Shaft seal mother pipe cooling device and low-pressure cylinder shaft seal device

Abstract

The utility model belongs to the technical field of shaft seal mother pipe cooling of steam turbines, and relates to a shaft seal mother pipe cooling device and a low-pressure cylinder shaft seal device. The first spray head is mounted on the main temperature reduction side of the shaft seal mother pipe; the second spray head is mounted on the auxiliary temperature reduction side of the shaft seal main pipe; the desuperheating water supply pipeline is communicated with the first nozzle and the second nozzle; according to the utility model, the first nozzle is arranged on the main temperature reduction side of the shaft seal mother pipe, the second nozzle is arranged on the auxiliary temperature reduction side of the shaft seal mother pipe, and the temperature reduction water sprayed by the second nozzle and the temperature reduction water sprayed by the first nozzle are convected and mixed in the central area of the shaft seal mother pipe; the desuperheating water sprayed by the first nozzle and the second nozzle is prevented from directly impacting the pipe wall of the shaft seal mother pipe, so that the temperature distribution of the pipe wall of the shaft seal mother pipe is uniform, local thermal stress concentration generated by the pipe wall of the shaft seal mother pipe is inhibited or eliminated, the shaft seal mother pipe is not easy to crack, and the service life of the shaft seal mother pipe is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of cooling the temperature of a shaft seal mother pipe of a steam turbine, in particular to a shaft seal mother pipe cooling device and a low-pressure cylinder shaft seal device. Background Art

[0002] The low-pressure cylinder is an important component of the steam turbine and is responsible for converting steam from thermal energy to mechanical energy; the shaft seal device is a key sealing device of the low-pressure cylinder. Steam is transported to the shaft seal device through an external shaft seal mother pipe for sealing, preventing outside air from entering the low-pressure cylinder or steam leakage inside the low-pressure cylinder; the shaft seal mother pipe temperature reduction device is used to control the steam transported to the shaft seal device to be within an appropriate temperature range.

[0003] Referring to the patent document with application number 202122256498.6, a steam turbine low-pressure shaft seal cooling device is recorded, including a pressure equalizing box, a pipeline, a cooling water jellyfish pipe, a water-pneumatic regulating valve, a bypass door, a rear shaft seal cooling water filter, a single-nozzle atomizing cooling device, a stop valve, a rear shaft seal and a steam inlet electric door, characterized in that a flute-shaped plug-in cooling device is provided on one side of the single-nozzle atomizing cooling device, and the flute-shaped plug-in cooling device includes a second cooler and a second isolation valve; the single-nozzle atomizing cooling device includes a first cooler and a first isolation valve, and the flute-shaped plug-in cooling device and the single The nozzle atomizing cooling device is installed in parallel; two small holes are provided on the first cooler and the second cooler; stop valves are provided on both sides of the water-pneumatic regulating valve and the rear shaft seal cooling water filter, and bypass doors are provided in parallel on one side of the water-pneumatic regulating valve and the rear shaft seal cooling water filter; under normal circumstances, the first isolation valve is opened, the second isolation valve is closed, and the single nozzle atomizing cooling device is used to cool the shaft seal mother pipe. When the single nozzle atomizing device is blocked, the first isolation valve is closed, the second isolation valve is opened, and the flute-shaped plug-in cooling device is switched to cool the shaft seal mother pipe to ensure the normal operation of the unit.

[0004] It can be seen from this that when a single-nozzle atomizing cooling device is used in the prior art to cool the steam in the shaft seal mother pipe, the cooling water sprayed by the single-nozzle atomizing cooling device directly impacts the wall of the shaft seal mother pipe, so that the area impacted by the cooling water always maintains a low temperature state, the temperature distribution of the wall of the shaft seal mother pipe is uneven, and there is local thermal stress concentration, which can easily cause the shaft seal mother pipe to rupture. Utility Model Content

[0005] In order to solve the technical problems in the background technology that cooling water directly impacts the wall of the shaft seal mother pipe, causing the area impacted by the cooling water to always maintain a low temperature state and the temperature distribution of the shaft seal mother pipe wall is uneven, the utility model provides a shaft seal mother pipe cooling device and a low-pressure cylinder shaft seal device.

