RU19163U1 - DEVICE FOR MEASURING TEMPERATURE OF METAL OF STEAM PIPES OF STEAM BOILERS - Google Patents

Description

.yCTPOPlGTBO FOR METERING TEMPERATURE OF METAL OF STEAM PIPES OF STEAM BOILERS

The utility model relates to the field of power engineering and is intended to measure the temperature of the metal pipes of the heating surfaces in the heating zone, mainly steam superheaters of energy steam boilers.

A known design of a device for measuring the temperature of the metal pipes of steam boilers, which is a piece of pipe with fins, in the wall of which a sleeve is welded and. in the cross section of which, on opposite sides of the pipe, two pairs of intersecting holes are made, into which thermocouples are inserted, one of which is hot-sealed together at the outer generatrix of the pipe, the other near the inner wall of the pipe. The hot junction of another thermocouple is mounted on the bottom of the sleeve. The free ends of the thermocouples are led out into a protective device (fitting) consisting of a cylindrical lining with closed ends and a pipe which, after installing the device in the screen tube, are in the outer insulation of the boiler, and the end of the pipe with the free ends of the thermocouples is outside (I.I. Belyakov , BBGolokov Universal insert for gas-tight screens, Power Engineering, 1977, No. 10, pp. 38 - 39).

A disadvantage of the known device is that the nipple protects the thermocouples only from mechanical damage and cannot be protected by overheating and corrosion of the thermocouple conductors in the heating zone of the furnace and boiler flues.

P1 is also known a device for measuring the temperature of the metal pipes of steam boilers, the output of the free ends of thermocouples in which is carried out inside a special output pipe of small diameter

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(D.N. Kemelman, N.B. Eskin, A.A.Davidov Adjustment of boiler units (reference book). Energy, Moscow, 1976, p. 107. Fig. 4-8).

A disadvantage of the known device is that it consists of small parts connected by welding, it is difficult to manufacture and install, and practically cannot be manufactured at their place: installation. In addition, clutter of the cross-section of the pipe with foreign bodies leads to a distortion of the measurement results, and can also cause the pipe to become clogged with corrosion products of the boiler’s steam and water duct and, as a result, to burn the pipe. Due to the thickening of the working part of the device and the longitudinal holes for installing thermocouples in it, the temperature field of the device differs from the temperature field of the pipe into which it is installed, which does not allow to quickly obtain the true temperature of the metal of the pipe and requires special conversion. The gas temperature at which the device can operate is also limited to 800. i.e., at the weekend, not the most heat-stressed steps of the superheater.

A device is also known for measuring the temperature of the outer surface of the pipes of steam boilers, in which thermocouples are laid outside the pipe under the linings, tightly pressed to the pipe wall through the insulation layer (D.K. Kemelman, N.B. Eskin, A.A.Davidov Setting up boiler units ( Handbook), Energy, Moscow, 1976, p. 110, Fig. 4-9). Prototype.

A disadvantage of the known design is that it consists of a large number of small parts, time-consuming to manufacture, and the working part of which can hardly be manufactured at the place of its installation. During the operation of the boiler, the joints of the ends of the lining that are not welded to the pipe with a continuous seam are decompressed when heated, which leads to the access of aggressive fuel combustion products to thermocouples, their overheating and corrosion. As a result of this ego, the pad was heated to leMiieparypbi much higher than the temperature of the pipe, which leads to its destruction due to scale formation. The execution of the lining of heat-resistant steels with

temperatures of gas flow above 700 ° C only slightly increases the life of the device.

The claimed solution allows: to increase the level of gas temperatures, in which the temperature of the metal of the pipes is measured, to simplify the design, assembly and installation, since the device is made of the same pipes as the pipes of the heating surfaces, which leads to increased reliability, accuracy of measurements and efficiency devices.

A device is proposed for measuring the temperature of the metal of the pipes of the heating surfaces of steam boilers, including a pipe with a longitudinal fin, in the wall of which a hole is made in which a thermocouple is installed, one end of which has an outlet to the outer surface of the pipe, and the other end to the longitudinal EZ groove} fin. At the same time, a wire made of a material with a high coefficient of thermal conductivity, for example, of red copper, snug against the walls of the groove is laid over the thermocouple.

