CN218624343U - Shaft seal heat regenerative system of million ultra-supercritical unit - Google Patents

Abstract

The utility model belongs to the technical field of steam turbines, and discloses a million ultra supercritical unit shaft seal heat recovery system, which comprises an auxiliary steam header, and an ultra high pressure cylinder, a medium pressure cylinder, a low pressure cylinder A and a low pressure cylinder B which are connected in sequence; the steam at the outlet of the auxiliary steam header is connected with a main shaft seal steam supply pipe, and the steam inlet sides of the shaft seals of the ultrahigh pressure cylinder, the high pressure cylinder, the intermediate pressure cylinder, the low pressure cylinder A and the low pressure cylinder B are connected with the main shaft seal steam supply pipe; shaft seal exhaust steam of the ultrahigh pressure cylinder is respectively discharged into the high pressure cylinder exhaust steam, the medium and low pressure communicating pipe and the shaft seal heater through three exhaust steam pipelines; shaft seal exhaust steam of the high-pressure cylinder is respectively exhausted into the medium-low pressure communicating pipe and the shaft seal heater through two exhaust steam pipelines; and shaft seal steam of the intermediate pressure cylinder and the two low pressure cylinders is exhausted to the shaft seal heater. The utility model discloses carry out classification to bearing seal steam exhaust and handle respectively, cause different systems to carry out the work with superhigh pressure, high-pressure cylinder shaft seal exhaust according to the pressure height, improve the utilization efficiency of bearing seal exhaust.

Description

Shaft seal heat regenerative system of million ultra-supercritical unit

Technical Field

The utility model belongs to the technical field of the steam turbine, more specifically relates to a million ultra supercritical unit bearing seal backheating system.

Background

In order to prevent steam from leaking out of the cylinder and air from leaking into the cylinder, the steam turbine must be provided with a shaft seal system which consists of a shaft seal steam supply system and a shaft seal steam extraction system. The shaft seal steam supply system introduces sealing steam with pressure higher than atmospheric pressure into the shaft seal to prevent air from leaking into the cylinder; the shaft seal steam extraction system establishes a steam chamber with the pressure lower than the atmospheric pressure in the shaft seal, extracts the shaft seal leakage and prevents steam from leaking out of the cylinder.

In the prior art, the source of steam supplied by the shaft seal is auxiliary steam and secondary reheating cold section steam, a steam heater is used for controlling the temperature of the shaft seal steam in the starting stage of the unit so as to prevent a steam turbine rotor from being locked, the returned steam of the shaft seal generally and directly returns to the shaft seal heater to heat condensed water and recover clean water while recovering a heat value, and the unit efficiency is improved.

The ultra-supercritical million units cause shaft seal steam to leak out easily due to high parameters such as unit operating temperature and pressure, namely the steam in a cylinder leaks out towards a shaft seal, normal shaft seal return steam returns to a shaft seal heater through a pipeline, the leakage is caused easily due to overlarge return steam pressure, the temperature at the shaft seal of equipment is overhigh, damage is caused to thermal control protection vibration and a rotating speed measuring point, the unit is easy to trip, and unnecessary heat source loss is caused by the leakage of the steam with high parameters (temperature and pressure) to the shaft seal heater and the leakage.

SUMMERY OF THE UTILITY MODEL

The be not enough to prior art, the utility model provides a million ultra supercritical unit bearing seal backheat system according to exhaust pressure, the temperature of ultrahigh pressure jar and high-pressure jar, causes the bearing seal steam exhaust different systems and carries out the acting, has solved steam turbine bearing seal temperature height, has leaked the problem outward, has improved the utilization efficiency of bearing seal steam exhaust.

