High-efficiency ultra-supercritical single-reheat split-shaft steam turbine bypass system

Abstract

A high-efficiency ultra-supercritical single-stage reheat split-shaft steam turbine bypass system includes a high-parameter module, which includes a high-pressure cylinder connected to a coaxial first-stage intermediate-pressure cylinder and generator A; a low-parameter module, which includes a second-stage intermediate-pressure cylinder connected to a coaxial low-pressure cylinder and generator B, with a condenser located at the outlet of the low-pressure cylinder; and a bypass system including a high-pressure bypass, a low-pressure bypass, and a connecting pipe bypass. The high-pressure bypass is connected to the superheater and reheater, the low-pressure bypass is connected to the reheater and the connecting pipe, and the connecting pipe bypass is connected to the connecting pipe and the condenser. This invention requires less high-temperature resistant material, has shorter pipe lengths and uses less pipe material, and fewer weld seams. The pipeline layout is simple, utilizing the connecting pipe's route from the semi-high-level turbine hall to the low-level turbine hall, reducing the use of large-diameter pipes, optimizing the plant layout, and facilitating inspection and maintenance. It is also low-cost and economical.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thermal power plant unit design, and particularly relates to a bypass system of a high-efficiency ultra-supercritical single-reheat split-shaft steam turbine. BACKGROUND

[0002] With the deepening development of coal energy conservation and emission reduction, the efficiency of coal-fired power generation gradually rises, and the high-parameter high-efficiency ultra-supercritical coal-fired power generation technology of 630-650 DEG C can effectively improve the energy utilization rate, which is a key technology for improving power generation efficiency and reducing unit energy consumption level. However, in such high-parameter generating units, the materials used in the conventional steam turbine cylinder and rotor and the high-temperature pipe material cannot meet the high-temperature requirements, and the main machine manufacturing is difficult, the high-temperature material research and development is difficult, and the price is expensive, so the conventional steam turbine type and arrangement method are no longer applicable, and the conventional bypass system is no longer applicable.

[0003] At present, in order to solve the problem, the method used in the market is disclosed in patent publication No. CN 103925013B, which is a bypass system of an ultra-supercritical double-shaft turbine, which is coaxial with the ultra-high pressure cylinder and the high pressure cylinder, and the medium pressure cylinder and the low pressure cylinder, and an ultra-high pressure bypass is arranged between the inlet and outlet of the ultra-high pressure cylinder, a high pressure bypass is arranged between the inlet and outlet of the high pressure cylinder, and a medium-low pressure bypass is arranged between the outlet of the secondary reheater and the condenser. But the pipeline of this system is complex, the amount of bypass system pipeline is large, the diameter of the pipeline after the bypass valve is usually about 1 meter, which is thick and long, which is not conducive to the layout of the plant and the waste of pipe material is serious. SUMMARY

[0004] In order to solve the problems of high-parameter ultra-supercritical steam turbine unit requiring high-temperature resistant materials, complex bypass system pipeline, long pipeline and large amount of pipe material, and difficult plant layout, the present application provides a bypass system of a high-efficiency ultra-supercritical single-reheat split-shaft steam turbine, which reduces the length of the high-temperature pipeline and the amount of high-temperature material, reduces the amount of bypass system pipeline, and optimizes the plant layout.

