scholarly journals Improvement in Performance of the Sulphuric Acid Transport Installation through Modification of Flow Characteristics Using Electric Actuators

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2797
Author(s):  
Stanisław Gil ◽  
Mariusz Wnęk ◽  
Robert Łudzień
Keyword(s):  
Sulphuric Acid ◽  
Flow Characteristics ◽  
Measuring System ◽  
Measurement Transducer ◽  
Flow Process ◽  
Industrial Installation ◽  
Research Procedure ◽  
Valve Opening ◽  
Real Flow ◽  
Opening And Closing

The paper presents a flow model of the installation for tank car filling with sulphuric acid (VI). For the mathematical modelling of the flow process in the industrial installation, a model diagram of the object and experiments carried out during the installation work were applied. The analysis of specific experimental series showed unusual shapes of mass flow characteristics vs. the valve opening level (too wide hysteresis), which markedly deviated from typical flow characteristics that are found in standards and literature. As a result of flow modelling in the sulphuric acid installation, a better-shaped characteristic was presented that should be obtained based on the measuring system values in the absence of the inertia-related error. In the experiments carried out according to the selected procedures, effects of the actuator speed on the characteristics of interest were determined. It was observed that the use of a “slower” actuator (i.e., longer transition time) narrows the characteristics in terms of a reduced difference in flow readings between the valve opening and closing courses. In the specified research procedure for the real flow characteristics, effects of the measurement transducer dynamics in the flow meter on the characteristic course were assessed. It was demonstrated that a faster transducer enabled closer flow recordings to the valve nominal characteristics. The variable speed can improve the positioning precision, with the use of the lowest possible speed rule directly before the positioning point.

Comparative analysis of transient valve-induced flow characteristics between opening and closing processes

2021 ◽  
pp. 095440892110630
Author(s):  
Qi Liu ◽  
Shuai Tian ◽  
Yong-xiang Wang ◽  
Zhe Lin ◽  
Zu-chao Zhu
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Transient Flow ◽  
Flow Characteristics ◽  
Flow Stability ◽  
Adjustment Process ◽  
Unstable Flow ◽  
Valve Opening ◽  
Induced Flow ◽  
Opening And Closing

Transient control of process valves, including opening and closing processes, is consistently encountered in many fluid transportation and control industries. During opening and closing processes, valve-induced transient flow presents different unstable flow characteristics. This transient valve-induced unstable flow that develops along the pipeline can cause violent pressure and velocity fluctuations that considerably influence accurate flow measurement downstream. In this paper, gate valve-induced flow characteristics during opening and closing processes were comparatively studied. An experimental system was developed to monitor the downstream pressure along the pipeline, and corresponding transient numerical simulations were performed on opening and closing processes using a user-defined function and dynamic grid technology. The pressure distributions along the pipeline's downstream area during valve opening and closing processes were investigated to verify the accuracy of the numerical simulation. The mechanism of transient flow difference under the same valve opening during opening and closing processes was determined to be a hysteresis effect. The jet flow intensity under a small valve opening in the opening process was greater than that in the closing process, and the difference in flow field under the 50% valve opening was the largest. Moreover, the velocity and turbulent kinetic energy distributions in different downstream cross-sections during valve opening and closing processes were comparatively analyzed. The change rate of the maximum turbulent kinetic energy was introduced to further analyze the different effects of opening and closing processes on the transient flow stability downstream of the valve. Results showed that the flow stability between 40% and 50% valve opening was the worst irrespective of the adjustment process, that is, a large pipeline distance was required to stabilize this transient flow. This study helps in understanding transient valve-induced flow characteristics in fluid transportation pipelines and provides guidance for accurate flow metering industrial applications.

scholarly journals Analysis of Flow Characteristics and Effects of Turbulence Models for the Butterfly Valve

2021 ◽  
Vol 11 (14) ◽  
pp. 6319
Author(s):  
Sung-Woong Choi ◽  
Hyoung-Seock Seo ◽  
Han-Sang Kim
Keyword(s):  
Turbulence Model ◽  
Dissipation Rate ◽  
Flow Characteristics ◽  
Turbulence Models ◽  
Flow Properties ◽  
Nominal Diameter ◽  
Large Pressure ◽  
Sst Model ◽  
Turbulence Effect ◽  
Valve Opening

