Motor cooling device, motor cooling control method and device, and water chiller

Abstract

The present invention discloses a motor cooling device, a motor cooling control method and device, and a chiller. Among them, the motor cooling device is applied to a unit including at least two compressors, and includes: a first cooling pipeline connected between a liquid taking end and the motor cavity of the compressor, a first valve is arranged on the first cooling pipeline, and the opening degree of the first valve is controlled according to user operation; a second cooling pipeline connected between the liquid taking end and the motor cavity of the compressor, a second valve is arranged on the second cooling pipeline, and the opening degree of the second valve is automatically controlled according to the unit load condition. The present invention cools the motor through manual cooling adjustment and real-time automatic cooling adjustment, adapts to the operating conditions of different compressor heat generation amounts, ensures that the motor obtains sufficient cooling, reaches an appropriate motor operating winding temperature, and the combined control scheme based on the first cooling pipeline and the second cooling pipeline is flexible and adjustable, with wide adaptability, improving the stable reliability of motor operation.

Description

Technical Field

[0001] The present invention relates to the technical field of units, and in particular to a motor cooling device, a motor cooling control method and device, and a chiller. Background Art

[0002] At present, the most common chillers are generally single-machine single-stage or single-machine two-stage compression types, which are suitable for general air-conditioning conditions or general low-temperature heat pump conditions. With the vigorous promotion of coal-to-electricity conversion and the diversification of industrial needs in northern my country in recent years, users require not only conventional air-conditioning conditions for refrigeration, but also ultra-high temperature heat pump units that require high outlet water temperature heat pump conditions, which are becoming more and more common. Since single-machine single-stage or single-machine two-stage compression chillers cannot meet this demand, dual-machine single-stage compression or dual-machine two-stage compression chillers are used in the unit design, especially dual-machine two-stage compression chillers in series or parallel, which can make the chiller not only adapt to conventional air-conditioning conditions for refrigeration, but also meet the requirements of high outlet water temperature conditions.

[0003] Compared with conventional single-machine single-stage or single-machine two-stage compression chillers, dual-compressor chillers consume more power and generate more heat in the motor. In order to maintain a suitable internal temperature of the motor during operation, the motor must be sufficiently cooled to avoid shutdown due to overheating of the internal winding of the motor, or even burning of the motor. Chillers generally use liquid cooling to cool the motor, that is, using water or refrigerant as the cooling medium, configuring cooling pipelines and cooling throttling devices, and sending the cooling medium into the motor cavity of the compressor to cool the motor and take away the heat generated by the motor during operation. Among them, there is a direct relationship between the contact area between the motor heating components and the cooling medium, the flow rate of the cooling medium, and the capacity of the throttling device.

[0004] Conventional single compressor motor cooling solutions are generally simple or have low throttling cooling efficiency, which makes the operating reliability of the chiller insufficiently guaranteed. Compared with dual compressors, the motor cooling solution has a relatively small cooling capacity and is insufficient to cope with the motor cooling when dual compressors are running.

[0005] With respect to the problem of insufficient cooling of the motor of a dual compressor chiller in the prior art, no effective solution has been proposed yet. Summary of the invention

[0006] Embodiments of the present invention provide a motor cooling device, a motor cooling control method and device, and a chiller to at least solve the problem of insufficient motor cooling in a dual-compressor chiller in the prior art.

[0007] In order to solve the above technical problems, an embodiment of the present invention provides a motor cooling device, which is applied to a unit including at least two compressors, and includes:

[0008] The first cooling pipeline is connected between the liquid extraction end and the motor chamber of the compressor. A first valve is provided on the first cooling pipeline, and the opening degree of the first valve is controlled according to the user operation.

[0009] The second cooling pipeline is connected between the liquid extraction end and the motor chamber of the compressor. A second valve is provided on the second cooling pipeline, and the opening degree of the second valve is automatically controlled according to the unit load condition.

[0010] Optionally, a first throttling device is provided on the first cooling pipeline.

[0011] Optionally, the second cooling pipeline includes: at least two cooling branches; at least one cooling branch is connected to the motor chamber of each compressor, and the second valve is provided on each cooling branch.

