Liquid cooling system applied to energy storage battery cabin

Abstract

The embodiment of the utility model provides a liquid cooling system applied to an energy storage battery cabin, and belongs to the field of liquid cooling systems. The liquid cooling system comprises a refrigeration system which comprises a screw type water chiller and a cross flow cooling tower, the screw type water chiller is communicated with the cross flow cooling tower through double pipelines, and the refrigeration system is used for preparing cooling water by using electricity price in a low ebb period and conveying the cooling water to a battery cabin through a pipeline between the refrigeration system and the battery cabin for cold release; the cold storage system comprises a cold storage tank, a water inlet of the cold storage tank is communicated with a water outlet pipeline of the screw type water chiller, a water outlet of the cold storage tank is communicated with the energy storage battery cabin, and the cold storage tank is used for storing cooling water prepared by the refrigerating system and releasing cold when the energy storage battery cabin is charged and discharged; and the PLC control system is used for controlling start and stop of the refrigerating system and the cold storage system. According to the refrigerating system, valley electricity is flexibly used for preparing cooling water, the operation cost of the system is reduced, the cooling water is stored in the cold storage tank, cold release is conducted during charging and discharging of the energy storage battery cabin, and then the energy-saving effect is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid cooling systems, and in particular to a liquid cooling system applied to an energy storage battery compartment. Background Art

[0002] Energy storage batteries will continue to generate heat during operation, and cooling is an important factor affecting the safety of energy storage power stations. At present, there are two mainstream thermal management methods for lithium battery units, air cooling and liquid cooling. Air cooling and liquid cooling each have their own characteristics. Compared with liquid cooling, liquid cooling and air cooling have the inherent characteristics of large heat load, low flow resistance, and high heat exchange efficiency. They are widely used in places where the battery pack has high energy density, fast charging and discharging speed, and large changes in ambient temperature.

[0003] Although the air cooling system has the advantages of small initial investment, low maintenance cost and easy maintenance, it is more suitable for small civilian or commercial battery thermal management. Liquid cooling has gradually become the mainstream battery cooling method in large-capacity and high-energy-ratio fields such as large ground power stations. Liquid cooling systems can take away heat better than air cooling systems.

[0004] The single liquid cooling solution is the solution with the most application cases and the highest market share. The system is simple and flexible in operation, but it has some defects, mainly: high operating costs, and the inability to flexibly use valley electricity, resulting in a waste of resources. Utility Model Content

[0005] The purpose of the embodiment of the utility model is to provide a liquid cooling system applied to an energy storage battery compartment, which reduces the system operation cost and achieves energy saving effect by flexibly utilizing valley electricity to prepare cooling water.

[0006] In order to achieve the above objectives, the present invention provides a liquid cooling system for an energy storage battery compartment, comprising:

[0007] A refrigeration system, the refrigeration system comprising a screw chiller and a cross-flow cooling tower, wherein the screw chiller is connected to the cross-flow cooling tower via a double pipeline, the refrigeration system is used to prepare cooling water using off-peak electricity prices, and to transport the cooling water to the energy storage battery compartment through a pipeline between the energy storage battery compartment and the energy storage battery compartment for cooling;

[0008] A cold storage system, the cold storage system comprising a cold storage tank, wherein the water inlet of the cold storage tank is connected to the water outlet pipeline of the screw chiller, the water outlet of the cold storage tank is connected to the energy storage battery compartment, the cold storage tank is used to store cooling water prepared by the refrigeration system and releases cooling when the energy storage battery compartment is charged and discharged; and

[0009] A PLC control system is connected to the refrigeration system and the cold storage system respectively, and is used to control the start and stop of the refrigeration system and the cold storage system.

[0010] Optionally, the screw chiller includes an evaporator and a condenser. Among them, the water outlet of the evaporator is communicated with the cold storage tank, and the water outlet of the condenser is communicated with the cross-flow cooling tower.

[0011] Optionally, the refrigeration system further includes: a chilled water circulation pump and a cooling water circulation pump, which are arranged at the water inlet end of the screw chiller. The chilled water circulation pump is used to transport the return water in the cold storage tank into the evaporator for cooling the return water of the cold storage tank, and the cooling water circulation pump is used to transport the cooled cooling water from the cooling tower into the condenser for heating and then transport it to the cross-flow cooling tower.

