Effect of hydrogen addition on the combustion and emission of a diesel free-piston engine. (19th July 2018)

• Record Type: Journal Article
• Authors: Yuan, Chenheng; Han, Cuijie; Liu, Yang; He, Yituan; Shao, Yiming; Jian, Xiaochun
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 29(2018)
• Page Start: 13583
• Page End: 13593
• Publication Date: 2018-07-19
• Subjects: Free-piston engine -- Hydrogen addition -- Combustion -- Emission -- Heat release; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.05.038
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The free-piston engine (FPE) is a new crankless engine, which operates with variable compression ratio, flexible fuel applicability and low pollution potential. A numerical model which couples with dynamic, combustion and gas exchange was established and verified by experiment to simulate the effects of different hydrogen addition on the combustion and emission of a diesel FPE. Results indicate that a small amount of hydrogen addition has a little effect on the combustion process of the FPE. However, when the ratio of hydrogen addition (RH2 ) is more than 0.1, the RH2 gives a positive effect on the peak in-cylinder gas pressure, temperature, and nitric oxide emission of the FPE, while soot emission decreases with the increase of hydrogen addition. Moreover, the larger RH2 induces a longer ignition delay, shorter rapid combustion period, weaker post-combustion effect, greater heat release rate, and earlier peak heat release rate for the FPE. Nevertheless, the released heat in rapid combustion period is significantly enhanced by the increase of RH2 . Highlights: The influence of hydrogen addition on a diesel FPE was investigated. A new method to simulate the FPE adding hydrogen was provided. Novel effects of hydrogen addition on the FPE operation were revealed.