Summer peak cooling system of air cooling unit

Abstract

The invention relates to the technical field of cooling systems of air cooling units, in particular to a summer peak cooling system of an air cooling unit. The invention provides a summer peak cooling system of an air cooling unit. The summer peak cooling system comprises a boiler, a steam turbine, a heating network heater, an air cooling island, a circulating water pipeline, a condensate well, a steam diversion pipe and a vacuum pump. The steam turbine comprises a steam turbine intermediate-pressure cylinder and a steam turbine low-pressure cylinder which are communicated through a pipeline, a steam inlet of the steam turbine intermediate-pressure cylinder is communicated with an air outlet of the boiler through an intermediate-pressure cylinder steam inlet pipe, and a steam outlet of the steam turbine intermediate-pressure cylinder is communicated with a steam inlet of the heat supply network heater through an intermediate-pressure cylinder steam supply pipe. The low-temperature circulating water in the heating network heater and the circulating water pipeline is used for cooling part of steam discharged by the low-pressure cylinder of the steam turbine, the burden of an air cooling island is relieved, the cooling efficiency of the steam discharged by the low-pressure cylinder of the steam turbine is guaranteed, and the total amount of the circulating water provided for the boiler in unit time is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of cooling systems for air-cooling units, and in particular to a summer peak cooling system for air-cooling units. Background Art

[0002] The high back pressure circulating water heating technology for air-cooled units is to recover the exhaust loss of the low-pressure cylinder of the air-cooled steam turbine generator set and achieve zero cold source loss during the heating period. The principle of the high back pressure circulating water heating technology for air-cooled units is to increase the back pressure of the steam turbine, use the air-cooled island to recover the waste heat of the steam turbine exhaust, and provide heat through the heat network circulating water system. The high back pressure circulating water heating technology for air-cooled units is widely used in urban centralized heating, especially in the winter heating period. It can effectively use the waste heat of the unit for heating, reduce energy waste, and improve heating efficiency.

[0003] The air-cooling island in the high back-pressure circulating water heating system of the air-cooled unit is mainly composed of 56 fans. Through these devices, the high-temperature steam discharged from the low-pressure cylinder of the turbine can be cooled to ensure the normal operation of the power plant. The working principle of the air-cooling island is realized through the air cooling system, which includes components such as air-cooled condensers, air supply systems and fin tube cleaning systems. Among them, the air-cooled condenser is the core equipment, which cools the high-temperature steam by heat exchange with the air. The air supply system provides the necessary air flow, while the fin tube cleaning system ensures the heat exchange efficiency. These devices work together to ensure the efficient operation of the air-cooling island.

[0004] However, the cooling efficiency of the air-cooled island is low in summer. The main reasons include the following aspects: High ambient temperature: The temperature is generally high in summer, and the air temperature at the air condenser inlet rises, resulting in a decrease in the cooling capacity of the air condenser and a decrease in the vacuum, thus affecting the heat exchange efficiency of the air cooling island.

[0005] ‌Hot air return‌: When the air-to-air condenser exchanges heat with the atmosphere, it heats the surrounding air. The heated air is then sucked in by the fan again and pressurized to re-cool the air-to-air condenser. This phenomenon is called hot air return. Hot air return will increase the temperature of the cold air entering the air-to-air condenser, resulting in a decrease in cooling capacity.

[0006] When summer comes, the cooling capacity of the air-cooling island will be reduced, and the steam cannot be condensed quickly, thereby reducing the circulating water provided to the boiler per unit time, ultimately affecting the efficiency of the boiler. Summary of the invention

[0007] The problem to be solved by the present invention is that in the high back pressure circulating water heating system of the air-cooled unit, the cooling capacity of the air-cooled island decreases when the temperature rises in summer, and the air-cooled island cannot condense steam quickly, thereby reducing the circulating water provided to the boiler per unit time, ultimately affecting the efficiency of the boiler.

