Capital cost targets for networks with non-uniform heat exchanger specifications

Abstract

Heat exchanger networks (HENS) in the chemical and process industries often require exchangers made of special and expensive materials of construction, different pressure ratings, and different heat transfer devices. The economic implications of such network designs are often very significant; it is important that the performance of such networks be reliably determined before their actual designs. Accurate assessment of such networks requires that the differences in the exchanger requirements of the process streams in the network be adequately represented during the targeting stage. The distribution of the heat transfer surface area and of the total number of heat transfer units between the different exchangers specifications can significantly affect the accuracy of the cost target. In this paper, we examine the relative effects of these factors on the network cost; and develop a general procedure for predicting their distributions and determining the total costs for such networks before the design.