CN218971278U - System for assisting steam turbine - Google Patents

Abstract

The utility model relates to the technical field of gas-steam combined cycle units, in particular to a system for assisting a steam turbine. A system for assisting a steam turbine, comprising: starting the boiler, and respectively connecting the boiler with a high-pressure cylinder of the steam turbine and a middle-low pressure cylinder of the steam turbine through a first auxiliary steam pipeline and a second auxiliary steam pipeline which are arranged in parallel; the waste heat boiler is connected with the high-pressure cylinder of the steam turbine and the medium-low pressure cylinder of the steam turbine respectively through a first main steam pipeline and a second main steam pipeline which are arranged in parallel; the condenser is provided with an input end which is suitable for being connected with the exhaust-heat boiler and the high-pressure cylinder of the steam turbine, and an output end which is respectively connected with the starting boiler and the exhaust-heat boiler. The utility model provides a system for assisting a steam turbine to flush and turn by steam, which is uniformly heated and has small vibration.

Description

System for assisting steam turbine

Technical Field

The utility model relates to the technical field of gas-steam combined cycle units, in particular to a system for assisting a steam turbine.

Background

With the development of gas turbines and the further development of natural gas resources, gas-steam combined cycle power generation units using gas turbines as main power sources have been increasingly becoming available in some power plants in recent years. The gas-steam combined cycle is a combined power cycle taking a gas power cycle as a top cycle and a steam power cycle as a bottom cycle, wherein the gas which does work in a gas turbine enters a waste heat boiler to heat water to generate high-temperature and high-pressure steam, and the high-temperature and high-pressure steam enters different cylinders of the turbine to continuously push the turbine to do work.

In the normal starting process, the gas turbine is started at a speed far faster than that of the steam turbine, so that the gas turbine can be normally started within 30 minutes, and the cold starting time of the steam turbine can be as long as 4-6 hours, so that the coordinated operation of the gas turbine and the steam turbine is a major consideration in the combined cycle. After the gas turbine is started, the gas turbine needs to be warmed up, the load of the gas turbine can be continuously increased, otherwise, the steam parameters generated by the waste heat boiler are too high, the rapid change of the steam temperature and the steam pressure easily causes the thermal stress and the vibration of the gas turbine to be too large, the machine set jumps, equipment is damaged even when serious, and unnecessary economic loss is caused. In the prior art, a steam bypass device is arranged on a gas steam combined unit to control the steam boosting speed of the boiler start, so that the start time is shortened, the overpressure protection and working medium recovery functions are achieved, but auxiliary steam sequentially warms and rotates a high-pressure cylinder and a low-pressure cylinder of a steam turbine in the operation process, so that the steam turbine is heated unevenly and vibrates excessively, and normal use is affected.

Disclosure of Invention

Therefore, the technical problem to be solved by the utility model is to overcome the defects that the steam turbine is affected in normal use due to uneven heating and overlarge vibration caused by the fact that auxiliary steam sequentially warms and rotates a high-pressure cylinder and a low-pressure cylinder of the steam turbine in the prior art, so that a system for assisting steam to rotate the steam turbine in a flushing manner is provided.

In order to solve the technical problem, the utility model provides a system for assisting a steam turbine, which comprises:

starting the boiler, and respectively connecting the boiler with a high-pressure cylinder of the steam turbine and a middle-low pressure cylinder of the steam turbine through a first auxiliary steam pipeline and a second auxiliary steam pipeline which are arranged in parallel;

the waste heat boiler is connected with the high-pressure cylinder of the steam turbine and the medium-low pressure cylinder of the steam turbine respectively through a first main steam pipeline and a second main steam pipeline which are arranged in parallel;

the condenser is provided with an input end which is suitable for being connected with the exhaust-heat boiler and the high-pressure cylinder of the steam turbine, and an output end which is respectively connected with the starting boiler and the exhaust-heat boiler.

