Vehicle Cabin Cooling with Electric Compressor Speed Control

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Solution Overview

Problem

In vehicles, traditional HVAC systems rely on engine-driven compressors, leading to inefficient cooling when the engine is off, as the engine must be kept running to provide cooling, wasting energy and causing unnecessary refrigerant compressor operation.

Innovation Solution

An air conditioning system with an electric compressor powered by a battery pack, controlled by a module that varies compressor speed based on discharge pressure and power consumption to maintain efficient cooling without the engine running, using an inverter drive and control module to manage blower speeds and valve operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an engine-driven compressor is used to provide cooling, then cooling function is available, but the engine must remain running causing energy waste and unnecessary operation

Engineering Contradiction:
Improvecooling function availabilityVSAvoidengine energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the engine-driven mechanical compressor with an electric compressor that operates independently. This allows the cooling system to function without the engine running, substituting mechanical coupling with electrical power delivery from the vehicle's electrical system.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent separates the cooling function from the propulsion system by using an independent electric compressor. This segmentation allows the air conditioning system to operate autonomously without requiring engine operation, enabling the engine to be turned off when cooling is needed but propulsion is not required.

Inventive Principle:
Principle #1Segmentation

2Temperature

If the engine is kept running to provide cooling, then cooling is maintained, but energy is wasted and battery life is reduced

Engineering Contradiction:
Improvecabin cooling temperatureVSAvoidbattery energy consumption
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent implements variable speed control for the electric compressor based on real-time monitoring of cabin temperature, evaporator temperature, and power availability. The compressor speed adjusts dynamically to match cooling demand, preventing energy waste while maintaining effective cooling.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates multiple sensors (cabin temperature sensor, evaporator temperature sensor, power availability sensor) that provide continuous feedback to the control module. This feedback enables the controller to optimize compressor operation and minimize energy consumption while maintaining desired cooling levels.

Inventive Principle:
Principle #23Feedback

3Productivity

If the compressor operates at high speed to provide rapid cooling, then cooling effectiveness improves, but power consumption increases

Engineering Contradiction:
Improvecooling rateVSAvoidcompressor power consumption
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The patent implements periodic cycling of the compressor based on cooling demand and power availability. The compressor operates at high speed when rapid cooling is needed and power is available, then cycles off or reduces speed when cooling targets are reached or power is limited, creating a periodic operation pattern.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes operational parameters (compressor speed, duty cycle) based on real-time conditions including cabin temperature differential, evaporator temperature, and available power. This parameter adjustment optimizes the balance between cooling effectiveness and power consumption.

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

Enables cooling of vehicle cabins without the engine running, improving efficiency and extending battery life by optimizing compressor speed and blower operations, reducing energy waste and enhancing comfort.

Implementation Method 1

A condenser is configured to receive refrigerant output by an electric compressor and transfers heat from the refrigerant within the condenser to air passing the condenser

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

A first evaporator is configured to receive refrigerant from the condenser when a first control valve is open and transfers heat from air passing the first evaporator to the refrigerant within the first evaporator

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

A second evaporator is configured to receive refrigerant from the condenser when a second control valve is open and transfers heat from air passing the second evaporator to the refrigerant within the second evaporator

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 4

A condenser is configured to receive refrigerant output by an electric compressor

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3687843B1Temperature control systems and methods for vehicles
Publication Date: 2024.08.07 COPELAND LP
  • EP3687843B1 patent drawingFigure 1A~1B
  • EP3687843B1 patent drawingFigure 2~3
  • EP3687843B1 patent drawingFigure 4~5

AI summary

An air conditioning system of a vehicle having an internal combustion engine includes a condenser configured to receive refrigerant output by an electric compressor and transfer heat from the refrigerant within the condenser to air passing the condenser. A first evaporator is configured to receive refrigerant from the condenser when a first control valve is open and transfer heat from air passing the first evaporator to the refrigerant within the first evaporator. A first blower is configured to blow air across the first evaporator to a first section of a cabin of the vehicle. A second evaporator is configured to receive refrigerant from the condenser when a second control valve is open and transfer heat from air passing the second evaporator to the refrigerant within the second evaporator. A second blower is configured to blow air across the second evaporator to a second section of the cabin of the vehicle.