opening of the electronic expansion valve to be the theoretical opening.

[0066] Among them, the refrigerant temperature in the refrigerant pipeline is related to the refrigerant pressure. The opening of the electronic expansion valve will affect the refrigerant pressure in the refrigerant pipeline. The refrigerant pressure in the refrigerant pipeline is positively correlated with the opening of the electronic expansion valve, that is, the larger the opening of the electronic expansion valve, the greater the refrigerant pressure in the refrigerant pipeline, and the smaller the opening of the electronic expansion valve, the smaller the refrigerant pressure in the refrigerant pipeline.

[0067] Specifically, the theoretical temperature can be converted into the theoretical pressure according to the corresponding relationship between the refrigerant temperature and pressure in the refrigeration pipeline, and then the magnitude relationship between the theoretical pressure and the actual pressure can be compared. If the theoretical pressure is greater than the actual pressure, the theoretical pressure and the actual pressure are calculated to determine the theoretical opening of the electronic expansion valve, and the opening of the electronic expansion valve is controlled to increase to the theoretical opening. If the theoretical pressure is less than the actual pressure, the theoretical pressure and the actual pressure are calculated to determine the theoretical opening of the electronic expansion valve, and the opening of the electronic expansion valve is controlled to increase to the theoretical opening. In this way, by adjusting the opening of the electronic expansion valve, the difference between the refrigerant temperature in the refrigerant pipeline in the evaporator and the liquid temperature in the liquid supply pipeline reaches the preset temperature deviation, so as to improve the heat exchange efficiency between the refrigerant and the liquid, while ensuring the refrigerant supply in the evaporator, and improving the working reliability of the temperature control equipment.

[0068] The technical solution of the embodiment of the present invention obtains the actual temperature of the liquid in the liquid supply pipeline, the set temperature, the preset temperature deviations corresponding to each temperature range, and the actual pressure of the refrigerant in the refrigerant pipeline, so as to determine the working mode of the temperature control device and control the temperature control device to be in the working mode according to the size relationship between the actual temperature and the set temperature, so that in this working mode, the theoretical temperature in the refrigerant pipeline is determined according to the preset temperature deviation of the temperature range corresponding to the actual temperature, and then the theoretical opening of the electronic expansion valve is determined according to the theoretical temperature and the actual pressure, and the current opening of the electronic expansion valve is controlled to be the theoretical opening. In this way, by setting the corresponding preset temperature deviation for each temperature range, the refrigerant in the refrigerant pipeline in the evaporator and the liquid in the liquid supply pipeline have a higher heat exchange efficiency, while ensuring the refrigerant flow in the refrigeration pipeline, preventing the small opening of the electronic expansion valve from affecting the normal operation of the temperature control device, and improving the working reliability and stability of the temperature control device.

[0069] Embodiment 3

[0070] On the basis of the above-mentioned embodiments, the embodiments of the present invention illustrate the situation of determining the working mode of the temperature control device according to the actual temperature and the set temperature. Figure 3 A flow chart of another method for controlling an electronic expansion valve in a temperature control device provided by an embodiment of the present invention, such as Figure 3 As shown, the control method includes:

[0071] S201, obtaining the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline.

[0072] S202, determine whether the actual temperature is greater than the set temperature; if so, execute S203.

[0073] Specifically, if the actual temperature is greater than the set temperature, it means that the temperature of the liquid in the liquid supply pipeline is high. At this time, it is necessary to control the refrigerant temperature in the refrigerant pipeline in the evaporator to maintain a lower temperature to reduce the liquid in the liquid supply pipeline so that the temperature of the liquid in the liquid supply pipeline reaches the set temperature as soon as possible.

[0074] S203: Determine that the working mode of the temperature control device is a cooling mode, and control the temperature control device to be in the cooling mode.

[0075] The working mode at least includes a cooling mode.

