WO2021063088A1

WO2021063088A1 - Cooling system and method for inverter, and air conditioning apparatus

Info

Publication number: WO2021063088A1
Application number: PCT/CN2020/103659
Authority: WO
Inventors: 卓明胜; 陈培生; 程琦; 黄凯亮; 林少丹
Original assignee: 珠海格力电器股份有限公司
Priority date: 2019-09-30
Filing date: 2020-07-23
Publication date: 2021-04-08
Also published as: CN110677014A; CN110677014B

Abstract

A system and method for cooling an inverter, and an air conditioning apparatus. The system comprises: a first cooling branch (2), in communication at one end with an inlet pipe (1), in communication at the other end with an outlet pipe (5) via air between an inverter housing (41) and a work module (42), and used for exchanging heat with the air between the inverter housing (41) and the work module (42), thus reducing the temperature of the air between the inverter housing (41) and the work module (42); and a second cooling branch (3), in communication at one end with the inlet pipe (1), in communication at the other end with the outlet pipe (5) via the inverter work module (42), and used for exchanging heat with the inverter work module (42), thus reducing the temperature of the inverter work module (42). The employment of the two branches to separately cool the inverter work module (42) and the inverter housing (41) implements the uniform cooling of the inverter, avoids the problem of inverter condensation caused by an excessive temperature difference due to localized cooling, and increases the reliability and service life of the air conditioning apparatus.

Description

Inverter cooling system, method and air conditioning equipment

Cross-references to related applications

This application is based on the application with the CN application number 201910945491.X and the filing date of September 30, 2019, and claims its priority. The disclosure of the CN application is hereby incorporated into this application as a whole.

Technical field

The present disclosure relates to the technical field of air conditioners, and in particular, to a cooling system and method of a frequency converter, and air conditioning equipment.

Background technique

The long-term operation of the frequency converter in the frequency conversion unit will cause the temperature of the working module of the frequency converter and the outer casing to increase abnormally, so it needs to be cooled. An inverter cooling method known to the inventor of the present disclosure is to add a cooling device (such as a fan) to the inverter to dissipate heat. This method increases the space structure of the inverter and increases the cost, but the cooling effect is not good. . Another cooling method known to the inventor of the present disclosure is to use the low-temperature refrigerant in the air-conditioning refrigerant circulation system for cooling. However, the inventor of the present disclosure found that while enhancing the cooling effect, it is likely to cause temperature differences due to local cooling. If it is too large, it will cause condensation of the inverter and damage the inverter.

Summary of the invention

The present disclosure provides a cooling system for a frequency converter. The system includes: an inlet pipeline connected to the outlet of the condenser for introducing the refrigerant discharged from the condenser; a first cooling branch, one end of which is connected to the inlet pipeline, and the other end passes between the inverter box and the working module, and the outlet The pipeline is connected to exchange heat with the air between the inverter box and the working module, thereby reducing the temperature of the inverter box; the second cooling branch has one end connected to the inlet pipeline, and the other end passes through The working module of the frequency converter is connected with the outlet pipeline for heat exchange with the working module of the frequency converter, thereby reducing the temperature of the working module of the frequency converter; the outlet pipeline is connected with the inlet of the evaporator, To discharge the refrigerant in the first cooling branch and the second cooling branch.

In some embodiments, the system further includes: a first valve, arranged on the first cooling branch, for controlling whether the refrigerant flows through the first cooling branch by opening or closing.

In some embodiments, the system further includes: a second valve arranged on the second cooling branch for controlling whether the refrigerant flows through the second cooling branch by opening or closing.

In some embodiments, a third valve is provided on the second cooling branch for controlling the flow rate of the refrigerant in the second cooling branch by adjusting the opening degree.

In some embodiments, the system further includes: a bypass branch connected in parallel with the second cooling branch, and a fourth valve is provided on the bypass branch to control whether the refrigerant flows through opening or closing. Via the bypass branch.

In some embodiments, a capillary tube is provided on the outlet pipeline, and a bypass outlet is provided in parallel with the capillary tube, and a fifth valve is provided on the bypass outlet for controlling the first valve by opening or closing. Whether the refrigerant flowing out of a cooling branch and the second cooling branch flows through the bypass outlet.

The present disclosure also provides an air-conditioning device, including the cooling system of the above-mentioned frequency converter.

The present disclosure also provides a method for cooling the inverter, wherein the method includes: obtaining the air temperature between the inverter box and the working module, the temperature of the air outside the inverter box, and the operating state of the compressor; The air temperature between the inverter cabinet and the working module and the outside air temperature of the inverter cabinet are controlled to open or close the first valve according to the first preset strategy; according to the operating state of the compressor, according to the second A preset strategy controls the opening or closing of the second valve; wherein, the first valve is arranged on the first cooling branch, the second valve is arranged on the second cooling branch, and the first valve and The initial state of the second valve is open.

In some embodiments, controlling the opening or closing of the first valve according to the first preset strategy includes: calculating the first difference between the air temperature between the inverter cabinet and the working module and the air temperature outside the inverter cabinet. difference △ T1; △ T1 if the first difference is greater than a first predetermined _set difference △ T1, the first control valve remains open; if the first difference △ T1 equal to or less than the first predetermined difference The value △T1 _{is set} to determine whether the air temperature between the inverter cabinet and the working module is less than or equal to the first preset temperature T1. If not, control the first valve to keep open; if it is, control The first valve is closed; after the first valve is controlled to be closed, if the air temperature between the inverter box and the working module is greater than the second preset temperature T2, the first valve is controlled to open.

In some embodiments, controlling the opening or closing of the second valve according to the second preset strategy includes: if the operating state of the compressor is open, controlling the second valve to open; if the operating state of the compressor is closed, then After the air conditioner compressor is turned off for a first preset time, the second valve is controlled to be closed.

