Cooling device for steam turbine of power plant

Abstract

The invention discloses a power plant steam turbine cooling device, which belongs to the technical field of steam turbines, and comprises a medium-pressure wheel shell, a low-pressure wheel shell, a steam extraction mechanism, a condensation mechanism and a condensate water conveying mechanism, and the medium-pressure wheel shell conveys steam to a steam turbine blade in the low-pressure wheel shell through a steam conveying pipeline. The steam extraction mechanism is connected with the medium-pressure turbine shell and is used for extracting part of steam in the medium-pressure turbine shell; the condensation mechanism is connected with the steam extraction mechanism and is used for cooling the extracted steam into condensed water; the condensate water conveying mechanism is connected with the condensation mechanism and used for conveying condensate water into the low-stage pinch roller shell and cooling steam turbine blades in the low-stage pinch roller shell. By means of the design, part of steam in the middle-pressure wheel shell can be extracted and cooled into condensate water through the condensation pipeline, then the condensate water is used for cooling steam turbine blades in the low-pressure wheel shell, and therefore resource recycling is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of steam turbines, and in particular relates to a steam turbine cooling device for a power plant. Background Art

[0002] Steam turbines are key equipment in power plants, and their operating efficiency and reliability directly impact the economic benefits and safety of the power plant. Steam turbine blades operate under the action of high-temperature, high-pressure steam, requiring effective cooling measures to ensure their performance and lifespan. Traditional cooling methods include using internal cooling systems within the turbine, but these methods have certain limitations, such as:

[0003] The cooling system inside the steam turbine can only cool the components in the direction of the main shaft, but cannot cool the blades outside the main shaft, so the efficiency is low. In addition, the existing cooling device lacks the collection and utilization of steam, which will cause a certain degree of waste of steam resources.

[0004] In view of the deficiencies in the prior art, the present invention provides a steam turbine cooling device for a power plant, aiming to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a steam turbine cooling device for a power plant, which can extract part of the steam in the intermediate-pressure turbine casing, cool it into condensate using a condensation pipe, and then use the condensate to cool the turbine blades in the low-pressure turbine casing, thereby realizing resource recycling, improving cooling efficiency, reducing cooling medium consumption, and reducing the impact on the environment.

[0006] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0007] A steam turbine cooling device for a power plant includes an intermediate-pressure turbine housing and a low-pressure turbine housing, wherein the intermediate-pressure turbine housing transports steam to turbine blades in the low-pressure turbine housing through a steam transport pipe, and further includes:

[0008] a steam extraction mechanism connected to the intermediate pressure turbine housing and used to extract part of the steam from the intermediate pressure turbine housing;

[0009] a condensing mechanism connected to the steam extraction mechanism and configured to cool the extracted steam into condensed water;

[0010] and a condensed water delivery mechanism connected to the condensing mechanism, for delivering condensed water into the low-pressure turbine housing to cool the turbine blades in the low-pressure turbine housing.

[0011] Preferably, the steam extraction mechanism comprises:

[0012] a steam extraction pipe connected to the steam outlet on the side of the intermediate pressure turbine casing;

[0013] The steam regulating valve is arranged on the steam extraction pipeline and is used to regulate the steam flow.

[0014] Preferably, the condensing mechanism includes:

[0015] a condensation pipe connected to the steam outlet of the steam extraction pipe;

[0016] A cooling water tank is provided on the outer periphery of the condensing pipe and wraps the condensing pipe;

[0017] A cooling water pump is arranged on the top of the cooling water tank and is used to circulate the water inside the cooling water tank.

[0018] Preferably, the condensed water conveying mechanism includes:

[0019] A main delivery pipeline passes through the cooling water tank and is connected to the outlet end of the condensation pipeline;

[0020] a delivery control valve, provided on the delivery main pipeline, for controlling the flow of condensed water;

[0021] The two spray diversion pipes are both connected to the outlet end of the main delivery pipe, and the outlet ends of the two spray diversion pipes are respectively connected to the low-pressure turbine casing and lead to the interior thereof.

[0022] Preferably, it also includes a reflux pipeline and a reflux control valve; wherein,

[0023] One end of the return pipe is connected to the side of the low-pressure turbine housing, and the other end is connected to the cooling water tank, so as to return the condensed water in the low-pressure turbine housing to the cooling water tank, thereby realizing the recycling of the condensed water;

[0024] The reflux control valve is arranged on the reflux pipeline.

[0025] Preferably, a filter screen is further provided at the inlet end of the steam extraction pipe.

[0026] Preferably, the condensation pipe is made of heat exchange material.

