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Effects of orifice on pressure difference in pilot-control globe valve by experimental and numerical methods

Pilot-Control Globe Valve (PCGV) can utilize pressure difference caused by fluid flow through the orifice on valve core as its power, for open and close the main valve with a small pilot valve. It has obvious advantages of energy conservation and quick response. Orifice structure on the valve core is the main component to determine the pressure difference, which is used to push the valve core. In

Municipal wastewater treatment by microsieving, microfiltration and forward osmosis : Concepts and potentials

Conventional wastewater treatment plants are designed for treating manmade wastewater (e.g., from households and industries) and to protect the environment (e.g., receiving water bodies) and humans from adverse effects.The objective of this work was to investigate the feasibility of treating municipal wastewater without a biological treatment step by applying different separation processes, such a

Experimental analysis on filter press and energy consumption performance of diaphragm press drying device in chemical post-processing integrated equipment

Higher efficiency, lower energy consumption and less pollution are become more and more important in chemical engineering. Post-process is one of the key parts for producing chemical productions. Thus, we develop a novel device, Chemical Post-Processing Integrated Equipment (CPPIE), which can deal with crystallization, filtration, washing and drying in the same tank by changing the position of it.

CFD analysis on flow resistance characteristics of six-start spirally corrugated tube

Heat transfer enhancement technology has been widely used in heat exchangers. The six-start spirally corrugated tube is a novel heat transfer tube, and its flow resistance characteristics have not been studied. In this paper, the flow resistance characteristics of the six-start spirally corrugated tube are studied. Specifically, the effect of influencing factors such as geometric parameters (pitch

Mach number analysis on multi-stage perforated plates in high pressure reducing valve

High pressure reducing valve (HPRV) is a key device for the pressure control of high temperature and pressure steam in industrial processes. Perforated plate is used as the throttling element to ensure the suitable pressure of steam and reduce aerodynamic noise inside HPRV and the linked pipelines. Mach number is the parameter to reflect the compressibility of steam flow. Higher Mach number may ca

Numerical analysis of flow and cavitation characteristics in a pilot-control globe valve with different valve core displacements

The pilot-control globe valve (PCGV) is a novel globe valve with a piston-type valve core and a small pilot valve. It can utilize a pressure difference to control the state of the main valve by the pilot valve. In this paper, a mathematical model of PCGV is established and a computational fluid dynamics (CFD) method is used to numerically simulate its flow and cavitation characteristics. Analysis

Transmission loss analysis of thick perforated plates for valve contained pipelines

Valve contained pipelines have witnessed a great growth and there exists a lot of noise caused by valves. Thick perforated plates are especially used is valve contained pipelines for the noise control, but there are limited literatures about its noise control performances under different structural parameter of thick perforated plates, which limits its popularization and application. In this paper

Limit bending moment for pipes with two circumferential flaws under combined internal pressure and bending

By assuming the neutral axis is perpendicular to the bending plane, this paper presents a general analytical solution to predict the limit bending moment for pipes with two inner surface circumferential flaws under combined internal pressure and bending moment. The circumferential stress caused by internal pressure is taken into account through Mises yield criterion. Based on the general solution,

Numerical analysis of flow and temperature characteristics in a high multi-stage pressure reducing valve for hydrogen refueling station

Hydrogen refueling station is one of the most important parts for the hydrogen energy utilization. In this paper, a novel high multi-stage pressure reducing valve (HMSPRV) is proposed, which can be used for hydrogen stable decompression in hydrogen refueling station. In HMSPRV, the inner and outer porous shrouded valve core is used to replace piston valve core to achieve the first-stage throttling

CFD analysis on the dynamic flow characteristics of the pilot-control globe valve

The pilot-control globe valve (PCGV) is a new kind valve with simple structures and low driving energy consumption. It can utilize the pressure difference before and after the valve to control the action of the valve core. However, systematic theoretical research and numerical analysis are deficient at present. In this paper, the mathematical model of PCGV is established and Computational Fluid Dy

Energy consumption prediction of university buildings in China and strategies for energy efficiency management

In 2007, Chinese Ministry of Education (MOE) and Ministry of Housing & Urban-Rural Development (MOHURD) carried out the Campus Resource Conservation Actions, in order to take full use of resources and to improve the energy efficiency. However, due to the large amounts of universities, the total energy consumption and the energy efficiency situation have no objective statistics. Taking modeling

Transient simulation of valve core movement of pilot-control globe valve in vertical pipelines

A novel pilot-control globe valve, which can be used in vertical pipelines with a lower driving energy consumption, is proposed. A governing equation for valve core motion is obtained through a theoretical analysis of the forces applied on the valve core. A 3D simulation of valve core motion is conducted in Fluent by using User Defined Function (UDF) to involve different spring stiffness, steady s

Numerical simulation of flow-induced noise in high pressure reducing valve

The main objective of this paper is to study the characteristics of flow-induced noise in high pressure reducing valve (HPRV) and to provide some guidance for noise control. Based on computational fluid dynamics (CFD), numerical method was used to compute flow field. Ffowcs Williams and Hawkings Model was applied to obtain acoustic signals. The unsteady flow field shows that noise sources are loca

Interaction between Bile Salt Sodium Glycodeoxycholate and PEO-PPO-PEO Triblock Copolymers in Aqueous Solution

The interactions of the anionic bile salt NaGDC with three triblock copolymers based on poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), denoted P65, P123 and F127, were investigated using high-sensitive differential scanning calorimetry (DSC), turbidimetry, dynamic and static light scattering and small angle X-ray scattering (SAXS). P65 and P123 had the same hydrophilic PEO block lengt

Policy Changes in Community Mental Health: Interventions and Strategies Used in Sweden over 20 Years

The deinstitutionalization of mental health care has changed the responsibilities of involved authoritiesand has led to a continuous need for new treatment forms and interventions. This articledescribes this development in Europe, and in particular how these new conditions have been handledin Sweden over the past 20 years at the level of governmental policy-making. Three major policydocuments from

Critical Components in Implementing Evidence-based Practice: A Multiple Case Study of Individual Placement and Support for People with Psychiatric Disabilities

When developing Community Mental Health Services to support people with psychiatric disabilities, European countries are advocating evidence-based practice (EBP). Individual Placement and Support (IPS) is an evidence-based model designed to support people in acquiring and maintaining competitive employment. Implementation science is a growing research field, with a focus on components that impact

Riksrevisionens effektivitetsgranskningar : Kvalitet ur ett intressentperspektiv

När den statliga revisionen har ett främjande syfte och är problemorienterad kan värdet av revisionen inte utvärderas på traditionellt sätt. Då ligger värdet främst i själva granskningsprocessen och i det kunskapsutbyte som sker under denna. För att undersöka hur Riksrevisionens effektivitetsrevisioner upplevs, har en enkätstudie genomförts. Studien riktade sig till involverade i granskningarna un

Oberoendet inget frikort

Att göra problemen i Riksrevisionens ledning enbart till en fråga om felrekryteringar, såsom Gunnar Axen gör i sin replik, är att göra det lätt för sig. Riksrevisorerna i Sverige har betydligt mer makt än riksrevisorer i övriga nordiska länder. Det finns därför en gräns för hur fritt spelrum de bör ha. Oberoende ska inte föranleda beröringsskräck och det vaccinerar inte mot ansvar. Oberoende ska i