Pressure Regulator Valve Research Articles

Lumped Parameter Analysis of Autogenous Propellant Pressurization System for Nuclear Thermal Rocket

This work proposes a new propellant management configuration for an ammonia-fueled nuclear thermal propulsion system. The suggested configuration maximizes the advantage deriving from the autogenous pressurization of ammonia by exploiting the thermal power lost by the nuclear reactor toward the vacuum space due to leaking radiation. In this layout, a tank containing ammonia in saturated conditions is placed near the nuclear reactor and receives an input thermal power proportional to the dose of gamma rays and neutrons absorbed by the tank walls and the ammonia itself. Such a thermal power accelerates the vaporization process of the saturated ammonia, thus increasing the pressure in the tank. A pressure regulator valve exploits this overpressure to pressurize the ammonia propellant contained in a run tank to the level required by the mission by connecting the two ammonia volumes. The pressure achieved inside the run tank pushes the propellant with an adequate mass flow rate inside the nuclear reactor. The developed lumped parameter analysis shows how this propellant management system can provide a constant mass flow to the nuclear reactor without using a turbopump assembly. Moreover, it is shown how the proposed concept allows for a reduction in the radiation shield mass.

Control valve simulation method integrable into the global gradient algorithm

ABSTRACT This paper presents a refinement of a method that simulates flow- and pressure-regulating valves by replacing them with pipes and adjusting the resistances (diameters) of those pipes to meet the valve settings. The method, referred to as the replacing pipe method (RPM), is readily integrable into the global gradient algorithm, which is the heart of the commonly used EPANET 2 water distribution system modeling software. The RPM proved to be more robust, yet slower than the EPANET 2 valve handling heuristics. In this work, the RPM was modified to increase its computational speed. The modification involved the RPM check valve handling algorithm and condition for updating the diameters of the valve-replacing pipes. The modified RPM was tested as part of a hybrid simulator, which switches from the EPANET 2 valve handling heuristics to the RPM when the former fails. The test networks included a large network with thousands of nodes, pipes, and valves, and a case of an ill-posed problem. As the testing showed, the modified RPM offers a significant reduction in the number of iterations compared to its previous version.

Electronic brake system-based hierarchical motion control of commercial vehicle for autonomous obstacle avoidance

As a high-level autonomous driving technology, efficient and safe automatic obstacle avoidance on highway is one of the critical and ongoing topics that requires in-depth research for commercial vehicles. Electronic control air pressure brake system, owing to its fast response and active braking ability, is an effective active-chassis technology to function path tracking and stability control in such condition. Yaw motion stability control problem of autonomous driving commercial vehicle based on active braking control with electronic air brake system for automatic obstacle avoidance is investigated. First, a hierarchical yaw motion dynamics control architecture is introduced after vehicle and brake system modeling. The quintic polynomial curve-based trajectory planning method and a Model Predictive Control based trajectory tracking control strategy are formulated. Second, to evade the possible stability losing issue in this circumstance, Cubature Kalman Filter (CKF) is utilized to estimate the vehicle motion states, and a fuzzy PID control-based differential brake stability control strategy is designed for the electronic brake system composed of front-and-rear two sets of dual-channel pressure regulator and ABS solenoid valve. Finally, the proposed hierarchical yaw stability control strategy for a commercial vehicle in typical obstacle avoidance conditions is comparatively verified based on the joint simulation tools. After the yaw stability control, the peak value of the lateral displacement error of trajectory tracking can be reduced by 44.7%. The yaw stability control strategy based on fuzzy PID control can reduce the yaw rate by 46%–57% and the sideslip angle by 60%–73% under different conditions. The results show that the proposed control strategy can effectively improve the yaw stability of the vehicle while avoiding obstacles at high speed.

Insight process safety of a hydrogen turbine supply system: A comprehensive dynamic risk assessment using a fuzzy Bayesian network

This study conducts a comprehensive risk assessment for a selected hydrogen supply system within a pilot hydrogen power plant. The assessment begins with hazard identification through Hazard and Operability (HAZOP) analysis, followed by quantification using bow-tie analysis and consequence modeling to evaluate the impacts of credible scenarios resulting from random failures. Furthermore, a fuzzy Bayesian network is employed to address uncertainties inherent in the quantitative approaches and to account for event combinations and dependencies. Sensitivity analysis is subsequently conducted to identify critical events. Utilizing three quantitative approaches, fault tree analysis, the Bayesian network, without and with evidence updating, the probability of the top event is determined to be 4.52 × 10−2/year, 4.50 × 10−2/year, and 4.70 × 10−2/year, respectively. Additionally, the estimated firezone resulting from the explosion's 300 mbar overpressure was 12 m. The findings highlight the significant role of pressure regulator valve and pressure transmitter failures, with posterior probabilities of 0.17/year and 1.90 × 10−3/year, in ensuring the system's safety.

