Correction method and device of electronic expansion valve, air-cooled chiller unit and storage medium

Abstract

The invention relates to a correction method and device for an electronic expansion valve, an air-cooled chiller unit and a storage medium, and the method comprises the steps that in the operation process of the air-cooled chiller unit, under the condition that it is detected that the electronic expansion valve in the air-cooled chiller unit is abnormal, a pore plate electromagnetic valve in the air-cooled chiller unit is started, and the pore plate electromagnetic valve is started; first pressure of an outlet of the electronic expansion valve and second pressure of an outlet of a throttling orifice in the air-cooled chiller unit are obtained; the opening degree of the electronic expansion valve is controlled so that the first absolute value of the first pressure and the second pressure can be smaller than a first preset threshold value, and the target opening degree matched with the target instruction is displayed; and when the opening degree of the electronic expansion valve is controlled to reach the target opening degree again from zero, a second absolute value of the first pressure and the second pressure is obtained, and whether correction of the electronic expansion valve succeeds or not is determined according to a comparison result of the second absolute value and a second preset threshold value.

Description

Technical Field

[0001] The present application relates to the field of air-cooled chillers, and particularly to a calibration method and device for an electronic expansion valve, an air-cooled chiller, and a storage medium. Background Art

[0002] In existing air-cooled chillers, the electronic expansion valve is the main throttling component. Commonly used large-capacity electronic expansion valves are usually driven by a stepping motor to control the valve body. During the startup and shutdown of the whole machine, affected by the air flow impact, the valve body will cause the motor to shake, resulting in the valve not being able to open to the expected opening degree or not being able to close completely. During operation, the impact of gaseous refrigerant will cause the valve body to not be able to open or close effectively, resulting in the problem that the actual opening degree of the valve body is inconsistent with the target opening degree, further leading to abnormal regulation of the whole machine system. In actual use, it is manifested as inaccurate control of the water temperature on the user side, easily resulting in faults such as low pressure and oil shortage in the whole machine.

[0003] For the above problems in the prior art, there is currently no effective solution. Summary of the Invention

[0004] The present application provides a calibration method and device for an electronic expansion valve, an air-cooled chiller, and a storage medium, to solve the problem in the prior art that during the operation of an air-cooled chiller, if there is an impact of gaseous refrigerant, it will cause the valve body to not be able to open or close effectively, resulting in the problem that the actual opening degree of the valve body is inconsistent with the target opening degree.

[0005] In a first aspect, the present application provides a calibration method for an electronic expansion valve, including: during the operation of an air-cooled chiller, when it is detected that the electronic expansion valve in the air-cooled chiller is abnormal, opening an orifice solenoid valve in the air-cooled chiller, and obtaining a first pressure at the outlet of the electronic expansion valve and a second pressure at the outlet of a throttle orifice plate in the air-cooled chiller, where the electronic expansion valve and the throttle orifice plate are connected in parallel in the air-cooled chiller; controlling the opening degree of the electronic expansion valve so that the first absolute value of the first pressure and the second pressure is less than a first preset threshold, and displaying a target opening degree matching a target command, where the target opening degree is the opening degree required for the electronic expansion valve to make the absolute value of the first pressure and the second pressure less than the first preset threshold; when controlling the opening degree of the electronic expansion valve from zero to the target opening degree again, obtaining a second absolute value of the first pressure and the second pressure, and determining whether the electronic expansion valve is calibrated successfully according to the comparison result between the second absolute value and a second preset threshold.

[0006] Optionally, controlling the opening degree of the electronic expansion valve such that the first absolute value of the first pressure and the second pressure is less than a first preset threshold includes: when the first pressure is greater than the second pressure and the first absolute value is greater than the first preset threshold, closing the electronic expansion valve to make the first absolute value less than the first preset threshold; when the first pressure is less than the second pressure and the first absolute value is greater than the first preset threshold, opening the electronic expansion valve to make the first absolute value less than the first preset threshold; when the first pressure is equal to the second pressure, keeping the opening degree of the electronic expansion valve unchanged.

[0007] Optionally, determining whether the electronic expansion valve is successfully calibrated according to the comparison result between the second absolute value and a second preset threshold includes: when the second absolute value is less than or equal to the second preset threshold, determining that the electronic expansion valve is successfully calibrated; when the second absolute value is greater than the second preset threshold, determining that the current calibration of the electronic expansion valve fails, and calibrating the electronic expansion valve again.

[0008] Optionally, the method further includes: when the number of times of calibrating the electronic expansion valve again exceeds a preset number of times, determining that the electronic expansion valve is abnormal.

