燃煤热载体炉的冗余控制系统设计

在许多重要工业应用场合，需要长期、连续、安全可靠的控制保障。冗余控制是一种解决方案，在SIEMENS的S7系列PLC中，有S7—400H的硬冗余和S7—300的软冗余2种解决方案。文中介绍的是另一种解决方案，即用S7—300和S7—200控制器共同实现的热载体炉的冗余控制。比起前2种方案来，本方案更经济，冗余范围更大，但仅限于允许2套系统切换时间在几秒或更长一点的非无人值守的过程控制系统中。

Design of Redundant Control System of Coal-Fired Heat-Transfer Material Heater

In many important industrial fields, long-period, continuous, safe are reliable control guarantee is needed, redundant control may be a solution. There are hardware redundant system with S7-400 and the software redundant system with S7-300 In Siemens S7 serial PLC. A new kind of redundant system solution combined with S7-300 and s7-200 controllers is introduced, which is applied to the redundant control in heat-transfer material boiler. Compared to classic redundant systems with hardware or software scheme, this solution is more economical, and its range of redundancy is much wider. However, this system can only be used in manned control systems where the response time interval for redundant system switch is permitted to be longer than a couple of seconds.