阅读说明：本技术 一种火电厂三级旁路系统 (Tertiary bypass system of thermal power plant ) 是由 程瑞华 邬江虎 付利民 周桓 钟铭 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种火电厂三级旁路系统,包括锅炉过热器、连接块、活动块、限位板、配重块和限位筒,所述安全阀主体的上方设置有安全阀上盖,所述安全阀主体与安全阀上盖的连接处安装有紧固螺栓,所述安全阀上盖的内部设置有限位弹簧,所述限位弹簧的下方设置有连接块,所述连接块的下方安装有活动块,所述活动块的末端设置有限位板,所述限位板与连接管的末端相连接,所述连接块的上方连接有配重块,所述配重块的外侧设置有限位筒,且限位筒安装在安全阀上盖的上方。该火电厂三级旁路系统设置有高压旁路、中压旁路布置在锅炉侧,充分考虑了汽轮机旁路系统整体布置的合理性,便于汽机房二列式布置,降低汽机房工程造价。(The invention discloses a three-level bypass system of a thermal power plant, which comprises a boiler superheater, a connecting block, a movable block, a limiting plate, a balancing weight and a limiting cylinder, wherein an upper safety valve cover is arranged above a main safety valve body, a fastening bolt is arranged at the joint of the main safety valve body and the upper safety valve cover, a limiting spring is arranged inside the upper safety valve cover, the connecting block is arranged below the limiting spring, the movable block is arranged below the connecting block, the limiting plate is arranged at the tail end of the movable block, the limiting plate is connected with the tail end of a connecting pipe, the balancing weight is connected above the connecting block, the limiting cylinder is arranged outside the balancing weight, and the limiting cylinder is arranged above the upper safety valve cover. This tertiary bypass system of thermal power plant is provided with high-pressure bypass, middling pressure bypass and arranges in the boiler side, has fully considered the rationality that steam turbine bypass system wholly arranged, and the steam turbine room of being convenient for is two to be listed as and is arranged, reduces steam turbine room engineering cost.)

1. The utility model provides a tertiary bypass system of thermal power plant, includes boiler superheater (1), connecting block (26), movable block (27), limiting plate (28), balancing weight (29) and spacing section of thick bamboo (30), its characterized in that: the high-pressure bypass (18) is provided with a boiler superheater (1), a VHP bypass valve (2), a VHP regulating valve (3), a VHP vent valve (4) and an ultrahigh-pressure cylinder VHP (5), the medium-pressure bypass (19) is provided with a primary reheater RH1 (6), an HP bypass valve (7), an HP regulating valve (8), an HP check valve (9), a high-pressure cylinder HP (10) and an HP vent valve (11), the low-pressure bypass (20) is provided with a secondary reheater RH2 (12), an IP regulating valve (13), an IP bypass valve (14) and a medium-pressure cylinder IP (15), the inside of the tail end of the safety valve main body (21) is provided with a connecting pipe (22), a safety valve upper cover (23) is arranged above the safety valve main body (21), a fastening bolt (24) is arranged at the joint of the safety valve main body (21) and the safety valve upper cover (23), and a limit spring (25) is arranged inside the safety valve upper, the safety valve is characterized in that a connecting block (26) is arranged below the limiting spring (25), a movable block (27) is arranged below the connecting block (26), a limiting plate (28) is arranged at the tail end of the movable block (27), the limiting plate (28) is connected with the tail end of the connecting pipe (22), a balancing weight (29) is connected above the connecting block (26), a limiting cylinder (30) is arranged on the outer side of the balancing weight (29), and the limiting cylinder (30) is arranged above the upper cover (23) of the safety valve.

2. The three-stage bypass system of a thermal power plant as recited in claim 1, wherein: the high-pressure bypass (18) is arranged on the boiler room about 80m layer, the medium-pressure bypass (19) is arranged on the furnace front 8.6m layer, and the low-pressure bypass (20) is arranged on the steam turbine room 8.6 m.

3. The three-stage bypass system of a thermal power plant as recited in claim 1, wherein: the high-pressure bypass (18) adopts a three-way valve system with a safety valve function, the capacity is 100 percent BMCR, the capacities of the medium-pressure bypass (19) and the low-pressure bypass (20) are set according to the requirement of meeting the starting flow of the unit, and the VHP bypass valve (2), the HP bypass valve (7) and the IP bypass valve (14) are hydraulically controlled.