[0006] The utility model discloses a shaft seal mother pipe cooling device and a low-pressure cylinder shaft seal device, a first nozzle is arranged on the main cooling side of the shaft seal mother pipe, a second nozzle is arranged on the auxiliary cooling side of the shaft seal mother pipe, and the cooling water sprayed by the second nozzle is convected with the cooling water sprayed by the first nozzle and mixed in the central area of ​​the shaft seal mother pipe, so as to avoid the cooling water sprayed by the first nozzle and the second nozzle directly impacting the pipe wall of the shaft seal mother pipe, so that the temperature distribution of the pipe wall of the shaft seal mother pipe is uniform, the local thermal stress concentration generated by the pipe wall of the shaft seal mother pipe is suppressed or eliminated, the shaft seal mother pipe is not easy to rupture, and the service life of the shaft seal mother pipe is improved.

[0007] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0008] A shaft seal mother pipe cooling device comprises a first nozzle, a second nozzle and a cooling water supply pipeline; the shaft seal mother pipe is placed horizontally, and the side of the shaft seal mother pipe away from the ground is the main cooling side, and the side of the shaft seal mother pipe close to the ground is the auxiliary cooling side; the first nozzle is placed in the tube cavity of the shaft seal mother pipe, and the first nozzle is installed on the main cooling side of the shaft seal mother pipe; the second nozzle is placed in the tube cavity of the shaft seal mother pipe, and the second nozzle is installed on the auxiliary cooling side of the shaft seal mother pipe, the cooling water sprayed by the second nozzle is convected with the cooling water sprayed by the first nozzle and mixed in the central area of ​​the shaft seal mother pipe; the cooling water supply pipeline passes through the tube wall of the shaft seal mother pipe and extends into the tube cavity of the shaft seal mother pipe to communicate with both the first nozzle and the second nozzle.

[0009] In a specific feasible implementation scheme, a plurality of the first nozzles are provided, and the plurality of first nozzles are all provided on the main cooling side of the shaft seal mother pipe, and the plurality of first nozzles are linearly distributed along the axial direction of the shaft seal mother pipe, and each first nozzle is connected to the cooling water supply pipeline; a plurality of the second nozzles are provided, and the plurality of second nozzles are all provided on the secondary cooling side of the shaft seal mother pipe, and the plurality of second nozzles are linearly distributed along the axial direction of the shaft seal mother pipe, and each second nozzle is connected to the cooling water supply pipeline, and the plurality of second nozzles correspond one-to-one to the plurality of first nozzles.

[0010] In a specific embodiment, the diameter of the first nozzle is larger than the diameter of the second nozzle.

[0011] In a specific feasible implementation scheme, the cooling water supply pipeline includes a main water supply pipeline and a main water supply pipeline; the main water supply pipeline is connected to the main water supply pipeline; the main water supply pipeline penetrates the wall of the shaft seal mother pipe and extends into the lumen of the shaft seal mother pipe and is connected to both the first nozzle and the second nozzle.

[0012] In a specific feasible implementation scheme, the cooling water supply pipeline also includes a first side branch pipeline and a second side branch pipeline; the first side branch pipeline and the second side branch pipeline are both connected to the main water supply pipeline; the first side branch pipeline penetrates the wall of the shaft seal mother pipe and extends into the lumen of the shaft seal mother pipe to be connected to the first nozzle; the second side branch pipeline penetrates the wall of the shaft seal mother pipe and extends into the lumen of the shaft seal mother pipe to be connected to the second nozzle.

[0013] In a specific feasible implementation scheme, the cooling water supply pipeline also includes an auxiliary water supply pipeline connected in parallel with the main water supply pipeline; the auxiliary water supply pipeline is connected to the main water supply pipeline for providing backup cooling water, and the auxiliary water supply pipeline is connected to the first nozzle through a first side branch pipeline, and the auxiliary water supply pipeline is connected to the second nozzle through a second side branch pipeline.

[0014] A low-pressure cylinder shaft sealing device is formed based on the shaft sealing mother pipe cooling device mentioned above.

