Steam turbine cooling system based on electric power spot market

Abstract

The utility model relates to the technical field of steam turbine cooling, in particular to a steam turbine cooling system based on an electric power spot market, which comprises an adjusting mechanism, the adjusting mechanism is connected with a high-pressure cylinder cooling mechanism, and the adjusting mechanism is used for controlling the gas displacement of the high-pressure cylinder cooling mechanism; the adjusting mechanism is further connected with an intermediate-pressure cylinder cooling mechanism and used for controlling the gas displacement of the intermediate-pressure cylinder cooling mechanism. The cooling efficiency of the steam turbine can be efficiently controlled, and meanwhile the production cost can be saved.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbine cooling, in particular to a steam turbine cooling system based on the electricity spot market. Background Art

[0002] The 300MW steam turbine rapid cooling technology is an important measure to improve the flexibility and efficiency of the generator set. It is mainly used to quickly reduce the temperature of the high-temperature components of the steam turbine after it is shut down, so as to reduce the downtime for maintenance and improve the availability of the unit. The key to this technology is to effectively control the cooling rate to avoid equipment damage caused by excessive thermal stress.

[0003] In the prior art, for the cooling of steam turbines, most of them connect the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder through cooling pipes. By controlling the temperature of compressed air, the temperature of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder is lowered layer by layer to achieve a direct and one-time cooling effect. However, in the way of controlling the cooling efficiency by controlling the temperature of compressed air, the actual temperatures of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder are not the same after the steam turbine is shut down due to their different devices and different use environments. If the temperatures of the three are directly, once and layer by layer lowered, when the compressed air enters the medium-pressure cylinder and the low-pressure cylinder after exiting the high-pressure cylinder, the temperature of the compressed air changes and is difficult to control. If the temperature of the compressed air is too high, the cooling efficiency is reduced; if the temperature of the compressed air is too low, it may damage the cylinder body. Because the temperature difference is too large, thermal stress or cold brittleness is generated, which in turn causes cracks or fractures inside the cylinder body of the medium-pressure cylinder and the low-pressure cylinder. In particular, during rapid cooling, the thermal stress generated inside the cylinder body may exceed its tolerance limit.

[0004] At the same time, based on the current electricity spot market context, if the electricity price is low, although the steam turbine needs to be started, blindly and quickly cooling the steam turbine will increase the cooling cost and increase the production cost. Utility Model Content

[0005] A steam turbine cooling system based on the electricity spot market is provided to achieve the purpose of efficiently controlling the steam turbine cooling efficiency while also saving production costs.

[0006] The following technical solution is adopted: a steam turbine cooling system based on the electricity spot market, including a regulating mechanism, which is connected to a high-pressure cylinder cooling mechanism, and the regulating mechanism is used to control the exhaust volume of the high-pressure cylinder cooling mechanism; the regulating mechanism is also connected to an intermediate-pressure cylinder cooling mechanism, and the regulating mechanism is used to control the exhaust volume of the intermediate-pressure cylinder cooling mechanism.

[0007] Beneficial effects: First, compared with the prior art, the regulating mechanism of this solution can more accurately and efficiently control the cooling efficiency of the turbine while ensuring that the high-pressure cylinder and the intermediate-pressure cylinder are not damaged, while also reducing costs.

[0008] Secondly, by connecting the regulating mechanism to the high-pressure cylinder cooling mechanism and the intermediate-pressure cylinder cooling mechanism respectively, and the regulating mechanism is used to control the exhaust volume of the intermediate-pressure cylinder cooling mechanism, the high-pressure cylinder and the intermediate-pressure cylinder can be cooled at the same level and at one time.

[0009] Finally, based on the current electricity spot market, the exhaust volume of the high-pressure cylinder and the medium-pressure cylinder cooling mechanism is controlled by the regulating mechanism to efficiently control the cooling of the steam turbine. It can ensure that when the electricity spot market environment is at a low price, the cooling time of the steam turbine is increased, and the use and power of the equipment used to cool the steam turbine are reduced to reduce production costs. When the electricity spot market environment is at a high price, the regulating structure needs to be adjusted to quickly cool the steam turbine and put the steam turbine into use immediately to increase the benefits of electricity production.

