EP2289605A1 - Transportable water circulation channel - Google Patents

Abstract

The channel has a deflecting channel (7.1) provided on an upstream side (12) of a pump (4) and formed by a rounded front edge (6) of an intermediate bottom (2). A half-pipe (8) exhibits a concave inner side for surrounding the front edge of the intermediate bottom. Cross section of the deflecting channel is extended from a lower side of the intermediate bottom to a lower side of the intermediate bottom. A small diffuser (9) is provided downstream of the pump, and includes segmental plates (11) arranged in a flow chamber. Areas of the diffuser are directed parallel to a flow direction.

Description

The invention relates to a portable, compact water circulation channel, which consists of a swimming pool with free water surface and integrated measuring section, an intermediate floor and a return flow, wherein the swimming pool is separated from the return flow channel by means of an intermediate floor.

Water circulation ducts are used for carrying out flow tests, for training purposes for athletes, preferably by swimmers, but also canoeists or for therapeutic applications in the healing treatment. The water flowing in the channel opens up possibilities for training and rehabilitation, which are not given in standing water. In addition, the flowing water has a gentle massage effect that works evenly and intensively on the entire body surface.

In the field of elite sports, flow channels have become an indispensable training tool and ergometer. When swimming in a flow channel, the swimmer does not move from the spot, this allows the coach to accurately analyze the movements of the swimmer and give the athlete hints for an optimized movement.

In particular, for training in high performance sports, it is important that the water circulation channel has a substantially uniform velocity distribution orthogonal to the main flow of water. The more constant the course of the flow velocity of the water over the depth of the water, the higher the quality of the water circulation channel. An almost constant flow velocity of the water over the entire depth, in which the float moves, is a prerequisite for a realistic replica of swimming in stagnant water.

In the field of rehabilitation, flow channels offer the possibility to carry out a particularly gentle training of the rehabilitants. The flowing water causes uniformly distributed pressures and stresses on the body in the water. The even distribution of the load is very gentle on the joints, so that can be started at a very early stage with load training. By adjusting the flow velocity accordingly, the load can be precisely metered, unlike when training outside the water, where always the full gravitational force acts on the body.

Various solutions for water circulation channels are known from the prior art.

The patent CH 176 562 A There is a swimming pool, which is flowed through by circulating and adjustable in its speed water, so that it can be swum in the flowing water. In a first embodiment, the basin is divided by an intermediate floor in an upper space for receiving the float and in a lower space for at least one water screw. In a second embodiment, the basin is divided by two intermediate walls parallel to the outer walls into a space between the intermediate walls for receiving the float and two spaces between the intermediate walls and the outer walls for the drive means for generating the flow. For the deflection of the flow at the beginning and end of the partition walls no special technical means are required.

In DE 22 22 594 A1 is described a swimming pool with a circulating flow, in which the water flows in through a Wassereinströmfläche and passes through a permeable pool floor in the water return system. Due to the fact that the water passes into the water return system via the permeable pool bottom, a drop in the flow velocity occurs in the swimming pool in the direction of flow. However, over the cross section of the swimming pool, perpendicular to the main flow direction of the water, an approximately constant velocity distribution should be present.

Out DD 246 461 A3 Axial pumps are small diameter in parallel with nozzles and diffusers, which convert the flow from about square to circular cross-section and vice versa, known. The nozzles are designed with a length of 0.4 to 0.7 times and the diffusers with a length of 1.5 to 2.5 times the clear pump inside diameter. With a control device is ensures that all pumps are brought to the same volume flow rate.

Due to the high speed of the pumps, however, small differences in losses lead to large differences in the operating point. Failure to adhere to the above dimensions may result in unstable or uneven operating conditions of the pumps, which mechanically stress the pumps and result in unevenness in pumping. Axial pumps, which are arranged in the manner described, are therefore particularly suitable for use in large water circulation channels.

The DD 246 462 A1 shows a stabilizing device for high-speed, preferably adjacent and parallel axial thrust pumps with non-rotationally symmetrical transition nozzles, in which a stable and monotonously decreasing delivery height characteristic is achieved by the use of a profile ring as a stabilizer whose ratio of profile thickness to profile length is 0.2 to 0.4 and protrudes into the transition nozzle with about half of its length. The stabilizing effect is achieved by a targeted rotationally symmetric recirculation.

With the patent DE 39 21 015 C1 discloses a flow pool for floats, in which on the downstream side of the pumping device, a riser pipe is arranged, whose outlet opening has a higher level than the swimming pool, wherein the riser in a flow-connected via an outlet with the pool tower opens. For the 180 ° deflection from the flow basin in the underlying return flow no special precautions have been taken.

