Integral vehicle thermal management system for plug-in hybrid electric vehicle

Abstract

The invention discloses an integral vehicle thermal management system for a plug-in hybrid electric vehicle. The integral vehicle thermal management system comprises a high-temperature cooling system,a medium-temperature cooling system, a low-temperature cooling system, a battery cooling system and an air conditioning system. The integral vehicle thermal management system for the plug-in hybrid electric vehicle has advantages that by design according to heating quantity and cooling demands of different parts, mutual influences of parts are avoided, high requirements on utilization temperatureof each part can be met, functions and performances of each part are guaranteed, and the service life of each part is prolonged while efficiency of each part is improved; by integration of a power battery thermal management system and the air conditioning system, the maximum utilization rate of integral vehicle thermal environmental resources is achieved; when warm air is required under a pure electric operating condition, engine waste heat and transmission heat are fully used while a PTC (positive temperature coefficient) heater is applied so as to reduce engine starting frequency, and energy saving, environmental friendliness and comfort of the whole vehicle are improved; by adoption of transmission heat for engine preheating under the pure electric operating condition, the engine starting performance is improved, and economy and emission performances of the whole vehicle are effectively improved.

Description

technical field [0001] The invention belongs to the field of thermal management of hybrid electric vehicles, in particular to a vehicle thermal management system of a plug-in hybrid electric vehicle. Background technique [0002] The thermal management system of the water-cooled power battery plug-in hybrid electric vehicle increases the cooling requirements of the motor, motor controller, battery, charger and DCDC on the basis of the traditional vehicle thermal management system. Coolant temperature requirements vary widely. Engine and transmission coolant temperature requirements are generally above 95°C, intercooler and turbocharger coolant temperature requirements are generally between 75 and 90°C, and motor coolant requirements are generally 70°C Below, the motor controller, charger and DCDC coolant temperature requirements are generally below 65°C, and the battery coolant temperature requirements are generally 18-25°C. Independent cooling of each component is required ...

AI Technical Summary

Problems solved by technology

For the system disclosed in Patent Document 3, the transmission is not integrated in the system, and the charger and DCDC are not integrated in the battery cooling circuit; at the same time, the heat generated by the internal components of the system is not used to provide warm air during pure electric driving , the resources in the system are not fully utilized, resulting in frequent engine starts, increased fuel consumption and increased pollutant emissions; and when driving purely electric, the engine is not heated, and the economy and emission performance of the engine are not improved when starting

[0007] At present, the air-conditioning system and power battery thermal management system of existing hybrid electric vehicles are generally independent, and few integrate the power battery thermal management system and air-conditioning system together. Low, did not reach the maximum utilization rate of the thermal environment resources of the vehicle

[0008] Existing hybrid electric vehicles generally do not make full use of the waste heat of the engine and the heat of other heat-generating components when driving under pure electric conditions, and the heat of other heat-generating components does not reach the maximum utilization rate of thermal management resources. It is necessary to start the engine, causing the engine to start frequently. Increased fuel consumption, increased pollutant emissions, unable to take into account energy saving, environmental protection and comfort of the vehicle

[0009] In existing hybrid electric vehicles, when the engine is shut down for a long time under pure electric conditions, the temperature of the engine coolant will drop, and the heat from other heat-generating components will not be fully utilized to preheat the engine to the greatest extent, and the maximum utilization of thermal management resources will not be achieved. When the engine restarts, the lubricating oil viscosity is low, the frictional resistance is too large, and the fuel injection volume increases, which affects the vehicle economy and emission performance

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