Experimental test on the coil's temperature running of electromagnetic movable coil control rod drive mechanism

This paper summarily introduces the experiment platform and experiment method of electromagnetic movable coil control rod drive mechanism of nuclear reactor, including experiment control system, data collection, record and save system, etc. The coil's temperature running has been discussed in detail. The temperature of the coil increases from room temperature to heat transfer balance, so the balance time of coil's temperature and capability of heat dissipation has been gotten. The experiment results are as follows: The balance time of coil's temperature is about 6 hours while the retentive current value is 3 A, 3.5 A, 4 A, 4.5 A, or 5 A. The balance temperature increases with the current value. The highest surface temperature of the second coil is 68.0 degree C when the current value is 5 A, but it drops to 30.1 degree C when the current value is 3 A. The disparity of highest surface temperature of the coil reaches 37.9 degree C. Different coil's balance temperature is different. The temperature of the second coil is highest, the first one is lower, and the third one is the lowest. The coil's voltage is different in various conditions. The coil's voltage becomes higher when the retentive current value increases, and it also becomes higher when the temperature increases. The coil's current value is almost unconverted, and the retentive current value equals to the summation of the three coils' in same condition. The resistance of the second coil is 50.2 Ω when its current value is 5 A and reaches heat transfer balance. The highest inner temperature can be ciphered out to be 102.2 degree C when the current value is 5 A by formula that on resistance and temperature. Now the inner temperature is probably the highest. All coils can reach heat transfer balance in 6 hours with no coil destroyed, so the coil's capability of heat dissipation is acceptable. The rigidity of the electromagnetic control rod drive mechanism will debase when the temperature increases too much, so does the dynamic running capability of the drive mechanism. (authors)