CN115030290A - Reduced-pressure shaft for weakening influence of nappe and method for obtaining position of air flow pipeline and shaft interface in shaft - Google Patents

Reduced-pressure shaft for weakening influence of nappe and method for obtaining position of air flow pipeline and shaft interface in shaft Download PDF

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Publication number
CN115030290A
CN115030290A CN202210500947.3A CN202210500947A CN115030290A CN 115030290 A CN115030290 A CN 115030290A CN 202210500947 A CN202210500947 A CN 202210500947A CN 115030290 A CN115030290 A CN 115030290A
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shaft
nappe
water
inlet pipe
vertical shaft
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CN115030290B (en
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魏佳芳
芦三强
陈健
张源
王立荣
樊新建
南军虎
郑健
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Lanzhou University of Technology
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Lanzhou University of Technology
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    • E—FIXED CONSTRUCTIONS
    • E03—WATER SUPPLY; SEWERAGE
    • E03F—SEWERS; CESSPOOLS
    • E03F5/00—Sewerage structures
    • E03F5/04—Gullies inlets, road sinks, floor drains with or without odour seals or sediment traps
    • E—FIXED CONSTRUCTIONS
    • E03—WATER SUPPLY; SEWERAGE
    • E03F—SEWERS; CESSPOOLS
    • E03F5/00—Sewerage structures
    • E03F5/08—Ventilation of sewers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/20—Hydro energy

Abstract

The invention provides a reduced-pressure vertical shaft for weakening influence of a nappe, which comprises a vertical shaft and a gas communication structure, wherein a water inlet pipe and a gas inlet pipe are arranged on one side of the vertical shaft, the gas inlet pipe is positioned above the water inlet pipe, and the gas communication structure is arranged on the other side of the vertical shaft; the gas communication structure comprises a gas flow pipeline, and two ends of the gas flow pipeline are connected with the vertical shaft to form a first interface and a second interface; the water flow flows into the vertical shaft from the water inlet pipe to form a water tongue, the position where the water tongue impacts on the wall of the vertical shaft is the tail end position of the water tongue, the first interface is arranged on the tail end position of the water tongue, and the second interface is arranged below the tail end position of the water tongue, so that gas intercepted by the water tongue in the vertical shaft forms circulation in the vertical shaft through the airflow pipeline. The invention also provides a method for obtaining the position of the interface between the airflow pipeline and the vertical shaft in the reduced-pressure vertical shaft. The vertical shaft structure can effectively reduce the air pressure at the position of the nappe, thereby effectively reducing the overall air pressure in the vertical shaft and eliminating the influence of the nappe on the air pressure in the vertical shaft.

Description

Reduced-pressure shaft for weakening influence of nappe and method for obtaining position of air flow pipeline and shaft interface in shaft
Technical Field
The invention relates to the technical field of municipal engineering sewage pipes, in particular to a reduced-pressure vertical shaft for weakening influence of a nappe and a method for obtaining a position of a joint between an airflow pipeline and the vertical shaft in the vertical shaft.
Background
The drop shaft is one of water conveying buildings which are common in urban drainage systems and hydraulic engineering and is mainly used for transferring water flow at a high position to a downstream pipeline at a relatively low position. The height of a common flow falling vertical shaft is generally about 20m and can even reach 40-100 m in a deep drainage system, the high fall enables the flow falling vertical shaft to suck a large amount of outside air, after the air is transferred to downstream, air pressure in a downstream pipeline is increased suddenly and the air is gathered easily, and odor released in a municipal sewage system is released because the air escapes from openings after the downstream sewage pipeline is pressurized.
In order to prevent the pressurization of a pipeline at the downstream of a vertical shaft, reduce the entrainment air quantity in the vertical shaft and alleviate the odor problem, a great deal of researchers carry out a great deal of research on the air pressure distribution condition and the air entrainment mechanism in a falling flow vertical shaft, and the result shows that falling water flow mostly turns into water drops after falling to a certain height, the contact area of water and air is greatly increased due to a great number of water drops, so that a great amount of air in the shaft is dragged to the bottom of the shaft by the water drops, the top of the vertical shaft presents negative pressure, the bottom of the vertical shaft gradually becomes positive pressure, the air pressure in the vertical shaft at a position below Z (5 m) basically presents linear increase, and the air pressure distribution rule at a position above 5m with a water tongue is not clear.
