锅炉汽包水位三冲量控制的水位补偿计算及应用

锅炉汽包水位主要采用三冲量控制,但是汽包中汽液的密度变化造成水位测量不准,从而导致控制效果变差。本文采用多测孔技术各增设了三块现场仪表来分别测量汽包的实时温度和压力,进而对汽包水位进行补偿计算,并在DCS系统进行了组态和现场应用。实际应用效果表明提高了水位测量精度,满足了汽包控制及联锁的要求。

Compensation of water level for the three impulse control of boiler stream drum and its practical application

Three impulse control method is usually applied to maintain water level of boiler stream drum. Because the densities of steam and water in the drum are always changed, water level is not measured correctly and then control performance is degraded. Three instruments are installed to measure the real-time temperature and pressure in the steam drum, which are used to compensate water level and are also configurated in the control system. The proposed method is applied to a practical steam drum. Results demonstrate that accuracy of the water level is improved, and requirement of steam drum control and interlock are satisfied.