Control method of electronic expansion valve

Abstract

The application relates to a control method of an electronic expansion valve, which comprises the following steps: periodically acquiring a current outdoor environment temperature and a current operating frequency of a compressor, obtaining a first valve step value of the electronic expansion valve according to a preset corresponding relationship formula of the compressor operating frequency and the first valve step, and substituting the acquired current outdoor environment temperature value and the first valve step value into a first preset formula to obtain an operating valve step of the electronic expansion valve. The valve step of the electronic expansion valve adopting the control method of the electronic expansion valve is sensitive in response, and the demand of the system for rapid response can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refrigeration equipment, and particularly relates to a control method of an electronic expansion valve. BACKGROUND

[0002] At present, the control method of the electronic expansion valve in the air conditioner is relatively simple, and generally adopts superheat temperature control or discharge temperature control. The superheat temperature control is to adjust the opening degree of the electronic expansion valve through the difference between the return air temperature and the evaporator outlet temperature, that is, the opening degree of the electronic expansion valve, so that the temperature difference is maintained in a reasonable range. If the difference is greater than the set temperature difference, it means that the superheat is too large, and the valve needs to be opened according to the set program, that is, the opening degree of the electronic expansion valve is increased; otherwise, the valve needs to be closed according to the set program, that is, the opening degree of the electronic expansion valve is reduced. The discharge temperature control is to use the frequency converter to automatically adjust the opening degree of the electronic expansion valve within a certain compressor discharge temperature range.

[0003] The above two methods have simple control logic, but when the ambient temperature is high or low, the air conditioning equipment needs to produce a large amount of refrigerating capacity or heating capacity, which leads to overloading of the compressor of the air conditioning equipment. In the case of overloading, the valve step response of the electronic expansion valve is not sensitive, and cannot meet the demand of rapid response of the system. SUMMARY

[0004] Therefore, it is necessary to provide a control method of an electronic expansion valve to solve the problem that the valve step response of the existing electronic expansion valve is not sensitive and cannot meet the demand of rapid response of the system.

[0005] The control method of the electronic expansion valve provided by the present application comprises the following steps: periodically acquiring a current outdoor environment temperature and a current operating frequency of a compressor, obtaining a first valve step value of the electronic expansion valve according to a pre-set corresponding relationship formula of the operating frequency of the compressor and the first valve step, and substituting the acquired current outdoor environment temperature value and the first valve step value into a first preset formula to obtain a running valve step of the electronic expansion valve.

[0006] In one of the embodiments, in the refrigeration mode, the first preset formula is f = δf + (t-35)*K, where f is the running valve step value of the electronic expansion valve, δf is the first valve step value, t is the current outdoor environment temperature value, K is an empirical coefficient, and 3≤K≤10.

[0007] In one of the embodiments, in the refrigeration mode, the method for obtaining the value of the first valve step is: dividing the compressor operating frequency into multiple ranges; in the standard working condition, the valve step of the electronic expansion valve corresponding to the maximum frequency in a certain compressor operating frequency range is measured, and the valve step of the electronic expansion valve corresponding to the maximum frequency in the range is the first valve step corresponding to the range; wherein the standard working condition is that the outdoor dry-bulb temperature is 35℃, the wet-bulb temperature is 24℃, the indoor dry-bulb temperature is 27℃, and the wet-bulb temperature is 19℃.

[0008] In one of the embodiments, in the refrigeration mode, the corresponding relationship between the compressor operating frequency and the first valve step of the electronic expansion valve is: when the compressor operating frequency is less than or equal to 30HZ, the corresponding first valve step is 170P; when the compressor operating frequency is greater than 30HZ and less than or equal to 40HZ, the corresponding first valve step is 200P; when the compressor operating frequency is greater than 40HZ and less than or equal to 50HZ, the corresponding first valve step is 240P; when the compressor operating frequency is greater than 50HZ and less than or equal to 60HZ, the corresponding first valve step is 280P; when the compressor operating frequency is greater than 60HZ and less than or equal to 70HZ, the corresponding first valve step is 330P; when the compressor operating frequency is greater than 70HZ and less than or equal to 80HZ, the corresponding first valve step is 360P; and when the compressor operating frequency is greater than 80HZ, the corresponding first valve step is 390P.

