Study on Dynamic Behavior of a Gas Pressure Relief Valve for a Big Flow Rate

Author(s):  
Victor Sverbilov ◽  
Dmitry Stadnick ◽  
Georgy Makaryants

The paper investigates instable behavior of a poppet-type gas pressure relief valve operating at a big flow rate (more than 2 kg/s) under super critical pressure drop. Instability is experienced as noise and vibration and leads to severe damage of a seat and other elements. Significant and unsteady flow forces coupled with small inherent damping make it difficult to stabilize the system. In previous works, the analytical and experimental research was carried out to reveal the most essential factors influencing stability and dynamic properties of the valve. The impact of the pilot valve dynamics on the system behavior was studied for the purpose of obtaining required accuracy and stability in a wide range of flow rate. It was shown in some testing that unstable behavior of the main valve occurred when the pilot valve was stable. This paper considers inherent stability of the main valve in the gas flow. CFD software ANSYS FLUENT is employed to study the effect of the poppet geometry on aerodynamic lifting force and valve stability in axial and lateral direction. The results have been verified through comparison with experimental data.

Author(s):  
Antonio Giuffrida ◽  
Rosario Lanzafame

The lubrication system for automotive internal combustion engines consists of several components. Oil flow rate for lubrication is generated by a positive displacement pump equipped with a pressure relief valve, usually present in the casing of the pump to prevent high oil pressures building up in the system and to deliver to the sump the exceeding generated flow rate. This study focuses on the static and dynamic characteristics of the pressure relief valve with considerations about the stability of the overall system, according to design parameters of both the valve and the system itself.


2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Sang Chan Jang ◽  
Jung Ho Kang

An important safety factor to be considered when designing a plant is the prevention of overpressure-induced explosions, to which many plants are vulnerable because of pressurized fluids in plant components. A pilot-operated pressure relief valve is a core device for venting off overpressure formed inside vessels and pipelines. The pilot-operated pressure relief valve has a highly complicated structure, and its design and production should be thoroughly studied. In this study, a simplified structure for the pilot-operated pressure relief valve was proposed to facilitate the design and production processes, and the effective ranges of its design variables were determined to enable the prediction of the impact of the design variables in the design and production processes. The ranges determined were validated by a numerical flow analysis and experiment as follows. We calculated the maximum orifice diameter at which the main valve does not open and examined the minimum orifice diameter that can resist the impact of strong shock waves. Additionally, we defined the orifice diameter range that ensures the stable opening and closing of the main valve under various pressure conditions. The effective ranges of the design variables determined in this study can be used to ensure safe operation of a pilot-operated pressure relief valve under various pressure conditions with the design of the proposed simplified structure.


Author(s):  
Giorgio Altare ◽  
Massimo Rundo ◽  
Micaela Olivetti

The paper deals with the 3D and 0D simulation of a conical popped pressure relief valve with flow force compensation. The commercial CFD code PumpLinx® was used to create a dynamic model of the valve and the interaction between the poppet dynamics and pressure field was taken into account. The model is able to determine the equilibrium position of the poppet in order to estimate the regulated pressure as function of the flow rate. A good agreement with the experimental data was found in the evaluation of the effect of the flow force compensation. Once validated, the CFD code was used to study the influence of the deflector geometry on the opening force. Moreover it was also used for determining some proper data to be supplied as input to a lumped parameters model of the valve. The tuning of the 0D model involved the discharge coefficient and the flow force. For the evaluation of the flow force compensation, a lookup table was calculated by the CFD code and then interpolated in the 0D model as function of the poppet displacement and of the flow rate.


Author(s):  
Manoj Sorade

Abstract: The problem of over speeding vehicles in highway transportation is one of major problem faced in the current scenario of Indian traffic. The issue of over speeding not only damages the vehicle but the serious consequence of this is there due to loss of precious life. In real life scenario accidents in are totally unavoidable we can only have counter measures to prevent them and avoid the fatalitiesinvolved. Safety impact guard is one of the real-time counter measures which reduce the impact when the vehicle is involved in high speed impact. The proposed design which is being discussed in detail throughout this paper is for design of a re-usable safety impact damper with pressure relief valve. This design discusses the force of energy or impact that is dampened due to the action of the impact damper with the pressure relief valve. The entire objective of the project is to reduce the fatalities by designing an impact damper which provides safety against the front and rear end collisions. Keywords: Impact, Pressure relief valve, Damper


2021 ◽  
Vol 11 (2) ◽  
pp. 466
Author(s):  
Włodzimierz Kęska ◽  
Jacek Marcinkiewicz ◽  
Łukasz Gierz ◽  
Żaneta Staszak ◽  
Jarosław Selech ◽  
...  

The continuous development of computer technology has made it applicable in many scientific fields, including research into a wide range of processes in agricultural machines. It allows the simulation of very complex physical phenomena, including grain motion. A recently discovered discrete element method (DEM) is used for this purpose. It involves direct integration of equations of grain system motion under the action of various forces, the most important of which are contact forces. The method’s accuracy depends mainly on precisely developed mathematical models of contacts. The creation of such models requires empirical validation, an experiment that investigates the course of contact forces at the moment of the impact of the grains. To achieve this, specialised test stations equipped with force and speed sensors were developed. The correct selection of testing equipment and interpretation of results play a decisive role in this type of research. This paper focuses on the evaluation of the force sensor dynamic properties’ influence on the measurement accuracy of the course of the plant grain impact forces against a stiff surface. The issue was examined using the computer simulation method. A proprietary computer software with the main calculation module and data input procedures, which presents results in a graphic form, was used for calculations. From the simulation, graphs of the contact force and force signal from the sensor were obtained. This helped to clearly indicate the essence of the correct selection of parameters used in the tests of sensors, which should be characterised by high resonance frequency.


2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Hyunjun Kim ◽  
Sanghyun Kim ◽  
Youngman Kim ◽  
Jonghwan Kim

A direct spring loaded pressure relief valve (DSLPRV) is an efficient hydraulic structure used to control a potential water hammer in pipeline systems. The optimization of a DSLPRV was explored to consider the instability issue of a valve disk and the surge control for a pipeline system. A surge analysis scheme, named the method of characteristics, was implemented into a multiple-objective genetic algorithm to determine the adjustable factors in the operation of the DSLPRV. The forward transient analysis and multi-objective optimization of adjustable factors, such as the spring constant, degree of precompression, and disk mass, showed substantial relaxation in the surge pressure and oscillation of valve disk in a hypothetical pipeline system. The results of the regression analysis of surge were compared with the optimization results to demonstrate the potential of the developed method to substantially reduce computational costs.


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