Cement Rotary Kiln Surface Waste Heat Recovery And Utilization Technology Research

There are a lot of energy waste in the cement production line, such as the high temperature exhaust gas come from the kiln hood clinker cooler and preheater, rotary kiln surface radiation and convection heat losses to the environment. The high temperature exhaust gas escaped from the kiln hood clinker cooler and preheater has been recycling, the recycling technology is highly developed. But cooling the rotary kiln surface rely on the cooling fan. The heat which can be recycled has been wasted. Although domestic and foreign cement plant take some measures to reduce the rotary kiln radiation and convection heat loss, these all belongs to the experience and there is no rigorous analysis of using heat transfer and thermal design method, resulting the poor efficiency of the recovery equipment、installation and maintenance more difficult, so the system is not yet used widely.Therefore, study the heat recovery technology of the cement rotary kiln surface, adequate and reasonable use of the waste heat is a significant measures to improve the cement plant waste heat cascade utilization and effectively reduce the pollution from the waste heat emissions, protecting the environment. It is the way to resource-saving society and environment-friendly society, to achieve energy conservation and regional sustainable development of the strategic objectives of great importance.In this paper, the cement plant "heat"-rotary kiln is the main study object. First of all, we analysis the potential of the waste heat recovery from cement rotary kiln surface. By the energy flow diagram of the dry cement production process and according to measured data of rotary kiln temperature distribution from a domestic cement plant shows the great potential of its recycling and then proceed to analysis the use of scheme based on cement rotary kiln shell surface characteristics of the waste heat. After that, we analysis the structure of the rotary kiln surface recovery device. On the basis of summing up the characteristics of the existing rotary kiln surface waste heat recovery device, we put forward a new type of cement rotary kiln surface waste heat recovery device. Thirdly, take the heat transfer analysis for the proposed new device and using the thermal network model, established and solved the mathematical model based on the heat transfer analysis. Finally, the new cement rotary kiln surface heat recovery device has been optimized according to the solution results. The conclusion is: waste heat of cement rotary kiln has considerable recycling vale, the form of the new cement rotary kiln surface heat recovery device should adopt the arc compatible with the rotary kiln, because it is helpful for heat exchange; the distribution of the collector pipes has a greater impact on the effect of heat transfer, when it is densely arranged, the collector pipes surface area involved is much better, the heat recovery is also higher; the spacing between the collector and the cement rotary kiln also influential to heat recovery, in the principle of pursuit of recoveries maximize, we should keep the spacing between collector and the cement rotary kiln as small as possible; collector pipes less than or equal to10m in length meet all the assumptions, and recovery efficiency up to63.21%; for specification of04-m x L60m rotary kiln, heat recovery can be up to2.5MW, for residential of energy conservation building, the heat recovery can be driven by heating an area of3.91thousand square meter space.