Modular Truck Air Conditioning System for Engine-Off Cooling

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Solution Overview

Problem

Over-the-road trucks without no-idle air conditioning systems face challenges in maintaining a comfortable temperature during rest periods, leading to increased fuel costs and pollution when the engine is left running, and inadequate rest due to high temperatures when the engine is turned off, with retrofitting such systems being complex due to space constraints.

Innovation Solution

A modular, compressor-driven air conditioning system with a variable speed electric or DC motor-driven compressor, utilizing multiple heat exchangers and fans to ensure efficient cooling and heating without engine operation, and can be easily installed in the side luggage compartment to prevent air recirculation and enhance efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the engine is left running to provide air conditioning during rest periods, then the sleeping compartment can be cooled, but fuel costs increase and pollution is produced

Engineering Contradiction:
Improvesleeping compartment temperatureVSAvoidfuel consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent replaces the engine-belt driven compressor with an electric motor-driven compressor. This substitution allows the air conditioning system to operate independently of the engine, enabling the engine to be turned off during rest periods while still providing cooling to the sleeping compartment through battery-powered compression.

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

Solution Approach 2:

The air conditioning system is designed to provide both engine-on and engine-off operation capabilities. The electric compressor can draw power from either the engine alternator or the vehicle battery, making the system universally operational regardless of engine state, thus resolving the contradiction between maintaining temperature control and reducing fuel consumption.

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

2Use of energy by moving object

If the engine is turned off to reduce fuel costs, then fuel consumption decreases, but the sleeping compartment cannot be cooled

Engineering Contradiction:
Improvefuel consumptionVSAvoidsleeping compartment temperature
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

By replacing the engine-belt driven compressor with an electric motor-driven compressor, the system enables cooling operation during engine-off periods. The electric compressor draws power from the battery, maintaining sleeping compartment temperature control without requiring engine operation.

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

3Adaptability or versatility

If a no-idle air conditioning system is retrofitted into existing vehicles, then engine-off cooling capability is provided, but the retrofitting process is complex due to space constraints

Engineering Contradiction:
Improveengine-off cooling capabilityVSAvoidretrofitting complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The air conditioning system is divided into modular components including the electric compressor, condenser, evaporator, and control systems. This segmentation allows for easier retrofitting into existing vehicle architectures by enabling selective installation in available spaces without requiring complete system redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes the vertical space above the wheel well as an installation location for the condenser and other components. By utilizing this underutilized three-dimensional space in existing vehicle architectures, the system reduces retrofitting complexity while providing full no-idle cooling functionality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 comfortable temperature control in the vehicle cabin without engine operation, reducing fuel costs and pollution, while being easily retrofitted into existing vehicles, improving operational safety and efficiency by ensuring effective heat dissipation and airflow.

Implementation Method 1

a first heat exchanger positioned in one section of the housing and a second heat exchanger positioned in the other section of the housing

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

air movement through a first fluid path defined in the housing through the first section of the housing and intersecting the first heat exchanger

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the second flow path is defined in the housing though the first opening of the front panel, through the second heat exchanger a first time, through the second section of the housing, through the second heat exchanger a second time

Methodology Applied
Scientific EffectConduction: Conduction (thermal)

Data Source

PatentEP1961599B1Truck electrified engine-off air conditioning system
Publication Date: 2013.07.10 BERGSTROM INC
  • EP1961599B1 patent drawingFigure 1
  • EP1961599B1 patent drawingFigure 2
  • EP1961599B1 patent drawingFigure 3

AI summary

An air conditioning system for cooling an environment in an over-the-road vehicle is provided. The air conditioning system includes an electrically driven, variable speed compressor (18), which enables operation of the system when the engine of the over-the-road vehicle is not running. The system is modular and is adapted to be installed in a side luggage compartment of the vehicle to enable existing vehicles to be retrofitted to provide no-idle air conditioning. The housing (11) of the system defines two flow paths therethrough: one cold air path (24,26,28) and one hot air path (32,34,36). The hot air path is configured to intersect the condenser (20) at least twice, and draws and expels the air through the same wall of the housing (11). An air direction device is used to reduce the amount of air recirculation through the hot air path (32,34,36) to increase the efficiency of the system.