A quick cooling system for high and intermediate pressure combined cylinder of steam turbine and steam turbine

Abstract

The utility model discloses a kind of for steam turbine high-pressure combined cylinder's quick cooling system and steam turbine, the quick cooling system includes compressed air source and air distribution device, compressed air source is connected with air distribution device by first connecting pipe, air distribution device is used to be connected with high-pressure combined cylinder on corresponding interface by multiple second connecting pipes.This utility model is matched by compressed air source and air distribution device with inlet main pipe, at least three way outlet branch pipe, independent flow control component and air trap, can inject dry cooling air as needed, multi-point, controllably in different key areas of steam turbine high-pressure combined cylinder, realize uniform, efficient and safe initiative cooling.Compared with traditional method which relies on natural cooling or low-temperature steam cooling, the scheme can significantly shorten the time required for cylinder to drop to maintenance temperature, and avoid the thermal shock and structural damage caused by supercooling or condensate, thereby improving the shutdown maintenance efficiency and safety of unit.

Description

Technical Field

[0001] This utility model relates to the field of steam turbine maintenance technology, and in particular to a rapid cooling system for the high-pressure and intermediate-pressure cylinder of a steam turbine and the steam turbine itself. Background Technology

[0002] In large nuclear power plants, half-speed turbine units are commonly used to achieve high power output and operational reliability. A significant structural feature of these units is their integrated high-pressure / intermediate-pressure (HP / IP) cylinder design. This integrated structure results in a large physical volume and thermal capacity (thermal inertia) of the cylinder.

[0003] When a generator unit is shut down for maintenance, this enormous heat capacity becomes a pressing technical challenge. Under natural cooling conditions, the high-temperature cylinder metal body requires an extremely long time to cool down to a safe temperature (e.g., 100°C) for cylinder opening and maintenance. Taking a certain megawatt-class unit as an example, it can take up to 6 days (approximately 144 hours) to cool naturally from 176°C after shutdown to 100°C. This significantly prolongs the unit's downtime for maintenance, directly reducing the unit's annual availability and power generation efficiency, resulting in substantial economic losses.

[0004] To shorten the cooling time, attempts were made to optimize the shutdown procedure and utilize the low-temperature steam during low-load operation to cool the cylinder to some extent. However, the cooling effect of this method was limited. Although the cooling time was shortened, it still required more than 3 days (approximately 84 hours), and the problem of excessively long shutdown waiting time could not be solved.

[0005] Therefore, there is an urgent need in this field for a more efficient and safer rapid cooling solution to shorten downtime during major overhauls or temporary maintenance and improve the overall economic benefits of nuclear power units. Utility Model Content

[0006] The main purpose of this invention is to provide a rapid cooling system for the high-pressure and intermediate-pressure cylinder of a steam turbine and a steam turbine in order to solve the above-mentioned technical problems.

[0007] The objective of this utility model can be achieved by adopting the following technical solution:

[0008] A rapid cooling system for a high-pressure and intermediate-pressure cylinder of a steam turbine includes a compressed air source and an air distribution device. The compressed air source is connected to the air distribution device via a first connecting pipe. The air distribution device is used to connect to corresponding interfaces on the high-pressure and intermediate-pressure cylinder via multiple second connecting pipes. The air distribution device includes: an inlet main pipe connected to the compressed air source via the first connecting pipe, the inlet main pipe being used to receive cooling air from the compressed air source; at least three outlet branch pipes, each outlet branch pipe having an upstream end connected to the inlet main pipe and a downstream end connected to the corresponding interface on the high-pressure and intermediate-pressure cylinder; a flow control component, correspondingly disposed on each outlet branch pipe, the flow control component being used to independently adjust and monitor the flow rate of cooling air passing through each outlet branch pipe; and a drain valve disposed on the inlet main pipe, the drain valve being used to separate condensate from the cooling air before the cooling air enters the outlet branch pipe.

[0009] The flow control component includes a flow regulating valve and a flow meter connected in series on the outlet branch pipe.

[0010] The air distribution device further includes a backup branch pipe, the upstream end of which is connected to the inlet main pipe, and the downstream end of which is provided with a sealing element.

[0011] The air distribution device further includes a movable support, and the inlet main pipe, the outlet branch pipe, the flow control component, the drain valve, and the spare branch pipe are all integrated on the movable support.