In DE 44 14 382 B4 a water circulation channel is described in which the water conveyor is arranged in the horizontal side of the measuring section, wherein the measuring section is connected to at least one return channel via different manifolds. One manifold narrows in the direction of flow along a 90 ° bend and is provided with an accelerator grid, another manifold expands along the second 90 ° bend and is equipped with a retard grid fitted. According to the invention, the delay grid is designed as a composite grid in which the delay of the flow is achieved via two or more delay gratings acting in the composite. The inner wall of the bend and the radii of the blades are determined by the thickness of the false bottom between the measuring section and the return channel. Downstream of each pump is a conventional transition diffuser of round to rectangular cross-section.

In US 4,979,243 a flow pool for training swimmers is disclosed in which the flow channel (with the swimming pool) is arranged above the return flow channel. The separation of the channels is made by a horizontal floor. The pumps are arranged in the return flow channel. The cross-sectional area of the portion of the return flow channel downstream of the pumps increases with increasing distance from the pumps. The deflection of the flow from the flow into the return flow channel and from the return flow through the flow channel takes place by means of a plurality of spaced deflecting vanes, the flow passages being defined by adjacent deflecting vanes or by a respective deflecting vane and the rounded front edge of the bottom or the wall of the flow basin.

The presented water circulation channels are consistently very large in size and suitable only for stationary construction. The reason for this is that with large dimensions, a uniform distribution of the flow velocity over the cross section perpendicular to the flow direction in the measuring section can be achieved; Speed differences and vortices are reduced. At the same time, however, large systems require large delivery rates of the pumps because a significant amount of water must be moved through the components to improve the velocity distribution. A high delivery rate of the pumps is also associated with a high demand for electrical energy and associated operating costs.

The positive effects of flowing water as part of rehabilitation and the ability to analyze the movement patterns of competitive swimmers, increase the popularity of flow channels. Also the increase of the individual and adventure sports arouse the desire for an easier use of flow channels.

However, a wider application of flow channels is currently opposed by the large dimensions and the high acquisition and operating costs of such systems. Water circulation systems, which require a permanently reduced construction costs and have smaller dimensions for a given water surface of the swimming pool, are a prerequisite for this.

Also the in DE 44 14 382 presented circulation channel solves the problem of achieving a uniform flow in a water circulation channel with small dimensions, not, especially since the rectifier used for the equalization of the flow increase the flow resistance and thus the requested performance pumps.

Sharp deflections of the water, as they occur at the leading edges of the intermediate floor of the water circulation channel and strong enlargements of the flow cross-section on a short path lead to flow separation, to fluidized areas and uneven velocity distributions. The areas in which these disturbances of the flow occur, viewed in the flow direction, one behind the other and directly at the intermediate floor, so that their effects mutually reinforce each other. With high-speed pumps, these flow disturbances can lead to unstable operating conditions.

Although equalization of the flow can be achieved by rectifiers, screens and nozzles, these measures are accompanied by an increase in the flow losses and an increase in the dimensions of the overall system.

The object of the invention is therefore to provide a compact water circulation channel with a uniform flow velocity distribution orthogonal to the main flow direction of the water, which has dimensions that make it portable and at the same time ensures relatively low operating costs by using small pumps with low drive power. According to the invention, this object is achieved by the features of claim 1; advantageous embodiments of the invention will become apparent from the dependent claims.

The water circulation channel according to the invention is characterized in that it has at least on the downstream side of the pump, which has at least one impeller and is designed either with or without stator, for deflecting the flow except elbows with blade grids and a deflection channel. This is formed by the rounded end edge of the intermediate bottom and a half-tube, the concave inner side of which encloses the end edge of the intermediate bottom distally. The half tube is positioned so that the cross section of the deflection channel widens from the underside of the intermediate bottom to the top side of the intermediate base. Furthermore, the water deflection channel comprises a short diffuser arranged downstream of the at least one pump and having a plurality of segment plates which are arranged in the flow space of the short diffuser (9) and whose surfaces are aligned parallel to the flow direction.

The intermediate floor, which separates the swimming pool from the return flow channel, is preferably only a few centimeters thick for weight reasons (complicated lightweight / waffle constructions are ruled out for cost reasons). In water channels, which are operated stationary, the intermediate floors, however, are usually between 0.5 to 1 m thick, which has the advantage that the usually round running front edges of the intermediate floors have larger radii and therefore the flow exclusively by means of aerodynamically favorable blade grid to the two Transitions from the flow into the return flow and the Rückström- can be performed in the flow channel.