In some embodiments, the method further includes: obtaining the temperature of the working module of the frequency converter, and a second difference ΔT2 between the temperature of the working module of the frequency converter and the target temperature value; according to the temperature of the working module of the frequency converter and the first difference The two difference value ΔT2 adjusts the opening degree of the third valve according to the third preset strategy to control the cooling speed of the working module of the frequency converter; the third valve is arranged on the second cooling branch.

In some embodiments, adjusting the opening of the third valve according to the third preset strategy to control the cooling speed of the working module of the frequency converter includes: if the temperature of the working module of the frequency converter> the third preset temperature T3, And the second difference △T2>the second preset difference △T2 _{is set} , then the opening of the third valve is controlled to decrease to increase the cooling speed; if the temperature of the inverter working module>the third preset Temperature T3, and the second difference value △T2≤the third preset difference value △T3 _{is set} , control the opening of the third valve to increase to reduce the cooling speed; if the temperature of the working module of the frequency converter>the first Three preset temperature T3, and the third preset difference value △T3 _{is set} <the second difference value △T2≤the second preset difference value △T2 _{is set} , then the opening degree of the third valve is controlled to remain unchanged; If the temperature of the working module of the frequency converter is ≤ the third preset temperature T3, and the second difference △T2>the second preset difference △T2 _{is set} , the opening of the third valve is controlled to decrease to reduce the cooling speed ; If the temperature of the inverter working module is ≤ the third preset temperature T3, and the second difference △T2≤the third preset difference △T3 _{is set} , then the third valve is controlled to increase its opening to increase Large cooling speed; if the temperature of the inverter working module ≤ the third preset temperature T3, and the third preset difference △T3 _{is set} <the second difference △T2≤the second preset difference △T2 _Suppose , the opening degree of the third valve is controlled to remain unchanged, wherein the initial state of the third valve is to open the preset number of steps.

In some embodiments, the method further includes: obtaining the temperature of the working module of the frequency converter; if the temperature of the working module of the frequency converter is greater than the fourth preset temperature T4, controlling the fourth valve to close to maintain the temperature of the working module of the frequency converter The cooling rate remains unchanged; after the fourth valve is controlled to close, the third difference △T3 between the temperature of the inverter working module and the air temperature between the inverter cabinet and the working module is obtained; if the third difference △T3 less than a preset difference △ T4 equal to the fourth _set, it is determined that the drive operating module temperature is less than or equal to the fifth predetermined temperature T5 is established, if so, the fourth control valve opening; if not, the control the fourth valve is closed; if the third difference is greater than the fourth preset difference △ T3 _provided △ T4, the fourth control valve closed; wherein said fourth valve disposed in the bypass branch, the The initial state of the fourth valve is open, and the bypass branch is connected in parallel with the second cooling branch.

In some embodiments, the method further includes: obtaining the temperature of the working module of the frequency converter and the evaporation temperature of the air conditioning system; if the evaporation temperature of the air conditioning system is less than the sixth preset temperature T6 within the second preset time, controlling the fifth valve Closed; if the temperature of the inverter working module is greater than or equal to the seventh preset temperature T7, the air temperature between the inverter cabinet and the working module is greater than or equal to the eighth preset temperature T8, and the evaporation temperature of the air conditioning system is greater than The ninth preset temperature T9, if any one of the conditions is met, the fifth valve is controlled to open to increase the cooling speed of the inverter working module and the inverter cabinet; wherein, the fifth valve is set at On the bypass outlet, the initial state of the fifth valve is open, and the bypass outlet is arranged on the outlet pipeline.

In some embodiments, the method further includes: obtaining the working state of the compressor; if the working state of the compressor is off, controlling the first valve to close after the air conditioner compressor is turned off for a first preset time.

The present disclosure also provides a computer-readable storage medium on which a computer program is stored, characterized in that the program is executed by a processor to implement the above method.

Description of the drawings

Fig. 1 is a structural diagram of a cooling system of a frequency converter according to some embodiments of the present disclosure;

Fig. 2 is a structural diagram of a cooling system of a frequency converter according to other embodiments of the present disclosure;

Fig. 3 is a flowchart of a cooling method of a frequency converter according to some embodiments of the present disclosure;

Fig. 4 is a flowchart of a cooling method of a frequency converter according to other embodiments of the present disclosure;

Fig. 5 is a flowchart of a cooling method of a frequency converter according to other embodiments of the present disclosure;

Fig. 6 is a flowchart of a cooling method of a frequency converter according to other embodiments of the present disclosure;

Fig. 7 is a flowchart of a cooling method of a frequency converter according to other embodiments of the present disclosure.

Detailed ways

In order to make the objectives, technical solutions, and advantages of the present disclosure clearer, the present disclosure will be described in detail in some embodiments with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of them. example. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.

The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments, and are not intended to limit the present disclosure. The singular forms of "a", "said" and "the" used in the embodiments of the present disclosure and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, "multiple" Generally contains at least two types.

It should be understood that the term "and/or" used in this text is only an association relationship describing the associated objects, indicating that there can be three types of relationships, for example, A and/or B can mean that A alone exists, and both A and A exist at the same time. B, there are three cases of B alone. In addition, the character "/" in this text generally indicates that the associated objects before and after are in an "or" relationship.

It should be understood that although the terms first, second, third, etc. may be used to describe the preset temperature in the embodiments of the present disclosure, these preset temperatures should not be limited to these terms. These terms are only used to distinguish the preset temperature. For example, without departing from the scope of the embodiments of the present disclosure, the first preset temperature may also be referred to as the second preset temperature, and similarly, the second preset temperature may also be referred to as the first preset temperature.