[0012] The compressed air source is a mobile compressed air source.

[0013] The compressed air source includes an oil-free air compressor and a refrigerated dryer, with the refrigerated dryer located between the oil-free air compressor and the inlet header.

[0014] A steam turbine capable of rapid cooling includes: an intermediate-high pressure combined cylinder and a rapid cooling system as described above; wherein, the intermediate-high pressure combined cylinder is provided with a high-pressure steam inlet, an intermediate-pressure steam inlet, and an intermediate-pressure cylinder stage extraction steam inlet, and the downstream ends of at least three outlet branch pipes of the rapid cooling system are respectively connected to the high-pressure steam inlet, the intermediate-pressure steam inlet, and the intermediate-pressure cylinder stage extraction steam inlet.

[0015] The flow control component of the rapid cooling system is configured such that the flow rate to the outlet branch pipe leading to the intermediate-pressure cylinder stage extraction port accounts for 60%-80% of the total flow rate, the flow rate to the outlet branch pipe leading to the high-pressure steam inlet port accounts for 8%-15% of the total flow rate, and the flow rate to the outlet branch pipe leading to the intermediate-pressure steam inlet port accounts for 15%-25% of the total flow rate.

[0016] It also includes a low-pressure cylinder connected to the exhaust end of the high-pressure cylinder, and the low-pressure cylinder is provided with a manhole, which is configured as the exhaust port for cooling air during the cooling process.

[0017] The high-pressure steam inlet, the intermediate-pressure steam inlet, and the intermediate-pressure cylinder stage extraction steam inlet are all connected to the turbine's drain line via their respective connecting adapters. The connecting adapters include flanged pipes and reducing pipes.

[0018] The beneficial technical effects of this invention are as follows: By combining a compressed air source with an air distribution device equipped with an inlet header, at least three outlet branch pipes, an independent flow control component, and a drain valve, this invention can inject dry cooling air into different key areas of the high- and medium-pressure combined cylinder of a steam turbine on demand, at multiple points, and in a controllable manner, achieving uniform, efficient, and safe active cooling. Compared with traditional methods that rely on natural cooling or low-temperature steam cooling, this solution can significantly shorten the time required for the cylinder to drop to maintenance temperature and avoid thermal shock and structural damage caused by overcooling or condensation, thereby improving the efficiency and safety of unit shutdown maintenance. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of a rapid cooling system provided in an embodiment of this utility model;

[0021] Figure 2 A schematic diagram of the air distribution device in the rapid cooling system provided in this embodiment of the utility model;

[0022] Figure 3 A schematic diagram of the cooling process of a steam turbine provided for an embodiment of this utility model;

[0023] Figure 4 A schematic diagram of the connection adapter in the steam turbine provided in this embodiment of the utility model.

[0024] Explanation of reference numerals in the attached figures:

[0025] In the diagram: 3-First connecting pipe, 4-Second connecting pipe, 11-Oil-free air compressor, 12-Refrigerated dryer, 21-Inlet main pipe, 22-Outlet branch pipe, 24-Drain valve, 25-Spare branch pipe, 27-Moving support, 50-High and medium pressure combined cylinder, 51-High pressure steam inlet, 52-Medium pressure steam inlet, 53-Medium pressure cylinder interstage extraction steam inlet, 60-Low pressure cylinder, 61-Manhole, 71-Connecting pipe, 72-Reducing pipe, 231-Flow regulating valve, 232-Flow meter, 251-Sealing component. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0027] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0028] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0029] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0030] like Figures 1-2 As shown, this embodiment of the invention provides a rapid cooling system for the high- and intermediate-pressure cylinder of a steam turbine. During shutdown maintenance of large steam turbine units such as nuclear power plants, the high- and intermediate-pressure cylinders, due to their large structure and high heat capacity, require a long time to cool down to the temperature permissible for cylinder opening maintenance under natural cooling conditions, severely impacting the unit's availability and maintenance efficiency. The rapid cooling system provided in this embodiment aims to safely and efficiently shorten the cooling time by actively and controllably introducing cooling air into the high-temperature steam turbine cylinder.

