Refrigeration system, control method and machine room air conditioner for preventing cold pipe condensation during low-temperature start-up

Abstract

This invention provides a refrigeration system, control method, and computer room air conditioner to prevent condensation on cold pipes during low-temperature startup. The system includes a compressor, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger. The outdoor heat exchanger and the throttling device are connected via a first pipeline. The system also includes a second pipeline, at least a portion of which is connected in parallel with the first pipeline. The second pipeline is equipped with a first heat exchanger and a first control valve. The first heat exchanger dissipates heat and cools the controller. When the compressor is started at an outdoor ambient temperature lower than a first preset temperature, the first control valve can be closed to shut off heat exchange between the first heat exchanger and the controller. During normal operation of the refrigeration system, the first control valve can be opened to enable heat exchange between the first heat exchanger and the controller. This invention ensures effective heat dissipation for the controller and also addresses the problem of controller condensation during low-temperature startup, guaranteeing the normal and effective startup of the refrigeration system.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, specifically to a refrigeration system, control method, and computer room air conditioner that prevents condensation on cold pipes during low-temperature startup. Background Technology

[0002] For some industries, such as data center air conditioning, fixed-frequency models have been the primary standard for many years. In recent years, due to factors such as improved energy efficiency, frequency-inverter data center air conditioners have begun to be used. While overall energy efficiency has improved, this has brought the challenge of effectively dissipating heat from the inverter modules. Currently, liquid cooling is a very effective solution, but the need for data center air conditioners to maintain cooling operation at low temperatures leads to condensation issues on the controller, directly impacting system safety.

[0003] Because existing data center air conditioners suffer from condensation issues during low-temperature startup due to liquid cooling, which affects the lifespan of the air conditioning unit and threatens the operational safety of data center equipment, this invention researches and designs a refrigeration system, control method, and data center air conditioner to prevent condensation on cold pipes during low-temperature startup. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that when the controller of the computer room air conditioner adopts a liquid cooling solution during low-temperature cooling start-up, condensation occurs, which affects the life of the air conditioning unit and thus threatens the operational safety of the data center equipment. The present invention provides a cooling system, control method and computer room air conditioner that prevents condensation on the cold pipes during low-temperature start-up.

[0005] To address the above problems, the present invention provides a refrigeration system for preventing condensation on cold pipes during low-temperature startup, comprising:

[0006] The system includes a compressor, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger. The outdoor heat exchanger and the throttling device are connected via a first pipeline. The system also includes a second pipeline, which is connected in parallel with at least a portion of the first pipeline. The second pipeline is equipped with a first heat exchanger and a first control valve. The first heat exchanger can dissipate heat and cool the controller. When the compressor is started at an outdoor ambient temperature lower than a first preset temperature, the first control valve can be controlled to close, thereby shutting down heat exchange between the first heat exchanger and the controller. When the refrigeration system is operating normally, the first control valve can be controlled to open, thereby enabling heat exchange between the first heat exchanger and the controller.

[0007] In some implementations...

[0008] A second control valve is installed on a section of the first pipeline connected in parallel with the second pipeline. A refrigerant temperature sensing component is installed on the second pipeline. The refrigerant temperature sensing component can detect the temperature of the refrigerant in the second pipeline. When the detected refrigerant temperature in the second pipeline is higher than a second preset temperature, the first control valve is controlled to open, and the second control valve is controlled to open or close. When the detected refrigerant temperature in the second pipeline is lower than the second preset temperature, the first control valve is controlled to close, and the second control valve is controlled to open.

[0009] In some implementations...

[0010] The first heat exchanger is a variable frequency module liquid cooling plate, the controller includes a variable frequency module, the variable frequency module liquid cooling plate is connected to the variable frequency module to dissipate heat and cool the variable frequency module; the first control valve is a solenoid valve, the second control valve is a solenoid valve; the throttling device is an electronic expansion valve.

[0011] In some implementations...

[0012] The first pipeline includes a first pipe section connected in parallel with the second pipeline and a second pipe section located between the first pipe section and the throttling device;

[0013] A second heat exchanger is also provided on the second pipe section. The indoor heat exchanger is connected to the compressor through a third pipe. A portion of the third pipe passes through the second heat exchanger and exchanges heat with the refrigerant in the second pipe section that has passed through the second heat exchanger.

[0014] In some implementations...

[0015] The second heat exchanger is a plate heat exchanger.

[0016] In some implementations...

[0017] The first pipeline also includes a third pipeline located between the first pipeline segment and the outdoor heat exchanger. The cold pipe temperature sensing component is disposed on the second pipeline near the third pipeline segment relative to the first control valve. The first heat exchanger is disposed on the second pipeline near the first pipeline segment relative to the first control valve.

[0018] The present invention also provides a control method for a refrigeration system as described above for preventing condensation on cold pipes during low-temperature startup, comprising:

[0019] The testing steps include checking if the compressor is running and checking the outdoor ambient temperature T. 外环 ;

[0020] The judgment step is to determine the outdoor ambient temperature T. 外环With the first preset temperature T 低温限值 The relationship between them;

[0021] Control steps: When the compressor is first turned on and T is detected... 外环 ≤T 低温限值 When the first control valve is closed, the second control valve is opened.

