High-flow high-efficiency circulating water pump for power station environment-friendly modernized reconstruction project

Abstract

The utility model relates to a high-flow high-efficiency circulating water pump for an environment-friendly modernized transformation project of a power station, which comprises a pump body provided with a vertical inlet and a vertical outlet, pump covers connected to two sides of the pump body, and a pump shaft penetrating through the pump covers and the pump body, a double-suction impeller is connected to the middle of the pump shaft in the pump body, and blades on two sides of the double-suction impeller are arranged in a staggered manner. A driving side bearing body and a non-driving side bearing body are arranged on the two sides of the pump shaft and are in a full-flange form, a mechanical seal is arranged at the joint of the pump shaft and the pump cover, a shell sealing ring and an impeller sealing ring are arranged at the matching position of the pump cover and the impeller, and a graphite stainless steel wound gasket is arranged at the joint of the pump body and the pump cover. The bearing body comprises a radial bearing adopting a deep groove ball bearing and a thrust bearing adopting two angular contact ball bearing structures which are arranged back to back, and an oil pool of the bearing body is cooled by adopting a finned tube through cooling water. The sealing device is stable and efficient in operation, small in vibration and good in sealing effect.

Description

Technical Field

[0001] The utility model relates to a large-flow and high-efficiency circulating water pump, in particular to a large-flow and high-efficiency circulating water pump for the environmental protection modernization project of a power station, which has stable and efficient operation, small vibration and good sealing effect. Background Technique

[0002] The circulating water pump is a medium and large-sized power-consuming auxiliary machine in the forced circulation hot water waste heat boiler of a thermal power plant. Its design and selection directly affect the safe operation and good economy of the whole power plant. The circulating water pump is mainly used to provide circulating power for the waste heat boiler water and is a device that operates continuously for a long time. With the increasing requirements for energy conservation and environmental protection in the domestic and foreign markets, it has accelerated the technological development and application of the circulating water pump.

[0003] The circulating water pump is one of the core moving equipment of a power plant and is the core equipment for transporting circulating water in the waste heat boiler supporting a gas turbine. Its main transport medium is circulating water. However, the current circulating water pumps in power plants have problems such as low efficiency and large vibration. Therefore, it is of great significance for power plants to save energy and reduce consumption by using a circulating water pump with large flow, high efficiency, small vibration and stable operation. Content of the Utility Model

[0004] In view of the above problems, the main purpose of the utility model is to provide a large-flow and high-efficiency circulating water pump for the environmental protection modernization project of a power station, which has stable and efficient operation, small vibration and good sealing effect.

[0005] The utility model solves the above technical problems through the following scheme: A large-flow and high-efficiency circulating water pump for the environmental protection modernization project of a power station, the large-flow and high-efficiency circulating water pump for the environmental protection modernization project of a power station includes: a pump body (7) provided with a vertical inlet and a vertical outlet, a drive-side pump cover (5) and a non-drive-side pump cover (16) connected to both sides of the pump body (7); a pump shaft (1) passing through the drive-side pump cover (5) and the non-drive-side pump cover (16) and arranged in the pump body (7), a double-suction impeller (12) is connected to the middle of the pump shaft (1), and the blades on both sides of the double-suction impeller (12) are arranged staggeredly.

[0006] Drive-side bearing bodies (2) and non-drive-side bearing bodies (17) are arranged on both sides of the pump shaft (1), and the drive-side bearing bodies (2) and non-drive-side bearing bodies (17) adopt a full flange form.

[0007] Mechanical seals (4) are provided at the connection between the pump shaft (1) and the drive side pump cover (5) and the non-drive side pump cover (16); a first housing sealing ring (10) and a first impeller sealing ring (11) are provided at the fit between the drive side pump cover (5) and the front of the double suction impeller (12); a second housing sealing ring (13) and a second impeller sealing ring (14) are provided at the fit between the non-drive side pump cover (16) and the rear of the double suction impeller (12).

[0008] The drive-side bearing housing (2) is a radial bearing (3) with a deep groove ball bearing, and the non-drive-side bearing housing (17) is a thrust bearing (18) with two back-to-back angular contact ball bearings.

