THERMOCOUPLE AND THERMOWELL RESPONSE TIME STUDY FOR STEAM TEMPERATURE CONTROL - PART Ⅱ

摘要

Sensor response time is an important factor in the control loop performance. For steam temperature control in a fossil steam power plant, the temperature measurement at the desuperheater outlet location should be fast to improve the loop disturbance rejection performance. Previous work studied the impact of thermocouple and thermowell design on response time. In this paper, a new thermocouple and thermowell were installed in the boiler and response tested to verify the predicted values. In addition the old thermowell which was removed was inspected and tested in a laboratory environment in the as-found condition and in a clean condition. The closed loop performance of the steam temperature after installation of the new equipment is also presented.