800 MW燃气-蒸汽联合循环机组单轴和多轴配置的比较

单轴和多轴配置需要综合考虑装置性能、建设成本和运行维护成本、操作的方便性和建设空间的大小。从机组性能、机组配置和环境影响3个方面对单轴布置和多轴布置方式进行分析与比较。机组性能涉及机组总的功率输出、机组总效率，机组辅助电源需求，机组电气损耗和机组轴功率。机组配置涉及占地空间和扩展能力。环境影响涉及CO₂和NO_x的排放。分析比较结果表明，单轴机组适用于对机组性能、NO_x排放、CO₂排放、启动要求和扩展可能性要求更高的机组;多轴机组更适用于由于空间局限并且对汽轮机可用性与可靠性要求较高的机组。

Comparison Between Single-Shaft and Multi-Shaft of 800-MW Combined Gas-Steam Cycle Units

Multi-shaft and single-shaft configurations require full consideration of the unit performance, capital investment, operation and maintenance cost, operating convenience and the construction space. The analysis and comparison on the two types of configuration are conducted from three aspects, i.e., unit performance, unit configuration and environmental impacts. The unit performance deals with the gross power output, gross efficiency, auxiliary power demand, generator losses and shaft power. The unit configuration involves space limitations and expansion capability. And the environmental impacts include CO₂ and NO_x emissions. The results show that the single-shaft configuration is more suitable for the units with better requirements on unit performance, NO_x emissions, CO₂ emissions, start-up and expansion possibilities, while the multi-shaft configuration is better for the units with limited space but with higher requirement on steam turbine availability and reliability.