[0009] Optionally, detecting whether the electronic expansion valve in the air-cooled chiller is abnormal includes: detecting the low-pressure change ratio at the suction port of the compressor in the air-cooled chiller within a first preset time period; when the low-pressure change ratio is less than a third preset threshold, detecting whether the fan frequency increase rate within the first preset time period is greater than or equal to a fourth preset threshold or whether the water temperature decrease rate is greater than or equal to a fifth preset threshold; when the fan frequency increase rate within the first preset time period is greater than or equal to the fourth preset threshold or the water temperature decrease rate is greater than or equal to the fifth preset threshold, determining that the electronic expansion valve is normal; when the fan frequency increase rate within the first preset time period is less than the fourth preset threshold and the water temperature decrease rate is less than the fifth preset threshold, determining that the electronic expansion valve is abnormal.

[0010] Optionally, after the electronic expansion valve is successfully calibrated, the method further includes: after receiving a shutdown instruction, controlling the bypass solenoid valve in the air-cooled chiller to open; after detecting that the high pressure at the exhaust port of the compressor in the air-cooled chiller is balanced with the low pressure at the suction port, closing the electronic expansion valve and then closing the bypass solenoid valve after the electronic expansion valve is closed.

[0011] Optionally, after the air-cooled chiller is shut down, the method further includes: after receiving a startup instruction, controlling the orifice solenoid valve in the air-cooled chiller to open; after the compressor operates for a second preset duration, controlling the main path solenoid valve in the air-cooled chiller to open, and after opening the electronic expansion valve to a target opening degree, controlling the orifice solenoid valve to close.

[0012] In a second aspect, the present application provides a correction device for an electronic expansion valve, including: a first processing module, configured to, during the operation of the air-cooled chiller, when detecting that the electronic expansion valve in the air-cooled chiller is abnormal, open the orifice solenoid valve in the air-cooled chiller, and obtain a first pressure at the outlet of the electronic expansion valve and a second pressure at the outlet of the throttle orifice plate in the air-cooled chiller, wherein the electronic expansion valve and the throttle orifice plate are connected in parallel in the air-cooled chiller; a second processing module, configured to control the opening degree of the electronic expansion valve so that a first absolute value of the first pressure and the second pressure is less than a first preset threshold, and display a target opening degree matching a target instruction, wherein the target opening degree is the opening degree required for the electronic expansion valve to make the absolute value of the first pressure and the second pressure less than the first preset threshold; a third processing module, configured to, when controlling the opening degree of the electronic expansion valve to reach the target opening degree again from zero, obtain a second absolute value of the first pressure and the second pressure, and determine whether the electronic expansion valve is successfully corrected according to a comparison result between the second absolute value and a second preset threshold.

[0013] In a third aspect, the present application provides an air-cooled chiller, including: at least one communication interface; at least one bus connected to the at least one communication interface; at least one processor connected to the at least one bus; at least one memory connected to the at least one bus, wherein the processor is configured to execute the correction method for the electronic expansion valve described in the first aspect of the present application.

[0014] In a fourth aspect, the present application further provides a computer storage medium storing computer-executable instructions, and the computer-executable instructions are used to execute the correction method for the electronic expansion valve described in the first aspect of the present application.

[0015] The above technical solution provided by the embodiments of the present application has the following advantages compared with the prior art: In the method provided by the embodiments of the present application, when it is detected that the electronic expansion valve is abnormal, the opening degree of the electronic expansion valve is adjusted so that the absolute value of the first pressure at the outlet of the electronic expansion valve and the second pressure at the outlet of the throttle orifice plate in the air-cooled chiller is less than the first preset threshold. At this time, the opening degree of the electronic expansion valve can be considered as the target opening degree, and this target opening degree is known. Therefore, the currently displayed opening degree can also be set as the target opening degree, and then the opening degree of the electronic expansion valve is controlled to increase from zero to the target opening degree again. Furthermore, the second absolute value of the first pressure and the second pressure is obtained again. If the second absolute value is less than the second preset threshold, it indicates that the calibration is successful; otherwise, multiple calibrations are required or it is determined that the electronic expansion valve is faulty. It can be seen that in the embodiments of the present application, after the electronic expansion valve appears abnormal, it can be self-calibrated. After the calibration is successful, it can ensure that the actual opening degree of the valve body is consistent with the target opening degree, thereby ensuring the stable operation of the whole machine system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present invention and, together with the specification, are used to explain the principles of the present invention.

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] One or more embodiments are illustrated by way of example in the accompanying drawings, and these exemplary illustrations do not limit the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated, and the drawings in the figures do not constitute a proportional limitation.

[0019] Figure 1 It is a schematic structural diagram of an air-cooled chiller provided by the embodiments of the present application; Figure 2 It is a flowchart of a method for calibrating an electronic expansion valve provided by the embodiments of the present application; Figure 3 It is a flowchart of a self-calibration control method for an electronic expansion valve provided by the embodiments of the present application; Figure 4 It is a schematic structural diagram of a calibration device for an electronic expansion valve provided by the embodiments of the present application; Figure 5 It is an alternative schematic structural diagram of an air-cooled chiller provided by the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts fall within the scope of protection of this application.

