การปรับปรุงระบบปรับอากาศสำหรับห้องพ่นสีของโรงงานผลิตรถยนต์ / อรรถพล ปิ่นโภคินทร์ = The improvement of air supply unit for spray booth in car assembly factory / Attapol Pinpokintr
The car assembly factory has long production stop about 290 minute every year on November to January of next year, because Air Supply Unit (ASU) has not make standard air condition for Spray Booth to set point. It effects to quality of painting on car body, and big loose of production. Management of car assembly factory would like to prevent production stop from this problem by minimizes budget. So objectives of this thesis is redesign and improve control system of Air Supply Unit for TopCoat Spray Booth. To make air condition in control limit to reduce down time. Cause of ASU has not make air condition for Spray Booth to set point is Enthalpy ambient on winter has lower capacity design limit. In this condition, ASU has wonted more energy from steam boiler to make air condition to set point. But new steam boiler is use high installation cost and high operation cost. So problem solving is focus to redesign and improvement ASU process controller. Before improvement ASU has used Proportion Integral Derivative(PID) controller, advantage is process control has high stabilization but inferior is unflexilibility. To solve this problem we has improve process control to Fuzzy Logic. It make wide set point range, so it effect to increase process capacity and energy saving. After improvement ASU process controller, down time from ASU in winter of year 2000 is 0 minute (from December 2000 to January 2001). Beside it can apply to other process control if process control has same as ASU process control improved.
