Method of detecting a loss of refrigerant charge of a refrigeration system
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Solution Overview
Problem
Refrigeration systems, particularly transcritical systems operating at high pressures, face challenges in detecting refrigerant charge loss efficiently, which can lead to reduced efficiency or system failure due to the higher risk of refrigerant leaks.
Innovation Solution
A method involving an electronic controller that calculates real-time air side temperature differences across an evaporator using pre-programmed T-Maps representative of normal and refrigerant charge loss conditions, coupled with input parameters like supply/return air temperature, ambient temperature, compressor speed, and evaporator fan speed, to detect refrigerant charge loss and initiate corrective actions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high pressure operation is used in transcritical refrigeration systems, then cooling efficiency is improved, but the risk of refrigerant leaks increases
Solution Approach 1:
The system performs preliminary detection of refrigerant charge loss by continuously monitoring air side temperature differences and comparing them against pre-stored T-Maps. This early detection mechanism allows the system to identify charge loss conditions before they lead to significant efficiency degradation or system failure, addressing the reliability concern while maintaining high-pressure operation for cooling efficiency
2Device complexity
If traditional refrigerant charge detection methods are used, then system complexity is minimized, but detection accuracy and timeliness deteriorate
Solution Approach 1:
The system uses air side temperature difference as an intermediary parameter to indirectly detect refrigerant charge conditions. By measuring the temperature difference between supply and return air across the evaporator and comparing it against T-Maps, the system achieves accurate charge loss detection without requiring direct refrigerant sensors or complex diagnostic equipment, thus maintaining simplicity while improving detection accuracy
Solution Approach 2:
The invention replaces traditional mechanical or direct sensing methods for refrigerant charge detection with a computational approach using temperature measurements and algorithmic comparison. The electronic controller performs calculations and comparisons of temperature differences against stored T-Maps, substituting complex mechanical detection systems with a more accurate and timely electronic measurement and processing system
Data Source
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AI summary
A method of determining charge loss of a refrigeration system includes the steps of inputting an ambient temperature, a box temperature, and a compressor speed into an electronic controller of the refrigeration system, and calculating a first air side temperature difference across an evaporator by applying an algorithm having a first T-Map representative of normal operating conditions. The controller may then confirm a detection prerequisite is satisfied. Upon confirmation, the controller calculates a second air side temperature difference across the evaporator by applying the algorithm having a second T-Map representative of a loss of refrigerant charge. An action may then be taken from the controller if the first air side temperature difference is less than the second air side temperature difference.