Theoretical investigation on a novel CO2 transcritical power cycle using solar energy

Abstract

CO2, which is a stable power cycle working fluid, is used in the power cycle system, with the advantages of nontoxic, nonflammable and cheap. A novel CO2 transcritical power cycle was proposed, with the aim of solving the problem that CO2 is hard to condense in the conventional CO2 transcritical power cycle using traditional cooling water. The theoretical analysis method was used to study the variations of performance parameters of the new cycle, with solar energy as heat source. The results showed that the mass flow rate in internal inverse cycle increases slightly with the increase of the final cooled temperature and decreases with the increase of the cooled pressure, which is contrary to the variation trend of that in internal normal cycle. The outlet temperature of the cooling water increases with the increase of the final cooled temperature and the cooled pressure. The net power output decreases with the increase of the final cooled temperature and the cooled pressure. The cycle thermal efficiency decreases with the increase of the final cooled temperature and increases with the increase of the cooled pressure, the cycle thermal efficiency reaches 0.3028 under the cooled pressure of 9.0 MPa and the final cooled temperature of 30.5°C.