Steam delivery device of CCPP conventional steam turbine
By designing the export steam device of the CCPP conventional steam turbine, including the steam delivery device and the water replenishment device, the problem that the existing generator sets are not designed to export low-pressure steam system is solved, and the dual capabilities of power generation and low-pressure steam are realized, which improves energy utilization efficiency and reduces production costs.
Patent Information
- Application Number
- CN202411860557.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-03-14
AI Technical Summary
The existing CCPP generator sets have not designed an external low-pressure steam system, which results in insufficient deoxygenation capacity of the deaerator when it is necessary to externalize low-pressure steam, and the steam replenishment parameters of the low-pressure system do not meet the requirements, resulting in energy waste and equipment operation safety affected.
A CCPP conventional steam turbine export steam device including a steam delivery device and a water replenishment device is designed. The steam delivery device transports the steam after de-heating and decompression to the low-pressure steam pipeline network through the delivery pipeline. The water replenishing device replenishes refined desalinated water in the condenser and deaerator through the spray atomizer and deaerator to ensure the system's deaeration capacity and steam delivery capacity.
The original generator set has the dual ability of generating power and exporting low-voltage steam, which improves the utilization efficiency of equipment and energy, reduces the production costs of enterprises, and solves the problems of insufficient deoxygenation capacity of the deaerator and the inconsistency of low-voltage system steam replenishment parameters.
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Figure CN119616614A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a steam delivery device for a conventional steam turbine of a CCPP (gas-steam combined cycle power generation unit), belonging to the technical field of heating. Background Art
[0002] In industrial enterprises, low-pressure steam is widely used as a heat source in many fields such as metallurgy, mining, textiles, power plants, equipment and petrochemicals, becoming a relatively important heat source. At present, the steam used to generate electricity for units in steel enterprises or power plants is basically medium-temperature medium-pressure or high-temperature high-pressure or even higher-parameter steam, and low-pressure steam is generally obtained from the external low-pressure steam system of the generator set.
[0003] Some industrial enterprises' original generator sets are not designed with low-pressure steam transmission systems. For example, the two 50,000-kilowatt CCPP M251 generator sets currently used by Handan Iron and Steel have waste heat boilers that are double-pressure, self-deoxidizing, and natural circulation sub-high-pressure waste heat boilers. The high-pressure steam flow rate is 77.3t / h, the rated steam pressure is 6.08 Mpa, and the rated steam temperature is 483℃; the low-pressure steam flow rate is 9.9t / h, the steam pressure is 0.3 Mpa, and the rated steam temperature is 190℃. Figure 1 This is a schematic diagram of the structure of this generator set, and its operation mode is: the high-temperature and high-pressure steam from the waste heat boiler 1 is delivered to the steam turbine 15 through the high-pressure steam valve 8, and condenses into water after the steam turbine 15 does work; the low-pressure steam from the waste heat boiler 1 is delivered to the steam turbine 15 through the front low-pressure steam valve 9 and the rear low-pressure steam valve 10 in turn, and condenses into water after the steam turbine 15 does work. When the unit is started or shut down in an emergency, the high-pressure bypass valve 11, the high-pressure regulating valve 12 and the low-pressure bypass valve 14 of the system will automatically open, and the high-temperature and high-pressure steam will be desuperheated and depressurized by the desuperheater 13, and then enter the condenser 16 of the steam turbine 15 together with the low-pressure steam to condense into water. The condensate is pressurized by the condensate pump 17 and sent to the deaerator 4. The water in the deaerator 4 is divided into two paths, which are pressurized by the high-pressure feed water pump 7 and the low-pressure feed water pump 6. After the tube screen in the waste heat boiler 1 absorbs heat, it enters the high-pressure drum 2 and the low-pressure drum 3 respectively. The water in the high-pressure drum 2 and the low-pressure drum 3 is heated to form steam, and then the steam is sent to the turbine 15 through the high-pressure steam valve 8, the front low-pressure steam valve 9, and the rear low-pressure steam valve 10 to condense into water. The medium circulates and works over and over again. In this cycle, the steam medium consumption is about 5~6t / h. Since the unit was not designed with an external steam system during design and construction, the unit does not have the ability to externally transport steam.