In the present study, the flow characteristics of butterfly valves with different sizes DN 80 (nominal diameter: 76.2 mm), DN 262 (nominal diameter: 254 mm), DN 400 (nominal diameter: 406 mm) were numerically investigated under different valve opening percentages. Representative two-equation turbulence models of two-equation k-epsilon model of Launder and Sharma, two-equation k-omega model of Wilcox, and two-equation k-omega SST model of Menter were selected. Flow characteristics of butterfly valves were examined to determine turbulence model effects. It was determined that increasing turbulence effect could cause many discrepancies between turbulence models, especially in areas with large pressure drop and velocity increase. In addition, sensitivity analysis of flow properties was conducted to determine the effect of constants used in each turbulence model. It was observed that the most sensitive flow properties were turbulence dissipation rate (Epsilon) for the k-epsilon turbulence model and turbulence specific dissipation rate (Omega) for the k-omega turbulence model.

Effects of Valve Disc on Flow Characteristics Inside a Swing Check Valve During Opening and Closing Processes

2021 ◽  
Author(s):  
Yi-xiang Xu ◽  
Qiang Ru ◽  
Huai-yu Yao ◽  
Zhi-jiang Jin ◽  
Jin-yuan Qian
Keyword(s):  
Flow Field ◽  
Working Conditions ◽  
Power Plants ◽  
Flow Characteristics ◽  
Check Valve ◽  
Opening Angle ◽  
Piping System ◽  
Total Moment ◽  
Valve Disc ◽  
Opening And Closing

Abstract The check valve is one of the most important devices for safety protection of the piping system in thermal and nuclear power plants. As the key component of the check valve, the valve disc accounts for a major effect on the flow characteristics especially during the opening and closing processes. In this paper, a typical swing check valve is taken as the research object. In order to make a comparative study, three working conditions of 30% THA (Turbine Heat Acceptance), 50% THA and 100% THA are selected. Focusing on the effects of valve disc, how does the valve disc motion interact with the flow field around the valve disc is analyzed with the help of the dynamic mesh technology. The results show that under the combined action of fluid force and gravity, the check valve can be opened and closed quickly. During the opening process, the maximum total moment of the disc appears between 45° ∼ 50° opening angle, and during the closing process the maximum total moment occurs when the disc fully closed. The flow field near the valve disc has similar variation rules with the rotation of the valve disc in the three working conditions, and the pressure near the valve disc reaches the maximum value at the moment of opening and closing. This study can provide some suggestions for the further optimal design of similar swing check valve.

Numerical Study on Flow Characteristics in High Multi-Stage Pressure Reducing Valve

2017 ◽  
Author(s):  
Fu-qiang Chen ◽  
Zhi-xin Gao ◽  
Jin-yuan Qian ◽  
Zhi-jiang Jin
Keyword(s):  
Energy Consumption ◽  
Numerical Study ◽  
Research Work ◽  
Flow Characteristics ◽  
Temperature Fields ◽  
Turbulent Dissipation ◽  
Technological Support ◽  
Multi Stage ◽  
Valve Opening ◽  
Pressure Reducing Valve

In this paper, a new high multi-stage pressure reducing valve (HMSPRV) is proposed. The main advantages include reducing noise and vibration, reducing energy consumption and dealing with complex conditions. As a new high pressure reducing valve, its flow characteristics need to be investigated. For that the valve opening has a great effect on steam flow, pressure reduction and energy consumption, thus different valve openings are taken as the research points to investigate the flow characteristics. The analysis is conducted from four aspects: pressure, velocity, temperature fields and energy consumption. The results show that valve opening has a great effect on flow characteristics. No matter for pressure, velocity or temperature field, the changing gradient mainly reflects at those throttling components for all valve openings. For energy consumption, in the study of turbulent dissipation rate, it can be found that the larger of valve opening, the larger of energy consumption. It can be concluded that the new high multi-stage pressure reducing valve works well under complex conditions. This study can provide technological support for achieving pressure regulation, and benefit the further research work on energy saving and multi-stage design of pressure reducing devices.

scholarly journals Design and Build Temperature Control and Monitoring in Diesel Engines Using Mobile

2020 ◽  
Vol 10 (1) ◽  
pp. 31-37
Author(s):  
Mohammad Hasan Fuadi
Keyword(s):  
Diesel Engine ◽  
Temperature Control ◽  
Diesel Engines ◽  
Temperature Sensor ◽  
Cooling System ◽  
Cooling Water ◽  
Solenoid Valve ◽  
Valve Opening ◽  
Opening And Closing ◽  
And Control

