scholarly journals Improving the Response Performance of Anti-Surge Control Valve for Gas Compressors

2021 ◽  
Vol 6 (7) ◽  
pp. 62-68
Author(s):  
Haruna A. Ogweda ◽  
Joseph E. Okhaifoh
Keyword(s):  
Response Time ◽  
Great Improvement ◽  
Control Valve ◽  
Initial System ◽  
Design Modification ◽  
Average Percentage ◽  
Percentage Improvement ◽  
Surge Control ◽  
Response Performance ◽  
Set Up

Anti-surge control valves are used for the protection of gas compressors by opening to relief sudden pressures (surge) which could damage the compressor internals. It is of great importance that the response of the anti-surge valves to surge detection is swift and within a few seconds since a little delay could cause catastrophic damages to the compressor it is meant to protect. In this paper, a design modification was done on an existing anti-surge valve to improve its response time. The modified system was designed and implemented, installed, and commissioned on a mixed refrigerant compressor. The modified system was tested, and the response performance was recorded. Results obtained showed average percentage improvement of 86% to that of the initial system. Also, the response performance of the modified system was less than 3 seconds as compared to the initial set-up which averages 9 seconds. This is indeed a great improvement in comparison to the initial system.

Remote-mount Actuation Control: A Veritable Solution to Unreliability of Anti-surge Control Valves in Gas Compressors

2021 ◽  
Vol 6 (7) ◽  
pp. 160-163
Author(s):  
Haruna A. Ogweda ◽  
Joseph E. Okhaifoh
Keyword(s):  
Control Valve ◽  
Industrial Plant ◽  
Test Results ◽  
Average Percentage ◽  
Design And Implementation ◽  
System A ◽  
Surge Control ◽  
Set Up ◽  
Stress Fatigue ◽  
Component Failures

This paper presents the design and implementation of a remotely mounted Anti-surge Control Valve (ASCV) for a mixed refrigerant gas compressor deployed in an industrial plant. The traditional ASCV model which is usually self-mounted is plagued by component failures due to stress fatigue from excessive vibrations leading to unreliability of the system. A new system with a remote-mount actuation control system was developed, tested, installed and commissioned in place of the initial self-mount system. Test results showed that average percentage of trips caused by failure of the ASCV dropped from 70% with the initial set-up to 0% with the modified set-up. Hence, a lasting solution to the issue of component fatigue failure from vibrations has been resolved using the highly reliable developed remote-mount actuation control.

scholarly journals PENERAPAN MODEL PEMBELAJARAN KOOEPERATIF TIPE MAKE A MATCH UNTUK MENINGKATKAN HASIL BELAJAR IPS SISWA KELAS V SEKOLAH DASAR

2018 ◽  
Vol 7 (1) ◽  
pp. 170
Author(s):  
Samsur Samsur
Keyword(s):  
Student Learning ◽  
Learning Outcomes ◽  
Implementation Strategies ◽  
Learning Models ◽  
Class V ◽  
Average Percentage ◽  
Average Value ◽  
Percentage Improvement ◽  
Match Type ◽  
Academic Year

This research is motivated by the lack of IPS student learning outcomes can be seen from the results of thestudents' social studies class V SD Negeri 54 Sebangar with an average value of 60.65. Therefore, theresearchers provide an alternative implementation strategies in the classroom to the application of learningmodels kooeperatif make a match type in the class V SD Negeri 54 Sebangar in the academic year 2014/2015.This research aims to improve learning outcomes IPS V grade students of SD Negeri 54 Sebangar with theapplication of learning models kooeperatif make a match type in the class V Implementation Strategy. Form ofresearch is the Classroom Action Research (PTK) with 2 cycles. Based on research data anlisis after applying oflearning models kooeperatif make a match type, the average percentage of the activity of teachers in the firstcycle 74.99% increased to 91.06% in the second cycle. The average percentage of student activity alsoincreased, namely 67.85% in the first cycle increased to 82.14% in the second cycle. Student learning outcomesin basic score by the average value of 60.65 and the first cycle increased with an average value of 75.00 classwith a 23.66% increase in the percentage of learning outcomes and the percentage of students who completed84.61%, and the second cycle increased again by an average of 82.30 with the percentage improvement classlearning outcomes 35.69% and the percentage of students who completed 88.46%. These results indicate that theapplication the application of learning models kooeperatif make a match type in the class V IPS grade studentsof SD Negeri 54 Sebangar.

