Circulating water cooling system of thermal power plant

Abstract

According to the circulating water cooling system of the thermal power plant, the cooling system of the first unit communicates with the cooling system of the second unit by arranging the hot circulating water connecting pipe and the cold circulating water connecting pipe, and the cooling system is controlled to be switched between a one-machine-one-tower mode and a two-machine-one-tower mode through the first valve and the second valve; the requirement for unit cooling can be met when the boiler unit is in high load, and the energy-saving and anti-freezing purposes of the unit can be achieved when the boiler unit is in low temperature and in low load. According to the system, the cooling task of the boiler unit under different loads can be effectively completed and guaranteed, and the system has the advantages of being easy to control and convenient to switch. In addition, the two indirect cooling towers are arranged, one indirect cooling tower is used, the other indirect cooling tower is standby, and the two indirect cooling towers can be alternately used and can also be independently used when the boiler unit load is large, so that the requirements of different working conditions can be met.

Description

Technical Field

[0001] This application relates to the field of thermal power generation technology, and in particular to a circulating water cooling system for thermal power plants. Background Technology

[0002] In thermal power units, the cooling system is responsible for heat dissipation and consists of the last stage of the low-pressure turbine cylinder, condenser, cooling tower, circulating water pump, circulating water supply system, and air extraction system. In water-scarce regions, indirect air-cooling systems, with indirect air-cooled towers as the main heat dissipation equipment, are commonly used. In my country, most indirect air-cooled units are laid out as one unit per tower, where each air-cooled tower is responsible for the heat dissipation of only one unit.

[0003] However, due to factors such as peak-valley characteristics of power grid users, frequency regulation and peak shaving, system power flow, equipment maintenance and faults, thermal power plants often need to frequently adjust their power generation between low and medium loads and high loads. This leads to the need to adjust the cooling operation of the cooling system accordingly. Under low and medium loads, the layout of one unit and one cooling tower often results in the cooling capacity provided by the cooling tower being greater than that required by the unit. This leads to an excessively high subcooling of the steam condensate in the unit's condenser, which increases the energy required for water heating and thus increases the energy consumption of the entire unit. Furthermore, in winter, the low ambient temperature can easily lead to adverse consequences such as pipe freezing.

[0004] Therefore, it is necessary to set up a system that can meet the cooling needs of the unit under different operating conditions and different ambient temperatures. Utility Model Content

[0005] This application provides a circulating water cooling system for thermal power plants to achieve the purpose of cooling boiler units under different loads.

[0006] This application provides a circulating water cooling system for a thermal power plant, including a first unit, a second unit, a first cooling tower, and a second cooling tower;

[0007] The first unit is connected in sequence to the first hot circulating water pipeline, the first cooling tower, and the first cold circulating water pipeline to form a loop;

[0008] The second unit is connected in sequence to the second hot circulating water pipeline, the second cooling tower, and the second cold circulating water pipeline to form a loop;

[0009] The first hot circulating water pipeline and the second hot circulating water pipeline are connected by a hot circulating water connecting pipe equipped with a hot circulating water pump.

[0010] The first cold circulating water pipeline and the second cold circulating water pipeline are connected by a cold circulating water connecting pipe equipped with a cold circulating water pump.

[0011] A first check valve is installed on the first hot circulating water pipeline between the connection point of the hot circulating water connecting pipe and the first unit.

[0012] A second check valve is installed on the second cold circulating water pipeline between the connection point of the cold circulating water connecting pipe and the second cold tower.

[0013] A first valve is installed between the second check valve and the second cooling tower;

[0014] A second valve is installed on the second hot circulating water pipeline between the connection point of the hot circulating water connecting pipe and the second unit.

[0015] Optionally, the second hot water circulation pipeline and the second cold water circulation pipeline are connected by an internal circulation valve;

[0016] The connection point of the internal circulation valve to the second hot water pipeline is located between the second valve and the second cooling tower.

[0017] The connection point of the internal circulation valve to the second cold water pipeline is located between the first valve and the second cooling tower.