[0076] Specifically, after determining that the working mode of the temperature control device is the cooling mode, the electronic expansion valve can be controlled to open and the evaporator and other refrigeration devices can be controlled to work, so that the temperature control device is in the cooling mode, so as to reduce the refrigerant temperature in the refrigerant pipeline in the evaporator and improve the heat exchange efficiency between the refrigerant and the liquid.

[0077] Optionally, controlling the temperature control device to be in a cooling mode includes: controlling the current opening of the electronic expansion valve to be a preset opening and the duration of the opening to be a preset holding time.

[0078] Among them, the preset opening degree and the preset holding time can be set according to actual needs. For example, the preset opening degree is 50%, and the preset holding time is 2 minutes. It can also be other values, which are not specifically limited here.

[0079] Specifically, the temperature control device enters the cooling mode by controlling the electronic expansion valve to open the preset opening, and the time for the electronic expansion valve to maintain the preset opening is controlled to be the preset holding time, so that the refrigerant in the refrigerant pipeline can establish a stable dynamic pressure difference within the preset holding time. When the opening of the electronic expansion valve is subsequently adjusted, the impact of the increased or decreased refrigerant on the dynamic balance in the refrigerant pipeline can be reduced, thereby improving the operating stability of the temperature control device.

[0080] In an optional embodiment, the temperature control device also includes a heater, which is used to heat the liquid in the liquid supply pipeline, so that when the actual temperature is lower than the set temperature, the electronic expansion valve can be controlled to close, and the heater works to put the temperature control device into a heating mode, thereby heating the liquid in the liquid supply pipeline so that the temperature of the liquid in the liquid supply pipeline reaches the set temperature.

[0081] S204: Determine the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each preset temperature deviation corresponding to each temperature range segment.

[0082] S205. Determine the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure, and control the current opening of the electronic expansion valve to be the theoretical opening.

[0083] The technical solution of the embodiment of the present invention obtains the actual temperature of the liquid in the liquid supply pipeline, the set temperature, the preset temperature deviations corresponding to each temperature range, and the actual pressure of the refrigerant in the refrigerant pipeline. If the actual temperature is greater than the set temperature, it means that the temperature of the liquid in the liquid supply pipeline is high and the liquid needs to be cooled. Then, the working mode of the temperature control device is determined to be the cooling mode, and the electronic expansion valve is controlled to open the preset opening, so that the temperature control device is in the cooling mode, which is convenient for further adjustment of the opening of the electronic expansion valve, and improves the efficiency of reducing the temperature of the liquid in the liquid supply pipeline.

[0084] Embodiment 4

[0085] Based on the above embodiments, the embodiments of the present invention illustrate the situation of determining the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and the preset temperature deviations corresponding to the temperature range segments. Figure 4A flow chart of a control method of an electronic expansion valve in a temperature control device provided by another embodiment of the present invention, such as Figure 4 As shown, the control method includes:

[0086] S301, obtaining the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline.

[0087] S302: Determine the working mode of the temperature control device according to the actual temperature and the set temperature and control the temperature control device to be in the working mode.

[0088] The working mode at least includes a cooling mode.

[0089] S303: When the working mode is the cooling mode, according to the actual temperature and each temperature range segment, the temperature range segment including the actual temperature is used as the reference temperature range segment.

[0090] Among them, each temperature range segment and the preset temperature deviation corresponding to each temperature range segment are related to the refrigerant type, etc., and can be set according to actual needs. For example, in the cooling mode, each temperature range segment is 250℃~300℃, 200℃~250℃, 150℃~200℃, 100℃~150℃, 50℃~100℃, 0℃~50℃, -30℃~0℃, -80℃~-30℃. The preset temperature deviations corresponding to the above temperature range segments are 15℃, 15℃, 12℃, 12℃, 10℃, 10℃, 8℃, and 5℃ respectively.

