Unloading and liquid adding device for skid-type liquid adding station and unloading and liquid adding method

Abstract

The invention discloses an unloading and liquid adding device for a skid-type liquid adding station and an unloading and liquid adding method. The device comprises a storage tank prying block, a liquid adding prying block and a gas collecting prying block, wherein the storage tank prying block comprises a storage tank prying block base, a liquefied natural gas storage tank, a temperature preservation pipeline and a plurality of stop valves and a plurality of safety relief valves, wherein the plurality of stop valves and the plurality of safety relief valves are arranged on the temperature preservation pipeline; the liquid adding prying block comprises a liquid adding prying block base, an immersed pump, a pressurization and gasification device, a temperature preservation pipeline and a plurality of stop valves and a plurality of safety relief valves, wherein the plurality of stop valves and the plurality of safety relief valves are arranged on the temperature preservation pipeline; and the gas collecting prying block comprises a gas collecting prying block base, a gaseous natural gas storage tank and a temperature preservation pipeline. The device can achieve partial pipeline rapid precooling before unload and liquid adding, and has the function of collecting relieving gases, improves the safety and reliability, and reduces resource waste.

Description

technical field [0001] The invention relates to the field of liquefied natural gas, in particular to a vehicle unloading and liquid filling device and a method for unloading and liquid filling of a skid-mounted liquid filling station. Background technique [0002] LNG is the abbreviation of Liquefied Natural Gas in English. After natural gas is purified (removing impurities such as CO2, sulfide, hydrocarbons, and water), it is cryogenically cooled to -162°C under normal pressure, and changes from a gaseous state to a liquid state. It is called liquefied natural gas, and the volume of liquefied natural gas is the same The volume of gaseous natural gas is 1 / 625, the weight is about 45% of the same volume of water, no pollution, high heat. With the dwindling of oil resources, natural gas, as a clean energy source, gradually replaces gasoline and diesel as a new generation of vehicle fuel. The LNG refueling stations that have emerged are divided into fixed refueling stations an...

AI Technical Summary

Problems solved by technology

However, the current skid-mounted LNG refueling station has the following disadvantages: First, when the current skid-mounted LNG refueling station is unloading and refilling, the temperature of the LNG is below -162°C, and it will absorb gas directly into the normal temperature pipeline. The heat will cause a large amount of gasification, and the gasified natural gas will directly enter the storage tank or vehicle-mounted gas cylinder, which will cause the air pressure in the storage tank and vehicle-mounted gas cylinder to rise rapidly, which is not conducive to unloading and filling; second, prying The pipeline of the installed LNG filling station is heated unevenly. Due to gasification, there will often be a sudden increase in the local pipeline pressure. The usual filling device is only equipped with a relief valve on the LNG storage tank, resulting in a lack of necessary ventilation in the pipeline. Safety release system, the gas cannot be released quickly, and a large amount of gas accumulates in the pipeline, which greatly shortens the service life of the low-temperature pipeline and easily causes local pipeline rupture; When the pressure in the tank is greater than the set pressure value of the safety valve, a large amount of gaseous natural gas will be released directly into the air, resulting in a large amount of waste and the risk of explosion

Images