Liquefied hydrogen is attracting attention as an energy source of the future due to its hydrogen storage rate and low risk. However, the disadvantage is that the unit price is high due to technical difficulties in production, transportation, and storage. This study was conducted to improve the design accuracy and development period of needle valves, which are important parts with a wide technical application range among liquefied hydrogen equipment. Since the needle valve must discharge an appropriate flow rate of the liquefied fluid, it is important to determine the needle valve design parameters suitable for the target flow rate. Computational Fluid Dynamics and Artificial Neural Network technology used to determine the design variables of fluid flow were applied to improve the setting and analysis time of the parameter. In addition, procedures and methods for applying the design parameter of needle valves to Convolutional Neural Networks were presented. The procedure and appropriate conditions for selecting parameters and functional conditions of the Convolutional Neural Network were presented, and the accuracy of predicting the flow coefficient according to the design parameter was secured 95%. It is judged that this method can be applied to other structures and machines.

The flange spreader has been used to withdraw butterfly valves during maintenance. The typical flange spreaders required an excessive working space, and the pipe and flange are damaged by the load. In the previous study, the author developed a valve easy out tool with collet, and designed collet shape to ensure structural safety. However, clamping force of the collet had not been checked. In this study, design of collet shape was performed to improve clamping force. Techniques of structural analysis were established and design parameters were selected. Through parametric study, the collet shape with clamping force of 159,748N was suggested. This will contribute to stability and efficiently of valve maintenance.

In order to cope with climate change, the UN Climate Summit announced a policy to reduce carbon emissions to 0% by 2050. As a result, hydrogen energy is attracting attention as a new energy. Hydrogen energy is one of the future clean energy sources and is the most abundant and ideal fuel on Earth that does not emit pollutants. On the other hand, there is a risk of wide explosion range, easy ignition, and fast flame speed. As a result, There is limited use of hydrogen gases, and research is being conducted to safely use hydrogen gases. However, the localization rate of hydrogen-related equipment parts is low and dependence on foreign countries is high. In order to reduce dependence on foreign countries, this study designed and analysis a model of ultra-high pressure relief valve, which is a safety device for hydrogen charging stations. In order to evaluate the structural stability, a spring, a valve disk, a valve guide, and a valve spindle, which are components of an ultra high pressure relief valve, were applied with pressure resistance test and water pressure test criteria according to KS B ISO 19880-3, and analyzed using an Ansys workbench 2021 R1. Through the analysis results, the structural stability of the relief valve under the water pressure test and the pressure resistance test conditions confirmed.

The flange spreader has been used to withdraw gaskets and valves during butterfly valve maintenance. When using the conventional flange spreader, an excessive working space (pipe separation distance) appears, and the pipe and flange are damaged by the load. Also, the equipment can’t be operated safely when the pipe has eccentric fitting. To solve the problems, a valve easy out tool with collet was developed for safely fixing and spreading flange. By using Ansys Workbench 2021 R2, the structural analysis of the original collet was performed, and shape design of the collet was carried out to improve structural safety.

An AVL research engine, type 520, is modified to adapt to the 3.5L four-valve SI engine. With these given engine configurations, a test rig is constructed which allows easy changing of the different pistons and engine heads with a motoring capacity up to 3500 rpm. Nearly complete optical access to the inside of the cylinder is obtained by installing a transparent quartz cylinder on an AVL single cylinder engine. To avoid lubrication and to minimize scratches in the quartz cylinder the piston rings are made of Rulon-LD. With this experimental engine, researches for the in-cylinder flow characteristics by changing the induction system have been carried out using the laser based flow diagnostic techniques. In accordance with the previous result, it is evident that larger sized particles would be required in order to observe the flow characteristics of interest. The flow visualization taken with microballoon particles shows significant improvement. This provide detailed information.

The various hydraulic equipments including main control valves are composed of relatively long replacement parts, so the stability is very important. These systems ensure system safety by not delivering pressure to actuators when pressure exceeds the limiting pressure. According to various hydraulic equipments, the required pressure of every hydraulic actuators are differenced. So the optimal design of the main valve is indeed needed. In the previous study, the detail shapes and the boundary conditions of the main control valve were studied by CFD analysis using FLUENT. Based on the previous study, the optimal design of the main control valve is done by applying the parametric modeling technique and then the optimum design of the main control valve is investigated by CFD analysis.

Direct spring loaded pressure relief valve(DSLPRV) is a safety valve to relax surge pressure of the pipeline system. DSLPRV is one of widely used safety valves for its simplicity and efficiency. However, instability of the DSLPRV can caused by various reasons such as insufficient valve volume, natural vibration of the spring, etc. In order to improve reliability of DSLPRV, proper selection of design factors of DSLPRV is important. In this study, methodology for selecting design factors for DSLPRV was proposed. Dynamics of the DSLPRV disk was integrated into conventional 1D surge pressure analysis. Multi-objective genetic algorithm was also used to search optimum design factors for DSLPRV.