In order to achieve the above purpose, the utility model discloses a following technical scheme realizes: a shaft seal regenerative system of a million ultra supercritical unit comprises an auxiliary steam header, and an ultra high pressure cylinder, a medium pressure cylinder, a low pressure cylinder A and a low pressure cylinder B which are sequentially connected; the steam at the outlet of the auxiliary steam header is connected with a main shaft seal steam supply pipe, and the steam inlet sides of the shaft seals of the ultrahigh pressure cylinder, the high pressure cylinder, the intermediate pressure cylinder, the low pressure cylinder A and the low pressure cylinder B are connected with the main shaft seal steam supply pipe; the shaft seal steam exhaust of the ultrahigh pressure cylinder is respectively connected with the high pressure cylinder steam exhaust, the middle and low pressure communicating pipe and the shaft seal steam return main pipe through three steam exhaust pipelines; the shaft seal steam exhaust of the high-pressure cylinder is respectively connected with the middle-low pressure communicating pipe and the shaft seal steam return main pipe through two steam exhaust pipelines; the shaft seal steam exhaust of the intermediate pressure cylinder, the low pressure cylinder A and the low pressure cylinder B is respectively connected with a shaft seal steam return main pipe through respective steam exhaust pipelines; the shaft seal steam return main pipe is connected with the shaft seal heater.

In some embodiments of the present application, the outlet steam of the auxiliary steam header is connected with a steam supply main pipe of the shaft seal through a steam adjusting pipeline.

In some embodiments of the present application, a shaft seal steam heater and a first pressure regulating valve are sequentially disposed on a steam regulating pipeline, the steam regulating pipeline is provided with a steam regulating bypass and a steam heating bypass, the steam heating bypass is connected in parallel with the steam heater, and the steam regulating bypass is connected in parallel with the first pressure regulating valve.

In some embodiments of the present application, a first electric valve and a first manual valve are respectively disposed in front of and behind the shaft seal steam heater, and a second manual valve is disposed on both sides of the first pressure regulating valve; and a second electric valve is arranged on the steam heating bypass, and a bypass regulating valve is arranged on the steam regulating bypass.

In some embodiments of the present application, the shaft seal steam supply main pipe, the steam adjusting pipeline, the steam adjusting bypass and the steam heating bypass are all provided with a drain pipe.

In some embodiments of the present application, manual butterfly valves are disposed on the steam exhaust pipes of the ultrahigh pressure cylinder, the high pressure cylinder, the intermediate pressure cylinder, the low pressure cylinder a and the low pressure cylinder B to the shaft seal steam return main pipe.

In some embodiments of the application, one path of desuperheating water for cooling steam in the steam main pipe is connected to the side, close to the low-pressure cylinder, of the shaft seal steam supply main pipe, a second pressure regulating valve is arranged on the desuperheating water pipeline, and a manual vacuum stop valve and a third manual valve are respectively arranged at the front and the rear of the second pressure regulating valve.

In some embodiments of the present application, an overflow pipe is disposed on the shaft seal steam supply main pipe, the overflow pipe is connected to the condenser and the low pressure heater through a pipeline, a third pressure regulating valve is disposed on the overflow pipe, and fourth manual valves are disposed before and after the third pressure regulating valve.

The utility model discloses a set up 3 ways with super high pressure cylinder bearing seal steam extraction, arrange respectively to high pressure cylinder steam extraction, well low pressure communicating pipe, bearing seal heater, set up 2 ways with high pressure cylinder steam extraction, arrange respectively to well low pressure communicating pipe, bearing seal heater, the shaft seal steam extraction of shaft seal is classified and is handled respectively, does work with super high pressure, the bearing seal steam extraction of high pressure cylinder according to the pressure height to the system of difference, has avoided causing the outer hourglass to cause the trouble because of vapor return pressure is too big easily, has improved steam utilization efficiency moreover.

Drawings

Fig. 1 is a schematic structural diagram of the shaft seal regenerative system of the million supercritical units of the present invention.