[0009] In one of the embodiments, in the refrigeration mode, after the corresponding first valve step of the compressor changes for a first preset time, the obtained value of the current outdoor environment temperature and the value of the first valve step are substituted into the first preset formula.

[0010] In one of the embodiments, in the refrigeration mode, and within a preset time of the initial operation of the compressor, the first preset formula is: f = δf + (t-35)*K, wherein f is the running valve step value of the electronic expansion valve, δf is the maximum value of the first valve step, t is the value of the current outdoor environment temperature, and K is an empirical coefficient, and 3≤K≤10. max max It can be understood that such setting is beneficial to save the adjustment time of the electronic expansion valve, prevent the protection shutdown of the air conditioning equipment caused by the slow adjustment of the electronic expansion valve, and further ensure the stable operation of the air conditioning equipment.

[0011] In one of the embodiments, in the heating mode, the first preset formula is: f = δf + (t-7)*K, wherein f is the running valve step value of the electronic expansion valve, δf is the first valve step value, t is the value of the current outdoor environment temperature, and K is an empirical coefficient, and 3≤K≤10.

[0012] ​In one of the embodiments, in the heating mode, the method for obtaining the value of the first valve step is: dividing the compressor operating frequency into multiple ranges; in the standard working condition, measuring the valve step of the electronic expansion valve corresponding to the maximum frequency in a certain compressor operating frequency range, and the valve step of the electronic expansion valve corresponding to the maximum frequency in the range is the first valve step corresponding to the range; wherein, the standard working condition is that the outdoor dry-bulb temperature is 7℃, the wet-bulb temperature is 6℃, the indoor dry-bulb temperature is 20℃, and the wet-bulb temperature is 15℃.

[0013] In one of the embodiments, in the heating mode, the corresponding relationship between the compressor operating frequency and the first valve step of the electronic expansion valve is: when the compressor operating frequency is less than or equal to 30HZ, the corresponding first valve step is 100P; when the compressor operating frequency is greater than 30HZ and less than or equal to 40HZ, the corresponding first valve step is 130P; when the compressor operating frequency is greater than 40HZ and less than or equal to 50HZ, the corresponding first valve step is 160P; when the compressor operating frequency is greater than 50HZ and less than or equal to 60HZ, the corresponding first valve step is 180P; when the compressor operating frequency is greater than 60HZ and less than or equal to 70HZ, the corresponding first valve step is 200P; when the compressor operating frequency is greater than 70HZ and less than or equal to 80HZ, the corresponding first valve step is 220P; and when the compressor operating frequency is greater than 80HZ, the corresponding first valve step is 240P.

[0014] In one of the embodiments, in the heating mode, after the corresponding first valve step of the compressor changes for a second preset time, the obtained value of the current outdoor environment temperature and the value of the first valve step are substituted into the first preset formula.

[0015] In one of the embodiments, in the heating mode, and within a preset time of the initial operation of the compressor, the first preset formula is: f = δf max + (t-7) * K, wherein, f is the operating valve step value of the electronic expansion valve, δf max is the maximum value of the first valve step, t is the value of the current outdoor environment temperature, and K is an empirical coefficient, and 3≤K≤10. It can be understood that, by such setting, the adjustment time of the electronic expansion valve can be saved, the protection shutdown of the air conditioning equipment caused by the slow adjustment of the electronic expansion valve can be prevented, and the stable operation of the air conditioning equipment can be ensured.