[0031] The rapid cooling system includes a compressed air source and an air distribution device. The compressed air source is connected to the air distribution device via a first connecting pipe 3. The air distribution device is used to connect to corresponding interfaces on the high-pressure and intermediate-pressure cylinder 50 via multiple second connecting pipes 4. The air distribution device comprises: an inlet main pipe 21 connected to the compressed air source via the first connecting pipe 3, the inlet main pipe 21 being used to receive cooling air from the compressed air source; at least three outlet branch pipes 22, each outlet branch pipe 22 having an upstream end connected to the inlet main pipe 21 and a downstream end connected to the corresponding interface on the high-pressure and intermediate-pressure cylinder 50; a flow control component, correspondingly disposed on each outlet branch pipe 22, the flow control component being used to independently adjust and monitor the flow rate of cooling air passing through each outlet branch pipe 22; and a drain valve 24 disposed on the inlet main pipe 21, the drain valve 24 being used to separate condensate from the cooling air before the cooling air enters the outlet branch pipe 22.

[0032] In this embodiment, the rapid cooling system includes a compressed air source and an air distribution device. The compressed air source generates compressed air with a certain pressure and flow rate. The compressed air source is connected to the air distribution device via a first connecting pipe 3, delivering the generated compressed air to the air distribution device. The air distribution device is then connected to corresponding interfaces on the high-pressure mixing cylinder 50 via multiple second connecting pipes 4, thereby precisely distributing and injecting the compressed air into specific positions within the high-pressure mixing cylinder 50.

[0033] The air distribution device includes the following components:

[0034] Inlet header 21: Inlet header 21 is a main pipe that connects to the compressed air source via the first connecting pipe 3. Inlet header 21 serves as a channel for receiving and collecting all cooling air from the compressed air source, ensuring that compressed air can uniformly enter the distribution system.

[0035] At least three outlet branch pipes 22: each outlet branch pipe 22 has an upstream end and a downstream end. The upstream ends of all outlet branch pipes 22 are connected to the inlet header pipe 21 to divert cooling air from the inlet header pipe 21. The downstream end of each outlet branch pipe 22 is connected to the corresponding interface on the high-pressure mixing cylinder 50 through a corresponding second connecting pipe 4, delivering the distributed cooling air to the designated location. Through the parallel design of multiple outlet branch pipes 22, multi-point injection of cooling air is achieved, ensuring comprehensive cooling coverage of the high-pressure mixing cylinder.

[0036] Flow control components: Each flow control component is installed on each outlet branch pipe 22. Each flow control component is used to independently adjust and monitor the flow rate of cooling air through each outlet branch pipe 22. Through the flow control components, operators can accurately and independently distribute and adjust the air flow rate entering different positions of the high-pressure and intermediate-pressure mixing cylinder according to the preset cooling scheme, thereby achieving effective control of the temperature field and cooling rate of the entire high-pressure and intermediate-pressure mixing cylinder, ensuring that the cooling process is carried out efficiently within a safe range.

[0037] Drain valve 24: Drain valve 24 is installed on the inlet header 21, specifically at a lower position. The function of drain valve 24 is to pre-separate condensate from the cooling air before it enters the outlet branch pipe 22. This ensures that the cooling air entering the turbine cylinder is dry, preventing high-temperature components from experiencing significant thermal stress due to contact with liquid water, thus guaranteeing the safety of the cooling process.

[0038] In this embodiment, by setting up a cooling system consisting of a compressed air source and an air distribution device, active and forced ventilation cooling of the high-temperature cylinder is achieved, thereby changing the traditional method of relying on natural cooling or inefficient steam cooling. Specifically, in this embodiment, cooling air from the compressed air source is uniformly received through the inlet header 21, and then distributed to multiple points through three outlet branch pipes 22, which are then delivered to different parts of the high- and medium-pressure cylinder. This multi-point, parallel air injection method ensures that the cooling medium can fully cover specific parts of the cylinder, achieving uniform and efficient cooling.

[0039] Furthermore, by installing flow control components on each outlet branch pipe 22, independent monitoring and adjustment of the cooling air flow rate for each path can be achieved, ensuring precise flow distribution according to the preset scheme. The drain valve 24 installed on the inlet header pipe 21 can pre-extract any condensate that may be present in the cooling air before it enters the cylinder block, ensuring the dryness of the cooling medium and guaranteeing the safety of the cooling process.

