Experimental research on cooling the condensation area to flat micro heat pipe using the inverted Seebeck effect Silviu SPRINCEANA 1) , Ioan Mihai 1) 1) Department of Mechanics and Technologies, Stefan cel Mare University of Suceava, Romania, 13 University Street, 720229, Stefan cel Mare University, Suceava, Romania e-mail: silviu_sprinceana@yahoo.com ABSTRACT This paper presents the experimental results obtained by cooling the condensation zone of a flat micro heat pipe (FMHP) using the inverted Seebeck effect (Peltier mode). In all cases of heat pipes, the working liquid must flow when there is a temperature difference between the evaporation zone and the condensation zone. The condensing area is cooled by blowing air through a radiator, which uses a Peltier module with a power of 50W as a cooler. At low temperatures, the vapor pressure of the liquid in the evaporator is very low. As the condenser pressure cannot be less than zero, the difference in vapor pressure is insufficient to exceed the viscous and gravitational forces, thus preventing the operation of FMHP at the heat transfer limit. The condenser is cooled after it reaches a thermal equilibrium. It is desired to highlight the temperature variations on the condensation area at the time of cooling air, as well as the temperature variation on the radiator of the Peltier module. The analysis starts from the theoretical component of cooling the condensing zone and compares the results obtained from the experimental research with those obtained by calculations. The research shows the temperatures recorded in the cooled area of the condenser, using forced cooling with air blowing using a Peltier module, powered by a direct current source. It also highlights the experimental contribution to the capture of the phenomenon of forced convection, possibly used for cases where FMHP should work at temperatures close to the occurrence of thermal blockage. The temperature values were taken by means of thermocouples mounted in thermal contact on the FMHP surface and are recorded by a data-logger in order to draw the graphs of temperature variation. This highlights the possibility of transporting high heat fluxes through FMHP, other than if it is conventionally cooled. For the calculations, the Mathcad programming environment will be used to plot the graphs of temperature variation on the condensation zone at forced cooling. Keywords: flat micro heat pipe, biphasic transformation, inverted seebeck effect 1. THE HEAT TRANSFER IN THE CONDENSATION AREA AT FMHP The study of heat transfer in the condensation zone highlights how the working liquid inside the FMHP passes from the vapor phase to the liquid phase. If we refer to the surface of the working liquid inside the FMHP, during evaporation liquid molecules leave the surface in a continuous flow. If the liquid is in thermodynamic equilibrium with the vapors above its surface, then the flow of molecules will return to the liquid with no loss or gain of mass. However, when a surface of liquid loses mass by evaporation clearly the pressure and temperature of the liquid’s vapors must be less than the equilibrium value. The same principle applies to th e condensation zone. In order to achieve a total condensation of liquid vapors in the condenser, the vapor pressure and temperature must be higher than the equilibrium value. Condensation occurs when vapors resulting from vaporization in the vaporization zone meet the cooled surfaces of the condenser. The heat transported by the vapor to the condenser is thus transferred, and through it is dissipated in the ambient environment. The greater the cooling of the condensation zone, the more heat flux can be transported through the FMHP. The value of the temperature drop can be estimated as follows: first the vapor parameters near the liquid-vapor interface are considered. The average speed ̇ va , of the vapors at temperature T va and M molecular mass of liquid vapor, according to the kinetic theory, the average speed of the vapors can be written as [1],[2],[3],[4]: 8 , B va va kT v M  = (1.1) It was noted with k B – Boltzmann’s constant. The average flow of liquid vapor molecules ̇ va in every direction is given by: 1 . 4 va va nv S  − =  (1.2) In this way, the heat flux corresponding to the average vapor flux can be expressed, respectively: 1 , 4 va va M nv Q S  − =  (1.3)