However, in practice, the movement transfer of gas is blocked after the water tongue is formed, so that a huge negative pressure is formed at the water tongue, and the negative pressure region can also suck external gas, so that the gas pressure distribution in the shaft is influenced, therefore, the gas pressure at the water tongue needs to be treated.
Disclosure of Invention
The invention provides a reduced-pressure vertical shaft for weakening the influence of a nappe, which can effectively reduce the air pressure at the nappe position, thereby effectively reducing the overall air pressure in the vertical shaft and eliminating the influence of the nappe on the air pressure in the vertical shaft.
According to a first aspect of the invention, the invention provides a reduced-pressure vertical shaft for weakening influence of a nappe, which comprises a vertical shaft and a gas communication structure, wherein a water inlet pipe and a gas inlet pipe are arranged on one side of the vertical shaft, the gas inlet pipe is positioned above the water inlet pipe, and the gas communication structure is arranged on the other side of the vertical shaft;
the gas communication structure comprises a gas flow pipeline, and two ends of the gas flow pipeline are connected with the vertical shaft to form a first interface and a second interface;
the water flow flows into the vertical shaft from the water inlet pipe to form a water tongue, the position where the water tongue impacts on the wall of the vertical shaft is the tail end position of the water tongue, the first interface 11 is arranged on the tail end position of the water tongue, and the second interface is arranged below the tail end position of the water tongue, so that gas intercepted by the water tongue in the vertical shaft forms circulation in the vertical shaft through the airflow pipeline.
Preferably, the airflow pipeline comprises a first pipeline, a second pipeline and a third pipeline which are connected in sequence;
one end of the first pipeline is vertically connected with one end of the second pipeline, and the other end of the first pipeline is vertically connected with the vertical shaft to form a first interface;
the other end of the second pipeline is obliquely connected with one end of a third pipeline, and the other end of the third pipeline is obliquely connected with the vertical shaft to form a second interface;
preferably, the other end of the third pipeline is connected with the vertical shaft in an inclined way, and the angle is 30-60 degrees.
Preferably, the diameter of the airflow pipeline is 1/4-1/2 of the diameter of a vertical shaft.
Preferably, the diameter of the first pipeline is 1/4-1/2 of the diameter of the shaft, and the length of the first pipeline is 1.25-1.5 times of the diameter of the shaft.
Preferably, the diameter of the second pipeline is 1/4-1/2 of the diameter of the shaft, and the length of the second pipeline is 1/9-2/9 of the height of the shaft.
Preferably, the diameter of the third pipeline is 1/4-1/2 of the diameter of the shaft, and the length of the third pipeline is 1.4-1.8 times of the diameter of the shaft.