[0005] In order to achieve the above object, the technical scheme of the present application is: a bypass system of high-efficiency ultra-supercritical once-reheat split-shaft steam turbine, comprising: a high-parameter module, comprising a high-pressure cylinder, the high-pressure cylinder being connected with a coaxial first intermediate-pressure cylinder and a generator A; a low-parameter module, comprising a second intermediate-pressure cylinder, the second intermediate-pressure cylinder being connected with a coaxial low-pressure cylinder and a generator B, and the low-pressure cylinder being provided with a condenser at an outlet thereof; a boiler system, comprising a superheater and a reheater, the superheater being connected with the high-pressure cylinder through a pipeline, and the reheater being connected with the first intermediate-pressure cylinder and the high-pressure cylinder through a pipeline, the boiler system comprising an economizer, and an inlet of the economizer being communicated with a high-pressure feedwater pipeline; a bypass system, comprising a high-pressure bypass, a low-pressure bypass and a communication-pipe bypass, an inlet and an outlet of the high-pressure bypass being respectively communicated with an outlet pipeline of the superheater and an inlet pipeline of the reheater, an inlet and an outlet of the low-pressure bypass being respectively communicated with an outlet pipeline of the reheater and a communication pipe between the two intermediate-pressure cylinders, and an inlet and an outlet of the communication-pipe bypass being respectively communicated with the communication pipe between the two intermediate-pressure cylinders and an interface of the condenser. In the arrangement of the steam turbine house, the high-parameter module is arranged in a semi-high-position steam turbine house, and the low-parameter module is arranged in a low-position steam turbine house. This split-shaft arrangement mode makes the temperature and pressure of steam decreased after entering the low-parameter module from the high-parameter module, so that the cylinder body, rotor and related pipelines in the low-parameter module adopt conventional materials, thereby reducing the amount of high-temperature materials, which is beneficial to reducing the cost and saving the economy; the split-shaft arrangement mode optimizes the arrangement of the plant house, and the maintenance and operation are more convenient.

[0006] As a preferred, the first intermediate-pressure cylinder is provided with a communication pipe A and a communication pipe B, and the communication pipe A and the communication pipe B are respectively connected with the second intermediate-pressure cylinder. The first intermediate-pressure cylinder and the second intermediate-pressure cylinder are connected through the communication pipe A and the communication pipe B. The steam in the first intermediate-pressure cylinder does work and then enters the communication pipe A and the communication pipe B from the outlet of the first intermediate-pressure cylinder, and then enters the second intermediate-pressure cylinder to continue to do work. In the arrangement of the plant house, the communication pipe A and the communication pipe B are also the communication system of the high-parameter module arranged in the semi-high-position steam turbine house and the low-parameter module arranged in the low-position steam turbine house. Since the steam parameters of the communication pipes are low, high-temperature materials are not needed, which is beneficial to the arrangement and optimization of the plant house.

[0007] As a preferred, the low-pressure cylinder comprises a low-pressure cylinder A and a low-pressure cylinder B, and the condenser comprises a condenser A and a condenser B, the low-pressure cylinder A is connected with the condenser A, and the low-pressure cylinder B is connected with the condenser B. The low-pressure cylinder is located between the second intermediate-pressure cylinder and the generator B, and the low-pressure cylinder B is adjacent to the generator B. In the low-parameter module, the two ends of the shaft are respectively arranged with the second intermediate-pressure cylinder and the generator B, and the middle part is the low-pressure cylinder A close to the side of the second intermediate-pressure cylinder and the low-pressure cylinder B close to the side of the generator. The low-pressure cylinder A is connected with the condenser A at a steam exhaust port thereof. The exhaust steam from the low-pressure cylinder A enters the condenser to be condensed. The low-pressure cylinder B is connected with the condenser B at a steam exhaust port thereof, which is used for condensing the steam discharged from the low-pressure cylinder B.

[0008] As preferred, the high-pressure bypass comprises a high-pressure bypass valve, one end of which is communicated with the pipeline between the superheater and the high-pressure cylinder through a pipeline, and the other end of which is communicated with the pipeline between the reheater and the high-pressure cylinder through a pipeline. When the unit starts and is tripped off under load rejection, since the high-pressure cylinder admission valve is closed, the steam flowing from the superheater to the high-pressure cylinder does not enter the high-pressure cylinder, but directly flows into the high-pressure bypass, passes through the high-pressure bypass valve along the pipeline in the high-pressure bypass system, enters the pipeline between the high-pressure cylinder exhaust port and the reheater inlet, returns to the boiler reheater, thereby bypassing the high-pressure cylinder. The entire high-pressure bypass system is arranged on the operation layer of the semi-high-position turbine house, compared with the conventional low-position arranged high-temperature bypass system, the length of the pipeline in front of the high-temperature bypass valve is shorter, the amount of high-temperature material is saved, the system is simple and conducive to reducing the investment cost.