[0018] Optionally, the input end of the hot circulating water pump is connected to a first water pump protection valve, and the output end is connected to a second water pump protection valve.

[0019] The cold circulating water pump is equipped with a third water pump protection valve at the input end and a fourth water pump protection valve at the output end.

[0020] Optionally, the first unit includes a boiler, a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder, and a condenser connected in series in a loop;

[0021] The intermediate-pressure cylinder and the low-pressure cylinder are connected by a first steam valve;

[0022] The intermediate-pressure cylinder and the condenser are connected by a second steam valve;

[0023] The condenser is also connected to the first hot circulating water pipeline and the first cold circulating water pipeline.

[0024] Optionally, the first cold tower includes the main body;

[0025] The main body is divided into multiple cooling sectors, which are evenly distributed along the circumference of the main body.

[0026] Each cooling sector is connected to the inlet water pipeline via an inlet valve, to the outlet water pipeline via an outlet valve, and to the underground water tank via at least one drain valve;

[0027] The inlet water pipeline is connected to the first hot circulating water pipeline;

[0028] Water outlet pipeline and first cold circulation water pipeline.

[0029] Optionally, an expansion tank is also provided inside the body;

[0030] The expansion tank is connected to the underground water tank and the outlet pipeline.

[0031] Optionally, the number of cooling sectors is 6 to 18.

[0032] This application provides a circulating water cooling system for a thermal power plant. The system connects the cooling systems of the first and second generating units via hot and cold circulating water connecting pipes. First and second valves control the switching between a one-unit-one-tower mode and a two-unit-one-tower mode. This system can meet the cooling needs of the generating units under high load, and also achieve energy saving and anti-freezing purposes under low temperature and low load conditions. The system effectively ensures the completion of cooling tasks for the boiler units under different loads and is characterized by ease of operation and convenient switching. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of a circulating water cooling system for a thermal power plant provided in an embodiment of this application;

[0035] Figure 2 A schematic diagram of a circulating water cooling system for a thermal power plant provided in another embodiment of this application;

[0036] Figure 3 This is a schematic diagram of the structure of a first cold tower provided in an embodiment of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. First unit; 2. Second unit; 3. First cooling tower; 4. Second cooling tower; 5. Hot water circulation pump; 6. Cold water circulation pump; 10. First hot water circulation pipeline; 11. Boiler; 12. High-pressure cylinder; 13. Intermediate-pressure cylinder; 14. Low-pressure cylinder; 15. Condenser; 20. First cold water circulation pipeline; 30. Second hot water circulation pipeline; 31. Main unit; 32. Cooling sector; 33. Underground water tank; 34. Expansion tank; 40. Second cold water circulation pipeline; 50. Hot water circulation connecting pipe; 60. Cold circulation... Water connection pipe; 100, equipped with a first check valve; 200, a second check valve; 300, a first valve; 400, a second valve; 500, an internal circulation valve; 1100, a first steam valve; 1200, a second steam valve; 3010, an inlet water line; 3020, an outlet water line; 3100, an inlet water valve; 3200, an outlet water valve; 3300, a drain valve; 5100, a first water pump protection valve; 5200, a second water pump protection valve; 6100, a third water pump protection valve; 6200, a fourth water pump protection valve. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0040] like Figure 1 As shown, this application provides a circulating water cooling system for a thermal power plant, including a first unit 1, a second unit 2, a first cooling tower 3, and a second cooling tower 4.

[0041] The first unit 1 is connected in sequence to the first hot circulating water pipeline 10, the first cooling tower 3 and the first cold circulating water pipeline 20 to form a loop;

[0042] The second unit 2 is connected in sequence to the second hot circulating water pipeline 30, the second cooling tower 4, and the second cold circulating water pipeline 40 to form a loop;

[0043] The first hot circulating water pipeline 10 and the second hot circulating water pipeline 30 are connected by a hot circulating water connecting pipe 50 equipped with a hot circulating water pump 5.

[0044] The first cold circulating water pipeline 20 and the second cold circulating water pipeline 40 are connected by a cold circulating water connecting pipe 60 equipped with a cold circulating water pump 6.

