Improvement of the Liquefied Natural Gas Vapor Utilization System Using a Gas Ejector

Abstract

The production, transportation, and storage of liquefied natural gas (LNG) is a promising area in the gas industry due to a number of the fuel’s advantages, such as its high energy intensity indicators, its reduced storage volume compared to natural gas in the gas-air state, and it ecological efficiency. However, LNG storage systems feature a number of disadvantages, among which is the boil-off gas (BOG) recovery from an LNG tank by flaring it or discharging it to the atmosphere. Previous attempts to boil-off gas recovery using compressors, in turn, feature such disadvantages as large capital investments and operating costs, as well as low reliability rates. The authors of this article suggest a technical solution to this problem that consists in using a gas ejector for boil-off gas recovery. Natural gas from a high-pressure gas pipeline is proposed as a working fluid entraining the boil-off gas. The implementation of this method was carried out according to the developed algorithm. The proposed technical solution reduced capital costs (by approximately 170 times), metal consumption (by approximately 100 times), and power consumption (by approximately 55 kW), and improved the reliability of the system compared to a compressor unit. The sample calculation of a gas ejector for the boil-off gas recovery from an LNG tank with a capacity of 300 m3 shows that the ejector makes it possible to increase the boil-off gas pressure in the system by up to 1.13 MPa, which makes it possible to not use the first-stage compressor unit for the compression of excess vapours.

Development of the automated temperature control system of the main gas pipeline

“…The papers 23 , 24 describe the tasks of ensuring the safe operation of oil and gas pipelines. In the other studies conducted by scholars, they analyzed the need to develop a thermal field control system in various operating conditions and pipeline operating conditions 25 – 33 . Thus, in works 34 , 35 the authors analyzed the existing problem of pipeline systems safety.…”

Predicting Service Life of Polyethylene Pipes under Crack Expansion using "Random Forest" Method

“…With the improvement of raw material performance, the resistance of PE pipes to crack sprouting and to rapid crack expansion has dramatically increased. Most of the methods for rapid crack evaluation of PE pipes [14][15][16] *Corresponding Author Email: 75829472@qq.com (T. Yifan) generally suffer from complex experimental conditions and poor reproducibility, which seriously restrict the development process of PE pipes [17][18][19]. There are still many blank areas for research exploration in various aspects of PE pipe manufacturing, welding and laying, testing and maintenance.…”

Experimental Determination of the Flow Coefficient for a Constrictor Nozzle with a Critical Outflow of Gas

“…Based on the analysis of the problems of the energy market [1][2][3] and the current green energy agenda [4][5][6], it may be concluded that the issues of waste energy source recovery are among the most pressing. For liquefied natural gas (LNG), one of the possible ways to solve this issue is the recovery and recycling of its boil-off gas, which nowadays is discharged from the LNG tanks using ejectors [7][8][9]. The use of the ejectors as energy-efficient pumps was the subject of the works of the authors [10][11][12][13]; the works of the scientists [14][15][16] are dedicated to the outflow of gases and liquids from the nozzles of different designs-these are the main components of the ejectors; the papers of the authors [17,18] deal with the calculation of the nozzle geometry and its computer modelling.…”