Urban Peak Shaving Station

The demand for natural gas in summer and winter is very different. Although our country has already stared at the import of natural gas from neighboring countries, it is still in great gap. Moreover, the construction cycle of pipeline gas is long, the construction cost is high, and it is difficult to solve the current dilemma at present. In order to effectively promote the balanced use of urban natural gas and make the gas users get enough gas supply with sufficient flow and normal pressure, effective peak adjustment measures must be taken to promote the balance of supply and demand of gas transmission and distribution system.

With the rapid development of LNG, the lngc peak regulating station has the functions of unloading, storage, vaporization, pressure regulating, bog recovery and loading, and is an effective solution to the "gas shortage".

System flow chart

Technological process

After LNG is transported to the station by tank truck, the differential pressure between tank truck pressure and storage tank is greater than 0.2MPa by pressurization of unloading supercharger, and LNG in tank truck enters storage tank through differential pressure; When peak shaving gas supply is needed, the LNG of the storage tank enters the cryogenic pump through the discharge pipeline to pressurize to the process pressure. The pressurized LNG enters the LNG gasifier in turn to gasify into gas and the reheater to reheat to normal temperature. Then it is sent to the urban pipe network after being stabilized by the pressure regulating metering skid. In addition, LNG liquid can also be exported through loading pump and loading skid.

Bog gas generated in the process of loading and unloading is first collected in the gas phase space of the storage tank, then reheated by bog gas heater, pressurized by compressor to process pressure, and sent to the main pipe network to avoid waste. After gathering, EAG of the station is reheated to normal temperature and then discharged into the venting tower.

Equipment features

● The process characteristics of LNG station are "low temperature storage and normal temperature use". The design temperature of the storage tank can reach minus 196 ℃ (the boiling point of LNG at normal temperature is minus 162 ℃), and the temperature of the natural gas at the exit station shall not be lower than the ambient temperature of 10 ℃.

● The low temperature storage tank and low temperature liquid pump have good thermal insulation performance, and the valves and pipe fittings have good thermal insulation performance.

● The equipment, pipelines, instruments, valves and their accessories in the low temperature area of LNG station have good operation performance under low temperature conditions, good mechanical strength, sealing and corrosion resistance

● The starting process of cryogenic liquid pump depends on the frequency converter to continuously increase the speed, so as to improve the power, increase the flow and provide high output pressure. Therefore, duel cryogenic liquid pump has high frequency, which can meet the requirements in a few seconds to more than ten seconds, and has good cold insulation performance.

● The manufacturing and daily operation management of low temperature storage tanks and filters have been incorporated into the national standards for manufacturing, acceptance and inspection of pressure vessels,