[0045] A first check valve 100 is installed on the first hot circulating water pipeline 10 between the connection point of the hot circulating water connecting pipe 50 and the first unit 1.

[0046] A second check valve 200 is installed on the second cold circulating water pipeline 40 between the connection point of the cold circulating water connecting pipe 60 and the second cooling tower 4.

[0047] A first valve 300 is provided between the second check valve 200 and the second cooling tower 4;

[0048] A second valve 400 is installed on the second hot circulating water pipeline 30 between the connection point of the hot circulating water connecting pipe 50 and the second unit 2.

[0049] When in use, each piece of equipment operates normally in independent operation mode. In this mode, the hot circulating water pump 5 and the cold circulating water pump 6 are shut down, and the first unit 1 and the first cooling tower 3, the second unit 2 and the second cooling tower 4 operate independently. Taking the operation of the first unit 1 and the first cooling tower 3 as an example, during normal operation, the hot circulating water output from the first unit 1 is fed into the first cooling tower 3 through the first hot circulating water pipeline 10 after heat exchange for cooling. The cooled cold circulating water is then returned to the first unit 1 through the first cold circulating water pipeline 20 for cooling the condenser.

[0050] Similarly, when the second unit 2 is cooling, the hot circulating water output from the second unit 2 enters the second hot circulating water pipeline 30, and then flows into the second cooling tower 4 to cool the hot water. Since the structure of the second cooling tower 4 is exactly the same as that of the first cooling tower 3, the same cooling process as the first cooling tower 3 is carried out in the second cooling tower 4. The cooled circulating water flows into the second cold circulating water pipeline 40 and is then returned to the second unit 2 through the first valve 300 for recycling.

[0051] When operating in a two-unit-one-tower mode, this mode is used when the boiler is at a low load or the ambient temperature is low. Initially, a certain amount of water should be injected into the second cooling tower 4, the first valve 300 and the second valve 400 should be closed, and the hot circulating water pump 5 and the cold circulating water pump 6 should be turned on at the same time.

[0052] Under this operating condition, the steam utilization and condensation process of Unit 1 is the same as that in the independent operation state described above, and will not be repeated here. At this time, the hot circulating water generated during the operation of Unit 2 is transferred to the first hot circulating water pipeline 10 by the hot circulating water pump 5, merged with the hot circulating water output from Unit 1, and enters the first cooling tower 3 for cooling. After cooling, part of the circulating water is transferred to the second cold circulating water pipeline 40 by the cold circulating water pump 6 and returned to Unit 2. At the same time, the second cooling tower 4 is in internal circulation mode, that is, the corresponding circulation pump is started to make the water in the tower circulate slowly to prevent the water in the pipeline from condensing and clogging under low temperature conditions.

[0053] This application provides a circulating water cooling system for a thermal power plant. The cooling systems of the first unit 1 and the second unit 2 are connected by a hot circulating water connecting pipe 50 and a cold circulating water connecting pipe 60. The system switches between a one-unit-one-tower mode and a two-unit-one-tower mode via a first valve 300 and a second valve 400. This allows the system to meet the cooling needs of the boiler units under high load, and also achieves energy saving and anti-freezing purposes under low temperature and low boiler unit load conditions. The system effectively ensures the completion of cooling tasks for the boiler units under different loads and is easy to operate and switch between modes. Furthermore, this application includes two indirect cooling towers, one for operation and one for standby. These towers can be used alternately or independently when the boiler unit load is high, thus meeting the needs of different operating conditions.

[0054] like Figure 1 As shown, optionally, the second hot circulating water pipeline 30 and the second cold circulating water pipeline 40 are connected by an internal circulation valve 500.

[0055] The connection point of the internal circulation valve 500 to the second hot circulating water pipeline 30 is located between the second valve 400 and the second cooling tower 4.

[0056] The connection point of the internal circulation valve 500 to the second cold circulating water pipeline 40 is located between the first valve 300 and the second cooling tower 4.

