Battery system thermal management device special for electric bus

Abstract

The utility model relates to a special battery system heat management device for an electric bus, which comprises a vehicle-mounted liquid-cooled battery pack, a battery pack cooling pipeline system and a battery heat management unit, the battery heat management unit is fixed at a bus station or a charging station, the battery heat management unit comprises a constant-temperature water tank, and an evaporator and an electric heater are arranged in the constant-temperature water tank. An outlet pipeline of the evaporator is sequentially connected with a thermostatic expansion valve, an inverter compressor, a condenser, a liquid storage tank and a thermostatic expansion valve, and is connected with an inlet pipeline of the evaporator to form a closed loop; the quick connector is divided into a vehicle-mounted connecting end and a battery heat management unit connecting end, a liquid outlet and a liquid return port of the constant-temperature water tank are respectively connected with the vehicle-mounted connecting end, and a water inlet end and a water outlet end of the battery pack cooling pipeline system are connected with the battery heat management unit connecting end. According to the utility model, the weight of the whole vehicle can be effectively reduced, heat exchange can be continuously carried out on batteries of different vehicles, heat exchange can also be carried out on batteries of a plurality of vehicles simultaneously, and the utilization efficiency of a heat management device unit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of transportation, and in particular to a thermal management device for a battery system dedicated to an electric bus, which is suitable for bus operation conditions. Background Art

[0002] As the popularity of electric vehicles in my country increases, especially in the public transportation sector, new and replacement buses are encouraged to use new energy electric vehicles.

[0003] At present, the power batteries used in new energy vehicles are mainly lithium batteries, and temperature is an important factor affecting the performance of lithium-ion batteries. Therefore, ensuring that the power battery has a suitable temperature environment plays a huge role in the battery's charging and discharging performance. Since the operating area of ​​electric buses is relatively fixed, the operating time is long, and the daily mileage is long, the charging time is relatively frequent. Frequent high-current charging of electric vehicles will cause the temperature of the power battery pack to rise rapidly. At this time, the power battery needs to be cooled. In addition, in winter, when the temperature is low and the pressure is 0 degrees Celsius, the battery cannot be charged and the battery needs to be heated. Since the power battery belongs to electrochemical energy storage, the environment and temperature in the battery pack have a great influence on the overall performance of the power battery, including the battery's charging and discharging efficiency, capacity, power, safety and life. Therefore, the power battery thermal management system is introduced to perform low-temperature heating, high-temperature heat dissipation and thermal insulation management on the battery.

[0004] The inventor discovered during the process of implementing the utility model:

[0005] Although the on-board battery thermal management system can solve the above problems, it also has its shortcomings: first, it consumes the lithium battery power of the entire vehicle when it is working, reducing the cruising range; second, the vehicle is equipped with an on-board thermal management system, which increases the weight of the vehicle and thus increases the energy consumption of the vehicle; third, the installation of the on-board thermal management system increases the cost of the vehicle (8,000 yuan); fourth, the utilization rate of the on-board thermal management system is not high. The equipment only works for four months in most parts of my country, and is idle for the rest of the time.

[0006] At the same time, through the analysis of bus operation data in recent years, it is found that the temperature of the power battery rises significantly during charging, and the temperature rise during normal operation is much smaller than that during charging. The operating characteristics of electric buses are to charge 3-5 times a day, which is significantly more frequent than ordinary commercial vehicles and passenger cars. This causes the battery to be high in summer when the bus is running, and the battery is prone to overheating and runaway, affecting safety. Therefore, it is necessary to control the temperature rise of the power battery when the electric vehicle is charged to solve the pain points of electric bus operation in summer; and when charging and discharging at low temperatures in winter, the battery needs to be heated first, and then small current charging and discharging can be started after heating to a certain temperature. Summary of the invention

[0007] In order to solve the problem in the prior art that abnormal battery temperature affects battery use due to high cost of thermal management devices for electric bus battery systems and low installation rate caused by insufficient vehicle installation space, the utility model proposes a thermal management device for a battery system dedicated to electric buses. When the electric vehicle returns to the station for charging, the power battery is cooled or heated to maintain a suitable operating temperature.

[0008] To this end, the technical solution of the utility model is: a battery system thermal management device for electric buses, including a vehicle-mounted liquid-cooled battery pack and a matching battery pack cooling pipeline system, characterized in that it also includes an external fixed battery thermal management unit,

[0009] The battery thermal management unit is fixed at the bus station or charging station, including a constant temperature water tank, an evaporator and an electric heater are arranged in the constant temperature water tank, a water replenishment tank connected to the inner cavity is arranged on the top of the constant temperature water tank, and a liquid outlet and a liquid return port are arranged at the bottom of the constant temperature water tank.

