Vehicle Coolant Circuit Control for Pipe Heat Loss Compensation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In vehicle air conditioning systems, pipe heat loss in coolant passages leads to a decrease in coolant temperature, resulting in insufficient heating capacity for cabins and batteries, as the heat of the coolant is wasted due to complications in the coolant circuit.

Innovation Solution

A control device with a processor that calculates and corrects the target coolant temperature to account for pipe heat loss, using outside air temperature and coolant flow rate to maintain optimal heating performance by adjusting heat sources such as a coolant heater and heat exchanger in the vehicle coolant circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the coolant passage is complicated to connect multiple heat sources and heat using portions, then the system functionality is improved, but the pipe heat loss increases and coolant temperature decreases

Engineering Contradiction:
Improvesystem functionalityVSAvoidpipe heat loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The control device performs preliminary calculation of pipe heat loss based on coolant flow rate and outside air temperature, and applies correction to the target coolant temperature before controlling the heat sources. This preliminary correction action compensates for the inevitable heat loss in the complicated coolant passage system.

Inventive Principle:
Principle #10Preliminary action

2Temperature

If the coolant temperature decreases due to pipe heat loss, then the heating capacity for the vehicle cabin becomes insufficient, but the system structure remains the same

Engineering Contradiction:
Improvecoolant temperatureVSAvoidheating capacity
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The control device continuously monitors coolant flow rate and outside air temperature, calculates the resulting pipe heat loss, and adjusts the target coolant temperature accordingly. This feedback mechanism ensures that the heating capacity remains sufficient despite heat losses in the coolant passage.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control device changes the target coolant temperature parameter based on calculated correction values derived from coolant flow rate and outside air temperature. By dynamically adjusting this parameter, the system compensates for pipe heat loss and maintains adequate heating capacity.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the coolant temperature decreases due to pipe heat loss, then the warming capacity for the battery becomes insufficient, but the system structure remains the same

Engineering Contradiction:
Improvecoolant temperatureVSAvoidwarming capacity
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The control device uses feedback from coolant flow rate and outside air temperature sensors to calculate pipe heat loss and adjust the target coolant temperature, ensuring sufficient warming capacity for the battery despite heat losses in the coolant passage.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control device dynamically changes the target coolant temperature parameter based on correction values calculated from operating conditions, ensuring that the battery warming capacity remains adequate even when pipe heat loss occurs.

Inventive Principle:
Principle #35Parameter changes

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 effectively suppresses the decrease in coolant temperature due to pipe heat loss, ensuring adequate heating capacity for vehicle cabins and batteries by dynamically adjusting the coolant circuit's heat sources based on calculated correction values.

Implementation Method 1

a water pump configured to circulate a coolant

Methodology Applied
Scientific EffectFluid circulation: Pump

Implementation Method 2

a plurality of heat sources configured to heat the coolant

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

a heat using portion configured to use heat of the coolant

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

The heater core is arranged in a blower duct that is a passage of blow air, and heats the blow air with the coolant flowing through the heater core

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 5

a loss of heat of the coolant in the coolant passage

Methodology Applied
Scientific EffectThermal insulation loss: Thermal Insulation

Data Source

PatentEP3974215B1Control device and control method
Publication Date: 2023.11.08 TOYOTA JIDOSHA KK
  • EP3974215B1 patent drawingFigure 1
  • EP3974215B1 patent drawingFigure 2
  • EP3974215B1 patent drawingFigure 3~4

AI summary

A control device configured to control a vehicle coolant circuit includes a processor (6; 6a). The processor (6; 6a) is configured to calculate a target coolant temperature, and control heat sources based on the target coolant temperature. The processor (6; 6a) is configured to correct the target coolant temperature in consideration of a loss of heat of a coolant in a coolant passage.