[0091] Specifically, when the difference between the refrigerant temperature in the refrigerant pipeline in the evaporator and the liquid in the liquid supply pipeline is equal to the preset temperature deviation, the refrigerant in the refrigerant pipeline and the liquid in the liquid supply pipeline have a higher heat exchange efficiency. Therefore, after obtaining the actual temperature of the liquid in the liquid supply pipeline, the temperature range segment containing the actual temperature is compared with each temperature range segment, and the temperature range segment containing the actual temperature is used as the reference temperature range segment, so that the theoretical temperature of the refrigerant can be determined later according to the reference temperature range segment and the preset temperature deviation corresponding to the reference temperature range segment. For example, the actual temperature is 270°C, the set temperature is -30°C, and the reference temperature range segment is 250°C to 300°C.

[0092] S304: Determine the theoretical temperature in the refrigerant pipeline according to the preset temperature deviation and the actual temperature corresponding to the reference temperature range.

[0093] Specifically, the preset temperature deviation corresponding to the reference temperature range segment is used as the preset temperature deviation corresponding to the actual temperature. The theoretical temperature in the refrigerant pipeline is related to the actual temperature and the preset temperature deviation corresponding to the actual temperature. The actual temperature and the preset temperature deviation corresponding to the actual temperature can be substituted into the calculation formula of the theoretical temperature for calculation, and then the theoretical temperature in the refrigerant pipeline can be obtained, so that the electronic expansion valve can be adjusted according to the theoretical temperature later to make the refrigerant pipeline reach the theoretical temperature.

[0094] Optionally, the theoretical temperature in the refrigerant pipeline is determined based on the preset temperature deviation corresponding to the reference temperature range segment and the actual temperature, including: calculating the temperature difference between the actual temperature and the preset temperature deviation corresponding to the reference temperature range segment, and using the temperature difference as the theoretical temperature in the refrigerant pipeline.

[0095] Specifically, since the current state is in cooling mode, the refrigerant in the refrigerant pipeline needs to be able to increase the temperature to a lower level. Therefore, the temperature difference between the actual temperature and the preset temperature deviation is calculated, and the temperature difference is used as the theoretical temperature in the refrigerant pipeline. For example, if the actual temperature is 270°C and the set temperature is -30°C, the reference temperature range is 250°C to 300°C, and the preset temperature deviation corresponding to the temperature range of 250°C to 300°C is 15°C, so the theoretical temperature in the refrigerant pipeline is 255°C, which is the temperature difference between the actual temperature of 270°C and the preset temperature deviation of 15°C. In this way, a preset temperature deviation is set in each temperature range, so that when the actual temperature in the liquid supply pipeline is within each temperature range, the temperature of the refrigerant pipeline in the evaporator is controlled to be the theoretical temperature, so that the temperature difference between the refrigerant and the liquid reaches the preset temperature deviation. Under the preset temperature deviation, the refrigerant and the liquid have a higher heat exchange efficiency, which can shorten the temperature drop time of the liquid supply pipeline and improve the temperature control efficiency of the temperature control device.

[0096] S305: Determine the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure, and control the current opening of the electronic expansion valve to be the theoretical opening.

[0097] The technical solution of the embodiment of the present invention, when the working mode is the cooling mode, according to the actual temperature and each temperature range segment, the temperature range segment including the actual temperature is used as the reference temperature range segment, so as to calculate the temperature difference value of the preset temperature deviation corresponding to the actual temperature and the reference temperature range segment, and use the temperature difference value as the theoretical temperature in the refrigerant pipeline. It is convenient to determine the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure, and control the current opening of the electronic expansion valve to the theoretical opening, thereby improving the control efficiency of the temperature control device on the liquid temperature in the liquid supply pipeline.

[0098] Embodiment 5

[0099] On the basis of the above-mentioned embodiment, the embodiment of the present invention describes the situation of determining the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure. Figure 5 A flow chart of a control method of an electronic expansion valve in a temperature control device provided by an embodiment of the present invention is shown in FIG. Figure 5 As shown, the control method includes:

[0100] S401, obtaining the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline.