[0040] In summary, this embodiment successfully solves the problems of long cooling time, low efficiency, and insufficient safety in the prior art by actively introducing, precisely distributing, and pre-treating dry cooling air, providing an effective technical solution for achieving rapid, safe, and efficient cooling of the high-pressure mixing cylinder 50.

[0041] In one embodiment, the flow control assembly includes a flow regulating valve 231 and a flow meter 232 connected in series on the outlet branch pipe 22.

[0042] In this embodiment, a flow regulating valve 231 and a flow meter 232 are connected in series on each outlet branch pipe 22. The flow meter 232 is used to monitor the instantaneous flow rate of the cooling air passing through the branch pipe in real time. By reading the reading of the flow meter 232, the operator can accurately determine the supply of cooling air for each branch and obtain the current flow rate value.

[0043] The flow control valve 231 can be a manual or automatic control valve. The operator can adjust the opening of the flow control valve 231 manually or automatically to change the flow resistance of the branch pipe and thus control the airflow through that branch pipe. When it is necessary to increase the cooling airflow in a certain path, the opening of the corresponding flow control valve 231 can be increased; when it is necessary to decrease the flow, the opening can be decreased.

[0044] In a preferred embodiment, the flow regulating valve 231 is located upstream of the flow meter 232, meaning that the cooling air first passes through the flow regulating valve 231 for flow regulation, and then passes through the flow meter 232 for flow measurement. This series configuration ensures that the flow meter 232 measures the actual flow value after regulation, providing accurate flow feedback information to the operator.

[0045] Closed-loop control can be achieved through the combination of flow regulating valve 231 and flow meter 232. The operator first observes the current flow rate value through flow meter 232, then adjusts the opening of flow regulating valve 231 according to the preset cooling scheme requirements, and finally confirms through flow meter 232 whether the adjusted flow rate reaches the target value. This flow control capability allows the system to precisely and independently distribute and adjust the airflow entering different locations in the high- and intermediate-pressure cylinder (such as the high-pressure section, intermediate-pressure section, and intermediate-pressure stage extraction position) according to the needs of different cooling stages.

[0046] This flow control component design, based on flow regulating valve 231 and flow meter 232, provides precise flow distribution capability for the entire cooling system, ensuring that the cooling process can proceed according to preset safety parameters, thus guaranteeing cooling efficiency and avoiding thermal stress damage to turbine components due to excessively fast cooling rates.

[0047] In one embodiment, the air distribution device further includes a backup branch pipe 25, the upstream end of which is connected to the inlet main pipe 21, and the downstream end is provided with a sealing element 251.

[0048] In this embodiment, in addition to the aforementioned inlet main pipe 21, three outlet branch pipes 22, flow control component and drain valve 24, the air distribution device also includes a spare branch pipe 25.

[0049] The standby branch pipe 25 has a similar structure to the outlet branch pipe 22. Its upstream end is connected to the inlet main pipe 21, and it can divert cooling air from the inlet main pipe 21. The downstream end of the standby branch pipe 25 is provided with a sealing element 251, which can be in the form of a blind flange, a pipe cap, or a threaded plug, depending on the interface type of the downstream end of the standby branch pipe 25.

[0050] During normal cooling operations, when the existing three outlet branch pipes 22 are sufficient to meet the cooling requirements, the standby branch pipe 25 is idle. At this time, the sealing element 251 seals the outlet of the standby branch pipe 25 to prevent compressed air from leaking from its outlet, ensuring that all cooling air can be effectively delivered to the designated location through the outlet branch pipe 22 in use.

[0051] When a branch pipe 22 malfunctions, becomes blocked, or requires maintenance, a backup branch pipe 25 can be used as an alternative channel. Operators simply need to remove the sealing component 251 and connect the corresponding second connecting pipe 4 to put the backup branch pipe 25 into use, ensuring the continuity of cooling operations. The backup branch pipe 25 can also be equipped with a flow control component to independently adjust and monitor the flow rate through it when in use.

[0052] In one embodiment, the air distribution device further includes a movable support 27, on which the inlet main pipe 21, the outlet branch pipe 22, the flow control component, the drain valve 24, and the spare branch pipe 25 are all integrated.

