scholarly journals 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

2021 ◽  
pp. 49-53
Author(s):  
M. Semerak ◽  
T. Hlova ◽  
B. Hlova ◽  
O. Petruchenko
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Toxic Substances ◽  
Gas Leakage ◽  
Emergency Situations ◽  
Time Flow ◽  
Steel Tanks ◽  
The Difference ◽  
Cylindrical Tanks

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.

scholarly journals Investigation on influences of loose gas on gas-solid flows in a circulating fluidized bed (CFB) reactor using full-loop numerical simulation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengju Huo ◽  
Xiaohong Li ◽  
Yang Liu ◽  
Haiying Qi
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Separation Efficiency ◽  
Circulation Rate ◽  
Solid Mass ◽  
Gas Flow Rate ◽  
Gas Leakage ◽  
Mass Circulation

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.

scholarly journals Foaming of industrial lean methyldiethanolamine solution in the presence of hydrocarbon and fatty acid based corrosion inhibitors

2018 ◽  
Vol 73 ◽  
pp. 76 ◽  
Author(s):  
Mohammad Keewan ◽  
Fawzi Banat ◽  
Priyabrata Pal ◽  
Jerina Zain ◽  
Emad Alhseinat
Keyword(s):  
Fatty Acid ◽  
Pore Size ◽  
Corrosion Inhibitor ◽  
Flow Rate ◽  
Gas Flow ◽  
Corrosion Inhibitors ◽  
Liquid Volume ◽  
Operating Parameters ◽  
Time Flow ◽  
Foaming Time

In natural gas sweetening alkanolamine processes one of the regularly used chemical is the corrosion inhibitor. For better operation of the plant it is essential to understand the effect of their presence on foaming of industrial lean Methyldiethanolamine (MDEA) used as solvents at different temperatures. This study aimed at investigating the effect of HydroCarbon Based (HCB) and fatty acid based corrosion inhibitor having chemical name Bis(2-Hydroxyethyl)Cocoalkylamine (BHCL) on the foaming tendency of industrial real lean MDEA solutions. Experiments were conducted with different operating parameters, including liquid volume of the solution, foaming time, flow rate of nitrogen gas, concentration of the corrosion inhibitors, temperature of the solution, and gas diffuser pore size using the Foam Scan instrument. With the increase in solution volume and foaming time foaming happens to be more. The foaming tendency of lean MDEA solutions decreased with increasing temperature in absence of corrosion inhibitors but showed different behavior in their presence. At small diffuser pore size and high gas flow rate, the final foam volume increased in the presence of HCB but decreased with the BHCL inhibitor. Optimizing the operating parameters to minimize foaming was verified to be a function of the type of inhibitor used.

scholarly journals Measurement Standards of Ukraine for Gas Volume Flow Rate at Pressures of 1 MPa to 5 MPa

2021 ◽  
Vol 2 ◽  
Author(s):  
Mykhailo Rozhnov ◽  
Dmytro Melnyk ◽  
Ovsiy Levbarg
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Primary Standard ◽  
Metrological Traceability ◽  
Gas Flow Rate ◽  
Flow Measurements ◽  
Working Standard ◽  
Measurement Standards ◽  
Primary Measurement

The characteristics of the primary measurement standards of the volume gas flow rate at high pressure developed in various countries are considered. A hierarchical scheme for gas flow measuring instruments and a corresponding metrological traceability chain are presented. Described is a PVTt method, on which the primary standards of gas flow rate used in the USA, France, Japan, and Taiwan are based. The need to create in Ukraine primary measurement standards of gas flow rate at high pressure covering different parts of the total flow rate interval from 0,3 m3/h to 1800 m3/h at a pressure of 1 MPa to 5 MPa is substantiated. Metrological traceability of gas flow measurements is realized through a sequence of critical flow Venturi nozzles, which play a role of the reference flow rate material measures. The standards might be used to calibrate the primary reference Venturi nozzles of the most common 0,1 mm to 8 mm diameters. The characteristics and parameters of the standards are determined. By their metrological and technical characteristics, the standards will correspond to the state-of-the-art level. According to the programme of developing the measurement-standard facilities in Ukraine, in 2019 the primary standard PVTt-65 was created and work had started on the development of the primary standard PVTt-1800 and the working standard PE-5400. A detailed study of the metrological characteristics of the measurement standards will be the topic of further work.

