Refrigerant recovery method and device of direct cooling system

Abstract

The invention provides a refrigerant recovery method and device of a direct cooling system, and the refrigerant recovery method of the direct cooling system comprises the steps that when a refrigerant recovery instruction is received, the direct cooling system is controlled to enter a refrigerant recovery mode, in the refrigerant recovery mode, a refrigerant flows from a first heat exchanger to a second heat exchanger through a first valve, and the refrigerant flows from a second heat exchanger through a second valve; flowing from the second heat exchanger to the compressor through the second valve; when the first system pipeline pressure at the outlet of the compressor is smaller than the first preset pressure, and / or the operation duration of the compressor in the refrigerant recovery mode is larger than the first preset duration, the first valve is indicated to be closed; and under the condition that the second system pipeline pressure at the inlet of the compressor is smaller than the second preset pressure, the second valve is indicated to be closed, and the compressor is controlled to stop. The problem that the refrigerant recovery efficiency of a direct cooling system is low is at least solved.

Description

Technical Field

[0001] The present application relates to the field of refrigerant treatment technology, and in particular to a refrigerant recovery method and device for a direct cooling system. Background Art

[0002] During the actual operation of the direct cooling system, there is an urgent need to recycle the refrigerant. As the core heat transfer medium in the direct cooling system, the effective management and recycling of the refrigerant can not only improve the overall energy efficiency of the direct cooling system, but also significantly reduce the adverse impact on the environment. When the battery is maintained separately after sales, the refrigerant recovery of the direct cooling system can avoid refrigerant loss as much as possible and avoid the need to add refrigerant. In the process of realizing the present application, the inventors found that the prior art has at least the following technical problems: the refrigerant recovery efficiency of the direct cooling system in the prior art is low. The refrigerant recovery efficiency refers to the ratio of the amount of recovered refrigerant to the amount of refrigerant before recovery. Summary of the invention

[0003] The present application provides a refrigerant recovery method and device for a direct cooling system, which are at least used to improve the problem of low refrigerant recovery efficiency of the direct cooling system.

[0004] According to a first aspect of an embodiment of the present application, a refrigerant recovery method for a direct cooling system is provided, wherein the direct cooling system comprises a compressor, a first heat exchanger, a second heat exchanger, a first valve, and a second valve connected to each other; the second heat exchanger is used to exchange heat for a plurality of batteries in an energy storage system;

[0005] The method comprises:

[0006] When receiving a refrigerant recovery instruction, controlling the direct cooling system to enter a refrigerant recovery mode, wherein in the refrigerant recovery mode, the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve, and flows from the second heat exchanger to the compressor through the second valve;

[0007] Instructing the first valve to close when the first system pipeline pressure at the outlet of the compressor is less than a first preset pressure and / or the operating time of the compressor in the refrigerant recovery mode is greater than a first preset time;

[0008] When the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the second valve is instructed to close, and the compressor is controlled to stop.

[0009] Optionally, the instructing the first valve to close includes:

[0010] Outputting a first prompt message, wherein the first prompt message is used to remind the user to manually close the first valve;

[0011] or,

[0012] The first valve is controlled to be closed.

[0013] Optionally, the instructing the second valve to close comprises:

[0014] Outputting second prompt information, wherein the second prompt information is used to remind the user to manually close the second valve;

[0015] or,

[0016] The second valve is controlled to be closed.

[0017] Optionally, controlling the compressor to stop includes:

[0018] The compressor is controlled to run at a reduced speed, and after instructing the second valve to close, the compressor is controlled to stop after a second preset time period.

[0019] Optionally, the method further comprises:

[0020] When the first valve is not closed, the second valve is not closed, and the operating time of the compressor in the refrigerant recovery mode is greater than the preset maximum operating time, the compressor is controlled to stop and a third prompt message is output, wherein the third prompt message is used to prompt that the refrigerant recovery fails.

[0021] Optionally, the method further comprises:

[0022] When the first system pipeline pressure at the outlet of the compressor is greater than the third preset pressure, fourth prompt information is output, wherein the fourth prompt information is used to prompt that the first system pipeline pressure at the outlet of the compressor is too high.

[0023] Optionally, the direct cooling system further includes a fan, a third heat exchanger, a refrigeration electronic expansion valve, a heating electronic expansion valve and an air-supplying electronic expansion valve; the fan is arranged on one side of the first heat exchanger; the third heat exchanger includes a first heat exchange part and a second heat exchange part that exchanges heat with the first heat exchange part; the first heat exchanger is connected to a first end of the first heat exchange part, the second end of the first heat exchange part is connected to a first end of the refrigeration electronic expansion valve, the second end of the refrigeration electronic expansion valve is connected to the first valve, the second end of the first heat exchange part is connected to a first end of the air-supplying electronic expansion valve, the second heat exchange part is connected between the second end of the air-supplying electronic expansion valve and the air-supplying port of the compressor, and the heating electronic expansion valve is connected between the second end of the first heat exchange part and the first heat exchanger;

[0024] The controlling the direct cooling system to enter a refrigerant recovery mode includes:

[0025] Control the operating frequency of the compressor to be adjusted to a preset frequency, control the fan to run at full speed, adjust the opening of the refrigeration electronic expansion valve according to the suction superheat, control the heating electronic expansion valve to be closed, and control the air supply electronic expansion valve to be closed.

