Cooling Device Drip Tray Heater Control for Defrost Energy Reduction

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Solution Overview

Problem

Existing cooling devices face inefficiencies and increased energy consumption due to improper timing and duration of the drip tray heater operation during the defrost process, leading to unnecessary energy wastage and reduced operational efficiency.

Innovation Solution

A control unit determines the operation duration of the drip tray heater based on the number of times the door has been opened, using either a constant or variable time period, considering environmental and operational parameters, and energizes the heater when the compressor is not operating or when refrigerant delivery is prevented, ensuring the heater operates only as needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the drip tray heater is operated continuously or at fixed intervals to evaporate water, then the water in the drip tray is removed, but energy consumption increases unnecessarily

Engineering Contradiction:
Improveenergy consumption of heaterVSAvoidwater level in drip tray
Core Design Contradiction:
Loss of energyVSQuantity of substance

Solution Approach 1:

The control unit continuously monitors the water level sensor in the drip tray and adjusts heater operation based on real-time water level feedback. The heater is activated only when the sensor detects water presence, creating a closed-loop control system that eliminates unnecessary energy consumption while ensuring water is removed when present.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses the existing defrost process and natural water accumulation in the drip tray to trigger heater operation automatically. The heater serves itself by responding to water level conditions without requiring external scheduling or manual intervention, operating only when and where water actually exists.

Inventive Principle:
Principle #25Self-service

2Loss of energy

If the heater is operated for longer duration to ensure complete water evaporation, then the drip tray is emptied, but energy wastage increases

Engineering Contradiction:
Improveheater operation durationVSAvoiddrip tray discharge reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The control unit monitors the water level sensor continuously during heater operation and terminates heating immediately when the sensor detects that water has been fully evaporated or removed. This feedback-based termination prevents over-heating and energy wastage while ensuring complete water removal for reliable drip tray discharge.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Instead of using fixed or excessive heater operation durations, the system applies heating action only to the extent necessary - activating the heater only when water is detected and maintaining it only until water is removed. This partial action approach avoids the energy wastage of excessive operation while achieving the required reliability.

Inventive Principle:
Principle #16Partial or excessive action

3Loss of energy

If the heater is operated based on water level sensor alone without considering door opening frequency, then water evaporation is achieved, but energy consumption increases due to unnecessary operations

Engineering Contradiction:
Improveheater energy consumptionVSAvoiddefrost process efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The control unit dynamically adjusts heater operation duration based on the frequency of door openings during the defrost process. When door openings are frequent (indicating active use and higher humidity), the heater operates longer to compensate for increased water accumulation. When door openings are infrequent, heater operation is reduced or eliminated, optimizing energy consumption while maintaining defrost efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the heater based on door opening frequency data. The control unit modifies heating duration and intensity as a function of observed door usage patterns, adapting the heater's behavior to match actual operational conditions and water generation rates during the defrost process.

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

This approach ensures the heater is operated at the right time and for the optimal duration, reducing energy wastage and maintaining efficient operation by aligning the heater's operation with usage patterns and environmental conditions.

Implementation Method 1

a heater for vaporizing the water in the drip tray (5) by heating

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

at least one compressor (8) for maintaining the refrigeration cycle

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

at least one evaporator (4) that cools the interior volume of the cabin (2) by absorbing the thermal energy

Methodology Applied
Scientific EffectAbsorption of thermal energy: Absorption (physical)

Data Source

PatentEP2313718B1A cooling device
Publication Date: 2017.09.06 ARCELIK AS
  • EP2313718B1 patent drawingFigure 1
  • EP2313718B1 patent drawingFigure 2
  • EP2313718B1 patent drawingFigure 3

AI summary

The present invention relates to a cooling device (1) that comprises at least one cabin (2) wherein articles to be cooled are placed, one or more doors (3) allowing access into the cabin (2), at least one evaporator (4) that cools the interior volume of the cabin (2) by absorbing the thermal energy, at least one drip tray (5) for collecting the water resulting from melting the frost accumulated on the evaporator (4), at least one heater (6) that vaporizes the water in the drip tray (5) by heating and a control unit (7) that determines the operating time of the heater (6) (theater).