LPG Tank Research Articles

About Failure of the LPG Tank Fastening Welds on the Chassis of Trucks

Abstract The international road transport of dangerous goods is subject to strict regulations. Traffic realities and experiences accumulated as a result of periodic inspections of specific equipment (tanks) lead to their constant updating and improvement. This article is focused to a study related to the appearance over time of some cracks in the welded joints between the tank and the mounting supports on the truck chassis.

Modeling the behavior of LPG tanks exposed to partially engulfing pool fires

Accident scenarios leading to full or partial fire engulfment represent a serious threat to tanks used for the transportation and storage of dangerous goods. The present study focuses on the impact of partial engulfing fire scenarios on an LPG tank. An experimentally validated CFD modeling approach was further developed and applied to perform a parametric study by varying the exposure mode and the filling degree. The results of the simulations show that both these factors have a strong influence on the pressurization rate, the energy accumulation, and the high-temperature mechanical weakening of the tank structure. Fire scenarios where the flame zone is at the top or at the end of the tank are particularly critical when the liquid filling degree is low or medium. Liquid thermal stratification is evident in all the case studies analyzed and, in most of them, it strongly affects the vessel pressurization curve. The comparison to the results obtained using a lumped model showed that this provides non-conservative pressurization results for high filling levels (80%). The results show that a validated CFD approach can be used as a virtual workbench to support tank design within a digital twinning approach.

CFD simulations of instantaneously released liquefied gas in urban areas: A case study of LPG tank truck accident in Wenling, China

The accidental release and ignition of flammable liquefied gas can cause catastrophic events, such as flash fires, vapor cloud explosions, and boiling liquid expanding vapor explosion, which severely endanger urban residents and the environment. In the current study, a method for simulating liquefied gas instantaneous release accidents was established to explore the vapor cloud diffusion behavior in urban areas. The rare liquefied petroleum gas instantaneous release accident in Wenling, China is considered as a test case. To this end, an instantaneous release source model that considers the gas phase, liquid pool, and droplets was developed. The CFD model was validated using the damage distribution at the accident site. The simulation results revealed that droplets in the release source, terrains, and large obstacles significantly affected the dispersion behavior and extension distance of the vapor cloud. The evaporation of droplets resulted in a mushroom-shaped cloud. In addition, when the cloud was ignited, the area covered by the LFL was 1.94 and 2.07 times larger in the cases with droplets than those without. The method developed in this study is applicable to developing hazardous chemical transportation and emergency response measures in urban environments to maintain the sustainable cities development.

The Risk Calculation of Hazardous Zones Created By Flammable And Explosive Chemicals, LPG Tank Example

The determining of hazardous areas created by flammable and explosive chemicals is important to obtain a safe working environment. Taking precautions and prevent explosions require detailed investigations and accurate calculations instead of superficial and personal experience. In this context, possible leakages and leaks occurring around the LPG tank and its connections in a real enterprise were evaluated and the border of possible explosive atmosphere areas was calculated by the ALOAH program according to the TS 60079-10-1 standard. Based on the secondary discharge of the LPG from the bottom of the tank, the discharge characteristics were calculated as 4.946578 3.926692 m3/s at sonic and subsonic conditions respectively, and region radii, 10.8 m. The explosive atmosphere of the LPG tank was concluded that matched well the definition of Zone 2. The risk severity score of explosive atmospheres was calculated as 12 by using the risk assessment method of matrix system with approximations, possible in a week (3P), and the effect that could cause serious injury (4P). Serious threats and devastating effects were fictionalized clearly by explosion scenarios of the LPG tank. The calculations of explosive borders for flammable chemicals are necessary to prevent explosions, fires, and toxic effects of leaked chemicals by taking measurements on time. It is also necessary to calculate explosive areas and possible sceneries for each chemical separately for accurate results and effective control.