In the figure, 100, an ultrahigh pressure cylinder; 200. a high pressure cylinder; 300. an intermediate pressure cylinder; 400. a low pressure cylinder A; 500. a low pressure cylinder B; 600. a shaft seal heater; 700. an auxiliary steam header; 10. a steam conditioning line; 20. shaft seal steam supply main pipe; 30. shaft sealing a steam return main pipe; 40. a high pressure cylinder exhaust pipe; 50. a middle-low pressure communicating pipe; 60. an overflow pipe; 70. a temperature-reducing water pipe; 80. a steam heating bypass; 90. a steam conditioning bypass; 1. a shaft seal steam heater; 2. a first electrically operated valve; 3. a first manual valve; 5. a second manual valve; 6. a first pressure regulating valve; 8. a second electrically operated valve; 9. A bypass regulating valve; 11. a third pressure regulating valve; 12. a fourth manual valve; 13. a second pressure regulating valve; 14. a third manual valve; 15. a manual vacuum stop valve; 16. a manual butterfly valve; .

Detailed Description

The following detailed description of the present invention will be made with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it should be noted that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in this application will be understood to be a specific case for those of ordinary skill in the art.

As shown in fig. 1, in some embodiments of the present application, a shaft seal regenerative system for a million supercritical unit includes an auxiliary steam header 700, and an ultrahigh pressure cylinder 100, a high pressure cylinder 200, an intermediate pressure cylinder 300, a low pressure cylinder a400, and a low pressure cylinder B500, which are connected in sequence, where outlet steam of the auxiliary steam header 700 is connected to a shaft seal steam supply main pipe 20 through a steam adjusting pipeline 10, and shaft seal steam inlet sides of the ultrahigh pressure cylinder 100, the high pressure cylinder 200, the intermediate pressure cylinder 300, the low pressure cylinder a400, and the low pressure cylinder B500 are all supplied with steam by the shaft seal steam supply main pipe 20.

After the steam is sealed in the shaft seal cavity, the steam is discharged from the innermost shaft seal of the ultra-high pressure cylinder 100 with the highest pressure and the highest temperature, is discharged to the steam discharge pipe 40 of the high pressure cylinder through the steam discharge pipeline, enters the boiler again through the secondary reheating cold section pipeline for heating, and then becomes secondary reheating main steam which enters the intermediate pressure cylinder for applying work, in order to prevent the steam discharged from the high pressure cylinder from flowing backwards to enter the shaft seal, a check valve is arranged in the steam discharge pipe 40 of the high pressure cylinder, the steam discharged from the middle shaft seal is slightly lower than the steam discharged from the inner shaft seal and slightly lower in temperature, is introduced into the intermediate and low pressure communicating pipe through the steam discharge pipeline, enters the low pressure cylinder and pushes the rotor of the low pressure cylinder to apply work together with the steam discharged from the intermediate pressure cylinder 300, the steam discharged from the shaft seal at the outermost side is lowest in pressure and temperature, and is discharged to the steam return main pipe 30 through the steam discharge pipeline; shaft seal exhaust steam of the high-pressure cylinder 200 is respectively exhausted to the middle-low pressure communicating pipe 50 and the shaft seal steam return main pipe 30 through two exhaust steam pipelines according to the pressure; shaft seal exhaust steam of the intermediate pressure cylinder 300, the low pressure cylinder A400 and the low pressure cylinder B500 is exhausted to the shaft seal steam return main pipe 30 through an exhaust steam pipeline, and steam of the shaft seal steam return main pipe 30 returns to the shaft seal heater 600. Through classifying and processing the shaft seal steam exhaust of the ultrahigh pressure cylinder 100 and the high pressure cylinder 200, the steam is exhausted to different systems according to the pressure, so that the fault caused by leakage due to overlarge steam return pressure can be avoided, and the steam utilization efficiency is improved.

Specifically, the origin of the auxiliary steam header 700 is from a No. 3 machine auxiliary steam header, a steam adjusting pipeline 10 comprises a steam heating main path and a steam adjusting main path, a shaft seal steam heater 1 is arranged on the steam heating main path, a first electric valve 2 and a first manual valve 3 are respectively arranged in front of and behind the shaft seal steam heater 1, the steam heating main path is provided with a parallel steam heating bypass 80, the shaft seal steam heater 1 is used for heating the shaft seal steam temperature (the shaft seal steam temperature in the startup stage is low and needs to be heated to prevent the steam turbine rotor from locking), when the shaft seal steam heater 1 does not need to be used, the steam heating bypass 80 can be connected in parallel to enter the steam adjusting pipeline 10, and a second electric valve 8 is arranged on the steam heating bypass 80; be provided with first pressure regulating valve 6 on the steam regulation main road, all be provided with the manual valve 5 of second around first pressure regulating valve 6, the steam regulation main road is provided with parallelly connected steam regulation bypass 90, and when the steam regulation main road broke down, the parallelly connected steam regulation bypass 90 of accessible was adjusted, is provided with bypass control valve 9 on the steam regulation bypass 90.

