Steam turbine bypass system
By adding parallel bypass adjustment doors and condensate circuit bypasses in the turbine bypass system, the problems of easy damage to the adjustment doors and high power consumption of the condensate pump in the existing system are solved, and the stable operation of the unit and power saving are achieved.
Patent Information
- Application Number
- CN202421683373.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-17
- Publication Date
- 2025-04-29
- Estimated Expiration
- 2034-07-17
AI Technical Summary
The existing steam turbine bypass system has problems such as easy damage to the adjustment door, long maintenance period, high power consumption of the condensate pump, and shutdown for maintenance when the pump body is damaged.
In the original bypass system, a set of bypass adjustment doors are added in parallel with the original bypass adjustment doors, and a condensate circuit bypass is added. The frequency conversion of the condensate pump is adjusted when the sealed water booster pump is operated through each valve.
This avoids the problem of unit failure caused by damage to the bypass adjustment door, improves production efficiency, reduces the adverse effects of unit start and stop, and saves factory electricity through frequency conversion adjustment.
Smart Images
Figure CN222810856U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of steam turbines in power plants, in particular to a steam turbine bypass system. Background Art
[0002] Modern large-capacity thermal power generating units use unit units and intermediate reheating, so during operation, the operating conditions between the boiler and the steam turbine must be well coordinated. During the start-up and shutdown of the boiler and the steam turbine, as well as the adjustment of the boiler operating conditions when the steam turbine fails. In order to adapt the reheat unit to these special requirements and make it have good load adaptability, a bypass system is set up for the reheat unit, which is mainly used for heating the front shaft seal of the steam turbine. When the unit is started under various working conditions (cold, warm, hot and extremely hot), the bypass system is put into use to control the boiler steam temperature so that it matches the metal temperature of the steam turbine cylinder more quickly, thereby shortening the unit startup time and reducing steam discharge to the air, reducing the loss of the turbine cycle life, and achieving the best startup of the unit.
[0003] However, the existing bypass system has the following problems:
[0004] (1) Due to the large throttling amount and high steam parameters, the turbine bypass regulating valve frequently gets stuck and damaged, the maintenance period is long, and the unit cannot be started during maintenance.
[0005] (2) Since the steam temperature is high when the unit is started in hot state, the bypass system requires a large amount of cooling water, which requires increasing the condensate pressure, resulting in high power consumption of the condensate pump. In addition, when the water supply is high, if the pump body is damaged, it can only be shut down for maintenance.
[0006] In view of the above disadvantages, an improved steam turbine bypass system is provided. Summary of the invention
[0007] The technical solution adopted by the utility model to solve its technical problems is:
[0008] A steam turbine bypass system is provided, comprising a bypass connected to a first main steam pipeline and a second main steam pipeline, a condensate water loop is arranged at the front end of the bypass, a first sealing water booster pump and a second sealing water booster pump are arranged in parallel on the condensate water loop, a manual door in front of a desuperheating water regulating valve, a desuperheating water regulating valve and a manual door behind the desuperheating water regulating valve are arranged in series at the rear ends of the first sealing water booster pump and the second sealing water booster pump, a desuperheating water pipeline is arranged at the rear end of the manual door behind the desuperheating water regulating valve, a bypass desuperheater is arranged at the rear end of the desuperheater, a desuperheater rear bypass pipeline is arranged at one end of the bypass desuperheater, and a steam cooler is arranged at one end of the bypass desuperheater. A bypass first regulating gate and a bypass outlet electric gate are also sequentially arranged at the rear end of the desuperheater, and a desuperheating water bypass gate is added in parallel between the inlet end of the manual gate in front of the desuperheating water regulating gate and the outlet end of the manual gate behind the desuperheating water regulating gate of the desuperheating water pipeline; a bypass second regulating gate is added in parallel between the outlet end and the inlet end of the bypass first regulating gate; a condensate water circuit bypass is added between the condensate water circuit and the desuperheating water pipeline, the condensate water circuit bypass is connected in parallel with the first sealing water booster pump and the second sealing water booster pump, and a total desuperheating water outlet gate after the pump is arranged at the common outlet end of the first sealing water booster pump and the second sealing water booster pump, and a second check valve is arranged on the condensate water circuit bypass.
