A model reference load controller with adaptation using a two stage pressure relief valve

2001 ◽  
Author(s):  
Rong Zhang ◽  
A. Alleyne
Keyword(s):  
Pressure Relief Valve ◽  
Relief Valve ◽  
Two Stage ◽  
Pressure Relief ◽  
Model Reference

Bond Graph Modeling of a Two-Stage Pressure Relief Valve

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Osama Gad
Keyword(s):  
Mathematical Model ◽  
Graph Model ◽  
Bond Graph ◽  
Fluid Power ◽  
Pressure Relief Valve ◽  
System Component ◽  
Bond Graphs ◽  
Relief Valve ◽  
Two Stage ◽  
Pressure Relief

This study examined the use of bond graphs for the modeling and simulation of a fluid power system component. A new method is presented for creating the bond graph model, based upon a previously developed mathematical model. A nonlinear dynamic bond graph model for a two-stage pressure relief valve has been developed in this paper. Bond graph submodels were constructed considering each element of the studied valve assembly. The overall bond graph model of the valve was developed by combining these submodels using junction structures. Causality was then assigned in order to obtain a computational model, which could be simulated. The simulation results of the causal bond graph model were compared with those of a mathematical model, which had been also developed in this paper based on the same assumptions. The results were found to correlate very well both in the shape of the curves, magnitude, and response times. The causal bond graph model was verified experimentally in the dynamic mode of operation. As a result of comparison, bond graphs can quickly and accurately model the dynamics in a fluid power control system component. During the simulation study, it was found that nonlinearity occur due to three factors: changes in pressure, which cause nonlinear velocity changes of the flow rate; changes in the throttling area of the valve restriction, which usually changes nonlinearly; and changes in the discharge coefficient of the throttling area of the valve restriction, which does not remain constant.

scholarly journals Research on the water hydraulic pressure relief valve

2021 ◽  
Author(s):  
Franc Majdič
Keyword(s):  
Environmental Sustainability ◽  
Maximum Flow ◽  
Pressure Relief Valve ◽  
Hydraulic Pressure ◽  
Relief Valve ◽  
Two Stage ◽  
Pressure Relief ◽  
Water Hydraulics ◽  
Water Hydraulic ◽  
Cfd Analyses

Water hydraulics is increasingly becoming a viable alternative to oil hydraulics due to its environmental sustainability. The leakage of water hydraulic components is one of the reasons why water hydraulics is not more widely used. One of the missing water hydraulic components is also the two- stage pressure relief valve. Various valve designs have been investigated. FEM and CFD analyses of the relief valve were performed. Some prototypes were made and tested in the pressure range of 50 to 200 bar at a maximum flow rate of 30 lpm. The functional characteristics of the valve were studied, and the influence of each component was determined. It was found that the manufacture of a two-stage water valve is technologically feasible with appropriate design adjustments.

Optimization of Operation Parameters for Direct Spring Loaded Pressure Relief Valve in a Pipeline System

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Hyunjun Kim ◽  
Sanghyun Kim ◽  
Youngman Kim ◽  
Jonghwan Kim
Keyword(s):  
Pressure Relief Valve ◽  
Pipeline System ◽  
Relief Valve ◽  
Pressure Relief ◽  
Computational Costs ◽  
Constant Degree ◽  
System A ◽  
Disk Mass ◽  
Analysis Scheme ◽  
Surge Control

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.

The Effect of Pressure Relief Valve Blowdown and Fire Conditions on the Thermo-Hydraulics Within a Pressure Vessel

2006 ◽  
Vol 128 (3) ◽  
pp. 467-475 ◽  
Author(s):  
A. M. Birk ◽  
J. D. J. VanderSteen
Keyword(s):  
Thermal Stratification ◽  
Pressure Vessels ◽  
Pressure Relief Valve ◽  
Relief Valve ◽  
Pressure Relief ◽  
Pressure Transducers ◽  
Hydrocarbon Pool ◽  
Computer Controlled ◽  
C 50 ◽  
Fire Conditions

In the summers of 2000 and 2001, a series of controlled fire tests were conducted on horizontal 1890liter (500 US gallon) propane pressure vessels. The test vessels were instrumented with pressure transducers, liquid space, vapor space, and wall thermocouples, and an instrumented flow nozzle in place of a pressure relief valve (PRV). A computer controlled PRV was used to control pressure. The vessels were heated using high momentum, liquid propane utility torches. Open pool fires were not used for the testing because they are strongly affected by wind. These wind effects make it almost impossible to have repeatable test conditions. The fire conditions used were calibrated to give heat inputs similar to a luminous hydrocarbon pool fire with an effective blackbody temperature in the range of 850°C±50°C. PRV blowdown (i.e., blowdown=poppressure−reclosepressure) and fire conditions were varied in this test series while all other input parameters were held constant. The fire conditions were varied by changing the number of burners applied to the vessel wall areas wetted by liquid and vapor. It was found that the vessel content’s response and energy storage varied according to the fire conditions and the PRV operation. The location and quantity of the burners affected the thermal stratification within the liquid, and the liquid swelling (due to vapor generation in the liquid) at the liquid∕vapor interface. The blowdown of the PRV affected the average vessel pressure, average liquid temperature, and time to temperature destratification in the liquid. Large blowdown also delayed thermal rupture.

scholarly journals Forensic Engineering Techniques For Testing And Predicting Lp-Gas Container Relief Venting

2004 ◽  
Vol 21 (2) ◽  
Author(s):  
James A. Petersen
Keyword(s):  
Test Data ◽  
Pressure Relief Valve ◽  
Relief Valve ◽  
Pressure Relief ◽  
Temperature Changes ◽  
Flammable Gas ◽  
Forensic Engineering ◽  
Pressure Changes ◽  
Liquefied Gas

When An Lp-Gas Container Is Involved In A Fire, Flammable Gas Is Usually Vented From The Relief Valve. One Of The First Questions Is Whether The Container Vented The Gas That Caused The Fire Or Whether Gas Was Vented Due To The Fire Heating The Container. If The Relief Valve Vents Gas That Initiates The Fire, It Is Usually Due To An Overfilled Container. This Paper Discusses; 1) The Prediction Of The Rate Of Container Warming Due To Normal Temperature Changes, 2) The Resulting Pressure Changes Of The Liquefied Gas, 3) The Reaction Of The Pressure Relief Valve And The Quantity Of Lp-Gas Vented During The Operation Of The Relief Valve, 4) Designing The Experiment And 4) Adjusting The Model To Reflect Test Data.

Sign in / Sign up

Export Citation Format

Share Document