TY - JOUR
T1 - Performance analysis of a rotary active magnetic refrigerator
AU - Lozano, Jaime
AU - Engelbrecht, Kurt
AU - Bahl, Christian R.H.
AU - Nielsen, Kaspar Kirstein
AU - Eriksen, Dan
AU - Olsen, Ulrik Lund
AU - Barbosa Jr., J.R.
AU - Smith, Anders
AU - Prata, A.T.
AU - Pryds, Nini
PY - 2013
Y1 - 2013
N2 - Performance results for a novel rotary active magnetic regenerator (AMR) and detailed numerical model of it are presented. The experimental device consists of 24 regenerators packed with gadolinium (Gd) spheres rotating inside a four-pole permanent magnet with magnetic field of 1.24T. A parametric study of the temperature span, cooling power, coefficient of performance (COP) and efficiency of the system was carried out over a range of different hot reservoir temperatures, volumetric flow rates and cooling powers. Detailed modeling of the AMR using a 1D model was performed and compared with the experimental results. An overall mapping of the thermal losses of the system was performed, and good agreement between the experimental and numerical results was found when parasitic heat losses were subtracted from the modeling results. The performance of the system was evaluated via the COP, the exergetic-equivalent cooling power (ExQ), and the overall second law efficiency, η2nd. Losses mapping indicated that friction and thermal leakage to the ambient are the most important contributors to the reduction of the system performance. Based on modeling results, improvements on the flow distributor design and reduction of the cold end thermal parasitic losses are expected to enhance the efficiency of the system. For an operating frequency of 1.5Hz, a volumetric flow rate of 400L/h, a hot reservoir temperature of 297.7K, and thermal loads of 200 and 400W, the obtained temperature spans, δTS, were 16.8K and 7.1K, which correspond to COPs of 0.69 and 1.51, respectively. The maximum overall second-law efficiency was 5.6% for a δTS of 12.9K at 500L/h and 400W. © 2013 Elsevier Ltd.
AB - Performance results for a novel rotary active magnetic regenerator (AMR) and detailed numerical model of it are presented. The experimental device consists of 24 regenerators packed with gadolinium (Gd) spheres rotating inside a four-pole permanent magnet with magnetic field of 1.24T. A parametric study of the temperature span, cooling power, coefficient of performance (COP) and efficiency of the system was carried out over a range of different hot reservoir temperatures, volumetric flow rates and cooling powers. Detailed modeling of the AMR using a 1D model was performed and compared with the experimental results. An overall mapping of the thermal losses of the system was performed, and good agreement between the experimental and numerical results was found when parasitic heat losses were subtracted from the modeling results. The performance of the system was evaluated via the COP, the exergetic-equivalent cooling power (ExQ), and the overall second law efficiency, η2nd. Losses mapping indicated that friction and thermal leakage to the ambient are the most important contributors to the reduction of the system performance. Based on modeling results, improvements on the flow distributor design and reduction of the cold end thermal parasitic losses are expected to enhance the efficiency of the system. For an operating frequency of 1.5Hz, a volumetric flow rate of 400L/h, a hot reservoir temperature of 297.7K, and thermal loads of 200 and 400W, the obtained temperature spans, δTS, were 16.8K and 7.1K, which correspond to COPs of 0.69 and 1.51, respectively. The maximum overall second-law efficiency was 5.6% for a δTS of 12.9K at 500L/h and 400W. © 2013 Elsevier Ltd.
KW - Cooling
KW - Flow control
KW - Flow rate
KW - Magnetic refrigeration
KW - Meteorology
KW - Regenerators
KW - Telecommunication links
KW - Efficiency
U2 - 10.1016/j.apenergy.2013.05.039
DO - 10.1016/j.apenergy.2013.05.039
M3 - Journal article
VL - 111
SP - 669
EP - 680
JO - Applied Energy
JF - Applied Energy
SN - 0306-2619
ER -