单元机组主控系统(中英对照翻译).doc

单元机组主控系统
Master Control System of Unit Plant
单元机组主控系统一般设置有四种运行方式：即汽轮机手动控制，锅炉手动控制的基本方式(BASE方式)；以锅炉为基础的汽轮机跟随方式 (TF方式)；以汽轮机为基础的锅炉跟随方式(BF方式)和汽轮机一锅炉综合功率控制的协调控制方式(CCS方式)。四种运行方式之间的切换必须是平稳无扰动的。操作员可根据机组的运行情况进行选择。一般情况下，机组适宜在滑压控制方式和CCS方式下运行。事故工况时，则通常选择在TF方式和定压方式下运行。
The master control system of the unit plant generally provides four modes of operation, including the base mode of steam turbine manual control and boiler manual control; the boiler-based turbine following mode (TF mode); the steam turbine-based boiler following mode (BF mode), and the Coordinated Control System (CCS) mode of steam turbine-boiler integrated power control. Switching amongst the four modes must be smooth without disturbance. The operator may make choices based on the unit running conditions. Under normal circumstances, the unit is suitable to operate in the sliding pressure control mode and the CCS mode. In accident conditions, it will usually run in the TF mod and the constant pressure mode.
单元机组主控系统的前三种运行方式的根本区别在于对功率和主汽压力的控制处理上。在单元机组中，汽轮机进汽压力是反映机、炉能量平衡和机组运行稳定的重要指标。
The fundamental difference between the first three modes of the master control system of the unit plant lies in the control and treatment of power and main steam pressure. In the unit plant, the inlet steam pressure of the steam turbine is an important indicator to reflect energy balance of the unit and the furnace as well as the unit running stability.
BF方式：汽轮机接受负荷指令，调节功率，能快速响应负荷要求；锅炉负责调节主汽压力，维持主汽压力的稳定，但由于锅炉动态响应慢，因此动态过程中主汽压波动大。特点：可以利用锅炉蓄热提高经济性，但主汽压波动大，影响机组的安全运行。
BF mode: the steam turbine accepts load demand, adjusts the power and is able to quickly respond to load requirements; the boiler is responsible for regulating the main steam pressure and maintaining the stability of the main steam pressure. However, the main steam pressure will greatly fluctuate in the dynamic process due to slow dynamic response of the boiler. Features: boiler heat storage can be taken advantage of to improve the economy, but great fluctuations of the main steam pressure will affect safe operation of the unit.
TF方式：锅炉接受负荷指令，调节功率，满足负荷要求，汽轮机负责调节主汽压力，但锅炉动态响应慢，因此，负荷响应能力差。其特点：由于汽轮机负责调节主汽压力，因而主汽压力稳定，但会产生附加蓄热，机组经济性下降。
TF mode: the boiler accepts load demand, adjusts the power and meets the load requirements; the steam turbine is responsible for regulating the main steam pressure. However, the load response capacity is poor due to slow dynamic response of the boiler. Features: the main steam pressure is stable as the steam turbine is responsible for regulating the main steam pressure, but the unit economy will decline due to the generation of additional heat storage.
协调控制方式（CCS）较好地解决机组的负荷适应性与稳定性这一对矛盾。协调控制系统的一个重要思想，就在于蓄能的合理利用和补偿：利用锅炉的蓄能，同时要防止利用的无限性；补偿蓄能，动态超调锅炉的能量输入。
The CCS mode can better solve the contradiction between the unit’s load adaptability and stability. Rational utilization and compensation of energy storage is an important idea of the coordinated control system: to make use of the boiler energy storage but prevent unlimited use; to compensate energy storage and dynamically over-shoot the boiler energy input.
单元主控中的锅炉主控制器相当于负荷指令处理回路与燃烧控制系统之间的接口，它产生的锅炉指令作为锅炉子控制系统的定值信号，通过该回路可以将经过修正的机组负荷指令信号传送到风量控制回路及燃料控制回路，以协调锅炉出力与负荷指令的匹配关系。该主控回路既可以工作在自动方式，也可以工作在手动方式，均能够相应地完成单元机组在各种工况下的控制功能。
The boiler master controller in the unit master is equivalent to the interface between the load demand processing loop and the combustion control system. It generates boiler demands as the set signal of the boiler sub-control system. This loop can send modified load demand signal of the unit to the air volume control loop and the fuel control loop, so as to coordinate the matching relation between boiler output and load demand. The master control loop is able to complete the unit’s control functions in different operating conditions either in automatic mode or manual mode.
单元主控中的汽轮机主控制器的任务是接受机组负荷指令，经各种运算及运行方式的切换，最终产生汽轮机负荷指令的步进增／减信号。汽轮机主控回路相当于负荷指令处理回路与DEH系统之间的接口，通过DEH系统改变汽轮机调节汽门开度，使进入汽轮机的蒸汽量与机组的负荷指令相适应，从而协调机炉之间的能量需求。
The master controller of the steam turbine of the unit master is responsible for receiving load demands of the unit and ultimately generating the stepping increment / decrement signal of load demands of the steam turbine by switching between different methods of calculation and modes of operation. The master control loop of the steam turbine is equivalent to the interface between the load demand processing loop and the DEH system. The DEH system changes the adjustable valve opening of the steam turbine so that the amount of steam entering the steam turbine adapts to the unit’s load demand, thereby coordinating the energy demand between the unit and the boiler.
单元主控还设有辅机故障减负荷(Run Back,简称RB)和机组快速甩负荷(Fast Cut Back．简称FCB)工况的负荷指令控制回路，机组迫升／迫降负荷指令控制回路和增闭锁／减闭锁负荷指令控制回路。
The unit master is also provided with a load demand control loop for the auxiliary machine failure run back (RB) and unit fast cut back (FCB) conditions, a unit runup / rundown load demand control loop, and a block increase / decrease load demand control loop.