Control method of air conditioning system

Abstract

The invention relates to the technical field of air conditioning systems, particularly provides a control method of an air conditioning system, and aims to solve the problem that the energy efficiency ratio of the air conditioning system is reduced due to heat exchange nonuniformity of an outdoor heat exchanger. In order to achieve the purpose, according to the control method of the air conditioning system, whether the air conditioning system is in the high-temperature operation environment and / or the high-load operation environment or not can be judged according to the pressure interval where the first exhaust pressure is located and the temperature interval where the outdoor environment temperature is located, and when the air conditioning system is in the environment, the first throttling element is closed, so that the air conditioning system is in the high-temperature operation environment and / or the high-load operation environment. A refrigerant originally flowing to the first heat exchange area with weak heat exchange capacity is changed to flow to the second heat exchange area with strong heat exchange capacity, so that refrigerant distribution can be optimized, energy loss caused by the fact that the refrigerant flows through the low-efficiency heat exchange area is reduced, the energy efficiency ratio is improved, the heat exchange efficiency of the outdoor heat exchanger can be improved, the heat exchange performance of the air conditioning system is improved, and the service life of the air conditioning system is prolonged. And more excellent use experience is brought to the user.

Description

Technical Field

[0001] The present invention relates to the field of air conditioning systems, and specifically provides a control method for an air conditioning system. Background Art

[0002] In an air conditioning system, the cooling performance of the outdoor heat exchanger is closely related to the flow distribution of the refrigerant inside it. Currently, a throttling element is usually used to regulate the refrigerant flow rate inside the outdoor heat exchanger, thereby adjusting the heat exchange efficiency and effect of the outdoor heat exchanger. However, currently, a single throttling element is usually used to control the refrigerant flow rate inside the outdoor heat exchanger. However, when facing high-temperature or high-load working conditions, its limitations gradually become apparent. Specifically, when the air conditioning system is in an extremely high-temperature and / or high-load working state, due to the problem of uneven heat exchange in the outdoor heat exchanger itself, the control strategy of a single throttling element will significantly exacerbate the heat exchange non-uniformity, affecting the energy efficiency ratio of the entire air conditioning system and thus the user experience.

[0003] Therefore, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0004] To solve at least one problem in the prior art, that is, to solve the problem of the decrease in the energy efficiency ratio of the air conditioning system caused by the uneven heat exchange of the outdoor heat exchanger, the present application provides a control method for an air conditioning system. The air conditioning system includes a compressor and an outdoor heat exchanger. The outdoor heat exchanger includes a first heat exchange area and a second heat exchange area. The heat exchange capacity of the first heat exchange area is less than that of the second heat exchange area. The first heat exchange area is provided with a first throttling element. The control method includes:

[0005] When the first throttling element is in an open state, obtain the first discharge pressure of the compressor and the outdoor ambient temperature;

[0006] Judge the pressure range where the first discharge pressure is located and the temperature range where the outdoor ambient temperature is located;

[0007] Based on the judgment result, selectively control the first throttling element to close.

[0008] In a preferred technical solution of the above control method, the step of "based on the judgment result, selectively control the first throttling element to close" further includes:

[0009] When the first discharge pressure is in a first pressure range and / or the outdoor ambient temperature is in a first temperature range, control the first throttling element to close.

[0010] In a preferred technical solution of the above control method, before the step of "selectively control the first throttling element to close", it further includes:

[0011] When the first exhaust pressure is in the first pressure range and / or the outdoor ambient temperature is in the first temperature range, obtain the first operating frequency of the compressor;

[0012] Compare the magnitude of the first operating frequency with a first preset frequency;

[0013] Based on the comparison result, selectively control the first throttling element to close.

[0014] In a preferred technical solution of the above control method, the step of "selectively controlling the first throttling element to close" further includes:

[0015] When the first operating frequency is less than or equal to the first preset frequency, control the first throttling element to close.

[0016] In a preferred technical solution of the above control method, the control method further includes:

[0017] When the first operating frequency is greater than the first preset frequency, control the first operating frequency to drop below the first preset frequency;

[0018] When the first operating frequency drops below the first preset frequency, control the first throttling element to close.

