EP3702684B1 - Air conditioning of rooms with source air supply and temperature control - Google Patents

Description

The invention relates to a device for air conditioning rooms and a method for air conditioning rooms.

The air conditioning of rooms involves influencing various parameters of the room air. The present invention deals on the one hand with temperature control, ie heating and/or cooling, and on the other hand with air exchange in the form of a desired displacement ventilation by supplying displacement air.

There are already known devices for room air conditioning, which are arranged in floor ducts. For example, describes the DE 91 06 753.7 U1 a device for air conditioning rooms with a heating element and a supply air supply element. The device is used for the combined supply of warm air and colder supply air (displacement air) into a room and is installed in a corner area in the floor. One or two adjacent convectors form the heating element. The supply air supply element is designed as an elongated shaft and has an air outlet on its upper open side, which is formed by a perforated plate with a large number of large-area, circular openings and is covered with a filter mat. During operation, air is fed in via an air inlet connector and discharged upwards through the air outlet. Room air coming from the room enters an air inlet duct through an air inlet, is heated by the convectors and is discharged at an air outlet of the heating element.

From the DE 20 2011 004 136 U1 a device for air-conditioning a room is known, which is used to control the temperature of secondary air and enables source air to be supplied as required. For this purpose, the device has an inflow chamber, a mixing chamber, an air distribution chamber and an outflow chamber. Source air can flow out of the air distribution chamber through controllable outflow nozzles. The controllable outflow nozzles make it possible to mix at least part of the source air with the heated secondary air in the mixing chamber. Heated secondary air and part of the source air then enter the room to be tempered from a common air outlet. This known device requires a large number of chambers, above all outflow nozzles which can be controlled with a corresponding control system, in order to mix cold source air with the heated secondary air as required.

It can be regarded as an object to enable room air conditioning in a particularly efficient manner.

The object is achieved by a device for air-conditioning rooms according to claim 1 and a method for air-conditioning rooms according to claim 11. Dependent claims relate to advantageous embodiments of the invention.

The device according to the invention comprises a duct which is intended in particular to be arranged as a floor duct. The direction in which the channel extends is referred to here as the longitudinal direction. A first channel section and a second channel section run parallel to one another in the longitudinal direction.

The first duct section serves to supply source air as primary air. For this purpose, at least one source air supply to the first duct section is provided, preferably several, for example in the form of multiple source air sockets arranged spaced apart in the longitudinal direction. In order to release the source air, the first duct section has a first opening section, which is oriented toward an opening side of the duct. In the preferred bottom mounting of the duct, the opening side is preferably the top. The first opening section is designed to discharge the source air into the room.

The second duct section is designed for the temperature control of room air (secondary air) and has a second opening section, which is also aligned towards the opening side of the duct. The first and second opening sections are preferably arranged next to one another on the opening side of the channel, particularly preferably directly adjacent to one another.

The second opening section is designed to take in secondary air and to release temperature-controlled secondary air. For temperature control of the secondary air is in the second Channel section arranged a temperature control element. The temperature control can include heating and/or cooling the air. The temperature control element can be designed, for example, as a heat exchanger, radiator or convector. A fan for conveying the secondary air can also be provided in the second duct section.

In analyzing known air conditioning devices, the invention has identified as a possible problem the placement of both inlets and outlets on the opening side of the duct. In particular, a considerable part of the displacement air discharged at the first opening section can be taken up again at the second opening section. However, this is disadvantageous for effective displacement ventilation with the desired formation of a source air lake in the room. Displacement air, usually treated outside air, can preferably be supplied at a temperature slightly (for example 2 to 4 K) below room temperature, with a low air velocity being aimed for in order to create a room climate that is perceived as pleasant. An air supply can preferably be designed in such a way that a source air sea forms in the room. If the source air is heated by heat sources, for example people, electrical devices, etc., there is a buoyancy so that the air, which is contaminated in this way, rises to the ceiling of the room, where it can be extracted, for example.

On the other hand, a temperature control of the room air is aimed at for room air conditioning, in particular a heating of the room air during the heating period.

The invention is based on the finding that, in order to achieve a desired displacement ventilation with the formation of a source air lake, it is advantageous to separate the air flows, ie the secondary air on the one hand and the source air on the other. It is therefore proposed according to the invention to provide a special outlet shape at the first opening section for discharging the source air, which can support a separation of the air flows.

