Perforated Roller Night Cover for Refrigerated Display Cases

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Solution Overview

Problem

Refrigerated display cases with open fronts experience hotspots and increased energy consumption due to ambient air ingress, leading to temperature fluctuations and condensation issues, which are not adequately addressed by existing night cover designs.

Innovation Solution

A night cover with strategically sized and spaced apertures, specifically circular holes of 9-11mm diameter in a grid pattern, covering 30-40% of the area, to regulate airflow and prevent hotspots without breaching the air curtain, thereby improving refrigeration efficiency and reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a night cover is deployed to cover the open front of the display case, then heat ingress is reduced and energy consumption is reduced, but gaps between the blind and case sides allow warmer moisture-laden air to ingress causing condensation on products

Engineering Contradiction:
Improveenergy consumptionVSAvoidcondensation on products
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The night cover incorporates a perforated fabric material with numerous small apertures distributed across its surface. This porous structure allows controlled airflow through the cover while maintaining the barrier function, enabling moisture-laden air to pass through without causing condensation on products while still reducing heat ingress.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The night cover features non-uniform aperture distribution with different aperture densities in different zones. The upper portion has a higher density of apertures to manage the cold air curtain flow, while the lower portion has fewer apertures to prevent warm air ingress that would cause condensation. This local quality variation optimizes both energy savings and condensation prevention.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If apertures are added to the night cover to promote non-turbulent air circulation, then condensation is reduced, but the night cover material complexity increases

Engineering Contradiction:
Improvecondensation eliminationVSAvoidnight cover material complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Rather than adding separate aperture components to an existing solid cover, the invention integrates the aperture function directly into the fabric material itself. The perforated fabric is a single-layer material with holes formed during manufacturing, eliminating the need for additional layers, frames, or mounting hardware while achieving the desired airflow control.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The night cover uses a composite structure combining the fabric base material with the aperture pattern in a single integrated layer. This composite approach merges the barrier function of the fabric with the airflow control function of the apertures, reducing overall system complexity compared to layered or assembled constructions.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If a perforated fabric is used for the night cover, then condensation on products is reduced, but the heat insulation effectiveness is compromised

Engineering Contradiction:
Improvecondensation preventionVSAvoidheat insulation effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The night cover implements spatially varying aperture density to balance insulation and condensation prevention. The upper zone with higher aperture density manages the cold air curtain to prevent turbulence and condensation, while the lower zone with lower aperture density maintains better thermal insulation. This local differentiation allows the perforated fabric to achieve both condensation prevention and acceptable heat insulation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention optimizes the aperture parameters including size, shape, and distribution pattern to minimize thermal impact. By carefully selecting aperture dimensions and spacing, the cover maintains sufficient thermal resistance while providing adequate airflow paths to prevent condensation. The aperture parameters are tuned to allow moisture-laden air passage while restricting heat transfer.

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 solution effectively eliminates hotspots, maintains product safety, and reduces energy consumption by 10% by evenly diffusing ambient air and maintaining the air curtain integrity, while being cost-effective and easily retrofittable to existing display cases.

Implementation Method 1

The refrigeration system includes a compressor, a condenser and an evaporator which cools air that is pumped from a base of the display case up a rear channel, along a top panel toward the front of the display case where the air forms a cooling air curtain that is blown downwardly over the open front surface

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

Where the roller is manually deployed, so the roller is biased by a tension spring so that the blind is deployed against the bias of the tension spring and rewound, i.e. re-deployed, by virtue of the tension of the spring

Methodology Applied
Scientific EffectElastic potential energy: Spring

Data Source

PatentEP3373771B9Night cover for refrigerated display case and refrigerated display case
Publication Date: 2019.06.26 THERMASOLUTIONS INT LTD
  • EP3373771B9 patent drawingFigure 1
  • EP3373771B9 patent drawingFigure 2a~2c
  • EP3373771B9 patent drawingFigure 3a

AI summary

A refrigerated display case 1 of the open front type has a roller mounted night cover (51) formed of flexible material which, in a deployed position, is arranged to close the front opening of the display case. The flexible material of the night cover has a plurality of apertures (54) arranged in a first section (51) that are disposed in an upper 30% - 40% of the front opening. The apertures have a constant diameter D, chosen to be a fixed dimension in the range 9mm - 11mm, that are arranged in a vertical and a horizontal grid. The spacing between the aperture centres in the vertical direction y of the grid is 3D and the spacing between aperture centres in the horizontal direction x of the grid is in the range 2D to 4D, preferably 3D. The specific dimensions of the first section and of the apertures and their grid arrangement is arranged to eliminate hotspots and improve the efficiency of the refrigeration system.