Parallel Heat-Exchangers Network Optimization Using Sliding Mode Extremum Seeking with integral Anti Wind Up Scheme

Taha Adel Al-Gadery ,Shibly Ahmed Al-Samarraie

doi:10.33103/uot.ijccce.21.2.6

Abstract

In this paper, we study the Sliding Mode Extremum Seeking (SMES) optimization method for a Heat Exchangers Network. The studied network is constructed from plate Heat Exchangers, in which several thermal sources are used to heat a common cold stream that is distributed between the several branches of the network. The considered optimization problem is the optimization of the thermal power gained from different hot sources. The control variables are the split ratios of the cold stream to the different heat exchangers. The dynamical model for general Heat Exchanger Network with (n) Heat Exchangers was driven and the special case of two Heat Exchangers in parallel was considered as a case study. The SMES algorithm was modified with an integral anti-windup scheme to constrain the search within the admissible region. The simulation results obtained by using Matlab program confirmed the effectiveness of the approach. Index Terms— Heat Exchangers Network, Sliding Mode Based Extremum Seeking, Real-time Optimization.

Highlights

Heat Exchanger is a very important piece of equipment in process industries where it is used to transfer heat between two or more fluids for either heating or cooling processes [1]
Since we only have two branches, u2 can be represented in terms of u1: Let u1 = u → u2 = 1 − u, the problem is reduced to a single parameter optimization problem
The dynamical model for the general heat exchangers network with (n) heat exchanger was derived and the special case of two heat exchangers in parallel was considered as a case study

Summary

INTRODUCTION

Heat Exchanger is a very important piece of equipment in process industries where it is used to transfer heat between two or more fluids for either heating or cooling processes [1] They are often arranged in networks to distribute the available hot streams effectively [2]. The sliding mode based extremum seeking scheme will be used to optimize the heating utility of a parallel heat exchanger network. This approach was based on the sliding mode concepts, one of the strong nonlinear control techniques that have been used widely in observation and control [16]-[17].

SYSTEM DESCRIPTION AND MODELING

THE OPTIMIZATION PROBLEM

SLIDING MODE WITH EXTREMUM SEEKING OPTIMIZATION

ADMISSIBLE SEARCH REGION

SIMULATIONS AND RESULTS

CONCLUSION