[0009] Preferably, a cooling water filter is further provided on the cooling water pipeline, and a cooling water filter front manual door is provided at the front end of the cooling water filter, and a cooling water filter rear manual door is provided at the rear end.
[0010] Preferably, a desuperheated water filter bypass door is provided at the front end of the desuperheated water filter front manual door and the rear end of the desuperheated water filter rear manual door.
[0011] Preferably, a first bypass drain gate is provided at the rear end of the first bypass regulating gate, and a second bypass drain gate is provided at the rear end of the second bypass regulating gate.
[0012] Preferably, the first check valve is provided at the rear end of the post-pump total desuperheating water outlet gate.
[0013] Preferably, a flow measuring device is provided at the front end of the second check valve.
[0014] Preferably, a bypass front gate is provided on the bypass pipe after the desuperheater, and a steam-water separator is provided at the rear end of the bypass front gate.
[0015] Preferably, a steam trap is provided at the rear end of the steam-water separator, a front manual door of the steam trap is provided at the front end of the steam trap, and a rear manual door of the steam trap is provided at the rear end of the steam trap.
[0016] Preferably, a drain bypass door is provided between the front end of the steam trap front manual door and the steam trap rear manual door.
[0017] The beneficial effect of the utility model is that the utility model adds a set of bypass regulating doors on the basis of the original regulating doors and connects them in parallel with the original bypass regulating doors, so as to avoid the failure of the unit to start due to damage of the bypass regulating doors. After adding a set of bypass regulating doors, the original bypass regulating doors can also be repaired and maintained when the unit is running, so as to improve production efficiency and effectively avoid the disadvantages caused by the start and stop of the unit.
[0018] In addition, a condensate water circuit bypass is added. Firstly, it can replace the original condensate water bypass during maintenance. Secondly, it can be put into operation at the same time as the original condensate water bypass. By switching the valves, when the sealing water booster pump is running, the condensate water pump can be frequency-controlled to a low speed to save factory electricity. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0020] Figure 1 It is a schematic diagram of the structure of a steam turbine bypass system in the prior art;
[0021] Figure 2 It is a schematic diagram of the structure of the improved steam turbine bypass system in the embodiment of the utility model;
[0022] In the figure: a-bypass, b1-first main steam pipeline, b2-second main steam pipeline, c-high pressure cylinder, d-condensate circuit, e-steam cooler, f-desuperheating water pipeline, g-bypass pipeline after desuperheater, h-condensate circuit bypass, 1-bypass outlet electric door, 2-bypass desuperheater, 3-first sealing water booster pump, 4-second sealing water booster pump, 6-manual door before desuperheating water regulating valve, 7-desuperheating water regulating valve, 8-manual door after desuperheating water regulating valve, 9-desuperheating water bypass door, 10-bypass first regulating door, 11- Manual door in front of cooling water filter, 12-cooling water filter, 13-manual door after cooling water filter, 14-cooling water filter bypass door, 15-bypass front cut-off door, 16-steam-water separator, 17-manual door in front of steam trap, 18-steam trap, 19-manual door after steam trap, 20-drain bypass door, 21-total cooling water outlet door after pump, 22-first check valve, 23-flow measuring device, 24-second check valve, 25-bypass second regulating door, 26-bypass first drain gate, 27-bypass second drain gate. DETAILED DESCRIPTION
[0023] The above scheme is further described below in conjunction with specific examples. It should be understood that these examples are used to illustrate the utility model rather than to limit the scope of the utility model. The implementation conditions used in the examples can be further adjusted according to the conditions of the specific manufacturer, and the implementation conditions not specified are usually the conditions in conventional experiments.
[0024] In a specific embodiment, a turbine bypass system is provided, including a bypass a connected to the existing first main steam pipeline b1 and the second main steam pipeline b2. As in the prior art, the first main steam pipeline b1 and the second main steam pipeline b2 in this example are both connected to the high-pressure cylinder c. Bypass a is mainly used for heating the front shaft seal of the turbine. The bypass system is put into use to control the boiler steam temperature so that it matches the metal temperature of the turbine cylinder more quickly, so that it has good load adaptability, shortens the unit startup time and reduces steam discharge to the air, reduces the loss of turbine cycle life, and achieves the best startup of the unit.