[0019] In a preferred technical solution of the above control method, a second throttling element is provided in the second heat exchange area, and the step of "controlling the first throttling element to close" further includes, simultaneously, after or before:

[0020] Obtain the second exhaust pressure of the compressor again;

[0021] Compare the magnitude of the second exhaust pressure with a preset pressure;

[0022] Based on the comparison result, selectively reduce the opening degree of the second throttling element.

[0023] In a preferred technical solution of the above control method, the step of "based on the comparison result, selectively reducing the opening degree of the second throttling element" further includes:

[0024] When the second exhaust pressure is greater than the preset pressure, reduce the opening degree of the second throttling element.

[0025] In a preferred technical solution of the above control method, the control method further includes:

[0026] When the second exhaust pressure is less than or equal to the preset pressure, maintain the opening degree of the second throttling element during operation.

[0027] In a preferred technical solution of the above control method, the control method further includes:

[0028] When the first exhaust pressure is in the second pressure range and the outdoor ambient temperature is in the second temperature range, obtain the second operating frequency of the compressor;

[0029] Compare the magnitude of the second operating frequency with a second preset frequency;

[0030] Based on the comparison result, selectively control the second operating frequency of the compressor to be below the second preset frequency;

[0031] Wherein, the upper limit value of the second pressure range is less than or equal to the lower limit value of the first pressure range, and the upper limit value of the second temperature range is less than or equal to the upper limit value of the first temperature range.

[0032] In a preferred technical solution of the above control method, the step of "based on the comparison result, selectively control the second operating frequency of the compressor to be reduced below the second preset frequency" further includes:

[0033] When the second operating frequency is greater than the second preset frequency, control the second operating frequency of the compressor to be below the second preset frequency; and / or

[0034] When the second operating frequency is less than or equal to the second preset frequency, control the first throttling element to close.

[0035] Those skilled in the art can understand that for the control method of the air-conditioning system in this application, based on the pressure range where the first exhaust pressure is located and the temperature range where the outdoor ambient temperature is located, it is possible to determine whether the air-conditioning system is in a high-temperature working environment and / or a high-load operating environment. When the air-conditioning system is in a high-temperature working environment and / or a high-load operating environment, by closing the first throttling element in the first heat exchange area, the refrigerant that originally flowed to the first heat exchange area with weak heat exchange capacity is redirected to the second heat exchange area with strong heat exchange capacity. This can not only optimize the refrigerant distribution, reduce the energy loss caused by the refrigerant flowing through the low-efficiency heat exchange area, thereby improving the energy efficiency ratio, but also enhance the heat exchange efficiency of the outdoor heat exchanger, and further improve the heat exchange performance of the air-conditioning system, bringing a better user experience to the user.

[0036] Furthermore, when the first exhaust pressure is in the first pressure range and / or the outdoor ambient temperature is in the first temperature range, it can indicate that the air-conditioning system is in a high-temperature working environment and / or a high-load operating environment. By closing the first throttling element, all the refrigerant flows to the second heat exchange area with strong heat exchange capacity, thereby reducing the energy loss caused by the refrigerant flowing through the low-efficiency heat exchange area and improving the energy efficiency ratio of the air-conditioning system.

[0037] Further, when the air conditioning system is in a high-temperature working environment and / or a high-load operating environment, in order to avoid the problem of excessive exhaust temperature caused by too high a frequency when the compressor operates in the above environment, it is necessary to judge the magnitude relationship between the first operating frequency of the compressor and the first preset frequency before controlling the first throttling element to close.

[0038] Further, when the first operating frequency is less than or equal to the first preset frequency, by closing the first throttling element, all the refrigerant flows to the second heat exchange area with strong heat exchange capacity, thereby improving the energy efficiency ratio of the air conditioning system, ensuring the heat exchange performance of the air conditioning system, and further improving the user experience.

