จำนวน Repository ( 3611 )
รูปแบบการระบายความร้อนด้วยน้ำที่ส่งผลต่อสัมประสิทธิ์สมรรถนะของระบบปรับอากาศแบบแยกส่วน
The purpose of this research was to investigate cooling water profile that effect to coefficient of performance of spilt type air- conditioning system. Air conditioner size of 12000 Btu/h was used in this experiment. There are three experiment of cooling water profiles in this work such as water spray water drop and heat exchanger profile. The ambient temperature conditions were controlled at 35 40 43 and 45 oC. The results of this study were found that heat exchanger profile had the highest average coefficient of performance and energy efficiency as 4.94 and 9.15 Btu/Wh which increased as 20.1% and 8.47% respectively when comparing with the normal working.
มาตรฐานน้ำดื่มบรรจุขวดที่จำหน่ายในจังหวัดอ่างทอง
In this study water quality standard of bottled drinking water distributed in Ang Thong Province was investigated. The results showed that clear plastic bottled drinking water presented completely label information and MFD./EXP. clearly appearance and odourless presented in all samples while Total Dissolved Solid (TDS) of tested clear plastic bottled drinking water samples were in a range of 1±0.00 to 277±0.00 mg/L. Coliform bacteria and fecal coliform bacteria of all tested water samples were less than 2.2 MPN/100 mL and E. coli and total heterotrophic bacteria were not found in all samples. pH values of 18 tested samples were less than 6.5 (60.00%) plastic bottled drinking water samples. Tested opaque plastic bottled drinking water samples showed completely label information and MFD./EXP. clearly appearance and odourless found in all samples while TDS of tested opaque plastic bottled drinking water samples were in a range of 12±0.00 to 13±0.00 mg/L. Coliform bacteria and fecal coliform bacteria of tested water samples were less than 2.2 MPN/100 mL and E. coli and total heterotrophic bacteria were not found in all samples. pH values of 3 tested samples were less than 6.5 (100.00%). Indeed assessment of both types of bottled drinking water samples distributed in Ang Thong Province Thailand based on 6 qualities assessment of standard for drinking water in sealed container set by Ministry of Public Health of Thailand revealed that the tested clear and opaque plastic bottled drinking water samples met the standard for 40.00% and 0% based on pH respectively.
การติดตั้งแหล่งผลิตไฟฟ้าแบบกระจายตัวเพื่อเพิ่มความเชื่อถือได้ในระบบจำหน่ายไฟฟ้า
This paper presents reliability evaluation in distribution system with distributed generation. The main objective is to minimize the customer interruption cost subject to given number of distributed generation. The minimization problem for customer interruption cost in solved by the developed tabu search algorithm together with reliability worth analysis that provide an indirect measure for cost implication associated with power outages. The developed methodology is tested with a distribution system of Roy Billinton Test System (RBTS) bus 2 consist of 15 buses and 22 load points. Numerical results from the tests demonstrate that the optimal distributed generation placement can be used to promote reliability of the distribution systems.
การหาค่าพารามิเตอร์ของตัวควบคุมแบบสัดส่วนบวกอินทิกรัลแบบ อัตโนมัติด้วยขั้นตอนวิธีเชิงพันธุกรรมสำหรับระบบการขับเคลื่อนมอเตอร์ซิงโครนัสชนิดแม่เหล็กถาวร
Proportional plus integral controller has been widely used in permanent magnet synchronous motor (PMSM) drive system due to its simple structure while achieving zero steady-state error. However finding out the optimal parameters of the controller is not an easy task. For this reason this paper presents an automated optimization of proportional plus integral controller for permanent magnet synchronous motor drive system using genetic algorithms. Simulation and experimental results verify the effectiveness than ones of the trial and error method.
การลดของเสียในกระบวนการผลิตชิ้นงานความเที่ยงตรงสูงโดยใช้หลักแนวคิดของลีน กรณีศึกษา : บริษัท อาร์แอนด์ดี พรีซิชั่น จำกัด
R & D PRECISION CO.LTD manufactures various types of work. Yet there were defects of work in previous working and the company was unable to deliver products to customers as required and some might have been destroyed. As the information referred to the waste detected each month from January 2014 to June 2014 it is found that the volume of defect rate was 9.56 percent resulting in losing cost of production and other business opportunities. This research aims to reduce waste in the production of high precision with lean concepts. The study starts from the analysis of employees working information by creating a value stream mapping. The study found that cylindrical grinding takes the longest time. Then the study explored and determined the root cause of the problem by using a Pareto Diagram together with a Fish-Bone Diagram to analyze the minor causes. It is found that most wastes are caused by measuring control especially for the work that has a shaft hole with thickness of 2.25 mm. Thus the study and experiment were conducted to determine the flow rate of the coolant for the work piece in the cylindrical grinding machine and a fixed value is the rate of decreasing the size of work speed of stone wheel and work type of coolant and type of grinding stones. The goal is to reduce waste by not less than five percent and to improve the process of reducing waste effectively which will affect the environment having lesser wastes from production. It also supports competitiveness and rapid change of industry manufacturing highprecision parts in the future even better.