A new concept of porous thermoelectric module using a reciprocating flow for cooling/heating system

This paper presents the conceptual design of a novel thermoelectric cooler and/or heater utilizing the heat transfer effect due to forced convection. A porous thermoelectric converter combined with a reciprocating flow system in which the flow direction of air passing through the element is reversed after regular intervals is proposed. This flow system in effect makes the thermal conductivity insignificant and contributes toward the achievement of a high efficient cooler and/or heater. For the first phase, a one-dimensional numerical analysis is performed to examine the detailed characteristics of the device by systematically varying the relevant thermo-fluid parameters. In particular, the flow velocity and the porosity of the thermoelectric elements are the most important parameters which directly affect the system performance. For example in a porous thermoelectric cooler, the lowest temperature of air is approximately -20/spl deg/C for an ambient temperature of 27/spl deg/C, which is attained with a flow velocity u=0.35 m/s, a material porosity /spl epsiv/=0.5, and 2.5 cm thick thermoelectric elements. As a notable feature, the temperature of the cooling section of the system varies considerably with the velocity, and it attains a minimum at u=0.35 m/s. Subsequently, on the basis of the proposed cooling system, an extended concept aimed to realize commercial coolers and/or heaters is briefly discussed.