[0039] Further, when the first operating frequency of the compressor exceeds the first preset frequency, by reducing it below the first preset frequency and then closing the first throttling element, this measure can not only effectively prevent the problem of excessive exhaust temperature caused by too high a frequency when the compressor is in a high-temperature working environment and / or a high-load operating environment, but also enable the air conditioning system to have a high energy efficiency ratio when all the refrigerant flows to the second heat exchange area, thereby ensuring the heat exchange performance of the air conditioning system and improving the user experience.

[0040] Further, when the air conditioning system is in a high-temperature working environment and / or a high-load operating environment and the first throttling element is closed, by judging the magnitude relationship between the second exhaust pressure and the preset pressure, the operating condition of the compressor can be judged, and when the first exhaust pressure is greater than the preset pressure, by reducing the opening degree of the second throttling element, the air conditioning system can still ensure the stable operation of the compressor when operating in a high-temperature working environment and / or a high-load operating environment.

[0041] Further, when the second exhaust pressure is less than the preset pressure, by maintaining the original operating opening degrees of the first and second throttling elements, the normal operation of the compressor and the heat exchange capacity of the air conditioning system can be ensured.

[0042] Further, when the first exhaust pressure is in the second pressure range and the outdoor ambient temperature is in the second temperature range, when the first operating frequency is greater than the second preset frequency, by reducing the first operating frequency of the compressor below the second preset frequency, the air conditioning system can avoid problems such as increased energy consumption and poor heat exchange performance caused by too high an operating frequency when operating in an environment with relatively high temperature and load.

[0043] Further, when the first operating frequency is less than or equal to the second preset frequency, by controlling the first throttling element to close, the heat exchange efficiency of the outdoor heat exchanger can be improved, and further the heat exchange performance of the air conditioning system can be improved, bringing a better user experience to the user. Description of the Drawings

[0044] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

[0045] Figure 1 is a flowchart of the control method of the air conditioning system of the present application;

[0046] Figure 2 is a system diagram of the air conditioning system of the present application;

[0047] Figure 3 is a logic diagram of a possible implementation manner of the control method of the air conditioning system of the present application.

[0048] Description of reference numerals:

[0049] 1. Outdoor heat exchanger; 11. First heat exchange area; 12. Second heat exchange area; 2. Compressor; 3. Indoor heat exchanger; 4. First expansion valve; 5. Second expansion valve. Specific embodiments

[0050] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application.

[0051] It should be noted that in the description of the present application, the terms indicating the direction or positional relationship such as "upper", "lower", "inner", "bottom", "end", etc. are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0052] In addition, it should be noted that in the description of the present application, unless otherwise clearly specified and limited, the terms "set", "connected", "communicated" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0053] First, in combination with Figure 1-2 , the control method of the air conditioning system of the present application will be introduced.

[0054] As Figure 1As shown in the figure, to solve the problem of the decrease in the energy efficiency ratio of the air-conditioning system caused by the uneven heat exchange of the outdoor heat exchanger 1. The air-conditioning system of the present application includes a compressor 2 and an outdoor heat exchanger 1. The outdoor heat exchanger 1 includes a first heat exchange area 11 and a second heat exchange area 12. The heat exchange capacity of the first heat exchange area 11 is less than that of the second heat exchange area 12. A first throttling element is provided in the first heat exchange area 11. Through the above setting method, the problem that the uneven heat exchange of the outdoor heat exchanger 1 is aggravated due to the high-temperature and / or high-load operating environment of the air-conditioning system can be alleviated, so that the refrigerant originally flowing to the first heat exchange area 11 with weak heat exchange capacity is diverted to the second heat exchange area 12 with strong heat exchange capacity, thereby optimizing the refrigerant distribution and reducing the energy loss caused by the refrigerant flowing through the low-efficiency heat exchange area.

[0055] Next, refer to Figure 1 , the air-conditioning system further includes an indoor heat exchanger 3. The compressor 2, the outdoor heat exchanger 1 and the indoor heat exchanger 3 form a refrigerant circuit. The first heat exchange area 11 and the second heat exchange area 12 are arranged in parallel with each other. The inlet sides of the first heat exchange area 11 and the second heat exchange area 12 are both connected to the compressor 2, and the outlet sides are both connected to the indoor heat exchanger 3. A first throttling element is provided on the outlet side of the first heat exchange area 11, and a second throttling element is provided on the outlet side of the second heat exchange area 12. Both the first throttling element and the second throttling element are expansion valves. Through these two throttling elements, the flow direction of the refrigerant can be controlled, the heat exchange efficiency of the outdoor heat exchanger 1 can be improved, and a better user experience can be brought to the user.

