Liquefied Petroleum Gas Storage Tank Research Articles

Ultrasonic testing and Monitoring of Hydrogen blistering and Hydrogen-induced Cracking of LPG Storage Tanks

Due to the presence of various corrosive chemicals in LPG (liquefied petroleum gas, or propane) storage tanks, it is very likely to cause different degrees of corrosion in the tank and derive various defects. This article analyzes the main characteristics and types of defects found in storage tanks and provides an overview of ultrasonic testing and monitoring of defects such as hydrogen blistering and hydrogen-induced cracking.

Consequence Analysis of An Industrial Accident at a Fuel Station

Major industrial accident is a type of technological disaster that may require extraordinary intervention in areas outside the facility, in addition to those affected within the facility. It causes damage to the environment and loss of life at the time it occurs or afterward. Studies to be carried out to prevent these accidents Zor to reduce their effects are important. In this study, a case study for the consequences of an industrial accident that may occur in a fuel station was analyzed. Firstly, possible accident scenarios were created by obtaining chemical, atmospheric and source data. The LPG (Liquefied Petroleum Gas) storage tank (40m3) was considered in modeling a fuel station in the Korfez district of Kocaeli province, where the industry is dense in Turkey. The average atmospheric data of the province for the months of August and January were used to represent summer and winter conditions, respectively. Threat zones were produced with ALOHA (Areal Locations of Hazardous Atmospheres) software based on a release to atmosphere without burning, a jet fire as a result of a leak in the LPG tank and BLEVE scenarios. The two most dangerous scenarios were determined as a possible jet fire in August and a possible BLEVE (Boiling Liquid Expanding Vapor Explosion) in January. Overpressure effects were also obtained using the BST (Baker-Strehlow-Tang) method, thus ensuring the validation. With the software, the vapor cloud explosion distance as a result of the leak in August was obtained as 456m and 268m for the yellow (6.89kPa) and orange (24.13kPa) threat zones, respectively. Overpressure in an area of 500 meters was calculated as 5.06kPa with BST method. This calculated overpressure has the potential for damage that can lead to glass and window breakage in parallel with the ALOHA output. It has been determined that indirect injuries may occur to living beings.

Experimental evaluation and quantitative modeling of thermal behavior of surface-attached insulation polymers and steel structures under combustion

The surfaces of liquefied petroleum gas (LPG) storage vessels are usually coated with polymer insulation to maintain low temperatures. However, this insulation layer poses a potential fire risk. This study aimed to investigate the heat feedback mechanism and its impact on steel structures when bonded thermal insulation materials combust. Thermal insulation materials were bonded to Q345 steel surface, which is commonly used in LPG storage tanks, and experiments were conducted by designing a burning experimental rig of the combustible material attached to steel plate. Results revealed the existence of an equivalent temperature layer in the flame zone above the insulation material. Equations for predicting radiative and convective heat feedback were formulated. As combustion of the insulation material stabilized, the predicted heat feedback from the equations closely matched experimental values. A quantitative evaluation method, based on the inverse heat transfer problem, was proposed. This method determines the thermal decay function of heat feedback through the insulation material and steel plate. By establishing three key performance indicators, this work achieved independent quantification of potential thermal concerns and robustness evaluations of steel structures with surface-bonded insulation materials under combustion.

Unavailability Assessment Based on Improved-Dependent Uncertain Ordered Weighted Averaging Operator and Fault Tree Analysis

The fire-fighting system is one of the proactive technical barriers related to liquefied petroleum gas storage tank safety. This paper presents an integrated approach that uses fuzzy set theory, an improved-dependent uncertain ordered weighted averaging operator and fault tree analysis to handle uncertainty in the unavailability assessment of fire-fighting systems. In this study, the center of area is used to defuzzify triangular fuzzy numbers. Furthermore, for the fire-fighting system fault tree, importance analysis, including Fussell–Vesely importance measure and risk reduction worth of basic events, are performed to identify the weak links of the fire-fighting system. In addition, a real case study on a fire-fighting system for a liquefied petroleum gas storage system in an LPG unit in Algeria is provided to illustrate the effectiveness of the proposed methodology. The research results show that the proposed methodology makes it possible to assess the unavailability of the entire system by analyzing weak links. Consequently, some suggestions are given to take preventive–corrective actions in advance, in order to reduce the failure probability of fire-fighting system and assist the practitioners in setting priorities for improving safety procedures in liquefied petroleum gas storage tanks. The study provides references for analyzing safety barriers in a complex system.