[0057] In this application, an internal circulation valve 500 is provided to connect the second hot circulating water pipeline 30 and the second cold circulating water pipeline 40, so that when the two-machine-one-tower mode is running, the circulating water in the second cold tower 4 is in a flowing state, preventing the water in the pipeline of the second cold tower 4 from freezing and blocking the pipeline due to the low outside temperature.

[0058] like Figure 1 As shown, optionally, the input end of the hot circulating water pump 5 is connected to a first water pump protection valve 5100, and the output end is connected to a second water pump protection valve 5200.

[0059] The cold circulating water pump 6 is equipped with a third water pump protection valve 6100 at its input end and a fourth water pump protection valve 6200 at its output end.

[0060] In this application, the aforementioned protective valve is provided to prevent damage from water flow impact when the hot circulating water pump 5 and the cold circulating water pump 6 are in a stopped state.

[0061] like Figure 2 As shown, optionally, the first unit 1 includes a boiler 11, a high-pressure cylinder 12, an intermediate-pressure cylinder 13, a low-pressure cylinder 14 and a condenser 15 connected in series in a loop.

[0062] The intermediate-pressure cylinder 13 and the low-pressure cylinder 14 are connected by a first steam valve 1100;

[0063] The intermediate pressure cylinder 13 and the condenser 15 are connected by a second steam valve 1200;

[0064] The condenser 15 is also connected to the first hot circulating water pipeline 10 and the first cold circulating water pipeline 20.

[0065] In this application, during normal operation of the first unit 1, the first steam valve 1100 is open and the second steam valve 1200 is closed. Steam generated during boiler 11's operation is sequentially fed into the high-pressure cylinder 12, the intermediate-pressure cylinder 13, and the low-pressure cylinder 14. Finally, the exhaust steam from the low-pressure cylinder 14 enters the condenser 15, where it is cooled and condensed using circulating cooling water. The resulting condensate is then heated by a heater before entering the boiler to absorb heat and generate steam. The circulating water condensing the steam in the condenser 15 absorbs heat, its temperature rises, and it is then output from the condenser 15.

[0066] When the first unit 1 is in cylinder cut-off operation, the first steam valve 1100 is closed and the second steam valve 1200 is opened to isolate the low-pressure cylinder 14. The steam after the intermediate-pressure cylinder 13 has done work enters the condenser 15 through the second steam valve 1200 and is condensed by circulating cooling water. The heated circulating water enters the first hot circulating water pipeline 10 and enters the first cooling tower 3 together with the hot circulating water of the second unit 2 transported by the hot circulating water pump 5. A portion of the cooled circulating water is transported by the cold circulating water pump 6 to the second cold circulating water pipeline 40 and returned to the second unit 2.

[0067] like Figure 3 As shown, optionally, the first cold tower 3 includes a body 31;

[0068] The main body 31 is divided into multiple cooling sectors 32, which are evenly distributed along the circumference of the main body 31.

[0069] Each cooling sector 32 is connected to the inlet pipe 3010 via an inlet valve 3100, to the outlet pipe 3020 via an outlet valve 3200, and to the underground water tank 33 via at least one drain valve 3300.

[0070] The inlet water pipeline 3010 is connected to the first hot circulating water pipeline 10;

[0071] Water outlet pipeline 3020 and first cold circulation water pipeline 20.

[0072] In this application, the hot circulating water output from the first unit 1 is fed into the first cooling tower 3 through the first hot circulating water pipeline 10 after heat exchange and is cooled. During the cooling process, the hot circulating water enters the inlet pipeline 3010 of the first cooling tower and enters the cooling sector 32 through the open inlet valve 3100 (because each cooling sector is set in parallel with the inlet pipeline 3010, the number of cooling sectors 32 that are introduced into operation can be determined according to the water inlet and the ambient temperature). The circulating hot water is cooled to a certain temperature, such as 15~20℃, by multiple cooling triangles. The cooled cold circulating water enters the outlet pipeline 3020 through the outlet valve 3200 and is returned to the first unit 1 through the first cold circulating water pipeline 20 for cooling of the condenser.