[0009] As preferred, the low-pressure bypass comprises a low-pressure bypass A and a low-pressure bypass B, the low-pressure bypass A comprises a low-pressure bypass valve A, one end of which is communicated with the pipeline between the reheater and the first-stage intermediate-pressure cylinder through a pipeline, and the other end of which is communicated with the communication pipe B through a pipeline. When the unit starts and is tripped off under load rejection, since the first-stage intermediate-pressure cylinder admission valve is closed, the steam from the high-pressure bypass flowing from the reheater to the first-stage intermediate-pressure cylinder does not enter the first-stage intermediate-pressure cylinder, but directly flows into the low-pressure bypass A, enters the communication pipe B through the low-pressure bypass valve A, and flows to the communication pipe bypass B of the low-position turbine house; the low-pressure bypass outlet pipeline is directly connected with the communication pipe, the system is simple and conducive to the space layout inside the plant, and the entire low-pressure bypass valve is arranged in the semi-high-position turbine house, compared with the conventional low-position arranged bypass system, the length of the pipeline in front of the low-pressure bypass valve is shorter, the amount of high-temperature material is saved, and the investment cost is reduced.

[0010] As preferred, the low-pressure bypass B comprises a low-pressure bypass valve B, one end of which is communicated with the pipeline between the reheater and the first-stage intermediate-pressure cylinder through a pipeline, and the other end of which is communicated with the communication pipe A through a pipeline. After the steam enters the reheater and is heated, it flows to the first-stage intermediate-pressure cylinder from two branch pipes, one of which is connected with the low-pressure bypass A, and the other of which is connected with the low-pressure bypass B; after the steam enters the low-pressure bypass B, it enters the communication pipe A through the low-pressure bypass valve B, and flows to the communication pipe bypass A of the low-position turbine house; the first-stage intermediate-pressure cylinder is bypassed through the low-pressure bypass A and the low-pressure bypass B.

[0011] As preferred, the bypass system comprises a communication pipe bypass A and a communication pipe bypass B, the communication pipe bypass A comprises a communication bypass valve A, one end of which is communicated with the communication pipe A through a pipeline, and the other end of which is communicated with the condenser A through a pipeline. When the unit starts and is tripped off under load rejection, since the second-stage intermediate-pressure cylinder admission valve is closed, the steam from the low-pressure bypass B does not enter the second-stage intermediate-pressure cylinder, but flows downward in the communication pipe A to the communication pipe bypass valve A, and then enters the condenser A for condensation.

[0012] As preferred, the intercommunication pipe bypass B comprises an intercommunication bypass valve B, one end of which is communicated with the intercommunication pipe B through a pipeline, and the other end of which is communicated with the condenser B through a pipeline. When the unit starts and is tripped off under load shedding, due to the closing of the inlet valve of the secondary intermediate pressure cylinder, the steam from the low pressure bypass A does not enter the secondary intermediate pressure cylinder, but flows downward in the intercommunication pipe B to the intercommunication pipe bypass valve B, and then enters the condenser B to be condensed; the secondary intermediate pressure cylinder and the low pressure cylinder are bypassed through the intercommunication pipe bypass A and the intercommunication pipe bypass B. The low pressure bypass cooperates with the intercommunication pipe bypass, so that the work of bypassing the primary intermediate pressure cylinder, the secondary intermediate pressure cylinder and the low pressure cylinder is completed.

[0013] As preferred, the secondary intermediate pressure cylinder is communicated with the low pressure cylinder A and the low pressure cylinder B through pipelines respectively.

