Page 206 - Energy from Toxic Organic Waste for Heat and Power Generation
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184   Energy from Toxic Organic Waste for Heat and Power Generation


          and improved swirl and squish motion of air and is the main cause for the
          observed trends of result. Lowered HC and CO levels in the exhaust were
          associated with increased BTE. During tri-fuel operation, higher percent-
          age of fuel oil in HOME leads to incomplete combustion. It could be due
          to retarded combustion caused by use of high-octane number fuel in the
          blend. However, with basic combustion chamber (HCC), proper mixing of
          fuels may not occur, leading to higher HC and CO emission levels caused
          by the incomplete combustion. The HC values for HOME-PG(HCC) and
          HOME-PG(RCC) operation with 10%, 20%, and 30% fuel oil were found
          to be 46, 44, 41 ppm and 38 ppm, respectively, compared to 33 ppm for
          diesel-PG operation (HCC). Similarly, CO values for HOME-PG(HCC)
          and HOME-PG(RCC) operation with 10%, 20%, and 30% fuel oil were
          found to be 0.36%, 0.32%, 0.312% and 0.29%, respectively, compared to
          0.24% for diesel-PG operation (HCC).
             For the same combustion chambers used in the study, higher NO x  lev-
          els were obtained for diesel-PG combination when compared to HOME-
          producer gas dual fuel operation over the entire load range (Fig. 11.25).
          Better burning of the diesel-PG fuel combination during premixed com-
          bustion phase rather than diffusion combustion phase is responsible for
          these observed trends. In addition to lower energy content of both HOME
          and producer gas, incomplete combustion due to poor utilization of air
          during combustion is also responsible for these observed trends. However,
          NO x  emission levels were increased with increase in fuel oil in HOME
          blends and use of RCC further adds to these trends. Improved  combustion


                          Speed: 1500 RPM, CR: 17.5
                          Inj.timing: 27bTDC, Biomass: Babul wood
                      140  Injector: For diesel 3hole, 0.2 mm, for HOME 4hole, 0.3mm
                          IOP: For diesel 205bar, for HOME 230bar
                      120  Carburetor: Parallel flow gas entry
                     Nitric oxide (ppm)  80
                      100

                       60
                                                   Diesel-PG (HCC)
                       40
                                                   HOME-PG (HCC)
                                                   HOME+FO10-PG (RCC)
                       20                          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. 11.25  Effect of combustion chamber shape and fuel oil addition on nitric oxide
          emission.
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