CNG Storage:
1. It is mainly applied for natural gas pressure regulating, flow metering and impurity filtration. It is also adopted to recycle the exhausted gas of compressor and dehydration and centrally store the waste water and oil. The equipment is composed of surge tank, natural gas buffer tank, blowdown tank, sewage tank and their relevant valve, pipeline and pressure gage. It is widely used in NGV refueling station.
2. Some industrial stations need to adopt natural gas PRU to decompress the high-pressure CNG to about 3bar.
Classification
1. Gas Pressure Regulating and Metering Skid: It owns the capacity of gas filtration, pressure regulating and metering in the gas station, and it consists of double-lines system, mating valve, pipeline, flow meter, pressure gage, pressure regulating meter, common base, metal protecting casing and etc.
2. Gas Desulphurization Tower: It adopts the specialized and high-efficiency desulfurizer to achieving the purpose of desulfurating purification to the raw natural gas. The sulphur content of the high-purity natural gas is below 6m/Nm3 after processing, which does contribution to avoiding H2S doing stress corrosion to the station equipments and H2S’ recontaminating of vehicles’ exhaust emission.
3. Buffer Tank: The natural gas pressure in the pipeline of CNG station is usually fluctuating in a certain range, while the pressure-fluctuating gas may affect the lifetime of compressor’s accessories including input and drain tap. Therefore, it is really necessary to adopt a pressure buffer tank to make the natural gas in a stable condition before it is sent into the compressor and dehydration equipments.
4. Blow Down Tank: Blow down tank is designed to collect compressor blowdown gas and safety valve vent gas and then flow it back to compressor again.
5. Sewage Tank: It plays the role of gas-liquid separation and storage of the exhaust gas from the compressors and deep dehydration equipment resurgent gases. It consists of natural gas sewage (1m3), globe valve, safety valve and pipeline. The natural gas recycling tanks should match the sewage tanks to achieve the goal of safety and environmental protection.
6. PRU (Pressure reduction unit): it is used to reduce the pressure of the compressed natural gas and to reduce the high pressure gas in the tube storage from 250bar to the customers’ desired pressure (usually 3bar). Two stages pressure reduction are needed, meanwhile gas must be heated by electric heater or gas burn boiler, during which the latter one presents a better performance.