[0027] Preferably, the outside of the main delivery pipeline and the two spray branch pipelines are provided with insulation materials for maintaining the temperature of the condensed water.

[0028] Preferably, the steam extraction mechanism further includes a pressure sensor and a temperature sensor, which are respectively provided on the steam extraction pipeline for monitoring the pressure and temperature of the steam in real time to ensure that the extracted steam parameters meet the cooling requirements.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention extracts part of the steam in the intermediate-pressure turbine housing, cools it into condensed water using a condensing mechanism, and then uses the condensed water to cool the turbine blades in the low-pressure turbine housing. The used condensed water is eventually returned to the cooling box through a return pipe. This not only cools the turbine blades to a certain extent, but also achieves resource recycling and reduces cooling medium consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present invention.

[0032] Figure 2 It is a structural schematic diagram of the condensation pipeline of the present invention.

[0033] Figure 3 It is a structural schematic diagram of the steam extraction pipeline of the present invention.

[0034] in:

[0035] 1. Medium-pressure turbine housing; 11. Steam delivery pipeline; 2. Low-pressure turbine housing; 21. Turbine blades; 3. Steam extraction mechanism; 31. Steam extraction pipeline; 32. Steam regulating valve; 33. Filter; 4. Condensation mechanism; 41. Condensation pipeline; 42. Cooling water tank; 43. Cooling water pump; 5. Condensate delivery mechanism; 51. Delivery main pipeline; 52. Delivery control valve; 53. Spray diversion pipeline; 54. Return pipeline; 55. Return control valve. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] Example 1

[0040] refer to Figure 1-Figure 3 This embodiment provides a steam turbine cooling device for a power plant, comprising an intermediate-pressure turbine housing 1 and a low-pressure turbine housing 2, wherein the intermediate-pressure turbine housing 1 transports steam to turbine blades 21 in the low-pressure turbine housing 2 through a steam transport pipe 11, and further comprising:

[0041] a steam extraction mechanism 3 connected to the intermediate pressure turbine housing 1 and used to extract part of the steam from the intermediate pressure turbine housing 1;

[0042] a condensing mechanism 4 connected to the steam extraction mechanism 3 and configured to cool the extracted steam into condensed water;

[0043] And a condensed water delivery mechanism 5 is connected to the condensing mechanism 4 and is used to deliver condensed water into the low-pressure turbine housing 2 to cool the turbine blades 21 in the low-pressure turbine housing 2.

[0044] Specifically, the steam extraction mechanism 3 includes:

[0045] A steam extraction pipe 31 is connected to the steam outlet on the side of the intermediate pressure turbine housing 1;

[0046] The steam regulating valve 32 is provided on the steam extraction pipe 31 and is used to regulate the steam flow.

[0047] It should be noted that, in this embodiment, a filter screen 33 is also provided at the inlet end of the steam extraction pipe 31; this design is to effectively filter out impurities in the steam, prevent impurities from entering the cooling system, and reduce wear and blockage of equipment such as the condensation pipe 41 and the cooling water pump 43.

[0048] In this embodiment, the present invention designs a steam extraction mechanism 3, which avoids steam waste by extracting part of the steam from the medium-pressure turbine casing 1, improves the utilization rate of the steam resources of the power plant, and allows the steam that may have been discharged to be re-integrated into the cooling system, saving energy costs for the power plant.

[0049] Furthermore, the condensing mechanism 4 includes:

[0050] a condensation pipe 41 connected to the steam outlet of the steam extraction pipe 31;

[0051] A cooling water tank 42 is provided on the outer periphery of the condensing pipe 41 and wraps the condensing pipe 41;

[0052] The cooling water pump 43 is provided on the top of the cooling water tank 42 and is used to circulate the water inside the cooling water tank 42 .

[0053] It should be noted that, in this embodiment, the condensation pipe 41 is made of heat exchange material to improve condensation efficiency.

[0054] In this embodiment, the present invention designs a condensing mechanism 4, which, through the coordinated use of the condensing pipe 41 and the cooling water tank 42, can quickly cool the extracted steam into condensed water through the circulation of water inside the cooling water tank 42, with high cooling efficiency, and provides sufficient cooling medium for the turbine blades 21 in the low-pressure turbine housing 2, effectively reducing the temperature of the blades and extending the service life of the blades.

[0055] Furthermore, the condensed water conveying mechanism 5 includes:

[0056] The main delivery pipe 51 passes through the cooling water tank 42 and is connected to the outlet end of the condensation pipe 41;

[0057] A delivery control valve 52 is provided on the delivery main pipeline 51 and is used to control the flow of condensed water;

[0058] The two spray branch pipes 53 are both connected to the outlet end of the main delivery pipe 51, and the outlet ends of the two spray branch pipes 53 are respectively connected to the low-pressure turbine casing 2 and lead to the interior thereof.