The resulting model is illustrated in the figure, where in FIG. 1 shows a general view of the device, FIG. 2 is a sectional view taken along section AA.

The device includes a pipe 1 with a longitudinal fin 2. made integral with the pipe 1 or welded to it from the sides by a continuous seam. A hole 3 is made in the wall of the pipe 1, in which a thermocouple is mounted 4. One of the ends 5 of the hole 3 has an exit to the outer surface of the pipe 1. Near the outer surface of the pipe 1, a hot junction 6 of thermocouple 4 is fixed, which is externally minted by the pipe metal and / or / fused fuzzy layer of filler metal. The other end 7 of the opening 3 has an exit into the longitudinal groove 8 of a rectangular shape, made in the fin 2 along the entire length and having a base 9 near the outer forming pipe 1. At the exit end of the end 7 of the hole 3 in the groove 8, the thermocouple 4 has a bend in the exit stop and is laid to base 9 of groove 8. Free end 10 of thermocouple

4 protrudes from the fin 2 at the outlet of the pipe 1 to a predetermined length. In the groove 8, along the entire length of the fin 2, a wire 10 made of a material with a high coefficient of thermal conductivity, for example, made of red copper, with a diameter slightly smaller than the width of the groove 8, tightly adjacent to its walls, is laid over the thermocouple 4, with an allowance for the end of the fin 2 on exit from the pipe 1 beyond the boundary of the heating zone 12.

The state of the walls of the groove 9 in the fin 2 is shown in FIG. 2: before laying the wire 11 with a dashed line, after with solid lines. The top joint of the walls of the groove 8 along the entire length of the fin 2 is fused with filler metal with a solid seam to prevent contact of the conductors 13 of the thermocouple 4 with aggressive flue gases. The free space in the groove 8 between the thermocouple 4 and the wire AND is filled with insulating material (not shown conditionally), for example, asbestos or fiberglass. The deposition of metal from the side of the hot junction 6 and along the junction of the walls of the groove 8 is shown in FIG. 2 black fill.

The device operates as follows. The flue gas heats the pipe 1, in the wall of which, at the end 5 of the hole 3, a hot junction 6 of thermocouple 4 is fixed. Thermocouple 4, laid on the base 9 of groove 8 in fin 2. has a free end 10, as well as red copper wire 11 outside the zone heating 12. As a result of heating the pipe 1 with a hot junction 6 of the thermocouple 4, fixed in the wall of the pipe 1, a thermopower arises in temperature. When the measuring device is connected to the conductors 13 of the thermocouple 4 of the measuring device, the temperature of the metal of the pipe 1 in the cross section of the hole 3 is determined. The dimensions of the groove 9 in the fin 2 are such that the thermocouple 4. laid in the groove 9 moves freely in it when the device is heated and cooled. Wire 11. Tightly adjacent to the walls of groove 9, has constant contact with fin metal 2. Due to the higher coefficient of thermal conductivity of copper wire I., the thermal conductivity coefficient of pipe metal 1 is an order of magnitude higher, and the heat of fin metal 2 is removed along the wire And, like a rod. zones

heating at the inlet of the pipe 1 to a colder one at the outlet outside the heating zone 12. thereby lowering the temperature of the fin 2 and the free space of the groove 8 under the wire 11 with a thermocouple 4. protecting its conductors 13 from overheating.

As a result of this, the device operates stably at a temperature of 1-element in the heating zone of 1200 C, which is significantly higher than the permissible temperature of 800 ° C for known devices.

Claims (1)

A device for measuring the temperature of the metal pipes of steam boilers, including a pipe with a longitudinal fin, in the wall of which a hole is made in which a thermocouple is installed, one end of which has an outlet to the outer surface of the pipe, and the other end to the longitudinal groove of the fin, characterized in that Above the thermocouple, a wire of material with a high coefficient of thermal conductivity, for example, of red copper, is laid tightly against the walls of the groove.