Optionally, the start boiler is connected with the first auxiliary steam pipeline and the second auxiliary steam pipeline through an auxiliary steam main pipe, the auxiliary steam main pipe is connected with the condenser through a drainage pipeline, a drainage valve is arranged on the drainage pipeline, and an auxiliary steam main pipe stop valve is arranged on the auxiliary steam main pipe.

Optionally, the high-pressure regulating valve is arranged at the inlet of the high-pressure cylinder of the steam turbine, and the medium-pressure regulating valve is arranged at the inlet of the medium-pressure cylinder of the steam turbine.

Optionally, the first auxiliary steam pipeline is further provided with a high-pressure auxiliary steam regulating valve and a high-pressure auxiliary steam stop valve, and the second auxiliary steam pipeline is further provided with a medium-pressure auxiliary steam regulating valve and a medium-pressure auxiliary steam stop valve.

Optionally, the first main steam pipeline is further connected with a high-pressure steam bypass, one end of the high-pressure steam bypass is arranged between the exhaust-heat boiler and the high-pressure regulating valve, and the other end of the high-pressure steam bypass is arranged between the high-pressure cylinder of the steam turbine and the exhaust-heat boiler.

Optionally, the outlet of the high-pressure cylinder of the steam turbine is connected with the condenser and the waste heat boiler respectively through pipelines.

Optionally, a high-discharge ventilation valve is arranged on a pipeline between the outlet of the high-pressure cylinder of the steam turbine and the middle-low pressure cylinder of the steam turbine, and a high-discharge check valve is arranged on a pipeline between the outlet of the high-pressure cylinder of the steam turbine and the waste heat boiler.

Optionally, the pipeline that the output of condenser with exhaust-heat boiler meets is first condensate header, with the pipeline that the start-up boiler meets is the second condensate header, all be equipped with the condensate pump on first condensate header and the second condensate header, the condensate pump both sides divide and are equipped with electric valve before the condensate pump and electric valve behind the condensate pump.

Optionally, the auxiliary steam main pipe and the first main steam pipe are respectively provided with a steam temperature detection device and a pressure detection device.

The technical scheme of the utility model has the following advantages:

1. the utility model provides a system for assisting steam to flush a turbine, which comprises a starting boiler, a waste heat boiler and a condenser, wherein the starting boiler is respectively connected with a high-pressure cylinder of the turbine and a middle-low pressure cylinder of the turbine through a first auxiliary steam pipeline and a second auxiliary steam pipeline which are arranged in parallel, the preheating boiler is respectively connected with the high-pressure cylinder of the turbine and the middle-low pressure cylinder of the turbine through a first main steam pipeline and a second main steam pipeline which are arranged in parallel, an input end respectively connected with the waste heat boiler and the high-pressure cylinder of the turbine and an output end respectively connected with the starting boiler and the waste heat boiler are arranged on the condenser, and auxiliary steam generated by the starting boiler enters the high-pressure cylinder of the turbine and the middle-low pressure cylinder of the turbine through the first auxiliary steam pipeline and the second auxiliary steam pipeline respectively to apply work, so that the high-pressure cylinder and the middle-low pressure cylinder of the turbine are simultaneously subjected to warming-up effect and flush, and thermal stress among different cylinders during operation of a unit is reduced, and the problem that vibration is overlarge and normal use is influenced due to uneven heating of the cylinders is prevented. The auxiliary steam generated by starting the boiler is used for warming up and flushing the steam turbine, so that the flushing of the steam turbine can be realized under the condition of not igniting the gas turbine, faults and defects generated when the steam turbine operates at the rated rotation speed are found in advance and eliminated, and the operation time of the whole set of unit is reduced.

2. The auxiliary steam turbine system is characterized in that an auxiliary steam main pipe is connected with a first auxiliary steam pipeline and a second auxiliary steam pipeline through an auxiliary steam main pipe, a drainage pipeline is used for connecting the auxiliary steam main pipe with a condenser, a drainage valve is arranged on the drainage pipeline, an auxiliary steam main pipe stop valve is arranged on the auxiliary steam main pipe, and condensed water of the auxiliary steam main pipe and the first main steam pipeline can be conveniently discharged.

