Monitoring HVAC and R performance degradation using relative COP

A method of monitoring an HVAC&R system, the method comprising:

• acquiring, at a data acquisition processor, observations about the HVAC&R system, the observations including fluid temperature measurements for a condenser and fluid temperature measurements for an evaporator, the observations further including compressor input power parameter measurements corresponding to the fluid temperature measurements;
• learning, at a compressor input power parameter (CIPP) processor, a CIPP relation between fluid temperature measurements for an evaporator intake temperature and a condenser intake temperature and the compressor input power parameter measurements;
• computing, at the CIPP processor, a predicted value for a compressor input power parameter using the CIPP relation;
• learning, at an evaporator discharge temperature (EDT) processor, an EDT relation between the fluid temperature measurements for the evaporator intake temperature, the condenser intake temperature, and an evaporator temperature drop;
• computing, at the EDT processor, a predicted value for an evaporator temperature drop using the EDT relation;
• computing, at a relative coefficient of performance (COP) processor, a relative coefficient of performance for the HVAC&R system based on the predicted value for the compressor input power parameter and the predicted value for the evaporator temperature drop;
• receiving, at a degradation detection processor, the relative coefficient of performance from the relative COP processor;
• and
• shutting off power to the HVAC&R system in response to the relative coefficient of performance exceeding one or more predefined thresholds.

A monitoring and detection system, comprising:

• a data acquisition processor operable to acquire observations about a first system, the observations including specified system temperature measurements and input power measurements corresponding to the specified temperature measurements;
• an input power parameter relation processor operable to learn a power parameter relation between the specified system temperature measurements and the input power measurements, the power parameter relation processor configured to compute a predicted value for an input power parameter using the power parameter relation;
• a temperature parameter relation processor operable to learn a temperature parameter relation between the specified system temperature measurements, the temperature parameter relation processor configured to compute a predicted value for a specified system temperature using the temperature parameter relation;
• a relative coefficient of performance (COP) processor operable to compute a relative coefficient of performance for the system based on the predicted value for the input power parameter and the predicted value for the specified system temperature;
• and
• a degradation detection processor operable to receive the relative coefficient of performance from the relative coefficient of performance processor, the degradation detection processor further operable to shut off power to the first system in response to the relative coefficient of performance exceeding one or more predefined thresholds;
• wherein one or more of the data acquisition processor, the input power parameter relation processor, the temperature parameter relation processor, the relative COP processor, or the degradation detection processor is a hardware-based processor.