WO2022238516A1

WO2022238516A1 - Heating, ventilation and/or air-conditioning unit

Info

Publication number: WO2022238516A1
Application number: PCT/EP2022/062858
Authority: WO
Inventors: Raghu Tejaswi BELLUR; Christian Jonhatan SOTO; Jan Liska; Juraj LEPOT
Original assignee: Valeo Klimasysteme Gmbh
Priority date: 2021-05-12
Filing date: 2022-05-11
Publication date: 2022-11-17
Also published as: DE102021112521A1

Abstract

What is specified is a heating, ventilation and/or air-conditioning unit (10), having a housing (12) which has a base trough (18) in which a condensation-water outflow (32) is formed, having an evaporator (20) and having a fresh-air inlet (22), wherein an air guide for air sucked in through the fresh-air inlet (22) extends from the fresh-air inlet (22) through the housing (12) to the evaporator (20), and from the evaporator (20) to an air outlet (28), and wherein provision is made of a bypass channel (34) to the evaporator (20), which, after the fresh-air inlet (22), branches off from the air guide and, further downstream of the fresh-air inlet (22) and downstream of the evaporator (20), opens out directly into the base trough (18).

Description

HEATING, VENTILATION AND/OR AIR-CONDITIONING UNIT

The invention relates to a heating, ventilation and/or air-conditioning unit for a motor vehicle.

Heating, ventilation and/or air-conditioning units are designed to generate one or more temperature-controlled air streams. In motor vehicles, such units are used for aeration and air-conditioning of a vehicle interior.

For this purpose, firstly, an air stream is sucked in via a fresh-air inlet by means of a fan, which air stream can subsequently be temperature-controlled by means of an evaporator and a heating device. When the fresh air is being sucked in, it may occur that not only air but also water is sucked in, for example in case of rain or if, during a washing process, water runs into the fresh-air inlet.

At a standstill, when the fan is not operating or when the fan runs only at low rotational speed, the water can flow out in a downward direction. At a higher rotational speed of the fan, in particular from a rotational speed of 4000 rpm, the suction power of the fan is however so high that the water can no longer readily flow out. Furthermore, owing to the flow conditions in a housing of the heating, ventilation and/or air-conditioning unit, a high rotational speed of the fan gives rise to a relatively high air pressure in a lower region of the housing, which can force ingressing water even upwards.

Consequently, there is the risk of water passing into the fan or into a filter arranged upstream of the evaporator, which can impair the function of the heating, ventilation and/or air-conditioning unit.

It is therefore an object of the invention to provide a heating, ventilation and/or air-conditioning unit with which sucked-in water is reliably removed even at a high suction power of the fan.

Said object is achieved according to the invention by a heating, ventilation and/or air conditioning unit having a housing which has a base trough in which a condensation-water outflow is formed, having an evaporator and having a fresh- air inlet, wherein an air guide for air sucked in through the fresh-air inlet extends - 2 from the fresh-air inlet through the housing to the evaporator, and from the evaporator to an air outlet, and wherein provision is made of a bypass channel to the evaporator, which, after the fresh-air inlet, branches off from the air guide and, further downstream of the fresh-air inlet and downstream of the evaporator, opens out directly into the base trough.

The bypass channel constitutes a water-outflow channel by way of which water possibly sucked in through the fresh-air inlet can reliably be removed in a downward direction and discharged through the condensation-water outflow from the heating, ventilation and/or air-conditioning unit. The fact that the bypass channel opens out directly into the base trough means that ingressing water can run from the bypass channel directly into the base trough and, consequently, can be discharged particularly quickly from the heating, ventilation and/or air-conditioning unit. In particular, backing-up of water is avoided.

For example, the bypass channel extends directly along a side wall of the evaporator. This contributes to a particularly compact design of the heating, ventilation and/or air-conditioning unit.

In particular, the bypass channel extends continuously and rectilinearly along the evaporator.

According to one embodiment, the heating, ventilation and/or air-conditioning unit comprises a fan, and an inlet of the bypass channel is situated below the level of the fan in the installed state of the heating, ventilation and/or air-conditioning unit. This ensures that ingressing water can flow into the bypass channel before flowing to the fan.

The inlet of the bypass channel is preferably arranged upstream of the fan. This likewise contributes to the reliable removal of ingressing water before it can pass into the fan.

The bypass channel may be formed by a protuberance in the housing, which protuberance directly adjoins the evaporator and/or a seal arranged on the evaporator. The fact that the bypass channel is formed by a protuberance in the housing means that the bypass channel can be realized without the need for an - 3 - additional component. Moreover, in the form of a protuberance, the bypass channel can be formed particularly easily in the housing.