[0010] Preferably, the high-pressure cylinder cooling mechanism includes a high-pressure cylinder intake valve, the high-pressure cylinder intake valve is connected to the high-pressure cylinder air supply pipe, the high-pressure cylinder exhaust is connected to the high-pressure cylinder, and the high-pressure cylinder is connected to a high-pressure air duct; the high-pressure air duct is connected to a first high-pressure regulating valve, and the high-pressure air duct is also connected to a second high-pressure regulating valve; the first high-pressure regulating valve is connected to a first main steam valve, the second high-pressure regulating valve is connected to a second main steam valve, and the first main steam valve and the second main steam valve are connected to a cold exhaust pipe.

[0011] Beneficial effect: By controlling the first high-pressure regulating gate and the second high-pressure regulating gate, not only the cooling efficiency of the medium-pressure cylinder can be accelerated, but also the cooling efficiency of the medium-pressure cylinder can be accurately controlled.

[0012] Preferably, the medium-pressure cylinder cooling mechanism includes a medium-pressure cylinder air inlet valve, which is connected to a medium-pressure cylinder delivery pipeline; the medium-pressure cylinder delivery pipeline is connected to a first medium-pressure regulating valve, which is also connected to a second medium-pressure regulating valve, and both the first medium-pressure regulating valve and the second medium-pressure regulating valve are connected to the medium-pressure cylinder; the medium-pressure cylinder is connected to a low-pressure cylinder, which is connected to a condenser, and the condenser is connected to a vacuum breaking valve.

[0013] Beneficial effect: In the cooling of the medium-pressure cylinder, by controlling the first medium-pressure regulating door or the second medium-pressure regulating door, not only can the cooling efficiency of the medium-pressure cylinder be accelerated, but also the cooling efficiency of the medium-pressure cylinder can be accurately controlled. At the same time, since the temperature of the low-pressure cylinder is lower than that of the medium-pressure cylinder during actual operation. After shutdown, the medium-pressure cylinder is cooled first, and then the compressed air from the medium-pressure cylinder enters the low-pressure cylinder for cooling, which can achieve rapid cooling without damaging the low-pressure cylinder. At the same time, the medium-pressure cylinder and the low-pressure cylinder are connected by pipelines and cooled directly in sequence. When controlling the temperature of the compressed air, there is no need to connect another pipeline directly to the low-pressure cylinder, which can also reduce the cost of modification.

[0014] Preferably, a plurality of low-pressure exhaust valves are provided on the low-pressure cylinder for directly exhausting the gas on the low-pressure cylinder.

[0015] Beneficial effects: Exhaust can be directly carried out on the low-pressure cylinder, which can speed up the exhaust speed of the low-pressure cylinder, improve the cooling speed of the steam turbine, and reduce the cooling time of the steam turbine.

[0016] Preferably, the regulating mechanism includes a terminal control platform, the terminal control platform is electrically connected to a compressed air intake valve, the terminal control platform is electrically connected to a heater, the heater is connected to a compressed air intake valve pipeline; the heater pipeline is connected to a quick cooling manifold, the quick cooling manifold is connected to a quick cooling manifold regulating door, and the quick cooling manifold regulating door is respectively connected to the medium-pressure cylinder intake valve and the high-pressure cylinder intake valve.

[0017] Beneficial effect: The regulating mechanism can control the temperature of the compressed air by controlling the heater, and at the same time separate the high-pressure cylinder air intake and the medium-pressure cylinder air intake on the quick-cooling header regulating door, so that the high-pressure cylinder, the medium-pressure cylinder 35 and the low-pressure cylinder can be cooled in batches to achieve more precise cooling of the three cylinders.

[0018] Preferably, a check mechanism is also included, the check mechanism includes a reheater, the reheater is connected to a high-discharge check valve, and the high-discharge check valve is connected to the high-pressure cylinder air supply pipeline.

[0019] Beneficial effects: The check mechanism not only closes quickly when the steam turbine is shut down or urgently unloaded to prevent steam from flowing back from the reheater to the high-pressure cylinder, but also avoids damage to the steam turbine caused by the water hammer effect caused by steam backflow, thereby protecting the steam turbine from damage and extending the life of the equipment.

[0020] Preferably, it also includes a central door mechanism, which includes a central door drain air-controlled door, and the central door drain air-controlled door is connected to a central door drain manual door; the central door drain manual door is connected to the medium-pressure cylinder delivery pipeline.

[0021] Beneficial effect: The central door mechanism discharges condensed water in the pipeline in time to prevent water hammer effect and corrosion. At the same time, it maintains the steam quality and ensures the dryness and thermal efficiency of the internal components of the steam turbine.

