Effects of ammonia contamination by water on OTEC-power-system performance

Abstract

Tests were conducted with evaporators produced by Trane, Johns Hopkins University's Applied Physics Laboratory (APL), and Linde to determine the loss in heat-transfer performance resulting from contamination of ammonia by water. A stepwise integration procedure was developed to determine the overall heat-transfer coefficients from the experimental data. Results indicated that the heat-transfer coefficient of the evaporator decreases with increasing water content of the ammonia. At water concentrations below 0.1%, the reduction in the overall heat-transfer coefficient was less than 1% for al three evaporators. For more than 0.1% water, the loss in performance becomes increasingly significant. At 1% water, the reduction in the heat-transfer coefficient was found to be 4%, 8%, and 10%, for the Trane, APL, and Linde evaporators, respectively.