Development And Application Of Natural Gas Sealed Combustion Unit

In the process of exploration and development,the amount of waste natural gas generated by test gas operation is small,the output time is short,and the recovery cost is high.The on-site treatment is mainly carried out by high-altitude torch or combustion tank.At present,most of the commonly used ignition devices are external combustion,which is very easy to produce a large number of noise pollution,light pollution and thermal radiation,which will cause serious impact on the surrounding ecological environment.Especially for external burning torch,due to its short burning time and low burning temperature,it is very easy to cause insufficient combustion,which will release some harmful gases into the air and further aggravate environmental pollution.The promulgation of "new two laws" puts forward higher requirements for the protection of ecological environment in the production and construction of oil and gas industry.Therefore,under the dual premise of safe production and environmental protection,the development of closed combustion device is of great significance.Based on the present situation of closed combustion equipment at home and abroad,this paper develops closed combustion equipment and carries out field application.The design of the device includes furnace design,burner design,thermocouple,flame detector,pneumatic cutting valve selection and overall design.In addition,the valve selection of the device pressure control system.The device adopts PLC automatic control system and automatic ignition device to improve safety performance.PLC system hardware mainly USES Siemens PCS7 series products,and realizes the monitoring of the whole device through graphic programming.The device is designed as a vertical cylindrical furnace with a downward air supply.The furnace body is 2.924 m in diameter and 13 m in height.S310 stainless steel plate is selected as the innermost layer of the barrel refractory,while aluminum silicate insulation fiber cotton and refractory coating material 0Cr25Ni20 are selected as the intermediate layer.The device uniformly arranges 3 ignition heads and 40 combustion heads in a ring on the fuel distribution plate.4 ion flame detectors are installed on the combustion head,and 3 platinum-rhodium thermocouples are installed in the middle and bottom of the furnace to measure the temperature.The inlet pipe of the device is equipped with a variable frequency blower,which provides excessive air for combustion and ensures that the furnace temperature is maintained at 900 ? toeliminate the risk of explosion.Besides,a sound muffler is installed to eliminate noise.The device is equipped with a pneumatic cut-off valve to automatically cut off the natural gas supply when the flame is detected to go out to prevent natural gas leakage.Domestic GPR-S200 and GPR-A200 pressure regulating valves and BYV-300 class back pressure valve are selected to control the pressure of the device.Most of the devices use skid mounted structure to facilitate transport and installation.The device has been applied on site in Well An Tan 3 well.The application results show that the temperature of the furnace outer wall is 193?,and the safety and environmental protection meets the chemical standard HG/T 20570.When burning,there is no black smoke above the furnace body,natural gas is completely burned in the furnace body,and tail gas emission conforms to the national standard GB 13271 and GB 16297.The natural gas sealed combustion device studied in this paper has good practical value.