[0021] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0022] To solve the problem in the prior art that during the operation of an air-cooled chiller, if there is a gaseous refrigerant impact, the valve body cannot be effectively opened or closed, resulting in the actual opening of the valve body being inconsistent with the target opening, this application provides an air-cooled chiller, as Figure 1 shown, the air-cooled chiller includes: a compressor 1, a water-side heat exchanger 2, an air-cooled fin heat exchanger 3, a system electronic expansion valve 4, an orifice plate 5, a bypass solenoid valve 6, an orifice plate solenoid valve 7, a main path solenoid valve 8, a first check valve 9, and a second check valve 10.

[0023] Based on Figure 1 the air-cooled chiller in, this application provides a method for calibrating an electronic expansion valve, as Figure 2 shown, the steps of the method include: Step 201, during the operation of the air-cooled chiller, when it is detected that the electronic expansion valve in the air-cooled chiller is abnormal, open the orifice plate solenoid valve in the air-cooled chiller, and obtain the first pressure at the outlet of the electronic expansion valve and the second pressure at the outlet of the orifice plate in the air-cooled chiller, where the electronic expansion valve and the orifice plate are in parallel in the air-cooled chiller; It should be noted that when it is detected that the electronic expansion valve is abnormal, opening the orifice plate solenoid valve first is to avoid blockage of the system flow path and cause other failures. Then, the electronic expansion valve is self-regulated to make the electronic expansion valve return to normal.

[0024] Step 202, control the opening of the electronic expansion valve so that the first absolute value of the first pressure and the second pressure is less than a first preset threshold, and display the target opening that matches the target command, where the target opening is the opening required for the electronic expansion valve to make the absolute value of the first pressure and the second pressure less than the first preset threshold; In a specific example, the target opening can be set accordingly according to actual requirements. However, in a specific application scenario, it is preferably set to 50%, and other openings close to 50% are also feasible, such as 49%, 51%, etc.

[0025] Step 203: When controlling the opening of the electronic expansion valve from zero to the target opening again, obtain the second absolute value of the first pressure and the second pressure, and determine whether the electronic expansion valve is successfully calibrated according to the comparison result between the second absolute value and the second preset threshold.

[0026] As can be seen from the above steps 201 to 203, when an abnormality of the electronic expansion valve is detected, the opening of the electronic expansion valve is adjusted to make the absolute value of the first pressure at the outlet of the electronic expansion valve and the second pressure at the outlet of the throttle orifice plate in the air-cooled chiller less than the first preset threshold. At this time, it can be considered that the opening of the electronic expansion valve is the target opening, and this target opening is known. Therefore, the currently displayed opening can also be set as the target opening, and then control the opening of the electronic expansion valve from zero to the target opening again. Furthermore, obtain the second absolute value of the first pressure and the second pressure again. If the second absolute value is less than the second preset threshold, it indicates that the calibration is successful; otherwise, multiple calibrations are required or it is determined that the electronic expansion valve is faulty. It can be seen that in the embodiment of the present application, after the electronic expansion valve appears abnormal, it can be calibrated by itself. After the calibration is successful, it can ensure that the actual opening of the valve body is consistent with the target opening, thereby ensuring the stable operation of the whole machine system.

[0027] In the embodiment of the present application, the difference between the first pressure and the second pressure can be adjusted by controlling the opening of the electronic expansion valve. Therefore, for the method of controlling the opening of the electronic expansion valve in step 202 to make the first absolute value of the first pressure and the second pressure less than the first preset threshold, it can further include: Step 21: When the first pressure is greater than the second pressure and the first absolute value is greater than the first preset threshold, perform a closing adjustment on the electronic expansion valve to make the first absolute value less than the first preset threshold; Step 22: When the first pressure is less than the second pressure and the first absolute value is greater than the first preset threshold, perform an opening adjustment on the electronic expansion valve to make the first absolute value less than the first preset threshold; Step 23: When the first pressure is equal to the second pressure, keep the opening of the electronic expansion valve unchanged.

[0028] For the above steps 21 to 23, in combination with Figure 1In a specific example, it can be as follows: First, open the orifice plate solenoid valve 7, and then compare the pressure P1 (the first pressure) after the electronic expansion valve 4 with the pressure P2 (the second pressure) after the throttle orifice plate 5. When P1 > P2, the electronic expansion valve 4 is adjusted to close. When P1 < P2, the electronic expansion valve 4 is adjusted to open. When P1 = P2, the valve remains stationary. After opening the orifice plate solenoid valve 7, the absolute value of P1 - P2 is calculated synchronously. When the absolute value ≤ X, the valve adjustment stops.

