A highly integrated, low-power dual-circulation liquid cooling system

Abstract

The present invention provides a highly integrated, low-power dual-circulation liquid cooling system, comprising: a condenser; a compressor, one end of the compressor being connected to the condenser; a first heat exchanger, a first end of the first heat exchanger being connected to the other end of the compressor, and an expansion valve being connected to the condenser and the second end of the first heat exchanger; a heater, one end of the heater being connected to the third end of the first heat exchanger; a battery system; a PCS system, one end of the PCS system being connected to the second end of the second heat exchanger, the other end of the PCS system being connected to one end of a second water pump, and the other end of the second water pump being connected to the third end of the second heat exchanger; a liquid storage tank, one end of the liquid storage tank being connected to the fourth end of the second heat exchanger, and a controlled ball valve being connected between the liquid storage tank and the second water pump; and a fan, the fan being placed on one side of the condenser, and the fan being used to dissipate heat from the condenser.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid cooling systems, and more particularly to a high-integration, low-power dual-circulation liquid cooling system. Background Art

[0002] Currently, there are two ways to dissipate heat from a liquid-cooled PCS: 1) Using a compressor for cooling in a parallel or series battery coolant loop. This will occupy the compressor's cooling power, increasing the initial investment of the unit. At the same time, due to the low water temperature, condensation may occur inside the PCS, posing a risk of explosion. 2) Setting up a separate air-cooled radiator for PCS heat dissipation. This method requires an additional set of pipelines and integrating the PCS air-cooled radiator and fan into the system, increasing the difficulty and cost of system integration. At the same time, the fan is running, and the system power consumption increases.

[0003] Currently, the system operates in low-temperature environments, and the charge and discharge performance of the battery cells is significantly affected by temperature. To achieve full battery performance, the cells must be heated. Existing liquid cooling systems use liquid cooling units for heating to compensate for heat leakage. In Northwest China and Inner Mongolia, heating causes the system's auxiliary power consumption to account for a significant portion of the operating cycle, impacting the system's overall conversion efficiency.

[0004] In the current fire protection system, water fire protection requires external access to the station. Only one-time fire fighting agents are involved in the system, which has no continuous suppression capability and cannot play a role in the reheating and re-ignition problem of thermal runaway. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-integration, low-power dual-circulation liquid cooling system.

[0006] The present invention aims to solve the problems existing in the prior art.

[0007] Compared with the prior art, the technical solution of the present invention and its beneficial effects are as follows:

[0008] A highly integrated, low-power dual-circulation liquid cooling system, characterized in that it comprises: a condenser; a compressor, one end of the compressor being connected to the condenser; a first heat exchanger, a first end of the first heat exchanger being connected to the other end of the compressor, and an expansion valve being connected to the condenser and the second end of the first heat exchanger; a heater, one end of the heater being connected to the third end of the first heat exchanger; a battery system, one end of the battery system being connected to the fourth end of the first heat exchanger; a second heat exchanger, a first end of the second heat exchanger being connected to the other end of the battery system, a first water pump being connected between the heater and the second heat exchanger, one end of a first control valve being connected to the expansion valve and the first heat exchanger, the other end of the first control valve being connected to the second heat exchanger, one end of the second control valve being connected to the compressor and the first heat exchanger, and the other end of the second control valve being connected to the second heat exchanger; a PCS system, one end of the PCS system being connected to the second end of the second heat exchanger, The other end of the PCS system is connected to one end of the second water pump, and the other end of the second water pump is connected to the third end of the second heat exchanger; a liquid storage tank, one end of the liquid storage tank is connected to the fourth end of the second heat exchanger, and a controlled ball valve is connected between the liquid storage tank and the second water pump; a fan, the fan is placed on one side of the condenser, and the fan is used to dissipate heat from the condenser; wherein, the battery system uses a compressor for cooling, and the refrigerant of the compressor and the coolant of the battery system exchange heat; when the system is working, the compressor on the battery system side runs for cooling, and heat is exchanged with the battery system through the first heat exchanger; the first water pump provides circulation power, and the first heat exchanger, the second heat exchanger and the battery system exchange heat; the coolant of the liquid storage tank, the battery system and the PCS system are connected, and when the system pressure drops, the liquid is automatically replenished; the PCS system temperature is divided into multiple gears, and the heat generated by the PCS system is transferred to the coolant, and the heat exchange circuit is controlled by the second heat exchanger and the second water pump.