[0008] Technical Solution A summer peak cooling system for an air-cooled unit comprises a boiler, a steam turbine, a heat network heater, an air-cooled island, a circulating water pipeline, a condensate well, a steam diversion pipe and a vacuum pump; the steam turbine comprises a steam turbine intermediate pressure cylinder and a steam turbine low pressure cylinder connected by a pipeline, the steam inlet of the steam turbine intermediate pressure cylinder and the gas outlet of the boiler are connected by an intermediate pressure cylinder steam inlet pipe, the steam outlet of the steam turbine intermediate pressure cylinder and the steam inlet of the heat network heater are connected by an intermediate pressure cylinder steam delivery pipe, and the steam outlet of the steam turbine low pressure cylinder and the steam inlet of the air-cooled island are connected by a low pressure cylinder steam outlet pipe; The drain outlet of the heating network heater and the drain outlet of the air cooling island are respectively connected to the condensate well through pipelines; One end of the circulating water pipeline is connected to the water outlet of the heating network heater, and the other end is connected to the water inlet of the heating network heater. A circulating water pump is installed on the circulating water pipeline; One end of the steam shunt pipe is connected to the low-pressure cylinder steam outlet pipe, and the other end is connected to the heat network heater, and is used to transport part of the steam in the low-pressure cylinder steam outlet pipe to the heat network heater. At least one valve body for controlling its on and off is installed on the steam shunt pipe; It also includes a circulating water heat dissipation mechanism and an air suction mechanism, wherein the circulating water heat dissipation mechanism is installed on the circulating water pipeline to dissipate the heat of the circulating water in the circulating water pipeline; One end of the air suction mechanism is close to the circulating water heat dissipation mechanism, and the other end is close to the boiler blower, and is used to transport the high-temperature air near the circulating water heat dissipation mechanism to the vicinity of the boiler blower; The steam side of the heating network heater has an exhaust port, the suction port of the vacuum pump is connected to the exhaust port of the heating network heater through a pipeline, the outlet of the vacuum pump is connected to the exhaust system through a pipeline, and the vacuum pump is used to exhaust non-condensable gases on the steam side of the heating network heater.

[0009] According to one embodiment of the present invention, the circulating water heat dissipation mechanism includes a radiator, a water inlet pipe, a water outlet pipe, a water pump and a switch valve, one end of the water inlet pipe is connected to the water inlet of the radiator, and the other end thereof is connected to the water outlet of the water pump, the water inlet of the water pump is connected to the circulating water pipeline through a first pipe, one end of the water outlet pipe is connected to the water outlet of the radiator, and the other end thereof is connected to the circulating water pipeline, and at least one switch valve is installed on the first pipeline and the water outlet pipe.

[0010] According to one embodiment of the present invention, the air suction mechanism includes an air inlet pipe, an air supply pipe, a suction fan and an air suction hood, one end of the air inlet pipe is connected to the air suction hood, and the other end thereof is connected to the air inlet of the suction fan, one end of the air supply pipe is connected to the air outlet of the suction fan, and the other end thereof is close to the boiler supply fan, and the air suction hood is close to the radiator.

[0011] According to one embodiment of the present invention, a steam inlet hole is provided on the side wall of the intermediate-pressure cylinder steam supply pipe, and the end of the steam diverter pipe away from the low-pressure cylinder steam outlet pipe is connected with the steam inlet hole on the side wall of the intermediate-pressure cylinder steam supply pipe; a first valve is installed at one end of the steam diverter pipe close to the low-pressure cylinder steam outlet pipe, and a third valve is installed at the other end; a second valve is installed at the portion of the intermediate-pressure cylinder steam supply pipe located between the intermediate-pressure cylinder of the steam turbine and the steam diverter pipe.

[0012] According to one embodiment of the present invention, a steam inlet is provided on the heat network heater, and one end of the steam diversion pipe away from the low-pressure cylinder steam outlet pipe is connected to the steam inlet of the heat network heater.

[0013] According to one embodiment of the present invention, at least one fourth valve is installed at one end of the intermediate pressure cylinder steam supply pipe close to the intermediate pressure cylinder of the steam turbine.

[0014] According to one embodiment of the present invention, it includes a condensate pump, a deaerator, a low-pressure heater, a feed water pump, a high-pressure heater and an economizer which are connected in sequence, the water outlet of the condensate well is connected to the water inlet of the condensate pump, and the water outlet of the economizer is connected to the water inlet of the boiler through a pipeline.

[0015] According to one embodiment of the present invention, it comprises a hot water transfer station and a user hot water network, wherein the hot water transfer station is connected to the circulating water pipeline, and the hot water transfer station is used to supply hot water to the user hot water network.

[0016] According to one embodiment of the present invention, a generator is included, and the generator is connected to the low-pressure cylinder of the steam turbine.

[0017] Beneficial effects of the present invention: In order to ensure the cooling efficiency of the steam discharged from the low-pressure cylinder of the steam turbine, the valve body on the steam diverter pipe can be opened. At this time, the valve body on the medium-pressure cylinder steam delivery pipe is in a closed state. In this way, after the low-pressure steam discharged from the low-pressure cylinder of the steam turbine enters the low-pressure cylinder steam outlet pipe, a part of the low-pressure steam enters the air-cooling island along the low-pressure cylinder steam outlet pipe, and the condensate formed after cooling in the air-cooling island flows into the condensate well. The remaining steam in the low-pressure cylinder steam outlet pipe enters the steam diverter pipe from the low-pressure cylinder steam outlet pipe, and then enters the heat network heater. The heat network heater conducts the heat in the steam to the circulating water, and the steam condenses to form condensate and is transported to the condensate well through the pipeline.

