Investigation into Operation of a Semitower Boiler of a 158-MW Power Unit and Prospects for Application of Such Boilers in Russia
摘要
Steam boilers of various arrangements (or profiles) exist in the world. The most widely used ones include, for example, semitower boilers (or L-paso boilers). In Russia, there is not sufficient experience in designing such boilers, especially in their practical application. The paper analyzes advantages and disadvantages of semitower boilers. As with tower boilers, their main advantage is a small footprint. However, compared to tower boilers, the L-paso boilers have a lower height. According to the performed analysis, the semitower configuration is best suited to boilers fired with gaseous or liquid fuel. In Russia, due to its climatic conditions, semitower boilers can be used for replacements of obsolete (type E) natural circulation gas-and-fuel oil-fired boilers with a steam output of 210–420 t/h. As an example, the paper presents a brief description of the L‑paso (type Ep) natural circulation reheat boiler manufactured by the well-known Babcock–Wilcox Co. This boiler, which is a part of a 158-MW power unit, has been successfully fired with sulfur fuel oil for many years. A customized numerical model of the boiler was developed in the Boiler Designer software package. Multivariant calculations of the boiler were performed on the basis of this model. An analysis of the predictions has confirmed that the boiler can operate in a wide range of loads while maintaining the design steam conditions. The furnace heat release rate qF, the furnace cross-section heat release rate qV, and the flue gas temperature at the furnace outlet