[0016] Compared with the prior art, the control method of the electronic expansion valve provided in the application is simple and fast in acquisition of the current outdoor environment temperature and the current operating frequency of the compressor, so that the operating valve step rate of the electronic expansion valve calculated according to the current outdoor environment temperature value and the current operating frequency value of the compressor is also fast, thereby facilitating fast adjustment of the operating valve step of the electronic expansion valve. That is, the valve step of the electronic expansion valve adopting the control method of the electronic expansion valve provided in the application is sensitive in response, and can meet the demand of fast response of the system. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0018] Figure 1 The flow chart of the control method of the electronic expansion valve provided in an embodiment of the application. DETAILED DESCRIPTION

[0019] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0020] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0021] In this application, unless otherwise clearly indicated otherwise, the terms "mounting", "connected", "connecting", "fixed", and "fixing" should be construed broadlyly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through intermediate medium, can be internal communication of two elements or interaction relationship between two elements, unless otherwise clearly indicated. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0022] In this application, unless otherwise clearly indicated otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0023] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can be a mediating element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a mediating element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0025] The control method of the electronic expansion valve in the current air conditioner is relatively simple, and generally uses superheat temperature control or discharge temperature control. The superheat temperature control is to adjust the opening of the electronic expansion valve through the difference between the return air temperature and the evaporator outlet temperature, that is, the opening of the electronic expansion valve, so that the temperature difference is maintained within a reasonable range. If the difference is greater than the set temperature difference, it means that the superheat is too large, and the valve needs to be opened according to the set program, that is, the opening of the electronic expansion valve is increased. If the difference is less than the set temperature difference, it means that the superheat is too small, and the valve needs to be closed according to the set program, that is, the opening of the electronic expansion valve is reduced. The discharge temperature control is to use the frequency converter to automatically adjust the opening of the electronic expansion valve within a certain compressor discharge temperature range.

[0026] The control logic of the above two methods is simple, but when the ambient temperature is high or low, the air conditioning equipment needs to produce a large amount of cooling or heating capacity, which leads to overloading of the compressor of the air conditioning equipment. In the case of overloading, the valve step response of the electronic expansion valve is not sensitive, and cannot meet the demand of rapid response of the system.

[0027] Please refer to Figure 1 , in order to solve the problem that the valve step response of the existing electronic expansion valve is not sensitive and cannot meet the demand of rapid response of the system. The present application provides a control method of an electronic expansion valve, which comprises the following steps: step S100, periodically acquiring the current outdoor environment temperature and the current operating frequency of the compressor, step S200, obtaining the first valve step value of the electronic expansion valve according to the pre-set corresponding relationship formula between the operating frequency of the compressor and the first valve step of the electronic expansion valve, step S300, substituting the acquired value of the current outdoor environment temperature and the value of the first valve step into a first preset formula to obtain the operating valve step of the electronic expansion valve.

[0028] It should be noted that periodically acquiring means acquiring data once at a certain interval, that is, the shorter the interval, the higher the frequency of data acquisition, so that the calculated value of the operating valve step of the electronic expansion valve is more accurate. Specifically, data can be collected once at intervals of 1s, 2s or 3s, but not limited to this, which will not be listed one by one here. It should be noted that when the outdoor environment temperature or the operating frequency of the compressor changes suddenly, the frequency of collecting the current outdoor environment temperature data and the current operating frequency data of the compressor can also be increased accordingly, that is, the interval of collecting data can be further shortened, so as to further improve the calculation accuracy of the operating valve step of the electronic expansion valve.

[0029] Further, it should be noted that the current outdoor environment temperature can be acquired by real-time measurement through a temperature sensor, and the current operating frequency of the compressor is controlled by a controller, so the current operating frequency of the compressor can be directly acquired by the controller.

[0030] Further, it needs to be noted that the unit of the compressor operating frequency is HZ, and the unit of the first valve step of the electronic expansion valve is P, and the valve step is also referred to as the pulse number. Generally, the pulse number is used to describe how many pulses of a periodic cyclic signal occur in a unit of time. Both the compressor operating frequency and the first valve step of the electronic expansion valve substituted into the pre-set corresponding relationship formula are values without units.

[0031] Since the current outdoor environment temperature and the current operating frequency of the compressor are relatively simple and fast to obtain, the operating valve step rate of the electronic expansion valve calculated according to the current outdoor environment temperature value and the current operating frequency value of the compressor is also relatively fast, thereby being conducive to quickly adjusting the operating valve step of the electronic expansion valve. That is, the valve step of the electronic expansion valve adopting the control method of the electronic expansion valve provided in the present application is sensitive in response, and can meet the demand of fast response of the system.

