Simulation on an Experimental System for the Dynamic Characteristics of Safety Valves with High Pressure and Large Flow Rate

2012 ◽  
Vol 263-266 ◽  
pp. 748-755 ◽  
Author(s):  
Xiao Feng He ◽  
Long Jun Luo ◽  
Xiang Lin Liu ◽  
Xiao Hui Luo
Keyword(s):  
Flow Rate ◽  
Dynamic Performance ◽  
Control Valve ◽  
Experimental System ◽  
Test System ◽  
Software Modeling ◽  
Dynamic Experiment ◽  
Negative Effects ◽  
Hydraulic Support ◽  
Large Flow

Safety valves play very important role in protecting the safety of hydraulic support in coal mine. However, its development is greatly limited by the corresponding test bench for the dynamic experiment. In this paper, an experimental system for testing the dynamic performance of the safety valve with rated pressure up to 50MPa and rated flow rate up to 2000L/min, is introduced. Based on AMEsim software, modeling and simulation on the designed system is carried out. Some parameters of the system are also analyzed and their influences to the tested valve’s dynamic performance are obtained by simulation. It is found that the designed system, which adopting the combination of a piston and a plunger cylindersas well as accumulators, can fulfill the demands of the relevant standard. Among all the investigated factors, both the volume and pre-charged gas pressure of the accumulators have optimum values matching with the other parameters of the system. The stroke of the plunger cylinder, the rated flow rates of the cartridge valve and its pilot control valve, are required to be higher than a certain value to avoid negative effects on the dynamic performance of the tested valve. The research presented in this paper is helpful to the design of the test system.

Analysis and Modification of the Design of Fluid Power Control System for the Improvement of Product Quality

2013 ◽  
Author(s):  
Tahany W. Sadak ◽  
Taha E. Mkawee
Keyword(s):  
Flow Control ◽  
Flow Rate ◽  
System Performance ◽  
Dynamic Performance ◽  
Control Valve ◽  
Operating Conditions ◽  
Flow Control Valve ◽  
Supply Pressure ◽  
System Designs ◽  
Proportional Flow

This research investigation is focused on providing system performance under different operating conditions, with special focus on variations in the supply pressure. The investigations have been carried out for different system designs. The analysis of the results introduces the effect of system designs on its static and dynamic performance. Also, the investigations provide the effect of variations of system operating conditions and load value. A hydraulic system has been designed with variable velocity, pressure and load. The detailed examination has been carried out on a system that consists of a hydraulic power supply unit, control valves (pressure control valve, flow control valve, throttle valve and directional control valve). We have investigated the effect of adding a flow control valve (FCV) in the chosen circuit and also replacing the FCV with a proportional flow control valve (PFCV). In order to study the effect of this valve on system performance we examine the role of change of operating conditions and loading values on the system performance. Thus the displacement and speed of the piston of the hydraulic cylinder has been experimented under different values of supply pressure, flow rate, and load. We make this investigation to develop the performance evaluation by replacing the (FCV) by proportional flow control valve (PFCV) via position control so that one can achieve the static and dynamic performance of the system more accurate. Apparent improvement in flow rate ranges from 8% to 29.5% and dynamic response from 30 to 64%. The results reveal that this methodology allows one to achieve high quality of the product.

Power Test System Development and Dynamic Performance State Estimation Based on Hub Motor Vehicle

2020 ◽  
Vol 13 (2) ◽  
pp. 126-140
Author(s):  
Jing Gan ◽  
Xiaobin Fan ◽  
Zeng Song ◽  
Mingyue Zhang ◽  
Bin Zhao
Keyword(s):  
Real Time ◽  
Dynamic Performance ◽  
Test System ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Maximum Speed ◽  
Performance Parameters ◽  
Power Performance ◽  
Power Test ◽  
The Real