Specifically, in order to prevent water in shaft seal steam from entering the cylinder shaft seal, drain pipelines are arranged on the shaft seal steam supply main pipe 20, the steam heating main pipe, the steam adjusting main pipe, the steam heating bypass 80 and the steam adjusting bypass 90, a drain manual valve stop valve is arranged on the drain pipelines, drainage is needed in the starting process of the unit, and the normal running state is a normally closed state.

Specifically, in order to ensure that the pressure of the shaft seal steam pipeline does not exceed a designed value, an overflow pipe 60 is arranged on the shaft seal steam supply main pipe 20, a third pressure regulating valve 11 is arranged on the overflow pipe 60, fourth manual valves 12 are arranged at the front and the rear of the third pressure regulating valve 11, and when the shaft seal pressure is too high, the shaft seal steam is overflowed to a low-pressure heater and a condenser through the overflow pipe 60.

Specifically, because the internal temperature of the low-pressure cylinder is low, the corresponding shaft seal steam temperature is also reduced, a temperature reduction water pipe 70 is arranged in a shaft seal supply pipeline of the low-pressure cylinder, a second pressure regulating valve 13 is arranged on the temperature reduction water pipe 70, and a manual vacuum stop valve 15 and a third manual valve 14 are respectively arranged at the front and the rear of the second pressure regulating valve 13, and enter the low-pressure cylinder after the steam is subjected to temperature reduction through condensed water.

Specifically, the manual butterfly valves 16 are arranged on steam exhaust pipelines from the ultrahigh pressure cylinder 100, the high pressure cylinder 200, the intermediate pressure cylinder 300, the low pressure cylinder a400 and the low pressure cylinder B500 to the shaft seal steam return main pipe 30, and are used for adjusting steam return amount to prevent shaft seal steam from leaking outwards.

To sum up, the utility model provides a million ultra supercritical unit bearing seal backheat system, the steam of assisting vapour header 700 gets into the bearing seal after 1 heating of bearing seal steam heater and 6 regulation pressure of first pressure regulating valve and supplies the female pipe 20 of vapour, supply the female pipe of vapour to ultra-high pressure cylinder 100 respectively, high-pressure cylinder 200, intermediate pressure cylinder 300, the steam is supplied to the steam inlet side of low-pressure cylinder A400 and low-pressure cylinder B500, steam is after the bearing seal cavity accomplishes the seal, the bearing seal steam discharge of ultra-high pressure cylinder 100 is arranged to high-pressure cylinder steam discharge pipe 40 respectively through three steam discharge pipeline according to the steam pressure size, well low pressure communicating pipe 50, the female pipe 30 of bearing seal, the bearing seal steam discharge of high-pressure cylinder 200 is arranged to well low pressure communicating pipe 50 respectively through two steam discharge pipelines, the female pipe 30 of gland seal, the intermediate pressure cylinder 300, the bearing seal steam discharge of low-pressure cylinder A400 and low-pressure cylinder B500 is arranged to the female pipe 30 of gland seal steam return respectively through respective steam discharge pipeline, the steam in the female pipe 30 of return gets back to the heater 600. The utility model discloses a system has effectively reduced that ultrahigh pressure cylinder bearing seal steam leaks outward and carries out hierarchical processing to bearing seal steam backsteam, has improved the utilization ratio of bearing seal steam extraction.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and replacements can be made without departing from the technical principle of the present invention, and these modifications and replacements should also be regarded as the protection scope of the present invention.

