Perhitungan Sisa Umur Preheater Tube HRSG Unit 1.1 PLTGU PT. PJB UP Gresik
Heat Recovery Steam Generator (HRSG) is a tool that serves to increase the efficiency of Gas Turbine. HRSG works by utilizing exhaust gases from Gas Turbines to produce steam which will be used to drive Steam Turbine. In the HRSG unit is often found the problem of leakage HRSG tube. Preheater tubes are part of the most frequently experienced leaked HRSG tubes. In this study discuss the calculation of remaining life of preheater tube. To find the corrosion rate that occurs in the preheater tube obtained through calculations based on the results of thickness test and immersion test. Immersion Corrosion Test uses specimens of ST 37.8 with a surface area of 27.234 cm2, the variables in this test are water temperature 90 ° C, 97 ° C, and 104 ° C. Immersion Test is done within 24 hours. Immersion test result with variation of water temperature lifetime value obtained is: 4,315 years at temperature 90 ° C, 3,437 years at temperature 97 ° C, and 1,075 years at temperature 104 ° C. Based on thickness test The average lifetime value of preheater tube inlet is 13,645 years and 40,003 years for preheater outlet tube.