Depending on the context, the words "if" and "if" as used herein can be interpreted as "when" or "when" or "in response to determination" or "in response to detection". Similarly, depending on the context, the phrase "if determined" or "if detected (statement or event)" can be interpreted as "when determined" or "in response to determination" or "when detected (statement or event) )" or "in response to detection (statement or event)".

It should also be noted that the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a commodity or system that includes a series of elements not only includes those elements, but also includes those elements that are not explicitly listed. Other elements of, or also include elements inherent to this kind of commodity or system. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the commodity or system that includes the element.

The inventor of the present disclosure found that, in the cooling means in the known technology, the problem of excessive temperature difference caused by condensation of the inverter due to local cooling occurs.

In view of this, the present disclosure provides a cooling system for an inverter to solve the problem of condensation of the inverter due to excessive temperature difference due to local cooling in the prior art.

Some embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Example 1

Fig. 1 is a structural diagram of a cooling system of a frequency converter according to some embodiments of the present disclosure. As shown in Fig. 1, the system includes: an inlet pipe 1 connected with the outlet of the condenser 6, so that the low-temperature refrigerant discharged from the condenser 6 enters the first cooling branch and the second cooling branch. The system also includes: a first cooling branch 2, with one end connected to the inlet pipe 1, and the other end passing through the air between the frequency converter box 41 and the frequency converter working module 42, and communicating with the outlet pipe 5, for communicating with the The air between the inverter box 41 and the inverter working module 42 exchanges heat, thereby reducing the temperature of the inverter box 41. The system also includes: a second cooling branch 3, one end of which is connected to the inlet pipe 1, and the other end is connected to the outlet pipe 5 through the frequency converter working module 42 for heat exchange with the frequency converter working module 42, thereby Lower the temperature of the inverter working module 42. The system also includes: the outlet pipe 5 communicates with the inlet of the evaporator 8 so that the refrigerant discharged from the first cooling branch and the second cooling branch flows into the evaporator 8.

The refrigeration cycle path of the refrigerant of the air conditioning equipment is: compressor 9→oil separator 10→condenser 6→electronic expansion valve 7→evaporator 8→compressor 9. The cooling path of the cooling system of the inverter includes the first cooling path: condenser 6 → inlet pipe 1 → first cooling branch 2 → air between the inverter box 41 and the inverter working module 42 → outlet pipe 5 ; And the second cooling path: condenser 6 → inlet pipe 1 → second cooling branch 3 → frequency converter working module 42 → outlet pipe 5. According to the refrigeration principle of air-conditioning equipment, the condenser 6 discharges low-temperature refrigerant, and the low-temperature refrigerant discharged from the condenser 6 is introduced into the first cooling branch 2 and the second cooling branch 3 through the inlet pipe 1 communicating with the outlet of the condenser 6. The first cooling branch 2 passes through the air between the inverter box 41 and the inverter working module 42. Since the air temperature between the inverter box 41 and the inverter working module 42 is higher than the temperature of the low-temperature refrigerant in the first cooling branch 2, the air between the inverter box 41 and the inverter working module 42 will It exchanges heat with the low-temperature refrigerant in the first cooling branch 2. The heat of the air between the inverter box 41 and the inverter working module 42 will be transferred to the low-temperature refrigerant in the first cooling branch 2. The low-temperature refrigerant in the first cooling branch 2 takes away the heat of the air between the working modules 42 of the frequency converter, thereby reducing the temperature of the frequency converter cabinet 41 and achieving the purpose of cooling the frequency converter cabinet 41.

It should be noted that since the inverter box is a one-layer shell, the pipes of the first cooling branch 2 cannot pass through it. Therefore, the inverter box must be cooled by heat exchange to make the first cooling branch. The pipeline of a cooling branch 2 passes through the air between the inverter box 41 and the inverter working module 42. By reducing the temperature of the air between the inverter box 41 and the inverter working module 42, it can indirectly realize the control of the inverter. Cooling of the cabinet body.

The pipeline of the second cooling branch 3 passes through the inside of the inverter working module 42. When the low-temperature refrigerant in the second cooling branch 3 passes through the inverter working module 42, heat exchange occurs. The low-temperature refrigerant in the second cooling branch 3 takes away the heat of the working module 42 of the frequency converter, so that the temperature of the working module 42 of the frequency converter is reduced, and the purpose of cooling the working module 42 of the frequency converter is realized.

In the above-mentioned embodiment, by setting the first cooling branch and the second cooling branch, the inverter working module and the inverter cabinet are separately cooled in a dual-branch way, which can realize the separation of the inverter working module and the inverter cabinet. The box body is cooled evenly, avoiding the problem of condensation of the inverter caused by excessive temperature difference due to local cooling, and improving the reliability and service life of the air conditioning equipment. In addition, the embodiment of the present disclosure utilizes the refrigeration system by-pass cooling, does not require an additional cooler, and has a simple structure; and the refrigerant flows through the frequency converter to exchange heat and then throttles back to the refrigeration cycle for recycling, which is economical and energy-saving.

Example 2

Fig. 2 is a structural diagram of a cooling system of a frequency converter according to other embodiments of the present disclosure.

As shown in Figure 2, on the basis of the system of Embodiment 1, the cooling system further includes: a first valve 21, which is arranged on the first cooling branch 2, and is used to control whether the refrigerant flows through opening or closing. Via the first cooling branch 2. For example, the first valve 21 may be a solenoid valve, which is controlled to be opened or closed by an electric signal. The first valve 21 may also be other types of valves, which are not specifically limited in this disclosure. By setting the first valve 21, the opening or closing of the first cooling branch 2 can be controlled, and the opening or closing of the first cooling branch 2 can be controlled under different conditions, thereby controlling whether there is refrigerant flowing through the first cooling branch 2 , So as to control whether to cool down the inverter box 41. In some embodiments, the first cooling branch 2 is further provided with a first capillary tube 22 for controlling the pressure difference between the inlet end and the outlet end of the first cooling branch 2 and restricting the flow of refrigerant through the first cooling branch. The speed of the road enhances the heat exchange effect.

