1. Radiation heat transfer.
In terms of radiation heat transfer, it is only related to the temperature difference and the structure and characteristics of the material. The structure and characteristics of the material mainly refer to the transmission and reflection properties of the heat radiation, which is related to the color depth and surface state of the material. Apparently, the color of the foam concrete insulation board is deeper than that of the organic foam board, and the former is easier to crystallize than the latter, and the surface roughness is inevitably lower than the latter. The heat transfer capability of the two is difficult to judge.
2, conduction heat transfer.
As far as conduction heat transfer is concerned, it is only related to the temperature difference and the nature of the material. In terms of the nature of the material, the constituent elements of the foam concrete are Si, 0, Ca, H and some other metal elements, all of which have been present in the form of compounds. There are no free electrons that can transfer heat quickly; the constituent elements of the organic foam insulation board are C, H, and N. These elements are also in the form of a compound, and there is no free electron capable of rapid heat transfer. The only difference is the chemical bond. Differently, it can be seen that the "heat" conducted by the two kinds of insulation materials is intensified by the vibration of the heated atom and transmitted through the chemical bond. In other words, accepting the same energy, the mass of a large atomic vibration is generally smaller than that of a small atom. In this sense, the heat transfer heat transfer capacity of foam concrete insulation boards should be lower than that of organic foam boards.
3. Convective heat transfer.
In the case of convective heat transfer, if the medium in the hole is air, the air convective heat transfer is only related to the temperature difference and the hole size of the material. In general, the foam concrete insulation board has a much larger hole than the organic foam insulation board. It is not difficult to find that the same temperature difference is added to the foam concrete insulation board and the organic foam insulation board of the same thickness, and the temperature difference of the single hole of the foam concrete insulation board and the organic foam insulation board is different, that is, the former is much larger than the latter. The result is that the convective heat transfer capability of the former is much greater than the latter.
4, phase change heat transfer.
In terms of "phase change" heat transfer, the foamed concrete slab contains a certain amount of free water, some easily lost crystal water or adsorbed water, which may cause phase change heat transfer during testing and use; organic The foam insulation board has a strong hydrophobic effect, so there is no phase change heat transfer problem of moisture, but the foaming agent and the flame retardant used in the production often contain volatile components and cause phase change heat transfer. Since the vaporization heat of water is larger than the heat of vaporization of general low-boiling organic matter, and the volatile components in the organic foam insulation board will become less and less with time, the phase change heat transfer capacity of the foam concrete insulation board must be greater than Organic foam insulation board.
This article is reproduced from Dacheng County, Hebei Province, Quanhe Thermal Building Materials Factory: http://
Heat transfer difference between foam concrete and foam insulation board