Performance Study of Low-Pressure Vertical Feedwater Heater with SS304 as the Tube Material

Abstract

Most of the power generated comes from the steam power plant based on modified Rankine cycle. Researchers always attempt to increase the thermal efficiency of the steam power cycle. Due to increasing competition, it has become necessary for electric utilities to operate their facilities in the most cost-effective way possible. Even a slight increase in thermal efficiency reduces fuel consumption, and subsequently, the fuel cost is also saved. Feedwater heater is one of the components that increase the cycle efficiency. Low-pressure feedwater heater is used in a steam power plant to preheat the feedwater. But the tubes of the heater are subjected to frequent failures. So it becomes necessary to study the performance of the heater to check for its degradation. Effective monitorization of the process can be a very useful tool for diagnostic purposes. The performance of feedwater heaters can be studied by measuring a few thermodynamic properties. Terminal temperature difference (TTD), drain cooler approach (DCA), pressure drop and temperature rise are the four main parameters used in the analysis of feed water heaters. A simplified routine performance test on feedwater heater at a frequency of five minutes is conducted for a period of two hours. Using this test, the actual performance parameters are calculated. These results are compared with the computed values. This will help in identifying the deviations of the performance parameters under normal conditions. Based on the comparison, suitable decision can be made of whether to operate the heater or to replace it.