[0025] In order to realize the operation of bypass a, a condensate water circuit d is specifically arranged at the front end of bypass a, and a first sealing water booster pump 3 and a second sealing water booster pump 4 are arranged in parallel on the condensate water circuit d, and a manual door 6 in front of a cooling water regulating valve, a cooling water regulating valve 7 and a manual door 8 after the cooling water regulating valve are arranged in series at the rear ends of the first sealing water booster pump 3 and the second sealing water booster pump 4, a cooling water pipeline f is arranged at the rear end of the manual door 8 after the cooling water regulating valve, a bypass desuperheater 2 is arranged at the rear end of the bypass desuperheater 2, a bypass pipe g after the desuperheater is arranged at one end, and a steam cooler e is arranged at one end of the bypass desuperheater 2, and a bypass first regulating door 10 and a bypass outlet electric door 1 are also arranged in sequence at the rear end of the bypass desuperheater 2.
[0026] In order to avoid the unit being unable to start after the existing bypass system fails, resulting in the occurrence of an unplanned shutdown of the unit, this example adds an auxiliary pipeline in parallel at the faulty component and adds a parallel pipeline regulating gate. In addition, since the steam temperature is high when the unit is hot-started, the bypass system requires a large amount of cooling water, so a condensate loop bypass h is also added. Specifically, a cooling water bypass gate 9 is added in parallel between the inlet end of the cooling water regulating gate front manual gate 6 of the cooling water pipeline f and the outlet end of the cooling water regulating gate rear manual gate 8. When the cooling water regulating gate 7, the cooling water regulating gate front manual gate 6 and the cooling water regulating gate rear manual gate 8 need to be repaired or fail, the cooling water bypass gate 9 can be started to maintain the normal operation of the unit;
[0027] Similarly, a bypass second regulating door 25 is added in parallel at the outlet and inlet of the bypass first regulating door 10; when the bypass first regulating door 10 is overhauled, the bypass second regulating door 25 is started to maintain the normal operation of the unit.
[0028] In addition, a condensate circuit bypass h is added between the condensate circuit d and the cooling water pipeline f, the condensate circuit bypass h is connected in parallel with the first sealing water booster pump 3 and the second sealing water booster pump 4, and a post-pump total cooling water outlet gate 21 is arranged at the common outlet end of the first sealing water booster pump 3 and the second sealing water booster pump 4, and a first check valve 24 is arranged on the condensate circuit bypass h. Similarly, the condensate circuit bypass h can replace the first sealing water booster pump 3 and the second sealing water booster pump 4 to ensure the normal operation of the bypass system during maintenance or failure. In addition, the condensate circuit bypass h and the first sealing water booster pump 3 and the second sealing water booster pump 4 can be put into operation at the same time, and the valves can be switched. When the sealing water booster pump is running, the condensate pump can be frequency-controlled to a low speed to save factory electricity.
[0029] On this basis, in order to achieve pipeline filtration and prevent unmeasured water from entering the unit, thus extending the life of the unit, a cooling water filter 12 is also provided on the cooling water pipeline f, and a cooling water filter front manual door 11 is provided at the front end of the cooling water filter 12, and a cooling water filter rear manual door 13 is provided at the rear end. Similarly, in order to avoid shutdown during maintenance or failure, a cooling water filter bypass door 14 is provided at the front end of the cooling water filter front manual door 11 and the rear end of the cooling water filter rear manual door 13.
[0030] In addition, a bypass first drain gate 26 is provided at the rear end of the bypass first regulating gate 10, and a second drain gate 27 is provided at the rear end of the bypass second regulating gate 25. In this way, the remaining water can be drained during maintenance and repair, and the cleaning water can be discharged when cleaning the bypass.
[0031] A first check valve 22 is provided at the rear end of the total cooling water outlet gate 21 after the pump to prevent water from flowing back during inspection and maintenance, thereby facilitating maintenance operations.
[0032] In addition, a flow measurement device 23 is provided at the front end of the second check valve 24, which can facilitate the detection of the bypass flow of the condensate circuit and help control the condensate flow.