Diesel engines is generally used for industrial and agricultural machines. Few people care about the engine temperature so it is forced to reach temperature of 100oC, which causes overheating of the diesel engine and has an impact on the performance itself. This also uses a hopper cooling system which is certainly not effective, because it's necessary to see that the water in the reservoir is still or not, also not equipped with an engine temperature display so it's difficult to ascertain the temperature inside. This study aims to monitor and control the temperature of cooling water. Operation of temperature control uses a telecontrol system that is connected to network (Internet of Things) so diesel temperature control can be done remotely. Monitoring of temperature and water level in the reserve tank using Web Mobile. In addition, there is a temperature sensor that is used to measure the temperature of the cooling water so that users can monitor the temperature of the diesel engine on Web Mobile. The test results obtained, the temperature sensor has an average temperature reading error of 0.031004%. Diesel engines with controlled solenoid valve cooling systems can produce ideal temperatures compared to when the solenoid valve is open (using the radiator continuously) or when the solenoid valve is Closed (without using a radiator). When the solenoid is controlled the engine temperature can be ideal because the solenoid valve opening and closing system has the lowest temperature of 56.34oC and the highest temperature of only 80.85oC.

Research on the Periodicity of Flow Field in a Compressor Sector Cascade

2020 ◽  
Author(s):  
Wenfeng Xu ◽  
Peng Sun ◽  
Guogang Yang
Keyword(s):  
Flow Field ◽  
Design Method ◽  
Flow Characteristics ◽  
Suction Side ◽  
Low Energy ◽  
Experimental Conditions ◽  
Flow Passage ◽  
Aerodynamic Parameters ◽  
Real Flow ◽  
Annular Cascade

Abstract Sector cascade experiments can not only be convenient to measure various aerodynamic parameters but also reveal the real flow characteristics in turbomachinery. However, the sector cascade is only a part of the whole annular cascade. The circumferential angle, the structure of the side guide plate (SGP) and the suction mode on the SGP have a great effect on the periodicity of the flow field. Therefore, the effect of structure on periodicity must be taken into consideration in order to obtain accurate data of the sector cascade experiment. In this paper, a compressor sector cascade composed of a row of adjustable guide vanes (AGVs) and a row of stators is designed. The effect of the circumferential angle, SGP structure and suction position on the periodicity is studied by numerical simulation. An optimal cascade scheme is selected for experimental research. The results show that a larger circumferential angle can weaken the effect of low-energy fluid near the SGP on the middle passages. However, given the limited experimental conditions, the circumferential angle is set at 110° which consists of 15 AGVs and 14 stators. What’s more, the SGP with the same bowed angle of AGV on both sides of the cascade can reduce the influence of the SGP on the adjacent passages and obtain a regular periodicity. The low-energy fluids still accumulate near the SGP. The suction near the stator suction side of the SGP can alleviate the blockage in the flow passage and further improve the periodicity of the cascade. Serious analysis of the experiment results have further identified that the suction near the stator suction side of SGP can make the aerodynamic parameters of the flow field uniform and lead to a good periodicity. At the same time, the feasibility of this design method is verified.

scholarly journals Flow Characteristics and Stress Analysis of a Parallel Gate Valve

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 803 ◽  
Author(s):  
Hui Wu ◽  
Jun-ye Li ◽  
Zhi-xin Gao
Keyword(s):  
Reynolds Number ◽  
Gate Valve ◽  
High Stress ◽  
Flow Characteristics ◽  
Groove Depth ◽  
Loss Coefficient ◽  
Flow Coefficient ◽  
Piping System ◽  
Valve Opening ◽  
Contact Position

Gate valves have been widely used in the piping system and have attracted a lot of attention from researchers. In this paper, a wedge-type double disk parallel gate valve is chosen to be analyzed. The Reynolds number varying from 200 to 500,000, and the valve opening degree varying from 20% to 100%, and the groove depth varying from 2.3 mm to 9 mm are chosen to investigate their effects on the flow and loss coefficients of the gate valve. The results show that the loss coefficient decreases and the flow coefficient increases with the increase of the Reynolds number and the valve opening degree, while with the increase of the groove depth, the loss coefficient barely changes, but the flow coefficient increases if the Reynolds number is larger than 10,000. In addition, the effects of the gaps between the disk and the limit stop on the stress distribution of the bolt are also investigated, and the results show that if the gaps are negative, high stress will act on the bolt at the contact position between the bolt and the limit stop.

