Design and Evaluation of Cyclone Separator for Cleaning of Volumetric air Receiver

Abstract

Rajasthan and Gujarat receives almost the highest amount of solar irradiation in India. This can be harnessed using line and point focusing technology. At IIT Jodhpur one of the two technologies, namely, open porous volumetric air receiver based point focusing technology is considered for process heat application. This system uses air as heat transfer fluid and is expected to achieve a temperature as high as 800 0C. These receivers on account of volumetric heating, is exposed to a high heat flux, even, up-to 1000 suns (1sun = 1kW/m2). As this receiver is open to atmosphere, the dust storms in region, like, Rajasthan can block the receiver pores and also enters in the system. Due to lower thermal conductivity of sand in comparison to receiver material, high temperature gradients are expected on the receiver. This may even result in mechanical damage of the system due to resulting thermal stress. Considering the above-mentioned fact, the thesis aims at cleaning and collection of the removed dust from pores of receiver. For collection of dust, a cyclone separator is proposed. For the given system, the design requirements are: mass flow rate of air as 4-6g/sec and 12m/s of inlet air velocity corresponding to this mass flow rate. The required cyclone separator is calculated to be ~50mm in diameter. For the given design parameters, a 2D2D cyclone separator is selected based on Lapple model. The cut point diameter of dust particle to be collected is estimated using various models for the proposed design. In the considered design the ANSYS FLUENT 13.0 is used as CFD tool. Experiments are performed using the designed cyclone separator for estimating collection efficiency with particle size <50m with different inlet velocities of air. Furthermore, experiment and CFD analysis for pressure drop in a cyclone separator for various diameters are performed and compared. As already explained in brief, this thesis presents: - Design of a cyclone separator for collection of deposited dust in volumetric air receiver - Experiments on pressure drop measurement and CFD analysis - Experiments on collection efficiency - A derived correlation for pressure drop.