The multi-objective optimal design for a 200 MW multi-start helical coiled tube heat exchanger was carried out

with the help of the genetic algorithm

in which the total heat exchange area and total pressure drop were taken as the objective functions

and six parameters such as the helix angle

number of helix coiled tubes in the inner layer

number of the helix coiled layers

diameter of the helix coiled tubes

radial pitch

diameter of the newel were set as the decision variables.The results showed that

the Pareto optimal functions for the above two objective functions had a relationship of interaction;the design corresponding to points on the Pareto curve where the total heat transfer area AZ≤1 811.8 m2 and the total pressure drop Δpz≤0.711 1 MPa was superior to the conventional designs.This optimization method reduces the dependence of designer on experience

and is of generality.