Study of air-cooling methods for air entering the gas turbine compressor

Abstract

Relevance: the continuous growth of the population leads to a steady increase in the demand for electrical and
thermal energy. In the Republic, the main generating capacities for electricity production are predominantly based
on thermal power plants, combined cycle power plants, and cogeneration technologies. One of the key factors
limiting the production capacity of modern gas-turbine thermal power plants is the inverse functional relationship
between ambient temperature and gas turbine power output. An increase in atmospheric air temperature primarily
leads to a decrease in its density, which in turn reduces the mass flow rate of air entering the gas turbine compressor.
As a result, the electrical power generated by the gas turbine decreases by a certain amount. Environmental param
eters such as humidity, pressure, and temperature may vary within a wide range depending on geographical location
and seasonal factors. These factors have a direct effect on air density and an indirect impact on the power output of
the gas turbine unit. During the summer period, an increase in temperature up to +45 0C leads to an increase in the
specific work of the compressor, which results in a decrease in the turbine efficiency and a reduction in the gener
ated power by up to 30%. In this study, it is shown that at the “Toshkent IEM” branch, due to the integration of
evaporative (pad-type) cooling of the air at the inlet of the Hitachi H25 gas turbine compressor, the average power
output has increased by 11–12%.
Aim: it is planned to assess the potential for stabilizing generating capacities, improving operational efficiency,
reducing the specific fuel consumption, and decreasing the amount of harmful substances emitted into the atmos
phere under various climatic conditions, particularly through the application of technology for preliminary cooling
of the ambient air entering the compressor.
Methods: to assess the power losses occurring as a result of changes in ambient temperature at gas-turbine thermal
power plants and to identify possibilities for their reduction, scientific studies conducted by foreign and domestic
researchers were used, along with theoretical analysis, comparative analysis, approaches aimed at improving effi
ciency, and methods of techno-economic evaluation.
Results: the results of experimental and test studies carried out on the basis of monitoring the temperature and
relative humidity parameters of the air entering the compressor of the Hitachi H25 gas turbine with a nominal
capacity of 28.6 MW, installed at the “Tashkent Thermal Power Plant” branch, are presented.