[0056] It should be noted that there are various methods to achieve that the heat exchange capacity of the first heat exchange area 11 is less than that of the second heat exchange area 12. For example, in the design of the outdoor unit of the air conditioner, when the air outlet is set at the top, if the first heat exchange area 11 in the outdoor heat exchanger 1 is located below the second heat exchange area 12 and the corresponding areas of the two are the same, and the internal heat exchange components (such as heat exchange fins) are exactly the same in terms of quantity, size and structure, the heat exchange air volume of the first heat exchange area 11 is less than that of the second heat exchange area 12 due to the position of the first heat exchange area 11, so that the heat exchange capacity of the first heat exchange area 11 is relatively small. In addition, the purpose that the heat exchange capacity of the first heat exchange area 11 is less than that of the second heat exchange area 12 can also be achieved by adjusting the size of different areas, or setting different types of heat exchange components in different areas, changing the fin spacing and fin shape on the same heat exchange component, or selecting fins made of different materials.

[0057] In addition, the first throttling element can also be provided on the inlet side of the first heat exchange area 11, and / or the second throttling element can be provided on the inlet side of the first heat exchange area 11, as long as the throttling element can control the flow direction of the refrigerant.

[0058] As Figure 2 shown, based on the above setting method, the control method of the air-conditioning system of the present application includes:

[0059] S101. When the first throttling element is in the open state, obtain the first exhaust pressure and the outdoor ambient temperature. For example, the first exhaust pressure of the compressor 2 is obtained by setting a pressure sensor at the exhaust port of the compressor 2, and the outdoor ambient temperature is obtained by setting a temperature sensor on the outdoor unit.

[0060] S102. Determine the pressure range where the first exhaust pressure is located and the temperature range where the outdoor ambient temperature is located. For example, the pressure range is preset. After obtaining the first exhaust pressure, it is compared with the endpoint values of the preset pressure range to determine the range where the first exhaust pressure is located. The temperature range is preset. After obtaining the outdoor ambient temperature, it is compared with the endpoint values of the preset temperature range to determine the range where the outdoor ambient temperature is located.

[0061] S103. Based on the judgment result, selectively control the first throttling element to close. For example, when the first exhaust pressure is within the pressure range and the outdoor ambient temperature is within the temperature range, the first throttling element can be controlled to close. When the first exhaust pressure is not within the pressure range or the outdoor ambient temperature is not within the temperature range, the operating state of the first throttling element can be maintained.

[0062] Through the pressure range where the first exhaust pressure is located and the temperature range where the outdoor ambient temperature is located, the present application can determine whether the air-conditioning system is in a high-temperature working environment and / or a high-load operating environment. When the air-conditioning system is in a high-temperature working environment and / or a high-load operating environment, by closing the first throttling element in the first heat exchange area 11, the refrigerant that originally flowed to the first heat exchange area 11 with weak heat exchange capacity is redirected to the second heat exchange area 12 with strong heat exchange capacity. This can not only optimize the refrigerant distribution, reduce the energy loss caused by the refrigerant flowing through the low-efficiency heat exchange area, thereby improving the energy efficiency ratio, but also improve the heat exchange efficiency of the outdoor heat exchanger 1, and further improve the heat exchange performance of the air-conditioning system, bringing a better user experience to users.

[0063] The preferred embodiments of the control method for the air-conditioning system of the present application are introduced below.

[0064] In one embodiment, the step of "based on the judgment result, selectively control the first throttling element to close" further includes:

[0065] When the first exhaust pressure is within the first pressure range and / or the outdoor ambient temperature is within the first temperature range, control the first throttling element to close.