[0015] In a specific possible implementation scheme, the low-pressure cylinder shaft sealing device further includes a shaft sealing mechanism; the shaft sealing mechanism is arranged on the low-pressure cylinder body, and the shaft sealing mechanism is connected to the shaft sealing mother pipe.

[0016] In summary, the utility model includes the following beneficial technical effects:

[0017] 1. The utility model provides a shaft seal mother pipe cooling device, a first nozzle is arranged on the main cooling side of the shaft seal mother pipe, a second nozzle is arranged on the auxiliary cooling side of the shaft seal mother pipe, and the cooling water sprayed by the second nozzle is convected with the cooling water sprayed by the first nozzle and mixed in the central area of ​​the shaft seal mother pipe, so as to avoid the cooling water sprayed by the first nozzle and the second nozzle directly impacting the tube wall of the shaft seal mother pipe, so that the temperature distribution of the tube wall of the shaft seal mother pipe is uniform, the local thermal stress concentration generated by the tube wall of the shaft seal mother pipe is suppressed or eliminated, the shaft seal mother pipe is not easy to rupture, and the service life of the shaft seal mother pipe is improved.

[0018] 2. The shaft seal mother pipe cooling device of the utility model is provided with a plurality of first nozzles and a plurality of second nozzles along the axial direction of the shaft seal mother pipe, and the plurality of second nozzles correspond one to one to the plurality of first nozzles, so as to facilitate comprehensive cooling of the tube wall of the shaft seal mother pipe along the axial direction of the shaft seal mother pipe, so that the temperature distribution of the tube wall of the shaft seal mother pipe is more uniform, and the service life of the shaft seal mother pipe is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the shaft seal mother pipe cooling device of the utility model.

[0020] Figure 2 It is a partial schematic diagram of the shaft seal mother pipe cooling device of the utility model, and is intended to illustrate the first nozzle and the second nozzle.

[0021] Figure 3It is a partial schematic diagram of the shaft seal mother pipe cooling device of the utility model, and is intended to illustrate the first side branch pipeline and the second side branch pipeline.

[0022] Figure 4 It is a partial schematic diagram of the shaft seal mother pipe cooling device of the utility model, and is intended to illustrate the first side branch pipeline and the second side branch pipeline.

[0023] Explanation of the reference numerals: 1. first nozzle; 2. second nozzle; 3. cooling water supply pipeline; 31. main water supply pipeline; 32. main water supply pipeline; 33. first branch pipeline; 34. second branch pipeline; 35. auxiliary water supply pipeline; 4. shaft seal mother pipe. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further explained below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the implementation methods described below.

[0025] Reference Figure 1 and Figure 2 A shaft seal mother pipe cooling device comprises a first nozzle 1, a second nozzle 2 and a cooling water supply pipe 3. The shaft seal mother pipe 4 is placed horizontally, and the side of the shaft seal mother pipe 4 away from the ground is the main cooling side, and the side of the shaft seal mother pipe 4 close to the ground is the auxiliary cooling side; the first nozzle 1 is placed in the tube cavity of the shaft seal mother pipe 4, and the first nozzle 1 is installed on the main cooling side of the shaft seal mother pipe 4; the second nozzle 2 is placed in the tube cavity of the shaft seal mother pipe 4, and the second nozzle 2 is installed on the auxiliary cooling side of the shaft seal mother pipe 4, and the cooling water sprayed by the second nozzle 2 is convected with the cooling water sprayed by the first nozzle 1 and mixed in the central area of ​​the shaft seal mother pipe 4; the cooling water supply pipe 3 penetrates the tube wall of the shaft seal mother pipe 4 and extends into the tube cavity of the shaft seal mother pipe 4 to communicate with the first nozzle 1 and the second nozzle 2, and the first nozzle 1 is connected in parallel with the second nozzle 2. Specifically, a centrifugal pump is connected to the shaft seal mother pipe 4 , so that the cooling water in the shaft seal mother pipe 4 flows along the axial direction of the shaft seal mother pipe 4 .