[0032] Generally, the air conditioning equipment has two situations of refrigeration operation and heating operation in actual use, and the calculation methods of the operating valve step of the electronic expansion valve are different under the two different working conditions. It needs to be noted that the outdoor environment temperature under the refrigeration working condition is generally greater than or equal to 30℃, and the outdoor environment temperature under the heating working condition is generally less than or equal to 10℃. The control method of the electronic expansion valve is described below under the refrigeration working condition and the heating working condition.

[0033] Refrigeration working condition

[0034] In the refrigeration mode, the method for obtaining the value of the first valve step is to divide the compressor operating frequency into multiple ranges. Under the standard working condition, the valve step of the electronic expansion valve corresponding to the maximum frequency in a certain compressor operating frequency range is measured, and the valve step of the electronic expansion valve corresponding to the maximum frequency in the range is the first valve step corresponding to the range, so that the first valve step is relatively large in the range, which is beneficial to the discharge of the compressor and obtaining a smaller discharge temperature, and is beneficial to obtaining a lower system pressure. Thus, it is beneficial to the stable operation of the unit without easily reaching the warning value set by the customer. Among them, the standard working condition is that the outdoor dry-bulb temperature is 35℃, the wet-bulb temperature is 24℃, the indoor dry-bulb temperature is 27℃, and the wet-bulb temperature is 19℃.

[0035] Specifically, when the compressor operating frequency is changing, the corresponding relationship between the compressor operating frequency and the electronic expansion valve first valve step is: when the compressor operating frequency is less than or equal to 30 HZ, the corresponding first valve step is 170P, when the compressor operating frequency is greater than 30 HZ and less than or equal to 40 HZ, the corresponding first valve step is 200P, when the compressor operating frequency is greater than 40 HZ and less than or equal to 50 HZ, the corresponding first valve step is 240P, when the compressor operating frequency is greater than 50 HZ and less than or equal to 60 HZ, the corresponding first valve step is 280P, when the compressor operating frequency is greater than 60 HZ and less than or equal to 70 HZ, the corresponding first valve step is 330P, when the compressor operating frequency is greater than 70 HZ and less than or equal to 80 HZ, the corresponding first valve step is 360P, and when the compressor operating frequency is greater than 80 HZ, the corresponding first valve step is 390P. Of course, in other embodiments, other compressor frequency ranges can be divided.

[0036] The following table is the corresponding relationship table of the above-mentioned compressor operating frequency value and the electronic expansion valve first valve step value.

[0037]

[0038] As can be seen from the above table, the first valve step value is positively correlated with the compressor operating frequency value, and the first valve step value is constant when the compressor operating frequency value is within a certain range.

[0039] Further, when the compressor operating frequency is changing, the first preset formula is: f = δf + (t-35) * K, wherein f is the operating valve step value of the electronic expansion valve, δf is the first valve step value, t is the current outdoor environment temperature value, K is an empirical coefficient, and 3 ≤ K ≤ 10. Specifically, taking K = 5, when the current outdoor environment temperature t is 30℃ and the compressor operating frequency is 25 HZ, the corresponding first valve step value is 170, t = 30 and δf = 170 are substituted into the above-mentioned first preset formula, f = 170 + (30-35) * 5 = 145 is obtained. When the current outdoor environment temperature t is 35℃ and the compressor operating frequency is 75 HZ, the corresponding first valve step value is 360, t = 35 and δf = 360 are substituted into the above-mentioned first preset formula, f = 360 + (35-35) * 5 = 360 is obtained. When the current outdoor environment temperature t is other values, or the compressor operating frequency value is other values, the above-mentioned first preset formula can also be substituted, which is not listed here.

[0040] It should be noted that in the refrigeration mode, the corresponding first valve step of the compressor changes for a first preset time, and then the obtained current outdoor environment temperature value and the first valve step value are substituted into the first preset formula. The first preset time is usually 10 seconds.

