City Peak Shaving Station

The demand for natural gas varies greatly between summer and winter. Although our country has significantly increased the import of natural gas from neighboring countries, there is still a large gap. Moreover, the construction cycle for pipeline gas is long, and the construction costs are high, making it difficult to resolve the current predicament in the short term. To effectively promote the balanced use of urban natural gas and ensure that gas users receive sufficient flow and normal pressure of gas supply, effective peak shaving measures must be taken to promote the supply-demand balance of the gas transmission and distribution system.

With the vigorous development of LNG, LNG city peak shaving stations have functions such as unloading, storage, vaporization, pressure regulation, BOG recovery, and loading, making them an effective solution to address the "gas shortage".

Product Details

Process Flow

After LNG is transported to the station by tank truck, it is pressurized by the unloading booster to ensure that the pressure difference between the tank truck and the storage tank is > 0.2 MPa. The LNG in the tank truck enters the storage tank through the pressure difference; when peak shaving gas supply is needed, the LNG in the storage tank is pumped through the liquid discharge pipeline to the low-temperature pump, which boosts it to the process pressure. The boosted LNG then enters the LNG vaporizer to be vaporized into gas and is reheated to normal temperature in the reheater. After being stabilized by the pressure regulation and measurement skid, it is sent into the urban pipeline network. In addition, LNG liquid can also be sold externally through loading pumps and loading skids.

The BOG gas generated during the loading and unloading process first enters the vapor space of the storage tank for collection, then is reheated and compressed to process pressure by the BOG gas heater and compressor, and sent to the main pipeline to avoid waste. The EAG at the station is collected and reheated to normal temperature before entering the flare tower for centralized flaring.

Equipment Features

● The process characteristics of the LNG station are low-temperature storage and normal-temperature use. The design temperature of the storage tank reaches -196 degrees Celsius (the boiling point of LNG at normal temperature is -162 degrees Celsius), while the temperature of the natural gas leaving the station is required to be no lower than 10 degrees Celsius above the ambient temperature.

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

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

● The startup process of the low-temperature liquid pump relies on the inverter to continuously increase the speed to achieve increased power, flow, and high output pressure. Therefore, the low-temperature liquid pump has a high frequency, usually meeting requirements within a few to several seconds, and has good thermal insulation performance.

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