[0022] In some implementations...

[0023] When the refrigeration system is operating normally or starting up:

[0024] The detection step also involves detecting the refrigerant temperature in the second pipeline using the cold pipe temperature sensing component;

[0025] The control steps include controlling the first control valve to open and the second control valve to open or close when the refrigerant temperature in the second pipeline is higher than the second preset temperature; and controlling the first control valve to close and the second control valve to open when the refrigerant temperature in the second pipeline is lower than the second preset temperature.

[0026] In some implementations...

[0027] In the control steps, the second preset temperature is the return air dew point temperature of the first heat exchanger; and when the compressor has been running for more than a preset time t1, and the refrigerant temperature T in the second pipeline... 冷管 When the temperature remains below the return air dew point for a preset time t2, the first control valve is closed and the second control valve is opened.

[0028] In some implementations...

[0029] The detection step can also detect the temperature T of the controller. 变频模块 ;

[0030] The judgment step determines T. 变频模块 With T 预警 The relationship between them;

[0031] The control step, when T 变频模块 ≥T 预警 When the time is right, the first control valve is opened and the second control valve is closed.

[0032] In some implementations...

[0033] The detection step can also detect the temperature T of the controller. 变频模块 ;

[0034] The judgment step determines T. 变频模块 With T 预警 The relationship between them;

[0035] The control steps are as follows: when the compressor is just turned on and T is detected... 外环 ≤T 低温限值 And simultaneously detected T 变频模块 ≥T 预警 At that time, the first control valve and the second control valve are intermittently switched on and off.

[0036] In some implementations...

[0037] The control step, during the intermittent switching opening of the first control valve and the second control valve, continues to detect T. 变频模块 And when T 变频模块 <T 预警 When T = -T0, the second control valve is opened and the first control valve is closed; when T = -T0, the second control valve is opened and the first control valve is closed. 变频模块 ≥T 预警 At that time, the first control valve and the second control valve continue to be intermittently switched on and off.

[0038] In some implementations...

[0039] T 预警 =T 保护 -δT, where T 保护 δT is the temperature protection value of the controller, and δT is a constant.

[0040] The present invention also provides a computer room air conditioner, which includes the aforementioned refrigeration system for preventing condensation on cold pipes during low-temperature startup.

[0041] The refrigeration system, control method, and computer room air conditioner provided by this invention for preventing condensation on cold pipes during low-temperature startup have the following beneficial effects:

[0042] 1. This invention connects the throttling device to the outdoor heat exchanger via a first pipeline. A second pipeline connected in parallel to the first pipeline, with a first heat exchanger installed on the second pipeline, allows for heat exchange with and cooling of the controller. Furthermore, this invention can close the first control valve when the compressor starts at an outdoor ambient temperature lower than a first preset temperature, effectively preventing condensation on the cold pipe (second pipeline) and / or the controller during low-temperature refrigeration startup. This solves the condensation problem during low-temperature refrigeration startup. During normal operation, the first control valve is opened to effectively cool and dissipate heat from the controller, ensuring effective heat dissipation and addressing the condensation problem during low-temperature startup, thus guaranteeing the normal and effective startup of the refrigeration system.

[0043] 2. This invention also provides effective control of the pipe section connected in parallel with the second pipe on the first pipe by installing a second control valve. Furthermore, a cold pipe temperature sensing component installed on the second pipe effectively detects the temperature of the refrigerant in the second pipe. When the refrigerant temperature in the second pipe is lower than a second preset temperature, the first control valve is closed and the second control valve is opened, further preventing condensation on the cold pipe and / or controller due to excessively low refrigerant temperature during startup or normal operation, ensuring the normal and effective operation or startup of the refrigeration system. Conversely, when the refrigerant temperature in the second pipe is higher than the second preset temperature, the first control valve is opened, and the second control valve is opened or closed, effectively utilizing the second pipe and the first heat exchanger to dissipate heat and cool the controller, ensuring its normal operation while preventing condensation.

[0044] 3. The present invention also avoids the situation where the refrigerant temperature is too low and the controller condenses further when the second pipeline and the first heat exchanger are connected in parallel before the throttling device (i.e., between the throttling device and the outdoor heat exchanger). Furthermore, the present invention also provides a second heat exchanger on the second section of the first pipeline and exchanges heat between the third pipeline between the indoor heat exchanger and the compressor and the second section at the second heat exchanger. This further cools the refrigerant in the second section, thereby increasing the subcooling and effectively compensating for the subcooling lost by the liquid cooling pipeline in heat dissipating the controller. This improves the overall energy efficiency of the unit and also ensures that the whole system has a certain suction superheat.