[0066] For example, taking the lower limit value of the first pressure range as 40 bar and the first throttling element as the first expansion valve 4 for illustration. When the first exhaust pressure is in the range greater than 40 bar, it indicates that the air-conditioning system is operating under overload. At this time, the first expansion valve 4 can be controlled to close, so that the refrigerant originally flowing to the first heat exchange area 11 flows to the second heat exchange area 12, thereby improving the heat exchange uniformity of the outdoor heat exchanger 1, and further improving the energy efficiency ratio of the air-conditioning system and the user experience.

[0067] Another example is given. Taking the lower limit value of the first temperature range as 50 °C and the first throttling element as the first expansion valve 4 for illustration. When the outdoor ambient temperature is in the range greater than 50 °C, it indicates that the air-conditioning system is in an ultra-high temperature operating environment. At this time, in order to improve the heat exchange uniformity of the outdoor heat exchanger 1, the first expansion valve 4 can be controlled to close, thereby improving the energy efficiency ratio of the air-conditioning system and the user experience.

[0068] Another example is given. Taking the lower limit value of the first pressure range as 40 bar, the lower limit value of the first temperature range as 50 °C, and the first throttling element as the first expansion valve 4 for illustration. When the first exhaust pressure is in the range greater than 40 bar and the outdoor ambient temperature is in the range greater than 50 °C, it indicates that the air-conditioning system is not only in an ultra-high temperature operating environment, but also the compressor 2 is operating under overload. At this time, by controlling the first expansion valve 4 to close, the refrigerant originally flowing to the first heat exchange area 11 flows to the second heat exchange area 12, reducing the energy loss caused by the refrigerant flowing through the low-efficiency heat exchange area, thereby improving the energy efficiency ratio, and also being able to improve the heat exchange uniformity of the outdoor heat exchanger 1, and further improving the heat exchange performance of the air-conditioning system, bringing a better user experience to the user.

[0069] In one implementation, before the step of "selectively controlling the first throttling element to close", it further includes:

[0070] Obtaining the first operating frequency of the compressor 2;

[0071] Comparing the first operating frequency with a first preset frequency;

[0072] Based on the comparison result, selectively controlling the first throttling element to close.

[0073] It should be noted that when the air-conditioning system is in an ultra-high temperature operating environment and / or operating under overload, the compressor 2 may have a problem of too high exhaust temperature due to a large operating frequency. Therefore, it is necessary to obtain the first operating frequency of the compressor 2 before the first expansion valve 4 is closed, compare it with the first preset frequency, and according to the size relationship between the two, reduce the operating frequency of the compressor 2 to avoid the problem of too high exhaust temperature caused by too high operating frequency of the compressor 2.

[0074] Further, the step of "selectively controlling the first throttling element to close based on the comparison result" further includes:

[0075] When the first operating frequency is less than or equal to the first preset frequency, control the first throttling element to close.

[0076] For example, taking the operating frequency of the full-frequency operation of the compressor 2 as 200 Hz, the first operating frequency as 100 Hz, the first throttling element as the first expansion valve 4, and the air-conditioning system being in a high-temperature and high-load working environment for illustration. When the air-conditioning system is in an ultra-high-temperature and overloaded working environment, the operating state is as follows. At this time, before controlling the first expansion valve 4 to close, it is necessary to compare the magnitudes of the first operating frequency and the first preset frequency. When the first operating frequency is less than or equal to 100 Hz, it indicates that the first operating frequency is below 50% of the full frequency of the compressor 2. At this time, it can be determined that the operating frequency of the compressor 2 is normal, and only the first expansion valve needs to be controlled to close.

[0077] Further, the control method further includes:

[0078] When the first operating frequency is greater than the first preset frequency, control the first operating frequency to drop below the first preset frequency;

[0079] When the first operating frequency drops below the first preset frequency, control the first throttling element to close.