According to a second aspect of the object of the invention, a method for obtaining the position of the air flow pipeline and the shaft interface in the reduced-pressure shaft for reducing the influence of the nappe is provided, which comprises the following specific steps:
s1, establishing a model
The water flow flows into the vertical shaft from the water inlet pipe, the water flow forms a water tongue in the vertical shaft, at the moment, the vertex of a right angle of the lower edge of the tail end of the water inlet pipe is taken as a water tongue starting end O point, and the position of the water tongue impacting on the wall of the vertical shaft is taken as a water tongue tail end C point;
when the water tongue falls down, the water tongue performs the quasi-horizontal projectile motion, and then the horizontal speed of the water tongue during the quasi-horizontal projectile motion is V X Vertical velocity of V Y The time of the horizontal projectile motion of the nappe is T, and the vertical falling distance of the nappe is Y;
s2, determining the position of the C point at the tail end of the nappe
1. Determining the horizontal velocity V of the nappe in the process of horizontal projectile-like movement X
Horizontal velocity V when the nappe is doing quasi-flat throwing motion X Namely the flow rate of the water flow in the water inlet pipe, namely calculated according to the formula (1):
Figure BDA0003634286590000021
in the formula: q w M is the flow in the inlet pipe 3 S; a is the sectional area of the water inlet pipe, m 2 ；V X The horizontal speed m/s when the nappe is in horizontal throwing motion;
2. determining the time T of the nappe performing the quasi-horizontal projectile motion, and calculating according to the formula (2):
Figure BDA0003634286590000022
in the formula: t is the time required for the spray tongue to fall from the water inlet pipe to impact on the well wall, s; x is the horizontal distance of the movement of the nappe, m; v X The horizontal velocity is m/s when the nappe performs horizontal throwing motion;
3. determining the vertical velocity V of the nappe in the process of horizontal projectile-like movement Y Calculated according to equation (3):
V Y ＝gT (3)
in the formula: v Y The vertical speed m/s of the nappe in horizontal throwing motion; g is the acceleration of gravity, m/s 2 (ii) a T is the time required for the nappe to fall from the water inlet pipe to impact the well wall, s;
4. determining the vertical distance Y of the falling of the nappe, and calculating according to the formula (4):
Y＝V Y T 2 (4)
in the formula: y is the vertical distance of the falling of the nappe, m; v Y The vertical speed m/s when the nappe is in horizontal throwing motion; t is the time required for the spray tongue to fall from the water inlet pipe to impact on the well wall, s;
therefore, the position Y meters below the water inlet pipe is the position of the C point at the tail end of the nappe;
s3, determining the position of the air flow pipeline and the shaft interface
Determining the minimum flow of the water flow forming the water tongue and the maximum flow of the water flow;
calculating according to the step S2, obtaining that the point C under the minimum flow rate of the water flow forming the water tongue is positioned at the point C1 at the Y1 m below the water inlet pipe, and the point C under the maximum flow rate is positioned at the point C2 at the Y2 m below the water inlet pipe;
therefore, the first interface is positioned at any position between the C2 point and the top end of the shaft, and the second interface is positioned at any position between the C1 point and the bottom end of the shaft.
The invention has the beneficial effects that:
1. the air pressure reducing vertical shaft for weakening the influence of the water tongue is characterized in that an air communicating structure communicated with the vertical shaft is arranged on the wall of the vertical shaft opposite to the water inlet pipe, so that an air communicating channel is provided, air cut off by the water tongue in the vertical shaft flows in the vertical shaft through the airflow pipeline to form circulation, the continuously increased negative pressure at the top of the vertical shaft is balanced, the air pressure at the position of the water tongue is reduced, the flow state of water and air phases at the position of the water tongue is improved, the influence of the water tongue on the air pressure in the vertical shaft is eliminated, and the whole air pressure in the vertical shaft is favorably reduced.
2. The pressure reduction vertical shaft for weakening the influence of the nappe can also reduce the entrainment air volume in the vertical shaft, when the negative pressure at the top of the vertical shaft is reduced through the arranged air communicating structure, the pressure difference at the position of the air inlet pipe is reduced, and compared with the negative pressure at the top of the vertical shaft, the air inlet pipe can enter less air under the action of the external atmospheric pressure, and meanwhile, the air transferred to the downstream pipeline of the vertical shaft is less, so the entrainment air volume in the vertical shaft is reduced, and the air pressure in the downstream drainage pipeline is correspondingly reduced.
Drawings
Fig. 1 is a schematic diagram of the structure of the reduced-pressure shaft for reducing the influence of the nappe of the invention.
Fig. 2 is a schematic diagram of a model of the movement of a nappe in the method of the invention for obtaining the position of an airflow duct in a shaft at the interface with the shaft.
Figure 3 is a graph comparing the air pressure difference of the original shaft at different flow rates in example 2 and the nappe section of the shaft structure of example 1.
Figure 4 is a graph comparing the pressure difference upstream and downstream of the virgin shaft at different flow rates in example 2 and the shaft of example 1.
Fig. 5 is a graph comparing the amount of entrainment gas for the virgin silo at different flow rates in example 2 and the silo of example 1.
