Vehicle Cabin Heating and Dehumidification via Liquid Receiver Switching

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Solution Overview

Problem

Existing air-conditioning devices cannot perform dehumidification while maintaining a cabin-heating state, as they require switching to a cabin-cooling mode for dehumidification.

Innovation Solution

An air-conditioning device with a compressor, outdoor heat exchanger, evaporator, heater unit, liquid receiver, restrictor mechanism, and expansion valve, which switches between a heat pump cabin-heating mode and a dehumidifying cabin-heating mode by storing liquid-phase refrigerant in a liquid receiver and using it for dehumidification during cabin-heating operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the refrigeration cycle is switched to the cabin-cooling mode to perform dehumidification, then dehumidification can be achieved, but the cabin-heating state is lost

Engineering Contradiction:
ImprovehumidityVSAvoidcabin temperature
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent segments the refrigeration cycle into two independent loops: a heat pump loop for heating and an evaporating loop for dehumidification. This allows both heating and dehumidification to occur simultaneously in separate cycles, resolving the contradiction between maintaining cabin heat and removing humidity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The refrigeration system is designed to perform multiple functions simultaneously through dual-loop architecture. The heat pump loop provides heating while the evaporating loop provides dehumidification, enabling the system to achieve both heating and dehumidification objectives at the same time without mode switching.

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

2Adaptability or versatility

If a single refrigeration loop is used, then the system structure is simple, but it cannot perform dehumidification while maintaining heating

Engineering Contradiction:
Improveoperation modesVSAvoidrefrigeration cycle structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The refrigeration system is divided into two independent loops with separate compressors, heat exchangers, and expansion devices. This segmentation enables each loop to perform its specific function (heating or dehumidification) independently while allowing flexible combination of modes to meet diverse operational requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-dimensional (single-loop) refrigeration system to a two-dimensional (dual-loop) system. This dimensional expansion allows the system to operate in multiple modes (heating only, dehumidification only, or both simultaneously) by independently controlling each loop, thereby enhancing adaptability without excessive complexity.

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

3Power

If the evaporating unit is used for heating, then heating efficiency is high, but dehumidification cannot be performed

Engineering Contradiction:
Improveheating efficiencyVSAvoidhumidity
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The patent assigns dedicated functions to separate units: the heat pump loop (with outdoor heat exchanger and indoor heater) is optimized for heating efficiency, while the evaporating loop (with evaporating unit) is optimized for dehumidification. This functional segmentation allows each unit to operate at peak efficiency for its designated purpose.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system can pre-cool the evaporating unit below the dew point temperature before introducing humid air, creating conditions optimal for condensation. This preliminary action ensures that when humid air passes through the evaporating unit, moisture condenses efficiently while the heat pump loop simultaneously maintains cabin heating.

Inventive Principle:
Principle #10Preliminary 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

Enables dehumidification to be performed while maintaining the cabin-heating state by switching between operation modes, effectively managing humidity and temperature within the vehicle cabin.

Implementation Method 1

a compressor configured to compress a refrigerant

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

an outdoor heat exchanger configured to perform heat exchange between the refrigerant and outside air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

an evaporating unit configured to evaporate the refrigerant by causing the refrigerant to absorb heat of air to be guided to a vehicle cabin of the vehicle

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 4

a heater unit configured to heat the air to be guided to the vehicle cabin by using the heat of the refrigerant compressed by the compressor

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 5

a liquid receiver arranged at a downstream side of the outdoor heat exchanger, the liquid receiver being configured to separate the refrigerant guided from the outdoor heat exchanger into a liquid-phase refrigerant and a gaseous-phase refrigerant and to store the liquid-phase refrigerant

Methodology Applied
Scientific EffectPhase separation: Phase Change

Implementation Method 6

a restrictor mechanism provided between the heater unit and the outdoor heat exchanger, the restrictor mechanism being configured to cause the refrigerant to be decompressed and expanded

Methodology Applied
Scientific EffectDecompression: Depressurisation

Implementation Method 7

an expansion valve provided between the outdoor heat exchanger and the evaporating unit, the expansion valve being configured to cause the refrigerant that has passed through the outdoor heat exchanger to be decompressed and expanded

Methodology Applied
Scientific EffectDecompression: Depressurisation

Data Source

PatentEP3693197B1Air conditioning device
Publication Date: 2024.06.19 MARELLI CABIN COMFORT JAPAN CORPORATION
  • EP3693197B1 patent drawingFigure 1
  • EP3693197B1 patent drawingFigure 2
  • EP3693197B1 patent drawingFigure 3

AI summary

An air-conditioning device (100) includes: a compressor (21); an outdoor heat exchanger (23); an evaporating unit (25) configured to evaporate refrigerant by causing the refrigerant to absorb heat of air to be guided to a vehicle cabin of a vehicle; a heater unit (42) configured to heat the air to be guided to the vehicle cabin by using the heat of the refrigerant compressed by the compressor; a liquid receiver (24) arranged at the downstream side of the outdoor heat exchanger (23), the liquid receiver (24) being configured to separate the refrigerant guided from the outdoor heat exchanger (23) into a liquid-phase refrigerant and a gaseous-phase refrigerant and to store the liquid-phase refrigerant; and a restrictor mechanism (27) provided between the heater unit (42) and the outdoor heat exchanger (23), the restrictor mechanism (27) being configured to cause the refrigerant to be decompressed and expanded, wherein, in an operation state in which the flow of the refrigerant is restricted by the restrictor mechanism (27) and heat is released in the heater unit (42), a first operation mode and a second operation mode are switched, the first operation mode being set such that the liquid-phase refrigerant is stored in the liquid receiver (24) and the gaseous-phase refrigerant is guided to the compressor (21) and the second operation mode being set such that the liquid-phase refrigerant stored in the liquid receiver (24) is guided to the evaporating unit (25).