Secondary water supply pipeline with spiral yang rifling and flow velocity calculation method thereof

Abstract

The invention belongs to the technical field of fluid conveying water supply pipelines, and particularly relates to a secondary water supply pipeline with a spiral rifling and a flow velocity calculation method thereof.The flow velocity calculation method comprises the steps that the gradually-changed cross sectional area of the spiral rifling is obtained through an equivalent cycloid and an arc line; obtaining the effective cross sectional area of the conical pipeline; and the flow velocity of any point in the conical pipeline is obtained by using a Bernoulli equation and a continuity equation, and the flow of the whole section of the conical pipeline is accurately calculated through integration. According to the calculation method, the precision and accuracy of a calculation result are improved, so that the flow and flow velocity values generated by the secondary water supply pipeline with the spiral rifling can be calculated and analyzed more clearly and accurately, and reference can be provided for designing a secondary water supply system.

Description

Technical Field

[0001] The invention belongs to the technical field of fluid transport water supply pipelines, and in particular relates to a secondary water supply pipeline provided with spiral grooves and a flow rate calculation method thereof. Background Art

[0002] Water pipes are essential equipment for water supply. According to the material of the water pipes, they can be divided into: metal pipes, plastic-coated metal pipes, and plastic pipes. The most commonly used water pipes in daily life are stainless steel pipes among metal pipes and PPR pipes among plastic pipes. Stainless steel is safe, hygienic, healthy, and durable. It eliminates the problem of plastic pipe pollution and is much cheaper than copper pipes. It is the preferred water pipe material. As a new type of water pipe, PPR pipe can be used as both a cold pipe and a hot water pipe. It is non-toxic, lightweight, pressure-resistant, and corrosion-resistant. However, no matter what kind of pipe is used, under the same initial conditions, the speed and head of the water flow in the pipe are almost the same. There is still room for improvement in the existing water supply pipes in terms of energy and water conservation.

[0003] The invention patent with publication number CN 107906086 A provides a sleeve-type spiral flow generating device. The design of the spiral blades will affect the flow uniformity of the fluid in the pipeline. If the fluid flows unevenly, it may cause the local pressure to be too high or too low, which will affect the efficiency and stability of the entire system. In addition, due to the small space between the spiral blades and the inner tube and the complex design of the spiral blades, it will cause difficulties in cleaning and maintenance, increase the workload of the operator, and affect the long-term operating efficiency of the device.

[0004] The invention patent with publication number CN 118623102 A provides a water supply pipeline of a novel secondary water supply device. Since the water supply pipeline with spiral rifling is a straight pipeline, the effect of increasing the flow rate is limited. Summary of the invention

[0005] In view of the above technical problems, the present invention provides a secondary water supply pipeline with spiral grooves and a flow rate calculation method thereof, which reduces energy consumption, saves water costs, and achieves the same water supply effect under low-level power motor drive. In order to solve the above technical problems, the technical solution adopted by the present invention is: A secondary water supply pipeline with spiral rifling comprises a straight pipeline, a tapered pipeline, spiral rifling, a square connecting flange, an O-type sealing groove and a straight groove bolt through hole, wherein one end of the straight pipeline is connected to the large end of the tapered pipeline, the tapered pipeline is provided with spiral rifling, two square connecting flanges are provided, one of the square connecting flanges is connected to the other end of the straight pipeline, and the other square connecting flange is connected to the small end of the tapered pipeline, the square connecting flange at the other end of the straight pipeline is connected to the outlet of a water pump through a straight groove bolt through hole, the square connecting flange at the small end of the tapered pipeline is connected to a pipe network pipeline through a straight groove bolt through hole, and both of the two square connecting flanges are provided with O-type sealing grooves.

[0006] The straight pipeline and the tapered pipeline are made of galvanized steel pipes, stainless steel pipes or cast iron pipes.