According to the invention, one or more slot outlets are provided at the first opening portion, each of which is aligned in the longitudinal direction. Surprisingly, it has been found that by using one or more slot outlets, an air flow can be achieved which counteracts the source air being sucked in at the second opening section. In contrast to other forms of outlet, such as a round outlet, perforated plate, etc., a slot outlet tends to generate a flat air flow with a low tendency to turbulence. As explained in more detail below, in preferred embodiments in particular, a targeted alignment of the flow in a direction pointing away from the second opening section is possible. In this way, the proportion of the discharged source air that is subsequently taken in again at the second opening section can be significantly reduced.

A slit outlet is understood to mean any outlet shape which, as the outlet opening, has an elongate shape oriented in the longitudinal direction, ie the extent of which is greater in the longitudinal direction than in the transverse direction. In the slot outlet, the extension of the outlet opening in the longitudinal direction is preferably more than 3 times the extension in the transverse direction, particularly preferably more than 5 times. A plurality of slot outlets can preferably be arranged one behind the other in the longitudinal direction in the first opening section, more preferably with a small spacing of, for example, less than 50%, particularly preferably less than 20% of the length of the individual slot outlets.

In a particularly preferred embodiment, hole outlets for discharging the source air are arranged on the first opening section in addition to the slot outlet or slot outlets. The hole outlets can be provided, for example, as perforations in a wall element, preferably a metal sheet. The perforations can have any shape, for example round or rectangular. For example, one or more rows of holes aligned in the longitudinal direction can be provided, for example in an equidistant arrangement.

It is further preferred that at least one slot outlet or preferably a row of slot outlets is arranged in the transverse direction of the channel between the hole outlets and the second opening section. The slot outlets and the directed air flow discharged therefrom thus form a barrier between the flow of source air from the hole outlets and the second opening portion of the duct. In some designs, additional outlets, for example slot outlets, can also be provided at another location. Advantageously, however, the aim is to provide at least one row of slot outlets on an edge of the first opening section that borders on the second opening section.

The slot outlet or slot outlets preferably has an air guiding element. This means that the slot outlet is preferably not just a slot-shaped (elongated) opening in an outlet plane of a first opening section, but an air guiding element, which preferably extends at least essentially transversely to the outlet plane, for guiding the emitted source air is arranged. The air guiding element can thus shape and direct the discharged air flow. For example, a wall element delimiting the slit in the transverse direction and projecting from the slit opening into the interior of the first duct section can serve as an air guiding element. The wall element can have a flat shape, as will be explained below with reference to preferred embodiments, but it can preferably also be curved and in particular have part-circular sections.

The air guiding element can preferably be designed to guide the discharged source air in a direction which has a desired angle to the outlet plane. For example, the angle can be 20 to 90° to the outlet plane. The angle is preferably less than 90°, so that the air guiding element guides the discharged source air in an oblique direction. For example, directions in the range of up to 60° relative to the outlet plane are preferred. The direction is particularly preferably directed away from the second opening section in order to prevent, but at least to significantly reduce, mixing with the secondary air sucked in there. For example, the slot outlet with the air guiding element can be designed to discharge displacement air at an angle of, for example, 20 to 60°, preferably 50° or less, particularly preferably 40° or less.

In a preferred embodiment, at least one of the slot outlets can have an adjustment element for adjusting the slot width and/or outlet device. As a result, a desired air flow can be achieved, in particular also taking into account the conditions of the room, for example the position of obstacles. The adjusting element can preferably be arranged within an air guiding element. Particularly preferably, the adjustment element can be aligned in the longitudinal direction and can be displaced to adjust the slot outlet. In particular, the adjusting element can be displaceable in a transverse direction in order to enable the slot width and/or the outlet device to be adjusted.

In a particularly preferred embodiment, the adjustment element can have a round cross section, at least essentially and/or at least in sections, preferably on an outer surface. An air guiding element can also have a round cross section, at least partially and/or at least in sections, preferably on an inner surface. In addition to circular cross sections, this also includes other rounded cross sections such as oval shapes. Such rounded surfaces favorably result in a low flow resistance.

In a particularly preferred embodiment of an adjustable slot outlet, an adjustment element can be displaced by rotating an adjustment element. The adjustment element can be rotatable about an adjustment axis, which is preferably aligned in the longitudinal direction of the slot. The adjustment element can be attached to the adjustment element eccentrically to the adjustment axis, so that it can be displaced by rotating the adjustment axis.