[0004] The 50,000-kilowatt CCPP M251 generator set is designed with a temperature and pressure reducer 13, which is used to reduce energy waste and ensure the safe operation of the unit during the start-up and shutdown process. The temperature and pressure reducer 13 adopts a two-stage temperature and pressure reduction method. The first stage of temperature and pressure reduction adopts a composite temperature and pressure reduction method. The steam pressure before temperature and pressure reduction is 5.75Mpa and the temperature is 480℃. The temperature reduction water uses the high-pressure water at the outlet of the high-pressure feed water pump, with a pressure of about 7.5Mpa and a temperature of about 110℃. The temperature reduction and pressure reduction valve are integrated. After the first stage of temperature and pressure reduction, the steam pressure drops to 0.4Mpa and the temperature drops to 180℃. The temperature reduction water of the second stage of temperature and pressure reduction uses the pressure water at the outlet of the rehydration pump, with a pressure of about 0.6Mpa and a temperature of about 50℃. The water spraying method is adopted for temperature reduction. After the second stage of temperature and pressure reduction, the steam pressure drops to 0.03~0.04Mpa and the temperature drops to 50~60℃.
[0005] With the change of business situation, some enterprises using the above-mentioned generator sets also have the demand of sending steam to other enterprises. Replacing the new generator sets with the ability to send steam to other enterprises requires huge investment and will cause waste of the original equipment. It is undoubtedly the most economical, time-saving and reasonable solution to transform the original units, which can improve the utilization efficiency of equipment and energy. However, there are the following problems in directly using the original equipment: 1. The deaerator has insufficient deoxygenation capacity. The original deaerator is designed according to the pure condensing condition of the steam turbine. If the steam is sent to other enterprises, the system needs to be supplemented with refined desalted water equivalent to the amount of steam sent to other enterprises. If the refined desalted water is directly supplemented to the deaerator, the boiler water quality will be unqualified, which will seriously affect the operation safety of the equipment. 2. When all the steam generated by the boiler is sent to other enterprises, the low-pressure supplementary steam parameters generated by the low-pressure system cannot meet the requirements of the external transmission, and directly discharging it will cause waste of energy. When the gas turbine is running at high load, the original temperature and pressure reducer does not have the ability to send all the steam to other enterprises.
[0006] Therefore, how to make the generator set that originally did not have the ability to export low-pressure steam have the dual capabilities of generating electricity and exporting low-pressure steam through design and modification has become a problem faced by relevant personnel. Summary of the invention
[0007] The purpose of the present invention is to provide a steam export device for a conventional steam turbine of a CCPP in view of the drawbacks of the prior art, so that a generator set that originally did not have the ability to export low-pressure steam has the dual capabilities of generating electricity and exporting low-pressure steam, thereby improving the utilization efficiency of equipment and energy and reducing the production cost of the enterprise.
[0008] To achieve the above object, the present invention adopts the following technical solution: A steam export device for a conventional steam turbine of a CCPP comprises a steam export device and a water supply device, wherein the steam export device comprises an export pipeline, an isolation electric valve and an export steam electric valve, wherein the isolation electric valve is installed between a temperature reducing and pressure reducing device of a generator set and a bypass steam inlet of a condenser, one end of the export pipeline is connected to a pipeline between the isolation electric valve and the temperature reducing and pressure reducing device, and the other end is connected to a low-pressure steam pipeline network in a plant area, and the export steam electric valve is installed on the export pipeline; the water supply device comprises a water supply regulating valve and a spray atomizer arranged inside the condenser, one end of the water supply regulating valve is connected to the spray atomizer through a pipeline, and the other end is connected to a refined desalted water source of an external network.
[0009] The steam delivery device of the conventional steam turbine of the CCPP mentioned above, the water supply device also includes a deaerator water supply valve, a heating steam regulating valve and a deaerator heater located inside the deaerator, one end of the deaerator water supply valve is connected to the liquid inlet on the deaerator shell, and the other end is connected to the external network refined desalted water source through a pipeline, one end of the heating steam regulating valve is connected to the deaerator heater through a pipeline, and the other end is connected to the steam source.
[0010] The steam export device of the conventional steam turbine of the CCPP mentioned above is also provided with a steam export manual valve and a safety valve on the export pipeline of the steam export device.
[0011] In the steam delivery device of the conventional steam turbine of the CCPP, the spray atomizer is a water pipe horizontally fixed inside the condenser, both ends of the water pipe are blocked and a plurality of nozzles distributed along the axial direction are installed on the pipe wall of the water pipe, and the inner cavity of the water pipe is connected to one end of the water supply regulating valve through a pipeline.
[0012] In the steam delivery device of the conventional steam turbine of the CCPP, the deaerator heater is a heating pipe with both ends blocked, which is horizontally fixed inside the deaerator. A plurality of jet holes distributed along the axial direction are provided on the wall of the heating pipe, and the inner cavity of the heating pipe is connected to the heating steam regulating valve through a pipeline.
