An immersed dual-medium independent closed-loop energy storage water chiller system and a control method thereof

Abstract

The application relates to an immersed double-medium independent closed-loop energy storage water chiller system and a control method, the system comprising a PCS-side refrigeration circuit and a battery-side refrigeration circuit which are physically independently operated, the PCS side adopts a PCS cooling liquid solution as a heat exchange medium, and the battery side adopts an energy storage special cooling liquid as a heat exchange medium; a heat exchanger and an electromagnetic three-way valve are arranged between the two circuits to realize mode switching of independent heat exchange and collaborative heat exchange. According to the control method, the battery-side operation mode is switched in combination with the cell temperature, the PCS liquid supply temperature and the environment temperature in the liquid cooling integrated cabinet charging and discharging and standing phases, and the double-circuit collaborative heat exchange is realized through the heat exchanger under extreme temperature conditions. The application can accurately adapt to different working conditions, guarantees accurate control of cell temperature fluctuation, eliminates the risk of medium mixing, reduces the energy consumption of the system, improves the safety, operation energy efficiency and extreme environment adaptation capability of the thermal management of the energy storage system, and is suitable for high-rate and large-capacity immersed energy storage liquid cooling integrated cabinets.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for battery energy storage systems, specifically to a dual-medium independent closed-loop chiller system and control method adapted to the differentiated thermal management requirements of liquid-cooled battery packs and energy storage converters (PCS). Background Technology

[0002] With the rapid development of the new energy industry, energy storage systems, as core equipment for smoothing grid fluctuations and improving energy utilization efficiency, are iteratively evolving towards high-rate charging and discharging, large-capacity integration and low-energy-consumption operation, with related technical indicators continuously being upgraded.

[0003] Liquid cooling technology, with its core advantages of high heat dissipation efficiency, accurate temperature control, and low operating noise, has become a core technology configuration for medium and high power energy storage systems. Currently, integrated liquid-cooled energy storage cabinets that combine liquid-cooled battery packs, energy storage converters (PCS), high-voltage power distribution modules, thermal management units, and fire protection components have achieved large-scale application. This trend places increasingly stringent requirements on the flexibility of media adaptation, the accuracy of energy consumption control, the safety and reliability of operation, and the adaptability to extreme environments of thermal management systems.

[0004] Current mainstream integrated liquid-cooled energy storage cabinets adopt either a single-loop or dual-loop design, with both types using PCS coolant as the sole heat exchange medium. PCS coolant has become a standard choice in the field of energy storage thermal management due to its excellent antifreeze properties, moderate thermal conductivity, controllable cost, and strong chemical stability.

[0005] However, from the perspective of load-side thermal management requirements, there are significant differences in the heat dissipation requirements of battery packs and PCS, and the performance requirements for heat exchange media are completely different.

[0006] On the one hand, the high-rate cells in the battery pack need to maintain an optimal operating range of 25~35℃, with temperature fluctuations controlled within ±2℃. Furthermore, the cell's cold plate has narrow flow channels and is in direct contact with the high-voltage tabs, placing extremely high demands on the insulation, thermal stability, and permeability of the medium. Existing commonly used ethylene glycol-based chillers have certain shortcomings on the battery side: First, ethylene glycol is conductive; if the pipeline or cold plate seal fails and leaks occur, it can easily lead to cell short circuits, thermal runaway, and other accidents. Second, its long-term operating temperature limit is low, and it is prone to oxidation and decomposition, generating sludge that clogs narrow flow channels and causes localized heat dissipation failure. Third, its low-temperature fluidity is poor; in extreme environments below -30℃, additional antifreeze needs to be added, still posing a risk of icing or requiring special configurations, making it unsuitable for high-altitude and extremely cold regions. Oil-cooling media (such as ester oils and other energy storage-specific insulating oils) can overcome the above-mentioned defects: they are completely insulating and non-conductive, which can completely eliminate the risk of leakage and short circuit; they have strong chemical stability and a longer replacement cycle than ethylene glycol; at the same time, they have moderate viscosity and strong penetrating power, which can fill the narrow flow channels of the battery cell to ensure uniform heat dissipation, and naturally have antifreeze properties without the need for additional measures, making them the optimal choice for battery-side thermal management.

[0007] On the other hand, the core requirement for IGBT heat dissipation on the PCS side is "efficiently dissipating locally concentrated heat," rather than "precise temperature control." Safe operation is achieved as long as the supply liquid temperature is controlled below 60℃. The IGBT heat dissipation cold plate flow channel design on the PCS side circuit is intricate, with a compact pipeline layout, resulting in high flow resistance and low flow rate. Furthermore, the heat dissipation channel is isolated from high-pressure components through a sealed structure, eliminating rigid requirements for the insulation of the medium. If the chiller system uses oil-cooled medium on the PCS side, there are significant performance redundancies and compatibility issues: First, oil-cooled medium is far more expensive than ethylene glycol and has a higher viscosity. Adapting to the high flow resistance and low flow rate conditions on the PCS side requires a high-power dedicated oil pump, increasing system power consumption and adding to equipment costs due to the selection of oil-resistant pipelines and seals. Second, existing PCS thermal management systems are already compatible with mature coolant solutions, with pipelines and cold plates designed to be water-based and compatible, allowing for seamless integration without reconstruction, making implementation and maintenance convenient. Full oil cooling, however, requires re-matching of the flow channel, pump body, and sealing system, resulting in poor compatibility and a long development cycle.

[0008] In summary, the core contradiction of existing single-medium energy storage chillers lies in "forcibly adapting to differentiated needs with a single medium": the all-water-based ethylene glycol solution cannot guarantee the high safety and high-rate heat dissipation requirements of the battery side, while the all-oil-cooled solution suffers from poor adaptability, soaring costs, and reduced energy efficiency on the PCS side. Neither can simultaneously ensure the system's safety, economy, and reliability. These shortcomings have become a technical bottleneck restricting the development of energy storage systems towards higher rates, larger capacities, and adaptability to more extreme environments. Summary of the Invention

[0009] The purpose of this invention is to provide an immersion-type dual-medium independent closed-loop energy storage chiller system and control method. By constructing a dual-medium independent closed-loop architecture with oil cooling on the battery side and ethylene glycol on the PCS side, physical isolation of the loop and on-demand distribution of the medium are achieved. This not only leverages the safety advantages of oil cooling on the battery side but also retains the adaptability and cost advantages of ethylene glycol on the PCS side. This solves the core pain points of existing single-medium solutions and overcomes the core problem that existing energy storage chillers cannot simultaneously meet the differentiated thermal management needs of the battery pack and the energy storage converter (PCS).

[0010] To achieve the above objectives, the first technical solution of this invention is: an immersion-type dual-medium independent closed-loop energy storage chiller system, comprising two independently operating PCS-side refrigeration circuits and a battery-side refrigeration circuit, the innovation of which lies in: The battery-side cooling circuit is divided into a compressor cooling system and a coolant circulation circuit, with heat exchange between the two achieved through an evaporator. The coolant circulation circuit is sealed to the battery cold plate to form an independent closed loop. The refrigeration circuit on the PCS side is sealed to the PCS cold plate to form an independent closed loop. The PCS-side refrigeration circuit and the battery-side refrigeration circuit use different heat exchange media. The PCS-side refrigeration circuit uses PCS coolant as the heat exchange medium, while the battery-side refrigeration circuit uses a dedicated battery coolant. A heat exchanger is installed between the PCS-side and battery-side refrigeration circuits, serving as the only indirect heat exchange channel between the two circuits. The two different heat exchange media are completely physically isolated within the internal flow channels of the heat exchanger. An electromagnetic three-way valve is provided between the PCS-side refrigeration circuit and the PCS-side flow channel of the heat exchanger. The electromagnetic three-way valve is electrically connected to the central control unit and is used to control the flow path of the heat exchange medium on the PCS side, realize the switching between independent heat exchange or collaborative heat exchange modes of the two circuits of the PCS-side refrigeration circuit and the battery-side refrigeration circuit, and prevent the mixing of the two media.

[0011] In the first technical solution mentioned above, the heat exchange medium used in the battery-side cooling circuit is a special battery insulating coolant, which can be any one of silicone oil, fluorinated liquid, or hydrocarbon coolant.

[0012] In the first technical solution mentioned above, the heat exchange medium in the PCS-side refrigeration circuit is pure water or a mixture of water and ethylene glycol aqueous solution.