According to one embodiment, the heating, ventilation and/or air-conditioning unit comprises a filter which is arranged upstream of the evaporator, and the opening of the bypass channel into the base trough is situated downstream of the filter. In this way, a situation in which water which is removed by way of the bypass channel can come into contact with the filter after the water has exited the bypass channel is avoided. In particular, with the fan active, the water exiting the bypass channel can be diverted, in a direction away from the filter, from the air stream flowing through the heating, ventilation and/or air-conditioning unit.

The vertical height of the bypass channel and the maximum fan power are preferably matched to one another in such a way that, at maximum fan rotational speed, water present in the bypass channel remains below the inlet of the bypass channel owing to the hydrostatic pressure. This ensures that, in any operating state of the heating, ventilation and/or air-conditioning unit, the hydrostatic pressure which builds up in the bypass channel is high enough to avoid a situation in which ingressed water passes into the fan or the filter.

The bypass channel preferably extends over more than half of the vertical height of the evaporator. In particular, the bypass channel extends over more than 3/4 of the vertical height of the evaporator. In this way, if the bypass channel is completely filled with water, the hydrostatic pressure is high enough for an air pressure at the outlet of the bypass channel to be overcome in any operating state of the heating, ventilation and/or air-conditioning unit. Preferably, the vertical height of the bypass channel is at least 10 cm, in particular up to 20 cm.

According to one embodiment, the bypass channel extends along one side of the evaporator, and at least one wall of the bypass channel is formed by the evaporator and/or by a seal arranged on the evaporator. In this way, the bypass channel can be realized particularly easily. In particular, there is no need for a peripherally closed channel to be produced in the housing, but rather the wall of the evaporator and the seal are used to peripherally close the bypass channel. This contributes to a compact design of the heating, ventilation and/or air- conditioning unit. - 4 -

A seal arranged on the evaporator may be split in the region of the bypass channel in such a way that a part of the bypass channel extends in the seal. In this way, a cross section of the bypass channel can be increased without the external dimensions of the heating, ventilation and/or air-conditioning unit being influenced. The function of the seal is likewise not impaired by the splitting. A larger cross section of the bypass channel is advantageous to the extent that, with the same vertical height, the bypass channel has a larger volume and, consequently, ingressing water can be removed quickly even in relatively large quantities.

For example, the bypass channel at least sectionally narrows in the direction of its outlet. More precisely, the protuberance which forms the bypass channel flattens towards the outlet and transitions into a housing wall. Consequently, there is no need for sealing of the bypass channel towards the outside in the region of the outlet.

A housing wall of the housing may, downstream of the fresh-air inlet, slope down towards the inlet of the bypass channel. This contributes to targeted running in the direction of the bypass channel, and into the latter, of water entering through the fresh-air inlet.

The housing is preferably of multi-part form. In particular, in addition to the base trough, the housing comprises two housing shells, wherein the bypass channel is formed in one of the two housing shells.

Further advantages and features of the invention emerge from the following description and from the appended drawings, to which reference is made. In the drawings:

Figure 1 shows a heating, ventilation and/or air-conditioning unit according to the invention,

Figure 2 shows a cross section through the heating, ventilation and/or air- conditioning unit from Figure 1 ,

Figure 3 shows a base trough of the heating, ventilation and/or air- conditioning unit from Figure 1 ,

Figure 4 shows a further sectional illustration of the heating, ventilation and/or air-conditioning unit from figure 1 , - 5 -

Figure 5 shows a perspective illustration of the heating, ventilation and/or air-conditioning unit from Figure 1 ,

Figure 6 shows a detail view in the region of an inlet of a bypass channel, and - Figure 7 shows a further view of the heating, ventilation and/or air- conditioning unit from figure 1.

Figure 1 shows a heating, ventilation and/or air-conditioning unit 10 in a side view. Figure 2 shows a cross section through the heating, ventilation and/or air- conditioning unit 10. Such heating, ventilation and/or air-conditioning units 10 are commonly used in motor vehicles for aeration and air-conditioning of a vehicle interior.

The heating, ventilation and/or air-conditioning unit 10 comprises a housing 12 having two housing shells 14, 16 which are fastened to one another (see Figure 2). The housing 12 moreover comprises a base trough 18 which is connected in a fluid-tight manner to the two housing shells 14, 16 and which forms a base of the housing 12. The base trough 18 is illustrated separately in Figure 3.

The housing 12 is in particular a fan housing for accommodating an evaporator 20 (see Figure 2) and for accommodating fan flaps. For the sake of simplicity, the fan flaps are not illustrated in the figures.

The heating, ventilation and/or air-conditioning unit 10 has a fresh-air inlet 22 through which fresh air is sucked in, in particular by means of a fan 24 which is accommodated in the housing 12.

The fresh-air inlet 22 is formed in an inlet connector 26, which likewise forms a part of the housing 12.