[0012] Optionally, the second cooling pipeline further includes: a main cooling path; one end of the main cooling path is connected to the liquid extraction end, and the other end of the main cooling path is connected to each cooling branch; a second throttling device is provided on the main cooling path.

[0013] Optionally, if two or more cooling branches are connected to the motor chamber of the same compressor, the two or more cooling branches are respectively connected to different positions on the motor chamber of the compressor.

[0014] Optionally, the first cooling pipeline and the second cooling pipeline are connected to different positions on the motor chamber of the compressor.

[0015] An embodiment of the present invention further provides a method for controlling motor cooling. The method is implemented based on the motor cooling device described in the embodiment of the present invention, and the method includes:

[0016] Detect the unit load condition, and automatically control the second valve on the second cooling pipeline according to the unit load condition;

[0017] Receive the user operation, and control the first valve on the first cooling pipeline according to the user operation.

[0018] Optionally, automatically controlling the second valve on the second cooling pipeline according to the unit load condition includes:

[0019] Determine the starting condition of the compressor according to the unit load condition;

[0020] Control the second valve on the second cooling pipeline according to the unit load condition and the starting condition of the compressor.

[0021] Optionally, the second cooling pipeline includes: at least two cooling branches, at least one cooling branch is connected to the motor chamber of each compressor, and a second valve is provided on each cooling branch;

[0022] Controlling the second valve on the second cooling pipeline according to the unit load condition and the starting condition of the compressor includes:

[0023] Controlling the second valve on the cooling branch connected to the started compressor according to the unit load condition and the number of cooling branches connected to the started compressor;

[0024] Controlling the second valve on the cooling branch connected to the unstarted compressor to be closed.

[0025] Optionally, controlling the second valve on the cooling branch connected to the started compressor according to the unit load condition and the number of cooling branches connected to the started compressor includes:

[0026] If the started compressor is connected to one cooling branch, directly controlling the second valve on the cooling branch connected to the started compressor to be opened;

[0027] If the started compressor is connected to two or more cooling branches, controlling the second valves on the set number of cooling branches among the two or more cooling branches connected to the started compressor to be opened according to the interval where the unit load is located, wherein a corresponding relationship between the load interval and the set number is preset.

[0028] Optionally, controlling the second valve on the second cooling pipeline according to the unit load condition and the starting condition of the compressor includes: when a closing instruction for a started compressor is detected, controlling the second valve corresponding to the compressor in the opened state to be closed after a preset time delay.

[0029] Optionally, after detecting the unit load condition, it further includes: controlling the opening degree of the second throttling device on the second cooling pipeline according to the unit load condition.

[0030] An embodiment of the present invention further provides a motor cooling control device, which is used to implement the motor cooling control method described in the embodiment of the present invention. The motor cooling control device includes:

[0031] A first control module, configured to detect the unit load condition and automatically control the second valve on the second cooling pipeline according to the unit load condition;

[0032] A second control module, configured to receive user operations and control the first valve on the first cooling pipeline according to the user operations.

[0033] An embodiment of the present invention further provides a chiller, including: the motor cooling device described in the embodiment of the present invention, and the motor cooling control device described in the embodiment of the present invention.

[0034] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the motor cooling control method described in the embodiment of the present invention.

[0035] An embodiment of the present invention further provides an electronic device, including: one or more processors; a memory for storing one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the motor cooling control method described in the embodiment of the present invention.

[0036] Applying the technical solution of the present invention, a first cooling pipeline and a second cooling pipeline are arranged between the liquid taking end and the motor cavity of the compressor. The first cooling pipeline can be controlled according to the user operation, and the second cooling pipeline can be automatically controlled according to the unit load condition. Through manual cooling adjustment and real-time automatic cooling adjustment, the motor is jointly cooled to adapt to the operating conditions with different compressor heat generation amounts, ensuring that the motor can obtain sufficient cooling under the full load condition, reaching an appropriate motor operating winding temperature, avoiding malfunction shutdown or even burning out of the motor due to overheating of the internal windings of the motor. Based on the joint control scheme of the first cooling pipeline and the second cooling pipeline, it is flexible and adjustable and has a wide adaptability, improving the stable and reliable operation of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic structural diagram of the motor cooling device provided in Embodiment 1 of the present invention;

[0038] Figure 2 is another schematic structural diagram of the motor cooling device provided in Embodiment 1 of the present invention;

[0039] Figure 3 is a flowchart of the motor cooling control method provided in Embodiment 2 of the present invention;

[0040] Figure 4 is a schematic structural diagram of the chiller provided in Embodiment 3 of the present invention;

[0041] Figure 5 is a structural block diagram of the motor cooling control device provided in Embodiment 4 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0044] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0045] Embodiment 1

[0046] This embodiment provides a motor cooling device, which is applied to a unit including at least two compressors and can ensure that the motor can obtain sufficient cooling under full-load conditions.