[0009] The beneficial effects of the present invention are:

[0010] The present invention sets up a separate PCS cooling circuit, and the coolant exchanges heat with the coolant after the battery outlet, eliminating the need for additional air-cooled radiators and fans, thereby reducing system power consumption.

[0011] The present invention uses a stepped thermal management strategy to control, combining data collected from ambient temperature, PCS temperature, battery cell temperature, and liquid temperature to store PCS heat and store heat using coolant as a carrier. During the static or heating stage, the stored heat temperature is used to heat the battery, reducing the intervention of the PTC of the liquid cooling unit and lowering the auxiliary power consumption of the system. When rapid heating is required, the two work simultaneously, greatly improving the system heating rate, achieving rapid system response, and throughput of the expected power.

[0012] The present invention has an internal integrated liquid storage tank containing a large amount of coolant, which not only meets the heat dissipation requirements of the system but also provides immersion fire protection for the system, and continuously submerges to suppress and control thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of a highly integrated, low-power dual-circulation liquid cooling system provided by an embodiment of the present invention.

[0014] Figure 2 Schematic diagram of a temperature drop rate curve provided by an embodiment of the present invention.

[0015] Figure 3 Schematic diagram of temperature-operating condition curve provided by an embodiment of the present invention.

[0016] In the picture:

[0017] 1. Condenser 2. Expansion valve 3. Fan

[0018] 4. Compressor 5. First control valve 6. Second control valve

[0019] 7. First heat exchanger 8. Heater 9. First water pump 10. Second heat exchanger 11. Battery system 12. Liquid storage tank 13. PCS system 14. Second water pump 15. Controlled ball valve DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0022] Reference Figures 1 to 3 As shown, a highly integrated, low-power dual-circulation liquid cooling system includes:

[0023] Condenser 1;

[0024] A compressor 4, one end of the compressor 4 is connected to the condenser 1;

[0025] a first heat exchanger 7, wherein a first end of the first heat exchanger 7 is connected to the other end of the compressor 4, and an expansion valve 2 is connected to the condenser 1 and the second end of the first heat exchanger 7;

[0026] a heater 8, one end of the heater 8 being connected to the third end of the first heat exchanger 7;

[0027] a battery system 11, one end of the battery system 11 being connected to the fourth end of the first heat exchanger 7;

[0028] a second heat exchanger 10, wherein a first end of the second heat exchanger 10 is connected to the other end of the battery system 11, a first water pump 9 is connected between the heater 8 and the second heat exchanger 10, one end of the first control valve 5 is connected to the expansion valve 2 and the first heat exchanger 7, and the other end of the first control valve 5 is connected to the second heat exchanger 10, one end of the second control valve 6 is connected to the compressor 4 and the first heat exchanger 7, and the other end of the second control valve 6 is connected to the second heat exchanger 10;

[0029] a PCS system 13, one end of the PCS system 13 being connected to the second end of the second heat exchanger 10, the other end of the PCS system 13 being connected to one end of a second water pump 14, the other end of the second water pump 14 being connected to the third end of the second heat exchanger 10;

[0030] a liquid storage tank 12 , one end of the liquid storage tank 12 being connected to the fourth end of the second heat exchanger 10 , and a controlled ball valve 15 being connected between the liquid storage tank 12 and the second water pump 14 ;

[0031] A fan 3 is placed on one side of the condenser 1 and is used to dissipate heat from the condenser 1;

[0032] The battery system 11 is cooled by the compressor 4, and the refrigerant of the compressor 4 exchanges heat with the coolant of the battery system 11. When the system is working, the compressor 4 on the battery system 11 side operates to cool the battery system 11, and heat is exchanged with the battery system 11 through the first heat exchanger 7.

[0033] The first water pump 9 provides circulation power, and the first heat exchanger 7, the second heat exchanger 10 and the battery system 11 perform heat exchange;

[0034] The coolant of the liquid storage tank 12, the battery system 11 and the PCS system 13 are connected, and when the system pressure drops, the liquid is automatically replenished;

[0035] The temperature of the PCS system 13 is divided into multiple levels. The heat generated by the PCS system 13 is transferred to the coolant, and the heat exchange circuit is controlled by the second heat exchanger 10 and the second water pump 14.

[0036] Also includes:

[0037] The temperatures collected by the PCS system are divided into three levels: 45°C, 65°C, and 85°C;

[0038] When the PCS system temperature is ≤45°C, the circulating liquid temperature does not need to be cooled, and the PCS system coolant does not pass through the second heat exchanger and goes through a straight channel, which reduces the operating resistance of the second water pump and reduces power consumption;

[0039] When the PCS system temperature is 45℃<65℃, the PCS system coolant will fully exchange heat with the battery system through the second heat exchanger.

