Central tube for a linear concentrating solar thermal power plant, having an absorber layer, and method for applying said absorber layer

摘要

A central tube for linear concentrating solar thermal power plants, has an absorber layer. The absorber layer is generated by cold gas sputtering, wherein suitable method parameters can in particular generate an increased surface roughness by means of pores in the surface region of the absorber layer. An absorber layer can thus be advantageously produced, having a quadratic roughness of no more than 1 μm, measured in a close range of no more than 50 μm diameter, and preferably being made of a corrosion-proof hard alloy comprising tungsten carbide, in particular WC—CoCr, WC—Co, WC—FeCo, WC—FeC, WC—FeNi, WC—Ni or WC—NiCr.

主权项

1. A method comprising:
providing a solar-thermal-power-plant-linear-concentrating central tube; and depositing a corrosion-resistant tungsten-carbide-based cemented carbide by cold gas spraying to thereby apply an absorber layer onto the central tube, the absorber layer applied to have a surface with a roughness, a surface profile of which can be described by a two-dimensional Fourier spectrum of a location-dependent height position H of the surface, and the two-dimensional Fourier spectrum defined such that within spatial frequencies which correspond to spatial periods of greater than 6 μm and less than 50 μm, the amplitudes are not greater than a maximum amplitude within spatial frequencies which correspond to spatial periods of less than 6 μm.