In some embodiments, the system further includes: a second valve 311 disposed on the second cooling branch 3 for controlling whether the refrigerant flows through the second cooling branch 3 by opening or closing. For example, the second valve 311 may be a solenoid valve, which is controlled to be opened or closed by an electric signal. For another example, the second valve 311 may also be other types of valves, which are not specifically limited in the present disclosure. By setting the second valve 311, the opening or closing of the second cooling branch 3 can be controlled, and the opening or closing of the second cooling branch 3 can be controlled under different conditions, thereby controlling whether there is refrigerant flowing through the second cooling branch 3 , Thereby controlling whether to cool down the inverter working module 42.

In some embodiments, the second cooling branch 3 is further provided with a third valve 312 for controlling the flow rate of the refrigerant in the second cooling branch 3 by adjusting the opening degree. For example, the third valve is an electronic expansion valve, and the opening degree can be controlled according to an electric signal. For another example, the third valve may also be another regulating valve with an analog opening degree, which is not specifically limited in this disclosure. By providing the third valve 312, the flow rate of the refrigerant in the second cooling branch 3 can be adjusted. When the temperature of the inverter working module 42 is greater than a certain value, increasing the refrigerant flow rate can make the temperature of the refrigerant flowing through the inverter working module 42 lower, thereby improving the heat exchange effect between the second cooling branch 3 and the inverter working module 42 , Thereby achieving the purpose of accelerating the cooling speed of the working module 42 of the frequency converter. When the temperature of the inverter working module 42 is less than or equal to a certain value, the flow rate of the refrigerant is reduced, and the amount of refrigerant flowing through the second cooling branch 3 is also reduced. Therefore, the heat exchange effect will be reduced at this time, thereby reducing the working module of the inverter. 42's cooling rate.

In some embodiments, the system further includes a bypass branch 32 connected in parallel with the second cooling branch 3. The bypass branch 32 is provided with a fourth valve 321 for controlling whether the refrigerant flows through the bypass branch 32 by opening or closing. Since the third valve 312 is provided on the second cooling branch 3, the temperature of the refrigerant flowing out of the second cooling branch 3 can be lowered, and the bypass branch 32 is provided to divide the refrigerant path into two, and the outflow bypass The temperature of the refrigerant in the branch 32 is higher than the temperature of the refrigerant flowing out of the second cooling branch 3. After the two temperatures are neutralized, the temperature of the refrigerant that finally flows through the inverter working module 42 can be increased, thereby reducing the cooling speed of the inverter working module 42 and further avoiding local temperature cooling too fast, too low, and condensation.

In some embodiments, the outlet pipe 5 is provided with a capillary tube (may be referred to as a second capillary tube) 511, and a bypass line arranged in parallel with the capillary tube 511. A fifth valve 521 is provided on the bypass outlet. The fifth valve 521 is opened or closed to control whether the refrigerant flowing out of the first cooling branch 2 and the second cooling branch 3 flows through the bypass outlet, thereby adjusting the frequency converter box and the The cooling speed of the working module of the frequency converter. Since the second capillary tube 511 is provided on the outlet pipe 5, the heat transfer from the refrigerant inflow end of the outlet pipe 5 to the refrigerant outflow end is slow. However, when the temperature of the inverter box 41 and the inverter working module 42 is too high, the fifth valve 521 can be opened to make the low-temperature refrigerant discharged from the system expansion solenoid valve 7 and the outlet pipeline 5, as well as the inverter box 41 and the inverter The working module 42 exchanges heat, thereby increasing the cooling speed of the inverter box 41 and the inverter working module 42.

Example 3

Fig. 3 is a flowchart of a cooling method of a frequency converter according to some embodiments of the present disclosure. As shown in Fig. 3, the method includes steps S301 to S302.

In step S301, the air temperature between the inverter box and the working module, the temperature of the air outside the inverter box, and the operating state of the compressor are acquired.

The air temperature between the inverter box and the working module can be reflected by setting a temperature sensor in the air between the inverter box and the working module, that is, in the inverter cabinet, and detecting the temperature in the inverter cabinet through the temperature sensor. The temperature of the inverter cabinet. The temperature of the working module of the inverter can be detected by setting a temperature sensor in the working module of the inverter. The operating state of the compressor can be acquired through a detection system inside the air-conditioning device.

In step S302, according to the air temperature between the inverter box and the working module and the air temperature outside the inverter box, the opening or closing of the first valve is controlled according to the first preset strategy, and the first valve is controlled according to the compression The operating state of the engine controls the opening or closing of the second valve according to the second preset strategy.

It should be noted that, controlling the opening or closing of the first valve according to the first preset strategy and controlling the opening or closing of the second valve according to the second preset strategy may not be performed at the same time or at the same time. The control of the first valve and the control of the second control valve are realized through preset control conditions and do not affect each other.

In this embodiment, the initial state of the first valve and the second valve is open. For example, while the compressor is on, the first valve and the second valve can be controlled to open. If it is detected that the operating state of the compressor is open, the first valve and the second valve are controlled to open. If it is detected that the operating state of the compressor is off, the first valve and the second valve are controlled to close after the air conditioner compressor is turned off for a first preset time. The first valve is arranged on the first cooling branch. By controlling the opening or closing of the first valve, it is controlled whether the refrigerant flows through the first cooling branch. The second valve is arranged on the second cooling branch. By controlling the opening or closing of the second valve, it is controlled whether the refrigerant flows through the second cooling branch. The initial state of the first valve and the second valve is open.

