Analysis of thermal system network of an ammonia plant using genetic algorithms – part I: synthesis and optimisation

Abstract

Optimum and efficient use of energy through conservation and management is vital in any energy intensive industry. As there are many heat exchangers in a chemical plant, it is important to build the heat exchanger network optimally. The synthesis and optimisation of thermal network of an ammonia plant using combined approach of pinch technology and genetic algorithms is presented in Part I. Two approaches of pinch technology, viz., minimum temperature approach and minimum flux approach are adopted and compared. For this, steady state on line process data captured from an existing network of heat exchangers of an ammonia plant is used. The maximum possible saving in total annual cost of production of ammonia using minimum temperature approach and minimum flux approach are found to be 3.14% and 15.73% respectively. Based on the above results, modification techniques are employed for the ammonia plant and are presented in Part II.