[0026] Optionally, the method further comprises:

[0027] When the first system pipeline pressure at the outlet of the compressor is less than the first preset pressure, and / or the operation time of the compressor in the refrigerant recovery mode is greater than the first preset time, the refrigeration electronic expansion valve is controlled to be closed;

[0028] When the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the fan is controlled to be closed with a time delay.

[0029] Optionally, the method further comprises:

[0030] In the refrigerant recovery mode, the alarms of the compressor and the fan are turned off.

[0031] According to a second aspect of an embodiment of the present application, a refrigerant recovery device of a direct cooling system is provided, wherein the direct cooling system comprises a compressor, a first heat exchanger, a second heat exchanger, a first valve, and a second valve connected to each other; the second heat exchanger is used to perform heat exchange on a plurality of batteries in an energy storage system;

[0032] The refrigerant recovery device comprises:

[0033] a control unit, configured to control the direct cooling system to enter a refrigerant recovery mode when receiving a refrigerant recovery instruction, wherein in the refrigerant recovery mode, the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve, and flows from the second heat exchanger to the compressor through the second valve;

[0034] A first processing unit, configured to instruct the first valve to close when a first system pipeline pressure at an outlet of the compressor is less than a first preset pressure and / or when the operating time of the compressor in the refrigerant recovery mode is greater than a first preset time;

[0035] The second processing unit is used to instruct the second valve to close and control the compressor to stop when the second system pipeline pressure at the inlet of the compressor is less than a second preset pressure.

[0036] In the present application, the direct cooling system includes a compressor, a first heat exchanger, a second heat exchanger, a first valve and a second valve which are interconnected. The second heat exchanger is used to exchange heat for multiple batteries in the energy storage system. When a refrigerant recovery instruction is received, the direct cooling system is controlled to enter a refrigerant recovery mode. In the refrigerant recovery mode, the refrigerant flows from the first heat exchanger through the first valve to the second heat exchanger, and from the second heat exchanger through the second valve to the compressor.

[0037] When the pressure of the first system pipeline at the outlet of the compressor is less than the first preset pressure, and / or the running time of the compressor in the refrigerant recovery mode is greater than the first preset time, part of the refrigerant in the second heat exchanger has been recovered. Since the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve in the refrigerant recovery mode, the first valve is indicated to be closed at this time to prevent the recovered refrigerant from flowing into the second heat exchanger again. When the pressure of the second system pipeline at the inlet of the compressor is less than the second preset pressure, the refrigerant in the second heat exchanger flows out of the second heat exchanger after heat exchange, the refrigerant in the second heat exchanger has been completely recovered, and there is no refrigerant in the second heat exchanger. Since in the refrigerant recovery mode, the refrigerant flows from the second heat exchanger to the compressor through the second valve, the second valve is instructed to close at this time to prevent the refrigerant from leaking into the second heat exchanger through the second valve, and the compressor is controlled to stop, stopping the refrigerant recovery, reducing the possibility of refrigerant residue in the second heat exchanger, and improving the refrigerant recovery efficiency of the direct cooling system. In the process of after-sales disassembly and assembly of the batteries in the energy storage system, since the second heat exchanger is used to exchange heat for multiple batteries in the energy storage system, the possibility of refrigerant residue in the second heat exchanger is reduced through refrigerant recovery, thereby greatly reducing the direct discharge of refrigerant into the air, eliminating the need to replenish refrigerant, and improving the refrigerant recovery efficiency of the direct cooling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0039] Figure 1 A schematic flow chart of a refrigerant recovery method for a direct cooling system provided in an embodiment of the present application;

[0040] Figure 2 A schematic diagram of a direct cooling system in a refrigerant recovery mode provided in an embodiment of the present application;

[0041] Figure 3 This is a schematic diagram of the structure of a direct cooling system provided in an embodiment of the present application;

[0042] Figure 4 A schematic flow chart of a refrigerant recovery method for a direct cooling system provided in an embodiment of the present application;

[0043] Figure 5 This is a schematic diagram of the structure of a refrigerant recovery device for a direct cooling system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] Exemplary Methods

[0046] See also Figure 1 In an exemplary embodiment, a refrigerant recovery method for a direct cooling system is provided. The direct cooling system includes a compressor, a first heat exchanger, a second heat exchanger, a first valve, and a second valve connected to each other, and the second heat exchanger is used to exchange heat for multiple batteries in an energy storage system.

[0047] like Figure 1 As shown, the process of the refrigerant recovery method of the direct cooling system mainly includes:

[0048] Step 101, when a refrigerant recovery instruction is received, the direct cooling system is controlled to enter a refrigerant recovery mode.

