CN101975321B - A Rectangular Duct Divided Combination and Rectification Tee - Google Patents

Abstract

The invention discloses a rectangular air duct separation type confluence and rectification tee, which comprises a first inlet section, a second inlet section and an outlet section, wherein the extension line of the first inlet section and the second inlet section forms an included angle of 90°, The lower end of the first inlet section is connected to the linear confluence section, one side of the second inlet section is connected to the curved confluence section, the linear confluence section and the curved confluence section are connected to the buffer section, and there is an outlet section below the buffer section A connected rectifying section; the upper end of the rectifying section is provided with rectifying vanes, and each rectifying vane is equipped with a guide vane to divide the rectifying section into five fluid passages of equal size. The unique design of the invention eliminates the velocity stratification formed after the fluid passes through the rectangular air pipe separation type confluence tee, so as to finally achieve the purpose of rectifying the fluid after passing through the rectangular air duct separation type confluence tee.

Description

The interflow rectification threeway of a kind of rectangular air duct separated type

Technical field

The present invention relates to a kind of interflow threeway member, relate in particular to the interflow rectification threeway of a kind of rectangular air duct separated type.

Background technique

The interflow threeway is the change direction of flow very common in the HVAC motive fluid machinery and the pipe fitting at interflow; In the pipeline of interflow; Because the turning of fluid; Occurred from the centrifugal force of centre of curvature to the pipe outer arced surface, this just make fluid from bending tube section (turn round finish before) when carrying out the transition to the straightway of pipeline, the increased pressure of outer arced surface and the pressure reduction of intrados.So flow rate of fluid will reduce at the outer arced surface place, and flow rate of fluid correspondingly increases at the intrados place.Therefore, diffusion effect occurs at the outer arced surface annex, and blockage effect occurring near the intrados place.Fluid when carrying out the transition to bending tube section, has opposite phenomenon to take place from straight length (back of turning round) again, promptly produces diffusion effect near the intrados, produces blockage effect near the outer arced surface.Diffusion effect makes fluid break away from wall, and the bending tube section fluid is owing to the motion that inertia flows to outer arced surface has more aggravated the separation from intrados simultaneously.

Owing to above reason, fluid is after flowing through threeway of rectangular air duct separated type interflow and interflow, and fluid can be because diffusion and blockage effect and layering is as shown in Figure 1, and the flow velocity that causes fluid right side shown in the figure is greater than the left side.This just means that rate of flow of fluid is inhomogeneous.At field of heating ventilation air conditioning, if this part fluid is directly sent into the room, will influence indoor air flow and distribute, make indoor actual travelling comfort not meet design requirement.

Summary of the invention

The purpose of this invention is to provide the interflow rectification threeway of a kind of rectangular air duct separated type; The unique design of this rectangular air duct separated type interflow rectification threeway eliminated fluid through the interflow threeway after formed speed layering, thereby finally reach the purpose of carrying out rectification to through the fluid after the threeway of interflow.

To achieve these goals, the present invention is achieved through following technological scheme:

The interflow rectification threeway of a kind of rectangular air duct separated type; Comprise first entrance, second entrance and outlet section, wherein, the elongation line of first entrance becomes 90 ° of angles with the elongation line of second entrance; The first entrance downstream links to each other with straight line type interflow section; One side of second entrance links to each other with flexure type interflow section, and straight line type interflow section links to each other with breeze way with flexure type interflow section jointly, is provided with the rectification section that links to each other with outlet section in the breeze way downstream side; Upstream extremity is provided with straightener(stator) blade in the described rectification section, has guide vane on each straightener(stator) blade rectification section is divided into five equal-sized fluid passages.

Other technologies characteristics of the present invention are:

Breeze way length is identical with first entrance or the second entrance channel width.

It is acute triangle to described straightener(stator) blade along rectification section, and with coming flow path direction certain inclination angle is arranged, and makes to form five fluid passages that inlet varies in size in the rectification section.

Described guide vane comes flow path direction to be acute triangle dorsad, and vertically is parallel to each other with rectification section.

In addition, a kind of inlet size that designs five fluid passages that form between interior each straightener(stator) blade of above-mentioned rectangular air duct separated type interflow rectification threeway and the rectification section longitudinal direction is confirmed method, and this method comprises the steps:

Step 1, confirm the fluid flow fields state in the threeway of rectangular air duct separated type interflow; According to first entrance and the second entrance line size and entrance liquid speed; Adopt reynolds stress model and combine the SIMPLE algorithm; Simulate then the rectification section interior velocity field of rectangular air duct separated type interflow three-way pipeline before is set, thereby obtain the velocity distribution value of rectification section position fluid;

The inlet of step 2, five fluid passages confirming to form between rectangular air duct separated type interflow rectification each straightener(stator) blade of threeway and the rectification section longitudinal direction is big or small; The velocity distribution value of the rectification section position fluid of trying to achieve according to step 1; Utilize area branch principle, try to achieve five fluid passages inlet sizes when satisfying each fluid passage inner fluid flow the same terms.