[0029] It should be noted that the throttle orifice plate 5 in the embodiment of the present application is matched by design selection, that is, it is necessary to maintain the same throttling effect as the 50% opening (target opening) of the electronic expansion valve 4, that is, the pressures after throttling of the two are basically the same. In addition, in the present application, the orifice plate solenoid valve 7 is opened first to avoid blockage of the system flow path and cause other failures. Because of the detection differences, it is difficult to keep P1 and P2 completely consistent, so the capacity value X is given. X is usually set to 5 - 10%. It is considered that the actual opening of the valve is 50% at this time, and then the target command and the display opening at this time are both corrected to 50%. Among them, the target command is the command sent to the air-cooled chiller to control the opening of the electronic expansion valve, that is, the opening indicated by the target command is how much, and the opening of the electronic expansion valve is how much, and the display opening of the air-cooled chiller is consistent with the opening indicated by the target command.

[0030] The above steps 21 to 23 are actually self-adjustments of the electronic expansion valve. In order to verify whether the above self-adjustment results are accurate, it is also necessary to further check whether the difference between the outlet pressures of the electronic expansion valve and the throttle orifice plate when the electronic expansion valve is opened from zero to the target opening during the actual operation process is within the preset range. If it is within the preset range, it indicates that the outlet pressures of the electronic expansion valve and the parallel throttle orifice plate are equivalent at this time, and the electronic expansion valve returns to normal. If the difference in pressure is not within the preset range, it may be necessary to perform self-adjustment again or it is considered that the electronic expansion valve has failed and cannot be corrected through self-adjustment. Therefore, for the method of determining whether the electronic expansion valve is successfully corrected according to the comparison result of the second absolute value and the second preset threshold involved in the above step 203, it can further include: Step 31, when the second absolute value is less than or equal to the second preset threshold, it is determined that the electronic expansion valve is corrected successfully; Step 32, when the second absolute value is greater than the second preset threshold, it is determined that the electronic expansion valve fails to be corrected this time, and the electronic expansion valve is corrected again.

[0031] For the above steps 31 and 32, on the basis of the above steps 21 to 23, combined with Figure 1The process can be as follows: Control the valve body from 0 to 50% again, and detect the pressure P1 after the electronic expansion valve 4 and the pressure P2 after the orifice plate 5 (since the orifice plate 5 is selected and matched in design, that is, it maintains the same throttling effect as the 50% opening of the electronic expansion valve 4, that is, the pressures after throttling of the two are basically the same). At the same time, calculate the absolute value of P1 - P2. When the absolute value ≤ Ps, where Ps is the throttling pressure comparison value, which is a preset value set according to the differences between the orifice plate and the electronic expansion valve during matching, usually set at 15 - 30 kPa, it is considered that the reset correction is successful. Then open the electronic expansion valve 4 to 100% opening for normal adjustment, and then close the orifice solenoid valve 7; if the absolute value > Ps, the reset is unsuccessful, and the valve body correction action is continued to be repeated.

[0032] In the embodiment of the present application, it is possible that the electronic expansion valve cannot be accurately corrected through one correction, and multiple corrections may be required. For example, although the default opening is 50% (target opening) after the first correction, the actual opening may be 40%. A second correction is required. After the correction, the default target opening is basically the same as the actual opening, then the correction is successful. However, it is also possible that the correction fails after several corrections, then it is considered that the electronic expansion valve itself has a fault and cannot self-adjust and recover. Based on this, the method in the embodiment of the present application further includes: Step 41, when the number of times of correcting the electronic expansion valve again exceeds the preset number of times, determine that the electronic expansion valve is abnormal.

[0033] In this regard, in a specific example, the preset number of times can be set to 3 times, 4 times, etc.

[0034] In the embodiment of the present application, before self-adjusting the electronic expansion valve, it is necessary to first determine that the electronic expansion valve is abnormal. Based on this, in the embodiment of the present application, the method for detecting whether the electronic expansion valve in the air-cooled chiller is abnormal may include the following steps: Step 51, detect the low-pressure change ratio at the suction port of the compressor in the air-cooled chiller within the first preset duration; Step 52, when the low-pressure change ratio is less than the third preset threshold, detect whether the fan frequency increase rate within the first preset duration is greater than or equal to the fourth preset threshold or whether the water temperature decrease rate is greater than or equal to the fifth preset threshold; Step 53, when the fan frequency increase rate within the first preset duration is greater than or equal to the fourth preset threshold or the water temperature decrease rate is greater than or equal to the fifth preset threshold, determine that the electronic expansion valve is normal; Step 54, when the fan frequency increase rate within the first preset duration is less than the fourth preset threshold and the water temperature decrease rate is less than the fifth preset threshold, determine that the electronic expansion valve is abnormal.