scholarly journals Experimental Study on Pressure Distribution and Flow Coefficient of Globe Valve

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 875 ◽  
Author(s):  
Quang Khai Nguyen ◽  
Kwang Hyo Jung ◽  
Gang Nam Lee ◽  
Sung Bu Suh ◽  
Peter To
Keyword(s):  
Reynolds Number ◽  
Pressure Distribution ◽  
Full Range ◽  
Flow Characteristics ◽  
National Standards ◽  
Flow Coefficient ◽  
Test Loop ◽  
Close Range ◽  
Valve Opening ◽  
Globe Valve

In this study, the pressure distribution and flow coefficient of a globe valve are investigated with a series of experiments conducted in a flow test loop. The experiments are performed on a three-inch model test valve from an eight-inch ANSI (American National Standards Institute) B16.11—Class 2500# prototype globe valve with various pump speeds and full range of valve openings. Both inherent and installed flow characteristics are measured, and the results show that the flow coefficient depends not only on the valve geometry and valve opening but also on the Reynolds number. When the Reynolds number exceeds a certain value, the flow coefficients are stable. In addition, the pressures at different positions in the upstream and the downstream of the valve are measured and compared with recommendation per ANSI/ISA-75.01 standard. The results show that, in single-phase flow, the discrepancies in pressure between different measurement locations within close range of 10 nominal diameter from the valve are inconsiderable.

Quantitative Analysis of the Linkage between the interphalangeal Joints of the Index Finger

1995 ◽  
Vol 20 (5) ◽  
pp. 696-699 ◽  
Author(s):  
P. HAHN ◽  
H. KRIMMER ◽  
A. HRADETZKY ◽  
U. LANZ
Keyword(s):  
System Analysis ◽  
Measuring System ◽  
Dominant Hand ◽  
Rectangular Coordinate System ◽  
Simple Method ◽  
Significant Difference ◽  
Pip Joint ◽  
Distal Interphalangeal ◽  
Joint Flexion ◽  
Opening And Closing

We have established a simple method of measuring joint motion under physiological conditions. For this purpose we use an ultrasound measuring system employing marker points consisting of miniaturized ultrasound transmitters. This device was tested on a simple biomeehanical model, the linkage of the proximal and distal interphalangeal joints. The angles of these joints were recorded during opening and closing of the fist in 34 index fingers of 17 healthy persons. The results of the measurements were plotted on a rectangular coordinate system. Analysis showed an approximately linear linkage between the IP joints of the index linger. The curve for extension was the same as that for flexion. The linkage varies greatly. On average 1° of PIP joint flexion is equivalent to 0.76° of DIP joint flexion. Our study showed no significant difference between the dominant and non-dominant hand. The results showed that there is a linear linkage between the proximal and distal interphalangeal joints, which is equal for flexion and extension.

scholarly journals Selective Reduction of Ketones and Aldehydes in Continuous-Flow Microreactor—Kinetic Studies

Catalysts ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 221 ◽  
Author(s):  
Katarzyna Maresz ◽  
Agnieszka Ciemięga ◽  
Julita Mrowiec-Białoń
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Flow Characteristics ◽  
Selective Reduction ◽  
Kinetic Studies ◽  
Attractive Alternative ◽  
Batch Reactors ◽  
Flow Process ◽  
Micro Flow ◽  
Flow Microreactors

In this work, the kinetics of Meerwein–Ponndorf–Verley chemoselective reduction of carbonyl compounds was studied in monolithic continuous-flow microreactors. To the best of our knowledge, this is the first report on the MPV reaction kinetics performed in a flow process. The microreactors are a very attractive alternative to the batch reactors conventionally used in this process. The proposed micro-flow system for synthesis of unsaturated secondary alcohols proved to be very efficient and easily controlled. The microreactors had reactive cores made of zirconium-functionalized silica monoliths of excellent catalytic properties and flow characteristics. The catalytic experiments were carried out with the use of 2-butanol as a hydrogen donor. Herein, we present the kinetic parameters of cyclohexanone reduction in a flow reactor and data on the reaction rate for several important ketones and aldehydes. The lack of diffusion constraints in the microreactors was demonstrated. Our results were compared with those from other authors and demonstrate the great potential of microreactor applications in fine chemical and complex intermediate manufacturing.

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