Theoretical study of direct vapor generation for energy integrated solar absorption machines

Abstract

Integrating the vapor generator/separator of an absorption machine and the solar collector field is proposed as a means to reduce the cost and complexity of solar cooling and heating facilities. In order to further enhance the competitiveness of these facilities, some previous work on hybrid and combined absorption cycles is analyzed so that the proposed integration can be configured using these cycles. As a result, a single machine could in addition to pump heat can produce electricity and even consume it for fulfilling the cold and heat demand from the user when solar is not enough, this avoiding implementing a vapor mechanical compressor.The flow established inside the linear solar collector receiver tube is gravity driven and stratified under a counterflow regime. This configuration is numerically modeled in a steady-state 1D fashion, adapting established convective boiling correlations and including modifications for the mixture effects of the zeotropic dissolution NH3LiNO3. used as working fluid for the absorption machine.The results indicate that the proposal is viable with collector lengths compatible with industrial applications. A low sensitivity to the boiling heat transfer correlation chosen has been found.