[0013] In the above-mentioned steam export device of the conventional steam turbine of CCPP, the heating steam regulating valve is connected to the steam source through the heating steam valve.
[0014] In the above-mentioned steam delivery device of the conventional steam turbine of CCPP, the water supply regulating valve is connected to the refined desalted water source of the external network through the condenser water supply valve.
[0015] The present invention utilizes a steam delivery device to transport the steam after being desuperheated and depressurized by a desuperheater and decompressor to a low-pressure steam network in a factory area, and simultaneously utilizes a water replenishment device to replenish the system with refined desalted water, so that a generator set that originally did not have the ability to deliver low-pressure steam has the dual capabilities of generating electricity and delivering low-pressure steam, thereby greatly improving the utilization efficiency of equipment and energy and reducing the production cost of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0017] Figure 1 This is a schematic diagram of the structure of a conventional CCPP M251 generator set; Figure 2 It is the installation schematic diagram of the present invention; Figure 3 It is a structural schematic diagram of the deaerator water replenishment device; Figure 4 It is a structural schematic diagram of the condenser water supply device.
[0018] The numbers in the figure are as follows: 1. Waste heat boiler, 2. High-pressure drum, 3. Low-pressure drum, 4. Deaerator, 5. Generator, 6. Low-pressure feed water pump, 7. High-pressure feed water pump, 8. High-pressure steam valve, 9. Front low-pressure steam valve, 10. Rear low-pressure steam valve, 11. High-pressure bypass valve, 12. High-pressure regulating valve, 13. Desuperheater and pressure reducer, 14. Low-pressure bypass valve, 15. Steam turbine, 16. Condenser, 17. Condensate pump, 18. Deaerator water supply valve, 19. Heating steam valve, 20. Heating steam regulating valve, 21. Deaerator heater, 22. Spray atomizer, 23. Water supply regulating valve, 24. Condenser water supply valve, 25. Isolation electric valve, 26. External steam manual valve, 27. External steam electric valve, 28. Safety valve, 29. Nozzle. DETAILED DESCRIPTION
[0019] See also Figure 2-Figure 4 The present invention mainly includes a steam export device and a water replenishment device, wherein the steam export device includes an export pipeline, an isolation electric valve 25, an export steam manual valve 26, an export steam electric valve 27 and a safety valve 28. The isolation electric valve 25 is installed between the temperature reducer 13 of the generator set and the bypass steam inlet of the condenser 16. One end of the export pipeline is connected to the pipeline between the isolation electric valve 25 and the temperature reducer 13, and the other end is connected to the low-pressure steam pipeline network of the plant. The export steam manual valve 26, the export steam electric valve 27 and the safety valve 28 are installed on the export pipeline.
[0020] The water replenishment device includes a deaerator water replenishment device and a condenser water replenishment device, wherein the deaerator water replenishment device includes a deaerator water replenishment valve 18, a heating steam valve 19, a heating steam regulating valve 20 and a deaerator heater 21 located inside the deaerator 4, one end of the deaerator water replenishment valve 18 is connected to the liquid inlet on the outer shell of the deaerator 4, and the other end is connected to the external network refined desalted water source through a pipeline. The deaerator heater 21 is a section of a heating pipe with both ends blocked, which is horizontally fixed inside the deaerator 4. A plurality of jet holes distributed along its axial direction are provided on the pipe wall of the heating pipe. One end of the heating steam regulating valve 20 is connected to the inner cavity of the deaerator heater 21 through a pipeline, and the other end is connected to the steam source through the heating steam valve 19. The condenser water supply device includes a spray atomizer 22 arranged inside the condenser 16, and a water supply regulating valve 23 and a condenser water supply valve 24 arranged outside the condenser 16. The spray atomizer 22 is a water pipe horizontally fixed inside the condenser 16, with both ends blocked. A plurality of nozzles 29 distributed along the axial direction are installed on the pipe wall of the water pipe. One end of the water supply regulating valve 23 is connected to the inner cavity of the spray atomizer 22 through a pipeline, and the other end is connected to the external network refined desalted water source through the condenser water supply valve 24.
