(59c) A New Approach for Heat Exchanger Thermal Design

Heat exchanger network design is important for reducing the energy consumption of processes. Once the network configuration is designed and heat transfer duty is selected for each of the matches, the next important step is to design the heat exchanger equipment thermally. This paper describes a new approach to thermal design of shell & tube heat exchangers. Given the design parameter ranges and other constraints, the presented approach automatically generates a list of thermal designs that meet all of the specified design requirements.

The constraints that can be considered include velocity range on tube and shell side, maximum pressure drop on both sides, design margin ranges, ratio of film heat transfer coefficients of two sides, among others. This novel approach covers large number of design decisions such as header type, tube type, design pressure, baffle type and size parameters of tube side and shell side, etc. The candidate designs are ranked according to certain criteria, such as economics. The ranking compares the design parameters of different solutions and helps to make design decisions more efficiently. Compared to the conventional design approach which requires several trial-and-error procedures and usually only provides one design solution, the new approach automatically generates multiple design solutions for selection, reducing time and errors that might be made during the manual design process. A case study is presented to illustrate the application of the new approach as well as a comparison with the design solution obtained from the conventional approach.