Temperature reduction device for steam turbine shaft seal

Abstract

The utility model discloses a temperature reducing device for a steam turbine shaft seal, which comprises a pressure equalizing box, a plurality of water spraying pipelines are arranged on the pressure equalizing box, each water spraying pipeline is provided with a spraying electromagnetic valve, one end of each water spraying pipeline is provided with a nozzle, the nozzles are positioned in the pressure equalizing box, and the pressure equalizing box is provided with a plurality of nozzles. The other ends of the water spraying pipelines are jointly connected with an external water supply structure; a temperature sensor is arranged on the surge tank; the water spraying pipeline is opened or closed according to the temperature in the pressure equalizing box, and the pressure and the temperature in the pressure equalizing box are maintained in a set value range, so that the sealing stability of the shaft seal end and the normal operation of a unit are ensured; the technical problems that in the prior art, due to the fact that the temperature of a pressure equalizing box on a steam turbine is too high, steam turbine parts are damaged, a steam sealing system is solved, and the pressure equalizing box is abnormal in function are solved. The two redundant water spraying pipelines and the spraying electromagnetic valve are adopted to control attemperation water, and the problem that the attemperation water cannot be sprayed out in time when the spraying electromagnetic valve breaks down is solved.

Description

Technical Field

[0001] The utility model belongs to the field of steam turbines and relates to a cooling device, in particular to a cooling device for a steam turbine shaft seal. Background Art

[0002] During steam turbine operation, a suitable gap must be maintained between the rotor and the cylinder to prevent collisions. This gap inevitably causes high-pressure steam to leak out of the turbine, resulting in fluid loss, deteriorating the operating environment, and potentially heating the shaft or entering the bearings, degrading the lubricant. Air can also leak into the turbine's low-pressure cylinder, disrupting the vacuum, increasing the load on the steam extraction equipment and reducing unit efficiency. Shaft seals are installed to prevent steam leakage from the high-pressure cylinder, minimize air leakage losses, and prevent air from leaking into the low-pressure cylinder, potentially compromising the unit's vacuum.

[0003] However, while steam turbines are equipped with shaft seals, which can reduce some steam leakage, they cannot completely eliminate it. Furthermore, due to the high temperatures at the shaft seals, they are extremely susceptible to damage, which in turn affects the normal operation of the steam turbine. To address this issue, various approaches have been adopted, such as changing the shaft seal material and adding shaft seal cooling channels. However, these solutions have drawbacks, such as high material costs, poor cooling performance, and inability to improve steam turbine operating efficiency and reliability.

[0004] In order to completely prevent and avoid steam leakage, ensure normal start-up and shutdown and operation of the unit, and recover the leaked steam and utilize the heat of the leaked steam, the existing technology is to set a pressure equalizing tank between the high-pressure cylinder and the intermediate-pressure cylinder of the turbine to achieve pressure balance between the high-pressure steam and the intermediate-pressure steam. However, the temperature of the pressure equalizing tank is too high, which can cause damage to the turbine components, problems with the steam seal system, and abnormal function of the pressure equalizing tank. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a cooling device for a turbine shaft seal to solve the technical problems in the existing technology that the temperature of the equalizing pressure box on the turbine is too high, causing damage to turbine components, problems with the steam seal system and abnormal function of the equalizing pressure box.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A temperature reduction device for a steam turbine shaft seal, comprising a pressure equalizing tank, the pressure equalizing tank being provided with multiple water spray pipes, each of the water spray pipes being provided with a spray solenoid valve, one end of each water spray pipe being provided with a nozzle, the nozzle being located within the pressure equalizing tank, and the other end of each water spray pipe being commonly connected to an external water supply structure;

[0008] The pressure equalizing box is provided with a temperature sensor.

[0009] The utility model also includes the following steps:

[0010] A filtering structure is provided between the water spraying pipe and the external water supply structure.

[0011] The filtering structure is a Y-shaped filter screen or a filter.

[0012] Each of the water spray pipelines is provided with a stop valve.

[0013] The temperature sensor is a thermal resistor, a thermocouple or a remote thermometer.

[0014] It also includes an external control system, which is electrically connected to the spray solenoid valve and the temperature sensor respectively.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects:

[0016] (I) The present invention opens or closes the water spray pipe according to the temperature in the pressure equalizing box, and maintains the pressure and temperature in the pressure equalizing box within the set value range, thereby ensuring the stability of the shaft seal end and the normal operation of the unit, and solving the technical problems in the prior art of excessive temperature of the pressure equalizing box on the steam turbine, which leads to damage to the turbine components, problems with the steam seal system, and abnormal function of the pressure equalizing box.

[0017] (II) The present invention adopts two redundant water spray pipes and a spray solenoid valve to control the cooling water, thereby solving the problem that the cooling water cannot be sprayed out in time when the spray solenoid valve fails.

[0018] (III) The nozzle in the present invention is arranged in the pressure equalizing box, so that the timeliness of the temperature reduction can be more effectively ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the present utility model.

[0020] The meanings of the various numbers in the figure are: pressure equalizing box 1, water spraying pipe 2, spray solenoid valve 3, nozzle 4, temperature sensor 5, filtering structure 6, and stop valve 7.