[0009] In a specific embodiment of this utility model, the oil sump of the drive-side bearing body (2) and the non-drive-side bearing body (17) is cooled by cooling water passing through finned tubes (20).

[0010] In a specific embodiment of this utility model, the double suction impeller (12) is mounted on the pump shaft (1) in a sliding manner, and is fixedly connected to the pump shaft (1) by the shaft base of the pump shaft (1) and the impeller nut (15).

[0011] In a specific embodiment of this utility model, a graphite stainless steel spiral wound gasket (6) is provided at the connection between the pump body (7) and the drive-side pump cover (5), and at the connection between the pump body (7) and the non-drive-side pump cover (16).

[0012] In a specific embodiment of this utility model, an oil slinger ring (19) is provided on the pump shaft (1) between the radial bearing (3) and the thrust bearing (18), and an oil cup (21) is provided on the drive-side bearing body (2) and the non-drive-side bearing body (17). The oil pools of the drive-side bearing body (2) and the non-drive-side bearing body (17) are cooled by cooling water through finned tubes (20).

[0013] In a specific embodiment of this utility model, a throat bushing (8) is provided between the drive-side pump cover (5) and the pump shaft (1), and between the non-drive-side pump cover (16) and the pump shaft (1).

[0014] In a specific embodiment of this utility model, the mechanical seal (4) is a cartridge mechanical seal, the mechanical seal (4) is a self-circulating mechanical seal that is flushed through a flushing pipeline, and the bottom of the pump body (7) is connected to the drain pipeline in the form of a flange.

[0015] In a specific embodiment of this utility model, the flushing pipeline and the mechanical seal (4) are connected by a union with a sealing pipe thread. The flushing pipeline is equipped with a magnetic filter, a heat exchanger, a shut-off valve and a thermometer. Two gate valves connected in series are installed on the drain pipeline at the bottom of the pump body (7).

[0016] In a specific embodiment of this utility model, the first housing sealing ring (10), the first impeller sealing ring (11), the second housing sealing ring (13), and the second impeller sealing ring (14) are all sealing rings that have undergone heat treatment.

[0017] In a specific embodiment of this utility model, the pump body (7), the drive-side pump cover (5), the non-drive-side pump cover (16), and the double-suction impeller (12) are all integrally cast.

[0018] The positive and progressive effects of this utility model are as follows: Compared with common similar technologies, the high-flow-rate, high-efficiency circulating water pump provided by this utility model for power plant environmental modernization projects has the following advantages:

[0019] 1. The impeller of this utility model adopts a single-stage double-suction closed impeller. The blades on both sides of the impeller are arranged in an alternating manner, which can balance the main axial force during pump shaft operation and bear the residual axial force through the thrust bearing. This can prevent vibration caused by pressure pulsation and enhance the stability of the pump during operation.

[0020] 2. This utility model has sealing rings at the joints between the impeller and the drive-side pump cover and the non-drive-side pump cover, which can play a role in throttling and pressure reduction. In addition, the radial bearing that plays a supporting role uses a deep groove ball bearing with point contact with the pump shaft, resulting in a low coefficient of friction. This can further improve the high-speed and stable operation of the pump and improve the working efficiency of the pump.

[0021] 3. A graphite-stainless steel spiral wound gasket is installed at the connection between the pump body and the drive-side pump cover and the non-drive-side pump cover. This can effectively prevent leakage from the sealing surface, avoid the leakage risk caused by the easy failure of O-ring seals, ensure the sealing effect, and improve the working efficiency of the pump.

[0022] 4. The bearing body of this utility model adopts a full flange form, which further reduces vibration. The oil sump of the bearing body is cooled by cooling water through finned tubes, which improves the cooling effect of the bearing body and ensures the stable operation of the pump. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0024] Figure 2 This is a cross-sectional view of the present invention.

