Experimental Investigation on Some Performance Parameters of a Diesel Engine Using Ceramic Coating on the Top of the Piston 970207

The experimental investigation was conducted on a CI version Ricardo variable compression single cylinder naturally aspirated engine to examine the effects of ceramic coating on performance and exhaust emissions. Tests were carried out at 1500rpm over a wide range of part loads, varying injection timings and compression ratios (CR). The top of the piston was insulated by using Yttria-partially stabilized zirconia with a bond coat alumino boro silicate. The technology by which the piston head was insulated is much more economical and simpler than the plasma-spray process usually used for coating with ceramics. Results show that at 30% of the rated load, BSFC decreases upto 9.99% at 40° injection bTDC (before top dead centre) for CR-19 resulting higher thermal efficiency than base line engine. Ignition delay is longer in ceramic coated engine than its counter part. For CR-18 and 19 these ranges are 1.3% to 7.94% at different injection timings. Volumetric efficiency drops over the ranges 3.1% to 6.04% at different compression ratios from base line engine. NO_x level is lower in ceramic coated piston engine. At 30% of the rated load, NO_x level decreases 32.14% to 45.77% with injection angles 30° bTDC and 40° bTDC respectively for CR-19 in ceramic coated piston engine than the metal piston engine. CO level is higher in ceramic coated engine than base line level. But this increase is comparatively lower at CR-19 and even lower with higher injection angle 40° bTDC. At higher compression ratios CR-19 and 20 smoke density decreases upto 37.93% and 37.5% at 40° bTDC from base line engine.