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Show • Pressure drop across the unit was increased only 0.4 in. wc because of the presence of the porous matrix, and was also affected by combustion. • The interaction between combustion and heat transfer in the porous matrix was demonstrated as an essential mechanism controlling the performance of the surface combustor-heater. The results of the surface combustor-heater testing are rather promising. Although not optimized, the collected data show that the concept of the ultra-low emission, high efficiency surface combustor-heater is sound and worthy of further development. The following is recommended for the next phase of experimentation: • Obtain baseline data operating without the porous matrix at various firing rates, firing modes, and tube arrangements • Obtain the same set of data as in the baseline with the porous matrix • Operate the surface combustor-heater at optimum conditions determined from the above testing and obtain data for analytical modeling. Combined theoretical and experimental study to further explore the interaction of combustion-heat transfer in the surface combustor-heater should entail establishing a mathematical model for further design optimization and for successful scale-up and commercialization of the proposed device. ACKNOWLEDGMENTS The authors wish to acknowledge the Gas Research Institute (GRI) for supporting this project under GRI Contract No. 5082-241-0772. REFERENCES 1. Kunc, W. and Khinkis, M.J., IICombustion System: A Porous Matrix Burner and a Surface Combustor,1I GRI Topical Report, Contract No. 5082-241-0772, 1987. 2. Ravich, M.B., IIGas and Its Utilization,1I Science, Moskva, 1974 (in Russian). 3. Ravich, T.W. and Sathe, S.B., IIHeat Transfer Characteristics of Porous Radiant Burners,1I Collected Papers in Heat Transfer, K.T. Yang, ed. ASME~, 147-155, 1988. 21 INSTITUTE o F GAS TEe H N 0 LOG Y |