Hydronic Battery Thermal Loop for EV Occupant Zone Comfort

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Electric vehicles face challenges in maintaining optimal battery performance, efficiency, and longevity due to temperature variations, which also affect occupant comfort in the vehicle's cabin.

Innovation Solution

A battery heating and cooling system is integrated with an occupant zone hydronic system, allowing the system to direct coolant from the battery heating and cooling loop to the occupant zone to maintain both optimal battery temperature and occupant comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a separate occupant zone heating and cooling system is used, then occupant comfort is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improveoccupant comfortVSAvoidsystem complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The battery thermal management system is designed to serve dual purposes: cooling the battery during charging and providing ancillary heating or cooling to the occupant zone. The hydronic circuit is configured to redirect coolant from the battery cooling loop to occupant zone hydronic objects (seats, floor panels, steering wheel), allowing one system to fulfill multiple thermal management functions and eliminating the need for a completely separate occupant comfort system.

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

2Reliability

If battery cooling is prioritized during charging, then battery performance is improved, but occupant zone temperature control deteriorates

Engineering Contradiction:
Improvebattery performanceVSAvoidoccupant zone temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The system incorporates dynamic control mechanisms including a three-way valve and pump control that can redirect coolant flow between the battery cooling circuit and the occupant zone hydronic circuit based on real-time thermal conditions. The controller monitors battery temperature, occupant zone temperature, and charging state to dynamically adjust coolant distribution, ensuring battery performance is maintained while providing ancillary comfort when conditions permit.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (coolant flow direction, flow rate, temperature) based on system state. During fast charging when battery cooling is critical, coolant is directed to the battery. During standard charging or when battery temperature is acceptable, coolant is redirected to the occupant zone to provide heating or cooling, thus adapting system behavior to current conditions.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If ancillary heating and cooling is provided to occupant zone, then occupant comfort is improved, but energy available for battery charging decreases

Engineering Contradiction:
Improveoccupant comfortVSAvoidcharging energy
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system uses the battery's own thermal energy to provide occupant zone heating or cooling during charging operations. When the battery is being cooled during charging, the extracted thermal energy is redirected to heat or cool the occupant zone, effectively making the battery serve its own thermal management needs and providing free ancillary comfort without requiring additional energy input from the charging system.

Inventive Principle:
Principle #25Self-service

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 integrated system efficiently manages battery temperature and provides ancillary heating and cooling to the occupant zone, enhancing both battery performance and occupant comfort within a target temperature range.

Implementation Method 1

operate the refrigeration circuit to heat or cool coolant circulating though the battery heating/cooling loop to heat or cool the battery toward a target battery temperature

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

direct the coolant circulating though the battery heating/cooling loop to the hydronic system heating/cooling loop to heat or cool the occupant zone

Methodology Applied
Scientific EffectHeat transfer: Convection

Data Source

PatentEP4538071A1Hydronic occupant zone heating and cooling
Publication Date: 2025.04.16 PACCAR INC
  • EP4538071A1 patent drawingFigure 1
  • EP4538071A1 patent drawingFigure 2
  • EP4538071A1 patent drawingFigure 3

AI summary

A battery heating and cooling system may be used to provide ancillary heating and cooling to an occupant zone (103b) of a vehicle. The battery heating and cooling system may include a battery heating/cooling loop (116) and a hydronic system heating/cooling loop (216) . Upon receiving an indication to heat/cool the occupant zone, a battery management system may cause the battery heating and cooling system to direct coolant to the hydronic system heating/cooling loop to heat/cool the occupant zone toward a target occupant zone temperature. In some examples, the battery heating and cooling system directs coolant to the hydronic system heating/cooling loop during battery preconditioning or while heating/cooling the battery during operation of the vehicle. The target occupant zone temperature may correspond to a target battery temperature.