新型石灰回转窑竖式预热器出口处废气温度在250℃左右,采用以水为工质的郎肯循环回收烟气余热存在发电功率低、热效率低、项目投资回收期长等问题.针对石灰窑废气余热,采用循环热水和有机工质双工质系统对余热进行回收发电,研究了分别采...新型石灰回转窑竖式预热器出口处废气温度在250℃左右,采用以水为工质的郎肯循环回收烟气余热存在发电功率低、热效率低、项目投资回收期长等问题.针对石灰窑废气余热,采用循环热水和有机工质双工质系统对余热进行回收发电,研究了分别采用R21,R123,R245ca,R245 fa 4种有机工质系统余热发电的各项性能指标.结果表明,R123在较小的窄点温差和120～ 170℃的蒸发温度下,发电功率最高.为保证换热过程的高效并获得尽可能高的余热利用率,R123和R21系统适合采用小窄点温差;R245 ca和R245fa适合采用大窄点温差;从发电功率来看,几种工质相差不大,但考虑价格因素,选用R123工质.展开更多
Convection heat transfer coefficient and air pressure drop in sinter layer are important factors for the design of sinter cooling craft. Due to the lack of necessary data, the two parameters are studied by experimenta...Convection heat transfer coefficient and air pressure drop in sinter layer are important factors for the design of sinter cooling craft. Due to the lack of necessary data, the two parameters are studied by experimental method. The experimental results show that heat conduction of sinter impacts the measurement of convection heat transfer coefficient. Convection heat transfer increases with the increase of air volumetric flow rate. Sinter layer without small particles(sample I) gives higher convection heat transfer coefficient than that with small particles(sample II). Under the considered conditions, volumetric convection heat transfer coefficient is in the range of 400-1800 W/(m3·°C). Air pressure drop in sinter layer increases with the increase of normal superficial velocity, as well as with the rise of air temperature. Additionally, air pressure drop also depends on sinter particle size distribution. In considered experimental conditions, pressure drop in sinter sample II is 2-3 times that in sinter sample I, which resulted from 17% small scale particles in sinter sample II.展开更多
文摘新型石灰回转窑竖式预热器出口处废气温度在250℃左右,采用以水为工质的郎肯循环回收烟气余热存在发电功率低、热效率低、项目投资回收期长等问题.针对石灰窑废气余热,采用循环热水和有机工质双工质系统对余热进行回收发电,研究了分别采用R21,R123,R245ca,R245 fa 4种有机工质系统余热发电的各项性能指标.结果表明,R123在较小的窄点温差和120～ 170℃的蒸发温度下,发电功率最高.为保证换热过程的高效并获得尽可能高的余热利用率,R123和R21系统适合采用小窄点温差;R245 ca和R245fa适合采用大窄点温差;从发电功率来看,几种工质相差不大,但考虑价格因素,选用R123工质.
基金Project(51306198)supported by the National Natural Science Foundation of China
文摘Convection heat transfer coefficient and air pressure drop in sinter layer are important factors for the design of sinter cooling craft. Due to the lack of necessary data, the two parameters are studied by experimental method. The experimental results show that heat conduction of sinter impacts the measurement of convection heat transfer coefficient. Convection heat transfer increases with the increase of air volumetric flow rate. Sinter layer without small particles(sample I) gives higher convection heat transfer coefficient than that with small particles(sample II). Under the considered conditions, volumetric convection heat transfer coefficient is in the range of 400-1800 W/(m3·°C). Air pressure drop in sinter layer increases with the increase of normal superficial velocity, as well as with the rise of air temperature. Additionally, air pressure drop also depends on sinter particle size distribution. In considered experimental conditions, pressure drop in sinter sample II is 2-3 times that in sinter sample I, which resulted from 17% small scale particles in sinter sample II.