4. The three-stage bypass system of a thermal power plant as recited in claim 1, wherein: the safety valve main body (21) and the safety valve upper cover (23) are fixedly connected through a fastening bolt (24), and the limiting cylinder (30) and the safety valve upper cover (23) are fixedly connected.

5. The three-stage bypass system of a thermal power plant as recited in claim 1, wherein: the movable block (27) forms a vertical movable structure in the safety valve upper cover (3) through a limiting spring (25).

6. The three-stage bypass system of a thermal power plant as recited in claim 1, wherein: the inside of a limiting cylinder (30) is of a hollow structure, and a balancing weight (29) inside the limiting cylinder (30) forms an up-and-down sliding structure through a connecting block (26).

Technical Field

The invention relates to the field of main reheat steam and bypass systems of thermal power plants, in particular to a three-level bypass system of a thermal power plant.

Background

The million secondary reheating ultra-supercritical unit is suitable for the constant pressure and sliding pressure operation of the unit at present, the cold state, temperature state and hot state starting performance of the unit is improved, the condition that a reheater is not burnt is guaranteed, a high-pressure, medium-pressure and low-pressure three-level series bypass system is adopted, a high-pressure bypass is connected out from two main steam pipelines in front of an inlet of an ultra-high pressure cylinder of a steam turbine and is connected to a cold primary reheating steam pipeline after temperature and pressure reduction, a medium-pressure bypass is connected out from two branch pipes of steam in a front primary reheating section in the inlet of a high pressure cylinder of the steam turbine respectively and is connected into a secondary reheating cold section steam pipeline after temperature and pressure reduction, and a low-pressure bypass is connected out from two branch pipes of steam in a front secondary reheating section.

The existing design law generally arranges a high-pressure bypass on about 13.7m layers of a steam turbine room, and has no safety door function; the medium and low pressure bypass device is a starting bypass, a medium pressure bypass valve is arranged on a layer of 8.60m in front of the boiler, a low pressure bypass is arranged on a layer of 8.60m in a steam turbine room, and two problems exist:

(1) the high-pressure bypass is arranged on about 13.7m layer of a steam turbine room, a safety valve must be designed at the outlet of a boiler superheater, the pressure grade of the safety valve is very high, the safety valve is easy to generate non-return seat when the safety valve moves out, and the internal leakage is easy to occur;

(2) the high, medium and low pressure bypasses are uniformly arranged in the steam turbine room, so that the space of the steam turbine room is occupied, the layout is unreasonable, and the construction cost is increased;

we propose a three-stage bypass system for a thermal power plant in order to solve the problems set forth above.

Disclosure of Invention

The invention aims to provide a three-level bypass system of a thermal power plant, which aims to solve the problems that the safety valve provided by the background technology has high pressure level, is easy to generate non-return seat when moving and is easy to leak inwards; the high, medium and low pressure bypasses are uniformly distributed in the steam turbine room, which can cause the space of the steam turbine room to be occupied and unreasonable layout and increase the construction cost.

In order to achieve the purpose, the invention provides the following technical scheme: a three-level bypass system of a thermal power plant comprises a boiler superheater, a connecting block, a movable block, a limiting plate, a balancing weight and a limiting cylinder, wherein the boiler superheater, a VHP bypass valve, a VHP regulating valve, a VHP vent valve and a VHP pressure cylinder are arranged on a high-pressure bypass, a primary reheater RH1, an HP bypass valve, an HP regulating valve, an HP check valve, a high-pressure cylinder HP and an HP vent valve are arranged on a medium-pressure bypass, a secondary reheater RH2, an IP regulating valve, an IP bypass valve and a medium-pressure cylinder are arranged on a low-pressure bypass, a connecting pipe is arranged inside the tail end of a safety valve main body, a safety valve upper cover is arranged above the safety valve main body, a fastening bolt is installed at the connecting position of the safety valve main body and the safety valve upper cover, a limiting spring is arranged inside the safety valve upper cover, a connecting block is arranged below the, the end of the movable block is provided with a limiting plate, the limiting plate is connected with the end of the connecting pipe, a balancing weight is connected above the connecting block, a limiting cylinder is arranged on the outer side of the balancing weight, and the limiting cylinder is arranged above the upper cover of the safety valve.

Preferably, the high-pressure bypass is arranged on about 80m layers of the boiler room, the medium-pressure bypass is arranged on 8.6m layers in front of the boiler, and the low-pressure bypass is arranged on 8.6m layers of the steam turbine room.

