The calculation is taken oil tank truck as an example, the calculation methods are valuable to some liquid vessel with insulated layer, and large space in which natural heat transfer,and forced heat transfer occure.

Natural heat transfer and flow patterns in a cylindrical annulus filled with saturated porous medium were numerically studied. The inner wall of the annulus is heated locally at constant temperature and the outer wall is isothermally cooled in order to simulate the electronic element heat process.

With the growing of frost layer in the initial growth period, the frost surface temperature is gradually increasing, and the frost growth rate, the effective thermal conductivity and the natural heat transfer coefficient are decreasing.

Passive space heating uses natural heat transfer processes to collect, store, and distribute heat.

For instance, radiant is a large portion of the natural heat transfer of the Mono lithic Dome.

The traditional calculation of type Gl7 insulated oil tank truck was pr esented in the paper. The process of heat transfer is a non-stable process because the oil temperature in truck is decreased with the elapse of time. The calculation is taken oil tank truck as an example, the calculation methods are valuable to some liquid vessel with insulated layer, and large space in which natural heat transfer,and forced heat transfer occure.

Natural heat transfer and flow patterns in a cylindrical annulus filled with saturated porous medium were numerically studied. The inner wall of the annulus is heated locally at constant temperature and the outer wall is isothermally cooled in order to simulate the electronic element heat process. Numerical results show that effects of Ra and κ on the tempreture and velocity fields are significant. The center of core flow moves to upper and outer wall as Ra and κ increase and convective...

Natural heat transfer and flow patterns in a cylindrical annulus filled with saturated porous medium were numerically studied. The inner wall of the annulus is heated locally at constant temperature and the outer wall is isothermally cooled in order to simulate the electronic element heat process. Numerical results show that effects of Ra and κ on the tempreture and velocity fields are significant. The center of core flow moves to upper and outer wall as Ra and κ increase and convective velocities are higher in the upper half than the lower half of the annulus. The local Nusselt number on the heated wall increases as κ increases and decreases as Z increases, and the case is reversed on the outer wall. The average Nusselt number on the heated wall increases as Ra and κ increase and the average Nusselt number is correlated by a relation of the form Nui=mRan.

An experimental investigation was carried out on the characteristics of the frost layer during the initial growth period which developed on a cold flat plate under natural convection conditions. The cold plate temperatures were varied in the-34 to-19 ℃ range. A series of microscopic observation was conducted with the aid of a video microscope. The frost-air interface temperature and the temperature distribution above the interface were measured by employing two-exposure holographic interferometry technique....

An experimental investigation was carried out on the characteristics of the frost layer during the initial growth period which developed on a cold flat plate under natural convection conditions. The cold plate temperatures were varied in the-34 to-19 ℃ range. A series of microscopic observation was conducted with the aid of a video microscope. The frost-air interface temperature and the temperature distribution above the interface were measured by employing two-exposure holographic interferometry technique. The heat flux on the plate and the variation of frost layer with time were also measured. The effective thermal conductivity of frost layer and the natural convective heat transfer coefficient were obtained based on the experimental measurements in the present study. An empirical correlation for the heat transfer coefficient was obtained. The significant difference of characteristics between the initial growth period and the full growth period was found. With the growing of frost layer in the initial growth period, the frost surface temperature is gradually increasing, and the frost growth rate, the effective thermal conductivity and the natural heat transfer coefficient are decreasing. The heat transfer coefficient and the frost growth rate are increasing with the decreasing of the cold plate temperature, while the influence on the effective thermal conductivity is not remarkable. The effective thermal conductivity is the ice thermal conductivity of 11.7 % to 1.7 %.