[0021] The specific contents of the present invention are further explained in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0022] It should be noted that, unless otherwise specified, all components in the present invention are components known in the art.

[0023] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the scope of protection of the present invention.

[0024] The utility model discloses a temperature reduction device for a steam turbine shaft seal, such as Figure 1 As shown, it includes a pressure equalizing box 1, on which multiple water spray pipes 2 are provided, each of which is provided with a spray solenoid valve 3, and one end of each water spray pipe 2 is provided with a nozzle 4, which is located inside the pressure equalizing box 1, and the other end of each water spray pipe 2 is commonly connected to an external water supply structure;

[0025] A temperature sensor 5 is provided on the pressure equalizing box 1 .

[0026] In the above technical solution, when the temperature in the pressure equalizing tank 1 is higher than the set temperature, the cooling water is divided into two paths from the external water supply structure and enters the water spray pipe 2 respectively, and reaches the nozzle 4 of the pressure equalizing tank after passing through the spray solenoid valve 3. The temperature sensor 5 to be remotely transmitted monitors the temperature in the pressure equalizing tank 5. When the temperature of the pressure equalizing tank is higher than 200°C, the spray solenoid valve 3 is opened, and the water spray pipe 2 is controlled to open, and the cooling water is sprayed from the nozzle; when the temperature of the pressure equalizing tank is lower than 190°C, the spray solenoid valve 3 is closed, and the spray solenoid valve 3 controls the water spray pipe 2 to close, and the nozzle stops spraying.

[0027] The water spray pipe 2 is opened or closed according to the temperature in the pressure equalizing box 1, and the pressure and temperature in the pressure equalizing box 1 are maintained within the set value range, thereby ensuring the stability of the shaft seal end and the normal operation of the unit, and solving the technical problems in the prior art of excessive temperature of the pressure equalizing box 1 on the turbine causing damage to turbine components, steam seal system problems and abnormal function of the pressure equalizing box.

[0028] Two redundant water spray pipes 2 and spray solenoid valves 3 are used to control the cooling water, which solves the problem that the cooling water cannot be sprayed out in time when the spray solenoid valve 3 fails. The nozzle 4 is set in the pressure equalizing box 1, which can more effectively ensure the timeliness of cooling.

[0029] A filtering structure 6 is provided between the water spraying pipe 2 and the external water supply structure.

[0030] In the above technical solution, the filter structure 6 is used to filter out impurities in the water, ensure the cleanliness of the spray water, and prevent the water spray pipe 2 or the nozzle 4 from being blocked.

[0031] The filtering structure 6 is a Y-shaped filter or a filter.

[0032] In the above technical solution, considering the simplicity of installation, it is recommended to use a Y-type filter.

[0033] Each water spray pipeline 2 is provided with a stop valve 7 .

[0034] In the above technical solution, the stop valve 7 is used to manually control whether the water spray pipe 2 is open, so that when the spray solenoid valve 3 is out of control, manual adjustment can be made to control the on and off of the water spray pipe.

[0035] The temperature sensor 5 is a thermal resistor, a thermocouple or a remote thermometer.

[0036] It also includes an external control system, which is electrically connected to the spray solenoid valve 3 and the temperature sensor 5 respectively.

[0037] In the above technical solution, the temperature alarm value of the pressure equalizing box is set to 200°C, and the temperature sensor 5 transmits the temperature of the pressure equalizing box 1 to the control system (DCS / CCS, etc.). When the temperature is higher than 200°C, the control system sends a signal to the spray solenoid valve 3, and the spray solenoid valve 3 controls the water spray pipe 2 to open, and the cooling water is sprayed from the nozzle 4; when the temperature is lower than 190°C, the control system sends a signal to the spray solenoid valve 3, and the spray solenoid valve 3 controls the cooling water circuit to close, and the cooling water stops being sprayed from the nozzle 4.

Claims

1. A temperature reduction device for a steam turbine shaft seal, comprising a pressure equalizing box (1), characterized in that: The pressure equalizing box (1) is provided with a plurality of water spray pipes (2), each of which is provided with a spray solenoid valve (3), one end of each of which is provided with a nozzle (4), the nozzle (4) being located inside the pressure equalizing box (1), and the other end of each of which is commonly connected to an external water supply structure; The pressure equalizing box (1) is provided with a temperature sensor (5).

2. The temperature reducing device for a steam turbine shaft seal according to claim 1, characterized in that: A filtering structure (6) is provided between the water spraying pipe (2) and the external water supply structure.

3. The temperature reduction device for a steam turbine shaft seal according to claim 2, characterized in that: The filtering structure (6) is a Y-shaped filter screen or a filter.

4. The temperature reducing device for a steam turbine shaft seal according to claim 1, characterized in that: Each of the water spray pipes (2) is provided with a stop valve (7).

5. The temperature reduction device for a steam turbine shaft seal according to claim 1, characterized in that: The temperature sensor (5) is a thermal resistor, a thermocouple or a remote thermometer.

6. The temperature reduction device for a steam turbine shaft seal according to claim 1, characterized in that: It also includes an external control system, which is electrically connected to the spray solenoid valve (3) and the temperature sensor (5) respectively.

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