[0035] In the embodiments of the present application, the first preset duration can be set within 1 to 2 minutes. If the time is too short, the valve body adjustment cycle cannot keep up. If the time is too long, it is impossible to clearly distinguish whether the abnormality is caused by system operation or the valve body. In addition, the normal value of the third preset threshold can be set to 1% - 2%.

[0036] Based on this, for the above steps 51 to 54, combined with Figure 1 , in a specific example, it can be: During the operation of the unit, the opening (increase in flow area) action of the electronic expansion valve body is detected. When it is detected that within the time t1 of the valve body, the low - pressure rise ratio △P L ≤m%, it is determined that the opening of the valve body has no obvious effect at this time, and it is necessary to further determine whether the valve body is abnormal. When the effect of the valve body opening on the low - pressure is not obvious, it is simultaneously determined whether there is a situation of fan frequency increase or water temperature decrease within this t1 time. If there is a fan frequency increase rate ≥Δf (the fourth preset threshold) or a water temperature decrease rate ≥ΔT (the fifth preset threshold), it is considered to be the influence of the fan or water temperature, and no correction adjustment is required; when there is no fan frequency increase rate ≥Δf or water temperature decrease rate ≥ΔT, it is determined that the actual opening of the valve body does not match the target opening, and correction adjustment is required.

[0037] In the embodiments of the present application, after the electronic expansion valve is corrected successfully, it is also necessary to balance the on - off pressure difference to ensure that the expansion valve is not affected by air flow impact when opening and closing, and can be stably closed and stably opened. Based on this, for preventing air flow impact during shutdown, the embodiments of the present application also include: Step 61, after receiving the shutdown instruction, control the bypass solenoid valve in the air - cooled chiller to open; Step 62, after detecting that the high pressure at the compressor exhaust port and the low pressure at the compressor suction port in the air - cooled chiller are balanced, close the electronic expansion valve and then close the bypass solenoid valve after the electronic expansion valve is closed.

[0038] Regarding this, because during shutdown, if there is gaseous refrigerant passing through the expansion valve, the air flow impact will cause the valve body to shake, making the valve unable to be normally closed to 0%, which will cause the valve body to be directly out of adjustment during the next startup. Therefore, in the embodiments of the present application, when the whole machine receives the shutdown instruction and the compressor is turned off, the bypass solenoid valve 6 is controlled to open. Among them, opening the bypass solenoid valve 6 is to bypass the high - low pressure difference. When the high - low pressure difference is consistent, the refrigerant inside the system will no longer flow at high speed, and thus will not cause impact on the valve body. After detecting that the high pressure at the compressor exhaust port and the low pressure at the compressor suction port are balanced, then close the electronic expansion valve 4, and close the bypass solenoid valve 6 after the electronic expansion valve 4 is completely closed, thereby avoiding the air flow impact during shutdown.

[0039] And for preventing air flow impact during startup, the method in the embodiments of the present application also includes: Step 71, after receiving the power-on instruction, control the orifice solenoid valve in the air-cooled chiller to open; Step 72, after the compressor runs for a second preset duration, control the main circuit solenoid valve in the air-cooled chiller to open, and after opening the electronic expansion valve to the target opening, control the orifice solenoid valve to close.

[0040] In this regard, when starting up, there is a large amount of gaseous refrigerant in the fin heat exchanger, and the impact at this time will also cause the valve body to vibrate. However, opening the bypass solenoid valve 6 flow path at this time will have no throttling effect, and there will be no pressure difference between high and low pressures. It is easy for the compressor to run idly after starting. Therefore, when receiving the power-on signal, first open the orifice solenoid valve 7. After the compressor runs for the initial time t3 (t3 is usually the set value of the initial running time for protecting the compressor. During this period, the compressor maintains the minimum load without moving), open the main circuit solenoid valve 8, and open the electronic expansion valve 4 to 50% opening. Then close the orifice solenoid valve 7, and the electronic expansion valve 4 and the compressor are controlled conventionally.

[0041] Next, in combination with the specific implementation manners of the embodiments of the present application, the present application will be explained. The specific implementation manner provides a self-calibration control method for an electronic expansion valve. Combining Figure 1 , the method in this specific implementation manner, as Figure 3 shown, includes: Step 301, during the normal operation of the unit, detect that the valve opening of the electronic expansion valve is greater than or equal to 3 times or the valve opening is greater than or equal to 5% within the time t1; In this regard, this detection time t1 is usually set between 1 and 2 minutes. If the time is too short, the valve body adjustment cycle cannot keep up, and if the time is too long, it is impossible to clearly distinguish whether it is an abnormality caused by system operation or an abnormality caused by the valve body.

