จำนวน Repository ( 44 )
การประเมินสมรรถนะการป้องกันฟ้าผ่าระบบสายส่งย่อย และสายจำหน่าย ของ กฟน
Design of grounding system to protect against lightning and fault is important for both safety and reliability especially for Metropolitan Electricity Authority (MEA) as mostly Metropolitan Electricity Authority operates on overhead networks. This thesis assesses lightning performance for 69 kV 115 kV overhead subtransmission lines 24 kV distribution line using case study from Metropolitan Electricity Authority. Because of the limitation of the right of way distribution feeders are regularly installed together with subtransmission lines in a single concrete pole. Overhead Ground Wire (OHGW) installed at top of the pole and grounding system in concrete pole protects fault current or direct lightning surge to ground. Metropolitan Electricity Authority has developed lightning protection based on an IEEE standard which uses international data for insulation coordination. As a result reliability of the system is lower than the designed value. This thesis suggests a methodology to improve the performance in order to increase the reliability of subtransmission and distribution lines feeding distribution substations. This thesis recommends installation of addition external ground wire on the outer surface of the concrete pole to reduce top pole voltage and back flashover rate or installation of bundle overhead ground wires to protect shielding failure. As all the case studies presented in the thesis which constitute this thesis are applied to existing systems of Metropolitan Electricity Authority it is expected that the proposed methodologies can be served as useful practical guidelines for lightning performance assessment subtransmission lines and distribution lines of Metropolitan Electricity Authority.
การประเมินสมรรถนะการป้องกันฟ้าผ่าระบบสายส่งย่อย 69 กิโลโวลต์ บนเสาไฟฟ้าโมโนโพล
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. The thesis evaluation of lightning performance in subtransmission line 69 kV study on MEA. 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.
การออกแบบเครื่องแต่งกายที่สะท้อนสีสันของธรรมชาติโดยศึกษาการดึงดูดของสนามแม่เหล็กจากดวงอาทิตย์และโลกผ่านแสงแห่งออโรร่า
The purpose of this fashion thesis is to study the characteristics of the light color and the shape of the light of Aurora and designed the work to be novel interesting by showing the design of the ladys style costume by using the light color characteristics of Aurora a color scheme that can be combined with the technique of clothing editing binding. Dyeing batik making in costume design That makes the consumer look new unique more beautiful. The tools used in this study Is an aurora light analysis model. The sample used in this study is a photograph of Norwegian photographer Ole Christian Salomonsen. The criteria in the analysis are 2 aspects which are 1) Body 2) Color and overall analysis to be used Creative costume The results show that the aurora outline and color light is caused by charged particles in the space passing through the Earths atmosphere releasing energy in the form of light in which different colored light characteristics occur. The light curtain that you see has various shapes such as helical scrolls. Flutter wave tear streak or all three forms Applied to the costume design by paying attention to the style of the dress and the selection of various techniques including Fabric overlapping tie dyeing Batik making suitable for clothing styles for creating new and unique costume designs that meet the needs of consumers.
การศึกษาและพัฒนาวัสดุปลูกพืชน้ำหนักเบาจากต้นกล้วยเพื่อใช้กับสวนแนวตั้ง
The study and Development Lightweight growing media by banana tree to use a Vertical garden.To create thermal comfort for building users are the main factors causing the air conditioning. The cause of the electrical consumption. Thus bringing the tree into the building. In the past the building that used tree. Create a homey Subsequently it has adopted a large tree used for the purpose of lowering the temperature of the surrounding buildings. Developed into a roof garden Reduce heat to pass through the roof. And is currently being applied in the manner of a green wall. This helps reduce the heat that enters the building through the building envelope as well. The behavior of the tree to absorb water from the roots to the leaves and then passed to photosynthesis. Such a process makes the water evaporates and the air has been cooled by the surrounding trees The Heat pulled away for the evaporation of water. Such a process which happens from time to time no matter how much humidity in the air. The cool environment is another factor that manipulates the ambient environment to environment and buildings The benefits of trees in the green areas of the city this is helping to reduce and prevent the phenomenon of urban heat island The study and Development Lightweight growing media by banana tree to use a Vertical To reduce the weight of structural data were collected to design the plant material. Then the data from design professionals and vertical landscaping questionnaire. And interviews to analyze the result. And amends To test plant material vegetation series of 12 trials by planting vegetation. On the wall a series of three experiments wall. (Width 1.20 m. Height 3.00 m.) Of the test data and the growth of vegetation. Found that plants grow well on a series of plant material. The unit is lightweight and planting is not burdened with the weight of the building structure.
คุณสมบัติเชิงกลของคอนกรีตมวลเบาผสมวัสดุปอซโซลาน
This research study the effect of pozzolanic materials on light weight concrete by replacement cement with fly ash and Meta kaolin which affect the properties of concrete by using pumics aggregate. Coarse in aerated concrete and consider mechanical properties. Aerated concrete replacement cement by fly ash 20% 35% and 50% respectively and meta-kaolin is replaced. From the results it was found that the compressive strength of light weight concrete at 28 days w/b = 0.55 was higher than that of every 14 days of cement and cement cement replacement by fly ash 50% highest value compressive strength. More than all the ingredients replaced with fly ash and Meta kaolin. When considering the flexural strength of replacement cement with 10% by Meta kaolin the maximum flexural strength of 80 ksc was higher than that of control concrete and all other ingradient. Experimental tensile strength at 28 days result found that replacement cement by fly ash at 35% gave the highest tensile strength of 28 ksc and gave higher tensile strength than all other ingradient. From the impact strength test at age 28 days it was found that the replacement cement 35% by fly ash gave the highest impact strength of 92.00 joule than the 20% and 50% respectively and higher impact strength than that of all kaolin. Except for control concrete.