Application of modified Kalina cycle in biomass chp plants

Abstract

This paper presents alternatives to Kalina cycles typically used in place of the organic Rankine cycle in biomass power plants. Overviews of both Rankine and Kalina cycles are given alongside the possibilities of using biomass as a viable energy source and recommended guidelines from the engineering practice for selection and management of these cycles. Benefits of Kalina novel bottoming cycle (and the alternative cycles presented herewith) over the Rankine cycle are the higher thermodynamic cycle efficiency and lower capital expenditures combined with the possibility of using low-grade heat sources, such as biomass or waste heat from exhaust gases. Analysis of ammonia-water binary system under various operating conditions has been performed for all the proposed cycles based on the published references and it has been shown that the proposed alternative models prove to be simpler and to have similar or even greater thermodynamic efficiency compared with the Kalina novel bottoming cycle.