Numerical Analysis of Gas Leakage Problem Based on Improved Gas Storage Vessel Leakage Model

2016 ◽  
Author(s):  
Liping Sun ◽  
Zhiqiang Wan ◽  
Shangmao Ai ◽  
Jiaji Li
Keyword(s):  
Gas Storage ◽  
Differential Method ◽  
Residual Pressure ◽  
Gas Treatment ◽  
Storage Vessel ◽  
Leakage Model ◽  
Gas Leakage ◽  
Matlab Program ◽  
Residual Amount ◽  
Time Point

The gas leakage accidents always lead to great damages in the process of off-shore oil and gas treatment, consisting of health, wealth and environment losses. When leakage happens, the leakage duration, leak amount and other corresponding parameters are very important on the topic of emergency reaction and decision. The leaking process is complex and cumbersome, so the solving of the leakage problem could be quite difficult. On this point view, a specific and direct solution is given to the leakage problem on the basis of the leakage theory in this paper. According to the improved gas storage vessel leakage model, the mathematical differential method and discretization method are conducted to calculate the result of gaseous container leakage of any kind, consisting of leakage duration, leak amount, residual amount of gas and the residual pressure in the container. There are two probable flowing state of gas during the leakage. So, there is a requirement for different solving methods and principles for gas leakage in different flowing states. There is also calculation for residual amount of gas and residual gas pressure in the container at any given time point. The MATLAB program language is conducted to design the specific computing program and finish the GUI achievement of the program according to the fixed calculative methods and parameters concerned. Carry out the calculation of a fictive leakage problem with the designed MATLAB program, and get the result. It shows that the computing program comes to good leakage result, and the program can also result in acceptable outcome at any chosen time point on the issue of calculating residual amount and residual pressure of gas in the container. The computing program can solve the leakage problem veritably to some degree.

Research on sealing characteristics of annular power cylinder based on twin-rotor piston engine

2021 ◽  
pp. 095440622110214
Author(s):  
Dibo Pan ◽  
Haijun Xu ◽  
Bolong Liu ◽  
Congnan Yang
Keyword(s):  
Compression Ratio ◽  
Simulation Analysis ◽  
Piston Engine ◽  
Leakage Model ◽  
Gas Leakage ◽  
Power Cylinder ◽  
Sealing Performance ◽  
Piston Seal ◽  
Realization Process ◽  
Twin Rotor

The sealing characteristics of an annular power cylinder based on the Twin-rotor piston engine are studied, which provides a theoretical foundation for the sealing design of a new high-power density piston engine. In this paper, the basis thermodynamic realization process of an annular power cylinder is presented. The Runge Kutta equation is used to establish the coupled leakage model of adjacent working chambers under annular piston seal. And the sealing performance of the annular power cylinder is analyzed in detail. Moreover, the influence of rotor speed and compression ratio on the sealing characteristics and leakage is studied. Finally, some tests are carried out to verify the sealing principle and simulation results, which verifies the theoretical basis of simulation analysis. Results show that there are double pressure peaks in the leakage chamber between two working chambers, which is beneficial to reduce the leakage rate. Besides, increasing the speed and decreasing the compression ratio can help to reduce gas leakage. Furthermore, the effects of speed variation on the leakage are only significant when rotating at low speed. Changing the compression ratio has a greater effect on the slope of the leakage curve at a low compression ratio, and the lower the compression ratio, the better the sealing effect.

Analysis of the Pressure and the Gasleak of the Piston Ring of a New Double-Rotor Engine

2014 ◽  
Vol 620 ◽  
pp. 104-110
Author(s):  
Wen Min Li ◽  
Cun Yun Pan ◽  
Jin Zhou Chen
Keyword(s):  
Numerical Solution ◽  
Strong Evidence ◽  
Rotational Speed ◽  
Piston Ring ◽  
Gas Leakage ◽  
Matlab Program ◽  
Room Volume

This paper modeling the piston ring of a new double-rotor engine based on the analysis, use Matlab program some code and woke out the numerical solution of the model,analyze the change of the gas leakage in the condition of different gas-room volume, different opening area, different spindle rotational speed, which provide strong evidence for improving sealing of the new double-rotor engine and ameliorating sealing design.

scholarly journals Seepage and Heat Transfer Characteristics of Gas Leakage under the Condition of CAES Air Reservoir Cracking