According to the invention, an inlet section for admitting the secondary air and an outlet section for discharging the temperature-controlled secondary air are arranged on the second opening section. The inlet and outlet sections are arranged parallel to one another in the longitudinal direction. According to the invention, the inlet section is arranged between the outlet section and the first opening section.

A distribution wall element can be provided in the first duct section between at least one of the source air supply lines and the first opening section. The distribution wall member may extend longitudinally. The distribution wall element can be arranged on the second opening section for at least partially separating a direct connection line between the source air supply and an opening. It can thus contribute to better air distribution, in particular to a more even distribution in the longitudinal direction. In the case of a plurality of displacement air feeds spaced apart in the longitudinal direction, a plurality of separate distribution wall elements can be provided, or alternatively a single distribution wall element can also extend over the entire length. The distribution wall element is preferably a flat, planar element, particularly preferably a metal sheet.

In a particularly preferred embodiment, the distribution wall element can be arranged obliquely to the outlet plane of the first opening section, for example. at an angle of 20 to 70° to the outlet plane, preferably 30 to 60°. By arranging the distribution wall element at an angle, a direction of the discharged air flow of the source air can be specified or at least supported. For this purpose, the distribution wall element can preferably be inclined in a direction away from the second opening section.

The distribution wall element is particularly preferably arranged in such a way that it leaves a passage area free between the source air supply and the first opening section, which is significantly reduced compared to the width of the first duct section. For example, the passband can correspond to less than 50% of the width of the first channel section, preferably 25% or less. A width of the passband can be determined, for example, in a plane parallel to the outlet plane of the first opening section.

In preferred embodiments, the temperature control element can be designed as a heat exchanger. For this purpose, it can have at least one line for a tempering liquid, ie a cooling or heating medium. The temperature control element preferably also has a number of lamellae in order to achieve an increased surface area for temperature control of the secondary air flow. The line for the heat transfer liquid can be connected to a cooling and/or heating device.

In a preferred air conditioning arrangement, the device according to the invention can be arranged within a room in a floor duct. The floor duct can particularly preferably be arranged along a wall or a facade element, for example a window. The second channel section is preferably arranged in the direction of the wall or the facade element, ie between this and the first channel section. More preferably, the second opening section can be arranged flush with or at only a small distance from the wall or from the facade element, so that the air flow of the secondary air can be aligned along the wall or the facade element.

The method according to the invention includes the use of the device described above, with source air being supplied for source air supply and the temperature control element being operated for temperature control of the secondary air. The operation has proven to be very efficient and well suited to the formation of displacement ventilation and the formation of a spring air lake.

Fig. 1

in perspektivischer Darstellung eine erste Ausführungsform einer Klimatisierungsvorrichtung, wobei eine Abdeckung nur teilweise dargestellt ist;

Fig.2

einen Querschnitt durch die Klimatisierungsvorrichtung aus Fig. 1 entlang der Linie A..A;

Fig. 3

einen Querschnitt, teilweise schematisch, durch eine Klimatisierungsanordnung mit der Klimatisierungsvorrichtung aus Fig. 1, Fig. 2 in einem Raum;

Fig. 4

in Draufsicht einen Schlitzauslass der Klimatisierungsvorrichtung aus Fig. 1, Fig. 2;

Fig. 5

einen Querschnitt entlang der Linie B..B des Schlitzauslasses aus Fig. 4;

Fig. 6

in perspektivischer Darstellung eine zweite Ausführungsform einer Klimatisierungsvorrichtung mit nur teilweiser dargestellter Abdeckung;

Fig. 7

in perspektivischer Darstellung eine dritte Ausführungsform einer Klimatisierungsvorrichtung mit nur teilweiser dargestellter Abdeckung;

Fig. 8

in perspektivischer Darstellung eine vierte Ausführungsform einer Klimatisierungsvorrichtung mit nur teilweiser dargestellter Abdeckung.

Embodiments of the invention are described in more detail below with reference to drawings. show:

1

a perspective view of a first embodiment of an air conditioning device, wherein a cover is only partially shown;

Fig.2

a cross section through the air conditioning device 1 along line A..A;

3

a cross section, partially schematic, through an air conditioning arrangement with the air conditioning device 1 , 2 in a room;

4

in plan view, a slot outlet of the air conditioning device 1 , 2 ;

figure 5

a cross-section along the line B..B of the slot outlet 4 ;

6

a perspective view of a second embodiment of an air conditioning device with only a partial cover shown;

7

a perspective view of a third embodiment of an air conditioning device with only a partial cover shown;

8

a perspective view of a fourth embodiment of an air conditioning device with only a partial cover shown.

one inside 1 and 2 The first embodiment of an air conditioning device 10 shown comprises a duct 12 with a sheet metal wall formed on three sides and an upper opening side 14. The duct 12 is divided by a partition 16 in a longitudinal direction L into a first duct section 18 and a second duct section 20. In 1 only part of the channel 12 is shown, which otherwise extends further in the longitudinal direction L.

