Double-cold-source coupling cooling system and control method and system

Abstract

The invention provides a double-cold-source coupling cooling system and a control method and system.The cooling system comprises a first cooling unit and a second cooling unit, the first cooling unit comprises a compressor, a first heat exchanger and a condenser, and a first cooling medium circularly flows in the compressor and the first heat exchanger; the second cooling unit comprises a second heat exchanger connected with a natural cold source, and the natural cold source is used for providing a second cooling medium for natural refrigeration; the natural cold source is connected with the second heat exchanger and the condenser through a first three-way valve. The second heat exchanger is connected with the natural cold source and the condenser through a second three-way valve. The control method comprises the step of controlling the states of the first three-way valve and the second three-way valve according to real-time working conditions. According to the control method, the problem of energy backward flowing under the low-load working condition is fundamentally avoided, the series-connection type pre-cooling advantage and the parallel-connection type low-resistance characteristic are fused, and the unit is always in the optimal operation state under the current working condition through dynamic mode switching.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioner control, and particularly to a dual-cooling-source coupled cooling system, a control method and a system thereof. Background Art

[0002] With the rapid development of AIGC technology, the power density of a single cabinet in a data center continues to rise, and higher requirements are put forward for the heat dissipation capacity in high-performance computing (AI, HPC, etc.) scenarios. Traditional air-cooling technology has been difficult to meet the cooling requirements of high-density cabinets. The dual-cooling-source computer room air conditioner, due to its advantage of combining natural cold source and mechanical refrigeration, has become a key technology for reducing the PUE of data centers and achieving green and low-carbon operation. Existing dual-cooling-source systems mainly adopt a series or parallel architecture, but both have significant limitations.

[0003] In the series architecture, as shown in the figure, the cooling water flows through the water coil (natural cold source) and the water-to-refrigerant plate heat exchanger (condenser) in sequence. Although the natural cooling duration can be extended by precooling the return air, there are the following defects: First, the series water circuit leads to an increase in the water resistance of the system, and a high-lift water pump needs to be configured, resulting in increased energy consumption; Second, when the cooling water heated by the water coil enters the condenser, the condensation pressure rises, and the energy efficiency of the compressor decreases significantly; Third, in low-load or low-temperature conditions, the return air temperature may be lower than the cooling water temperature, causing the water coil to heat the return air in the reverse direction, instead increasing the compressor power consumption. In the parallel architecture, by diverting the cooling water to the water coil and the condenser, although the water resistance can be reduced and the energy efficiency of the compressor can be improved, its control logic is complex, and limited by the setting of the switching temperature difference, the natural cooling duration cannot be maximally utilized. Summary of the Invention

[0004] The purpose of the present invention is to provide a dual-cooling-source coupled cooling system, a control method and a system that can dynamically switch the operating mode and integrate the advantages of series and parallel.

[0005] To achieve the above purpose, the present invention provides a control method for a dual-cooling-source coupled cooling system. The cooling system includes a first cooling unit and a second cooling unit. The first cooling unit includes a compressor, a first heat exchanger and a condenser. A first cooling medium circulates in the compressor and the first heat exchanger. The second cooling unit includes a second heat exchanger connected to a natural cold source. The natural cold source is used to provide a second cooling medium for natural refrigeration, and the indoor return air passes through the second heat exchanger and the first heat exchanger in sequence;

[0006] The condenser has a first channel and a second channel. The first channel is connected to the compressor and the first heat exchanger, and the second channel is connected to the natural cold source;

[0007] Based on the first channel and the second channel, the first cooling medium and the second cooling medium perform heat exchange in the condenser;

[0008] The output end of the natural cold source is connected to the inlet end of the second heat exchanger and the second channel of the condenser respectively through a first three-way valve;

[0009] The outlet end of the second channel of the condenser is connected to the recovery end of the natural cold source;

[0010] The outlet end of the second heat exchanger is connected to the recovery end of the natural cold source and the inlet end of the second channel of the condenser respectively through a second three-way valve;

[0011] The control method includes:

[0012] Control the states of the first three-way valve and the second three-way valve according to the relationship between the temperature of the second cooling medium and the indoor supply air temperature and return air temperature, and the load of the compressor.