[0018] It can be seen that the summer peak cooling system of this air-cooled unit uses the heat network heater and the low-temperature circulating water in the circulating water pipeline to cool part of the steam discharged from the low-pressure cylinder of the turbine, thereby reducing the burden on the air-cooling island, ensuring the cooling efficiency of the steam discharged from the low-pressure cylinder of the turbine, ensuring the total amount of circulating water provided to the boiler per unit time, and ensuring the working efficiency of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of a summer peak cooling system for an air-cooling unit provided by an embodiment of the present invention; Figure 2 A schematic diagram of another summer peak cooling system for an air-cooling unit provided in an embodiment of the present invention.

[0021] Icons: 1. Boiler; 2. Steam turbine high-pressure cylinder; 3. Steam turbine intermediate-pressure cylinder; 4. Steam turbine low-pressure cylinder; 5. Heat network heater; 6. Air-cooling island; 7. Condensate well; 8. Circulating water pipeline; 9. Radiator; 10. Suction fan; 11. Hot water transfer station; 12. User hot water pipeline network; 13. Condensate pump; 14. Deaerator; 15. Low-pressure heater; 16. Feed water pump; 17. High-pressure heater; 18. Economizer; 19. Medium-pressure cylinder steam inlet pipe; 20. Medium-pressure cylinder steam outlet pipe; 21. Low-pressure cylinder steam outlet pipe; 22. Steam diverter pipe; 23. First valve; 24. Medium-pressure cylinder steam supply pipe; 25. Second valve; 26. Third valve; 27. Circulating water pump; 28. Switch valve; 29. ​​Suction hood; 30. Air supply pipe; 31. Generator; 32. Fourth valve. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, one embodiment of the present invention provides a summer peak cooling system for an air-cooled unit, comprising a boiler 1, a steam turbine, a heat network heater 5, an air-cooling island 6, a circulating water pipeline 8, a condensate well 7, a steam diversion pipe 22 and a vacuum pump; the steam turbine comprises a steam turbine intermediate pressure cylinder 3 and a steam turbine low pressure cylinder 4 connected by a pipeline, the steam inlet of the steam turbine intermediate pressure cylinder 3 and the air outlet of the boiler 1 are connected through an intermediate pressure cylinder steam inlet pipe 19, the steam outlet of the steam turbine intermediate pressure cylinder 3 and the steam inlet of the heat network heater 5 are connected through an intermediate pressure cylinder steam delivery pipe 24, the steam outlet of the steam turbine low pressure cylinder 4 and the steam inlet of the air-cooling island 6 are connected through a steam delivery pipe 25. The steam outlet of the heat network heater 5 and the air cooling island 6 are connected to the condensate well 7 through pipelines; one end of the circulating water pipeline 8 is connected to the water outlet of the heat network heater 5, and the other end is connected to the water inlet of the heat network heater 5. A circulating water pump 27 is installed on the circulating water pipeline 8; one end of the steam shunt pipe 22 is connected to the low-pressure cylinder steam outlet pipe 21, and the other end is connected to the heat network heater 5, which is used to transport part of the steam in the low-pressure cylinder steam outlet pipe 21 to the heat network heater 5. At least one valve body for controlling its on and off is installed on the steam shunt pipe 22; It also includes a circulating water heat dissipation mechanism and an air suction mechanism. The circulating water heat dissipation mechanism is installed on the circulating water pipeline 8 and is used to dissipate the heat of the circulating water in the circulating water pipeline 8; one end of the air suction mechanism is close to the circulating water heat dissipation mechanism, and the other end of the air suction mechanism is close to the boiler blower, and is used to transport the high-temperature air near the circulating water heat dissipation mechanism to the vicinity of the boiler blower; the steam side of the heat network heater 5 is provided with an exhaust port, the air suction port of the vacuum pump is connected with the exhaust port of the heat network heater 5 through a pipeline, and the air outlet of the vacuum pump is connected with the exhaust system through a pipeline, and the vacuum pump is used to exhaust the non-condensable gas on the steam side of the heat network heater 5.

[0024] In this embodiment, when summer comes, the cooling capacity of the air-cooling island 6 will be reduced, and the steam cannot be condensed quickly. The volume of condensed water in the condensate well 7 is small, thereby reducing the circulating water provided to the boiler 1 per unit time, and finally affecting the efficiency of the boiler 1. In order to ensure the cooling efficiency of the steam discharged from the low-pressure cylinder 4 of the steam turbine, the valve body on the steam diverter pipe 22 can be opened, and the valve body on the medium-pressure cylinder steam delivery pipe 24 is in a closed state. In this way, after the low-pressure steam discharged from the low-pressure cylinder 4 of the steam turbine enters the low-pressure cylinder steam outlet pipe 21, a part of the low-pressure steam enters the air-cooling island 6 along the low-pressure cylinder steam outlet pipe 21, and the condensed water formed after being cooled by the air-cooling island 6 flows into the condensed water well 7. The remaining steam in the low-pressure cylinder steam outlet pipe 21 enters the steam diverter pipe 22 from the low-pressure cylinder steam outlet pipe 21, and then enters the heat network heater 5. The heat network heater 5 conducts the heat in the steam to the circulating water, and the steam condenses to form condensed water and is transported to the condensed water well 7 through the pipeline.

