Cold-Storage Heat Exchanger Layout to Prevent Frost Breaks

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Solution Overview

Problem

Conventional cold-storage heat exchangers require separate evaporators for vehicle compartment cooling and trucker nap cooling, leading to increased costs and vulnerability to frost breaks due to condensed water freezing between the refrigerant tube and cold storage container.

Innovation Solution

A single cold storage heat exchanger design featuring refrigerant tubes with clearances and cold storage containers with protrusion portions arranged in a zigzag manner, improving drainage and surface treatment, which prevents frost breaks and enhances brazing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single cold storage heat exchanger is used for both vehicle compartment cooling and trucker nap cooling, then device complexity and cost are reduced, but the risk of frost breaks increases due to condensed water freezing in clearances

Engineering Contradiction:

Improvenumber of evaporatorsVSAvoidfrost break resistance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent converts the harmful effect of condensed water freezing into a beneficial drainage mechanism. By designing protrusion portions on the cold storage container that contact the refrigerant tube, condensed water that would normally freeze and cause frost breaks is instead channeled through clearances formed by these protrusions, allowing it to drain away before freezing can occur.

Inventive Principle:

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

Solution Approach 2:

The cold storage container surface is segmented into multiple protrusion portions that create discrete contact points and clearances with the refrigerant tube. This segmentation allows condensed water to be divided into smaller channels for drainage, preventing large volumes of water from accumulating and freezing in any single location.

Inventive Principle:

Principle #1Segmentation

2Strength

If refrigerant tubes and cold storage container are bonded and brazed, then heat exchange efficiency is improved, but clearances are created that allow condensed water to enter and freeze

Engineering Contradiction:

Improveheat exchange efficiencyVSAvoidcondensed water intrusion

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The cold storage container has different surface qualities at different locations: protrusion portions that contact the refrigerant tube for efficient heat exchange, and clearance regions between these protrusions that allow condensed water to drain. This local differentiation of surface properties resolves the contradiction between maintaining good thermal contact and preventing water accumulation.

Inventive Principle:

Principle #3Local quality

3Reliability

If protrusion portions are added to cold storage container surface, then drainage performance is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvedrainage performanceVSAvoidcontainer fabrication

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The protrusion portions are designed with specific geometric parameters (height, width, spacing) that optimize drainage performance while remaining compatible with standard manufacturing processes. By carefully controlling these parameters, the design achieves effective water drainage without requiring complex or specialized fabrication techniques.

Inventive Principle:

Principle #35Parameter changes

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

The design enables effective cooling of both the vehicle compartment and the cold storage material using a single heat exchanger, while preventing frost breaks and improving the rigidity and brazing performance of the cold storage container.

Implementation Method 1

a cold storage heat exchanger includes a plurality of refrigerant tubes having therein refrigerant passages, and arranged to provide a clearance therebetween, and a plurality of cold storage containers, each of the plurality of cold storage containers being interposed between adjacent refrigerant tubes, bonded to the adjacent refrigerant tubes

Methodology Applied

Scientific EffectHeat exchange: Conduction (thermal)

Implementation Method 2

A surface of each of the plurality of cold storage containers has a plurality of protrusion portions, and each of the plurality of protrusion portions protrudes outward and is in contact with the adjacent refrigerant tubes. The plurality of protrusion portions are arranged in a zigzag manner.

Methodology Applied

Scientific EffectSurface tension and drainage: Surface Tension

Data Source

PatentUS10132549B2Cold-storage heat exchanger

Publication Date: 2018.11.20 DENSO CORP

AI summary

A cold storage heat exchanger includes multiple refrigerant tubes arranged to provide a clearance therebetween, multiple cold storage containers each of which is interposed between adjacent refrigerant tubes, bonded to the adjacent refrigerant tubes and defining a compartment receiving a cold storage material. A surface of each cold storage container has multiple protrusion portions, and each protrusion portion protrudes outward and is in contact with the adjacent refrigerant tubes. The multiple protrusion portions are arranged in a zigzag manner or extend continuously in an air flow direction.