[0053] In this embodiment, the air distribution device also includes a movable support 27. The aforementioned inlet main pipe 21, three outlet branch pipes 22, flow control component, drain valve 24, and spare branch pipe 25 are all integrated and fixed on the movable support 27 to form a complete and movable distribution unit.

[0054] The mobile support 27 has a robust frame structure capable of supporting the weight of all piping components and maintaining the relative positions of each component during movement. The mobile support 27 is equipped with casters or pulleys at its base, allowing the entire air distribution unit to be easily pushed or dragged by workers to a designated location within the turbine building.

[0055] By integrating all distribution piping and valve accessories onto a single mobile support 27, the system's mobility and on-site deployment efficiency are greatly improved. When the rapid cooling system is required, the operator simply pushes the entire mobile support 27 to a suitable position near the high-pressure mixing cylinder, connects it to the compressed air source via the first connecting pipe 3, and connects it to the corresponding interfaces on the high-pressure mixing cylinder 50 via multiple second connecting pipes 4, and it is ready for use.

[0056] This integrated design eliminates the need for complex piping assembly on-site, reducing system preparation and deployment time. Once cooling is complete, the entire air distribution unit can be removed as a single unit simply by disconnecting the external connections, facilitating storage and future use.

[0057] In one embodiment, the compressed air source is a mobile compressed air source.

[0058] In this embodiment, the compressed air source that provides compressed air to the entire rapid cooling system is a mobile compressed air source with rollers on its main structure to facilitate placement in a suitable location within the turbine building.

[0059] Combined with the mobile air distribution device in the aforementioned embodiments, the entire rapid cooling system (including the air source and distribution device) is mobile. When rapid cooling is required, simply transport the mobile compressed air source and the mobile air distribution device to the site and connect them via the first connecting pipe 3 to quickly establish a complete cooling system.

[0060] This design greatly enhances the system's applicability. The same rapid cooling system can be easily applied to different turbine units, improving equipment utilization. Especially in emergency situations such as unplanned shutdowns for maintenance, the mobile compressed air source can respond quickly, providing a reliable guarantee for timely cooling operations.

[0061] In one embodiment, the compressed air source includes an oil-free air compressor 11 and a refrigerated dryer 12, wherein the refrigerated dryer 12 is disposed between the oil-free air compressor 11 and the inlet header 21.

[0062] In this embodiment, the mobile compressed air source specifically includes two main components: an oil-free air compressor 11 and a refrigerated dryer 12. These components are connected in series in a specific order to form a complete compressed air preparation device.

[0063] The oil-free air compressor 11 is used to compress atmospheric air to the required operating pressure. Unlike traditional oil-lubricated air compressors, the oil-free air compressor 11 does not use lubricating oil during the compression process, therefore the compressed air it produces is completely free of oil. This characteristic is crucial for rapid cooling applications in steam turbines, because when oil-containing compressed air enters the high-temperature turbine cylinder, the oil may undergo thermal decomposition or form carbon deposits at high temperatures, causing contamination and damage to the internal components of the turbine.

[0064] The refrigerated air dryer 12 is located downstream of the oil-free air compressor 11, specifically between the oil-free air compressor 11 and the inlet header 21 of the air distribution device. After being output from the oil-free air compressor 11, the compressed air first enters the refrigerated air dryer 12 for cooling and dehumidification. The refrigerated air dryer 12, through a refrigeration cycle system, lowers the temperature of the compressed air to a level close to that of the cooling water, causing a large amount of water vapor in the air to condense and precipitate, thereby reducing the moisture content of the compressed air.

[0065] Compressed air processed by the refrigerated dryer 12 has a pressure dew point that is much lower than that of ambient temperature. This means that under normal ambient temperature conditions, this compressed air will hardly condense, effectively avoiding the risk of condensation in pipelines and turbine cylinders.

[0066] By combining the oil-free air compressor 11 and the refrigerated dryer 12 in series, the mobile compressed air source of this embodiment can continuously and stably provide high-quality compressed air that is both oil-free and extremely dry. This cooling medium is of great significance in preventing excessive thermal shock to high-temperature turbine components, avoiding water vapor condensation inside the cylinder, and preventing equipment corrosion, thus ensuring the safety and reliability of the entire rapid cooling process.

[0067] In addition, the oil-free air compressor 11 and the refrigerated dryer 12 can be integrated on the same mobile chassis to form a compact mobile compressed air source unit, which facilitates overall transportation and on-site deployment, further improving the practicality and convenience of the system.

