Electronic expansion valve opening degree adjusting method, device, controller and heat pump host

Abstract

This invention relates to a method, apparatus, controller, and heat pump unit for adjusting the opening degree of an electronic expansion valve. The electronic expansion valve opening degree adjustment method of this invention includes the following steps: obtaining the compressor's discharge temperature T. 排 ; in T 排 When the value is less than the first threshold, it is determined that within time t1, the value of T... 排 Does the temperature rise exceed ΔT1? Where, at T... 排 When the temperature is below the first threshold, the opening of the electronic expansion valve is adjusted to a first target value T0, which includes a preset exhaust superheat value or intake superheat value. If so, the opening of the electronic expansion valve is increased by a first adjustment amplitude P1, and the opening of the electronic expansion valve is adjusted to a second target value T1, wherein the second target value T1 is obtained by decreasing the first target value T0 by a second adjustment amplitude P2. The electronic expansion valve opening adjustment method of the present invention can adjust the opening of the electronic expansion valve in a timely manner, so that the opening is adapted to the exhaust temperature rise rate, and the system can operate smoothly.

Description

Technical Field

[0001] This invention relates to the field of heat pump system technology, and in particular to an electronic expansion valve opening adjustment method, device, controller, and heat pump host. Background Technology

[0002] In current heat pump systems, the electronic expansion valve is generally controlled based on the return gas superheat or the exhaust gas superheat. Specifically, when the exhaust gas temperature is lower than the set exhaust gas temperature threshold, the opening of the electronic expansion valve is adjusted by the set return gas superheat target value. When the exhaust gas temperature is higher than the set exhaust gas temperature threshold, the opening of the electronic expansion valve is adjusted by the exhaust gas temperature target value.

[0003] However, when using the above-mentioned traditional control method, if the exhaust temperature rises too quickly, the adjustment rate of the electronic expansion valve is insufficient to control the exhaust temperature, which can easily lead to a continuous rise in exhaust temperature until the unit enters shutdown protection. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide an electronic expansion valve opening adjustment method, device, controller and heat pump host, which can adjust the opening of the electronic expansion valve in a timely manner so that the opening is adapted to the exhaust temperature rise rate and realize the stable operation of the system.

[0005] According to a first aspect of some embodiments of this application, an electronic expansion valve opening adjustment method is provided, comprising the following steps:

[0006] Obtain the discharge temperature T of the compressor in the heat pump system 排 ;

[0007] At the discharge temperature T of the compressor 排 When the temperature is less than the first threshold, it is determined that the discharge temperature T of the compressor is within time t1. 排 Whether the temperature rise is greater than ΔT1; wherein, at the discharge temperature T of the compressor 排 When the value is less than the first threshold, the opening of the electronic expansion valve is adjusted to a first target value T0, which includes a preset exhaust superheat value or intake superheat value.

[0008] If so, the opening of the electronic expansion valve is increased by a first adjustment range P1, and the opening of the electronic expansion valve is adjusted to a second target value T1, wherein the second target value T1 is obtained by decreasing the first target value T0 by a second adjustment range P2.

[0009] Furthermore, after increasing the opening of the electronic expansion valve by a first adjustment range P1 and adjusting the opening of the electronic expansion valve to a second target value T1, the method further includes:

[0010] Determine the discharge temperature T of the compressor within time t2. 排 Whether the temperature rise is greater than ΔT1 again within time t1, where t2 is greater than t1;

[0011] If so, the opening of the electronic expansion valve is further increased by the first adjustment range P1 to adjust the opening of the electronic expansion valve to a third target value T2, wherein the third target value T2 is obtained by reducing the second adjustment range P2 from the second target value T1.

[0012] Furthermore, after controlling the opening of the electronic expansion valve to increase by a first adjustment range P1 and controlling the first target value T0 to decrease by a second adjustment range P2, the method further includes:

[0013] Determine the discharge temperature T of the compressor within time t2. 排 Whether the temperature rise is greater than ΔT1 again within time t1;

[0014] If not, adjust the opening of the electronic expansion valve to the first target value T0.

[0015] Furthermore, it also includes the following steps:

[0016] At the discharge temperature T of the compressor 排 When the temperature exceeds the first threshold, the opening of the electronic expansion valve is increased by a third adjustment range P3, and at each time interval t3, the opening of the electronic expansion valve is increased by a fourth adjustment range P4 until the discharge temperature T of the compressor is reached. 排 Less than a second threshold, wherein the second threshold is less than or equal to the first threshold.

[0017] Furthermore, at the discharge temperature T of the compressor 排 If the temperature is less than the first threshold and greater than the third threshold, then the discharge temperature T of the compressor is determined to be within time t1. 排 Does the temperature rise exceed ΔT1?

[0018] Furthermore, within time t1, the discharge temperature T of the compressor 排 After the temperature rise exceeds ΔT1, it also enters the exhaust rapid heating mode.