[0080] For example, taking the first operating frequency as 100 Hz, the first throttling element as the first expansion valve 4, and the air-conditioning system being in a high-temperature and high-load working environment for illustration. When the air-conditioning system is in an ultra-high-temperature and overloaded working environment, the operating state is as follows. Before controlling the first expansion valve 4 to close, it is necessary to compare the magnitudes of the first operating frequency and the first preset frequency. When the first operating frequency is greater than 100 Hz, it indicates that the first operating frequency exceeds 50% of the full frequency of the compressor 2, and the operating frequency of the compressor 2 is high. At this time, the compressor 2 may have a problem that the exhaust temperature is too high due to the large operating frequency. Therefore, it is necessary to control the operating frequency of the compressor 2 to drop below 100 Hz to solve the above problem, and then control the first expansion valve 4 to close.

[0081] In one embodiment, a second throttling element is provided in the second heat exchange area 12. After the step of "controlling the first throttling element to close", the following further includes:

[0082] Obtain the second exhaust pressure of the compressor 2 again;

[0083] Compare the magnitude of the second exhaust pressure with a preset pressure;

[0084] Based on the comparison result, selectively reduce the opening degree of the second throttling element.

[0085] It should be noted that both the first exhaust pressure and the second exhaust pressure are the pressures at the same exhaust port of the compressor 2. The first exhaust pressure is obtained when the first throttling element is in the operating state, and the second exhaust pressure is obtained when the first throttling element is in the closed state. In order to facilitate the distinction of the exhaust pressure of the compressor 2 under different states of the first throttling element, the first exhaust pressure and the second exhaust pressure are used to represent them.

[0086] In addition, it should be noted that after the first throttling element is closed, there may still be a problem of high energy consumption ratio in the air-conditioning system. Therefore, it is necessary to obtain the second exhaust pressure of the compressor 2 again, compare it with the preset pressure, and then adjust the opening degree of the second throttling element according to the comparison result to determine whether the heat exchange efficiency of the air-conditioning system can meet the user's needs. In addition, since the second exhaust pressure of the compressor 2 is obtained after the first throttling element is closed, and due to the reduction of the refrigerant flow path, the working load of the compressor is reduced, so the second exhaust pressure is lower than the lower limit of the first pressure range.

[0087] Further, the step of "selectively reducing the opening degree of the second throttling element based on the comparison result" further includes:

[0088] When the second exhaust pressure is greater than the preset pressure, reduce the opening degree of the second throttling element.

[0089] For example, taking the preset pressure as 3 bar, the first throttling element as the first expansion valve 4, and the second throttling element as the second expansion valve 5 for illustration. After the first expansion valve 4 is closed, obtain the second exhaust pressure of the compressor 2 again and compare it with the preset pressure. When the second exhaust pressure is greater than 3 bar, it indicates that the exhaust pressure value of the compressor 2 is still relatively high. In order to maintain the stable operation of the air-conditioning system and improve the energy consumption ratio of the air-conditioning system, it is necessary to reduce the opening degree of the second expansion valve 5. And this cycle continues until the second exhaust pressure is less than or equal to the preset pressure.

[0090] Further, the step of "selectively controlling the first throttling element to close based on the comparison result" further includes:

[0091] When the second exhaust pressure is less than or equal to the preset pressure, maintain the opening degree of the second throttling element in operation.

[0092] For example, it is described with a preset pressure of 3 bar, the first throttling element being the first expansion valve 4, and the second throttling element being the second expansion valve 5. After the first expansion valve 4 is closed, the second exhaust pressure of the compressor 2 is obtained again and compared with the preset pressure. When the second exhaust pressure is less than or equal to 3 bar, it indicates that the value of the second exhaust pressure is small. At this time, if the opening degree of the second expansion valve 5 is reduced, the flow of the refrigerant will be restricted, affecting the heat exchange effect. Therefore, in order to ensure the heat exchange effect of the entire air conditioning system, there is no need to reduce the opening degree of the second expansion valve 5, and its original opening degree remains unchanged.

[0093] In one embodiment, the control method further includes:

[0094] When the first exhaust pressure is in the second pressure range and the outdoor ambient temperature is in the second temperature range, obtain the second operating frequency of the compressor 2;

[0095] Compare the magnitude of the second operating frequency with a second preset frequency;

[0096] Based on the comparison result, selectively control the second operating frequency of the compressor to drop below the second preset frequency;

[0097] Wherein, the upper limit value of the second pressure range is less than or equal to the lower limit value of the first pressure range, and the upper limit value of the second temperature range is less than or equal to the lower limit value of the first temperature range.

