Proposal and analysis of a high-efficiency combined desalination and refrigeration system based on the LiBr–H2O absorption cycle—Part 2: Thermal performance analysis and discussions

This paper continues and concludes the study of the proposed high-efficiency combined desalination and refrigeration system based on the LiBr–H2O absorption cycle introduced in the paper that is Part 1 [Proposal and analysis of a high-efficiency combined desalination and refrigeration system based on the LiBr–H2O absorption cycle––Part 1: System configuration and mathematical model. Energy Convers Manage 2010;52:220–7], in which also the mathematical model and its validation are presented in detail. Specifically, the thermal performance of the proposed ARHP–MEE (absorption refrigeration heat pump integrated with a multi-effect evaporation desalter) system, is analyzed, and a parametric sensitivity analysis and a rough economic evaluation are carried out, to clarify and quantify the performance of this combined refrigeration and water system. Typically, driving steam with saturation pressure of 0.15–0.35 MPa and corresponding saturation temperature of 111.4–138.9 °C is applied to run the system. The combined system has good internal synergy, as demonstrated by an energy saving rate of 42% compared with the separate refrigeration-only and water-only systems in a base-case study. The refrigeration-heat cogenerated ARHP subsystem is the main reason for the synergy, with a coefficient of performance of about 1.6 and exergy efficiency above 60% when driven by 0.25 MPa saturated steam. A rough economic analysis indicates qualitatively that there is no penalty in capital equipment for an ARHP–MEE system when compared with the two single-purpose systems, and the higher energy utilization rate of the system makes the energy/operating cost lower.