Optimization the reliability of emergency safety barriers based on the subjective safety analysis and evidential reasoning theory. Case study

PurposeThis study aims to improve the reliability of emergency safety barriers by using the subjective safety analysis based on evidential reasoning theory in order to develop on a framework for optimizing the reliability of emergency safety barriers.Design/methodology/approachThe emergency event tree analysis is combined with an interval type-2 fuzzy-set and analytic hierarchy process (AHP) method. In order to the quantitative data is not available, this study based on interval type2 fuzzy set theory, trapezoidal fuzzy numbers describe the expert's imprecise uncertainty about the fuzzy failure probability of emergency safety barriers related to the liquefied petroleum gas storage prevent. Fuzzy fault tree analysis and fuzzy ordered weighted average aggregation are used to address uncertainties in emergency safety barrier reliability assessment. In addition, a critical analysis and some corrective actions are suggested to identify weak points in emergency safety barriers. Therefore, a framework decisions are proposed to optimize and improve safety barrier reliability. Decision-making in this framework uses evidential reasoning theory to identify corrective actions that can optimize reliability based on subjective safety analysis.FindingsA real case study of a liquefied petroleum gas storage in Algeria is presented to demonstrate the effectiveness of the proposed methodology. The results show that the proposed methodology provides the possibility to evaluate the values of the fuzzy failure probability of emergency safety barriers. In addition, the fuzzy failure probabilities using the fuzzy type-2 AHP method are the most reliable and accurate. As a result, the improved fault tree analysis can estimate uncertain expert opinion weights, identify and evaluate failure probability values for critical basic event. Therefore, suggestions for corrective measures to reduce the failure probability of the fire-fighting system are provided. The obtained results show that of the ten proposed corrective actions, the corrective action “use of periodic maintenance tests” prioritizes reliability, optimization and improvement of safety procedures.Research limitations/implicationsThis study helps to determine the safest and most reliable corrective measures to improve the reliability of safety barriers. In addition, it also helps to protect people inside and outside the company from all kinds of major industrial accidents. Among the limitations of this study is that the cost of corrective actions is not taken into account.Originality/valueOur contribution is to propose an integrated approach that uses interval type-2 fuzzy sets and AHP method and emergency event tree analysis to handle uncertainty in the failure probability assessment of emergency safety barriers. In addition, the integration of fault tree analysis and fuzzy ordered averaging aggregation helps to improve the reliability of the fire-fighting system and optimize the corrective actions that can improve the safety practices in liquefied petroleum gas storage tanks.

Study of the situation deduction of a domino accident caused by overpressure in LPG storage tank area

The production and storage of liquefied petroleum gas (LPG) is gradually becoming larger and more intensive, which greatly increases the risk of the domino effect of an explosion accident in a storage tank area while improving production and management efficiency. This paper describes the construction of the domino effect scene of an explosion accident in an LPG storage tank area, the analysis of the characteristics of the LPG tank explosion shock wave and the target storage tank failure, and the creation of an ANSYS numerical model to derive the development trend and expansion law of the domino accident in the LPG storage tank area. The research showed that: 400 m3 tank T1 explosion shock waves spread to T2, T4, T5, T3, and T6, and the tank overpressures of 303 kPa, 303 kPa, 172 kPa, 81 kPa, and 61 kPa respectively. The critical values of the target storage tank failure overpressure-range threshold were 70 kPa and 60 m. After the explosion of the initial unit T1 tank, at 38 ms, the T2 and T4 storage tanks failed and exploded; at 56 ms, the T5 storage tank exploded for the third time; at 82 ms, the T3 storage tank exploded for the fourth time; and at 102 ms, the T6 storage tank exploded for the fifth time. With the increase of explosion sources, the failure overpressure of the target storage tank increased, and the interval between explosions continuously shortened, which reflected the expansion effect of the domino accident. The domino accident situation deduction in the LPG storage tank area provided a scientific basis for the safety layout, accident prevention and control, emergency rescue, and management of a chemical industry park.