[0059] It should be noted that, in this embodiment, multiple parallel channels are provided at the outlet ends of the two spray diversion pipes 53 to ensure that the condensed water can be evenly distributed and improve the cooling effect.

[0060] In order to maintain the temperature of the condensed water, in this embodiment, the outside of the main delivery pipe 51 and the two spray branch pipes 53 are both provided with insulation materials.

[0061] In order to monitor the pressure and temperature of the steam in real time and ensure that the extracted steam parameters meet the cooling requirements, in this embodiment, the steam extraction mechanism 3 also includes a pressure sensor and a temperature sensor, which are respectively arranged on the steam extraction pipeline 31.

[0062] In this embodiment, the present invention designs a condensate delivery mechanism 5, which can accurately deliver condensate to the low-pressure turbine casing 2 through the coordinated use of the delivery main pipeline 51 and the delivery control valve 52, ensuring that the condensate can smoothly reach the cooling part of the turbine blades 21, thereby achieving effective cooling of the blades and improving the reliability and stability of the cooling system; and the design of the two spray diversion pipes 53 can evenly distribute the condensate to different parts of the low-pressure turbine casing 2, making the cooling of the turbine blades 21 more uniform, avoiding overheating and damage of the blades due to insufficient local cooling, and further improving the cooling effect and service life of the turbine blades 21.

[0063] Example 2

[0064] refer to Figure 1 On the basis of the first embodiment, the present invention also has the following design.

[0065] The present invention also has a return pipe 54 and a return control valve 55; wherein,

[0066] One end of the return pipe 54 is in communication with the side of the low-pressure turbine housing 2, and the other end thereof is in communication with the cooling water tank 42, for returning the condensed water in the low-pressure turbine housing 2 to the cooling water tank 42, thereby realizing the recycling of the condensed water;

[0067] The reflux control valve 55 is disposed on the reflux pipe 54 .

[0068] In this embodiment, the present invention designs the return pipe 54 and the return control valve 55 to achieve the recycling of condensed water, reduce the waste of condensed water, reduce the water resource consumption of the power plant, and also reduce the impact of condensed water discharge on the environment, with significant energy-saving and environmental benefits.

[0069] Working Principle: The cooling process mainly includes five processes: steam extraction, steam condensation, condensate transportation, turbine blade 21 cooling and condensate recycling; among them:

[0070] 1. Steam extraction

[0071] Step 1.1: When the intermediate pressure turbine casing 1 is in operation, high-temperature and high-pressure steam is generated.

[0072] Step 1.2: Extract part of the steam from the steam outlet of the medium-pressure turbine housing 1 through the steam extraction pipe 31; the steam extraction pipe 31 is connected to the side steam outlet of the medium-pressure turbine housing 1 to ensure that the steam can be extracted smoothly.

[0073] Step 1.3: The steam regulating valve 32 is installed on the steam extraction pipeline 31 to adjust the steam flow according to the actual cooling demand to ensure that the extracted steam flow is stable and meets the cooling requirements.

[0074] Step 1.4: Pressure and temperature sensors monitor the steam pressure and temperature in real time to ensure that the extracted steam parameters meet cooling requirements. If the steam parameters are abnormal, the system will issue an alarm and automatically adjust the steam regulating valve 32.

[0075] 2. Steam condensation

[0076] Step 2.1: The extracted steam enters the condensation pipe 41 through the steam extraction pipe 31 .

[0077] Step 2.2: The condensing pipe 41 is arranged inside the cooling water tank 42. The cooling water in the cooling water tank 42 circulates through the cooling water pump 43, surrounding the condensing pipe 41 and taking away the heat of the steam.

[0078] Step 2.3: The steam is cooled in the condensation pipe 41 and gradually condenses into condensed water; the condensation pipe 41 is made of high-efficiency heat exchange material to improve condensation efficiency.

[0079] Step 2.4: The condensed water flows into the condensed water collecting device through the outlet of the condensation pipe 41 .

[0080] 3. Condensate transportation

[0081] Step 3.1: The condensed water is sequentially transported from the condensed water collecting device to the low-pressure turbine casing 2 through the main transport pipe 51 and the two spray branch pipes 53 .

[0082] Step 3.2: The delivery control valve 52 is installed on the delivery main pipeline 51 to control the flow rate and flow of the condensed water.

[0083] Step 3.3: The condensed water is evenly distributed to different locations in the low-pressure turbine casing 2 through the two spray branch pipes 53 .