[0019] Furthermore, t1 and t3 are 5 to 10 seconds, t2 is 20 to 30 seconds, ΔT1 is 2 to 5 degrees Celsius, and the first target value T0 is -2 to 3 degrees Celsius.

[0020] Furthermore, the heat pump system also includes a cooling refrigerant branch, one end of which is connected to the refrigerant pipeline at the compressor return port, and the other end is connected to the refrigerant pipeline between the electronic expansion valve and the plate reversing valve. A liquid injection bypass valve is installed on the cooling refrigerant branch. The method further includes:

[0021] When the heat pump system is in heating mode, the discharge temperature T of the compressor is... 排 If the value is greater than the first threshold, it is determined whether the electronic expansion valve has reached its maximum opening value;

[0022] If so, control the liquid injection bypass valve to open until the exhaust temperature T_exhaust of the compressor is less than the second threshold.

[0023] According to a second aspect of some embodiments of this application, an electronic expansion valve opening adjustment device is provided, comprising:

[0024] The exhaust temperature acquisition module is used to acquire the compressor's exhaust temperature T. 排 ;

[0025] The temperature rise determination module is used to determine the discharge temperature T of the compressor. 排 When the temperature is less than the first threshold, it is determined that the discharge temperature T of the compressor is within time t1. 排 Whether the temperature rise is greater than ΔT1; wherein, at the discharge temperature T of the compressor 排 When the value is less than the first threshold, the opening of the electronic expansion valve is adjusted to a first target value T0, which includes a preset exhaust superheat value or return superheat value.

[0026] An electronic expansion valve regulating module is used to control the discharge temperature T of the compressor within time t1. 排 When the temperature rise is greater than ΔT1, the opening of the electronic expansion valve is increased by a first adjustment range P1, and the opening of the electronic expansion valve is adjusted to a second target value T1, wherein the second target value T1 is obtained by decreasing the first target value T0 by a second adjustment range P2.

[0027] According to a third aspect of some embodiments of this application, a controller is provided, comprising:

[0028] At least one memory and at least one processor;

[0029] The memory is used to store one or more programs;

[0030] When the one or more programs are executed by the at least one processor, the at least one processor performs the steps of an electronic expansion valve opening adjustment method as described in any of the first aspects above.

[0031] According to a fourth aspect of some embodiments of this application, a heat pump host is provided, including a controller as described in the third aspect above.

[0032] The electronic expansion valve opening adjustment method, device, controller, and heat pump unit provided in this application have the following effects:

[0033] (1) By detecting the exhaust temperature of the compressor, when the exhaust temperature has not yet risen to the set threshold but the rate of rise is relatively fast, the opening of the electronic expansion valve is increased and the adjustment target value of the electronic expansion valve is reduced, which can increase the adjustment range and adjustment rate of the electronic expansion valve, so that the adjustment of the electronic expansion valve is adapted to the change of exhaust temperature.

[0034] (2) After adjusting the electronic expansion valve once, continuously monitor the compressor exhaust temperature. If the rate of increase in exhaust temperature is not stable, continue to increase the opening of the electronic expansion valve and decrease the adjustment target value of the electronic expansion valve until the exhaust temperature reaches a stable state. This avoids exhaust temperature runaway caused by the electronic expansion valve's adjustment rate not being able to adapt to the rate of increase.

[0035] (3) When the exhaust temperature rises to a higher temperature, the opening of the electronic expansion valve is continuously increased to achieve a rapid drop in the exhaust temperature of the system and avoid the unit from entering the shutdown protection due to excessive exhaust temperature.

[0036] (4) When the heat pump system is in heating mode, the cooling refrigerant branch is connected to the original refrigerant main line, allowing the low-temperature liquid refrigerant to enter the refrigerant pipeline between the electronic expansion valve and the heat exchanger through the jet bypass valve. This reduces the temperature of the refrigerant entering the electronic expansion valve, and after being throttled by the electronic expansion valve, further reduces the temperature of the refrigerant entering the compressor, thereby reducing the compressor's discharge temperature and protecting the compressor. On the other hand, the reduced temperature of the refrigerant entering the electronic expansion valve also effectively protects the electronic expansion valve.

[0037] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0038] Figure 1 This is a schematic diagram illustrating the steps of an electronic expansion valve opening adjustment method according to an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the heat pump system structure used in an electronic expansion valve opening adjustment method according to an embodiment of the present invention.

[0040] Figure 3 This is a flowchart illustrating an electronic expansion valve opening adjustment method according to an embodiment of the present invention.

[0041] Figure 4 This is a flowchart illustrating another electronic expansion valve opening adjustment method according to an embodiment of the present invention.

[0042] Figure 5 This is a schematic diagram of an electronic expansion valve opening adjustment device according to an embodiment of the present invention.

[0043] Figure label:

[0044] 1. Compressor; 2. Four-way valve; 3. Plate heat exchanger; 4. Electronic expansion valve; 5. Filter; 6. Finned heat exchanger; 7. Liquid injection bypass valve. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0046] It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.

