CN210949153U

CN210949153U - Small-flow ultrahigh-pressure boiler feed pump

Info

Publication number: CN210949153U
Application number: CN201921858063.5U
Authority: CN
Inventors: 李斌; 白书哲
Original assignee: Shenyang Qiyuan Industrial Pump Manufacturing Co ltd
Current assignee: Shenyang Qiyuan Industrial Pump Manufacturing Co ltd
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-07-07
Anticipated expiration: 2029-10-31

Abstract

A small-flow ultrahigh-pressure boiler feed pump belongs to the technical field of boiler feed pumps, and particularly relates to a single-shell, horizontal, multistage, segmental, centrifugal and small-flow (85 m)³A/h) and ultrahigh pressure (18-20 MPa) boiler feed pump. The utility model provides aThe small-flow ultrahigh-pressure boiler feed pump is convenient to overhaul, safe, stable and reliable to operate. The utility model is characterized in that: be provided with sealed letter body and bearing body on the pump shaft at pump body both ends, be mechanical seal in the sealed letter body, its characterized in that: a connecting flange matched with the pump body is arranged outside the sealing box body, and a fixing flange matched with the connecting flange is arranged on the bearing body; the sealing box body is provided with an annular cooling groove on the opposite face of the pump body, an isolation rib is arranged in the annular cooling groove, and a water inlet and a water outlet which are communicated with the annular cooling groove are formed in the sealing box body and located on two sides of the isolation rib.

Description

Small-flow ultrahigh-pressure boiler feed pump

Technical Field

The utility model belongs to the technical field of the boiler feed pump, the more specifically single casing, horizontal, multistage, festival section, centrifugal, little flow (85 m 3/h), superhigh pressure (18 ~ 20 MPa) boiler feed pump that says so.

Background

In a thermal power generation system, a boiler feed water pump is used for conveying deoxygenated water with a certain temperature in a deaerator water tank to a boiler or a high-pressure heater.

In a 100 MW-200 MW thermal power generator set, the flow of a feed water pump is generally 450-750 m3/h, and the outlet pressure is 18-20 MPa. When the main power supply system fails temporarily and the main feed water pump stops running, in order to prevent the boiler from water shortage, the small-flow feed water pump is arranged as an emergency feed water pump to protect the boiler, and an independent power supply system or a steam turbine, a diesel engine and the like are configured to drive the feed water pump to run. The rated flow of the emergency water-feeding pump is generally 80-85 m3/h, and the outlet pressure is 18-20 MPa.

In addition, with the maturity of power generation technologies adopting circular economy and comprehensive resource utilization, such as biomass energy power generation, coal gas power generation, steel heat recovery coke ovens and other industrial residual energy waste heat high-efficiency recovery and utilization, more and more small-sized 75T/h boilers are popularized and applied. In order to improve the heat efficiency of the unit and save energy, the pressure of the novel boiler is designed to be ultrahigh pressure from the traditional medium-high pressure. The rated flow of a matched boiler feed pump is generally 80-85 m3/h, and the outlet working pressure is 17-20 MPa.

The highest outlet pressure of a traditional single-shell, multi-stage, segmental and centrifugal feed water pump with rated flow of 80-85 m3/h can only reach 14.5 MPa. In order to realize the ultrahigh pressure lift, when blank models of guide vanes, middle sections and other parts are not changed, the diameter of the impeller is only increased due to structural space limitation, and the single-stage lift of the impeller can be increased by only 3-4% at most; or, the pump shaft is too long and the bearing span is increased due to the adoption of increasing the impeller stage number to obtain high lift, so that the faults of overproof vibration of the pump set, grinding of the rotor component and the like are easily caused; the pump lift is increased, the shaft power is increased, and if the diameter and the structure of the pump shaft are not improved and increased, serious accidents that the pump shaft is broken due to insufficient mechanical strength can be caused.

