Using turbine thermal kit data to benchmark condenser performance calculations

摘要

In the past, the performance of a condenser has been judged by empirical criteria such as cleanliness factor, terminal temperature difference and/or cooling water pressure drop. However, these criteria vary with load, cooling water inlettemperature and cooling water flow rate. Thus, to base maintenance or operating decisions on deviations in the empirical criteria requires that these other factors be taken into account.One way to avoid this is to develop a benchmark or reference condenser duty. A source for this reference can be found in the analysis of turbine thermal kit data to create a design model of the turbine LP stage. Provided that the turbogenerator isoperating with the equipment configuration on which the thermal kit data was based; and that the boiler operating conditions are close to design for a given load; then the exhaust enthalpy and flow entering the condenser can be calculated as a function of load and back pressure, and these used to estimate present condenser duty. Thus, the performance of a condenser can be compared against a calibrated and stable frame of reference, which changes only very slowly over time.The method allows cooling water flow rates to be estimated and compared; while tube fouling factors and condenser ambient heat discharges can also be quantified. Further, the excess heat discharges due to the fouling of the condenser and its effect on the turbogenerator are initially calculated in MBTU/h. However, they can also be converted to the equivalent economic loss in s/h; as well as the equivalent lbs. of excess CO{sub}2 emissions per hour.