[0047] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0048] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0049] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0050] When a heat pump system operates at low temperature and low frequency, there is relatively little refrigerant flowing in the system. Since the compressor's temperature is often carried away by the flowing refrigerant, insufficient refrigerant flow will prevent the compressor from carrying away its heat, thus causing the compressor's exhaust temperature to rise.

[0051] When the exhaust temperature is lower than the set exhaust temperature threshold, the system adjusts the opening of the electronic expansion valve according to the set exhaust superheat target value or intake superheat target value. Since the electronic expansion valve lacks precision in self-adjustment based on the target value and the adjustment rate is slow, it may be impossible to control the continuous rise of exhaust temperature.

[0052] When the exhaust temperature exceeds the set threshold, the electronic expansion valve switches to regulating based on the target exhaust temperature. However, the valve's adjustment rate is insufficient to control the exhaust temperature, causing it to continue rising until the heat pump system enters high-temperature shutdown protection. Therefore, in this situation, the electronic expansion valve's regulation method needs to be adjusted to increase the flow of refrigerant in the heat pump system, thereby reducing the exhaust temperature.

[0053] To address this technical problem, this application provides an electronic expansion valve opening adjustment method. This method can be executed by an electronic expansion valve opening adjustment device, wherein the electronic expansion valve opening adjustment device can be a controller of a heat pump system or a water system, and the electronic expansion valve can be an electromagnetic electronic expansion valve or an electric electronic expansion valve.

[0054] like Figure 1 As shown, Figure 1 This application provides a schematic diagram of the steps for adjusting the opening of an electronic expansion valve, which includes the following steps:

[0055] S101: Obtain the compressor's discharge temperature T 排 .

[0056] This application involves determining whether to adjust the electronic expansion valve by detecting the compressor's discharge temperature. Therefore, it is necessary to monitor the compressor's discharge temperature T. 排 Continuous monitoring allows for timely adaptive adjustments to the electronic expansion valve in response to changes in the compressor's discharge temperature. In one example, the compressor's discharge temperature T can be acquired at fixed intervals via a discharge temperature sensor. 排The value is optional, and the time interval can be 5 to 10 seconds.

[0057] S102: At the discharge temperature T of the compressor 排 When the temperature is less than the first threshold, it is determined that the discharge temperature T of the compressor is within time t1. 排 Whether the temperature rise is greater than ΔT1; wherein, at the discharge temperature T of the compressor 排 When the opening is less than the first threshold, the opening of the electronic expansion valve is adjusted to a first target value T0, which includes a preset exhaust superheat value or return superheat value.

[0058] The first threshold is a preset threshold, which is set at the compressor's exhaust temperature T. 排 When the exhaust temperature is below the first threshold, the exhaust temperature is within a relatively controllable range, and the opening of the electronic expansion valve can be adjusted according to the first target value T0, which includes the preset exhaust superheat value or intake superheat value.

[0059] Specifically, exhaust superheat refers to the difference between the temperature at the compressor exhaust outlet and the saturated condensing temperature corresponding to the exhaust pressure. When the electronic expansion valve is adjusted with exhaust superheat as the target value, the opening of the electronic expansion valve is automatically adjusted by detecting the exhaust port temperature and obtaining the saturated condensing temperature corresponding to the exhaust pressure. Suction superheat refers to the difference between the temperature at the compressor suction port and the temperature at the evaporator inlet. The opening of the electronic expansion valve is automatically adjusted by detecting the suction port temperature and the evaporator inlet temperature.

[0060] Preferably, the first target value T0 is a preset target value for intake superheat. Optionally, the range of the first target value T0 when it is the target value for intake superheat is -2 to 3℃.

[0061] S103: If so, control the opening of the electronic expansion valve to increase by a first adjustment range P1, and adjust the opening of the electronic expansion valve to a second target value T1, wherein the second target value T1 is obtained by decreasing the first target value T0 by a second adjustment range P2.

[0062] Among them, the discharge temperature T of the compressor within time t1 is determined. 排 When the temperature rise is greater than ΔT1, it indicates that although the compressor's discharge temperature T 排 It is still less than the first threshold, but the exhaust temperature rises at a relatively high rate. The original method of adjusting the opening of the electronic expansion valve according to the first target value T0 is no longer sufficient to meet the exhaust temperature rise rate. To avoid the exhaust temperature rising too quickly, it is necessary to add adaptive adjustment to the electronic expansion valve in advance.

