Heat exchange effect with fuel gas in thermoelectric and Nernst elements

In order to increase the figure of merit, low thermal conductivity materials are studied. The method of a fuel gas and air blowing from the low temperature side of the porous semiconductor was proposed to reduce the effective thermal conduction. This principle is already being used as a gas cool current lead for a superconducting magnet system since 1975. The superconducting magnet system is composed of the low temperature magnet and the room-temperature power supply and these are connected by the current-lead in electrically, therefore, the current-lead has a large temperature difference. In order to operate the system stably and economically, the heat leak to the low temperature system must be minimized. If low temperature helium gas passes through from the low temperature side to the room-temperature side, the Ohmic and thermal conduction heat fluxes are transferred to the low temperature helium gas in the current-lead, therefore, the effective thermal-conduction is reduced to one-fiftieth. If this process works well even in thermoelectric and Nernst generators, we can expect the improvement of the conversion efficiency. Here, a one dimensional model is used to analyze the gas-cooled generation elements, and we propose a new idea.