Exhaust steam cooling device of steam turbine

Abstract

The utility model belongs to the technical field of cooling devices, and relates to a steam turbine exhaust steam cooling device which comprises a steam turbine exhaust steam pipeline, a cooling header pipe, cooling branch pipes and sprayers. The main cooling pipe is arranged outside the steam exhaust pipeline of the steam turbine, the branch cooling pipes are arranged on the inner wall of the steam exhaust pipeline of the steam turbine, the sprayers are arranged on the branch cooling pipes and located in the steam exhaust pipeline of the steam turbine, the main cooling pipe is communicated with the sprayers through the branch cooling pipes, and the sprayers are used for spraying mist to cool dead steam in the steam exhaust pipeline of the steam turbine. Cooling water is introduced into the steam exhaust pipeline of the steam turbine through the cooling main pipe and the cooling branch pipes, the spray is formed through the spray heads to cool dead steam, the exhaust temperature is low, the efficiency of the steam turbine is improved, the service life of equipment is prolonged, and the maintenance cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the cooling device technical field relates to a steam turbine exhaust steam cooling device. BACKGROUND

[0002] Steam turbine is a kind of steam power equipment commonly used in industrial production, and the working principle is the process that steam is converted into mechanical work in steam turbine. Steam is injected by nozzle, makes blade rotate, and then generates mechanical work. Steam accelerates in nozzle, makes blade rotate, and thus converts heat energy into mechanical energy.

[0003] In the work of steam turbine, the superheated steam with thermal potential is introduced into steam turbine through pipeline, and the thermal potential is converted into kinetic energy, and then the steam discharged from the steam turbine exhaust port is called exhaust steam. The treatment mode of this part of exhaust steam at present stage is sent to air cooling island to condense to form condensate water, and then returned to production system to realize recycling. However, due to the small heat dissipation area of air cooling island blade, and the large exhaust capacity of steam turbine, the temperature of exhaust gas is still high, so that the operation of steam turbine has the following problems, which are as follows:

[0004] (1) steam turbine efficiency is reduced: high exhaust temperature of steam turbine leads to that heat cannot be completely converted into work, heat loss increases, and thus the efficiency of steam turbine is reduced, and power generation capacity is reduced;

[0005] (2) affect the service life of equipment: high temperature leads to that the hub, blade and other components of steam turbine are in high temperature environment for a long time, which is easy to be affected by corrosion, oxidation and the like, and the service life of equipment is shortened;

[0006] (3) increase maintenance cost: due to high exhaust temperature of steam turbine, long period operation shortens the service life of components of steam turbine, and frequent maintenance and replacement increase maintenance cost. INVENTION CONTENTS

[0007] In view of the technical problems that the temperature of exhaust steam of existing steam turbine is still high, which leads to that the efficiency of steam turbine is reduced, the service life of equipment is affected and the maintenance cost is increased, the utility model provides a steam turbine exhaust steam cooling device.

[0008] The utility model discloses a cooling main pipe and cooling branch pipe are introduced to the inside of steam turbine exhaust steam pipeline with cooling water, and the spray head forms the spray to the exhaust steam cooling, and the exhaust temperature is low, and then the efficiency of steam turbine is improved, the service life of equipment is prolonged, and the maintenance cost is reduced.

[0009] In order to realize the above-mentioned purpose, the technical scheme adopted by the utility model is:

[0010] A steam turbine exhaust cooling device, comprising a steam turbine exhaust pipe, a cooling main pipe, a cooling branch pipe and a nozzle; the cooling main pipe is arranged outside the steam turbine exhaust pipe, the cooling branch pipe is arranged on the inner wall of the steam turbine exhaust pipe, the nozzle is arranged on the cooling branch pipe and located in the steam turbine exhaust pipe, the cooling main pipe is communicated with the nozzle through the cooling branch pipe, and the nozzle is used for spraying spray to cool the exhaust steam in the steam turbine exhaust pipe.

