System for preventing circulating water from flowing backwards and freezing during low-position arrangement of indirect cooling tower

Abstract

The utility model provides a circulating water backflow prevention and anti-freezing system during low-position arrangement of an indirect cooling tower, the highest point of a water inlet and outlet upheaval pipe of each sector is higher than the top elevation of a high-position circulating water pipeline of a factory area, two ends of the water inlet and outlet upheaval pipe of each sector are connected with upheaval pipe front blow-down pipes, and upheaval pipe front blow-down valves are arranged on the upheaval pipe front blow-down pipes; the indirect cooling tower water inlet ring pipe and the indirect cooling tower water return ring pipe are connected with the main water tank through emergency water drain pipes respectively, hydraulic control emergency water drain valves are arranged on the emergency water drain pipes, and the indirect cooling tower emptying ring pipe is connected with the main water tank through a main water tank water inlet pipeline which is provided with a main water tank water inlet electric valve. The indirect cooling tower emptying ring pipe is connected with the stored water receiving water tank through a stored water receiving water tank water inlet pipeline; and the top elevation of the main water tank breather pipe is higher than that of the factory high-position circulating water pipeline. According to the utility model, the pipeline above the freezing line of each sector is free from freezing influence.

Description

Technical Field

[0001] This utility model relates to the field of indirect air-cooled towers and is applicable to indirect air-cooled towers arranged at low levels in a factory area. In particular, it relates to a system for preventing backflow of circulating water and preventing freezing when indirect air-cooled towers are arranged at low levels. Background Technology

[0002] Due to site constraints, the air-cooled tower may need to be located at a low position within the factory area. During emergency water discharge operations in winter, water from the high-level circulating water pipes in the factory area may backflow into the underground water tank inside the air-cooled tower and overflow through the underground water tank. This can lead to flooding of the air-cooled tower, significant water loss from the circulating water system, and freezing damage to the water stored in the cooling triangle. Utility Model Content

[0003] The present invention aims to solve the above-mentioned problems, thereby providing a system for preventing backflow of circulating water and preventing freezing when the indirect cooling tower is arranged at a low position.

[0004] To achieve the above-mentioned utility model objectives, this utility model provides a system for preventing backflow and freezing of circulating water when an indirect cooling tower is arranged at a low position. The system includes a cooling triangle, a main water tank, and a water receiving tank. The cooling triangle's inlet pipe is connected to the sector inlet ring pipe, and the cooling triangle's outlet pipe is connected to the sector return ring pipe. The sector inlet ring pipe is connected to the sector inlet pipe, and the sector return ring pipe is connected to the sector return pipe. The sector inlet pipe is connected to the indirect cooling tower inlet ring pipe, and the sector return pipe is connected to the indirect cooling tower return ring pipe. The upper parts of the sector inlet pipe and the sector return pipe are respectively connected to the sector vent pipe via a sector venting electric valve, and the sector vent pipe is connected to the indirect cooling tower vent ring pipe. The sector inlet pipe is sequentially equipped with sector inlet / outlet raised pipes and a sector inlet electric valve from the sector inlet ring pipe to the indirect cooling tower inlet ring pipe. The water pipes are arranged sequentially from the sector return water pipe to the indirect cooling tower return water loop pipe, with sector inlet and outlet water risers and sector return water electric valves. The highest point of each sector inlet and outlet water riser is higher than the top elevation of the plant's high-level circulating water pipeline. Both ends of the sector inlet and outlet water risers are connected to the vent pipes before the risers, and the vent pipes before the risers are equipped with vent valves. The indirect cooling tower inlet loop pipe and the indirect cooling tower return loop pipe are connected to the main water tank through emergency drain pipes. The emergency drain pipes are equipped with hydraulically controlled emergency drain valves. The indirect cooling tower vent loop pipe is connected to the main water tank through the main water tank inlet pipe. The main water tank inlet pipe is equipped with a main water tank inlet electric valve. The indirect cooling tower vent loop pipe is connected to the storage receiving water tank through the storage receiving water tank inlet pipe. The top elevation of the main water tank vent pipe is higher than the top elevation of the plant's high-level circulating water pipeline.