[0063] Specifically, t1 can be 5–10 seconds, and the temperature rise ΔT1 can be 2–5°C. The specific values ​​can be set according to actual conditions. When this temperature rise rate is met, the opening of the electronic expansion valve is increased by a first adjustment range P1, and the electronic expansion valve is automatically adjusted to a second target value T1. The second target value T1 is the original first target value T0 reduced by a second adjustment range P2. In one example, the electronic expansion valve is an electrically operated electronic expansion valve. The controller controls the number of steps of the stepper motor inside the electronic expansion valve to adjust the opening. Optionally, the first adjustment range P1 is 10–20 steps, and the second target value T1 can be the intake superheat target value corresponding to the first target value T0, with a temperature range of -2–3°C. For example, when the first target value T0 is 3°C, the second target value T1 is 1°C obtained by reducing the first target value T0 by the second adjustment range P2.

[0064] The adjustment methods in S101 to S103 are as follows: when the exhaust temperature has not yet risen to the set threshold of exhaust temperature, but the rate of rise is relatively fast, the opening of the electronic expansion valve is increased and the adjustment target value of the electronic expansion valve is reduced. This can increase the adjustment range and adjustment rate of the electronic expansion valve, so that the adjustment of the electronic expansion valve adapts to the change of exhaust temperature.

[0065] In one embodiment, the discharge temperature T of the compressor is [value missing] within time t1. 排 After the temperature rise exceeds ΔT1, it also enters the exhaust rapid heating mode.

[0066] Specifically, during time t1, the compressor's discharge temperature T 排 If the temperature rise is greater than ΔT1, the compressor's exhaust temperature rises too quickly. Therefore, it is determined that the system has entered the exhaust rapid temperature rise mode. The electronic expansion valve needs to be adjusted in the manner corresponding to the exhaust rapid temperature rise mode, as in step S103 above, so as to reduce the rate of exhaust temperature rise and avoid exhaust temperature runaway due to the electronic expansion valve's adjustment rate being unable to adapt to the exhaust temperature rise rate.

[0067] In one embodiment, after adjusting the electronic expansion valve to the exhaust rapid heating mode, the exhaust temperature will stabilize for a period of time, but will also experience a rapid heating again after stabilization. Therefore, continuous monitoring of the exhaust temperature is required. After controlling the opening of the electronic expansion valve to increase by the first adjustment range P1 and adjusting the opening of the electronic expansion valve to the second target value T1, the method further includes:

[0068] Determine the discharge temperature T of the compressor within time t2. 排 Whether the temperature rise is greater than ΔT1 again within time t1, where t2 is greater than t1;

[0069] If so, the opening of the electronic expansion valve is further increased by the first adjustment range P1 to adjust the opening of the electronic expansion valve to a third target value T2, wherein the third target value T2 is obtained by reducing the second adjustment range P2 from the second target value T1.

[0070] Specifically, it is necessary to monitor the temperature rise of the exhaust gas within time t2. If the temperature rise exceeds ΔT1 within time t1 again within time t2, it is determined that the exhaust gas temperature has not completely stabilized. In this case, the opening of the electronic expansion valve needs to be further adjusted by a first adjustment range P1, and the electronic expansion valve should be automatically adjusted to a third target value T2. Optionally, the value of time t2 can be in the range of 20–30 seconds.

[0071] In this embodiment, if the exhaust temperature rise exceeds ΔT1 multiple times within time t1, the opening of the electronic expansion valve and its target adjustment value are adjusted multiple times, with the adjustment range being the same each time. In other examples, the adjustment range can be different each time; for example, the adjustment range can gradually increase or decrease as the exhaust temperature rises.

[0072] Furthermore, to avoid excessively frequent adjustments, in some cases, adjustments can be made again after a set interval following the completion of an initial adjustment. During this interval, even if the temperature rise of the exhaust gas is detected to be greater than ΔT1 within time t1, no further adjustments will be made. Additionally, a total number of adjustments or a total adjustment range can be set. If the total number of adjustments or the total adjustment range reaches the set value within an adjustment cycle, no further adjustments will be made.

[0073] Correspondingly, in one embodiment, after adjusting the electronic expansion valve according to the rapid heating mode, the exhaust temperature enters a sustained stable state. Specifically, after increasing the opening of the electronic expansion valve by a first adjustment range P1 and adjusting the opening of the electronic expansion valve by a second target value T1, the method further includes:

[0074] Determine the discharge temperature T of the compressor within time t2. 排 Whether the temperature rise is greater than ΔT1 again within time t1;

[0075] If not, adjust the opening of the electronic expansion valve to the first target value T0.

[0076] If, within 20 to 30 seconds, the system does not exhibit a temperature rise greater than ΔT1 within time t1 within time t2, it is determined that after adjusting the electronic expansion valve, the system enters a stable operating state and exits the exhaust rapid heating mode. Based on this, the control system resumes adjusting the opening of the electronic expansion valve to the original first target value T0.

[0077] In one embodiment, the following steps are also included:

[0078] At the discharge temperature T of the compressor 排 When the temperature exceeds the first threshold, the opening of the electronic expansion valve is increased by a third adjustment range P3, and at each time interval t3, the opening of the electronic expansion valve is increased by a fourth adjustment range P4 until the discharge temperature T of the compressor is reached. 排 Less than a second threshold, wherein the second threshold is less than or equal to the first threshold.

