RU1815485C - Steam cooling device - Google Patents

Abstract

Use: energy. SUMMARY OF THE INVENTION: the edges of the outlet holes 5, 7 of the tubes 6 and nozzles 8 located on the lateral surface of the cylindrical part of the venturi are tangent, and the angle between the axis of the tubes 6 and the radius is at least. 2 ill.

Description

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The invention relates to steam cooling technology and can be used in the field of energy at large thermal power plants.

An object of the invention is to increase the rate of cooling of steam.

In Fig, 1 shows the proposed device, a longitudinal section; figure 2 - section aa in fig. 1.

The steam cooling device comprises a steam pipe 1, inside which a mixing chamber 3 is formed with a gap 2 and is made in the form of a venturi. On the lateral surface of the cylindrical part 4 of the venturi, there are holes 5 provided with tubes 6, the axis of the tubes b are located at an angle a. to the radius of the cross-section of the cylindrical part 4 of the venturi. Next to the holes 5 on the side surface of the cylindrical part 4 are openings 7, which are provided with nozzles 8. The axes of the nozzles 8 are also at an angle to the radius of the cylindrical part 4, the tubes 6 and nozzles 8 being in the opposite direction. The centers of the outlet openings 5 and 7 are located in the same plane of the cross section of the mixing chamber 3, and the edges of the outlet openings of the tubes and nozzles (5 and 7, respectively) are tangent. The angle between the axis of the tubes 6 and the cross-sectional radius of the chamber 3 is at least 20-25 °. The tubes b communicate with the cavity of the manifold provided with a nozzle 10 ..

The operation of the device is as follows.

The main steam flow through the steam line 1 enters the mixing chamber 3. A part of the steam through the annular gap 2 enters the cavity formed by the steam pipe 1 and the mixing chamber 3. The cooling water through the pipe 10 enters the manifold 9, from where it flows evenly through the tubes 6 of them into the steam stream by a system of chordal jets. In this case, the vapor stream acquires a tangential velocity component, which helps to intensify the cooling of the vapor along the length of the mixing chamber 3. A part of the vapor enters the nozzles 8 and flows out of them into the main vapor stream using a chordal jet system. Moreover, the direction of the steam jets and the views relative to the radius of the mixing chamber are opposite. The arrangement of the openings 5 and 7 determines the pairwise impact of the steam jets and water. In this case, more intensive crushing of the jets of cooling water takes place. In addition, due to the action of the steam jets, not only does the steam jets deviate from the initial supply (angle change). but also a more intense expansion of water jets.

Regarding the feed angle a. In the absence of steam jets (or supplying them coaxially with water jets), an excess of 20–25 ° is not advisable, since with an increase in a (a), cooling water is mainly distributed in the peripheral layers of the mixture flow, which leads to a decrease in the efficiency of mass transfer processes) although the swirling flow increases). When supplying steam jets, it is advisable to increase the value of a. The optimal value of a depends on the ratio of the flow rate of steam (entering the cavity) and cooling water. Changing the flow rate of steam entering through the nozzles can be achieved by various methods, for example, by changing the size (overlapping) of the annular gap.

Tests of the model of the proposed technical solution were carried out in a wide range of parameters: about 0-60 °, 3 0.01-0, t, n 4-16, G 0.02-0.2. Here ,

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water, n is the number of nozzles, G is the mass flow rate. Indices: s - nozzle, c.t. is the cylindrical part of the venturi, n is steam, and c is cooling water. It was found that the proposed technical solution allows to significantly intensify mass transfer processes in the device. So, for example, at -a- 40 °, G 0.2, p 8, 5 0.02, the mixing intensity along the length increases by 80%, and the stability of mass transfer characteristics by 4.5 times (compared with radial feed). Here G is the relative flow rate of steam (relative to cooling water) supplied in the form of jets. It should be noted that steam jets squeeze drops of cooling water from the walls of the mixing chamber and the steam pipe, which leads to an increase in the reliability of the device.

The proposed device allows to increase the efficiency of steam cooling, which allows us to recommend it as a desuperheater for boilers, including large unit capacities.

Claims (1)

SUMMARY OF THE INVENTION A device for cooling steam, comprising a mixing chamber installed in the steam line, made in the form of a venturi with holes in its narrow part in communication with water supply pipes and nozzles, confuser and diffuser sections, the first of which is located with the formation of an annular gap relative to the inner surface of the steam pipe, and the second adjacent to the latter, characterized in that, in order to increase the intensity of cooling the steam, the axes of the water supply pipes and nozzles are located at angles to the radius of the Venturi pipe, the outlet sections of the tubes and nozzles adjoin one another and are directed in opposite directions, while the centers of the outlet sections are located in the same transverse plane, and the angle of inclination of the axes of the tubes to the radius is at least 20 ... 25 °. Aa