[0042] Step 302, judge whether the low-pressure rise ratio △P L is less than or equal to m%; In this regard, △P L is the change ratio of the low pressure within the time t1, and the low-pressure detection position is the compressor suction port. Assume that the initial low pressure is P 始 , and after the time t1, the low pressure is P 终 , △P L = (P 终 - P 始 ) / P 始 , and m% is a set value, usually set to 1% - 2%.

[0043] Step 303, within the time t1, judge whether the fan frequency increase rate is greater than or equal to Δf or the water temperature decrease rate is greater than or equal to ΔT; In this regard, the increase in the fan frequency will cause the high pressure to decrease, and the synchronization will cause the low pressure to decrease, offsetting the influence of the opening of the valve body on the low pressure. Similarly, assume the initial fan frequency is f 始 , after a time t1, the fan frequency is f 终 , and the frequency increase rate = (f 始 - f 终 ) / t1; similarly, the decrease in the water temperature will also cause the low pressure to decrease, offsetting the influence of the opening of the valve body on the low pressure. The water temperature decrease rate = (f 始 - f 终 ) / t1. Therefore, if the fan frequency increase rate ≥ Δf or the water temperature decrease rate ≥ ΔT, it is considered to be the influence of the fan or the water temperature, and no correction adjustment is required.

[0044] Step 304, determine that the actual opening of the valve body does not match the target opening, and correction adjustment is required; Step 305, first open the orifice solenoid valve 7, and then compare the pressure P1 after the electronic expansion valve 4 with the pressure P2 after the throttle orifice 5. When P1 > P2, the electronic expansion valve 4 is adjusted to close; when P1 < P2, the electronic expansion valve 4 is adjusted to open; when P1 = P2, the valve remains unchanged. After opening the orifice solenoid valve 7, the absolute value of P1 - P2 is calculated synchronously. When the absolute value ≤ X, the valve adjustment stops; if the actual opening of the valve is considered to be 50% at this time, then the target command and the displayed opening at this time are both corrected to 50%.

[0045] Step 306, control the valve body to move from 0 to 50% again, detect the pressure P1 after the electronic expansion valve 4 and the pressure P2 after the throttle orifice 5, and calculate the absolute value of P1 - P2 at the same time; Step 307, compare P1 with P2 and count the number n. Whether the absolute value of P1 - P2 is less than or equal to Ps; if yes, execute Step 308, if no, execute Step 309; Step 308, the reset is successful, the electronic expansion valve 4 is opened to 100% opening, and the orifice solenoid valve 7 is closed; Step 309, when n is greater than or equal to 4, the unit synchronously feedbacks a fault.

[0046] When comparing P1 with P2, the number of times is recorded once for each comparison. When the number of times recorded n ≥ 4, it indicates that the valve body is stuck at a certain fixed position and cannot be corrected and repaired. At this time, the opening and closing commands of the valve body are no longer given, the main path solenoid valve 8 is opened, and the current state is maintained. The whole machine keeps running, and a fault alarm is synchronously feedback: the expansion valve body is abnormal.

[0047] Corresponding to the above Figure 2 , the embodiment of the present application also provides a correction device for an electronic expansion valve, as Figure 4 shown, the device includes: The first processing module 402 is configured to, during the operation of the air-cooled chiller, when it is detected that the electronic expansion valve in the air-cooled chiller is abnormal, open the orifice solenoid valve in the air-cooled chiller, and obtain the first pressure at the outlet of the electronic expansion valve and the second pressure at the outlet of the throttle orifice in the air-cooled chiller, where the electronic expansion valve and the throttle orifice are in parallel in the air-cooled chiller; The second processing module 404 is configured to control the opening degree of the electronic expansion valve so that the first absolute value of the first pressure and the second pressure is less than the first preset threshold, and display the target opening degree matching the target instruction, where the target opening degree is the opening degree required for the electronic expansion valve to make the absolute value of the first pressure and the second pressure less than the first preset threshold; The third processing module 406 is configured to, when controlling the opening degree of the electronic expansion valve to the target opening degree again from zero, obtain the second absolute value of the first pressure and the second pressure, and determine whether the electronic expansion valve is successfully calibrated according to the comparison result between the second absolute value and the second preset threshold.

[0048] Through the device according to the embodiment of the present application, when it is detected that the electronic expansion valve is abnormal, the opening degree of the electronic expansion valve will be adjusted to make the absolute value of the first pressure at the outlet of the electronic expansion valve and the second pressure at the outlet of the throttle orifice in the air-cooled chiller less than the first preset threshold. At this time, it can be considered that the opening degree of the electronic expansion valve is the target opening degree, and this target opening degree is known. Therefore, the currently displayed opening degree can also be set to the target opening degree, and then the opening degree of the electronic expansion valve is controlled to the target opening degree again from zero. Furthermore, the second absolute value of the first pressure and the second pressure is obtained again. If the second absolute value is less than the second preset threshold, it indicates that the calibration is successful; otherwise, multiple calibrations are required or it is determined that the electronic expansion valve is faulty. It can be seen that in the embodiment of the present application, after the electronic expansion valve appears abnormal, it can be calibrated by itself. After the calibration is successful, it can ensure that the actual opening degree of the valve body is consistent with the target opening degree, thereby ensuring the stable operation of the whole machine system.

