New Approach for Heat Exchanger Networks pesign

Abstract

The problem of heat exchanger network synthesis (HENS) has received a considerable attention over the last twenty years. An important feature of beat exchanger network design is the energy-capital trade-off. This trade-off has been regarded as complex due to the number of • structural networks usually available, each being subject to continuous optimization. The disadvantage of this approach is that optimality is local to the structures examined. Alternatively, mathematical programmmg can be used but user interaction with the solution is more complicated and generally performed at higher levels in the problem formulation rather than in the design. So, until now, no generalized technique has been introduced for the prediction of global optimum cost networks that allow user interaction with the network structure. However, a number of works has been published turning attention to the thermodynamic analysis which yields key points and interrelations (the pinch point and composite curves) as well as the design targets (maximum heat recovery, minimum area of units). The present study is divided into two parts. The objective of the first part is to create heat exchanger network systems using different procedures forming the optimal synthesis of HENs. The system (hot and cold streams) is described to the heat exchanger parameters (supply temperature, target temperature and heat capacity flow rate of each stream) and economic parameters (prices of equipment, heating steam and cooling water). Two procedures are used in the present study. The first proposed procedure is based on the Mcp1iMcpc heuristic, in which the highest heat capacity of the hot stream is matched with the highest heat capacity of the