Performance of compact boiler using high temperature air

A new concept of compact boiler utilizing high temperature air was proposed and experimental demonstration was conducted. The combustion led to a very low NO_x emission, though the average temperature in the furnace was higher than that by the conventional combustion. The temperature distribution in the furnace was very even and there was no hot spot, so that low NO_x emission and relatively high average temperature in the furnace can be obtained. Thus, large radiative heat transfer was expected. This boiler is also suitable for low BTU gas derived from gasification process of coal and wastes with no dioxin emission. The boiler boasts of its features such as uniform heat flux field, augmented heat transfer, reduced combustion noise level, suppression of NO_x emission and compactness. The performance of such boiler was demonstrated by preliminary experiments using natural gas as fuel. Original is an abstract.