[0013] In the first technical solution described above, the PCS-side refrigeration circuit is sealed and fixedly connected to the interface corresponding to the PCS cold plate through the first liquid inlet and the first liquid outlet, forming a complete and independent circulation channel to continuously supply low-temperature coolant to the PCS cold plate, thereby achieving heat dissipation and cooling of the PCS. The PCS-side refrigeration circuit is equipped with a PCS-side water pump, a water-air heat exchanger, an expansion tank branch, and a first pressure and temperature monitoring component. The first liquid inlet is connected to the inlet pipe of the water-air heat exchanger through the PCS-side water pump. The first valve port of the electromagnetic three-way valve is connected to the outlet water line A of the water-air heat exchanger, the second valve port is connected to the inlet water line B of the heat exchanger, and the third valve port is connected in parallel to the outlet water line C of the heat exchanger. The outlet of the heat exchanger is connected to the first liquid outlet. The expansion tank branch is connected in parallel to the inlet of the PCS-side water pump to achieve system pressure stabilization. The first pressure and temperature monitoring component is set in the circulation channel between the PCS-side refrigeration circuit and the PCS cold plate.

[0014] In the first technical solution described above, the first pressure-temperature monitoring component includes a first pressure sensor, a first temperature sensor, a second pressure sensor, and a second temperature sensor. A first pressure sensor and a first temperature sensor are installed on the pipeline connecting the first liquid inlet and the water pump inlet on the PCS side to collect the liquid supply pressure and temperature. The pipeline also has a first injection / drain port for adding, draining, and periodically replenishing the coolant. A second pressure sensor and a second temperature sensor are installed on the pipeline connecting the first liquid outlet and the outlet water path C of the heat exchanger to collect the return liquid pressure and temperature.

[0015] In the first technical solution mentioned above, the electromagnetic three-way valve can be adjusted to be fully closed, fully open, or any opening degree from 0 to 180°, to achieve a flow distribution of the coolant on the PCS side through water path C, water path B, or B and C. When the electromagnetic three-way valve is fully closed, the coolant in the PCS-side refrigeration circuit flows entirely from water circuit A to water circuit C, meaning the PCS-side refrigeration circuit is disconnected from the heat exchanger and operates independently. When the electromagnetic three-way valve is fully open, the coolant flows completely from water circuit A to water circuit B, and all the coolant in the PCS-side refrigeration circuit enters the heat exchanger to exchange heat with the battery-side coolant. When the electromagnetic three-way valve is at any angle from 0 to 180°, water circuit B and water circuit C operate in parallel, meaning that the coolant passes through both water circuit B and water circuit C simultaneously, thus achieving precise control of the coolant volume.

[0016] In the first technical solution described above, the coolant circulation loop is sealed and fixedly connected to the battery cold plate through a second inlet and a second outlet, forming a complete and independent circulation channel to continuously provide low-temperature coolant to the battery cold plate, thereby achieving battery heat dissipation and cooling. The coolant circulation loop includes an oil pump, an expansion tank structure, a temperature compensation branch, and a second pressure and temperature monitoring component. The second inlet is connected to the inlet of the oil pump through the expansion tank structure. The outlet of the oil pump is connected to the inlet liquid path M of the heat exchanger. The outlet liquid path N of the heat exchanger is connected to the second outlet via the evaporator. The temperature compensation branch is connected in parallel between the coolant inlet D and the coolant outlet E of the evaporator. The second pressure and temperature monitoring component is installed in the circulation channel between the coolant circulation loop and the battery cold plate.

[0017] In the first technical solution described above, the second pressure-temperature monitoring component includes a third pressure sensor, a third temperature sensor, a fourth pressure sensor, and a fourth temperature sensor. A third pressure sensor and a third temperature sensor are installed on the pipeline connecting the second inlet to the expansion tank structure to collect the supply pressure and temperature. The pipeline also has a second filler / drain port for adding, draining, and periodically replenishing the coolant. A fourth pressure sensor and a fourth temperature sensor are installed on the pipeline connecting the second liquid outlet and the heat exchanger to collect the return liquid pressure and temperature.

[0018] In the first technical solution mentioned above, the temperature compensation branch consists of a PTC heater and a throttle valve connected in series. The throttle valve is electrically connected to the central control unit and can adjust the coolant flow rate of the branch, thus forming a dual-path temperature control mode of main heat exchange and branch heating.

[0019] In the first technical solution mentioned above, the expansion tank structure has a built-in level gauge and level switch for monitoring the coolant level. When the level is lower than a preset threshold, an automatic coolant replenishment command is triggered.

[0020] In the first technical solution mentioned above, the oil-side flow channel of the heat exchanger is connected in series between the oil pump outlet end of the battery-side coolant circulation loop and the coolant inlet D of the evaporator, and its PCS-side flow channel is connected in series to the PCS-side refrigeration loop.

[0021] In the first technical solution mentioned above, the compressor refrigeration system includes a compressor, a condenser, and an expansion valve. The outlet of the compressor is sealed and connected to the refrigerant inlet F of the evaporator through the condenser and the expansion valve. The refrigerant outlet G of the evaporator is sealed and connected to the inlet of the compressor, so that the refrigerant side channel of the evaporator is connected in series to the compressor refrigeration system and together they form a closed-loop refrigerant circulation.

[0022] In the first technical solution mentioned above, the water-air heat exchanger of the PCS side refrigeration circuit and the condenser of the compressor refrigeration system share a set of cooling fans, and the air outlet of the cooling fans is set facing the heat exchange surface of the water-air heat exchanger and the heat exchange surface of the condenser.

[0023] To achieve the above objectives, the second technical solution of the present invention is: a control method for a submerged dual-medium independent closed-loop energy storage chiller, including the above-mentioned submerged dual-medium independent closed-loop energy storage chiller system, the innovation of which is: specifically including the following steps: The preset cell over-temperature threshold is T. B-max The low-temperature threshold of the battery cell is T B-min Cell heating stop threshold T B-heat Cell cooling threshold T B-cool The PCS over-temperature threshold is T P-max , S1, when the liquid-cooled integrated cabinet is in the charging / discharging stage, the PCS-side cooling circuit is in operation, and the start / stop of the battery-side cooling circuit is adjusted according to the cell temperature. Based on the real-time temperature T of the battery cell B Cell temperature difference ΔT B and PCS side liquid supply temperature T P Control the battery-side cooling circuit to switch to standby mode, automatic mode, heating mode, or self-circulation mode. S2, when the liquid-cooled integrated cabinet is in a static state, the PCS-side cooling circuit is in standby mode, and the start and stop of the battery-side cooling circuit are adjusted according to the cell temperature. Based on the real-time temperature T of the battery cell B Cell temperature difference ΔT B and PCS side liquid supply temperature T P It controls the battery-side cooling circuit to switch to standby mode, automatic mode, heating mode, or self-circulation mode.

[0024] In the second technical solution described above, in step S1, S11: If the cell temperature is normal, T B-min <T B <T B-max And the cell temperature difference T B-max -T B-min If the temperature difference is less than ΔT, where ΔT is a preset cell temperature difference threshold, then the battery-side cooling circuit remains in standby mode. S12: If the cell temperature is too high, T B >T B-max If the battery switches to automatic mode, the compressor cooling system in the battery-side cooling circuit will start, forcibly cooling the battery cells. S13: If the cell temperature is too low, T B<T B-min If the battery is switched to heating mode, the heater in the temperature compensation branch of the battery-side cooling circuit will be activated to force heating of the battery cell.

[0025] In the second technical solution described above, in step S2, S21: If the cell temperature is within the normal range, T B-min <T B <T B-max Then, the compressor refrigeration system of the battery-side refrigeration circuit is in standby mode, and the temperature compensation branch in the battery-side refrigeration circuit is also in standby mode. S22: If the cell temperature is too high, T B >T B-max Then, the battery-side cooling circuit switches to automatic mode, and the compressor cooling system of the battery-side cooling circuit starts to perform forced cooling on the battery cells. S23: If the cell temperature is too low, T B <T B-min Then the battery-side cooling circuit switches to heating mode, and the heater in the temperature compensation branch of the battery-side cooling circuit is activated to perform forced heating on the battery cell.

[0026] In the second technical solution described above, in step S12, when the battery-side cooling circuit performs cooling, if the real-time temperature of the cell drops to T... B <T B-cool Immediately stop the refrigeration process and the compressor refrigeration system.