[0025] The following are the names corresponding to the reference numerals in this utility model:

[0026] Pump shaft (1), drive-side bearing body (2), radial bearing (3), mechanical seal (4), drive-side pump cover (5), graphite stainless steel spiral wound gasket (6), pump body (7), throat bushing (8), O-ring (9), first housing sealing ring (10), first impeller sealing ring (11), double suction impeller (12), second housing sealing ring (13), second impeller sealing ring (14), impeller nut (15), non-drive-side pump cover (16), non-drive-side bearing body (17), thrust bearing (18), oil slinger ring (19), finned tube (20), oil cup (21). Detailed Implementation

[0027] The preferred embodiments of this utility model are given below with reference to the accompanying drawings to illustrate the technical solution of this utility model in detail.

[0028] Figure 1 This is a schematic diagram of the overall structure of this utility model. Figure 2 This is a cross-sectional view of the present invention. (See image below.) Figure 1-2 As shown: This utility model proposes a high-flow, high-efficiency circulating water pump for a power plant environmental modernization project, comprising a pump body 7. The pump body 7 is a radially split double-volute casing with centerline support. Both the inlet and outlet of the pump body 7 are vertically upward. The driving side of the pump body 7 is connected to a driving side pump cover 5, and the non-driving side of the pump body 7 is connected to a non-driving side pump cover 16. The pump shaft 1 passes through the driving side pump cover 5 and the non-driving side pump cover 16 and is disposed inside the pump body 7. A double-suction impeller 12 is connected to the middle of the pump shaft 1 inside the pump body 7. The double-suction impeller 12 is mounted on the pump shaft 1 in a sliding manner and is fixedly connected to the pump shaft 1 by a shaft base and impeller nut 15. The double-suction impeller 12 can bear the main axial force during the operation of the pump shaft 1.

[0029] In this invention, the pump shaft 1 has a drive-side bearing housing 2 and a non-drive-side bearing housing 17 at both ends. The drive-side bearing housing 2 includes a radial bearing 3, and the non-drive-side bearing housing 17 includes a thrust bearing 18. The radial bearing 3 is a deep groove ball bearing, which has point contact with the track, resulting in a low coefficient of friction suitable for high-speed and stable pump operation. The thrust bearing 18 uses a structure of two back-to-back angular contact ball bearings. The staggered arrangement of the blades on both sides of the double-suction impeller 12 prevents pressure pulsation. The double-suction impeller 12 bears the main axial force, while the thrust bearing 18 bears the residual axial force, thereby enhancing the pump's stability.

[0030] In this invention, the drive-side pump cover 5 and the double-suction impeller 12 are respectively provided with a first housing sealing ring 10 and a first impeller sealing ring 11 at their mating points. The non-drive-side pump cover 16 and the double-suction impeller 12 are respectively provided with a second housing sealing ring 13 and a second impeller sealing ring 14 at their mating points, which can achieve the function of throttling and pressure reduction. The first housing sealing ring 10 and the second housing sealing ring 13, as well as the first impeller sealing ring 11 and the second impeller sealing ring 14, are heat-treated to form different surface hardnesses for the friction pairs, making the pump safer and more stable during operation. The pump body 7 and the drive-side pump cover 5 and the non-drive-side pump cover 16 have threaded holes circumferentially arranged on their connecting surfaces. The connecting surfaces of the drive-side pump cover 5 and the non-drive-side pump cover 16 with the pump body 7 have through holes that match the threaded holes on the pump body 7. The pump body 7, the drive-side pump cover 5, and the non-drive-side pump cover 16 are connected together by studs and nuts through the threaded holes and through holes. In this invention, a graphite stainless steel spiral wound gasket 6 is provided at the connection between the pump body 7, the drive-side pump cover 5, and the non-drive-side pump cover 16 for sealing. The graphite stainless steel spiral wound gasket 6 can effectively prevent leakage from the sealing surfaces of the pump body 7, the drive-side pump cover 5, and the non-drive-side pump cover 16, and avoid the leakage risk caused by the easy failure of O-ring seals commonly used in the current technology.

[0031] To facilitate disassembly of the drive-side pump cover 5 and the non-drive-side pump cover 16 during maintenance, set screw holes are provided on both. A throat bushing 8 is provided between the pump shaft 1 and the drive-side pump cover 5 and the non-drive-side pump cover 16, which serves a throttling function. To seal the entire pump and ensure its sealing performance, a mechanical seal 4 is provided at the contact point between the pump shaft 1 and the drive-side pump cover 5 and the non-drive-side pump cover 16.