[0021] The present invention adds a steam delivery device and a water supply device on the basis of the original CCPP M251 generator set, so that it has the ability to deliver steam. The operation mode after the system transformation: the high-temperature and high-pressure steam from the waste heat boiler 1 passes through the high-pressure steam valve 8, and a part of it enters the steam turbine 15 to generate electricity and condenses into water. A part of the high-pressure steam passes through the high-pressure bypass valve 11 and the high-pressure regulating valve 12 in the high-pressure bypass and enters the temperature and pressure reducer 13. After being reduced in temperature and pressure by the temperature and pressure reducer 13, it is transported to the low-pressure steam network in the plant area through the steam delivery device. The flow path of the low-pressure steam remains unchanged, and it is still transported to the steam turbine 15 through the front low-pressure steam valve 9 and the rear low-pressure steam valve 10 in sequence, and condenses into water after the steam turbine 15 does work. Part of the refined desalted water from the external network enters the spray atomizer 22 through the condenser water supply valve 24 and the water supply regulating valve 23, and then is sprayed into the condenser 16 through the nozzle 29. The water supply enters the bottom of the condenser 16 after heat exchange with the heat exchange tube in the condenser 16. The water supply regulating valve 23 is interlocked with the liquid level of the deaerator 4. The liquid level of the deaerator 4 changes constantly with the amount of steam delivered. The water supply regulating valve 23 is automatically adjusted according to the change of the liquid level of the deaerator 4. Part of the refined desalted water from the external network enters the deaerator 4 through the deaerator water supply valve 18. The steam used to heat the deoxygenated water enters the deoxygenation heater 21 through the heating steam valve 19 and the heating steam regulating valve 20, and then is sprayed into the deoxygenated water in the deaerator 4 through the jet holes on the deoxygenation heater 21 to heat the deoxygenated water. The heating steam regulating valve 20 is automatically adjusted according to the temperature of the deoxygenated water in the deaerator 4, so that the temperature of the deoxygenated water in the deaerator 4 reaches the temperature required for deoxygenation.
[0022] The present invention has low investment and good operation effect, effectively improves the utilization rate of steam, and significantly improves the balance capacity of the steam network. In addition, the present invention is easy to implement on site and easy to maintain. Therefore, the implementation effect is good and the applicability is strong, and it can be applied to systems with steam demand but only conventional generator sets.
Claims
1. A steam delivery device for a conventional steam turbine of a CCPP, characterized in that: The invention comprises a steam delivery device and a water replenishment device, wherein the steam delivery device comprises a delivery pipeline, an isolation electric valve (25) and a delivery steam electric valve (27), wherein the isolation electric valve (25) is installed between a temperature reducing and pressure reducing device (13) of a generator set and a bypass steam inlet of a condenser (16), wherein one end of the delivery pipeline is connected to a pipeline between the isolation electric valve (25) and the temperature reducing and pressure reducing device (13), and the other end is connected to a low-pressure steam pipeline network in a plant area, and the delivery steam electric valve (27) is installed on the delivery pipeline; the water replenishment device comprises a water replenishment regulating valve (23) and a spray atomizer (22) arranged inside the condenser (16), wherein one end of the water replenishment regulating valve (23) is connected to the spray atomizer (22) through a pipeline, and the other end is connected to a refined desalted water source of an external network.
2. The steam export device of a conventional steam turbine of CCPP according to claim 1, characterized in that: The water replenishment device further comprises a deaerator water replenishment valve (18), a heating steam regulating valve (20) and a deaerator heater (21) located inside the deaerator (4); one end of the deaerator water replenishment valve (18) is connected to a liquid inlet on the outer shell of the deaerator (4), and the other end is connected to an external network refined desalted water source through a pipeline; one end of the heating steam regulating valve (20) is connected to the deaerator heater (21) through a pipeline, and the other end is connected to a steam source.
3. The steam export device of a conventional steam turbine of CCPP according to claim 2, characterized in that: The steam delivery pipe of the steam delivery device is also equipped with a steam delivery manual valve (26) and a safety valve (28).
4. The steam export device of a conventional steam turbine of CCPP according to claim 3, characterized in that: The spray atomizer (22) is a water pipe horizontally fixed inside the condenser (16), the two ends of the water pipe are blocked and a plurality of nozzles (29) distributed along the axial direction of the water pipe are installed on the pipe wall of the water pipe, and the inner cavity of the water pipe is connected to one end of the water supply regulating valve (23) through a pipeline.
5. The steam export device of a conventional steam turbine of CCPP according to claim 4, characterized in that: The deaerator heater (21) is a heating tube with both ends blocked, which is horizontally fixed inside the deaerator (4). A plurality of jet holes distributed along the axial direction are provided on the tube wall of the heating tube, and the inner cavity of the heating tube is connected to the heating steam regulating valve (20) through a pipeline.
6. The steam export device of a conventional steam turbine of CCPP according to claim 5, characterized in that: The heating steam regulating valve (20) is connected to a steam source via a heating steam valve (19).
7. The steam export device of a conventional steam turbine of CCPP according to claim 6, characterized in that: The water supply regulating valve (23) is connected to the refined desalted water source of the external network through the condenser water supply valve (24).