[0005] Furthermore, a connecting pipe is provided between the main water tank and the water receiving tank, and a manual valve is installed on the connecting pipe.

[0006] This invention features raised sections on the inlet and outlet water pipes of each sector, with the highest point of each raised section determined to be higher than the top elevation of the high-level circulating water pipes in the plant area. In the event of an emergency water drain due to a malfunction of the inlet / outlet electric valves in the indirect air-cooling system, these raised sections can block water from entering the plant's circulating water pipes before reaching the raised section. Water in the pipes after the raised section and in the cooling triangle can still drain normally into the water receiving tank, thus solving the problem of freezing damage to the water in the cooling triangle. After the malfunction of the inlet / outlet valves in the sector is resolved, water in the valves and the pipes at the highest point of the raised section can also drain into the water receiving tank through the drain valves. This ensures that pipes above the frost line in each sector are not affected by freezing.

[0007] All inlet and outlet electric valves and venting electric valves in this system are located in underground valve wells, unaffected by freezing. All of these electric valves are automatically controlled by a DCS (Distributed Control System).

[0008] Compared to conventional systems, this system does not require an increase in the total volume of the underground water tank, and the increased investment compared to indirect air-cooling systems is negligible. Attached Figure Description

[0009] Figure 1 Diagram of a low-level indirect cooling tower anti-backflow and anti-freezing system;

[0010] Figure 2 Cross-sectional view of the underground water tank for the low-level indirect cooling tower anti-backflow and antifreeze system;

[0011] The components include: 1. Cooling triangle; 2. Main water tank; 3. Water receiving tank; 4. Sector inlet loop pipe; 5. Sector return loop pipe; 6. Indirect cooling tower inlet loop pipe; 7. Indirect cooling tower return loop pipe; 8. Indirect cooling tower vent loop pipe; 9. Sector inlet pipe; 10. Sector return pipe; 11. Sector vent pipe; 12. Sector inlet / outlet raised pipe; 13. Vent pipe before raised pipe; 14. Emergency drain pipe; 15. Main water tank inlet pipe; 16. Water receiving tank inlet pipe; 17. Water tank connecting pipe; 18. Sector... 19. Electric valve for water inlet; 20. Electric valve for sector return water; 21. Electric valve for sector venting; 22. Manual venting valve before the raised pipe; 23. Hydraulic emergency drain valve; 24. Electric valve for main water tank inlet; 25. Electric valve for water storage receiving tank inlet; 26. Manual valve for underground water tank connection; 27. Vent pipe for main water tank; 28. Vent pipe for water storage receiving tank; A. Ground elevation; B. Top elevation of vent pipe for main water tank; C. Top elevation of vent pipe for water storage receiving tank; D. Top elevation of raised pipe in sector. Detailed Implementation

[0012] To better understand the purpose, structure, and function of this utility model, the following description, in conjunction with the accompanying drawings, provides a more detailed account of a system for preventing backflow of circulating water and preventing freezing when an indirect cooling tower is arranged at a low position.