[0027] In the second technical solution mentioned above, when the battery-side cooling circuit is in heating mode and performing temperature rise, if the real-time temperature of the cell rises to T... B >T B-heat Stop the heating process; If the battery-side cooling circuit has undergone cooling or heating operations, and the cell temperature difference still satisfies ΔT B If the value is greater than ΔT, the battery side switches to self-circulation mode; After the battery-side cooling circuit is in self-circulation mode, if the detected cell temperature difference is less than ΔT-2, the chiller will standby; if the cell temperature difference is still greater than ΔT-2, the self-circulation mode will continue to run, with only the oil pump in the battery-side cooling circuit starting up and running, while the compressor in the compressor cooling system and the heater in the temperature compensation branch will be locked and shut down simultaneously.

[0028] In the second technical solution mentioned above, when the ambient temperature is between -10 and 50°C, the electromagnetic three-way valve is fully closed. At this time, the two circuits of the PCS-side refrigeration circuit and the battery-side refrigeration circuit exchange heat independently, and the PCS-side coolant and the battery-side coolant do not exchange heat. When the ambient temperature is below -10℃ or above 50℃, the electromagnetic three-way valve is fully open or at any opening degree from 0 to 180°. At this time, the coolant in the PCS side refrigeration circuit exchanges heat with the coolant in the battery side refrigeration circuit through the heat exchanger.

[0029] In the second technical solution mentioned above, when the ambient temperature is >50℃ and T P >T P-max When the compressor refrigeration system is started, the solenoid three-way valve is opened, and indirect heat exchange between the low-temperature battery coolant and the high-temperature PCS coolant is achieved through the heat exchanger, so as to reduce the supply temperature of the PCS side. When the ambient temperature is < -10℃ and T B >T B-max When the time comes, open the solenoid three-way valve; When the liquid-cooled integrated cabinet is in the charging and discharging stage, it achieves indirect heat exchange and cooling through two loops via a heat exchanger. When the liquid-cooled integrated cabinet is in the static stage, the PCS-side refrigeration circuit switches from standby mode to operating mode, coupling the cold source output by the compressor refrigeration system to perform dual cooling regulation on the battery coolant on the battery side until the temperature drops to a preset threshold.

[0030] In the second technical solution described above, in step S1, if the ambient temperature is >50℃ and the liquid supply temperature T on the PCS side... p Exceeding the preset upper limit threshold T p-max This means that the liquid supply on the PCS side exceeds the temperature, which triggers the dual-loop coordinated heat exchange mechanism. The specific actions are as follows: The compressor refrigeration system switches to automatic mode and simultaneously opens the solenoid three-way valve, allowing the low-temperature battery coolant in the battery-side circulation loop and the high-temperature PCS coolant in the PCS-side circulation loop to exchange heat indirectly within the heat exchanger through independently isolated flow channels. Heat transfer is achieved using the temperature difference between the media, thus cooling the PCS coolant. In step S1, if the ambient temperature is less than -10°C and the cell temperature exceeds the preset upper limit threshold T... B >T B-max The battery cooling circuit is in automatic mode. At this time, the dual-circuit collaborative heat exchange mechanism is triggered. The specific actions are as follows: the electromagnetic three-way valve is opened, so that the coolant in the battery side circulation circuit and the coolant in the PCS side circulation circuit can complete indirect heat exchange in the heat exchanger through mutually isolated flow channels, and heat transfer is achieved by utilizing the temperature difference between the heat exchange media.

[0031] In the second technical solution mentioned above, in step S2, the ambient temperature is below -10℃, and the cell temperature exceeds the preset upper limit threshold T. B >T B-maxThe battery-side compressor refrigeration system is already in automatic control mode. At this time, the dual-loop collaborative heat exchange enhancement mechanism is triggered, and the specific actions are as follows: When the PCS-side cooling circuit switches from standby mode to operating mode, the electromagnetic three-way valve is simultaneously opened, forming a passage with the heat exchanger. This allows the coolant in the battery-side circulation circuit and the coolant in the PCS-side circulation circuit to complete indirect heat exchange within the heat exchanger through independently isolated flow channels, utilizing the temperature difference between the media to achieve initial heat transfer. At the same time, the cold source output from the coupled compressor refrigeration system provides dual cooling regulation for the battery-side coolant, ultimately precisely reducing the battery-side coolant temperature to within a preset threshold range.

[0032] The positive effects of this invention are as follows: After adopting the immersion-type dual-medium independent closed-loop energy storage chiller system and control method of this invention, the battery-side refrigeration circuit of the system is divided into a compressor refrigeration system and a coolant circulation circuit, and heat exchange between the two is achieved through an evaporator. The coolant circulation circuit is sealed to the battery cold plate to form an independent closed loop. The refrigeration circuit on the PCS side is sealed to the PCS cold plate to form an independent closed loop. The PCS-side refrigeration circuit and the battery-side refrigeration circuit use different heat exchange media. The PCS-side refrigeration circuit uses PCS coolant as the heat exchange medium, while the battery-side refrigeration circuit uses a dedicated battery coolant. A heat exchanger is installed between the PCS-side and battery-side refrigeration circuits, serving as the only indirect heat exchange channel between the two circuits. The two different heat exchange media are completely physically isolated within the internal flow channels of the heat exchanger. An electromagnetic three-way valve is provided between the PCS-side refrigeration circuit and the PCS-side flow channel of the heat exchanger. The electromagnetic three-way valve is electrically connected to the central control unit and is used to control the flow path of the heat exchange medium on the PCS side, realize the switching of the two circuits of independent heat exchange or collaborative heat exchange between the PCS-side refrigeration circuit and the battery-side refrigeration circuit, and prevent the mixing of the two media. The control method specifically includes the following steps: The preset cell over-temperature threshold is T. B-max The low-temperature threshold of the battery cell is T B-min Cell heating stop threshold T B-heat Cell cooling threshold T B-cool The PCS over-temperature threshold is T P-max , S1, when the liquid-cooled integrated cabinet is in the charging / discharging stage, the PCS-side cooling circuit is in operation, and the start / stop of the battery-side cooling circuit is adjusted according to the cell temperature. Based on the real-time temperature T of the battery cell B Cell temperature difference ΔT Band PCS side liquid supply temperature T P Control the battery-side cooling circuit to switch to standby mode, automatic mode, heating mode, or self-circulation mode. S2, when the liquid-cooled integrated cabinet is in a static state, the PCS-side cooling circuit is in standby mode, and the start and stop of the battery-side cooling circuit are adjusted according to the cell temperature. Based on the real-time temperature T of the battery cell B Cell temperature difference ΔT B and PCS side liquid supply temperature T P Control the battery-side cooling circuit to switch to standby mode, automatic mode, heating mode or self-circulation mode; The advantages of this invention are: (1) The immersion dual-medium independent closed-loop energy storage chiller system provided by the present invention can accurately adapt to the different operating conditions of the battery pack and the PCS side, taking into account the high-rate heat dissipation requirements of 0.5C and above and the high-efficiency operation requirements of the system: the battery side uses insulating oil medium, which has excellent permeability and can stably withstand the high-rate heat load of the battery cells, accurately controlling the temperature fluctuation of the battery cells within ±2℃, effectively ensuring the consistency of the battery cells and extending the cycle life of the battery; the PCS side uses low-viscosity ethylene glycol medium, which is adapted to its high flow resistance and low flow rate operating conditions, and can quickly remove the local concentrated heat of the IGBT without configuring a high-power pump body, avoiding the problem of cold energy waste or insufficient heat dissipation caused by the forced adaptation of a single medium. The PCS side uses water-air heat exchanger for heat convection heat exchange, which can reduce the cooling capacity supply requirements of the compressor refrigeration system, thereby reducing the overall cooling power consumption and significantly improving the overall heat exchange efficiency of the system.

