Natural gas dehydration unit of gas station
Natural gas dehydration unit of gas station
Unit configuration
(1) The dehydration unit is skid mounted, and the electrical equipment and instruments on the skid are explosion-proof.
(2) The dehydration unit is installed indoors. The supplier shall design the relevant system according to the low temperature environment in winter to ensure the normal operation of the dehydration unit in winter.
(3) All process pipes are connected to the skid side, and all safety valve vent pipes and blowdown pipes are connected to the skid side through manifold.
(4) It shall be able to work efficiently under the conditions listed in the equipment data.
(5) All flanges to be connected by the owner shall be matched butt welding flange with gasket, bolt and nut. The flange standard is Hg / t20592-2009, the flange adopts RF face, B series, and the material is 16Mn; the spiral wound gasket standard is Hg / t20610-2009, the pressure grade is the same as the flange, the gasket adopts the spiral wound gasket with inner ring and centering ring, the centering ring is carbon steel, the material of metal belt and inner ring is 0Cr18Ni9, the packing is flexible graphite belt; the stud is special-purpose full thread stud (35CrMo), according to Hg / t20613-2009; the nut is type II hex nut (30CrMo), according to GB / t6175.
(6) The regeneration process is an equal pressure closed cycle with external electric heating.
(7) The filter is equipped at the inlet with a filter accuracy ≤ 10 μ m, which can effectively protect the adsorbent from being soaked and polluted by liquid and extend the service life of the adsorbent; the dust filter is equipped at the outlet with a filter accuracy of 3 μ m, which can protect the normal operation of subsequent compressors.
(8) The regeneration system adopts the circulation compressor to drive the circulation regeneration, and the regeneration system is equipped with a gas water separator to make the regeneration circulation gas cleaner.
(9) The gas-water separator has double separation of gravity and filtration, with good separation effect. A liquid storage tank is set behind the gas-water separator with a liquid storage volume of 0.05m3 to meet the total discharge of regeneration.
(10) Control system: PLC program control includes constant temperature control and touch screen. After the control parameter input is processed, it will be displayed on the LCD screen, and the set program will automatically control the normal operation of circulating fan, heater, cooler and anti freezing and heat preservation device. Equipped with local instrument and indoor control instrument, as well as remote control instrument. The start and stop of regeneration cooler, circulating booster and electric heater can realize electric interlock control and manual independent control, and manual control is preferred. Multi point temperature sensor monitoring, accurate display and control of heater outlet, regeneration gas outlet and cooler outlet temperature, control parameters input to PLC central processor for processing, and control the action of regeneration system according to the set program, and equipped with remote communication interface, RS485 interface, communication protocol is MODBUS-RTU. Heater overheat protection switch, avoid heater dry burning, protect electric heating element life.
(11) The PLC control cabinet is arranged in the power distribution room in the station, and the PLC control cabinet shall be equipped with space heaters to ensure the normal operation of the low temperature environment in winter.
(12) Safety protection function: the heater barrel and outlet are provided with temperature protection function; the motor is provided with thermal protection and short circuit protection, and the electrical system is provided with short circuit and leakage protection.
(13) The motor adopts flameproof asynchronous motor, the explosion-proof level is not less than Exd Ⅱ BT4, the protection level of electrical equipment is not less than IP54, and the protection level of field instrument is not less than IP55.
(14) Air cooler: tube fin heat exchanger
Structure configuration
(1) After the adsorption tower is wrapped with thermal insulation material, it is wrapped with aluminum decorative plate, which has good corrosion resistance and beautiful appearance.
(2) The electric heating tube is of integral type, made of stainless steel 1Cr18Ni9Ti. The heating power on the surface of the electric heating tube reaches 2.0w/cm 2.
(3) Dew point analyzer sampling port is set at the outlet of dehydration unit. Equipped with online dew point meter.
(4) The adsorption tower is equipped with a local display pressure gauge and thermometer to display the working pressure and temperature of the adsorption tower; the regeneration system is equipped with a thermometer, pressure gauge and thermocouple to remotely transmit the outlet temperature of the regeneration heater, cooler and regeneration gas of the adsorption tower to the control room; the control cabinet is equipped with PLC control instruments.
(5) All electrical equipment on the device is explosion-proof design. The on-site explosion-proof level is not less than Exd Ⅱ BT4, the protection level is IP54, and the on-site instrument protection level is not less than IP65.
(6) All external nozzles are connected to the skid.
(7) The adsorption tower is equipped with a special loading and unloading port for molecular sieve, which is convenient and fast for molecular sieve replacement.
(8) There is a safety valve in the regeneration system.
(9) The equipment such as adsorption tower, regeneration gas heater, inlet separation filter blowdown, regeneration gas water separator, liquid gathering tank blowdown and their connecting pipelines shall be insulated. When the ambient temperature is lower than 5 ℃, the blowdown system can be started for heat preservation and tracing.
Anti corrosion and heat preservation treatment
(1) Party B shall be responsible for spraying primer and finish paint on all parts except stainless steel products and standard parts.
(2) Party B shall be responsible for the procurement and wrapping of insulation materials and aluminum plates for adsorption tower, electric heater and pipeline.
Customer needs to provide information
Air inlet pressure, air inlet flow, air inlet water dew point and gas outlet water dew point (in case of unconventional natural gas, in addition, air inlet temperature and gas composition shall be provided. Unconventional natural gas generally includes well gas, coalbed gas, shale gas, biogas, gas, etc.).