Realize the control of the first valve and the second valve through different control strategies, so as to realize the control of the first cooling branch and the second cooling branch, so as to realize the cooling of the inverter box and the inverter working module. . This can achieve uniform cooling of the inverter working module and the inverter cabinet, avoid the problem of condensation of the inverter caused by excessive temperature difference due to local cooling, and improve the reliability and service life of the air-conditioning equipment. The temperature of the inverter cabinet and the inverter working module can be controlled separately by controlling the valve, which can be realized according to the air temperature between the inverter cabinet and the operating module, the temperature of the inverter operating module and the outside of the inverter cabinet. The air temperature and the operating state of the compressor are automatically controlled.

Example 4

4 is a flowchart of a method for cooling a frequency converter according to other embodiments of the present disclosure. As shown in FIG. 4, based on the control method of Embodiment 3, the opening or opening of the first valve is controlled according to the first preset strategy. The shutdown includes the following steps.

Control the first valve to open.

Next, calculate the first difference ΔT1 between the air temperature between the inverter cabinet and the working module and the outside air temperature of the inverter cabinet.

If the first difference is greater than a first predetermined difference value △ T1 _provided △ T1, the first control valve opening. For example, a first _set of preset difference △ T1 3 ℃. If the difference between the air temperature between the inverter box and the working module and the outside air temperature of the inverter box is greater than 3°C, it indicates that the air temperature between the inverter box and the working module is still higher than the inverter box. The outside air temperature is much higher. At this time, the inverter cabinet still needs to be cooled. Since the first valve is already in the open state, it continues to remain open. _Set if the first difference ΔT1 is less than or equal to the first preset difference ΔT1. For example, if the difference between the air temperature between the inverter box and the working module and the outside air temperature of the inverter box is less than or equal to 3°C, it is determined that the air temperature between the inverter box and the working module is less than or equal to Whether the first preset temperature T1 is established. If not, control the first valve to keep open, if yes, control the first valve to close. For example, the air temperature between the inverter box and the working module is greater than T1℃. Although the air temperature between the inverter box and the working module is less than the outside air temperature of the inverter box at this time, the inverter box The body itself has a high temperature and needs to continue to cool down, so the first valve is controlled to keep open. If the air temperature between the inverter box and the working module is less than or equal to T1°C, it indicates that the air temperature between the inverter box and the working module has been reduced to less than the outside air temperature of the inverter box at this time, and The temperature of the air temperature between the inverter box and the working module is also within a reasonable temperature range. At this time, the cooling of the inverter box can be ended, that is, the first valve is closed.

After controlling the first valve to close, continue to obtain the air temperature between the inverter box and the working module. If the air temperature between the inverter box and the working module is greater than the second preset temperature T2, the first valve is controlled to open. For example, the air temperature between the inverter box and the working module is greater than T2°C, indicating that the temperature of the inverter box itself rises again at this time, and the first valve needs to be controlled to open at this time to start cooling again. If the air temperature between the inverter box and the working module is less than or equal to the second preset temperature T2, indicating that the air temperature between the inverter box and the working module has not reached the limited range, the first valve is controlled to keep closed . It should be noted that the second preset temperature T2 is greater than the first preset temperature T1.

By obtaining the difference between the air temperature between the inverter box and the working module and the outside air temperature of the inverter box, as well as the air temperature between the inverter box and the working module, control the opening or closing of the first valve, And then control whether to cool down the inverter cabinet. This can be achieved according to the actual temperature of the inverter box to determine whether to cool the inverter box, so that the cooling operation is more targeted.

Example 5

Fig. 5 is a flowchart of a cooling method of a frequency converter according to other embodiments of the present disclosure. As shown in FIG. 5, based on the control method of Embodiment 3, the method further includes the following steps.

Open the third valve and adjust the opening to the initial opening. For example, adjust to 350B and keep the current opening.

Obtain the temperature of the working module of the inverter and the second difference △T2 between the temperature of the working module of the inverter and the target temperature value. The temperature target value of the working module of the frequency converter is a preset fixed value. According to the temperature of the working module of the frequency converter and the second difference ΔT2, the opening degree of the third valve is adjusted according to a third preset strategy to control the cooling speed of the working module of the frequency converter. For example, if the temperature of the working module of the frequency converter>the third preset temperature T3, and the second difference △T2>the second preset difference △T2 _{is set} , the opening of the third valve is controlled to decrease to Increase the cooling rate. At this time, the temperature of the working module of the inverter is relatively high and the difference between the target temperature and the target temperature is large. Therefore, it is necessary to control the opening to decrease to increase the cooling speed. At this time, the third valve plays a throttling role, and the smaller the opening degree, the more obvious the change in refrigerant pressure, which leads to the greater the temperature drop. At this time, the system pressure difference is large, and the refrigerant flow rate used to cool the inverter is sufficient. Therefore, reducing the opening of the third valve makes the temperature of the refrigerant behind the valve lower and enhances the heat exchange effect. If the temperature of the inverter working module> the third preset temperature T3, and the second difference △T2 ≤ the third preset difference △T3 _set , at this time, the temperature of the inverter working module has a small difference from the target value , You can control the opening of the third valve to increase to reduce the cooling rate. If the temperature of the working module of the frequency converter>the third preset temperature T3, and the third preset difference value △T3 _{is set} <the second difference value △T2≤the second preset difference value △T2 _{is set} , at this time, the frequency conversion The difference between the temperature of the working module of the device and the target temperature is within the normal range, and the opening degree of the third valve can be controlled to remain unchanged to maintain the current cooling rate. If the temperature of the inverter working module is ≤ the third preset temperature T3, and the second difference △T2>the second preset difference △T2 _{is set} , then the opening of the third valve is controlled to decrease to decrease Cooling speed. At this time, the principle of controlling the cooling speed is opposite to that of the working module temperature of the frequency converter> the third preset temperature T3, that is, the opening of the third valve decreases, and the cooling speed also decreases. At this time, the temperature of the refrigerant used to cool the inverter is low enough, so reducing the opening of the third valve makes the flow of refrigerant behind the valve smaller and reduces the heat exchange effect. If the temperature of the working module of the frequency converter ≤ the third preset temperature T3, and the second difference △T2≤the third preset difference △T3 _{is set} , the opening of the third valve is controlled to increase to increase Cooling speed. If the temperature of the inverter working module is ≤ the third preset temperature T3, and the third preset difference △T3 _{is set} <the second difference △T2≤the second preset difference △T2 _{is set} , then control The opening degree of the third valve remains unchanged. The third valve is arranged on the second cooling branch, and its initial state is to open a preset number of steps. It should be noted that, in this embodiment, the third preset difference ΔT3 _{is set} <the second preset difference ΔT2 _{is set} .