[0011] Further limited, the nozzle is one or more, and the multiple nozzles are distributed on the cooling branch pipe.

[0012] Further limited, the cooling branch pipe is a C-shaped pipe, and one end of the C-shaped pipe is communicated with the cooling main pipe.

[0013] Further limited, the cooling branch pipe is one or more, and the multiple cooling branch pipes are distributed along the axial direction of the steam turbine exhaust pipe.

[0014] Further limited, the nozzles on every two cooling branch pipes are staggered.

[0015] Further limited, the steam turbine exhaust cooling device further comprises a cooling water storage tank arranged outside the steam turbine exhaust pipe and communicated with the cooling main pipe.

[0016] Further limited, the steam turbine exhaust pipe is further provided with connecting pipes, the number of the connecting pipes is the same as that of the cooling branch pipes and the connecting pipes are communicated with the cooling branch pipes one by one, and the cooling main pipe is communicated with the cooling branch pipes through the connecting pipes.

[0017] Further limited, the cooling main pipe is provided with a main control valve, and the cooling main pipe is communicated with the connecting pipes through the main control valve.

[0018] Further limited, the connecting pipes are respectively provided with branch pipe control valves and branch pipe flow meters.

[0019] Further limited, the steam turbine exhaust cooling device further comprises temperature sensors arranged on the inlet end of the steam turbine exhaust pipe and the outlet end of the steam turbine exhaust pipe respectively.

[0020] Compared with the prior art, the steam turbine exhaust cooling device has the following beneficial effects:

[0021] 1、in the utility model, through setting up cooling main pipe and cooling branch pipe, cooling water is introduced into the steam turbine exhaust pipe, and spray is formed by the nozzle and sprayed into the steam turbine exhaust pipe, the exhaust steam is cooled in the process of being discharged from the steam turbine exhaust pipe, the exhaust temperature is low, and the temperature meets the temperature requirement of the exhaust steam cooling, so that the steam turbine efficiency is improved, the equipment life is prolonged, and the maintenance cost is reduced.

[0022] 2. The utility model discloses a cooling branch pipe is C-shaped pipe, is easy to install in the steam turbine exhaust pipe, and does not affect the exhaust of the steam, and the spray head is one or more, and multiple spray heads are distributed on the cooling branch pipe, can spray the steam from multiple positions and cool, improve the cooling effect.

[0023] 3. The utility model discloses a plurality of cooling branch pipes, and multiple cooling branch pipes are distributed along the axial direction of the steam turbine exhaust pipe, and the spray heads on every two cooling branch pipes are staggered. Not only realize multistage cooling, and the position point of the spray head is more uniform, reduce the dead angle area of the spray, enhance the cooling effect.

[0024] 4. The utility model discloses that the number of connecting pipes is same with the number of cooling branch pipes and one-to-one correspondence intercommunication, realizes the intercommunication of cooling manifold and multiple cooling branch pipes through connecting pipe, and the connection between pipes is convenient.

[0025] 5. The utility model discloses that the total control valve is set up on the cooling manifold, and the branch pipe control valve and branch pipe flowmeter are set up on the connecting pipe respectively, and the flow of cooling water is convenient to control, makes the cooling water form the mist, reduces the temperature of the exhaust steam while not affecting the exhaust of the steam, and the flow and the switching between branch pipes are convenient to adjust through the valve, and easy operation.

[0026] 6. The utility model discloses that temperature sensor is set up on the steam turbine exhaust pipe import end and the steam turbine exhaust pipe export end respectively, and the flow of cooling water is adjusted through the temperature difference of the steam of import and export, and the cooling effect is improved. DRAWINGS

[0027] Figure 1 The steam turbine exhaust cooling device structure schematic diagram is provided for example 1;

[0028] Figure 2 For Figure 1 The left side schematic diagram in the middle;

[0029] Figure 3 The steam turbine exhaust cooling device structure schematic diagram is provided for example 2;

[0030] Figure 4 The steam turbine exhaust cooling device structure schematic diagram is provided for example 3;

