Cooling Structure for Heat-Generating Component, Air Conditioner, and Control Method

Abstract

The present invention discloses a cooling structure for a heating component, an air conditioner and a control method, including: a heat dissipating component, provided with a refrigerant inlet and a refrigerant outlet, for cooling the heating component; an ejector branch, one end of which is connected to the exhaust side of the compressor, and the other end is connected to the refrigerant inlet, and an ejector solenoid valve and an ejector are provided on the ejector branch; a cooling refrigerant branch, one end of which is connected to the outlet side of the evaporator, and the other end is connected to the ejector. By setting the ejector branch and the cooling refrigerant branch, when the temperature is too high, the ejector solenoid valve can be opened, so that the high-temperature and high-pressure exhaust gas on the exhaust side of the compressor will pass through the ejector at high speed, automatically suck the low-temperature and low-pressure refrigerant from the evaporator through the cooling refrigerant branch, converge at the jet orifice of the ejector, and finally enter the heat dissipating component, improving the cooling effect and avoiding the situation that the heating component is prone to over-temperature protection shutdown under the condition of rapid unloading of the compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a cooling structure for a heating component, an air conditioner and a control method. Background Art

[0002] With the development of variable-frequency air conditioning technology, large-scale chillers on the market are gradually adopting variable-frequency technology instead of fixed-frequency technology. Common variable-frequency chillers are typically equipped with a variable-frequency compressor, shell-and-tube heat exchanger, inverter, finned heat exchanger, and electrical control box. As the drive for the variable-frequency compressor, the inverter typically consists of electronic components such as an inverter board and a rectifier board. During operation, the inverter generates significant heat, which can be harmful to the inverter if not properly cooled.

[0003] Common VFD cooling methods can be categorized into two types: One is to use a fan installed in the enclosure to force convection cooling of the components within the board; this method is relatively simple, but the heat dissipation effect is poor. The second method combines air conditioning circulation with a coil or small finned heat exchanger installed behind the VFD electrical component board, using low-temperature refrigerant to cool the VFD electrical components. This method has significant heat dissipation effects, but is prone to condensation due to overcooling, which can affect the normal operation of the electrical components. Therefore, a common cooling solution is to run a bypass pipe from the condenser to transport the condensed liquid refrigerant to the VFD heating module area for cooling. However, during VFD operation, the amount of refrigerant bypassing the VFD cannot be maintained constant due to the loading and unloading of the unit's compressor and the adjustment of the system's electronic expansion valve. If the compressor unloads rapidly and the electronic expansion valve opens widely, the VFD's cooling effect will be sharply reduced due to the reduction in the bypass refrigerant volume, causing the VFD to shut down due to overtemperature protection.

[0004] In response to the above issues, the patent of this invention proposes a cooling technology and temperature control method based on refrigerant cooling, which can effectively prevent the inverter from over-temperature protection due to unstable adjustment of the refrigerant system. Summary of the Invention

[0005] In order to solve the technical problem of over-temperature protection of the inverter caused by unstable regulation of the refrigerant system in the above-mentioned prior art, the present invention proposes a cooling structure for heating components, an air conditioner and a control method.

[0006] The technical solution adopted in the present invention is:

[0007] The present invention proposes a heat-generating component cooling structure, comprising:

[0008] A heat sink, provided with a refrigerant inlet and a refrigerant outlet, for cooling the heating component;

[0009] The ejector branch, one end of which is connected to the exhaust side of the compressor and the other end is connected to the refrigerant inlet, and an ejector solenoid valve and an ejector are provided on the ejector branch;

[0010] The cooling refrigerant branch, one end of which is connected to the outlet side of the evaporator and the other end is connected to the ejector.

[0011] The present invention further includes:

[0012] The heat dissipation branch, one end of which is connected to the outlet side of the condenser and the other end branches into two pipelines, namely the second branch and the third branch, and both are connected to the refrigerant inlet. A cooling solenoid valve is provided on the second branch, a cooling throttle valve is provided on the third branch, and the ejector branch is connected to the second branch.