[0068] like Figure 3 and Figure 4 As shown, corresponding to the above-mentioned rapid cooling system for the intermediate and high-pressure combined cylinder of a steam turbine, this utility model embodiment also provides a steam turbine capable of rapid cooling, including an intermediate and high-pressure combined cylinder and the rapid cooling system of the aforementioned embodiment; wherein, the intermediate and high-pressure combined cylinder is provided with a high-pressure steam inlet 51, an intermediate-pressure steam inlet 52 and an intermediate-pressure cylinder stage extraction steam inlet 53, and the downstream ends of at least three outlet branch pipes 22 of the rapid cooling system are respectively connected to the high-pressure steam inlet 51, the intermediate-pressure steam inlet 52 and the intermediate-pressure cylinder stage extraction steam inlet 53.

[0069] In this embodiment, the turbine system includes a high- and intermediate-pressure combined cylinder 50 and a rapid cooling system as described in the previous embodiment. The high-pressure and intermediate-pressure combined cylinder 50 is characterized by combining the high-pressure section and the intermediate-pressure section within the same outer cylinder.

[0070] To achieve forced ventilation cooling, the intermediate-pressure combined cylinder 50 utilizes multiple existing pipe interfaces, specifically including: High-pressure steam inlet interface 51 (high-pressure cylinder steam inlet pipe interface): This interface connects to the main steam pipe and is used to supply cooling air to the high-pressure section of the turbine. Intermediate-pressure steam inlet interface 52 (intermediate-pressure cylinder steam inlet pipe interface): This interface connects to the reheat steam pipe and is used to supply cooling air to the intermediate-pressure section of the turbine. Intermediate-pressure cylinder stage extraction steam interface 53 (intermediate-pressure cylinder stage extraction steam pipe interface): This is an extraction steam pipe interface located in an intermediate stage of the intermediate-pressure section (such as after intermediate-pressure cylinder stage 2), and is a major cooling air injection point in this embodiment.

[0071] During rapid cooling operations, the downstream ends of the three outlet branch pipes 22 of the rapid cooling system are connected one-to-one with the high-pressure steam inlet 51, the intermediate-pressure steam inlet 52, and the intermediate-pressure cylinder-stage extraction steam inlet 53 via their respective second connecting pipes 4. Specifically, the first outlet branch pipe 22 is connected to the high-pressure steam inlet 51, the second outlet branch pipe 22 is connected to the intermediate-pressure steam inlet 52, and the third outlet branch pipe 22 is connected to the intermediate-pressure cylinder-stage extraction steam inlet 53. In this way, the cooling air from the air distribution device can be divided into three paths to simultaneously cool the high-pressure zone, the intermediate-pressure reheat steam inlet zone, and the middle section of the intermediate-pressure expansion path of the high- and medium-pressure combined cylinder 50. Through this multi-point injection connection method, the cooling air can comprehensively cover the temperature field of the entire cylinder block, especially focusing on cooling key areas with concentrated heat, thereby achieving a highly efficient and uniform cooling effect and effectively shortening the waiting time for downtime maintenance.

[0072] In one embodiment, the flow control component of the rapid cooling system is configured such that the flow rate to the outlet branch pipe 22 leading to the intermediate-pressure cylinder stage extraction port 53 accounts for 60%-80% of the total flow rate, the flow rate to the outlet branch pipe 22 leading to the high-pressure steam inlet port 51 accounts for 8%-15% of the total flow rate, and the flow rate to the outlet branch pipe 22 leading to the intermediate-pressure steam inlet port 52 accounts for 15%-25% of the total flow rate.

[0073] In this embodiment, to achieve optimal cooling while ensuring the temperature drop rate of each turbine component remains within a safe range and preventing excessive thermal stress, a reasonable distribution of airflow into the three different interfaces is required. By operating the flow control components on the air distribution device, the following flow distribution ratios can be achieved: The outlet branch pipe 22 leading to the interstage extraction port 53 of the intermediate-pressure cylinder receives 60% to 80% of the total cooling airflow for rapid cooling. The outlet branch pipe 22 leading to the high-pressure inlet port 51 receives 8% to 15% of the total cooling airflow; a relatively small flow rate is sufficient to meet its cooling requirements. The outlet branch pipe 22 leading to the intermediate-pressure inlet port 52 receives 15% to 25% of the total cooling airflow. This section is used to cool the reheat steam inlet area of ​​the intermediate-pressure cylinder, which is also a high-temperature area, requiring a moderate flow rate.