[0031] Figure 5 The steam turbine exhaust cooling device structure schematic diagram is provided for example 4;

[0032] Among them:

[0033] 10 - turbine exhaust pipe; 20 - cooling water storage tank; 30 - cooling main pipe; 40 - cooling branch pipe; 401 - first cooling branch pipe; 402 - second cooling branch pipe; 403 - third cooling branch pipe; 50 - spray head; 501 - first spray head; 502 - second spray head; 503 - third spray head; 60 - main control valve; 70 - first branch pipe control valve; 80 - first branch pipe flow meter; 90 - second branch pipe control valve; 100 - second branch pipe flow meter; 110 - third branch pipe control valve; 120 - third branch pipe flow meter. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments, all other embodiments obtained by those skilled in the art without any creative effort fall within the scope of the present application.

[0035] Unless otherwise defined, the technical terms or scientific terms used in the following embodiments shall have the meanings commonly understood by those skilled in the art. The terms "first", "second" and similar terms used in the embodiments do not represent any order, number or importance, but are only used to distinguish different components. The terms "comprise", "include" and similar terms mean that the components or objects before the terms cover the components or objects listed after the terms and their equivalents, and do not exclude other components or objects. "Up", "down", "left", "right" and the like are only used to represent relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships may also be changed accordingly.

[0036] Embodiment 1

[0037] Referring to Figure 1 The steam turbine exhaust cooling device provided by the embodiment comprises a steam turbine exhaust pipe 10, a cooling main pipe 30, a cooling branch pipe 40 and a spray head 50. The cooling main pipe 30 is arranged outside the steam turbine exhaust pipe 10, the cooling branch pipe 40 is arranged on the inner wall of the steam turbine exhaust pipe 10, and the spray head 50 is arranged on the cooling branch pipe 40 and located in the steam turbine exhaust pipe 10. The cooling main pipe 30 is communicated with the spray head 50 through the cooling branch pipe 40, and the spray head 50 is used to spray mist to cool the exhaust steam in the steam turbine exhaust pipe 10.

[0038] In the embodiment, the cooling branch pipe 40 is a C-shaped pipe, one end of which is communicated with the cooling main pipe 30. The outer wall contour of the C-shaped pipe is matched with the inner wall contour of the steam turbine exhaust pipe 10, facilitating the installation of the cooling branch pipe 40 in the steam turbine exhaust pipe 10, and meanwhile, the exhaust of the exhaust steam is not affected and can be normally discharged from the steam turbine exhaust pipe 10. The cooling branch pipe 40 is fixed on the inner wall of the steam turbine exhaust pipe 10 by spot welding.

[0039] In the embodiment, the spray head 50 is one, and the spray head 50 can also be multiple, and the multiple spray heads 50 are distributed on the cooling branch pipe 40 at intervals. In the implementation, the spray head 50 is two, three, four, five or more.

[0040] In the embodiment, the cooling branch pipe 40 is one, and the cooling branch pipe 40 can also be multiple, and the multiple cooling branch pipes 40 are distributed at intervals along the axial direction of the steam turbine exhaust pipe 10. In the implementation, the cooling branch pipe 40 is two, three, four, five or more. In order to make the spray position of the spray head 50 more and the spray coverage area larger, the spray heads 50 on every two cooling branch pipes are staggered, so that the sprays of the spray heads 50 intersect, the spray coverage area is increased, and the cooling effect is improved.

[0041] Preferably, the spray head 50 is four, and the cooling branch pipe 40 is two, which are respectively a first cooling branch pipe 401 and a second cooling branch pipe 402. The outer diameter of the steam turbine exhaust pipe 10 is 3000 mm, the specification of the cooling main pipe 30 is DN50 mm, the specification of the cooling branch pipe 40 is DN15 mm, and the material of the cooling main pipe 30 and the material of the cooling branch pipe 40 are both 0Cr18Ni9Ti stainless steel; the flow rate of a single spray head is 2 t / h and the spray is in the form of mist.

