Optimal dimensioning of pipe networks: the new situation when the distribution and the transportation functions are disconnected

In [9], De Wolf and Smeers consider the problem of the optimal dimensioning of a gas transmission network when the topology of the network is known. The pipe diameters must been chosen to minimize the sum of the investment and operating costs. This two stage problem was solved by application of the bundle method for nonsmooth optimization. This model does not reflect any more the current situation on the gas industry. Today, the transportation function and gas buying function are separated. This work considers the new situation for the transportation company. The objective for the transportation company is to determine the flows in the network that minimize the energy used for the gas transport. This corresponds to the minimization of the power used in the compressors. We introduce in the investment problem new decision variables, namely the maximal power of the compressor. We present here first results obtained on the belgian gas network and on a realistic network corresponding to a part of the french network.