[0025] In summer, the circulating water in the circulating water pipeline 8 is idle. In this embodiment, the heat network heater 5 and the low-temperature circulating water in the circulating water pipeline 8 are used to cool part of the steam discharged from the low-pressure cylinder 4 of the steam turbine, thereby reducing the burden of the air-cooling island 6, ensuring the cooling efficiency of the steam discharged from the low-pressure cylinder 4 of the steam turbine, ensuring the total amount of circulating water provided to the boiler 1 per unit time, and ensuring the working efficiency of the boiler 1.

[0026] When winter comes, the valve body on the steam diversion pipe 22 is closed. At this time, the valve body on the intermediate pressure cylinder steam supply pipe 24 is in an open state. In this way, all the steam discharged from the low pressure cylinder 4 of the steam turbine enters the air cooling island 6 through the low pressure cylinder steam outlet pipe 21, and part of the high temperature steam in the intermediate pressure cylinder 3 of the steam turbine enters the heat network heater 5 through the intermediate pressure cylinder steam supply pipe 24. The heat network heater 5 uses the high temperature steam to heat the circulating water in the circulating water pipeline 8.

[0027] It should be noted that, in addition to the main low-pressure steam, there are some non-condensable gases on the steam side of the heating network heater 5, such as air, steam dissolved oxygen, etc. These non-condensable gases will have the following adverse effects on the normal operation of the heating network heater 5.

[0028] First, it hinders steam condensation: the non-condensable gas will occupy the space inside the heating network heater 5, reducing the contact area between the steam and the condensation surface, hindering the condensation process of the steam. Steam condensation is a key link in heat release. The condensation is hindered, which will lead to a decrease in the heat exchange efficiency of the heating network heater 5, and it will not be able to transfer enough heat to the heating network circulating water, thereby reducing the condensation heat exchange efficiency.

[0029] Second, the condensation heat exchange efficiency is reduced: the presence of non-condensable gas will form a gas film to isolate the steam from the condensation surface. The thermal resistance of this gas film is large, which reduces the condensation temperature of the steam and reduces the release of the condensation latent heat of the steam. At the same time, the gas film will also hinder the flow of condensed water, affect the discharge of condensed water, and further reduce the condensation heat exchange efficiency of the heating network heater 5.

[0030] In this embodiment, the pressure inside the heat network heater 5 is reduced by a vacuum pump to form a negative pressure environment. The non-condensable gas inside the heat network heater 5 will be sucked into the vacuum pump due to the pressure difference. The non-condensable gas sucked into the vacuum pump is finally discharged to the exhaust system after the compression and exhaust process of the pump. In this way, the non-condensable gas content inside the heat network heater 5 is gradually reduced. After the non-condensable gas is discharged, the space inside the heat network heater 5 is more sufficient, and the exhaust gas of the low-pressure cylinder 4 of the steam turbine can enter the heat network heater 5 more smoothly. This not only increases the steam flow rate of the heat network heater 5, but also ensures the effective utilization of the low-pressure steam discharged from the low-pressure cylinder 4 of the steam turbine, and avoids the influence of excessive exhaust pressure on the operation of the low-pressure cylinder 4 of the steam turbine. Moreover, the reduction of non-condensable gas increases the contact area between the steam and the condensation surface, and the steam condensation process of the heat network heater 5 is smoother. The condensation temperature is increased, the latent heat of condensation is released more fully, and the flow and discharge of condensed water are also smoother. These factors work together to significantly improve the condensation heat exchange efficiency of the heat network heater 5.

[0031] In order to ensure that the interior of the heating network heater 5 is in a state of low non-condensable gas content for a long time, the vacuum pump is usually continuously operated or started regularly to continuously discharge the newly generated non-condensable gas to maintain the vacuum degree inside the heating network heater 5.

[0032] It should be noted that the main function of the heat network heater 5 is to use the steam extraction of the steam turbine to heat the circulating water in the hot water supply system to meet the requirements of the heating users. The hot water supply system includes a circulating water pipeline 8, a hot water transfer station 11 and a user hot water pipeline network 12 that are connected in sequence, and a valve is installed in the hot water pipeline between the circulating water pipeline 8 and the hot water transfer station 11. In winter, the heat network heater 5 uses the medium-pressure steam discharged from the medium-pressure cylinder 3 of the steam turbine to heat the circulating water in the circulating water pipeline 8. The heated hot water in the circulating water pipeline 8 is distributed to the user hot water pipeline 12 through the hot water transfer station 11, so that the user can use hot water in winter. In summer, the hot water supply system does not work, that is, the circulating water in the circulating water pipeline 8 is in an idle state, and the circulating water in the circulating water pipeline 8 does not need to be supplied to the user end.