On the top of the channel 12 is covered by a cover grating 28, which is only partially shown here for reasons of clarity.

The first channel section 18 includes an interior space 22 which is delimited by the wall of the channel 12 and the partition wall 16 . The first channel section 18 has a first opening section 24 on the opening side 14 of the channel 12 .

Source air 30 is supplied to the interior space 22 of the first duct section 18 by a plurality of source air sockets 26, which are spaced apart in the longitudinal direction L, and discharged through the first opening section 24 at the top.

A distribution plate 32 serves to better distribute the supplied source air 30 over the length L. The distribution plate 32 covers a direct straight connection between the fresh air supply 26 and the first opening section 24. The lower end of the distribution plate 32 is at a distance D from the partition 16 arranged, which is considerably smaller than the entire width B1 of the first channel section 18.

In addition, the distribution plate 32 is arranged obliquely in the interior 22, in the example shown at an angle α of approximately 50° to the horizontal.

At the first opening portion 24, various types of outlets are arranged within a horizontal outlet plane. In the first embodiment shown, this comprises a number of slot outlets 32 arranged in a row along the longitudinal direction L and hole outlets 34 arranged in a row in the longitudinal direction L relative to one another. The slot outlets 32 are on the inside of the first opening section 24, i.e. adjacent to the second Channel section 20 and the hole outlets 34 arranged on the outside.

In the embodiment shown, the hole outlets 34 are round bores in a flat cover plate.

The slot outlets 32 are in Figure 4, Figure 5 shown in more detail. As shown there, they comprise a slit-shaped outlet opening 36 which is aligned in the longitudinal direction L. In the example shown, the slit opening 36 is subdivided by separating discs 38 .

The slot opening 36 is bounded by a slot frame 40, from which (see figure 5 ) Wall elements 42 extend downwards in the direction of the interior space 22 of the first channel section 18 . The wall elements 42 are rounded and have an inner contour which in some sections has the shape of a cylindrical surface of a circular cylinder. The wall elements 42 define an inner region 44 of the slot outlet 32 with a circular border in cross-section in sections and a first longitudinal center axis L1.

An adjusting element 46 is movably arranged within the inner region 44 of the slot outlet 32 . The adjustment element 46 is designed as a circular cylinder with a central longitudinal axis L2 and has a smaller diameter than the inner area 44. The adjustment element 46 is arranged eccentrically within the inner area 44 of the slot outlet 32, so that the longitudinal axes L1 and L2 are spaced apart from one another.

At one end of the slit outlet 32 is a round adjuster 48 disposed. The adjustment element 48, adjustment element 46 and the cutting discs 38 can preferably be formed in one piece. The adjusting element 46 can be displaced by rotating the unit formed from these elements within the inner area 44 of the slot outlet 32 about the axis L1, so that different parts of the inner area 44 are covered depending on the position specified by rotating the adjusting element 48 . On the one hand, an effective flow available for the throughflow Slot width can be adjusted. On the other hand, it is also possible to adjust the direction of the source air 30 flowing out at the slot outlet 32 .

For example, a significant narrowing of the outlet can be achieved by shifting the adjustment element 46 in front of the slot opening 36 . A lateral shift, such as in figure 5 shown, a delivery direction of the source air 30 that is oblique to the vertical can be specified. Due to the partially round shape of the wall elements 42, as in figure 5 schematically represented by arrows, an oblique deflection of the air flow 30. The wall elements 42 thus serve as air guiding elements.

As in 2 is shown schematically, the source air flow 30 that is discharged at the first opening section 24 is composed of a first portion that is discharged through the slot outlets 32 and a second portion that flows out through the hole outlets 34 .

The first portion of the source air 30 flowing through the slot outlets 32 is a largely level, directed flow with little turbulence due to the shape of the slot. As a result of the routing described above, the first portion of the source air exits in a targeted manner at an oblique angle to the outlet plane, directed away from the second duct section 20 .