[0045] 4. The control method for preventing condensation on the cooling pipes during low-temperature refrigeration startup of the present invention adds return air dew point temperature, liquid cooling pipe inlet temperature, and controller temperature (inverter module temperature detection device) and control logic. This effectively ensures that condensation does not occur on the controller and cooling pipes during low-temperature refrigeration startup, thus preventing disruption to normal startup. It also ensures that the refrigerant temperature on the cooling pipes does not drop too low during normal system operation, preventing condensation on the cooling pipes and / or controller and affecting normal operation. Furthermore, it incorporates a controller temperature condition: if the controller temperature is too high and exceeds the warning temperature, the first control valve opens and the second control valve closes to fully dissipate heat and cool the controller. If the controller temperature is below the warning temperature, the second control valve opens, and the first control valve can also be opened or closed simultaneously. This ensures that the refrigeration system can operate while simultaneously dissipating heat and cooling the controller. Moreover, the present invention can simultaneously satisfy T... 外环 ≤T 低温限值 and T 变频模块 ≥T 预警The system intermittently switches the opening of the first and second control valves, allowing for the evaporation of small amounts of condensate by intermittently switching the flow path of the cold plate and the bypass solenoid valve. Specifically, when the first control valve is open and the second control valve is closed, the controller's heat is used to heat the cold air in the cold pipe, thereby cooling the controller. When the first control valve is closed and the second control valve is open, the controller's heat is used to evaporate the condensate on the cold pipe. This method effectively and completely evaporates the condensate, making reasonable use of heat to evaporate the condensate and preventing condensation from appearing in the system. This ensures the normal operation of the controller while also preventing condensation. Attached Figure Description

[0046] Figure 1 This is a system structure diagram of the refrigeration system for preventing condensation on cold pipes during low-temperature startup, as described in this invention.

[0047] Figure 2 This is a control flowchart of the refrigeration system for preventing condensation on cold pipes during low-temperature startup, as described in this invention.

[0048] The attached figures are labeled as follows:

[0049] 1. Compressor; 2. Outdoor heat exchanger; 3. Throttling device; 4. Indoor heat exchanger; 5. First heat exchanger; 6. First control valve; 7. Second control valve; 8. Cold pipe temperature sensing component; 9. Second heat exchanger; 101. First pipeline; 102. Second pipeline; 103. Third pipeline; 104. First pipe section; 105. Second pipe section; 106. Third pipe section; 200. Cold plate heat dissipation section. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0052] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0053] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0054] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0055] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0056] like Figure 1As shown, the present invention provides a refrigeration system for preventing condensation on cold pipes during low-temperature refrigeration startup (here, "low temperature" refers to the operating condition when the outdoor ambient temperature is lower than a first preset temperature), which includes:

[0057] The system comprises a compressor 1, an outdoor heat exchanger 2, a throttling device 3, and an indoor heat exchanger 4. The outdoor heat exchanger 2 and the throttling device 3 are connected via a first pipeline 101. The system also includes a second pipeline 102, which is connected in parallel with at least a portion of the first pipeline 101. The second pipeline 102 is equipped with a first heat exchanger 5 and a first control valve 6. The first heat exchanger 5 can dissipate heat and cool the controller. When the compressor is started at an outdoor ambient temperature lower than a first preset temperature, the first control valve 6 can be controlled to close, thereby shutting down the heat exchange between the first heat exchanger 5 and the controller. When the refrigeration system is operating normally, the first control valve 6 can be controlled to open, thereby enabling the heat exchange between the first heat exchanger 5 and the controller.

[0058] This invention connects a throttling device to an outdoor heat exchanger via a first pipeline. A second pipeline connected in parallel to the first pipeline, with a first heat exchanger installed on it, allows for heat exchange with and cooling of the controller. Furthermore, this invention can close the first control valve when the compressor starts at an outdoor ambient temperature lower than a first preset temperature, effectively preventing condensation on the cold pipe (second pipeline) and / or the controller during low-temperature cooling startup. This solves the condensation problem during low-temperature cooling startup. During normal operation, the first control valve is opened to effectively cool and dissipate heat from the controller, ensuring effective heat dissipation and addressing the condensation problem during low-temperature startup, thus guaranteeing the normal and effective startup of the refrigeration system.

[0059] This invention ensures that the controller frequency converter module can still be effectively cooled under extreme operating conditions through a reasonable system layout scheme and an effective control scheme, while also taking into account the reliability of the unit operation.

[0060] Traditional liquid cooling solutions for controllers cause condensation during low-temperature startup because the system hasn't yet circulated enough to create a pressure and temperature difference. The controller directly dissipates heat from the outdoor low-temperature refrigerant. While the controller cools during operation, the liquid cooling pipes are in close contact with the controller for heat exchange, so the condensation generated during startup typically remains on the control board. Over time, this increases the risk of the controller short-circuiting and burning out.

[0061] This invention primarily addresses low-temperature startup by using a solenoid valve to delay the connection of the liquid cooling pipeline, thus preventing immediate condensation on the controller. Simultaneously, it ensures refrigerant circulation in the liquid cooling pipeline when the inverter module temperature reaches a warning value, allowing for timely heat dissipation and ensuring stable and reliable operation of the entire unit.

[0062] In some implementations...

[0063] A second control valve 7 is installed on a section of the first pipeline 101 connected in parallel with the second pipeline 102. A refrigerant temperature sensing component 8 is installed on the second pipeline 102. The refrigerant temperature sensing component 8 can detect the temperature of the refrigerant in the second pipeline 102. When the detected temperature of the refrigerant in the second pipeline 102 is higher than a second preset temperature, the first control valve 6 is controlled to open, and the second control valve 7 is controlled to open or close. When the detected temperature of the refrigerant in the second pipeline 102 is lower than the second preset temperature, the first control valve 6 is controlled to close, and the second control valve 7 is controlled to open.

