A refrigerated display case

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Solution Overview

Problem

Refrigerated display cases in supermarkets consume significant energy due to the infiltration of warm ambient air when doors are opened, which reduces the efficiency of the air curtain and increases energy consumption, especially in freezer display cases.

Innovation Solution

An airflow inhibiting apparatus with angled outlet apertures and a fan system that directs air jets outward to prevent ambient air from entering the display area when doors are opened, using a conduit with inlet and outlet slots around the perimeter of the display case to maintain the air curtain and reduce energy loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a conventional air curtain system is used in refrigerated display cases, then the display case can maintain cold temperatures, but warm ambient air infiltrates when doors are opened causing significant energy consumption

Engineering Contradiction:
Improveenergy consumptionVSAvoidair curtain efficiency
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The system activates the fan and angled air jets in advance when door opening is detected, creating a protective air barrier before significant warm air infiltration can occur. This preliminary action prevents the energy loss that would otherwise happen during door operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The angled air jets from the outlet apertures act as an intermediary barrier between the cold display case interior and the warm ambient air. This intermediate air flow redirects and repels incoming ambient air, reducing direct infiltration into the display case.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If the air curtain is strengthened to prevent ambient air infiltration, then energy efficiency improves, but the system complexity increases

Engineering Contradiction:
Improveenergy efficiencyVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The air curtain system is segmented into multiple distributed outlet apertures around the perimeter of the display case opening. Each aperture produces individual angled air jets that collectively form a comprehensive protective barrier, replacing a single complex high-capacity air curtain system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses pneumatic principles by employing a fan to generate pressurized air jets that are directed through angled outlet apertures. This pneumatic approach creates an effective air barrier using fluid dynamics rather than mechanical barriers or complex control systems.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Loss of energy

If ambient air infiltration is prevented during door opening, then cold air is retained within the display area, but additional airflow control mechanisms are required

Engineering Contradiction:
Improvecold air retentionVSAvoidairflow control mechanisms
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

Instead of trying to contain cold air directly or using seals to prevent infiltration, the system inverts the approach by actively projecting air outward from the display case perimeter. This outward projection creates a pressure barrier that passively prevents warm air entry without requiring complex containment mechanisms.

Inventive Principle:
Principle #13The other way round (Inversion)

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 prevents warm ambient air from entering the refrigerated display case, enhancing the efficiency of the air curtain and reducing energy consumption by maintaining the cold air within the display area, particularly in freezer conditions.

Implementation Method 1

a fan fluidically connected to the conduit and configured to draw air into the conduit via the inlet and to discharge a jet of air from each of the plurality of outlet apertures

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

the outlet apertures are each arranged such that the jet of air is angled outwards away from the display area to repel ambient air away from the display area so as to prevent airflow into the display area

Methodology Applied
Scientific EffectAir repulsion:

Implementation Method 3

Refrigerated display cases utilise an air curtain which is cooled to below ambient temperature and propelled downward, across the front of the display case and behind the door(s)

Methodology Applied
Scientific EffectAir curtain:

Data Source

PatentEP4099869B1A refrigerated display case
Publication Date: 2023.11.29 WIRTH RESEARCH
  • EP4099869B1 patent drawingFigure 1
  • EP4099869B1 patent drawingFigure 2
  • EP4099869B1 patent drawingFigure 3

AI summary

There is provided a refrigerated display case (102) comprising: a refrigerated display area (15); a door (9) configured to selectively close an opening to the refrigerated display area (15); an air outlet (20) and an air inlet (18) opening into the display area (15) and spaced from one another; a duct (16) fluidically coupling the air inlet (18) to the air (outlet 20), the duct (16) being configured to direct air flow out of the air outlet (20) across the display area (15) and toward the air inlet (18) to form an air curtain (26) across the display area (15); and an airflow inhibiting apparatus (130) comprising: a conduit having an (inlet 142) and a plurality of outlet apertures (144, 146), the outlet apertures (144, 146) arranged around a perimeter of an upper portion of the opening; a fan (150) fluidically connected to the conduit and configured to draw air into the conduit via the inlet (142) and to discharge a jet of air from each of the plurality of outlet apertures (144, 146); wherein the outlet apertures (144, 146) are each arranged such that the jet of air is angled outwards away from the display area (15) to repel ambient air away from the display area when the door is opened so as to prevent airflow into the display area (15).