The refrigeration systems are used in domestic and commercial freezing applications. This systems are needed to be used energy efficiently to get the economic operation condition. The vapour compression refrigeration cycle (VCR) is getting replaced by vapour absorption refrigeration system (VARS) as they can use low grade energy. This VARS can be used by making use of waste energy in the form of heat which is readily available for many applications. Performance of the VARS is dependent on the generator and absorber performance. In generator the performance is coordinated by the required amount of heat energy to be added, while in absorber it is based on the amount of refrigerant absorbed and the solution flow rate. Experimental and Numerical study of bubble absorber and effect of nanoparticle on ammonia water mass transfer is carried out.

In this study, different designs for the absorber chamber are viewed and compared together, based on the research did earlier. Looking at the aspects of bubble type absorber designs, these designs give  better mass transfer performance as compared to other designs. These designs may be improved  to get the energy efficient design of the absorber. Present study includes the enhancement of mass transfer rate by the addition of nanoparticles using aluminum oxide (Al~2~O~3~).Here, sparged vessels with NH~3~-H~2~O binary fluid are arranged with varying percentage of nanoparticle (Al~2~O~3~). The experimentation is carried out with above mentioned test conditions and the results obtained are analyzed further using numerical results and the results obtained by the previous researchers. Generally we have seen that the nanoparticles are used to prepare the Nano-fluids, where ultimate objective is to obtain the higher heat transfer coefficient. This particular study includes the study of mass transfer enhancements by using nanoparticles.

Based on the experimental results carried out for the varying mass flow rates it is found that the mass transfer rate is enhanced significantly, it is because the interfacial area is enhanced by the addition of nanoparticles to the base fluids. Fine particles in suspension adsorb solute from the gas and rapidly transfer the same to the liquid. The particles collide with the gas-liquid interface, consequently breaking the bubble into smaller bubbles. More bubbles mean a larger interfacial area which would promote the mass transfer rate from the gas to the liquid. Decrease in film thickness due to shearing action by the particles is also proposed as an augmenting mechanism for convective mass transfer.


Mass Transfer Rate Enhancement in Sparged Vessel for Ammonia-Water Nano-Fluid in VARS by Adding Nanoparticles

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

IMECE2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.