Jet ventilator for ventilating tunnels, jet ventilator system and method

Abstract

The invention relates to a jet ventilator for ventilating tunnels, in particular road tunnels, to a jet ventilator system and to a method for producing a jet ventilator for ventilating tunnels. In particular, the invention relates to a jet ventilator for ventilating tunnels, in particular road tunnels, comprising a ventilator unit (106) for generating an air flow, a noise damper (110, 130) arranged on the ventilator unit (106), with a proximal portion (112) and a distal portion (116) adjoining the proximal portion (112), characterized in that the distal portion and the proximal portion are at an angle (120, 122) to one another.

Description

[0001] The invention relates to a jet fan for the ventilation of tunnels, in particular road tunnels, a jet fan system and a method for manufacturing a jet fan for the ventilation of tunnels.

[0002] Jet fans for tunnel ventilation are a well-known technology. These fans supply and exhaust air to tunnels, particularly road tunnels, thus preventing high concentrations of exhaust fumes. Jet fans generate an airflow using a fan located in a fan shaft. This airflow enters the tunnel at one end and exits at the other. The entry and exit points of this airflow can also be located at different points within the tunnel, for example, through air inlets in the middle. To reduce noise emissions, these jet fans are typically equipped with silencers.

[0003] The airflow within a tunnel exhibits a velocity profile, with low flow velocities in the floor, ceiling, and side sections, increasing towards the center of the tunnel. The highest flow velocity is typically achieved in the tunnel's center. From a fluid dynamics perspective, it would be advantageous to position the jet fan in the tunnel's center. However, such an arrangement would reduce the tunnel's clearance height and is therefore generally impractical, as either the clearance would be insufficient or the tunnel's height would have to be increased disproportionately.

[0004] Consequently, jet fans are typically positioned near the tunnel walls and / or ceiling. However, the closer the jet fan is to the tunnel wall or ceiling, the less effectively its power is converted into airflow throughout the tunnel. This means, in particular, that the closer a jet fan is to the tunnel wall or ceiling, the lower its efficiency.

[0005] German patent DE19920513A1 describes a jet fan with a nozzle arrangement at both the fan inlet and outlet. This jet fan draws air more easily from the center of the tunnel and expels the accelerated airflow back towards the center. While this jet fan improves tunnel ventilation, it negatively impacts the clearance height.

[0006] Furthermore, a jet fan is known from publication US 2014 299 402 A1.

[0007] Since jet fans used for tunnel ventilation reduce the clearance height, potentially necessitating a greater tunnel height, it is essential that these fans have minimal negative impact on the clearance. Furthermore, it is crucial that as few jet fans as possible are used to provide a defined airflow through the tunnel, as the fans themselves, along with their installation, maintenance, and the necessary cabling, incur significant costs.

[0008] It is therefore an object of the invention to provide a jet fan for tunnel ventilation, in particular road tunnels, a jet fan system for tunnel ventilation, in particular road tunnels, and a method for manufacturing a jet fan for tunnel ventilation, in particular road tunnels, which reduce or eliminate one or more of the aforementioned disadvantages. In particular, it is an object of the invention to provide a solution that reduces the number of jet fans required within a tunnel and / or the cost of jet fans for tunnel ventilation.

[0009] According to the invention, this problem is solved by a jet fan for ventilating tunnels, comprising the features of claim 1.

[0010] The invention is based on the understanding that the silencers of a jet fan have a significant influence on the clearance between the jet fan and the roadway. Since the efficiency of a jet fan decreases the closer it is to the tunnel ceiling or wall, known jet fans are either positioned at a greater distance from the tunnel ceiling or wall, or the silencer is inclined relative to the fan unit so that the airflow is directed towards the center of the tunnel.

[0011] The inclined arrangement of the silencers reduces the clearance between the jet fan and the roadway. Alternatively, a jet fan with essentially non-inclined silencers can be used; however, this requires a larger diameter fan unit, which also reduces the clearance. Furthermore, increasing the number of jet fans is an option, but this is generally not a viable solution from an economic perspective.