This shows; The present invention at first collaborates through flexure type interflow section convection cell; Fluid cushions in breeze way then; After formation has metastable fluid characteristics, wait the flow cutting through five fluid passage convection cells that vary in size that form between straightener(stator) blade and the rectification section again, and through forming the transverse velocity of five equal and opposite in direction passage eliminate fluids between guide vane and the rectification section.Thereby eliminate fluid through the interflow threeway after formed speed layering, finally reach the purpose of carrying out rectification to through the fluid of interflow after the threeway.As shown in Figure 2.

Description of drawings

Flow velocity isoline map when Fig. 1 collaborates threeway for fluid through traditional rectangular airduct separated type.

Fig. 2 is the flow velocity isoline map when fluid is through the interflow threeway after the interflow rectification threeway of installation rectangular air duct separated type of the present invention.

Fig. 3 is a structural representation of the present invention.

Fig. 4 is the velocity distribution integrogram of traditional threeway outlet section transverse section fluid.

Fig. 5 is an embodiment of the invention rectangular air duct separated type interflow rectification threeway outlet section transverse section velocity contour.

The following information of each symbolic representation among the figure: 1, first entrance; 2, straight line type interflow section; 3, breeze way; 4,5 straightener(stator) blades; 6, outlet section; 7, guide vane; 8,9 straightener(stator) blades; 10, second entrance; 11, flexure type interflow section, 12 rectification sections; Other, the direction of arrow is represented fluid flow direction.

Do explanation in further detail below in conjunction with the accompanying drawing specific embodiments of the invention.

Embodiment

As shown in Figure 3; The interflow rectification threeway of a kind of rectangular air duct separated type; Comprise first entrance 1, second entrance 10 and outlet section 6, wherein, the elongation line 1 of first entrance becomes 90 ° of angles with the elongation line of second entrance 10; First entrance, 1 downstream links to each other with straight line type interflow section 2; One side of second entrance 10 links to each other with flexure type interflow section 11, and straight line type interflow section 2 links to each other with breeze way 3 with flexure type interflow section 11 jointly, and being designed for of breeze way 3 guarantees to form in the three-way pipe of whole interflow the fluid with metastable fluid characteristics here.Be provided with the rectification section 12 that links to each other with outlet section 6 in breeze way 3 downstream side.Upstream extremity is provided with straightener(stator) blade (4,5,8,9) in the described rectification section 12; Have guide vane 7 on each straightener(stator) blade rectification section 12 is divided into five equal-sized fluid passages, thereby realize the fluid in the three-way pipeline of whole interflow is waited the flow cutting.

Because fluid is becoming unstable through flow characteristic after the break-in; For after it can being formed have metastable fluid characteristics; And then waiting flow cutting through five fluid passage convection cells that vary in size that form between straightener(stator) blade and the rectification section, the present invention is provided with length and first entrance or the identical breeze way of the second entrance channel width before rectification section.

The problem that the resistance that causes for fear of cutting fluid increases; And more effectively convection cell cuts; It vertically is acute triangle to described straightener(stator) blade (4,5,8,9) along rectification section 12; And with coming flow path direction certain inclination angle is arranged, make to form five fluid passages that inlet varies in size in the rectification section 12.Surface of contact area when this type guide vane and fluid collision is littler, and the resistance to impact that has this to produce is also little, because the possibility of collision generation fluid swirling is also little.Can effectively reduce the caused resistance of cutting fluid with this.

The problem that the resistance that causes for fear of cutting fluid equally increases, and can carry out water conservancy diversion by effective more fluid to the straightener(stator) blade of flowing through, guide vane 7 comes flow path direction to be acute triangle dorsad, and vertically is parallel to each other with rectification section 12.When fluid through flexure type interflow section 11 and section 2 backs, straight line type interflow formed with come the perpendicular velocity component of flow path direction to be eliminated by guide vane 7, thereby eliminated the possibility that fluid forms vortexs through flexure type interflow section 11 and section 2 backs, straight line type interflow and increases resistance.

The present invention through reynolds stress model and combine that the SIMPLE algorithm drawn flow through the interflow threeway of rectangular air duct separated type after rate of flow of fluid distribute and size; Confirm the spacing size between each straightener(stator) blade and whole rectification section 12 longitudinal directions, the fluid flow at each passage that makes fluid flow through behind the straightener(stator) blade is identical.Because the straightener(stator) blade convection cell cuts, fluid can be cut back formation vortex.Commutator lug among the present invention (4,5,8,9) is under the big or small constant situation of cross section, and the transverse velocity of convection cell is offset, thereby eliminates its formed vortex, makes fluid only have longitudinal velocity.Thereby, reach the rectification purpose, referring to shown in Figure 2 in the layering of the speed of elimination.