Modeling the consequences of gas leakage and explosion fire in liquefied petroleum gas storage tank in Istanbul technical university, Maslak campus

AbstractOne of the substances with high potential to cause damage that is used widely in chemical plants is liquefied petroleum gas (LPG). The aim of the present study is to model the consequences of leakage from a storage tank containing LPG using different scenarios. ALOHA software was used as one of the best modeling programs for identification of emergency responses required at the time of the gas leakage based on modeling results. According to ALOHA program modeling results, the area called TEEL‐3 was located within a distance of 187 m from the tank, and the threat to people in this area was determined. In case of LPG leakage from the storage tank, the concentration of LPG was about 2100 ppm which is equal to the lower explosive limit at the distance of 187 m. The consequences of combustion and explosion of LPG gas at a distance of 65 m from the storage tank were the most serious danger that threatens humans. This paper has an important role in modeling the harmful effects of the release of LPG and hazardous substances in different scenarios.

Means of refueling gas&cylinder cars. Lecture № 7. Part 3. Features of operation of stationary automobile gas filling stations with liquefied petroleum gas (LPG)

The characteristics and master plan of a stationary automobile gas filling station (AGPS) of liquefied petroleum gas (LPG) with ground and underground reservoirs are presented. A schematic diagram of architectural and planning solutions of a stationary gas station is presented. The requirements for the maintenance of the territory, buildings and structures of the gas filling station are set out. The calculation of the required number of filling columns and filling stations is given. The calculation of the gas consumption of LPG AGZS is given. The feature of inspection and filling of LPG storage tanks is formulated. Keywords liquefied hydrocarbon gas; architectural solutions; underground and overground station; exploitation stations; the inspection of tanks; gas equipment; filling tanks; the calculation of fuel dispensers and gas stations

Improved quantitative risk model for integrity management of liquefied petroleum gas storage tanks: Mathematical basis, and case study

AbstractChemical, petrochemical, and refinery sectors have been facing tougher safety, environmental and mechanical integrity regulations as well as challenges associated with the need for cost reduction to improve competitiveness. Risk‐based Inspection (RBI) is a cost‐effective approach to manage operational risks by making an informed decision on inspection frequency, extent of inspections, and types of non‐destructive testing. This paper presents a comprehensive practical risk model that can simulate all components of liquefied petroleum gas (LPG) tanks, that is, roof, shell, nozzles, and bottom plates. The probability of failure (PoF) model was developed based on failure frequency data from four different sources to determine the adequate general failure frequencies, moreover, it addresses the fatigue effect due to cyclic loading. Reviewing past losses of containment incidents revealed that fires and explosion are the most likely outcomes, therefore, this risk model introduced area affected consequence of failure (CoF) simulation. The CoF model addresses all the main components of the LPG tank and deploys a practical gas dispersion model to estimate the vapor cloud explosion (VCE) and flash fire consequence affected areas. Furthermore, modified mass release equations are presented to account for the decline in the release rate with time to determine the pool fire area and leak duration. Consequence areas are determined based on serious personnel injuries and component damage from thermal radiation and explosions. To validate the risk model, a proof of concept assessment was performed on seven tanks.