[0012] Optionally, the liquid cooling system further includes a water processor, which is arranged between the cross-flow cooling tower and the cooling water circulation pump, and is used to filter and remove dirt from the cooled cooling water from the cross-flow cooling tower and then transport it to the condenser through the cooling water circulation pump.

[0013] Optionally, the liquid cooling system further includes a dirt remover, which is arranged between the energy storage battery compartment and the screw chiller, and is used to remove dirt from the return water flowing out of the energy storage battery compartment when it enters the refrigeration system for cooling.

[0014] Optionally, the liquid cooling system further includes a water replenishing system, which is connected to the water replenishing port of the cold storage tank and is used to replenish water to the liquid cooling system.

[0015] Optionally, the water replenishing system includes a water softener, a water tank and a variable-frequency water supply device. Among them, one end of the water softener is connected to the tap water pipe, the other end is connected to the water inlet of the water tank, the water outlet of the water tank is connected to one end of the variable-frequency water supply device, and the other end of the variable-frequency water supply device is connected to the water replenishing port of the cold storage tank.

[0016] Through the above technical solutions, the refrigeration system flexibly uses valley electricity to prepare cooling water, reducing the system operation cost. Moreover, by storing the cooling water in the cold storage tank and releasing cold during the charging and discharging of the energy storage battery compartment, the energy-saving effect is achieved.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification. Together with the following specific implementation, they are used to explain the embodiments of the present invention, but do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0019] Figure 1 is a schematic structural diagram of a liquid cooling system applied to an energy storage battery compartment provided by an embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of a refrigeration system provided by an embodiment of the present utility model;

[0021] Figure 3 is a detailed schematic structural diagram of a refrigeration system provided by an embodiment of the present utility model.

[0022] Description of the reference numerals

[0023] 10 Refrigeration system 100 Screw chiller

[0024] 1000 Evaporator 1001 Condenser

[0025] 101 Crossflow cooling tower 102 Refrigerant circulation pump

[0026] 103 Cooling water circulation pump 11 Cold storage system

[0027] 110 Cold storage tank 12 Energy storage battery compartment

[0028] 13 PLC controller 14 Water treatment device

[0029] 15 Strainer 16 Make-up water system Detailed implementation manners

[0030] The following will describe in detail the specific implementation manners of the embodiments of the present utility model with reference to the accompanying drawings. It should be understood that the specific implementation manners described herein are only for explaining and illustrating the embodiments of the present utility model, and are not used to limit the embodiments of the present utility model.

[0031] Refer to Figure 1 shown, which is a schematic structural diagram of a liquid cooling system applied to an energy storage battery compartment provided by an embodiment of the present utility model. The liquid cooling system includes: a refrigeration system 10, and the refrigeration system 10 includes a screw chiller 100 and a crossflow cooling tower 101. Among them, the screw chiller 100 is connected to the crossflow cooling tower 101 through a double pipeline. The refrigeration system 10 is used to prepare cooling water using the electricity price during off-peak hours and transport the cooling water to the energy storage battery compartment 12 through a pipeline between the refrigeration system 10 and the energy storage battery compartment 12 for heat release;

[0032] a cold storage system 11, and the cold storage system 11 includes a cold storage tank 110. The water inlet of the cold storage tank 110 is connected to the outlet pipeline of the screw chiller 100, and the water outlet of the cold storage tank 110 is connected to the energy storage battery compartment 12. The cold storage tank 110 is used to store the cooling water prepared by the refrigeration system 10 and release heat when the energy storage battery compartment 12 is charged and discharged; and

[0033] The PLC control system 13 is respectively connected to the refrigeration system 10 and the cold storage system 11, and is used to control the start and stop of the refrigeration system 10 and the cold storage system 11.

[0034] In some embodiments, referring to Figure 2 As shown, the screw chiller 100 includes an evaporator 1000 and a condenser 1001. Among them, the water outlet of the evaporator 1000 is communicated with the cold storage tank 110, and the water outlet of the condenser 1001 is communicated with the cross-flow cooling tower 101.

[0035] In some embodiments, referring to Figure 2 As described, the refrigeration system 10 further includes: a chilled water circulation pump 102 and a cooling water circulation pump 103, which are arranged at the water inlet end of the screw chiller 100. The chilled water circulation pump 102 is used to transfer the return water in the cold storage tank 110 into the evaporator 1000 for cooling the return water of the cold storage tank 110, and the cooling water circulation pump 103 is used to transfer the cooled cooling water in the cross-flow cooling tower 101 into the condenser 1001 for heating and then transfer it to the cross-flow cooling tower 101.

