Shukur Nasirov
Azerbaijan State Oil and Industry University
PhD in Technical Sciences
https://orcid.org/0000-0001-6421-7549
shukur.nasirov@asoiu.edu.az
Aydan Aliyeva
Azerbaijan State Oil and Industry University
Master's student
https://orcid.org/0009-0009-9732-5699
aliyavaaydan2002@gmail.com
Seymur Hashimov
Azerbaijan State Oil and Industry University
Master's student
https://orcid.org/0009-0006-6771-6451
seymurhashimov773@gmail.com
Analysis of the Heating Scheme and Operating Mode of
Steam-Gas Plants
Abstract
This study presents a comprehensive analysis of the thermal efficiency of triple-pressure combined cycle power plants based on actual operational measurement data. The influence mechanisms of the main variables of the thermal scheme on the overall efficiency of the plant are investigated. The key operating parameters of both gas turbine and steam turbine sections are examined in an integrated manner, taking into account the thermophysical properties of the steam–water mixture used as the working fluid.
The results indicate that, when an optimal intermediate reheating pressure is selected, an increase in steam temperature leads to a significant rise in the useful power output of the steam turbine, thereby enhancing the overall efficiency of the combined cycle plant. It is also established that condenser pressure is one of the dominant factors determining the net power output of the system. A reduction in condensation pressure increases the expansion ratio of the working fluid at the turbine outlet, resulting in higher mechanical work generation.
Various operating modes of the triple-pressure combined cycle plant are analyzed, and corresponding characteristic operating curves are developed. The analysis shows that, under constant exhaust gas temperature and condenser pressure, the power output of the gas turbine, steam turbine, and the entire power unit remains relatively stable.
The obtained results are of practical importance for the design, modernization, and operational optimization of combined cycle power plants.
Keywords: combined cycle power plant, operating parameters, air compressor, gas turbine, heat recovery steam generator, power unit