Indirect Heat Transfer Technology For Waste Heat Recovery Can Save You Money

Abstract

Several methods to recover energy from existing flue gas stacks have been successfully demonstrated in recent years. There is no one method that can be singled out as the most economical approach for all applications. Quite often the mere spatial constraints of an existing installation makes the conventional flue gas to air energy recovery technology impractical to employ. A successful alternative is the transfer of waste heat to an intermediate heat transfer fluid (i.e., DOWTHERM Heat Transfer Fluid) that eliminates the large diameter ducting associated with the direct heat transfer technology. This paper presents a method to project, during the preliminary engineering phase of a flue gas energy recovery project, the capital cost and payback period for systems utilizing DOWTHERM fluids. This method is demonstrated by completing the simplified economic analysis of several example projects ranging in size from 5 to 40 million Btu/hr of recoverable energy.