[0007] A method for calculating the flow rate of a secondary water supply pipeline provided with a spiral groove comprises the following steps: S1. Equivalent the cross section of the spiral rifling to the area enclosed by the cycloid and the arc, and calculate the cross section area of ​​the spiral rifling; S2, according to the cross-sectional area of ​​the spiral rifling calculated in S1, calculate the effective cross-sectional area of ​​the tapered pipe; S3, according to the effective cross-sectional area of ​​the tapered pipe calculated in S2, the flow velocity at any point of the tapered pipe is calculated by the Bernoulli equation; S4. Calculate the flow rate of the entire cross section of the tapered pipe according to the flow velocity at any point in the tapered pipe calculated in S3.

[0008] The method for calculating the cross-sectional area of ​​the spiral rifling in S1 is: According to the cutting method, the cross-sectional area of ​​the spiral rifling is equivalent to the area enclosed by the cycloid and the arc; The equivalent curve expression of the cycloid is: ; The value range of is [0-2π]; Differentiate it to get: ; Then the area formed by the cycloid is: ; The equivalent curve expression of the arc is: ; Differentiate it to get: ; The area formed by the arc is: ; The cross-sectional area of ​​the spiral rifling is: ; in: is the cross-sectional area of ​​the spiral rifling; is the area composed of the cycloids; is the area of ​​the arc; is the rolling angle, the value range is [0-2π]; is radians; a is the height of the spiral rifling; b is the width of the spiral rifling; R is the gradual radius of the tapered pipe, , is the radius of the small end of the tapered pipe, is the radius of the large end of the tapered pipe, .

[0009] The method for calculating the effective cross-sectional area of ​​the tapered pipe in S2 is: ; in: A 2 is the effective cross-sectional area of ​​the tapered pipe; n is the number of spiral rifling lines; R is the gradient radius of the tapered pipe, .

[0010] The method for calculating the flow velocity at any point in the tapered pipe in S3 is: ignoring the head loss, the Bernoulli equation is as follows: ; Then from the continuity equation ; get ; Thus, the flow velocity at any point in the conical pipe is obtained: ; in: is the flow velocity in the straight pipe; is the flow velocity at any point in the tapered pipe; ρ is the density of water in the tapered pipe; is the pressure in the straight pipeline; is the pressure at any point in the tapered pipe; is the acceleration due to gravity; is the cross-sectional area of ​​the straight pipe; is the effective cross-sectional area of ​​the tapered pipe.

[0011] The method for calculating the flow rate of the entire cross section of the tapered pipe in S4 is: ; in: Q It is the flow rate of the entire cross section of the tapered pipe.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for calculating the flow rate of a secondary water supply pipeline provided with a spiral yang rifling. By equating the cross section of the spiral yang rifling to the area enclosed by a cycloid and an arc, the cross-sectional area of ​​the spiral yang rifling is obtained, and then the effective cross-sectional area of ​​the tapered pipeline is obtained. The Bernoulli equation and the known flow rate and pressure at a certain point are used to obtain the flow rate of any point in the tapered pipeline, and the flow rate of the entire cross section of the tapered pipeline is accurately calculated through integration. The calculation method of the present invention improves the precision and accuracy of the calculation results, so that the flow rate and flow rate values ​​generated by the secondary water supply pipeline provided with the spiral yang rifling can be calculated and analyzed more clearly and accurately, and can provide a reference for designing a secondary water supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0014] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0015] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 is a cross-sectional view of the water supply pipeline of the present invention; Figure 3 It is a front view of the present invention; Figure 4 It is a schematic diagram of an equivalent curve of the arc of the present invention.