[0032] The drive-side bearing housing 2 and the non-drive-side bearing housing 17 are equipped with oil cups 21. Sufficient lubricating oil is added to the oil cups 21 in a single injection. An oil slinger ring 19 is installed on the shaft 1. When the pump shaft 1 rotates, the drive-side bearing housing 2 and the non-drive-side bearing housing 17 drive the oil slinger ring 19 to throw oil, achieving self-lubrication of the bearing housings. The oil cups 21 in this invention can automatically replenish oil to the bearing housings according to their own oil level, thus enabling automatic oil replenishment and lubrication of the drive-side bearing housing 2 and the non-drive-side bearing housing 17, ensuring the pump's long-term normal operation.

[0033] The pump body 7, drive-side pump cover 5, and non-drive-side pump cover 16 of this utility model are made of ZG270-500 material; the double-suction impeller 12 is made of ZG1Cr13Ni material; the first housing sealing ring 10 and the second housing sealing ring 13 are made of 1Cr13MoS material; the first impeller sealing ring 11 and the second impeller sealing ring 14 are made of 3Cr13 material; the pump shaft 1 is made of 40CrVA material; and the drive-side bearing body 2 and the non-drive-side bearing body 17 are made of ZG230-450 material. These features enhance the pump's corrosion resistance and ensure its service life. The pump body 7, drive-side pump cover 5, non-drive-side pump cover 16, and double-suction impeller 12, after structural optimization, are all integrally cast using precision casting technology. This results in high dimensional accuracy and a high degree of surface finish within the flow channels, improving the pump's working efficiency and ensuring the performance and usage requirements of the user.

[0034] The mechanical seal 4 in this invention employs a self-circulating flushing method. This self-circulating flushing uses the medium within the sealing cavity to prevent leakage of the pumped medium and potential hazards. The mechanical seal 4 features a self-circulating flushing structure where the flushing fluid is supplied through a flushing pipeline. The flushing pipeline and the mechanical seal 4 are connected via a union with sealing threads. The flushing pipeline is equipped with a magnetic filter, heat exchanger, shut-off valve, and thermometer to ensure the cleanliness and cooling of the medium and to facilitate switching of the magnetic filter. Additionally, a thermometer is installed on the flushing pipeline for on-site monitoring of the flushing fluid temperature. The pump body 7 in this invention uses a flange to connect to the drain pipeline at its bottom. Two gate valves are installed in series on the drain pipeline. During normal operation, the gate valves are closed. When the pump needs maintenance and liquid needs to be drained from the pump body 7, the two closed gate valves can be opened to completely drain the liquid from the pump body 7.

[0035] This utility model provides a high-flow, high-efficiency circulating water pump for a power plant environmental modernization project, the working principle of which is as follows:

[0036] The circulating water pump provided by this utility model is a radially split horizontal single-stage double-suction double-volute centrifugal pump. The pump's drive side is directly connected to the motor via a flexible diaphragm coupling. The pump and motor are assembled on the same base. During operation, the deaerator tank pipeline of the device is connected to the pump inlet via an inlet flange. Circulating water enters the pump body 7 from the inlet. The motor drives the pump shaft 1 to rotate at high speed. The pump shaft 1 drives the double-suction impeller 12 in the middle to rotate at high speed, which pressurizes the circulating water entering the pump body 7 and discharges it from the outlet of the pump body 7. The water then enters the steam drum through the feed water pipeline, and is then heated by the waste heat boiler to generate steam. The steam enters the accumulator through the steam pipeline, and then the steam drives the turbine to drive the generator to generate electricity, thus achieving the purpose of waste heat recovery.

[0037] This utility model provides a high-flow, high-efficiency circulating water pump for power plant environmental modernization projects. It operates at high speed and stability, has high working efficiency, low vibration, good sealing effect, strong corrosion and wear resistance, and long service life, ensuring the long-term use and continuous operation of the equipment. It also provides reliable protection for waste heat boiler devices and can be widely used in forced circulation hot water waste heat boiler projects.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection of this utility model as defined by the appended claims and their equivalents.

