Research On Steady-State Operation Optimization Model And Algorithm Of Natural Gas Pipeline Network

Reciprocating compressor and centrifugal compressor are commonly used in natural gas pipeline network system.Reciprocating compressor and centrifugal compressor have their own advantages,which are suitable for different working conditions and widely used in natural gas pipeline system.This paper studies the above two different types of compressors in two parts.The main contents are as follows:(1)For reciprocating compressors,this paper studies the modeling and solution of operation optimization of multi-source natural gas pipeline network,we first introduce 0-1 integer variables to describe compressor switches,and relax the nonlinear constraint of pipeline Weymouth equations.Based on these,we establish a new nonlinear mixed integer programming model.Secondly,a sequential linear mixed integer programming algorithm is proposed to solve this model.Finally,a variety of comparative experiments are carried out in three gas pipeline networks of different sizes.The numerical results show that the new model and its algorithm can effectively reduce the cost and the energy consumption of compressors.In addition,the required time is greatly shortened.(2)For centrifugal compressors,it takes tens of hours to solve the operation optimization problem of a large natural gas pipeline network system,in which the calculation time of the compressor power accounts for the vast majority of the run time.For centrifugal compressors that are widely used but extremely difficult to calculate power consumption,in order to improve the calculation efficiency and accelerate the speed of solving operation optimisation problems,three new fitting functions of centrifugal compressor power are proposed.The numerical performances of these three new fitting functions are tested with three types of compressors as experimental objects.The experimental results show that for the three types of compressors,the accuracy of the power calculation has improved a lot after using the three new fitting functions.In addition,these three new fitting functions are applied to operation optimisation of a virtual gas pipeline network and the results are compared with the traditional method for calculating the compressor power.The numerical results show that using three new fitting functions to calculate the compressor power can greatly reduce the solution time while ensuring the accuracy of the solution.