Description of reference numerals: 10. a shaft; 11. a first interface; 12. a second interface; 20. a gas communication structure; 21. an air flow conduit; 211. a first conduit; 212. a second pipe; 213. a third pipeline; 30. a water inlet pipe; 40. an air inlet pipe; 50. the position of the tail end of the nappe; 60. and (4) a flow outlet pipe.
Detailed Description
In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.
In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways.
When the flow in the water inlet pipe is large, the water flow can collide with the wall of the well after flowing down to form a huge water tongue, so that the normal flow of gas in the shaft is blocked, a negative pressure zone is easily formed at the top of the shaft, the air pressure distribution in the shaft is influenced, the air pressure fluctuation at the position of the water tongue is severe, the entrainment air volume of the shaft is greatly increased, and the air pressure distribution of the shaft is influenced.
In order to solve the problems, the invention provides the air pressure reducing vertical shaft for weakening the influence of the nappe, which can effectively reduce the pressure difference at the nappe position, effectively reduce the whole air pressure in the vertical shaft, effectively reduce the entrainment air volume of the vertical shaft, research the influence of the nappe at different flow rates on the air pressure distribution in the vertical shaft by adopting a numerical simulation method, and provide theoretical guidance for the structure optimization and design of the vertical shaft.
As shown in fig. 1, in an exemplary embodiment of the present invention, a reduced pressure shaft for reducing influence of nappe is provided, which includes a shaft 10 and a gas communication structure 20, wherein one side of the shaft 10 is provided with a water inlet pipe 30 and a gas inlet pipe 40, the gas inlet pipe 40 is positioned above the water inlet pipe 30, and the gas communication structure 20 is arranged at the other side of the shaft.
The gas communication structure 20 comprises a gas flow pipeline 21, and both ends of the gas flow pipeline 21 are connected with the shaft 10 to form a first interface 11 and a second interface 12.
The water flow flows into the vertical shaft from the water inlet pipe to form a water tongue, the position where the water tongue impacts the wall of the vertical shaft is the tail end position 50 of the water tongue, the first connector 11 is arranged above the tail end position 50 of the water tongue, and the second connector 12 is arranged below the tail end position 50 of the water tongue, so that gas cut off by the water tongue in the vertical shaft is circulated in the vertical shaft through the gas flow pipeline, and the gas is prevented from being blocked by the water tongue.
In a preferred embodiment, the air flow duct 21 comprises a first duct 211, a second duct 212 and a third duct 213 connected in series.
One end of the first pipeline 211 is vertically connected with one end of the second pipeline 212, and the other end of the first pipeline 211 is vertically connected with the shaft 10 to form a first interface 11 for air passing.
The other end of the second pipe 212 is connected to one end of the third pipe 213 in an inclined manner, and the other end of the third pipe 213 is connected to the shaft 10 in an inclined manner, so as to form a second interface 12.
In a more preferred embodiment, the other end of the third conduit 213 is connected to the shaft at an angle of 30 ° to 60 °. The third pipeline is set in an inclined mode to prevent falling water flow from flowing back into the airflow pipeline and influencing the circulation of air in the airflow pipeline.
In a preferred embodiment, the diameter of the airflow duct 21 is 1/4-1/2 of the diameter of a vertical shaft.
In a preferred embodiment, the diameter of the first pipeline 211 is 1/4-1/2 of the diameter of the shaft, and the length of the first pipeline 211 is 1.25-1.5 times of the diameter of the shaft.
In a preferred embodiment, the diameter of the second conduit 212 is 1/4-1/2 of the shaft diameter, and the length of the second conduit 212 is 1/9-2/9 of the shaft height.
In a preferred embodiment, the diameter of the third conduit 213 is 1/4-1/2 of the shaft diameter, and the length of the third conduit is 1.4-1.8 times the shaft diameter.
It will be appreciated that the bottom end of the shaft is also provided with an outlet duct 60, which is conventional in the art and will not be described further herein.
The positions of the first connector 11 and the second connector 12 need to be determined according to the positions of the tail ends of the nappes, and in the practical process, when the size of the vertical shaft changes, the flow rate of water which can affect the nappes also changes, so that the positions of the nappes also change.
