จำนวน Repository ( 816 )

อาคารสำเร็จรูปครึ่งทรงกลมจากโครงสร้างเหล็กแบบถอดประกอบง่าย
อาคารสำเร็จรูปครึ่งทรงกลมจากโครงสร้างเหล็กแบบถอดประกอบง่าย

The objectives of this research are to develop the structure to create the knowledge of construction technology to test the properties to construction the prototype building and to transfer the technology of hemisphere pre-engineered building with easy assembly steel structure type. The load and resistance factor design (LRFD) method was used to design the structure by regarding the strength material type construction and deconstruction step and cost. From the design the prototype of hemisphere pre-engineered building (only the frame structure) was construction with 5 meters of diameter 3.5 meters of height 19.635 square meters of useful space 200000 Baht of material cost (10186 Baht per square meter for all materials) 27 hours or 3 days of construction period. According to the modular coordination system this hemisphere pre-engineered building cans construction and deconstruction fast especially when apply to help disaster victims. After tested the structure that the calculation value of safety factor (S.F.) is 1.76. The envelope of this building used the ratio of Portland cement type 1: fine sand: coconut fiber: waterproofed liquid: tap water which equal to 1:3: 0.1: 0.02: 0.5 by weight and reinforced by round bar and wire mesh steel. According to the testing the building-envelope properties are following: density 1582 kg/m3 thermal conductivity coefficient 0 .3 7 1 watt/m.Kelvin water absorption 1 7 .3 1 % compressive strength 118.47 ksc and bending strength 28.88 ksc. Moreover these results can register the copyright and draft the research paper to transfer the technology for target group.

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การพัฒนาผลิตภัณฑ์แผ่นฝ้าเพดานจากเส้นใยปาล์มน้ำมันสำหรับวิสาหกิจชุมชน
การพัฒนาผลิตภัณฑ์แผ่นฝ้าเพดานจากเส้นใยปาล์มน้ำมันสำหรับวิสาหกิจชุมชน

This research aims to study the using oil palm fiber to develop ceiling board product. The mixture ratios of Gypsum plaster: oil palm fiber: tap water: catalyst are 1 : 0.15 : 1: 0.03 1 : 0.20 : 1: 0.03 1 : 0.25 : 1: 0.03 1 : 0.30: 1: 0.03 and 1 : 0.35 : 1: 0.03 by weight. The ceiling board samples are cast in 30 x 30 x 1 centimeter in dimension. The ceiling board sample testing follows the TIS 219-2552. The results show that the longitudinal and lateral breaking load Nail pull resistance density and thermal conductivity of ceiling board with high quantity of oil palm fiber are lower than ceiling board with low quantity of oil palm fiber while that the deflection and water absorption of ceiling board with high quantity of oil palm fiber are higher. However all of oil palm fiber samples with lower than 0.2 of ratio can pass the standard.

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การวิเคราะห์แรงดันตกชั่วขณะเมื่อมีการติดตั้งแหล่งผลิตไฟฟ้าแบบกระจายตัวในระบบจำหน่าย
การวิเคราะห์แรงดันตกชั่วขณะเมื่อมีการติดตั้งแหล่งผลิตไฟฟ้าแบบกระจายตัวในระบบจำหน่าย

This research presents an Analysis of Voltage Sags on the Installation of Distributed Generation in the Distribution System. The computer program PSCAD/EMTDC (Power Systems Computer Aided Design / Electromagnetic Transient in DC system) version 4.2 is applied to provide electrical parameters for the modeling and simulation and to analyze the fault occurred which resulted in voltage sag. Test results from PSCAD/EMTDC show the values of voltage sag when 5 types of fault are occurred (Single Line to Ground Fault Double Line to Ground Fault Three Phase to Ground Fault Line to Line Fault and Three Phase Fault). For all cases the value of root mean square voltage before fault is 100% or 1.0 pu. It can be seen that for both radial line and closed circuit when DG are installed in the system the value of phase to ground RMS residual voltage and phase to phase RMS residual voltage at the bus of Bang-pa-in 2 substation are more than the values in case of the system without DG.

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การลดผลกระทบจากฟ้าผ่าในระบบจำหน่ายไฟฟ้า
การลดผลกระทบจากฟ้าผ่าในระบบจำหน่ายไฟฟ้า

Most of Metropolitan Electricity Authority (MEA) electric power system is using overhead line. It is 94% in the system including subtransmission distribution and low voltage system. All of them were installed on concrete pole. At present many public facilities have been built such as Sky-Train. It causes more constrains for construction with concrete pole due to lack of right of way. MEA needs to using electrical monopole plays an important role. It’s easier than concrete pole for construction and it requires less construction area than concrete pole. This research evaluation of The Reduce Effect of Lightning on Transmission Line. Case lightning strike on overhead ground wire (OHGW) at pole top of electrical monopole with suspension insulator Focusing on three factors is pole top voltage critical current and back flashover rate (BFOR). ATP-EMTP software is used for simulation. The results show that BFOR is reduced by 79% on electrical monopole structure with suspension insulator compared with existing concrete pole. BFOR is also reduced by 33.17% on concrete pole with external ground wire. The results could be served as a guideline in subtransmission line design and improvement in MEA power system.

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แบบจำลองการควบคุมเครื่องกำเนิดไฟฟ้าสามเฟสสำหรับควบคุมแรงดันและกำลังไฟฟ้า
แบบจำลองการควบคุมเครื่องกำเนิดไฟฟ้าสามเฟสสำหรับควบคุมแรงดันและกำลังไฟฟ้า

This project presents the simulation of a three-phase generator. The aim is to study and analyze the condition of the generator functions. By simulating the operation of the generator used in factory which use this generator as a backup power source to replace primary power source of electricity-supplier. In this test can start or stop the generator to determine the parameters at that time. The generator is used when the main electrical power distribution error and the generator is disabled when electric power system of electricity-supplier back to normal.

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