Gas turbines are used in various industries, including aviation, oil and gas, transportation, and power plants to generate electricity. One of the critical issues in the operation of gas turbines in cold weather is to prevent ice formation at the inlet guide vanes and bell-mouth of the compressor. Among the various anti-icing methods, the use of hot air extraction from the compressor is preferred due to its straightforward design, low maintenance costs, and high efficiency. In the present paper, a numerical study is performed on using the anti-icing system by hot air extracted from the compressor for the Nowshahr 460 MW combined cycle power plant. The effects of hot air flow rate, number of anti-icing tubes, number of nozzles, and injection angles on the ice formation are investigated. The predicted results and experimental data are in good agreement. The results show that the outlet temperature from the air intake and temperature of filter surfaces increases favorably by using an anti-icing system. Also, the increase in the hot air flow rate, the number of injection nozzles and the anti-icing tubes decrease the possibility of ice formation on the filter surfaces. At the inlet temperature of −5 °C, by increasing the number of nozzles from six to ten, the average surface temperature of the filters increases by 2 °C, and the outlet temperature of the air intake increases by 152%. Ice formation is significantly reduced when two anti-icing tubes are used instead of one with an identical hot air flow rate.
