Yazar "Alzaed, Ali Nasser" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Experimental and numerical analysis of the thermal performance of pebble solar thermal collector
    (Cell Press, 2024) Naik, N. Channa Keshava; Priya, R. Krishna; Agulut, Umit; Gurel, Ali Etem; Shaik, Saboor; Alzaed, Ali Nasser; Alwetaishi, Mamdooh
    In this work, pebbles of higher specific heat than the conventional absorber materials like aluminium or copper are proposed as a absorber in the solar flat plate collector. The proposed collector are integrated into the building design and constructed with masonry. Tests were conducted by varying the operating parameters which influence its performance, like the flow rate of the heat-absorbing medium, and the tilt of the collector using both coated and uncoated pebbles. The maximum temperature difference that could be measured for a conventional absorber was approximately 8 degrees C for a flow rate of 0.6 L/min. While for a coated and uncoated absorber, it was 7 degrees C and 5.5 degrees C respectively. This difference decreased with an increase in flow rates from 0.6 L/min to 1.2 L/min. For all the flow rates, it was observed that the average difference in efficiency between the coated and the conventional absorber collector is 5.82 %, while the difference between the coated and uncoated absorber collector is 15.68 %. Thus, it is very much evident that by replacing the conventional absorber with the proposed coated pebble absorber, the overall loss in efficiency is just 5.82 %, but the advantages are enormous. Along with the experimental study, numerical analysis was also carried out with CFD modeling. The numerical results agreed well with experimental results with the least error. Therefore, CFD simulation can be further used to optimize the design of the collector.
  • Küçük Resim
    Öğe
    A study on a milk chiller latent storage system with phase change material encapsulated spherical balls
    (Elsevier Ltd, 2023) Jilte, Ravindra; Afzal, Asif; Ağbulut, Ümit; Alahmadi, Ahmad Aziz; Alwetaishi, Mamdooh; Alzaed, Ali Nasser
    For dispersed or remotely located families, the collection of raw milk takes place less frequently or transportation to the nearest center is not feasible. It requires chilling of collected milk from udder temperature (?35 °C) to storage temperature (?4 °C) and maintaining it throughout thus it demands running chilling at the discrete locations. In this study, a novel design of a milk chiller for coolness storage of 12/24 h based on phase change material is presented. System performance has been demonstrated following the prevailing practice of milk collection and loading/unloading of milk. By switching off the refrigeration after a certain interval, the coolness storage was demonstrated to meet the chilling conditions even during the non-availability of power. The study proposes an integrated portable mobile milk chilling system that can move between solar PV plants and the nearest electric grid during non-sunny days. The proposed milk chiller latent storage system (MC-LSS) contains three major components: a helical coil for refrigerant circulation during charging of the system, spherical capsules for encapsulating phase change materials and interspaced occupied brine solution for storing coolness and circulating throughout PCM-filled capsules. MC-LSS is tested under two cases: FLS-12(first loading of milk chiller and storage for 12 h) and SLS-12 (second loading of milk and storage for 12 h). The temperature history of the Milk chiller latent storage system for the FLS-12 h case is qualitatively analyzed which shows an appreciable reduction in milk temperature around 10–15 °C within the first 20 min and in another ?40 min of further cooling, milk temperature attains the desired storage temperature (4–5 °C). © 2023 Elsevier Ltd