Page 210 - Energy from Toxic Organic Waste for Heat and Power Generation

188 Energy from Toxic Organic Waste for Heat and Power Generation

70 Speed: 1500 RPM, CR: 17.5
Inj.timing: 27bTDC, Biomass: Babul wood
Combustion duration (degree CA) 40 Carburetor: Parallel flow gas entry
60
Injector: For diesel 3hole, 0.2 mm, for HOME 4hole, 0.3 mm
IOP: For diesel 205bar, for HOME 230 bar
50

30
Diesel-PG (HCC)
20
HOME-PG (HCC)
HOME+FO10-PG (RCC)
10
HOME+FO20-PG (RCC)
HOME+FO30-PG (RCC)
0
0.00 0.74 1.48 2.22 2.96 3.70
Brake power (kW)
Fig. 11.28 Effect of combustion chamber shape and fuel oil addition on combustion
duration.

operation. Further higher viscosity of HOME and reduction of air-fuel
mixing rates along with slow-burning producer gas is responsible for the
trends shown. This leads to less fuel being prepared for rapid combustion
followed by the ignition delay. Therefore, more burning occurs in the dif-
fusion phase rather than in the premixed phase with HOME-producer gas
operation. Significantly higher combustion rates during the later stages with
HOME-producer gas operation lead to higher exhaust temperatures and
lower thermal efficiency. However, improvement in heat release rate can be
achieved for HOME-producer gas operation with RCC when compared
to the operation with HCC as RCC shows maximum peak heat release
rate compared to HCC. It can be concluded that, in the case of RCC,
maximum amount of evaporated fuel is accumulated resulting in improved
mixing with air-producer gas combination due to better squish and swirl
leading to lower ignition delay, and hence, comparatively shorter combus-
tion duration with RCC. The combustion duration values at 80% load for
HOME-producer gas (HCC) and HOME-producer gas (RCC) opera-
tion with 10%, 20%, and 30% fuel oil were found to be 39.1, 37.4, 36.65
degree CA and 34.5 degree C, respectively, compared to 31.5 degree C for
diesel-producer gas operation (HCC).
Fig. 11.29 shows in-cylinder pressure versus crank angle (CA) for differ-
ent dual fuel combinations with HCC and RCC configurations. The cylin-
der pressure-crank angle history was obtained for 100 cycles for all the fuel
combinations tested at 80% load, and the averaged pressure variation with