Hydrodynamic Analysis Of Water Hammer Phenomena In Hydropower Stations Under Turbine Extreme Operating Conditions

This research article investigates transient hydraulic effects, particularly water hammer phenomena, in a hydropower plant (HEPP) through a comprehensive mathematical model and simulation analysis. Utilizing methods of characteristics and FORTRAN programming, the study develops a model that incorporates water hammer considerations, including friction, in the water conveyance system of the HEPP. The system layout encompasses an upstream reservoir, penstock, turbine unit, and downstream reservoir. The research explores the influence of guide vane closure and pressure regulating valve (PRV) opening and closing laws on pressure variations, mass oscillations, and water level fluctuations within the system. Numerical results indicate that PRV failure may not significantly impact turbine speed, but it results in excessive pressure oscillations in the spiral casing head, exceeding allowable pressure control values. The study identifies a critical PRV diameter of 0.6m, causing a maximum pressure in the spiral case of 370m, surpassing the acceptable limit of 250m, with a speed rise rate exceeding 50%. Conversely, a PRV diameter greater than or equal to 0.9m leads to unnecessary water energy loss. The findings emphasize the importance of carefully selecting PRV parameters to optimize system stability and efficiency. The study's comprehensive analysis provides valuable insights into the interplay of various parameters, contributing to a scientific basis for optimizing operational parameters and ensuring reliable and efficient hydropower plant performance.
 

Electrochemical-energy- exergy analysis of reversible solid oxide cell-based small-scale stand-alone energy storage system

The present renewable energy systems should shift towards more storage-based systems due to their inherent intermittency. This study examines the electrochemical, energy, and exergy performances of a Reversible Solid Oxide Cell (ReSOC) based stand-alone energy storage system “with a pressurized gas tank”. The system operates in the fuel cell mode (SOFC) for power generation and electrolysis cell mode (SOEC) for syngas production. The exergy analysis gives a detailed insight into the irreversibility points in both system operation modes. The ReSOC system model is based on a validated ReSOC stack electrochemical model and system components’ mass-energy balance model. The power extraction level in the ReSOC stack was shown to determine the thermal management required through the electrochemical analysis. The energy analysis resulted in a system roundtrip efficiency of 51 % at the considered operating conditions. In addition, the highest points of exergy loss/destruction are the exhaust air (SOFC: 32 %, SOEC: 34 %), ReSOC stack (SOFC: 25 %, SOEC: 28 %), and pressure regulation valve (SOFC: 11 %, SOEC: 17 %). The results also show that the SOEC mode performed better than the SOFC mode in the energy and exergy analyses. This study may be used as a basis for stand-alone system performance improvement leading to higher efficiency.

Prediction of the performance of the pressure-regulating valve in a large high-speed jet wind tunnel

Prediction of the performance of the pressure-regulating valves in a large high-speed jet wind tunnel is important for obtaining and adjusting a high-quality flow field in the test section. In this work, we proposed a prediction method that corrects the theoretical characteristics of the pressure-regulation of the valve based on the experimental testing data of the ratio between the high- and low-pressure of the valve. The current method was validated for a given Mach number of 0.8, and the results showed that compared with the theoretical characteristics, the displacement deviation of the spool was reduced by 9.84%, and the total pressure deviation of the settling chamber was reduced by 43.61%. The results also show that compared with the single low-pressure ratio correction characteristic, the displacement deviation of the spool was reduced by 0.94%, and the total pressure deviation of the settling chamber was reduced by 3.4%. This method can consider the variation of the pressure loss for different pressure ratios and improve the pressure prediction of the valve.

