Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histo...Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histogram equalization and noise detection were performed to modify the evenly-distributed membership functions of error and error change rate into unevenly-distributed membership functions.Then,the experimental results with evenly and unevenly distributed membership functions were compared under the same outside environment conditions.The experimental results show that the steady-state error is reduced around 40% and the noise disturbance is rejected successfully even though noise range is 60% of the control precision range.The control precision is improved by reducing the steady-state error and the robustness is enhanced by rejecting noise disturbance through the fuzzy logic controller with unevenly-distributed membership function.Moreover,the system energy efficiency and lifetime of electronic expansion valve(EEV) installed in chamber cooling system are improved by adopting the unevenly-distributed membership function.展开更多
A burnup calculation has been performed to evaluate heavy rare earth (terbium--Tb, dysprosium--Dy) production in spent gadolinium oxide (Gd203) installed as a BP (burnable poison). Each amount of Tb and Dy produ...A burnup calculation has been performed to evaluate heavy rare earth (terbium--Tb, dysprosium--Dy) production in spent gadolinium oxide (Gd203) installed as a BP (burnable poison). Each amount of Tb and Dy production derived from the BP has been about 30-40 times larger than those created in FP (fission products). Required cooling time to achieve exemption level on radioactivity concentration produced Tb and Dy derived from the BP are much shorter (BP-Tb: 7.9y, BP-Dy: 〈 0.1y) than those created in FP (FP-Tb: 3,616y, FP-Dy: 6.9y). However, the BP is mixed homogeneously with UO2 pellet in current nuclear fuel system of LWRs (light water reactors), and hence mixing of FP cannot be not avoided. In such a mixture case, the required cooling time of recovered Tb will become 2,653y and that of recovered Dy be 4.8y. For this reason, recovered Tb is unlikely to be resource for utilization, while recovered Dy must be the resource provided the precise separation from the other FP.展开更多
文摘Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histogram equalization and noise detection were performed to modify the evenly-distributed membership functions of error and error change rate into unevenly-distributed membership functions.Then,the experimental results with evenly and unevenly distributed membership functions were compared under the same outside environment conditions.The experimental results show that the steady-state error is reduced around 40% and the noise disturbance is rejected successfully even though noise range is 60% of the control precision range.The control precision is improved by reducing the steady-state error and the robustness is enhanced by rejecting noise disturbance through the fuzzy logic controller with unevenly-distributed membership function.Moreover,the system energy efficiency and lifetime of electronic expansion valve(EEV) installed in chamber cooling system are improved by adopting the unevenly-distributed membership function.
文摘A burnup calculation has been performed to evaluate heavy rare earth (terbium--Tb, dysprosium--Dy) production in spent gadolinium oxide (Gd203) installed as a BP (burnable poison). Each amount of Tb and Dy production derived from the BP has been about 30-40 times larger than those created in FP (fission products). Required cooling time to achieve exemption level on radioactivity concentration produced Tb and Dy derived from the BP are much shorter (BP-Tb: 7.9y, BP-Dy: 〈 0.1y) than those created in FP (FP-Tb: 3,616y, FP-Dy: 6.9y). However, the BP is mixed homogeneously with UO2 pellet in current nuclear fuel system of LWRs (light water reactors), and hence mixing of FP cannot be not avoided. In such a mixture case, the required cooling time of recovered Tb will become 2,653y and that of recovered Dy be 4.8y. For this reason, recovered Tb is unlikely to be resource for utilization, while recovered Dy must be the resource provided the precise separation from the other FP.