| 摘要 |
A solar collector panel consists of a metal sheet and a number of straight metal tubes intimately connected to the sheet in order to obtain maximum thermal conductivity. One tube each is connected to a sheet by slotting the latter along a straight line by equidistant parallel short cuts and pressing the areas between two consecutive cuts into semi-cylindrical bulges alternately in opposite direction from the sheet surface. These bulges have a concave semi-circular cross section of a diameter slightly larger than the outer diameter of the tube, and all bulges along the straight line form a continuous passage into which the tube is inserted. After insertion the tube is expanded by mechanical means or by hydraulic pressure and pressed onto the semi-cylindrical portions of the sheet, satisfactory contact being obtained by dimensioning the expanding pressure to a magnitude that the tube material is stressed beyond its yield point, while the sheet metal is stressed below its elastic limit. A suitable number of tubes is, in this manner, connected to a single sheet, and their ends are subsequently connected to form the required water circuit. |
