Analysis of Variants of Reforming of a Part of the Fuel (on the Example of Propane) in a Mixture with Internal Combustion Engine Exhaust Gas to Add the Reformate to the Combustion Chamber

Thermochemical recovery of the heat of automotive internal combustion engine (ICE) exhaust gas saves fuel and reduces harmful emissions. Two designs of thermochemical heat recovery in propane-fueled ICEs are numerically analyzed. In both designs, a mixture of 10–20% of the initial propane with part of the ICE exhaust gas is subjected to catalytic reforming, and then the hydrogen-containing reforming products together with propane are added to the combustion chamber. In the first design, the reforming is carried out in an adiabatic reactor; and in the second, in a tubular one. In the analysis, the fraction of the exhaust gas recycle is varied within the range 0.1–0.5 and the temperature in the range 470–690°С. The second design is shown to be more efficient; it ensures an increase in the chemical enthalpy of the fuel mixture by 1.9–3.6% at a hydrogen mass fraction of 0.3–0.9%. For the operating conditions of an ICE with an effective power of 30 kW, the characteristics of an adiabatic reformer and a tubular reformer with a Ni/Cr2O3/Al2O3 catalyst are calculated.