[0014] The present application has the advantages of small demand for high temperature resistant materials, short pipeline length, small amount of pipe material, small number of welding seams, simple pipeline arrangement, reduced amount of large diameter pipeline by using the intercommunication pipe to be arranged from the semi-high position of the turbine room to the low position of the turbine room, optimized plant layout, and convenient inspection and maintenance, low cost and good economy. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a system schematic diagram of a high-efficiency ultra-supercritical once-reheat split-shaft steam turbine bypass system of the present application;

[0016] MEDIUM: 1. high pressure cylinder, 2. primary intermediate pressure cylinder, 2.1. intercommunication pipe A, 2.2. intercommunication pipe B, 3. generator A, 4. secondary intermediate pressure cylinder, 5. low pressure cylinder, 5.1. low pressure cylinder A, 5.2. low pressure cylinder B, 6. generator B, 7. superheater, 8. reheater, 9. economizer, 10. high pressure bypass, 10.1. high pressure bypass valve, 11. low pressure bypass, 11.1. low pressure bypass A, 11.1.1. low pressure bypass valve A, 11.2. low pressure bypass B, 11.2.1. low pressure bypass valve B, 12. condenser, 12.1. condenser A, 12.2. condenser B, 13. intercommunication pipe bypass A, 13.1. intercommunication bypass valve A, 14. intercommunication pipe bypass B, 14.1. intercommunication bypass valve B. DETAILED DESCRIPTION

[0017] Specific embodiment: as Figure 1As shown, a bypass system of a high-efficiency ultra-supercritical single-reheat split-shaft steam turbine includes a low-parameter module and a high-parameter module, wherein the high-parameter module is arranged in a semi-high-position turbine room, and the low-parameter module is arranged in a low-position turbine room; the high-parameter module includes a high-pressure cylinder 1, a first-stage intermediate-pressure cylinder 2 and a generator A 3 connected coaxially in sequence, and the low-parameter module includes a second-stage intermediate-pressure cylinder 4 and a generator B 6 connected coaxially, and a low-pressure cylinder 5 between the two, wherein the low-pressure cylinder 5 includes a low-pressure cylinder A 5.1 adjacent to the second-stage intermediate-pressure cylinder 4 and a low-pressure cylinder B 5.2 adjacent to the generator B 6, an exhaust port of the low-pressure cylinder A 5.1 is connected with a condenser A 12.1, and an exhaust port of the low-pressure cylinder B 5.2 is connected with a condenser B 12.2, the first-stage intermediate-pressure cylinder 2 is respectively provided with a communication pipe A 2.1 and a communication pipe B 2.2 at an exhaust port thereof, and the communication pipe A 2.1 and the communication pipe B 2.2 are connected with an inlet of the second-stage intermediate-pressure cylinder 4; the second-stage intermediate-pressure cylinder 4 is respectively communicated with the low-pressure cylinder A 5.1 and the low-pressure cylinder B 5.2 through pipelines.

[0018] The boiler system includes a superheater 7 and a reheater 8, wherein an inlet side of the superheater 7 is connected with an economizer 9 through a pipeline, and an exhaust port of the superheater 7 is connected with an inlet of the high-pressure cylinder 1 through a pipeline; an inlet of the reheater 8 is connected with an exhaust port of the high-pressure cylinder 1 through a pipeline, and an exhaust port of the reheater 8 is connected with an inlet of the first-stage intermediate-pressure cylinder 2 through a pipeline.