Claims (8)

1. A shaft seal regenerative system of a million ultra supercritical unit is characterized by comprising an auxiliary steam header (700), and an ultra high pressure cylinder (100), a high pressure cylinder (200), an intermediate pressure cylinder (300), a low pressure cylinder A (400) and a low pressure cylinder B (500) which are sequentially connected; steam at an outlet of the auxiliary steam header (700) is connected with a main shaft seal steam supply pipe (20), and shaft seal steam inlet sides of the ultrahigh pressure cylinder (100), the high pressure cylinder (200), the intermediate pressure cylinder (300), the low pressure cylinder A (400) and the low pressure cylinder B (500) are connected with the main shaft seal steam supply pipe (20); the shaft seal steam exhaust of the ultrahigh pressure cylinder (100) is respectively connected with the high pressure cylinder steam exhaust pipe (40), the middle and low pressure communicating pipe (50) and the shaft seal steam return main pipe (30) through three steam exhaust pipelines; the shaft seal steam exhaust of the high-pressure cylinder (200) is respectively connected with the middle-low pressure communicating pipe (50) and the shaft seal steam return main pipe (30) through two steam exhaust pipelines; shaft seal steam exhaust of the intermediate pressure cylinder (300), the low pressure cylinder A (400) and the low pressure cylinder B (500) are respectively connected with a shaft seal steam return main pipe (30) through respective steam exhaust pipelines; the shaft seal steam return main pipe (30) is connected with the shaft seal heater (600).

2. The shaft seal regenerative system of the million ultra supercritical units according to claim 1, characterized in that the steam at the outlet of the auxiliary steam header (700) is connected to the main shaft seal steam supply pipe (20) through a steam adjusting pipeline (10).

3. The shaft seal heat recovery system of the million supercritical units according to claim 2 is characterized in that a shaft seal steam heater (1) and a first pressure regulating valve (6) are sequentially arranged on a steam regulating pipeline (10), the steam regulating pipeline (10) is provided with a steam regulating bypass (90) and a steam heating bypass (80), the steam heating bypass (80) is connected with the steam heater (1) in parallel, and the steam regulating bypass (90) is connected with the first pressure regulating valve (6) in parallel.

4. The shaft seal heat recovery system of the million supercritical units according to claim 3 is characterized in that a first electric valve (2) and a first manual valve (3) are respectively arranged at the front and the back of the shaft seal steam heater (1), and second manual valves (5) are respectively arranged at both sides of the first pressure regulating valve (6); the steam heating bypass (80) is provided with a second electric valve (8), and the steam adjusting bypass (90) is provided with a bypass adjusting valve (9).

5. The shaft seal heat recovery system of the million supercritical units according to claim 3 is characterized in that the shaft seal steam supply main pipe (20), the steam adjusting pipeline (10), the steam adjusting bypass (90) and the steam heating bypass (80) are all provided with a drain pipeline.

6. The shaft seal regenerative system of the million supercritical units according to claim 1, wherein manual butterfly valves (16) are disposed on the steam exhaust pipes of the ultrahigh pressure cylinder (100), the high pressure cylinder (200), the intermediate pressure cylinder (300), the low pressure cylinder a (400) and the low pressure cylinder B (500) to the shaft seal steam return main pipe (30).

7. The shaft seal heat recovery system of the million supercritical unit according to claim 1, wherein a path of temperature reducing water pipe (70) for reducing the temperature of the steam in the steam main pipe is connected to the side of the shaft seal steam supply main pipe (20) close to the low pressure cylinder, a second pressure regulating valve (13) is arranged on the temperature reducing water pipe (70), and a manual vacuum stop valve (15) and a third manual valve (14) are respectively arranged in front of and behind the second pressure regulating valve (13).

8. The shaft seal heat recovery system of the million supercritical units according to claim 1, wherein an overflow pipe (60) is arranged on the shaft seal steam supply main pipe (20), the overflow pipe (60) is connected with a condenser and a low pressure heater through a pipeline, a third pressure regulating valve (11) is arranged on the overflow pipe (60), and fourth manual valves (12) are arranged at the front and the rear of the third pressure regulating valve (11).

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