3. The system for assisting the steam to impact the turbine is provided with the high-pressure regulating valve at the inlet of the high-pressure cylinder of the turbine, and the medium-pressure regulating valve at the inlet of the middle-pressure cylinder and the low-pressure cylinder of the turbine, so that the consumption of auxiliary steam entering the high-pressure cylinder of the turbine and working of the middle-pressure cylinder and the low-pressure cylinder of the turbine can be controlled conveniently.

4. The utility model provides a system for assisting steam to flush a turbine, which is characterized in that a high-exhaust ventilation valve is arranged on a pipeline between an outlet of a high-pressure cylinder of the turbine and a middle-low pressure cylinder of the turbine, and a high-exhaust check valve is arranged on a pipeline between the outlet of the high-pressure cylinder of the turbine and a waste heat boiler, so that exhaust steam after working of the high-pressure cylinder of the turbine is prevented from flowing back to a cylinder body.

5. According to the system for assisting the steam turbine in flushing and rotating, the condenser is connected with the waste heat boiler through the first condensation water main pipe, the condenser is connected with the starting boiler through the second condensation water main pipe, the condensation water pumps are arranged on the first condensation water main pipe and the second condensation water main pipe, the front electric valve of the condensation water pump and the rear electric valve of the condensation water pump are respectively arranged on two sides of the condensation water pump, and circulation is assisted between steam and condensation water through the action of the condensation water pump.

6. The system for the auxiliary steam turbine is characterized in that a main auxiliary steam pipe and a main first steam pipe are respectively provided with a steam temperature detection device and a pressure detection device, so that auxiliary steam and a waste heat boiler can be regulated and controlled conveniently to accurately realize the switching of high-pressure main steam.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of an auxiliary steam turbine system provided by the utility model.

Reference numerals illustrate:

1. starting the boiler; 2. a waste heat boiler; 3. a high pressure main steam valve; 4. a high pressure regulating valve; 5. a medium pressure main steam valve; 6. a medium pressure regulating valve; 7. an auxiliary steam main pipe stop valve; 8. a high pressure auxiliary steam regulating valve; 9. a high pressure auxiliary steam shut-off valve; 10. a medium pressure auxiliary steam regulating valve; 11. a medium pressure auxiliary steam shut-off valve; 12. a high pressure main steam isolation valve; 13. a high pressure bypass valve; 14. a high-row vent valve; 15. a high-discharge check valve; 16. reheat steam gate valve; 17. a medium pressure bypass valve; 18. a drain valve; 19. a condensate pump; 20. a front electric valve of the condensate pump; 21. a condenser; 22. a turbine high pressure cylinder; 23. a low pressure cylinder in the steam turbine; 24. a first main steam line; 25. a high pressure steam bypass; 26. an auxiliary steam main pipe; 27. a reheater cold section steam line; 28. a medium pressure steam bypass; 29. a first condensate header; 30. a second condensate header; 31. a second main steam line; 32. a second auxiliary steam line; 33. and an electric valve behind the condensate pump.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

One embodiment of an auxiliary steam turbine system, as shown in fig. 1, includes a start-up boiler 1, a waste heat boiler 2, and a condenser 21.