[0084] 4. Turbine blade 21 cooling

[0085] Step 4.1: After the condensed water enters the low-pressure turbine casing 2 , it is evenly sprayed onto the turbine blades 21 through the spray diversion pipe 53 .

[0086] Step 4.2: The condensed water flows on the surface of the blade, absorbs the heat of the blade and reduces the temperature of the blade.

[0087] 5. Condensate recycling

[0088] Step 5.1: The condensed water after absorbing heat returns to the cooling water tank 42 through the return pipe 54 ; one end of the return pipe 54 is connected to the side of the low-pressure turbine housing 2 , and the other end is connected to the cooling water tank 42 .

[0089] Step 5.2: The reflux control valve 55 is installed on the reflux pipe 54 to control the reflux speed and flow rate of the condensed water to ensure that the condensed water can smoothly return to the cooling water tank 42.

[0090] Step 5.3: The condensed water returned to the cooling water tank 42 circulates again through the cooling water pump 43 to cool the new steam, thereby realizing the recycling of the condensed water and reducing the waste of cooling water.

[0091] In summary, the present invention extracts some steam from the intermediate-pressure turbine casing 1, cools it to condensate using the condensation pipe 41, and then transports the condensate to the low-pressure turbine casing 2 to cool the low-pressure turbine blades. The condensate, having absorbed heat, returns to the cooling water tank 42 via the return pipe 54, achieving condensate recycling. This process not only improves cooling efficiency and reduces cooling medium consumption, but also minimizes environmental impact, resulting in significant energy-saving and environmental benefits.

[0092] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A steam turbine cooling device for a power plant, comprising a medium-pressure turbine housing (1) and a low-pressure turbine housing (2), wherein: The medium-pressure turbine housing (1) transports steam to the turbine blades (21) in the low-pressure turbine housing (2) through a steam transport pipe (11), and is characterized in that it also includes: A steam extraction mechanism (3) is connected to the intermediate pressure turbine housing (1) and is used to extract part of the steam from the intermediate pressure turbine housing (1); a condensing mechanism (4), connected to the steam extraction mechanism (3), and configured to cool the extracted steam into condensed water; and a condensate delivery mechanism (5) connected to the condensation mechanism (4) for delivering condensate into the low-pressure turbine housing (2) to cool the turbine blades (21) in the low-pressure turbine housing (2).

2. The power plant steam turbine cooling device according to claim 1, characterized in that: The steam extraction mechanism (3) comprises: A steam extraction pipe (31) connected to a steam outlet on a side of the intermediate pressure turbine housing (1); A steam regulating valve (32) is provided on the steam extraction pipe (31) and is used to regulate the steam flow rate.

3. The power plant steam turbine cooling device according to claim 2, characterized in that: The condensing mechanism (4) comprises: a condensation pipe (41) connected to the steam outlet of the steam extraction pipe (31); A cooling water tank (42) is provided on the outer periphery of the condensing pipe (41) and wraps the condensing pipe (41); A cooling water pump (43) is provided on the top of the cooling water tank (42) and is used to circulate the water inside the cooling water tank (42).

4. The power plant steam turbine cooling device according to claim 3, characterized in that: The condensed water conveying mechanism (5) comprises: A main delivery pipe (51) passes through the cooling water tank (42) and is connected to the outlet end of the condensation pipe (41); a delivery control valve (52), provided on the delivery main pipeline (51), for controlling the flow of condensed water; The two spray branch pipes (53) are both connected to the outlet end of the main delivery pipe (51), and the outlet ends of the two spray branch pipes (53) are respectively connected to the low-pressure turbine housing (2) and lead to the interior thereof.

5. The power plant steam turbine cooling device according to claim 2, characterized in that: It also includes a reflux pipeline (54) and a reflux control valve (55); wherein, One end of the return pipe (54) is in communication with the side of the low-pressure turbine housing (2), and the other end thereof is in communication with the cooling water tank (42). The return control valve (55) is provided on the return pipe (54).

6. The power plant steam turbine cooling device according to claim 2, characterized in that: The inlet end of the steam extraction pipe (31) is also provided with a filter screen (33).

7. The power plant steam turbine cooling device according to claim 3, characterized in that: The condensation pipe (41) is made of heat exchange material.

8. The power plant steam turbine cooling device according to claim 3, characterized in that: The exteriors of the main delivery pipeline (51) and the two spray branch pipelines (53) are both provided with heat-insulating materials.

9. The power plant steam turbine cooling device according to claim 1, characterized in that: The steam extraction mechanism (3) further comprises a pressure sensor and a temperature sensor, which are respectively arranged on the steam extraction pipeline (31) and are used to monitor the pressure and temperature of the steam in real time.

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