[0047] Figure 1 is a schematic structural diagram of the motor cooling device provided in Embodiment 1 of the present invention. As Figure 1 shown, the motor cooling device includes:

[0048] A first cooling pipeline 10 is connected between the liquid extraction end 30 and the motor cavity of the compressor 40. A first valve 11 is provided on the first cooling pipeline 10, and the opening degree of the first valve 11 is controlled according to user operations;

[0049] A second cooling pipeline 20 is connected between the liquid extraction end 30 and the motor cavity of the compressor 40. A second valve 21 is provided on the second cooling pipeline 20, and the opening degree of the second valve 21 is automatically controlled according to the unit load condition.

[0050] Among them, the liquid extraction end can be a condenser, an economizer, an evaporator, a liquid storage tank, etc. That is, the liquid used for motor cooling can be extracted from the condenser, the economizer, the evaporator, or the liquid storage tank. The liquid used for motor cooling can be a refrigerant or water. For example, water can be obtained from the inlet and outlet pipes of the evaporator or the condenser to cool the motor. At least two compressors can be connected in series, in parallel, or in a combination of series and parallel.

[0051] One end of the first cooling pipeline is connected to the liquid extraction end, and the other end is connected to each compressor motor cavity. The flow rate of the liquid flowing through the first cooling pipeline can be controlled by the first valve on the first cooling pipeline. The first valve is a valve that can be adjusted by the user. For example, it can be an adjustable ball valve or an electric butterfly valve, etc. The larger the opening of the first valve, the greater the flow rate of the liquid flowing through the first cooling pipeline, and the greater the cooling capacity of the motor. During commissioning or user operation, the user can adjust the opening of the first valve according to the cooling requirement to change the cooling capacity of the motor to meet the user's cooling requirement for the motor.

[0052] One end of the second cooling pipeline is connected to the liquid extraction end, and the other end is connected to each compressor motor cavity. The flow rate of the medium flowing into the compressor motor cavity through the second cooling pipeline for cooling and the cooling position can be controlled by the second valve on the second cooling pipeline. The second valve can be a solenoid valve, a butterfly valve, etc. Automatically controlling the second valve according to the unit load condition can realize reasonable real-time automatic control of the motor cooling capacity of the second cooling pipeline according to the actual operation condition of the unit.

[0053] In the motor cooling device of this embodiment, a first cooling pipeline and a second cooling pipeline are arranged between the liquid extraction end and the motor cavity of the compressor. The first cooling pipeline can be controlled according to the user operation, and the second cooling pipeline can be automatically controlled according to the unit load condition. Through manual cooling adjustment and real-time automatic cooling adjustment, the motor is jointly cooled to adapt to the operating conditions of different compressor heat generation amounts, ensure that the motor can be sufficiently cooled under full load conditions, reach an appropriate motor operating winding temperature, avoid malfunction shutdown or even burning of the motor due to overheating of the internal windings of the motor. Based on the combined control scheme of the first cooling pipeline and the second cooling pipeline, it is flexible and adjustable, has a wide adaptability, and improves the stable reliability of motor operation.

[0054] The first cooling pipeline 10 and the second cooling pipeline 20 are connected to the same position on the motor cavity of the compressor, or the first cooling pipeline 10 and the second cooling pipeline 20 are connected to different positions on the motor cavity of the compressor. If they are connected to different positions, the liquids in the first cooling pipeline and the second cooling pipeline enter the motor cavity through different positions, which can cool the motor more evenly and accelerate the cooling speed. Exemplarily, the first cooling pipeline is connected to the top of the motor cavity, and the second cooling pipeline is connected to the bottom of the motor cavity.