According to the current working module temperature of the inverter, and the difference between the current working module temperature of the inverter and the target temperature, the cooling speed is adjusted in real time to achieve precise control of the cooling process, which can prevent the temperature of the working module of the inverter from falling too fast and causing the inverter Local temperature is too low, causing condensation.

For example: after the second valve is opened, the third valve is hit to the initial number of steps (for example, 350 steps). After maintaining for 1 minute, adjust the third valve according to the temperature of the inverter working module and the second difference ΔT2, and adjust once every 30 seconds. The controller detects the second difference ΔT2 every 5 seconds, and calculates the average value of the second difference ΔT2 in 30 seconds. After the second valve is closed when cooling is satisfied, the third valve is closed for 20 steps after reaching 0 step.

The second difference △T2=Max(t1, t2, t3)-X°C, where Max(t1, t2, t3) represents the maximum value of the inverter working module temperature value obtained three times, and X is the settable target Temperature value. For example, the range of X is 30-50°C. For example, in this embodiment, X may take a value of 40°C. A third preset temperature T3 = 35 ℃, the second predetermined _set difference △ T2 = 2 ℃, the third predetermined _set difference △ T3 = 0 ℃, there are:

0℃＜the second difference △T2≤2℃, the number of adjustment steps=0

Situation 1: The temperature of the working module of the inverter>35℃

The second difference △T2>2°C, the number of adjustment steps=3*(2-target deviation), the specific number of steps is the decimal part of the calculation result is rounded off.

The second difference △T2≤0°C, the number of adjustment steps=3*(-target deviation), and the specific number of steps is rounded off after the decimal part of the calculation result is removed.

Case 2: The temperature of the inverter's working module is ≤35°C

The second difference △T2>2°C, the number of adjustment steps=3*(target deviation-2), and the specific number of steps is rounded off the decimal part of the calculation result.

The second difference △T2≤0°C, the number of adjustment steps=3*(target deviation), and the specific number of steps is rounded off after the decimal part of the calculation result is removed.

In the above embodiment, the target deviation is the second difference ΔT2.

If the rounding calculated according to the formula is a positive value, the third valve will increase the corresponding number of steps at the current opening; if the rounding calculated according to the formula is a negative value, the third valve will be adjusted at the current opening The corresponding adjustment steps are small.

Example 6

Fig. 6 is a flowchart of a cooling method of a frequency converter according to other embodiments of the present disclosure. As shown in FIG. 6, on the basis of the control method of Embodiment 3, the method further includes the following steps.

Control the fourth valve to open.

Next, get the temperature of the working module of the inverter. If the temperature of the working module of the frequency converter is greater than the fourth preset temperature T4, for example, the working module temperature of the frequency converter Max(t1, t2, t3) is greater than T4 (Max(t1, t2, t3) represents the operation of the frequency converter obtained three times The module temperature value is the maximum value), indicating that the temperature of the working module of the inverter is high at this time, and it needs to be cooled as soon as possible. When the fourth valve is opened, the refrigerant path is divided into two paths, and the temperature of the refrigerant flowing out of the bypass branch is higher than the temperature of the refrigerant flowing out of the second cooling branch. After the two temperatures are neutralized, the temperature of the refrigerant finally flowing through the working module of the frequency converter can be increased, thereby reducing the cooling speed of the working module of the frequency converter. Therefore, in order to ensure that the temperature is lowered as soon as possible, the fourth valve should be controlled to close at this time to keep the temperature lowering speed of the working module of the frequency converter unchanged.

Next, after controlling the closing of the fourth valve, obtain the temperature of the working module of the frequency converter and the third difference ΔT3 of the air temperature between the case of the frequency converter and the working module. If less than the third difference △ T3 equal to the fourth preset difference △ T4 _{is provided,} e.g., a fourth _set preset difference △ T4 = 3 ℃, the inverter and inverter casing temperature operating module and the operating module The difference between the air temperature is less than or equal to 3°C (in other embodiments, it can also be 4, 5, 8, 10, 15, etc., which can be set by those skilled in the art according to the actual situation), indicating the temperature of the inverter working module The air temperature difference between the inverter cabinet and the working module is small, and condensation will not occur. At this time, it is determined whether the temperature of the working module of the frequency converter is less than or equal to the fifth preset temperature T5. For example, determine whether the temperature Min(t4, t5, t6) of the inverter working module is less than or equal to T5 ((Min(t4, t5, t6) represents the minimum value of the inverter working module temperature obtained three times). If yes, It indicates that the temperature of the working module of the frequency converter is also reduced to a certain range at this time, then the fourth valve is controlled to open to reduce the cooling speed of the working module of the frequency converter. If not, it indicates that the temperature of the working module of the frequency converter is still high. the fourth control valve remains closed, to maintain the cooling rate of the drive operation of the module if the third difference is greater than the fourth preset difference △ T3 _provided △ T4, the fourth control valve is closed. when the third difference △ T3 greater than the fourth preset value is a difference △ T4 _set, indicates that the air temperature difference between the temperature in the frequency converter modules and inverter modules work with the larger box, condensation may occur, the first to be controlled The four valves are closed to maintain the cooling speed of the working module of the inverter, so as to reduce the temperature as soon as possible, so as to prevent the temperature difference between the working module of the inverter and the air temperature between the inverter cabinet and the working module from increasing. In this embodiment, T4 is greater than T5, The fourth valve is arranged on the bypass branch, and its initial state is open.

