Experimental research on heat transfer in a molten salt-heat pipe-thermoelectric generator system based on micro-MSR

Abstract

The heat pipe-cooled micro molten salt reactor (micro-MSR) utilizes heat pipes for transferring the fission energy produced in the core to thermoelectric generators (TEG). In order to assess the heat transfer performance, an integrated experimental setup comprising a molten salt – heat pipe – thermoelectric generator was established. Experiments were carried out to assess the system’s performance during start-up and operation under various operational conditions. Two different methods of salt addition were tested, revealing that the introduction of liquid molten salt led to temperature fluctuations, while the heat pipe start-up process was influenced by the melting of molten salt during cold start-up. During steady power operation, the system exhibited stability, with natural convection of molten salt in the annular gap enhancing heat transfer. The primary factor affecting thermoelectric conversion efficiency was identified as the thermal resistance between the condensation section of the heat pipe and the TEG. With increasing heating temperatures, the wall temperatures of each part of heat pipe rose accordingly, resulting in improving heat transfer efficiency and thermoelectric conversion. This investigation is expected to offer valuable insights for the start-up and operation of micro-MSRs.