Experimental Analysis of Hydrogen Energy share in a compressed ignition engine under dual fuel mode with Karanja B20 at different Injection Operating Pressures

The present experiment is to improvement of hydrogen energy share in 3.5 kW single cylinder direct injection diesel engine under dual fuel mode. The experimental test is conducted at the injection operating pressure (IOP) varying from 200 to 240 bar using pure diesel, B20, and B20 with various less concentration flow rate of hydrogen at 100% load with 1500 rpm constant. The acquisition data of the test fuels is compared with 200 bar pressure of diesel baseline. The energy share of hydrogen for performance parameters like Brake thermal efficiency (BTE) is high with maximum IOP and also the specific fuel consumption (SFC) reducing with increasing with maximum IOP. The combustion parameters of Net Heat Release Rate (NHRR) and Cylinder Peak pressure also increases with increasing IOP. The emission parameters of HC, CO, and CO2 reduces with share of hydrogen at high IOP meanwhile the NOx emissions increases with increasing hydrogen and IOP. Keyword Dual Fuel Engine, Karanja Oil, Hydrogen, Efficiency, Emissions

In this present work, a single cylinder direct injection diesel engine is modified to work in the dual fuel mode with hydrogen as an introduced fuel. Karanja oil methyl ester (KOME) blend (B20) is used as the injected fuel and most of the engine's energy is derived from it. It is injected by the conventional fuel injection system. Experiments were conducted at a constant speed of 1500 rpm, full load conditions and the quantity of hydrogen and Injection Operating pressure were varied. Comparison has been made with results obtained while using base line diesel as the pilot fuel instead of the KOME blend.

II. EXPERIMENTAL SETUP AND TEST PROCEDURE
A Single cylinder water cooled DI diesel engine developing 3.5 kW at 1500 rpm with the fuel of pure diesel. Specifications of the engine details are shown in Table II. A schematic view of experimental set up illustrated in Fig 1.With the help of high-speed digital data acquisition system to traced the output signal of pressure. The piezoelectric transducer and crankshaft position optical encoder were employed for the measurement of cylinder pressure as a function of crank angle. The exhaust emissions of Engine were quantified by advanced MN-05 multi-gas analyzer (5 gas version). The combustion study was carried on the averaged value of 100 cycles after the engine attained steady state condition. For the duration of the first stage of operation the engine was in progress of fuel on pure diesel to produce baseline data. In the second stage of operation, the engine was made to use on B20 fuel after arriving at stable conditions the outcomes are contrasted to baseline data. In the third stage of process engine running on B20 fuel and inducted air is augmented with a small concentration of hydrogen (5, 10 and 15 lpm), the results were achieved at full loading conditions for three different injection opening pressures of 200, 220and 240 bar.

D. Emiss
The di bar is 0. 2

IV. CONCLUSION
A single cylinder compression ignition diesel engine was operated successfully using B20 as pilot fuel and hydrogen as introduced fuel at unlike injection operating pressures. Tests carried out at 200, 220, and 240 bar IOP point out that 240 bar IOP is most favorable pressure for improved performance, combustion and smallest amount emissions. The following conclusions are recapitulated based on the experimental results acquired for hydrogen operated engine with B20 as pilot fuel injected with 240 bar injection operating pressure and contrasted to pure diesel operation at base line injection opening pressure of 200 bar at 100% load.
 B20 and B20 with hydrogen can be directly used in diesel engines with or without any modifications.
 The maximum BTE of 27% was observed at IOP of about 240 bars and at 100% engine load. BTE was found lowest at 200 bars.  B20 with 15lpm of hydrogen reduces BSFC by 27%. Brake specific fuel consumption was continuously decreasing with the increase in IOP. Minimum brake specific fuel consumption was noticed at 240 bars and BSFC was found maximum at 200 bar of injection operating pressure.  Peak cylinder pressure and Net heat release rate was detected at 240 bar of IOP.
 Compared with pure diesel, exhaust emissions of CO, CO2 and HC are reduced while NOx emissions are increased with B20 and B20 among hydrogen with diesel. Experimental analysis exposed that the supply of 15 lpm hydrogen in direct injection diesel engine running on B20 and operated with increased injection operating pressure of 240 bar gives maximum brake thermal efficiency than at 200 bar. Also, HC and CO emissions are reduced at the penalty of increased NOx emissions than that of diesel fuel operation