[0033] In this embodiment, in order to improve the utilization rate of the steam discharged from the low-pressure cylinder 4 of the steam turbine, this embodiment also provides a one-to-one corresponding circulating water heat dissipation mechanism and an air suction mechanism, wherein the circulating water heat dissipation mechanism is installed on the circulating water pipeline 8 to dissipate the heat of the circulating water in the circulating water pipeline 8, so as to quickly reduce the water temperature of the circulating water in the circulating water pipeline 8.

[0034] In this embodiment, before the low-pressure steam discharged from the low-pressure cylinder 4 of the steam turbine enters the heat network heater 5, the vacuum pump is turned on, and the non-condensable gas content inside the heat network heater 5 gradually decreases. At the same time, the circulating water heat dissipation mechanism dissipates heat and cools the circulating water in the circulating water pipeline 8, so that the temperature of the circulating water is lower. Thereafter, when the low-pressure steam enters the heat network heater 5, firstly, due to the reduction of the non-condensable gas content inside the heat network heater 5, the contact area between the low-pressure steam and the condensation surface in the heat network heater 5 increases, the steam condensation process of the heat network heater 5 is smoother, the condensation temperature is increased, the condensation latent heat is released more fully, and the flow and discharge of the condensed water are also smoother. Secondly, due to the effect of the circulating water heat dissipation mechanism, the water temperature of the circulating water in the circulating water pipeline 8 is lower, and when the water temperature of the circulating water is low, the temperature difference with the steam in the heat network heater 5 is large. According to the heat transfer theory, the greater the temperature difference, the higher the heat exchange efficiency. These factors work together to significantly improve the condensation heat exchange efficiency of the entire cooling system, ensure the total amount of circulating water provided to the boiler 1 per unit time, and ensure the working efficiency of the boiler 1.

[0035] In the subsequent continuous cooling work, the circulating water heat dissipation mechanism continuously cools the circulating water in the circulating water pipeline 8, and the vacuum pump will continue to operate or start regularly to continuously discharge the newly generated non-condensable gas to ensure the cooling capacity of the entire system.

[0036] Furthermore, one end of the air suction mechanism is close to the circulating water heat dissipation mechanism, and the other end thereof is close to the boiler blower, so as to transport the high-temperature air near the circulating water heat dissipation mechanism to the vicinity of the boiler blower.

[0037] It should be noted that the boiler blower is a power device that delivers air required for fuel combustion into the boiler, and generally adopts a centrifugal blower, whose structure includes an air intake box, a shell, a rotor, etc. Specifically, after the air passes through the air preheater, the blower delivers the hot air to the furnace of the boiler 1, providing the oxygen required for combustion and supporting the full combustion of the fuel.

[0038] In this embodiment, since the temperature near the circulating water heat dissipation mechanism is high, the suction mechanism can be turned on to transport the high-temperature air near the circulating water heat dissipation mechanism to the vicinity of the boiler blower. In this way, the boiler blower can directly transport the high-temperature air to the furnace of the boiler 1, provide the oxygen required for combustion, and support the full combustion of the fuel without turning on the air preheater, or the air preheater can be kept at low power, thereby saving electric energy and improving the utilization rate of the steam discharged by the low-pressure cylinder 4 of the steam turbine.

[0039] In this embodiment, if Figure 1 As shown, the circulating water heat dissipation mechanism includes a radiator 9, a water inlet pipe, a water outlet pipe, a water pump and a switch valve 28, and a first opening and a second opening are opened on the side wall of the circulating water pipeline 8, wherein one end of the water inlet pipe is connected to the water inlet of the radiator 9, and the other end thereof is connected to the water outlet of the water pump, the water inlet of the water pump is connected to the first opening of the circulating water pipeline 8 through a first pipe, one end of the water outlet pipe is connected to the water outlet of the radiator 9, and the other end thereof is connected to the second opening on the side wall of the circulating water pipeline 8, and further, a switch valve 28 is respectively installed at one end of the first pipeline close to the first opening of the circulating water pipeline 8 and at one end of the water outlet pipe close to the second opening of the circulating water pipeline 8.

[0040] Specifically, Figure 1 As shown, the air suction mechanism includes an air inlet pipe, an air supply pipe 30, a suction fan 10 and an air suction hood 29, wherein one end of the air inlet pipe is connected to the suction hood 29, and the other end thereof is connected to the air inlet of the suction fan 10, one end of the air supply pipe 30 is connected to the air outlet of the suction fan 10, and the other end thereof is close to the boiler supply fan, and further, the opening end of the suction hood 29 is close to the radiator 9.

