Evaluation of Material and Characteristic for Alkali-Metal based High Temperature Heat Pipe and TEC (Thermal-to-Electric Convertor)

다국어 초록 (Multilingual Abstract)

Heat pipe generally transfer thermal energy from one regime to another essentially evaporator to condenser. Superalloy envelope with alkali-metal (sodium, potassium) working fluid for high temperature heat pipe (HP). Na-AMTEC convert between thermal energy and electrical energy, in specific terms, the static energy conversion subjected to electrochemical reaction mainly depending on its chemical kinetics and temperature. In particular, Na-AMTEC convert energy between heat and electricity transpired via ionization of natrium as known as reduction and oxidation (REDOX) which is differentiate it from the dynamic energy conversion. In specific terms, 1) the input of thermal energy is converted into electrical energy as same as a thermoelectric cell, 2) the input of thermal energy is converted into the sum of electrical energy P_e and thermal energy P_th, as same as a combined heat & power (CHP) and 3) the input of electrical energy is converted into thermal energy as same as an electrochemical heat pump. Na-AMTEC could highly utilized in aforementioned objectives with efficiencies potentially near Carnot theorem.
In case of thermal energy in both of Na HP and Na-AMTEC, the alkali-metal is an energy medium of heat transfer (HF) and heat transfer fluid (HTF). The purpose of Na HP is transferring thermal energy from source to sink with maximizing heat transfer rate and minimizing the heat loss to ambient surroundings. Similarly, the purpose of Na-AMTEC, alkali-metal based thermopower HP, is to convert thermal source into electricity in order to reduce several conventional stages of conversion processes e.g. thermal energy loss during phase change of HTF, energy loss in terms of temperature and pressure during the energy transportation and energy loss during relative mechanical motion results from energy loss and materials squander due mainly to friction and wear. This study is to report the development efforts of Na HP and thermopower HP fabricated for high grade to low grade temperature power generation.