Electrical cost savings through “in line process” small scale cogeneration

Distributed power generation in industrial, urban and commercial applications is a key topic for the strategic development and implementation of modern energy policies. Small scale cogeneration plants can play an important role to improve environmental and economic impact of such policies. As a result of advances in the design and development of twin-screw wet steam turbines (TSTs), they now appear as an efficient enabling technology for this small-scale decentralized cogeneration plants. TSTs can generate power by reducing the pressure between the steam source and the downstream steam/heat user, but with the advantage of adopting wet steam as working fluid. The twin screw steam turbine can use wet steam thanks to low tip speeds of the rotors, robust design, and special rotor profile, introducing the opportunity of power generation in several applications where it was not possible or not economically viable in the past. Theoretical models elaborated over 20 years of research, design optimization and dedicated tests demonstrated the validity of the twin screw wet steam turbine technology which, after some pilot installations, is now fully proved and commercially available. This presentation will describe the principles of steam screw turbine operation and performance characterization and offer examples of application in the oilseed industry resulting in electrical cost savings in excess of 10%.