Experiemtal Study And Numerical Analyses Of Flow And Heat Transfer Characteristics Of Heat Collector Systems On Rotary Kilns

Cement production is still a high energy consumption industries, its energy usage accounts for 70％of energy usage in the building materials industry. The internal temperature of Cement kiln is 900～1600℃, the kiln shell surface temperature is still high with covering the bricks on kiln skin and other insulation measures, distributed in 100～450℃and concentrated in the 280 to 350℃. The heat loss of rotary kiln surface accounted for 28.6％to 56.6％of surface heat loss of the whole Clinker System, accounting for 3.1％to 7.7％of the total energy consumption of the entire system of clinker, the recovery value is particularly high. Waste heat recovery equipment has become the focus of research within the industry. In this paper, the heat collectors for surface heat recovery as the research object, by means of numerical analysis and experimental study, the basic characteristics of flow and heat transfer in a regular hexagon heat collector are studied and explore the appropriate way of the heat collector pipe connection. The main work is as follows:1. The physical model of the heat collector was established by using Pro/E software, using ANSYS ICEM software to mesh the model, the model is validated by grid independence, the appropriate number of mesh have been determined. The numerical simulation method of heat transfer and radiation heat transfer coupling of heat conduction and convection heat transfer in a double basin is adopted. The appropriate turbulence model, thermal radiation model and appropriate solver settings are selected. Reasonable boundary conditions are set up.2. The simplified calculation model of Radiation type heat collector and its change of import and export structure were constructed, the rule of temperature field and velocity field of Radiation type heat collector is studied by numerical simulation method. Compared with four kinds of import and export of heat collector, the influence of the change of the inlet and outlet forms on the temperature field and velocity field distribution of the heat collector and the influence of the heat transfer performance and resistance performance of the heat collector were obtained.3. The calculation model of Coupled type heat collector and its different pipeline connection forms was constructed by using 1:1 ratio, The distribution of temperature and velocity fields and the flow and heat transfer performance of Coupled type heat collector are studied by numerical simulation method. The difference of heat transfer performance between the Radiation type collector and the Coupled type is analyzed. The influence of the inlet and outlet air flow velocity on the heat transfer performance of the Coupled type heat collector and the influence of the rotation of the rotary kiln surface on the heat transfer performance of the Coupled type heat collector were investigated. Eight kinds connection forms of Coupled type heat collectors were analyzed.4. The experimental scheme is designed and the experimental platform is built, and the performance of the heat collector is also set up. The error analysis of the experimental data has confirmed the reliability and accuracy of the experimental data. The variation of water temperature and pressure in the inlet and outlet of the collector and the response rule and the characteristics and the difference of the heat transfer performance of the heat collector with different structure are studied.