[0064] The present invention further enables effective control of the pipe section connected in parallel with the second pipe on the first pipe by installing a second control valve. Additionally, a cold pipe temperature sensing component installed on the second pipe effectively detects the temperature of the refrigerant in the second pipe. Furthermore, when the refrigerant temperature in the second pipe is lower than a second preset temperature, the first control valve is closed and the second control valve is opened, further effectively preventing condensation on the cold pipe and / or controller due to excessively low refrigerant temperature during startup or normal operation, ensuring the normal and effective operation or startup of the refrigeration system. Conversely, when the refrigerant temperature in the second pipe is higher than the second preset temperature, the first control valve is opened, and the second control valve is opened or closed, effectively utilizing the second pipe and the first heat exchanger to dissipate heat and cool the controller, ensuring its normal operation while simultaneously preventing condensation.

[0065] In some implementations...

[0066] The first heat exchanger 5 is a variable frequency module liquid cooling plate, the controller includes a variable frequency module, the variable frequency module liquid cooling plate is connected to the variable frequency module to dissipate heat and cool the variable frequency module; the first control valve 6 is a solenoid valve, the second control valve 7 is a solenoid valve; the throttling device 3 is an electronic expansion valve.

[0067] This is the preferred structural form of the first heat exchanger of the present invention, and the preferred structural form of the controller, namely, the contact between the liquid cooling plate of the frequency converter module and the frequency converter module can effectively dissipate heat; the first and second control valves of the present invention are both preferably solenoid valves, which are convenient for effective control of the first and second pipelines, and the throttling device is preferably an electronic expansion valve that can perform throttling and pressure reduction.

[0068] The specific system implementation of the present invention is as follows:

[0069] This invention preferably uses a single-cooling air conditioner for the computer room, employing a highly efficient and reliable variable frequency module cooling solution to ensure the reliability of the entire unit under extreme operating conditions.

[0070] The main cooling circuit of this invention consists of a compressor, an outdoor heat exchanger, a first heat exchanger (preferably a liquid-cooled plate (more preferably an IPM heat dissipation module)), a fluorine filter, a plate heat exchanger, an electronic expansion valve, an indoor heat exchanger, high and low pressure switches, sensors, and various temperature sensors and solenoid valves.

[0071] The liquid cooling plate branch is connected in series with a first control valve 6 and an additional cold pipe temperature sensing bulb; the liquid cooling plate branch is connected in parallel with a flow path connected to a second control valve 7.

[0072] The main purpose of the second control valve 7 is to open under low outdoor temperature conditions. This prevents the outdoor low-temperature refrigerant, which has not yet circulated after the compressor is turned on, from being directly drawn into the liquid cooling plate, causing condensation on the liquid cooling plate and remaining there for a long time (it takes at least ten minutes for the system temperature and pressure to build up. When the unit is first turned on, the temperature of the refrigerant returning from the outside is still the outdoor ambient temperature. In low outdoor conditions, this temperature needs to gradually rise from below zero. Although the outdoor side does release heat after the refrigeration cycle is established, the outdoor refrigerant temperature does not rise that quickly, so the temperature of the liquid cooling plate is still very low when the unit is first turned on), which in turn compromises the reliability of the liquid cooling controller.

[0073] The main purpose of the first control valve 6 is to open it and dissipate heat from the liquid-cooled sensing bulb when the temperature reaches above the return air dew point temperature in the same branch (the refrigerant absorbs heat on the liquid-cooled plate to cool the IPM module. This process involves medium-temperature refrigerant dissipating heat from the high-temperature IPM module; the condensation process still occurs in the outdoor unit heat exchanger). After passing through a refrigerant filter to remove impurities, and then through a plate heat exchanger to further reduce the outlet temperature, the liquid phase composition is ensured to be high before entering the expansion valve. After passing through an electronic expansion valve for throttling, and entering the indoor heat exchanger to cool and dehumidify the equipment in the computer room, it exchanges heat with the high-temperature liquid refrigerant that entered the plate heat exchanger. This ensures the compressor's suction superheat, and finally, the refrigerant is drawn into the compressor to complete the entire refrigeration cycle.

[0074] In some implementations...

[0075] The first pipeline 101 includes a first pipe section 104 connected in parallel with the second pipeline 102 and a second pipe section 105 located between the first pipe section 104 and the throttling device 3;

[0076] A second heat exchanger 9 is also provided on the second pipe section 105. The indoor heat exchanger 4 is connected to the compressor 1 through a third pipe 103. A portion of the third pipe 103 passes through the second heat exchanger 9 and exchanges heat with the refrigerant in the second pipe section 105 that passes through the second heat exchanger 9.

[0077] This invention also avoids the situation where the refrigerant temperature is too low and the controller condenses further due to the placement of the second pipeline and the first heat exchanger in parallel before the throttling device (i.e., between the throttling device and the outdoor heat exchanger). Furthermore, by setting the second heat exchanger on the second section of the first pipeline and exchanging heat between the third pipeline between the indoor heat exchanger and the compressor and the second section at the second heat exchanger, the refrigerant in the second section is further cooled, thereby increasing the subcooling and effectively compensating for the subcooling lost by the liquid cooling pipeline in dissipating heat to the controller, thus improving the overall energy efficiency. At the same time, it can also ensure that the whole system has a certain suction superheat.