[0026] There are multiple first nozzles 1, all of which are arranged on the main cooling side of the shaft seal mother pipe 4, and the multiple first nozzles 1 are linearly distributed along the axial direction of the shaft seal mother pipe 4, and each first nozzle 1 is connected to the cooling water supply pipeline 3; there are multiple second nozzles 2, all of which are arranged on the secondary cooling side of the shaft seal mother pipe 4, and the multiple second nozzles 2 are linearly distributed along the axial direction of the shaft seal mother pipe 4, and each second nozzle 2 is connected to the cooling water supply pipeline 3, and the multiple second nozzles 2 correspond to the multiple first nozzles 1 one by one. Specifically, there is no specific requirement for the number of the first nozzles 1 and the second nozzles 2, and any setting method that provides a sufficient amount of cooling water to the shaft seal mother pipe 4 by setting an appropriate number of first nozzles 1 and second nozzles 2 is acceptable.

[0027] The desuperheating water supply pipeline 3 includes a main water supply pipeline 31 and a main water supply pipeline 32. The main water supply pipeline 31 is connected to the main water supply pipeline 32; the main water supply pipeline 32 penetrates the wall of the shaft seal mother pipe 4 and extends into the lumen of the shaft seal mother pipe 4 to communicate with the first nozzle 1 and the second nozzle 2. Specifically, the main water supply pipeline 31 and the main water supply pipeline 32 are both connected with valves for controlling the circulation of desuperheating water.

[0028] Reference Figure 1 and Figure 3 A low-pressure cylinder shaft sealing device is formed based on a shaft sealing mother pipe cooling device. The shaft sealing mother pipe cooling device cools the steam in the shaft sealing mother pipe 4. The cooled steam enters the shaft sealing mechanism along the tube cavity of the shaft sealing mother pipe 4, so that the temperature of the steam delivered to the low-pressure cylinder shaft sealing device is between 122°C and 177°C, thereby ensuring the sealing performance of the low-pressure cylinder shaft sealing device.

[0029] Example 1

[0030] Reference Figure 1 and Figure 2 , a shaft seal mother pipe cooling device, the diameter of the first nozzle 1 is larger than the diameter of the second nozzle 2. The first nozzle 1 is located on the main cooling side, and the second nozzle 2 is located on the auxiliary cooling side. The steam temperature on the main cooling side is higher than the steam temperature on the auxiliary cooling side. The first nozzle 1 has a larger diameter, which is convenient for spraying more cooling water on the main cooling side of the shaft seal mother pipe 4, improving the mixing rate of steam and cooling water on the main cooling side of the shaft seal mother pipe 4, and ensuring that the steam on the main cooling side of the shaft seal mother pipe 4 is adjusted to a suitable range.

[0031] Example 2

[0032] Reference Figure 1 and Figure 4 In the shaft seal mother pipe cooling device of this embodiment, the cooling water supply pipeline 3 also includes a first side branch pipeline 33 and a second side branch pipeline 34. The first side branch pipeline 33 and the second side branch pipeline 34 are both connected to the main water supply pipeline 32; the first side branch pipeline 33 penetrates the wall of the shaft seal mother pipe 4 and extends to the lumen of the shaft seal mother pipe 4 to communicate with the first nozzle 1; the second side branch pipeline 34 penetrates the wall of the shaft seal mother pipe 4 and extends to the lumen of the shaft seal mother pipe 4 to communicate with the second nozzle 2. The first side branch pipeline 33 and the second side branch pipeline 34 are both connected with valves for controlling the circulation of cooling water.

[0033] Example 3

[0034] Reference Figure 1In the cooling device for the shaft seal mother pipe of this embodiment, the cooling water supply pipeline 3 also includes an auxiliary water supply pipeline 35 connected in parallel with the main water supply pipeline 32. The auxiliary water supply pipeline 35 is connected to the main water supply pipeline 31 to provide standby cooling water, and the auxiliary water supply pipeline 35 is connected to the first nozzle 1 through the first side branch pipeline 33, and the auxiliary water supply pipeline 35 is connected to the second nozzle 2 through the second side branch pipeline 34. A valve for controlling the circulation of cooling water is connected to the auxiliary water supply pipeline 35. When the main water supply pipeline 32 needs maintenance or fails, the auxiliary water supply pipeline 35 provides cooling water to the first nozzle 1 through the first side branch pipeline 33 and provides cooling water to the second nozzle 2 through the second side branch pipeline 34, so as to ensure the normal operation of the cooling device for the shaft seal mother pipe.

