Experimental Testing of Mesoscale Combustor

The foregoing parametric study of a single catalytic channel dictated the construction of a mesoscale combustor with metallic walls, operating at high inlet velocities and low equivalence ratios, with the dimensioning mentioned in the experimental section. The combustor was subsequently tested for the experimental conditions of Table 5.2. 

For a given set of inlet pressure p, equivalence ratio (p and inlet temperature Tin, the mass inflow (air and propane streams) was varied from a minimum of 2.3 g/s up to 6.6 g/s with increments of 0.5 g/s. After each mass inflow increment, exhaust gas temperature measurements were recorded once the combustor 

Inlet pressure pm (bar) Inlet temperature Tin (K) Equivalence ratio p Mass inflow miu (g/s) 

Measured operational maps of thermal power output versus mass inflow, such as the one provided in Fig. 5.7, were constructed based on efihciency measurements for various sets of inlet pressure, temperature and mixmre composition. These maps 

A combination of reduced catalytic reactivity and short residence times at the low inlet pressures are, to a certain extent, responsible for the significant efficiency differences between operating pressures at constant mass inflows. However, for all cases considered in this work, the maximum combustor efficiency observed was 85%, which indicates that heat losses to the surroundings and potential fuel breakthrough can further reduce the thermal power output of the combustor. 

---