[0098] It should be noted that the first operating frequency and the second operating frequency are both the operating frequencies of the same compressor 2. The first operating frequency is obtained when the first exhaust pressure is in the first pressure range and / or the outdoor ambient temperature is in the first temperature range, and the second operating frequency is obtained when the first exhaust pressure is in the second pressure range and the outdoor ambient temperature is in the second temperature range. In order to facilitate the distinction of the exhaust pressures of the compressor 2 under different conditions, the first operating frequency and the second operating frequency are used to represent. Among them, the first preset frequency and the second preset frequency may be the same or different, as long as the heat exchange effect and the energy efficiency ratio of the air conditioning system can be improved. Further, the step of "based on the comparison result, selectively control the second operating frequency of the compressor to drop below the second preset frequency" further includes:

[0099] When the second operating frequency is greater than the second preset frequency, control the second operating frequency of the compressor 2 to drop below the second preset frequency.

[0100] For example, it is described that the upper limit value of the second pressure range is equal to the lower limit value of the first pressure range and is 40 bar, the lower limit value of the second pressure range is 30 bar, the upper limit value of the second temperature range is equal to the lower limit value of the first temperature range and is 50 °C, the lower limit value of the second temperature range is 45 °C, the first operating frequency is 120 Hz, and the second throttling element is the second expansion valve 5. When the first discharge pressure is in the range greater than 30 bar and less than or equal to 40 bar, and the outdoor ambient temperature is in the range greater than 45 °C and less than or equal to 50 °C, it indicates that the air-conditioning system is in an environment with relatively high temperature and load. At this time, if the operating frequency of the compressor 2 is relatively large, it may not only damage the compressor 2 due to high discharge temperature, but also reduce the energy efficiency ratio of the air-conditioning system. Therefore, after obtaining the second operating frequency of the compressor 2, it is necessary to compare the second operating frequency with the second preset frequency, and when the second operating frequency is greater than 120 Hz, control the second operating frequency of the compressor 2 to drop below 120 Hz to solve the problems of high discharge temperature and low energy efficiency ratio caused by the large operating frequency of the compressor 2.

[0101] Furthermore, the control method further includes:

[0102] When the second operating frequency is less than or equal to the second preset frequency, control the first throttling element to close.

[0103] For example, it is described with the second preset frequency being 120 Hz and the first throttling element being the first expansion valve 4. When the second operating frequency is less than 120 Hz, it indicates that the operating frequency of the compressor 2 is normal. However, since the air-conditioning system is in an environment with relatively high temperature and load, the operation of the air-conditioning system in this environment can also exacerbate the non-uniformity of the outdoor heat exchanger 1, resulting in poor energy efficiency ratio and heat exchange effect of the air-conditioning system. Therefore, to improve the energy efficiency ratio and heat exchange effect of the air-conditioning system, it is necessary to control the first expansion valve 4 to close.

[0104] The following combines Figure 3 , and briefly describes a possible operation process of the control method of the air-conditioning system of the present application. Figure 3 It is a logic diagram of a possible implementation manner of the control method of the air-conditioning system of the present application.

[0105] S201. When the first expansion valve 4 is in the open state, obtain the outdoor ambient temperature and the first discharge pressure, and then execute S202.

[0106] S202. Determine whether the outdoor ambient temperature is in the range greater than 50 °C, and whether the first discharge pressure is in the range greater than 40 bar? If so, execute S203; if not, execute S210.

[0107] S203. Obtain the first operating frequency of the compressor 2, and then execute S204.

[0108] S204. Determine whether the first operating frequency is less than or equal to 100 Hz. If so, execute S205; otherwise, execute S206.

[0109] S205. Close the first expansion valve 4, and then execute S207.

[0110] S206. Reduce the first operating frequency of the compressor 2 to below 100 Hz, and then execute S205.

[0111] S207. Obtain the second discharge pressure of the compressor 2 again, and then execute S208.