The Analysis of the LPG Storage Tank Planning Based on the Potential Demand in Belitung Island

The growing demand for LPG has increased the number of LPG tanker ships/gas carriers entering X Port, resulting in queues that will impede the distribution of LPG to the people of Belitung Island. PT XYZ in-tends to construct an LPG tank in the X Port area to facilitate LPG distribution on Belitung Island. The tank capacity is expected to meet Belitung Island’s LPG demand for the next five years. The authors forecast the potential demand for the next five years using LPG revenue data from January 2019 to February 2021, with forecasting results from March 2021 to February 2026. The Time Series Method was used to forecast by comparing the smallest MAD (Mean Absolute Deviation) values between the Linear Trend Model and the Exponential Trend Model. According to the forecasting calculations conducted using the linear trend mod-el, the potential demand for February 2026 is 973.4098 Tons with a ten-day stock resistance. According to these calculations, the proposed tank is a spherical tank with a capacity of 1000 tons, which means that the LPG tank stock resistance in the last period, namely February 2026, is 11 days, which is in compliance with the Regulation of the Ministry of Energy and Mineral Resources Number 26 of 2009 concerning the Provision and Distribution of Liquefied Petroleum Gas.

Simulation of LPG tank truck leakage and explosion accident based on CFD

Road transportation of hazardous chemicals has a high risk and is likely to cause serious road traffic accidents. In this paper, the most common LPG tanker in hazardous chemical transportation is taken as the research object. Based on theCFD method, we used FLACS software to simulate LPG tank car accident in Italy. The leakage process of LPG tank car after leakage was simulated, and the diffusion process of propane and butane mixture in one minute when the accident occurred. It was further analyzed that the leakage material exploded when it encountered the ignition source, and the shock wave overpressure was the highest at 2.5 seconds after the explosion, with the shock wave pressure exceeded 0.26MPa. Also, the attenuation of theblast wave is higher in the area far away from the explosion source. The research results can provide effective data support for on-site emergency disposal and personnel evacuation of similar accidents.

Numerical simulation analysis of leakage gas cloud explosion in LPG tank farm

a LPG tank farm model was established by FLACS software to simulate the leaking gas cloud explosion. The propagation process of explosion flame and the change process of explosion overpressure field and temperature field were studied under the influences of different leakage rate, wind speed and wind direction. The results show that, the larger the leakage rate is, the larger the impact area of gas cloud explosion is, the higher the explosion overpressure and temperature are. When the wind speed is larger than 4 m/s, the higher the wind speed, the faster the heavy gas will be diluted by the ambient gas, and the explosion will be suppressed. Under the influence of different wind directions, the impact area of explosion is also different.

Development of a predictive accident model for dynamic risk assessment of propane storage tanks

Investigation of past accidents has shown that LPG tank accidents cause significant damage to the industry due to the storage of large volumes of flammable materials in them. This study aimed for developing a predictive accident model for dynamic risk assessment of propane storage tanks of the refinery. Hazards and safety barriers were identified using MIMAH methodology. The basis of MIMAH methodology is Bow-tie method. To construct the Bow-tie diagram, first, accidents that occurred on LPG tanks were extracted from the databases of accidents and valid sources. The top events of the accidents were identified and analyzed by the fault tree. The Bow-tie diagrams were constructed and the barriers on the diagrams were identified and verified by refinery experts. According to the SHIPP model, safety barriers were categorized into seven main barriers. The failure rates of the fault tree basic events were extracted from reliable sources and the prior probability of barriers was calculated. Based on the failure or success of safety barriers, 6 levels of severity of consequences, safe, near miss, mishap, incident, and catastrophic accident were considered. Using the prior probability of failure of the barriers, the probability of occurrence of each level of severity of consequences was calculated with the event tree. In the next step, this paper employed LPG storage tanks past accidents to construct a likelihood function and update prior probability using the Bayesian equation. Finally, the posterior probability of occurrence of the consequences was calculated using the posterior probability of failure of the barriers. Because LPG accidents occur with low probability and high severity, predicting accidents dynamically helps people to always be prepared to prevent their occurrence.