[0079] Among them, at the compressor's discharge temperature T 排 When the exhaust temperature exceeds the first threshold, it is determined that the exhaust temperature has risen to a high level. The self-regulating rate of the electronic expansion valve, which uses the intake superheat value or exhaust superheat value as the target adjustment value, cannot control the rise in exhaust temperature. Therefore, it is necessary to directly increase the opening of the electronic expansion valve. Specifically, the third adjustment range P3 can be 10 to 20 steps of the stepper motor, and the interval time t3 is in the range of 5 to 10 seconds. The fourth adjustment range P4 can also be 10 to 20 steps of the stepper motor, and the fourth adjustment range P4 is less than the third adjustment range P3, until the exhaust temperature is lower than the second threshold.

[0080] In other examples, the electronic expansion valve can also be an electromagnetic electronic expansion valve, which changes the valve opening degree according to the received control signal. Specifically, the voltage or current applied to the electromagnetic coil inside the electronic expansion valve can be reduced according to the control signal, causing the electromagnetic force on the plunger made of magnetic material to decrease, thus moving it downward and increasing the valve opening degree.

[0081] In one embodiment, the heat pump system to which the electronic expansion valve opening adjustment method is applied further includes a cooling refrigerant branch. One end of the cooling refrigerant branch is connected to the refrigerant pipeline at the compressor return port, and the other end is connected to the refrigerant pipeline between the electronic expansion valve and the plate reversing valve. A liquid injection bypass valve is provided on the cooling refrigerant branch. The method further includes:

[0082] When the heat pump system is in heating mode, the discharge temperature T of the compressor is... 排 If the value is greater than the first threshold, it is determined whether the electronic expansion valve has reached its maximum opening value;

[0083] If so, control the liquid injection bypass valve to open until the compressor's exhaust temperature T 排 It is less than the second threshold.

[0084] like Figure 2 As shown, Figure 2This is a schematic diagram of the refrigerant piping of a heat pump system in heating mode. At this time, compressor 1 compresses and outputs high-temperature refrigerant, which enters through port D of four-way valve 2 and then flows out through port C. The high-temperature refrigerant enters plate heat exchanger 3 to exchange heat with the fluid to be heated, and then passes through electronic expansion valve 4 to form low-temperature liquid refrigerant. After being filtered by filter 5, the low-temperature liquid refrigerant enters finned heat exchanger 6 to absorb heat energy from the air and forms low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant enters through port E of four-way valve 2, flows out through port S, and then enters compressor 1, completing the refrigerant cycle in heating mode.

[0085] Because the refrigerant compression ratio of compressor 1 is large in heating mode, the exhaust temperature is difficult to control. When the exhaust temperature of the heat pump system rises too high, even if the electronic expansion valve 4 is adjusted to the maximum opening, it cannot effectively reduce the exhaust temperature. Therefore, a cooling refrigerant branch is set on the refrigerant pipeline at the return port of compressor 1. One end of the cooling refrigerant branch is connected to the refrigerant pipeline at the return port of compressor, and the other end is connected to the refrigerant pipeline between the electronic expansion valve and the plate heat exchanger.

[0086] Specifically, when the heat pump system is in heating mode, the discharge temperature T of compressor 1 is... 排 When the temperature exceeds the first threshold, the exhaust temperature rises to a higher level. The electronic expansion valve 4 may have already been adjusted to its maximum or near-maximum opening using the aforementioned adjustment methods. It is then determined whether the electronic expansion valve 4 has reached its maximum opening value. If so, the liquid injection bypass valve 7 is opened, connecting the cooling refrigerant branch to the main refrigerant line. A portion of the low-temperature liquid refrigerant flowing from port S flows into compressor 1, and a portion flows into the cooling refrigerant branch. This portion then enters the refrigerant pipeline between the electronic expansion valve 4 and the plate heat exchanger 3 via the liquid injection bypass valve 7 of the cooling refrigerant branch. This cools the high-temperature refrigerant in that section of the pipeline, thereby reducing the temperature of the refrigerant entering the electronic expansion valve 4. After being throttled by the electronic expansion valve 4, the temperature of the refrigerant entering compressor 1 is further reduced, thus lowering the exhaust temperature of compressor 1 and protecting compressor 1. Furthermore, the reduced temperature of the refrigerant entering the electronic expansion valve 4 also effectively protects the electronic expansion valve 4.

[0087] In one embodiment, at the compressor's discharge temperature T 排 The temperature range below the first threshold also includes temperature sub-ranges, which can be:

[0088] At the discharge temperature T of the compressor 排 If the temperature is less than the first threshold and greater than the third threshold, then the discharge temperature T of the compressor is determined to be within time t1. 排 Does the temperature rise exceed ΔT1?

