The Study of Evaluation About Safety Performance of Transportable Pressure Vessel

Author(s):  
Kejian An ◽  
Huipo Geng ◽  
Honglei Dong ◽  
Qian Zhang ◽  
Xiaoli Liu

Collisional safety is the most important factor for all kinds of vehicle development and manufacturing. Transportable pressure vessel should satisfy the vehicle collision safety requirement, and also should insure storage tank safety. Nowadays the vehicular collision safety research focuses on passenger vehicle. The safety evaluation is mainly concerned with the vehicle structure’s integrity and passengers degree of injury. The criteria of collision about transportable pressure vessel and the safety evaluation after collision is still not determined. This paper introduces the existing safety situation and related standards in both domestic (China) and overseas locations, and points out the direction of future study of collisional safety for the transportable pressure vessel.

2012 ◽  
Vol 569 ◽  
pp. 598-602 ◽  
Author(s):  
Eui Soo Kim ◽  
Jong Hyuk Kim ◽  
Byung Sun Moon ◽  
Jae Mo Goh

CNG vehicles have to be equipped with a safe and reliable storage tank, such as composite pressure vessels, since the failure of the CNG storage tank induces fatal damages to passengers. In this research, the cause of vessel facture is investigated through formal inspection and engineering test procedures. Specifically, the composite pressure vessel design will be validated using the finite element method. In order to validate values of the optimal design variables in accordance with standard of the high pressure gas safety management, we used safety probability such as Von-Mises yield criterion, Tsai-Hill theory and stress ratio.


2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Tetsuaki Takeda

When a depressurization accident of a very-high-temperature reactor (VHTR) occurs, air is expected to enter into the reactor pressure vessel from the breach and oxidize in-core graphite structures. Therefore, in order to predict or analyze the air ingress phenomena during a depressurization accident, it is important to develop a method for the prevention of air ingress during an accident. In particular, it is also important to examine the influence of localized natural convection and molecular diffusion on the mixing process from a safety viewpoint. Experiment and numerical analysis using a three-dimensional (3D) computational fluid dynamics code have been carried out to obtain the mixing process of two-component gases and the flow characteristics of localized natural convection. The numerical model consists of a storage tank and a reverse U-shaped vertical rectangular passage. One sidewall of the high-temperature side vertical passage is heated, and the other sidewall is cooled. The low-temperature vertical passage is cooled by ambient air. The storage tank is filled with heavy gas and the reverse U-shaped vertical passage is filled with a light gas. The result obtained from the 3D numerical analysis was in agreement with the experimental result quantitatively. The two component gases were mixed via molecular diffusion and natural convection. After some time elapsed, natural circulation occurred through the reverse U-shaped vertical passage. These flow characteristics are the same as those of phenomena generated in the passage between a permanent reflector and a pressure vessel wall of the VHTR.


2018 ◽  
Vol 3 (3) ◽  
pp. 21
Author(s):  
Barinyima Nkoi ◽  
Barinadaa Thaddeus Lebele-Alawa ◽  
Benedict Odobeatu

This research paper focuses on re-engineering design and fabrication of a modified potable biogas digester for the production of biogas as a renewable energy source for domestic use. Digesters used around the world are commonly big in size. There is need to modify and re-engineer an existing biogas digester to fit in to modern day design for better efficiency, portability and safety. Floating drum and Flexible balloon are digesters to be modified as a thin walled pressure vessel with radius-thickness ratio  greater than 10. ASME codes and standards were used to carry out the sizing calculations, thickness and pressure calculations for the cylindrical pressure vessel shells and also calculations for the storage tank hemisphere shell. AISI 304 (Chromium-Nickel steel) is used for the vessel shell and the maximum allowable stress is 137 MPa. Weld efficiency (85%), corrosion allowance (0.02mm),  of 24 (for digester),  of 18 (for collector) and  of 20 (storage tank). 17 kg of cow dung and 34 kg of water with temperature of 32oC were the raw materials used for this research to produce a cumulative gas volume of 0.1243 m3 for 30 days. Furthermore, a bike pump is modified and used to increase methane gas pressure from 4.903 kPa to 345 kPa to suit the modern day gas cookers design and storage tank. Unlike other biogas plant, an electronic smoke alarm detector (model: Ei100) is placed 300 mm below the digester top for effective fire protection. Series of tests were performed to ensure that the constructed prototype met the specifications/standards. Such test include, smoke detector test, pressure testing, gas leak test, and a unit test run also confirmed that the aim of research was achieved.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3885
Author(s):  
Dong Wang ◽  
Lili Zheng ◽  
Xichao Li ◽  
Guangchao Du ◽  
Zhichao Zhang ◽  
...  