[0049] In an alternative embodiment of the embodiment of the present application, the second processing module in the embodiment of the present application may further include: a first processing unit, configured to, when the first pressure is greater than the second pressure and the first absolute value is greater than the first preset threshold, perform a closing adjustment on the electronic expansion valve to make the first absolute value less than the first preset threshold; a second processing unit, configured to, when the first pressure is less than the second pressure and the first absolute value is greater than the first preset threshold, perform an opening adjustment on the electronic expansion valve to make the first absolute value less than the first preset threshold; a third processing unit, configured to, when the first pressure is equal to the second pressure, keep the opening degree of the electronic expansion valve unchanged.

[0050] In an alternative implementation of the embodiment of the present application, the third processing module in the embodiment of the present application may further include: a fourth processing unit, configured to determine that the electronic expansion valve correction is successful when the second absolute value is less than or equal to a second preset threshold; a fifth processing unit, configured to determine that the current correction of the electronic expansion valve fails and correct the electronic expansion valve again when the second absolute value is greater than the second preset threshold.

[0051] In an alternative implementation of the embodiment of the present application, the device in the embodiment of the present application further includes: a fourth processing module, configured to determine that the electronic expansion valve is abnormal when the number of times of correcting the electronic expansion valve again exceeds a preset number of times.

[0052] In an alternative implementation of the embodiment of the present application, the first processing module in the embodiment of the present application includes: a sixth processing unit, configured to detect the low-pressure change ratio of the compressor suction port in the air-cooled chiller within a first preset duration; a seventh processing unit, configured to detect whether the fan frequency increase rate is greater than or equal to a fourth preset threshold or the water temperature decrease rate is greater than or equal to a fifth preset threshold when the low-pressure change ratio is less than a third preset threshold; an eighth processing unit, configured to determine that the electronic expansion valve is normal when the fan frequency increase rate is greater than or equal to the fourth preset threshold or the water temperature decrease rate is greater than or equal to the fifth preset threshold within the first preset duration; a ninth processing unit, configured to determine that the electronic expansion valve is abnormal when the fan frequency increase rate is less than the fourth preset threshold and the water temperature decrease rate is less than the fifth preset threshold within the first preset duration.

[0053] In an alternative implementation of the embodiment of the present application, the device in the embodiment of the present application further includes: a fifth processing module, configured to control the bypass solenoid valve in the air-cooled chiller to open after receiving a shutdown command; a sixth processing module, configured to close the electronic expansion valve and then close the bypass solenoid valve after the electronic expansion valve is closed after detecting that the high pressure at the compressor discharge port in the air-cooled chiller is balanced with the low pressure at the suction port.

[0054] In an alternative implementation of the embodiment of the present application, the device in the embodiment of the present application further includes: a seventh processing module, configured to control the orifice plate solenoid valve in the air-cooled chiller to open after receiving a startup command; an eighth processing module, configured to control the main path solenoid valve in the air-cooled chiller to open after the compressor operates for a second preset duration, and control the orifice plate solenoid valve to close after opening the electronic expansion valve to a target opening degree.

[0055] As Figure 5 shown, the embodiment of the present application provides an air-cooled chiller, including a processor 511, a communication interface 512, a memory 513, and a communication bus 514. Among them, the processor 511, the communication interface 512, and the memory 513 communicate with each other through the communication bus 514. A memory 513 for storing a computer program; In an embodiment of the present application, when the processor 511 executes the program stored on the memory 513, it implements the control method of the electronic expansion valve provided in any of the foregoing method embodiments, and the functions it performs are similar, so details are not described herein again.

[0056] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the control method of the electronic expansion valve provided in any of the foregoing method embodiments.

[0057] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0058] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the related technology, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0059] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be executed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that alternative or additional steps may be used.

[0060] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A calibration method for an electronic expansion valve, characterized in that, Including: During the operation of the air-cooled chiller, when it is detected that the electronic expansion valve in the air-cooled chiller is abnormal, the orifice solenoid valve in the air-cooled chiller is opened, and the first pressure at the outlet of the electronic expansion valve and the second pressure at the outlet of the throttle orifice plate in the air-cooled chiller are obtained, wherein the electronic expansion valve and the throttle orifice plate are connected in parallel in the air-cooled chiller; Control the opening degree of the electronic expansion valve so that the first absolute value of the first pressure and the second pressure is less than a first preset threshold, and display the target opening degree that matches the target instruction, wherein the target opening degree is the opening degree required for the electronic expansion valve to make the absolute value of the first pressure and the second pressure less than the first preset threshold; When controlling the opening degree of the electronic expansion valve from zero to the target opening degree again, obtain the second absolute value of the first pressure and the second pressure, and determine whether the electronic expansion valve is successfully calibrated according to the comparison result between the second absolute value and a second preset threshold.