[0055] In one embodiment, a first throttling device 12 is provided on the first cooling pipeline 10. The first throttling device may be an electronic expansion valve, a capillary tube, a throttle orifice plate, etc. By throttling and cooling the liquid in the first cooling pipeline through the first throttling device, a better motor cooling effect can be achieved.

[0056] In one embodiment, as Figure 2 shown, the second cooling pipeline 20 includes: at least two cooling branches; at least one cooling branch is connected to the motor cavity of each compressor, and a second valve 21 is provided on each cooling branch. In this embodiment, at least one cooling branch is connected to the motor cavity of each compressor, and a second valve is provided on each cooling branch. By the second valve, the liquid flow rate of the corresponding cooling branch can be controlled, and thus the motor cooling of each compressor can be flexibly controlled according to the unit load condition, achieving precise control for the load condition and realizing segmented control of motor cooling.

[0057] Furthermore, the second cooling pipeline further includes: a main cooling path; one end of the main cooling path is connected to the liquid taking end, and the other end of the main cooling path is connected to each cooling branch; a second throttling device 22 is provided on the main cooling path. In this embodiment, the liquid taking end is connected to each cooling branch through the main cooling path to ensure that the liquid can smoothly enter the cooling branch, and a second throttling device is provided on the main cooling path. The second throttling device may be an electronic expansion valve, a capillary tube, etc. By throttling and cooling the liquid in the second cooling pipeline through the second throttling device, a better motor cooling effect can be achieved.

[0058] If two or more cooling branches are connected to the motor cavity of the same compressor, the two or more cooling branches may be connected to the same position on the motor cavity of the compressor, or the two or more cooling branches may be respectively connected to different positions on the motor cavity of the compressor. If two or more cooling branches are connected to different positions of the same compressor motor cavity, the liquid enters the motor cavity through different positions, which can cool the motor more evenly and achieve the effect of rapid cooling. Exemplarily, one cooling branch is connected to the front bottom of the motor cavity, and the other cooling branch is connected to the rear bottom of the motor cavity.

[0059] It should be noted that the number of cooling branches connected to each compressor in the same unit may be different or the same. For example, each compressor in the unit has two cooling branches connected to its motor cavity, or the unit includes two compressors, one compressor is connected with one cooling branch, and the other compressor is connected with two cooling branches.

[0060] In practical applications, those skilled in the art can set the number of cooling branches and the number of valves according to actual needs.

[0061] Embodiment 2

[0062] This embodiment provides a method for controlling motor cooling, which is implemented based on the motor cooling device described in the above embodiment.

[0063] Figure 3 is a flowchart of the motor cooling control method provided in Embodiment 2 of the present invention. As Figure 3 shown, the method includes the following steps:

[0064] S301, Detect the unit load condition, and automatically control the second valve on the second cooling pipeline according to the unit load condition.

[0065] S302, Receive the user operation, and control the first valve on the first cooling pipeline according to the user operation.

[0066] Among them, the unit load condition refers to the current load of the unit, for example, it can be represented by the unit load rate. The user operation refers to the operation of the user controlling the first valve, which can be that the user directly adjusts the first valve by hand, or the user inputs a control instruction for the first valve through an input device such as a touch screen or a button. Steps S301 and S302 can be executed simultaneously or sequentially, specifically depending on the actual operating conditions of the unit and the timing of the user operation.

[0067] In the motor cooling control method of this embodiment, a first cooling pipeline and a second cooling pipeline are provided between the liquid taking end and the motor cavity of the compressor. The second valve on the second cooling pipeline is automatically controlled according to the unit load condition, and the first valve on the first cooling pipeline is controlled according to the user operation. Through manual cooling adjustment and real-time automatic cooling adjustment, the motor is jointly cooled to adapt to the operating conditions of different compressor heat generation amounts, ensure that the motor can obtain sufficient cooling under full load conditions, reach an appropriate motor operating winding temperature, avoid malfunction shutdown due to overheating of the internal windings of the motor, and even burn out the motor. Based on the joint control scheme of the first cooling pipeline and the second cooling pipeline, it is flexible and adjustable, has a wide adaptability, and improves the stable reliability of motor operation.

