International Conference on Power Engineering-2019 (ICOPE-19)

512 / 2019-01-02 18:38:32

Thermodynamics Testing of the Feedwater Pump Efficiency with a Normal Temperature Measuring System

feedwater pump efficiency; thermodynamics testing; temperature measuring system

Plenary track > Turbines

Thermodynamics testing of the feedwater pump efficiency is the most economical way to monitor the performance of the large feedwater pumps in power plant. Due to the high measuring accuracy requirement of the feedwater temperature difference of the pumps, very special test equipment is required for this testing method, which creates an unsolvable obstacle for the power plant engineers. The objectives of the study in this paper including: (1). to find a measuring method based on the normal temperature measuring system which can provide high accuracy for the temperature difference measurement concerned; (2). to analyze the theoretical error incurred by the proposed method.
First, the thermodynamics testing of the feedwater pump was introduced, and test equipment frequently used to fulfill this requirement was described. Comparatively, the proposed measuring method was provided and compared with the frequently used equipment. The proposed method was built on the two separate measuring of the temperature difference data of the feedwater pump, and the temperature measuring was made by the normal Class A PT100 temperature probes. The final accurate temperature difference was the average of the two temperature difference data measured.
Secondly, the detailed theoretical analysis was made for the proposed measuring method. Based on the analysis, under the most unfavorable working conditions, the maximum error of the calculated final temperature difference could be controlled within 0.05℃, which was suitable for calculation of the feedwater pump using thermodynamics method.
An application of the proposed measuring method was submitted for a 600MW supercritical generation unit. It is concluded that the proposed method is easy to carry out on site conditions, thus providing another possible mean to monitor the feedwater pump performance periodically.