Battery Chiller Control to Prevent Cabin Air Temperature Spikes

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Solution Overview

Problem

In PHEV vehicles, the cooling of the battery using the air conditioning circuit can temporarily increase the temperature of the air conditioning fluid, leading to a perceived rise in temperature in the passenger compartment, which is perceived as poor performance of the air conditioning system.

Innovation Solution

A method that temporarily cuts off the water circulation in the battery cooling circuit after a cooling request is made, using solenoid valves to prevent the warm water from entering the chiller and heating the air conditioning fluid, with the circulation restored after a short period to ensure battery cooling, managed by a central computing unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If water circulation is cut off immediately when battery cooling is requested, then the air conditioning fluid temperature remains stable, but the battery cooling is delayed

Engineering Contradiction:
Improveair conditioning fluid temperatureVSAvoidbattery cooling response time
Core Design Contradiction:
TemperatureVSLoss of time

Solution Approach 1:

The system uses periodic action by temporarily closing the solenoid valve for a brief period (just long enough to prevent warm water from reaching the chiller), then reopening it to allow battery cooling to proceed. This periodic control strategy balances the need to maintain air conditioning fluid temperature stability with the need to provide timely battery cooling.

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

This method effectively reduces the temporary rise in passenger compartment temperature, improving the perceived performance of the air conditioning system without requiring structural modifications or additional components, ensuring the battery remains within safe temperature limits.

Implementation Method 1

a chiller, which brings air conditioning refrigerant into contact with a water circulation system that cools the battery

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

two solenoid valves and two expansion valves

Methodology Applied
Scientific EffectValve flow control: Valve

Data Source

PatentEP3931009B1Method for managing an air-conditioning circuit connected to a battery cooling circuit
Publication Date: 2024.04.03 RENAULT SA
  • EP3931009B1 patent drawingFigure 1~2
  • EP3931009B1 patent drawingFigure 3

AI summary

The invention relates to a method for managing an air-conditioning system (1) of a vehicle comprising an electric battery (2), the system (1) comprising a first circuit (4) for circulating an air-conditioning fluid, connected via a chiller (6) to a second circuit (5) for circulating water intended to cool the battery (2). According to the invention, the method comprises the following steps: - A step of requesting the cooling of the battery (2), - A step of cutting off the circulation of water in the second circuit (5) during a given period, this step being triggered just after the step of requesting the cooling of the battery (2), - A step of restoring the circulation of water in the second circuit (5) after the given period in order to reactivate the chiller (6) and thus cool the battery (2).