Introduction to integrated solution for thermal
management of electric vehicles
The thermal management system of electric vehicles consists of many components, such as electronic expansion valve (EXV), solenoid valve (SOV), chiller, water pump, gas-liquid separator, kettle, etc. To optimize pipeline connections and reduce heat exchange To reduce losses and reduce assembly difficulty, thermal management systems are developing in the direction of integrated design. According to the degree of integration, it can be divided into three methods: local integration, regional integration and system integration.
Local integration
Partial integration is the integrated design of components with similar functions, such as EXV and SOV, or components with similar locations, such as Chiller and EXV. It transforms a large number of system components into small integrated modules without changing the overall layout of the system. Under the premise, it can effectively reduce the assembly time of parts.
Figure 4 is a model diagram that integrates the three components of the Chiller, EXV and plate heat exchanger (PHX). The Chiller is a heat exchange component for cooling the power battery, and an EXV is generally equipped on the refrigerant inlet side to regulate Flow. PHX is a heat exchanger for heating the power battery. The three are integrated into one through a certain assembly relationship, and the interior is connected through the flow channel. When assembling the system, only need to connect the refrigerant pipeline at the condenser outlet to the EXV inlet The system functions can be realized by connecting the brine refrigerant pipeline to the quick-plug connector of Chiller and PHX.
Multi-way valve is another common form of partial integration. It is generally composed of a valve shell and a valve core. The valve shell is equipped with multiple valve ports, and the valve core is equipped with multiple flow channels. Different functions are realized through the action of the valve core. The connection between valve ports is used to replace multiple one-way valves or reversing valves. The heat transfer loss and pressure loss of multi-way valves have a great impact on system performance.
Regional integration
Regional integration is the integrated design of a certain area or components that implement a certain function, such as integrating the EXV, SOV, gas-liquid separator and other components of the refrigerant circuit, or integrating the water pump, water valve, etc. of the refrigerant circuit Integration of components such as kettles. Compared with local integration, regional integration can reduce the number and length of connecting pipelines, the system will be more simplified, and can significantly reduce the number of components and system assembly time, reduce costs and improve reliability.
Figure 5 shows the thermal management area integrated module that integrates the refrigerant loop flow adjustment module, refrigerant flow adjustment module, heat exchange component module and mounting bracket module. This solution greatly reduces the use of materials, processing and Cost of assembly.
System integration
From the perspective of vehicle layout, the electric vehicle thermal management system includes front-end heat exchange components (such as radiators, fans, etc.), cabin heat distribution components (such as compressor and refrigerant circuit, PTC and secondary refrigerant circuit, etc.), and passenger cabin Air volume distribution components (such as air conditioning boxes, air ducts, etc.). System integration is to design the cabin heat distribution components into a module according to certain principles to maximize the integration of plate heat exchangers, EXV, SOV, sensors, multi-way valves, Water pumps, kettles and other components are integrated together, and switching between different modes is achieved through complex internal flow channel design and precise flow control. System integration can not only reduce assembly time, but also effectively reduce the weight and space of the vehicle. At the same time Since the flow channel is integrated into the module, the pressure drop is reduced to a certain extent and the system efficiency is improved.