[0013] Preferably, a check valve is further arranged between the second three-way valve and the inlet end of the second channel of the condenser, and the check valve controls the one-way flow of the second cooling medium in the direction of the second channel.

[0014] Preferably, when the temperature of the second cooling medium output by the natural cold source is greater than or equal to the indoor return air temperature, control the state of the first three-way valve to open the communication channel between the natural cold source and the inlet end of the second channel of the condenser, and close the communication channel between the natural cold source and the inlet end of the second heat exchanger; control the state of the second three-way valve to close the communication between the outlet end and the inlet end of the second channel of the condenser at the second three-way valve.

[0015] Preferably, when the temperature of the second cooling medium output by the natural cold source is less than the indoor return air temperature and greater than the indoor supply air temperature, and the load of the compressor is less than a preset load threshold, control the state of the first three-way valve to open the communication channel between the natural cold source and the inlet end of the second channel of the condenser, and at the same time open the communication channel between the natural cold source and the inlet end of the second heat exchanger; control the state of the second three-way valve to open the communication channel between the outlet end of the second heat exchanger and the recovery end of the natural cold source, and disconnect the communication channel between the outlet end of the second heat exchanger and the inlet end of the second channel of the condenser.

[0016] Preferably, when the temperature of the second cooling medium output by the natural cold source is less than or equal to the indoor return air temperature and greater than the indoor supply air temperature, and the load of the compressor is greater than or equal to a preset load threshold, control the state of the first three-way valve to open the communication channel between the natural cold source and the inlet end of the second heat exchanger, and disconnect the communication channel between the natural cold source and the inlet end of the condenser; control the state of the second three-way valve to open the communication channel between the outlet end of the second heat exchanger and the inlet end of the second channel of the condenser, and disconnect the communication channel between the outlet end of the second heat exchanger and the recovery end of the natural cold source.

[0017] Preferably, when the temperature of the second cooling medium output by the natural cold source is less than or equal to the indoor supply air temperature, control the state of the first three-way valve to open the communication channel between the natural cold source and the inlet end of the second heat exchanger, and disconnect the communication channel between the natural cold source and the inlet end of the second channel of the condenser; control the state of the second three-way valve to open the communication channel between the outlet end of the second heat exchanger and the recovery end of the natural cold source, and disconnect the communication channel between the outlet end of the second heat exchanger and the inlet end of the second channel of the condenser.

[0018] Preferably, the second cooling medium includes cold water.

[0019] The present invention also provides a dual cold source coupled cooling system, which includes a first cooling unit, a second cooling unit and a controller. The first cooling unit includes a compressor, a first heat exchanger and a condenser. A first cooling medium circulates in the compressor and the first heat exchanger. The second cooling unit includes a second heat exchanger connected to a natural cold source. The natural cold source is used to provide a second cooling medium for natural refrigeration, and the indoor return air sequentially passes through the second heat exchanger and the first heat exchanger;

[0020] The condenser has a first channel and a second channel. The first channel is connected to the compressor and the first heat exchanger, and the second channel is connected to the natural cold source;

[0021] Based on the first channel and the second channel, the first cooling medium and the second cooling medium perform heat exchange in the condenser;

[0022] The output end of the natural cold source is respectively connected to the inlet end of the second heat exchanger and the second channel of the condenser through a first three-way valve;

[0023] The outlet end of the second channel of the condenser is connected to the recovery end of the natural cold source;

[0024] The outlet end of the second heat exchanger is respectively connected to the recovery end of the natural cold source and the inlet end of the second channel of the condenser through a second three-way valve;

[0025] The controller controls the states of the first three-way valve and the second three-way valve based on the dual cold source coupled cooling system control method as described above.

[0026] The present invention also provides a dual cold source coupled cooling control system, which includes:

[0027] One or more processors;

[0028] A memory;

[0029] And one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors. The programs include instructions for executing the dual cold source coupled cooling system control method as described in any one of the above.

[0030] The present invention also provides a computer-readable storage medium, which includes a computer program that can be executed by a processor to complete the dual cold source coupled cooling system control method as described in any one of the above.