[0042] Referring to Figure 1 and Figure 2 , the left end of the steam turbine exhaust pipe 10 is connected with the steam turbine unit, for discharging the exhaust steam generated by the steam turbine unit. In the axial direction of the steam turbine exhaust pipe 10, the first cooling branch pipe 401 and the second cooling branch pipe 402 are arranged in sequence along the exhaust direction (from left to right), and the spacing between the first cooling branch pipe 401 and the second cooling branch pipe 402 is 0.5 m. Four first spray heads 501 are arranged on the outer wall of the first cooling branch pipe 401, and since the first cooling branch pipe 401 is a C-shaped pipe, the four first spray heads 501 are uniformly distributed along the contour line of the first cooling branch pipe 401. Similarly, four second spray heads 502 are uniformly distributed along the contour line of the second cooling branch pipe 402, and the distribution positions of the four second spray heads 502 and the four first spray heads 501 are staggered.

[0043] In the embodiment, when the exhaust steam flows from the steam turbine exhaust pipe 10, it first passes through the first cooling branch pipe 401, and the four first nozzles 501 spray mist from four directions to cool the exhaust steam; then the exhaust steam passes through the second cooling branch pipe 402, and the four second nozzles 502 cool the exhaust steam from another four directions, i.e. from eight positions, so that the temperature of the exhaust steam is lower than 65℃ and is discharged from the steam turbine exhaust pipe 10. In the embodiment, the nozzles are arranged at multiple positions, so that the spray coverage area is large and the exhaust steam cooling effect is good.

[0044] In the embodiment, the steam turbine exhaust cooling device further comprises a cooling water storage tank 20 arranged outside the steam turbine exhaust pipe 10 and in communication with the cooling main pipe 30; the cooling water storage tank 20 stores cooling water. Preferably, the temperature of the cooling water is 20-25℃, and the cooling water is cold desalted water.

[0045] Embodiment 2

[0046] Referring to Figure 3 On the basis of Embodiment 1, the steam turbine exhaust cooling device provided in the embodiment further comprises a connecting pipe arranged outside the steam turbine exhaust pipe 10, and the cooling main pipe 30 is in communication with the cooling branch pipe 40 through the connecting pipe.

[0047] In the embodiment, the cooling main pipe 30 is provided with a main control valve 60; the cooling main pipe 30 is in communication with the connecting pipe through the main control valve 60. The flow rate of the cooling water in the cooling main pipe 30 is controlled by the opening degree of the main control valve 60.

[0048] In the embodiment, a branch pipe control valve and a branch pipe flow meter are arranged on the connecting pipe, respectively; the flow rate of the cooling water in the cooling branch pipe 40 is controlled by the opening degree of the branch pipe control valve; and the flow rate of the cooling water entering the cooling branch pipe 40 is monitored by the branch pipe flow meter.

[0049] In implementation, in order to facilitate connection, the number of the connecting pipes is the same as that of the cooling branch pipes 40 and they are in one-to-one correspondence. Preferably, the number of the cooling branch pipes 40 is two, and the number of the connecting pipes is also two.

[0050] Specifically, a first branch pipe control valve 70 and a first branch pipe flow meter 80 are arranged in sequence on the connecting pipe between the cooling main pipe 30 and the first cooling branch pipe 401; the flow rate of the cooling water in the first cooling branch pipe 401 is controlled by the opening degree of the first branch pipe control valve 70; and the flow rate of the cooling water entering the first cooling branch pipe 401 is monitored by the first branch pipe flow meter 80.

[0051] Specifically, on the connecting pipe between the cooling main pipe 30 and the second cooling branch pipe 402, a second branch pipe control valve 90 and a second branch pipe flow meter 100 are arranged in sequence, the flow of the cooling water in the second cooling branch pipe 402 is controlled by the valve opening degree of the second branch pipe control valve 90, and the flow of the cooling water into the second cooling branch pipe 402 is monitored by the second branch pipe flow meter 100.