In order to prevent the leakage of high-temperature deoxygenated water, mechanical seals are generally adopted for shaft end seals of a boiler feed water pump. The mechanical seal is arranged between the tail cover and the bearing body, and between the suction section and the bearing body. The mechanical seal belongs to a quick-wear part and needs to be periodically disassembled, overhauled and replaced. Before the mechanical seal is removed, the bearing body, the bearing shell, etc. must be removed. The bearing bush of the traditional water supply pump is generally of a split type and consists of an upper half part and a lower half part, and parts such as an upper bearing cover, an upper bearing bush, a lower bearing bush, a bearing body and the like need to be gradually disassembled. When the device is reloaded, the shaft needs to be lifted and aligned again, certain manpower and material resources are wasted, and the overhaul period is prolonged.

Disclosure of Invention

The utility model discloses to above-mentioned problem, the small discharge superhigh pressure boiler feed pump that provides one kind and overhauls conveniently, operation safety, stability, reliable.

In order to realize the above object of the utility model, the utility model discloses a following technical scheme, the utility model discloses a pump body is provided with pump shaft and impeller, its characterized in that in the pump body: be provided with sealed letter body and bearing body on the pump shaft at pump body both ends, be mechanical seal in the sealed letter body, its characterized in that: a connecting flange matched with the pump body is arranged outside the sealing box body, and a fixing flange matched with the connecting flange is arranged on the bearing body; an annular cooling groove is formed in the opposite surface of the sealing box body and the pump body, an isolation rib is arranged in the annular cooling groove, and a water inlet and a water outlet which are communicated with the annular cooling groove are formed in the sealing box body and positioned on the two sides of the isolation rib; the inside sealed water hole that is provided with and mechanical seal and the outside intercommunication of sealed letter body of isolation rib.

As a preferred scheme of the utility model, a plurality of adjusting bolts are arranged on the fixed flange of the bearing body; the sealing box body is provided with a matching surface corresponding to the adjusting bolt.

As another preferred scheme of the utility model, the mounting flange lower part of the bearing body and the flange's of sealed letter body lower part are provided with corresponding taper hole, are provided with the taper pin in the taper hole.

As the utility model discloses a third kind preferred scheme, the pump shaft sets up to phi 92mm with impeller wheel hub cooperation position diameter, and pump shaft and axle bush cooperation position diameter set up to phi 75mm, and impeller sunction inlet wheel hub department diameter sets up to phi 103mm, and the impeller diameter sets up to phi 305mm, and the blade cornerite sets up to 154.5, and the blade of impeller sets up to 8 pieces.

As the fourth preferred embodiment of the present invention, the bearing body and the bearing bush in the bearing body are integrated.

The utility model has the advantages that: 1. the utility model discloses pump shaft diameter increases to phi 92, and the cross-sectional area theory increases 32%, effectively improves the mechanical strength of pump shaft, improves the rigidity, ensures the operation reliable and stable.

2. The utility model discloses increase impeller diameter to phi 305, improve blade cornerite to 154.5, blade quantity increases to 8 pieces, realizes that the single-stage lift of impeller improves 10%, need not change the blank model of parts such as stator, middle section, effectively reduces manufacturing cost. The single-stage lift is improved, the number of stages of the impeller needing to be increased is reduced, the pump shaft is not overlong, the running reliability is improved, and the reduction of the vibration value is facilitated.

3. The utility model discloses an axle bush, bearing body are monolithic structure, do not need the special equipment processing middle-split face, only need conventional horizontal lathe can accomplish whole cutting process, simplify procedures such as mechanical clamping, processing, reduce manufacturing cost. The work of lifting the shaft and aligning the professional technical requirements is completed by a pump factory, and the conical pins and the conical holes are arranged at the lower sides of the fixed flange and the connecting flange for positioning, so that the engineering field operation procedure is simplified, and the overhaul period is effectively shortened.

4. The utility model discloses the water-cooling cavity structure of sealed letter body has been improved, the one shot casting shaping can be realized. The open-type cooling cavity is convenient for cleaning circulating scale, impurities and the like.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a partially enlarged view of fig. 1.

Fig. 3 is a schematic structural view of the impeller.

Fig. 4 is a side view of fig. 3.

Fig. 5 is a schematic view of the assembly of the bearing shell and the bearing body.

Fig. 6 is a side view of fig. 5.

FIG. 7 is a cross-sectional view of a sealing box.

Fig. 8 is a side view of fig. 7.

Fig. 9 is a sectional view of a conventional pump.