[0041] By opening the switch valve 28, the water pump and the suction fan 10 on the first pipeline and the water outlet pipe, under the action of the water pump, the hot circulating water in the circulating water pipeline 8 flows into the first pipeline and the water inlet pipe in sequence, and then flows into the radiator 9. The hot circulating water exchanges heat with the outside air in the radiator 9, and the circulating water after cooling flows back to the circulating water pipeline 8 from the water outlet pipe of the radiator 9. Since the opening end of the suction hood 29 is close to the radiator 9, under the action of the suction fan 10, the high-temperature air near the radiator 9 is sucked into the suction hood 29, and then passes through the air inlet pipe and the air supply pipe 30 in sequence, and is finally sent to the vicinity of the boiler blower. The boiler blower directly transports the high-temperature air to the furnace of the boiler 1, providing the oxygen required for combustion, supporting the full combustion of the fuel, and ensuring the sufficiency and efficiency of combustion. In this way, there is no need to open the air preheater or keep the air preheater at a low power, thereby saving electric energy and improving the utilization rate of the steam discharged by the low-pressure cylinder 4 of the steam turbine.

[0042] Exemplarily, a plurality of corresponding circulating water heat dissipation mechanisms and air suction mechanisms are installed in sequence at one end of the circulating water pipeline 8 close to the heat network heater 5, that is, a plurality of groups of radiators 9 are used to fully dissipate the heat of the circulating water, and then the high-temperature air near the radiator 9 is transported to the vicinity of the boiler blower by the air suction fan 10.

[0043] It should be noted that the boiler 1 and the heat network heater 5 are both located in the power plant, and the circulating water pipeline 8 needs to be extended to the city to provide hot water for heating or other purposes. Therefore, the length of the circulating water pipeline 8 is about tens of kilometers. Therefore, as the circulating water circulates in the circulating water pipeline 8, the farther away from one end of the heat network heater 5, the lower the temperature of the circulating water. Therefore, the radiator 9 is set at the end of the circulating water pipeline 8 close to the heat network heater 5, and the radiator 9 is still located in the power plant.

[0044] As a specific embodiment, Figure 1 As shown, a steam inlet hole is provided on the side wall of the intermediate pressure cylinder steam supply pipe 24, and a connecting hole is provided on the side wall of the low pressure cylinder steam outlet pipe 21. One end of the steam diverter pipe 22 is connected to the connecting hole on the side wall of the low pressure cylinder steam outlet pipe 21, and the end of the steam diverter pipe 22 away from the low pressure cylinder steam outlet pipe 21 is connected to the steam inlet hole on the side wall of the intermediate pressure cylinder steam supply pipe 24. Further, a first valve 23 is installed at the end of the steam diverter pipe 22 close to the low pressure cylinder steam outlet pipe 21, and the first valve 23 is close to the connecting hole on the side wall of the low pressure cylinder steam outlet pipe 21. A third valve 26 is installed at the other end of the steam diverter pipe 22, and the third valve 26 is close to the steam inlet hole on the side wall of the intermediate pressure cylinder steam supply pipe 24. Further, the section from the end of the intermediate pressure cylinder steam supply pipe 24 close to the intermediate pressure cylinder 3 of the steam turbine to the steam inlet hole on its side wall is called the first section of the intermediate pressure cylinder steam supply pipe 24. The section from the steam inlet hole on the side wall of the intermediate pressure cylinder steam delivery pipe 24 to the end near the heat network heater 5 is the second section of the intermediate pressure cylinder steam delivery pipe 24. The fourth valve 32 and the second valve 25 are sequentially installed on the first section of the intermediate pressure cylinder steam delivery pipe 24, wherein the fourth valve 32 is close to the intermediate pressure cylinder 3 of the steam turbine, and the second valve 25 is close to the steam inlet hole on the side wall of the intermediate pressure cylinder steam delivery pipe 24.

[0045] In winter, the first valve 23 and the third valve 26 are closed, and the fourth valve 32 and the second valve 25 are opened. The passage between the intermediate pressure cylinder steam delivery pipe 24 and the low pressure cylinder steam outlet pipe 21 is cut off to prevent the low pressure steam in the low pressure cylinder steam outlet pipe 21 from entering the intermediate pressure cylinder steam delivery pipe 24. Since the third valve 26 is in the closed state, the steam in the intermediate pressure cylinder steam delivery pipe 24 will not enter the steam diversion pipe 22.

[0046] In summer, the fourth valve 32 and the second valve 25 are closed, the first valve 23 and the third valve 26 are opened, and part of the low-pressure steam in the low-pressure cylinder steam outlet pipe 21 flows into the heating network heater 5 through the steam diverter pipe 22. Since the second valve 25 is in a closed state, the steam transported through the steam diverter pipe 22 will not enter the first section of the medium-pressure cylinder steam delivery pipe 24.