[0022] Beneficial effects of the utility model

[0023] Compared with the prior art, by controlling the temperature of compressed air, the temperatures of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder are lowered layer by layer to achieve a direct and one-time cooling effect.

[0024] Firstly, the structure of the present invention is different from that of the prior art. The regulating mechanism of the present invention can control the cooling efficiency of the steam turbine more accurately and efficiently while ensuring that the high-pressure cylinder and the intermediate-pressure cylinder are not damaged, and can also reduce costs.

[0025] Secondly, by connecting the regulating mechanism to the high-pressure cylinder cooling mechanism and the intermediate-pressure cylinder cooling mechanism respectively, and the regulating mechanism is used to control the exhaust volume of the intermediate-pressure cylinder cooling mechanism, the high-pressure cylinder and the intermediate-pressure cylinder can be cooled at the same level and at one time.

[0026] Finally, multiple adjustment gates are set on the high-pressure cylinder and the medium-pressure cylinder to effectively control the cooling efficiency of the cylinder. At the same time, the medium-pressure cylinder and the low-pressure cylinder are connected by pipelines and cooled directly in sequence. When controlling the compressed air temperature, there is no need to connect another pipeline directly to the low-pressure cylinder, which can also reduce the cost of transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of a steam turbine cooling system based on the electricity spot market of the utility model. DETAILED DESCRIPTION

[0028] The following is further explained in detail through specific implementation methods.

[0029] The reference numerals in the drawings of the specification include:

[0030] Compressed air intake valve 11, heater 12, quick cooling header 13, cold header regulating valve 14, high-pressure cylinder intake valve 21, high-pressure cylinder air delivery pipeline 22, high-pressure cylinder 23, high-pressure air guide pipe 24, first high-pressure regulating valve 25, first main steam valve 26, second high-pressure regulating valve 27, second main steam valve 28, cold exhaust pipeline 29, medium-pressure cylinder intake valve 31, medium-pressure cylinder delivery pipeline 32, first medium-pressure regulating valve 33, second medium-pressure regulating valve 34, medium-pressure cylinder 35, low-pressure cylinder 36, low-pressure exhaust valve 361, condenser 37, vacuum breaking valve 38, reheater 41, high-discharge check valve 42, central door drain air control valve 51, central door drain manual door 52.

[0031] Embodiment 1

[0032] This embodiment is basically Figure 1 As shown, this embodiment provides a steam turbine cooling system based on the electricity spot market, including a check mechanism, a center door mechanism, a regulating mechanism, a high-pressure cylinder cooling mechanism and an intermediate-pressure cylinder cooling mechanism.

[0033] Specifically, the high-pressure cylinder cooling mechanism includes a high-pressure cylinder intake valve 21, a high-pressure cylinder air supply pipeline 22, a high-pressure cylinder, a high-pressure air guide pipe 24, a first high-pressure regulating valve 25, a first main steam valve 26, a second high-pressure regulating valve 27, a second main steam valve 28 and a cold exhaust pipe 29. The high-pressure cylinder intake valve 21 is fixedly connected to the high-pressure cylinder air supply pipeline 22, the high-pressure cylinder air supply pipeline 22 is fixedly connected to the high-pressure cylinder 23, and the high-pressure cylinder 23 is fixedly connected to four high-pressure air guide pipes 24. Among them, two high-pressure air guide pipes 24 are fixedly connected to two first high-pressure regulating valves 25, and two high-pressure air guide pipes 24 are fixedly connected to two second high-pressure regulating valves 27; the two first high-pressure regulating valves 25 and the two second high-pressure regulating valves 27 are respectively connected to one first main steam valve 26 and one second main steam valve 28 by pipeline. The first main steam valve 26 and the second main steam valve 28 are fixedly connected to the cold exhaust pipe 29.

