Investigation of Liquid Metal Heat Exchanger Designs for Fission Surface Power

2016

JAFM

The effect of conjugation on the enhancement of heat transfer in a liquid metal flow past a thermally conducting and sinusoidally oscillating infinite flat plate, when a constant temperature gradient is superimposed on the fluid, is investigated. The plate is made up of the materials compatible with the liquid metals used and is considered to be of finite thickness. Analytical solutions for the velocity and the temperature of the fluid and the solid are obtained. The effects of thermal conductivity and the thickness of the plate on the total time averaged heat flux transported and the thermal boundary layer thickness are investigated in detail. It is found that the effects of wall thickness and wall thermal conductivity on the heat flux transported depend on their effects on the transverse temperature gradient at any frequency. The optimum value of wall thickness at which the net heat flux transported attains the maximum value, for each fluid and for each wall material under consideration, is reported. A maximum increase of 46.14 % in the heat flux transported can be achieved by optimizing the wall thickness. A maximum convective heat flux of 1.87 × 10 8 W /m 2 is achieved using Na with AISI 316 wall. All the results obtained have been compared with the experimental and analytical results reported in the literature and are found to be in good agreement. It is believed that the new insights gained will be of significant use while designing liquid metal heat transfer systems.

Section: Introductionmentioning

confidence: 99%

Enhancement of Heat Transfer in a Liquid Metal Flow past a Thermally Conducting and Oscillating Infinite Flat Plate

2016

JAFM

“…Further, the possibility of using liquid metal heat pipes for cooling space nuclear reactors has been demonstrated by several prototype experiments without any reported failures . For additional information on liquid metal heat exchanger design for fission surface power for Moon and Mars surface missions, one may refer to .…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Heat Transfer in a Laminar Hydromagnetic Flow of a Liquid Metal Past a Thermally Conducting and Oscillating Infinite Flat Plate

2016

Heat Trans. Asian Res.

The combined effects of conjugation and magnetic field on the heat transfer enhancement in a laminar liquid metal flow past a thermally conducting and sinusoidally oscillating infinite flat plate are investigated. The wall materials used are compatible with the liquid metals and are assumed to be of finite thickness. Analytical solutions are obtained for the velocity and the temperature distributions. The combined effects of thermal conductivity, the thickness of the plate, and the transverse magnetic field on the net heat flux transported are analyzed in detail and it is found that such effects are same as those on the transverse temperature gradient at any frequency. Due to oscillation, the heat flux is enhanced by O(10 3 ). The optimum value of wall thickness and the corresponding boundary layer thickness for which the maximum heat flux is obtained are reported. The heat flux transported can be increased by choosing a wall of low thermal conductivity. A maximum increase of 52.03% in heat flux can be achieved by optimizing the wall thickness. These information may be useful while designing magnetohydrodynamic liquid metal heat transfer systems. All the results obtained are in good agreement with the results reported earlier. C⃝

“…Heat transmission by oscillating the liquid metals is a topic of current interest owing to its tremendous applications in transporting thermal energy from Sterling and Brayton engines [8,9] and cooling of space nuclear reactors [10], high power electrical and electronic equipments. Further details on the designs of heat removal devices using liquid metals for fission surface power for Mars Moon and surface missions are well explained in [11].…”

Section: Introductionmentioning

confidence: 99%

Study of Conjugate Heat Transfer in Electromagnetic Liquid Metal Dream Pipe

Archive of Mechanical Engineering

2017

The combined effect of conjugation, external magnetic field and oscillation on the enhancement of heat transfer in the laminar flow of liquid metals between parallel plate channels is analyzed. In order to make our results useful to the design engineers, we have considered here only the wall materials that are widely employed in liquid metal heat exchangers. Indeed, all the results obtained through this mathematical investigation are in excellent agreement with the available experimental results. The effective thermal diffusivity κ e is increased by 3 · 10 6 times due to oscillation and that the heat flux as high as 1.5 · 10 10 (W/m 2 ) can be achieved. Based on our investigation, we have recommended the best choice of liquid metal heat carrier, wall material and its optimum thickness along with the optimum value of the frequency to maximize the heat transfer rate. At the optimum frequency, by choosing a wall of high thermal conductivity and optimum thickness, an increase of 19.98% in κ e can be achieved. Our results are directly relevant to the design of a heat transfer device known as electromagnetic dream pipe which is a very recent development.