Artificial intelligence treating the problem of uncertainty in quantitative risk analysis (QRA)

PurposeNowadays, artificial intelligence computational methods, such as knowledge-based systems, neural networks, genetic algorithms and fuzzy logic, have been increasingly applied to several industrial research studies, the purpose of this paper is to study the contribution of fuzzy and possibilistic techniques to quantitative risk analysis (QRA) in the presence of imperfect knowledge about the occurrence and consequences of accidental phenomena.Design/methodology/approachTo solve the problem of uncertainties related to the elements of the accident scenario such as the frequency and severity of the consequences, the authors used fuzzy logic. Using this type of analysis, it is possible to visualize the contours of the dead or fuzzy injury by fireball thermal effect (first- and second-degree burn, death) and lesions caused by vapor cloud explosion overpressure (lung damage, eardrum rupture, head impact, whole-body displacement). The frequency and severity of fuzzy results are calculated by extended multiplication using the alpha-cuts method.FindingsThis research project aims to reflect the real situation in the in Amenas industrial area (SONATRACH company), specifically the liquefied petroleum gas storage tank On-Spec 05-V-411A, to deal with this type of risk. Using this analysis allows us to estimate the fuzzy individual risk using the approach of fuzzy logic to treating this uncertainty in the parameter information of accident scenarios. This index individuel risk (IR) was evaluated against the criterion of acceptability and then used for decision-making in the field of industrial risk analysis and evaluation.Originality/valueThe originality of the work is to identify the weak points of the classical QRA to solve the problem of the uncertainties related to the elements of the accident scenario such as the frequency and severity of the consequences to visualize the fuzzy risk contours. On the one hand and the development of software to calculate the probability of death by the overpressure effect and classify the most sensitive organs on the other hand. Given the importance of this study, it can be generalized for similar sites in the region.

Microstructural and Mechanical Properties of Welded High Strength Steel Plate Using SMAW and SAW Method for LPG Storage Tanks

Indonesian government policy to convert energy consumption for domestic household from kerosene to liquefied petroleum gas (LPG) may lead to the increasing demand for LPG storage tank. LPG storage tank with a large capacity generally used the HSLA steel material of ASTM A516 Grade 70 joined by SMAW or combination between SMAW and SAW method. The heat input can affect the microstructure and mechanical properties of the weld area. The input heat is proportional to the welding current and the arc voltage, but inversely proportional to its welding speed. The result shows that the combination of SMAW-SAW process yield the lower hardness in the HAZ and the fusion zone compared to the singe SMAW process. PWHT mainly applied to reduce residual stress of welded joint. The result shows that PWHT can reduce the hardness in the HAZ and the fusion zone in comparing with the singe SMAW process. The microstructure of weld joint shows a coarser structure in the combined welding process (SMAW-SAW) comparing with the single welding process (SMAW).

Experimental and numerical study of the behavior of LPG tanks exposed to wildland fires

Abstract The safety of small and medium LPG (liquefied petroleum gas) storage tanks in civil and industrial facilities when affected by forest fires in the framework of Wildland–Urban Interface (WUI) was investigated. Large scale experimental tests were carried to characterize the behavior of LPG tanks in case of distant source radiation caused by forest fires. A data set was obtained and used for the validation of a dedicated two-dimensional computational fluid dynamic (2D CFD) model for the analysis of pressure build-up in vessels exposed to different types of transient heat radiation, featuring different geometry types and operating conditions. The combined experimental and numerical analysis allowed determining the critical exposure conditions for LPG vessels. Specific key performance indicators were defined and calculated on the basis of 2D CFD simulation results in order to derive conservative indications on failure conditions of LPG storage vessels induced by forest fires.

Large-Scale Wireless Temperature Monitoring System for Liquefied Petroleum Gas Storage Tanks.

Temperature distribution is a critical indicator of the health condition for Liquefied Petroleum Gas (LPG) storage tanks. In this paper, we present a large-scale wireless temperature monitoring system to evaluate the safety of LPG storage tanks. The system includes wireless sensors networks, high temperature fiber-optic sensors, and monitoring software. Finally, a case study on real-world LPG storage tanks proves the feasibility of the system. The unique features of wireless transmission, automatic data acquisition and management, local and remote access make the developed system a good alternative for temperature monitoring of LPG storage tanks in practical applications.

