Experimental Investigation of Gas Turbine Recuperator Fouling

Abstract

This paper discusses an experimental investigation of recuperator fouling currently underway at the David Taylor Naval Ship Research and Development Center. The overall approach involves testing different heat exchangers in the exhaust gas stream of a gas turbine. The two heat exchangers initially tested were the plate-fin type and differed in the gas-side heat transfer surface geometry. Primary surface heat exchangers are being considered for future tests also. Test conditions are defined such that the critical part of full-scale recuperators (i.e., the colder end of the gas passages) is simulated in the small test heat exchangers. The composition of the gas stream is measured to determine amounts of gaseous, particulate, and condensible hydrocarbon emissions. Fuel samples taken during each test are analyzed. The test heat exchangers are specially constructed to allow inspection and measurement of the fouling film inside the unit following each test. The temperature distribution inside the test exchanger is measured, as well as air and gas inlet and exit temperatures. Measurements of fouling film thickness are made using an optical microscope and photographs of fouling deposits were taken. The early results obtained from fouling tests conducted with the first heat exchanger are discussed. Tests were also conducted to demonstrate a fouling removal technique.