MATHEMATICAL MODEL AND DYNAMICS OF A PILOT CONTROL PRESSURE-REDUCING VALVE

Energy consumption is currently on the rise. To control large energy flows, larger sizes of actuators and control mechanisms are required.One of the main control elements of the system is the pressure regulator. A pressure regulator or pressure reducing valve (RV) is a device designed to reduce and continuously maintain a certain, preconfigured, pressure level («after itself»), which is different from the nominal one. High requirements are imposed on the operation of the RV to maintain the set pressure value, such as: high speed, no overshoot and static error, since the presence of these dynamic properties in the RV can cause the «start of disasters». Modern methods for the development and analysis of technical systems are based on the widespread use of mathematical models based on detailed knowledge of the processes and phenomena occurring in the systems under consideration. The use of a mathematical model is of great and urgent importance – it allows not to carry out expensive and costly physical experiments both in terms of time and money. The results obtained in the course of computer simulation can be used to optimize systems, determine operating modes and causes of possible failures. The article describes the principle of operation and the scheme of the pressure reducing valve of indirect action. The developed mathematical model of an indirect pressure reducing valve is presented. With the help of the created mathematical model, the dynamic characteristics of the indirect pressure reducing valve were analyzed depending on the change in its design parameters. The limit of stability of the pressure reducing valve is determined, when the values of which are exceeded, self-oscillations are observed in the system of the pressure reducing valve. Recommendations are given for choosing and setting the value of pressure p2 at the outlet of the reducing controlled valve. The scientific novelty of the work should include the created mathematical model of a pressure reducing controlled valve of indirect action and the results of the analysis of its dynamic properties.

Hydraulic Pressure Management of Yerevan City’s Water Supply Systems

The system’s excessive pressure management after zoning is essential for improving the existing water supply operation efficiency. Our original research proves that pressure control reduces the leaks in the water supply network, increasing the reliability level of the internal and external networks and saving energy consumed in pumping systems. In recent years, 243 pressure regulating valves (PRV) have been installed in the 97 zones of the expanded water supply network in the Yerevan city (the difference between the levels in the city reaches up to 500 meters) for pressure control in complex terrain conditions.

Experimental Study on a Multi-Evaporator Refrigeration System Equipped with EEV-Based Ejector.

This study presents an experimental rig of a multi-evaporator refrigeration system, in which the pressure difference between two evaporators can be maintained by using both the pressure-regulating valve (PRV) and electronic expansion valve (EEV)-based ejector. The proposed EEV-based ejector that is used to partially recover the throttling losses of the PRV consists of an EEV and the main body of an ejector. The established experimental system can work in both PRV-based mode and ejector-based mode by switching the valves. Via experimental means, the performances of both modes were evaluated by varying the cooling loads. Moreover, the effects of the spindle-blocking area percentage of the EEV-based ejector and the condensing temperature on the system performance were identified. The results showed that: (1) the system performance of the ejector-based mode was 3.6% higher than the PRV-based mode; (2) both entrainment ratio and coefficient of performance dropped along with the increase in ejector spindle-blocking area percentage; (3) compared to ejector spindle-blocking area percentage, the condensing temperature had a more evident influence on the system performance.

Evaluating Sustainability Improvement of Pressure Regime in Water Distribution Systems Due to Network Partitioning

Water distribution networks (WDNs) represent essential civil infrastructures providing freshwater for domestic and industrial uses. Pressure management in WDNs is a key issue in operation and management, especially in big and complex networks, and this is the case with Messina City’s WDN. Water network partitioning (WNP) into district zones helps improve water network management; it simplifies water budget computation and consequently helps in the identification and reduction of water loss. In this study, an approach based on sustainability indices (SIs) is proposed to evaluate the improvement in terms of WDN pressure performances after WNP. The sustainability indices are based upon performance criteria including reliability, resiliency, and vulnerability. Three different scenarios are analyzed: (1) the first sees the WDN in the current configuration without partitioning, (2) the second sees the WDN partitioned into district zones for each of which SI is evaluated, and (3) the third sees, in addition to partitioning, the introduction of pressure regulating valves (PRV). Results show an improvement in pressure sustainability at the global- and district-scale and evidence how districts with greater differences in altitude values of terrain topography take more benefits from the installation of PRV.

Research on recovery and utilization of waste heat in advanced compressed air energy storage system

In order to improve the efficiency of the advanced compressed air energy storage system, a method for recycling the system exhaust gas and waste heat of heat exchange working medium is proposed. A low expansion ratio expander is added to the original system. Residual heat enters the expander to work to increase the total output of the system. The Aspen Plus software is used to establish a four-stage advanced compressed air energy storage system model under steady-state operating conditions and perform simulation. The simulation results show the maximum increment of system output power is 4713.72 kW and its corresponding increment of system efficiency is 7.34% in comparison with no waste heat recovery, and verifies the effects of different expander exhaust pressures and pressure regulator valve outlet pressures on system efficiency and output power.

