Riser Design Approach for Particle-Circulation-Type Heat Exchangers

입자 순환식 열교환기의 상승관 설계방법

In this paper a systematic design approach to determine the optimum size (height) of circulating fluidized bed heat exchanger for exhaust gas heat recovery is prososed. Unlike the convensional heat exchangers where the length of the heat exchanger section is not very much emphasized, the vertical length of heat exchanger tube in the case of fluidized bed heat exchangers is important because this length determines the time interval during which particles reside and transfer heat in the heat exchanger section. For particles initial conditions are nearly stationary, accelerating particles motion should be considered rather than simply assuming fully developed condition. A way to estimate optimum tube length at different fluid velocity and particle sizes is suggested based on the required conditioning time for heat transfer from the flue gas to solid particles.