[0101] S402: Determine the working mode of the temperature control device according to the actual temperature and the set temperature and control the temperature control device to be in the working mode.

[0102] The working mode at least includes a cooling mode.

[0103] S403: Determine the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each preset temperature deviation corresponding to each temperature range segment.

[0104] S404: Obtain a mapping relationship between the temperature and pressure of the refrigerant in the refrigerant pipeline.

[0105] The mapping relationship may be a graph of the temperature and pressure of the refrigerant, a corresponding table of the temperature and pressure of the refrigerant, or a calculation formula of the temperature and pressure of the refrigerant, which may be obtained through experiments or experience. For example, the mapping relationship is a calculation formula of the temperature and pressure of the refrigerant, which is as follows: P = 3*10 -13 *T 6 +6*10 -12 *T 5 +1*10 -9 *T 4 +1*10 -6 *T 3 +2*10 -4 *T 2 +0.0193*T+0.6101-0.101, this calculation formula is applicable to the case where the refrigerant includes a non-azeotropic mixture, and can also be other, which is not specifically limited here.

[0106] S405. According to the mapping relationship, determine the pressure corresponding to the theoretical temperature as the theoretical pressure.

[0107] Specifically, when the mapping relationship is a curve graph of the temperature and pressure of the refrigerant, after determining the theoretical temperature, the curve graph of the temperature and pressure of the refrigerant can be directly compared to determine the pressure on the curve graph corresponding to the theoretical temperature as the theoretical pressure. Alternatively, when the mapping relationship is a corresponding table of the temperature and pressure of the refrigerant, after determining the theoretical temperature, the table can be directly looked up to obtain the pressure corresponding to the theoretical temperature, and the pressure is determined as the theoretical pressure. When the mapping relationship is a corresponding calculation formula of the temperature and pressure of the refrigerant, after determining the theoretical temperature, the theoretical temperature is substituted into the calculation formula to calculate the theoretical pressure corresponding to the theoretical temperature.

[0108] S406: Determine the theoretical opening of the electronic expansion valve according to the theoretical pressure and the actual pressure, and control the current opening of the electronic expansion valve to be the theoretical opening.

[0109] The theoretical opening is determined by the theoretical pressure and the actual pressure, that is, the theoretical opening of the electronic expansion valve is related to the theoretical pressure and the actual pressure.

[0110] Specifically, if the difference between the actual pressure and the theoretical pressure is large, the actual pressure has a large difference with the theoretical pressure. If the difference between the actual pressure and the theoretical pressure is small, the actual pressure has a small difference with the theoretical pressure.

[0111] Optionally, the theoretical opening of the electronic expansion valve is determined according to the theoretical pressure and the actual pressure, including determining the theoretical opening of the electronic expansion valve based on the theoretical pressure and the actual pressure and based on the PID control algorithm. That is, the theoretical pressure and the actual pressure are fed back to the PID control algorithm, and the theoretical opening of the electronic expansion valve is determined according to the specific PID control algorithm, so that the electronic expansion valve can be adjusted accordingly according to the theoretical opening. It can be understood that the PID control algorithm can be specifically designed according to actual needs, and the embodiment of the present invention is not specifically limited here.

[0112] The technical solution of the embodiment of the present invention, after determining the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each preset temperature deviation corresponding to each temperature range segment, obtains the mapping relationship between the temperature and pressure of the refrigerant in the refrigerant pipeline, and determines the pressure corresponding to the theoretical temperature as the theoretical pressure according to the mapping relationship. The theoretical pressure is compared with the actual pressure, and then the theoretical opening of the electronic expansion valve is determined and the current opening of the electronic expansion valve is controlled to be the theoretical opening, so that when the opening of the electronic expansion valve is the theoretical opening, the difference between the refrigerant temperature in the refrigerant pipeline in the evaporator and the liquid temperature in the liquid supply pipeline can reach the preset temperature deviation, thereby improving the heat exchange efficiency between the refrigerant and the liquid, and improving the temperature control rate of the temperature control device.