In the transportable water circulation channel according to the invention, however, a pure deflection by means of blade grids with small profile lengths is not possible for reasons of vibration, because the water flow can not be with these to the narrow radii that occur at the rounded end edges of the thin intermediate floor, steered. If this were attempted nevertheless, it would lead to the formation of strong detachments in the area of the rounded front edges of the false floor. For this Reason, the water circulation channel according to the invention, at least downstream of the pump in addition to the blade lattice and the one deflection channel. The half tube acts as a turning vane. The deflection channel (the turning vane) can be kept very short for reasons of geometry, that is, there is no friction over a large length.

Preferably, both end edges are provided with a deflection channel, wherein the respective half-pipe extends over the entire length of the end edge of the intermediate bottom. The concave inner side of the half tube faces the front edge of the intermediate bottom approximately parallel; the half tube is horizontally and vertically spaced from the end edge.

The horizontal distance of the half tube to the end edge of the intermediate bottom is preferably selected such that it corresponds to the radius of the half tube minus half the thickness of the intermediate bottom. As a result, the inlet and outlet openings of the deflection channels are vertically in line with the beginning of the rounding at the front edge of the intermediate floor.

In the vertical direction, the half-tube is positioned so that the distance between the lower end edge of the half-tube to the bottom of the intermediate bottom is smaller than the distance of the upper end edge of the half-tube to the top of the intermediate bottom. Thus, an extension of the cross section of the Umlenkkanals is effected from the bottom of the false bottom to the upper side.

erfüllt sein.

• mit: a₁ = lichte Weite des Umlenkkanals am Eintritt
• a₂ = lichte Weite des Umlenkkanals am Austritt
• r_i = Außenradius des Zwischenbodens (Innenradius des Umlenkkanals)
• r_a = Innenradius des Halbrohrs (Außenradius des Umlenkkanals)

In order to achieve a fluidically particularly favorable deflection, the relation must $$\frac{r_a}{r_i}<\frac{4}{\left(\frac{a_2}{a_1}\right)}$$

be fulfilled.

• with: a ₁ = clear width of the deflection channel at the inlet
• a ₂ = clear width of the deflection channel at the outlet
• r _i = outer radius of the intermediate bottom (inner radius of the deflection channel)
• r _a = inner radius of the half tube (outer radius of the deflection channel)

Typical values of a ₂ / a ₁ (corresponds to the extension of the cross section of the deflection channel) are in the range between 1.5 and 2.5. Correspondingly, then the cross-sectional widening is about 10 °, ie, in the longitudinal section of the settlement (the curved portions of the channel are straightened) of the Umlenkkanals the channel walls extend at an angle of 10 ° to each other. At values of a ₂ / a ₁ <1.5, the risk of separation is much lower, so that the calculated angles are then less than 10 °.

If the water flows into the deflection channel, it is deflected around the front edge of the intermediate bottom (180 °) free of flow and turbulence via the inner surface of the bent half pipe at the front edge of the intermediate bottom. In the remaining (further from the front edge) region of the flow cross-section, the water is deflected by means of blade lattices.

By extending the cross section of the Umlenkkanals from the bottom of the false floor to the top of the false floor, a slowing down of the flow velocity of the water is achieved. This counteracts the disadvantageous effect that the flow velocity in the region of the blade lattice increases towards the intermediate bottom.

Since transportable water circulation channels have inherently smaller dimensions than stationary ones and the flow velocities over longer lengths self-equalize in water flows, in small transportable water circulation channels alone with the deflection according to the invention (from the flow into the return flow channel and from the return flow into the flow channel) none sufficiently uniform distribution (as in stationary channels) of the flow velocity can be achieved.

As a further measure for equalizing the flow velocity, therefore, a short diffuser with a plurality of segment plates (as a segment plate is defined in each case one of the axis to the housing of the short diffuser reaching sheet metal) used. The segment plates in the diffuser cause, first, that in the diffuser by a redistribution of the areas with high flow velocity equalization of the total flow is achieved, and secondly, it is possible to make the diffuser shorter and still achieve stable operating conditions. The diffuser can be made shorter, the more segmental panels are used. So z. B. without segment plates a diffuser through which a transition from a round to a square cross section is performed, the square cross section is about twice the clear diameter of the pump required, the length of which is at least twice as large as the diameter of the round cross section , while even with the use of four segment sheets, the length of the diffuser may be shorter than the diameter of the round cross section.