[0033] (2) This invention significantly improves system safety, operational efficiency, and adaptability to extreme environments through a dual independent closed-loop architecture and a collaborative heat exchange control strategy: the two loops are physically isolated to completely eliminate the risk of mutual interference between different media; this invention establishes an indirect heat exchange channel for the two loops through a heat exchanger. Under normal operating conditions, the two loops operate independently to achieve on-demand temperature control; in extreme high-temperature environments, the low-temperature coolant on the battery side serves as an additional cold source, and the heat exchanger further cools the coolant on the PCS side, solving the heat dissipation bottleneck under high ambient temperature conditions; in extreme low-temperature environments, the coolant on the PCS side is coupled with the cooling capacity output by the compressor refrigeration system to perform dual cooling regulation of the coolant on the battery side, ensuring that the system supply temperature remains stable within the preset threshold range. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the specific implementation structure of the immersion dual-medium independent closed-loop energy storage chiller system of the present invention; Figure 2 This is a block diagram of the temperature control logic principle of the immersion dual-medium independent closed-loop chiller of the present invention; Figure 3 This is a schematic diagram of the working principle of the dual-medium independent closed-loop chiller of the present invention; Figure 4 This is a schematic diagram of the synergistic heat exchange working principle of the chiller of this invention under extreme high / low temperature conditions. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] Example 1 like Figure 1 , 3 As shown in Figure 4, a submerged dual-medium independent closed-loop energy storage chiller system includes two independently operating PCS-side refrigeration circuits 1 and battery-side refrigeration circuits 2. The battery-side cooling circuit 2 is divided into a compressor cooling system 21 and a coolant circulation circuit 22, and heat exchange between the two is achieved through an evaporator 31. The coolant circulation circuit 22 is sealed to the battery cold plate to form an independent closed loop. The PCS-side refrigeration circuit 1 is sealed to the PCS cold plate to form an independent closed loop. The PCS-side refrigeration circuit 1 and the battery-side refrigeration circuit 2 use different heat exchange media. The PCS-side refrigeration circuit 1 uses PCS coolant as the heat exchange medium, while the battery-side refrigeration circuit 2 uses a dedicated battery coolant. A heat exchanger 3 is installed between the PCS-side refrigeration circuit 1 and the battery-side refrigeration circuit 2, serving as the only indirect heat exchange channel between the two circuits. The two different heat exchange media are completely physically isolated within the internal flow channels of the heat exchanger 3. An electromagnetic three-way valve 18 is provided between the PCS-side refrigeration circuit 1 and the PCS-side flow channel of the heat exchanger 3. The electromagnetic three-way valve 18 is electrically connected to the central control unit and is used to control the flow path of the heat exchange medium on the PCS side, realize the switching of the two circuits of PCS-side refrigeration circuit 1 and battery-side refrigeration circuit 2 for independent heat exchange or collaborative heat exchange, and prevent the mixing of the two media.

[0038] Furthermore, to achieve dedicated cooling of the battery cold plate using a specialized battery coolant and improve cooling performance, the heat exchange medium used in the battery-side refrigeration circuit 2 of this invention is a specialized battery insulating coolant, which can be any one of silicone oil, fluorinated liquid, or hydrocarbon coolant. Its selection and performance parameters fully consider the safety and heat dissipation requirements of high-rate cells, the narrow flow channel structure of the battery cold plate, and the heat exchange logic of the active refrigeration cycle, making it a core medium ensuring the safety, stability, and efficiency of battery-side heat dissipation.

[0039] Furthermore, the heat exchange medium in the PCS-side cooling circuit 1 is pure water or a mixture of water and ethylene glycol aqueous solution.

[0040] Furthermore, such as Figure 1 As shown, in order to circulate the coolant, the PCS-side refrigeration circuit 1 is sealed and fixedly connected to the interface corresponding to the PCS cold plate through the first inlet 101 and the first outlet 102, forming a complete and independent circulation channel to continuously supply low-temperature coolant to the PCS cold plate, thereby achieving heat dissipation and cooling of the PCS. The PCS-side refrigeration circuit 1 is equipped with a PCS-side water pump 14, a water-air heat exchanger 15, an expansion tank branch 16, and a first pressure and temperature monitoring component. The first inlet 101 is connected to the water-air heat exchanger 15 through the PCS-side water pump 14. The inlet pipe of heat exchanger 15 is connected to the first valve port of the electromagnetic three-way valve 18, which is connected to the outlet water passage A of water-air heat exchanger 15; the second valve port is connected to the inlet water passage B of heat exchanger 3; and the third valve port is connected in parallel to the outlet water passage C of heat exchanger 3. The outlet water passage C of heat exchanger 3 is connected to the first liquid outlet 102. The expansion tank branch 16 is connected in parallel to the inlet of the PCS side water pump 14 to achieve system pressure stabilization. The first pressure and temperature monitoring component is set in the circulation channel between the PCS side refrigeration circuit 1 and the PCS cold plate.

[0041] The circulation path of the PCS-side refrigeration circuit is as follows: the coolant flowing out from the PCS cold plate outlet flows out through the first inlet 101 and then passes through the PCS-side water pump 14 and the water-air heat exchanger 15 in sequence along the pipeline; after the PCS coolant completes heat exchange and cooling in the water-air heat exchanger 15, it flows out from the medium outlet end of the heat exchanger and enters the input end of the electromagnetic three-way valve 18, and then flows back to the inlet end of the PCS cold plate through the first outlet 102 from the output end of the electromagnetic three-way valve 18, thus forming a complete independent closed loop of the PCS-side refrigeration circuit.

[0042] Furthermore, such as Figure 1 As shown, in order to monitor the pressure and temperature of the PCS-side refrigeration circuit, the first pressure and temperature monitoring component includes a first pressure sensor 111 and a second pressure sensor 112, which respectively monitor the return liquid and supply liquid pressure of the PCS-side refrigeration circuit in real time and accurately; the first temperature sensor 121 and the second temperature sensor 122 respectively collect the return liquid and supply liquid temperature of the PCS-side refrigeration circuit in real time. The four sensors work together to synchronously feed back the collected pressure and temperature parameters to the liquid cooler control unit, which provides data for the speed adjustment of the PCS-side water pump 14 and the heat exchange power control of the water-air heat exchanger 15, and can also trigger an early warning signal in time when the circuit experiences a sudden pressure rise or abnormal temperature exceedance, so as to realize real-time control of the circuit operation status. Specifically: The first pressure and temperature monitoring component includes a first pressure sensor 111, a first temperature sensor 121, a second pressure sensor 112, and a second temperature sensor 122. A first pressure sensor 111 and a first temperature sensor 121 are installed on the pipeline connecting the first liquid inlet 101 and the water inlet of the PCS-side water pump 14 to collect the liquid supply pressure and temperature. A first injection / drainage port 17 is also provided on this pipeline for adding, draining, and periodically replenishing the coolant. A second pressure sensor 112 and a second temperature sensor 122 are installed on the pipeline connecting the first liquid outlet 102 and the outlet water path C of the heat exchanger 3 to collect the return liquid pressure and temperature.

[0043] The PCS-side water pump 14 is the power core of the PCS-side refrigeration circuit. It can pressurize and transport the coolant in the circuit to ensure that the coolant maintains a stable circulation flow rate and meets the liquid supply flow requirements of the PCS cold plate. The water-air heat exchanger 15 is the core cooling component of the PCS-side refrigeration circuit 1. It quickly removes the heat absorbed by the coolant during the flow of the PCS cold plate through heat exchange, thereby cooling the coolant and ensuring that the temperature of the coolant returning to the PCS cold plate is always within the preset low temperature range.

[0044] Furthermore, the electromagnetic three-way valve 18 can be adjusted to be fully closed, fully open, or any opening degree from 0 to 180°, enabling the coolant on the PCS side to flow entirely through water path C, fully through water path B, or in parallel through water paths B and C. When the electromagnetic three-way valve 18 is fully closed, the coolant in the PCS-side refrigeration circuit 1 flows entirely from water circuit A to water circuit C, meaning that the PCS-side refrigeration circuit 1 is disconnected from the heat exchanger 3 and operates independently. When the electromagnetic three-way valve 18 is fully open, the coolant flows completely from water circuit A to water circuit B, and all the coolant in the PCS-side refrigeration circuit 1 enters the heat exchanger 3 to exchange heat with the battery-side coolant. When the electromagnetic three-way valve 18 is at any angle from 0 to 180°, water circuit B and water circuit C operate in parallel, meaning that the coolant passes through both water circuit B and water circuit C simultaneously, thus achieving precise control of the coolant volume.

[0045] Furthermore, such as Figure 1 As shown, the battery-side cooling circuit 2 consists of a compressor cooling system 21 and a coolant circulation circuit 22. The two exchange heat through an evaporator 31. The coolant circulation circuit 22 is sealed and fixedly connected to the battery cold plate through a second inlet 401 and a second outlet 402, forming a complete and independent circulation channel to continuously provide low-temperature coolant to the battery cold plate, thereby achieving battery heat dissipation and cooling.