[0113] Embodiment 6

[0114] On the basis of the above-mentioned embodiment, the embodiment of the present invention describes the situation after the theoretical opening of the electronic expansion valve is determined according to the theoretical temperature and the actual pressure and the current opening of the electronic expansion valve is controlled to be the theoretical opening. Figure 6 A flow chart of a method for controlling an electronic expansion valve in a temperature control device provided by an embodiment of the present invention, such as Figure 6 As shown, the control method includes:

[0115] S501, obtaining the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline.

[0116] S502: Determine the working mode of the temperature control device according to the actual temperature and the set temperature and control the temperature control device to be in the working mode.

[0117] S503: Determine the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each preset temperature deviation corresponding to each temperature range segment.

[0118] S504: Determine the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure, and control the current opening of the electronic expansion valve to be the theoretical opening.

[0119] S505: Control the current opening of the electronic expansion valve to be the theoretical opening for a period of T, and return to execute S501 until the temperature control device is powered off.

[0120] Among them, 1s≤T≤5s.

[0121] Specifically, after the current opening of the electronic expansion valve is controlled to be the theoretical opening, in order to ensure that the refrigerant can complete at least one cycle in the refrigerant pipeline, the electronic expansion valve is controlled to maintain the theoretical opening for a time period T of at least 1 second, thereby reducing the refrigerant temperature in the refrigerant pipeline in the evaporator. When the time period T that the electronic expansion valve maintains the theoretical opening is greater than 5 seconds, the liquid in the liquid supply pipeline may have undergone significant changes, and the refrigerant temperature corresponding to the current theoretical opening cannot meet the cooling rate of the liquid in the liquid supply pipeline, and the liquid temperature in the liquid supply pipeline cannot be reduced in time. Therefore, by setting the time period T that the electronic expansion valve maintains the theoretical opening within the range of 1 second to 5 seconds, the temperature of the liquid in the liquid supply pipeline in each temperature range can be controlled, thereby improving the temperature control efficiency of the temperature control device on the liquid.

[0122] It is understandable that, since each time the electronic expansion valve is adjusted, the time for which the electronic expansion valve maintains the theoretical opening is the holding time T, the actual temperature of the liquid in the liquid supply pipeline may be equal to the set temperature during this time period. If the actual temperature is still consistent with the set temperature when returning to execute to obtain the actual temperature and set temperature of the liquid in the liquid supply pipeline, the electronic expansion valve is controlled to maintain the current opening for the second preset time. Since the liquid in the liquid supply pipeline is easily affected by factors such as the external environment, the liquid temperature in the liquid supply pipeline may increase or decrease within the second preset time. When the second preset time expires, the return is returned to execute to obtain the actual temperature and set temperature of the liquid in the liquid supply pipeline. If the actual temperature is greater than the set temperature, the electronic expansion valve is adjusted according to the preset temperature deviation mentioned in the above embodiment. The relevant principles can be referred to the relevant description, which will not be repeated here. If the actual temperature is less than the set temperature when the second preset time expires, the electronic expansion valve is controlled to close to prevent the refrigerant from continuing to cool down and further reduce the liquid temperature of the liquid supply pipeline. Since the temperature of the liquid in the liquid supply pipeline is unstable, the process of regulating the theoretical opening of the electronic expansion valve is cyclical until the temperature control device is powered off, so that the temperature of the liquid in the liquid supply pipeline can reach the set temperature or approach the set temperature at a faster rate during the operation of the temperature control device, thereby improving the temperature regulation efficiency of the temperature control device.

