Refrigeration Compressor Diagnostics with Fewer Fault Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional compressor protection systems in refrigeration systems require multiple sensors to accurately diagnose faults, leading to frequent shutdowns and inefficient repairs due to their inability to precisely indicate specific faults without a plurality of sensors.
Innovation Solution
A diagnostic system that uses a combination of sensors such as current, power, liquid-line temperature, ambient temperature, and discharge-line temperature sensors, along with processing circuitry to determine non-measured operating parameters like condenser temperature, subcooling, and discharge superheat, allowing for precise fault detection and reduced sensor complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors are used to accurately diagnose faults, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent makes a single sensor serve multiple diagnostic functions by using it in combination with compressor map data. The sensor measurements are processed to derive multiple operating parameters (condenser temperature, subcooling, discharge superheat) that would otherwise require separate sensors. This multi-functional approach maintains accurate fault detection while reducing the total number of sensors needed in the system.
Solution Approach 2:
The patent introduces compressor map data as an intermediary element that bridges the gap between limited sensor measurements and comprehensive system diagnostics. The compressor map serves as a reference database that translates single-sensor readings into multiple operating parameters, enabling accurate fault detection without requiring direct measurement of each parameter. This intermediary approach resolves the contradiction by adding information processing capability rather than physical sensors.
2Measurement precision
If multiple sensors are deployed to monitor operating parameters, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent enables a single sensor to monitor multiple operating parameters simultaneously by combining its measurements with compressor map data. The processing circuitry derives condenser temperature, subcooling values, and discharge superheat from a single sensor reading, making the sensor perform multiple monitoring functions. This reduces the sensor network complexity while maintaining comprehensive parameter monitoring accuracy.
Solution Approach 2:
The compressor map acts as an intermediary that converts limited sensor data into comprehensive operating parameter information. Instead of deploying multiple sensors to directly measure each parameter, the system uses the compressor map as a reference to calculate multiple parameters from single-sensor measurements, thereby simplifying the sensor network while preserving monitoring precision.
3Device complexity
If discrete switches are used for temperature and pressure sensing, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent uses compressor map data as an intermediary to enhance the precision of simple sensor measurements. The discrete switches and single sensors provide basic measurements, but the compressor map translates these into precise operating parameters (condenser temperature, subcooling, discharge superheat) that enable accurate fault diagnosis. This intermediary approach maintains system simplicity while achieving high measurement precision.
Solution Approach 2:
The patent transforms simple sensor measurements into multiple derived operating parameters through mathematical relationships embedded in the compressor map. Instead of using complex sensors to directly measure each parameter, the system changes the measurement approach by calculating parameters from basic sensor data, thereby maintaining device simplicity while achieving precise fault indication capability.
Data Source
AI summary
A system includes a compressor and a compressor motor functioning in a refrigeration circuit. A sensor produces a signal indicative of one of current and power drawn by the motor and a liquid-line temperature sensor provides a signal indicative of a temperature of liquid circulating within the refrigeration circuit. Processing circuitry processes the current or power signal to determine a condenser temperature of the refrigeration circuit and a subcooling value of the refrigeration circuit from the condenser temperature and the liquid-line temperature signal.