Therefore the definite method of inlet size of five fluid passages in the interflow rectification threeway of the above-mentioned rectangular air duct separated type of design, forming between each straightener(stator) blade (4,5,8,9) and rectification section 12 longitudinal directions of the present invention comprises the steps:

Step 1, confirm the fluid flow fields state in the threeway of rectangular air duct separated type interflow, according to first entrance 1 and second entrance, 10 line sizes and entrance liquid speed, the employing reynolds stress model also combines the SIMPLE algorithm:

At first, find the solution momentum equation:

${\stackrel{\‾}{u}}_j\frac{\∂{\stackrel{\‾}{u}}_i}{\∂x_j}=-\frac{1}{\mathrm{\ρ}}\frac{\∂\stackrel{\‾}{p}}{\∂x_i}+\frac{{\mathrm{\μ}}_t}{\mathrm{\ρ}}\frac{{\∂}^2{\stackrel{\‾}{u}}_i}{\∂x_j\∂x_j}-\frac{\∂}{\∂x_j}{R}_{\mathrm{ij}}$

Find the solution pressure modified continuous property equation then:

$\frac{\∂{\stackrel{\‾}{u}}_i}{\∂x_i}=0$

Wherein ρ is a fluid density; u _i, u _jBe speed, i, j are the tensor subscript, i, j=1,2,3; μ, μ _:Be dynamic viscosity, subscript t representes that this physical quantity is caused by the turbulent flow pulsation; σ _k, σ _τBe constant; C _μ, C ₁, C ₂Be empirical coefficient, its value is as shown in the table.

And upgrade pressure, just face mass flow rate and find the solution the Reynolds stress equation with this.And judge whether convergence, if convergence then stop to calculate, if would not do not restrain then continue to find the solution momentum equation.The RSM model constants, as shown in table 1:

Table 1. model constants

Coefficient	C μ	C 1	C 2	σ k	σ ε
						Numerical value	0.09	1.44	1.92	1.0	1.3

Simulate then the rectification section 12 interior velocity field of rectangular air duct separated type interflow three-way pipeline before is set, thereby obtain the velocity distribution value of rectification section 12 position fluids;

The inlet of step 2, five fluid passages confirming to form between rectangular air duct separated type interflow rectification each straightener(stator) blade of threeway (4,5,8,9) and rectification section (12) longitudinal direction is big or small; The velocity distribution of rectification section (12) the position fluid of trying to achieve according to step 1, as shown in Figure 4.Obtain the velocity magnitude of each point in the cross section, rectification position; From left to right the distance of flow velocity and fluid and rectification section inwall is carried out integration; When flow satisfy total discharge 1/5 the time stop integration, the distance of being tried to achieve is the spacing that is provided with between distance and each straightener(stator) blade that is provided with of straightener(stator) blade and rectification section inwall.So just satisfy these five fluid passage inner fluid flows and all be communicate be all 1/5 of total discharge.Utilize area branch principle, thereby accomplish the setting of the size of five fluid passages inlets when satisfying each fluid passage inner fluid flow the same terms.

Specific embodiment:

Below provide specific embodiment of the present invention, need to prove that the present invention is not limited to following specific embodiment, all equivalents of on present techniques scheme basis, doing all fall into protection scope of the present invention.

Follow technique scheme, connect with the central air-conditioner airduct and use the optimizing process of rectangular air duct separated type interflow threeway to be example, at first confirm pipeline each several part size; The size 300mm of entrance section * 300mm wherein; Outlet section is of a size of 600mm * 300mm, and crooked interflow section camber is 1.5, and rectification section length is 300mm; Straightener(stator) blade length in the rectification section is 100mm, guide vane length 300mm.List the discrete scheme of momentum equation and equation of continuity then, use the simple method to find the solution, can draw the velocity distribution of place, rectification section 10 positions fluid when never adding rectification section.Confirm rectification section ingress size then, as shown in Figure 4, according to integral principle, the area that the curve among Fig. 4 surrounded and big or small for flow is that 7m/s is an example with the ingress wind speed, and total inlet mentions that flow is 7m/s * 300mm * 300mm=0.63m ³/ s.The present invention is altogether five runners, and then the fluid volume that flows through of each runner planted agent is 0.126m ³/ s.So as long as the left end from Fig. 4 carries out integration along channel width successively to right-hand member, integration stops to get final product when integral value reaches 0.126m3/s.Through calculating when width reaches 80mm, 40mm, 50mm, 60mm, 70mm respectively from left to right successively, the volume flowrate integral value in its each runner is all 0.126m ³/ s (at this moment, the mean velocity in five runners is followed successively by 5.25m/s, 10.5m/s, 8.4m/s, 7m/s, 6m/s).The size that so just can determine ingress, five fluid passages is respectively 80mm * 300mm, 40mm * 300mm, 50mm * 300mm, 60mm * 300mm, 70mm * 300mm from left to right.Through this fluid cutting; Fluid flow in five fluid passages equates; So fluid passage outlet size also equates; Its fluid passage outlet size is followed successively by 60mm * 300mm, 60mm * 300mm, 60mm * 300mm, 60mm * 300mm, 60mm * 300mm (at this moment, the mean velocity in five runners is 7m/s) from left to right.

