Unit backpressure reducing device based on flushing water of air cooling system
By setting up a flushing water unit and atomization spray head in the air-cooling system, the cooling fins and exhaust pipes of the air-cooling unit are cooled and cooled, which solves the problem of not being easy to reduce the back pressure under high load and high ambient temperature in summer, and achieves stable and safe operation and high reliability of the unit.
Patent Information
- Application Number
- CN202421778865.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-25
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-07-25
AI Technical Summary
The direct air-cooled unit does not easily reduce the back pressure of the direct air-cooled unit under high load and high ambient temperature in summer, resulting in unstable unit operation and limited safety.
A unit back pressure reduction device based on air-cooling system flushing water is designed. By setting up a flushing water unit on the air-cooling island, the heat dissipation fins are flushed and cooled by spraying, spraying or atomizing spray heads, and the exhaust pipe is initially cooled through the atomizing spray head to achieve a graded full heat exchange and cooling.
It effectively reduces the back pressure of direct air-cooled units at high loads and extremely high ambient temperatures in summer, ensures the normal and safe operation of the unit, improves the reliability of summer operation, and adapts to load and ambient temperature changes through automatic control systems.
Smart Images
Figure CN222849813U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of direct air-cooling units, and in particular relates to a unit back pressure reducing device based on flushing water of an air-cooling system. Background Art
[0002] The biggest advantage of the direct air cooling system is water saving. However, due to its own summer unit back pressure limitation, the back pressure problem of the unit under high load in summer is particularly prominent. At present, there are mainly the following solutions to reduce the back pressure of the air-cooled island in summer: 1. Increase the speed of the air-cooling fan and increase the cooling air volume of the air-cooling island fins. However, under high load and high ambient temperature conditions, even if all air-cooling fans are running at full frequency, the cooling air volume still cannot meet the full load operation of the unit under high temperature weather. At this time, it is necessary to reduce the unit load to ensure the safe operation of the unit; 2. Add an atomizing device at the inlet of the air-cooling island fan to reduce the ambient temperature at the inlet of the air-cooling fan. However, according to the change of load, the effect is not obvious when the ambient temperature reaches 33°C, and the load adaptation characteristics are poor; 3. Increase the heat load of the air-cooling island by adding an air-cooling island cooling unit, but its installation process is more complicated and the equipment cost is high. Utility Model Content
[0003] The utility model aims to provide a unit back pressure reducing device based on flushing water of an air cooling system, which solves the problem that the back pressure of the existing direct air cooling unit is difficult to reduce under high load and high ambient temperature in summer.
[0004] Utility model The technical solution adopted by the utility model is: a unit back pressure reducing device based on flushing water of an air cooling system, including a flushing water unit arranged corresponding to an air cooling island, a water collection ditch extending to the bottom of an exhaust pipe is opened around the outer ground of the air cooling island, the water collection ditch is connected to a water collection well, the water collection well is connected to a cooling pipe through a pipe via a lifting pump, and the cooling pipe is connected to an atomizing nozzle facing the exhaust pipe.
[0005] The utility model is also characterized in that:
[0006] The flushing water unit comprises a flushing pump connected to a cleaning water source, and the flushing pump is sequentially connected to a high-pressure accumulator and a flushing device corresponding to the heat dissipation fins on the air-cooling island through a pipeline.
[0007] The flushing device adopts a spray nozzle, a shower nozzle or an atomizing nozzle.
[0008] The heat dissipation fins on the air-cooling island are connected to the exhaust device of the low-pressure cylinder of the turbine through the exhaust pipe.
[0009] A filter is arranged on the communicating pipeline between the water collecting well and the lifting pump.
[0010] The beneficial effects of the utility model are as follows: the unit back pressure reducing device based on air cooling system flushing water of the utility model can ensure the normal and safe operation of the direct air cooling unit under high load and extremely high ambient temperature in summer, protect the direct air cooling unit from operating at full load and reducing back pressure in summer, and improve the reliability of the direct air cooling unit's operation in summer. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 The utility model is a schematic structural diagram of a unit back pressure reducing device based on flushing water of an air cooling system.
[0012] In the figure, 1. low-pressure cylinder of steam turbine, 2. exhaust device, 3. exhaust pipe, 4. air-cooling island, 5. flushing pump, 6. flushing device, 7. heat dissipation fins, 8. water collection ditch, 9. water collection well, 10. filter, 11. lifting pump, 12. cooling pipe, 13. atomizing nozzle, 14. high-pressure accumulator. DETAILED DESCRIPTION
[0013] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.