[0035] Example 4

[0036] Reference Figure 1 and Figure 4 , a low-pressure cylinder shaft sealing device, further comprising a shaft sealing mechanism. The shaft sealing mechanism is arranged on the low-pressure cylinder body, and the shaft sealing mechanism is connected to the shaft sealing mother pipe 4. Specifically, a rotor is installed inside the low-pressure cylinder body, and the two ends of the rotor are respectively connected to the two ends of the low-pressure cylinder body through bearings, the shaft sealing mechanism is connected to the inner wall of the low-pressure cylinder body, and the shaft sealing mechanism is distributed in an annular shape along the radial direction of the rotor, there is a gap between the shaft sealing mechanism and the rotor, and the gap between the shaft sealing mechanism and the rotor together constitutes a shaft sealing area, and the shaft sealing mother pipe 4 provides steam to the shaft sealing area, and the steam provided forms a steam barrier in the shaft sealing area to achieve shaft sealing of the low-pressure cylinder.

[0037] The present embodiment provides a low-pressure cylinder shaft sealing method, comprising the following steps:

[0038] S1. Install the low-pressure cylinder shaft sealing device mentioned above;

[0039] S2. The appropriate range of steam temperature delivered to the shaft seal mechanism is 122°C to 177°C. The standard temperature of steam in the shaft seal mother pipe 4 is 158°C. Different steam cooling methods are selected according to the temperature of steam in the shaft seal mother pipe.

[0040] When the temperature of the steam in the shaft seal mother pipe 4 is higher than 185°C, which is greatly different from the standard temperature of 158°C, the required cooling range of the steam in the shaft seal mother pipe 4 is large, and the first nozzle 1 and the second nozzle 2 are opened at the same time. On the main cooling side of the shaft seal mother pipe 4, the steam in the shaft seal mother pipe 4 is mixed with the cooling water provided by the first nozzle 1 and the second nozzle 2 to form cooled steam, so as to cool the steam so that the temperature of the steam flowing to the shaft seal mechanism is between 122°C and 177°C.

[0041] When the temperature of the steam in the shaft seal mother pipe 4 is between 122°C and 153°C or between 163°C and 185°C, which is greatly different from the standard temperature of 158°C, the required cooling range of the steam in the shaft seal mother pipe 4 is large, the first nozzle 1 is opened, and the second nozzle 2 is closed. On the main cooling side of the shaft seal mother pipe 4, the first nozzle 1 provides a large amount of cooling water, and the steam in the shaft seal mother pipe 4 and the cooling water provided by the first nozzle 1 are mixed to form cooled steam, so as to achieve the cooling of the steam, so that the temperature of the steam flowing to the shaft seal mechanism is between 122°C and 177°C;

[0042] When the temperature is between 153°C and 163°C, which is close to the standard temperature of 158°C, the required cooling range of the steam in the shaft seal mother pipe 4 is small, the first nozzle 1 is closed, and the second nozzle 2 is opened. On the auxiliary cooling side of the shaft seal mother pipe 4, the second nozzle 2 provides a small amount of cooling water. The steam in the shaft seal mother pipe 4 and the cooling water provided by the second nozzle 2 are mixed to form cooled steam, so that the temperature of the steam flowing to the shaft seal mechanism is between 122°C and 177°C.

[0043] S4. The steam after cooling enters the shaft sealing mechanism along the tube cavity of the shaft sealing mother pipe 4 and forms a steam barrier in the shaft sealing area to realize the shaft sealing of the low-pressure cylinder.