[0089] In other words, when the exhaust temperature is below the first threshold but above the third threshold, the system determines whether to enter the rapid exhaust temperature rise mode. When the exhaust temperature is below the third threshold, the system's exhaust temperature is considered to be within a stable and controllable range, and it is not necessary to enter the rapid exhaust temperature rise mode. The electronic expansion valve is then kept adjusting at the first target value T0. Specifically, the adjustment target value of the electronic expansion valve can be directly reset to the first target value T0, or the current adjustment target value can be slowly reduced to the first target value T0 according to a preset reduction rate to avoid excessive fluctuations in the opening of the electronic expansion valve.

[0090] In a specific example, such as Figure 3 As shown in the embodiments of this application, the electronic expansion valve opening adjustment method includes the following steps:

[0091] S201: The compressor's exhaust temperature is divided into three control zones: the first control zone, the second control zone, and the third control zone. The minimum value of the second control zone is the third threshold, and the maximum value of the second control zone is the first threshold.

[0092] S202: Obtain the compressor's discharge temperature T at fixed intervals. 排 And determine the compressor's discharge temperature T. 排 The control zone in which it is located.

[0093] S203: Determine the compressor's discharge temperature T 排 Is it located within the first control zone?

[0094] If so, jump to S204 and adjust the opening of the electronic expansion valve to the first target value T0;

[0095] If not, proceed with S205.

[0096] S205: Determine the compressor's discharge temperature T 排 Is it located in the second control zone?

[0097] If so, execute S206;

[0098] If not, proceed to S210.

[0099] S206: Determine the compressor's discharge temperature T within time t1. 排 Is the temperature rise greater than ΔT1?

[0100] If so, execute S207;

[0101] If not, proceed to S204 and adjust the opening of the electronic expansion valve to the first target value T0.

[0102] S207: The system enters the exhaust rapid heating mode, controls the opening of the electronic expansion valve to increase the first adjustment range P1, and adjusts the opening of the electronic expansion valve to a second target value T1, wherein the second target value T1 is obtained by decreasing the first target value T0 by the second adjustment range P2.

[0103] S208: Determine the compressor's discharge temperature T within time t2. 排 Whether the temperature rise is greater than ΔT1 again within time t1, where t2 is greater than t1;

[0104] If so, the system is still in the exhaust rapid heating mode and returns to the adjustment mode of S207, that is, the opening of the electronic expansion valve is controlled to continue to increase the first adjustment range P1, and the opening of the electronic expansion valve is adjusted to the third target value T2, wherein the third target value T2 is obtained by reducing the second adjustment range P2 from the second target value T1.

[0105] If not, proceed with S209.

[0106] S209: The system exits the exhaust rapid heating mode and jumps to S204, controlling the opening of the electronic expansion valve to be adjusted to the first target value T0.

[0107] S210: Determine the compressor's discharge temperature T 排 Is it located in the third control zone?

[0108] If so, execute S211.

[0109] S211: Control the opening of the electronic expansion valve to increase by the third adjustment range P3, and at each interval t3, control the opening of the electronic expansion valve to increase by the fourth adjustment range P4.

[0110] S212: Determine the compressor's discharge temperature T 排 Whether it is less than the second threshold, where the second threshold is less than or equal to the first threshold;

[0111] If so, proceed to S202 and check the compressor's discharge temperature T at fixed intervals. 排 And determine the compressor's discharge temperature T. 排 The control zone in which it is located;

[0112] If not, return to the adjustment mode of S211, that is, continue to increase the opening of the electronic expansion valve by the third adjustment range P3, and increase the opening of the electronic expansion valve by the fourth adjustment range P4 at each interval t3.

[0113] In another specific example, such as Figure 4As shown in the embodiment of this application, an electronic expansion valve opening adjustment method is provided. When the heat pump system is in heating mode, the method further includes the following steps after step S210:

[0114] If so, execute S213.

[0115] S213: Determine whether the electronic expansion valve has reached its maximum opening value;

[0116] If so, execute S214.

[0117] If not, proceed with S211.

[0118] S214: Control the opening of the liquid injection bypass valve.

[0119] S212: Determine the compressor's discharge temperature T 排 Whether it is less than the second threshold, where the second threshold is less than or equal to the first threshold;

[0120] If so, execute S215;

[0121] If not, proceed to S213.

[0122] S215: After the liquid injection bypass valve is closed, the process jumps to S202, and the compressor discharge temperature T is checked at fixed intervals. 排 And determine the compressor's discharge temperature T. 排 The control zone in which it is located.

[0123] For example, the first threshold can be 90℃, and the third threshold can be 75℃. That is, the first control range is when the exhaust temperature is less than 75℃, the second control range is 75℃ to 90℃, and the third control range is when the exhaust temperature is greater than 90℃. Correspondingly, the adjustment method corresponding to the third control range is executed until the exhaust temperature is less than the second threshold. The value range of the second threshold is less than or equal to the first threshold, which is 85℃ to 90℃.