It is provided, the hub on which at least one impeller and possibly the stator of the pump are arranged, not as usual, at the level or shortly behind (seen in the direction of flow) end of the pump, but the hub axially into the short diffuser or to pass through it. With small hub ratios, the hub is also formed as a tip. As a result, the generation of vortices / detachments downstream behind the hub is largely prevented, in particular in the case of rotating hubs (to a lesser extent, however, also in the case of non-rotating hubs).

The segment plates are preferably arranged radially extending between the hub and the housing of the short diffuser and extend over the entire length of the short diffuser. The number of segment plates is, in order to prevent resonance vibrations, not equal to the number of blades of the impeller or, if present, the stator of the pump.

In conventional diffusers (without hub and without segment plates), thick boundary layers form on the walls of the diffuser, at which the flow velocity is greatly reduced. In the area of the pump axis, on the other hand, it is high. This has a particularly detrimental effect on the distribution of the flow velocity, especially in the case of compact, transportable water circulation channels.

With the short diffuser with hub and segmental plates, boundary layers are formed not only on the outer walls of the diffuser, but also on the segmental plates and at the hub. However, the thickness of these boundary layers is very small, compared to the boundary layer forming only on the outer wall in conventional diffusers. In addition, the boundary layers are distributed over the entire cross section of the diffuser, so that a very uniform distribution of the flow velocity adjusts over a short diffuser length over the cross section of the diffuser and thus also over the cross section of the return channel. This has a positive effect on the distribution of the flow velocities in the flow channel / swimming pool.

It can therefore be achieved in the water circulation channel according to the invention only by the combination of the short diffuser with deflecting channel and blade deflectors formed a uniform distribution of flow velocities, as previously in the larger stationary water circulation channels.

In addition, the deflection and the short diffuser require only a relatively small construction effort.

Since the deflection devices and the short diffuser have in total only a small flow resistance and can be dispensed with additional means for equalizing the flow (screens, rectifiers and nozzles), pumps are comparatively low power consumption sufficient to flow rates in the pool of up to 2, 5 m / s to reach.

For the purpose of reducing the mass of the water circulation channel consists essentially of plastic, which is surrounded by a stabilizing metal support frame, or alternatively made of steel, preferably made of stainless steel.

Due to its low weight and compact geometry, it is possible to load the water circulation duct onto a transporter and transfer it completely assembled to the destination, so that it only needs to be filled with water and connected to the power supply network.

Fig. 1

einen Wasserumlaufkanal im Längsschnitt;

Fig. 2

einen Umlenkkanal im Längsschnitt;

Fig. 3

eine Pumpe mit Kurzdiffusor im Längsschnitt;

Fig. 4

einen Kurzdiffusor mit Nabe und Segmentblechen, von der Abströmsei- te aus gesehen.

The invention will be described below with reference to FIG FIGS. 1 to 4 explains; show here:

Fig. 1

a water circulation channel in longitudinal section;

Fig. 2

a deflection channel in longitudinal section;

Fig. 3

a pump with short diffuser in longitudinal section;

Fig. 4

a short diffuser with hub and segment plates, seen from the downstream side.

The in Fig. 1 illustrated water circulation channel consists of the swimming pool 1, the intermediate floor 2 and the return channel 3 in the lower area. In the return channel 3, the pump 4 is accommodated for flow propulsion. The rounded end edges 6 of the intermediate bottom 2 have, together with the half-tubes 8, the two deflection channels 7.1 and 7.2. Through the deflection channels 7.1 and 7.2, the flow of water is deflected by 180 °.

Between the bent (with radius r _a ) half-tubes 8, which form the outer walls of the deflection channels 7.1 and 7.2 and the walls of the water circulation channel sit the elbows, which are provided with the blade grids 5.1 - 5.4. The flow of the water is deflected by 90 ° via the vane grids of the elbows.

At the pump 4 sits the short diffuser 9 with the hub 10 and the segment plates 11; the short diffuser 9 is located on the outflow side 12 of the pump 4th

A circulation of the water is therefore as follows:

On the inflow side 13 of the pump 4, the water is sucked in and pumped through the short diffuser 9 with hub 10 and segmental plates 11 in the downstream region of the return flow channel 3. At the end of the return flow channel 3, the water meets the first deflection channel 7.1 and the first elbow provided with blade grids 5.1. Of the blade grids 5.1 of the first manifold, the water is deflected by 90 ° upwards, of the blade grids 5.2 of the second manifold, the flow is in turn deflected by 90 °; the water is now owned by the Water surface 15 to the intermediate bottom 2 a flow direction 14 which is opposite to the flow direction in the return channel 3. A flow deflection through 180 ° likewise experiences the water which flows on the underside of the intermediate bottom into the first deflection channel 7.1. The water now flows through the swimming pool 1 with a uniform, uniform flow velocity. At the end of the swimming pool, the water meets the third bend with the blade grid 5.3 and the second deflection channel 7.2. After the water has flowed through the third and fourth manifolds with the blade grids 5.3 and 5.4 and the second deflection channel 7.2, it is again at the inflow side 13 of the pump 4th

