核电池热功率测量装置校准用标准热源设计

Design of Standard Heat Source for Calibration of Nuclear Battery Thermal Power Measurement Device

核电池在空间探测、核工业等领域应用十分广泛,由于核电池结构和材料的特殊性,多采用基于等效热功率的方法对其进行功率测量。目前我国用于对核电池热功率测量装置进行计量的热功率标准装置存在准确度较低、稳定性较差的问题,为解决此问题,本文研制了一套标准热源装置,该装置由高精度恒流源、标准电阻、发热体、八位半数字多用表等部分组成,利用电流的焦耳效应将电能转化为热能。经试验证明,该装置在电流小于等于3 A的范围内,能够产生0.7~147 W的功率,相对扩展不确定度不大于2×10^(-3)(k=2),为保障核电池热功率准确溯源起到了重要作用。

Nuclear batteries are widely used in space exploration,nuclear industry and other fields.Because of the particular structure and materials of nuclear battery,methods based on equivalent thermal power are often applied when measuring their power.At present,the thermal power standard device used for measuring the nuclear battery thermal power measurement device in China has the problems of low levels of accuracy and stability.In order to solve these problems,this paper developed a set of standard heat source device.It is consisted of a high-precision constant current source,a standard resistance,a standard heat source,an eight-and-a-half-digit digital multimeter,etc.The device converts electrical energy into heat energy by the means of Joule effect.It has been verified by experiments that when the range of current is within 3A,the device can generate 0.7~147 W of power,and the relative expanded uncertainty would be equal to or less than 2×10^(-3)(k=2),wlich plays an important role in ensuring the accurate traceability of the thermal power of nuclear batteries.