In the attached drawing, 1 is a bearing body, 2 is a pump shaft, 3 is a sealing box body, 4 is a pump body, 5 is an impeller, 6 is a mechanical seal, 7 is a fixed flange, 8 is an adjusting bolt, 9 is a connecting flange, 10 is a conical pin, 11 is a sealing water hole, 12 is an isolation rib, 13 is a water outlet, 14 is a water inlet, and 15 is an annular cooling groove.

Detailed Description

The utility model discloses a pump body 4 is provided with pump shaft 2 and impeller 5, its characterized in that in the pump body 4: be provided with sealed letter body 3 and bearing body 1 on the pump shaft 2 at 4 both ends of the pump body, be mechanical seal 6, its characterized in that in the sealed letter body 3: a connecting flange 9 matched with the pump body 4 is arranged outside the sealing box body 3, and a fixing flange 7 matched with the connecting flange 9 is arranged on the bearing body 1; an annular cooling groove 15 is formed in the opposite surface of the sealing box body 3 and the pump body 4, an isolation rib 12 is arranged in the annular cooling groove 15, and a water inlet 14 and a water outlet 13 which are communicated with the annular cooling groove 15 are formed in the sealing box body 3 and located on the two sides of the isolation rib 12; the inside of the isolation rib 12 is provided with a sealing water hole 11 communicated with the mechanical seal 6 and the outside of the sealing box body 3.

As a preferred scheme of the present invention, a plurality of adjusting bolts 8 are disposed on the fixing flange 7 of the bearing body 1; the sealing box 3 is provided with a mating surface corresponding to the adjusting screw 8.

As another preferred embodiment of the present invention, the lower portion of the fixing flange 7 of the bearing body 1 and the lower portion of the connecting flange 9 of the sealing box body 3 are provided with corresponding taper holes, and the taper holes are provided with taper pins 10.

As the utility model discloses a third kind preferred scheme, pump shaft 2 sets up to phi 92mm with 5 wheel hub cooperation position diameters of impeller, and pump shaft 2 sets up to phi 75mm with axle bush cooperation position diameter, and 5 sunction inlet wheel hub department diameters of impeller set up to phi 103mm, and 5 diameters of impeller set up to phi 305mm, and blade cornerite α sets up to 154.5, and the blade of impeller 5 sets up to 8 pieces.

As the fourth preferred embodiment of the present invention, the bearing bush in the bearing body 1 and the bearing body 1 is an integral structure.

The utility model discloses increase the diameter of

pump shaft

2 and 5 wheel hub cooperation positions of impeller to phi 92mm by former phi 80mm, the diameter at axle bush position is increased to phi 75mm by former phi 70 mm. The mechanical strength of the pump shaft 2 is effectively improved, the rigidity is improved, and the stable and reliable operation is ensured.

The diameter of the impeller 5 matched with the pump shaft 2 is increased, and the diameter of a suction inlet of the impeller 5 is correspondingly increased. The diameter of the suction inlet of the impeller 5 is increased from original phi 131mm to phi 133mm, and the diameter of the hub of the suction inlet of the impeller 5 is increased from original phi 96 to phi 103. The diameter of the impeller 5 is increased from original phi 300 to phi 305. By adopting a newly developed impeller 5 hydraulic model, the wrap angle of the blades is increased to 154.5 degrees, and the number of the blades of the impeller 5 is increased to 8 from the original 7. The single-stage lift of the impeller 5 is improved by 10 percent, the stage number of the impeller 5 is slightly increased, and the total lift of the pump is improved.

The bearing body 1 is also of an integral structure by adopting a cylindrical integral bearing bush. The bearing bush is arranged inside the bearing body 1. The bearing body 1 and the sealing box body 3 are connected through flanges, the inner diameter of each flange and the outer diameter of the sealing box body 3 are provided with movable spigots, and a certain adjusting gap is reserved. 6 adjusting bolts 8 are arranged on the circumference of the mounting flange of the bearing body 1 and used for rotating the screwing depth of the adjusting screws when the shaft is lifted and aligned, so that the bearing body 1 can move up and down or left and right until the upper gap and the left and right gap between the bearing bush and the shaft meet the specified technical requirements, and then the bearing body 1 is fixed. Then, taper holes are integrally processed at the lower parts of the bearing body 1 and the sealing box body 3 connecting flange 9, the taper holes are in tight fit with the taper pins 10, and the bearing body 1 can be positioned by knocking in the taper pins 10.