[0078] In some implementations...

[0079] The second heat exchanger 9 is a plate heat exchanger.

[0080] This is a preferred structural form of the second heat exchanger of the present invention. The plate heat exchanger can exchange heat between the refrigerant entering the third pipeline from the outlet of the indoor heat exchanger and the refrigerant on the second section of the first pipeline, thereby cooling the refrigerant in the second section and enhancing its subcooling.

[0081] The additional plate heat exchanger in this invention is mainly due to the fact that after the refrigerant exits the condenser (or the outdoor heat exchanger during refrigeration), it still needs to dissipate heat to the cold plate, which leads to an increase in temperature and insufficient subcooling, and even the generation of a certain amount of flash gas. In order to ensure that the system has sufficient subcooling before entering the electronic expansion valve, a plate heat exchanger is added here for further precooling.

[0082] In some implementations...

[0083] The first pipeline 101 also includes a third pipeline 106 located between the first pipeline segment 104 and the outdoor heat exchanger 2. The cold pipe temperature sensing component 8 is disposed on the second pipeline 102 near the third pipeline segment 106, relative to the first control valve 6. The first heat exchanger 5 is disposed on the second pipeline 102 near the first pipeline segment 104, relative to the first control valve 6.

[0084] This is the preferred placement of the first control valve and the cold pipe temperature sensing component in this invention. Positioning the first control valve (solenoid valve) behind the cold pipe temperature sensing component (cold pipe temperature sensor) ensures that the cold pipe temperature sensor accurately reflects the refrigerant temperature during system operation and accurately reflects whether condensation will occur at locations prone to condensation on the controller, ensuring T... 冷管 The comparison with the return air dew point temperature is accurate and effective; and by placing the first control valve (solenoid valve) in front of the first heat exchanger, it is ensured that the operation of the solenoid valve to block the flow path is effective and timely, thus guaranteeing the timeliness and effectiveness of the control pipeline.

[0085] like Figure 2 As shown, the present invention also provides a control method for a refrigeration system to prevent condensation on cold pipes during low-temperature startup, as described above, comprising:

[0086] The testing steps include checking if the compressor is running and checking the outdoor ambient temperature T. 外环 ;

[0087] The judgment step is to determine the outdoor ambient temperature T. 外环 With the first preset temperature T 低温限值 The relationship between them;

[0088] Control steps: When the compressor is first turned on and T is detected... 外环 ≤T 低温限值 When the first control valve 6 is closed, the second control valve 7 is opened.

[0089] This invention can control the first control valve to close when the compressor is started at an outdoor ambient temperature lower than a first preset temperature, thereby effectively avoiding and preventing condensation on the cold pipe (second pipe) and / or controller caused by refrigerant passing through during low-temperature refrigeration startup. This solves the problem of condensation during low-temperature refrigeration startup. Furthermore, during normal operation, the first control valve is opened to effectively cool and dissipate heat from the controller, ensuring effective heat dissipation for the controller and also addressing the issue of controller condensation during low-temperature startup, thus ensuring the normal and effective startup of the refrigeration system.

[0090] In some implementations...

[0091] When the refrigeration system is operating normally or starting up:

[0092] The detection step also involves detecting the refrigerant temperature in the second pipe 102 using the cold pipe temperature sensing component 8;

[0093] The control steps include controlling the first control valve 6 to open and the second control valve 7 to open or close when the refrigerant temperature in the second pipeline 102 is higher than the second preset temperature; and controlling the first control valve 6 to close and the second control valve 7 to open when the refrigerant temperature in the second pipeline 102 is lower than the second preset temperature.

[0094] This invention closes the first control valve and opens the second control valve when the refrigerant temperature in the second pipeline is lower than the second preset temperature, further effectively preventing condensation from occurring in the cold pipe and / or controller due to excessively low refrigerant temperature during startup or normal operation, thus ensuring the normal and effective operation or startup of the refrigeration system. Furthermore, when the refrigerant temperature in the second pipeline is higher than the second preset temperature, the first control valve is opened, and the second control valve is opened or closed, effectively utilizing the second pipeline and the first heat exchanger to dissipate heat and cool the controller, ensuring the normal operation of the controller while also preventing condensation.

[0095] The control scheme of the present invention:

[0096] When the unit is operating in cooling mode, the main flow direction of the refrigerant system is as follows:

[0097] 1) During low-temperature refrigeration startup, i.e., when the compressor has just started and the temperature is detected... 外环 ≤T 低温限值 hour:

[0098] 2) During refrigeration operation, if the cold plate temperature is lower than the return air dew point temperature, i.e., the compressor has been running for more than 5 minutes and the temperature of the cold plate (Tcold plate) is ≤ Tdew point (continuous monitoring for 3 minutes).

[0099] If either 1) or 2) is satisfied, the system will operate according to the following mode.