[0036] In some embodiments, according to the change of the end load of the air-conditioning system, calculate the operating percentage of the flow rate of the chilled water circulation pump 102, compare the change value of the temperature difference between the chilled water inlet and outlet of the chiller, and realize the mutual reference and automatic control of the operating frequencies of the chilled water circulation pump 102 and the cooling water circulation pump 103 with multiple parameters, save the hydraulic transmission energy consumption, and ensure that the supply and return water temperature difference is not greater than the design value.

[0037] In some embodiments, the refrigeration system 10 adopts a double-pipe closed system. In order to better match the air-conditioning working conditions, cold storage working conditions, load changes and energy-saving operation of the unit, the corresponding chilled water circulation pump 102 and cooling water circulation pump 103 are both frequency-controlled, and the screw chiller 100, the chilled water circulation pump 102 and the cooling water circulation pump 103 are started and stopped in sequence according to the load requirements.

[0038] In some embodiments, the cooling and cold storage working conditions of the screw chiller 100 are as follows:

[0039] The return water of the system is pumped into the evaporator 1000 of the screw chiller 100 by the refrigeration circulation pump 102. After being cooled to 15°C in the evaporator 1000, it enters the main water supply pipe. The cold water in the main pipe is transported to the energy storage battery compartment 12 through the cold supply pipe network. The cold water that has been heated to 20°C after heat exchange in the battery compartment 12 re-enters the evaporator 1000 of the screw chiller 100 through the factory return water pipe network. The return water of the cold storage tank 110 is pumped into the evaporator 1000 of the screw chiller 100 by the refrigeration circulation pump 102. After being cooled to 7°C in the evaporator 1000, it enters the main cold water supply pipe. The cold water flows through the water distributor at the lower part of the cold storage tank 110 for cold storage. The high-temperature cold water at 20°C from the water distributor at the upper part of the cold storage tank 110 enters the evaporator 1000 of the screw chiller 100 after being pressurized by the refrigeration circulation pump 102. Among them, the conversion between the cold storage working condition and the cold supply working condition is automatically switched by an electric valve.

[0040] In some embodiments, the main equipment of the liquid cooling system is shown in Table 1 as follows:

[0041] Table 1 List of Main Equipment

[0042]

[0043]

[0044] In some embodiments, refer to Figure 2 As shown, the liquid cooling system further includes a water processor 14, which is arranged between the cross-flow cooling tower 101 and the cooling circulation pump 103, and is used for filtering and removing dirt from the cooling water cooled by the cross-flow cooling tower 101 and then transmitting it to the condenser 1001 through the cooling circulation pump 103.

[0045] In some embodiments, the cooling water in the refrigeration machine room adopts a double-pipe open mechanical circulation system. The cooling circulation pump 103 and the main engine are set one-to-one and operate with variable flow. The designed supply and return water temperatures are 32°C / 37°C. In summer, the 32°C cooling water cooled by the cross-flow cooling tower 101 enters the energy station. After being filtered and decontaminated by the comprehensive water processor 14, it is pumped into the condenser 1001 of the screw chiller 100 by the cooling circulation pump 103. After absorbing heat in the condenser 1001, it is heated to 37°C and re-enters the cross-flow cooling tower 101. In winter, in the free cooling and energy-saving operation mode, the return water temperature of the cooling water is controlled for adjustment.

[0046] In some embodiments, refer to Figure 2 As shown, the liquid cooling system further includes a dirt remover 15, which is arranged between the energy storage battery compartment 12 and the screw chiller 100, and is used for removing dirt from the return water flowing out of the energy storage battery compartment when it enters the refrigeration system for cooling.

[0047] In some embodiments, refer to Figure 2As shown, the liquid cooling system further includes a water replenishing system 16, which is connected to the water replenishing port of the cold storage tank and is used to replenish water to the liquid cooling system.

[0048] Preferably, the constant pressure value of the water replenishing system is 0.12 MPa.

[0049] Specifically, refer to Figure 3 As shown, the water replenishing system 16 includes a water softener 160, a water tank 161 and a variable frequency water supply device 162. Among them, one end of the water softener 160 is connected to the tap water pipe, and the other end is connected to the water inlet of the water tank 161. The water outlet of the water tank 161 is connected to one end of the variable frequency water supply device 162, and the other end of the variable frequency water supply device 162 is connected to the water replenishing port of the cold storage tank 110.