[0123] The technical solution of the embodiment of the present invention is to control the electronic expansion valve to maintain the theoretical opening for a holding time T, so that the refrigerant in the refrigerant pipeline can complete at least one cycle within the holding time T, so that the temperature of the refrigerant in the refrigerant pipeline in the evaporator can be reduced, and then heat is exchanged with the liquid in the liquid supply pipeline to reduce the temperature of the liquid in the liquid supply pipeline. After the holding time T, the steps of obtaining the actual temperature and setting are returned to be executed, so as to obtain the temperature in the liquid supply pipeline in real time, and then the electronic expansion valve is controlled accordingly. During the whole process of the liquid temperature in the liquid supply pipeline reaching the set temperature, the electronic expansion valve is adjusted according to the temperature range segment where the actual temperature is located, so that the refrigerant supply in the evaporator is always maintained at a state with a high utilization rate, so that the refrigerant can have a high heat exchange efficiency with the liquid.

[0124] Embodiment 7

[0125] Figure 7 This is a schematic diagram of the structure of a control device for an electronic expansion valve in a temperature control device provided by an embodiment of the present invention. The control device can be implemented in the form of hardware and / or software and can be integrated into the temperature control device. Figure 7 As shown, the control device includes:

[0126] The parameter acquisition module 91 is used to acquire the actual temperature of the liquid in the liquid supply pipeline, the set temperature, the preset temperature deviations corresponding to the temperature range segments, and the actual pressure of the refrigerant in the refrigerant pipeline.

[0127] The working mode determination module 92 is used to determine the working mode of the temperature control device according to the actual temperature and the set temperature and control the temperature control device to be in the working mode; the working mode at least includes the cooling mode.

[0128] The theoretical temperature determination module 93 is used to determine the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and the preset temperature deviations corresponding to the temperature range segments.

[0129] The opening degree determination control module 94 is used to determine the theoretical opening degree of the electronic expansion valve according to the theoretical temperature and the actual pressure and control the current opening degree of the electronic expansion valve to be the theoretical opening degree.

[0130] The control device of the electronic expansion valve in the temperature control device provided in the embodiment of the present invention can execute the control method of the electronic expansion valve in the temperature control device provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. The similarities can be referred to the above description.

[0131] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for controlling an electronic expansion valve in a temperature control device, characterized in that: The temperature control device at least includes an evaporator, an electronic expansion valve, a liquid supply pipeline, a temperature sensor and a pressure sensor; the evaporator includes part of the liquid supply pipeline and the refrigerant pipeline, and the outlet of the electronic expansion valve is connected to the refrigerant inlet of the evaporator; the temperature sensor is used to detect the actual temperature of the liquid in the liquid supply pipeline, and the pressure sensor is used to detect the actual pressure in the refrigerant pipeline; The control method of the electronic expansion valve in the temperature control device comprises: Obtaining the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline; According to the actual temperature and the set temperature, determining the working mode of the temperature control device and controlling the temperature control device to be in the working mode; the working mode at least includes a cooling mode; Determining a theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each of the preset temperature deviations corresponding to each of the temperature range segments; Determining the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure and controlling the current opening of the electronic expansion valve to be the theoretical opening; Determining the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and each of the preset temperature deviations corresponding to each of the temperature range segments includes: When the working mode is the cooling mode, according to the actual temperature and each of the temperature range segments, the temperature range segment including the actual temperature is used as a reference temperature range segment; The theoretical temperature in the refrigerant pipeline is determined according to the preset temperature deviation and the actual temperature corresponding to the reference temperature range.

2. The control method according to claim 1, characterized in that: Determine the working mode of the temperature control device according to the actual temperature and the set temperature; the working mode at least includes a cooling mode, including: Determining whether the actual temperature is greater than the set temperature; If so, it is determined that the working mode of the temperature control device is the cooling mode, and the temperature control device is controlled to be in the cooling mode.

3. The control method according to claim 2, characterized in that: Controlling the temperature control device to be in the cooling mode includes: The duration for which the current opening of the electronic expansion valve is controlled to be a preset opening is a preset holding duration.