[0049] In the refrigerant recovery mode, the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve, and flows from the second heat exchanger to the compressor through the second valve.

[0050] In some embodiments, Figure 2 Shown is a schematic diagram of a direct cooling system in refrigerant recovery mode. Figure 2 In the direct cooling system, the compressor, the first heat exchanger, the second heat exchanger, the first valve and the second valve are connected to each other. In the refrigerant recovery mode, the first heat exchanger is connected between the outlet of the compressor and the first valve, the first valve is connected between the first heat exchanger and the second heat exchanger, the second heat exchanger is connected between the first valve and the second valve, and the second valve is connected between the second heat exchanger and the inlet of the compressor. In the refrigerant recovery mode, the refrigerant flows from the outlet of the compressor to the first heat exchanger, from the first heat exchanger to the second heat exchanger through the first valve, and from the second heat exchanger to the inlet of the compressor through the second valve. Figure 2Only the direct cooling system including a compressor, a first heat exchanger, a second heat exchanger, a first valve and a second valve is shown. As needed, the direct cooling system may also include other components, such as a fan, etc., and this application does not limit this. Figure 2 The graphics of the components are for illustration only and do not restrict the selection of the components. For example, Figure 2 The first valve in the valve can be a mechanical valve or an electronic valve, and the second valve can be a mechanical valve or an electronic valve.

[0051] In an exemplary embodiment, the first heat exchanger may be an outdoor heat exchanger, and the second heat exchanger may be a cold plate. There is no limit on the number of cold plates. The second heat exchanger is used to exchange heat between multiple batteries in the energy storage system. The cold plate and the multiple batteries in the energy storage system may be in direct contact, and heat is exchanged between the multiple batteries in the energy storage system by direct cooling.

[0052] In some embodiments, Figure 3 The figure shows a schematic diagram of the structure of a direct cooling system. Figure 3 In the invention, the direct cooling system includes a compressor, a first heat exchanger, a second heat exchanger, a first valve, a second valve, a fan, a third heat exchanger, a refrigeration electronic expansion valve, a heating electronic expansion valve and an air supply electronic expansion valve. The fan is arranged on one side of the first heat exchanger, and the third heat exchanger includes a first heat exchange part and a second heat exchange part that exchanges heat with the first heat exchange part. The first heat exchanger is connected between the outlet of the compressor and the first end of the first heat exchange part, the second end of the first heat exchange part is connected to the first end of the refrigeration electronic expansion valve, the second end of the refrigeration electronic expansion valve is connected to the first valve, the second heat exchanger is connected between the first valve and the second valve, the second valve is connected between the second heat exchanger and the inlet of the compressor, the second end of the first heat exchange part is connected to the first end of the air supply electronic expansion valve, the second heat exchange part is connected between the second end of the air supply electronic expansion valve and the air supply port of the compressor, and the heating electronic expansion valve is connected between the second end of the first heat exchange part and the first heat exchanger.

[0053] Figure 3 Only the direct cooling system is shown, including a compressor, a first heat exchanger, a second heat exchanger, a first valve, a second valve, a fan, a third heat exchanger, a refrigeration electronic expansion valve, a heating electronic expansion valve and an air supply electronic expansion valve. According to needs, the direct cooling system may also include other components, such as a four-way valve, a liquid reservoir, an oil separator, a gas-liquid separator, a filter, a pressure sensor, a temperature sensor, a one-way valve, etc., and this application does not limit this. Figure 3 The graphics of the components are for illustration only and do not restrict the selection of the components. For example, Figure 3 The first valve in the valve can be a mechanical valve or an electronic valve, and the second valve can be a mechanical valve or an electronic valve.

[0054] In an exemplary embodiment, the first heat exchanger may be an outdoor heat exchanger, the second heat exchanger may be a cold plate, and the number of cold plates is not limited. The second heat exchanger is used to exchange heat between multiple batteries in the energy storage system, and the cold plate may be in direct contact with multiple batteries in the energy storage system, and heat is exchanged between multiple batteries in the energy storage system by direct cooling. The third heat exchanger may be an economizer.

[0055] In some embodiments, the direct cooling system may also include a four-way valve, a first interface of the four-way valve connected to the first heat exchanger, a second interface of the four-way valve connected to the outlet of the compressor, a third interface of the four-way valve connected to the inlet of the compressor, and a fourth interface of the four-way valve connected to the second valve.

[0056] In the cooling mode, the coil of the four-way valve is in a power-off state, the first interface of the four-way valve is connected to the second interface of the four-way valve, the third interface of the four-way valve is connected to the fourth interface of the four-way valve, and the refrigerant flows from the outlet of the compressor to the first heat exchanger, from the first heat exchanger to the second heat exchanger through the first valve, and from the second heat exchanger to the inlet of the compressor through the second valve.

[0057] In the refrigerant recovery mode, the coil of the four-way valve is in a power-off state, the first interface of the four-way valve is connected to the second interface of the four-way valve, the third interface of the four-way valve is connected to the fourth interface of the four-way valve, and the refrigerant flows from the outlet of the compressor to the first heat exchanger, from the first heat exchanger to the second heat exchanger through the first valve, and from the second heat exchanger to the inlet of the compressor through the second valve.