Claims

1. A high-flow-rate, high-efficiency circulating water pump for a power plant environmental modernization renovation project, characterized in that: The high-flow, high-efficiency circulating water pump used in the power plant's environmental modernization project includes: a pump body (7) with a vertical inlet and a vertical outlet; a drive-side pump cover (5) and a non-drive-side pump cover (16) connected to both sides of the pump body (7); a pump shaft (1) passing through the drive-side pump cover (5) and the non-drive-side pump cover (16) and located inside the pump body (7); a double-suction impeller (12) connected to the middle of the pump shaft (1); and blades on both sides of the double-suction impeller (12) arranged alternately. The pump shaft (1) is provided with a drive-side bearing body (2) and a non-drive-side bearing body (17) on both sides. The drive-side bearing body (2) and the non-drive-side bearing body (17) are in the form of a full flange. Mechanical seals (4) are provided at the connection between the pump shaft (1) and the drive-side pump cover (5) and the non-drive-side pump cover (16); a first housing sealing ring (10) and a first impeller sealing ring (11) are provided at the fit between the drive-side pump cover (5) and the front of the double-suction impeller (12); a second housing sealing ring (13) and a second impeller sealing ring (14) are provided at the fit between the non-drive-side pump cover (16) and the rear of the double-suction impeller (12); The drive-side bearing housing (2) is a radial bearing (3) with a deep groove ball bearing, and the non-drive-side bearing housing (17) is a thrust bearing (18) with two back-to-back angular contact ball bearings.

2. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization renovation project according to claim 1, characterized in that: The oil sump of the drive-side bearing housing (2) and the non-drive-side bearing housing (17) is cooled by cooling water through finned tubes (20).

3. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization renovation project according to claim 1 or 2, characterized in that: The double-suction impeller (12) is mounted on the pump shaft (1) in a sliding manner, and is fixedly connected to the pump shaft (1) by the shaft platform and impeller nut (15).

4. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization renovation project according to claim 1 or 2, characterized in that: Graphite stainless steel spiral wound gaskets (6) are provided at the connection between the pump body (7) and the drive side pump cover (5), and at the connection between the pump body (7) and the non-drive side pump cover (16).

5. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization renovation project according to claim 1, characterized in that: An oil slinger ring (19) is provided on the pump shaft (1) between the radial bearing (3) and the thrust bearing (18). An oil cup (21) is provided on the drive-side bearing body (2) and the non-drive-side bearing body (17). The oil pools of the drive-side bearing body (2) and the non-drive-side bearing body (17) are cooled by cooling water through finned tubes (20).

6. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization renovation project according to claim 1, characterized in that: A throat bushing (8) is provided between the pump cover (5) on the drive side and the pump shaft (1), and between the pump cover (16) on the non-drive side and the pump shaft (1).

7. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization renovation project according to claim 1, characterized in that: The mechanical seal (4) is a cartridge mechanical seal, and the mechanical seal (4) is a self-circulating mechanical seal that is flushed through a flushing pipeline. The bottom of the pump body (7) is connected to the drain pipeline in the form of a flange.

8. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization renovation project according to claim 7, characterized in that: The flushing pipeline and the mechanical seal (4) are connected by a union with a sealing pipe thread. The flushing pipeline is equipped with a magnetic filter, a heat exchanger, a shut-off valve and a thermometer. Two gate valves are connected in series on the drain pipeline at the bottom of the pump body (7).

9. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization renovation project according to claim 1, characterized in that: The first housing sealing ring (10), the first impeller sealing ring (11), the second housing sealing ring (13), and the second impeller sealing ring (14) are all sealing rings that have undergone quenching and tempering treatment.

10. The high-flow-rate, high-efficiency circulating water pump used in the power plant environmental modernization project according to claim 1, characterized in that: The pump body (7), the drive-side pump cover (5), the non-drive-side pump cover (16), and the double-suction impeller (12) are all integrally cast.

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