Analysis of NH3-H2O-LiBr absorption refrigeration system based on membrane separator

The existence of lithium bromide can significantly improve the process of generation and reduce energy consumption of rectification. But it has negative effect on the absorption process of ammonia. Therefore, the new cycle of NH3-H2O-LiBr absorption refrigeration system based on membrane separator was proposed to separate lithium bromide from the solution stream entering absorber and improve absorption performance. And the experiment for separating lithium bromide in the membrane separator was carried out. The results showed that the separation efficiency of lithium bromide can reach 98% after twice solution cycle in membrane separator. Based on the separation efficiency of experiments, the Aspen Plus monitor process was used for further simulating and analyzing the NH3-H2O-LiBr absorption refrigeration system with membrane separator. Simulation results indicated that due to the application of membrane separator, the energy consumption of new cycle based on membrane separator was lower than the normal absorption system and the COP can be improved nearly 10%. When generator temperature increased from 60℃ to 120℃, the generator heat load decreased and the COP of absorption cycle increased with the highest value of 0.5869 at the mass fraction of lithium bromide ranging from 0-30%. © 2019, Chemical Industry Press. All right reserved.