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Fa Wan ◽  
Zhong-Ming Jiang
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Gas Storage ◽  
Heat Transfer Process ◽  
Surrounding Rock ◽  
Compressed Air ◽  
Heat Transfer Characteristics ◽  
Gas Reservoir ◽  
Gas Leakage ◽  
Transfer Characteristics

The contradiction between supply and demand of energy leads to more and more attention on the large-scale energy storage technology; Compressed Air Energy Storage (CAES) technology is a new energy storage technology that is widely concerned in the world. The research of coupled heat transfer and seepage in fractured surrounding rocks is the necessary basis to evaluate the operation safety and effectiveness of CAES. Current studies point to the possibility of cracking in concrete liner seals, but the thermodynamic processes and leakage characteristics of compressed air in the presence of cracking and the heat transfer characteristics of seepage have not been addressed and reported. In order to investigate the leakage, the gas seepage and heat transfer law in fractured rock when the hard rock CAES gas reservoir seal cracks, the COMSOL fracture Darcy module, and the non-Darcy Forchheimer model are used as the constitutive seepage. The global ODE is used to calculate the thermodynamic process of compressed air in gas storage with coupled seepage and heat transfer process. The pressure and temperature of compressed air are obtained as the unsteady boundary of the seepage heat transfer model. A program for calculating the seepage and heat transfer characteristics of fractured surrounding rock in the CAES gas reservoir is established. On this basis, with the proposed Suichang CAES cavern as the background, the seepage and heat transfer characteristics of the fractured surrounding rock of the gas storage are studied. The results showed that when there are fewer cracks in the lining and surrounding rock of the air reservoir, the air pressure decreases due to a small amount of air leakage after 30 operation cycles, and the leakage rate of each cycle is 0.7% of the gas storage capacity, but it still meets the engineering requirements. If the plant is operating under these conditions, the charging rate will need to be increased by 1.2 kg/s per cycle charging stage. In the discharging and power generation phase, the high-pressure air that previously percolated into the rock mass cracks could flow back into the air storage through the lining cracks. Therefore, it is incorrect and unreliable to consider the gas which flows out from the inner surface of the lining as unusable. When the lining crack width is less than 0.3 mm, the seepage flow is Darcy flow and the non-Darcy effect can be ignored; when the lining crack width is greater than 0.5 mm, the non-Darcy effect of seepage cannot be ignored. The gas velocity in the surrounding rock fracture medium is on the order of 0.01 m/s with an influence range of over 100 m, and the gas velocity in the pore medium is on the order of 10-6 m/s with an influence range of 50 m. The findings of this study contribute to a better understanding of the interaction between the thermodynamic properties of compressed air and the seepage heat transfer process in compressed air storage underground reservoirs, as well as the gas leakage process in the event of liner seal cracking.

Research on gas leakage and collapse in the cavern roof of underground natural gas storage in thinly bedded salt rocks

2020 ◽  
Vol 31 ◽  
pp. 101669 ◽  
Author(s):  
Wei Liu ◽  
Zhixin Zhang ◽  
Jinyang Fan ◽  
Deyi Jiang ◽  
Zhengyi Li ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Storage ◽  
Natural Gas Storage ◽  
Salt Rocks ◽  
Gas Leakage

Liquefied natural gas ship-to-ship bunkering chain planning: Case studies of Busan, Singapore, and Rotterdam ports

2016 ◽  
Vol 231 (2) ◽  
pp. 511-520
Author(s):  
Joohee Lee ◽  
Jiheon Ryu ◽  
Hyun Chung
Keyword(s):  
Integer Programming ◽  
Natural Gas ◽  
Case Studies ◽  
Programming Model ◽  
Gas Storage ◽  
Liquefied Natural Gas ◽  
Great Promise ◽  
Technical Feasibility ◽  
Gas Treatment ◽  
Proposed Model

Liquefied natural gas–fuelled ships, beginning with small-sized ships produced in the 2000s to large merchant ships, are expected to show a rapid increase in number. According to Lloyd’s Register, liquefied natural gas shows great promise as fuel for new ships. In line with this trend, it is necessary to establish adequate infrastructure for liquefied natural gas fuelling systems. In the bunkering chain, bunkering shuttles retrieve fuel from the terminals to fuel liquefied natural gas–fuelled ships berthing at the ports. Many researches have dealt with the technical feasibility or the necessity of ship-to-ship bunkering considering the liquefied natural gas bunkering processes, but none has covered them at the same time. This study examines the liquefied natural gas ship-to-ship bunkering chain considering the technically feasible combinations of liquefied natural gas storage and boil off gas treatment system. The suggested method decomposes this large infrastructure problem into two steps, which are pre-processing to estimate port statistics and integer programming model. The model can represent any port as long as the port’s ship statistics and their data are provided. We select three major ports with high liquefied natural gas bunkering potential as case studies to verify the proposed model.

