การศึกษากลไกการสูญเสียของเครื่องยนต์สเตอร์ลิงแบบผลต่างอุณหภูมิปานกลาง

• Main Author: กฤษลิน ถมยาบัตร
• Other Authors: อังคีร์ ศรีภคากร
• Format: Theses and Dissertations
• Language: Thai
• Published: จุฬาลงกรณ์มหาวิทยาลัย 2010
• Subjects: เครื่องยนต์สเตอร์ลิงค์; เครื่องแลกเปลี่ยนความร้อน
• Online Access: https://digiverse.chula.ac.th/Info/item/dc:43680

The present work investigates the loss mechanism in a Stirling engine with moderate temperature difference (MDSE) in order to identify the major loss mechanism. The result for the 100-W Beta-type Stirling engine indicated that the heat loss to the environment and the heat dissipated on the hot side are the major loss mechanisms. The finding indicates three improvements to be performed to the engine: to optimize the regenerator via Taguchi’s method, to change the material for the piston ring and to change the working fluid from air to helium. The optimization result on the regenerator was found to increase the shaft power output by 35%. The improvement of the piston ring material prolongs the life of the piston ring but the result was still inadequate for actual use. The use of helium in place of air for the working fluid resulted in a decrease in the shaft power output. The mechanical inertia is suspected to limit the running speed of the engine and make the engine unable to reach the optimum speed for use with helium. A comparison of the loss of MDSE with engines with high temperature difference (HDSE) and low temperature difference (LDSE) using the method of Iwamoto, S. pointed to the deficiency of this method by not including the effect of charged pressure. To improve the comparison, this study adopted the method of Prieto, J.L. The comparison indicated an increase in the dimensionless loss term from LDSE, MDSE and HDSE respectively. The existing MDSE also has the dimensionless loss term of a comparable value to the HDSE which indicate that improvement can still be done on the thermal design of the engine.