[0019] The bypass system includes a high-pressure bypass 10 and a low-pressure bypass 11, wherein the high-pressure bypass 10 is located in the semi-high-position turbine room, one end of the high-pressure bypass 10 is communicated with a pipeline between an exhaust port of the superheater 7 and an inlet of the high-pressure cylinder 1 through a pipeline, and the other end is communicated with a pipeline between an exhaust port of the high-pressure cylinder 1 and an inlet of the reheater 8 through a pipeline, and the high-pressure bypass 10 includes a high-pressure bypass valve 10.1; the low-pressure bypass 11 includes a low-pressure bypass A 11.1 and a low-pressure bypass B 11.2, wherein the low-pressure bypass A 11.1 includes a low-pressure bypass valve A 11.1.1, one end of the low-pressure bypass A 11.1 is communicated with a pipeline between an exhaust port of the reheater 8 and an inlet of the first-stage intermediate-pressure cylinder 2 through a pipeline, and the other end is communicated with the communication pipe B 2.2 through a pipeline; the low-pressure bypass B 11.2 includes a low-pressure bypass valve B 11.2.1, one end of the low-pressure bypass B 11.2 is communicated with a pipeline between an exhaust port of the reheater 8 and an inlet of the first-stage intermediate-pressure cylinder 2 through a pipeline, and the other end is communicated with the communication pipe A 2.1; the bypass system further includes a communication pipe bypass A 13 and a communication pipe bypass B 14, the communication pipe bypass A 13 includes a communication bypass valve A 13.1, one end of the communication pipe bypass A 13 is communicated with the communication pipe A 2.1 through a pipeline, and the other end is connected with an inlet of the condenser A 12.1; the communication pipe bypass B 14 includes a communication bypass valve B 14.1, one end of the communication pipe bypass B 14 is communicated with the communication pipe B 2.2 through a pipeline, and the other end is connected with an inlet of the condenser B 12.2 through a pipeline.

[0020] The main steam and high-temperature reheat steam generated in the operation of the unit are both 650 DEG C, in the high-pressure bypass 10, the pipeline before the high-pressure bypass valve A10.1 is made of 650 DEG C high-temperature material; in the low-pressure bypass 11, the pipelines before the low-pressure bypass valve A11.1.1 and the low-pressure bypass valve B11.2.1 are made of 650 DEG C high-temperature material; when the unit starts and is tripped off load, the high-pressure main steam at the outlet of the superheater 7 enters the high-pressure bypass 10, the steam flows out of the high-pressure bypass 10 and enters the reheater 8; the steam is reheated in the reheater 8 and enters the low-pressure bypass A11.1 and the low-pressure bypass B11.2; the steam entering the low-pressure bypass A11.1 then flows into the connecting pipe B2.2, the steam entering the low-pressure bypass B11.2 then flows into the connecting pipe A2.1; the steam in the connecting pipe A2.1 enters the connecting pipe bypass A13.1 and finally enters the condenser A12.1 to be condensed; at the same time, the steam in the connecting pipe B2.2 enters the connecting pipe bypass B14.1 and finally enters the condenser A12.2 to be condensed.

[0021] The above is only the preferred embodiment of the present application, not any limitation of the present application, any simple modification, change and equivalent transformation of the above embodiment according to the technical essence of the present application are still within the protection scope of the technical solution of the present application.

Claims

1. A high efficient ultra supercritical single reheat split shaft steam turbine bypass system, characterized in that, The utility model relates to a high parameter module, a low parameter module, a boiler system and a bypass system. The high parameter module comprises a high pressure cylinder (1), a coaxial first intermediate pressure cylinder (2) connected to the high pressure cylinder (1) and a generator A (3). The low parameter module comprises a second intermediate pressure cylinder (4), a coaxial low pressure cylinder (5) connected to the second intermediate pressure cylinder (4) and a generator B (6), and a condenser (12) arranged at the outlet of the low pressure cylinder (5). The boiler system comprises a superheater (7) and a reheater (8), wherein the superheater (7) is connected to the high pressure cylinder (1) through a pipeline, the reheater (8) is connected to the first intermediate pressure cylinder (2) and the high pressure cylinder (1) through a pipeline respectively, and the boiler system further comprises an economizer (9) having an inlet communicated with a high pressure water supply pipeline and an outlet communicated with the inlet of the superheater (7). The bypass system comprises a high pressure bypass (10), a low pressure bypass (11) and a communication pipe bypass (13, 14), wherein the inlet and outlet of the high pressure bypass (10) are respectively communicated with the outlet pipeline of the superheater (7) and the inlet pipeline of the reheater (8), the inlet and outlet of the low pressure bypass (11) are respectively communicated with the outlet pipeline of the reheater (8) and the communication pipe (2.1, 2.2) between the two intermediate pressure cylinders, and the inlet and outlet of the communication pipe bypass (13, 14) are respectively communicated with the communication pipe A (2.1) and the communication pipe B (2.2) and the condenser (12). The first intermediate pressure cylinder (2) is provided with the communication pipe A (2.1) and the communication pipe B (2.2), and the communication pipe A (2.1) and the communication pipe B (2.2) are respectively connected to the second intermediate pressure cylinder (4).

