RESUMO
For absorption cooling cycles using water as a refrigerant, H2O/LiCl mixtures are suitable for replacing conventional H2O/LiBr mixtures. In addition, membrane devices can be used to develop compact and lighter absorption systems, and they can operate with H2O/LiCl mixtures. The present paper describes an experimental evaluation of a membrane desorber/condenser operating at atmospheric pressure. Two operation modes were analyzed: continuous cycle operation and intermittent operation. For the first operation mode, the maximum desorption rate was 3.49 kg/h·m2, with a solution temperature of 90.3 °C and a condensation temperature of 25.1 °C. The lowest desorption rate value was 0.26 kg/h·m2, with a solution temperature of 75.4 °C and a condensation temperature of 40.1 °C. In the second mode, after three operating hours, the refrigerant fluid produced, per 1 m2 of membrane area, 7.7, 5.6, 4.3, and 2.2 kg, at solution temperatures of 90.3, 85.3, 80.4, and 75.4 °C, respectively. A one-dimension heat and mass transfer model is presented. The calculated values of desorption rate and outlet temperatures were compared with the experimental data; a square correlation coefficient of 0.9929 was reached for the desorption rate; meanwhile, for the outlet solution temperatures and the outlet cooling-water temperatures, a square correlation coefficient up to 0.9991 was achieved. The membrane desorber has the advantages of operating at atmospheric-pressure conditions, high condensation temperature, the ability to use different saline solution working mixtures, and different operation methods. These advantages can lead to new absorption systems.
RESUMO
The role of heat pumps is linked to the actions of human life. Even though the existing technologies perform well in general, they have still some problems, such as cost, installation area, components size, number of components, noise, etc. To address these issues, membrane technologies have been introduced in both heat and cooling devices. The present work proposes and studied the review of the role of membrane technology in the heat pumps. The study focuses on the advancement and replacement of membrane in the place of absorption and compression heat pump components. The detailed analysis and improvements are focused on the absorber, desorber, and heat and mass exchanger. The parameters conditions and operation of membrane technologies are given in detail. In addition to this, the innovation in the heat pumps using the membrane technology is given in detail.