[0041] Further, in the refrigeration mode, in order to save the adjusting time of the electronic expansion valve, prevent the air conditioning equipment from being protected from stopping due to the electronic expansion valve adjusting too slowly, and further ensure the stable operation of the air conditioning equipment. Within the preset time of the initial operation of the compressor, the first preset formula is: f = δf max + (t - 35) * K, wherein f is the running valve step value of the electronic expansion valve, δf max is the first valve step maximum value, t is the current outdoor environment temperature value, K is an empirical coefficient, and 3 ≤ K ≤ 10. Generally, the value of δf max is 390, specifically, the value of K is 5, when the current outdoor environment temperature t is 30℃, K = 5, t = 30 and δf max = 390 are substituted into the above first preset formula, f = 390 + (30 - 35) * 5 = 365 is obtained, when the current outdoor environment temperature t is 35℃, t = 35 is substituted into the above first preset formula, f = 390 + (35 - 35) * 5 = 390 is obtained, and when the current outdoor environment temperature t is other values, the above first preset formula can also be substituted, which is not listed here. It should be noted that the preset time of the initial operation of the compressor is 3min-5min.

[0042] Further, the preset time of the initial operation of the compressor is equal to one frequency change period of the compressor, for example, the preset time of the initial operation of the compressor is 5s, 10s, 20s or 100s, which is not listed here.

[0043] When the preset time of the initial operation of the compressor ends, if the fixed frequency unit is directly locked, the running frequency of the compressor remains constant, the first valve step corresponding to the running frequency of the compressor remains constant, and the running valve step of the electronic expansion valve remains constant. If the running frequency of the compressor changes, the first valve step corresponding to the running frequency of the compressor changes, and the running valve step of the electronic expansion valve changes synchronously.

[0044] Heating condition

[0045] In the heating mode, the method for obtaining the value of the first valve step is: dividing the running frequency of the compressor into multiple ranges. In the standard condition, the valve step of the electronic expansion valve corresponding to the maximum frequency in a certain range of the divided compressor running frequency is measured, and the valve step of the electronic expansion valve corresponding to the maximum frequency in this range is the first valve step corresponding to this range, so that the first valve step is relatively large in this range, which is beneficial to the exhaust of the compressor and obtaining a smaller exhaust temperature, and is beneficial to obtaining a lower system pressure. Thus, it is beneficial to the stable operation of the unit without easily reaching the warning value set by the customer. Wherein, the standard condition is that the outdoor dry-bulb temperature is 7℃, the outdoor wet-bulb temperature is 6℃, the indoor dry-bulb temperature is 20℃, and the indoor wet-bulb temperature is 15℃.

[0046] Specifically, in one embodiment, when the compressor operating frequency is changing, the corresponding relationship between the compressor operating frequency and the electronic expansion valve first valve step is: when the compressor operating frequency is less than or equal to 30 HZ, the corresponding first valve step is 100P, when the compressor operating frequency is greater than 30 HZ and less than or equal to 40 HZ, the corresponding first valve step is 130P, when the compressor operating frequency is greater than 40 HZ and less than or equal to 50 HZ, the corresponding first valve step is 160P, when the compressor operating frequency is greater than 50 HZ and less than or equal to 60 HZ, the corresponding first valve step is 180P, when the compressor operating frequency is greater than 60 HZ and less than or equal to 70 HZ, the corresponding first valve step is 200P, when the compressor operating frequency is greater than 70 HZ and less than or equal to 80 HZ, the corresponding first valve step is 220P, and when the compressor operating frequency is greater than 80 HZ, the corresponding first valve step is 240P. Of course, in other embodiments, other compressor frequency ranges can be divided.

[0047] The following table is the corresponding relationship table of the above-mentioned compressor operating frequency value and the electronic expansion valve first valve step value.

[0048]

[0049] As can be seen from the above table, the first valve step value is positively correlated with the compressor operating frequency value, and the first valve step value is constant when the compressor operating frequency value is within a certain range.

