Experimental Study of Heat Transfer of Heat Carriers in a V-shaped Down-flow Tube Biomass Pyrolysis Reactor

摘要

The heat transfer between heat carriers and biomass in the down-flow tube reactor is very complicated. In order to simplify the study, a V-shaped down-flow tube apparatus was designed and fabricated and the heat transfer experiments were conducted in the V-shaped down-flow tube apparatus without the presence of biomass. Temperatures at various positions of apparatus and the final temperature of heat carriers were measured and the coefficients of convective heat exchange between heat carriers and air were then determined for different initial temperatures of the heat carriers (50 degrees C, 60 degrees C, and 70 degrees C). The experimental results show that the final temperature of heat carriers at the outlet of the reactor, the temperature of the tube, and the temperature of the air increase exponentially, and the temperature of the tube and the temperature of the air delay the temperature of heat carriers. The heat flow across the wall of the tube and the heat flow across the air increase with the increase of the initial temperature of heat carriers similarly. The convective heat transfer coefficient between heat carriers and air also increase with the increase of the air temperature.