[0124] Corresponding to the above-described method for adjusting the opening of an electronic expansion valve, this application also provides an electronic expansion valve opening adjustment device, such as... Figure 5 As shown, Figure 5 This is a schematic diagram of a control device for a heat pump unit provided by the present invention. The device 300 includes:

[0125] The exhaust temperature acquisition module 301 is used to acquire the compressor's exhaust temperature T. 排 ;

[0126] The temperature rise determination module 302 is used to determine the discharge temperature T of the compressor. 排 When the temperature is less than the first threshold, it is determined that the discharge temperature T of the compressor is within time t1. 排Whether the temperature rise is greater than ΔT1; wherein, at the discharge temperature T of the compressor 排 When the value is less than the first threshold, the opening of the electronic expansion valve is adjusted to a first target value T0, which includes a preset exhaust superheat value or return superheat value.

[0127] Electronic expansion valve regulating module 303 is used to regulate the discharge temperature T of the compressor within time t1. 排 When the temperature rise is greater than ΔT1, the opening of the electronic expansion valve is increased by a first adjustment range P1, and the opening of the electronic expansion valve is adjusted to a second target value T1, wherein the second target value T1 is obtained by decreasing the first target value T0 by a second adjustment range P2.

[0128] In an optional embodiment, the device 300 further includes:

[0129] The reheating judgment module is used to determine the discharge temperature T of the compressor within time t2. 排 Whether the temperature rise is greater than ΔT1 again within time t1;

[0130] If so, the opening of the electronic expansion valve is further increased by the first adjustment range P1 to adjust the opening of the electronic expansion valve to a third target value T2, wherein the third target value T2 is obtained by reducing the second adjustment range P2 from the second target value T1.

[0131] In an optional embodiment, the reheat determination module of the device 300 further includes:

[0132] The second judgment unit is used to determine the discharge temperature T of the compressor within time t2. 排 If the temperature rise is greater than ΔT1 again within time t1, then adjust the opening of the electronic expansion valve to the first target value T0.

[0133] In an optional embodiment, the device 300 further includes:

[0134] Direct adjustment module for controlling the discharge temperature T of the compressor 排 When the temperature exceeds the first threshold, the opening of the electronic expansion valve is increased by a third adjustment range P3, and at each time interval t3, the opening of the electronic expansion valve is increased by a fourth adjustment range P4 until the discharge temperature T of the compressor is reached. 排 Less than a second threshold, wherein the second threshold is less than or equal to the first threshold.

[0135] In an optional embodiment, the temperature rise determination module 302 of the device 300 further includes:

[0136] Sub-interval determination unit, used for determining the discharge temperature T of the compressor 排 If the temperature is less than the first threshold and greater than the third threshold, then the discharge temperature T of the compressor is determined to be within time t1. 排 Does the temperature rise exceed ΔT1?

[0137] In an optional embodiment, the temperature rise determination module 302 of the device 300 is further used to determine the discharge temperature T of the compressor within time t1. 排 When the temperature rise exceeds ΔT1, the system is determined to have entered the exhaust rapid heating mode.

[0138] In an optional embodiment, the device 300 further includes:

[0139] The refrigerant branch control module is used to execute the heating mode in the heat pump system, wherein the compressor discharge temperature T 排 If the value is greater than the first threshold, it is determined whether the electronic expansion valve has reached its maximum opening value;

[0140] If so, control the liquid injection bypass valve to open until the compressor's exhaust temperature T 排 It is less than the second threshold.

[0141] For the apparatus embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The apparatus embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, apparatuses, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0142] Corresponding to the above-described method for adjusting the opening of an electronic expansion valve, this application embodiment also provides a controller for the opening of an electronic expansion valve, including:

[0143] At least one memory and at least one processor;

[0144] The memory is used to store one or more programs;

[0145] When the one or more programs are executed by the at least one processor, the at least one processor performs the steps of an electronic expansion valve opening adjustment method as described in any of the above embodiments.

[0146] Corresponding to the above-mentioned method for adjusting the opening of an electronic expansion valve, this application also provides a heat pump host, which...

[0147] This includes a controller as described in the above embodiments.

[0148] The electronic expansion valve opening adjustment method, device, controller, and heat pump unit provided in this application have the following effects:

[0149] (1) By detecting the compressor's exhaust temperature, before the exhaust temperature rises to the set exhaust temperature threshold, but before the exhaust temperature reaches the set threshold, the compressor's exhaust temperature is detected.

[0150] When the rate of increase is relatively fast, the opening of the electronic expansion valve is increased and the adjustment target value of the electronic expansion valve is reduced, which can increase the adjustment range and adjustment rate of the electronic expansion valve, so that the adjustment of the electronic expansion valve can adapt to the change of exhaust temperature.