The method comprises the steps of starting the boiler 1, connecting an auxiliary steam main pipe 26 with a first auxiliary steam pipeline and a second auxiliary steam pipeline 32 which are arranged in parallel respectively with a high-pressure cylinder 22 of the steam turbine and a middle-low pressure cylinder 23 of the steam turbine, wherein an auxiliary steam main pipe stop valve 7 is arranged on the auxiliary steam main pipe 26, so that auxiliary steam is fed into the steam turbine after passing through the auxiliary steam main pipe 26 and the auxiliary steam main pipe stop valve 7 after self-starting an outlet of the boiler 1 and then passing through the first auxiliary steam pipeline and the second auxiliary steam pipeline 32, a high-pressure auxiliary steam regulating valve 8 and a high-pressure auxiliary steam stop valve 9 are also arranged on the first auxiliary steam pipeline, and a medium-pressure auxiliary steam regulating valve 10 and a medium-pressure auxiliary steam stop valve 11 are also arranged on the second auxiliary steam pipeline 32; the auxiliary steam main pipe 26 is connected with the condenser 21 through a drainage pipeline, the drainage pipeline consists of an auxiliary steam drainage pipeline and a high-pressure main steam drainage pipeline, and the drainage pipeline is provided with a drainage valve 18, so that condensed water in the auxiliary steam main pipe 26 and condensed water in the first main steam pipeline 24 are conveniently discharged into the condenser 21 together, and the flow of steam in the pipeline is accelerated; the steam turbine high pressure cylinder 22 import department is equipped with high pressure main steam valve 3 and high pressure governing valve 4, is convenient for control steam turbine high pressure cylinder 22's admission flow, steam turbine low pressure cylinder 23 import department is equipped with middling pressure main steam valve 5 and middling pressure governing valve 6, is convenient for control steam turbine low pressure cylinder 23's admission flow, be equipped with steam temperature detection device and pressure detection device on auxiliary steam main pipe 26 and the first main steam pipeline 24, be convenient for regulate and control auxiliary steam and exhaust-heat boiler 2 in order to realize the switching of high pressure main steam.

The waste heat boiler 2, through parallelly connected first main steam pipeline 24 and the second main steam pipeline 31 that set up respectively with steam turbine high pressure jar 22 low pressure jar 23 links to each other in the steam turbine, be equipped with high pressure main steam isolation valve 12 on the first main steam pipeline 24 for control waste heat boiler 2's high pressure main steam flow, be equipped with reheat steam gate valve 16 on the second main steam pipeline 31, first main steam pipeline 24 still is connected with high pressure steam bypass 25, the one end of high pressure steam bypass 25 is located waste heat boiler 2 with between the high pressure governing valve 4, the other end is located steam turbine high pressure jar 22 with between the waste heat boiler 2, be equipped with high pressure bypass valve 13 on the high pressure steam bypass 25, when the high pressure main steam of waste heat boiler 2 output does not satisfy the steam turbine acting condition, can make it get into waste heat boiler 2 reheater through high pressure steam bypass 25, the export of steam turbine high pressure jar 22 is by-pass high pressure bypass valve 14 and is flowed into condenser 21 in the condenser 21, and the other is equipped with the bypass 28 is by-pass in the high pressure steam bypass valve 21 in the condenser section 2 the bypass 28 in the condenser section is gone into the high pressure steam bypass valve 21.

The condenser 21 is provided with an input end suitable for being connected with the exhaust-heat boiler 2 and the high-pressure cylinder 22 of the steam turbine, and an output end respectively connected with the starting boiler 1 and the exhaust-heat boiler 2, a pipeline of the output end of the condenser 21 connected with the exhaust-heat boiler 2 is a first condensate water main 29, a pipeline of the condenser connected with the starting boiler 1 is a second condensate water main 30, water consumed by the auxiliary steam generated by the starting boiler 1 is supplemented, condensate water pumps 19 are arranged on the first condensate water main 29 and the second condensate water main 30, and a front condensate water pump electric valve 20 and a rear condensate water pump electric valve 33 are respectively arranged on two sides of the condensate water pump 19, and condensate water flow is controlled through valve opening.

Before the gas-steam combined cycle generator set is started, the high-pressure main steam isolation valve 12, the high-pressure bypass valve 13, the high-pressure main steam valve 3, the high-pressure regulating valve 4, the medium-pressure main steam valve 5, the medium-pressure regulating valve 6, the auxiliary steam main pipe stop valve 7, the high-pressure auxiliary steam regulating valve 8, the high-pressure auxiliary steam stop valve 9, the medium-pressure auxiliary steam regulating valve 10, the medium-pressure auxiliary steam stop valve 11, the high-pressure check valve 15, the reheat steam gate valve 16, the medium-pressure bypass valve 17 and the drain valve 18 are closed, the condensate pump 19, the condensate pump front electric valve 20 and the condensate pump rear electric valve 33 on the first condensate main pipe 29 are closed, the condensate pump 19, the condensate pump front electric valve 20 and the condensate pump rear electric valve 33 on the second condensate main pipe 30 are opened, the high-pressure ventilation valve 14 is opened, and at the moment, the set is supplied with steam by a shaft seal system, and vacuum is established.