[0013] Further, the refrigerant outlet of the heat dissipation component is connected to the inlet side of the evaporator.

[0014] Preferably, the heat dissipation component is a fin heat exchanger.

[0015] The present invention also proposes an air conditioner, including the above-mentioned heating component cooling structure.

[0016] Further, the air conditioner includes: the compressor, the condenser, the system throttle valve and the evaporator which are connected in a circulating pipeline.

[0017] Further, the heating component is the frequency converter of the air conditioner.

[0018] The present invention also proposes a control method for an air conditioner, using the above-mentioned air conditioner, including the steps of:

[0019] Detecting the temperature of the heating component;

[0020] When the temperature of the heating component is higher than the fourth threshold, opening the cooling solenoid valve, opening the cooling throttle valve to the maximum opening degree, and opening the ejector solenoid valve, and closing the ejector solenoid valve until the temperature of the heating component is lower than the third threshold.

[0021] Further, when the temperature of the heating component is higher than the second threshold, controlling the cooling throttle valve to open to the maximum opening degree and opening the cooling solenoid valve.

[0022] When the cooling throttle valve is opened to the maximum opening degree and the cooling solenoid valve is opened, and the temperature of the heating component is reduced to be lower than the first threshold, closing the cooling solenoid valve and reducing the opening degree of the cooling throttle valve.

[0023] Compared with the prior art, by providing an ejector branch and a cooling refrigerant branch, the present invention can open the ejector solenoid valve when the temperature is too high, so that the high-temperature and high-pressure exhaust gas on the exhaust side of the compressor will pass through the ejector at high speed, automatically draw the low-temperature and low-pressure refrigerant from the evaporator through the cooling refrigerant branch, converge at the jet orifice of the ejector, and finally enter the heat sink, improving the cooling effect and avoiding the situation that the heating components are prone to over-temperature protection shutdown under the condition of rapid unloading of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] Figure 1 is a structural schematic diagram of an embodiment of the present invention;

[0026] Figure 2 is a flowchart of an embodiment of the present invention.

[0027] 1. Compressor; 2. Condenser; 3. System throttle valve; 4. Evaporator; 5. Cooling throttle valve; 6. Frequency converter; 7. Cooling solenoid valve; 8. Ejector solenoid valve; 9. Ejector; 11. Ejector branch; 12. Refrigerant cooling branch; 13. Heat dissipation branch; 14. Second branch; 15. Third branch. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] The principle and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0030] Common frequency converter cooling methods can be divided into two types: one is to set a fan on the box structure to perform forced convection heat dissipation on the components inside the board; this method is relatively simple, but the heat dissipation effect is poor. The second is to combine the cycle of the air conditioner, and a coil or a small fin heat exchanger is set behind the electrical component board of the frequency converter, and low-temperature refrigerant is used to cool the electrical components of the frequency converter. This method has obvious heat dissipation effect, but it is easy to generate condensation due to overcooling, affecting the normal operation of the electrical components. Therefore, a common cooling solution is to lead out a bypass pipe from the back of the condenser and transport the condensed liquid refrigerant to the heating module area of the frequency converter for cooling. However, during the operation of the frequency conversion unit, as the compressor of the unit loads and unloads and the electronic expansion valve in the system adjusts, the amount of refrigerant bypassed to the frequency converter cannot remain constant. Once the compressor quickly unloads and the opening of the electronic expansion valve is large, the cooling effect of the frequency converter will sharply decay due to the reduction of the bypass refrigerant amount, resulting in the over-temperature protection shutdown of the frequency converter. In view of the above problems, based on refrigerant cooling, the present invention proposes a cooling technology and a temperature control method that can effectively prevent the frequency converter from over-temperature protection caused by the unstable adjustment of the refrigerant system.

