Heat-Transfer Wall Composed of Two Plate-Like Parts

The invention relates to a heat-transfer wall composed of two plate-like parts for separating two rooms at different temperatures, having several tubular sections substantially parallel to each other, enclosed between the plate-like parts and being in heat conducting connection with at least one part, which tubular sections carry a streaming medium, the two plate-like parts being firmly connected together along an interface which extends substantially parallel to the two principal directions of the wall.

Such a wall is known wherein the tubular sections have a circular cross section, so that for reasons of assembly the interface between the plate-like parts lies in the region of the plane in which also the longitudinal axes of the tubular sections extend. The tubular sections, therefore, each have half their cross section lying in respective channel-like cutouts of the two plate-like parts. As the cutouts of both wall parts must fit together exactly and must be arranged around the tubular sections so as to match, the precision requirements for making such a wall as well as the costs are quite high.

It is the object of the invention to improve a heat-transfer wall of the initially mentioned kind so that it can be made at considerably lower cost for equally good performance.

According to the invention, this problem is solved in that the interface between the plate-like parts is arranged so that it lies outside the outer contour of the tubular sections and that the plate-like part containing the tubular sections faces the room at the higher temperature. This solution is based on the finding that because of the different temperatures in the rooms separated by the wall the heat conduction through the wall can be associated in large part with one of the two plate-like wall parts. The other wall part then serves primarily as covering and/or reinforcing element. This obviates channel-like cutouts for receiving tubular sections in the plate-like wall part which faces the room at the low temperature. Hence also the necessity is eliminated to fit together exactly cutouts in both wall parts and around the tubular sections. In the new wall, therefore, the cost of adapting is considerably reduced. Also assembly of the new wall is much simpler, damage to the tubular sections during the bringing together of the two wall parts being practically ruled out. Of advantage is also that the tubular sections can be secured in one wall part only and can then be handled together with it as a structural unit.

Avoiding damage to the tubular sections during assembly is especially important when the wall is to be installed under difficult operating conditions. This is the case for example when high pressures and temperatures act on the wall simultaneously, possibly combined further with stress from radiactive radiation.

Some embodiment examples of the invention will be explained more specifically in the following description with reference to the drawings, which in

FIGS. 1 to 10 show each a partial transverse section of a wall according to the invention.

According to FIG. 1, a metallic, flat, heat-transferring wall 100 separates a hot room 300 from a cooler room 200. The wall 100 consists of two plate-like parts 2 and 3 and of straight tubular sections 11 enclosed between them. The tubular sections are parallel and are traversed by a cooling medium, e.g. water, which has on the average about the same temperature as the cooler room 200. The other contour of the tubular sections 11 is rectangular. Each tubular section is embedded in a channel-like cutout 31 of the wall part 3. Approximately three fourths of the outer circumference of each tubular section 11 are in heat-conducting contact with the periphery of the respective cutout 31. The corners of the cutouts are rounded, and the corners of the tubular sections 11 associated with them are adapted accordingly, so that good heat flow takes place between the thicker wall part 3 and the tubular sections. The tubular sections 11 are secured in the cutouts 31 by means of solder material 4. The thinner wall part 2, which is formed like a sheetmetal plate, is connected gas-tight with the thicker wall part 3 along a planar interface 50. Approximately one fourth of the outer surface of each tubular section 11 extends along the interface 50 and touches the part 2 when the wall is in the assembled state. Thus, the interface 50 is disposed outside the outer contour of the tubular sections 11 and does not intersect with the plane of the tubular section. The clear cross section of the tubular sections is circular and shifted with respect to the total cross section of each tubular section from the center toward the hotter room 300.

To produce a wall according to FIG. 1, the tubular sections 11 together with a solder foil for each as intermediate layer are inserted in the cutouts 31 of the thicker wall part 3; the tubular sections are soldered to part 3 by heating, thereby creating the heat-conducting connection. Thereafter the planes of the two parts 2 and 3 facing each other as well as the still free surfaces of the tubular sections 11 are machined to ensure a satisfactory, smooth abutting of the parts along the interface 50. Subsequently the thinner wall part 2 is sealingly connected with the thicker wall part 3 along the interface, e.g. by hard soldering, diffusion soldering or welding or by explosion plating. Owing to this manufacturing process, each tubular section 11 touches also the part 2, so that the entire circumference of each tubular section participates in the good heat flow in the wall 100.

The form of realization according to FIG. 2 differs from that according to FIG. 1 only in that the externally rectangular tubular sections 12 are beveled relatively much at the edges facing the thinner wall part 2, so that grooves 5 form. Into these grooves solder material, e.g. in the form of wires, is inserted, which can move up during the soldering in of the tubular sections 11. The grooves 5 may be made so large that after completion of the wall 100 continuous channels 5 remain free, which can serve for control and possibly removal of leaks.

In the embodiments according to FIG. 3 and 4, tubular sections 13 are provided, in which the side toward the thinner wall part 2 is rectangular while the side away from part 2 is semicircular, whereby--with the cutout adapted accordingly--a stabilization of the heat flow and of the mechanical stresses is achieved. According to FIG. 3, the plane of part 3 bordering on room 300 is adapted to the semicircular contour of the tubular sections, so that part 3 has essentially a constant wall thickness. In the example according to FIG. 4, the tubular sections 13 and the cutouts have the same contour as in FIG. 3, but the plane of part 3 toward room 300 is flat rather than being corrugated.

In the embodiment examples according to FIGS. 5 to 10, normal circular tubes 15 are used. The variants per FIGS. 5, 6, 9 and 10 are usable for relatively small heat quantities. Here a free space 6 remains between the tubes 15 and the thinner wall part 2 which--similar to the grooves or small channels 5 in FIGS. 2, 3 and 4--can serve for control and possibly for the removal of leaks.

In the case of the walls according to FIGS. 5 and 9, the thicker wall part 3 is of the same design with respect to its plane toward room 300 as in the example according to FIG. 3. However, the thinner wall parts 2 have ribs 7 which are each aligned with a web between two adjacent cutouts and join with these webs along the interface 50. The interface is disposed between the two wall parts 2 and 3 in a region of lower mechanical load.

In FIGS. 9 and 10, the webs are widened in flange fashion in the region of the interface 50, so that there exists a sufficiently large connecting area between parts 2 and 3 despite a thin-walled construction.

The embodiments according to FIGS. 7 and 8 are in principle of the same structural design as in FIG. 6, but in space 6 filling material in the form of sectional rods 8 and 9 is arranged; they are soldered in between the tubes 15 and the thinner wall part 2. In FIG. 7, each section 8 fills the entire interspace, whereas in FIG. 8 narrow spaces 6' remain free on either side of the sectional rod 9; they serve for control and possibly removal of leaks.

Although all examples relate to a flat wall with parallel, straight tubular sections, the wall may alternatively have a curved form, with the parallel tubes either following the curvature or extending in parallel arrangement crosswise to the curvature. The interface between the two parts 2 and 3 then also follows the curvature. Generally the tubular sections are connected in parallel with respect to the coolant stream; but a connection in series is also possible.

The wall according to the invention can be applied in various technical areas, e.g. for chemical reactors, in nuclear plants, or in low temperature engineering. For the forms of realization according to FIGS. 7 and 8, it is possible to connect the tubes with the surrounding wall parts by explosion welding or hydraulic reaming.