[0046] To achieve stable circulation of the battery-side coolant, the coolant circulation loop 22 is sealed and fixedly connected to the battery cold plate through the second inlet 401 and the second outlet 402, forming a complete and independent circulation channel. This continuously provides low-temperature coolant to the battery cold plate, achieving heat dissipation and cooling of the battery. The coolant circulation loop 22 includes an oil pump 45, an expansion tank structure 44, a temperature compensation branch, and a second pressure and temperature monitoring component. Each component is connected in series or in parallel through oil-resistant sealed pipelines, forming a complete circulation system adapted to the heat dissipation requirements of high-rate battery cells. The second inlet 401 is connected to the inlet of the oil pump 45 through the expansion tank structure 44. The outlet of the oil pump 45 is connected to the inlet liquid path M of the heat exchanger 3. The outlet liquid path N of the heat exchanger 3 is connected to the second outlet 402 through the evaporator 31. The temperature compensation branch is connected in parallel between the coolant inlet D and the coolant outlet E of the evaporator 31. The second pressure and temperature monitoring component is installed in the circulation channel between the coolant circulation loop 22 and the battery cold plate.

[0047] Furthermore, such as Figure 1As shown, in order to achieve temperature regulation, a second pressure and temperature monitoring component is installed on the coolant circulation loop 22 on the battery side. Following the layout logic of "supply end + return end," the loop operating parameters are monitored throughout the entire process. The second pressure and temperature monitoring component includes a third pressure sensor 411, a third temperature sensor 421, a fourth pressure sensor 412, and a fourth temperature sensor 422. A third pressure sensor 411 and a third temperature sensor 421 are installed on the pipeline connecting the second liquid inlet 401 and the expansion tank structure 44 to collect the liquid supply pressure and temperature. A second injection / drainage port 43 is also provided on this pipeline for adding, draining, and periodically replenishing the coolant. A fourth pressure sensor 412 and a fourth temperature sensor 422 are installed on the pipeline connecting the second liquid outlet 402 and the heat exchanger 3 to collect the return liquid pressure and temperature.

[0048] Specifically, the fourth temperature sensor 422 and the fourth pressure sensor 412 at the liquid supply end are located on the pipeline between the coolant outlet E and the second outlet 402 of the evaporator 31, collecting real-time data on the temperature and pressure of the coolant flowing into the battery pack cold plate; the third temperature sensor 421 and the third pressure sensor 411 are located between the second inlet 401 and the oil pump 45, collecting real-time data on the temperature and pressure of the supplied and returned coolant. The signals collected by each sensor are synchronously fed back to the control unit, providing accurate data for the speed regulation of the compressor 32 and the start / stop of the temperature compensation branch.

[0049] The battery-side coolant circulation loop 22 is further optimized, with an oil pump 45 serving as the power core. The outlet of the oil pump 45 is divided into two paths via pipelines: one main path connects to the coolant inlet D of the evaporator 31, where the coolant is cooled by heat exchange in the coolant-side flow channel of the evaporator 31 and then flows out from the coolant outlet E of the evaporator 31, and is then connected to the second outlet 402 via pipelines to supply constant-temperature coolant to the battery pack cold plate; the other path is a temperature compensation branch, which is connected in parallel to the main pipeline between the coolant inlet D and the coolant outlet E of the evaporator 31.

[0050] Furthermore, such as Figure 1 As shown, the temperature compensation branch consists of a PTC heater 47 and a throttle valve 46 connected in series. The throttle valve 46 is electrically connected to the central control unit and can adjust the coolant flow rate of the branch, thereby adjusting the opening degree of the throttle valve and precisely controlling the coolant flow rate of the heater branch. Therefore, the battery coolant circulation loop is constructed into a dual-path temperature control mode of main circuit heat exchange and branch circuit heating.

[0051] To ensure stable system back pressure and prevent sudden pressure rises and falls in the circuit, both the PCS-side circuit and the battery-side circuit are equipped with their own pressure stabilizing devices. An expansion tank branch 16 is used on the PCS side, fixedly installed on the inlet pipe of the water pump 14. Due to the risk of material incompatibility between the coolant and conventional expansion tank bladders, the battery-side coolant circulation circuit 22 uses an expansion tank structure 44 for pressure stabilization. The expansion tank structure 44 has a built-in level gauge and level switch to monitor the coolant level. When the level falls below a preset threshold, an automatic coolant replenishment command is triggered, achieving precise coolant replenishment and ensuring sufficient medium in the circuit.

[0052] Furthermore, a heat exchanger 3 is installed between the PCS-side refrigeration circuit 1 and the battery-side refrigeration circuit 2. This heat exchanger 3 serves as the sole indirect heat exchange channel between the two independent closed-loop circuits, enabling precise transfer of cooling capacity between the two circuits under specific operating conditions while maintaining physical isolation between them to prevent the risk of media mixing. The heat exchanger 3 employs a plate heat exchanger structure, with its core design adapted to the media characteristics and heat exchange requirements of both circuits. The internal oil and water circuits of the heat exchanger are completely physically isolated, allowing only heat transfer. The oil-side flow channel of the heat exchanger 3 is connected in series between the outlet of the oil pump 45 of the battery-side coolant circulation circuit 22 and the coolant inlet D of the evaporator 31, and its PCS-side flow channel is connected in series to the PCS-side refrigeration circuit 1.

[0053] Furthermore, such as Figure 1 As shown, the compressor refrigeration system 21 includes a compressor 32, a condenser 33, and an expansion valve 34. The evaporator 31 adopts a medium dual-chamber isolation structure design, in which the refrigerant flow channel and the coolant side flow channel are completely physically isolated and do not communicate with each other. The evaporator 31 is provided with a coolant inlet D, a coolant outlet E, a refrigerant inlet F, and a refrigerant outlet G. The outlet of the compressor 32 is sealed and connected to the refrigerant inlet F of the evaporator 31 through the condenser 33 and the expansion valve 34. The refrigerant outlet G of the evaporator 31 is sealed and connected to the inlet of the compressor 32, so that the refrigerant side flow channel of the evaporator 31 is connected in series to the compressor refrigeration system 21 and together they form a closed-loop refrigerant circulation.

[0054] Furthermore, the water-air heat exchanger 15 of the PCS-side refrigeration circuit 1 shares a set of cooling fans with the condenser 33 of the compressor refrigeration system 21, realizing a shared supply of heat exchange airflow. The outlet of the cooling fan is positioned facing the heat exchange surfaces of both the water-air heat exchanger 15 and the condenser 33. Specifically, the outlet of the cooling fan is positioned facing both the heat exchange surfaces of the water-air heat exchanger 15 and the condenser 33 of the compressor refrigeration system 21, allowing the same airflow to simultaneously remove heat from both the water-air heat exchanger 15 and the condenser 33, achieving efficient cooling. To further explain Example 1, based on the core structural characteristics of the oil-water dual-medium chiller and combined with the temperature control requirements of the energy storage system throughout its entire operating cycle, it was formulated according to the principle of "phased, medium-specific, and precise coordination". The core objective is to achieve stable temperature control of the battery cells and PCS, while maximizing the unit's operating efficiency and reducing energy consumption.

[0055] Example 2 like Figure 1 , 2 As shown in Figures 3 and 4, a control method for a submerged dual-medium independent closed-loop energy storage chiller includes the submerged dual-medium independent closed-loop energy storage chiller system of Example 1. Based on the heat source characteristics of different operating stages of the energy storage system, differentiated control strategies are formulated for the charging / discharging stage and the resting stage to achieve precise control of the cell temperature and optimization of system energy consumption. Specifically, the method includes the following steps: The preset cell over-temperature threshold is T. B-max The low-temperature threshold of the battery cell is T B-min Cell heating stop threshold T B-heat Cell cooling threshold T B-cool The PCS over-temperature threshold is T P-max , S1, when the liquid-cooled integrated cabinet is in the charging / discharging stage, the PCS-side cooling circuit 1 is in operation, and the start / stop of the battery-side cooling circuit is adjusted according to the cell temperature. Based on the real-time temperature T of the battery cell B Cell temperature difference ΔT B and PCS side liquid supply temperature T P Control the battery-side cooling circuit 2 to switch to standby mode, automatic mode, heating mode, or self-circulation mode. S2, when the liquid-cooled integrated cabinet is in a static state, the PCS-side cooling circuit 1 is in standby mode, and the start and stop of the battery-side cooling circuit are adjusted according to the cell temperature. Based on the real-time temperature T of the battery cell B Cell temperature difference ΔT B and PCS side liquid supply temperature T P The battery-side cooling circuit 2 is controlled to switch to standby mode, automatic mode, heating mode or self-circulation mode.