[0014] Example 1
[0015] The utility model provides a unit back pressure reduction device based on air cooling system flushing water, such as Figure 1 As shown, in the air-cooling system, the exhaust device 2 of the low-pressure cylinder 1 of the steam turbine is connected to the heat dissipation fins 7 on the air-cooling island 4 through the exhaust pipe 3. When the unit is running, the low-pressure cylinder 1 of the steam turbine is filled with exhaust steam after the steam turbine has done work. The exhaust steam after the work is transported to the exhaust device 2 through the low-pressure cylinder 1 of the steam turbine, and then transported to the heat dissipation fins 7 on the air-cooling island 4 through the exhaust pipe 3 for cooling. The utility model is provided with a flushing water unit corresponding to the air-cooling island 4, and the flushing water unit includes a flushing pump 5 connected to a cleaning water source, and the flushing pump 5 is sequentially connected to a high-pressure accumulator 14 and a flushing device 6 corresponding to the heat dissipation fins 7 on the air-cooling island 4 through a pipeline, and each heat dissipation fin 7 is equipped with a flushing device 6. Since the flushing device 6 is provided with a high-pressure accumulator 14 in front, the flushing device 6 can adopt a spray nozzle, a shower nozzle or an atomizing nozzle in various forms to meet the flushing pressure, and the water flows through the flushing pump 5 to be pressurized and enter the high-pressure accumulator 14, and the flushing device 6 sprays a high-speed water flow to flush and cool the heat dissipation fins 7 to about 30°C. A water collection ditch 8 is provided around the outer ground of the air-cooling island 4 and extends to the bottom of the exhaust pipe 3. The water collection ditch 8 is connected to a water collection well 9. The water collection well 9 is connected to a cooling pipe 12 through a pipe with a filter 10 and a lifting pump 11. The cooling pipe 12 is connected to an atomizing nozzle 13 facing the exhaust pipe 3 to cool the exhaust pipe 3 to about 35°C.
[0016] Through the above-mentioned method, the utility model of the unit back pressure reducing device based on the flushing water of the air cooling system performs preliminary cooling of the exhaust steam pipe 3 with a higher temperature through the atomizing nozzle 13, and then further cools the heat dissipating fins 7 with a lower temperature through the flushing device 6, and the temperature of the water flow sprayed from the flushing device 6 is also lower than that of the atomizing nozzle 13, thereby achieving graded and sufficient heat exchange cooling, improving the cooling effect and heat exchange efficiency, and ensuring the normal and safe operation of the direct air-cooling unit under high load and extremely high ambient temperature in summer, protecting the direct air-cooling unit from full load and reduced back pressure operation in summer, and improving the reliability of the direct air-cooling unit in summer operation.
[0017] Example 2
[0018] The utility model provides a back pressure reduction device for a unit based on flushing water of an air cooling system. When the unit is running, the low-pressure cylinder 1 of the steam turbine is filled with exhaust steam from the steam turbine. The exhaust steam from the steam turbine is transported to the exhaust device 2 through the low-pressure cylinder 1, and then transported to the air cooling island 4 through the exhaust pipe 3 for cooling. When the steam turbine unit is running at high load and high temperature, the temperature of the air cooling island 4 reaches 60°C and the ambient temperature reaches 32°C (PID automatic), and the flushing pump 5 is started. The flushing pump 5 drains desalted water with high purity and less impurities through the high-pressure accumulator 14 to the flushing device 6. The flushing device 6 flushes the cooling fins 7. The flushing of the desalted water reduces the scaling of the cooling fins 7 and improves the heat exchange efficiency. The flushing water after cooling the cooling fins 7 to about 30°C is collected to the water collection well 9 through the water accumulation ditch 8. The liquid level of the water collection well 9 reaches 1000mm (PID automatic) and the lifting pump 11 is started. The lifting pump 11 drains the desalted water through the filter 1 0 is transported to the cooling pipe 12, and the impurities carried by the flushing water when it flows through the ground are filtered out by the filter 10. The cooling pipe 12 atomizes the desalted water through the atomizing nozzle 13 and sprays it out to cool the exhaust pipe 3. The exhaust pipe 3 is cooled to about 35°C, and the dripping liquid water is collected into the water collection well 9 through the water accumulation ditch 8. When the water collection well 9 reaches a higher liquid level between the upper limit of the capacity, the collected water is discharged to an external special water treatment equipment for filtration, purification, desalination and other treatments, and is fully cooled. The desalted water after sufficient cooling is used as the cleaning water source of the flushing pump 5 again, so as to achieve recycling.
[0019] Through the above-mentioned method, the unit back pressure reducing device based on air cooling system flushing water of the utility model can ensure the normal and safe operation of the direct air cooling unit under high load and extremely high ambient temperature in summer, protect the direct air cooling unit from operating at full load and reducing back pressure in summer, and can be automatically controlled by PID according to the unit load and ambient temperature at any time, thereby improving the reliability of the direct air cooling unit's operation in summer.