Background: The power performance of an electric vehicle is the basic parameter. Traditional test equipment, such as the expensive chassis dynamometer, not only increases the cost of testing but also makes it impossible to measure all the performance parameters of an electric vehicle. Objective: A set of convenient, efficient and sensitive power measurement system for electric vehicles is developed to obtain the real-time power changes of hub-motor vehicles under various operating conditions, and the dynamic performance parameters of hub-motor vehicles are obtained through the system. Methods: Firstly, a set of on-board power test system is developed by using virtual instrument (Lab- VIEW). This test system can obtain the power changes of hub-motor vehicles under various operating conditions in real-time and save data in real-time. Then, the driving resistance of hub-motor vehicles is analyzed, and the power performance of hub-motor vehicles is studied in depth. The power testing system is proposed to test the input power of both ends of the driving motor, and the chassis dynamometer is combined to test so that the output efficiency of the driving motor can be easily obtained without disassembly. Finally, this method is used to carry out the road test and obtain the vehicle dynamic performance parameters. Results: The real-time current, voltage and power, maximum power, acceleration time and maximum speed of the vehicle can be obtained accurately by using the power test system in the real road experiment. Conclusion: The maximum power required by the two motors reaches about 9KW, and it takes about 20 seconds to reach the maximum speed. The total power required to maintain the maximum speed is about 7.8kw, and the maximum speed is 62km/h. In this article, various patents have been discussed.

scholarly journals Thermal Efficiency and Economics of a Boil-Off Hydrogen Re-Liquefaction System Considering the Energy Efficiency Design Index for Liquid Hydrogen Carriers

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4566
Author(s):  
Minsoo Choi ◽  
Wongwan Jung ◽  
Sanghyuk Lee ◽  
Taehwan Joung ◽  
Daejun Chang
Keyword(s):  
Flow Rate ◽  
Life Cycle Cost ◽  
Specific Energy Consumption ◽  
Liquid Hydrogen ◽  
Efficient Design ◽  
Fuel Cell Stack ◽  
Energy Efficiency Design Index ◽  
The Cost ◽  
Large Flow

This study analyzes the thermodynamic, economic, and regulatory aspects of boil-off hydrogen (BOH) in liquid hydrogen (LH2) carriers that can be re-liquefied using a proposed re-liquefaction system or used as fuel in a fuel cell stack. Five LH2 carriers sailing between two designated ports are considered in a case study. The specific energy consumption of the proposed re-liquefaction system varies from 8.22 to 10.80 kWh/kg as the re-liquefaction-to-generation fraction (R/G fraction) is varied. The economic evaluation results show that the cost of re-liquefaction decreases as the re-liquefied flow rate increases and converges to 1.5 $/kg at an adequately large flow rate. Three energy efficient design index (EEDI) candidates are proposed to determine feasible R/G fractions: an EEDI equivalent to that of LNG carriers, an EEDI that considers the energy density of LH2, and no EEDI restrictions. The first EEDI candidate is so strict that the majority of the BOH should be used as fuel. In the case of the second EEDI candidate, the permittable R/G fraction is between 25% and 33%. If the EEDI is not applied for LH2 carriers, as in the third candidate, the specific life-cycle cost decreases to 67% compared with the first EEDI regulation.

scholarly journals Off-Design Dynamic Performance Analysis of a Solar Aided Coal-Fired Power Plant

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2950
Author(s):  
Vinod Kumar ◽  
Liqiang Duan
Keyword(s):  
Power Plant ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Dynamic Performance ◽  
Feed Water ◽  
Saving Rate ◽  
Coal Consumption ◽  
Dynamic Performance Analysis

Coal consumption and CO2 emissions are the major concerns of the 21st century. Solar aided (coal-fired) power generation (SAPG) is paid more and more attention globally, due to the lesser coal rate and initial cost than the original coal-fired power plant and CSP technology respectively. In this paper, the off-design dynamic performance simulation model of a solar aided coal-fired power plant is established. A 330 MW subcritical coal-fired power plant is taken as a case study. On a typical day, three various collector area solar fields are integrated into the coal-fired power plant. By introducing the solar heat, the variations of system performances are analyzed at design load, 75% load, and 50% load. Analyzed parameters with the change of DNI include the thermal oil mass flow rate, the mass flow rate of feed water heated by the solar energy, steam extraction mass flow rate, coal consumption, and the plant thermal efficiency. The research results show that, as DNI increases over a day, the coal saving rate will also increase, the maximum coal saving rate reaches up to 5%, and plant thermal efficiency reaches 40%. It is analyzed that the SAPG system gives the best performance at a lower load and a large aperture area.

