Development of method for calculating the components of thermal efficiency reserve of combined-cycle plants

The components of the thermal efficiency reserve of thermal power plant equipment are the overexpenditure or savings of fuel due to the deviation of the actual values of the equipment performance from their nominal values. They are determined in tons of reference fuel for a certain period. The components of the thermal efficiency reserve are the most essential element of the technical record-keeping and reporting systems of power plants. They allow us to quantitatively assess the technical condition of the equipment and, on this basis, effectively plan repair programs. The methods to calculate the components of the thermal efficiency reserve of steam power plants are well developed and regulated according to the regulatory documents. Regulatory requirements for combined-cycle plants in this area contain inaccuracies and do not cover a full list of the components of the thermal efficiency reserve. Thus, it is necessary to develop a method that allows us to calculate the components of the thermal efficiency reserve of combined-cycle plants. When developing the methodology for combined-cycle plants, the authors have applied the approaches to calculate the components of the thermal efficiency reserve that are used for steam power plants. In addition, available methods for assessing the thermal efficiency of thermal power plant equipment have been used. The developed methods have been tested based on actual data on the operation of combined-cycle plant PGU-116. A methodology to calculate the components of the thermal efficiency reserve of combined-cycle plants with waste-heat boilers without fuel afterburning has been developed. The methodology has been tested in assessing the thermal efficiency indicators of combined-cycle plant in operation. Shortcomings in regulatory documents of the energy industry in terms of calculating the components of the thermal efficiency reserve of combined-cycle equipment have been identified. The developed methodology can be recommended for use in the systems of technical record-keeping and reporting of power plants when monitoring the indicators of thermal efficiency of combined-cycle plants. To ensure the objectivity of the results of the analysis of the efficiency of operated combined-cycle power units in Russia, it is necessary to adjust industry regulatory documents. They should contain uniform scientifically substantiated methods for calculating the components of the reserve of thermal efficiency of combined-cycle equipment.