Hybrid Vehicle Battery Heating via Engine Cooling Circuit
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Solution Overview
Problem
Conventional battery temperature raising devices for hybrid vehicles are insufficient in raising battery temperature effectively due to the heat capacity disparity between the battery and other components, leading to reduced performance and increased fuel consumption in low temperature conditions.
Innovation Solution
A battery temperature raising device that includes an engine cooling circuit, a motor generator cooling circuit, a first battery circuit connected in parallel to the engine cooling circuit, a heat exchanger for heat exchange between the two circuits, and a temperature raising control unit that switches connections to optimize heat transfer from the engine and motor generator to the battery, ensuring efficient temperature raising in both engine and motor traveling modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the battery temperature is raised using only the heat generation of the electric power converter and motor, then the battery temperature increases, but the temperature raising effect is insufficient due to the large heat capacity of the battery compared to these components
Solution Approach 1:
The patent merges the engine cooling circuit with the battery temperature raising function. The cooling water from the engine cooling circuit, which contains thermal energy, is directed to the battery through the first battery circuit. This combines the cooling function for the engine with the temperature raising function for the battery, allowing the battery to be heated by the engine's waste heat, thereby significantly improving temperature raising efficiency.
Solution Approach 2:
The cooling water circulation system is designed to serve multiple functions: cooling the engine when needed and raising the battery temperature when needed. By using the same cooling water circuit for both purposes, the system achieves multi-functionality, eliminating the need for separate heating systems and improving overall system efficiency.
2Reliability
If exclusive cooling systems are used for the engine, motor generator, and battery, then each component can be cooled independently, but the device complexity increases and temperature raising efficiency decreases
Solution Approach 1:
The patent implements a universal cooling water circulation system that can serve multiple purposes: cooling the engine, cooling the motor generator, and raising the battery temperature. The first battery circuit is connected in parallel to the engine cooling circuit, allowing the same cooling water to be used for different functions depending on the switching unit's configuration, thereby reducing device complexity while maintaining reliable cooling control.
Solution Approach 2:
The system uses switching units to dynamically reconfigure the cooling water flow paths based on operational requirements. When battery heating is needed, the switching unit directs cooling water through the first battery circuit; when engine cooling is needed, the water flows through the engine. This dynamic reconfiguration allows a single system to adapt to different operational modes, reducing complexity while maintaining reliability.
3Device complexity
If the battery operates in a low temperature state, then the device structure remains simple, but the charge/discharge efficiency decreases and fuel consumption increases
Solution Approach 1:
The system uses the engine's own waste heat to raise the battery temperature, rather than requiring an external heating source. The cooling water, which absorbs heat from the engine during normal operation, is redirected to the battery when heating is needed. This self-service approach utilizes already-present thermal energy in the system, avoiding additional energy consumption while maintaining simple device structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables sufficient and efficient battery temperature raising, improving electric power consumption and extending traveling distance by utilizing the heat capacity of the engine and motor generator, thereby overcoming the limitations of conventional devices.
Implementation Method 1
a heat exchanger which is arranged in the first bypass flow path and performs heat exchange between the cooling water of the engine cooling circuit and the refrigerant of the motor generator cooling circuit
Implementation Method 2
the cooling water heated by heat generation of the electric power converter and the motor
Data Source
AI summary
The disclosure is a battery temperature raising device for hybrid vehicle that raises the temperature of a battery. In an engine travelling mode, when an engine water temperature is higher than a specified cooling water temperature, a first battery circuit is connected to a main circuit and the temperature of the battery is raised by cooling water in the main circuit (first temperature raising control). In a motor travelling mode, when a motor generator temperature is higher than a battery temperature, the first battery circuit and a heat exchanger flow path are connected to the main circuit, and thereby a closed circuit through which cooling water circulates without passing through an engine is formed, and the temperature of the battery is raised by the cooling water that is raised in temperature by heat exchange with a refrigerant in a heat exchanger (second temperature raising control).