[0073] Each naturally ventilated indirect cooling tower is equipped with an independent cleaning system. The air required for heat exchange in the indirect cooling tower is supplied by an air supply system, employing a naturally ventilated hyperbolic tower (existing technology). The tower is divided into 12 cooling sectors 32, each containing several cooling triangles. The cooling triangles are arranged vertically along the circumference of the indirect cooling tower. Each sector is equipped with one inlet valve 3100, one outlet valve 3200, and two drain valves 3300. By operating these valves, each sector can be individually filled and drained.

[0074] If the inlet valve 3100 and outlet valve 3200 are in the open position while the drain valve 3300 is in the closed position, the cooling sector 32 is in a water-filled state, which is the normal operating mode of the cooling triangle. In this state, circulating cooling water flows through the parallel-arranged cooling triangle radiators to exchange heat with the air. Operators can drain the water in the sector 32 into the underground water tank 33 through the drain pipe connected to the underground water tank 33. During this process, the inlet valve 3100 and outlet valve 3200 are closed, and the drain valve 3300 is open. Each cooling sector 32 is connected to the inlet pipe 3010 through the inlet valve 3100 and to the outlet pipe 3020 through the outlet valve 3200. When the sector is filled with water, the normal circulation loop of the circulating cooling water through the cooling tower is: First hot circulating water pipeline 10 - Inlet pipeline 3010 - Sector - Sector cooling triangle - Outlet pipeline 3020 - First cold circulating water pipeline 20. The cooling tower has bypass pipelines to allow for bypass operation when the sector is in a draining state.

[0075] In this application, when multiple drain valves 3300 are installed, they are connected in parallel. Multiple underground water tanks 33 can be connected in series, or a single large-volume water tank capable of meeting the drainage requirements can be installed.

[0076] If the back pressure in the pipeline inside the tower rises abnormally during system operation, the drain valve 3300 can be opened to drain the water in the cooling sector 32 into the underground water tank 33 to prevent safety accidents from occurring.

[0077] like Figure 3 As shown, optionally, an expansion tank 34 is also provided inside the main body 31;

[0078] The expansion tank 34 is connected to the underground water tank 33 and the outlet pipeline 3020 respectively.

[0079] In this application, the expansion tank 34 is positioned at a high level, that is, its vertical position inside the tower is higher than the outlet pipe 3020. The expansion tank 34 can serve as a buffer.

[0080] Expansion tank 34 is connected to outlet water line 3020 via a pipeline, allowing for the thermal expansion of the circulating cooling water. Expansion tank 34 is located above the cooling triangle. As the highest point of the cooling water circulation loop in outlet water line 3020, the water level in expansion tank 34 determines the pressure within the cooling system. Water discharge from the expansion tank to the underground water tank 33 is accomplished through an overflow valve and the drain pipeline of expansion tank 34 connected to the underground water tank 33.

[0081] Optionally, the number of cooling sectors 32 is 6 to 18.

[0082] In this application, setting up multiple cooling sectors 32 can improve the cooling efficiency of circulating water.

[0083] A circulating water cooling system for a thermal power plant operates as follows:

[0084] When in use, each piece of equipment operates normally in independent operation mode. In this mode, hot circulating water pump 5 and cold circulating water pump 6 are closed, and the first water pump protection valve 5100, the second water pump protection valve 5200, the third water pump protection valve 6100, and the fourth water pump protection valve 6200 are all closed. At this time, the first unit 1 and the first cooling tower 3, the second unit 2, and the second cooling tower 4 operate independently. Taking the operation of the first unit 1 and the first cooling tower 3 as an example, during normal operation, the first steam valve 1100 is open, and the second steam valve 1200 is closed. The steam generated during the operation of boiler 11 is sequentially input into the high-pressure cylinder 12, the intermediate-pressure cylinder 13, and the low-pressure cylinder 14. Finally, the exhaust steam after working is output from the low-pressure cylinder 14 and enters the condenser 15 for cooling and condensation by circulating cooling water. The condensate obtained is then heated by the heater and enters the boiler to absorb heat to generate steam. The circulating water that condenses the steam in condenser 15 absorbs heat and its temperature rises before being output from condenser 15.

