Deviations in Predicted Condenser Performance for Power Plants Using HEI Correction Factors: A Case Study

The Heat Exchange Institute (HEI) Standards for Steam Surface Condensers are used to design and predict the performance of condensers for power plant applications. Since their inception, the Standards have undergone numerous changes to incorporate technological advances and revisions to various factors based on testing and operating experiences. Admiralty and copper-nickel (CuNi) tubes were very popular until the 1970’s. Subsequently, increasing concerns with the use of copper-based alloys in nuclear power plants as well as other factors led to specification and use of stainless steel (SS) and titanium. The first condenser designed with titanium tubes was put into service in 1977. In 1978, the HEI published the seventh edition of the HEI Standards for Steam Surface Condensers. The eighth edition was issued in 1984 followed by Addendum 1 in 1989. The ninth edition was issued in 1995 and Addendum 1 to the ninth edition was published in 2002. Notable differences between the ninth and seventh editions include: higher circulating water inlet temperature correction factors below 70.0 °F; for Admiralty, higher tube material and gauge correction factors for tube wall gauge below 16 BWG and lower values above 20 BWG; for 90/10 CuNi and 304 SS, higher tube material and gauge correction factors for tube wall gauge between 12 BWG and 24 BWG; and, for titanium, higher tube material and gauge correction factors for tube wall gauge above 18 BWG. Depending upon the tube diameter, material, wall gauge and the correction factors used for a specific condenser application and its operating range, there could be substantial deviations in predicted condenser performance and associated impact on output. Using a case study, this paper examines the use of the correction factors from the seventh and ninth editions in power plant condenser performance predictions. It provides recommendations for developing proper benchmarks and for ensuring optimum condenser performance.