循环流化床锅炉机组有很强的深度调峰能力，在近年来得到大力发展。同时，其安全经济运行问题也受到广泛关注。本文旨在从两个方面入手提升机组能效，保障机组安全运行。首先是通过热经济性计算模型在机组设计改造阶段对热力系统布置结构进行优化，挖掘机组节能潜力。其次是建立稳态及动态流程模型，分析机组响应特性，指导现场调控，同时有利于后续控制系统的开发。通过完善冷渣器这一关键部件的接入热力系统设计方案对能效分布矩阵的数学影响，将广义能效分布矩阵方程的应用范围拓宽到循环流化床锅炉机组中。揭示了冷渣器接入热力系统设计方案对于660 MWe超超临界循环流化床锅炉机组热经济性的影响规律。此外，开展了热经济性影响因素定量分析并提供运行监测优化建议。研究发现，660 MWe超超临界机组循环效率为50.464%，和600 MWe超临界机组相比有了显著提升，在机组的20种冷渣器接入热力系统设计方案中，串联在第5级加热器热经济性最高。基于Aspen Plus和Fortran开发了可求解热力系统热力参数的耦合传热子模型的循环流化床锅炉稳态流程模型。分析了一次风流量、二次风流量、给水温度、一次风温度改变对工质温度及烟气组分的影响，优化了变负荷运行中控制参数。研究发现，在稳态工况下，高温过热器出口工质温度对于输入参数变化更为敏感。最优煤水比随着给煤量的增加而降低，变化幅度相对较小。在稳态流程模型基础上，基于Aspen Dynamics和Fortran开发了耦合传热子模型和燃烧子模型的循环流化床锅炉动态流程模型。分析了输入参数阶跃扰动时锅炉动态响应特性。研究发现，在给煤量、一次风量和二次风量的阶跃扰动下，炉内受热面热负荷分布变化不大；与再热蒸汽温度相比，过热蒸汽温度对阶跃信号扰动更为敏感。在低阶跃幅值时，一次风量扰动的稳定时间低于给煤量扰动的稳定时间；随着阶跃幅值的增加，一次风量扰动的稳定时间快速增加并超出后者。基于Aspen Dynamics, Aspen Custom Model和Fortran开发了耦合回热加热器自平衡子模型的机组动态流程模型。利用模型分析了典型深度调峰技术——低压缸切缸运行技术应用过程中机组响应特性。研究表明，切缸运行后，机组输出功率先急剧降低，后缓慢降低；给水温度显著下降；汽机侧的响应时间远低于锅炉侧阶跃扰动的响应时间。

The circulating fluidized bed boiler (CFB) unit has a strong ability of depth peak regulation and has been developed vigorously in recent years. At the same time, its security and economic operation has been widely concerned. This paper aims to improve thermal efficiency, tap the unit energy saving potential and ensure operation safety of the CFB unit from two main aspects. Firstly, optimize the thermal system layout through thermal economy calculation model at the stage of unit design. Secondly, develop its accurte and comprehensive both steady state and dynamic flowsheet model to analyze its response characteristics and guide the operation, which is also beneficial to the further development of control system.The application field of the Generalized Energy Efficiency Distribution Matrix (GEEDM) is extended to the CFB boiler unit by adding the mathematical influence of the slag cooler, the indispensable component of CFB boiler unit. The influence of slag cooler connection scheme on the thermal economy of a 660 MWe ultra-supercritical CFB boiler unit is revealed. In addition, quantitative analysis of thermal efficiency influencing factors are carried out and suggestions for operation monitoring and optimization are provided. It is found that the cycle efficiency of the 660 MWe ultra-supercritical unit is 50.464%, which is significantly improved compared with that of the 600 MWe super-supercritical unit. Among the 20 kinds of slag cooler connection schemes of the unit, the cycle efficiency of the fifth stage heater in series is the highest.Based on Aspen Plus and Fortran, the steady state flowsheet model of CFB boiler coupled with heat transfer submodel is developed. The influences of the primary air flow, secondary air flow, feed water temperature and primary air temperature on working medium temperature and flue gas composition are analyzed. The control parameters in variable load operation are optimized as well. It can be concluded that the outlet working medium temperature of high temperature superheater is more sensitive to the change of input parameters. The optimal coal-water ratio decreases with the increase of coal flow rate and the variation range is relatively small.Based on Aspen Dynamics and Fortran, a dynamic flowsheet model of the CFB boiler coupled with heat transfer submodel and combustion submodel is further developed. The dynamic response characteristics under step disturbances of input parameters are analyzed. Results show that under the step disturbance of coal flow rate, primary air flow rate and secondary air flow rate, the heat load distribution of the heating surfaces in the furnace remains almost unchaged. The temperature of superheated steam is more sensitive to step signal disturbance than that of reheated steam. At low step amplitude, the stability time of primary air volume disturbance is lower than that of coal flow rate disturbance. With the increase of step amplitude, the stability time of primary air volume disturbance increases rapidly and exceeds the latter.Based on Aspen Dynamics, Aspen Custom Model and Fortran, the dynamic flowsheet model coupled with regenerative heater self-balancing submodel is finally developed. The model is then applied to analyze the unit response characteristics during the application of the low pressure cylinder cutting technology, a typical deep peak shaving method. The results show that the output power of the unit decreases sharply at the beginning stage and then slowly. The feedwater temperature decreases significantly and the response time of turbine step disturbance is much lower than that of boiler step disturbance.