[0100] compressor Outdoor heat exchanger (copper tubes with aluminum fins) The second control valve 7 is open (the first control valve 6 is closed). Plate heat exchanger (for subcooling) Electronic expansion valve powered® indoor heat exchanger (copper tube with aluminum fins) Plate heat exchanger (for superheating) compressor.

[0101] 3) Under normal refrigeration operation conditions (except as described above):

[0102] compressor Outdoor heat exchanger (copper tubes with aluminum fins) First control valve 6 is open (second control valve 7 is closed). Plate heat exchanger (for subcooling) Electronic expansion valve powered on Indoor heat exchanger (copper tubes with aluminum fins) Plate heat exchanger (for superheating) compressor.

[0103] In some implementations...

[0104] In the control steps, the second preset temperature is the return air dew point temperature of the first heat exchanger 5; and when the compressor has been running for more than a preset time t1, and the refrigerant temperature T in the second pipeline 102 is... 冷管 When the temperature remains below the return air dew point for a preset time t2, the first control valve 6 is closed and the second control valve 7 is opened.

[0105] The present invention provides a control method for preventing condensation on the cooling pipes during low-temperature refrigeration startup. This method incorporates return air dew point temperature, liquid cooling pipe inlet temperature, and controller temperature (frequency converter module temperature detection device) and control logic. It can effectively ensure that the controller and cooling pipes do not condense during low-temperature refrigeration startup, thus preventing normal startup. It can also ensure that the refrigerant temperature on the cooling pipes does not become too low during normal system operation, thus preventing condensation on the cooling pipes and / or controller and affecting normal operation.

[0106] In some implementations...

[0107] The detection step can also detect the temperature T of the controller. 变频模块 ;

[0108] The judgment step determines T. 变频模块 With T 预警 The relationship between them;

[0109] The control step, when T 变频模块 ≥T 预警 At that time, the first control valve 6 is opened and the second control valve 7 is closed.

[0110] The present invention also incorporates a controller temperature condition. If the controller temperature is too high and exceeds the warning temperature, the first control valve opens and the second control valve closes to fully dissipate heat and cool the controller. When the controller temperature is lower than the warning temperature, the second control valve opens and the first control valve can also be opened or closed at the same time. That is, the refrigeration system can be maintained while the controller is being cooled.

[0111] In some implementations...

[0112] The detection step can also detect the temperature T of the controller. 变频模块 ;

[0113] The judgment step determines T. 变频模块 With T 预警 The relationship between them;

[0114] The control steps are as follows: when the compressor is just turned on and T is detected... 外环 ≤T 低温限值 And simultaneously detected T 变频模块 ≥T 预警 At that time, the first control valve 6 and the second control valve 7 are intermittently switched to open.

[0115] This invention can also simultaneously satisfy T 外环 ≤T 低温限值 and T 变频模块 ≥T 预警 The system intermittently switches the opening of the first and second control valves, allowing a small amount of condensation to evaporate by intermittently switching the flow path of the cold plate and bypass solenoid valve. Specifically, when the first control valve is open and the second control valve is closed, the controller's heat is used to heat the cold air in the cold pipe (at this time, the heat is preferentially exchanged with the cold air in the cold pipe, and the condensation is not heated and evaporated), thereby cooling the controller. When the first control valve is closed and the second control valve is open, the controller's heat is used to evaporate the condensation on the cold pipe. This method can more effectively and completely evaporate the condensation, making reasonable use of heat to evaporate the condensation, so that no condensation occurs in the system, ensuring the normal operation of the controller, while also preventing condensation.

[0116] In some implementations...

[0117] The control step, during the intermittent switching opening of the first control valve 6 and the second control valve 7, continues to detect T. 变频模块 And when T 变频模块 <T 预警 When T = -T0, the first control valve 6 is closed and the second control valve 7 is opened; when T = -T0, the first control valve 6 is closed and the second control valve 7 is opened. 变频模块 ≥T 预警 At that time, the first control valve 6 and the second control valve 7 continue to be intermittently switched open.

[0118] During normal refrigeration operation (i.e., the first control valve 6 is open and the second control valve 7 is closed), because the refrigeration cycle is continuous, the heat dissipation of the inverter module is directly carried away by the nearby cryogenic cold plate and is not used to evaporate condensate (condensation is caused by indoor ambient air coming into contact with the cryogenic liquid cooling plate and forming condensation on the liquid cooling plate). Therefore, a flow path switching scheme is needed to better ensure complete evaporation of condensate (while simultaneously satisfying the above T). 变频模块 ≥T 预警 and T 冷管 ≤T 露 In the case of)

[0119] As mentioned above, the cooling mode needs to be switched accordingly in the following situations.

[0120] ①、 T 变频模块 ≥T 预警 The following procedures should be followed:

[0121] The first control valve 6 is open, and the second control valve 7 is closed.

[0122] This situation is most likely to occur when the system is first booted up. If the above situation ① occurs simultaneously with ②T 冷管 ≤T 露 ;

[0123] When the above conditions occur simultaneously, and condensation will definitely form on the liquid cooling plate, after the unit has been running for a period of time, a small amount of condensation will be evaporated by intermittently switching the cooling plate and bypassing the solenoid valve flow path (after switching to the second control valve, the heat dissipation of the IPM can evaporate the condensation. After the condensation has evaporated, switch back to the first control valve to cool down the controller IPM module).