[0010] The inlet and outlet of the evaporator extend out of the thermostatic water tank through pipes respectively, and the outlet pipe is sequentially connected with a thermal expansion valve, a variable frequency compressor, a condenser, a liquid storage tank, the thermal expansion valve, and the inlet pipe of the evaporator to form a closed loop;

[0011] It also includes a quick connector, which is divided into a vehicle-mounted connection end and a battery thermal management unit connection end. The liquid outlet of the constant temperature water tank is connected to a plurality of water outlet branch pipelines through a speed regulating water pump, and the end of each water outlet branch pipeline is connected to a quick connector. The return liquid port of the constant temperature water tank is connected to a plurality of water return branch pipelines through a return water main pipeline, and the free end of each water return branch pipeline is connected to a quick connector. The quick connectors of the water outlet branch pipeline and the water return branch pipeline are respectively plugged into the corresponding ports of the vehicle-mounted connection end. The water inlet and water outlet of the battery pack cooling pipeline system are respectively connected with quick connectors, which are connected to the battery thermal management unit connection end when in use, so that the water outlet branch pipeline is connected to the water inlet end of the battery pack cooling pipeline system, and the water return branch pipeline is connected to the water outlet end of the battery pack cooling pipeline system;

[0012] The battery thermal management unit operates automatically through a microprocessor control system.

[0013] A further improvement to the above technical solution is that a refrigerant pressure switch is provided on the pipeline between the variable frequency compressor and the condenser, a fan is provided in the condenser, and the variable frequency compressor, the fan, and the refrigerant pressure switch are all connected to a microprocessor control system. The compressor 13 and the condenser are controlled to cool down by the microprocessor control system.

[0014] A further improvement to the above technical solution is that: the constant temperature water tank is equipped with a temperature sensor, and also includes an ambient temperature sensor for reading ambient temperature information. Each outlet branch pipe is provided with a pressure temperature sensor, and each return branch pipe is provided with a flow temperature sensor. The temperature sensor, pressure temperature sensor, and flow temperature sensor are all connected to the microprocessor control system. The ambient temperature information is read by the ambient temperature sensor to decide whether the temperature needs to be lowered or raised; the microprocessor control system can also read the battery temperature information through the charging pile interaction to decide whether the vehicle battery needs temperature control; the closed-loop control of the pressure flow sensor and the flow temperature sensor is used to precisely control the battery pack to work in the appropriate temperature range, and to detect the working status of each cooling circuit. When the pipeline is not connected properly or there is a leak, the system will alarm.

[0015] A further improvement to the above technical solution is that the evaporator is an evaporator coil with a cooling function, and the electric heater is an electric heating tube with a heating function. The evaporator coil and the electric heating tube automatically heat or cool down under the control of a microprocessor control system to meet the temperature control requirements of the battery of the entire vehicle.

[0016] Beneficial effects: The utility model combines the on-board liquid-cooled battery pack cooling pipe system with an external fixed battery thermal management unit, and fixes the battery thermal management unit at the charging station. When cooling or heating the battery of the entire vehicle, the power battery is not consumed. In addition, since the battery thermal management unit is external, the weight of the entire vehicle is effectively reduced, the power consumption of the electric bus is reduced, and the energy saving level is greatly improved. In addition, the use of an external fixed battery thermal management unit can maximize its utilization efficiency, which plays a role in reducing costs and increasing efficiency. The battery system thermal management device can continuously provide thermal management for different vehicles, and can also perform heat exchange on the batteries of multiple vehicles at the same time, and both benefits and efficiency can be improved. It can enable electric buses to work around the clock in summer; it solves the problem of power battery overheating during the operation of buses in summer with the lowest investment, and at the same time solves the problem of serious reduction in battery efficiency during the operation of electric buses in winter, achieving the optimal configuration of cost and benefit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a principle diagram of the utility model.

[0018] As shown in the figure: 1. Constant temperature water tank; 2. Evaporator; 3. Electric heater; 4. Water supply tank; 5. Liquid outlet; 6. Liquid return port; 7. Thermal expansion valve; 8. Frequency conversion compressor; 9. Condenser; 10. Liquid storage tank; 11. Quick connector; 12. Water outlet main line; 13. Speed ​​regulating water pump; 14. Water outlet branch line; 15. Return water main line; 16. Return water branch line; 17. Microprocessor control system; 18. Refrigerant pressure switch; 19. Temperature sensor; 20. Ambient temperature sensor; 21. Pressure temperature sensor; 22. Flow temperature sensor. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings, but this embodiment should not be understood as a limitation to the present invention.