[0058] In the heating mode, the coil of the four-way valve is energized, the first interface of the four-way valve is connected to the third interface of the four-way valve, the second interface of the four-way valve is connected to the fourth interface of the four-way valve, and the refrigerant flows from the outlet of the compressor through the second valve to the second heat exchanger, from the second heat exchanger through the first valve to the first heat exchanger, and from the first heat exchanger to the inlet of the compressor.

[0059] In some embodiments, controlling the direct cooling system to enter a refrigerant recovery mode includes:

[0060] Control the operating frequency of the compressor to the preset frequency, control the fan to run at full speed, adjust the opening of the refrigeration electronic expansion valve according to the suction superheat, control the heating electronic expansion valve to close, and control the air supply electronic expansion valve to close.

[0061] In an exemplary embodiment, controlling the operating frequency of the compressor to be adjusted to a preset frequency may be controlling the compressor to adjust the operating frequency to the preset frequency according to the frequency increase or decrease rate of the system compressor. After the operating frequency of the compressor is controlled to be adjusted to the preset frequency, the compressor continues to operate at the preset frequency.

[0062] In an exemplary embodiment, the preset frequency refers to a preset operating frequency of the refrigerant transfer compressor. For example, the preset frequency may be 45 rps, where rps is the abbreviation of “revolutions per second”, which means “revolutions per second”.

[0063] In an exemplary embodiment, controlling the fan to run at full speed may be to increase the frequency of the fan to run at full speed, and at this time the fan is not regulated by the first system pipeline pressure (ie, high pressure) at the outlet of the compressor.

[0064] Controlling the operating frequency of the compressor to the preset frequency and controlling the fan to run at full speed can speed up the flow of the refrigerant, thereby increasing the speed of refrigerant recovery. According to the suction superheat, the opening of the refrigeration electronic expansion valve is adjusted, the heating electronic expansion valve is controlled to be closed, and the air supply electronic expansion valve is controlled to be closed. At this time, the refrigerant can flow from the outlet of the compressor to the first heat exchanger, and from the first heat exchanger to the refrigeration electronic expansion valve through the first heat exchange part of the third heat exchanger. Since the air supply electronic expansion valve is closed, the refrigerant will not flow to the second heat exchange part of the third heat exchanger through the air supply electronic expansion valve, and will not flow from the second heat exchange part of the third heat exchanger to the air supply port of the compressor. Since the heating electronic expansion valve is closed, the refrigerant will not flow from the first heat exchanger to the refrigeration electronic expansion valve through the heating electronic expansion valve. The refrigerant flows from the refrigeration electronic expansion valve to the second heat exchanger through the first valve, and from the second heat exchanger to the inlet of the compressor through the second valve.

[0065] In some other embodiments, controlling the direct cooling system to enter the refrigerant recovery mode includes:

[0066] Control the operating frequency of the compressor to the preset frequency, control the fan to run at full speed, adjust the opening of the refrigeration electronic expansion valve to the preset opening, control the heating electronic expansion valve to close, and control the air supply electronic expansion valve to close.

[0067] Step 102: When the first system pipeline pressure at the outlet of the compressor is less than the first preset pressure and / or the operation time of the compressor in the refrigerant recovery mode is greater than the first preset time, instruct the first valve to close.

[0068] In an exemplary embodiment, a high-pressure pressure sensor may be provided at the outlet of the compressor, and the first system pipeline pressure at the outlet of the compressor is detected by the high-pressure pressure sensor, where the first system pipeline pressure is also the high-pressure pressure.

[0069] In an exemplary embodiment, the first preset pressure refers to a preset high pressure of refrigerant transfer, for example, the first preset pressure may be 2.3 MPaG. MPaG is a unit for indicating gauge pressure, wherein MPa is a pressure unit, i.e., megapascal, and G stands for gauge pressure, which refers to the pressure indicated by the pressure gauge, and is a pressure value relative to atmospheric pressure.

[0070] In an exemplary embodiment, the first preset time duration refers to a preset duration of the refrigerant transfer. For example, the first preset time duration may be 2 minutes.

[0071] In some embodiments, step 102 may include: when the first system pipeline pressure at the outlet of the compressor is less than the first preset pressure, indicating that the first valve is closed. Step 102 may also include: when the operating time of the compressor in the refrigerant recovery mode is greater than the first preset time, indicating that the first valve is closed. Step 102 may also include: when the first system pipeline pressure at the outlet of the compressor is less than the first preset pressure, and the operating time of the compressor in the refrigerant recovery mode is greater than the first preset time, indicating that the first valve is closed. This application is not limited to this.

[0072] When the first system pipeline pressure at the outlet of the compressor is less than the first preset pressure, and / or the operating time of the compressor in the refrigerant recovery mode is greater than the first preset time, part of the refrigerant in the second heat exchanger has been recovered. Since in the refrigerant recovery mode, the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve, the first valve is indicated to close at this time to prevent the recovered refrigerant from flowing into the second heat exchanger.

