Search

An intermittent spray cooling system is applied to fuel cell vehicle heat dissipation using a plate-fin heat exchanger. The effects of various system parameters on cooling performances are evaluated. Experimental results indicate that the cooling performance can be increased by 20% to 80% at various operating conditions and fixed spray area percentage of 45%. An empirical correlation is constructed to characterize heat transfer enhancement percentage. For the 124 data points examined, 92.73% of the data are within 20% of the error range, and 81.8% are within 15% of the error range. The average absolute deviation is 9.30%. [ABSTRACT FROM AUTHOR]

To prevent flow maldistribution and imbalanced temperature, a disturbance observer-based control strategy is presented for microchannel cooling systems with multiple heat exchangers. A disturbance observer is designed using the extended Kalman filter for estimating the states and disturbance. The performance of the observer is validated using experimental data from a pumped liquid cycle testbed. Disturbance observer-based control is applied to systems with two and three heat exchangers. The findings demonstrate that the wall temperatures and the temperature differences for the heat exchangers could be maintained at the desired values. When the heat exchangers are subjected to heat loads in the form of square, sinusoidal, and sawtooth functions, the temperature fluctuation could be suppressed by 60%-80% and the temperatures could be maintained at the same values. Our research demonstrates that the proposed control strategy has acceptable accuracy and robustness for the system with multiple heat exchangers undergoing various operating situations. [ABSTRACT FROM AUTHOR]

Based on the features of large heating power per unit volume and small cooling surface area, the thermal management is one of the key technologies and plays a significant role for the pulsed inductor. A mathematical model that describes the heat transfer and thermal accumulation processes with the operating condition of periodic pulse loading for the pulsed inductor has been developed and validated in this paper, and the model results show a fine accuracy as compared with the test data. In addition, a computer code has been implemented to simulate the thermal accumulation and performance of natural cooling with different operating conditions (as the various of pulse voltage, pulse spacing, and pulse duration). The results show that the pulse voltage, pulse spacing, and pulse duration are the focus factors to the thermal accumulation for the pulsed inductor, and the effect of the natural cooling by surface area of the inductor is poor under the periodic pulse loading. [ABSTRACT FROM PUBLISHER]