Door Handle Proximity Sensing for Preemptive Refrigeration Control
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Solution Overview
Problem
Current refrigerated display cases cannot anticipate when the doors are about to be opened, preventing preemptive implementation of control strategies to maintain temperature-controlled conditions.
Innovation Solution
Integration of a proximity sensor with the door handle to detect the presence of an object, estimating the distance and transitioning the refrigeration circuit between normal and anti-ingression modes to prevent ambient air ingress before the door is opened.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the refrigeration circuit operates in normal refrigeration mode continuously, then energy consumption is reduced, but temperature control effectiveness deteriorates when the door is opened
Solution Approach 1:
The proximity sensor detects when a user approaches the door handle and triggers the anti-ingression mode before the door is actually opened. This preliminary action allows the system to prepare for potential heat ingress by activating the cooling system in advance, ensuring temperature stability is maintained when the door opens, while avoiding continuous operation that would waste energy.
Solution Approach 2:
The system uses feedback from the proximity sensor to dynamically adjust the refrigeration circuit operation. When the sensor detects an object (user) near the handle, it sends a signal to switch from normal mode to anti-ingression mode. This feedback mechanism enables the system to respond adaptively to user presence, optimizing both energy efficiency and temperature control effectiveness.
2Reliability
If the refrigeration circuit switches to anti-ingression mode continuously, then temperature control effectiveness is improved, but energy consumption increases
Solution Approach 1:
The system activates anti-ingression mode only preliminarily when a user approaches the door, not continuously. This selective preliminary action ensures the cooling system is ready when needed while avoiding unnecessary energy consumption during periods when the door is closed and no user is present.
Solution Approach 2:
The refrigeration circuit operates in different modes periodically based on user presence detection. It switches between normal refrigeration mode (when no user is present) and anti-ingression mode (when a user is detected near the handle), creating a periodic operation pattern that optimizes energy efficiency while maintaining temperature control effectiveness when needed.
3Loss of information
If a proximity sensor is integrated with the door handle, then the ability to anticipate door opening is improved, but device complexity increases
Solution Approach 1:
The proximity sensor is merged with the door handle assembly, combining two functional elements into a single integrated unit. This merging approach allows the system to gain door opening anticipation capability while minimizing the increase in device complexity by reusing the existing handle structure and integrating the sensor within it.
Solution Approach 2:
The door handle assembly is given multi-functionality by integrating the proximity sensor into it. The handle not only serves its traditional mechanical function of opening the door but also acts as a mounting platform for the sensor, enabling door opening anticipation. This universal approach reduces the need for separate components and minimizes overall system complexity.
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
Enhances the effectiveness of temperature control by maintaining optimal conditions within the display case and improving energy efficiency by initiating anti-ingression measures before the door is opened.
Implementation Method 1
The proximity sensor is a projected capacitive sensor integrated with the handle
Data Source
AI summary
A temperature-controlled display device includes a temperature-controlled space and a refrigeration circuit configured to provide cooling for the temperature-controlled space. The refrigeration circuit is configured to operate in multiple cooling modes including a normal refrigeration mode and an anti-ingression mode. A proximity sensor is configured to detect an object such as a human hand or forearm within a detection zone adjacent to a door handle of the temperature-controlled display device. A controller estimates a distance between the handle and the detected object using an input from the proximity sensor. The controller causes the refrigeration circuit to transition between the multiple cooling modes based on the estimated distance.