Owing to the differences among the calorific values and oxygen content of the fuels tested, the comparison must be effected at the same engine brake mean effective pressure, i.e. load, and not at air/fuel ratio. in this also tests are considered accuracy of measurements and the below table shoes accuracy of measurements and uncertainty of computed results.
Engine tests were carried out 2500 rpm and 0.8 MPa of brake mean effective pressure.
If the power delivered is increased by any change other than an increase in speed or cylinder dimensions, its brake mean effective pressure increases proportionately.
The results showed that the combustion pressure, brake mean effective pressure, cylinder temperature and thermal efficiency were simultaneously increased after the hydrogen blending.
Therefore, brake mean effective pressure is markedly increasing, leading to increased risks of knock onset and abnormal combustions in last-generation SI engines.
Engine torque, power, brake mean effective pressure, specific fuel consumption, fuel flow, and exhaust emissions such as SO2, CO2, NOx and smoke level (%N) have been investigated.
The optimization considers five decision variables, including engine frequency, mean effective pressure, temperature of heating source, number of wires in regenerator matrix, and the wire diameter of regenerator, as multiple objectives.
Engine investigations showed that the top combustion pressure at 1200 rpm and 100% load (7.8 brake mean effective pressure (bmep)) was 79 bar for diesel fuel and 78 bar for the charcoal slurry fuel.
Results show an improvement of indicated mean effective pressure-gross (IMEPg) and a reduction of soot formation with the introduction of flash boiling spray under cold start condition.
In addition, the comparison of the Indicated Mean Effective Pressure IMEPP) with the results of the previous 26-step mechanism has been done.
The direct problems of the estimation of the angle of 50% of fuel mass fraction burnt (MFB50) and of the Indicated Mean Effective Pressure (IMEP) are addressed as well as the inverse problems of determining optimal start of injection (SOI) timing for target values of MFB50 and IMEP.