[0151] (2) After adjusting the electronic expansion valve once, continuously monitor the compressor exhaust temperature. If the rate of increase in exhaust temperature is not stable, continue to increase the opening of the electronic expansion valve and decrease the adjustment target value of the electronic expansion valve until the exhaust temperature reaches a stable state. This avoids exhaust temperature runaway caused by the electronic expansion valve's adjustment rate not being able to adapt to the rate of increase.

[0152] (3) When the exhaust temperature rises to a higher temperature, the opening of the electronic expansion valve is continuously increased to achieve a rapid drop in the exhaust temperature of the system, thus avoiding the unit from entering the shutdown protection due to excessively high exhaust temperature.

[0153] (4) When the heat pump system is in heating mode, the cooling refrigerant branch is connected to the original refrigerant main line, so that the low-temperature liquid refrigerant enters the refrigerant pipeline between the electronic expansion valve and the heat exchanger through the jet bypass valve, thereby reducing the temperature of the refrigerant when it enters the electronic expansion valve. After being throttled by the electronic expansion valve, the temperature of the refrigerant entering the compressor is further reduced, thereby reducing the compressor's discharge.

[0154] The lower refrigerant temperature protects the compressor. On the other hand, the reduced refrigerant temperature entering the electronic expansion valve also effectively protects the electronic expansion valve.

[0155] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for adjusting the opening degree of an electronic expansion valve, characterized in that, Includes the following steps: Obtain the discharge temperature T of the compressor in the heat pump system 排 ; At the discharge temperature T of the compressor 排 If the temperature is less than the first threshold and greater than the third threshold, then the discharge temperature T of the compressor is determined to be within time t1. 排 Is the temperature rise greater than T1; where T is the exhaust temperature of the compressor. 排 When the value is less than the first threshold, the opening of the electronic expansion valve is adjusted to a first target value T0, which includes a preset exhaust superheat value or intake superheat value. If so, the opening of the electronic expansion valve is increased by a first adjustment range P1, and the opening of the electronic expansion valve is adjusted by a second target value T1, wherein the second target value T1 is obtained by decreasing the first target value T0 by a second adjustment range P2; Then, the discharge temperature T of the compressor within time t2 is determined. 排 Does the temperature rise again exceed the value within time t1? T1, where t2 is greater than t1; If so, the opening of the electronic expansion valve is further increased by the first adjustment range P1 to adjust the opening of the electronic expansion valve to a third target value T2, wherein the third target value T2 is obtained by decreasing the second adjustment range P2 from the second target value T1. If not, adjust the opening of the electronic expansion valve to the first target value T0; At the discharge temperature T of the compressor 排 When the temperature exceeds the first threshold, the opening of the electronic expansion valve is increased by a third adjustment range P3, and at each time interval t3, the opening of the electronic expansion valve is increased by a fourth adjustment range P4 until the discharge temperature T of the compressor is reached. 排 Less than a second threshold, wherein the second threshold is less than or equal to the first threshold.

2. The method for adjusting the opening degree of an electronic expansion valve according to claim 1, characterized in that: The t1 and t3 are 5–10 s, the t2 is 20–30 s, and the... T1 is 2-5℃.

3. The method for adjusting the opening degree of an electronic expansion valve according to claim 1, characterized in that: The heat pump system further includes a cooling refrigerant branch, one end of which is connected to the refrigerant pipeline at the compressor return port, and the other end is connected to the refrigerant pipeline between the electronic expansion valve and the plate heat exchanger. A liquid injection bypass valve is installed on the cooling refrigerant branch. The method further includes: When the heat pump system is in heating mode, the discharge temperature T of the compressor is... 排 If the value is greater than the first threshold, it is determined whether the electronic expansion valve has reached its maximum opening value; If so, control the liquid injection bypass valve to open until the compressor's exhaust temperature T 排 It is less than the second threshold.

4. An electronic expansion valve opening adjustment device for performing the electronic expansion valve opening adjustment method as described in claim 1, characterized in that, include: The exhaust temperature acquisition module is used to acquire the compressor's exhaust temperature T. 排 ; The temperature rise determination module is used to determine the discharge temperature T of the compressor. 排 When the temperature is less than the first threshold, it is determined that the discharge temperature T of the compressor is within time t1. 排 Is the temperature rise greater than T1; where T is the exhaust temperature of the compressor. 排 When the value is less than the first threshold, the opening of the electronic expansion valve is adjusted to a first target value T0, which includes a preset exhaust superheat value or return superheat value. An electronic expansion valve regulating module is used to control the discharge temperature T of the compressor within time t1. 排 The temperature rise is greater than At time T1, the opening of the electronic expansion valve is increased by a first adjustment range P1, and the opening of the electronic expansion valve is adjusted to a second target value T1, wherein the second target value T1 is obtained by decreasing the first target value T0 by a second adjustment range P2.

5. A controller, characterized in that, include: At least one memory and at least one processor; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the at least one processor implements the steps of the electronic expansion valve opening adjustment method as described in any one of claims 1 to 3.

6. A heat pump main unit, characterized in that: Includes a controller as described in claim 5.

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