[0031] As Figure 1 shown, the present invention proposes a cooling structure for a heating component, which is specifically applied to an air conditioner and includes: a heat dissipation component, an ejector branch 11, and a cooling refrigerant branch. The heat dissipation component is directly attached to the heating component, so that the heat of the heating component can be directly conducted to the heat dissipation component; at the same time, the heat dissipation component is provided with a refrigerant inlet and a refrigerant outlet, and the refrigerant can flow through, and the heat on the heat dissipation component is taken away through refrigerant heat exchange, thereby cooling the heating component. One end of the ejector branch 11 is connected to the exhaust side of the air conditioner compressor 1 (it should be noted that the exhaust side, the outlet side, and the inlet side all refer to the pipe interfaces), and the other end is connected to the refrigerant inlet of the heat dissipation component. At the same time, an ejector 9 and an ejector solenoid valve 8 are provided on the ejector branch 11, and the ejector solenoid valve 8 is used to switch the ejector branch 11. One end of the cooling refrigerant branch is connected to the outlet side of the evaporator 4 of the air conditioner, specifically, it can be connected to the bottom of the evaporator 4, and the other end of the cooling refrigerant branch is connected to the suction end of the ejector 9. When the ejector solenoid valve 8 is opened, the high-temperature and high-pressure exhaust gas on the exhaust side of the compressor 1 will pass through the ejector 9 at high speed, automatically suck the low-temperature and low-pressure refrigerant from the evaporator 4 through the cooling refrigerant branch, converge at the jet orifice of the ejector 9, and finally enter the heat dissipation component, improving the cooling effect and avoiding the situation that the heating component is prone to over-temperature protection shutdown when the compressor quickly unloads.

[0032] Specifically, the cooling mechanism for the heating component of the present invention further includes a heat dissipation branch 13. One end of the heat dissipation branch 13 is connected to the outlet side of the air conditioner condenser 2, and the other end branches into two pipes, namely a second branch 14 and a third branch 15. Both the second branch 14 and the third branch 15 are connected to the refrigerant inlet. A cooling solenoid valve 7 is provided on the second branch 14, and a cooling throttle valve 5 is provided on the third branch 15. The other end of the above-mentioned ejector branch 11 can be directly connected to the second branch 14 to communicate with the refrigerant inlet of the heat dissipation component, saving the layout of the pipeline.

[0033] Specifically, the refrigerant outlet of the heat dissipation component is directly connected to the inlet side of the air conditioner evaporator 4 through a pipeline, and can be adjusted according to the type of the air conditioner.

[0034] In a preferred embodiment, the heat dissipation component is a fin heat exchanger, or a heat exchanger in the form of a coil, etc. The specific type is not limited, as long as it can circulate the refrigerant and cool the heating component, it is within the protection scope of the present invention.

[0035] The present invention also proposes an air conditioner, including the above-mentioned cooling structure for the heating component.

[0036] The air conditioner can specifically be a variable-frequency air conditioner, such as a variable-frequency chiller. The heating component is an inverter 6, and the heat dissipation component is used to cool the inverter 6. The air conditioner mainly includes: a compressor 1, a condenser 2, a system throttle valve 3, and an evaporator 4 that are connected in a circulating pipeline. The air conditioner also includes other necessary components, such as an electrical box, etc., which are not the focus of the present invention and will not be specifically described.

[0037] Preferably, the above-mentioned throttle valves are all electronic expansion valves.

[0038] The specific refrigerant flow direction of the air conditioner is described as follows:

[0039] The high-temperature and high-pressure refrigerant gas compressed by the compressor 1 becomes a normal-temperature and high-pressure refrigerant liquid after condensation in the condenser 2 and enters the liquid pipe, and then enters the main path and the auxiliary path respectively. In the main path, the refrigerant passes through the system throttle valve 3 and is throttled and then enters the evaporator 4 for heat exchange, and finally returns to the compressor 1 to complete the main path cycle. The auxiliary path is the heat dissipation branch 13. The liquid refrigerant passes through the cooling throttle valve 5 and is throttled to become a low-temperature two-phase state, and then enters the fin heat exchanger (i.e., the heat dissipation component) in the inverter 6. After heat exchange with the inverter 6, it returns to the main path side and is throttled and then reaches the inlet side of the evaporator 4 to complete the refrigerant cycle. The above is a detailed explanation of the cooling of the inverter 6 by the refrigerant during the normal operation of the unit.