[0068] In one embodiment, automatically controlling the second valve on the second cooling pipeline according to the unit load condition includes: determining the opening condition of the compressor according to the unit load condition; controlling the second valve on the second cooling pipeline according to the unit load condition and the opening condition of the compressor.

[0069] Among them, for a unit including at least two compressors, a compressor control strategy is set. For example, under different unit load conditions, which compressors to start and the operating frequencies of the started compressors, etc.

[0070] This embodiment automatically controls the second valve on the second cooling pipeline according to the unit load condition and the startup condition of the compressor, thereby enabling real-time automatic control of the motor cooling capacity based on the actual operation condition of the unit, ensuring that the motor cooling can meet the unit operation condition, and improving the operation stability and reliability of the unit.

[0071] In one embodiment, the second cooling pipeline includes: at least two cooling branches, at least one cooling branch is connected to the motor cavity of each compressor, and a second valve is provided on each cooling branch; controlling the second valve on the second cooling pipeline according to the unit load condition and the startup condition of the compressor includes: controlling the second valve on the cooling branch connected to the started compressor according to the unit load condition and the number of cooling branches connected to the started compressor; controlling the second valve on the cooling branch connected to the unstarted compressor to be closed.

[0072] In this embodiment, for the unstarted compressor, there is no need to cool its motor, and the second valve of the cooling branch connected thereto is directly closed. For the started compressor, controlling the second valve on the cooling branch connected to the started compressor according to the unit load condition and the number of cooling branches connected to the started compressor can ensure motor cooling based on the actual operation condition of the unit, avoiding both insufficient cooling and excessive cooling.

[0073] In one embodiment, controlling the second valve on the cooling branch connected to the started compressor according to the unit load condition and the number of cooling branches connected to the started compressor includes: if the started compressor is connected to one cooling branch, directly controlling the second valve on the cooling branch connected to the started compressor to be opened; if the started compressor is connected to two or more cooling branches, controlling the second valves on a set number of the two or more cooling branches connected to the started compressor to be opened according to the interval in which the unit load is located, where a corresponding relationship between the load interval and the set number is preset.

[0074] Among them, the corresponding relationship between the load interval and the set number can be preset. The smaller the load interval, the fewer the corresponding set number. For example, the unit includes two compressors. The load interval is less than 35%, one compressor is started, and only one cooling branch of this compressor is opened; the load interval is greater than or equal to 35% and less than 70%, two compressors are started, and one cooling branch of each of the two compressors is opened; the load interval is greater than or equal to 70%, two compressors are started, and all cooling branches of the two compressors are opened.

[0075] This embodiment controls the opening of the cooling branch according to the unit load condition. Due to the difference in the load rate of each compressor, the multi-channel auxiliary is flexibly adjustable, and can perform more precise control on the part-load condition of the user, realizing segmented control of motor cooling.

[0076] In one embodiment, according to the unit load condition and the opening condition of the compressor, controlling the second valve on the second cooling pipeline includes: when a closing instruction for an already-opened compressor is detected, controlling the second valve corresponding to the compressor that is in the open state to close after a preset time delay. The preset time delay can be set in advance according to the actual situation of the compressor, for example, set to 2 minutes.

[0077] This embodiment takes into account that due to inertia, there will be a time difference of about dozens of seconds from when the compressor receives the closing command to when it completely stops rotating. Therefore, controlling the second valve to close with a time delay can ensure that there is still liquid to cool the motor before the compressor completely stops rotating.

[0078] In one embodiment, after detecting the unit load condition, it further includes: controlling the opening degree of the second throttling device on the second cooling pipeline according to the unit load condition. This embodiment controls the opening degree of the second throttling device on the second cooling pipeline according to the unit load condition, and can throttle and cool the liquid in the second cooling pipeline according to the actual operation condition of the unit, so as to achieve a better motor cooling effect.

[0079] Embodiment 3

[0080] This embodiment gives a specific example to illustrate the above-mentioned motor cooling device and motor cooling control method. However, it should be noted that this specific example is only for better explaining the present application and does not constitute an improper limitation to the present application. For the same or corresponding term explanations as the above embodiments, they will not be repeated in this embodiment.

[0081] This embodiment is described by taking the unit including two series-connected compressors and taking liquid from the condenser for motor cooling as an example.

