Vehicle air conditioning device

Solution Overview

Problem

In vehicle air conditioning systems, particularly in hybrid and electric vehicles, the rapid pressure drop in the accumulator during mode changes leads to refrigerant boiling and vaporization, causing 'bumping' which results in excessive liquid return to the compressor, reliability issues, and noise generation, compromising passenger comfort.

Innovation Solution

A vehicle air conditioning device with a control system that manages the switching between operation modes by opening the second opening/closing valve for a predetermined period when shifting from the first operation mode to the second, allowing refrigerant to return to the accumulator and preventing stable state disruption, thereby inhibiting bumping and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the operation mode is changed rapidly from heating mode to cooling mode, then the response speed of the air conditioning system is improved, but the pressure drop in the accumulator causes refrigerant boiling and bumping, leading to excessive liquid return to the compressor and noise generation

Engineering Contradiction:

Improvemode switching speedVSAvoidcompressor reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The control device opens the second opening/closing valve (solenoid valve 21) in advance before the mode switching is completed. This preliminary action allows refrigerant to continue flowing into the accumulator during the transition, preventing rapid pressure drop and subsequent bumping phenomenon, thereby protecting the compressor from liquid return while maintaining fast mode switching capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The second opening/closing valve (solenoid valve 21) acts as an intermediary component that mediates the refrigerant flow during mode transitions. By controlling this valve's opening timing, the system can smoothly transition between modes without causing harmful pressure drops in the accumulator, thus resolving the conflict between fast switching and compressor protection

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If the operation mode is changed rapidly from heating mode to cooling mode, then the responsiveness of the air conditioning system is improved, but noise is generated due to bumping in the accumulator

Engineering Contradiction:

Improvemode switching speedVSAvoidnoise

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The control device opens the second opening/closing valve (solenoid valve 21) in advance before the mode switching is completed. This preliminary action allows refrigerant to continue flowing into the accumulator during the transition, preventing rapid pressure drop and subsequent bumping phenomenon, thereby protecting the compressor from liquid return while maintaining fast mode switching capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The second opening/closing valve (solenoid valve 21) acts as an intermediary component that mediates the refrigerant flow during mode transitions. By controlling this valve's opening timing, the system can smoothly transition between modes without causing harmful pressure drops in the accumulator, thus resolving the conflict between fast switching and compressor protection

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Prevents liquid compression and noise in the accumulator, enhances the reliability of the air conditioning device, and improves passenger comfort by ensuring stable operation during mode changes.

Implementation Method 1

let the refrigerant absorb heat in the outdoor heat exchanger

Methodology Applied

Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 2

let the refrigerant discharged from the compressor radiate heat in the radiator

Methodology Applied

Scientific EffectHeat radiation: Thermal Radiation

Implementation Method 3

a compressor to compress a refrigerant

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 4

an outdoor expansion valve to decompress the refrigerant flowing out from the radiator

Methodology Applied

Scientific EffectPressure drop: Pressure Drop

Implementation Method 5

the refrigerant is once stored in this accumulator, thereby performing gas-liquid separation therein

Methodology Applied

Scientific EffectGas-liquid separation: Centrifugal Separation

Data Source

PatentUS10814698B2Vehicle air conditioning device

Publication Date: 2020.10.27 SANDEN CORP

AI summary

A vehicle air conditioning device which is capable of inhibiting liquid return to a compressor and generation of noise due to bumping in an accumulator. There are executed a heating mode to close a solenoid valve 17, open a solenoid valve 21, let a refrigerant from a compressor 2 radiate heat in a radiator 4, decompress the refrigerant through an outdoor expansion valve 6, let the refrigerant absorb heat in an outdoor heat exchanger 7, and send the refrigerant to an accumulator 12, and a dehumidifying and cooling mode to open the solenoid valve 17, close the solenoid valve 21, decompress the refrigerant through an indoor expansion valve 8, let the refrigerant absorb heat in a heat absorber, and send the refrigerant to the accumulator. When shifting from the heating mode to the dehumidifying and cooling mode, the solenoid valve 21 is opened for a predetermined period of time.