[0016] Among them: 1 is a straight pipeline, 2 is a tapered pipeline, 3 is a spiral rifling, 4 is a square connecting flange, 5 is an O-type sealing groove, and 6 is a straight groove bolt through hole. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. These descriptions are only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0018] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0019] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0020] A secondary water supply pipeline provided with spiral rifling, such as Figure 1 , Figure 2 As shown, it includes a straight pipe 1, a tapered pipe 2, a spiral groove 3, a square connection flange 4, an O-type sealing groove 5 and a straight groove bolt through hole 6. One end of the straight pipe 1 is connected to the large end of the tapered pipe 2, and the tapered pipe 2 is provided with a spiral groove 3. There are two square connection flanges 4, one of which is connected to the other end of the straight pipe 1, and the other is connected to the small end of the tapered pipe 2. The square connection flange 4 at the other end of the straight pipe 1 is connected to the outlet of the water pump through the straight groove bolt through hole 6, and the square connection flange 4 at the small end of the tapered pipe 2 is connected to the pipe network through the straight groove bolt through hole 6. O-type sealing grooves 5 are provided in both square connection flanges 4, and O-type sealing rings are provided in the O-type sealing grooves 5. Under the action of the spiral grooves 3, when the water flow passes through the tapered pipe 2 at high speed, the collision flow field is changed into a rotating flow field. Compared with ordinary smooth pipes, when driven by a motor of the same power, water flows through the conical pipe 2 with spiral rifling 3, not only the spray distance is longer and the height is higher, but also the equipment cost and energy consumption can be further reduced.

[0021] like Figure 1-Figure 4 As shown, the tapered pipe 2 with spiral rifling 3 is directly connected to the pump outlet through a square connecting flange 4. The tapered pipe 2 has a gradual radius of R. m is the rolling angle, the value range is [0-2π];a is the height of the spiral rifling 3; b is the width of the spiral rifling 3; n is the number of spiral rifling 3, which is generally 3-5. In radians.

[0022] A method for calculating the flow rate of a secondary water supply pipeline with spiral rifling, such as Figure 3 , Figure 4 As shown, according to the cutting method, the cross-sectional area of ​​the spiral male rifling 3 is equivalent to the area enclosed by the cycloid (first part) and the arc (second part).

[0023] The equivalent curve expression of the first part is: (1) The value range is [0-2π] Differentiate it to get: (2) The area of ​​its composition is: (3) The equivalent curve expression of the second part is: (4) Differentiate it to get: (5) The area of ​​its composition is: (6) Then the cross-sectional area of ​​the spiral rifling 3 is: (7) The effective cross-sectional area of ​​the tapered pipe 2 is: (8) in: is the cross-sectional area of ​​the spiral rifling 3; is the area composed of the cycloids; is the area of ​​the arc; is the rolling angle, the value range is [0-2π]; is radians; a is the height of the spiral rifling 3; b is the width of the spiral rifling 3; R is the gradual radius of the tapered pipe 2, , is the radius of the small end of the tapered pipe, is the radius of the two large ends of the tapered pipe, .

[0024] Then, the flow velocity at any point in the conical pipe 2 is obtained according to the Bernoulli equation: Ignoring the head loss, the Bernoulli equation is as follows: (9) Then from the continuity equation

[0025] get (10) Substituting equation (10) into equation (9) yields the flow velocity at any point in the conical pipe 2: (11) Where: is the flow velocity in the straight pipe 1; is the flow velocity at any point in the tapered pipe 2; ρ is the density of water in the conical pipe 2; is the pressure in the straight pipeline 1; is the pressure at any point in the tapered pipe 2; is the acceleration due to gravity; is the cross-sectional area of ​​the straight pipeline 1; is the effective cross-sectional area of ​​the tapered pipe 2.

[0026] The flow rate of the entire section of the tapered pipe 2 is: (12) Only the preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention, and various changes should be included in the protection scope of the present invention.

