The Heat Exchange Institute (HEI) Standards for Steam Surface Condensers were promulgated to design and predict the performance of surface condensers for power plant applications by providing basic overall tube bundle heat transfer rates and correction factors to be applied to account for different tube diameters, wall thicknesses (BWG), tube materials, circulating water inlet temperatures and, average water velocities.
From 1958 to 1973, nonferrous alloys were generally the tube materials of choice for steam power plant surface condenser service. By the time the 7th edition of the HEI Standards was issued in 1978, concerns with corrosion and other issues with nonferrous tubing materials had led to increased specification of stainless steel while titanium was still in its infancy.
Since then, operational experience gained with stainless steel and titanium coupled with technological advances in these materials have resulted in revisions and incorporation of additional correction factors in subsequent editions of the HEI Standards for Steam Surface Condensers. The latest edition (11th edition) was issued in October 2012. Significant developments in the HEI heat transfer correction factors since issuance of the 7th edition pertain to stainless steel and titanium.
Using a case study, this paper analyzes the impact of developments in HEI heat transfer correction factors on steam surface condenser performance and operation with focus on admiralty, austenitic, super-austenitic and super-ferritic stainless steels as well as titanium tube materials. The paper examines how changes in the correction factors affect condenser performance and plant operation. It highlights the importance of using and validating the proper correction factors to predict and ensure optimum condenser performance and operation.