Vehicle Battery Heating Control Using Superposed Multi-Loop Heat Sources

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Solution Overview

Problem

Existing thermal management systems for vehicle batteries, such as those in new energy vehicles, are inefficient in rapidly heating batteries due to the slow heating speed of heat pump systems, failing to meet customer demands for rapid heating in low ambient temperatures.

Innovation Solution

A thermal management system incorporating an electric-drive heat exchange system, a heat-pump heat exchange system, and a battery heat exchange system, utilizing multiple heat sources including an electric-drive locked-rotor, a heat pump system, and a heater to rapidly heat the battery by superposing heat through interconnected loops and controlled heat exchange processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a heat pump system is used to heat the battery, then energy efficiency is improved, but the heating speed is slow and cannot meet customer demands

Engineering Contradiction:
Improveenergy efficiencyVSAvoidheating speed
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The patent combines three heat sources (heat pump system, heater, and electric-drive locked-rotor) into a unified thermal management system. The heat pump system provides efficient heating while the heater and locked-rotor contribute additional heat to achieve rapid heating, thus maintaining energy efficiency while improving heating speed.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system dynamically switches between different heating modes based on temperature requirements. When rapid heating is needed, the heater and locked-rotor are activated alongside the heat pump. When moderate heating suffices, only the heat pump operates, optimizing energy efficiency.

Inventive Principle:
Principle #15Dynamics

2Speed

If multiple heat sources are superposed to heat the battery, then heating rate is improved, but system complexity increases

Engineering Contradiction:
Improveheating rateVSAvoidsystem complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The thermal management system is designed with multi-functionality, where the heat pump system, heater, and locked-rotor can operate independently or in combination. The control unit intelligently selects and coordinates these components based on heating requirements, achieving rapid heating without proportionally increasing system complexity through smart integration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control unit acts as an intermediary that coordinates the multiple heat sources. It manages the activation and coordination of the heat pump system, heater, and locked-rotor, simplifying the control of multiple components through a centralized intelligence that optimizes their combined operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If the heater and heat pump system are used together, then heating capability is improved, but energy consumption increases

Engineering Contradiction:
Improveheating capabilityVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The system applies partial action by using the heater and locked-rotor only when rapid heating is required, rather than continuously. The heat pump system operates as the primary heating source for normal conditions, while the heater and locked-rotor provide supplemental heat temporarily to achieve rapid temperature increase, then are deactivated to reduce energy consumption.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The heater and locked-rotor are activated periodically or temporarily during the heating process to provide rapid temperature increase, then deactivated. This periodic supplementation of heat sources achieves high heating capability during critical periods while maintaining lower energy consumption during non-critical periods when only the heat pump operates.

Inventive Principle:
Principle #19Periodic action

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 system achieves rapid battery heating by superposing heat from multiple sources, improving heating rates and efficiency, ensuring effective battery operation in low temperatures.

Implementation Method 1

a first pump and an electric-drive heat exchanger that are arranged in the first loop; a compressor, an indirect condenser, an electronic expansion valve and a cooler that are sequentially arranged in the second loop, where the first loop is connected to the cooler, the first loop being configured to exchange heat with the second loop

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a compressor, an indirect condenser, an electronic expansion valve and a cooler that are sequentially arranged in the second loop

Methodology Applied
Scientific EffectCompression heating: Compression

Implementation Method 3

the third loop is connected to the indirect condenser, the second loop is configured to exchange heat with the third loop

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

a heater and a battery heat exchanger that are arranged in the third loop

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 5

a heater and a battery heat exchanger that are arranged in the third loop, where the third loop is connected to the indirect condenser

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4578674A1Thermal management system and control method thereof, and vehicle
Publication Date: 2025.07.02 XIAOMI EV TECH CO LTD
  • EP4578674A1 patent drawingFigure 1
  • EP4578674A1 patent drawingFigure 2
  • EP4578674A1 patent drawingFigure 3

AI summary

A thermal management system includes: an electric-drive heat exchange system including a first loop (101); a heat-pump heat exchange system including a second loop (201), where the first loop (101) can exchange heat with the second loop (201); and a battery heat exchange system including a third loop (301), where the second loop (201) can exchange heat with the third loop (301).