The sealing box body 3 is connected with the suction section or the tail cover, a cavity is arranged on the corresponding connection side, and a rib plate is arranged on the upper portion of the cavity. Holes are drilled on two sides of the vertical center line of the rib plate and are respectively used for cooling a water inlet and a water return port. After the sealing box body 3 is assembled and connected with the suction section or the tail cover, a closed cavity is formed, and circulation is realized.

The following describes a single operation process of the present invention with reference to the accompanying drawings:

the prime motor drives the impeller 5, the shaft and other rotor components which are combined into a whole to rotate through the pump coupler, high-temperature deoxygenated water enters from the suction section and is pressurized step by step through the impeller 5, the guide vane, the middle section and the like to form ultrahigh pressure, and the ultrahigh pressure is discharged from the discharge section.

In actual work, the sealed letter body 3 of both sides with inhale the section, form closed cavity respectively with the tailcap, cooling water gets into from sealed letter body 3 one side, around internal circulation a week, the opposite side is discharged, realizes circulative cooling.

When the mechanical seal 6 needs to be overhauled and replaced, related parts are firstly loosened, the taper pin 10 is loosened, the bearing body 1 and the whole bearing bush are axially drawn out, and after the mechanical seal 6 is overhauled and replaced, the bearing body 1 and the whole bearing bush are integrally installed again. 2 taper pins 10 are knocked in, the bearing body 1 is automatically positioned without shaft lifting and alignment, and the overhaul period is effectively shortened.

It should be understood that the above detailed description of the present invention is only for illustrating the present invention and is not limited by the technical solutions described in the embodiments of the present invention, and those skilled in the art should understand that the present invention can still be modified or equivalently replaced to achieve the same technical effects; as long as the use requirement is satisfied, the utility model is within the protection scope.

Claims

1. The utility model provides a little flow superhigh pressure boiler feed pump, includes pump body (4), is provided with pump shaft (2) and impeller (5) in the pump body (4), its characterized in that: a sealing box body (3) and a bearing body (1) are arranged on the pump shaft (2) at two ends of the pump body (4), a mechanical seal (6) is arranged in the sealing box body (3), a connecting flange (9) matched with the pump body (4) is arranged outside the sealing box body (3), and a fixing flange (7) matched with the connecting flange (9) is arranged on the bearing body (1); an annular cooling groove (15) is formed in the opposite surface of the sealing box body (3) and the pump body (4), an isolation rib (12) is arranged in the annular cooling groove (15), and a water inlet (14) and a water outlet (13) which are communicated with the annular cooling groove (15) are formed in the sealing box body (3) and are positioned on the two sides of the isolation rib (12); and a sealing water hole (11) communicated with the mechanical seal (6) and the outside of the sealing box body (3) is arranged in the isolating rib (12).

2. A small flow ultra high pressure boiler feed water pump as claimed in claim 1, wherein: a plurality of adjusting bolts (8) are arranged on a fixed flange (7) of the bearing body (1); the sealing box body (3) is provided with a matching surface corresponding to the adjusting bolt (8).

3. A small flow ultra high pressure boiler feed water pump as claimed in claim 1, wherein: the lower parts of the fixing flange (7) of the bearing body (1) and the connecting flange (9) of the sealing box body (3) are provided with corresponding taper holes, and taper pins (10) are arranged in the taper holes.

4. The small-flow ultrahigh-pressure boiler feed pump according to claim 1, characterized in that the diameter of the matching part of the pump shaft (2) and the hub of the impeller (5) is set to be phi 92mm, the diameter of the matching part of the pump shaft (2) and the bearing bush is set to be phi 75mm, the diameter of the hub of the suction inlet of the impeller (5) is set to be phi 103mm, the diameter of the impeller (5) is set to be phi 305mm, the wrap angle α of the blades is set to be 154.5 degrees, and the blades of the impeller (5) are set to be 8.

5. A small flow ultra high pressure boiler feed water pump as claimed in claim 1, wherein: the bearing body (1) and the bearing bush in the bearing body (1) are of an integrated structure.