OPTIMIZATION OF TREE-STRUCTURED GAS DISTRIBUTION NETWORK USING ANT COLONY OPTIMIZATION: A CASE STUDY

An Ant Colony Optimization (ACO) algorithm is proposed for optimal tree-structured natural gas distribution network. Design of pipelines, facilities, and equipment systems are necessary tasks to configure an optimal natural gas network. A mixed integer programming model is formulated to minimize the total cost in the network. The aim is to optimize pipe diameter sizes so that the location-allocation cost is minimized. Pipeline systems in natural gas network must be designed based on gas flow rate, length of pipe, gas maximum drop pressure allowance, and gas maximum velocity allowance. We use the information regarding gas flow rates and pipe diameter sizes considering gas pressure and velocity restrictions. We apply the Minimum Spanning Tree (MST) technique to obtain a network with minimum number of arcs, spanning all the nodes with no cycle. As a main contribution here, we present and use an ant colony optimization algorithm for solving the problem. The proposed method is applied to a real life situation. Our obtained results are compared with the ones obtained by an exact method. The results show that ACO is an effective approach for gas distribution network optimization. A case study in Mazandaran gas company in Iran is conducted to illustrate the validity and effectiveness of the proposed approach.