Therefore, the invention also provides a method for obtaining the position of the interface between the airflow pipeline and the vertical shaft in the reduced-pressure vertical shaft for weakening the influence of the nappe, and theoretical guidance is provided for the design of the vertical shaft in actual production.
In another exemplary embodiment of the present invention, a method for obtaining the aforementioned location of the airflow duct to shaft interface in a reduced pressure shaft for reducing the effects of water lock is provided, comprising the specific steps of:
s1, establishing a model
Referring to fig. 1 and 2, the water flow flows into the vertical shaft from the water inlet pipe, the water flow forms a water tongue in the vertical shaft, at the moment, the vertex of a right angle of the lower edge of the tail end of the water inlet pipe is taken as a water tongue starting point O, and the position of the water tongue impacting on the wall of the vertical shaft is taken as a water tongue tail end point C;
when the water tongue falls down, the water tongue performs the quasi-horizontal projectile motion, and then the horizontal speed of the water tongue during the quasi-horizontal projectile motion is V X Vertical velocity of V Y The time of the horizontal projectile motion of the nappe is T, and the vertical falling distance of the nappe is Y;
s2, determining the position of the C point at the tail end of the nappe
1. Determining the horizontal velocity V of the nappe in the process of horizontal projectile-like movement X
Horizontal velocity V when the nappe is doing quasi-flat throwing motion X Namely the flow rate of the water flow in the water inlet pipe, namely calculated according to the formula (1):
Figure BDA0003634286590000051
in the formula: q w M is the flow in the inlet pipe 3 S; a is the sectional area of the water inlet pipe, m 2 ；V X The horizontal velocity m/s of the nappe in horizontal throwing motion.
2. Determining the time T of the nappe performing the quasi-horizontal projectile motion, and calculating according to the formula (2):
Figure BDA0003634286590000052
in the formula: t is the time required for the spray tongue to fall from the water inlet pipe to impact on the well wall, s; x is the horizontal distance of the movement of the nappe, m; v X When horizontal throwing movement is performed for nappeHorizontal velocity of (2), m/s.
3. Determining the vertical velocity V of the nappe in the process of horizontal projectile-like movement Y Calculated according to equation (3):
V Y ＝gT (3)
in the formula: v Y The vertical speed m/s when the nappe is in horizontal throwing motion; g is gravity acceleration, m/s 2 (ii) a T is the time required for the spray to fall from the water inlet pipe to impact on the well wall, s.
4. Determining the vertical distance Y of the falling of the nappe, and calculating according to the formula (4):
Y＝V Y T 2 (4)
in the formula: y is the vertical distance of the falling of the nappe, m; v Y The vertical speed m/s when the nappe is in horizontal throwing motion; t is the time required for the spray to fall from the water inlet pipe to impact on the well wall, s.
Therefore, the position Y meters below the water inlet pipe is the position of the C point at the tail end of the nappe.
S3, determining the position of the air flow pipeline and the shaft interface
The minimum flow rate of the inflow water flow forming the nappe and the maximum flow rate of the water flow are determined.
According to the calculation of the step S2, the point C under the minimum flow rate of the inflow water flow forming the water tongue is located at the point C1 at the Y1 m below the water inlet pipe, and the point C under the maximum flow rate is located at the point C2 at the Y2 m below the water inlet pipe.
Therefore, the first interface is positioned at any position between the C2 point and the top end of the shaft, and the second interface is positioned at any position between the C1 point and the bottom end of the shaft.
For better understanding, the present invention is further described below with reference to specific examples, but the present invention is not limited thereto.
[ example 1 ]
As shown in fig. 1, an optimized hoistway structure is established with the top center of the hoistway 10 as the origin and the coordinate axis Z in the downward positive direction.
Wherein the shaft 10 and the outlet pipe 60 have the same diameter of 0.38m, the height of the whole shaft 10 is about 9m, the distance from the bottom of the shaft 10 below the inlet pipe 30 is 7.72m, the length of the inlet pipe 30 is 2.28m, and the diameter is 0.19 m.