In this embodiment, according to the difference between the temperature of the inverter working module and the air temperature between the inverter cabinet and the working module, and the temperature of the inverter working module, it is controlled whether the fourth valve is opened, and then the inverter working module is controlled to cool down. speed. This can reduce the cooling speed of the inverter working module when the difference between the temperature of the inverter working module and the air temperature between the inverter cabinet and the working module is small. When the difference between the temperature of the working module of the inverter and the air temperature between the inverter cabinet and the working module is large, or the temperature of the working module of the inverter is high, the fourth valve is closed to ensure the cooling speed. Therefore, this embodiment can effectively prevent the temperature difference between the inverter working module and the inverter cabinet from being too large, and further prevent condensation.

Example 7

Fig. 7 is a flowchart of a cooling method of a frequency converter according to other embodiments of the present disclosure. As shown in FIG. 7, based on the control method of Embodiment 3, the method further includes the following steps.

Control the fifth valve to open.

Next, get the evaporation temperature of the air conditioning system. If the evaporating temperature of the air conditioning system is less than or equal to the sixth preset temperature T6 within the second preset time, for example, the evaporating temperature of the air conditioning system is less than or equal to T6 within 10 consecutive seconds, it means that the amount of refrigerant participating in the refrigeration cycle in the air conditioning system is insufficient , The fifth valve is controlled to close, so that more refrigerant participates in the refrigeration cycle.

Next, after controlling the fifth valve to close, continue to obtain the temperature of the inverter working module, the air temperature between the inverter cabinet and the working module, and the evaporation temperature of the air conditioning system. If the temperature of the working module of the inverter is greater than or equal to the seventh preset temperature T7, the air temperature between the inverter cabinet and the working module is greater than or equal to the eighth preset temperature T8, and the evaporation temperature of the air conditioning system is greater than The ninth preset temperature T9, for example, the temperature of the inverter working module is greater than or equal to T7, the air temperature between the inverter cabinet and the working module is greater than or equal to T8, the evaporation temperature of the air conditioning system is greater than T9, and any one of the conditions is true , Indicating that the temperature of the working module of the inverter or the temperature of the air between the inverter box and the working module is too high, or the amount of refrigerant involved in the refrigeration cycle inside the air conditioner is sufficient, then the fifth valve is controlled to open to increase the frequency conversion The cooling speed of the inverter working module and the inverter cabinet. Otherwise, control the fifth valve to close. In this embodiment, the fifth valve is set on the bypass outlet, and its initial state is open. The T6 is smaller than T9. The temperature of the working module of the frequency converter and the temperature of the air between the case of the frequency converter and the working module are the maximum values obtained after obtaining the temperature value for multiple times.

In this embodiment, the opening and closing of the fifth valve is controlled according to the evaporation temperature of the air conditioning system, the temperature of the working module of the inverter, and the temperature of the air between the inverter box and the working module, which can realize the participation in refrigeration in the air conditioning system. When the amount of circulating refrigerant is small, the cooling speed of the inverter working module and the inverter cabinet is reduced to use more refrigerant for the refrigeration cycle. When the air temperature between the inverter working module and the inverter cabinet and the working module is too high, or the amount of refrigerant involved in the refrigeration cycle in the air conditioning system is large, more refrigerant is used for the inverter working module and The frequency converter box realizes rapid temperature drop.

Example 8

The present disclosure also provides a non-transitory computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the above method is realized, and the temperature of the inverter working module and the inverter cabinet is uniformly cooled. It avoids the problem of inverter condensation caused by excessive temperature difference due to partial cooling, and improves the reliability and service life of air-conditioning equipment.

Through the description of the above implementation manners, those skilled in the art can clearly understand that each implementation manner can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution essentially or the part that contributes to the known technology of the inventor of the present disclosure 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 disc, etc., and includes several instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute each Examples or methods described in some parts of the examples.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, but not to limit them. Although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or equivalently replace some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

A cooling system for frequency converters, including:

The inlet pipeline is connected to the outlet of the condenser and is used to introduce the refrigerant discharged from the condenser;

The first cooling branch has one end connected to the inlet pipeline, and the other end passes through the air between the inverter box and the working module, and communicates with the outlet pipeline for communicating with the air between the inverter box and the working module. Heat exchange, thereby reducing the temperature of the inverter cabinet;

The second cooling branch has one end connected to the inlet pipeline, and the other end passes through the frequency converter working module and communicates with the outlet pipeline for heat exchange with the frequency converter working module, thereby reducing the temperature of the frequency converter working module; with

The outlet pipeline communicates with the inlet of the evaporator and is used to discharge the refrigerant in the first cooling branch and the second cooling branch.
The cooling system according to claim 1, further comprising:

The first valve is arranged on the first cooling branch and is used to control whether the refrigerant flows through the first cooling branch by opening or closing.
The cooling system according to claim 1, further comprising:

The second valve is arranged on the second cooling branch and is used to control whether the refrigerant flows through the second cooling branch by opening or closing.
The cooling system according to claim 1, wherein a third valve is provided on the second cooling branch for controlling the flow rate of the refrigerant in the second cooling branch by adjusting the opening degree.
The cooling system according to claim 1, further comprising:

The bypass branch is connected in parallel with the second cooling branch, and a fourth valve is provided on the bypass branch to control whether the refrigerant flows through the bypass branch by opening or closing.
The cooling system according to claim 1, wherein:

