Experimental Investigation into the Effects of Thermal Recuperation on the Combustion Characteristics of a Non-Premixed Meso-Scale Vortex Combustor

Seyed Hosseini,Evan Owens,John Krohn,James Leylek

doi:10.3390/en11123390

Seyed Hosseini, Evan Owens + Show 2 more

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https://doi.org/10.3390/en11123390

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Abstract

In small-scale combustors, the ratio of area to the combustor volume increases and hence heat loss from the combustor’s wall is significantly enhanced and flame quenching occurs. To solve this problem, non-premixed vortex flow is employed to stabilize flames in a meso-scale combustion chamber to generate small-scale power or thrust for propulsion systems. In this experimental investigation, the effects of thermal recuperation on the characteristics of asymmetric non-premixed vortex combustion are studied. The exhaust gases temperature, emissions and the combustor wall temperature are measured to evaluate thermal and emitter efficiencies. The results illustrate that in both combustors (with/without thermal recuperator), by increasing the combustion air mass flowrate, the wall temperature increases while the wall temperature of combustor with thermal recuperator is higher. The emitter efficiency calculated based on the combustor wall temperature is significantly increased by using thermal recuperator. Thermal efficiency of the combustion system increases up to 10% when thermal recuperator is employed especially in moderate Reynolds numbers (combustion air flow rate is 120 mg/s).

Highlights

Investigations about small-scale combustion systems have been developed in recent years due to the progress in the miniaturization of electric power generation for running low weight mechanical devices
Setupmeso-scale vortex combustors have been fabricated in Combustion and Sustainable Energy Laboratory (ComSEL) at ATU, Two non-premixed
Two non-premixed meso-scale vortex combustors have been fabricated in ComSEL at ATU, one one with Two enhanced thermal recuperation and one without

Summary

Introduction

Investigations about small-scale combustion systems have been developed in recent years due to the progress in the miniaturization of electric power generation for running low weight mechanical devices (micro-pumps/motors/airplanes/rovers). Considering efficient energy conversion of small-scale combustion systems, application of these devices instead of current traditional batteries would result in weight reduction and lifetime augmentation of the mechanical systems [1]. The functionality of portable micro-electro-mechanic-systems (MEMS) will be significantly improved by availability of high-performance small-scale power generators. The increasing requests to reduce system weight, mitigate system cost and enhance unit operational lifetimes have encouraged MEMS investigators to study about various concepts behind of this new field [3]. One of the most important challenges in this new field is employing the high-specific energy of hydrocarbons in small-scale combustors to generate micro-power [4]. Since the transportation of liquid hydrocarbon fuels is easy and quite safe and they have

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Discussion

Conclusion