Battery Cooling Circuit Pressure Sensing for Thermal Runaway Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery systems face challenges in detecting abnormal operating conditions that can lead to thermal runaway, particularly over-temperature, without the need for expensive individual temperature sensors on each cell, which complicates manufacturing and requires significant installation space.
Innovation Solution
A method involving a battery management system (BMS) that utilizes a pressure sensor in the cooling circuit to detect pressure changes by switching off the coolant transfer member, measuring pressure differences, and determining if they exceed a threshold to indicate potential thermal runaway, thereby avoiding the need for individual cell temperature sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If each battery cell is equipped with its own temperature sensor, then the detection precision of abnormal operating conditions is improved, but the manufacturing cost and device complexity increase significantly
Solution Approach 1:
The patent segments the temperature monitoring function by dividing the battery system into multiple cooling circuits, each equipped with its own pressure sensor. This allows localized temperature monitoring of specific battery cell groups without requiring individual temperature sensors on each cell, thereby reducing overall system complexity while maintaining detection precision at the circuit level.
Solution Approach 2:
The patent introduces pressure as an intermediary parameter to indirectly measure temperature conditions. Instead of directly measuring temperature with temperature sensors, the system uses pressure sensors to detect pressure changes in the cooling circuit caused by thermal expansion of the coolant, which correlates with battery cell temperature. This intermediary approach reduces sensor requirements while maintaining detection capability.
2Ease of manufacture
If pressure sensing is used instead of temperature sensing, then the manufacturing cost is reduced, but the measurement precision of temperature-related conditions may be affected
Solution Approach 1:
The patent changes the measurement parameter from temperature to pressure. By monitoring pressure changes in the cooling circuit rather than direct temperature, the system achieves cost-effective manufacturing while maintaining detection accuracy through the established relationship between coolant pressure and battery cell temperature via thermal expansion principles.
Solution Approach 2:
The patent utilizes thermal expansion of the coolant as the physical mechanism linking temperature to pressure. When battery cells overheat, the coolant temperature increases, causing thermal expansion and corresponding pressure changes that are detected by the pressure sensor. This physical principle enables accurate indirect temperature measurement using pressure sensing technology.
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
This approach enhances the detection of abnormal conditions leading to thermal runaway, reduces manufacturing costs, and simplifies installation by relying on indirect pressure measurements instead of direct temperature sensing, while maintaining safety and reliability.
Implementation Method 1
detecting an initial pressure with the pressure sensor; switching off the coolant transfer member for a time period; capturing a subsequent pressure with the pressure sensor after switching off the coolant transfer member; and determining a pressure difference between the initial pressure and the subsequent pressure
Data Source
AI summary
A battery system includes a battery pack including battery cells and a cooling system including a coolant transfer member for circulating a liquid coolant in a cooling circuit, a first heat exchanger integrated into the cooling circuit and thermally contacting the battery cells, and a pressure sensor for detecting a change in pressure inside the cooling circuit. A battery management system is connected to the pressure sensor and the coolant transfer member and is for performing a detection mode including: detecting an initial pressure with the pressure sensor and switching off the coolant transfer member for a time period; after switching off the coolant transfer member, capturing the pressure with the pressure sensor; and determining a pressure difference between the initial pressure value and the captured pressure, when the pressure difference exceeds a threshold, determining an abnormal condition that could cause a thermal runaway of the battery pack.