Thermodynamic analyses of a solar assisted ejector enhanced vapor injection cycle with subcooler for heat pump dryer application

This paper presents a solar assisted ejector enhanced vapor injection cycle with a subcooler (SE-SVIC) for heat pump dryer applications. The proposed cycle improves the heat absorption per unit of mass in the evaporator because the lower subcooler outlet temperature can be obtained with the pressure lift ability of the ejector. The cycle performances of SE-SVIC are evaluated and compared with those of the basic subcooler vapor injection cycle (SVIC) and the ejector enhanced subcooler vapor injection cycle (E-SVIC). The results show that the COP_h of SE-SVIC is improved by 23.8 % and 19.0 % compared with SVIC and E-SVIC under the typical operating condition, respectively. The heating performance of SE-SVIC is largely dependent on the solar energy input ratio. Overall, the input of solar energy can achieve significant improvement in the heating capacity of SE-SVIC if there is sufficient solar radiation available for the solar collector. Further, the largest exergy destruction of SE-SVIC occurs in the solar collector. As the increase of the solar radiation intensity, the exergy input increases more obviously than the exergy destruction, and thus the exergy efficiency of SE-SVIC is increased. The theoretical results show the energy saving potential of the proposed cycle and its application perspective in the heat pump dryer.