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This paper is a brief review of the method for analyzing the space and time dependent exergy and irreversibility fields in processes. It presents the basic equations, the method for their use, major literature sources, and three examples from the authors' work: flow desiccation, combustion of oil droplets, and combustion of pulverized coal. Conclusions from this Second Law analysis are used to attempt...
This paper focuses on the effects of internal and cooled external exhaust gas recirculation (EGR) on the combustion and emission performance of diesel fuel homogeneous charge compression ignition (HCCI). The use of fuel injection before the top center (TC) of an exhaust stroke and the negative valve overlap (NVO) to form the homogeneous mixture achieves low NO x and smoke emissions HCCI. Internal...
In order to increase the efficiency of waste utilization in thermal conversion processes, pre-treatment is advantageous. With the Herhof Stabilat ® process, residual domestic waste is upgraded to waste-derived fuel by means of biological drying and mechanical separation of inerts and metals. The dried and homogenized waste-derived Stabilat ® fuel has a relatively high calorific value...
This paper presents results of experimental research into the ash behavior of different Bosnian coal types and biomass fired in an electrically heated entrained pulverized fuel flow experimental reactor. The results are derived from a series of tests performed under a range of temperature and air conditions for the fuel test matrix. In essence, the experimental reactor comprises a 3m length alumina–silicate...
An experimental study is conducted to evaluate the effects of using blends of ethanol with conventional diesel fuel, with 5%, 10% and 15% (by vol.) ethanol, on the combustion and emissions of a standard, fully instrumented, four-stroke, high-speed, direct injection (HSDI), ‘Hydra’ diesel engine located at the authors’ laboratory. The tests are conducted using each of the above fuel blends or neat...
The effects of biodiesel (rapeseed methyl ester, RME) and different diesel/RME blends on the diesel engine NO x emissions, smoke, fuel consumption, engine efficiency, cylinder pressure and net heat release rate are analysed and presented. The combustion of RME as pure fuel or blended with diesel in an unmodified engine results in advanced combustion, reduced ignition delay and increased heat...
Cooled exhaust gas recirculation (EGR) is a common way to control in-cylinder NO x production and is used on most modern high-speed direct injection (HSDI) diesel engines. However EGR has different effects on combustion and emissions production that are difficult to distinguish (increase of intake temperature, delay of rate of heat release (ROHR), decrease of peak heat release, decrease in...
Diesel engine development for use in light-, medium- and heavy-duty road vehicles is mainly driven by more and more stringent emission standards. Apart from air quality related emissions such as nitrogen oxides and particulates, also greenhouse gas (GHG) emissions are likely to become of more and more importance. Furthermore, oil-based fuel availability might become a problem due to limited reserves...
Possibly one of the most significant advantages that hydrogen may have as a fuel is its potential for increased second-law efficiency, due to fundamental differences in the mechanism of entropy generation during combustion with respect to the usual hydrocarbon-based fuels. A computational investigation of this effect is pursued for the case of mixtures of hydrogen and natural gas combusting in a diesel...
Through experiments conducted on a single cylinder direct injection (DI) diesel engine, effects of exhaust gas recirculatoin (EGR) on combustion and emission during cold start were investigated. Combustion of first firing cycle can be promoted significantly by introducing EGR. In experiments, when partially closed choking valve and partially or fully opened EGR valve, peak cylinder pressure of first...
In one of the largest agricultural companies in Serbia, with over 2000ha of soya plantations, there are 4000t/year of baled soya straw produced. Soya straw biomass is planned to be used as a renewable energy source for heating the greenhouses, with 5ha in area. Therefore, efforts have been made to develop a technology for utilizing large bales of soya straw for energy production. In the first phase,...
Airborne particulate matter (PM) now exceeds sulfur dioxide and nitrogen oxides to become principal urban pollutant in most major cities of China. This paper gives an overview of fundamental studies on the formation and control of combustion PM from many research groups in China. About 62.8% major cities in China have lowered their annual mean PM 10 concentrations to less than 100μg/m ...
Environmental concern and availability of petroleum fuels have caused interests in the search for alternate fuels for internal combustion engines. Waste plastics are indispensable materials in the modern world and application in the industrial field is continually increasing. In this context, waste plastics are currently receiving renewed interest. As an alternative, non-biodegradable, and renewable...
In this paper, a new approach is proposed for simplifying the calculation of flue gas specific heat and specific exergy value in one formulation depending on fuel chemical composition. Combustion products contain different gases such as CO 2 , SO 2 , N 2 , O 2 , H 2 O and etc., depending on the burning process. Specific heat and exergy of the flue gas differ...
The objective of the present work is to analyze the combustion characteristics of crude rice bran oil methyl ester (CRBME) blend (20% of CRBME with 80% no.2 diesel on volume basis) as a fuel in a stationary small duty direct injection (DI) compression ignition (CI) engine. When operating with CRBME blend the cylinder pressure was comparable to that of diesel. It was observed that the delay period...
Reactions of pulverized coal injection (PCI) in a blast furnace were simulated using a drop tube furnace (DTF) to investigate the burnout behavior of a number of coals and coal blends. For the coals with the fuel ratio ranging from 1.36 to 6.22, the experimental results indicated that the burnout increased with decreasing the fuel ratio, except for certain coals departing from the general trend. One...
With the increasing concern regarding diesel vehicle emissions and the rising cost of the liquid diesel fuel as well, more conventional diesel engines internationally are pursuing the option of converting to use natural gas as a supplement for the conventional diesel fuel (dual fuel natural gas/diesel engines). The most common natural gas/diesel operating mode is referred to as the pilot ignited natural...
During the generation of steam, most water impurities are not evaporated with the steam and thus concentrate in the boiler water. The concentration of the impurities is usually regulated by the adjustment of the continuous blowdown valve, which controls the amount of water (and concentrated impurities) purged from the steam drum. Since a certain amount of continuous blowdown must be maintained for...
Combustion in Porous Media provides interesting advantages compared with the free flame combustion due to the higher burning rates, increased power dynamic range, the extension of lean flammability limits, and the low emissions of pollutants. A numerical code is developed in order to evaluate the effects of different parameters of combustion in porous media. The governing equations including Navier–Stokes,...
This paper describes an experimental study conducted on a modern high speed common-rail automotive Diesel engine in order to evaluate the effects on combustion and pollutant emissions of water injected as a fine mist in the inlet manifold.First, a literature survey describing the several ways to introduce water in an internal combustion engine and reporting the main results from previous studies is...
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