[0012] The jet fan described above cleverly allows the fan to be positioned directly beneath a tunnel ceiling and, furthermore, enables a large clearance between the jet fan and the roadway by creating an angle between the distal and proximal sections, such that the distal section is inclined relative to the fan unit and / or the proximal section. The proximal section can be arranged coaxially with the fan unit. Thus, the jet fan described above combines the advantages of a jet fan without inclined silencers in terms of clearance and the advantages of a jet fan with inclined silencers in terms of effective airflow.

[0013] The invention thus makes it possible to use a jet fan with a larger diameter without reducing the clear height. The thrust generated by a jet fan is determined, among other things, by the fourth power of the diameter. For example, a 12% increase in diameter leads to a 50% increase in thrust. Consequently, increasing the size of the jet fans by one standard size, for example, can reduce the number of jet fans required for a tunnel by 30% to 35%, thus significantly lowering ventilation costs. The inventor has further discovered that an increase of two standard sizes is also possible, reducing the number of jet fans required for a tunnel by 60%. In Germany, for example, the standard sizes are defined by a standard.

[0014] Furthermore, it must be considered that there are regulatory requirements for noise levels in tunnels. For a given thrust, the length of the silencer is generally specified within a narrow design window. Prior art silencers inclined towards the roadway were limited in length to ensure sufficient clearance. The invention now makes it possible to provide the silencer in any desired length, since extending the proximal section does not reduce the clearance.

[0015] The jet fan comprises the fan unit for generating an airflow. The fan unit typically has a fan duct in which a propeller is rotatably mounted. The propeller is usually coupled to an electric drive that rotates it. The fan unit typically has an inlet and an outlet in the direction of airflow. Since it can be advantageous to reverse the direction of airflow, the inlet can also act as an outlet and vice versa. A silencer is preferably arranged at each inlet and / or outlet. At a minimum, a silencer is arranged at either the inlet or the outlet.

[0016] The silencer has at least one proximal section and one distal section. The proximal section faces the fan unit, while the distal section faces away from it. The angle between the distal and proximal sections is such that the distal section is inclined relative to the proximal section.

[0017] The angle is An external angle and / or an internal angle. It is particularly preferred that a passage axis of the proximal section and a passage axis of the distal section enclose a passage angle and / or are not parallel. The proximal section of the silencer can, for example, be designed as a cylindrical shell element. Furthermore, the distal section can also be designed as a cylindrical shell element. The silencer can be designed as a single piece or in two parts.

[0018] According to a preferred embodiment of the jet fan, the distal section is configured to direct an airflow generated by the fan unit from a radially outer section of the tunnel to a substantially central section of the tunnel. Furthermore, the distal section can be configured to direct an airflow generated by the fan unit from a substantially central section of the tunnel into the fan unit. Since the flow direction through the fan unit is reversible, the distal section can thus be used for either blowing air out or drawing air in. Such a configuration of the distal section achieves an advantageous airflow inside the tunnel.

[0019] A further development of the jet fan is characterized by the fact that the proximal section defines a proximal flow direction and the distal section a distal flow direction, with the proximal and distal flow directions forming a flow angle. During operation, the proximal flow direction can, for example, be essentially parallel to a longitudinal tunnel axis. The distal flow direction is preferably directed from a tunnel ceiling or wall towards a central section of the tunnel. Consequently, the flow angle is established between the proximal and distal flow directions.

[0020] Furthermore, according to the invention, the fan unit defines a fan flow direction, wherein the fan flow direction and / or the proximal flow direction, together with the distal flow direction, includes the flow angle. The flow angle corresponds in particular to the angle.

[0021] Among the previously mentioned flow directions—the proximal flow direction, the distal flow direction, and the fan flow direction—one main flow direction is particularly important. The main flow direction is defined as the fundamental flow direction within the jet fan. Of course, flows can occur, for example, near an inner wall of the jet fan or at elements located within the jet fan, that are partially perpendicular or even opposite to the main flow direction. However, such local flow directions occurring within the jet fan are generally not included in the flow directions mentioned above.

[0022] In a further preferred embodiment, the fan flow direction of the fan unit and the proximal flow direction are essentially parallel to each other. This advantageously ensures a short overhang length transverse to the tunnel axis.

[0023] According to the invention, the flow angle is between 6° and 8°. The inventors have found that good flow inside a tunnel can be achieved precisely at such flow angles, even with a small number of jet fans.