[0031] Compared with the prior art, the dual cold source coupled cooling system control method provided by the above technical solution of the present invention realizes the parallel / series switching of the cooling medium provided by the natural cold source between the condenser and the corresponding heat exchanger through the flexible adjustment of the first three-way valve and the second three-way valve. In the low load condition, the parallel mode can be preferentially adopted to reduce the water resistance of the system and the demand for the external water pump head; in the high load condition, it can be switched to the series mode to pre-cool the return air by the natural cold source and reduce the compressor load (retaining the advantages of the series type); thus, the above control method realizes the theoretical extreme value of the utilization time of the natural cold source, fundamentally avoids the problem of energy backflow under the low load condition, integrates the advantages of series pre-cooling and the low resistance characteristics of the parallel type, and enables the unit to always be in the optimal operating state under the current working condition through dynamic mode switching. Description of the Drawings

[0032] Figure 1 It is the principle structure diagram of the dual cold source coupled cooling system in the embodiment of the present invention. Detailed Embodiments

[0033] To describe the technical content, structural features, achieved purposes and effects of the present invention in detail, the following is described in detail in conjunction with the embodiments and the accompanying drawings.

[0034] This embodiment discloses a dual cold source coupled cooling system control method. The cooling system includes a first cooling unit, a second cooling unit and a controller.

[0035] The first cooling unit includes a compressor M, a first heat exchanger G1, and a condenser N. A first cooling medium circulates in the compressor M and the first heat exchanger G1. The first cooling medium in this embodiment is preferably Freon. Therefore, the first heat exchanger G1 is preferably a fluorine coil.

[0036] The second cooling unit includes a second heat exchanger G2 connected to a natural cold source. The natural cold source is used to provide a second cooling medium for natural refrigeration, and the indoor return air sequentially passes through the second heat exchanger G2 and the first heat exchanger G1.

[0037] The condenser N has a first channel L1 and a second channel L2. The first channel L1 is connected to the compressor M and the first heat exchanger G1, and the second channel L2 is connected to the natural cold source.

[0038] Based on the first channel L1 and the second channel L2, the first cooling medium and the second cooling medium exchange heat in the condenser N. Since the second cooling medium is natural cold, in the condenser N, the second cooling medium cools down the first cooling medium.

[0039] The output end of the natural cold source is respectively connected to the second heat exchanger G2 and the inlet end of the second channel L2 of the condenser N through a first three-way valve F1.

[0040] The outlet end of the second channel L2 of the condenser N is connected to the recovery end of the natural cold source.

[0041] The outlet end of the second heat exchanger G2 is respectively connected to the recovery end of the natural cold source and the inlet end of the second channel L2 of the condenser N through a second three-way valve F2.

[0042] Based on the cooling system with the above structure, the control method includes:

[0043] The controller controls the states of the first three-way valve F1 and the second three-way valve F2 according to the relationship between the temperature of the second cooling medium and the indoor supply air temperature and return air temperature, and the load of the compressor M, so as to control the second cooling medium to selectively flow into the second heat exchanger G2 and the condenser N in series or in parallel, or flow into the condenser N or the second heat exchanger G2 alone.

[0044] Further, a check valve F3 is also provided between the second three-way valve F2 and the inlet end of the second channel L2 of the condenser N. The check valve F3 controls the one-way flow of the second cooling medium in the direction of the second channel L2, and prevents the second cooling medium from flowing back from the second three-way valve F2 to the second heat exchanger G2.

[0045] Specifically, for the convenience of explaining the states of the first three-way valve F1 and the second three-way valve F2, the three ports of the first three-way valve F1 are respectively named AB, A, and B, and the three ports of the second three-way valve F2 are respectively named CD, C, and D.

[0046] Among them, port AB is connected to the output end of the natural cold source, port A is connected to the inlet end of the second heat exchanger G2, and port B is connected to the inlet end of the second channel L2 of the condenser N.

[0047] Port CD is connected to the outlet end of the second heat exchanger G2, port C is connected to the inlet end of the second channel L2 of the condenser N, and port D is connected to the recovery end of the natural cold source.