[0073] In some embodiments, there are multiple ways to indicate that the first valve is closed, including but not limited to the following ways:

[0074] Method 1

[0075] In the case where the first valve is a mechanical valve, a first prompt message is output, wherein the first prompt message is used to remind the user to manually close the first valve.

[0076] The first valve is a mechanical valve, for example, the first valve is a stop valve.

[0077] For example, outputting the first prompt information may be displaying the first prompt information in a pop-up window on the display screen of the hand operator, and the hand operator may also be made to buzz at the same time, or an external alarm of the hand operator may sound an alarm. Of course, there may be other ways of outputting the first prompt information, and the present application does not limit this.

[0078] When the first valve is a mechanical valve, a first prompt message is output, wherein the first prompt message is used to remind the user to manually close the first valve. The first prompt message can be used to remind the user to manually close the first valve to prevent the recovered refrigerant from flowing into the second heat exchanger.

[0079] Method 2

[0080] In the case that the first valve is an electronic valve, the first valve is controlled to be closed.

[0081] The first valve is an electronic valve, for example, the first valve is a solenoid valve.

[0082] When the first valve is an electronic valve, the first valve can be controlled to close automatically by controlling the first valve to close automatically without manual closing of the first valve, thereby increasing the speed of refrigerant recovery and realizing fully automatic refrigerant recovery after receiving the refrigerant recovery instruction. The whole process of refrigerant recovery does not require human intervention.

[0083] In some embodiments, the refrigerant recovery method of the direct cooling system further includes:

[0084] When a first system pipeline pressure at an outlet of the compressor is less than a first preset pressure, and / or the operating time of the compressor in a refrigerant recovery mode is greater than a first preset time, the refrigeration electronic expansion valve is controlled to close.

[0085] When the first system pipeline pressure at the outlet of the compressor is less than the first preset pressure, and / or the operating time of the compressor in the refrigerant recovery mode is greater than the first preset time, part of the refrigerant in the second heat exchanger has been recovered. Since in the refrigerant recovery mode, the refrigerant flows from the refrigeration electronic expansion valve through the first valve to the second heat exchanger, the refrigeration electronic expansion valve is controlled to be closed at this time to prevent the recovered refrigerant from flowing through the refrigeration electronic expansion valve to the first valve and then flowing into the second heat exchanger through the first valve.

[0086] In an exemplary embodiment, the execution order of the two steps of controlling the refrigeration electronic expansion valve to close and indicating the first valve to close can be simultaneous execution; or the step of controlling the refrigeration electronic expansion valve to close can be executed first, and then the step of indicating the first valve to close can be executed; or the step of indicating the first valve to close can be executed first, and then the step of controlling the refrigeration electronic expansion valve to close can be executed.

[0087] Step 103: When the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the second valve is instructed to close, and the compressor is controlled to stop.

[0088] In an exemplary embodiment, a low-pressure sensor may be provided at the inlet of the compressor, and the second system pipeline pressure at the inlet of the compressor is detected by the low-pressure sensor, where the second system pipeline pressure is also the low-pressure pressure.

[0089] In an exemplary embodiment, the second preset pressure refers to a preset refrigerant transfer low pressure. For example, the second preset pressure may be 0.2 MPaG.

[0090] When the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the refrigerant in the second heat exchanger flows out of the second heat exchanger after heat exchange, and the refrigerant in the second heat exchanger has been completely recovered. There is no refrigerant in the second heat exchanger. Since in the refrigerant recovery mode, the refrigerant flows from the second heat exchanger to the compressor through the second valve, the second valve is indicated to be closed at this time to prevent the refrigerant from leaking into the second heat exchanger through the second valve, and control the compressor to stop, stop refrigerant recovery, reduce the possibility of refrigerant residue in the second heat exchanger, and improve the refrigerant recovery efficiency of the direct cooling system. In the process of after-sales disassembly and assembly of the batteries in the energy storage system, since the second heat exchanger is used to exchange heat for multiple batteries in the energy storage system, the possibility of refrigerant residue in the second heat exchanger is reduced through refrigerant recovery, thereby greatly reducing the direct discharge of refrigerant into the air, avoiding the need to replenish refrigerant, and improving the refrigerant recovery efficiency of the direct cooling system.

[0091] In some embodiments, there are multiple ways to indicate that the second valve is closed, including but not limited to the following ways:

[0092] Method 1

[0093] In the case where the second valve is a mechanical valve, a second prompt message is output, wherein the second prompt message is used to remind the user to manually close the second valve.

[0094] The second valve is a mechanical valve, for example, the second valve is a stop valve.

[0095] For example, outputting the second prompt information may be to display the second prompt information in a pop-up window on the display screen of the hand operator, and at the same time turn off the output of the first prompt information, that is, stop the buzzer and alarm. Of course, there may be other ways to output the second prompt information, and this application does not limit this.