[0020] The utility model Figure 1 As shown:

[0021] A thermal management device for a battery system dedicated to an electric bus, comprising an on-board liquid-cooled battery pack M ( Figure 1 The four battery packs shown in the figure are for illustration only and can be adjusted as needed), a battery pack cooling pipe system P that matches the on-board liquid-cooled battery pack, an external fixed battery thermal management unit,

[0022] The external fixed battery thermal management unit is fixed at the bus station or charging station, and includes a constant temperature water tank 1, in which an evaporator 2 and an electric heater 3 are arranged. A water replenishment tank 4 connected to the inner cavity is arranged on the top of the constant temperature water tank. The water replenishment tank can replenish water quickly, and can automatically replenish water when the vehicle end or the water tank is short of water. It can automatically stop after replenishment. A liquid outlet 5 and a liquid return port 6 are respectively arranged at the bottom of the constant temperature water tank.

[0023] The inlet and outlet of the evaporator 2 extend out of the thermostatic water tank through pipes respectively, and the outlet pipe is sequentially connected to the thermal expansion valve 7 (having four ports connected in pairs), the variable frequency compressor 8, the condenser 9, the liquid storage tank 10, the thermal expansion valve 7, and the inlet pipe of the evaporator to form a closed loop. The temperature and flow of the coolant sent to the battery pack are precisely controlled through the closed loop control, so as to adjust the operating temperature range of the battery pack;

[0024] The thermostatic water tank also includes a quick connector 11, which is divided into a vehicle-mounted connection end 23 and a battery thermal management unit connection end 24. The liquid outlet 5 of the thermostatic water tank is connected to a plurality of water outlet branch pipes 14 through a speed regulating water pump 13 arranged on the water outlet main pipe 12. The end of each water outlet branch pipe is connected to a normally closed quick connector A1. The return liquid port 6 of the thermostatic water tank is connected to a plurality of water return branch pipes 16 through a water return main pipe 15. The free end of each water return branch pipe is connected to a normally closed quick connector A2. The quick connectors of the water outlet branch pipe and the water return branch pipe are respectively connected to the vehicle-mounted The connection end corresponds to the port plug, and the water inlet and outlet of the battery pack cooling pipe system are respectively connected with the normally closed quick connector B1 / B2, which is connected to the battery thermal management unit connection end when in use, and the internal self-closing water circuit is opened to realize that the outlet branch pipe 14 is connected to the water inlet of the battery pack cooling pipe system, and the return branch pipe 16 is connected to the water outlet of the battery pack cooling pipe system. When the on-board liquid-cooled battery pack reaches the appropriate temperature, the quick connector is disconnected, and the on-board connection end and the battery thermal management unit connection end are internally self-closed to prevent coolant leakage;

[0025] The external fixed battery thermal management unit is automatically operated through a microprocessor control system 17 .

[0026] In this embodiment, a refrigerant pressure switch 18 is provided on the pipeline between the variable frequency compressor 8 and the condenser 9, a fan is provided in the condenser, and the variable frequency compressor, the fan, and the refrigerant pressure switch are all connected to the microprocessor control system;

[0027] In this embodiment, the compressor 13 and the condenser 9 are controlled by a microprocessor control system to control the temperature reduction.

[0028] In this embodiment, a temperature sensor 19 is inserted in the thermostatic water tank, and an ambient temperature sensor 20 for reading ambient temperature information is also provided. A pressure temperature sensor 21 is provided on each outlet branch pipe, and a flow temperature sensor 22 is provided on each return branch pipe. The temperature sensor, the pressure temperature sensor, and the flow temperature sensor are all connected to the microprocessor control system.

[0029] This embodiment reads the ambient temperature information through the ambient temperature sensor 20 to decide whether cooling (cooling mode) or heating (heating mode) is required; the battery temperature information (not shown in the schematic diagram) can also be read interactively through the charging pile to determine whether the vehicle battery needs temperature control; the pressure flow sensor 20 and the flow temperature sensor 22 are used for closed-loop control to accurately control the battery pack so that it works within the appropriate temperature range, and to detect the working status of each cooling circuit. When the pipeline is not connected properly or there is a leak, the system will alarm.

[0030] In this embodiment, the evaporator 2 adopts an evaporator coil with a cooling function, and the electric heater 3 adopts an electric heating tube with a heating function. The evaporator coil and the electric heating tube automatically perform heating or cooling work under the control of the microprocessor control system to meet the temperature control requirements of the vehicle battery.