In theory of probability and mathematical statistics, variance (English Variance) is used for measuring the departure degree between stochastic variable and its mathematical expectation (being average).In many practical problems, the departure degree between research stochastic variable and the average has very important meaning.

$S^2=\frac{1}{n}[{(x_1-\stackrel{\‾}{x})}^2+{(x_2-\stackrel{\‾}{x})}^2+...+{(x_n-\stackrel{\‾}{x})}^2]$

Therefore, collaborate the different of three-way pipeline exit velocity distribution with traditional rectangular airduct separated type, introduce the notion of variance here it is carried out the analysis of flow speed stability property in order to analyze the present invention.

The speed variance of the present invention and traditional rectangular airduct separated type interflow three-way pipeline compares, and pipeline transverse section, traditional threeway outlet port speed variance is 0.888103, and outlet port of the present invention pipeline very section speed variance is 0.446058.Its velocity-stabilization degree has improved 49.8%.

Meanwhile; Through arrangement the present invention and traditional rectangular airduct separated type interflow three-way pipeline cross section velocity distribution value; As shown in Figure 5; The velocity distribution in outlet port of the present invention is obviously more even than traditional bend pipe, has so not only avoided tube fluid because of the uneven vibrating noise that causes of velocity flow profile but also can make the steady air current that gets into air-conditioned room, improves the comfort level of living space.

Claims (5)

1. A rectangular air duct separation type confluence and rectification tee, comprising the first inlet section (1), the second inlet section (10) and the outlet section (6), wherein the extension line of the first inlet section (1) and The extension line of the second inlet section (10) forms an included angle of 90°, and it is characterized in that: the downstream end of the first inlet section (1) is connected to the linear confluence section (2), and one side of the second inlet section (10) is connected to the The curved confluence section (11) is connected, the straight confluence section (2) and the curved confluence section (11) are connected to the buffer section (3), and the downstream side of the buffer section (3) is connected to the outlet section (6). The rectifying section (12); the upstream end in the described rectifying section (12) is provided with rectifying blades (4, 5, 8, 9), and each rectifying vane has guide vanes (7) to guide the rectifying section (12 ) is divided into five equal-flow fluid channels. 2. The rectangular air duct separation type confluence and rectification tee according to claim 1, characterized in that the length of the buffer section (3) is the same as the pipe width of the first inlet section (1) or the second inlet section (10). 3. The rectangular air duct separation type confluence and rectification tee according to claim 1, characterized in that: the rectification blades (4, 5, 8, 9) form an acute triangle along the longitudinal direction of the rectification section (12), and There is a certain inclination angle with the incoming flow direction, so that five fluid passages with different inlet sizes are formed in the rectifying section (12). 4. The rectangular air duct separation type confluence and rectification tee according to claim 1, characterized in that: the guide vanes (7) form an acute triangle with their backs to the incoming flow direction, and are parallel to the rectification section (12) longitudinally . 5. a design claim 1 The rectangular air duct separation type confluence rectification tee rectification section (12) is formed between each rectification blade (4, 5, 8, 9) and the rectification section (12) longitudinally. A method for determining the size of an inlet of a fluid channel, characterized in that the method comprises the steps of: Step 1. Determine the state of the fluid flow field in the rectangular air duct separated confluence tee: according to the pipe size of the first inlet section (1) and the second inlet section (10) and the fluid velocity at the inlet of the pipe, use the Reynolds stress model combined with SIMPLE Algorithm, then simulate the velocity field in the whole tee pipe before the rectification section (12) is set, so as to obtain the velocity distribution value of the fluid at the rectification section (12) position; Step 2. Determine the inlet sizes of the five fluid passages formed between the rectifying blades (4, 5, 8, 9) and the longitudinal direction of the rectifying section (12) of the rectangular air duct separation type combined rectifying tee: obtain according to step 1 The velocity distribution value of the fluid at the position of the rectification section (12) of the rectification section (12), using the principle of area integration, obtains the size of the inlets of the five fluid channels when the same condition of the fluid flow in each fluid channel is satisfied.

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