[0096] When the second valve is a mechanical valve, a second prompt message is output, wherein the second prompt message is used to remind the user to manually close the second valve. The second prompt message can be used to remind the user to manually close the second valve to prevent the refrigerant from leaking into the second heat exchanger through the second valve.

[0097] Method 2

[0098] In the case that the second valve is an electronic valve, the second valve is controlled to be closed.

[0099] The second valve is an electronic valve, for example, the second valve is a solenoid valve.

[0100] When the second valve is an electronic valve, the second valve can be controlled to close automatically without manual closing of the second valve, thereby increasing the speed of refrigerant recovery and realizing fully automatic refrigerant recovery after receiving a refrigerant recovery instruction. The entire process of refrigerant recovery does not require human intervention.

[0101] In some embodiments, the refrigerant recovery method of the direct cooling system further includes:

[0102] When the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the fan is controlled to be closed with a delayed shutdown.

[0103] When the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the refrigerant in the second heat exchanger flows out of the second heat exchanger after heat exchange, and the refrigerant in the second heat exchanger has been completely recovered. There is no refrigerant in the second heat exchanger, and the fan is controlled to be shut down with delay, so that all running components of the direct cooling system are stopped, and all electronic expansion valves of the direct cooling system are closed. No manual operation is required, thereby realizing automatic recovery of the refrigerant in the second heat exchanger of the direct cooling system.

[0104] In some embodiments, controlling the compressor to stop includes: controlling the compressor to decelerate, and controlling the compressor to stop after a second preset time period has passed after instructing the second valve to close.

[0105] In an exemplary embodiment, the second preset time length refers to the preset interval time length between the second valve closing and the compressor stopping. For example, the second preset time length may be 30 seconds.

[0106] The compressor is controlled to slow down, and after instructing the second valve to close, the compressor is controlled to stop after a second preset time. The compressor is delayed to stop, and the refrigerant flowing out of the second heat exchanger is further recovered to the first heat exchanger or to a separately arranged liquid storage device and other components. After the refrigerant recovery is completed, the compressor automatically stops, and there is no need to manually shut down the compressor, thereby realizing automatic recovery of the refrigerant in the second heat exchanger of the direct cooling system.

[0107] In some embodiments, the refrigerant recovery method of the direct cooling system also includes: when the first valve is not closed, the second valve is not closed, and the running time of the compressor in the refrigerant recovery mode is greater than the preset maximum running time, controlling the compressor to stop and outputting a third prompt message, wherein the third prompt message is used to prompt that the refrigerant recovery has failed.

[0108] In an exemplary embodiment, the preset maximum operating time refers to the preset maximum operating time of the refrigerant recovery logic compressor.

[0109] When the first valve is not closed, the second valve is not closed, and the running time of the compressor in the refrigerant recovery mode is greater than the preset maximum running time, it indicates that the refrigerant recovery has failed. At this time, the compressor is controlled to stop to prevent the compressor from running at the preset frequency all the time, so as to realize the automatic shutdown of the compressor when the refrigerant recovery fails. The third prompt information is output, wherein the third prompt information is used to prompt the refrigerant recovery failure and remind the user that the refrigerant recovery has failed.

[0110] In some embodiments, the refrigerant recovery method of the direct cooling system also includes: when the first system pipeline pressure at the outlet of the compressor is greater than the third preset pressure, outputting a fourth prompt information, wherein the fourth prompt information is used to prompt that the first system pipeline pressure at the outlet of the compressor is too high.

[0111] Realize the high pressure alarm of refrigerant recovery, and remind the user in time when the pressure of the first system pipeline at the outlet of the compressor is too high.

[0112] In some embodiments, the refrigerant recovery method of the direct cooling system further includes:

[0113] In refrigerant recovery mode, turn off the alarms of the compressor and fan.

[0114] In refrigeration mode, the compressor and fan will alarm under preset conditions, while in refrigerant recovery mode, even if the compressor and fan meet the preset conditions, it is the normal working state under refrigerant recovery mode and no alarm is needed. Therefore, in refrigerant recovery mode, the alarms of the compressor and fan are turned off, and the compressor and fan are not affected by alarm shutdown outside the refrigerant recovery mode, the oil return logic is not executed, and the third-level protection logic is not executed.

[0115] In some embodiments, Figure 4 As shown, the process of the refrigerant recovery method of the direct cooling system mainly includes:

[0116] Step 401, when receiving the refrigerant recovery instruction, control the operating frequency of the compressor to be adjusted to the preset frequency, control the fan to run at full speed, adjust the opening of the refrigeration electronic expansion valve according to the suction superheat, control the heating electronic expansion valve to be closed, and control the air supply electronic expansion valve to be closed.

[0117] The refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve, and flows from the second heat exchanger to the compressor through the second valve.

[0118] Step 402, when the first system pipeline pressure at the outlet of the compressor is less than the first preset pressure, and / or the operating time of the compressor in the refrigerant recovery mode is greater than the first preset time, instruct the first valve to close and control the refrigeration electronic expansion valve to close.