Overdischarge often occurs during the use of battery packs, owing to cell inconsistency in the pack. In this study, the overdischarge behavior of 2.9 Ah cylindrical NCM811 [Li(Ni0.8Co0.1Mn0.1)O2] batteries in an adiabatic environment was investigated. A higher overdischarge rate resulted in a faster temperature increase in the batteries. Moreover, the following temperatures increased: Tu, at which the voltage decreased to 0 V; Ti, at which the current decreased to 0 A; and the maximum temperature during the battery overdischarge (Tm). The following times decreased: tu, when the voltage decreased from 3 to 0 V, and ti, when the current decreased to 0 A. The discharge capacity of the batteries was 3.06–3.14 Ah, and the maximum discharge depth of the batteries was 105.51–108.27%. Additionally, the characteristic overdischarge behavior of the batteries in a high-temperature environment (55 °C) was investigated. At high temperatures, the safety during overdischarging decreased, and the amount of energy released during the overdischarge phase and short-circuiting decreased significantly. Shallow overdischarging did not significantly affect the battery capacity recovery. None of the overdischarging cases caused fires, explosions, or thermal runaway in the batteries. The NCM811 batteries achieved good safety performance under overdischarge conditions: hence, they are valuable references for battery safety research.


2018 ◽  
Vol 207 ◽  
pp. 03014
Author(s):  
Shuai Fei ◽  
Xiangdong Li ◽  
Yali Fan

Starting from the development status of the lifting machinery industry, this paper analyzes the data about safety accidents of bridge cranes, and identifies the assessment indicators affecting the safety performance of bridge cranes based on fault tree analysis (FTA), including fatigue factors, human factors, environmental factors, and management factors. Then, the weights of safety evaluation indicators are determined based on analytic hierarchy process (AHP). Finally, the safety evaluation system is established and demonstrated with use case diagram and role flow chart.


Author(s):  
Syeda Rubaiyat Aziz ◽  
Sunanda Dissanayake

The Highway Safety Manual (HSM) provides models and methodologies for safety evaluation and prediction of safety performance of various types of roadways. However, predictive methods in the HSM are of limited use if they are not calibrated for local conditions. In this study, calibration procedures given in the HSM were followed for rural segments and intersections in Kansas. Results indicated that HSM overpredicts fatal and injury crashes and underpredicts total crashes on rural multilane roadway segments in Kansas. Therefore, existing safety performance functions (SPFs) must be adjusted for Kansas conditions, in order to increase accuracy of crash prediction. This study examined a way to adjust HSM calibration procedures by development of new regression coefficients for existing HSM-given SPF. Final calibration factors obtained through modified SPFs indicated significant improvement in crash prediction for rural multilane segments in Kansas. Additionally, obtained calibration factors indicated that the HSM is capable of predicting crashes at intersections at satisfactory level.


Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3230
Author(s):  
Wenxian Su ◽  
Xiao Feng

Storage tanks with partition plates are widely used in the petrochemical industry. However, relevant standards do not propose corresponding design criteria and methods for this type of structure, and theoretical design formulas cannot be applied to ensure the reliability of its structure. Therefore, it is necessary to analyze and design the storage tank with a partition plate by using finite elements. This paper studies the problem of buckling depression and cracks in the welded parts of the S-shaped tank with a partition plate during its operation. We used the finite element software ANSYS to analyze the overall strength and stability of the structure and obtain the larger stress area. Based on this, a safe and economical optimization plan is proposed: under the condition of strictly controlling the liquid level difference on both sides of the partition, the tank structure is optimized by adding stiffeners and tie rods. The study revealed that the measure effectively improves the overall rigidity of the tank body and reduces the maximum stress of the structure and enhances the safety performance of storage tank. Additionally, it provides a reference for the structural strength design of storage tanks with partition plates.


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