The auxiliary steam header shutoff valve 7 on the start-up boiler 1 side is opened to fill the auxiliary steam header 26 with auxiliary steam. Drain valve 18 is opened to drain water, and whether the steam has sufficient superheat degree is judged according to temperature and pressure measuring points on auxiliary steam main 26. Closing a drain valve 18 on a drain pipeline, opening a high-pressure auxiliary steam regulating valve 8, a high-pressure auxiliary steam stop valve 9, a medium-pressure auxiliary steam regulating valve 10 and a medium-pressure auxiliary steam stop valve 11, and preheating a pipeline and a valve by using auxiliary steam for starting the boiler 1. And then the high-pressure main steam valve 3, the high-pressure regulating valve 4, the medium-pressure main steam valve 5 and the medium-pressure regulating valve 6 are opened to warm up the high-pressure cylinder 22 and the medium-pressure cylinder 23 of the steam turbine by auxiliary steam. Auxiliary steam flow entering a high-pressure cylinder 22 and a middle-pressure cylinder 23 of the steam turbine is controlled through a high-pressure regulating valve 4 and a middle-pressure regulating valve 6, so that the rotating speed of the steam turbine is gradually increased and stabilized at the warming-up rotating speed to fully warm up.

After the unit is preheated to be qualified, the opening degrees of the high-pressure regulating valve 4 and the medium-pressure regulating valve 6 are gradually increased, the auxiliary steam flow entering the high-pressure cylinder 22 and the middle-low pressure cylinder 23 of the steam turbine is increased, the rotating speed of the steam turbine is increased at a uniform speed until the rated rotating speed is reached, and the steam turbine runs stably. In this state, the turbine friction inspection and the empty load test can be performed, and faults and defects of the turbine when the turbine operates at the rated rotation speed can be found and eliminated. For starting the gas-steam combined cycle generator set, the steam turbine runs at a constant speed after being pushed by auxiliary steam to be rushed to rotate to a rated rotation speed, and at the moment, the SFC variable frequency starting device is used for lifting the rotation speed of the gas turbine to 780 rpm, so that the cleaning and blowing of the gas turbine are carried out. And after the purging is finished, the rotating speed of the gas turbine is reduced to about 500 rpm, and the ignition and the starting of the gas turbine are carried out. Because the steam turbine is pushed by auxiliary steam to rotate to the rated rotation speed, the gas turbine can gradually rise to the rated rotation speed and carry out grid connection and load under the pushing action of SFC, high temperature and high pressure gas, and the steam turbine does not need to be operated for a long time under the low load working condition to warm up, so that the operation economy of the combined cycle unit is greatly improved. After the ignition start of the combustion engine, the condensate pump 19, the condensate pump front electric valve 20 and the condensate pump rear electric valve 33 on the first condensate header 29 are opened, and the high-pressure bypass valve 13 and the medium-pressure bypass valve 17 are opened. Checking the temperature and pressure measuring points on the first main steam pipeline 24 of the waste heat boiler 2, and discharging main steam of the waste heat boiler 2 into the condenser 21 through the high-pressure steam bypass 25 and the medium-pressure steam bypass 28 when the steam parameters do not meet the operation conditions of the steam turbine. After the main steam parameters are consistent with the auxiliary steam of the starting boiler 1, after the operation condition of the steam turbine is met, a high-pressure main steam isolation valve 12, a high-discharge check valve and a reheat steam gate valve 16 are opened, a high-discharge ventilation valve 14 is closed, the opening degrees of a high-pressure auxiliary steam regulating valve 8 and a medium-pressure auxiliary steam regulating valve 10 are gradually reduced, the main steam of the waste heat boiler 2 and the auxiliary steam of the starting boiler 1 are combined, the auxiliary steam supply to the main steam supply of the waste heat boiler 2 is gradually switched by controlling the opening degrees of the high-pressure regulating valve 4 and the medium-pressure regulating valve 6, and after the rotation speed of the steam turbine is stable, the steam turbine is subjected to grid connection and load operation.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the utility model.

