Refrigerant leakage determination device, freezing device including this refrigerant leakage determination device, and refrigerant leakage determination method
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Solution Overview
Problem
Typical air conditioners require a special operation to determine refrigerant leakage, which disrupts normal operation and is not feasible for all refrigeration apparatuses with refrigerant circuits.
Innovation Solution
A refrigerant leakage determination device calculates the deviation degree of the refrigerant circuit from a normal state using index values derived from pre-trip inspection and normal operation data, allowing for leakage determination without a special operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a special operation is performed to determine refrigerant leakage, then measurement precision is improved, but productivity deteriorates due to disruption of normal operation
Solution Approach 1:
The system collects and stores operation data during normal operation in advance, including compressor discharge temperature, ambient temperature, and operation time. This preliminary data collection enables subsequent leakage determination without requiring special operations, as the necessary data is already accumulated from routine operation.
Solution Approach 2:
The refrigerant leakage determination is performed continuously during normal operation by comparing current operation data with historically stored data. This eliminates the need to interrupt normal operation for special leakage testing, maintaining continuous productivity while achieving accurate leakage detection through ongoing data analysis.
2Productivity
If refrigerant leakage determination is integrated into normal operation, then productivity is improved, but measurement precision may deteriorate
Solution Approach 1:
The system establishes a relationship between compressor discharge temperature, ambient temperature, and operation time through continuous monitoring. This feedback mechanism allows the system to dynamically adjust and refine leakage determination by comparing current readings against established operational patterns, maintaining high precision during normal operation.
Solution Approach 2:
The system pre-establishes the relationship between operation conditions and temperature characteristics during normal operation. This preliminary characterization of normal operational behavior provides a baseline for accurate leakage detection, ensuring that integration into normal operation does not compromise measurement precision.
3Device complexity
If operation data is collected during normal operation, then device complexity is reduced, but loss of information increases due to varying operation conditions
Solution Approach 1:
The system transforms raw operation data into standardized parameters including operation time, compressor discharge temperature, and ambient temperature. By normalizing these parameters and establishing their relationships, the system accounts for varying operation conditions while maintaining data integrity and reducing the impact of operational variability on leakage determination.
Data Source
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AI summary
A refrigerant leakage determination device (60) includes a calculator (66) and a determination unit (67). The calculator (66) calculates a deviation degree of a refrigerant circuit (20) from a normal state based on data related to operation of a refrigeration apparatus (1). The determination unit (67) determines refrigerant leakage or estimates refrigerant leakage occurrence time based on a calculation result of the calculator (66). The calculator (66) calculates first and second index values respectively from data related to operation of the refrigeration apparatus (1) in a first period and a second period that differs in length from the first period and calculates the deviation degree of the refrigerant circuit (20) from the normal state based on the first and second index values. The determination unit (67) determines refrigerant leakage or estimates refrigerant leakage occurrence time based on the deviation degree of the refrigerant circuit (20) from the normal state.