FDS Simulation and Consequences Forecasting of LPG Storage Tank Pool Fire and Explosion

This paper analyzes the fire explosion risk of liquefied petroleum gas (LPG) storage tank through methods of model calculation and simulation. A large crude oil reserves library in Tianjin is the main study object in this paper, the fire process for the storage tank pool fire is simulated using the fire simulation software FDS, which produces the development of fire and the change of the radiation intensity in the case of fire. And the damage degree of explosion accident consequences has been calculated quantitatively by the vapor cloud explosion model, which obtains the casualties radius and property damage. Study results provide reference data and theoretical guidance for fire protection design and fire fighting tactics in LPG storage tank area.

Numerical Simulation of Liquefied Propane Gas Storage Tanks Full-Size Pool Fire Based on FDS

This paper takes a 50000 m3 liquefied petroleum gas storage tank in a chemical company in Tianjin for an example, and adopts the fire simulation software FDS to make numerical simulation for the whole-area pool fire accident in the liquefied propane gas tank. The variation of flame and the flue gas in the combustion process of pool fire is obtained from the simulation. The simulation results show that flame shape, smoke production rate and thermal radiation intensity is small in the early pool fire, and significantly increases with the development of combustion process, finally maintains in a relatively stable state.

Dynamic fracture toughness of aluminium 6063 with multilayer composite patching at lower temperatures

Aluminium alloys provide many benefits and challenges for use in marine environment. Attention on lightweight hulls leads to power saving, better handling and easy transportation. The stiffness and mass of the structure or member is responsible for its natural vibration. The hull panels and stiffeners vibrate at different frequencies when their stiffness is reduced by formation of a crack or any structural problems. If there is a monitoring system on board and by using a sensor detecting the modified vibrations, the maintenance crew senses the spot where urgent repair is needed. Application of composite laminates is convenient in view of portability and simplicity in procedure such as hand lay-up. In this study, the edge-cracked aluminium plates were repaired with one-sided composite patches and their temperature were varied to both low and high temperature levels. Dynamic fracture toughness was determined using Charpy impact test. Three different types of materials were used for composite patching: GFRP (glass-fibre-reinforced plastic), CFRP (carbon-fibre-reinforced plastic) and Kevlar. For each temperature level, two lay-ups were used, viz. three layered and five layered. Aluminium specimens with edge cracks of two different lengths, keeping the width of the crack constant, were prepared. Impact tests were performed for the prepared specimens at different temperatures. The fracture toughness of aluminium strips reinforced with patches was determined and compared with the energy absorbed during the impact of the corresponding specimen without the patch. It was observed that the specimen with patches gave a higher fracture toughness value when compared with that without the patch; corresponding observation on aluminium has been made along with patch at these temperatures. The patch using Kevlar was found to be the best among the three composites. Followed by these experiments, simulations using FRANC 2D software were carried out for finding stress intensity factor at different crack lengths with and without patches. The research has a spin-off application in the selection of materials used for patching and hence in the maintenance of LPG (liquefied petroleum gas) and LNG (liquefied natural gas) storage tanks under cryogenic conditions.

LPG용 압력방출밸브 방출관 설치기준 개선방안

LPG 저장설비에 부착된 압력방출밸브 방출관으로부터 분출된 가스의 확산에 대해 검토하였다. 통상 방출관은 안전한 장소인 수직 상방향으로 분출되도록 설치되어야 하며, 방출된 가스가 착화되더라도 저장탱크, 장치, 배관에 화염이 닿지 않도록 설치되어야 한다[1][2]. 그러나 우리나라에서는 방출구를 통한 분출방향에 대한 기준이 없이 다양한 방출구 형태가 존재한다. 따라서, 본 연구에서는 4가지 방출방향 즉 수직상방, 수직하방, 수평 2, 수직 4방향에 대해서 고려하였다. 방출구로부터 분출된 가스의 확산 시뮬레이션은 상용소프트웨어인 FLACS를 사용하였다. 이를 통해 수직하방, 수평 2, 수직 4방향으로 분출하도록 방출구를 설치하는 것은 지면에서의 착화를 방지하는 데 불리한 것으로 나타났다. 따라서 안전밸브로부터 분출된 가스를 방출구를 통해 안전하게 분출하기 위해서는 수직상방으로 분출되는 것이 최선임을 알 수 있었다. The dispersion of gas discharged from the vent pipes of pressure relief valves attached LPG (Liquefied Petroleum Gas) storage tank was studied. In general, vent pipes should be positioned so that they discharge vertically upwards in a safe place, and installed so that, in the event of ignition of discharged gas, flame impingement on any vessel, equipment or piping is avoided[1][2]. In Korea, on the other hand, there are various type of the end of vent pipes because there is no rule for discharge directions from the vent pipes. In this paper, we took 4 types of vent directions from the pipes in to account, such as vertically upward, vertically downward, vertically 4-way and horizontally 2-way direction. A software package, FLACS, was adopted to simulate gas dispersion from the vent pipes. We found that vertically downward, vertically 4-way and horizontally 2-way discharge from vent pipes were undesirable to avoid ignition on near ground. Therefore, it was obvious that vertically upward opening of a vent pipe is the best option to discharge in a safe place.