Application of CFD model in an LPG tank explosion accident

In this research, a 3D tank farm model of a petrochemical plant was built in order to analyze an LPG tank explosion accident. Furthermore, the Computational Fluid Dynamic (CFD) algorithm was also applied to reconstruct the scenario of the accident. With its 3D dynamic abilities, the CFD simulation results can be used to facilitate the understanding of the spatial and transient distribution of different hazardous physical variables, which cannot be observed from the traditional methods.After the maximum physical variables of overpressure, pressure-impulse, and thermal radiation temperature were calculated, the results were adopted to estimate the corresponding 3D individual risk value. With the aid of the CFD simulation and the analysis method of maximum physical variable, the researchers can use the simulation results to scrutinize the possible causes and consequences of a chemical accident.

Insight into the safety distance of ground and underground installations in typical petrochemical plants

Petrochemical plants are continuously turning into large-size corporations, the installations of facilities show a developing trend from ground to underground because of the difference in land using rate. In this regard, the safety distance of petrochemical equipment buried in both ground and underground cases were investigated based on risk assessment. As a case study, gasoline tank and LPG tank set on the ground and underground are singled out to compare the risks involved. The research showed that the setting case of installation had a great influence on safety distance. Two cases have 80% reduction of equivalent safety distance compared with the rest of the cases. It was found that when the gasoline storage tank was placed underground alone, the PLL value decreased by 36.7%. Only LPG tank was placed underground, and the PLL decreased by 6.33%, and the gasoline and LPG storage tanks were placed underground simultaneously, the PLL value declined by 42.3%. Thus, the layout of plants could be further optimized, which can greatly improve the performances of land use efficiency and safety. In addition, this paper, the selection of embedding methods and the sensitivity of underground case to overpressure was resumed from two aspects: soil properties and burial depth. For the soil properties, it was found that the water saturated sandy soil with high air content and the low density unsaturated sandy soil had better effects on weakening overpressure. Such properties are particularly beneficial to reducing the occurrence rate of accidents. In terms of burial depth, it can be observed that as the burial depth was changed from 0.5m to 1.1m, the value of overpressure has dropped dramatically. When the burial depth was 2m, the damage to personnel and buildings has been greatly reduced beyond 2m from the explosion center.

Analysis of the impact of wildland-urban-interface fires on LPG domestic tanks

Managing Wildland-Urban-Interface (WUI) fires is a challenging task due to the inherent complexity of the WUI environment. To ensure the success of strategies for the protection of population and structures, safety measures have to be implemented at different scales (landscape, community and homeowner). The present study is focused on the homeowner scale and deals with the threat related to the presence of LPG domestic tanks in a WUI fire scenario. Recent accidents have demonstrated that the risk associated with this type of installation is real, but often disregarded by residents. A methodology was developed, providing a set of indicators that may easily be compared with risk acceptance criteria, assessing whether the integrity of an LPG tank exposed to WUI fire scenarios is compromised or not. The methodology is applicable to a vast range of situations and at a different level of detail according to available data. A number of case studies were carried out, showing that WUI fire scenarios impacting on domestic LPG tanks complying with regulations currently adopted in several Mediterranean countries cannot be deemed safe. The methodology proposed represents an advanced tool to assist on safety distances sizing to be prescribed by standards, driving regulators towards better-informed decision-making.

Effect of transient temperature on 304 stainless steel LPG tank structure using numerical simulation approach

The use of numerical simulation approach to investigate the effect of transient boundary temperature on an LPG tank structure was investigated. Here, both transient thermal and structural system were coupled in ANSYS software version 19.2 to create an interaction between the thermal and mechanical load on the tank structure. The focus of this paper is to identify stress hotspot which may eventually lead to stress-corrosion using a non-linear solver. Literature has proven that temperature gradient acting on a material is a possible cause for failure in most engineering structures due to stress induced corrosion. In this study the effect of a time dependent change in the temperature of the material (304 stainless steel) was investigated. The temperature was set to increase from cryogenic to 30 °C, and the pressure which represents mechanical load was also implemented at the wall boundary. Results obtained showed that stress was concentrated at the principal plane connecting the tank roof to the cylindrical structure. However, a failure analysis was conducted were the mechanical load was increased to 3 × 1043 Pa. It was found that the material failed after 1,000,000 s time steps and the tensile yield strength obtained from the stress–strain curve was lower than the material standard value. This can be explained with the concept that the action of temperature disrupted the material microstructure, hence, reduced the material stiffness to fracture. The stress–strain curve was validated with the standard plot for the 304 stainless steel material type.

