Refrigerated Display Air Curtain Stabilization for Lower Heat Loss
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Solution Overview
Problem
Open refrigerated display cases (ORDCs) face significant energy losses due to entrainment of warm ambient air and turbulent mixing within the air curtain, leading to increased energy consumption and challenges in maintaining temperature homogeneity, especially in multi-decked designs.
Innovation Solution
The implementation of flow stabilizing devices with paired stabilizing beams and slots that converge to stabilize air flow, reducing entrainment and turbulent mixing by directing air flow out of the air outlet across the display area and toward the air inlet, forming an air curtain, and optionally incorporating an injector port to introduce additional air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If open-fronted display cases use air curtains to separate refrigerated interior from ambient air, then customer access and visibility are improved, but energy consumption increases significantly due to entrainment and turbulent mixing
Solution Approach 1:
The patent introduces flow stabilizing devices as intermediary elements within the air curtain system. These devices include stabilizing beams and slots that act as mediators to organize and stabilize the air flow, reducing turbulent mixing and entrainment while maintaining the open-fronted design benefits for customer access and visibility.
Solution Approach 2:
The patent modifies the physical parameters of the air curtain by introducing flow stabilizing devices with specific geometries (stabilizing beams, slots, converging sections). These parameter changes transform the chaotic turbulent flow into a more stable, laminar flow pattern, reducing energy losses from entrainment while preserving the air curtain's primary function of separating refrigerated interior from ambient air.
2Area of stationary object
If multi-decked designs are used to maximize display space, then display area increases, but entrainment issues and energy losses are exacerbated
Solution Approach 1:
The patent applies segmentation by dividing the air curtain into multiple stabilized sections using flow stabilizing devices at different levels. Each stabilizing device with its beams and slots creates localized flow control zones that prevent cumulative entrainment effects across multiple decks, allowing the display area to expand while controlling energy losses in each segment.
Solution Approach 2:
The patent introduces a new dimensional approach by adding vertical stabilization elements (stabilizing beams extending across the air curtain) that create additional flow control planes. This multi-dimensional flow organization prevents entrainment from propagating vertically across multiple decks, enabling expanded display area without proportional energy loss increases.
3Ease of operation
If air curtains are used in open refrigerated display cases, then physical barriers are eliminated, but turbulent mixing within the air curtain increases
Solution Approach 1:
The flow stabilizing devices serve as intermediary structures within the air curtain that mediate between the need for open accessibility and the need for flow stability. The stabilizing beams and slots act as subtle guides that organize the air flow without creating solid physical barriers, maintaining accessibility while reducing turbulent mixing through flow alignment and stabilization.
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 solution reduces convective heat losses by approximately 40% and stabilizes the air curtain, improving energy efficiency and maintaining temperature homogeneity across the display area.
Implementation Method 1
The air curtain separates the refrigerated interior of the display case from the ambient air surrounding the display case. The air curtain thus keeps the cool air inside the display case from spilling out due to buoyancy effects
Implementation Method 2
the stabilizing throat being configured to stabilize the air flow within the air curtain which exits the flow stabilizing device via the stabilizing outlet
Data Source
AI summary
An open refrigerated display case comprising: a refrigerated display area comprising one or more shelves; an air outlet and an air inlet opening into the display area and spaced from one another; a duct fluidically coupling the air inlet to the air outlet, the duct being configured to direct air flow out of the air outlet across the display area and toward the air inlet to form an air curtain across the display area; wherein each of the one or more shelves are provided with an associated flow stabilizing device; wherein each flow stabilizing device comprises a pair of stabilizing beams which are spaced from one another so as to define an innermost stabilizing beam and an outermost stabilizing beam; wherein a first slot is formed between the innermost and the outermost stabilizing beams, the first slot extending transversely across the display area perpendicular to the direction of the air flow within the air curtain, the first slot having a stabilizing inlet, a stabilizing outlet and a stabilizing throat disposed therebetween; wherein the innermost stabilizing beam is spaced from the adjacent shelf so as to form a second slot between the innermost stabilizing beam and the shelf; and wherein the one or more flow stabilizing devices are each positioned so that the stabilizing inlet of the first slot receives the air curtain, the stabilizing throat being configured to stabilize the air flow within the air curtain which exits the flow stabilizing device via the stabilizing outlet.