Investigation of parameters of leakage of toxic and explosive substances and gases under the action of high pressure from tanks of the special purpose during

Tanks for the storage of oil products and toxic substances in warehouses are the main ones. They can be in the form of separate tanks or a group of tanks. The most widespread are vertical steel tanks with a stationary roof that a placed in open areas. The tanks heat up, and the intensity of evaporation of the oil product increases in case of fire. If there is a permanent roof, the pressure in the tank will increase. If the capacity of the breathing valves is less than the intensity of evaporation then there is a risk of explosion. Explosions in the tank often lead to the separation of the bottom, and the side cylindrical surface and the roof fly away instantly, spilling oil on neighboring tanks and the territory of the tank’s park. Then the combustion area increases intensively. The destruction of the integrity of the tank, due to the separation of the bottom, contributes to temperature and power stresses, the value of which increases with increasing temperature of their heating and increasing pressure, respectively. The values of temperature stresses are added to the power stresses caused by pressure, and when the critical value is reached, destruction occurs. In the article by the method of mathematical modeling using the laws of thermodynamics and mechanics of liquids and gases, analytical dependences for research of parameters of leakage of toxic substances and gases at action of high pressure from capacities at their storage are received. Saint-Venant’s principle was used to model the gas flow rate process. The dependence of the duration of gas leakage from special purpose tanks at the change of the area of the emergency hole and the pressure drop is obtained. The obtained results allow determining the velocity and mass flow rate of the gas depending on the area of the hole, the time flow, and the difference of pressure. Therefore, the task of research the emergency situations of engineering cylindrical tanks under the influence of temperature and pressure, which leads to the spillage of toxic substances and gassiness is actual. The researches results are presented graphically.

Structural Integrity Assessment of Independent Type-C Cylindrical Tanks Using Finite Element Analysis: Comparative Study Using Stainless Steel and Aluminum Alloy

The International Maritime Organization stipulates that greenhouse gas emissions from ships should be reduced by at least 50% relative to the amount observed in 2008. Consequently, the demand for liquefied natural gas (LNG)-fueled ships has increased significantly. Therefore, an independent type-C cylindrical tank, which is typically applied as an LNG fuel tank, should be investigated. In this study, structural integrity assessments using finite element analysis are performed on C-type LNG fuel tanks for a sea-cleaning vessel. In addition, the applicability of stainless steel and aluminum alloys is evaluated for LNG tank construction. Structural analyses and fatigue limit evaluations, including heat transfer analyses for the tank based on IGC code requirements, are performed, and the results are compared. The results of this study are expected to facilitate the selection of materials used for independent type-C tanks.

Behavior of bolted lap joints in above ground liquid-filled steel cylindrical tanks

Leakage is the main concern in steel bolted liquid tanks. In this study, the performance of this type of construction is investigated using a detailed finite element (FE) analysis. The validity of AWWA design practice in terms of the safe design of this type of structure at a wide range of service loads is evaluated. The FE analysis is performed in two stages using shell and solid elements in a three-dimensional ANSYS environment including the effect of geometric nonlinearity. The proposed FE model is capable to estimate the ultimate behaviors such as capacity curve, yield/failure pattern, and the occurrence of ovalling and curling. The FE results are compared with experimental ones and a good agreement is found. This study shows that the bolt arrangement selected in design can efficiently improve joint performance. It is recommended to use the limited deformation criterion in the leak-resistant design of bolted lap joints.

IMPROVING THE ACCURACY OF MEASURING THE VOLUME AND MASS OF LIQUID PRODUCT IN HORIZONTAL CYLINDRICAL TANKS

The article is devoted to improving the accuracy of the system for measuring and controlling the level of liquid materials in horizontal cylindrical tanks. The task of ensuring continuous accurate control of the level, volume and mass of petroleum products, taking into account the shape of the bottom of the tank, is set. In order to improve the accuracy of the measuring device, a laser rangefinder is installed, which allows you to determine the distance from the tank lid to the point of the surface level of the liquid product and calculate the volume of the liquid material by determining the average temperature and correcting for temperature changes when calculating the density, volume and mass of petroleum products with different shapes of the bottoms of a horizontal cylindrical tank. The developed method provides high accuracy, low power consumption, implementation is simple and economical. The device has no mechanically moving parts, so the measuring equipment is protected from failures and has a long service life.

Definition of rate of dynamic water deposition in horizontal cylindrical tanks

One of the problems in petroleum industry is the process of thermo-chemical preparation of crude oil developed from wells containing water, gas and other mechanical impurities. Herewith, the path of water drops in horizontal cylindrical tank is specified with powers affecting them. In this case the size and form of the tank are necessary as well. The paper studies the issue of destruction of oil emulsions and dynamic deposition of water drops. A mathematical model for description of motion rate of water drops in the tank considering the powers affecting them and the tank parameters has been developed as well.