[0085] The hot circulating water output from the first unit 1 is fed into the first cooling tower 3 through the first hot circulating water pipeline 10 after heat exchange and is cooled. During the cooling process, the hot circulating water enters the inlet pipeline 3010 of the first cooling tower and enters the cooling sector 32 through the open inlet valve 3100 (because each cooling sector is set in parallel with the inlet pipeline 3010, the number of cooling sectors 32 that are put into operation can be determined according to the water inlet and the ambient temperature). The circulating hot water is cooled to a certain temperature, such as 15~20℃, through multiple cooling triangles. The cooled cold circulating water enters the outlet pipeline 3020 through the outlet valve 3200 and is returned to the first unit 1 through the first cold circulating water pipeline 20 for cooling of the condenser.

[0086] Similarly, when the second unit 2 is cooling, the hot circulating water output from the second unit 2 enters the second hot circulating water pipeline 30 and enters the second cooling tower 4 through the second valve 400 (at this time, the internal circulation valve 500 is in the closed state) to cool the hot water. Since the structure of the second cooling tower 4 is exactly the same as that of the first cooling tower 3, the same cooling process as the first cooling tower 3 is carried out in the second cooling tower 4. The cooled circulating water flows into the second cold circulating water pipeline 40 and is then returned to the second unit 2 through the first valve 300 for recycling.

[0087] When operating in a two-unit-one-tower mode, this mode is used when the boiler is at a low load or the ambient temperature is low. Initially, a certain amount of water should be injected into the second cooling tower 4, the first valve 300 and the second valve 400 should be closed, and the internal circulation valve 500 should be opened (correspondingly, a circulation pump for internal circulation is provided), and at the same time, the first water pump protection valve 5100, the second water pump protection valve 5200, the third water pump protection valve 6100, and the fourth water pump protection valve 6200 should be opened; the hot circulating water pump 5 and the cold circulating water pump 6 should be started.

[0088] Under this operating condition, the steam utilization and condensation process of Unit 1 is the same as that in the independent operation state described above, and will not be repeated here. At this time, the hot circulating water generated during the operation of Unit 2 is transferred to the first hot circulating water pipeline 10 by the hot circulating water pump 5, and merged with the hot circulating water output from the condenser 15 in Unit 1. The water then enters the first cooling tower 3 for cooling. After cooling, part of the circulating water is transferred to the second cold circulating water pipeline 40 by the cold circulating water pump 6 and returned to Unit 2. Meanwhile, in the second cooling tower 4, due to the internal circulation valve 500 and the activation of the corresponding circulation pump, the water in the tower circulates slowly to prevent the pipeline water from condensing and clogging under low temperature conditions.

[0089] When the boiler is switched off (used when the ambient temperature drops further or the boiler load is low), taking the first unit 1 as an example (the second unit 2 remains in normal operation), it still needs to operate in the two-unit-one-tower mode. On the basis of the two-unit-one-tower operation, the low-pressure cylinder 14 in the first unit 1 is "cut off", that is, steam does not enter the low-pressure cylinder 14 to do work, also known as the low-pressure cylinder zero-work state. At this time, the first steam valve 1100 is closed and the second steam valve 1200 is opened to isolate the low-pressure cylinder 14. The steam after the intermediate-pressure cylinder 13 has done work enters the condenser 15 through the second steam valve 1200 and is condensed by circulating cooling water. The heated circulating water enters the first hot circulating water pipeline 10 and enters the first cooling tower 3 together with the hot circulating water pump 5 of the second unit 2 for cooling. A portion of the cooled circulating water is transferred to the second cold circulating water pipeline 40 by the cold circulating water pump 6 and returned to the second unit 2.

