Method of efficiency and emissions performance improvement for the simple steam cycle

摘要

A method for improvement of a fossil fuel energy conversion into electrical energy for the simple sub- and supercritical steam cycle is proposed through introduction of additional regenerative cycle duties to improve the evaporation rate per unit of fuel burned, thus minimizing condenser heat loss of the working media. The additional duties provide a supplemental energy credit in the form of heat input to a steam generator where a modified combustion process is realized to convert fossil fuel into carbon monoxide and hydrogen at atmospheric pressure and thus achieving an essential reduction of nitrogen oxides (NOx) formation. The additional duties also involve a direct contact heat transfer to recover latent and thermal energy, contained in the discharged combustion products to provide yet another energy credit that satisfies both conventional and/or added regenerative cycle duties. A water surplus is also achieved in the said process of heat recovery from the combustion products to significantly improve water usage of the simple steam plant. The proposed heat recovery process also minimizes coolant usage while achieving a complete water recovery from combustion products and maintaining draft capabilities in the stack.