Modelling and Experimental Validation of a Controllable Energy Harvester for Pressure Regulation

2019 ◽  
Author(s):  
Youngmok Ko ◽  
Shi Miao Yu ◽  
Amy M. Bilton
Keyword(s):  
Pressure Drop ◽  
Energy Harvester ◽  
Guide Vane ◽  
Electrical Power ◽  
Computational Cost ◽  
Control Valve ◽  
Francis Turbine ◽  
Pressure Regulation ◽  
Cfd Model ◽  
Set Up

Abstract A pico-scale Francis turbine (or energy harvester) was designed, fabricated and tested for pressure regulation and power generation application. The prototype energy harvester contains pivotable guide vanes and a controllable load to change the runner speed. This allows the simultaneous variation of the pressure drop and the output power. A computational fluid dynamics (CFD) model of the turbine was developed in ANSYS CFX 18.1 to evaluate the turbine’s sensitivity to geometric parameters such as the clearance gap size of the guide vane and its modularity. In conjunction to the CFD model, the electric generator’s characteristics were used to predict the turbine performance at varying guide vane angles. The turbine was prototyped and tested using a custom-built experimental set-up. The pico-scale turbine, with a runner diameter of 1.42 inches, was able to output up to 100 W of electrical power at its rated flowrate of 29 GPM. By varying the guide vane angles, the pressure drop and the hydraulic efficiency varied between 3–22 psi and up to 60% respectively. When validated against the experimental results, the CFD model showed a good agreement despite its low computational cost. The energy harvester’s initial characteristics demonstrate its potential as a game changer in the control valve market.

Response Time Optimisation of the Rankine Compression Gas Turbine (RCG)

2006 ◽  
Author(s):  
H. Ouwerkerk ◽  
H. C. de Lange
Keyword(s):  
Response Time ◽  
Gas Turbine ◽  
Combined Cycle ◽  
Short Response Time ◽  
Part Load ◽  
Full Load ◽  
Ship Propulsion ◽  
Power Turbine ◽  
New Type ◽  
Set Up

The Rankine Compression Gas turbine (RCG) is a new type of combined cycle that delivers all power on one free power turbine. With its free power turbine the intended fields of application of the RCG are mechanical drives and ship propulsion. For the RCG to become successful in these fields of application a short response time from part-load to full-load is vital. Experiments with an experimental set-up at the Technische Universiteit Eindhoven showed that the response time would benefit from after-spray and supplementary firing. Therefore, these items were implemented in an overdrive controller that was designed to accelerate the RCG cycle more quickly. Simulations showed that the overdrive controller dramatically reduces the response time of the modeled RCG-cycle in a transient from 50% part-load to full-load from 20 minutes down to about 2 minutes. This is an impressive improvement of the response time and is believed to make the RCG suitable for mechanical drives and ship propulsion.

Dynamic Stochastic Modeling in Single Unit Job Lot Fabrication of Vehicle Components Assembly Test

2012 ◽  
Vol 628 ◽  
pp. 95-100
Author(s):  
Qian Ting Wang
Keyword(s):  
Production Process ◽  
Single Unit ◽  
Low Cost ◽  
Transition Probability ◽  
Transition Probability Matrix ◽  
Design Modification ◽  
High Efficient ◽  
Dynamic Stochastic ◽  
Vehicle Components ◽  
Set Up

The fabrication mode of vehicle components assembly tester belongs to single unit job lot production, with single quantity and mass operations. In order to produce them with high efficient and low cost, the resources configuration method plays an important role. The fabrication simulation model using a dynamic stochastic function is set up. First, the stochastic factors, including uncertainties of production task caused by market variety, production duration caused by design modification and production process caused by resource configuration diversity, are described with the change of production operations. Then the dynamic stochastic model of production process is set up on the basis of the transition probability matrix, preparation time and flexible time. As an example, the application method of this model for the synchronous fabrication process of drive axle performance tester and running tester is investigated. The results show that this method can be used for the planning and evaluation for the complex equipments fabrication within specified period.

scholarly journals An improved algorithm to minimize the total completion time in a two-machine no-wait flow-shop with uncertain setup times

2022 ◽  
Vol 7 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Muberra Allahverdi
Keyword(s):  
Completion Time ◽  
Flow Shop ◽  
Performance Measure ◽  
Setup Times ◽  
Total Completion Time ◽  
Average Percentage ◽  
Percentage Improvement ◽  
Wide Range ◽  
Test Of Hypothesis ◽  
No Wait

