scholarly journals Determination of variables for air distribution system with elastic valve for down-the-hole pneumatic hammer

2017 ◽  
Vol 53 ◽  
pp. 012025
Author(s):  
AYu Primychkin ◽  
AS Kondratenko ◽  
VV Timonin
Keyword(s):  
Distribution System ◽  
Air Distribution ◽  
Pneumatic Hammer ◽  
Elastic Valve

scholarly journals CALCULATUION OF DYNAMIC PARAMETERS OF REVERSE CHAMBER OF PNEUMATIC HAMMER WITH MECHANICAL LOCKING OF ELASTIC VALVE

2019 ◽  
Vol 2 (5) ◽  
pp. 98-102
Author(s):  
Alexander Chervov
Keyword(s):  
Distribution System ◽  
Cylindrical Part ◽  
Short Description ◽  
Air Pressure ◽  
Air Distribution ◽  
Pneumatic Hammer ◽  
Elastic Valve ◽  
Working Chamber ◽  
Method Of Calculation ◽  
Exhaust Line

In paper short description of construction and functioning of pneumatic hammer with air distribution system based on application of elastic valve in exhaust line of reverse chamber is carried out. Using specified parameters of pneumatic hammer (percussion energy, percussion speed, ration of chamber squares, form of working chamber, compressed air pressure and etc.) mass of striking pin, working path, diameters of working chamber and cylindrical part of reverse chamber, dimensions of circle elastic valve are calculated. Proposed method of calculation considers change of cross-section of reverse chamber when striking pin moves back. Obtained calculated values have allowed to develop diagram chart of change of air pressure in reverse chamber in dependence on time.

scholarly journals IMPROVEMENT OF DESIGN OF PNEUMATIC HAMMER FOR DRIVING VERTICAL PIPES WITH LARGE DIAMETER INTO SOIL

2020 ◽  
Vol 2 ◽  
pp. 219-225
Author(s):  
Vladimir V. Chervov
Keyword(s):  
Fatigue Failure ◽  
Distribution System ◽  
Work Performance ◽  
Large Diameter ◽  
Large Mass ◽  
Operating Principle ◽  
Main Element ◽  
Air Distribution ◽  
Pneumatic Hammer ◽  
Basic Parameters

A brief description of the equipment used for trenchless pipe laying is given. The basic parameters of a pneumatic hammer designed for driving pipes into soil with an open end greater than 426 mm in diameter are substantiated. The description of the device and operating principle of a pneumatic hammer with an air distribution system using an elastic circular valve as the main element is presented. Based on the analysis of many-year operation of equipment for trenchless pipe laying and driving vertical pipes, the frequency and sequence of crack appearance, destruction and failure of the main parts of the pneumatic hammer are determined. New principles of calculation and design of a pneumatic hammer with a large mass of the striking part without loss of work performance are proposed. The solution to the problems associated with fatigue failure of the main parts is a decrease in striking velocity.

scholarly journals DESIGNING ANNULAR ELASTIC VALVE THAT CONTROLS AIR EXHAUST FROM WORKING CHAMBER OF PNEUMATIC IMPACT MACHINE

2021 ◽  
Vol 2 (4) ◽  
pp. 78-86
Author(s):  
Alexander Yu. Primychkin
Keyword(s):  
Distribution System ◽  
Energy Performance ◽  
Design Stage ◽  
Air Distribution ◽  
Elastic Valve ◽  
Impact Machine ◽  
Energy Characteristics ◽  
Working Chamber ◽  
Pneumatic Impact ◽  
And Control

The paper considers one of the promising shut-off and control elements of the air distribution system of pneumatic impact machines - an annular elastic valve (CUV). This element allows you to reduce the energy consumption of pneumatic devices. Unfavorable combinations of factors that hinder the movement of the valve necessary for sealing the working chamber are considered. The paper presents a method for calculating the elastic valve that controls the release of energy from the return chamber of the pneumatic impact machine, which allows determining the main geometric dimensions of the valve device at the design stage, which provides a stable self-oscillating cycle of the pneumatic impact machine with the specified energy characteristics. The developed technique was used in the modernization of the air distribution system of the ring impact machine (KUM), designed for immersion of rod elements in the ground. Tests of the resulting sample in production conditions confirmed the increase in energy performance compared to previously produced machines of a similar type.

Determining the Norton’s Equivalent Model of Distribution System with Distributed Generation (DG) for Stability Analysis

2019 ◽  
Vol 12 (2) ◽  
pp. 190-198
Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar
Keyword(s):  
Distributed Generation ◽  
Normal Condition ◽  
Distribution System ◽  
Distribution Networks ◽  
Equivalent Model ◽  
Stability Factor ◽  
Matlab Simulation ◽  
The Stability ◽  
Stability Issues

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.

scholarly journals A CFD analysis of room aspect ratio on the effect of buoyancy and room air flow

2007 ◽  
Vol 11 (4) ◽  
pp. 79-94 ◽  
Author(s):  
Brajesh Tripathi ◽  
Moulic Sandipan ◽  
Late Arora
Keyword(s):  
Temperature Distribution ◽  
Distribution System ◽  
Air Distribution ◽  
Cooling Load ◽  
Cfd Analysis ◽  
Uniform Temperature ◽  
Air Volume ◽  
Recent Developments ◽  
Careful Design ◽  
Occupied Zone

Comfort conditions in air-conditioned rooms require that temperature in the occupied zone should not vary by more than 1?C and velocity, every where in the room, should be less than 0.15 m/s so that occupants do not feel draft. Recent developments in providing effective insulation and making leak tight buildings are considerably reduced the cooling load requirements and the supply airflow rates. Obtaining uniform temperature distribution with reduced air volume flow rates requires careful design of air distribution system. This study aims to find velocity and temperature distribution in the room towards this end.

scholarly journals Numerical Study on Coupled Operation of Stratified Air Distribution System and Natural Ventilation under Multi-Variable Factors in Large Space Buildings

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8130
Author(s):  
Ziwen Dong ◽  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Hao Huang
Keyword(s):  
Thermal Comfort ◽  
Working Conditions ◽  
Distribution System ◽  
Distribution Systems ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Air Distribution ◽  
Large Space ◽  
Air Conditioners ◽  
Air Supply

Stratified air distribution systems are commonly used in large space buildings. The research on the airflow organization of stratified air conditioners is deficient in terms of the analysis of multivariable factors. Moreover, studies on the coupled operation of stratified air conditioners and natural ventilation are few. In this paper, taking a Shanghai Airport Terminal departure hall for the study, air distribution and thermal comfort of the cross-section at a height of 1.6 m are simulated and compared under different working conditions, and the effect of natural ventilation coupling operation is studied. The results show that the air distribution is the most uniform and the thermal comfort is the best (predicted mean vote is 0.428, predicted percentage of dissatisfaction is 15.2%) when the working conditions are 5.9% air supply speed, 11 °C cooling temperature difference and 0° air supply angle. With the coupled operation of natural ventilation, the thermal comfort can be improved from Grade II to Grade I.

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