[0034] The intermediate pressure cylinder cooling mechanism includes an intermediate pressure cylinder air intake valve 31, an intermediate pressure cylinder delivery pipeline 32, a first intermediate pressure regulating valve 33, a second intermediate pressure regulating valve 34, an intermediate pressure cylinder 35, a low pressure cylinder 36, a condenser 37 and a vacuum breaking valve 38. The intermediate pressure cylinder air intake valve 31 is fixedly connected to the intermediate pressure cylinder delivery pipeline 32, and the intermediate pressure cylinder delivery pipeline 32 is fixedly connected to the first intermediate pressure regulating valve 33 and the second intermediate pressure regulating valve 34. The first intermediate pressure regulating valve 33 and the second intermediate pressure regulating valve 34 are both connected to the intermediate pressure cylinder 35 by pipeline. The intermediate pressure cylinder pipeline is connected to the low pressure cylinder 36, the low pressure cylinder 36 pipeline is connected to the condenser 37, and the condenser 37 pipeline is connected to the vacuum breaking valve 38.

[0035] The non-return mechanism includes a reheater 41 and a high-discharge non-return valve 42. The reheater 41 pipeline is connected to the high-discharge non-return valve 42, and the high-discharge non-return valve 42 is fixedly connected to the high-pressure cylinder air supply pipeline 22.

[0036] The central door mechanism includes a central door drain gas control door 51 and a central door drain manual door 52. The central door drain gas control door 51 is connected to the central door drain manual door 52 by a pipeline, and the central door drain manual door 52 is fixedly connected to the medium pressure cylinder delivery pipeline 32.

[0037] The regulating module comprises a terminal control platform, a compressed air intake door 11 , a heater 12 , a quick cooling header 13 and a quick cooling header regulating door 14 .

[0038] The terminal control platform is electrically connected to the compressed air intake valve 11, and the terminal control platform is electrically connected to the heater 12, and the heater 12 is connected to the compressed air intake valve 11 through a pipeline. The heater 12 is connected to the quick cooling manifold 13 through a pipeline, and the quick cooling manifold 13 is connected to the quick cooling manifold regulating door 14 through a pipeline, and the quick cooling manifold regulating door 14 is connected to the medium pressure cylinder intake valve 31 and the high pressure cylinder intake valve 21 through a pipeline respectively. The terminal control platform is electrically connected to the central gate drain gas control valve 51, the first high pressure regulating valve 25, the second high pressure regulating valve 27, the first medium pressure regulating valve 33, the second medium pressure regulating valve 34, the high pressure cylinder intake valve 21 and the medium pressure cylinder intake valve 31, and the terminal control platform can control the opening / closing of the gate drain gas control valve, the first high pressure regulating valve 25, the second high pressure regulating valve 27, the first medium pressure regulating valve 33, the second medium pressure regulating valve 34, the high pressure cylinder intake valve 21 and the medium pressure cylinder intake valve 31. The terminal control platform is a PLC control device.

[0039] How to use this embodiment

[0040] When the quick cooling system needs to be put into use, the compressed air intake manual door is opened, the heater 12 is powered on, the required temperature is set on the terminal control platform, and the air is heated to the required temperature. The high-discharge check valve 42, the central door drain manual door 52 and the central door drain air control door 51 can be closed manually or through the terminal control platform. The first high-pressure main steam valve, the first high-pressure regulating valve 25, the second high-pressure regulating valve 27, the second high-pressure main steam valve, the second high-pressure regulating valve 27, the first medium-pressure regulating valve 33, and the second medium-pressure regulating valve 34 can be opened manually or through the terminal control platform.

[0041] Specifically, through the adjustment mechanism, you can choose to use the high-pressure cylinder cooling mechanism or the medium-pressure cylinder cooling mechanism. The cooling process of the high-pressure cylinder cooling mechanism: compressed air enters from the high-pressure cylinder intake valve 21 - high-pressure cylinder air delivery pipeline 22 - high-pressure cylinder 23 - high-pressure air guide pipe 24 - first high-pressure regulating valve 25, second high-pressure regulating valve 27 - first high-pressure main steam valve, second high-pressure main steam valve - cold exhaust pipe 29 and discharged to the atmosphere. Medium-pressure cylinder intake process: compressed air enters from the medium-pressure cylinder intake valve 31 - medium-pressure cylinder delivery pipeline 32 - first medium-pressure regulating valve 33, second medium-pressure regulating valve 34 - medium-pressure cylinder 35 - low-pressure cylinder 36 - condenser 37 - vacuum breaking valve 38 and discharged to the atmosphere.

[0042] Embodiment 2

[0043] Different from the first embodiment, in this embodiment, a plurality of low-pressure exhaust valves 361 are provided on the low-pressure cylinder 36 for directly exhausting the air on the low-pressure cylinder 36 .