Micro Flow Sensor Based on Frequency Measurement of Micro Whistles

2012 ◽  
Vol 468-471 ◽  
pp. 2061-2064
Author(s):  
Yan Bin Di ◽  
Ying Miao
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Volume Flow Rate ◽  
Frequency Measurement ◽  
Flow Sensor ◽  
Fluid Properties ◽  
Micro Flow ◽  
The Difference ◽  
Rate Frequency ◽  
Geometrical Dimensions

In this work, several millimeter sized micro whistles have been tested as potential frequency analog gas flow sensors. The characteristic curves of the whistles were systematically investigated as a function of geometrical dimensions, the kind of gas applied, and temperature. Both a micro¬phone and a PVDF foil were employed to record the frequencies. The relation be¬tween oscillation frequency and volume flow rate only shows a weak function of fluid properties and temperature. At a given flow rate, the difference of argon and nitrogen is 120 Hz on average, which is corresponding to 1.4 %. For air flow at a given flow rate, frequency rises approximately 380 Hz (2.73 %) per 10 °C. This kind of micro whistle could be employed as gas flow sensor which is insensitive to fluid properties.

Calibration of High Pressure Gas Meters with Sonic Nozzles

1972 ◽  
Vol 5 (11) ◽  
pp. 440-446 ◽  
Author(s):  
M G Peignelin
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Pressure Effect ◽  
Critical Flow ◽  
Gas Flow Rate ◽  
A New Technique ◽  
Cylindrical Throat ◽  
Working Out ◽  
Venturi Nozzle

At present, gas meters are calibrated under low pressure with standard Bell provers. As the meters can be used under high pressure on the network, the pressure effect upon the error curve must be determined. To avoid this drawback, we have been searching for another standard of gas flow rate at the Gaz de France test station which disposes of a natural gas having steady characteristics and capable of operating at a pressure of 50 bar and a flow rate about 12 000 m3/h (N). This study led us to the working out of a new technique based upon a critical flow meter: the venturi nozzle with a cylindrical throat. This paper presents: the results of the sonic nozzles calibration a description of the equipment composed of sonic nozzles to calibrate meters and some examples of the use of this standard of flow rate.

scholarly journals The Long Bubbles Penetration through Viscoelastic Fluids with Shear-Thinning Viscosity in a Curved Tube

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Ching-Chuan Chang
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Viscoelastic Fluids ◽  
Weissenberg Number ◽  
Fluid Viscosity ◽  
Gas Flow Rate ◽  
Difference Variable ◽  
Curved Tube ◽  
Number Increase ◽  
The Difference

The purpose of this research is to investigate the behavior of a long bubbles penetrating through viscoelastic fluids in a curved tube. The injection gas flow is controlled by a mass flow controller (MFC). The results of the experiments show that the bubbles width approaches constant value at the location six-diameter upstream from the bubbles front. A difference variable is introduced at the six-diameter location to show the shifting deviation of the bubbles in the curved tube. It is shown that, with the same fluid viscosity and the curved angle, the difference is higher when the gas flow rate is higher. Also, the difference increases proportionally when the capillary number and the Weissenberg number increase.

scholarly journals MODELING OF GAS-DYNAMIC PROCESSES IN THE ELEMENTS OF IMPULSE EJECTOR

2021 ◽  
pp. 66-72
Author(s):  
G. O. Voropaiev ◽  
Ia. V. Zagumennyi ◽  
N. V. Rozumnyuk
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Dynamic Processes ◽  
Stable Operation ◽  
Operating Pressure ◽  
Gas Generator ◽  
Gas Dynamic ◽  
Ejector Nozzle

The paper presents the numerical results on gas-dynamic processes in various elements of the impulse ejector, including pre-chamber, supersonic nozzle and mixing chamber, to determine optimal geometric parameters providing the given flow rate characteristics. At an extra-high pressure of the ejecting gas (>100 bar) it is impossible to create a nozzle design with continuously changing cross-sectional area and limited nozzle length. So, it is necessary to place a pre-chamber between the gas generator and the ejector nozzle for throttling full gas pressure. In order to optimize the pre-chamber parameters in the ejector with discrete holes of the gas generator and the operating pressure in the range of 400÷1000 bar, a series of calculations were performed to determine the pre-chamber parameters, ensuring stable operation of the supersonic annular nozzle at the high pressure of 35÷45 bar and the flow rate of 0.5÷0.6 kg/s. 3D numerical simulation of the gas flow into the pre-chamber through the gas generator holes shows the degree of the flow pattern non-uniformity in the pre-chamber at the ejector nozzle inlet is quite low. This justifies the numerical simulation of gas flow in the ejector in axisymmetric formulation and allows restricting the number of the gas generator holes without inducing significant non-uniformity in the azimuthal direction.

