EV Battery Thermal Circuit with Insulated Auxiliary Loop

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Solution Overview

Problem

Electric vehicle batteries face challenges in temperature control due to high temperature fluctuations, requiring efficient heating and cooling systems that minimize energy losses and optimize battery performance for range and standby times.

Innovation Solution

A heating or cooling circuit with a base circuit for the electric motor and battery, featuring a bypass line and a thermally insulated auxiliary circuit that allows independent temperature control of the battery, using a smaller auxiliary pump to reduce energy consumption and parasitic losses, and utilizing waste heat from the electric motor for battery tempering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the main pump in the base circuit is used to temperature control the battery, then the battery can be temperature controlled, but parasitic energy losses are too high and charging time is extended

Engineering Contradiction:
Improveparasitic energy lossesVSAvoidcharging time
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The temperature control system is segmented into a base circuit for the electric motor and a separate auxiliary circuit for the battery. This allows independent temperature control of the battery using a dedicated auxiliary pump, avoiding the high parasitic losses of the main pump while enabling simultaneous operation without extending charging time

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If the electric motor is used for waste heat to temperature control the battery, then energy efficiency is improved, but the battery cannot be temperature controlled independently when the electric motor is stationary or off

Engineering Contradiction:
Improveenergy efficiencyVSAvoidindependent temperature control capability
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The system is divided into a base circuit that可以利用 waste heat from the electric motor and a separate auxiliary circuit that can operate independently. When the motor is running, the base circuit provides efficient waste heat utilization. When the motor is stationary or off, the auxiliary circuit with its dedicated pump and heater ensures the battery can still be temperature controlled independently

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The auxiliary circuit acts as an intermediary system that bridges the gap between waste heat availability and battery temperature control needs. It provides backup heating capability through a dedicated heater when waste heat is unavailable, ensuring continuous independent temperature control capability

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the main pump operates to temperature control both electric motor and battery together, then both components are cooled, but energy consumption increases and battery temperature control efficiency decreases

Engineering Contradiction:
Improvetemperature control reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The temperature control function is segmented between the base circuit for the electric motor and the auxiliary circuit for the battery. The auxiliary pump in the auxiliary circuit consumes significantly less energy than the main pump, enabling reliable battery temperature control with reduced energy consumption

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The auxiliary circuit provides dedicated battery temperature control with partial action - it only operates when battery temperature control is needed, not continuously like the main pump. This reduces overall energy consumption while maintaining reliable temperature control when required

Inventive Principle:
Principle #16Partial or excessive 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 solution enables efficient temperature control of the battery independently of the electric motor, reducing energy losses and enhancing battery performance by allowing autonomous temperature management, which increases efficiency and reduces charging time, while also utilizing waste heat for cabin heating.

Implementation Method 1

The auxiliary circuit includes means, for example in the form of a pump, that enable the flow of coolant through the auxiliary circuit independently of the main pump in the main circuit

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

The auxiliary circuit is thermally insulated from the main circuit. Thermally insulated means that the auxiliary circuit can be operated independently of the main circuit without exchanging heat with the main circuit

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

a main pump is provided in the base circuit to transport a coolant through the base circuit

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 4

a bypass line to allow the coolant to flow past the battery

Methodology Applied
Scientific EffectFluid flow: Convection

Data Source

PatentEP3873757B1Heating or cooling medium circuit for an electric vehicle
Publication Date: 2023.08.16 ROBERT BOSCH GMBH
  • EP3873757B1 patent drawingFigure 1
  • EP3873757B1 patent drawingFigure 2

AI summary

The invention relates to a heating or cooling medium circuit (100) for an electric vehicle, comprising a base circuit (10) for controlling the temperature of an electric motor (11) and a battery (12) of the electric vehicle, wherein a main pump (15) is provided in the base circuit (10) in order to pump a coolant through the base circuit (10), a bypass line (20) for allowing the coolant to flow past the battery (12), and a thermally insulated auxiliary circuit (30) for the battery (12) in order to control the temperature of the battery (12) independently of the electric motor (11).