[0050] In some embodiments, the total assembly capacity of the refrigeration system 10 is 1440 RT, and the cold storage capacity is 2952 RTH. The inlet and outlet water temperatures involved in this system are shown in Table 2:

[0051] Table 2 Inlet and Outlet Water Temperatures

[0052] Item Cold water parameter Designed supply and return water temperature (℃) 15 / 20 Chiller inlet and outlet water temperature under cold storage condition (℃) 7 / 14 Cold storage tank inlet and outlet water temperature (℃) 7 / 20

[0053] In some embodiments, a radial power supply form is adopted, and the metering is unified at the low-voltage distribution cabinet after the transformer. A multi-functional metering instrument with remote transmission function should be set at the switch of the low-voltage distribution cabinet. The grounding form of the low-voltage distribution system adopts the TN-S system, and the PE line and the N line should be strictly separated. All grounding electrodes of the metal shells of electrical equipment that are normally not energized but present voltage when the insulation is damaged are required to be reliably connected to the protective conductor. A local equipotential terminal box is set in the refrigeration machine room and is reliably connected to the reserved grounding terminal of the building. The grounding system is set by using the local equipotential terminal box, and is reliably connected to the distribution equipment shell, the foundation channel steel of the distribution cabinet, the protection main line, the metal base of the water pump, the electric valve, the metal main pipe for equipment entering and leaving the building, the metal components of the building, etc. with galvanized flat steel, and the grounding resistance is not greater than 1 Ω. All socket circuits are equipped with 30 mA leakage protection devices. For the grounding fault protection of the TN system distribution line with a nominal voltage of 220 V between the phase conductor and the ground, the time for cutting off the fault loop should meet the following requirements: for the distribution line or the end line only supplying power to fixed electrical equipment, it is not greater than 5 s; for the end line or socket circuit supplying power to hand-held electrical equipment or mobile electrical equipment, it is not greater than 0.4 s. To prevent lightning surges from invading, a surge protector of Class I test is installed at the entrance and exit of the cable from the building.

[0054] In some embodiments, a highly reliable PLC control system is adopted to automatically control the air conditioning system. It realizes the full-automatic operation control of the cold source machine room system (unattended machine room, the control system automatically starts / stops according to preset conditions, and adjusts the number of units, water volume, temperature, etc.), semi-automatic control (automatically adjusts the unit load, water volume, temperature, but does not automatically increase / decrease the number of operating units), and manual operation control and other functions. In addition, it also includes a precision verification system, an expert system, a historical record system, etc. to ensure monitoring and evaluation.

[0055] In some embodiments, a safety protection system is also provided to directly communicate with the screw chiller 100, read the status data of the screw chiller 100, such as: temperature, pressure, current and other conventional parameters of the screw chiller 100. At the same time, it can read: surge point (to ensure the safety of the unit), oil sump oil pump pressure (to judge whether maintenance is required), refrigerant liquid level, condenser saturation (as a reference point for the cooling water circulation), compressor operating condition (the percentage of the compressor operating current, which directly participates in the control of adding and subtracting units to achieve true safety and energy saving), and many other control parameters. By referring to these data, the control program of the entire system can be further improved to make the operation of the screw chiller 100 safer and the system more reliable.

[0056] The "soft start" and "soft shutdown" controls are adopted for the screw chiller 100. When loading the screw chiller 100, the system will first reduce the load of the currently operating screw chiller 100, then start the next screw chiller 100, and then increase the load of multiple operating screw chillers 100 at the same time; when unloading the screw chiller 100, first reduce the load of multiple operating screw chillers 100, then stop one screw chiller 100, and finally increase the load of the currently operating screw chiller 100. Through "soft start" and "soft shutdown", it is possible to avoid a huge impact on the power grid when the screw chiller 100 starts and stops, ensure the safety of the screw chiller 100 and the substation. At the same time, it can also make the screw chiller 100 enter the optimal operating condition faster.

[0057] The system is configured with an equal-time operation function module to automatically record the cumulative operation time of each screw chiller 100, water pump, and fan. When adding a unit, the device with the shortest operation time is preferentially started, and when subtracting a unit, the device with the longest operation time is preferentially stopped, so that the devices operate with relatively equal time, avoiding a significant reduction in the service life of the device due to continuous operation of a certain device. Balancing the operation time of each device can extend the service life of the device as a whole.