[0119] Step 403, when the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the second valve is instructed to close, the compressor is controlled to decelerate, and after the second valve is instructed to close, the compressor is controlled to stop after a second preset time, and the fan is controlled to be delayed shut down.

[0120] In summary, in the present application, the direct cooling system includes a compressor, a first heat exchanger, a second heat exchanger, a first valve and a second valve which are interconnected. The second heat exchanger is used to exchange heat for multiple batteries in the energy storage system. When a refrigerant recovery instruction is received, the direct cooling system is controlled to enter a refrigerant recovery mode. In the refrigerant recovery mode, the refrigerant flows from the first heat exchanger through the first valve to the second heat exchanger, and from the second heat exchanger through the second valve to the compressor.

[0121] When the pressure of the first system pipeline at the outlet of the compressor is less than the first preset pressure, and / or the running time of the compressor in the refrigerant recovery mode is greater than the first preset time, part of the refrigerant in the second heat exchanger has been recovered. Since the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve in the refrigerant recovery mode, the first valve is indicated to be closed at this time to prevent the recovered refrigerant from flowing into the second heat exchanger again. When the pressure of the second system pipeline at the inlet of the compressor is less than the second preset pressure, the refrigerant in the second heat exchanger flows out of the second heat exchanger after heat exchange, the refrigerant in the second heat exchanger has been completely recovered, and there is no refrigerant in the second heat exchanger. Since in the refrigerant recovery mode, the refrigerant flows from the second heat exchanger to the compressor through the second valve, the second valve is instructed to close at this time to prevent the refrigerant from leaking into the second heat exchanger through the second valve, and the compressor is controlled to stop, stopping the refrigerant recovery, reducing the possibility of refrigerant residue in the second heat exchanger, and improving the refrigerant recovery efficiency of the direct cooling system. In the process of after-sales disassembly and assembly of the batteries in the energy storage system, since the second heat exchanger is used to exchange heat for multiple batteries in the energy storage system, the possibility of refrigerant residue in the second heat exchanger is reduced through refrigerant recovery, thereby greatly reducing the direct discharge of refrigerant into the air, eliminating the need to replenish refrigerant, and improving the refrigerant recovery efficiency of the direct cooling system.

[0122] Exemplary Devices

[0123] Accordingly, the embodiment of the present application also provides a refrigerant recovery device for a direct cooling system. The direct cooling system includes a compressor, a first heat exchanger, a second heat exchanger, a first valve and a second valve connected to each other, and the second heat exchanger is used to exchange heat for multiple batteries in the energy storage system.

[0124] like Figure 5 As shown, the refrigerant recovery device of the direct cooling system includes:

[0125] The control unit 501 is configured to control the direct cooling system to enter a refrigerant recovery mode when receiving a refrigerant recovery instruction, wherein in the refrigerant recovery mode, the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve, and flows from the second heat exchanger to the compressor through the second valve;

[0126] A first processing unit 502 is configured to instruct the first valve to close when a first system pipeline pressure at an outlet of the compressor is less than a first preset pressure and / or when the operating time of the compressor in the refrigerant recovery mode is greater than a first preset time;

[0127] The second processing unit 503 is used to instruct the second valve to close and control the compressor to stop when the second system pipeline pressure at the inlet of the compressor is less than a second preset pressure.

[0128] The refrigerant recovery device for the direct cooling system provided in this embodiment belongs to the same application concept as the refrigerant recovery method for the direct cooling system provided in the above embodiments of this application, and can execute the refrigerant recovery method for the direct cooling system provided in any of the above embodiments of this application, and has the corresponding functional modules and beneficial effects of executing the refrigerant recovery method for the direct cooling system. For technical details not fully described in this embodiment, please refer to the specific processing content of the refrigerant recovery method for the direct cooling system provided in the above embodiments of this application, which will not be repeated here.

[0129] For the aforementioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0130] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0131] The steps in the methods of each embodiment of the present application can be adjusted in order, combined and deleted according to actual needs, and the technical features recorded in each embodiment can be replaced or combined.

[0132] The modules and sub-modules in the devices in the embodiments of the present application can be combined, divided and deleted according to actual needs.

[0133] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of modules or sub-modules is only a logical function division. There may be other division methods in actual implementation, such as multiple sub-modules or modules can be combined or integrated into another module, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0134] The modules or submodules described as separate components may or may not be physically separated, and the components of the modules or submodules may or may not be physical modules or submodules, that is, they may be located in one place, or they may be distributed on multiple network modules or submodules. Some or all of the modules or submodules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0135] In addition, each functional module or submodule in each embodiment of the present application may be integrated into one processing module, or each module or submodule may exist physically separately, or two or more modules or submodules may be integrated into one module. The above-mentioned integrated modules or submodules may be implemented in the form of hardware or in the form of software functional modules or submodules.