[0124] Intermittent control switching scheme for first control valve 6 and second control valve 7:

[0125] When both conditions ① and ② are met after power-on:

[0126] 4) First control valve 6 opens, second control valve 7 closes; when T 变频模块 <T 预警 When -T0 (T0 is generally assigned a value based on the system's operating conditions, typically 20~30℃) is used to switch as follows:

[0127] 5) First control valve 6 is closed, and second control valve 7 is open; when T 变频模块 ≥T 预警 When the time comes, switch to the running state as shown in 4) above.

[0128] 6) As above, 4) and 5) are performed once as one cycle. K cycles can be assigned according to the evaporation of condensate on the cold plate during actual use.

[0129] In some implementations...

[0130] T 预警 =T 保护 -δT, where T 保护 The temperature protection value of the controller (preferably including an IPM module) is δT, which is a constant.

[0131] The inverter module temperature can be automatically output via the circuit. The inverter module warning temperature provided here can be set to a value higher than the IPM module temperature protection value (T). 保护 Low δT, i.e., T 预警 =T 保护-δT, where δT is a correction value or margin, which is adjusted according to the actual situation to increase on-site adaptability.

[0132] The present invention also provides a computer room air conditioner, which includes the aforementioned refrigeration system for preventing condensation on cold pipes during low-temperature startup.

[0133] The key components and parameters of this invention are defined as follows:

[0134] 1. Key system operating components: compressor, indoor heat exchanger, first control valve 6, second control valve 7, electronic expansion valve, plate heat exchanger, liquid cooling plate;

[0135] 2. Indoor return air dew point temperature T 露 ;

[0136] 3. Cooling pipe temperature T 冷管 ;

[0137] 4. Real-time temperature T of IPM inverter module 变频模块 ;

[0138] 5. IPM inverter module protection temperature T 保护 ;

[0139] 6. IPM inverter module warning temperature T 预警 .

[0140] The inventive point of this invention lies in:

[0141] 1) Adjust the liquid cooling layout to a variable flow path via solenoid valves. By switching the system's operating flow path using solenoid valves, the controller can effectively dissipate heat while also addressing the condensation problem during low-temperature startup. Switch the solenoid valve flow path by detecting the liquid pipe temperature to avoid condensation on the cold plate. At the same time, provide a control scheme for periodically switching the solenoid valves to eliminate a small amount of condensation under harsh operating conditions.

[0142] 2) Placing the liquid-cooled piping before the throttling valve significantly reduces the likelihood of condensation during controller operation. Simultaneously, by arranging a plate heat exchanger after the cooling pipes and before the electronic expansion valve, the refrigerant before throttling is subcooled, offsetting the subcooling loss in the upstream liquid-cooled piping due to heat dissipation for the controller. This ensures the refrigerant has a certain degree of subcooling, thereby improving overall system efficiency. It also allows the entire system to maintain a certain level of suction superheat.

[0143] 3) Add detection devices and control logic for return air dew point temperature, liquid cooling pipe inlet temperature and frequency converter module temperature to ensure that both controller condensation and module temperature rise can be taken into account under extreme conditions; combine the IPM temperature and liquid cooling pipe temperature control scheme to achieve safe and reliable operation of the whole system.

[0144] The following technical problems were solved:

[0145] 1) When starting up with low-temperature cooling, the controller uses a liquid cooling solution, which causes condensation problems, affecting the lifespan of the air conditioning unit and thus threatening the operational safety of data center equipment (due to ineffective heat dissipation).

[0146] 2) The use of a pre-throttling liquid cooling heat dissipation scheme results in insufficient subcooling of the refrigerant before it enters the condenser, leading to a decrease in the overall energy efficiency of the unit.

[0147] 3) Effectively combine liquid cooling with IPM temperature to avoid IPM temperature being too high or too low (causing condensation around the device).

[0148] It has the following beneficial effects:

[0149] 1) Avoid IPM inverter module protection.

[0150] 2) Avoid condensation near the control panel.

[0151] 3) Improve overall energy efficiency.

[0152] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A refrigeration system for preventing condensation on cold pipes during low-temperature startup, characterized in that: include: The system comprises a compressor (1), an outdoor heat exchanger (2), a throttling device (3), and an indoor heat exchanger (4). The outdoor heat exchanger (2) and the throttling device (3) are connected by a first pipeline (101). The system also includes a second pipeline (102). At least a portion of the second pipeline (102) is connected in parallel with a section of the first pipeline (101). The second pipeline (102) is equipped with a first heat exchanger (5) and a first control valve (6). The first heat exchanger (5) can dissipate heat and cool the controller. When the compressor is started at an outdoor ambient temperature lower than a first preset temperature, the first control valve (6) can be controlled to close to shut off the heat exchange between the first heat exchanger (5) and the controller. When the refrigeration system is running normally, the first control valve (6) can be controlled to open to enable the heat exchange between the first heat exchanger (5) and the controller. A second control valve (7) is provided on a section of the first pipeline (101) connected in parallel with the second pipeline (102), and a cold pipe temperature sensing component (8) is provided on the second pipeline (102). The temperature of the refrigerant in the second pipeline (102) can be detected by the cold pipe temperature sensing component (8). The first pipeline (101) includes a first pipe section (104) connected in parallel with the second pipeline (102) and a second pipe section (105) located between the first pipe section (104) and the throttling device (3). A second heat exchanger (9) is also provided on the second pipe section (105). The indoor heat exchanger (4) is connected to the compressor (1) through a third pipe (103). A portion of the third pipe (103) passes through the second heat exchanger (9) and exchanges heat with the refrigerant in the second pipe section (105) that passes through the second heat exchanger (9).