[0013] Reference Figure 1 and Figure 2 When the indirect cooling tower is arranged at a low position, the anti-backflow and anti-freezing system for circulating water includes a cooling triangle 1, a main water tank 2, and a water receiving tank 3. The inlet pipe of the cooling triangle 1 is connected to the sector inlet ring pipe 4, and the outlet pipe of the cooling triangle 1 is connected to the sector return ring pipe 5. The sector inlet ring pipe 4 is connected to the sector inlet pipe 9, and the sector return ring pipe 5 is connected to the sector return pipe 10. The sector inlet pipe 9 is connected to the indirect cooling tower inlet ring pipe 6, and the sector return pipe 10 is connected to the indirect cooling tower return ring pipe 7. The upper parts of the sector inlet pipe 9 and the sector return pipe 10 are connected to the sector vent pipe 11 through the sector vent electric valve 20, and the sector vent pipe 11 is connected to the indirect cooling tower vent ring pipe 8. From the sector inlet ring pipe to the indirect cooling tower inlet ring pipe, the sector inlet pipe 9 is equipped with a sector inlet / outlet raised pipe 12 and a sector inlet electric valve 18 in sequence. The sector return water pipe 10 is sequentially equipped with sector inlet / outlet raised pipes 12 and sector return water electric valves 19 from the sector return water pipe to the indirect cooling tower return water loop pipe. The highest point of each sector inlet / outlet raised pipe is higher than the top elevation of the plant's high-level circulating water pipeline. Both ends of the sector inlet / outlet raised pipe are connected to the vent pipe before the raised pipe, and the vent pipe before the raised pipe is equipped with a vent valve. The indirect cooling tower inlet loop pipe and the indirect cooling tower return loop pipe are respectively connected to the main water tank through emergency drain pipes. The emergency drain pipe is equipped with a hydraulically controlled emergency drain valve. The indirect cooling tower vent loop pipe is connected to the main water tank through the main water tank inlet pipe. The main water tank inlet pipe is equipped with a main water tank inlet electric valve. The indirect cooling tower vent loop pipe is connected to the storage receiving water tank through the storage receiving water tank inlet pipe. The top elevation of the main water tank vent pipe is higher than the top elevation of the plant's high-level circulating water pipeline.

[0014] Under organized drainage conditions, each sector closes its corresponding sector inlet electric valve 18 and sector return electric valve 19; opens the sector vent electric valve 20, the vent valve 21 before the riser pipe, and the main water tank inlet electric valve 23; and closes the storage water receiving tank inlet electric valve 24. Water from the corresponding sector enters the main water tank 2 through the intercooling tower vent ring pipe 8 and the main water tank inlet pipe 15.

[0015] When the indirect air-cooled system enters emergency drainage mode, the sector inlet electric valve 18 and sector return electric valve 19 are opened, the sector vent electric valves 20 are closed, the main water tank inlet electric valve 23 is opened, the storage water receiving tank electric valve 24 is closed, and the hydraulically controlled emergency drain valve 22 is opened. Water in the circulating water system flows rapidly into the main water tank 15 through the emergency drain pipe 9. When the water level in the system drops to the top of the sector inlet / outlet raised pipe (elevation D), the main water tank inlet electric valve 23 is closed, the storage water receiving tank inlet electric valve 24 is opened, the sector vent electric valve 20 is opened, the sector inlet electric valve 18 and sector return electric valve 19 are closed, and the vent valve 21 before the raised pipe is opened. The water stored in the sector, the water after the sector raised pipe 12, and the water after the sector inlet / outlet electric valves and before the sector raised pipe enter the storage water receiving tank 3 through the underground vent ring pipe 10 and the storage water receiving tank inlet pipe 17.

[0016] If the emergency water discharge is caused by a malfunction of the sector inlet / outlet electric valve, then after troubleshooting the malfunction of the corresponding sector inlet / outlet electric valve, close the sector inlet electric valve 18 and the sector return electric valve 19, and open the vent valve 21 before the bulging pipe.

[0017] After the cooling triangle water storage and sector water inlet electric valve 18 and sector water return electric valve 19 are used, all the water enters the water storage receiving tank 4 and then the hydraulic emergency drain valve 22 is closed. The underground water tank connection electric valve 25 is opened to connect the liquid levels of the main water tank (2) and the water storage receiving tank 3, so that the water in the tank is lower than the freezing line, thereby emptying all the water above the freezing line in the indirect cooling tower and solving the freezing damage problem.