The intake duct 40 has a diameter of 0.1m, a distance of 0.4m from the top of the shaft 30, and a length of 0.4 m.
Under the size condition of the vertical shaft, when the flow rate is less than 25.8L/s, most of the water flow falls from the center of the vertical shaft, and the formed small water tongue has no influence on the vertical shaft, so that only the case that the flow rate is more than 25.8L/s is considered, and the flow rate is 47.6L/s is the maximum flow rate of the water inlet pipe, namely, under the size condition of the vertical shaft, the water flow rate is in the range of 25.8L/s-47.6L/s, and the water flow can collide with the wall of the vertical shaft to form the water tongue.
Therefore, calculations were performed according to equations (1) to (4) to obtain data of relevant parameters as shown in table 1.
TABLE 1
Flow rate Horizontal velocity Horizontal distance Time of exercise Vertical velocity Vertical distance
Q w (L/s) V X (m/s) X(m) T(s) V Y (m/s) Y(m)
25.8 0.91 0.38 0.42 4.09 1.71
33.5 1.18 0.38 0.32 3.15 1.01
42.8 1.51 0.38 0.25 2.47 0.62
47.6 1.67 0.38 0.23 2.22 0.50
According to the numerical values in the table 1, the point C is 1.71m below the water inlet pipe under the minimum flow (25.8L/s) of the water flow forming the water tongue; under the maximum flow (47.6L/s), the point C is 0.50m below the water inlet pipe.
Thus, it is possible by theoretical calculation that the first connection is located anywhere between 0.50m below the inlet pipe and the top end of the shaft and the second connection is located anywhere between 1.71m below the inlet pipe and the bottom end of the shaft.
According to the theoretical result, the gas flow structure is arranged on the shaft, the diameters of the gas flow pipelines (the first pipeline 211, the second pipeline 212 and the third pipeline 213) are all 0.1m, the length of the first pipeline 211 is 0.50m, the height (length) of the second pipeline 212 is 1m, the inclination angle of the third pipeline 213 is 30 degrees, and the length is 0.6 m.
The interface (first interface) of the first pipe 211 with the shaft may be provided at 0.3m above the upper wall surface of the inlet pipe, and the interface (second interface) of the third pipe 213 with the shaft may be provided at 3m from the top of the shaft.
[ example 2 ]
In order to analyze the influence of the water tongue on the air pressure distribution in the drop flow shaft, numerical simulation is respectively carried out on the original drop flow shaft and the shaft structure in the embodiment 1 on the basis of Fluent software by utilizing a readable k-epsilon turbulence model and a VOF two-phase flow model, the boundary condition is that an air inlet pipe is set as a pressure inlet (pressure-let), an air inlet pipe is set as a mass-flow-inlet (mass-flow-let), an outlet pipe is set as a pressure outlet (pressure-outlet), the current flow rates are 25.8L/s, 33.5L/s, 42.8L/s and 47.6L/s4, and simulation results are shown in the figure 3, the figure 4 and the figure 5.
As can be seen from fig. 3, the difference between the upper and lower pressure of the water tongue in the original shaft structure is large, when the flow rate is 47.6L/s, the difference between the upper and lower pressure of the water tongue reaches 160Pa, and the optimized shaft structure can greatly reduce the difference between the upper and lower pressure of the water tongue, when the flow rate is 25.8L/s and 33.5L/s, the difference between the upper and lower pressure of the water tongue tends to 0Pa, which indicates that the water tongue has no influence on the air pressure distribution in the drop shaft at this time; and when the flow rate is 42.8L/s and 47.6L/s, the pressure difference between the upper part and the lower part of the nappe section can be reduced by 84.6 percent and 78.9 percent, and the result shows that the vertical shaft structure has remarkable effect on improving the nappe influence.
As can be seen from fig. 3, the air pressure difference between the upstream and downstream of the shaft structure of the present invention is significantly reduced, and the air pressure difference can be reduced by 54.8%, 52.4%, 57.1% and 40.6% at 4 groups of flow rates, respectively, and is reduced by 51.2% on average.
