Air Cycle Cabin Climate Control Using Motorized Turbocharger

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Solution Overview

Problem

Existing air conditioning systems for land vehicles, particularly railway vehicles, face challenges such as high energy consumption, limited reliability, and increased height requirements due to bulky components, which are detrimental for high-speed trains and pose safety and aerodynamic issues. Additionally, these systems rely on harmful halogenocarbon-based heat transfer fluids and have inefficient heating capabilities with a coefficient of performance less than 1.

Innovation Solution

A method utilizing a motorized turbocharger with a rotary compressor and turbine, operating at pressures greater than or equal to atmospheric pressure, and an air cycle device with a set of pipes and controlled valves to manage heating and cooling modes efficiently, allowing for reduced dimensions and energy consumption, and enabling heating with a coefficient of performance greater than 1 by reversing the air circulation direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a two-phase cycle device with halogenocarbon heat transfer fluid is used, then cooling function is provided, but environmental harm and safety risks increase

Engineering Contradiction:
Improvecooling functionVSAvoidenvironmental harm
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful halogenocarbon heat transfer fluid from the system, replacing it with air as the working fluid. This eliminates the environmental harm and safety risks associated with CFCs, HCFCs, HFCs, and HFOs while maintaining the cooling function through an air-cycle refrigeration system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the physical state and composition parameters of the heat transfer fluid from halogenocarbon liquids/gases to air (oxygen-nitrogen mixture). This parameter change eliminates the harmful environmental properties while preserving the thermodynamic functionality needed for cooling.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If a two-phase cycle system is used, then cooling is achieved, but reliability decreases at high outdoor temperatures

Engineering Contradiction:
Improvecooling capabilityVSAvoidoperational reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent changes the operating parameters of the system by using air as the working fluid, which allows continuous operation at high outdoor temperatures without the limitations of two-phase cycle systems. The air-cycle system maintains reliable cooling performance even when ambient temperatures exceed the operational range of traditional refrigerants.

Inventive Principle:
Principle #35Parameter changes

3Stress or pressure

If electric compressors are used in direct loop air cycle device, then compression is achieved, but reliability and robustness decrease

Engineering Contradiction:
Improveair compressionVSAvoidsystem robustness
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The patent replaces the electric compressor mechanical system with a turbine-driven compression system. The turbine, driven by the expansion of air through it, provides the mechanical work needed for compression, eliminating the reliability issues associated with electric compressors that wear out quickly due to frequent stops and starts.

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

Solution Approach 2:

The patent implements continuous operation of the compression system through the turbine-compressor coupling. The turbine continuously drives the compressor during operation, eliminating the frequent stops and starts that cause wear and reduce reliability in electric compressor systems.

Inventive Principle:
Principle #20Continuity of useful action

4Temperature

If multiple rotating machines are used in direct loop air cycle device, then compression and cooling functions are achieved, but device complexity and weight increase

Engineering Contradiction:
Improvecooling functionVSAvoidnumber of rotating machines
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the compression and expansion functions into a single integrated turbine-compressor system. The turbine and compressor are coupled on the same shaft, allowing the expansion work from the turbine to directly drive the compressor, thereby reducing the number of separate rotating machines from four groups to a more compact integrated unit.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The turbine serves multiple functions: it expands the air for cooling, drives the compressor for compression, and can potentially drive other system components. This multi-functionality reduces the overall number of rotating machines needed in the system.

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

5Reliability

If reverse loop air cycle device is used, then reliability is improved, but height requirement increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidheight requirement
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent redistributes the system components in a different spatial arrangement, optimizing the layout to reduce height while maintaining reliability. By carefully arranging the turbine, compressor, heat exchangers, and control systems in a compact configuration, the system achieves reduced vertical dimension suitable for installation on railway vehicles.

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

6Temperature

If electric heater is used for heating cabin air, then heating function is provided, but energy efficiency decreases with coefficient of performance less than 1

Engineering Contradiction:
Improveheating functionVSAvoidenergy efficiency
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent converts the waste heat from the turbine exhaust and compressor discharge into useful heating energy for the cabin. By capturing and redirecting this otherwise wasted thermal energy, the system achieves heating with a coefficient of performance greater than 1, eliminating the need for inefficient electric heaters.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent recovers the thermal energy that would otherwise be discarded from the air cycle process. The hot air from the compressor and turbine exhaust are redirected through heat exchangers to provide cabin heating, transforming waste energy into a useful resource and achieving high energy efficiency.

Inventive Principle:
Principle #34Discarding and recovering

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 results in a more compact, reliable, and energy-efficient air conditioning system that can adapt to varying environmental conditions, reducing the footprint and weight of air conditioning units while achieving improved heating efficiency and lower energy consumption.

Implementation Method 1

a turbine, arranged to receive a flow of compressed air from the compressor, to expand the compressed air and cool it

Methodology Applied
Scientific EffectAdiabatic expansion: Adiabatic Cooling

Implementation Method 2

a rotary compressor, arranged to deliver a flow of compressed and heated air

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

at least one heat exchanger, arranged to cool the compressed air by outside air or recirculating air

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 4

an electric motor to transform electrical energy to mechanical energy in order to drive the compressor

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP3562727B1Method for supplying air at a controlled temperature to a cabin of a land vehicle, and land vehicle
Publication Date: 2021.01.27 LIEBHERR AEROSPACE TOULOUSE
  • EP3562727B1 patent drawingFigure 1
  • EP3562727B1 patent drawingFigure 2
  • EP3562727B1 patent drawingFigure 3

AI summary

The invention relates to a method for supplying air at a controlled temperature to a cabin (10) of a land vehicle, in which use is made of at least one air cycle device comprising at least one motorized turbo compressor. The air inlet (16) of the turbine (14) is arranged to receive a flow of compressed air from the compressor (15). At least one exchanger (20, 32) is interposed between the air outlet (19) of the compressor (15) and the air inlet (16) of the turbine (14). The air inlet (18) of the compressor (15) is arranged to receive air at a pressure greater than or equal to atmospheric pressure. The invention also relates to a land vehicle comprising at least one such air cycle device.