[0018] The top elevation of the main water tank vent pipe is determined to be higher than the top elevation of the high-level circulating water pipeline in the plant area. The high-level circulating water pipeline, the main water tank, the cooling triangle, and the circulating water pipeline inside the indirect cooling tower are interconnected. According to the principle of communicating vessels, after the hydraulically controlled emergency drain valve on the emergency drain pipe is opened, the water in the cooling triangle above the top elevation of the high-level circulating water pipeline in the plant area will enter the main water tank. In other words, the main water tank receives water from the cooling triangle above the top elevation of the high-level circulating water pipeline in the plant area. Because the top elevation of the main water tank vent pipe is higher than the top elevation of the high-level circulating water pipeline in the plant area, water from the external circulating water pipeline will not overflow from the main water tank vent pipe, thus preventing a large loss of water in the circulating water system and flooding of the air-cooled tower. Water below the top elevation of the high-level circulating water pipes in the cooling triangle and water stored after the electric valves of each sector's inlet and outlet (near the cooling triangle side) cannot enter the main water tank. Instead, water enters the storage water receiving tank (the second underground water tank) after the valve on its inlet pipe is opened. A connecting pipe is installed between the two underground water tanks, with a manual valve on it. The elevation of the vent pipe for the storage water receiving tank is designed for easy access by maintenance personnel. The main inlet pipes of the main water tank and the storage water receiving tank are connected to underground venting ring pipes, and the water intake of the underground water tank is controlled by opening and closing different electric valves.

Claims

1. A system for preventing backflow and freezing of circulating water when an indirect cooling tower is arranged at a low position, characterized in that: The system includes a cooling triangle (1), a main water tank (2), and a water receiving tank (3); the inlet pipe of the cooling triangle (1) is connected to the sector inlet ring pipe (4), and the outlet pipe of the cooling triangle (1) is connected to the sector return ring pipe (5); the sector inlet ring pipe (4) is connected to the sector inlet pipe (9), and the sector return ring pipe (5) is connected to the sector return pipe (10); the sector inlet pipe (9) is connected to the inlet ring pipe (6) of the cooling tower, and the sector return pipe (10) is connected to the return ring pipe of the cooling tower. Pipe (7); The upper parts of the sector inlet pipe (9) and sector return pipe (10) are connected to the sector vent pipe (11) through the sector vent electric valve (20), and the sector vent pipe (11) is connected to the vent ring pipe (8) of the intercooler tower; The sector inlet pipe (9) is provided with sector inlet and outlet water risers (12) and sector inlet electric valve (18) in sequence from the sector inlet ring pipe to the intercooler tower inlet ring pipe; The sector return pipe is provided with sector return water risers (12) and sector inlet electric valve (18) in sequence from the sector return water pipe to the intercooler tower return ring pipe. The secondary system includes sector inlet and outlet water risers (12) and sector return water electric valves (19); the highest point of each sector inlet and outlet water riser (12) is higher than the top elevation of the high-level circulating water pipeline in the plant area, and both ends of the sector inlet and outlet water risers (12) are connected to the vent pipes (13) in front of the risers, and the vent pipes (13) in front of the risers are equipped with vent valves (21); the inlet water ring pipe (6) and the return water ring pipe (7) of the indirect cooling tower are respectively connected to the main cooling tower through emergency drain pipes (14). The water tank (2) is equipped with a hydraulic emergency drain valve (22) on the emergency drain pipe (14). The venting loop pipe (8) of the intercooling tower is connected to the main water tank (2) through the main water tank inlet pipe (15). The main water tank inlet pipe (15) is equipped with a main water tank inlet electric valve (23). The venting loop pipe (8) of the intercooling tower is connected to the storage receiving water tank (3) through the storage receiving water tank inlet pipe (16). The top elevation of the main water tank vent pipe is higher than the top elevation of the high-level circulating water pipe in the plant area.

2. The anti-backflow and antifreeze system for low-level indirect cooling towers according to claim 1, characterized in that: A connecting pipe is provided between the main water tank (2) and the water receiving tank (3), and a manual valve is provided on the connecting pipe.

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