An Experimental Study Of Cold Storage Characteristic Of Basalt Fiber At Low Temperature

Porous media are commonly used in cooling and insulation of nuclear reactor, storage, exploitation and combustion of coal, transpiration cooling for high-temperature components, mass transfer and heat transfer in porous wick of heat-pipe, enhancement of heat and mass transfer for porous structure, chemical packed-bed, solar energy and energy storage of wasted heat, thermo-protection for aviation spacecraft, heating extraction of oil, geothermal reservoir, heat and mass diffusion of underground nuclear waste, garbage and wastewater treatment in environmental engineering, fire protection, heat and moisture transfer of building materials, drying processes and other fields. In this paper, heat transfer and cold storage characteristics of basalt fiber were studied. To study cryogenic heat transfer of basalt fiber, three experiments with basalt fiber were completed under vacuumizing and cryogenic conditions. The analysis of experimental data showed that basalt fiber can clearly enhance heat transfer, and has good cold storage performance.Firstly, the porous medium is defined, research methods and basic parameters of porous media are introduced, mechanism and types of fluid flow in porous media is concluded, and heat and mass transfer process of fluid in porous media is analyzed. Secondly, heat and mass transfer mechanism of two-phase flow in porous media is discussed, models of two-phase flow in porous media are summarized.To study cryogenic heat transfer of porous media, three experiments with test element unfilled and filled with 6mm, 8mm basalt fiber were completed under vacuumizing and cryogenic conditions. The corresponding curves of temperature, pressure and mess were present. The analysis of the curves showed that basalt fiber can clearly enhance heat transfer, effectively lower and stabilize the temperature of test element. Cold storage performance of basalt fiber is good, and cold storage performance of 8mm basalt fiber is better than that of 6mm. Compared with unfilled basalt fiber, the consumption of liquid nitrogen in test system increased when test element filled with basalt fiber, because of more consumption of liquid nitrogen used to maintain relatively low temperature on surfaces of test element. Pressure in test system depends on speed of vacuum pump.