[0056] Furthermore, in step S1, S11: If the cell temperature is normal, T B-min <T B <T B-max And the cell temperature difference T B-max -T B-min If the temperature difference is less than ΔT, where ΔT is a preset cell temperature difference threshold, then the battery-side cooling circuit 2 remains in standby mode. S12: If the cell temperature is too high, T B >T B-max If the battery switches to automatic mode, the compressor refrigeration system 21 of the battery-side refrigeration circuit 2 will start to perform forced cooling on the battery cell. When the battery-side refrigeration circuit is performing cooling, if the real-time temperature of the battery cell drops to T... B <T B-cool Immediately stop the refrigeration operation, and the compressor refrigeration system 21 stops running.

[0057] When the battery-side cooling circuit is in heating mode and performing temperature rise, if the real-time temperature of the cell rises to T... B >T B-heat Stop heating. If the battery-side cooling circuit has undergone cooling or heating operations, and the cell temperature difference still satisfies ΔT B If the value is greater than ΔT, the battery side switches to self-circulation mode. After the battery-side cooling circuit is in self-circulation mode, if the actual cell temperature difference is detected to be <ΔT-2, the chiller will stand by; if the cell temperature difference is still >ΔT-2, the self-circulation mode will continue to run, and only the oil pump in the battery-side cooling circuit 2 will start running, while the compressor in the compressor cooling system and the heater in the temperature compensation branch will be locked and shut down simultaneously. S13: If the cell temperature is too low, T B <T B-min If the mode is switched to heating mode, the heater in the temperature compensation branch of the battery-side cooling circuit 2 will be activated to perform forced heating on the battery cell.

[0058] Furthermore, in step S2, S21: If the cell temperature is within the normal range, T B-min <T B <T B-max Then, the compressor refrigeration system 21 of the battery-side refrigeration circuit 2 is in standby mode, and the temperature compensation branch in the battery-side refrigeration circuit 2 is also in standby mode. S22: If the cell temperature is too high, T B >T B-max Then, the battery-side cooling circuit 2 switches to automatic mode, and the compressor cooling system 21 of the battery-side cooling circuit 2 starts to perform forced cooling on the battery cells. S23: If the cell temperature is too low, T B <T B-min Then, the battery-side cooling circuit 2 switches to heating mode, and the heater in the temperature compensation branch of the battery-side cooling circuit 2 is activated to perform forced heating on the battery cell.

[0059] Example 3 like Figure 2 , 3As shown in Figure 4, the present invention implements thermal management control logic for different environmental conditions, and its specific implementation steps are as follows: The opening degree of the electromagnetic three-way valve can be adjusted as needed to accommodate different ambient temperatures. When the ambient temperature is between -10°C and 50°C, the electromagnetic three-way valve 18 is fully closed. At this time, the two circuits, PCS-side refrigeration circuit 1 and battery-side refrigeration circuit 2, exchange heat independently, and the PCS-side coolant and battery-side coolant do not exchange heat. When the ambient temperature is below -10°C or above 50°C, the electromagnetic three-way valve 18 is fully open or has an arbitrary opening of 0~180°. At this time, the coolant of the PCS side cooling circuit 1 exchanges heat with the coolant of the battery side cooling circuit 2 through the heat exchanger 3.

[0060] Specifically, when the ambient temperature is >50℃ and T P >T P-max When the compressor refrigeration system 21 is started, the electromagnetic three-way valve 18 is opened, and the indirect heat exchange between the low-temperature battery coolant and the high-temperature PCS coolant is achieved through the heat exchanger 3, so as to reduce the supply temperature of the PCS side. When the ambient temperature is < -10℃ and T B >T B-max At this time, open the solenoid three-way valve 18; When the liquid-cooled integrated cabinet is in the charging and discharging stage, indirect heat exchange and cooling through two loops are achieved through heat exchanger 3. When the liquid-cooled integrated cabinet is in the static stage, the PCS-side refrigeration circuit 1 switches from standby mode to operating mode, and couples the cold source output by the compressor refrigeration system 21 to perform dual cooling regulation on the battery coolant on the battery side until the temperature drops to the preset threshold.

[0061] In step S1, if the ambient temperature is >50℃ and the liquid supply temperature T on the PCS side is... p Exceeding the preset upper limit threshold T p-max This means that the liquid supply on the PCS side exceeds the temperature, which triggers the dual-loop coordinated heat exchange mechanism. The specific actions are as follows: The compressor refrigeration system 21 switches to automatic mode and simultaneously opens the solenoid three-way valve 18, allowing the low-temperature battery coolant in the battery-side circulation loop 2 and the high-temperature PCS coolant in the PCS-side circulation loop 1 to undergo indirect heat exchange within the heat exchanger 3 through independently isolated flow channels. Heat transfer is achieved using the temperature difference between the media, reducing the PCS-side supply liquid temperature to within a preset threshold range, thus providing a suitable cold source for the PCS cold plate. In step S1, if the ambient temperature is less than -10°C and the cell temperature exceeds the preset upper limit threshold T... B >T B-maxThe battery-side cooling circuit 2 is in automatic mode. At this time, the dual-circuit collaborative heat exchange mechanism is triggered. The specific actions are as follows: the electromagnetic three-way valve 18 is opened, so that the coolant in the battery-side circulation circuit 2 and the coolant in the PCS-side circulation circuit 1 can complete indirect heat exchange in the heat exchanger 3 through mutually isolated flow channels. The heat is transferred by utilizing the temperature difference between the heat exchange media to initially cool the coolant. Then the coolant is further cooled by passing through the heat exchanger.

[0062] In step S2, the ambient temperature is below -10℃, and the cell temperature exceeds the preset upper limit threshold T. B >T B-max The battery-side compressor refrigeration system 2 is in automatic control mode. At this time, the dual-loop collaborative heat exchange enhancement mechanism is triggered, and the specific actions are as follows: When the PCS-side cooling circuit 1 switches from standby mode to operating mode, the electromagnetic three-way valve 18 is simultaneously opened, forming a passage with the heat exchanger 3. This allows the coolant in the battery-side circulation circuit 2 and the coolant in the PCS-side circulation circuit 1 to complete indirect heat exchange within the heat exchanger 3 through independently isolated flow channels, achieving initial heat transfer by utilizing the temperature difference between the media. At the same time, the cold source output by the compressor refrigeration system 21 is coupled to perform dual cooling and regulation of the battery-side coolant, ultimately accurately reducing the battery-side coolant temperature to within a preset threshold range.

[0063] It should be noted that the ambient temperature ranges mentioned in this invention are typical values, and the actual operating ranges may be adjusted accordingly depending on the configuration of the system's cooling capacity.

[0064] In summary, the advantages of this invention are as follows: (1) The immersion dual-medium independent closed-loop energy storage chiller system provided by the present invention can accurately adapt to the different operating conditions of the battery pack and the PCS side, taking into account the high-rate heat dissipation requirements of 0.5C and above and the high-efficiency operation requirements of the system: the battery side uses insulating oil medium, which has excellent permeability and can stably withstand the high-rate heat load of the battery cells, accurately controlling the temperature fluctuation of the battery cells within ±2℃, effectively ensuring the consistency of the battery cells and extending the cycle life of the battery; the PCS side uses conventional coolant medium, which is adapted to its high flow resistance and low flow rate operating conditions, and can quickly remove the local concentrated heat of the IGBT without configuring a high-power pump body, avoiding the problem of wasted cooling capacity or insufficient heat dissipation caused by forced adaptation of a single medium. The PCS side uses water-air heat exchanger for heat convection heat exchange, which can reduce the cooling capacity supply requirements of the compressor refrigeration system, thereby reducing the overall cooling power consumption and significantly improving the overall heat exchange efficiency of the system.