The outlet pipeline is provided with a capillary tube and a bypass outlet arranged in parallel with the capillary tube, and

A fifth valve is provided on the bypass outlet to control whether the refrigerant flowing out of the first cooling branch and the second cooling branch flows through the bypass outlet by opening or closing.
An air conditioner, comprising the cooling system of the frequency converter according to any one of claims 1-6.
A method for cooling an inverter, applied to the cooling system for an inverter according to any one of claims 1-6, the method comprising:

Obtain the air temperature between the inverter cabinet and the working module, the outside air temperature of the inverter cabinet, and the operating status of the compressor;

Controlling the opening or closing of the first valve according to a first preset strategy according to the air temperature between the inverter box and the working module and the temperature of the air outside the inverter box;

Controlling the opening or closing of the second valve according to the second preset strategy according to the operating state of the compressor;

Wherein, the first valve is arranged on the first cooling branch, the second valve is arranged on the second cooling branch, and the initial states of the first valve and the second valve are open.
The method according to claim 8, wherein controlling the opening or closing of the first valve according to the first preset strategy comprises:

Calculate the first difference ΔT1 between the air temperature between the inverter cabinet and the working module and the outside air temperature of the inverter cabinet;

If the first difference is greater than a first predetermined difference value △ T1 provided △ T1, the first control valve remains open;

If the first difference is less than or equal to △ T1 first predetermined set difference △ T1, it is determined that the air temperature between the drive housing and the operating module less than or equal the first preset temperature T1 is satisfied, If not, control the first valve to keep open; if yes, control the first valve to close; and

After the first valve is controlled to close, if the air temperature between the inverter box and the working module is greater than the second preset temperature T2, the first valve is controlled to open.
The method according to claim 8, wherein controlling the opening or closing of the second valve according to the second preset strategy comprises:

If the operating state of the compressor is open, controlling the second valve to keep open;

If the operating state of the compressor is closed, the second valve is controlled to close after the air-conditioning compressor is closed for a first preset time.
The method according to claim 8, further comprising:

Obtain the temperature of the working module of the inverter, and the second difference △T2 between the temperature of the working module of the inverter and the target temperature;

Adjusting the opening degree of the third valve according to the third preset strategy according to the temperature of the working module of the frequency converter and the second difference ΔT2, so as to control the cooling speed of the working module of the frequency converter;

Wherein, the third valve is arranged on the second cooling branch.
The method according to claim 11, wherein adjusting the opening degree of the third valve according to a third preset strategy to control the cooling speed of the working module of the frequency converter comprises:

If the temperature of the working module of the frequency converter>the third preset temperature T3, and the second difference △T2>the second preset difference △T2 is set , control the opening of the third valve to decrease to increase Cooling rate

If the temperature of the working module of the frequency converter>the third preset temperature T3, and the second difference △T2≤the third preset difference △T3 is set , the opening of the third valve is controlled to increase to decrease Cooling rate

If the temperature of the inverter working module> the third preset temperature T3, and the third preset difference △T3 is set <the second difference △T2≤the second preset difference △T2 is set , control the third The opening of the valve remains unchanged;

If the temperature of the inverter working module is ≤ the third preset temperature T3, and the second difference △T2>the second preset difference △T2 is set , then the opening of the third valve is controlled to decrease to decrease Cooling rate

If the temperature of the working module of the frequency converter ≤ the third preset temperature T3, and the second difference △T2≤the third preset difference △T3 is set , the opening of the third valve is controlled to increase to increase Cooling rate

If the temperature of the inverter working module is ≤ the third preset temperature T3, and the third preset difference △T3 is set <the second difference △T2≤the second preset difference △T2 is set , then control The opening of the third valve remains unchanged,

Wherein, the initial state of the third valve is to open a preset number of steps.
The method according to claim 8, further comprising:

Obtain the temperature of the working module of the inverter;

If the temperature of the working module of the frequency converter is greater than the fourth preset temperature T4, control the fourth valve to close, and keep the temperature drop rate of the working module of the frequency converter unchanged;

After controlling the closing of the fourth valve, obtaining a third difference ΔT3 between the temperature of the working module of the frequency converter and the air temperature between the frequency converter box and the working module;

If less than the third difference △ T3 equal to the fourth preset difference △ T4 set, it is determined that the drive module temperature is less than or equal to the work of the fifth predetermined temperature T5 is established, if so, to control the fourth valve Open; if not, control the fourth valve to close;

If said third difference is greater than the fourth preset difference △ T3 provided △ T4, the fourth control valve closed;

Wherein, the fourth valve is arranged on the bypass branch, the initial state of the fourth valve is open, and the bypass branch is connected in parallel with the second cooling branch.
The method according to claim 8, further comprising:

Obtain the temperature of the inverter working module and the evaporation temperature of the air conditioning system;

If the evaporation temperature of the air conditioning system is less than the sixth preset temperature T6 within the second preset time, control the fifth valve to close;

If the temperature of the working module of the inverter is greater than or equal to the seventh preset temperature T7, the air temperature between the inverter cabinet and the working module is greater than or equal to the eighth preset temperature T8, and the evaporation temperature of the air conditioning system is greater than the ninth preset temperature. The temperature T9 is preset, and if any one of the conditions is satisfied, the fifth valve is controlled to open, so as to increase the cooling speed of the inverter working module and the inverter cabinet;

Wherein, the fifth valve is arranged on the bypass outlet, the initial state of the fifth valve is open, and the bypass outlet is arranged on the outlet pipeline.
The method according to claim 8, further comprising:

Obtain the working status of the compressor;

If the working state of the compressor is off, the first valve is controlled to close after the air conditioner compressor is closed for a first preset time.
A computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the method according to any one of claims 8 to 15 is realized.