As can be observed from fig. 4, the optimized shaft structure can reduce the entrainment air volume in the shaft, and the shaft air suction volume can be reduced by about 29.59% on average under 4 groups of flow compared with the original shaft.
In conclusion, the integral performance of the vertical shaft structure is greatly improved, the influence of the nappe on the air pressure distribution in the vertical shaft is improved, and the entrainment air quantity and the upstream and downstream pressure difference of the vertical shaft can be reduced.
Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims (8)

1. The reduced-pressure vertical shaft for weakening influence of the nappe is characterized by comprising a vertical shaft and a gas communication structure, wherein a water inlet pipe and a gas inlet pipe are arranged on one side of the vertical shaft, the gas inlet pipe is positioned above the water inlet pipe, and the gas communication structure is arranged on the other side of the vertical shaft;
the gas communication structure comprises a gas flow pipeline, and two ends of the gas flow pipeline are connected with the vertical shaft to form a first interface and a second interface;
rivers form the nappe from the inlet tube inflow in the shaft, and the position that the nappe strikes on the shaft wall of shaft is nappe terminal position, first interface is located on nappe terminal position, the second interface is located under nappe terminal position, makes the gas that is cut off by the nappe in the shaft form the circulation in the shaft through the air current pipeline.
2. The reduced pressure shaft for attenuating the effects of a nappe of claim 1, wherein the airflow conduit comprises a first conduit, a second conduit, and a third conduit connected in series;
one end of the first pipeline is vertically connected with one end of the second pipeline, and the other end of the first pipeline is vertically connected with the vertical shaft to form a first interface;
the other end of the second pipeline is obliquely connected with one end of a third pipeline, and the other end of the third pipeline is obliquely connected with the vertical shaft to form a second interface.
3. The reduced pressure shaft for attenuating the effects of napping as defined in claim 2 wherein the other end of the third conduit is connected to the shaft at an angle of between 30 ° and 60 °.
4. The reduced pressure shaft for attenuating the effects of napping as defined in claim 1 wherein the diameter of the airflow conduit is 1/4-1/2 of the shaft diameter.
5. The reduced pressure shaft for attenuating the effects of napping as defined in claim 2 wherein the diameter of the first conduit is 1/4-1/2 of the shaft diameter and the length of the first conduit is 1.25-1.5 times the shaft diameter.
6. The reduced pressure shaft for attenuating the effects of napping as defined in claim 2 wherein the second conduit diameter is from 1/4 to 1/2 shaft diameter and the length of the second conduit is from 1/9 to 2/9 shaft height.
7. The reduced pressure shaft for attenuating the effects of napping as defined in claim 2 wherein the third conduit diameter is from 1/4 to 1/2 shaft diameter and the length of the third conduit is from 1.4 to 1.8 times shaft diameter.
8. A method of obtaining the position of the air flow duct to shaft interface in a reduced pressure shaft for reducing the effects of napping as claimed in any one of claims 1 to 7, comprising the specific steps of:
s1, establishing a model
The water flow flows into the vertical shaft from the water inlet pipe, the water flow forms a water tongue in the vertical shaft, at the moment, the vertex of a right angle of the lower edge of the tail end of the water inlet pipe is taken as a water tongue starting end O point, and the position of the water tongue impacting on the wall of the vertical shaft is taken as a water tongue tail end C point;
when the water tongue falls down, the water tongue performs the quasi-horizontal projectile motion, and then the horizontal speed of the water tongue during the quasi-horizontal projectile motion is V X Vertical velocity of V Y The time of the horizontal projectile motion of the nappe is T, and the vertical falling distance of the nappe is Y;
s2, determining the position of the C point at the tail end of the nappe
1. Determining the horizontal velocity V of the nappe in the process of horizontal projectile-like movement X
Horizontal velocity V when the nappe is doing quasi-flat throwing motion X Namely the flow rate of the water flow in the water inlet pipe, namely calculated according to the formula (1):
