HG2T Method (Helium Gas Tracer Test) Solution To Increase Condenser Vacuum Tightness Solution to Increase Condenser Vacuum Tightness

Abstract

The condenser functions to condense the exhaust steam from the LP Turbine and plays an important role in the Closed Cycle of the PLTU thermal cycle. The PLTU Palabuhanratu uses a Steam Surface Shell & Tube condenser type. The model of the condenser itself is Single Pressure, Two Paths Pressure. In operation, the condenser pressure is much lower than the pressure in the outside air. The condenser is designed to be vacuum so that exhaust steam from the LP Turbine can be perfectly condensed to the Hotwell and recirculated back to the Boiler. Vacuum condenser or commonly called Condenser Backpressure is one of the important parameters in the operation of a PLTU. Condenser Backpressure occurs due to the process of condensing the steam into water, where there is a change in density from loose to denser. To help maintain the vacuum value, a Vacuum Pump is used in each unit to maintain the vacuum value within normal operating limits. One of the problems that are often encountered in condenser operation is an increase in the Condenser Backpressure value. Several factors affect the Condenser Backpressure value, including Circulating Cooling Water quantity, Air in-leakage/Ingress, the Vacuum Pump performance, Gland Seal Steam pressure, Excessive Drain Temperature & flow. One of the most common cases is high Air Ingress which causes an increase in the Condenser Backpressure value. Two methods can be used to detect air ingress, namely the Online Test and the Offline Test. Online Test is a test when the unit is operating normally with the Gas Tracer Test method which uses Helium or SF6 gas, so its called Helium Gas Tracer Test (HG2T), online testing with this method has a high level of accuracy because it is carried out when the unit is operating normally and is more measurable so that the level of leakage can be found in the gas detector. The HG2T method obtained a potential saving of IDR 4,253,663,000, while other benefits obtained from the HG2T method are that it makes it easier to identify areas that experience vacuum leaks and determine steps to execute follow-up repairs and foster a professional and learner culture to solve problems..