[0044] The above are all preferred embodiments of the present utility model, and are not intended to limit the protection scope of the present utility model. Therefore, any equivalent changes made based on the structure, shape, and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A shaft seal mother pipe cooling device, characterized in that: It comprises a first nozzle (1), a second nozzle (2) and a cooling water supply pipeline (3); The shaft seal mother pipe (4) is placed horizontally, and the side of the shaft seal mother pipe (4) away from the ground is the main cooling side, and the side of the shaft seal mother pipe (4) close to the ground is the auxiliary cooling side; The first nozzle (1) is placed in the tube cavity of the shaft seal mother pipe (4), and the first nozzle (1) is installed on the main temperature reduction side of the shaft seal mother pipe (4); The second nozzle (2) is placed in the tube cavity of the shaft seal mother pipe (4), and the second nozzle (2) is installed on the auxiliary cooling side of the shaft seal mother pipe (4), and the cooling water sprayed by the second nozzle (2) and the cooling water sprayed by the first nozzle (1) are convective and mixed in the central area of ​​the shaft seal mother pipe (4); The desuperheated water supply pipeline (3) penetrates the wall of the shaft seal mother pipe (4) and extends into the lumen of the shaft seal mother pipe (4) to communicate with both the first nozzle (1) and the second nozzle (2).

2. The shaft seal mother pipe cooling device according to claim 1, characterized in that: A plurality of the first nozzles (1) are provided, and the plurality of first nozzles (1) are all provided on the main cooling side of the shaft seal mother pipe (4), and the plurality of first nozzles (1) are distributed in a straight line along the axial direction of the shaft seal mother pipe (4), and each first nozzle (1) is connected to the cooling water supply pipeline (3); A plurality of the second nozzles (2) are provided, and the plurality of second nozzles (2) are all provided on the auxiliary cooling side of the shaft seal mother pipe (4), and the plurality of second nozzles (2) are distributed in a straight line along the axial direction of the shaft seal mother pipe (4), and each second nozzle (2) is connected to the cooling water supply pipeline (3), and the plurality of second nozzles (2) correspond one-to-one to the plurality of first nozzles (1).

3. The shaft seal mother pipe cooling device according to claim 1, characterized in that: The diameter of the first nozzle (1) is greater than the diameter of the second nozzle (2).

4. The shaft seal mother pipe cooling device according to claim 1, characterized in that: The desuperheated water supply pipeline (3) comprises a main water supply pipeline (31) and a main water supply pipeline (32); The main water supply pipeline (31) is in communication with the main water supply pipeline (32); The main water supply pipe (32) penetrates the wall of the shaft seal mother pipe (4) and extends into the lumen of the shaft seal mother pipe (4) to communicate with both the first nozzle (1) and the second nozzle (2).

5. The shaft seal mother pipe cooling device according to claim 4 is characterized in that: The desuperheated water supply pipeline (3) further comprises a first side branch pipeline (33) and a second side branch pipeline (34); The first side branch pipeline (33) and the second side branch pipeline (34) are both in communication with the main water supply pipeline (32); The first branch pipe (33) penetrates the wall of the shaft seal mother pipe (4) and extends into the lumen of the shaft seal mother pipe (4) to communicate with the first nozzle (1); The second branch pipe (34) penetrates the wall of the shaft seal mother pipe (4) and extends into the lumen of the shaft seal mother pipe (4) to communicate with the second nozzle (2).

6. The shaft seal mother pipe cooling device according to claim 5, characterized in that: The desuperheated water supply pipeline (3) further comprises a secondary water supply pipeline (35) connected in parallel with the main water supply pipeline (32); The auxiliary water supply pipe (35) is connected to the main water supply pipe (31) and is used to provide standby cooling water. The auxiliary water supply pipe (35) is connected to the first nozzle (1) through a first branch pipe (33), and the auxiliary water supply pipe (35) is connected to the second nozzle (2) through a second branch pipe (34).

7. A low-pressure cylinder shaft sealing device formed based on the shaft sealing mother pipe cooling device according to any one of claims 1 to 6.

8. The low-pressure cylinder shaft sealing device according to claim 7, characterized in that: The low-pressure cylinder shaft sealing device also includes a shaft sealing mechanism; The shaft sealing mechanism is arranged on the low-pressure cylinder body, and the shaft sealing mechanism is connected to the shaft sealing mother pipe (4).

Images