Preferably, the high-pressure bypass adopts a three-way valve system with a safety valve function, the capacity is 100% BMCR, the capacities of the medium-pressure bypass and the low-pressure bypass are set according to the requirement of meeting the starting flow of the unit, and the VHP bypass valve, the HP bypass valve and the IP bypass valve are hydraulically controlled.

Preferably, the safety valve main body and the safety valve upper cover form a fixed connection through a fastening bolt, and the limiting cylinder and the safety valve upper cover are fixedly connected.

Preferably, the movable block forms an up-and-down movable structure inside the safety valve upper cover through a limiting spring.

Preferably, the inside of a spacing section of thick bamboo is hollow structure, the balancing weight of the inside of a spacing section of thick bamboo passes through the connecting block and constitutes sliding structure from top to bottom.

Compared with the prior art, the invention has the beneficial effects that: this tertiary bypass system of thermal power plant is provided with:

(1) the high-pressure bypass and the medium-pressure bypass are arranged on the boiler side, the reasonability of the overall arrangement of a steam turbine bypass system is fully considered, the two-line arrangement of a steam turbine room is facilitated, and the engineering cost of the steam turbine room is reduced;

(2) the high-pressure bypass valve has the safety door function, a boiler superheater outlet safety door is omitted, the investment is reduced, meanwhile, the risk of leakage in the ultrahigh-pressure safety door is eliminated, and the operation safety of a steam turbine bypass system is fully considered.

Drawings

FIG. 1 is a schematic view of the position layout of the present invention;

FIG. 2 is a schematic view of the main section of the safety valve of the present invention;

FIG. 3 is a schematic view of the structure at A in FIG. 2 according to the present invention.

In the figure: 1. a boiler superheater; 2. a VHP bypass valve; 3. a VHP regulator valve; 4. a VHP vent valve; 5. an ultra-high pressure cylinder VHP; 6. primary reheater RH 1; 7. an HP bypass valve; 8. an HP regulator valve; 9. an HP check valve; 10. a high pressure cylinder HP; 11. an HP breather valve; 12. secondary reheater RH 2; 13. an IP regulating valve; 14. an IP bypass valve; 15. an intermediate pressure cylinder IP; 16. a low pressure cylinder LP; 17. a condenser; 18. a high pressure bypass; 19. a medium pressure bypass; 20. a low pressure bypass; 21. a safety valve main body; 22. a connecting pipe; 23. an upper cover of the safety valve; 24. fastening a bolt; 25. a limiting spring; 26. connecting blocks; 27. a movable block; 28. a limiting plate; 29. a balancing weight; 30. a limiting cylinder.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-3, the present invention provides a technical solution: a three-level bypass system of a thermal power plant comprises a boiler superheater 1, a VHP bypass valve 2, a VHP regulating valve 3, a VHP ventilation valve 4, an ultrahigh pressure cylinder VHP5, a primary reheater RH16, an HP bypass valve 7, an HP regulating valve 8, an HP check valve 9, a high pressure cylinder HP10, an HP ventilation valve 11, a secondary reheater RH212, an IP regulating valve 13, an IP bypass valve 14, an intermediate pressure cylinder IP15, a low pressure cylinder LP16, a condenser 17, a high pressure bypass 18, an intermediate pressure bypass 19, a low pressure bypass 20, a safety valve main body 21, a connecting pipe 22, a safety valve upper cover 23, a fastening bolt 24, a limiting spring 25, a connecting block 26, a movable block 27, a limiting plate 28, a balancing weight 29 and a limiting cylinder 30, wherein the boiler superheater 1, the VHP bypass valve 2, the VHP regulating valve 3, the VHP ventilation valve 4 and the ultrahigh pressure cylinder VHP5 are arranged on the high pressure bypass 18, a primary reheater RH16, the HP bypass valve 7, the HP, The high-pressure safety valve comprises an HP check valve 9, a high-pressure cylinder HP10 and an HP ventilation valve 11, wherein a secondary reheater RH212, an IP regulating valve 13, an IP bypass valve 14 and a medium-pressure cylinder IP15 are arranged on a low-pressure bypass 20, a connecting pipe 22 is arranged inside the tail end of a safety valve main body 21, a safety valve upper cover 23 is arranged above the safety valve main body 21, a fastening bolt 24 is installed at the joint of the safety valve main body 21 and the safety valve upper cover 23, a limiting spring 25 is arranged inside the safety valve upper cover 23, a connecting block 26 is arranged below the limiting spring 25, a movable block 27 is arranged below the connecting block 26, a limiting plate 28 is arranged at the tail end of the movable block 27, the limiting plate 28 is connected with the tail end of the connecting pipe 22, a balancing weight 29 is connected above the connecting block 26, a limiting.

