DE6604353U - PIPE ELEMENT FOR HEAT EXCHANGER - Google Patents

Description

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Dr.-Ing, Heinrich Vorkauf

1 000 Berlin 33, Davoser Str. 2 b

Tubular element for heat exchangers

The invention relates to a tubular element for heat exchangers, in particular steam generators, Consists of a pipe heated on one side, preferably vertical, connected to a lower distributor and upper collector with a> 5 »erem part thereof located closure point, below and above softer with this pipe several U-shaped, pipes projecting into a heating medium flow are connected and with one extending from the upper pipe part, leading to the lower pipe part and above ours Distributor opening into the vertical pipe again on the unheated pipe side lying return line.

In known pipe elements, the return line is in the interior of the vertical Tube arranged, in such a way that it is below the mouth of the U-shaped Pipes leading out into the lower distributor. This arrangement has several serious consequences Disadvantage. In order to be able to accommodate the return line, the pipe must be inside have a large cross-section. However, pipes with a large cross-section restrict the freedom of construction, are more difficult to process than those with a small cross-section Difficult to achieve a heating surface concentration, are difficult to distribute and collectors to connect and their wall thickness is disadvantageous for operation at high pressures. Through the confluence of the return line in the lower distributor, the prevailing there Bringing water flow into unrest and eddies appear, which lead to losses and unfavorable flow conditions. In this respect, the well-known museums are not sufficient for today's demands.

A pipe element of the type mentioned above which is improved in comparison has a return pipe located on the unheated side of the pipe, which is fed by the Confluence of the uppermost U-shaped pipe and the upper collector limited section of the vertical pipe goes out and above the lower manifold in this pipe Tired again. The deficiencies outlined above are largely worth it Fixed.

According to the innovation, the aforementioned is now for a tubular element Proposed genus that the return line limited by the termination on the one hand and the confluence of the innermost pipe coil on the other hand Pipe section goes out.

This maintains the advantage that the cross-section of the vertical Rohres can be small, whereby the heat exchanger is suitable for higher pressures and the heating surface concentration is improved. Furthermore, there is no influence the water flow in the lower manifold. As practical tests have shown increases due to the arrangement of the unheated return pipes outside of the heating surface carrying pipes also the speed of the water flowing downwards in them, which increases and improves the circulation significantly.

In addition, with the innovation according to the arrangement of the return pipe around 25% more water circulation compared to the version with above the Reached the connection of the return pipe located near the heating surface.

The vertical tube of the tubular element is at its upper and lower ends pulled in to a smaller diameter, which is known in the construction of heat exchangers Is. In the present case one achieves that a certain throttling is present at the upper outlet, which forces the water into the return line, the leading steam is allowed to flow away.

It is special in the context of improving water circulation advantageous that the unheated return pipe outside the manifold and near the lower taper opens into the full cross-section of the vertical tube.

The separation of the generated mixture into steam and water and one more Better supply of the heated pipes with circulating water can also be promoted by the fact that a connection from the return line to the upper collector will be produced. A practically complete separation of the mixture is then achieved if at the junction of this connection to the upper collector a vapor separator, z. B. a centrifugal separator is arranged.

The own circulation achieved through the innovation in each pipe element is allowed an enlargement of the heating surface connected to each vertical pipe, as a result the withdrawal of the water is given sufficient cross-section for the steam discharge and the water circulation is increased.

The subject of the innovation is explained using an exemplary embodiment. Fig. 1 shows the view of a tubular element schematically «Flg. 2 is a section along line IS-It in FIG. 1.

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The pipe element consists of a pipe 1, in the upper part of which there is a termination point 2 is located, below which U-shaped tubes 3 branch off, the In a heating medium flow protrude and open into the pipe 1 again above the terminating part 2. Dot tube 1 is connected at the bottom to the distributor 4 and at the top to the collector 5, which, for example, can lead to a steam separating drum. On the unheated On the side of the pipe 1, a return line 7 is provided, which branches off above the termination point 2 and below the confluence of the innermost pipe coil 3 'from the pipe 1 and above the distributor 4 near the lower taper 6 back into the pipe 1 joins. That produced in the lower part of pipe 1 and in the U-shaped pipes 3 The steam-water mixture is throttled in the mixture by the upper pipe taper 6 contained water occurs for the most part in the return line 7 to again to participate in the circulation. This own circulation in the pipe element, caused by the pulling in of the tubes 1 at their ends and the return tube 7, not only enables the Formation of a tight wall by laying the pipes 1 tightly, as shown in FIG. 2, but also enables the connection of a larger heating surface from tubes 3 by z. B. two parallel bundles of such U-shaped tubes, somewhat in height offset to each other- z. B. by a pipe diameter -, connected to the pipe 1 will. Furthermore, since smaller pipe cross-sections are used, manifolds and Collectors are kept small in their wall thickness and, due to the fact that they are in circulation, too are reduced in their cross-sections, which then allows the use of higher pressures.

Another advantage is the fact that the return lines 7 to carry insulation or sheet metal cladding are very suitable as they are always on the the pressure corresponding to the saturated steam temperature and so evenly to the other parts of the heat exchanger expand, including the expansion of an adjacent one Sheet metal jacket is then matched.

Claims (6)

Protective rules 1. Pipe element for heat exchangers, in particular steam generator, consisting of a unilaterally heated, preferably vertical pipe connected to a lower distributor and upper collector with a knock-off point located in its upper part, below and above which this pipe several U-shaped «, in one The heating center is connected to pipes protruding from the upper part of the pipe, leading to the lower part of the pipe and rejoining the vertical pipe (1) above the lower distributor ^ on the unheated side of the pipe, characterized by the fact that the return pipe GO from the pipe cut bounded by the connection point (2) on the one hand and the junction point of the innermost pipe coil (3 ') on the other hand. 2. Pipe element according to claim 1, characterized in that the vertical pipe (1) at its upper and lower connection end in a known V / before is drawn into a smaller pipe cross-section. 3. Pipe element according to claim I and 2, characterized in that the return line (7) near the lower locking point (6) in the full pipe cross-section joins. 4. Pipe element according to claim 1 to 3, characterized in that the return line (7) is additionally connected to the upper collector (5). 5. Pipe element according to claim 1 to 4, characterized in that a vapor separation device known per se is arranged in the RückJauf-IeIrung (7). 6. Pipe element according to claim 1 to 5, characterized in that on the vertical Tube (1) two parallel wooden flats made of U-shaped tubes (3), offset from one another in height * are connected.