Model Study of Foam as a Sealant for Leaks in Gas Storage Reservoirs

1970 ◽  
Vol 10 (01) ◽  
pp. 9-16 ◽  
Author(s):  
George G. Bernard ◽  
L.W. Holm
Keyword(s):  
Gas Flow ◽  
Pore Space ◽  
Economic Loss ◽  
Gas Storage ◽  
Flow In Porous Media ◽  
Underground Gas Storage ◽  
Foaming Agents ◽  
Storage Reservoir ◽  
Gas Leakage ◽  
Storage Reservoirs

Abstract Previous studies have shown that foam, because of its unique structure, reduces gas flow in porous media. This blocking action of foam appears to be especially suitable for sealing leaks in underground gas storage reservoirs. Such reservoirs often have permeable areas in the overlying caprock that allow permeable areas in the overlying caprock that allow vertical migration of gas from the storage zone to the upper formations. The escaped gas represents both a safety hazard and an economic loss. Our objectives in this study were to evaluate the effectiveness of foam in preventing the escape of gas from a leaky gas storage reservoir and to find the foaming agents that were most suitable for this purpose. We simulated the behavior of a leaky gas reservoir with a sandstone model and found that foam was 99-percent effective in reducing leakage of gas through the model. The amount of foaming agent required to seal a leak depends on the adsorption-desorption properties of the agent. After testing many foaming agents, we concluded that best results are obtained with certain modified anionic esters of relatively low molecular weight. Less than 0.3 lb of such agents is required per barrel of pore space in Berea sandstone. This study indicates that foam generation should be an effective and economical method for reducing or stopping gas leakage from an underground storage reservoir. Introduction The practicality of underground gas storage is greatly dependent upon the confinement that the caprock provides for the formation to be used as a storage reservoir. In spite of numerous precautions, several gas storage projects are plagued by vertical migration of gas from the intended storage zone to upper formations. Such gas leaks pose a safety hazard and represent an economic loss. If leakage is very high, the storage operation may be uneconomical. In at least one cases the leak problem is minimized by periodically collecting the escaped gas from the upper formation and reinjecting it into the storage reservoir. While such a solution is feasible, it is economically unattractive because the leak limits pressures and gas injection rates. Furthermore, energy must be expended in order to circulate the escaped gas. Recent studies have shown that foam, because of its unique structure, reduces gas flow in porous media. This blocking action of foam appears to be uniquely suitable for sealing leaks in underground gas storage reservoirs. Our objectives in this study were to determine the effectiveness of foam in reducing gas flow in a model of a "leaky" gas storage reservoir and to find foaming agents most suitable for this purpose. APPARATUS AND PROCEDURE PREPARATION OF THE MODEL PREPARATION OF THE MODELA laboratory model representing an estimated area of gas leakage in an Illinois gas storage reservoir was constructed of 24-in. × 6-in. × 1-in. Berea sandstone (See Fig. 1). The model was coated with Hysol plastic. The model represented an area of the reservoir approximately 600 ft wide, 2,400 ft long and 100 ft thick. The section contained about 2,000,000 bbl of pore space. The major portion of the reservoir is upstream of the inlet to this estimated area of leakage. The model, then, was geometrically scaled to this area of leakage in the reservoir. Distribution channels were installed on both ends of the model to permit linear gas flow through its entire width and thickness. Three injection wells were drilled into the model about one-third the distance from the inlet to the outlet. SPEJ P. 9

Reliability Analysis of Type III Gas Storage Vessel Under Pressure Loading

2019 ◽  
Vol 19 (2) ◽  
pp. 445-452 ◽  
Author(s):  
A. Ghouaoula ◽  
A. Hocine ◽  
M. Hadj Meliani ◽  
A. Maizia ◽  
Rami Suleiman
Keyword(s):  
Reliability Analysis ◽  
Gas Storage ◽  
Pressure Loading ◽  
Storage Vessel ◽  
Type Iii
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