A method to determine the economic cost of fouling of gas turbine compressors

A method to determine the economic cost of gas turbine compressor fouling was developed. The method is based on the calculation of the influence of the drop of compressor performances (isentropic efficiency, pressure ratio and air mass flow) on Heat Rate and full load power of the gas turbine. A statistical procedure to quantify the drop of compressor performances with fouling and to obtain ambient correction factors for the compressor was also developed. Finally, this method was applied to a real gas turbine in order to check its validity. It was demonstrated that the application of the correction factors obtained worked well. The method was used to check the evolution of the compressor efficiency over time and the effects of off-line washings on compressor performances. It could be concluded that the loss of maximum power is the most important factor to take into account to schedule off-line washings.