[0047] As an alternative embodiment, Figure 2 As shown, a connection hole is provided on the side wall of the low-pressure cylinder steam outlet pipe 21, and a steam inlet is provided on the heat network heater 5. One end of the steam diverter pipe 22 is connected to the connection hole on the side wall of the low-pressure cylinder steam outlet pipe 21. One end of the steam diverter pipe 22 away from the low-pressure cylinder steam outlet pipe 21 is connected to the steam inlet of the heat network heater 5. A first valve 23 is installed on the steam diverter pipe 22, and the first valve 23 is close to the low-pressure cylinder steam outlet pipe 21. A fourth valve 32 is installed on the intermediate-pressure cylinder steam delivery pipe 24, and the fourth valve 32 is close to the intermediate-pressure cylinder 3 of the steam turbine.

[0048] In winter, the first valve 23 is closed and the fourth valve 32 is opened, and the medium-pressure steam in the intermediate-pressure cylinder 3 of the steam turbine flows into the heat network heater 5 through the intermediate-pressure cylinder steam delivery pipe 24 to exchange heat with the circulating water and increase the temperature of the circulating water. The low-pressure steam generated by the low-pressure cylinder 4 of the steam turbine is delivered to the air cooling island 6 through the low-pressure cylinder steam outlet pipe 21 for cooling.

[0049] In summer, the fourth valve 32 is closed and the first valve 23 is opened. The low-pressure steam generated by the low-pressure cylinder 4 of the steam turbine enters the low-pressure cylinder steam outlet pipe 21, and part of the steam in the low-pressure cylinder steam outlet pipe 21 is directly transported to the heat network heater 5 through the steam diversion pipe 22, and the steam is quickly cooled by the cold circulating water in the heat network heater 5.

[0050] Preferably, Figure 1 As shown, the steam turbine further includes a steam turbine high-pressure cylinder 2, the air inlet end of the steam turbine high-pressure cylinder 2 is connected to a steam outlet of the boiler 1, and the steam outlet end of the steam turbine high-pressure cylinder 2 is connected to a steam inlet of the boiler 1 through a pipeline. Further, a steam outlet end of the steam turbine intermediate-pressure cylinder 3 is connected to the air inlet end of the steam turbine low-pressure cylinder 4 through an intermediate-pressure cylinder steam outlet pipe 20.

[0051] In this embodiment, if Figure 1As shown, the summer peak cooling system of the air-cooled unit also includes a condensate pump 13, a deaerator 14, a low-pressure heater 15, a feed water pump 16, a high-pressure heater 17 and an economizer 18 which are sequentially connected through pipelines, wherein the outlet of the condensate well 7 is connected to the water inlet of the condensate pump 13 through a pipeline, and the outlet of the economizer 18 is connected to the water inlet of the boiler 1 through a pipeline. Among them, the main function of the condensate pump 13 is to boost the condensate of the condensate well 7 and send it to the deaerator 14. The main function of the deaerator 14 is to remove dissolved oxygen in the water, prevent corrosion of thermal equipment, and ensure the safe operation of the unit. The main function of the low-pressure heater 15 and the high-pressure heater 17 is to use the steam that has done some work in the steam turbine to increase the temperature of the water, reduce the amount of steam discharged from the steam turbine to the air-cooled island 6, reduce energy loss, and improve the cycle efficiency of the thermal system. The main function of the economizer 18 is to recover the waste heat of the exhaust gas of the boiler 1 and heat the feed water of the boiler 1 into saturated water under the drum pressure. Since the economizer 18 absorbs the heat of the high-temperature flue gas, the exhaust temperature of the flue gas is reduced, energy is saved and efficiency is improved.

[0052] In this embodiment, the generator 31 is connected to the low-pressure cylinder 4 of the steam turbine through a coupling. The boiler 1 generates high-temperature and high-pressure steam by burning fuel. The steam is sent to the steam turbine, driving the steam turbine to rotate, thereby driving the generator 31 to rotate, and finally converting mechanical energy into electrical energy.

