Experimental Study of Inlet Manifold Water Injection on a Common Rail HSDI Automobile Diesel Engine, Compared to EGR with Respect to PM and Nox Emissions and Specific Consumption

Author(s):  
Samiur Rahman Shah ◽  
Alain Maiboom ◽  
Xavier Tauzia ◽  
Jean-Francois Hetet
Author(s):  
Eduardo Barrientos ◽  
Ivan Bortel ◽  
Michal Takats ◽  
Jiri Vavra

Engine induced swirl improves mixing of fuel and air and at optimal values accelerates burn, improves the combustion stability and can decrease particulate matter (PM). However, swirl increases convective heat loss and cylinder charge loss and could increase nitrogen oxides (NOx) emissions. High intensity of swirl could impede flame development and increases emissions of total hydrocarbons (THC) and carbon monoxide (CO). Therefore, careful and smart selection of optimal swirl values is paramount in order to obtain beneficial impact on combustion and emissions performance. This study is conducted on a 0.5L single cylinder research engine with common rail (CR) diesel injection system, with parameters corresponding to modern engines of passenger cars. The engine has three separate ports in the cylinder head. The change of swirl ratio is defined by closing appropriate ports. There are three levels of swirl ratio under study — 1.7, 2.9 and 4.5, corresponding to low, medium and high swirl levels respectively. This study highlights the influence of intake induced swirl on combustion parameters and emissions. Assessed combustion parameters are, among others, heat release rate, cylinder pressure rise and indicated mean effective pressure. Assessed emissions are standard gaseous emissions and smoke, with emphasis on PM emissions. An engine speed of 1500 rpm was selected, which well represents common driving conditions of this engine size. Various common rail pressures are used at ambient inlet manifold pressure (without boost pressure) and at 1 bar boosted pressure mode. It is found that when the swirl level is increased, the faster heat release during the premixed combustion and during early diffusion-controlled combustion causes a quick increase in both in-cylinder pressure and temperature, thus promoting the formation of NOx. However, since swirl enhances mixing and potentially produces a leaning effect, PM formation is reduced in general. However, maximum peak temperature is lower for high swirl ratio and boosted modes due to the increase of heat transfer into cylinder walls. Furthermore, it is necessary to find optimal values of common rail pressures and swirl ratio. Too much mixing allows increase on PM, THC and CO emissions without decrease on NOx emissions in general. Common rail injection system provides enough energy to achieve good mixing during all the injection time in the cases of supercharged modes and high common rail pressure modes. Positive influence of swirl ratio is found at lower boost pressures, lower revolution levels and at lower engine loads. The results obtained here help providing a better understanding on the swirl effects on diesel engine combustion and exhaust emissions over a range of engine operating conditions, with the ultimate goal of finding optimal values of swirl operation.


2019 ◽  
Vol 8 (2) ◽  
pp. 1902-1905

The present energy scenario hydrogen fuel plays a dominant role in the power generation. Due to its unique characteristics of an extensive range of flammability, high flame speed, and diffusivity. In this present investigation, the diesel engine is converted into dual-fuel mode devoid of major conversions of the engine. The tests are performed on a dual-fuel mode and investigated the efficiency, emissions, and combustion features of the diesel engine. In the present context, hydrogen and biogas are injected from the inlet manifold as subsidiary fuel and diesel are injected as pilot fuel. The gaseous fuel injected in two different flow rates they are, 3 litres per minute (lpm), and 4lpm. The results from the experimentation revealed that the diesel with 4 lpm of hydrogen shows the 31.11 % enhancement of brake thermal efficiency but it shows 4.14% higher NOX emissions when compared with the pure diesel. But it shows. At the same time diesel with 4 lpm of Biogas exhibits 15.90% enhancement of brake thermal efficiency and 8.96% decrease in the NOX emissions in contrast to that of the single-mode of fuel with diesel.


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