4. The control method according to claim 1, characterized in that: Determining a theoretical temperature in the refrigerant pipeline according to the preset temperature deviation corresponding to the reference temperature range and the actual temperature includes: A temperature difference between the actual temperature and the preset temperature deviation corresponding to the reference temperature range is calculated, and the temperature difference is used as the theoretical temperature in the refrigerant pipeline.

5. The control method according to claim 1, characterized in that: Determining the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure includes: Acquire a mapping relationship between the temperature and pressure of the refrigerant in the refrigerant pipeline; According to the mapping relationship, determining the pressure corresponding to the theoretical temperature as the theoretical pressure; The theoretical opening of the electronic expansion valve is determined according to the theoretical pressure and the actual pressure.

6. The control method according to claim 5, characterized in that: Determining the theoretical opening of the electronic expansion valve according to the theoretical pressure and the actual pressure includes: According to the theoretical pressure and the actual pressure, based on a PID control algorithm, the theoretical opening of the electronic expansion valve is determined.

7. The control method according to claim 1, characterized in that: After determining the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure and controlling the current opening of the electronic expansion valve to be the theoretical opening, the method further includes: The current opening of the electronic expansion valve is controlled to be maintained at the theoretical opening for a period of T, and the process returns to the steps of obtaining the actual temperature of the liquid in the liquid supply pipeline and determining the theoretical opening of the electronic expansion valve according to the theoretical temperature and the actual pressure, and controlling the current opening of the electronic expansion valve to be the theoretical opening, until the temperature control device is powered off; wherein, 1s≤T≤5s.

8. A control device for an electronic expansion valve in a temperature control device, characterized in that: The temperature control device at least includes an evaporator, an electronic expansion valve, a liquid supply pipeline, a temperature sensor and a pressure sensor; the evaporator includes part of the liquid supply pipeline and the refrigerant pipeline, and the outlet of the electronic expansion valve is connected to the refrigerant inlet of the evaporator; the temperature sensor is used to detect the actual temperature of the liquid in the liquid supply pipeline, and the pressure sensor is used to detect the actual pressure in the refrigerant pipeline; The control device comprises: A parameter acquisition module, used to acquire the actual temperature of the liquid in the liquid supply pipeline, the set temperature, each preset temperature deviation corresponding to each temperature range segment, and the actual pressure of the refrigerant in the refrigerant pipeline; A working mode determination module, used to determine the working mode of the temperature control device according to the actual temperature and the set temperature and control the temperature control device to be in the working mode; the working mode at least includes a cooling mode; a theoretical temperature determination module, for determining the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and the preset temperature deviations corresponding to the temperature range segments; determining the theoretical temperature in the refrigerant pipeline according to the working mode, the actual temperature, and the preset temperature deviations corresponding to the temperature range segments, including: when the working mode is the cooling mode, according to the actual temperature and the temperature range segments, taking the temperature range segment containing the actual temperature as a reference temperature range segment; determining the theoretical temperature in the refrigerant pipeline according to the preset temperature deviation corresponding to the reference temperature range segment and the actual temperature; The opening degree determination control module is used to determine the theoretical opening degree of the electronic expansion valve according to the theoretical temperature and the actual pressure and control the current opening degree of the electronic expansion valve to be the theoretical opening degree.

9. A temperature control device, characterized in that: include: Evaporator, electronic expansion valve, liquid supply pipeline, temperature sensor, pressure sensor and controller; The evaporator includes part of the liquid supply pipeline and the refrigerant pipeline, and the outlet of the electronic expansion valve is connected to the refrigerant inlet of the evaporator; the temperature sensor is used to detect the actual temperature of the liquid in the liquid supply pipeline, and the pressure sensor is used to detect the actual pressure in the refrigerant pipeline; The controller is electrically connected to the control end of the electronic expansion valve, the temperature sensor, and the pressure sensor respectively, and the controller is used to execute the control method of the electronic expansion valve in the temperature control device according to any one of claims 1-7.

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