1. Gas Distribution Network Optimization with Genetic Algorithm Kuntjoro Adji S. Lala Septem Riza Kusuma Chasanah Widita Febi Haryadi

2. Introduction Natural gas plays an important role in providing clean energy for the community. Gas companies have planned to design and build a new gas pipeline network in many places. To build pipeline network needs expensive cost in pipeline cost, investment cost, operasional cost, etc. So, pipe diameter optimization process must be done to minimize the investment cost with considering to the pressure and flow rates that have been agreed in the contract

3. Methodology INPUT DATA: 1.Fix pressure on inlet and outlet node 2.Schematic of pipeline network 3.Geometries of pipe 4.Flow rate on each outlet INPUT DATA: 1.Fix pressure on inlet and outlet node 2.Schematic of pipeline network 3.Geometries of pipe 4.Flow rate on each outlet GENETIC ALGORITHM 1.To optimize inside diameter with minimize total cost 2.To determine pressure distribution on junction With constrains: 1.Fix pressure on outlet node 2.Available pipe on market Output: 1.Optimal inside diameter 2.Cost calculation 3.Pressure on each node GENETIC ALGORITHM 1.To optimize inside diameter with minimize total cost 2.To determine pressure distribution on junction With constrains: 1.Fix pressure on outlet node 2.Available pipe on market Output: 1.Optimal inside diameter 2.Cost calculation 3.Pressure on each node VALIDATION OF PRESSURE DISTRIBUTION (Using Genetic Algorithm and Newton Method for checking/calculating of pressure distribution) Input: 1.Optimal inside diameter 2.Pressure on inlet node Output: 1.Pressure distribution on each node VALIDATION OF PRESSURE DISTRIBUTION (Using Genetic Algorithm and Newton Method for checking/calculating of pressure distribution) Input: 1.Optimal inside diameter 2.Pressure on inlet node Output: 1.Pressure distribution on each node OUTPUT DATA: 1.ID, OD, t 2.Pressure Distribution 3.Cost (investment, coating, installation) OUTPUT DATA: 1.ID, OD, t 2.Pressure Distribution 3.Cost (investment, coating, installation)

4. The problem formulation Minimize subject to is balancing equation at node i.

5. The Genetic Optimization Minimize subject to Pressure on each inlet is given. Inside diameter which available on market, 64 kind of ID (3 inch – 16 inch). flow rate on each outlet.

6. The model of gas flow in pipe The panhandle A: The equation system is constructed based on kirchoffs law: at any node, the sum of mass flow into that node is equal to the sum of mass flow out of that node

7. Continuity equations at the system:

8. Continuity equation at node m: QN m is the node flow (supply / demand rate) at node m

9. Continuity equation at node 6: Obtained: -N continuity equations

10. The economic model Investment cost: Coating cost: Installation cost: Operational cost(rule of thumb): 4% * investment cost.

11. Flow Chart of Genetic Algorithm

12. The Computation Method: The Genetic Algorithm To search the suitable pressure and index of inside diameter available on the market which give the best fitness. The representation of population:

13. The Computation Method: The Genetic Algorithm (cont) Fitness function: We use usual the Selection, crossover and mutation operator.

14. Case Study Input Data: 1). The schematic network, 2). There are 18 nodes: 1 inlet, 7 junctions, 10 outlet. And there are 17 pipe segments. 3). Pressure on inlet and on each outlet. To find: -Pressure on each junction -ID on each segments. -Cost calculation

15. The software OptDistNet

16. 1 st simulation To calculate the optimum diameter using GA Input: pressure on inlet S1 and pressure on each outlet, length of pipe. Output: ID on 17 segment pipe and pressure on each junction.

17. Result: Pressure Distribution on junction No.Node Pressure (psia) 1J01246.6 2J6234.2 3J7 219.3 4J1249.6 5J4248.5 6J02244.2 7J2234.3

18. Result: Optimum Pipe Diameter From NodeTo Node Inside Diameter (inch) Wall Thickness (inch) S1J017.90.344 J01D76,0650.28 J01J67.90.344 J6D84.0620.219 J6J78.1250.25 J7D96.2490.188 J7D108.1250.25 S1J18.2490.188 J1J46.0650.28 J4D56.0010.312 J4D64.0620.219 J1J028.1250.25 J02D16.1870.219 J02J28.2490.188 J2D24.1240.188 J2D46.0650.28 J2D34.1240.188

19. Result: Cost Calculation No.Item of costCost (US$) 1Investment2,965,132.42 2Coating396,032.68 3Installation5,733,666.24 4Operation1,344,466.04 Total cost 10,439,297.38

20. 2 nd Simulation To validate pressure on each node using optimum inside diameter. Input: – Inside diameter – Pressure on inlet – Flow rate on each outlet Output: – Pressure on each node.

21. Result: Pressure Distribution No Node Name PressureRate (Psia)(MMscfd) 1J01246.5690 2J6234.1620 3J7219.3090 4J1249.5780 5J02244.2210 6J2234.3240 7J4248.5060 8S125545.884 9D10193.628-16.209 10D9219.147-2.369 11D8234.076-0.832 12D7246.549-1.235 13D6243.064-1.273 14D5248.426-1.644 15D1243.851-6.284 16D3229.99-3.542 17D4232.661-3.994 18D2229.439-8.502

22. Conclusions The simple Genetic Algorithm can be helpful in finding an optimal inside diameter.

23. Thank You