Thermal management system and working method for electric vehicle battery pack

Abstract

The invention discloses a pure electric vehicle battery pack thermal management system and a working method thereof, comprising a liquid circulation path inside the battery box and a liquid circulation path outside the battery box; the liquid circulation path in the box includes Heating unit A, heat exchanger A, hydraulic pump A, three-way valve A and flow distribution unit; the liquid circulation path outside the tank includes fuel heater, on-off valve, on-off valve C, heat exchanger B, on-off valve A, three-way Valve B, radiator, air conditioning system, liquid storage tank and switch valve D. Keep the battery system at a good working temperature in the charging state and different driving states, ensure the temperature balance between the battery cells and reduce the thermal management energy consumption of the battery system, so as to ensure that the battery system is stable under different vehicle states. A reasonable thermal management method can be used to thermally manage the battery system, prolong the service life of the battery system, and reduce the cost of using the electric vehicle battery and the energy consumption of the entire vehicle.

Description

technical field [0001] The invention belongs to the field of thermal management of electric vehicle batteries, and more specifically relates to a thermal management system for electric vehicle battery packs, which is suitable for thermal management of power batteries during charging and discharging. Background technique [0002] Batteries are key components of electric vehicles and directly affect the performance of electric vehicles. The operating temperature of the battery has a crucial impact on the service life of the battery and the performance of the battery. If the temperature is too low, the discharge power and capacity of the battery will be affected, resulting in a significant decrease in vehicle performance; if the temperature is too high, the cycle life of the battery will be affected, so thermal management of the battery is very necessary. [0003] The Chinese patent document discloses a battery thermal management system with the application number 201110210364...

AI Technical Summary

Problems solved by technology

But this invention has the following disadvantages: 1. This invention uses electric heating as the only heating method for battery pack heating. In the case of cold start, there is no detailed explanation of the energy source of the heating device; 2. This invention combines the heating device with the refrigerator. The devices are connected in series in the same circuit and no heat preservation measures are taken. At the same time, the entire circulation pipeline is relatively long. Therefore, when the external ambient temperature is low, the heat dissipation effect of the cooling device and the circulation pipeline will cause energy loss and reduce 3. When the system enables air-conditioning refrigeration cooling and radiator cooling at the same time, the cooling device and the radiator are in a parallel positional relationship, and in this invention there is no convection of the liquid flow through the cooling device and the radiator control, resulting in imperfect control of the cooling process

[0004] At present, the heating device of most thermal management systems is electric heating, and in the low temperature environment, the energy source of the electric heating device has a big problem. The proper working temperature cannot be reached, so it will cause great damage to the battery pack, and at the same time, due to the power consumption, the battery life of the electric vehicle is also reduced

[0005] At the same time, the temperature difference between different battery cells also has a great impact on the working life of the entire battery pack. Although there are some methods to solve this problem, the problem of temperature balance among battery cells still needs to be further solved.

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