Development of a Ring Permeability Test System

2010 ◽  
Vol 136 ◽  
pp. 153-157
Author(s):  
Yu Hong Du ◽  
Xiu Ming Jiang ◽  
Xiu Ren Li
Keyword(s):  
Control System ◽  
Control Method ◽  
Dynamic Performance ◽  
Experimental Tests ◽  
Measuring Method ◽  
Test System ◽  
Fluid Theory ◽  
And Control ◽  
Relationship Of ◽  
The Mathematical Model

To solve the problem of detecting the permeability of the textile machinery, a dedicated test system has been developed based on the pressure difference measuring method. The established system has a number of advantages including simple, fast and accurate. The mathematical model of influencing factors for permeability is derived based on fluid theory, and the relationship of these parameters is achieved. Further investigations are directed towards the inherent characteristics of the control system. Based on the established model and measuring features, an information fusion based clustering control system is proposed to implement the measurement. Using this mechanical structure, a PID control system and a cluster control system have been developed. Simulation and experimental tests are carried out to examine the performance of the established system. It is noted that the clustering method has a high dynamic performance and control accuracy. This cluster fusion control method has been successfully utilized in powder metallurgy collar permeability testing.

Optimization of Inlet Ring Groove Arrangement for Suppression of Unstable Flow in a Centrifugal Impeller

2005 ◽  
Author(s):  
Masahiro Ishida ◽  
Daisaku Sakaguchi ◽  
Hironobu Ueki
Keyword(s):  
Flow Rate ◽  
The Other ◽  
Centrifugal Impeller ◽  
Shape Parameters ◽  
Unstable Flow ◽  
Ring Groove ◽  
Flow Rates ◽  
Small Flow ◽  
Specific Speed ◽  
Large Flow

An optimization of the inlet ring groove arrangement has been pursued in the present study for obtaining better impeller characteristics and a wider operation range at both small and large flow rates in a high specific speed type centrifugal impeller with inducer. The effects of the shape parameters with respect to the inlet ring groove on the impeller characteristic and the flow incidence were analyzed mainly based on numerical simulations, but also compared to the experimental results. At small flow rates, a significant improvement in the impeller characteristic is achieved due to reduction in the excessive-positive flow incidence by optimizing both location and width of the rear groove near the inducer tip throat. On the other hand, the impeller characteristic is improved at large flow rates by implementing the corner radius at the rear groove edge and by placing another front ring groove in the suction pipe. As a result, by the optimized configuration of the front and rear ring grooves, the unstable flow range of the test impeller can be reduced by about 50% without deterioration of the impeller characteristic even at the 125% flow rate.

Principle and structure of a multi-chamber piezoelectric pump with large flow rate integrated into printed circuit board

2022 ◽  
pp. 1045389X2110721
Author(s):  
Yun-Hao Peng ◽  
Dai-Hua Wang ◽  
Lian-Kai Tang
Keyword(s):  
Flow Rate ◽  
Compression Ratio ◽  
Layer Structure ◽  
Experimental Results ◽  
Processing Technology ◽  
Rate Model ◽  
Piezoelectric Pump ◽  
Central Deflection ◽  
Maximum Value ◽  
Large Flow

Parametric simulation of multi-chamber piezoelectric pump proposed by authors shows that its flow rate is positively correlated with chamber compression ratio when height of chamber wall is not less than central deflection of circular piezoelectric unimorph actuator (CPUA). Therefore, in this paper, principle and structure of multi-chamber piezoelectric pump with novel CPUAs with three-layer structure are proposed and realized, so as to improve its chamber compression ratio, and then improve its flow rate. Its processing technology compatible with PCB processing technology is studied and its flow rate model is established. Central deflection of CPUA with three-layer structure and the flow rate characteristics are tested. Experimental results show that when the central deflection of CPUA with three-layer structure reaches the maximum value of 106.8 μm, the chamber compression ratio and flow rate of multi-chamber piezoelectric pump reach the maximum value of 50% and 3.11 mL/min, respectively. The maximum flow rate is increased by 622% compared to unimproved pump. By comparing experimental results with numerical and finite element simulation results, the realized multi-chamber piezoelectric pump has large flow rate and the established flow rate model can predict its flow rate.

scholarly journals Investigation of Speed Matching Affecting Contrarotating Fan’s Performance Using Wireless Sensor Network including Big Data and Numerical Simulation

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hengxuan Luan ◽  
Liyuan Weng ◽  
Ranhui Liu ◽  
Yuanzhong Luan ◽  
Dongmin Li
Keyword(s):  
Big Data ◽  
Numerical Method ◽  
Flow Rate ◽  
Rate Condition ◽  
Small Flow Rate ◽  
Large Flow Rate ◽  
Small Flow ◽  
Power Capability ◽  
Two Stages ◽  
Large Flow