[0040] As Figure 2 shown, the present invention also proposes a control method for the above-mentioned air conditioner, specifically including the steps of:

[0041] Real-time detect the temperature of the heating component, specifically the temperature of the inverter;

[0042] Four temperature thresholds that increase in sequence are preset, namely the first threshold, the second threshold, the third threshold, and the fourth threshold. The threshold can be a temperature range or a temperature value;

[0043] First, determine whether the temperature of the heat-generating component is higher than the second threshold. If so, control the cooling throttle valve to open to the maximum opening degree and open the cooling solenoid valve. If not, control the opening degree of the cooling throttle valve according to the original control logic of the air conditioner;

[0044] When the cooling throttle valve is opened to the maximum opening degree and the cooling solenoid valve is opened, when the temperature of the heat-generating component further rises above the fourth threshold, keep the cooling solenoid valve open, and keep the cooling throttle valve open to the maximum opening degree, and open the ejector solenoid valve until the temperature of the heat-generating component is lower than the third threshold, then close the ejector solenoid valve.

[0045] When the cooling throttle valve is opened to the maximum opening degree and the cooling solenoid valve is opened, when the temperature of the heat-generating component drops below the first threshold, then close the cooling solenoid valve, and control the opening degree of the cooling throttle valve according to the original control logic of the air conditioner.

[0046] The following is a specific description of the above method. Here, the heat-generating component is specifically described as the heat-generating module of the frequency converter below, the system throttle valve is described as the system electronic expansion valve, and the cooling throttle valve is described as the cooling electronic expansion valve. Specifically as follows:

[0047] When the refrigerant amount in the frequency converter cooling pipeline is insufficient due to external factors (such as compressor unloading, too large opening degree of the system electronic expansion valve, etc.), the heat-generating module in the frequency converter will have a significant attenuation in cooling effect, resulting in an increase in the detected temperature. When the temperature of the heat-generating module of the frequency converter rises to the second threshold TH2, the cooling electronic expansion valve immediately opens to the maximum opening degree, and at the same time the cooling solenoid valve opens, reducing the pressure drop on the bypass side and increasing the refrigerant flow rate in the bypass pipeline to enhance the heat exchange effect. When the module temperature drops to the first threshold TH1, the cooling solenoid valve closes, and then the cooling electronic expansion valve is adjusted conventionally.

[0048] Note: Taking the R134a refrigerant system as an example, it is recommended that TH2 be taken between 65 and 70 °C. The reasons are as follows: There are only two reasons for insufficient refrigerant for frequency converter cooling: 1. The refrigerant amount in the main pipeline system decreases (usually caused by rapid compressor unloading); 2. The proportion of bypass refrigerant decreases (usually caused by too large opening degree of the system electronic expansion valve). Regardless of which reason, the condensation temperature in the system will decrease. The normal condensation temperature of the R134a refrigerant system is between 48 and 55 °C. Therefore, when the above situation occurs, the refrigerant condensation temperature in the system should be lower than 55 °C. It is recommended to maintain a heat exchange temperature difference of 10 to 15 °C between the refrigerant entering the frequency converter cooling and the heat-generating module of the frequency converter to ensure the heat exchange effect.

[0049] Note: Taking the R134a refrigerant system as an example, the recommended value of TH1 is between 55 and 60 °C. When the temperature of the inverter heating module is not higher than 60 °C, it is not recommended to turn on the cooling solenoid valve. Because at this time, the condensation temperature is generally high. Even if the cooling solenoid valve is turned on to increase the bypass refrigerant flow, due to the small heat exchange temperature difference, the cooling effect will be discounted. And if the bypass flow is too large, it will affect the state of the refrigerant after throttling and reduce the refrigeration capacity of the system.