2. A high efficient ultra supercritical single reheat split shaft steam turbine bypass system according to claim 1, characterized in that, The low pressure cylinder (5) comprises a low pressure cylinder A (5.1) and a low pressure cylinder B (5.2), and the condenser (12) comprises a condenser A (12.1) and a condenser B (12.2), wherein the low pressure cylinder A (5.1) is connected to the condenser A (12.1), the low pressure cylinder B (5.2) is connected to the condenser B (12.2), the low pressure cylinder (5) is located between the second intermediate pressure cylinder (4) and the generator B (6), and the low pressure cylinder B (5.2) is adjacent to the generator B (6).

3. A high efficient ultra supercritical single reheat split shaft steam turbine bypass system according to claim 1, characterized in that, The high pressure bypass (10) comprises a high pressure bypass valve (10.1), one end of the high pressure bypass valve (10.1) is communicated with the pipeline between the superheater (7) and the high pressure cylinder (1), and the other end of the high pressure bypass valve (10.1) is communicated with the pipeline between the high pressure cylinder (1) and the reheater (8).

4. A high efficient ultra supercritical single reheat split shaft steam turbine bypass system according to claim 1, characterized in that, The low pressure bypass (11) comprises a low pressure bypass A (11.1) and a low pressure bypass B (11.2), the low pressure bypass A (11.1) comprises a low pressure bypass valve A (11.1.1), one end of the low pressure bypass valve A (11.1.1) is communicated with the pipeline between the reheater (8) and the first intermediate pressure cylinder (2), and the other end of the low pressure bypass valve A (11.1.1) is communicated with the communication pipe B (2.2) through a pipeline.

5. A high-efficiency ultra-supercritical single reheat split shaft steam turbine bypass system according to claim 4, characterized in that, The low pressure bypass B (11.2) comprises a low pressure bypass valve B (11.2.1), one end of the low pressure bypass valve B (11.2.1) is communicated with the pipeline between the reheater (8) and the first intermediate pressure cylinder (2), and the other end of the low pressure bypass valve B (11.2.1) is communicated with the communication pipe A (2.1) through a pipeline.

6. A high efficient ultra supercritical single reheat split shaft steam turbine bypass system according to claim 1 or 2, characterized in that, The bypass system comprises a communication pipe bypass A (13) and a communication pipe bypass B (14), the communication pipe bypass A (13) comprises a communication bypass valve A (13.1), one end of the communication bypass valve A (13.1) is communicated with the communication pipe A (2.1) through a pipeline, and the other end of the communication bypass valve A (13.1) is communicated with the condenser A (12.1) through a pipeline.

7. A high-efficiency ultra-supercritical single reheat split shaft steam turbine bypass system according to claim 6, characterized in that, The bypass B of the communication pipe comprises a communication bypass valve B (14.1) which is communicated with the communication pipe B through a pipe at one end and communicated with the condenser B (12.2) through a pipe at the other end.

8. A high efficient ultra supercritical single reheat split shaft steam turbine bypass system according to claim 1, characterized in that, The secondary medium-pressure cylinder (4) is communicated with the low-pressure cylinder A (5.1) and the low-pressure cylinder B (5.2) through pipes respectively.

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