LNG Gasification Station

The gasification station integrates all functions of unloading, storage, gasification, reheating, pressure regulation, metering and odorization, and adopts PLC intelligent control. The process is simple, the structure is mostly skid, the site installation is convenient, the operation is simple, and the operation is reliable. The "double gasification + secondary reheating" can be used continuously for 24 hours under any environmental conditions. With the advantages of short construction period and fast meeting the demand of gas market, LNG gasification station has been gradually built in many small and medium-sized cities with developed economy and energy shortage along the southeast coast of China, becoming a permanent gas supply facility or a transitional gas supply facility before the arrival of pipeline natural gas.

Technological process

LNG is transported to the gasification station by the tank truck, and the pressure in the tank truck is increased by using the LNG unloading supercharger, and the LNG in the tank truck is sent to the LNG low temperature storage tank for storage. When the LNG is discharged from the LNG storage tank, the pressure of the storage tank is increased through the self pressurization system of the storage tank, then the liquid phase outlet valve of the storage tank is opened, and the LNG in the storage tank is sent to the gasifier through the pressure difference, and then sent to the municipal gas pipeline network through the pressure regulation, metering, odorization and other processes.

When the outdoor environment temperature is low and the natural gas temperature at the outlet of the air temperature gasifier is lower than 5 ℃, a water bath heater should be connected in series at the outlet of the air temperature gasifier to heat the gasified natural gas.

Main features

① 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 station shall not be lower than the ambient temperature of 10 ℃.

② The thermal insulation performance of cryogenic storage tank and cryogenic liquid pump is better, and the cold insulation performance of valves and pipe fittings is better.

③ The equipment, pipelines, instruments, valves and their accessories in the low temperature area of LNG station have good operation performance under low temperature conditions, and have good mechanical strength, sealing and corrosion resistance.

④ Because the start-up 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, the cryogenic liquid pump is required to increase the frequency and expand the power quickly, usually in a few seconds to more than ten seconds to meet the requirements, and the cold insulation performance is better.

⑤ The gasification equipment is required to be earthquake resistant, typhoon resistant and meet the design requirements under ordinary climate conditions to achieve the maximum gasification flow.

⑥ The manufacture and daily operation management of low temperature storage tank and filter have been included in the national standards for manufacture, acceptance and inspection of pressure vessels; Gasifier and low-temperature hydrocarbon pump are not regulated by relevant laws and regulations in China. In the manufacturing process, the relevant industry standards of the United States are implemented, and the position of welding, transformation, maintenance or moving pressure vessel on the pressure vessel body must be reported to the supervision unit of pressure vessel.