Analisis Kerusakan Trim Air Pressure Regulating and Shutoff Valve Pada Pesawat Boeing 737-800 Menggunakan Metode Failure Mode and Effect Analysis (FMEA) di PT.GMF Aeroasia,TBK.

Air Conditioning (AC) is the one of system in aircraft to make a passanger and all cabin crew comfortable. Trim Air Pressure Regulating and Shutoff Valve or also known as Trim Air PRSOV is a component on the Boeing 737-800 aircraft to regulate flow of hot air constantly before entering the aircraft cabin. Refering to the data for the last 6 years, the replacement of the component belonging to one of the Indonesian national flight carrier using Boeing 737-800 aircraft was the occurance of 84 times the cooling system failure which caused the light indiacator in the cockpit to light up. Among them happened 70 times unscheduled maintenance and 14 times scheduled maintenance. Thus, this essay was made to analyze the causes of the damage that occurred to the Trim Air PRSOV. The method used in this research is Failure Mode and Effect Analysis (FMEA) is the technique used to find, identify and eliminate failures or damage to a system or process. The first step is to analyze using a Pareto diagram and then continue with the FMEA method so that an analysis of the damage that often occurs is damage to the diaphragm with 42% damage with an RPN value of 389.1, erosion on the ring seal with 22% damage with an RPN value of 376 and shaft seal damaged with 12% damage with an RPN value of 295.1 for it requires aggressive treatment. Therefore, repairs with a long TAT of 14 days are expected to increase the reliability of the PRSOV Trim Pressure component. For this reason, repairs are carried out with a long TAT of 14 days, it is hoped that there will be an increase in the reliability of the PRSOV Trim Pressure componen.

Erratum for “Technique for the Pressure-Driven Analysis of Water Distribution Networks with Flow- and Pressure-Regulating Valves” by Nikolai B. Gorev, Vyacheslav N. Gorev, Inna F. Kodzhespirova, Igor A. Shedlovsky, and P. Sivakumar

Erratum for “Technique for the Pressure-Driven Analysis of Water Distribution Networks with Flow- and Pressure-Regulating Valves” by Nikolai B. Gorev, Vyacheslav N. Gorev, Inna F. Kodzhespirova, Igor A. Shedlovsky, and P. Sivakumar

Multi‐objective optimization and decision‐making of the combined control law of guide vane and pressure regulating valve for hydroelectric unit

AbstractThis paper aimed to investigate the multi‐objective optimization and decision‐making of the combined control law of guide vane (CCLGV) and pressure regulating valve (PRV) for hydroelectric unit under load rejection. Firstly, the multi‐objective optimization problem of CCLGV‐PRV is formulated. Then, a new multi‐objective gravitation search algorithm with non‐dominated screening and chaos mutation (NCMOGSA) is adopted to solve it. Moreover, an improved entropy weight method and relative objective proximity method are applied to select suitable solution. Finally, a comprehensive comparative study is carried out to reveal the mechanism between the CCLGV‐PRV and several basic parameters. The results indicate that replacing surge tank with PRV can effectively solve the contradictory between water pressure at the bottom of volute and rotational speed under load rejection. The NCMOGSA shows excellent performance in solving the multi‐objective optimization problem of CCLGV‐PRV and get a group of Pareto set. The improved entropy weight and relative objective proximity method make the final scheme clear. The rise rate of rotational speed is completely determined by the guide vane (GV), and the water pressure is jointly determined by the control law of the GV and PRV. The two‐stage closing and two‐stage opening (TCTO) is the final recommendation for CCLGV‐PRV.

​Weed Control using Pre-emergence Herbicide Strip Application System Along with Sowing/Planting Devices

A 6-row pre-emergence herbicide strip-application system was designed and developed at ICAR-CIAE, Bhopal as an attachment to inclined-plate planter to apply herbicide at the time of sowing in widely spaced crops to control weeds along the crop rows, often not possible in mechanical weeding. It consisted of a frame on which 6 flat fan spray nozzles were mounted by means of clamps, a single action piston pump with 9 l/min capacity, pressure regulator valve and pressure gauge and pressure pipes. The spacing between the spray nozzles, angle and height of spray nozzles can be varied by adjusting the clamps. The developed system has ability of strip as well as blanket application of herbicide. The same machine can be used as post-emergence herbicide/pesticide applicator after the removal of furrow openers and increasing the height of nozzles from the ground. The machine was tested and evaluated during Kharif season for soybean and pigeon pea crops. The field capacity of the developed system was found to be 0.4 ha/h. The operating cost of the pre-emergence herbicide applicator with inclined plate planter was worked out as Rs 1350/- per ha. It can save about 40-50% herbicide.