[0048] When the following condition one is satisfied, control the states of the first three-way valve F1 and the second three-way valve F2 so that the cooling system enters the mechanical cooling mode.

[0049] Condition one: T1≥T 回风 ;

[0050] Among them, T1 is the temperature of the second cooling medium output by the natural cold source, and T 回风 is the indoor return air temperature.

[0051] In the mechanical cooling mode, control the state of the first three-way valve F1 to open the communication channel between the natural cold source and the inlet end of the second channel L2 of the condenser N, and close the communication channel between the natural cold source and the inlet end of the second heat exchanger G2, that is, make AB conduct with B, and AB disconnect from A, so that the second cooling medium only flows into the condenser N and does not flow into the second heat exchanger G2.

[0052] Control the state of the second three-way valve F2 to close the communication between the outlet end and the inlet end of the second channel L2 of the condenser N at the second three-way valve F2, that is, disconnect C from D, to prevent the second cooling medium flowing out of the outlet end of the second channel L2 of the condenser N from returning to the inlet end.

[0053] On the other hand, when the following condition two is satisfied, control the states of the first three-way valve F1 and the second three-way valve F2 so that the cooling system enters the first mixing mode.

[0054] Condition two:

[0055] T 送风 <T1<T 回风 ;

[0056] And, P<P0;

[0057] Among them, T 送风 is the indoor supply air temperature, P is the load of the compressor M, and P0 is the preset load threshold.

[0058] In the first mixing mode, control the state of the first three-way valve F1 to open the communication channel between the natural cold source and the inlet end of the second channel L2 of the condenser N, and at the same time open the communication channel between the natural cold source and the inlet end of the second heat exchanger G2. That is, make AB conduct with A and AB conduct with B.

[0059] Control the state of the second three-way valve F2 to open the communication channel between the outlet end of the second heat exchanger G2 and the recovery end of the natural cold source, and disconnect the communication channel between the outlet end of the second heat exchanger G2 and the inlet end of the second channel L2 of the condenser N. That is, make CD conduct with D and CD disconnect from C.

[0060] In this first mixing mode, the second channel L2 of the condenser N is in parallel with the second heat exchanger G2. A part of the second cooling medium enters the second heat exchanger G2, and another part of the second cooling medium enters the second channel L2 of the condenser N.

[0061] On the other hand, when the following condition three is satisfied, control the states of the first three-way valve F1 and the second three-way valve F2 so that the cooling system enters the second mixing mode.

[0062] Condition three:

[0063] T 送风 <T1<T 回风 ;

[0064] And, P≥P0;

[0065] In addition, it should be noted that for P0, it is preferably 50% of the full load of the compressor.

[0066] In the second mixing mode, control the state of the first three-way valve F1 to open the communication channel between the natural cold source and the inlet end of the second heat exchanger G2, and disconnect the communication channel between the natural cold source and the inlet end of the condenser N. That is, make AB conduct with A and AB disconnect from B.

[0067] Control the state of the second three-way valve F2 to open the communication channel between the outlet end of the second heat exchanger G2 and the inlet end of the second channel L2 of the condenser N, and disconnect the communication channel between the outlet end of the second heat exchanger G2 and the recovery end of the natural cold source. That is, make CD conduct with C and CD disconnect from D.

[0068] In this second mixing mode, the second channel L2 of the condenser N is in series with the second heat exchanger G2. The second cooling medium first enters the second heat exchanger G2 from the first three-way valve F1, then flows out of the second heat exchanger G2 and enters the inlet end of the second channel L2 of the condenser N through the second three-way valve F2, and then returns to the recovery end of the natural cold source from the outlet end of the second channel L2.

[0069] On the other hand, when Condition 4 below is satisfied, control the states of the first three-way valve F1 and the second three-way valve F2 so that the cooling system enters the free cooling mode.

[0070] Condition 4: T1 ≤ T 送风 ;

[0071] In the free cooling mode, control the state of the first three-way valve F1 to open the communication channel between the free cooling source and the inlet end of the second heat exchanger G2, and disconnect the communication channel between the free cooling source and the inlet end of the second channel L2 of the condenser N. That is, make AB conduct with A and AB disconnect from B.