[0040] When the PCS system temperature is 85°C lower than the PCS system temperature, the first control valve and the second control valve are opened to introduce compressor cooling to perform heat exchange on the PCS system coolant.

[0041] Also includes:

[0042] When operating in a low-temperature environment, after the PCS system is working, the PCS system coolant heats the coolant on the battery system side, and the PTC heater is not turned on to heat the battery system;

[0043] When the system responds rapidly, the unit turns on the PTC heater and cooperates with the heat exchange on the PCS system side to achieve rapid heating of the system.

[0044] Also includes:

[0045] When the system is in standby mode for a long time, or the charge and discharge intervals are long, the second heat exchanger is closed by predicting the current curve, and the controlled ball valve is opened to connect to the liquid storage tank. The PCS system heats the coolant in the liquid storage tank to store heat. When the system is not working, the liquid in the liquid storage tank can keep the system warm without turning on the unit's PTC heater.

[0046] Also includes:

[0047] The ambient temperature in the cabin is collected and the temperature drop rate of the system at different temperatures is obtained through testing. The temperature drop rate formula is:

[0048] Temperature drop rate = -2e-06*T^4-8e-05*T^3+0.0018*T^2-0.1479*T+9.707;

[0049] Where T is time.

[0050] Also includes:

[0051] According to the working current, three characteristic currents are taken as parameters for estimating the temperature curve change;

[0052] The characteristic current is 0.5C:

[0053] Temperature = 4e-15*t^4-8e-11*t^3+5e-07*t^2+0.0005*t+25.005

[0054] The characteristic current is 0.33C:

[0055] Temperature = -5e-16*t^4+1e-11*t^3-1e-07*t^2+0.0008*t+25.031

[0056] The characteristic current is 1C:

[0057] Temperature = 3e-14*t^4-8e-11*t^3-6e-07*t^2+0.0056*t+24.972

[0058] Where t is time.

[0059] According to the collected ambient temperature and temperature drop rate, the actual standing time is calculated, that is:

[0060]

[0061] If the actual standstill time is less than or equal to the expected standstill time, the PCS system will be cooled normally.

[0062] If the actual standing time is greater than the expected standing time, the second heat exchanger is closed and the controlled ball valve is opened to connect the liquid storage tank. The PCS system heats the coolant in the liquid storage tank, and the liquid storage tank can store heat. When the system is not working, the liquid in the liquid storage tank can keep the system warm, and there is no need to turn on the PTC heater of the unit.

[0063] Estimate the subsequent temperature conditions based on the collected ambient temperature and the subsequent standing time (insulation time).

[0064] Taking 0.5°C as an example, when (4e-15*t^4-8e-11*t^3+5e-07*t^2+0.0005*t+25.005) / (-2e-06*T^4-8e-05*T^3+0.0018*T^2-0.1479*T+9.707) ≤ the expected standstill time, PCS cooling is performed normally.

[0065] When (4e-15*t^4-8e-11*t^3+5e-07*t^2+0.0005*t+25.005) / (-2e-06*T^4-8e-05*T^3+0.0018*T^2-0.1479*T+9.707)>the expected standstill time, close the second heat exchanger, open the control ball valve, connect the liquid storage tank, and the PCS heats the coolant in the liquid storage tank to store heat. When the system is not operating, the liquid in the liquid storage tank can keep the system warm, without turning on the unit's PTC heating.

[0066] When the system goes out of control and the fire-fighting agent is released, the fire may reheat and reignite. At this time, the coolant in the storage tank is used as water fire-fighting liquid to continuously submerge and suppress the out-of-control location, dissipate heat and cool it down, and prevent the spread of thermal runaway in the system.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Those skilled in the art should understand that any modifications and equivalent substitutions that do not depart from the spirit and scope of the present invention should fall within the scope of protection of the claims of the present invention.

