Experimental and sensitivity analysis of a rotary air preheater for the flue gas heat recovery

Energy saving is one of the key issues, not only from the viewpoint of fuel consumption but also for the protection of global environment. A rotary regenerator (also called an air preheater or a heat wheel) is a sizeable porous disk, fabricated from some materials having a fairly high heat capacity, which rotates between two side-by-side ducts; one for the cold gas; the other for the hot stream. Its application is in a wide range of temperature waste heat recovery systems. In this work, a rotary regenerator is simulated by solving a developed mathematical model and optimized with the experimental design method. In this method, the effect of dimensionless parameters on the effectiveness of rotary heat exchangers was investigated. Numerical results were obtained by solving continuity, momentum and energy equations, and a two-step, predictor–corrector procedure is used. Experimental results are obtained by using a lab-scale rotary type regenerator and factorial design of experiments was performed for the analysis of the data. The simulation results have been compared with the experimental data and good agreement has been obtained.