[0033] A bypass front gate 15 is provided on the bypass pipe g after the desuperheater, and a steam-water separator 16 is provided at the rear end of the bypass front gate 15. Due to the large amount of desuperheating water and poor atomization, the steam pipe after desuperheating of the bypass system vibrates greatly. A set of steam-water separators is added to the bypass pipe after the desuperheater to prevent the pipe vibration from damaging the equipment due to poor atomization of the desuperheating water. On this basis, in order to realize the automatic discharge of water at the rear end of the steam-water separator 16, a steam trap 18 is provided at the rear end of the steam-water separator 16, a steam trap front manual door 17 is provided at the front end of the steam trap 18, and a steam trap rear manual door 19 is provided at the rear end of the steam trap 18 to realize the control of the pipeline. Similarly, a steam trap bypass door 20 is provided between the front end of the steam trap front manual door 17 and the steam trap rear manual door 19 for easy maintenance and repair.
[0034] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the technical concept of the invention through the above description. The technical scope of the invention is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. A steam turbine bypass system, characterized in that: The invention comprises a bypass (a) connected to a first main steam pipeline (b1) and a second main steam pipeline (b2); a condensate circuit (d) is arranged at the front end of the bypass (a); a first sealing water booster pump (3) and a second sealing water booster pump (4) are arranged in parallel on the condensate circuit (d); a manual door (6) in front of a cooling water regulating valve, a cooling water regulating valve (7) and a manual door (8) behind the cooling water regulating valve are arranged in series at the rear ends of the first sealing water booster pump (3) and the second sealing water booster pump (4); a cooling water pipeline (f) is arranged at the rear end of the manual door (8) behind the cooling water regulating valve; a bypass desuperheater (2) is arranged at the rear end of the bypass desuperheater (2); a desuperheater rear bypass pipeline (g) is arranged at one end of the bypass desuperheater (2); a steam cooler (e) is arranged at the rear end of the bypass desuperheater (2); a steam cooler (e ... A bypass first regulating gate (10) and a bypass outlet electric gate (1) are provided, and are characterized in that: a cooling water bypass gate (9) is added in parallel between the inlet end of the manual gate (6) before the cooling water regulating gate and the outlet end of the manual gate (8) after the cooling water regulating gate of the cooling water pipeline (f); a bypass second regulating gate (25) is added in parallel between the outlet end and the inlet end of the bypass first regulating gate (10); a condensate water circuit bypass (h) is added between the condensate water circuit (d) and the cooling water pipeline (f), the condensate water circuit bypass (h) is connected in parallel with the first sealing water booster pump (3) and the second sealing water booster pump (4), and a total cooling water outlet gate (21) after the pump is provided at the common outlet end of the first sealing water booster pump (3) and the second sealing water booster pump (4), and a second check valve (24) is provided on the condensate water circuit bypass (h).
2. A steam turbine bypass system according to claim 1, characterized in that: A cooling water filter (12) is also provided on the cooling water pipeline (f), and a cooling water filter front manual door (11) is provided at the front end of the cooling water filter (12), and a cooling water filter rear manual door (13) is provided at the rear end.
3. A steam turbine bypass system according to claim 2, characterized in that: A desuperheated water filter bypass door (14) is provided at the front end of the desuperheated water filter front manual door (11) and the rear end of the desuperheated water filter rear manual door (13).
4. A steam turbine bypass system according to claim 1, characterized in that: A bypass first drain gate (26) is provided at the rear end of the bypass first regulating gate (10), and a second drain gate (27) is provided at the rear end of the bypass second regulating gate (25).
5. A steam turbine bypass system according to claim 1, characterized in that: A first non-return valve (22) is arranged at the rear end of the post-pump total desuperheated water outlet gate (21).
6. A steam turbine bypass system according to claim 1, characterized in that: A flow measurement device (23) is arranged at the front end of the second check valve (24).
7. A steam turbine bypass system according to claim 1, characterized in that: A bypass front gate (15) is arranged on the bypass pipe (g) after the desuperheater, and a steam-water separator (16) is arranged at the rear end of the bypass front gate (15).
8. A steam turbine bypass system according to claim 7, characterized in that: A steam trap (18) is arranged at the rear end of the steam-water separator (16), a steam trap front manual door (17) is arranged at the front end of the steam trap (18), and a steam trap rear manual door (19) is arranged at the rear end of the steam trap (18).
9. A steam turbine bypass system according to claim 8, characterized in that: A steam trap bypass door (20) is provided between the front end of the steam trap front manual door (17) and the steam trap rear manual door (19).