[0082] Such as Figure 4As shown in the figure, the unit includes: a compressor 1 and a compressor 2 connected in series, a condenser 3, a filter 4, a throttling device 5 and an evaporator 6. One end of the first cooling pipeline (i.e., the manual cooling adjustment pipeline) is connected to the bottom of the condenser shell tube or the condenser liquid collection package, and the other end is connected to the top of the motor chambers of the compressors 1 and 2. The first cooling pipeline takes high-pressure liquid refrigerant from the condenser and supplies the liquid refrigerant to the motor for cooling by using the pressure difference between the condenser and the motor chamber. A manually adjustable ball valve 7 and an orifice plate 8 are arranged on the first cooling pipeline. The opening degree of the manually adjustable ball valve 7 is 0% - 100%. According to the demand of the full-load design working condition, the opening degree of the ball valve is matched to control the refrigerant flow rate for cooling the motor. The orifice plate 8 calculates the aperture according to the flow rate required for cooling the motor under the design working condition and can play a role in throttling and cooling.

[0083] One end of the second cooling pipeline (i.e., the real-time automatic cooling adjustment pipeline) is connected to the bottom of the condenser shell tube or the condenser liquid collection package, and the other end is connected to the motor chambers of the compressor 1 and the compressor 2 through multiple cooling branches. An electronic expansion valve EXV is arranged on the second cooling pipeline, and a solenoid valve is arranged on each cooling branch. Specifically, two cooling branches are correspondingly connected to the motor chamber of the compressor 1, and solenoid valves SV1 and SV4 are respectively arranged. SV1 is connected to the front bottom of the motor chamber of the compressor 1, and SV4 is connected to the rear bottom of the motor chamber of the compressor 1. Two cooling branches are correspondingly connected to the motor chamber of the compressor 2, and solenoid valves SV2 and SV3 are respectively arranged. SV2 is connected to the front bottom of the motor chamber of the compressor 2, and SV3 is connected to the rear bottom of the motor chamber of the compressor 2.

[0084] The real-time automatic cooling adjustment pipeline is controlled by the electronic expansion valve EXV and the solenoid valves SV1 - SV4, and the two compressors are respectively cooled according to the set control method. The electronic expansion valve EXV throttles the refrigerant in the real-time automatic cooling adjustment pipeline and then diverts it to the cooling branches of the solenoid valves SV1, SV2, SV3, and SV4.

[0085] The unit is provided with a load rate detection, and the motor cooling pipeline is automatically controlled according to the unit load rate to realize segmented control of motor cooling. In the low-load working condition where the unit load rate is below 35%, either the compressor 1 or 2 is turned on alone to meet the load demand; in the partial load working condition where the unit load rate is 35% - 100%, both compressors are turned on to meet the load requirement.

[0086] The solenoid valves SV1 and SV4 are used to cool the compressor 1, and the solenoid valves SV2 and SV3 are used to cool the compressor 2. The control methods of the EXV and the SV1, SV2, SV3, and SV4 are as follows:

[0087] When the unit is in a low-load condition with a load factor of less than 35%, if the unit detects an opening command for compressor 1 or compressor 2, solenoid valve SV1 or solenoid valve SV2 will immediately open, and solenoid valves SV3 and SV4 will not open.

[0088] When the unit is in a partial-load condition with a load factor of 35% - 70%, both compressor 1 and compressor 2 are turned on, and solenoid valves SV1 and SV2 are opened simultaneously.

[0089] When the unit load factor ≥ 70%, both compressor 1 and compressor 2 are turned on, and solenoid valves SV1, SV2, SV3, and SV4 all execute the opening command.

[0090] When a closing command for compressor 1 or compressor 2 is detected, solenoid valve SV1 or solenoid valve SV2 will close with a 2-minute delay. Due to inertia, there will be a time difference of about dozens of seconds from when the compressor receives the closing command to when it completely stops rotating. The 2-minute delayed rotation of solenoid valve SV1 or solenoid valve SV2 can ensure that there is still refrigerant to cool the motor before the compressor completely stops rotating.