[0065] (2) This invention significantly improves system safety, operational efficiency, and adaptability to extreme environments through a dual independent closed-loop architecture and a collaborative heat exchange control strategy: the two loops are physically isolated to completely eliminate the risk of mutual interference between different media; this invention establishes an indirect heat exchange channel for the two loops through a heat exchanger. Under normal operating conditions, the two loops operate independently to achieve on-demand temperature control; in extreme high-temperature environments, the low-temperature coolant on the battery side serves as an additional cold source, and the heat exchanger further cools the coolant on the PCS side, solving the heat dissipation bottleneck under high ambient temperature conditions; in extreme low-temperature environments, the coolant on the PCS side is coupled with the cooling capacity output by the compressor refrigeration system to perform dual cooling regulation of the coolant on the battery side, ensuring that the system supply temperature remains stable within the preset threshold range.

[0066] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A submerged dual-medium independent closed-loop energy storage chiller system, comprising two independently operating PCS-side refrigeration circuits (1) and a battery-side refrigeration circuit (2), characterized in that: The battery-side cooling circuit (2) is divided into a compressor cooling system (21) and a coolant circulation circuit (22), and heat exchange between the two is achieved through an evaporator (31). The coolant circulation circuit (22) is sealed to the battery cold plate to form an independent closed loop. The PCS-side refrigeration circuit (1) is sealed to the PCS cold plate to form an independent closed loop. The heat exchange media in the PCS-side refrigeration circuit (1) and the battery-side refrigeration circuit (2) are different. The PCS-side refrigeration circuit (1) uses PCS coolant as the heat exchange medium, while the battery-side refrigeration circuit (2) uses a dedicated battery coolant as the heat exchange medium. A heat exchanger (3) is provided between the PCS-side refrigeration circuit (1) and the battery-side refrigeration circuit (2), and the heat exchanger (3) serves as the only indirect heat exchange channel between the two circuits. The two different heat exchange media are completely physically isolated in the internal flow channels of the heat exchanger (3). An electromagnetic three-way valve (18) is provided between the PCS-side refrigeration circuit (1) and the PCS-side flow channel of the heat exchanger (3). The electromagnetic three-way valve (18) is electrically connected to the central control unit and is used to control the flow path of the heat exchange medium on the PCS side, realize the switching of the two circuits of the PCS-side refrigeration circuit (1) and the battery-side refrigeration circuit (2) for independent heat exchange or collaborative heat exchange, and prevent the mixing of the two media.

2. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 1, characterized in that: The heat exchange medium used in the battery-side cooling circuit (2) is a special battery insulating coolant, which can be any one of silicone oil, fluorinated liquid, or hydrocarbon coolant.

3. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 1, characterized in that: The heat exchange medium in the PCS-side cooling circuit (1) is pure water or a mixture of water and ethylene glycol aqueous solution.

4. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 1, characterized in that: The PCS-side refrigeration circuit (1) is sealed and fixedly connected to the interface corresponding to the PCS cold plate through the first liquid inlet (101) and the first liquid outlet (102), forming a complete and independent circulation channel to continuously supply low-temperature coolant to the PCS cold plate, thereby achieving heat dissipation and cooling of the PCS. The PCS-side refrigeration circuit (1) is equipped with a PCS-side water pump (14), a water-air heat exchanger (15), an expansion tank branch (16), and a first pressure and temperature monitoring component. The first liquid inlet (101) is connected to the water-air heat exchanger (15) through the PCS-side water pump (14). The inlet pipe is connected, the first valve port of the electromagnetic three-way valve (18) is connected to the outlet water passage A of the water-air heat exchanger (15), the second valve port is connected to the inlet water passage B of the heat exchanger (3), and the third valve port is connected in parallel to the outlet water passage C of the heat exchanger (3). The outlet of the heat exchanger (3) is connected to the first liquid outlet (102). The expansion tank branch (16) is connected in parallel to the inlet of the PCS side water pump (14) to achieve system pressure stabilization. The first pressure and temperature monitoring component is set in the circulation channel between the PCS side refrigeration circuit (1) and the PCS cold plate.

5. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 4, characterized in that: The first pressure and temperature monitoring component includes a first pressure sensor (111), a first temperature sensor (121), a second pressure sensor (112), and a second temperature sensor (122). A first pressure sensor (111) and a first temperature sensor (121) are installed on the pipeline connecting the first liquid inlet (101) and the water inlet of the PCS-side water pump (14) to collect the liquid supply pressure and temperature. The pipeline is also equipped with a first injection / drainage port (17) for adding, draining and periodically replenishing the coolant. A second pressure sensor (112) and a second temperature sensor (122) are provided on the pipeline connecting the first liquid outlet (102) and the outlet water path C of the heat exchanger (3) to collect the return liquid pressure and temperature.

6. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 4, characterized in that: The electromagnetic three-way valve (18) can be adjusted to be fully closed, fully open, or any opening degree from 0 to 180°, so as to realize the flow distribution of the coolant on the PCS side through water circuit C, water circuit B, or water circuits B and C. When the electromagnetic three-way valve (18) is fully closed, the coolant in the PCS-side refrigeration circuit (1) flows completely from water path A to water path C, that is, the PCS-side refrigeration circuit (1) is disconnected from the heat exchanger (3) and operates independently. When the electromagnetic three-way valve (18) is fully open, the coolant flows completely from water circuit A to water circuit B, and all the coolant in the PCS-side refrigeration circuit (1) enters the heat exchanger (3) to exchange heat with the battery-side coolant. When the electromagnetic three-way valve (18) is at any angle from 0 to 180°, water circuit B and water circuit C operate in parallel, that is, the coolant passes through water circuit B and water circuit C at the same time, so as to achieve precise control of the coolant volume.

7. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 1, characterized in that: The coolant circulation loop (22) is sealed and fixedly connected to the battery cold plate through the second inlet (401) and the second outlet (402), forming a complete and independent circulation channel to continuously provide low-temperature coolant to the battery cold plate and achieve battery heat dissipation and cooling. The coolant circulation loop (22) includes an oil pump (45), an expansion tank structure (44), a temperature compensation branch and a second pressure and temperature monitoring component. The second inlet (401) is connected to the inlet of the oil pump (45) through the expansion tank structure (44). The outlet of the oil pump (45) is connected to the inlet liquid path M of the heat exchanger (3). The outlet liquid path N of the heat exchanger (3) is connected to the second outlet (402) through the evaporator (31). The temperature compensation branch is connected in parallel between the coolant inlet D and the coolant outlet E of the evaporator (31). The second pressure and temperature monitoring component is set in the circulation channel between the coolant circulation loop (22) and the battery cold plate.

8. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 7, characterized in that: The second pressure and temperature monitoring component includes a third pressure sensor (411), a third temperature sensor (421), a fourth pressure sensor (412), and a fourth temperature sensor (422). A third pressure sensor (411) and a third temperature sensor (421) are provided on the pipeline connecting the second liquid inlet (401) and the expansion tank structure (44) to collect the liquid supply pressure and temperature. A second liquid inlet / outlet (43) is also provided on the pipeline for adding, discharging and periodically replenishing the coolant. A fourth pressure sensor (412) and a fourth temperature sensor (422) are provided on the pipeline connecting the second liquid outlet (402) and the heat exchanger (3) to collect the return liquid pressure and temperature.

9. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 7, characterized in that: The temperature compensation branch consists of a PTC heater (47) and a throttle valve (46) connected in series. The throttle valve (46) is electrically connected to the central control unit and can adjust the coolant flow of the branch, thus forming a dual-path temperature control mode of main heat exchange and branch heating.

10. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 7, characterized in that: The expansion tank structure (44) has a built-in level gauge and level switch for monitoring the level of coolant. When the level is lower than a preset threshold, an automatic replenishment command is triggered.

11. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 1, characterized in that: The oil-side flow channel of the heat exchanger (3) is connected in series between the outlet end of the oil pump (45) of the battery-side coolant circulation loop (22) and the coolant inlet D of the evaporator (31), and its PCS-side flow channel is connected in series to the PCS-side refrigeration loop (1).

12. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 1, characterized in that: The compressor refrigeration system (21) includes a compressor (32), a condenser (33) and an expansion valve (34). The outlet of the compressor (32) is sealed and connected to the refrigerant inlet F of the evaporator (31) through the condenser (33) and the expansion valve (34). The refrigerant outlet G of the evaporator (31) is sealed and connected to the inlet of the compressor (32), so that the refrigerant side flow channel of the evaporator (31) is connected in series to the compressor refrigeration system (21) and together they form a closed-loop refrigerant circulation.

