New ways to generate electricity using steam evaporative cooling systems for high-temperature iron and steel plants

Abstract

Currently, the thermal energy of steam generated by evaporative cooling systems of high-temperature ferrous metallurgy units is used practically only for space heating and hot water supply. This ineffective use occurs because evaporative cooling systems generate steam with a steam content of 0.9 at best and often just a steam-water mixture. As a result, it cannot be used for the operation of steam turbines, and in the case of a steam-water mixture, for the operation of classic steam engines and conventional steampiston engines, which are high-speed single-expansion steam engines. This article will discuss the possibility of using a steam-piston engine to generate electricity from steam generated by evaporative cooling systems. In contrast to the classic reciprocating steam engines, the steam-piston engines have a relatively high rotational speed. As a result, they are smaller and can be connected directly to modern power generators with a 1500 rpm speed. Furthermore, such engines can be manufactured by converting serial internal combustion engines, which significantly reduces their cost and provides a short payback period for such equipment. The first option is to use steam-piston engines to operate on steam with a steam content of 0.9; in this operating mode, steam-piston engines have relatively high efficiency for steam parameters generated by evaporative cooling systems. However, this option requires the use of a steam separator. The second option involves using unique steam-piston engines that can operate on a steam-water mixture and even on overheated water. These engines can use a steam-water mixture directly from evaporative cooling systems without separation, but in this case, efficiency is considerably lower.