[0072] Control the state of the second three-way valve F2 to open the communication channel between the outlet end of the second heat exchanger G2 and the recovery end of the free cooling source, and disconnect the communication channel between the outlet end of the second heat exchanger G2 and the inlet end of the second channel L2 of the condenser N. That is, make CD conduct with D and CD disconnect from C.

[0073] In this free cooling mode, the compressor M shuts down, and the second cooling medium completely enters the second heat exchanger G2, and the return air is completely cooled by the second heat exchanger G2.

[0074] Furthermore, the second cooling medium includes cold water. Then, the second heat exchanger G2 includes a water coil.

[0075] In summary, the control method of the dual-cooling-source coupled cooling system provided by the above technical solution of the present invention realizes the parallel / series switching of the cooling medium provided by the free cooling source between the condenser N and the corresponding heat exchanger through the flexible adjustment of the first three-way valve F1 and the second three-way valve F2. In low load conditions, the parallel mode can be preferentially adopted to reduce the water resistance of the system and the demand for the external water pump head; in high load conditions, it can be switched to the series mode to pre-cool the return air with the free cooling source and reduce the load of the compressor M (retaining the advantages of the series type).

[0076] Therefore, the above control method realizes the theoretical extreme value of the utilization time of the free cooling source, fundamentally avoids the problem of energy backflow under low load conditions, combines the advantages of series pre-cooling and the low resistance characteristics of the parallel type, and enables the unit to always be in the optimal operating state under the current working conditions through dynamic mode switching.

[0077] The present invention also discloses a dual-cooling-source coupled cooling control system, which includes one or more processors, a memory, and one or more programs. Among them, the one or more programs are stored in the memory and are configured to be executed by the one or more processors. The programs include instructions for executing the control method as described above. The processor can be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, which are used to execute relevant programs to implement the functions required by the modules in the cooling control system of the embodiments of the present application, or to execute the control method of the method embodiments of the present application.

[0078] The present invention also discloses a computer-readable storage medium, which includes a computer program. The computer program can be executed by a processor to complete the control method as described above. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server or a data center that includes one or more integrated available media. The available medium can be a read-only memory (ROM), a random access memory (RAM), a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape, a magnetic disk, or an optical medium, such as a digital versatile disc (DVD), or a semiconductor medium, such as a solid state disk (SSD), etc.

[0079] The embodiments of the present application also disclose a computer program product or a computer program. The computer program product or the computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. The processor of the electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the electronic device executes the above control method.

[0080] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A dual-cold-source coupled cooling system control method, characterized in that: The cooling system comprises a first cooling unit and a second cooling unit, the first cooling unit comprises a compressor, a first heat exchanger and a condenser, a first cooling medium circulates in the compressor and the first heat exchanger, the second cooling unit comprises a second heat exchanger connected to a natural cold source, the natural cold source is used to provide a second cooling medium for natural cooling, and indoor return air passes through the second heat exchanger and the first heat exchanger in sequence; The condenser has a first channel and a second channel, the first channel is connected to the compressor and the first heat exchanger, and the second channel is connected to the natural cooling source; Based on the first channel and the second channel, the first cooling medium and the second cooling medium perform heat exchange in the condenser; The output end of the natural cooling source is connected to the inlet ends of the second heat exchanger and the second channel of the condenser respectively through a first three-way valve; The outlet end of the second channel of the condenser is connected to the recovery end of the natural cooling source; The outlet end of the second heat exchanger is connected to the recovery end of the natural cooling source and the inlet end of the second channel of the condenser respectively through a second three-way valve; The control method comprises: The states of the first three-way valve and the second three-way valve are controlled according to the relationship between the temperature of the second cooling medium and the indoor supply air temperature and return air temperature, and the load of the compressor.

2. The dual cold source coupled cooling system control method according to claim 1, characterized in that: A one-way valve is further provided between the second three-way valve and the inlet end of the second channel of the condenser, and the one-way valve controls the one-way flow of the second cooling medium toward the second channel.