[0052] Embodiment 3

[0053] Referring to Figure 4 Different from the embodiment 1, the steam turbine exhaust cooling device provided in the embodiment 3 has three cooling branch pipes, i.e., a first cooling branch pipe 401, a second cooling branch pipe 402 and a third cooling branch pipe 403.

[0054] Specifically, the left end of the steam turbine exhaust pipe 10 is connected with the steam turbine unit, for discharging the exhaust steam generated by the steam turbine unit. In the axial direction of the steam turbine exhaust pipe 10, the first cooling branch pipe 401, the second cooling branch pipe 402 and the third cooling branch pipe 403 are arranged in sequence along the direction of the exhaust steam, and the interval between the three cooling branch pipes is 0.5 m. Four first nozzles 501 are arranged on the outer wall of the first cooling branch pipe 401, and since the first cooling branch pipe 401 is a C-shaped pipe, the four first nozzles 501 are uniformly distributed along the contour line of the first cooling branch pipe 401. Similarly, four second nozzles 502 are uniformly distributed along the contour line of the second cooling branch pipe 402, and four third nozzles 503 are uniformly distributed along the contour line of the third cooling branch pipe 403, and the distribution positions of the four second nozzles 502, the distribution positions of the four third nozzles 503 and the distribution positions of the four first nozzles 501 are staggered.

[0055] In the embodiment, when the exhaust steam flows in the steam turbine exhaust pipe 10, it first passes through the first cooling branch pipe 401, and the four first nozzles 501 spray mist from four directions to cool the exhaust steam. Then, the exhaust steam passes through the second cooling branch pipe 402, and the four second nozzles 502 cool the exhaust steam from another four directions. Then, the exhaust steam passes through the third cooling branch pipe 403, and the four third nozzles 503 cool the exhaust steam from another four directions, i.e., the exhaust steam is cooled by spraying mist from 12 positions, so that the temperature of the exhaust steam is lower than 65℃ and the exhaust steam is discharged from the steam turbine exhaust pipe 10. In the embodiment, the number of the spraying positions of the nozzles is increased, the spraying coverage area is larger, there is no dead angle area, and the cooling effect of the exhaust steam is better.

[0056] Embodiment 4

[0057] Referring to Figure 5The steam turbine exhaust cooling device provided in this embodiment is additionally provided with a connecting pipe outside the steam turbine exhaust pipe 10, and the cooling main pipe 30 is communicated with the cooling branch pipe 40 through the connecting pipe.

[0058] In this embodiment, the cooling main pipe 30 is provided with a main control valve 60, and the cooling main pipe 30 is communicated with the connecting pipe through the main control valve 60.

[0059] In this embodiment, the connecting pipe is respectively provided with a branch pipe control valve and a branch pipe flow meter, the flow of the cooling water in the cooling branch pipe 40 is controlled through the valve opening of the branch pipe control valve, and the flow of the cooling water into the cooling branch pipe 40 is monitored through the branch pipe flow meter.

[0060] In the implementation, in order to facilitate the connection, the number of the connecting pipes is the same as the number of the cooling branch pipes 40 and is communicated one by one.

[0061] Specifically, the first branch pipe control valve 70 and the first branch pipe flow meter 80 are sequentially arranged on the connecting pipe between the cooling main pipe 30 and the first cooling branch pipe 401, the flow of the cooling water in the first cooling branch pipe 401 is controlled through the valve opening of the first branch pipe control valve 70, and the flow of the cooling water into the first cooling branch pipe 401 is monitored through the first branch pipe flow meter 80.

[0062] Specifically, the second branch pipe control valve 90 and the second branch pipe flow meter 100 are sequentially arranged on the connecting pipe between the cooling main pipe 30 and the second cooling branch pipe 402, the flow of the cooling water in the second cooling branch pipe 402 is controlled through the valve opening of the second branch pipe control valve 90, and the flow of the cooling water into the second cooling branch pipe 402 is monitored through the second branch pipe flow meter 100.