[0031] The working principle of this utility model:

[0032] The external fixed battery thermal management unit includes cooling and heating functions. The microprocessor control system automatically determines whether the system works in cooling mode or heating mode based on the air temperature value collected by the ambient temperature sensor and the battery pack temperature information obtained by interacting with the charging pile.

[0033] The microprocessor control system controls the working status of the compressor, condenser fan, water pump, and electric heating tube through the collected temperature signals, and ensures that the coolant temperature in the constant temperature water tank is kept within the stable working range suitable for the battery pack in real time; at the same time, the microprocessor control system uses the pressure temperature sensor and the flow temperature flow sensor as the monitoring feedback signal of each branch to realize the automatic circulation control of the coolant between the external fixed battery thermal management unit and each vehicle;

[0034] The utility model controls the cooling capacity through the evaporator, compressor, condenser, liquid storage tank and thermal expansion valve in the thermostatic water tank connected by pipelines; controls the heating capacity through the electric heating pipe, main liquid return pipeline and microprocessor control system in the thermostatic water tank; injects the coolant of suitable temperature into the battery pack of the whole vehicle for heat exchange, and then flows into the thermostatic water tank from the return port of the thermostatic water tank through the return branch pipeline and the return main pipeline, and heat exchange is performed again in the thermostatic water tank to become the coolant suitable for battery operation, which flows out from the water outlet, is pressurized by the pressure regulating water pump, and flows into the battery system of the whole vehicle from the outlet main pipeline through the vehicle-mounted connection end and the battery thermal management unit connection end for heat exchange. This process is continuously repeated to form heat exchange between the battery thermal management unit and the battery pack of the whole vehicle, thereby achieving the purpose of stabilizing the working temperature of the battery pack.

[0035] Parts not described in detail in this specification are well-known technologies in the art.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery system thermal management device for electric buses, comprising an on-board liquid-cooled battery pack and a matching battery pack cooling pipeline system, characterized in that: It also includes an external fixed battery thermal management unit. The battery thermal management unit is fixed at the bus station or charging station, including a constant temperature water tank, an evaporator and an electric heater are arranged in the constant temperature water tank, a water replenishment tank connected to the inner cavity is arranged on the top of the constant temperature water tank, and a liquid outlet and a liquid return port are arranged at the bottom of the constant temperature water tank. The inlet and outlet of the evaporator extend out of the thermostatic water tank through pipes respectively, and the outlet pipe is sequentially connected with a thermal expansion valve, a variable frequency compressor, a condenser, a liquid storage tank, the thermal expansion valve, and the inlet pipe of the evaporator to form a closed loop; It also includes a quick connector, which is divided into a vehicle-mounted connection end and a battery thermal management unit connection end. The liquid outlet of the constant temperature water tank is connected to a plurality of water outlet branch pipelines through a speed regulating water pump, and the end of each water outlet branch pipeline is connected to a quick connector. The return liquid port of the constant temperature water tank is connected to a plurality of water return branch pipelines through a return water main pipeline, and the free end of each water return branch pipeline is connected to a quick connector. The quick connectors of the water outlet branch pipeline and the water return branch pipeline are respectively plugged into the corresponding ports of the vehicle-mounted connection end. The water inlet and water outlet of the battery pack cooling pipeline system are respectively connected with quick connectors, which are connected to the battery thermal management unit connection end when in use, so that the water outlet branch pipeline is connected to the water inlet end of the battery pack cooling pipeline system, and the water return branch pipeline is connected to the water outlet end of the battery pack cooling pipeline system; The battery thermal management unit operates automatically through a microprocessor control system.

2. According to claim 1, a thermal management device for a battery system for an electric bus is characterized in that: A refrigerant pressure switch is arranged on the pipeline between the variable frequency compressor and the condenser, a fan is arranged in the condenser, and the variable frequency compressor, the fan and the refrigerant pressure switch are all connected to a microprocessor control system.

3. A thermal management device for a battery system for an electric bus according to claim 1 or 2, characterized in that: The constant temperature water tank is equipped with a temperature sensor, which also includes an ambient temperature sensor for reading ambient temperature information. Each water outlet branch pipe is provided with a pressure temperature sensor, and each water return branch pipe is provided with a flow temperature sensor. The temperature sensor, pressure temperature sensor, and flow temperature sensor are all connected to the microprocessor control system.

4. According to claim 3, a thermal management device for a battery system for an electric bus is characterized in that: The evaporator is an evaporator coil with a cooling function, and the electric heater is an electric heating tube with a heating function. The evaporator coil and the electric heating tube automatically perform heating or cooling work under the control of a microprocessor control system to meet the temperature control requirements of the battery of the entire vehicle.

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