Collision detection and response of multibody systems using a position difference method and non-interpenetration constraint in shipbuilding simulation

Collision detection and response between the block model in shipbuilding simulation are one of the most difficult issues in dynamic analysis. The existing collision programs are not appropriate to be applied in this domain because the model has unclosed meshes and very sharp edges. Therefore, this study proposed a position difference method to detect collision between unclosed meshes. This method calculates the intersection between the previous and current positions of the two meshes. Moreover, because the shape of the colliding body in the shipbuilding industry has too many meshes, it takes too much time to detect collision between two bodies. To increase performance, this study adopted a boundary volume hierarchy which is a kind of space-partitioning algorithm and exclusion boxes which exclude meshes inside boxes. For the collision response, this study derived a force-based method based on the non-interpenetration constraint to calculate the collision normal and tangential forces. This method can be applied to the multibody system and to consider material properties such as restitution coefficient and softness. As a result, it is successfully applied to the dynamic analysis of LPG tank erection by using a floating crane. The collision force between the tank and the hull structure is calculated due to the motion of the floating crane induced by environmental loads.

Static and Time History Earthquake Analysis of LPG Spherical Steel Tanks in Iraq

Spherical storage tanks are widely used in Iraq for store hazardous liquid petroleum gas LPG which, thus it must be adequately designed for seismic actions. This paper present static and time history analysis of LPG tanks in Iraq using UBC97 code. The time history analysis accomplished by using three artificial earthquakes generated using SIMQKE_GR program in additional to El Centro earthquake records scaled according to PGA. The investigations were performed on the tank in Maysan province which was selected to be representative the other tanks in Iraq due to recently seismic activity in Maysan. The study comprised finite element modeling using STAAD Pro program for the estimation of the dynamic and static responses of the tank structure. The study is performed for both conditions of empty tank and at operating with 100% fill of LPG. The description of the properties and allowable stresses LPG tank used in Iraq is presented. Its concluded that time history analysis govern the tank behavior. The dynamic magnification factor of 1.4 for displacements and stresses was obtained which reflect the importance of dynamic analysis. The stresses of columns and sphere are within allowable limits except at sphere/column connection which slightly exceed the allowable limit, while the stresses in diagonal bracings are exceed the yielding limit thus double angle section is inadequate

Analysis of tank safety with propane-butane on LPG distribution station

Abstract An analysis of the risk of failure in the safety valve – tank with propane-butane (LPG) system has been conducted. An uncontrolled outflow of liquid LPG, caused by a failure of the above mentioned system has been considered as a threat. The main research goal of the study is the hazardous analysis of propane-butane gas outflow for the safety valve – LPG tank system. The additional goal is the development of an useful method to fast identify the hazard of a mismatched safety valve. The results of the research analysis have confirmed that safety valves are basic protection of the installation (tank) against failures that can lead to loss of life, material damage and further undesired costs of their unreliability. That is why a new, professional computer program has been created that allows for the selection of safety valves or for the verification of a safety valve selection in installations where any technical or technological changes have been made.