[0044] Specifically, four low-pressure exhaust holes are provided on the low-pressure cylinder 36, and a low-pressure exhaust valve 361 is installed on each low-pressure exhaust hole. The low-pressure exhaust valve 361 is used to close / open the low-pressure exhaust hole. The low-pressure exhaust hole can be used for exhaust.

[0045] The beneficial effects of this embodiment

[0046] The low-pressure cylinder 36 in the prior art is airtight, and the gas can only be discharged into the cooling tower through a circulating water pump. Now, a low-pressure exhaust hole is provided on the low-pressure cylinder 36, and a low-pressure exhaust valve 361 is installed on the low-pressure exhaust hole. When cooling is not required, the low-pressure exhaust valve 361 is closed to make the low-pressure cylinder 36 a closed environment. When cooling is required, the low-pressure exhaust valve 361 is opened to allow the gas to be discharged directly from the low-pressure exhaust hole.

[0047] This embodiment is a brief description, and more corresponding details can be referred to the aforementioned embodiments.

[0048] In the description of the present utility model, it should be noted that the terms "upper", "lower", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model.

[0049] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] It should be understood that the term "and / or" used in this article is only a description of the same field of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0051] It should be noted that, with regard to other parts not mentioned, the parts include specific devices and implementation methods, please refer to the aforementioned method embodiment part, and no further details will be given here.

[0052] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.

[0053] The above is only an embodiment of the utility model. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the utility model before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to explain the content of the claims.

Claims

1. A steam turbine cooling system based on the electricity spot market, characterized in that: The regulating mechanism includes a regulating mechanism connected to a high-pressure cylinder cooling mechanism, and the regulating mechanism is used to control the exhaust volume of the high-pressure cylinder cooling mechanism; the regulating mechanism is also connected to an intermediate-pressure cylinder cooling mechanism, and the regulating mechanism is used to control the exhaust volume of the intermediate-pressure cylinder cooling mechanism; the high-pressure cylinder cooling mechanism includes a high-pressure cylinder intake valve, the high-pressure cylinder intake valve is connected to a high-pressure cylinder air supply pipeline, the high-pressure cylinder exhaust is connected to the high-pressure cylinder, and the high-pressure cylinder is connected to a high-pressure air guide pipe; The high-pressure air duct is connected to a first high-pressure regulating valve, and the high-pressure air duct is also connected to a second high-pressure regulating valve; the first high-pressure regulating valve is connected to a first main steam valve, and the second high-pressure regulating valve is connected to a second main steam valve, and the first main steam valve and the second main steam valve are connected to a cooling exhaust pipe; the intermediate-pressure cylinder cooling mechanism includes an intermediate-pressure cylinder intake valve, and the intermediate-pressure cylinder intake valve is connected to an intermediate-pressure cylinder delivery pipeline; The medium-pressure cylinder delivery pipeline is connected to a first medium-pressure regulating gate, the medium-pressure cylinder delivery pipeline is also connected to a second medium-pressure regulating gate, and the first medium-pressure regulating gate and the second medium-pressure regulating gate are both connected to the medium-pressure cylinder; The medium-pressure cylinder is connected to the low-pressure cylinder, the low-pressure cylinder is connected to the condenser, and the condenser is connected to the vacuum breaking door; the regulating mechanism includes a terminal control platform, the terminal control platform is electrically connected to the compressed air intake valve, the terminal control platform is electrically connected to the heater, and the heater is connected to the compressed air intake valve pipeline; The heater pipeline is connected with a quick cooling header, the quick cooling header is connected with a quick cooling header regulating door, and the quick cooling header regulating door is respectively connected with an intermediate pressure cylinder intake valve and a high pressure cylinder intake valve.

2. A steam turbine cooling system based on the electricity spot market according to claim 1, characterized in that: The low-pressure cylinder is provided with a plurality of low-pressure exhaust valves for directly exhausting the air on the low-pressure cylinder.

3. The steam turbine cooling system based on the electricity spot market according to claim 1, characterized in that: It also includes a check mechanism, which includes a reheater, the reheater is connected to a high-discharge check valve, and the high-discharge check valve is connected to the high-pressure cylinder air supply pipeline.

4. The steam turbine cooling system based on the electricity spot market according to claim 1, characterized in that: It also includes a central door mechanism, which includes a central door drain air-controlled door, and the central door drain air-controlled door is connected to a central door drain manual door; the central door drain manual door is connected to a medium-pressure cylinder delivery pipeline.

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