This paper describes the investigations performed to better understand two-stage rotor speed matching in a contrarotating fan. In addition, this study develops a comprehensive measuring and communication system for a contrarotating fan using ZigBee network. The investigation method is based on three-dimensional RANS simulations; the RANS equations are solved by the numerical method in conjunction with a SST turbulence model. A wireless measurement system using big data method is first designed, and then a comparison is done with experimental measurements to outline the capacity of the numerical method. The results show that when contrarotating fan worked under designed speed, performance of two-stages rotors could not be matched as the designed working condition was deviated. Rotor 1 had huge influences on flow rate characteristics of a contrarotating fan. Rotor 2 was influenced by flow rates significantly. Under large flow rate condition, the power capability of rotor 2 became very weak; under working small flow rate condition, overloading would take place to class II motor. In order to solve the performance mismatch between two stages of CRF under nondesigned working conditions, under small flow rate condition, the priority shall be given to increase of the speed of rotor 1, while the speed of rotor 2 shall be reduced appropriately; under large flow rate condition, the speed of rotor 1 shall be reduced and the speed of rotor 2 shall be increased at the same time.

scholarly journals Effect of Cooling Flow on the Operation of a Hot Rotor-Gas Foil Bearing System

2012 ◽  
Author(s):  
Keun Ryu ◽  
Luis San Andrés
Keyword(s):  
Thermal Management ◽  
Flow Rate ◽  
System Integration ◽  
Damping Ratio ◽  
Temperature Drop ◽  
Test System ◽  
The Body ◽  
Air Cooling ◽  
Cooling Flow ◽  
Management Procedures

Gas foil bearings (GFBs) operating at high temperature rely on thermal management procedures that supply needed cooling flow streams to keep the bearing and rotor from overheating. Poor thermal management not only makes systems inefficient and costly to operate but could also cause bearing seizure and premature system destruction. This paper presents comprehensive measurements of bearing temperatures and shaft dynamics conducted on a hollow rotor supported on two first generation GFBs. The hollow rotor (1.36 kg, 36.51 mm OD and 17.9 mm ID) is heated from inside to reach an outer surface temperature of 120°C. Experiments are conducted with rotor speeds to 30 krpm and with forced streams of air cooling the bearings and rotor. Air pressurization in an enclosure at the rotor mid span forces cooling air through the test GFBs. The cooling effect of the forced external flows is most distinct when the rotor is hottest and operating at the highest speed. The temperature drop per unit cooling flow rate significantly decreases as the cooling flow rate increases. Further measurements at thermal steady state conditions and at constant rotor speeds show that the cooling flows do not affect the amplitude and frequency contents of the rotor motions. Other tests while the rotor decelerates from 30 krpm to rest show that the test system (rigid-mode) critical speeds and modal damping ratio remain nearly invariant for operation with increasing rotor temperatures and with increasing cooling flow rates. Computational model predictions reproduce the test data with accuracy. The work adds to the body of knowledge on GFB performance and operation and provides empirically derived guidance for successful rotor-GFB system integration.

Research on Numerical Integration Algorithm for MDOF Pseudo-Dynamic Test

2012 ◽  
Vol 204-208 ◽  
pp. 4820-4826
Author(s):  
Xin Guo ◽  
Li Hua Zhu ◽  
Tian Li Wang
Keyword(s):  
Dynamic Test ◽  
Experimental System ◽  
Test System ◽  
Unconditional Stability ◽  
Comparison Study ◽  
Restoring Force ◽  
Integration Algorithm ◽  
Integration Algorithms ◽  
Simulation Results ◽  
Force Characteristics

This paper focuses on two integration algorithms used for pseudo-dynamic test, explicit Newmark algorithm and implicit alpha-C algorithm. The comparison study between the test and simulation results shows that: the non-uniform distribution of mass, restoring force characteristics and higher frequency vibration modality are simulated more accurately using the alpha-C algorithm than using explicit Newmark algorithm. The alpha-C algorithm also leads to high iterative accuracy and unconditional stability. Replacing the explicit Newmark algorithm in original experimental system by implicit alpha-C algorithm, the MDOF pseudo dynamic test system can be realized successfully.

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