The second portion of the source air 30 discharged through the hole outlets 34 is less oriented and laminar compared to the first portion. However, it still has a predominantly oblique outflow direction to the outlet plane, which is influenced by the oblique position of the separating plate 32 .

The overall result is an air flow of the source air in an oblique direction oriented to the top right in the drawings. The directed first portion of the source air covers the second portion and acts as a separating jet in relation to the second duct section 20.

The second channel section 20 includes an interior 48 in which a convector 50 is arranged as a temperature control element. The convector 50 comprises a multiplicity of sheet metal lamellae arranged upright (not shown in detail) and a temperature control medium line (not shown), which is connected to a heating and/or cooling device. Preferably, the convector 50 is used to heat room air and is operated with a heating medium. Then the result is as in 2 Convection, shown schematically at a second opening section 54 on the upper side of the duct 12, in which secondary air 56 is drawn in through a receiving section 58, heated by the convector 50 and discharged as heated secondary air 60 through an outlet section 62.

The air conditioning device 10 can, as in 3 shown schematically for air conditioning a room 64 as a floor duct along a facade element 66, for example a wall or a window. In the preferred arrangement shown, the second channel section 20 is arranged in the direction of the facade element 66 and the first channel section 18 in the direction of the center of the room.

Supplied source air 30 (solid lines) is discharged through the first opening portion 24 into the interior of the space 64 where it forms a source air sea 68 .

Room air is drawn in as secondary air 56 (dash-dotted lines) at the second opening section 54, heated by the convector 50 and released again at the second opening section 54 as heated secondary air 60 (dash-double-dotted line). Due to the arrangement of the outlet section of the second opening section 54 close to the facade element 66, the air flow of the heated secondary air 60 is aligned on the surface (Coanda effect).

Due to the special air flow that is generated due to the arrangement of the outlets 32, 34 on the first opening section 24, an immediate suction of supplied source air 30 into the adjacent second opening section 54 is largely avoided. Displacement air sucked in at the second opening portion 54 rises to the ceiling after being heated by the convector 50 and hardly contributes to the displacement ventilation in the room. This is avoided on the one hand by the oblique discharge direction of the displacement air flow 30 directed away from the second duct section 20 and on the other hand by the uniform, low-turbulence flow profile that is achieved by means of the slot outlets 32 .

As a result, the source air flow is a gentle air flow that flows in a directed manner over the floor into the room and contributes to the formation of a displacement ventilation with the formation of the source air lake 68 in the desired manner.

The operation preferably takes place in such a way that source air 30 is supplied at a temperature of 2 to 4 K below room air temperature. The source air is supplied in such a way that the mean air speed of the source air flow 30 in the room is less than 0.3 m/s, preferably less than 0.2 m/s.

It will be obvious to a person skilled in the art that the device, arrangement and mode of operation shown are only to be understood as examples and not as restrictive and that the invention can also be implemented in other ways as long as this does not contradict the scope of the claims.

For example, the type, number and arrangement of the outlets, in particular in the first opening section 24, can be changed. 6 , 7 and 8th each show alternative embodiments with a different number of hole outlets 34 and/or slot outlets 32.

Further changes are conceivable. For example, the arrangements of the receiving section 58 and the outlet section 62 can be switched. Likewise, cooling of secondary air can take place instead of heating. Furthermore, it is also possible to arrange a device for generating an air flow, for example a blower, ventilator, etc., in the second duct section 20 in order to support or ensure the intake and/or discharge of secondary air.

In addition, control elements can be provided, for example for the supplied source air, z. B. as sliding elements in the source air connection piece 26, in order to enable an air-technical comparison of a plurality of floor convectors with one another. 10 air conditioning device 12 channel B1 Width (of 18) 14 opening side D distance/width 16 partition wall L longitudinal direction 18 first canal section L1 first longitudinal central axis (of 44) 20 second canal section L2 Longitudinal central axis (of 46) 22 inner space 24 first opening section 26 Source air connector/fresh air supply 28 cover grid 30 displacement air/airflow 32 distribution plate/slot outlet/ divider 34 hole outlet 36 exhaust port/slot port 38 cutting disc 40 slot frame 42 Wall element/air duct element 44 interior 46 adjustment element 48 Adjustment element/interior 50 convector/tempering element/ heat exchanger 54 second opening section 56 secondary air 58 intake section/inlet section 60 heated secondary air 62 outlet section 64 Space 66 facade element 68 spring air lake

Claims (11)