[0050] When the temperature of the inverter heating module rises to the fourth threshold TH4, the ejector solenoid valve opens. Using the high-temperature and high-pressure exhaust gas, the high-speed air flow of the ejector sucks the low-temperature and low-pressure refrigerant from the evaporator. Finally, it converges with the exhaust gas at the jet orifice of the ejector and enters the refrigerant cooling branch of the inverter to compensate for the cooling effect of the inverter. When the module temperature is lower than the third threshold TH3, the ejector solenoid valve is closed.

[0051] Note: Taking the R134a refrigerant system as an example, the recommended value of TH4 is between 75 and 80 °C. Reason: Usually, the protection temperature of the inverter is set above 85 °C, and the value of TH4 needs to be 5 - 10 °C lower than the over-temperature protection value of the inverter.

[0052] Note: Taking the R134a refrigerant system as an example, the recommended value of TH3 is between 70 and 75 °C. When the temperature of the inverter is not close to the protection value, it is not recommended to turn on the ejector compensation cooling control. The ejector compensation cooling is to supplement part of the exhaust gas and the refrigerant in the evaporator into the inverter cooling circuit, so as to compensate for the cooling effect of the inverter. However, it may cause the evaporation temperature to decrease, resulting in the refrigeration capacity and energy efficiency of the system being affected. Therefore, the ejector compensation cooling is only turned on when making a trade-off between the system operation reliability and the energy efficiency, in order to reduce the impact of the inverter cooling on the operation of the whole system.

[0053] It should be noted that the terms used above are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0054] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary, and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

[0055] In the description of the present application, it should be understood that the orientation or positional relationship indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc. is generally based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation terms do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be construed as limiting the protection scope of the present application; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0056] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0057] In addition, it should be noted that the use of words such as "first", "second", etc. to limit components is only for the convenience of distinguishing the corresponding components. Without additional statement, the above words have no special meaning, and thus cannot be construed as limiting the protection scope of the present application.

[0058] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A cooling structure for a heating component, characterized in that, Comprising: A heat dissipation component, provided with a refrigerant inlet and a refrigerant outlet, for cooling the heat generating component; An ejector branch, one end connected to the exhaust side of the compressor, the other end connected to the refrigerant inlet, and an ejector solenoid valve and an ejector are provided on the ejector branch; A cooling refrigerant branch, one end connected to the outlet side of the evaporator, the other end connected to the ejector; A heat dissipation branch, one end connected to the outlet side of the condenser, the other end branched into a second branch and a third branch and both connected to the refrigerant inlet, a cooling solenoid valve is provided on the second branch, a cooling throttle valve is provided on the third branch, and the ejector branch is connected to the second branch.

2. The cooling structure for the heating component according to claim 1, wherein, The refrigerant outlet of the heat dissipation component is connected to the inlet side of the evaporator.

3. The cooling structure for the heat generating component according to claim 1, wherein, The heat dissipation component is a fin heat exchanger.

4. An air conditioner, characterized in that, Comprising the heat generating component cooling structure according to any one of claims 1 to 3.

5. The air conditioner according to claim 4, wherein The air conditioner comprises: the compressor, the condenser, the system throttle valve and the evaporator which are connected in a circulating pipeline.

6. The air conditioner according to claim 4, characterized in that, The heat generating component is an inverter of the air conditioner.

7. A control method for an air conditioner, characterized in that, Using the air conditioner according to any one of claims 4 to 6, comprising the steps of: Detecting the temperature of the heat generating component; When the temperature of the heat generating component is higher than a fourth threshold, keep the cooling solenoid valve open, keep the cooling throttle valve open to the maximum opening degree, and open the ejector solenoid valve until the temperature of the heat generating component is lower than a third threshold, then close the ejector solenoid valve.

8. The control method of the air conditioner according to claim 7, characterized in that, When the temperature of the heat generating component is higher than a second threshold, control the cooling throttle valve to open to the maximum opening degree and open the cooling solenoid valve.

9. The control method of the air conditioner according to claim 8, characterized in that, When the cooling throttle valve is opened to the maximum opening degree and the cooling solenoid valve is opened, and the temperature of the heat generating component is reduced to be lower than a first threshold, close the cooling solenoid valve and reduce the opening degree of the cooling throttle valve.

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