Research On Anti-surge Control Of Gas Turbine And Compressor Units

As clean and high quality energy,natural gas is increasingly favored by the government.However,natural gas resources in our country are mainly distributed in the Midwest,away from the eastern consumer market.In order to support long distance gas transmission,it is necessary to set up compressor stations on the natural gas transportation pipeline to make up for the loss of pressure which is caused by the gas flow.The main pressurized equipment in the compressor station is gas turbine and compressor units.Surge is the intrinsic characteristic of gas pressurization equipment.It will narrow the scope of equipment operation,result in damaged parts and have a great harm to industrial production.Therefore,that how to prevent the occurrence of surge has an important significance to improve the quality and efficiency of gas turbine and compressor units.This thesis mainly studies gas turbine and compressor units in gas station.The internal cause and external cause of the surge are analyzed under the premise of the working principle of the gas turbine units.With the adequate site investigation and deep theoretical study,the current anti-surge control method,the fixed limit flow method and the variable limit flow method are analyzed in detail.It shows that the fixed limit flow method can make the efficiency of units drop and result in energy loss.Combined with the actual working condition,the anti-surge controller of variable limit flow method is designed.Simulation result shows that when the unit inlet flow changes,the controller can respond to the input changes timely and adjust the output of the anti-surge valve to meet the requirements of anti-surge process.But considering that the adjustment time is too long and it can result in a larger range of output fluctuations,the anti-surge controller is designed by using the fuzzy control method.The analysis of Matlab simulation result proves that the fuzzy controller can adjust the opening of anti-surge valve through the change of the compressor inlet flow and effectively avoid the occurrence of surge phenomenon.Finally,the process of DCS control system in which the fuzzy control algorithm can be realized is described.DCS control system can not only reflect the safety and stability of the programmable controller,but also improve the intelligent degree of the system combined with the corresponding control algorithm.