In Fig. 2 the specifics of the deflection channel are shown. Evident is an end portion of the intermediate bottom 2 with the rounded end edge 6 (with radius r _i ). The front edge 6 and the half tube 8 form the deflection channel 7.1. This has at the top of the intermediate bottom 2 has a larger cross-section (a larger clear width a ₂ ) than at the bottom (smaller clear width a ₁ ). This arrangement of the half-pipe 8 ensures that the horizontally flowing water at the intermediate bottom 2 is guided around the front edge 6 of the intermediate bottom 2 free of stalling and slows in its speed.

In Fig. 3 it is clear that the short diffuser 9 has a length which is substantially shorter than twice the diameter of the clear space of the pump.

Fig. 4 shows the short diffuser 9 with hub 10 and segment plates 11 seen from the downstream side 12 from. You can see the radially extending from the hub 10 to the outside of the walls of the short diffuser 9 segment plates 11th

List of reference numbers used

1

Swimming pool / lazy river

2

false floor

3

backflow

4

pump

5.1

first scoop grid

5.2

second blade grid

5.3

third vane grid

5.4

fourth blade grid

6

Front edge on intermediate floor

7.1

first deflection channel

7.2

second deflection channel

8th

half pipe

9

short diffuser

10

hub

11

segment sheet

12

Downstream side of the pump

13

Upstream side of the pump

14

flow direction

15

waterline

a ₁

clear width of the deflection channel at the entrance

a ₂

clear width of the deflection channel at the outlet

_i

Outside radius of the intermediate floor

r _a

Inner radius of the half pipe

Claims (10)

Transportable water circulation channel consisting of a swimming pool (1) with free water surface and integrated measuring section, a return flow channel (3), an intermediate floor (2) which separates the swimming pool (1) from the return flow channel (3), at least one recirculating the water and in the return flow channel (3) arranged pump (4) and manifolds with blade grids (5.1, 5.2, 5.3, 5.4) for deflecting the flow, characterized in that the water circulation channel at least on the downstream side (12) of the at least one pump (4) has a deflection channel (7.1 ), which is formed by a rounded end edge (6) of the intermediate bottom (2) and a half tube (8) whose concave inner side the end edge (6) of the intermediate bottom (2) surrounds distally, that the cross section of the deflection channel (7.1 ) extends from the bottom of the intermediate bottom (2) to the top of the intermediate bottom (2) and that on the at least one pump (4) downstream a short diffuser (9) with more eren segment plates (11) arranged in the flow space of the short diffuser (9) and whose surfaces are aligned parallel to the flow direction is located. Water circulation channel according to claim 1, characterized in that for the clear width of the at least one deflection channel (7.1) at the inlet (a ₁ ) and the outlet (a ₂ ) and for the outer radius (r _i ) of the intermediate bottom (2) and the inner radius ( _a ) of the half-pipe (8) the relationship r _a / r _i <4 / (a ₂ / a ₁ ) applies. Water circulation channel according to claim 1 and 2, characterized in that the hub (10) starting from the at least one pump (4) extended in the direction of the end remote from the pump end of the short diffuser (9) and axially into the short diffuser (9) and / or passed through this. Water circulation channel according to claim 3, characterized in that the hub is formed with small hub ratios as a tip. Water circulation channel according to claim 3 and 4, characterized in that the segment plates (11) are arranged radially between the hub (10) and the side walls of the diffuser (9). Water circulation channel according to claim 1 to 5, characterized in that the number of segment plates (11) is not equal to the number of blades of the blade or the stator of the pump (4). Water circulation channel according to claim 1 to 6, characterized in that the thickness of the intermediate bottom (2) corresponds to 10 to 60% of the radius of the half-pipe. Water circulation channel according to claim 1 to 7, characterized in that the division ratio of the blades of the blade grid (5.1, 5.2, 5.3, 5.4) is 0.5 to 0.6. Water circulation channel according to claim 1 to 8, characterized in that all the pumps used (4) are high-speed axial pumps with the same performance parameters. Water circulation channel according to claim 1 to 9, characterized in that the swimming pool (1), the intermediate bottom (2) and the return flow channel (3) are arranged side by side, wherein the intermediate bottom (2) is a partition wall and the top and bottom of the view Flow respectively to a right and a left side.

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