Absorption systems are a sustainable solution as solar driven air conditioning devices in places with warm climatic conditions, however, the reliability of these systems must be improved. The absorbing component has a significant effect on the cycle performance, as this process is complex and needs efficient heat exchangers. This paper presents an experimental study of a bubble mode absorption in a plate heat exchanger (PHE)-type absorber with NH₃-LiNO₃ using a vapor distributor in order to increase the mass transfer at solar cooling operating conditions. The vapor distributor had a diameter of 0.005 m with five perforations distributed uniformly along the tube. Experiments were carried out using a corrugated plate heat exchanger model NB51, with three channels, where the ammonia vapor was injected in a bubble mode into the solution in the central channel. The range of solution concentrations and mass flow rates of the dilute solution were from 35 to 50% weight and 11.69 to 35.46 × 10⁻³ kg·s⁻¹, respectively. The mass flow rate of ammonia vapor was from 0.79 to 4.92 × 10⁻³ kg·s⁻¹ and the mass flow rate of cooling water was fixed at 0.31 kg·s⁻¹. The results achieved for the absorbed flux was 0.015 to 0.024 kg m⁻²·s⁻¹ and the values obtained for the mass transfer coefficient were in the order of 0.036 to 0.059 m·s⁻¹. The solution heat transfer coefficient values were obtained from 0.9 to 1.8 kW·m⁻²·K⁻¹ under transition conditions and from 0.96 to 3.16 kW·m⁻²·K⁻¹ at turbulent conditions. Nusselt number correlations were obtained based on experimental data during the absorption process with the NH₃-LiNO₃ working pair.

Dried, bitter orange leaves are widely used because of their nutritious and medicinal applications. As a result, many technologies have been used to accomplish its drying process. However, drying needs a long time and high energy demand, especially in humid climates. In this paper, bitter orange leaf drying was carried out using thermal and photovoltaic solar energy (integrated system, IS), eliminating the high humidity inside of the drying chamber to improve this process. A regular solar dryer (RD) was also used to compare the kinetics, mathematical modeling, and colorimetry study (as a quality parameter), evaluating both systems’ performances. The drying leaves’ weights were stabilized after 330 min in the RD and after 240 min in the IS, with a maximum drying rate of 0.021 kg water/kg dry matter∙min, reaching a relative humidity of 7.9%. The Page and Modified Page models were the best fitting to experimental results with an Ra² value of 0.9980. In addition, the colorimetric study showed a better-preserved color using the IS, with an ∆E of 9.12, while in the RD, the ∆E was 20.66. Thus, this system implementation can reduce agroindustry costs by reducing time and energy with a better-quality and sustainable product, avoiding 53.2 kg CO₂ emissions to the environment.

This paper presents the analysis of the experimental tests performed with an absorption refrigeration advanced Solar-GAX system, designed for 10.5kW (3 Ton) of cooling using ammonia-water mixture. The system designed for operation at heat source temperatures of around 200°C, consists of an absorber and generator of a falling film type and air cooled finned tube condenser and absorber, being an option for areas with water scarcity. Heat source temperatures of 160°C were established to simulate the conditions of using solar thermal concentrating technology to supply heat the system, this means the system operating at partial load. Cooling capacities from 3 to 7kW were obtained, with an average coefficient of performance (COP) of 0.37. Thermal stability was rapidly reached, after only 15minutes of operation

En los últimos años el Archipiélago de Chiloé sufre crisis hídricas estivales, a pesar de las intensas lluvias de invierno. La situación ha sido reconocida por el Estado y los gobiernos de turno, adoptando como principal medida la provisión de agua para uso humano en camiones aljibe. Para enfrentar este problema se propuso un trabajo a escala territorial local, realizando un diagnóstico socio-ecológico de la localidad rural de Catruman para evaluar la demanda de agua y las causas de la escasez hídrica. Se identificaron micro- cuencas abastecedoras de agua y se estableció un trabajo participativo, que incluye a ha bitantes y gobiernos locales, basado en los principios del manejo ecosistémico adaptati- vo. Se diseñó una Red Participativa de Agua Rural, que incluye una planificación territorial participativa a escala de microcuenca, monitoreo hidrológico, una red de distribución de agua potable de bajo costo y un humedal artificial depurador de aguas contaminadas. Se realizaron asambleas, capacitaciones y mingas, reconociendo e integrando el saber local. Esta iniciativa es un modelo de intervención territorial de largo plazo, a escala de microcuenca, flexible, escalable y replicable en otros territorios del sur de Chile.