A comparison of Miller and Otto cycle natural gas engines for small scale CHP applications

Abstract

This paper presents an investigation into the feasibility and potential advantages of a small scale Miller cycle natural gas engine for applications such as domestic combined heat and power systems. The Miller cycle engine is compared to a standard Otto cycle engine using cycle analyses and multidimensional simulation, and basic engine design implications are discussed. It is found that the Miller cycle engine has a potential for improved fuel efficiency, but at the cost of a reduced power to weight ratio. A fuel efficiency advantage of 5→10 per cent compared to a standard Otto cycle engine appears possible, however it is stated that further investigations, in particular into the topic of engine friction, are required in order to validate the findings.

Thermodynamic performance analysis and optimization of DMC (Dual Miller Cycle) cogeneration system by considering exergetic performance coefficient and total exergy output criteria

“…(19)e (22) and (29) into the Equation. (35), the average temperature (T a ) can be expressed in terms of T 2 as well.…”

“…Lin and Hou [18] investigated the effects of heat loss characterized by a percentage of fuel's energy, friction and variable specific heats of working fluid on the performance of an air-standard Miller cycle. Mikalsen et al [19] investigated the feasibility and potential advantages of a small scale Miller cycle natural gas engine for combined heat and power systems. Ebrahimi [20] analyzed the performance of an air standard Miller cycle by using finite-time thermodynamics.…”

Green Driver: Travel Behaviors Revisited on Fuel Saving and Less Emission

“…The CO 2 and GHG emission reduction is the main goal in the growth of green transportation [30]. So, it is essential to innovate the techniques reduce CO 2 and GHG emissions [31,32]. Doppelt and Markowitz [33] state that "there does not appear to be substantial research on how specific behavioral changes can lead to measurable reductions in GHG emissions".…”

Comparative performance analyses of irreversible OMCE (Otto Miller cycle engine)-DiMCE (Diesel miller cycle engine)-DMCE (Dual Miller cycle engine)

“…Wang et al [27] experimentally applied the MC to a diesel engine and minimize the NOx emissions and the SFC (specific fuel consumption) together at the expense of little power loss. Mikalsen et al [28] carried out a study on MC Otto engine. While the fuel efficiency enhanced, power output diminished in comparison with weight ratio.…”

“…The optimal engine design parameters at the MP, MPD and MEF (r mp , r mpd , r mef , b mp , b mpd , b mef , z mp , z mpd , z mef ) are obtained by using Eqs. (13)e(28). The relationship between _ W, _ W d , h and r M are found with respect to Eqs.…”