Study On Energy Saving And Optimal Operation Of Natural Gas Shallow Cooling Treatment Unit

There are 10 sets of natural gas shallow cooling treatment plants in Daqing oilfield,which deal with 70 thousand cubic meters of natural gas annually,90 thousand tons of light hydrocarbons,110 million kilowatts of electricity and 400 thousand tons of water.The comprehensive energy consumption of the products is 24 kilograms of coal per ton products.Shallow cooling device has the characteristics of low yield,high energy consumption,therefore,to find cases of Sanan shallow cold energy saving potential.The cooling temperature of Sanan shallow cooling device is 4?higher than the designed value,high recovery of key components in natural gas C3 ratio design(41.97%)is lower than the domestic industry standard(50%);two level three-phase separator glycol level often display inaccurate;the temperature control of the glycol regeneration tower is not stable.In order to solve these problems,we find out some measures to control the liquid level of propane evaporator,the suction pressure of propane machine,improve the heat exchange efficiency of propane condenser,discharge the non condensable gas in evaporator,and ensure the purity of propane.The refrigeration temperature reaches the design value(-35 C),natural gas C3 component recovery rate increased from 41.97%to 50.6%,the light hydrocarbon yield of1200 tons per year,to create economic benefits 1 million 416 thousand yuan/year,the comprehensive energy consumption of unit product is 24.6 kg per ton of coal products dropped to 23.2 kg per ton of coal products.The surface evaporative air cooler is installed in the propane compression refrigeration system.The consumption of electricity per thousand gas is reduced from 377 kWh to 342 kWh,which saves 32.2×10~4kWh throughout the year,saves 5×10~4t and saves 329 thousand yuan in operation cost.By optimizing the temperature control mode of the ethylene glycol electric heater,the temperature regulation is more accurate and the control is more stable.The MHYE series magnetic effect level gauge is installed.The two level three-phase separator has stable liquid level control,which ensures the separation effect of hydrocarbon and water and avoids the loss of light hydrocarbon and ethylene glycol.The system pressure increased from 1.0MPa to 1.15 MPa,and the yield of light hydrocarbons increased from 1.22 tons per cubic meter to 1.25 tons per million cubic meters.The comprehensive energy consumption of the device decreased by 0.41 kg per ton of coal products.In view of the large change in the load rate of the device,the minimum energy consumption control point for different compressor running stations is found through the field assessment.