[0024] Furthermore, it is preferred that the proximal section defines a proximal passage axis and the distal section a distal passage axis, wherein the proximal passage axis forms a passage angle with the distal passage axis. It is also preferred that the fan unit defines a fan passage axis and that the fan passage axis and the proximal passage axis are oriented substantially parallel to each other, and in a preferred embodiment, they may also be oriented coaxially. Furthermore, it is preferred that the proximal passage axis and the distal passage axis form an angle between 2° and 15°, in particular between 4° and 10°, preferably between 6° and 8°.

[0025] InIn another preferred embodiment of the jet fan, the proximal section is arranged between the distal section and the fan unit.

[0026] In particular, it is preferred that the proximal section is arranged in the fan flow direction and / or in the proximal flow direction and / or in the distal flow direction between the distal section and the fan unit. Such an arrangement advantageously influences the airflow through the jet fan.

[0027] Another preferred embodiment of the jet fan is characterized by a silencer designed in two parts, comprising a first silencer unit and a second silencer unit, with the first silencer unit comprising the proximal section and the second silencer unit comprising the distal section. Such a jet fan design ensures a simple and cost-effective construction of this jet fan, which positively influences the airflow.

[0028] According to the invention, the jet fan is characterized in that the proximal section extends with a proximal extent in the proximal flow direction, and the distal section extends with a distal extent in the distal flow direction. A further preferred embodiment is characterized in that the distal extent is smaller than the proximal extent. In this preferred embodiment, the ratio of distal extent to proximal extent is less than 1. In a further preferred embodiment of the jet fan, the ratio of distal extent to proximal extent is between 0.05 and 0.4, particularly between 0.1 and 0.3. The inventors have found that, especially with such a ratio, a further improvement in the flow conditions inside a tunnel can be achieved.

[0029] Furthermore, the jet fan is further developed according to the invention in such a way that the fan unit and / or the silencer has a flow diameter, and the ratio of distal extent to flow diameter is between 0.45 and 0.55, and the ratio of proximal extent to flow diameter is between 2 and 3.

[0030] The flow diameter is, in particular, a dimension of the cross-section whose orthogonal surface is aligned parallel to the flow direction and / or the passage axis. The flow diameter of the fan unit is generally understood to be negligible, neglecting any elements and / or systems installed within the fan unit.

[0031] InIn a further preferred embodiment of the jet fan, it is provided that it includes a second silencer, which preferably has the same features as the silencer, wherein the silencer is arranged at a first end and the second silencer is arranged at a second end of the fan unit opposite the first end in the direction of fan flow. The noise emission of the jet fan is further reduced by the silencer and the second silencer. In particular, this enables a mirror-symmetrical steel fan, thus advantageously allowing a reversal of the flow direction.

[0032] InIn a further preferred embodiment, the jet fan comprises a mounting unit arranged and configured to attach the jet fan to a tunnel ceiling and / or wall such that the overhang is less than 1.3 times, and in particular less than 1.1 times, the flow diameter. Furthermore, it is preferred that the distal flow direction on an outlet side of the jet fan is directed into a substantially central section of the tunnel.

[0033] Furthermore, it may be preferred that the jet fan has a nozzle element comprising a jacket segment extending from an inlet to an outlet with an annular segment-shaped cross-section and defining a nozzle flow direction, wherein the jacket segment has a circumferential opening section adjacent to the outlet, and furthermore includes connection means designed for coupling the nozzle element to the silencer and / or the second silencer.

[0034] According to another aspect, the aforementioned task is solved by a jet fan system for ventilating tunnels, in particular road tunnels, comprising at least one jet fan according to one of the embodiment variants described above, wherein the at least one jet fan has a supply cable that couples the jet fan to a power supply.

[0035] The invention is based on the understanding that approximately one-third of the total cost of a jet fan system is attributable to the electrical equipment, such as control cabinets, cables, etc. Therefore, reducing the total number of jet fans in a jet fan system is advantageous, as it reduces the total cable length required. Since another third of the total cost is attributable to installation and assembly, this further reduces costs.