Figure FDA0003634286580000021
in the formula: q w M is the flow in the inlet pipe 3 S; a is the sectional area of the water inlet pipe, m 2 ；V X The horizontal speed m/s when the nappe is in horizontal throwing motion;
2. determining the time T when the nappe performs the quasi-horizontal throwing motion, and calculating according to a formula (2):
Figure FDA0003634286580000022
in the formula: t is the time required for the spray tongue to fall from the water inlet pipe to impact on the well wall, s; x is the horizontal distance of the movement of the nappe, m; v X The horizontal velocity is m/s when the nappe performs horizontal throwing motion;
3. determining the vertical velocity V of the nappe in the process of horizontal projectile-like movement Y Calculated according to equation (3):
V Y ＝gT (3)
in the formula: v Y The vertical speed m/s when the nappe is in horizontal throwing motion; g is gravity acceleration, m/s 2 (ii) a T is the time required for the spray tongue to fall from the water inlet pipe to impact on the well wall, s;
4. determining the vertical distance Y of the falling of the nappe, and calculating according to the formula (4):
Y＝V Y T 2 (4)
in the formula: y is the vertical direction of falling of nappeDistance, m; v Y The vertical speed m/s when the nappe is in horizontal throwing motion; t is the time required for the spray tongue to fall from the water inlet pipe to impact on the well wall, s;
therefore, the position Y meters below the water inlet pipe is the position of the C point at the tail end of the nappe;
s3, determining the position of the air flow pipeline and the shaft interface
Determining the minimum flow of the water flow forming the water tongue and the maximum flow of the water flow;
calculating according to the step S2, obtaining that the point C under the minimum flow rate of the water flow forming the water tongue is positioned at the point C1 at the Y1 m below the water inlet pipe, and the point C under the maximum flow rate is positioned at the point C2 at the Y2 m below the water inlet pipe;
therefore, the first interface is positioned at any position between the C2 point and the top end of the shaft, and the second interface is positioned at any position between the C1 point and the bottom end of the shaft.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2066359C1 (en) * 1994-01-28 1996-09-10 Санкт-Петербургский государственный архитектурно-строительный университет Sewage drop structure
CN202610774U (en) * 2012-06-18 2012-12-19 中国水利水电科学研究院 Deep-hole cyclone shaft type flood drainage tunnel
CN108052773A (en) * 2017-12-29 2018-05-18 河海大学 Single flow shaft structure rolls up inspiratory capacity and the computational methods of intraductal atmospheric pressure
CN108104242A (en) * 2017-12-29 2018-06-01 河海大学 Reduce the single flow drop structure of sucking gas flow
CN108374469A (en) * 2018-04-28 2018-08-07 山东电力工程咨询院有限公司 Stablize the component of overflow after siphonic water-collecting well downflow weir for fire, nuclear power plant's drainage system
CN110004872A (en) * 2019-04-04 2019-07-12 天津大学 A method of measurement hypobaric model overflow outer rim is chosen away from aerial shift amount
CN114059501A (en) * 2021-12-28 2022-02-18 中国电建集团华东勘测设计研究院有限公司 Method for estimating flow distribution after water entering after surface deep hole water tongue air collision

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2066359C1 (en) * 1994-01-28 1996-09-10 Санкт-Петербургский государственный архитектурно-строительный университет Sewage drop structure
CN202610774U (en) * 2012-06-18 2012-12-19 中国水利水电科学研究院 Deep-hole cyclone shaft type flood drainage tunnel
CN108052773A (en) * 2017-12-29 2018-05-18 河海大学 Single flow shaft structure rolls up inspiratory capacity and the computational methods of intraductal atmospheric pressure
CN108104242A (en) * 2017-12-29 2018-06-01 河海大学 Reduce the single flow drop structure of sucking gas flow
CN108374469A (en) * 2018-04-28 2018-08-07 山东电力工程咨询院有限公司 Stablize the component of overflow after siphonic water-collecting well downflow weir for fire, nuclear power plant's drainage system
CN110004872A (en) * 2019-04-04 2019-07-12 天津大学 A method of measurement hypobaric model overflow outer rim is chosen away from aerial shift amount
CN114059501A (en) * 2021-12-28 2022-02-18 中国电建集团华东勘测设计研究院有限公司 Method for estimating flow distribution after water entering after surface deep hole water tongue air collision

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