2. The method according to claim 1, wherein Controlling the opening degree of the electronic expansion valve so that the first absolute value of the first pressure and the second pressure is less than a first preset threshold includes: When the first pressure is greater than the second pressure and the first absolute value is greater than the first preset threshold, perform a closing adjustment on the electronic expansion valve so that the first absolute value is less than the first preset threshold; When the first pressure is less than the second pressure and the first absolute value is greater than the first preset threshold, perform an opening adjustment on the electronic expansion valve so that the first absolute value is less than the first preset threshold; When the first pressure is equal to the second pressure, keep the opening degree of the electronic expansion valve unchanged.

3. The method according to claim 1, wherein Determining whether the electronic expansion valve is successfully calibrated according to the comparison result between the second absolute value and a second preset threshold includes: When the second absolute value is less than or equal to the second preset threshold, determine that the electronic expansion valve is successfully calibrated; When the second absolute value is greater than the second preset threshold, determine that the calibration of the electronic expansion valve fails this time, and calibrate the electronic expansion valve again.

4. The method according to claim 3, wherein The method further includes: When the number of times of calibrating the electronic expansion valve again exceeds a preset number of times, determine that the electronic expansion valve is abnormal.

5. The method according to claim 1, wherein Detecting whether the electronic expansion valve in the air-cooled chiller is abnormal includes: Detect the low-pressure change ratio at the suction port of the compressor in the air-cooled chiller within a first preset time period; When the low-pressure change ratio is less than a third preset threshold, detect whether the fan frequency increase rate within the first preset time period is greater than or equal to a fourth preset threshold or whether the water temperature decrease rate is greater than or equal to a fifth preset threshold; When the fan frequency increase rate within the first preset time period is greater than or equal to the fourth preset threshold or the water temperature decrease rate is greater than or equal to the fifth preset threshold, determine that the electronic expansion valve is normal; When the fan frequency increase rate within the first preset time period is less than the fourth preset threshold and the water temperature decrease rate is less than the fifth preset threshold, determine that the electronic expansion valve is abnormal.

6. The method according to claim 1, wherein After the correction of the electronic expansion valve is successful, the method further includes: After receiving a shutdown instruction, controlling the opening of a bypass solenoid valve in the air-cooled chiller; After detecting that the high pressure at the compressor discharge port and the low pressure at the compressor suction port in the air-cooled chiller are balanced, closing the electronic expansion valve and then closing the bypass solenoid valve after the electronic expansion valve is closed.

7. The method according to claim 6, wherein After the air-cooled chiller is shut down, the method further includes: After receiving a startup instruction, controlling the opening of an orifice plate solenoid valve in the air-cooled chiller; After the compressor operates for a second preset duration, controlling the opening of a main path solenoid valve in the air-cooled chiller, opening the electronic expansion valve to a target opening degree, and then controlling the closing of the orifice plate solenoid valve.

8. A calibration device for an electronic expansion valve, characterized in that, including: A first processing module, configured to, during the operation of the air-cooled chiller, when detecting an abnormality of the electronic expansion valve in the air-cooled chiller, open the orifice plate solenoid valve in the air-cooled chiller, and obtain a first pressure at the outlet of the electronic expansion valve and a second pressure at the outlet of the throttle orifice plate in the air-cooled chiller, wherein the electronic expansion valve and the throttle orifice plate are connected in parallel in the air-cooled chiller; A second processing module, configured to control the opening degree of the electronic expansion valve so that a first absolute value of the first pressure and the second pressure is less than a first preset threshold, and display a target opening degree matching a target instruction, wherein the target opening degree is the opening degree required for the electronic expansion valve to make the absolute value of the first pressure and the second pressure less than the first preset threshold; A third processing module, configured to, when controlling the opening degree of the electronic expansion valve to reach the target opening degree again from zero, obtain a second absolute value of the first pressure and the second pressure, and determine whether the correction of the electronic expansion valve is successful according to a comparison result between the second absolute value and a second preset threshold.

9. An air-cooled chiller, characterized in that, including: At least one communication interface; At least one bus connected to the at least one communication interface; At least one processor connected to the at least one bus; At least one memory connected to the at least one bus, wherein the processor is configured to execute the correction method of the electronic expansion valve according to any one of claims 1 to 7.

10. A computer storage medium, characterized in that, Stores computer-executable instructions for executing the correction method of the electronic expansion valve according to any one of claims 1 to 7.

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