INFLUENCE OF HEAT SOURCE COOLING LIMITATION ON ORC SYSTEM LAYOUT AND WORKING FLUID SELECTION: THE CASE OG ALUMINIUM INDUSTRY

摘要

Energy recovery from the raw gas in aluminium production plantis investigated in this paper. This hot gas contains acidcompounds and it should not be cooled below its dew point inorder to avoid corrosion problems. This limitation is generally notconsidered in the published literature Common working fluidswere screened, with two heat recovery configurations:Direct and indirect (thermal oil loop) systems. The powerproduction loss for an indirect heat recovery system compared to adirect system was relatively small, about 5%. The acid dew pointtemperature restriction had less influence on the indirect system,which could utilize fully the low heat sink temperature availableon the site. This factor almost fully compensates for thetemperature loss induced by a second heat exchanger.Indirect systems can use standard ORC modules which couldreduce the cost of the plant