The high-pressure bypass 18 is arranged on the layer of about 80m of the boiler room, the medium-pressure bypass 19 is arranged on the layer of 8.6m in front of the boiler, and the low-pressure bypass 20 is arranged on the layer of 8.6m of the steam turbine room, so that the overall arrangement reasonability of the steam turbine bypass system is fully considered.

The high-pressure bypass 18 adopts a three-way valve system with a safety valve function, the capacity is 100 percent BMCR, the capacities of the medium-pressure bypass 19 and the low-pressure bypass 20 are set according to the requirement of meeting the starting flow of the unit, the VHP bypass valve 2, the HP bypass valve 7 and the IP bypass valve 14 are all hydraulically controlled, and the operation safety of the turbine bypass system is considered.

The safety valve main body 21 and the safety valve upper cover 23 are fixedly connected through a fastening bolt 24, the limiting cylinder 30 and the safety valve upper cover 23 are fixedly connected, and the sealing performance of the device is maintained.

The movable block 27 forms a vertical movable structure inside the safety valve upper cover 3 through a limit spring 25.

The inside of the limiting cylinder 30 is of a hollow structure, and a balancing weight 29 inside the limiting cylinder 30 forms an up-and-down sliding structure through a connecting block 26.

The working principle is as follows: when the three-level bypass system of the thermal power plant is used, firstly, a first-level bypass BP1, namely a VHP5 bypass of an ultrahigh pressure cylinder is used, steam is exhausted from an outlet of a boiler superheater to a VHP5 of a turbine ultrahigh pressure cylinder, enters a first-level reheater RH16, enters the VHP5, is exhausted from the ultrahigh pressure cylinder VHP5 and then enters a first-level reheater RH16, the pressure of the first-level reheater RH16 is 4MPa when the system is started, so that the exhaust temperature of the ultrahigh pressure cylinder VHP5 is prevented from exceeding a maximum limit value of 530 ℃, a VHP ventilation valve 4 is configured on an ultrahigh pressure cylinder VHP5 exhaust cylinder, the valve does not participate in starting, the main functions are rapid exhaust during load shedding, a valve set of a high-pressure bypass 18 and an oil station are arranged on a layer of about 80m in a boiler room, and the high-pressure bypass 18 system adopts a three-purpose valve.

The medium pressure bypass 19 is a high pressure cylinder HP10 bypass, bypass steam is discharged from an outlet of a primary reheater RH16 to enter a secondary reheater RH212, namely is connected with high pressure cylinder HP10 exhaust steam, the steam entering a high pressure cylinder HP10 is discharged from a high pressure cylinder HP10 exhaust steam and also enters a secondary reheater, the medium pressure bypass 19 is used for controlling the pressure of the primary reheater RH16, when the high pressure reheater is started, the pressure of the secondary reheater RH212 is 0.5 MPa-1.3 MPa so as to avoid the limitation of the highest exhaust steam temperature of a high pressure cylinder HP10 to 500 ℃, the high pressure cylinder HP10 exhaust steam is also provided with an HP ventilation valve, similarly, the valve does not participate in the starting, the main function is rapid exhaust steam when load shedding is performed, and the medium pressure bypass 19 is arranged at a layer of 8.60m in front of the furnace.

The low-pressure bypass 20, namely the outlet of the secondary reheater RH212 to the condenser 17, plays a role in controlling the pressure of the secondary reheater RH2 RH212, and for the secondary reheat steam turbine, the influence of the pressure of the secondary reheater RH212 on the exhaust temperature of the high-pressure cylinder HP10 and the exhaust temperature of the intermediate pressure cylinder IP15 (low-pressure inlet) is opposite, therefore, the setting of the pressure of the secondary reheater RH212 during starting must ensure that the exhaust temperature of the high-pressure cylinder HP10 and the exhaust temperature of the intermediate pressure cylinder IP15 are in a safe range at the same time, and the low-pressure bypass 20 is arranged on a steam turbine room 8.60m layer. And those not described in detail in this specification are well within the skill of those in the art.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.