Claims (9)

1. A system for assisting a steam turbine, comprising:

the boiler (1) is started, and the boiler is respectively connected with a high-pressure cylinder (22) of the steam turbine and a medium-low pressure cylinder (23) of the steam turbine through a first auxiliary steam pipeline and a second auxiliary steam pipeline (32) which are arranged in parallel;

the waste heat boiler (2) is connected with the high-pressure cylinder (22) and the middle-low pressure cylinder (23) of the steam turbine through a first main steam pipeline (24) and a second main steam pipeline (31) which are arranged in parallel;

the condenser (21) is provided with an input end which is suitable for being connected with the waste heat boiler (2) and the high-pressure cylinder (22) of the steam turbine, and an output end which is respectively connected with the starting boiler (1) and the waste heat boiler (2).

2. The system of an auxiliary steam turbine according to claim 1, wherein the start-up boiler (1) is connected to a first auxiliary steam pipe and a second auxiliary steam pipe (32) through an auxiliary steam main pipe (26), the auxiliary steam main pipe (26) is connected to the condenser (21) through a drain pipe, a drain valve (18) is arranged on the drain pipe, and an auxiliary steam main pipe stop valve (7) is arranged on the auxiliary steam main pipe (26).

3. The system for assisting steam turbine according to claim 1, further comprising a high pressure regulating valve (4) at the inlet of the turbine high pressure cylinder (22) and a medium pressure regulating valve (6) at the inlet of the turbine medium pressure cylinder (23), respectively.

4. A system of an auxiliary steam turbine according to claim 3, characterized in that the first auxiliary steam line is further provided with a high pressure auxiliary steam regulating valve (8) and a high pressure auxiliary steam shut-off valve (9), and the second auxiliary steam line (32) is further provided with a medium pressure auxiliary steam regulating valve (10) and a medium pressure auxiliary steam shut-off valve (11).

5. The system of an auxiliary steam turbine according to claim 3 or 4, characterized in that the first main steam line (24) is further connected with a high pressure steam bypass (25), one end of the high pressure steam bypass (25) is arranged between the waste heat boiler (2) and the high pressure regulating valve (4), and the other end is arranged between the turbine high pressure cylinder (22) and the waste heat boiler (2).

6. System for auxiliary steam turbine according to any of claims 1-4, characterized in that the outlet of the turbine high pressure cylinder (22) is connected via a pipeline to the condenser (21) and the waste heat boiler (2), respectively.

7. The system for assisting steam turbine according to claim 6, wherein a high-discharge ventilation valve (14) is arranged on a pipeline between an outlet of the turbine high-pressure cylinder (22) and the turbine middle-low pressure cylinder (23), and a high-discharge check valve (15) is arranged on a pipeline between the outlet of the turbine high-pressure cylinder (22) and the waste heat boiler (2).

8. The system of an auxiliary steam turbine according to any one of claims 1 to 4, wherein the pipeline of the output end of the condenser (21) connected with the waste heat boiler (2) is a first condensate header (29), the pipeline connected with the start boiler (1) is a second condensate header (30), condensate pumps (19) are arranged on the first condensate header (29) and the second condensate header (30), and a front electric valve (20) and a rear electric valve (33) of the condensate pump are arranged on two sides of the condensate pump (19).

9. The system of auxiliary steam turbine according to claim 2, wherein the auxiliary main steam pipe (26) and the first main steam pipe (24) are provided with steam temperature detecting means and pressure detecting means.

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