[0050] Further, when the compressor operating frequency is changing, the first preset formula is: f = δf + (t - 7) * K, where f is the operating valve step value of the electronic expansion valve, δf is the first valve step value, t is the current outdoor environment temperature value, K is an empirical coefficient, and 3 ≤ K ≤ 10. Specifically, taking K = 5, the current outdoor environment temperature t is 0℃, and the compressor operating frequency is 25 HZ, the corresponding first valve step value is 100, t = 0 and δf = 100 are substituted into the above-mentioned first preset formula, f = 100 + (0 - 7) * 5 = 65 is obtained. The current outdoor environment temperature t is -5℃, and the compressor operating frequency is 75 HZ, the corresponding first valve step value is 220, t = -5 and δf = 220 are substituted into the above-mentioned first preset formula, f = 220 + (-5 - 7) * 5 = 160 is obtained. When the current outdoor environment temperature t is other values, or the compressor operating frequency value is other values, the above-mentioned first preset formula can also be substituted, which is not listed here.

[0051] It should be noted that in the heating mode, after the corresponding first valve step of the compressor changes for a second preset time, the obtained current outdoor environment temperature value and the first valve step value are substituted into the first preset formula. The second preset time is usually 10 seconds.

[0052] In the heating mode, in order to save the adjusting time of the electronic expansion valve, prevent the air conditioning equipment from being protected to stop due to the slow adjustment of the electronic expansion valve, and further ensure the stable operation of the air conditioning equipment. Within the preset time of the initial operation of the compressor, the first preset formula is: f = δf max + (t-7) * K, wherein f is the running valve step value of the electronic expansion valve, δf max is the first valve step maximum value, t is the current outdoor environment temperature value, K is an empirical coefficient, and 3 ≤ K ≤ 10. Specifically, when the current outdoor environment temperature t is 0℃, K = 5, t = 0 and δf max = 240 are substituted into the above first preset formula, f = 240 + (0-7) * 5 = 205 is obtained, when the current outdoor environment temperature t is -5℃, t = -5 is substituted into the above first preset formula, f = 240 + (-5-7) * 5 = 180 is obtained, and when the current outdoor environment temperature t is other values, the above first preset formula can also be substituted, which is not listed one by one. It should be noted that the preset time of the initial operation of the compressor is 3min-5min.

[0053] Further, the preset time of the initial operation of the compressor is equal to one frequency change period of the compressor, for example, the preset time of the initial operation of the compressor is 5s, 10s, 20s or 100s, which is not listed one by one.

[0054] When the preset time of the initial operation of the compressor ends, if the fixed-frequency unit is directly locked, the running frequency of the compressor remains constant, the first valve step corresponding to the running frequency of the compressor remains constant, and the running valve step of the electronic expansion valve remains constant. If the running frequency of the compressor changes, the first valve step corresponding to the running frequency of the compressor changes, and the running valve step of the electronic expansion valve changes synchronously.

[0055] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the description.

[0056] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A control method of an electronic expansion valve, characterized by, The method comprises the following steps: periodically acquiring a current outdoor environment temperature and a current operating frequency of the compressor, obtaining a value of a first valve step of the electronic expansion valve according to a preset corresponding relationship between the operating frequency of the compressor and the first valve step of the electronic expansion valve, substituting the acquired value of the current outdoor environment temperature and the value of the first valve step into a first preset formula to obtain an operating valve step of the electronic expansion valve; in the cooling mode, the method for obtaining the value of the first valve step is as follows: dividing the operating frequency of the compressor into multiple ranges; in a standard working condition, measuring a valve step of the electronic expansion valve corresponding to a maximum frequency in a certain operating frequency range of the compressor, and the valve step of the electronic expansion valve corresponding to the maximum frequency in the range is the first valve step corresponding to the range; in the cooling mode, the first preset formula is f = δf + (t-35)*K, wherein f is the operating valve step value of the electronic expansion valve, δf is the first valve step value, t is the current outdoor environment temperature value, and K is an empirical coefficient, and 3≤K≤10.

2. The control method of an electronic expansion valve according to claim 1, characterized by, The standard working condition is that the outdoor dry-bulb temperature is 35℃, the outdoor wet-bulb temperature is 24℃, the indoor dry-bulb temperature is 27℃, and the indoor wet-bulb temperature is 19℃.