[0112] S208. Determine whether the second discharge pressure is greater than 3 bar. If so, execute S209; otherwise, execute S207.

[0113] S209. Reduce the opening degree of the second expansion valve 5, and then execute S207.

[0114] S210. Obtain the second operating frequency of the compressor 2, and then execute S211.

[0115] S211. Determine whether the second operating frequency is greater than 120 Hz. If so, execute S212; otherwise, execute S213.

[0116] S212. Reduce the second operating frequency of the compressor 2 to below 120 Hz.

[0117] S213. Close the first expansion valve 4.

[0118] Those skilled in the art can understand that although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of this application and forms different embodiments. For example, in the claims of this application, any of the claimed embodiments can be used in any combination.

[0119] So far, the technical solution of this application has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of this application is obviously not limited to these specific embodiments. Without departing from the principle of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of this application.

Claims

1. A control method for an air conditioning system, characterized in that, The air conditioning system includes a compressor and an outdoor heat exchanger. The outdoor heat exchanger includes a first heat exchange area and a second heat exchange area. The heat exchange capacity of the first heat exchange area is less than that of the second heat exchange area. A first throttling element is provided in the first heat exchange area. The control method includes: When the first throttling element is in an open state, obtain the first discharge pressure of the compressor and the outdoor ambient temperature; Judge the pressure range where the first discharge pressure is located and the temperature range where the outdoor ambient temperature is located; Based on the judgment result, selectively control the first throttling element to close.

2. The control method according to claim 1, characterized in that, The step of "selectively controlling the first throttling element to close" further includes: When the first discharge pressure is in a first pressure range and / or the outdoor ambient temperature is in a first temperature range, control the first throttling element to close.

3. The control method according to claim 2, characterized in that Before the step of "selectively controlling the first throttling element to close", it further includes: When the first discharge pressure is in a first pressure range and / or the outdoor ambient temperature is in a first temperature range, obtain the first operating frequency of the compressor; Compare the magnitude of the first operating frequency with a first preset frequency; Based on the comparison result, selectively control the first throttling element to close.

4. The control method according to claim 3, characterized in that, The step of "selectively controlling the first throttling element to close" based on the comparison result further includes: When the first operating frequency is less than or equal to the first preset frequency, control the first throttling element to close.

5. The control method according to claim 4, wherein The control method further includes: When the first operating frequency is greater than the first preset frequency, control the first operating frequency to drop below the first preset frequency; When the first operating frequency drops below the first preset frequency, control the first throttling element to close.

6. The control method according to claim 4 or 5, characterized in that A second throttling element is provided in the second heat exchange area. After the step of "controlling the first throttling element to close", it further includes: Obtain the second discharge pressure of the compressor again; Compare the magnitude of the second discharge pressure with a preset pressure; Based on the comparison result, selectively reduce the opening degree of the second throttling element.

7. The control method according to claim 6, wherein The step of "selectively reducing the opening degree of the second throttling element" based on the comparison result further includes: When the second discharge pressure is greater than the preset pressure, reduce the opening degree of the second throttling element.

8. The control method according to claim 7, wherein The control method further includes: When the second discharge pressure is less than or equal to the preset pressure, maintain the opening degree of the second throttling element during operation.

9. The control method according to claim 2, wherein The control method further includes: When the first discharge pressure is in a second pressure range and the outdoor ambient temperature is in a second temperature range, obtain the second operating frequency of the compressor; Compare the magnitude of the second operating frequency with a second preset frequency; Based on the comparison result, selectively control the second operating frequency of the compressor to drop below the second preset frequency; Wherein, the upper limit value of the second pressure range is less than or equal to the lower limit value of the first pressure range, and the upper limit value of the second temperature range is less than or equal to the lower limit value of the first temperature range.

10. The control method according to claim 9, wherein, The step of "selectively controlling the second operating frequency of the compressor to drop below the second preset frequency based on the comparison result" further includes: When the second operating frequency is greater than the second preset frequency, controlling the second operating frequency of the compressor to drop below the second preset frequency; and / or When the second operating frequency is less than or equal to the second preset frequency, controlling the first throttling element to close.

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