Investigation on Fluidized Bed Combustion for Marine Application

Abstract

The fluidized bed combustion is expected to have advantages of being adaptable to many kinds of fuels, of being able to make compact in a furnace, , and of improving the thermal efficiency of power plant by raising steam conditions. Hence, its applications to the marine steam power, as well as to the land use, have been investigated.
In the paper, the effects of a rolling motion of ships on the performance of fluidized bed combustion are investigated experimentally with a small test furnace installed on a rolling frame. Further, the characteristics of the furnace in both cases of oil and coal combustions are obtained and compared with each other.
The inclination of the furnace raises a variance of temperature distribution in the bed and reduces the boiler efficiency of furnace, where there is no essential difference between the oil and coal combustions. In the rolling motion of the furnace, on the other hand, almost the same boiler efficiency as that in the vertical furnace is obtained in both oil and coal combustions. The fact is owing to a time-averaging effect caused from a large heat capacity of the bed material.
From these results described above, the fixed inclination is considered to be a critical design condition of the marine fluidized bed furnace. While, the performance of the furnace in actual operations should be influenced only by the components of rolling motion of the ships with a comparatively long period (more than about 10 minutes) .