[0090] In this application, the structures of the first unit 1 and the second unit 2 are completely identical, and the operating status of each device in the second unit 2 can be achieved by referring to the first unit 1; similarly, the structures of the first cooling tower 3 and the second cooling tower 4 are also identical, and the operating process of the second cooling tower 4 can also refer to the operating process of the first cooling tower 3. Other valves, etc., not shown in the figure, can be mutually referenced and set up between the system composed of the first unit 1 and the first cooling tower 3 and the system composed of the second unit 2 and the second cooling tower 4, and will not be described in detail here.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A circulating water cooling system for a thermal power plant, characterized in that, It includes the first unit (1), the second unit (2), the first cooling tower (3), and the second cooling tower (4); The first unit (1) is connected in sequence to the first hot circulating water pipeline (10), the first cooling tower (3) and the first cold circulating water pipeline (20) to form a loop; The second unit (2) is connected in sequence to the second hot circulating water pipeline (30), the second cooling tower (4), and the second cold circulating water pipeline (40) to form a loop; The first hot circulating water pipeline (10) and the second hot circulating water pipeline (30) are connected by a hot circulating water connecting pipe (50) equipped with a hot circulating water pump (5); The first cold circulating water pipeline (20) and the second cold circulating water pipeline (40) are connected by a cold circulating water connecting pipe (60) equipped with a cold circulating water pump (6); A first check valve (100) is provided between the connection point of the first hot circulating water pipeline (10) and the first unit (1) at the connection point of the hot circulating water connecting pipe (50). A second check valve (200) is installed between the connection of the second cold circulating water pipeline (40) and the second cold tower (4). A first valve (300) is provided between the second check valve (200) and the second cold tower (4); A second valve (400) is provided on the second hot circulating water pipeline (30) between the connection point of the hot circulating water connecting pipe (50) and the second unit (2).

2. The circulating water cooling system for thermal power plants according to claim 1, characterized in that, The second hot circulating water pipeline (30) and the second cold circulating water pipeline (40) are connected by an internal circulation valve (500); The connection point of the internal circulation valve (500) to the second hot circulating water pipeline (30) is located between the second valve (400) and the second cooling tower (4); The connection point of the internal circulation valve (500) to the second cold circulating water pipeline (40) is located between the first valve (300) and the second cold tower (4).

3. The circulating water cooling system for thermal power plants according to claim 1, characterized in that, The input end of the hot circulating water pump (5) is connected to a first water pump protection valve (5100), and the output end is connected to a second water pump protection valve (5200). The cold circulating water pump (6) is equipped with a third water pump protection valve (6100) at its input end and a fourth water pump protection valve (6200) at its output end.

4. The circulating water cooling system for thermal power plants according to claim 1, characterized in that, The first unit (1) includes a boiler (11), a high-pressure cylinder (12), a medium-pressure cylinder (13), a low-pressure cylinder (14), and a condenser (15) connected in series in a loop. The intermediate pressure cylinder (13) and the low pressure cylinder (14) are connected by a first steam valve (1100); The intermediate pressure cylinder (13) and the condenser (15) are connected by a second steam valve (1200); The condenser (15) is also connected to the first hot circulating water line (10) and the first cold circulating water line (20).

5. The circulating water cooling system for thermal power plants according to claim 1, characterized in that, The first cold tower (3) includes a main body (31); The body (31) is divided into multiple cooling sectors (32), and the multiple cooling sectors (32) are evenly distributed along the circumference of the body (31); Each of the cooling sectors (32) is connected to the inlet pipeline (3010) via an inlet valve (3100), to the outlet pipeline (3020) via an outlet valve (3200), and to the underground water tank (33) via at least one drain valve (3300); The inlet water pipeline (3010) is connected to the first hot circulating water pipeline (10); The outlet water pipeline (3020) and the first cold circulating water pipeline (20).

6. The circulating water cooling system for thermal power plants according to claim 5, characterized in that, An expansion tank (34) is also provided inside the main body (31). The expansion tank (34) is connected to the underground water tank (33) and the outlet pipeline (3020) respectively.

7. The circulating water cooling system for thermal power plants according to claim 5, characterized in that, The number of cooling sectors (32) is 6 to 18.

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