Modeling Analysis On The Partial Load Performance Of CFB Boiler

To develop large capacity CFB boiler, the prediction of the partial load performance of CFB is becoming more necessary. Based on the accumulated engineering experience of CFB technology by Tsinghua University, this paper develops a pseudo-static model to study the performance of a real 135MW CFB reheating boiler under partial load. This model is a semi-theoretical model in which some key parameters are according to the engineering experiences accumulated by Department of Thermal Engineering, Tsinghua University in the last fifteen years. In addition, the effect of mass-balance upon heat-transfer is studied, and attrition is also considered in the material balance model. The calculation software, which is compiled by Microsoft Visual C++, can calculate the characteristic parameters of water and steam more quickly and precisely than before. Further more, it can adjust the thermal parameters automatically. Using this software, the boiler's performance under any partial load can be predicted.The prediction results of the real 135 MW CFB boiler are compared with the operational data. Most predicted parameters are matching with the operating data. Few of them are different. Careful analysis proves that the unmatching operating data is not reasonable caused by measurement error. Generally, the calculation results are proved to be reliable.The performance of the real 135MW CFB boiler under various partial loads is investigated by this model. The calculation results provide some useful conclusions for boiler design and operation.