Parallel Multi-Evaporator Layout for Lower Refrigerant Pressure Drop

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Solution Overview

Problem

Existing vehicle air-conditioning systems face inefficiencies due to long refrigerant passages and excessive pressure drops, which reduce cooling performance and system efficiency, especially when cold storage units are not adequately cold-stored or when refrigerant is passed through multiple evaporators in series.

Innovation Solution

A multi-evaporation system with multiple evaporators arranged in parallel, an expanding means that branches and throttles refrigerant, and an ejector to mix refrigerants, optimizing temperature and pressure conditions for efficient evaporation and system performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If refrigerant is passed through multiple evaporators in series, then cooling performance is improved, but pressure drop increases and system efficiency decreases

Engineering Contradiction:
Improvecooling performanceVSAvoidsystem efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The single evaporator is segmented into multiple evaporators (first evaporator and second evaporator) arranged in parallel. Each evaporator has its own expansion device (first expansion device and second expansion device), allowing independent refrigerant flow control. This segmentation enables the system to achieve series-like cooling effect while maintaining parallel flow paths to reduce pressure drop.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-dimension series flow to a multi-dimension parallel flow structure. By arranging evaporators in parallel with separate expansion devices, the system creates multiple flow paths that can be independently controlled, effectively adding a dimensional aspect to the refrigerant distribution that reduces pressure losses while maintaining cooling effectiveness.

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

2Productivity

If refrigerant passage length is increased to improve evaporation efficiency, then cooling performance improves, but pressure drop increases excessively

Engineering Contradiction:
Improveevaporation efficiencyVSAvoidpressure drop
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The long single refrigerant passage is segmented into multiple shorter passages, each serving a separate evaporator. The first refrigerant passage connects the first expansion device to the first evaporator, and the second refrigerant passage connects the second expansion device to the second evaporator. This segmentation reduces the length of each individual passage, thereby reducing pressure drop while maintaining effective evaporation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces expansion devices as intermediaries between the condenser and evaporators. These expansion devices (first expansion device and second expansion device) act as mediators that regulate refrigerant flow into each evaporator independently, optimizing the refrigerant distribution and reducing pressure losses in the passages.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If cold storage unit is used to enhance cooling efficiency, then air cooling improves, but refrigerant flow control becomes difficult when driving is intermittent

Engineering Contradiction:
Improvecooling efficiencyVSAvoidrefrigerant flow control
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The cold storage function is segmented from the main evaporator system. The second evaporator can be configured to provide cold storage capability, while the first evaporator handles primary cooling. Each has its own expansion device, allowing independent control of refrigerant flow to each unit, making it easier to manage intermittent driving conditions and refrigerant distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic control capabilities through independent expansion devices for each evaporator. The first expansion device and second expansion device can be independently adjusted based on real-time cooling demands and driving conditions, enabling the system to dynamically adapt to intermittent operation and maintain optimal refrigerant flow control.

Inventive Principle:
Principle #15Dynamics

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 configuration reduces pressure drops, enhances cooling performance, and improves overall system efficiency by ensuring consistent refrigerant temperature and pressure distribution across evaporators, leading to increased cooling capacity and reduced energy consumption.

Implementation Method 1

an evaporator 40 which comprises at least two or more evaporating parts 41 to 4N so as to receive and evaporate the refrigerant discharged from the expanding means 30

Methodology Applied
Scientific EffectHeat absorption: Heat Exchanger

Implementation Method 2

the evaporator that absorbs vaporization heat from a peripheral portion while the wet vapor refrigerant is vaporized

Methodology Applied
Scientific EffectVaporization: Evaporation

Implementation Method 3

the gaseous refrigerant introduced from the evaporator to the compressor is compressed at a high pressure and high temperature

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

the compressed gaseous refrigerant radiates liquefaction heat to a peripheral portion while passing through the condenser so as to be liquefied

Methodology Applied
Scientific EffectHeat radiation: Thermal Radiation

Implementation Method 5

the compressed gaseous refrigerant radiates liquefaction heat to a peripheral portion while passing through the condenser so as to be liquefied

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 6

the liquefied refrigerant is passed through the expansion valve so as to be in a low pressure low temperature wet vapor state

Methodology Applied
Scientific EffectExpansion: Pressure Gradient

Data Source

PatentEP2314957B1Multi-evaporation system
Publication Date: 2016.06.29 HANON SYST CO LTD
  • EP2314957B1 patent drawingFigure 1
  • EP2314957B1 patent drawingFigure 2(A)~2(C)
  • EP2314957B1 patent drawingFigure 3

AI summary

Provided is a multi-evaporation system which carries out a multi-evaporation process in an air-conditioning cycle of a vehicle air conditioning system, thereby enhancing system efficiency. The multi-evaporation system includes a compressor 10 which sucks and compresses refrigerant; a condenser 20 which condenses the refrigerant compressed in the compressor 10; an expanding means 30 which receives the refrigerant condensed in the condenser 20 through an inlet port 31, branches the refrigerant into at lest two or more, discharges the refrigerant through at least two or more discharging part 32a to 32n, and throttles the refrigerant before or after the refrigerant is branched; and an evaporator 40 which comprises at least two or more evaporating parts 41 to 4N so as to receive and evaporate the refrigerant discharged from the expanding means 30 and then introduce the evaporated refrigerant into the compressor 10.