Abstract:
The heat pipe cooled reactor (HPR) has a multi-purpose application prospect due to its significant advantages such as simple system, compact structure, high inherent safety, etc. It is one of the best chooses for the power supply of new strategic weapons. However, the heat pipe reactor technology is still in its infancy, and the technical feasibility remains to be verified. This paper proposes a dual-mode heat pipe reactor concept design that combines dynamic thermoelectric conversion and static thermoelectric conversion, an integrated experimental device of “Core matrix-heat pipe-Stirling-thermoelectric power generation” was established, which utilized red copper matrix and heating rod to simulate the reactor core, utilized bending high-temperature potassium heat pipes to cool the core and transform the energy, utilized Stirling generators and bismuth telluride thermoelectric modules to realize dynamic and static thermoelectric conversion processes. Before the construction and experiment of the prototype, the pre-experiment of each important module was carried out. This research completed the development and test of bending high-temperature potassium heat pipes, the test of static thermoelectric conversion module and the test of dynamic thermoelectric conversion module. K-type thermocouple was used for experimental temperature measurement, and the error was less than 3 ℃. The relative uncertainty of temperature caused by thermocouple was within 3.0%. Voltmeter and ammeter with uncertainty of ±0.1 V and ±0.1 A were used to measure voltage and current, and the relative uncertainty of heat transfer power caused by instrument was within 2.5%. The results show that the developed bending high-temperature potassium heat pipe meets the design requirements. When the heating power is 878 W, the axial wall temperature difference of the heat pipe is less than 60 K, and the length of the non-condensable gas section is less than 5 cm. When the input power is 4.2 kW and the inlet cooling water temperature is 20 ℃, the hot side temperature of thermoelectric modules is 310 ℃. The power generation of 30 thermoelectric chips in 5 groups is 102.6 W, the thermoelectric conversion efficiency is 2.44%. When the heating power is 3.3 kW, the generation power of Stirling module is 429 W and the thermoelectric conversion efficiency is 13.1%. After the improvement, when the input power is 3 047.2 W, the average temperature of the evaporation section of the heat pipe is 627 ℃, the average temperature of Stirling hot end is 475.3 ℃, the temperature difference from heat pipe evaporation section to condensation section is 74 ℃, the temperature difference from heat pipe condensation section to Stirling hot end is 76 ℃, the generating power of a single Stirling energy conversion device is 673 W, and the overall thermoelectric conversion efficiency is 22.1%.