[0053] In the description of the present invention, it should be noted that the terms "upper", "lower", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0054] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the inside of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A summer peak cooling system for an air-cooled unit, characterized in that: It comprises a boiler (1), a steam turbine, a heat network heater (5), an air cooling island (6), a circulating water pipeline (8), a condensate well (7), a steam diversion pipe (22) and a vacuum pump; the steam turbine comprises a steam turbine intermediate pressure cylinder (3) and a steam turbine low pressure cylinder (4) which are connected via a pipeline, the steam inlet of the steam turbine intermediate pressure cylinder (3) and the air outlet of the boiler (1) are connected via an intermediate pressure cylinder steam inlet pipe (19), the steam outlet of the steam turbine intermediate pressure cylinder (3) and the steam inlet of the heat network heater (5) are connected via an intermediate pressure cylinder steam delivery pipe (24), and the steam outlet of the steam turbine low pressure cylinder (4) and the steam inlet of the air cooling island (6) are connected via a low pressure cylinder steam outlet pipe (21); The drain outlet of the heating network heater (5) and the drain outlet of the air cooling island (6) are respectively connected to the condensate well (7) through pipelines; One end of the circulating water pipeline (8) is connected to the water outlet of the heating network heater (5), and the other end is connected to the water inlet of the heating network heater (5). A circulating water pump (27) is installed on the circulating water pipeline (8); One end of the steam shunt pipe (22) is connected to the low-pressure cylinder steam outlet pipe (21), and the other end is connected to the heat network heater (5), and is used to transport part of the steam in the low-pressure cylinder steam outlet pipe (21) to the heat network heater (5). At least one valve body for controlling the on-off of the steam shunt pipe (22) is installed on the steam shunt pipe (22); It also includes a circulating water heat dissipation mechanism and an air suction mechanism, wherein the circulating water heat dissipation mechanism is installed on the circulating water pipeline (8) and is used to dissipate the heat of the circulating water in the circulating water pipeline (8); One end of the air suction mechanism is close to the circulating water heat dissipation mechanism, and the other end is close to the boiler blower, and is used to transport the high-temperature air near the circulating water heat dissipation mechanism to the vicinity of the boiler blower; The steam side of the heating network heater (5) has an exhaust port, the air intake port of the vacuum pump is connected to the exhaust port of the heating network heater (5) through a pipeline, and the air outlet of the vacuum pump is connected to the exhaust system through a pipeline. The vacuum pump is used to exhaust non-condensable gas on the steam side of the heating network heater (5).

2. The summer peak cooling system of an air-cooling unit according to claim 1, characterized in that: The circulating water heat dissipation mechanism comprises a radiator (9), a water inlet pipe, a water outlet pipe, a water pump and a switch valve (28); one end of the water inlet pipe is connected to the water inlet of the radiator (9), and the other end thereof is connected to the water outlet of the water pump; the water inlet of the water pump is connected to a first ventilation pipe of the circulating water pipeline (8); one end of the water outlet pipe is connected to the water outlet of the radiator (9), and the other end thereof is connected to the circulating water pipeline (8); and at least one switch valve (28) is installed on the first pipeline and the water outlet pipe.

3. The summer peak cooling system of an air-cooling unit according to claim 2, characterized in that: The air suction mechanism comprises an air inlet pipe, an air supply pipe (30), an air suction fan (10) and an air suction hood (29); one end of the air inlet pipe is connected to the air suction hood (29), and the other end thereof is connected to an air inlet of the air suction fan (10); one end of the air supply pipe (30) is connected to an air outlet of the air suction fan (10), and the other end thereof is close to the boiler air supply fan; and the air suction hood (29) is close to the radiator (9).

4. The summer peak cooling system of an air-cooling unit according to claim 1, characterized in that: A steam inlet hole is provided on the side wall of the intermediate-pressure cylinder steam supply pipe (24); one end of the steam diverter pipe (22) away from the low-pressure cylinder steam outlet pipe (21) is connected to the steam inlet hole on the side wall of the intermediate-pressure cylinder steam supply pipe (24); a first valve (23) is installed at one end of the steam diverter pipe (22) close to the low-pressure cylinder steam outlet pipe (21), and a third valve (26) is installed at the other end; a second valve (25) is installed at a portion of the intermediate-pressure cylinder steam supply pipe (24) located between the intermediate-pressure cylinder (3) of the steam turbine and the steam diverter pipe (22).

5. The summer peak cooling system of an air-cooling unit according to claim 1, characterized in that: A steam inlet is provided on the heat network heater (5), and one end of the steam diversion pipe (22) away from the low-pressure cylinder steam outlet pipe (21) is connected to the steam inlet of the heat network heater (5).

6. The summer peak cooling system of an air-cooling unit according to claim 4 or 5, characterized in that: At least one fourth valve (32) is installed at one end of the intermediate pressure cylinder steam supply pipe (24) close to the intermediate pressure cylinder (3) of the steam turbine.

7. The summer peak cooling system of an air-cooling unit according to claim 1, characterized in that: It comprises a condensate pump (13), a deaerator (14), a low-pressure heater (15), a feed water pump (16), a high-pressure heater (17) and an economizer (18) which are connected in sequence, wherein the water outlet of the condensate well (7) is connected to the water inlet of the condensate pump (13), and the water outlet of the economizer (18) is connected to the water inlet of the boiler (1) via a pipeline.

8. The summer peak cooling system of an air-cooling unit according to claim 1, characterized in that: It comprises a hot water transfer station (11) and a user hot water pipe network (12); the hot water transfer station (11) is connected to the circulating water pipe (8); the hot water transfer station (11) is used to supply hot water to the user hot water pipe network (12).

9. The summer peak cooling system of an air-cooling unit according to claim 1, characterized in that: It comprises a generator (31), wherein the generator (31) is connected to the low-pressure cylinder (4) of the steam turbine.

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