Host: The Japan Society of Mechanical Engineers
Name : International Conference on Power Engineering-2021(ICOPE-2021)
Date : October 17, 2021 - October 21, 2021
At a combined cycle power plant, data on gas turbine cooling air flow rate is needed in order to analyze not only the temperature of both stators and blades but also plant efficiency. However, an ultrasonic flowmeter is not useful because the measurement position becomes hot, usually exceeding 300 degrees centigrade. Accordingly, we tried to use the heater method. In this method, a circumferential heater is attached to the outside of a pipe and then the axial temperature distribution on the outside of the pipe, which is influenced by fluid velocity in the pipe, is measured by thermocouples. The velocity is analyzed on the basis of the temperature distribution in the pipe. Measurements were conducted at two kinds of cooling air pipe at an advanced combined cycle power plant. In one, cooling air is extracted from the 13th stage of a compressor and supplied to the 2nd stators of the gas turbine; in the other, cooling air is extracted from the 9th stage of the compressor and supplied to the 3rd stators of the gas turbine. As a result, it was clarified that the cooling air flow rate depends on atmospheric temperature.
