SU817276A1 - System for heating the flange connection of steam turbine cylinder - Google Patents

Description

The invention relates to power engineering, in particular steam turbine engineering. _λ

A known heating system for flanges and studs of steam turbine bodies, the heating of which is carried out by supplying a heating medium through pipelines from a common collector to the ducts and obnizka flange connections [11. The disadvantages of such systems are the restrictions on permissible pressure under the duct strength conditions, the limited steam consumption and therefore the insufficient loading rate of the unit. The presence of heating ducts significantly increases the volume of turbine repair work in connection with the development of thermally fatigue cracks in the zones of duct welding to the housing. The use of such systems at cylinder metal temperatures above 300 ° C (during start-ups after downtime for a day or less, with damping) is unacceptable, since steam is supplied with sharp cooling of flanges and studs.

Closest to the proposed one is a heating system for the flange connection of the cylinder of a steam turbine of a steam turbine with feet, comprising a low with jumpers and a supply line for heating steam, connected between the low side and the steam supply line to a 5 turbine equipped with a regulating

- authority [21.

The disadvantage of this system is the large 'steam consumption in a dual-flow heating circuit. The double-flow scheme • 0 ma complicates the layout and increases the length of the heating system pipelines, worsens the turbine insulation ·.

A common drawback of the well-known οποί 5 heating topics that use steam supplied to the cylinder as a heating medium is the large length of the steam supply pipelines to the heating system, the presence of manifolds, drain valves, etc., which significantly limits the turbine's maneuverability.

The purpose of the invention is to increase maneuverability and reliability.

This goal is achieved by the fact that the heating steam supply pipe is connected to the steam supply line to the turbine after the regulator and to the downstream side of the front foot, and jumpers are installed at the pipe connection to the downstream side to separate from the last steam supply area facing the front foot .

In FIG. 1 is a diagram of a heating system for flange connections of a turbine cylinder; in FIG. 2 view of the horizontal cylinder connector; in FIG. 3 - layout of pipelines of supply to the flanges of the flange connection.

The heating system of the flange connection 1 is connected to the cylinder 2 by the supply pipes 3 with valves 4. The pipes 3 supply the heating medium to the flange 5 of the flange connection 1. The medium is supplied to the pipeline 3 from the steam supply line 6 to the cylinder 2 of the turbine. The junction of pipelines 3 with line 6 is located between the regulating body 7 and cylinder 2. In the downcomer 5, with the help of jumpers 8, a steam supply zone 10 is formed in the area of the front foot 9. hole 12, and is discharged through a pipe 13.

The system operates as follows.

.When the system is turned on, the heating medium from line 6 is supplied through pipelines 3 through a fully open stop valve 4 to the most 'metal-intensive massive area of the flange connection - the front paw 9 of cylinder 2. The jumpers 8 provide efficient heating of the steam supply zone 10 with the hottest medium. In this case, the steam passes not only downstream 5, but also enters the annular channels between the studs 11 and cylinder 2, intensively heating the studs, reducing the temperature difference between the flange and the stud, which is the leading difference when using such a heating system.

The heating efficiency in the area of the forepaw 9 is determined, in particular, by the fact that the jumpers 8 provide a turn of the flow of the heating medium, exclude the formation of a stagnant dead-end aeon at the end of the dip in the region of the forepaw 9, which to a greater or lesser extent takes place in all known heating systems. This, in particular, allows us to switch from a two-line to a simpler, more convenient _f reliable and more economical single-line heating scheme. In the area of the front paw 9, the width of the flanges may be

1.5-1.7 times more than in the frontal zone, where operational control is usually performed.

Thanks to the efficient heating of the most massive, thick-walled part of the cylinder, the restrictions on the loading speed of the power unit, imposed by the condition for heating the cylinder, are lifted, its life is increased, and the warpage of the connector and bore is reduced.

Claims (2)

(54) HEATING SYSTEM OF FLANGED CONNECTION OF THE CYLINDER OF THE STEAM TURBINE Connecting the pipeline to the lowering to separate from the last zone under the water of steam facing the front paw. FIG. 1 is a diagram of the system for heating the flange connections of the turbine cylinder; in fig. 2 is a view of the horizontal connector of the cylinder in FIG. 3 shows the layout of the supply pipelines to the flange connections. The heating system of the flange joint 1 is connected to the cylinder 2 by supply lines 3 with fittings 4. The pipelines 3 feed the heating medium into the bottom 5 of the flange connection 1. The flow of the medium to the pipelines 3 is made from the steam supply line 6 to the turbine cylinder 2. The connection point of the pipelines 3 with the line b is between the regulating body 7 and the cylinder 2. In the lowering 5, a steam supply zone 10 is formed in the front pawl 9 by means of bridges 8. The studs 11 are screwed into the lower half of the cylinder 2. , and discharged through line 13. The system works as follows: simulate, ohm. . When the system is turned on, the medium from line 6 is supplied through pipelines 3 through the fully open stop valve 4 to the most metal-intensive massive flange area - the front foot 9 of cylinder 2. Jumpers 8 provide efficient heating of the steam supply zone 10 most hot medium. passes not only along the lower part 5, but also enters the annular channels between the needles 11 and cylinder 2, intensively heating the stud, reducing the temperature difference between the flange and the stud, which is the leading difference between Using such a heating system. The efficiency of heating in the front pawl 9 is determined, in particular, by the fact that jumpers 8 allow the flow of the heating medium to rotate, exclude the formation of a stagnant dead-end zone at the end of the lower leg at the front paw 9, which to a greater or lesser extent all known heating systems. This, in particular, allows a switch from a two-flow to a simpler, more convenient, reliable and more economical single-flow heating circuit. In the area of the forepaw 9, the width of the flanges may be 1.5-1.7 times larger than in the frontal zone, where operational control is usually performed. Due to the effective heating of the most massive, thick-walled part of the cylinder, the limitations on the loading rate of the power unit imposed by the warm-up condition of the cylinder are lifted, its life is increased and the distortion of the connector and bores is reduced. The invention The heating system of the flange connection of the cylinder of a steam turbine with legs, containing a jumper with bridges and a supply line for heating its steam, connected between the low and the steam supply line to the turbine, equipped with a regulator, characterized in that, in order to increase maneuverability and reliability, the heating steam supply pipe is connected to the steam supply line to the turbine after the regulator and to the lower side of the front foot, and jumpers are installed at the point where the pipeline is connected to the low side for Elena from zony.podvoda last couple facing the front paw. Sources of information taken into account in the examination 1. The author's certificate of the USSR 273213, cl. F 01 D 25/10, 1968. 2. Authors certificate of the USSR And 560393, cl. P 01 D 25/10, 1975. .l 2 s ten Pui.J