[0036] Preferred embodiments are explained by way of example with reference to the accompanying figures. These show: Fig. 1: a schematic, two-dimensional sectional view of an exemplary embodiment of a jet fan; Fig. 2: a schematic, three-dimensional side view of a jet fan in the prior art and of a jet fan according to the invention; Fig. 3: a schematic, three-dimensional side view of a jet fan in the prior art and of a jet fan according to the invention; and Fig. 4: a schematic view of a method.

[0037] In the figures, identical or essentially functionally equivalent or similar elements are designated with the same reference symbols.

[0038] The jet fan 100 extends from an inlet 102 to an outlet 104. In this exemplary illustration, air flows into the jet fan 100 at the inlet 102 and flows out again at the outlet 104. However, the flow direction of the jet fan 100 can also be reversed, so that air enters the jet fan 100 at the outlet 104 and exits the jet fan 100 at the inlet 102. The jet fan 100 comprises a fan unit 106, a first silencer 110, and a second silencer 130. The fan unit 106 defines a fan flow direction 108. In the intended operation of the jet fan 100, the fan flow direction 108 is essentially parallel to a longitudinal tunnel axis.

[0039] The first silencer 110 has a proximal section 112 with a proximal flow direction 114 and a distal section 116 with a distal flow direction 118. An angle 122 is formed between the distal section 116 and the proximal section 112. Due to this angle 122, an additional angle is formed between the proximal flow direction 114 and the distal flow direction 118, namely the flow angle 120. In the present exemplary embodiment, the sum of the flow angle 120 and the angle 122 formed at the outer surface between the distal section 116 and the proximal section 112 is 180 degrees.

[0040] The second silencer 130 is arranged on the side of the jet fan 100 facing away from the first silencer 110 in the direction of fan flow 108. The second silencer 130, like the first silencer 110, has a proximal section 132 and a distal section 134, between which an angle 136 is formed.

[0041] The jet fan 100 can be attached to a tunnel wall or ceiling using a mounting unit 138. The design of the silencers, with distal sections 116, 134 and proximal sections 112, 132, allows the fan unit 106 and the proximal sections 112, 132 to be positioned close to the wall or ceiling. Despite this placement close to the wall or ceiling, the angled distal sections 116, 134 generate a significant thrust on the airflow from the jet fan 100. Consequently, the jet fan 100 can be designed with a smaller flow diameter, or the total number of jet fans in a tunnel can be reduced.

[0042] This advantage is highlighted by the presentation in the Figures 2 and 3 clearly. In the Figure 2On the left side, a jet fan 200 known from the prior art is shown. This jet fan 200 is arranged on a tunnel ceiling 202 above a roadway 204. The distance between the tunnel ceiling 202 and the roadway 204, as well as the cantilever length 208, results in a clear height 206. The clear height 206, together with a safety margin, defines the clearance height of the tunnel. The conventional jet fan 200 must have a greater distance from the tunnel ceiling 202 to ensure its efficiency is not too low.

[0043] The clearance from the tunnel ceiling 202 significantly reduces the clear height 206. In the present example, with a total height between the roadway 204 and the ceiling 202 of 4 to 5 flow diameters, the clear height is only 2.5 to 3.5 times the flow diameter.

[0044] In contrast, the jet fan 210 shown on the right can achieve a greater clear height 216, three to four times the flow diameter. Furthermore, the jet fan 210 can be positioned closer to the tunnel ceiling 212. Due to this closer proximity to the tunnel ceiling 212, the overhang length 218 is smaller compared to the jet fan 210 arrangement, approximately 0.4 times the flow diameter.

[0045] In Figure 3The comparison between two jet fans is also shown: the conventional jet fan 200 and the jet fan 210 according to the invention. Due to the smaller distance from the tunnel ceiling 212, a larger diameter can be selected for the jet fan 210, thus achieving the same projection length 208, 218. However, the larger flow diameter of the jet fan 210 allows for a greater thrust, so that fewer jet fans 210 need to be arranged in the tunnel. This significantly reduces the assembly and installation work as well as the total cable length to be laid. Consequently, the costs for ventilating the tunnel are reduced.