1. Device for air-conditioning rooms, having

   - a channel (12) comprising at least a first channel portion (18) extending in a longitudinal direction (L) and a second channel portion (20) arranged parallel and next to the first channel portion (18),

   - wherein the first channel portion (18) has at least a source air feed (26) and a first opening portion (24) which is designed to discharge source air (30), wherein the first opening portion (24) is oriented towards an opening side of the channel (12),

   - the second channel portion (20) has a temperature-control element (50) and a second opening portion (54) which is designed to receive secondary air (56) and to discharge temperature-controlled secondary air (60), wherein the second opening portion (54) is oriented towards the opening side of the channel (12),

   - one or more slot outlets (32), oriented in the longitudinal direction (L), for discharging source air (30) are provided at the first opening portion (24),

   - the second opening portion (54) has an inlet portion (58) for admitting the secondary air (56) and an outlet portion (62) for discharging the temperature-controlled secondary air (60),

   - wherein the inlet portion (58) and the outlet portion (62) are arranged parallel to and alongside one another in the longitudinal direction (L), and

   - the inlet portion (58) is arranged between the outlet portion (62) and the first opening portion (24) .
2. Device according to Claim 1, in which

   - the first opening portion (24) additionally has hole outlets (34) for discharging the source air (30),

   - wherein the at least one slot outlet (32) is arranged between at least a part of the hole outlets (34) and the second opening portion (54).
3. Device according to either of the preceding claims, in which

   - the at least one slot outlet (32) has an air guiding element (42),

   - wherein the air guiding element (42) is designed to guide the discharged source air (30) in a direction at an angle of 20 to 90° to an outlet plane of the first opening portion (24).
4. Device according to one of the preceding claims, in which

   - the at least one slot outlet (32) has an adjusting element (46) for adjusting the slot width and/or outlet direction, in particular

   - the slot outlet (32) has an adjusting element (46) extending in the longitudinal direction (L),

   - wherein the adjusting element (46) is displaceable in order to adjust the slot outlet (32).
5. Device according to Claim 3 or 4, in which

   - the adjusting element (46) and/or the air guiding element (42) have at least substantially and/or at least partially a round cross section.
6. Device according to Claim 4 or 5, in which

   - a setting element (48) that is rotatable about a setting axis (L1) is provided at the slot outlet (32),

   - and the adjusting element (46) is attached to the setting element (48) eccentrically with respect to the setting axis (L1).
7. Device according to one of the preceding claims, in which

   - a distribution wall element (32) that extends in the longitudinal direction (L) is provided in the first channel portion (18) between the source air feed (26) and the first opening portion (24).
8. Device according to Claim 7, in which

   - the distribution wall element (32) is arranged at an angle of 20 to 70° to an outlet plane of the first opening portion (24).
9. Device according to Claim 7 or 8, in which

   - the distribution wall element (32) leaves a passage region free between the source air feed (26) and the first opening portion (24),

   - wherein a width (D) of the passage region corresponds to less than 50% of a width (B1) of the first channel portion (18).
10. Device according to one of the preceding claims, in which

    - the temperature-control element is in the form of a heat exchanger (50) with a line for temperature control liquid.
11. Method for air-conditioning rooms, in which

    - an air-conditioning device (10) is provided, having

    - a channel (12) comprising at least a first channel portion (18) extending in a longitudinal direction (L) and a second channel portion (20) arranged parallel and next to the first channel portion (18),

    - wherein the first channel portion (18) has at least a source air feed (26) and a first opening portion (24) which is designed to discharge source air (30), wherein the first opening portion (24) is oriented towards an opening side of the channel (12),

    - and the second channel portion (20) has a temperature-control element (50) and a second opening portion (54) which is designed to receive secondary air (56) and to discharge temperature-controlled secondary air (60), wherein the second opening portion (54) is oriented towards the opening side of the channel (12),

    - and wherein one or more slot outlets (32), oriented in the longitudinal direction, for discharging the source air (30) are provided at the first opening portion (24),

    - wherein source air (30) is fed to the source air feed (26) and discharged through the first opening portion (24),

    - the temperature control element (50) is operated to control the temperature of the secondary air (56) such that secondary air (56) is received through an inlet portion (58) of the second opening portion (54) and temperature-controlled secondary air (60) is discharged at the second opening portion (54) through an outlet portion (62) of the second opening portion (54),

    - and the inlet portion (58) is arranged between the outlet portion (62) and the first opening portion (24) .

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