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.