Abstract
In this study, a multidiameter design according to the critical heat flux of each tube was proposed for a vertical tube boiler in order to improve its performance. Two types of multidiameter boiler were designed menufactured utilizing the calculation method for single diameter boiler. One is compact type and another is uniform heat flux type. An experiment was carried out in a wind-tunnel test bench using Fuluorinert (FC5312) as the working fluid. Experimental parameters were the velocity and the temperature of the hot air. The experimental results were compared between the multidiameter and the single diameter boiler. As a conclusion, the compact type shows larger thermal performance also larger pressure drop and smaller volume, while the uniform heat flux type shows the same thermal performance with the single diameter type and lower pressure drop. Further, it can be confirmed that the calculation method for the single diameter boiler can be utilized to the multidiameter one.
