Evaporator Tank Layout for Uniform Refrigerant Flow at Low Rates

Solution Overview

Problem

Existing refrigerant evaporators experience uneven refrigerant distribution and temperature distribution issues during low flow rate operations, leading to inefficient cooling and temperature fluctuations in blown air.

Innovation Solution

The refrigerant evaporator design includes asymmetrically disposed communication holes in tank partitions and a dam portion to ensure uniform pressure loss and reliable refrigerant flow across heat-exchanging core portions, enhancing refrigerant distribution and reducing temperature fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If refrigerant flows through the heat-exchanging core portion of the first evaporation unit to the second evaporation unit via communication portions, then refrigerant distribution is enhanced, but during low flow rate operation, uneven refrigerant distribution occurs where liquid phase refrigerant flows only through one channel (AA) and not the other (BB)

Engineering Contradiction:

Improverefrigerant distributionVSAvoidrefrigerant flow stability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The communication portions are positioned asymmetrically with respect to the width direction of the heat-exchanging core portions. Specifically, one communication portion is positioned closer to one end in the width direction than the other communication portion is to the other end. This asymmetric arrangement ensures that during low flow rate operation, liquid phase refrigerant is distributed to both heat-exchanging core portions (AA and BB) rather than concentrating in one channel, thereby preventing temperature distribution issues in the blown air.

Inventive Principle:

Principle #4Asymmetry

2Device complexity

If the refrigerant evaporator is designed with symmetric communication portions, then structural simplicity is maintained, but during low flow rate operation, temperature distribution occurs in the blown air due to uneven refrigerant flow

Engineering Contradiction:

Improvestructural simplicityVSAvoidtemperature distribution in blown air

Core Design Contradiction:

Device complexityVSTemperature

Solution Approach 1:

The communication portions are positioned asymmetrically with respect to the width direction of the heat-exchanging core portions. Specifically, one communication portion is positioned closer to one end in the width direction than the other communication portion is to the other end. This asymmetric arrangement ensures that during low flow rate operation, liquid phase refrigerant is distributed to both heat-exchanging core portions (AA and BB) rather than concentrating in one channel, thereby preventing temperature distribution issues in the blown air.

Inventive Principle:

Principle #4Asymmetry

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 design improves refrigerant distribution and reduces temperature variations in blown air, ensuring effective cooling even at low flow rates by maintaining consistent refrigerant flow across the heat-exchanging core portions.

Implementation Method 1

A refrigerant evaporator functions as a cooling heat exchanger that cools fluid (for example, air) flowing outside by evaporating refrigerant (liquid phase refrigerant) flowing inside to absorb heat from the fluid

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 2

A refrigerant evaporator functions as a cooling heat exchanger that cools fluid (for example, air) flowing outside by evaporating refrigerant (liquid phase refrigerant) flowing inside to absorb heat from the fluid

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

providing a partition plate inside an upper tank portion of a windward evaporation unit disposed on an upstream side in a flow direction of the fluid to divide a tank interior in a top-down direction and by providing the partition plate with through-holes

Methodology Applied

Scientific EffectGravity: Gravitation

Data Source

PatentUS10161659B2Refrigerant evaporator

Publication Date: 2018.12.25 DENSO CORP

AI summary

A first evaporation unit and a second evaporation unit are coupled via a refrigerant interchanging portion having a first communication portion and a second communication portion. A first partition member is provided in a tank portion of the first evaporation unit to define a first tank internal space and a second tank internal space. The first partition member has a first communication hole to let the first tank internal space and the second tank internal space communicate with each other. A second partition member is provided in a tank portion of the second evaporation unit to define a third tank internal space and a fourth tank internal space. The second partition member has a second communication hole to let the third tank internal space and the fourth tank internal space communicate with each other.