[0091] In this embodiment, by combining manual cooling adjustment with real-time automatic cooling adjustment, the motor is cooled jointly to adapt to the operating conditions with different compressor heat generation. Manual cooling adjustment uses a fixed orifice plate and an adjustable ball valve to cool the dual compressors according to the cooling requirements; real-time automatic cooling adjustment opens and closes solenoid valves and electronic expansion valves according to the unit load factor to achieve an appropriate motor operating winding temperature. The combined control method is flexible and adjustable, with a wide adaptability, improving the stable and reliable operation of the motor. Moreover, according to the size of the total unit load factor, the motor cooling capacity is automatically adjusted in real time. According to the difference in the respective load factors of the dual compressors, the multi-channel auxiliary is flexible and adjustable, and can perform more precise control for the user's partial-load conditions, realizing segmented control of motor cooling.

[0092] Embodiment 4

[0093] Based on the same inventive concept, this embodiment provides a motor cooling control device, which can be used to implement the motor cooling control method described in the above embodiment. This motor cooling control device can be implemented through software and / or hardware, and this motor cooling control device can generally be integrated into the unit controller.

[0094] Figure 5 is the structural block diagram of the motor cooling control device provided in Embodiment 4 of the present invention. As Figure 5 shown, this motor cooling control device includes:

[0095] The first control module 51 is used to detect the unit load condition and automatically control the second valve on the second cooling pipeline according to the unit load condition;

[0096] The second control module 52 is configured to receive user operations and control the first valve on the first cooling pipeline according to the user operations.

[0097] Optionally, the first control module 51 includes:

[0098] A determination unit configured to determine the startup status of the compressor according to the unit load condition;

[0099] A control unit configured to control the second valve on the second cooling pipeline according to the unit load condition and the startup status of the compressor.

[0100] Optionally, the control unit includes:

[0101] A determination subunit configured to determine the startup status of the compressor according to the unit load condition;

[0102] A first control subunit configured to control the second valve on the second cooling pipeline according to the unit load condition and the startup status of the compressor.

[0103] Optionally, the second cooling pipeline includes: at least two cooling branches, each motor cavity of the compressor is connected to at least one cooling branch, and a second valve is provided on each cooling branch. The first control subunit is specifically configured to: control the second valves on the cooling branches connected to the started compressors according to the unit load condition and the number of cooling branches connected to the started compressors; control the second valves on the cooling branches connected to the unstarted compressors to be closed.

[0104] Optionally, the first control subunit is specifically configured to:

[0105] If the started compressor is connected to one cooling branch, directly control the second valve on the cooling branch connected to the started compressor to be opened;

[0106] If the started compressor is connected to two or more cooling branches, control the second valves on a set number of the two or more cooling branches connected to the started compressor to be opened according to the interval where the unit load is located, wherein a corresponding relationship between the load interval and the set number is preset.

[0107] Optionally, the control unit includes:

[0108] A second control subunit configured to, when a shutdown instruction for a started compressor is detected, control the second valve corresponding to the compressor in the open state to be closed after a preset time delay.

[0109] Optionally, the above-mentioned motor cooling control device further includes:

[0110] A third control module, configured to control the opening degree of a second throttling device on the second cooling pipeline according to the unit load condition after detecting the unit load condition.

[0111] The above-mentioned motor cooling control device can execute the motor cooling control method provided by the embodiments of the present invention, and has corresponding functional modules and beneficial effects for executing the motor cooling control method. Technical details not described in detail in this embodiment can be found in the motor cooling control method provided by the embodiments of the present invention.

[0112] Embodiment Five

[0113] This embodiment provides a water chiller, including: the motor cooling device described in the above embodiment and the motor cooling control device described in the above embodiment.

[0114] Embodiment Six

[0115] This embodiment provides an electronic device, including: one or more processors; a memory for storing one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the motor cooling control method as described in the above embodiment.

[0116] Embodiment Seven

[0117] This embodiment provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the motor cooling control method as described in the above embodiment.

[0118] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0119] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, also by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention 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 perform equivalent replacements for some of the technical features; and 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 various embodiments of the present invention.

Claims

1. An electric motor cooling device, characterized in that, the electric motor cooling device is applied to a unit including at least two compressors, and the electric motor cooling device includes: a first cooling pipeline, connected between a liquid taking end and the motor cavity of the compressor, a first valve is arranged on the first cooling pipeline, and the opening degree of the first valve is controlled according to user operation; a second cooling pipeline, connected between the liquid taking end and the motor cavity of the compressor, a second valve is arranged on the second cooling pipeline, and the opening degree of the second valve is automatically controlled according to the unit load condition, including: determining the starting condition of the compressor according to the unit load condition, and controlling the second valve according to the unit load condition and the starting condition of the compressor.