[0046] In Figure 4 A schematic view of a procedure is shown. In In step 300, a fan unit 106 is provided to generate an airflow. InStep 302 provides a silencer 110, 130 with a proximal section 112, 132 and a distal section 116, 134 adjacent to the proximal section 112, 132, wherein the distal section 116, 134 and the proximal section 112, 132 enclose an angle 122, 136 with each other. In In step 304, the silencer 110, 130 is attached to the fan unit 106, with the proximal section 112, 132 facing the fan unit 106 and the distal section 116, 134 facing away from the fan unit 106. The proximal section 112, 132 may, for example, have fastening means for attachment to the fan unit 106. REFERENCE MARK LIST

[0047] 100 Jet fan 102 Inlet 104 Outlet 106 Fan unit 108 Fan flow direction 110 First silencer 112 Proximal section 114 Proximal flow direction 116 Distal section 118 Distal flow direction 120 Flow angle 122 Angle 130 Second silencer 132 Proximal section 134 Distal section 136 Angle 138 Mounting unit 200 First jet fan 202 Tunnel ceiling 204 Roadway 206 Clearance 208 Cantilever length 210 Second jet fan 212 Tunnel ceiling 214 Roadway 216 Clearance 218 Cantilever length

Claims

1. A jet fan (100, 210) for ventilating tunnels, in particular road tunnels, comprising - a fan unit (106) for generating an air stream, - a silencer (110, 130) arranged on the fan unit (106) with a proximal section (112) and a distal section (116) adjacent to the proximal section (112), wherein the proximal section (112) extends in the proximal flow direction (114) with a proximal extension and the distal section (116) extends in the distal flow direction (118) with a distal extension, - characterized in that an angle (120, 122) is set on the outer skin between the distal section (116) and the proximal section (112) in such a way that a flow angle (120) is set between the proximal flow direction (114) and the distal flow direction (118) in such a way that the sum of the flow angle (120) and the angle (122) together is 180 arc degrees, wherein - - the fan unit (106) and the silencer (110, 130) have a flow diameter, and - the ratio of the distal extension to the flow diameter is between 0.45 and 0.55 and - the ratio of the proximal extension to the flow diameter is between 2 and 3, wherein the proximal section (112) defines a proximal flow direction (114) and a distal section (116) defines a distal flow direction (118), wherein the proximal flow direction (114) forms a flow angle (120) between 6° and 8°with the distal flow direction (118)..

2. The jet fan (100, 210) according to claim 1, wherein the distal section (116) is designed to guide an air stream generated by the fan unit (106) from a radially outer section of the tunnel into a substantially center section of the tunnel and / or from a substantially center section of the tunnel into the fan unit (106)..

3. The jet fan (100, 210) according to one of the preceding claims, wherein a fan flow direction (108) of the fan unit (106) and the proximal flow direction (114) are aligned substantially parallel to each other.

4. The jet fan (100, 210) according to one of the preceding claims, wherein the proximal section (112) is arranged between the distal section (116) and the fan unit (106),5. The jet fan (100, 210) according to one of the preceding claims, wherein the silencer (110, 130) is designed in two parts with a first silencer unit and a second silencer unit, the first silencer unit having the proximal section (112) and the second silencer unit having the distal section (116).

6. The jet fan (100, 210) according to one of the preceding claims, wherein the distal extension is smaller than the proximal extension.

7. The jet fan (100, 210) according to any one of the preceding claims, comprising a second silencer (110, 130), which preferably has the same features as the [sic; first] silencer (110, 130), wherein the [sic; first] silencer (110, 130) is arranged on a first end and the second silencer (110, 130) is arranged on a second end of the fan unit (106) in the fan flow direction opposite the first end.

8. The jet fan (100, 210) according to any one of the preceding claims, comprising a fastening unit (138), which is arranged and formed - to fasten the jet fan (100, 210) on a tunnel ceiling and / or tunnel wall so that a projection length is less than 1.3 times, in particular less than 1.1 times the flow diameter, and / or - that the distal flow direction (118) on an outlet side of the jet fan is directed into a substantially center section of the tunnel.

9. A jet fan system for ventilating tunnels, in particular road tunnels, comprising - at least one jet fan (100, 210) according to one of the preceding claims, wherein the at least one jet fan (100, 210) has a supply cable that connects the jet fan (100, 210) to a power supply.

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