3. The dual cold source coupled cooling system control method according to claim 2, characterized in that: When the temperature of the second cooling medium output by the natural cooling source is greater than or equal to the indoor return air temperature, the state of the first three-way valve is controlled to open the communication channel between the natural cooling source and the inlet end of the second channel of the condenser, and to close the communication channel between the natural cooling source and the inlet end of the second heat exchanger; The state of the second three-way valve is controlled to close the communication between the outlet end and the inlet end of the second channel of the condenser at the second three-way valve.

4. The dual cold source coupled cooling system control method according to claim 2, characterized in that: When the temperature of the second cooling medium output by the natural cooling source is lower than the indoor return air temperature and higher than the indoor supply air temperature, and the load of the compressor is lower than a preset load threshold, the state of the first three-way valve is controlled to open the communication channel between the natural cooling source and the inlet end of the second channel of the condenser, and at the same time, the communication channel between the natural cooling source and the inlet end of the second heat exchanger is opened; The state of the second three-way valve is controlled to open the communication channel between the outlet end of the second heat exchanger and the recovery end of the natural cooling source, and to disconnect the communication channel between the outlet end of the second heat exchanger and the inlet end of the second channel of the condenser.

5. The dual cold source coupled cooling system control method according to claim 1, characterized in that: When the temperature of the second cooling medium output by the natural cooling source is less than or equal to the indoor return air temperature and greater than the indoor supply air temperature, and the load of the compressor is greater than or equal to a preset load threshold, the state of the first three-way valve is controlled to open the communication channel between the natural cooling source and the inlet end of the second heat exchanger, and to disconnect the communication channel between the natural cooling source and the inlet end of the condenser; The state of the second three-way valve is controlled to open the communication channel between the outlet end of the second heat exchanger and the inlet end of the second channel of the condenser, and to disconnect the communication channel between the outlet end of the second heat exchanger and the recovery end of the natural cooling source.

6. The dual cold source coupled cooling system control method according to claim 1, characterized in that: When the temperature of the second cooling medium output by the natural cooling source is less than or equal to the indoor supply air temperature, the state of the first three-way valve is controlled to open the communication channel between the natural cooling source and the inlet end of the second heat exchanger, and disconnect the communication channel between the natural cooling source and the inlet end of the second channel of the condenser; the state of the second three-way valve is controlled to open the communication channel between the outlet end of the second heat exchanger and the recovery end of the natural cooling source, and disconnect the communication channel between the outlet end of the second heat exchanger and the inlet end of the second channel of the condenser.

7. The dual cold source coupled cooling system control method according to claim 1, characterized in that: The second cooling medium includes cold water.

8. A dual cold source coupled cooling system, characterized in that: The invention comprises a first cooling unit, a second cooling unit and a controller, wherein the first cooling unit comprises a compressor, a first heat exchanger and a condenser, wherein a first cooling medium circulates in the compressor and the first heat exchanger, and the second cooling unit comprises a second heat exchanger connected to a natural cold source, wherein the natural cold source is used to provide a second cooling medium for natural cooling, and indoor return air passes through the second heat exchanger and the first heat exchanger in sequence; The condenser has a first channel and a second channel, the first channel is connected to the compressor and the first heat exchanger, and the second channel is connected to the natural cooling source; Based on the first channel and the second channel, the first cooling medium and the second cooling medium perform heat exchange in the condenser; The output end of the natural cooling source is connected to the inlet ends of the second heat exchanger and the second channel of the condenser respectively through a first three-way valve; The outlet end of the second channel of the condenser is connected to the recovery end of the natural cooling source; The outlet end of the second heat exchanger is connected to the recovery end of the natural cooling source and the inlet end of the second channel of the condenser respectively through a second three-way valve; The controller controls the states of the first three-way valve and the second three-way valve based on the dual cold source coupled cooling system control method according to any one of claims 1 to 7.

9. A dual cold source coupled cooling control system, characterized in that: include: one or more processors; Memory; and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs comprising instructions for executing the dual cold source coupled cooling system control method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: It comprises a computer program, which can be executed by a processor to complete the dual cold source coupled cooling system control method as described in any one of claims 1 to 7.

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