Claims

1. A secondary water supply pipeline provided with spiral rifling, characterized in that: The invention comprises a straight pipe (1), a tapered pipe (2), a spiral groove (3), a square connecting flange (4), an O-type sealing groove (5) and a straight groove bolt through hole (6), wherein one end of the straight pipe (1) is connected to the large end of the tapered pipe (2), the tapered pipe (2) is provided with a spiral groove (3), two square connecting flanges (4) are provided, one of the square connecting flanges (4) is connected to the other end of the straight pipe (1), and the other of the square connecting flanges (4) is connected to the small end of the tapered pipe (2), the square connecting flange (4) at the other end of the straight pipe (1) is connected to the outlet of the water pump through the straight groove bolt through hole (6), the square connecting flange (4) at the small end of the tapered pipe (2) is connected to the pipe network through the straight groove bolt through hole (6), and the two square connecting flanges (4) are both provided with an O-type sealing groove (5).

2. A secondary water supply pipeline with spiral rifling according to claim 1, characterized in that: The straight pipeline (1) and the tapered pipeline (2) are made of galvanized steel pipes, stainless steel pipes or cast iron pipes.

3. A method for calculating the flow rate of a secondary water supply pipeline provided with spiral rifling, characterized in that: The following steps are involved: S1, equating the cross section of the spiral rifling (3) to the area enclosed by the cycloid and the arc, and calculating the cross section area of ​​the spiral rifling (3); S2, calculating the effective cross-sectional area of ​​the tapered pipe (2) according to the cross-sectional area of ​​the spiral rifling (3) calculated in S1; S3, calculating the flow velocity at any point of the tapered pipe (2) by using the Bernoulli equation according to the effective cross-sectional area of ​​the tapered pipe (2) calculated in S2; S4. Based on the flow velocity at any point in the tapered pipe (2) calculated in S3, the flow rate of the entire cross section of the tapered pipe (2) is calculated.

4. A method for calculating flow velocity of a secondary water supply pipeline provided with spiral rifling according to claim 3, characterized in that: The method for calculating the cross-sectional area of ​​the spiral rifling (3) in S1 is: According to the cutting method, the cross-sectional area of ​​the spiral rifling (3) is equivalent to the area enclosed by the cycloid and the arc; The equivalent curve expression of the cycloid is: ； The value range of is [0-2π]; Differentiate it to get: ； Then the area formed by the cycloid is: ； The equivalent curve expression of the arc is: ； Differentiate it to get: ； The area formed by the arc is: ； Then the cross-sectional area of ​​the spiral rifling (3) is: ； in: is the cross-sectional area of ​​the spiral rifling (3); is the area composed of the cycloids; is the area of ​​the arc; is the rolling angle, the value range is [0-2π]; is radians; a is the height of the spiral rifling (3); b is the width of the spiral rifling (3); R is the gradient radius of the tapered pipe (2), , is the radius of the small end of the tapered pipe (2), is the radius of the large end of the tapered pipe (2), .

5. The method for calculating the flow velocity of a secondary water supply pipeline provided with spiral rifling according to claim 3, characterized in that: The method for calculating the effective cross-sectional area of ​​the tapered pipe (2) in S2 is: ； in: A 2 is the effective cross-sectional area of ​​the tapered pipe (2); n is the number of spiral rifling lines (3); R is the gradient radius of the tapered pipe (2), .

6. The method for calculating the flow velocity of a secondary water supply pipeline provided with spiral rifling according to claim 3, characterized in that: The method for calculating the flow velocity at any point in the conical pipe (2) in S3 is: Ignoring the head loss, the Bernoulli equation is as follows: ； Then from the continuity equation ; get ; Thus, the flow velocity at any point in the conical pipe (2) is obtained: ； in: is the flow velocity in the straight pipe (1); is the flow velocity at any point in the conical pipe (2); ρ is the density of water in the conical pipe (2); is the pressure in the straight pipeline (1); is the pressure at any point in the tapered pipe (2); is the acceleration due to gravity; is the cross-sectional area of ​​the straight pipe (1); is the effective cross-sectional area of ​​the tapered pipe (2).

7. The method for calculating the flow velocity of a secondary water supply pipeline provided with spiral rifling according to claim 3, characterized in that: The method for calculating the flow rate of the entire cross section of the tapered pipe (2) in S4 is: ； in: Q is the flow rate of the entire cross section of the tapered pipe (2).

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