Моделирование поведения железнодорожной цистерны с СУГ в очаге пламени

Моделирование поведения железнодорожной цистерны с СУГ в очаге пламени

An innovative framework for determining the damage probability of equipment exposed to fire

When considering a quantitative risk assessment of domino effects in chemical process facilities, the Damage Probability of equipment exposed to Fire (DPF) is a key element. In this paper, an innovative framework is proposed to determine the DPF, and the approach is demonstrated using a vertical plate. Being different from the current Probit model, structural reliability methods are applied to a pre-established lumped temperature model to obtain the DPF. Moreover, the static and dynamic DPF are distinguished, where the static one is obtained through the first-order reliability method and response surface method with an innovation in the pre-analysis of stable state to derive the limit state equation, while the dynamic one is obtained solving the Kolmogorov backward equation using the finite difference method based on stochastic diffusion process and first passage failure theories. The vertical plate demonstration shows the feasibility and availability of the proposed framework. A more practical case study with a horizontal LPG tank is also discussed to validate the suggested approach.

FIRE AND EXPLOSION CONSEQUENCE ANALYSIS ON LPG (LIQUEFIED PETROLEUM GAS) TANK IN PT SURYA ESA PERKASA TBK PALEMBANG

Background: LPG plant has fires and explosions hazard which can occur due to a processing, storing, or distributing failure. PT Surya Esa Perkasa Tbk is one of LPG plant in Indonesia which has a high risk of fire and explosion due to leakage of the 150 tons capacity tank. Therefore, it is necessary to analyze the consequences of fire and explosion on the LPG tank in PT Surya Esa Perkasa Tbk Palembang. Method: This study was a descriptive research with quantitative approach. The consequence analysis will be made jet fire, fireball/BLEVE, flammable area/flash fire, and vapor cloud explosion (VCE) modeling by using ALOHA (Areal Location of Hazardous Atmosphere) software 5.4.4 version. The farthest threat zone will be analyzed to know the number of population at risk and analysis of emergency response plan (procedures, teams, facilities and infrastructure) which had been applied. Result: Jet fire modeling threat zone reached 150 meters, BLEVE modeling reached 1.3 kilometers, flammable area modeling reached 911 meters, and VCE modeling reached 398 meters. Population at risk was 81 workers. The application of emergency response plan (ERP) from procedure, team, and facilities aspects had been good but there were no ERP intended for surrounding communities. Conclusion: BLEVE modeling has the farthest consequences reaches 1.3 kilometers with 81 people as population at risk and ERP had been well implemented by PT Surya Esa Perkasa Tbk for workers but it still had no ERP for surrounding community. Keywords: working population at risk, emergency response plan.

BLEVE를 고려한 LPG 시설 Siting 분석

In previous studies on LPG siting in Korea, the scope have not included the probability of the secondary events of adjacent LPG tanks or structures from an explosion source. Therefore, it is essential to first identify the phenomenon which can be caused by BLEVE and then, properly assess their effects to each target including secondary event. In this study, we calculated the effects from a potential BLEVE of 15 ton LPG tank causing damages of storage tanks (LPG), structures and human using Phast ver. 6.7 and then suggested three risk zones (Zone I, II, III) assuming the consequences such as overpressure, heat radiation and missile effect by fragments. Zone I and II are divided at the line of 50% occurrence of the secondary event. Zone II and III are divided by Individual Risk(IR). The zone approach in this study can be used for more effective and safer Land Use Planning (LUP) for the future.

Study on affecting factors of temperature–pressure–stress-coupled field of lpg tank under fire based on Legendre wavelet finite element method

In recent years, many explosion accidents of LPG (Liquefied Petroleum Gas) tank happen due to fires, temperature-pressure-stress coupled field parameters of LPG tank under fire change nonlinearly, which are affected by many factors, such as fire type and filling rate. In order to improve the computing efficiency, the Legendre wavelet function is combined with traditional finite element to construct the Legendre finite element, and the effect of every affecting factor on changing rule of coupled field of LPG tank under fire can be analyzed effectively. First, the basic property of Legendre wavelet is analyzed. Second, temperature–pressure–stress-coupled model of LPG under fire is constructed; the temperature-pressure-stress coupled Legendre wavelet finite element is established; and then the effect of every affecting factor on coupled field of LPG tank under fire is obtained. Results show that analysis precision based on Legendre wavelet finite element method can be improved effectively.