[0074] In a preferred embodiment, the specific flow distribution ratio can be set as follows: the flow to the intermediate-pressure cylinder stage extraction port 53 accounts for 70% of the total flow, the flow to the high-pressure steam inlet port 51 accounts for 10% of the total flow, and the flow to the intermediate-pressure steam inlet port 52 accounts for 20% of the total flow.

[0075] By reading the flow meters 232 on each outlet branch pipe 22 in real time and adjusting the flow regulating valves 231 accordingly, the operator can accurately achieve and maintain this preset flow distribution ratio. This differentiated flow distribution strategy based on heat capacity and structural characteristics ensures that the entire high-pressure mixing cylinder 50 can cool down at a relatively uniform rate, avoiding local overcooling or insufficient cooling, which is the key to achieving safe, efficient and rapid cooling.

[0076] In one embodiment, a low-pressure cylinder 60 is also included, which is connected to the exhaust end of the high-pressure cylinder. The low-pressure cylinder 60 is provided with a manhole 61, which is configured as the exhaust port for cooling air during the cooling process.

[0077] In this embodiment, the turbine system includes at least one low-pressure cylinder 60 in addition to the intermediate-high pressure cylinder 50. The exhaust end of the intermediate-high pressure cylinder 50 is connected to the inlet end of the low-pressure cylinder 60 via a connecting pipe.

[0078] To provide a smooth exhaust path for the cooling air entering the high-pressure cylinder 50, this embodiment utilizes the existing manhole 61 on the low-pressure cylinder 60 as an exhaust port. During rapid cooling operations, the cover of the manhole 61 is opened.

[0079] This creates a complete, low-resistance flow loop from cooling air injection to exhaust: after being injected into the intermediate-high pressure combined cylinder 50 through the high-pressure steam inlet 51, intermediate-pressure steam inlet 52, and intermediate-pressure interstage extraction steam inlet 53, the cooling air flows through the flow passages within the cylinder, engaging in convective heat exchange with the high-temperature cylinder block, rotor, blades, and other components, absorbing a large amount of heat. Subsequently, this heat-carrying air follows the normal steam flow path, entering the low-pressure cylinder 60 from the exhaust end of the intermediate-high pressure combined cylinder 50, and finally exiting into the atmosphere through the opened manhole 61. In some cases, the cooling air may also be exhausted through the manhole on the wet reheater (MSR) shell.

[0080] In one embodiment, the high-pressure steam inlet 51, the intermediate-pressure steam inlet 52, and the intermediate-pressure inter-cylinder stage extraction steam inlet 53 are all connected to the turbine's drain line through their respective corresponding adapters. The adapters include a flanged pipe 71 and a reducing pipe 72.

[0081] In this embodiment, in order to facilitate the connection between the rapid cooling system and the existing steam turbine pipeline, and to avoid complex drilling operations on the heavy steam turbine cylinder or main steam pipeline, the high-pressure steam inlet 51, the intermediate-pressure steam inlet 52, and the intermediate-pressure cylinder stage extraction steam inlet 53 are all achieved by modifying the corresponding drainage pipelines.

[0082] Specifically, existing condensate lines connected to the main steam pipeline, reheat steam pipeline, and intermediate-pressure stage extraction steam pipeline are used as injection channels for cooling air. For this purpose, connection adapters are added to these condensate lines. These connection adapters specifically include a flanged connecting pipe 71 and a reducing pipe 72.

[0083] One end of the connector 71 is equipped with a standard flange, the specifications of which match the flange of the second connecting pipe 4 on the rapid cooling system side, for a quick and reliable bolted connection between the two. The other end of the connector 71 is connected to the reducer 72.

[0084] The reducer 72, also known as a reducer, connects to the connecting pipe 71 at one end and to the existing drain line on the turbine at the other end. Since the diameter of the second connecting pipe 4 (e.g., DN100 or DN65) is usually much larger than the diameter of the existing drain line (e.g., DN25), the function of the reducer 72 is to achieve a smooth transition from the larger diameter to the smaller diameter, ensuring that the cooling air can flow smoothly into the drain line and eventually into the main pipeline and the turbine cylinder.

