Battery Pack Cooling Control for Uniform Temperature Distribution

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Solution Overview

Problem

Existing new energy vehicles face issues with uneven temperature distribution in battery packs leading to thermal runaway and reduced service life due to inconsistent discharge, which is exacerbated by high heat generation and high temperature from increased energy density.

Innovation Solution

A temperature control method and apparatus that utilizes parallel passenger compartment and battery pack thermal management circuits, incorporating a compressor, condenser, evaporator, cooler, and water pump, with temperature sensors and valves to actively adjust refrigerant flow and coolant circulation based on temperature differences within the battery pack, ensuring precise temperature control and preventing thermal runaway.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the cooling level of the air conditioning compressor is controlled according to the maximum temperature value of the battery pack, then the battery pack temperature can be reduced, but uneven temperature distribution occurs throughout the battery pack

Engineering Contradiction:
Improvebattery pack temperatureVSAvoidtemperature distribution uniformity
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by dividing the battery pack into multiple temperature zones and controlling cooling to different regions based on their specific temperature needs. Temperature sensors are distributed throughout the battery pack to detect local temperature variations, and the control system adjusts refrigerant flow to specific areas rather than applying uniform cooling, thereby achieving both temperature reduction and uniform temperature distribution.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamic control by continuously monitoring temperature variations throughout the battery pack and adjusting the cooling system's operation in real-time. The control system modifies refrigerant flow rates, compressor output, and valve positions based on current temperature conditions, enabling adaptive response to changing thermal patterns and preventing both overheating and excessive cooling in different regions.

Inventive Principle:
Principle #15Dynamics

2Productivity

If high energy density power batteries are used to improve endurance mileage, then the endurance mileage increases, but high heat generation and high temperature occur

Engineering Contradiction:
Improveendurance mileageVSAvoidbattery temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent employs feedback control by continuously monitoring battery temperature through distributed sensors and using this information to adjust the thermal management system's operation. The control system receives temperature data, compares it against target ranges, and automatically modifies cooling parameters such as refrigerant flow rate and compressor output to maintain optimal battery temperature, thereby enabling high energy density batteries to operate safely.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces a cooler as an intermediary heat exchange device between the battery pack and the refrigerant circuit. The cooler facilitates efficient heat transfer from the battery coolant to the refrigerant, acting as a thermal mediator that enables effective temperature control of high energy density batteries without direct contact between the battery and refrigerant, thus managing heat generation while maintaining battery performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Achieves precise temperature control within the battery pack, preventing thermal runaway and improving the service life and safety of the battery pack by uniformly managing temperature distribution and reducing energy consumption.

Implementation Method 1

one side of the cooler facing the evaporator is refrigerant, and one side of the cooler facing the battery pack is coolant

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

the first water pump to drive the coolant into the battery pack and exchange heat between heat generated by the battery pack and the refrigerant of the cooler

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

turning on the compressor, the first water pump, and the stop valve

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

the first branch includes an evaporator and an electronic expansion valve connected to an inlet of the evaporator

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 5

exchange heat between heat generated by the battery pack and the refrigerant of the cooler

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 6

the main circuit includes a compressor, a condenser and a liquid reservoir arranged in sequence

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 7

the main circuit includes a compressor, a condenser and a liquid reservoir arranged in sequence

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP4704219A1Temperature control method, apparatus and device for battery pack, and new energy vehicle
Publication Date: 2026.03.04 CHONGQING CHANGAN AUTOMOBILE CO LTD
  • EP4704219A1 patent drawingFigure 1
  • EP4704219A1 patent drawingFigure 2
  • EP4704219A1 patent drawingFigure 3~4

AI summary

The present application relates to the field of new energy vehicle technologies and, in particular, to a temperature control method, apparatus and device for a battery pack and a new energy vehicle. The temperature control method for the battery pack includes: obtaining a maximum temperature value and a minimum temperature value inside the battery pack; comparing whether a difference between the maximum temperature value and the minimum temperature value is greater than a designed threshold, and whether the maximum temperature value is greater than or equal to a first tolerance temperature threshold of the battery pack; if so, turning on the compressor, the first water pump, and the stop valve to allow the first water pump to drive the coolant into the battery pack and exchange heat between heat generated by the battery pack and the refrigerant of the cooler. The present application can actively adjust the flow rate of the refrigerant according to the temperature difference inside the battery, achieving precise control of the internal temperature of the battery pack, avoiding thermal runaway caused by uneven discharge of the battery pack, and improving the service life of the battery pack.