Efficacy of water spray protection against propane and butane jet fires impinging on LPG storage tanks

Abstract Liquefied petroleum gas (LPG) storage tanks are often provided with water sprays to protect them in the event of a fire. This protection has been shown to be effective in a hydrocarbon pool fire but uncertainties remained regarding the degree of protection afforded in a jet fire resulting from a liquid or two-phase release of LPG. Two projects, sponsored by the Health and Safety Executive, have been undertaken to study, at full scale, the performance of a water spray system on an empty 13 tonne LPG vessel under conditions of jet fire impingement from nearby releases of liquid propane and butane. The results showed that a typical water deluge system found on an LPG storage vessel cannot be relied upon to maintain a water film over the whole vessel surface in an impinging propane or butane jet fire scenario. The deluge affects the fire itself, reducing the luminosity and smoke, resulting in a lower rate of wall temperature rise at the dry patches, when compared with the undeluged case. The results of these studies will be used by the HSE in assessing the risk of accidental fires on LPG installations leading to boiling liquid expanding vapour explosion (BLEVE) incidents.

Thermal Response Analyses of Spherical LPG Storage Tank.

Liquefied petroleum gas (LPG) is a very important fuel and chemical feed stock as well; however, the hydrocarbon has been involved in many major fires and explosions. One of these accidents is boiling-liquid, expanding-vapor explosion (BLEVE). It is a phenomenon that results from the sudden release from confinement of a liquid at a temperature above its atmospheric-pressure boiling point. The sudden decrease in pressure results in the explosive vaporization of a fraction of the liquid and a cloud of vapor and mist with the accompanying blast effects. Most BLEVEs involve flammable liquids, and most BLEVE releases are ignited by a surrounding fire and result in a fireball. The primary objective of this paper is to develop a computer model in order to determine the thermal response of a spherical LPG tank involved in fire engulfment accidents. The assessment of the safety spacing between tanks was also discussed.

PS-type cryogenic storage tank.

The PS-type cryogenic storage tank is a low temperature storage tank designed to provide double safety against leakage. The tank consists of an inner tank and an outer enclosure. The inner tank contains the low temperature and ultra-low temperature liquefied gases, such as liquefied petroleum gas (LPG) and liquefied natural gas (LNG). Even in the event of an accidental leakage occurring on the inner tank, the outer enclosure of prestressed concrete will serve as an integral secondary barrier to keep the gas from flowing out. This report presents the circumstances surrounding the development of the PS-type cryogenic storage tank, and covers the construction and field testing of a large-scale prestressed concrete structure (6 meters in diameter×6 meters in height), modelled under actual field conditions, to prove its effectiveness as an integral barrier and liquid restraining wall. Tests were also run to demonstrate resistance to seismic shock equivalent to or greater than that of a metal storage tank, and to demonstrate the necessary resistance to low temperature thermal shock to function as a liquid receiving vessel of flat bottomed cylindrical design. The results of these tests and their numerical analyses are reported, as well as the results of numerical analysis concerning structural safety with reference to the radiant heat from hypothetical adjacent fires. A 3, 000 ton ethylene storage tank and two 40, 000 ton LPG storage tanks have been constructed based on the results of this research and development project, and these tanks have received a high evaluation as safe storage facilities.