The Study of Characteristic Parameters for Pressurized Twin-Power-Piston Gamma-Type Stirling Engine

• Main Authors: Li-Wen Po, 柏立文
• Other Authors: Wen-Lih Chen
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/77987909248570637397

博士 === 崑山科技大學 === 機械與能源工程研究所 === 101 === In this study, a prototype helium-charged twin-power-piston γ-type Stirling engine has been built, and some of its geometrical and operational parameters have been investigated by a numerical model. Data taken from the prototype engine have been used to correct the values of some factors in the numerical model. The results include volume and temperature variations in the expansion and compression chambers, p-V diagrams, and the effects of regeneration effectiveness, the crank radius of the power piston, the initial pressure of working gas, and the rotation speed on engine’s power and efficiency. A Stirling engine uses temperature difference to expand and compress working gas to do work. The displacer cylinder in this study is designed as a regenerator as well. Explore the displacer cylinder of adiabatic heat transfer effect on engine performance. The citation of the single tube heat exchanger consider the effect of thermal radiation impact on the log mean heat transfer rate (LMHTR) method can be obtained more reliable solution concept. Further study shows that in a non-insulated double-pipe heat exchanger, the effect of the thermal radiation heat transfer needs to be considered, and the heat transfer characteristics have to be calculated by the total of the number of log mean heat transfer rate method. The conclusions of this study for the non-insulated double-pipe casing heat exchanger. When thermal radiation is ignored, using the LMHTR method to obtain the total heat transfer rate of the fluid of the inner tube and the result is the same log mean temperature difference (LMTD) method. Comparative use LMTD method and LMHTR method determined the fluid between the heat transfer rate in the inner tube or the inner and outer tubes, and the error is far exceeds the acceptable range of engineering, it must consider the effect of the heat radiation, and therefore only obtained apply LMHTR method canpractical and complete results. The results application of the γ-type Stirling engine of the present study design displacer cylinder, as the hot and cold ends temperature of the displacer cylinder, the inside of the cold end as the working gas, the external cooling water jacket, so the heat exchange process without considering the effect of the heat radiation effect. The calculation of the efficiency of heat transfer applies in the LMTD law. In this study, the design of the engine’s displacer to gas hot end of the cylinder structure of single-pipe heat exchange, the external coupled with a thermal sleeve that double-pipe structure. A direct impact on the performance of the Stirling engine; Therefore, the displacer cylinder double-pipe must install the appropriate thermal insulation material to prevent the impact of thermal radiation effects, so that heat can maintain the hot end of the Stirling engine to do work for a long time. The temperature of a hot end, the experiment of this study verify the working gas pressure values of the best engine performance, engine performance drop instead of increasing the helium pressure exceeds this optimum pressure value. Therefore obtain a valuable results for the optimum efficiency of the engine is only related to the temperature of the hot end, while the hot-end heat transfer efficiency is closely related to the design of the regenerator, so the regenerator performance affect the engine power in a certain range is the most important parameter. This study offers invaluable guides for the design and optimization of γ-type Stirling engines with similar construction.