Page 212 - Energy from Toxic Organic Waste for Heat and Power Generation

190 Energy from Toxic Organic Waste for Heat and Power Generation

Hence, considering brake thermal efficiency and emission levels, it is nec-
essary to determine the optimum HOME and fuel oil blend ratio for opti-
mized dual fuel engine operation. The cylinder pressure values at 80% load
for HOME-PG (HCC) and HOME-PG (RCC) operation with 10%, 20%,
and 30% fuel oil were found to be 57.2, 59.5, 62.6 bar and 64.58 bar, respec-
tively, compared to 68.4 bar for diesel-PG operation (HCC).
Fig. 11.30 shows heat release rate (HRR) versus crank angle for differ-
ent dual fuel combinations at 80% load with different combustion chamber
configurations adopted. Dual fuel operation with same combustion cham-
ber (HCC) showed diesel-PG combination, resulting in higher HRR when
compared to other fuel combinations. Differences in the combustion rates
during the premixed combustion phase have an impact on these trends
obtained. Lower HRR associated with HOME-PG (HCC) is mainly due
to poor spray characteristics of biodiesels along with their higher viscosity
and slower burning nature of producer gas leading to improper mixing. In
addition, differences in the energy content of the fuel combinations and
changes in the oxygen concentration of the charge and chemical kinetic
processes involved are also responsible for this trend of result shown. Addition
of fuel oil to HOME increases the HRR due to increased flame velocity
caused by the improvement in the fuel properties, viz, energy content and
volatility of HOME. Further, dual fuel operation with HOME+FO20-
producer gas combination and RCC resulted in higher HRR closer to
the baseline data. Increased premixed combustion compared to diffusion
combustion lowers the second peak during diffusion combustion phase.

Diesel-PG (HCC) HOME+FO20-PG (RCC)
HOME+FO30-PG (RCC) HOME+-PG (HCC)
HOME+FO10+-PG (HCC)
120
Speed: 1500 RPM, CR: 17.5
Inj.timing: 27 bTDC, Biomass: Babul wood
100
Heat release rate (J/CA) 80 IOP: For diesel 205 bar, for HOME 230 bar
Injector: For diesel 3 hole,0.2 mm,
for HOME 4 hole, 0.3 mm
Carburetor: Parallel flow gas entry
60
40
20
0
345 355 365 375 385 395
–20
Crank angle (degree CA)
Fig. 11.30 Variation of heat release rate with crank angle for different fuel combinations.