[0136] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0137] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly by hardware, software units executed by a processor, or a combination of the two. The software units may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0138] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0139] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A refrigerant recovery method for a direct cooling system, characterized in that: The direct cooling system comprises a compressor, a first heat exchanger, a second heat exchanger, a first valve and a second valve which are connected to each other; the second heat exchanger is used to exchange heat for a plurality of batteries in the energy storage system; The method comprises: When receiving a refrigerant recovery instruction, controlling the direct cooling system to enter a refrigerant recovery mode, wherein in the refrigerant recovery mode, the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve, and flows from the second heat exchanger to the compressor through the second valve; Instructing the first valve to close when the first system pipeline pressure at the outlet of the compressor is less than a first preset pressure and / or the operating time of the compressor in the refrigerant recovery mode is greater than a first preset time; When the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the second valve is instructed to close, and the compressor is controlled to stop.

2. The refrigerant recovery method for a direct cooling system according to claim 1, characterized in that: The instructing the first valve to close comprises: Outputting a first prompt message, wherein the first prompt message is used to remind the user to manually close the first valve; or, The first valve is controlled to be closed.

3. The refrigerant recovery method for a direct cooling system according to claim 1, characterized in that: The step of instructing the second valve to close comprises: Outputting a second prompt message, wherein the second prompt message is used to remind the user to manually close the second valve; or, The second valve is controlled to be closed.

4. The refrigerant recovery method for a direct cooling system according to claim 1, characterized in that: The controlling the compressor to stop comprises: The compressor is controlled to run at a reduced speed, and after instructing the second valve to close, the compressor is controlled to stop after a second preset time period.

5. The refrigerant recovery method for a direct cooling system according to claim 1, characterized in that: The method further comprises: When the first valve is not closed, the second valve is not closed, and the operating time of the compressor in the refrigerant recovery mode is greater than the preset maximum operating time, the compressor is controlled to stop and a third prompt message is output, wherein the third prompt message is used to prompt that the refrigerant recovery fails.

6. The refrigerant recovery method for a direct cooling system according to claim 1, characterized in that: The method further comprises: When the first system pipeline pressure at the outlet of the compressor is greater than the third preset pressure, fourth prompt information is output, wherein the fourth prompt information is used to prompt that the first system pipeline pressure at the outlet of the compressor is too high.

7. The refrigerant recovery method for a direct cooling system according to claim 1, characterized in that: The direct cooling system also includes a fan, a third heat exchanger, a refrigeration electronic expansion valve, a heating electronic expansion valve and an air-supplying electronic expansion valve; the fan is arranged on one side of the first heat exchanger; the third heat exchanger includes a first heat exchange part and a second heat exchange part that exchanges heat with the first heat exchange part; the first heat exchanger is connected to a first end of the first heat exchange part, the second end of the first heat exchange part is connected to a first end of the refrigeration electronic expansion valve, the second end of the refrigeration electronic expansion valve is connected to the first valve, the second end of the first heat exchange part is connected to a first end of the air-supplying electronic expansion valve, the second heat exchange part is connected between the second end of the air-supplying electronic expansion valve and the air-supplying port of the compressor, and the heating electronic expansion valve is connected between the second end of the first heat exchange part and the first heat exchanger; The controlling the direct cooling system to enter a refrigerant recovery mode includes: Control the operating frequency of the compressor to be adjusted to a preset frequency, control the fan to run at full speed, adjust the opening of the refrigeration electronic expansion valve according to the suction superheat, control the heating electronic expansion valve to be closed, and control the air supply electronic expansion valve to be closed.

8. The refrigerant recovery method for a direct cooling system according to claim 7, characterized in that: The method further comprises: When the first system pipeline pressure at the outlet of the compressor is less than the first preset pressure, and / or the operation time of the compressor in the refrigerant recovery mode is greater than the first preset time, the refrigeration electronic expansion valve is controlled to be closed; When the second system pipeline pressure at the inlet of the compressor is less than the second preset pressure, the fan is controlled to be closed with a time delay.

9. The refrigerant recovery method for a direct cooling system according to claim 7, characterized in that: The method further comprises: In the refrigerant recovery mode, the alarms of the compressor and the fan are turned off.

10. A refrigerant recovery device for a direct cooling system, characterized in that: The direct cooling system comprises a compressor, a first heat exchanger, a second heat exchanger, a first valve and a second valve which are connected to each other; the second heat exchanger is used to exchange heat for a plurality of batteries in the energy storage system; The refrigerant recovery device comprises: a control unit, configured to control the direct cooling system to enter a refrigerant recovery mode when receiving a refrigerant recovery instruction, wherein in the refrigerant recovery mode, the refrigerant flows from the first heat exchanger to the second heat exchanger through the first valve, and flows from the second heat exchanger to the compressor through the second valve; A first processing unit, configured to instruct the first valve to close when a first system pipeline pressure at an outlet of the compressor is less than a first preset pressure and / or when the operating time of the compressor in the refrigerant recovery mode is greater than a first preset time; The second processing unit is used to instruct the second valve to close and control the compressor to stop when the second system pipeline pressure at the inlet of the compressor is less than a second preset pressure.

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