Method to diagnose power plant degradation using efficiency models

A non-transitory computer readable medium comprising instructions configured to be executed by a processor of a monitoring system of a combined cycle power plant having a topping cycle performed by a gas turbine and a bottoming cycle performed by a steam turbine, wherein the instructions comprise instructions configured to cause the processor to:

• receive a first set of data indicating a first measurement value of an operating parameter of the bottoming cycle, wherein the operating parameter is associated with a process performed by the bottoming cycle of the combined cycle power plant;
• determine a baseline efficiency of the process based on the first measurement value using a bottoming cycle performance (BCP) model, wherein the BCP model is configured to determine the baseline efficiency based on a relationship between the first measurement value and an output of the combined cycle power plant, and wherein the baseline efficiency is associated with nominal operation of the combined cycle power plant;
• determine a threshold based on the baseline efficiency, wherein the threshold is associated with a range of deviation from the baseline efficiency;
• receive a second set of data indicating a second measurement value of the operating parameter after receiving the first set of data;
• compare the threshold to an operational efficiency, wherein the operational efficiency is determined based on the second measurement value using the BCP model;
• and
• provide an indication of a decrease in efficiency of the process if the operational efficiency is outside the threshold.

A method, comprising:

• receiving a first set of data indicating a first measurement value of an operating parameter of a bottoming cycle, wherein the operating parameter is associated with a process performed by a bottoming cycle of a combined cycle power plant;
• determining a baseline efficiency of the process based on the first measurement value using a bottoming cycle performance (BCP) model, wherein the BCP model is configured to determine the baseline efficiency based on a relationship between the first measurement value and an output of the combined cycle power plant, and wherein the baseline efficiency is associated with nominal operation of the combined cycle power plant;
• determining a threshold based on the baseline efficiency, wherein the threshold is associated with a range of deviation from the baseline efficiency;
• receiving a second set of data indicating a second measurement value of the operating parameter after receiving the first set of data;
• comparing the threshold to an operational efficiency, wherein the operational efficiency is determined based on the second measurement value using the BCP model;
• and
• providing an indication of a decrease in efficiency of the process if the operational efficiency is outside the threshold.