Claims

1. A high-integration, low-power dual-circulation liquid cooling system, characterized in that: include: condenser; a compressor, one end of the compressor being connected to the condenser; a first heat exchanger, wherein a first end of the first heat exchanger is connected to the other end of the compressor, and an expansion valve is connected to the condenser and the second end of the first heat exchanger; a heater, one end of the heater being connected to the third end of the first heat exchanger; a battery system, one end of the battery system being connected to the fourth end of the first heat exchanger; a second heat exchanger, wherein a first end of the second heat exchanger is connected to the other end of the battery system, a first water pump is connected between the heater and the second heat exchanger, one end of a first control valve is connected to the expansion valve and the first heat exchanger, the other end of the first control valve is connected to the second heat exchanger, one end of a second control valve is connected to the compressor and the first heat exchanger, and the other end of the second control valve is connected to the second heat exchanger; a PCS system, wherein one end of the PCS system is connected to the second end of the second heat exchanger, the other end of the PCS system is connected to one end of a second water pump, and the other end of the second water pump is connected to the third end of the second heat exchanger; a liquid storage tank, one end of the liquid storage tank being connected to the fourth end of the second heat exchanger, and a controlled ball valve being connected between the liquid storage tank and the second water pump; A fan is placed on one side of the condenser and is used to dissipate heat from the condenser; The battery system is cooled by a compressor, and the refrigerant of the compressor exchanges heat with the coolant of the battery system. When the system is working, the compressor on the battery system side operates to cool the battery system, and heat is exchanged with the battery system through the first heat exchanger. The first water pump provides circulation power, and the first heat exchanger, the second heat exchanger and the battery system perform heat exchange; The coolant of the liquid storage tank, battery system and PCS system is connected, and when the system pressure drops, the liquid is automatically replenished; The PCS system temperature is divided into multiple levels. The heat generated by the PCS system is transferred to the coolant, and the heat exchange circuit is controlled by the second heat exchanger and the second water pump; The ambient temperature in the cabin is collected and the temperature drop rate of the system at different temperatures is obtained through testing. The temperature drop rate formula is: Temperature drop rate = -2e-06*T^4-8e-05*T^3+0.0018*T^2-0.1479*T+9.707; where T is time; According to the working current, three characteristic currents are taken as parameters for estimating the temperature curve change; the characteristic current is 0.5C: Temperature = 4e-15*t^4-8e-11*t^3+5e-07*t^2+0.0005*t+25.005 Characteristic current is 0.33C: Temperature = -5e-16*t^4+1e-11*t^3-1e-07*t^2+0.0008*t+25.031 The characteristic current is 1C: Temperature = 3e-14*t^4-8e-11*t^3-6e-07*t^2+0.0056*t+24.972 Where t is time; According to the collected ambient temperature and temperature drop rate, the actual standing time is calculated, that is: If the actual standstill time is less than or equal to the expected standstill time, the PCS system will be cooled normally. If the actual standing time is greater than the expected standing time, the second heat exchanger is closed and the controlled ball valve is opened to connect the liquid storage tank. The PCS system heats the coolant in the liquid storage tank, and the liquid storage tank can store heat. When the system is not working, the liquid in the liquid storage tank can keep the system warm, and there is no need to turn on the PTC heater of the unit.

2. A high-integration, low-power dual-circulation liquid cooling system according to claim 1, characterized in that: Also includes: The temperatures collected by the PCS system are divided into three levels: 45°C, 65°C, and 85°C; When the PCS system temperature is ≤45°C, the circulating liquid temperature does not need to be cooled, and the PCS system coolant does not pass through the second heat exchanger and goes through a straight channel, which reduces the operating resistance of the second water pump and reduces power consumption; When the PCS system temperature is 45℃<65℃, the PCS system coolant will fully exchange heat with the battery system through the second heat exchanger. When the PCS system temperature is 85°C lower than the PCS system temperature, the first control valve and the second control valve are opened to introduce compressor cooling to perform heat exchange on the PCS system coolant.

3. The high-integration, low-power dual-circulation liquid cooling system according to claim 1, characterized in that: Also includes: When operating in a low-temperature environment, after the PCS system is working, the PCS system coolant heats the coolant on the battery system side, and the PTC heater is not turned on to heat the battery system; When the system responds rapidly, the unit turns on the PTC heater and cooperates with the heat exchange on the PCS system side to achieve rapid heating of the system.

4. The high-integration, low-power dual-circulation liquid cooling system according to claim 1, characterized in that: Also includes: When the system is in standby mode for a long time, or the charge and discharge intervals are long, the second heat exchanger is closed by predicting the current curve, and the controlled ball valve is opened to connect to the liquid storage tank. The PCS system heats the coolant in the liquid storage tank to store heat. When the system is not working, the liquid in the liquid storage tank can keep the system warm without turning on the unit's PTC heater.

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