Parameter study of Variation noise in outdoor of air conditioner

2021 ◽  
Vol 263 (4) ◽  
pp. 2822-2829
Author(s):  
Minkyu KIM ◽  
Byoungha Ahn ◽  
Simwon Chin
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
High Speed ◽  
Rapid Change ◽  
Volume Control ◽  
Parameter Study ◽  
Air Conditioner ◽  
Load Variations ◽  
Compressor Inlet ◽  
The Difference

In the outdoor unit of a room air conditioner, the main factors that made it possible to vary the ability of cooling and heating are the development of BLDC motors, advances in inverter technology, and the development of refrigerant volume control technology. The main reason for this change in cooling and heating capacity is that it is possible to change the RPS of compressors. As the range of the compressor's RPS expands, so does the range of response to load variations. This is mainly based on the capacity of the high-pressure refrigerant produced by the compressor. When the compressor rotates at high speed or low speed, the difference in noise occurs depending on the difference in rotational speed. Of course, fans and motors also contribute to noise fluctuations, but the overall governing factor is the greater contribution of refrigerant from compressors and compressors. The refrigerant flows into the cycle configured in the outdoor unit and varies in speed and flow rate depending on the amount of refrigerant. This results in vibration and noise appearing in the form of radiations, resonances, solid sounds, resonances, and so on. There are several factors that can cause vibration or noise changes depending on the flow velocity and flow rate. In this paper, we selected reactance of compressor motors, mufflers directly connected to compressor discharge ports and accumulator at compressor inlet where fluid vibrations occur the most. First of all, reactance of motor responds quickly to load fluctuations and has a large instantaneous torque to instantaneous load fluctuations. The muffler, which is directly connected to the compressor discharge port, is the first Cavity where high-pressure gas meets, and can evaluate the concentration of kinetic energy that generates noise and improve the collection center to reduce fluctuating noise. The Accumulator is the part with the lowest temperature of refrigerant gas entering the compressor, and the rapid change in the flow path causes the most fluid to generate vibration and radiation of the structure. For this reason, we select three elements first. In this paper, we specifically describe the background of selecting three elements of an air conditioning outdoor unit for the variability of noise over RPS changes. We demonstrate that these factors can review the feasibility of the experiment, explain the results of the analysis, and possibility of reduce the variation noise.

scholarly journals Simulation of High Pressure Separator Used in Crude Oil Processing

Processes ◽  
2018 ◽  
Vol 6 (11) ◽  
pp. 219 ◽  
Author(s):  
Najah Al-Mhanna
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Software Package ◽  
Gas Flow ◽  
Sensitivity Study ◽  
Simulation Software ◽  
Operating Conditions ◽  
Gas Concentration ◽  
Oil Processing ◽  
Simulation Results

The aim of this research was to simulate a high-pressure (HP) separator in order to investigate the effect of changing separator operating conditions on product properties. In this study, the results obtained using the CHEMCAD simulation software package were compared with those obtained using the UniSim software package. The simulation results were comparable with industrial data. A sensitivity study was conducted by changing the gas stream properties, such as temperature, pressure, and flow rate, in order to investigate and optimize the process. The results showed that increasing the separator inlet pressure from 30 to 80 bar decreased the outlet gas flow rate from 1202 to 871.15 kmol/h. Also, the methane mole fraction increased from 0.69 to 0.74; however, the preheater heating duty was increased from 8.71 to 11.48 GJ/h. The simulation results showed that increasing the temperature of the separator feed stream from 43 to 83 °C increased the flow rate of the outlet gas stream from 871.15 to 1142.98 kmol/h. However, this temperature change reduced the methane concentration in the gas product and decreased the heating duty of the heat exchanger. Finally, the study demonstrated that there is no effect of increasing the inlet feed flow rate on the produced methane gas concentration.

Ozone Mass Transfer in a Recirculating Loop Semibatch Reactor Operated at High Pressure

2010 ◽  
Vol 13 (1) ◽  
Author(s):  
Mohammadreza Moslemi ◽  
Simon H. Davies ◽  
Susan J. Masten
Keyword(s):  
Mass Transfer ◽  
High Pressure ◽  
Flow Rate ◽  
Ozone Concentration ◽  
Gas Flow ◽  
Water Flow Rate ◽  
Low Flow ◽  
Ozone Decomposition ◽  
Gas Flow Rate ◽  
Gaseous Ozone

AbstractThe effects of water flow rate, mixing, gaseous ozone concentration, inlet gas flow rate, temperature, and pH on ozone hydrodynamics at high pressure were studied. Varying the cross flow rate had only a slight influence on the ozone mass transfer rates, indicating that sufficient mixing in the reactor was attained at the low flow rates used. The addition of an inline static mixer had a negligible effect on aqueous ozone concentrations in the reactor, suggesting that mixing was sufficient without the mixer. The ozone mass transfer increased with increasing gaseous ozone concentration and with the inlet gas flow rate. The dissolved ozone concentration decreased with increasing pH due to the greater rate of ozone decomposition at higher pH. Increasing the temperature resulted in a decrease in the ozone mass transfer. A model to describe the ozone mass transfer was developed. Good agreement between the model predictions and the experimental data was achieved.

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