A computerized method of evaluating the design performance of a feedwater heater with a short drain cooler

Electric utilities purchase feedwater heaters for new plants, where they purchase several at a time, and older plants, where the individual heaters are replaced as tube pluggage becomes excessive. A high-pressure feedwater heater costs between one and five hundred thousand dollars depending on its size and design. High-pressure feedwater heaters are essential to the performance of a unit. If a unit is designed to have feedwater heaters in service and they are removed, the furnace heat input must increase. This will increase unit heat rate and may cause furnace tube overheating due to excessive furnace exit gas temperature. Since feedwater heaters are so important to unit performance, utilities need a method to evaluate the heater manufacturer`s performance specifications and understand the theory behind a heater`s design. Previously utilities have not had an available method that uses the heater manufacturer`s design data and accurately calculates the zone heat transfer coefficients and pressure drop when given only the heater design data. There are computer programs that the heater manufacturers use to design the heater, but these programs are proprietary and would be costly for a utility to use for the small number of heaters analyzed on a year basis. This paper describesmore » the Modified Delaware Method for evaluating the design performance of a feedwater heater and applies it to an actual design with the aid of the PEPSE computer program. PEPSE is an acronym for Performance Evaluation of Power System Efficiencies. Its systems may include a broad spectrum of components that are common in power generation, such as turbines, combustion turbines, heat exchangers, pumps, fossil furnace components, cooling towers, and others.« less