Study on the new hybrid thermodynamic cycle for an improved micro swing engine with heat recovery process. (25th January 2018)

• Record Type: Journal Article
• Authors: Xia, Chen; Zhang, Zhiguang; Huang, Guoping; Xu, Yikai
• Is Part Of: Applied thermal engineering. Volume 129(2018)
• Page Start: 1135
• Page End: 1149
• Publication Date: 2018-01-25
• Subjects: Micro swing engine -- Hybrid thermodynamic cycle -- Buffering recuperator -- Asynchronous heat exchange -- Intermittent flow; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2017.10.123
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: A new micro swing engine with 3 non-isometric chambers is proposed and works in a hybrid cycle with better performance. A recuperator suitable for the 3-arm micro swing engine is specially designed and heat recovery process is introduced. Gas in the four-stroke cylinders will recycle all the exhaust heat, while the gas in two-stroke ones absorb nothing. The buffering recuperator is validated by CFD method for asynchronous heat transfer process and intermittent flow. Simulations show that, the efficiency for our engine with recuperator attains 11.74%, a relative increase by 40.77%. Abstract: In this research, a novel hybrid thermodynamic cycle with an asynchronous buffering heat recovery process is proposed to overcome the extremely difficult problem for micro swing engine, i.e. the far too low efficiency. Firstly, the 3-arm micro swing engine is presented, which is proven to hold a better performance than the original 2-arm one. Among the 3 chambers, two are isometric and operate in four-stroke cycle while the rest has a slightly larger volume and works in two-stroke cycle. Then, depending on the reasonable structural design, a novel asynchronous buffering recuperator suitable for the 3-arm structure was designed and the hybrid thermodynamic cycle with heat recovery process was introduced. That is, the gas in the four-stroke chambers recycle all the exhaust heat while the gas in two-stroke ones do not. In the recuperator, the cold flow is intermittent and the heat exchange process is asynchronous. But CFD simulations demonstrate that this buffering recuperation method is effective in settling the problems. Finally, the performance of the hybrid cycle was analyzed. The results indicate that the efficiency of the novel engine reached as high as 11.74%, which was increased by 40.77% in comparison with the one without a recuperator.