[0020] Example 3
[0021] The steam discharged from the low-pressure cylinder of a 125MW steam turbine in a power plant enters the steam distribution pipe through a large steam pipe, where the steam is distributed to each downstream tube bundle. The air is forced to flow through the downstream tube bundle through a large axial flow fan. Most of the steam condenses into water on the inner surface of the finned tube of the downstream tube bundle and flows into the lower header. Some uncondensed steam and non-condensable gases enter the countercurrent tube bundle through the lower header. The steam condenses into water on the inner surface of the finned tube of the countercurrent tube bundle and flows into the lower header. The non-condensable gas is sucked into the water ring vacuum pump through the air extraction port and vacuum pipe at the top of the countercurrent tube bundle, and is compressed in the vacuum pump and discharged into the atmosphere. At the same time, the condensed water in the lower header enters the hot water well of the exhaust device through the condensate pipe due to gravity. The direct exhaust device system (ACC) of this unit consists of 4 columns, each with 4 fan units (1 fan per fan unit), for a total of 16 fan units. The second fan unit in each column (one, two, three, and four in order from the steam distribution pipe inlet) is a countercurrent fan unit. Vacuuming is completed by two water ring vacuum pumps. In the startup phase, both vacuum pumps are fully operational. During normal operation, one vacuum pump is used to maintain the vacuum of the exhaust device 2, and the other is used as a backup. Each radiating fin 7 is equipped with a flushing device 6. Each flushing device 6 is pressurized to 12MPa through a flushing pump 5 according to 12 groups of atomizing nozzles, forming a high-speed water flow to flush the radiating fins 7. The flushed water is collected in the water collection well 9, and then the exhaust pipe 3 is cooled after filtering impurities.
[0022] Steam turbine model: CC125-8.83 / 1.0 / 0.5 high-pressure double-cylinder double-exhaust, impulse, single-extraction direct air-cooled condensing type, air cooling system and through a DN50 304 pipe, the desalted water is pressurized to 12Mpa through the flushing pump 5, and the air-cooling island 4 is physically flushed. The flushing water passes through the (1000mm*80mm) annular water ditch 8 (365 meters) around the air-cooling island 4, and the collected flushing water is collected in the water collection well 9 (40 tons), filtered through the filter 10, and the filtered flushing water is pressurized to 1.6MPa by the lifting pump 11, and drained to 60 304 atomizing nozzles 13 through the cooling pipe 12, and the exhaust pipe 3 is atomized and cooled. The cooling water is collected in the water collection well 9 through the water ditch 8 for recycling.
[0023] The utility model steam turbine can operate at high load when the ambient temperature is higher than 32°C, and collect 85% of the high-pressure flushing water. The flushing water is calculated at 13.97 yuan per ton, or 139.7 yuan per hour, and the back pressure is reduced by 0.8 kpa. The coal consumption can be reduced by 1.3856 g / kwh. Calculated at 600 yuan, it can generate benefits of 1.7892 million yuan per hour, and a total of 76,460 yuan per day. Calculated at 90 days in summer, it can save 688,140 yuan per year.
Claims
1. A unit back pressure reduction device based on flushing water of an air cooling system, characterized in that: The invention comprises a flushing water unit arranged corresponding to the air cooling island (4); a water collection ditch (8) extending to the bottom of the exhaust steam pipe (3) is opened around the outer ground of the air cooling island (4); a water collection well (9) is connected in the water collection ditch (8); a cooling pipe (12) is connected in the water collection well (9) through a pipe via a lifting pump (11); and an atomizing nozzle (13) facing the exhaust steam pipe (3) is connected on the cooling pipe (12).
2. The unit back pressure reduction device based on air cooling system flushing water according to claim 1, characterized in that: The flushing water unit comprises a flushing pump (5) connected to a cleaning water source, wherein the flushing pump (5) is sequentially connected to a high-pressure accumulator (14) and a flushing device (6) corresponding to a heat dissipation fin (7) on an air-cooling island (4) through a pipeline.
3. The unit back pressure reduction device based on air cooling system flushing water according to claim 2, characterized in that: The flushing device (6) adopts a spray nozzle, a shower nozzle or an atomizing nozzle.
4. The unit back pressure reduction device based on air cooling system flushing water according to claim 1, characterized in that: The heat dissipation fins (7) on the air-cooling island (4) are connected to the exhaust device (2) of the low-pressure cylinder (1) of the steam turbine via an exhaust pipe (3).
5. The unit back pressure reduction device based on air cooling system flushing water according to claim 1, characterized in that: A filter (10) is provided on the communication pipeline between the water collection well (9) and the lifting pump (11).