Numerical evaluation on aerodynamic design of pressure-regulating valve in trisonic intermittent wind tunnel

The pressure-regulating valve can realize the rapid adjustment and precise controlling of operating pressure and Mach number, to stabilize the flow field and avoid the test interference such as the air source loss or the unstable flow. This paper takes the design and optimization of pressure-regulating valve in trisonic intermittent wind tunnel as the research object to investigate its special pressure-regulating characteristic and performance in the wind tunnel. According to the requirement of the wind tunnel, the annular-gap type pressure-regulating valve is selected to match its wide adjustment range of operating parameter, high regulation accuracy, and low running resistance. The design and optimization of the pressure-regulating valve are carried out, including aerodynamic and structural design, analysis on pressure regulation characteristics, kinematics analysis, flow field analysis, vibration analysis, and structure optimization. The design and selection of some important components are carried out based on the pneumatic design and performance requirements. The pressure regulation characteristics of the pressure regulating valve are discussed and the affecting factors of the irregular flow are analyzed and evaluated by numerical simulation. The final structure of the pressure-regulating valve is determined and the test results perform well with prediction of characteristic curve.

Design of a Compact Embedded Hydraulic Power Unit for Bipedal Robots

This letter proposes a design method of a compact embedded hydraulic power unit (HPU) for a bipedal robot and a controller to regulate the supply pressure. The HPU consists of an integrated pump-motor unit. The unit is immersed in hydraulic oil for efficient space utilization and heat dissipation from the motor. This HPU design is analyzed to establish a relationship between the thermal variables and the motor design parameters such as gap radius and wire radius via its thermal and electrical modeling. Through this analysis, the design parameters of suitable pump-driving motor are chosen. This letter also proposes a control method for the HPU to regulate the supply pressure while minimizing the energy loss caused by the bypass through a pressure-regulating valve. The HPU is mounted on top of the bipedal robot platform, LIGHT, with twelve degrees of freedom actuated by the proposed HPU. Finally, the durability of the designed HPU is demonstrated through a long-term driving test at a high pressure. Furthermore, air-walking and squat motion experiments are conducted with the bipedal robot to demonstrate the capabilities of the HPU and its controller.

Analysis of Dynamic Characteristics of Pressure-Regulating and Pressure-Limiting Combined Relief Valve

Aiming at the problem of the lack of a cooperation mechanism of combined relief valves, this paper proposes a new pressure-regulating and pressure-limiting combined relief valve. Combined with the ordinary relief valve dynamic characteristic analysis method, the dynamic model of the combined relief valve under normal working conditions was established, and its dynamic characteristics were simulated using Simulink. The results showed that the multi-pressure stabilization design of the combined relief valve improves its usability and stability. Under the same structural parameters, the overshoot of the combined relief valve was 5.7%, and the response time was 12 ms, which is better than the ordinary relief valve. Besides, it effectively improves the instability problems, such as the vibration and the large pressure fluctuation of the ordinary relief valve under high pressure and large flow conditions. When the sum of the effective force area on the upper side of the flange of the pressure-regulating valve core and the area of the tail vertebra is equal to the effective force area of the lower side of the flange of the pressure-regulating valve core, the dynamic performance of the relief valve is optimal. For example, if the effective force area under the flange is 1.8 cm2, then the inlet pressure overshoot is 2.8%, and the response time is 10 ms. An appropriate volume of the sensitive cavity, the quality of the valve core, and the fluid resistance of the pressure relief valve are factors that can effectively improve the dynamic performance of the pressure-regulating and pressure-limiting combined relief valve.

Technique for the Pressure-Driven Analysis of Water Distribution Networks with Flow- and Pressure-Regulating Valves

AbstractThis technical note presents a technique for the pressure-driven analysis (PDA) of water distribution networks with flow- and pressure-regulating valves. The technique is a combination of a...