2. The electric motor cooling device according to claim 1, characterized in that, a first throttling device is arranged on the first cooling pipeline.

3. The electric motor cooling device according to claim 1, characterized in that, the second cooling pipeline includes: at least two cooling branches; at least one cooling branch is connected to the motor cavity of each compressor, and the second valve is arranged on each cooling branch.

4. The electric motor cooling device according to claim 3, characterized in that, the second cooling pipeline further includes: a main cooling path; one end of the main cooling path is connected to the liquid taking end, and the other end of the main cooling path is connected to each cooling branch; a second throttling device is arranged on the main cooling path.

5. The electric motor cooling device according to claim 3, characterized in that, if two or more cooling branches are connected to the motor cavity of the same compressor, the two or more cooling branches are respectively connected to different positions on the motor cavity of the compressor.

6. The electric motor cooling device according to claim 1, characterized in that, the first cooling pipeline and the second cooling pipeline are connected to different positions on the motor cavity of the compressor.

7. An electric motor cooling control method, characterized in that, the method is implemented based on the electric motor cooling device according to any one of claims 1 to 6, and the method includes: detecting the unit load condition, and automatically controlling the second valve on the second cooling pipeline according to the unit load condition; receiving user operation, and controlling the first valve on the first cooling pipeline according to the user operation.

8. The electric motor cooling control method according to claim 7, characterized in that, automatically controlling the second valve on the second cooling pipeline according to the unit load condition, including: determining the starting condition of the compressor according to the unit load condition; controlling the second valve on the second cooling pipeline according to the unit load condition and the starting condition of the compressor.

9. The electric motor cooling control method according to claim 8, characterized in that, the second cooling pipeline includes: at least two cooling branches, at least one cooling branch is connected to the motor cavity of each compressor, and the second valve is arranged on each cooling branch; controlling the second valve on the second cooling pipeline according to the unit load condition and the starting condition of the compressor, including: Control the second valve on the cooling branch connected to the started compressor according to the unit load condition and the number of cooling branches connected to the started compressor; Control the second valve on the cooling branch connected to the unstarted compressor to be closed.

10. The motor cooling control method according to claim 9, characterized in that Controlling the second valve on the cooling branch connected to the started compressor according to the unit load condition and the number of cooling branches connected to the started compressor includes: If the started compressor is connected to one cooling branch, directly control the second valve on the cooling branch connected to the started compressor to open; If the started compressor is connected to two or more cooling branches, control the second valves on a set number of the two or more cooling branches connected to the started compressor to open according to the interval in which the unit load is located, wherein a corresponding relationship between the load interval and the set number is preset.

11. The motor cooling control method according to claim 8, characterized in that Controlling the second valve on the second cooling pipeline according to the unit load condition and the starting condition of the compressor includes: When a shutdown instruction for a started compressor is detected, control the second valve in the open state corresponding to the compressor to close after a preset time delay.

12. The motor cooling control method according to claim 7, characterized in that After detecting the unit load condition, it further includes: Control the opening degree of the second throttling device on the second cooling pipeline according to the unit load condition.

13. A motor cooling control device, characterized in that The motor cooling control device is used to implement the motor cooling control method according to any one of claims 7 to 12, and the motor cooling control device includes: A first control module, configured to detect the unit load condition and automatically control the second valve on the second cooling pipeline according to the unit load condition; A second control module, configured to receive user operations and control the first valve on the first cooling pipeline according to the user operations.

14. A water chiller, characterized in that including: The motor cooling device according to any one of claims 1 to 6, and the motor cooling control device according to claim 13.

15. A computer-readable storage medium, on which a computer program is stored, characterized in that When the program is executed by a processor, it implements the motor cooling control method according to any one of claims 7 to 12.

16. An electronic device, including: One or more processors; A memory, configured to store one or more programs, characterized in that when the one or more programs are executed by the one or more processors, the one or more processors implement the motor cooling control method according to any one of claims 7 to 12.

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