[0063] Specifically, the third branch pipe control valve 110 and the third branch pipe flow meter 120 are sequentially arranged on the connecting pipe between the cooling main pipe 30 and the third cooling branch pipe 403, the flow of the cooling water in the third cooling branch pipe 403 is controlled through the valve opening of the third branch pipe control valve 110, and the flow of the cooling water into the second cooling branch pipe 402 is monitored through the third branch pipe flow meter 120.

[0064] The utility model discloses still can set up one temperature sensor at the import end and the export end of steam turbine exhaust pipe 10, according to the temperature difference size of the exhaust steam, through the control valve opening of main control valve 60 and the valve opening of branch pipe control valve, adjust the water size of cooling water, when the temperature difference is big, will valve opening be adjusted, and flow is changed, and the spraying strength is big, and the temperature difference is small, and will valve opening be adjusted, and flow is adjusted, and the spraying strength is big.

[0065] In the utility model, the adjustment of each valve opening degree can be manual adjustment or automatic adjustment, for example, each valve and temperature sensor is connected into DCS control system to realize automatic adjustment of cooling and more accurate control.

[0066] The above is several preferred embodiments of the utility model. The above embodiments and the specific parameters in the embodiments are only for clearly describing the verification process of the application and are not used to limit the patent protection scope of the utility model, and the patent protection scope of the application is still subject to the claims, and equivalent structural changes made by referring to the content of the specification and drawings of the utility model should also be included in the protection scope of the utility model.

Claims

1. A steam turbine exhaust cooling device, characterized in that: The invention comprises a steam turbine exhaust pipe (10), a cooling main pipe (30), a cooling branch pipe (40) and a nozzle (50); the cooling main pipe (30) is arranged outside the steam turbine exhaust pipe (10), the cooling branch pipe (40) is arranged on the inner wall of the steam turbine exhaust pipe (10), the nozzle (50) is arranged on the cooling branch pipe (40) and is located inside the steam turbine exhaust pipe (10), the cooling main pipe (30) is connected to the nozzle (50) via the cooling branch pipe (40), and the nozzle (50) is used to spray a spray to cool the exhaust steam in the steam turbine exhaust pipe (10); There are one or more nozzles (50), and the plurality of nozzles (50) are spaced apart and distributed on the cooling branch pipe (40); the cooling branch pipe (40) is a C-shaped pipe, and one end of the C-shaped pipe is connected to the cooling main pipe (30); There are a plurality of cooling branches (40), and the plurality of cooling branches (40) are distributed at intervals along the axial direction of the steam turbine exhaust pipe (10); the plurality of cooling branches (40) are all connected to the cooling main pipe (30); and the nozzles (50) on every two cooling branches on the plurality of cooling branches (40) are all staggered.

2. The steam turbine exhaust cooling device according to claim 1, characterized in that: The steam turbine exhaust temperature reduction device further comprises a cooling water storage tank (20) disposed outside the steam turbine exhaust pipe (10) and connected to the cooling main pipe (30).

3. The steam turbine exhaust cooling device according to claim 2, characterized in that: A connecting pipe is further provided outside the steam turbine exhaust pipe (10), the number of the connecting pipes being the same as the number of the cooling branch pipes (40) and being connected in a one-to-one correspondence; the cooling main pipe (30) is connected to the cooling branch pipes (40) through the connecting pipe.

4. The steam turbine exhaust cooling device according to claim 3, characterized in that: The cooling main pipe (30) is provided with a main control valve (60); the cooling main pipe (30) is communicated with the connecting pipe after passing through the main control valve (60).

5. The steam turbine exhaust cooling device according to claim 4, characterized in that: A branch pipe control valve and a branch pipe flow meter are respectively provided on the connecting pipe.

6. The steam turbine exhaust cooling device according to claim 5, characterized in that: The steam turbine exhaust cooling device further comprises temperature sensors respectively arranged on the inlet end of the steam turbine exhaust pipe (10) and the outlet end of the steam turbine exhaust pipe (10).

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