660 MW燃煤机组瞬态过程能量分布特性研究

Study on Energy Distribution Characteristics during Transient Processes of 660 MW Coal-fired Unit

厘清变负荷瞬态过程中燃煤机组的能量分布特性是研究瞬态过程能耗的关键问题。本文以660 MW超超临界机组为对象,建立了全系统模型,获得了不同瞬态过程中机组各主要换热设备包括金属蓄热与工质蓄热在内的基础蓄热,以及受过程控制迟延影响的附加蓄热。结果表明:低压加热器和低温过热器分别为基础蓄热最小和最大的两个设备;变负荷过程中,基础蓄热随机组负荷值增大而增加,附加蓄热随机组负荷值增大而减小;整个工况下附加蓄热最大值为145.64 kW,与基础蓄热相比较小。

Clarifying the energy distribution characteristics in transient process is a key issue in studying energy consumption during transient process for coal-fired unit.An integrated-system model is developed with a 660 MW ultra-supercritical unit as the object,then the basic heat storage,including heat storages in metal materials and working fluid,and the additional heat storage influenced by the time delay of process control are calculated for the main thermal equipment during various transient processes.The results show that the low-pressure heater and low-temperature superheater are the two devices with the lowest and highest heat storage,respectively;during the load-cycling process,the basic heat storage increases with the increase of the unit load,and the additional heat storage value decreases with the increase of the unit load;the maximum process-controlled additional heat storage is 145.64 kW in the whole operating process,which is significant less than the basic heat storage.