3. The control method of an electronic expansion valve according to claim 2, characterized by, in the cooling mode, the corresponding relationship between the operating frequency of the compressor and the first valve step of the electronic expansion valve is as follows: when the operating frequency of the compressor is less than or equal to 30HZ, the corresponding first valve step is 170P, when the operating frequency of the compressor is greater than 30HZ and less than or equal to 40HZ, the corresponding first valve step is 200P, when the operating frequency of the compressor is greater than 40HZ and less than or equal to 50HZ, the corresponding first valve step is 240P, when the operating frequency of the compressor is greater than 50HZ and less than or equal to 60HZ, the corresponding first valve step is 280P, when the operating frequency of the compressor is greater than 60HZ and less than or equal to 70HZ, the corresponding first valve step is 330P, when the operating frequency of the compressor is greater than 70HZ and less than or equal to 80HZ, the corresponding first valve step is 360P, when the operating frequency of the compressor is greater than 80HZ, the corresponding first valve step is 390P.

4. The control method of an electronic expansion valve according to claim 2, characterized by, in the cooling mode, the acquired value of the current outdoor environment temperature and the value of the first valve step are substituted into the first preset formula after the corresponding first valve step of the compressor changes for a first preset time.

5. The control method of an electronic expansion valve according to claim 1, characterized by, In the refrigeration mode, and within a preset time of initial operation of the compressor, a first preset formula is: f=δf max + (t-35)*K, wherein f is a running valve step value of the electronic expansion valve, δf max is a first valve step maximum value, t is a current outdoor environment temperature value, and K is an empirical coefficient, and 3≤K≤10.

6. The control method of an electronic expansion valve according to claim 1, characterized by, in the heating mode, the first preset formula is f = δf + (t-7)*K, wherein f is the operating valve step value of the electronic expansion valve, δf is the first valve step value, t is the current outdoor environment temperature value, and K is an empirical coefficient, and 3≤K≤10.

7. The control method of the electronic expansion valve according to claim 1 or 6, characterized by, in the heating mode, the method for obtaining the value of the first valve step is as follows: dividing the operating frequency of the compressor into multiple ranges; in a standard working condition, measuring a valve step of the electronic expansion valve corresponding to a maximum frequency in a certain operating frequency range of the compressor, and the valve step of the electronic expansion valve corresponding to the maximum frequency in the range is the first valve step corresponding to the range; wherein the standard working condition is that the outdoor dry-bulb temperature is 7℃, the outdoor wet-bulb temperature is 6℃, the indoor dry-bulb temperature is 20℃, and the indoor wet-bulb temperature is 15℃.

8. The control method of an electronic expansion valve according to claim 7, characterized by, in the heating mode, the corresponding relationship between the operating frequency of the compressor and the first valve step of the electronic expansion valve is as follows: When the compressor operating frequency is less than or equal to 30HZ, the corresponding first valve step is 100P, When the compressor operating frequency is greater than 30HZ and less than or equal to 40HZ, the corresponding first valve step is 130P, When the compressor operating frequency is greater than 40HZ and less than or equal to 50HZ, the corresponding first valve step is 160P, When the compressor operating frequency is greater than 50HZ and less than or equal to 60HZ, the corresponding first valve step is 180P, When the compressor operating frequency is greater than 60HZ and less than or equal to 70HZ, the corresponding first valve step is 200P, When the compressor operating frequency is greater than 70HZ and less than or equal to 80HZ, the corresponding first valve step is 220P, When the compressor operating frequency is greater than 80HZ, the corresponding first valve step is 240P.

9. The control method of the electronic expansion valve according to claim 7, characterized by, In the heating mode, after the corresponding first valve step of the compressor changes for a second preset time, the obtained current outdoor environment temperature value and the first valve step value are substituted into the first preset formula.

10. The control method of the electronic expansion valve according to claim 1, characterized by, In the heating mode, and within a preset time of the initial operation of the compressor, the first preset formula is: f=δfmax+(t-7)*K, wherein f is the operating valve step value of the electronic expansion valve, δfmax is the first valve step maximum value, t is the current outdoor environment temperature value, K is an empirical coefficient, and 3≤K≤10.

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