13. The submersible dual-medium independent closed-loop energy storage chiller system according to claim 1, characterized in that: The water-air heat exchanger (15) of the PCS side cooling circuit (1) and the condenser (33) of the compressor refrigeration system (21) share a set of heat dissipation fans. The air outlet of the heat dissipation fan is set to face the heat exchange surface of the water-air heat exchanger (15) and the heat exchange surface of the condenser (33).

14. A control method for a submerged dual-medium independent closed-loop energy storage chiller, comprising the submerged dual-medium independent closed-loop energy storage chiller system according to any one of claims 1-13, characterized in that: Specifically, the steps include the following: The preset cell over-temperature threshold is T. B-max The low-temperature threshold of the battery cell is T B-min Cell heating stop threshold T B-heat Cell cooling threshold T B-cool The PCS over-temperature threshold is T P-max , S1, when the liquid-cooled integrated cabinet is in the charging and discharging stage, the PCS-side cooling circuit (1) is in operation, and the start and stop of the battery-side cooling circuit are adjusted according to the cell temperature. Based on the real-time temperature T of the battery cell B Cell temperature difference ΔT B and PCS side liquid supply temperature T P The battery-side cooling circuit (2) is controlled to switch to standby mode, automatic mode, heating mode or self-circulation mode. S2, when the liquid-cooled integrated cabinet is in a static state, the PCS-side cooling circuit (1) is in standby mode, and the start and stop of the battery-side cooling circuit are adjusted according to the cell temperature. Based on the real-time temperature T of the battery cell B Cell temperature difference ΔT B and PCS side liquid supply temperature T P Control the battery-side cooling circuit (2) to switch to standby mode, automatic mode, heating mode or self-circulation mode.

15. The control method for an immersion-type dual-medium independent closed-loop energy storage chiller according to claim 14, characterized in that: In step S1, S11: If the cell temperature is normal, T B-min <T B <T B-max And the cell temperature difference T B-max -T B-min <ΔT, where ΔT is a preset cell temperature difference threshold, then the battery-side cooling circuit (2) remains in standby mode. S12: If the cell temperature is too high, T B >T B-max If the battery switches to automatic mode, the compressor refrigeration system (21) of the battery-side refrigeration circuit (2) is activated to perform forced cooling on the battery cell. S13: If the cell temperature is too low, T B <T B-min If the battery is switched to heating mode, the heater in the temperature compensation branch of the battery-side cooling circuit (2) will be activated to perform forced heating on the battery cell.

16. The control method for an immersion dual-medium independent closed-loop energy storage chiller according to claim 14, characterized in that: In step S2, S21: If the cell temperature is within the normal range, T B-min <T B <T B-max Then the compressor refrigeration system (21) of the battery-side refrigeration circuit (2) is in standby mode, and the temperature compensation branch in the battery-side refrigeration circuit (2) is in standby mode. S22: If the cell temperature is too high, T B >T B-max Then the battery-side cooling circuit (2) switches to automatic mode, and the compressor cooling system (21) of the battery-side cooling circuit (2) starts to perform forced cooling on the battery cell. S23: If the cell temperature is too low, T B <T B-min Then the battery-side cooling circuit (2) switches to heating mode, and the heater of the temperature compensation branch in the battery-side cooling circuit (2) is activated to perform forced heating on the battery cell.

17. The control method for an immersion dual-medium independent closed-loop energy storage chiller according to claim 15, characterized in that: In step S12, when the battery-side cooling circuit performs cooling, if the real-time temperature of the cell drops to T... B <T B-cool Immediately stop the refrigeration action and the compressor refrigeration system (21) stops operating.

18. The control method for an immersion dual-medium independent closed-loop energy storage chiller according to claim 15, characterized in that: When the battery-side cooling circuit is in heating mode and performing temperature rise, if the real-time temperature of the cell rises to T... B >T B-heat Stop the heating process; If the battery-side cooling circuit has undergone cooling or heating operations, and the cell temperature difference still satisfies ΔT B If the value is greater than ΔT, the battery side switches to self-circulation mode; After the battery-side cooling circuit is in self-circulation mode, if the temperature difference of the battery cell is less than ΔT-2, the chiller will stand by; if the temperature difference of the battery cell is still greater than ΔT-2, the self-circulation mode will continue to run, and only the oil pump in the battery-side cooling circuit (2) will start running, while the compressor in the compressor cooling system and the heater of the temperature compensation branch will be locked and stopped simultaneously.

19. The control method for an immersion dual-medium independent closed-loop energy storage chiller according to claim 14, characterized in that: When the ambient temperature is between -10 and 50°C, the electromagnetic three-way valve (18) is fully closed. At this time, the two circuits of the PCS-side refrigeration circuit (1) and the battery-side refrigeration circuit (2) exchange heat independently, and the PCS-side coolant and the battery-side coolant do not exchange heat. When the ambient temperature is less than -10°C or the ambient temperature is greater than 50°C, the electromagnetic three-way valve (18) is in a fully open state or an arbitrary opening degree of 0~180°. At this time, the coolant of the PCS side cooling circuit (1) exchanges heat with the coolant of the battery side cooling circuit (2) through the heat exchanger (3).

20. The control method for an immersion dual-medium independent closed-loop energy storage chiller according to claim 19, characterized in that: When the ambient temperature is >50℃ and T P >T P-max When the compressor refrigeration system (21) is started, the electromagnetic three-way valve (18) is opened, and the indirect heat exchange between the low-temperature battery coolant and the high-temperature PCS coolant is achieved through the heat exchanger (3), so as to reduce the supply temperature of the PCS side. When the ambient temperature is < -10℃ and T B >T B-max When the time comes, open the solenoid three-way valve (18); When the liquid-cooled integrated cabinet is in the charging and discharging stage, the two-loop indirect heat exchange and cooling is achieved through the heat exchanger (3); When the liquid-cooled integrated cabinet is in the static stage, the PCS-side refrigeration circuit (1) switches from standby mode to operation mode, and couples the cold source output by the compressor refrigeration system (21) to perform dual cooling regulation on the battery coolant on the battery side until the temperature drops to the preset threshold.

21. The control method for an immersion dual-medium independent closed-loop energy storage chiller according to claim 14, characterized in that: In step S1, if the ambient temperature is >50℃ and the liquid supply temperature T on the PCS side is... p Exceeding the preset upper limit threshold T p-max This means that the liquid supply on the PCS side exceeds the temperature, which triggers the dual-loop coordinated heat exchange mechanism. The specific actions are as follows: The compressor refrigeration system (21) switches to automatic mode and simultaneously opens the electromagnetic three-way valve (18), allowing the low-temperature battery coolant in the battery-side circulation loop (2) and the high-temperature PCS coolant in the PCS-side circulation loop (1) to complete indirect heat exchange in the heat exchanger (3) through mutually isolated flow channels. Heat transfer is achieved by utilizing the temperature difference between the media, thereby cooling the PCS coolant. In step S1, if the ambient temperature is less than -10°C and the cell temperature exceeds the preset upper limit threshold T... B >T B-max The battery cooling circuit (2) is in automatic mode. At this time, the dual-circuit collaborative heat exchange mechanism is triggered. The specific actions are as follows: the electromagnetic three-way valve (18) is opened, so that the coolant of the battery side circulation circuit (2) and the coolant of the PCS side circulation circuit (1) can complete indirect heat exchange in the heat exchanger (3) through mutually isolated flow channels, and heat transfer is achieved by utilizing the temperature difference between the heat exchange media.

22. The control method for an immersion dual-medium independent closed-loop energy storage chiller according to claim 14, characterized in that: In step S2, the ambient temperature is below -10℃, and the cell temperature exceeds the preset upper limit threshold T. B >T B-max The battery-side compressor refrigeration system (2) is already in automatic control mode. At this time, the dual-loop collaborative heat exchange enhancement mechanism is triggered, and the specific actions are as follows: The PCS-side cooling circuit (1) switches from standby mode to operating mode and simultaneously opens the electromagnetic three-way valve (18) to form a passage with the heat exchanger (3). This allows the coolant in the battery-side circulation circuit (2) and the coolant in the PCS-side circulation circuit (1) to complete indirect heat exchange in the heat exchanger (3) through mutually isolated flow channels. The temperature difference between the media is used to achieve initial heat transfer. At the same time, the cold source output by the compressor refrigeration system (21) is coupled to perform dual cooling regulation on the battery-side coolant, and finally the temperature of the battery-side coolant is accurately reduced to within the preset threshold range.

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