2. The refrigeration system for preventing condensation on cold pipes during low-temperature startup as described in claim 1, characterized in that: When the refrigerant temperature in the second pipeline (102) is detected to be higher than the second preset temperature, the first control valve (6) is controlled to open and the second control valve (7) is controlled to open or close; when the refrigerant temperature in the second pipeline (102) is detected to be lower than the second preset temperature, the first control valve (6) is controlled to close and the second control valve (7) is controlled to open.

3. The refrigeration system for preventing condensation on cold pipes during low-temperature startup as described in claim 2, characterized in that: The first heat exchanger (5) is a variable frequency module liquid cooling plate, the controller includes a variable frequency module, the variable frequency module liquid cooling plate is connected to the variable frequency module to dissipate heat and cool the variable frequency module; the first control valve (6) is a solenoid valve, the second control valve (7) is a solenoid valve; the throttling device (3) is an electronic expansion valve.

4. The refrigeration system for preventing condensation on cold pipes during low-temperature startup as described in claim 1, characterized in that: The second heat exchanger (9) is a plate heat exchanger.

5. The refrigeration system for preventing condensation on cold pipes during low-temperature startup as described in claim 1, characterized in that: The first pipeline (101) also includes a third pipeline (106) located between the first pipeline segment (104) and the outdoor heat exchanger (2). The cold pipe temperature sensing component (8) is disposed on the second pipeline (102) and close to the third pipeline segment (106) relative to the first control valve (6). The first heat exchanger (5) is disposed on the second pipeline (102) and close to the first pipeline segment (104) relative to the first control valve (6).

6. A control method for a refrigeration system preventing condensation on cold pipes during low-temperature startup as described in any one of claims 2-5, characterized in that: include: The testing steps include checking if the compressor is running and checking the outdoor ambient temperature T. 外环 ; The judgment step is to determine the outdoor ambient temperature T. 外环 With the first preset temperature T 低温限值 The relationship between them; Control steps: When the compressor is first turned on and T is detected... 外环 ≤T 低温限值 When the first control valve (6) is closed, the second control valve (7) is opened.

7. The control method according to claim 6, characterized in that: When the refrigeration system is operating normally or starting up: The detection step also involves detecting the refrigerant temperature in the second pipeline (102) through the cold pipe temperature sensing component (8); The control steps are as follows: when the refrigerant temperature in the second pipeline (102) is higher than the second preset temperature, the first control valve (6) is controlled to open, and the second control valve (7) is controlled to open or close; when the refrigerant temperature in the second pipeline (102) is lower than the second preset temperature, the first control valve (6) is controlled to close, and the second control valve (7) is controlled to open.

8. The control method according to claim 7, characterized in that: In the control steps, the second preset temperature is the return air dew point temperature of the first heat exchanger (5); and when the compressor has been running for more than a preset time t1, and the refrigerant temperature T in the second pipeline (102) is... 冷管 When the temperature of the return air dew point is lower than the preset time t2, the first control valve (6) is closed and the second control valve (7) is opened.

9. The control method according to claim 8, characterized in that: The detection step can also detect the temperature T of the controller. 变频模块 ; The judgment step determines T. 变频模块 With T 预警 The relationship between T 预警 For early warning temperature; The control step, when T 变频模块 ≥T 预警 When the first control valve (6) is opened, the second control valve (7) is closed.

10. The control method according to claim 6, characterized in that: The detection step can also detect the temperature T of the controller. 变频模块 ; The judgment step determines T. 变频模块 With T 预警 The relationship between T 预警 For early warning temperature; The control steps are as follows: when the compressor is just turned on and T is detected... 外环 ≤T 低温限值 And simultaneously detected T 变频模块 ≥T 预警 At that time, the first control valve (6) and the second control valve (7) are intermittently switched to open.

11. The control method according to claim 10, characterized in that: The control step, during the intermittent switching opening of the first control valve (6) and the second control valve (7), continues to detect T. 变频模块 And when T 变频模块 <T 预警 When T = -T0, control the second control valve (7) to open and control the first control valve (6) to close; when T = -T0, control the second control valve (7) to open and control the first control valve (6) to close. 变频模块 ≥T 预警 At that time, the first control valve (6) and the second control valve (7) continue to be controlled to open intermittently, where T0 is a value assigned according to the system operation.

12. The control method according to claim 9, characterized in that: T 预警 =T 保护 -δT, where T 保护 δT is the temperature protection value of the controller, and δT is a constant.

13. A computer room air conditioner, characterized in that: The refrigeration system including any one of claims 1-5 for preventing condensation on the cold pipes during low-temperature startup.

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