[0058] In some embodiments, the full-automatic operation mode realizes the following functions: automatically starting and stopping the air-conditioning machine room system to achieve the function of unmanned machine room, automatically starting and stopping the screw chiller 100 for cooling according to preset conditions (schedule or environmental conditions), automatically supplying cooling according to the terminal load, dynamically adjusting the operation quantity and frequency of the screw chiller 100 and its auxiliary equipment, automatically shielding the faults of the operating equipment and starting the standby equipment, a full-automatic control process aiming at the optimal comprehensive operation efficiency of the machine room, and at the same time automatically balancing the priority operation of each unit according to the cumulative operation time (effective for units with the same power) and automatically evaluating the comprehensive operation EER value of the machine room and other functions.

[0059] The semi-automatic operation mode realizes the following functions: all functions are the same as those of the full-automatic mode except that the number of operating units (equipment in Table 1) is not automatically increased or decreased. Interlock control of the screw chiller 100, water pump, valve, etc. within a single unit can be achieved, the operation frequency of the water pump can be adjusted, and it is ensured that the single unit operates at the best efficiency condition in each load section. Dynamically operating data of various items such as the screw chiller 100, frequency converter, network electric meter, etc. are collected in real time, and the comprehensive efficiency of a single unit is evaluated.

[0060] The manual operation mode can be used to manually start and stop the screw chiller 100, water pump, valve, etc. in the system through the high-voltage professional control box (cabinet). The group control cabinet collects the dynamically operating data of various items such as the screw chiller 100, frequency converter, network electric meter, etc. in real time, and evaluates the efficiency of a single device.

[0061] The above are only embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A liquid cooling system for an energy storage battery compartment, characterized in that: include: A refrigeration system, the refrigeration system comprising a screw chiller and a cross-flow cooling tower, wherein the screw chiller is connected to the cross-flow cooling tower via a double pipeline, the refrigeration system is used to prepare cooling water using off-peak electricity prices, and to transport the cooling water to the battery compartment through a pipeline between the energy storage battery compartment and the battery compartment for cooling; A cold storage system, the cold storage system comprising a cold storage tank, wherein the water inlet of the cold storage tank is connected to the water outlet pipeline of the screw chiller, the water outlet of the cold storage tank is connected to the energy storage battery compartment, the cold storage tank is used to store cooling water prepared by the refrigeration system and releases cooling when the energy storage battery compartment is charged and discharged; and A PLC control system is connected to the refrigeration system and the cold storage system respectively, and is used to control the start and stop of the refrigeration system and the cold storage system.

2. The liquid cooling system according to claim 1, characterized in that: The screw chiller includes an evaporator and a condenser, wherein a water outlet of the evaporator is communicated with the cold storage tank, and a water outlet of the condenser is communicated with the cross-flow cooling tower.

3. The liquid cooling system according to claim 2, characterized in that: The refrigeration system also includes: a refrigeration circulation water pump and a cooling circulation water pump, which are arranged at the water inlet end of the screw chiller. The refrigeration circulation water pump is used to transfer the return water in the cold storage tank to the evaporator for cooling the return water of the cold storage tank. The cooling circulation water pump is used to transfer the cooling water after the cross-flow cooling tower is cooled to the condenser for heating and then transferred to the cross-flow cooling tower.

4. The liquid cooling system according to claim 3, characterized in that: The liquid cooling system also includes a water processor, which is arranged between the cross-flow cooling tower and the cooling circulation water pump, and is used to filter and remove dirt from the cooling water after the cross-flow cooling tower is cooled, and then transmit it to the condenser through the cooling circulation water pump.

5. The liquid cooling system according to claim 1, characterized in that: The liquid cooling system also includes a decontaminator, which is arranged between the energy storage battery compartment and the screw chiller and is used to decontaminate the return water flowing out of the energy storage battery compartment when it enters the refrigeration system for cooling.

6. The liquid cooling system according to claim 1, characterized in that: The liquid cooling system also includes a water replenishment system connected to the water replenishment port of the cold storage tank for replenishing water to the liquid cooling system.

7. The liquid cooling system according to claim 6, characterized in that: The water replenishment system includes a water softener, a water tank and a variable frequency water supply device, wherein one end of the water softener is connected to a tap water pipe, and the other end is connected to a water inlet of the water tank, the water outlet of the water tank is connected to one end of the variable frequency water supply device, and the other end of the variable frequency water supply device is connected to the water replenishment port of the cold storage tank.

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