[0085] By adding a connection adapter consisting of a flanged nozzle 71 and a reducer 72, this embodiment achieves a reliable connection from a larger diameter cooling system hose to a smaller diameter field drainage line. This solution, which utilizes the existing drainage line as an injection channel and adds a standard connection adapter, is a very economical and convenient modification method. It avoids direct modification of critical pressure-bearing components of the turbine, simplifies construction, ensures the integrity and safety of the system, and achieves "plug-and-play" operation of the rapid cooling system.

[0086] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A rapid cooling system for a high-pressure and intermediate-pressure cylinder of a steam turbine, comprising a compressed air source and an air distribution device, wherein the compressed air source is connected to the air distribution device via a first connecting pipe, and the air distribution device is used to connect to corresponding interfaces on the high-pressure and intermediate-pressure cylinder via multiple second connecting pipes, characterized in that, The air distribution device includes: The inlet header is connected to the compressed air source via the first connecting pipe, and the inlet header is used to receive cooling air from the compressed air source; At least three outlet branch pipes, each of the outlet branch pipes having an upstream end connected to the inlet main pipe and a downstream end connected to the corresponding interface on the high-pressure mixing cylinder; Flow control components are respectively installed on each of the outlet branch pipes, and the flow control components are used to independently adjust and monitor the flow rate of cooling air through each of the outlet branch pipes; and A steam trap is installed on the inlet main pipe. The steam trap is used to separate condensate from the cooling air before the cooling air enters the outlet branch pipe.

2. The rapid cooling system according to claim 1, characterized in that, The flow control assembly includes a flow regulating valve and a flow meter connected in series on the outlet branch pipe.

3. The rapid cooling system according to claim 1, characterized in that, The air distribution device further includes a backup branch pipe, the upstream end of which is connected to the inlet main pipe, and the downstream end of which is provided with a sealing element.

4. The rapid cooling system according to claim 3, characterized in that, The air distribution device also includes a movable support, and the inlet main pipe, the outlet branch pipe, the flow control component, the drain valve and the spare branch pipe are all integrated on the movable support.

5. The rapid cooling system according to claim 1, characterized in that, The compressed air source is a mobile compressed air source.

6. The rapid cooling system according to claim 5, characterized in that, The compressed air source includes an oil-free air compressor and a refrigerated dryer, with the refrigerated dryer located between the oil-free air compressor and the inlet header.

7. A steam turbine capable of rapid cooling, characterized in that, include: The high-pressure and intermediate-pressure cylinder and the rapid cooling system as described in any one of claims 1 to 6; wherein the high-pressure and intermediate-pressure cylinder is provided with a high-pressure steam inlet, an intermediate-pressure steam inlet, and an intermediate-pressure cylinder stage extraction steam inlet, and the downstream ends of at least three outlet branch pipes of the rapid cooling system are respectively connected to the high-pressure steam inlet, the intermediate-pressure steam inlet, and the intermediate-pressure cylinder stage extraction steam inlet.

8. The rapidly cooling steam turbine according to claim 7, characterized in that, The flow control component of the rapid cooling system is configured such that the flow rate to the outlet branch pipe leading to the intermediate-pressure cylinder stage extraction port accounts for 60%-80% of the total flow rate, the flow rate to the outlet branch pipe leading to the high-pressure steam inlet port accounts for 8%-15% of the total flow rate, and the flow rate to the outlet branch pipe leading to the intermediate-pressure steam inlet port accounts for 15%-25% of the total flow rate.

9. The rapidly cooling steam turbine according to claim 7, characterized in that, It also includes a low-pressure cylinder connected to the exhaust end of the high-pressure cylinder, and the low-pressure cylinder is provided with a manhole, which is configured as the exhaust port for cooling air during the cooling process.

10. The rapidly cooling steam turbine according to claim 7, characterized in that, The high-pressure steam inlet, the intermediate-pressure steam inlet, and the intermediate-pressure inter-cylinder stage extraction steam inlet are all connected to the turbine's drain line via their respective connecting adapters. The connecting adapters include flanged pipes and reducing pipes.

Images