Since scheduling literature has a wide range of uncertainties, it is crucial to take these into account when solving performance measure problems. Otherwise, the performance may severely be affected in a negative way. In this paper, an algorithm is proposed to minimize the total completion time (TCT) of a two-machine no-wait flowshop with uncertain setup times within lower and upper bounds. The results are compared to the best existing algorithm in scheduling literature: the programming language Python is used to generate random samples with respect to various distributions, and the TCT of the proposed algorithm is compared to that of the best existing one. Results reveal that the proposed one significantly outperforms the best one given in literature for all considered distributions. Specifically, the average percentage improvement of the proposed algorithm over the best existing one is over 90%. A test of hypothesis is conducted to further confirm the results.

Virtual Telemedicine and Virtual Telehealth

2012 ◽  
pp. 183-195
Author(s):  
Shazia Kareem ◽  
Imran Sarwar Bajwa
Keyword(s):  
Response Time ◽  
Low Cost ◽  
Operating Cost ◽  
Critical Factor ◽  
High Standard ◽  
Clinical Decision ◽  
Modern Technology ◽  
The People ◽  
Store And Forward ◽  
Set Up

Telemedicine is modern technology that is employed to provide low cost, high standard medical facilities to the people of remote areas. Store-and-Forward method of telemedicine suits more to the progressive countries like Pakistan as not only is it easy to set up but it also has a very cheap operating cost. However, the high response time taken by store & forward telemedicine becomes a critical factor in emergency cases, where each minute has a price. The response time factor can be overcome by using virtual telemedicine approach. In virtual telemedicine, a Clinical Decision Support System (CDSS) is deployed at rural station. The CDSS is intelligent enough to diagnose a patient’s disease and prescribe proper medication. In case the CDSS cannot answer a query, the CDSS immediately sends an e-mail to a medical expert (doctor), and when the response is received, the CDSS knowledge-base is updated for future queries. In this chapter, the authors not only report a NL-based CDSS that can answer NL queries, but also present a complete architecture of a virtual telemedicine setup.

The Proximal Interphalangeal Joint in Dupuytren’s Disease

1985 ◽  
Vol 10 (3) ◽  
pp. 358-364
Author(s):  
M. A. TONKIN ◽  
F. D. BURKE ◽  
J. P. W. VARIAN
Keyword(s):  
Surgical Approach ◽  
Proximal Phalanx ◽  
Flexion Contracture ◽  
Proximal Interphalangeal Joint ◽  
Interphalangeal Joint ◽  
Joint Contracture ◽  
Dupuytren’S Disease ◽  
Dupuytren's Disease ◽  
Average Percentage ◽  
Percentage Improvement

In one hundred patients with Dupuytren’s disease, one hundred and fifty-four operations were performed. The average pre-operative proximal interphalangeal joint contracture was 42° and the average percentage improvement in proximal interphalangeal joint extension at post­operative review was 41%. Fourteen amputations were performed (9.1%). The primary deformity is caused by disease involvement of the palmar fascial structures. Secondary changes may prevent correction of the deformity despite excision of the contracted fascia. The anatomy of the joint is reviewed together with the primary and secondary mechanisms of joint contracture in Dupuytren's disease. Arthrodesis, osteotomy of the proximal phalanx and joint replacement are considered as alternatives to amputation when a systematic surgical approach fails to correct the flexion contracture.

Application of GPC Algorithm in Level Control System

2014 ◽  
Vol 541-542 ◽  
pp. 1222-1227 ◽  
Author(s):  
Yan Xiang Wu ◽  
Zhong Yong Gao
Keyword(s):  
Control System ◽  
Predictive Control ◽  
Control Device ◽  
Generalized Predictive Control ◽  
Water Tank ◽  
Level Control ◽  
Control Effect ◽  
Response Performance ◽  
Set Up ◽  
Improved Methods

In order to improve the dependability and security of the lever control system, we introduced the generalized predictive control (GPC) algorithm. We used MATLAB/Simulink program development tools to control the double capacity water tank. At first, we used the water tank level control device as the object and set up a mathematical model of the control system. Then we put forward the generalized predictive control algorithm based on the model. The simulation results show that the presented algorithm has a good dynamic response performance, fast-track settings, and a preferable control effect. Experimental results show that the improved methods are reasonable and practicable.

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