According to the structure, solenoid valve can be categorized as spool valve or poppet valve. While various research on spool valve which has simple structure and fine susceptibility to contamination has been conducted, poppet valve which has less susceptibility to contamination and advantage in a long time operation still need much research because of its complicated structure. In order to design the poppet valve, various parameters such as the diameter of the poppet, the angle of the poppet, the diameter of the disk, the spring stiffness, the spring preload and flow path structure should be considered. Conventional studies on poppet valve usually take only one design parameters and did not much focused on the effect of the parameters on flow characteristics. In this paper, the change of the flow characteristics according to the design parameters of the poppet valve for 3/2Way solenoid valve is analyzed. The previous studies and the results of initial model analysis was referred for the selection of the design parameters. The effects of design parameters on maximum pressure, minimum pressure, and pressure drop was examined using analysis of means(ANOM).

Surge pressure is created by rapid change of flow rate due to operation of hydraulic component or accident of pipeline. Proper control of surge pressure in distribution system is important because it can damage pipeline and may have the potential to degrade water quality by pipe leakage due to surge pressure. Surge relief valve(SRV) is one of the most widely used devices and it is important to determine proper parameters for SRV’s installation and operation. In this research, determining optimum parameters affecting performance of the SRV were investigated. We proposed the methodology for finding combination of parameters for best performance of the SRV. Therefore, the objective function for evaluate fitness of candidate parameters and surge pressure simulation software was developed to validate proposed parameters for SRV. The developed software was integrated into genetic algorithm(GA) to find best combination of parameters.

In this paper, the geometric design for the body of a 3"-PFA-lined plug valve is concerned, and body model which has less deformed PFA-resin after infection molding process is proposed. A CAE software is used to simulate the deformation due to heat in coo

소화시스템에 사용되는 고압의 소화가스 저장용기에는 저장용기의 파손을 막아주는 안전밸브가 있다. 이러한 안전밸브의 내부에는 원형 박판의 파열 판이 들어 있는데, 저장용기의 내압이 위험수준에 도달하면 파열 판이 파손하여 내압을 배출하는 역할을 한다. 안전밸브의 설계인자는 파열 판의 두께, 안전밸브의 유로 직경, 플라스틱 패킹 링의 내부 직경 그리고 파열 판을 고정하는 볼트 안쪽의 필렛 반경이 있다. 이중에서 파열 판의 두께는 0.2mm로 고정을 하였다. 요인배치법을 사용하여 주효과를 결정하였고 회귀방정식을 유도하였다. 이러한 회귀방정식은 추후 안전밸브의 설계에 있어서 기초 설계 자료로서 활용할 수 있도록 실험 결과와 비교하여 검증하였다. 검증실험 및 회귀방정식에 의한 결과의 오차는 약 정도인 것을 확인하였다. 그리고 반응표면법을 사용하여 기밀테스트 압력인 25MPa에서 파열할 수 있는 안전밸브의 최적 모델을 결정하였다.

This paper is discussed the design of the Dome type control valve. It is designed by the results of Fluent analysis. The results of analysis is similar to the experimental data. Dome type control valve is possible to use the high pressure and temperature condition and is easy to control by the remote. It is operated by the air pressure and worked in the low pressure range. Also it can be changed the flow velocity line by the modified geometry of the rod & plug of valve.

Based on the practical process engineering design and commissioning and startup operation experiences focused on chemical process safety, the comprehensive review of engineering design and installation of the thermal relief valve with its surrounding facility in a chemical plant piping system is provided to enhance the better understanding of the piping system of characteristics of thermal relief valve which is comprised of the theoretical approach, correlation in terms of temperature and pressure increase caused by external heat supply in a piping system, consideration of thermal relief valve engineering design, pressure relieving system of serial thermal relief valves and exception of their installation. It is earnestly suggested that following topic should be implemented during thermal relief valve engineering design, installation and normal operation as well.

밸브는 선박에서 유체의 흐름과 유량을 제어하기 위해 사용된다. 유량 계수는 밸브의 설계에서 매우 중요한 요소이다. 본 연구에서는 상용프로그램인 CFX의 3차원 컴퓨터 시뮬레이션을 이용하여 동일한 유속이 적용될 경우 밸브의 형과 밸브 열림 각도에 따른 유량 계수를 계산하였다. 그리고 실험 결과와 비교하여 CFX 시뮬레이션 해석을 통해 얻은 결과의 신뢰성을 검증하였다.