An air guide for air sucked in through the fresh-air inlet 22 extends from the fresh-air inlet 22 through the housing 12 to the evaporator 20, and from the evaporator 20 to an air outlet 28. 6

Arranged upstream of the evaporator 20 is a filter 30 through which the sucked- in air likewise flows.

The air guide is formed in particular by housing walls and fan flaps, which influence a flow profile of the sucked-in air. In Figure 1 , a path of the air guide is illustrated schematically by way of example using a dashed line, wherein the precise path can vary according to the position of the fan flaps.

The housing 12 commonly has multiple air outlets 28, wherein an air stream is directed to specific air outlets 28 according to the position of the fan flaps.

A seal 31 is arranged on the evaporator 20. Preferably, the seal 31 extends at least along the side walls of the evaporator 20 and over the complete vertical height of the evaporator 20. In this way, a situation in which air flows laterally past the evaporator 20 and is consequently not cooled is avoided.

If the air flowing through the evaporator 20 has relatively high air humidity, there is generally water condensation at the evaporator 20.

The water drips from the evaporator 20 into the base trough 18 and runs to a condensation-water outflow 32 (see Figure 3).

The condensation-water outflow 32 is formed in the base trough 18 at a lowest point in the installation position. In particular, the condensation-water outflow 32 is an opening in the base trough 18.

Besides the condensation water which can form at the evaporator 20, it is also possible for water to pass into the heating, ventilation and/or air-conditioning unit 10 via the fresh-air inlet 22. This can occur for example during a washing process or in case of rain, in particular if the fan 24 is operated at a high rotational speed and the suction power of the fan 24 is consequently particularly high.

In order to avoid a situation in which the sucked-in water passes into the fan 24 or into the filter 30, provision is made of a bypass channel 34 to the evaporator, which, after the fresh-air inlet 22, branches off from the air guide and, further downstream of the fresh-air inlet 22 and downstream of the evaporator 20, opens out directly into the base trough 18, as can be seen from Figure 2 and the sectional illustration shown in Figure 4. - 7 -

Since the filter 30 is arranged upstream of the evaporator 20, the opening of the bypass channel 34 into the base trough 18 is situated downstream of the filter 30 too.

The opening of the bypass channel 34 into the base trough 18 constitutes an outlet 36 of the bypass channel 34.

By way of the bypass channel 34, sucked-in water can flow past the evaporator 20 directly into the base trough 18 and be discharged via the condensation-water outflow 32 from the heating, ventilation and/or air-conditioning unit 10 without flowing through the fan 24 or the filter 30. As can be seen in Figure 2, the bypass channel 34 extends directly along a side wall of the evaporator 20.

More precisely, a wall of the bypass channel 34 is formed at least partially by the seal 31 arranged on the evaporator 20.

An inlet 38 of the bypass channel 34 is arranged upstream of the fan 24. This can be seen in Figure 5, which shows a perspective view of the heating, ventilation and/or air-conditioning unit 10, wherein an upper part of the inlet connector 26 has been omitted in order to allow a view of the inlet 38 of the bypass channel 34.

For the purpose of illustration, a flow path of sucked-in air to the fan 24 is moreover indicated by a dashed line. In particular, the air stream makes a turn from the fresh-air inlet 22 to the fan 24.

Consequently, before being able to pass to the fan 24, ingressing water flows firstly to the bypass channel 34.

Moreover, quick flowing-out of water is promoted in that a housing wall of the housing 12, downstream of the fresh-air inlet 22, slopes down towards the inlet 38 of the bypass channel 34.

This can be seen particularly clearly in Figure 6, which shows a detail view in the region of the inlet 38 of the bypass channel 34.

Flere, the inlet 38 of the bypass channel 34 is situated below the level of the fan 24. 8

Figures 1 and 2 reveal that the bypass channel 34 is formed by a protuberance 40 in the housing 12, in particular in one of the housing shells 14, 16.

The bypass channel 34 narrows in the direction of its outlet.

Figure 7 shows a further view of the heating, ventilation and/or air-conditioning unit 10, wherein the housing shells 14, 16 have been omitted in Figure 7. Consequently, a particularly good view of the seal 31 is possible.

The seal 31 is split in the region of the bypass channel 34 in such a way that a part of the bypass channel 34 extends in the seal 31 .

The seal 31 is split in particular in such a way that two sealing strips 42, 44 of the seal 31 extend parallel to one another on a side wall of the evaporator 20.

One of the two sealing strips 42 ends on the side wall of the evaporator 20, while the further sealing strip 44 continues to a bottom side of the evaporator 20 and extends further along said bottom side.

As can be seen in Figure 7, this mismatch results in an opening between the sealing strips 42, 44, which opening forms the outlet 36 of the bypass channel 34.

Preferably, the sealing strip 42 which, of the two sealing strips 42, 44, is arranged further downstream in the flow direction is of shortened form. In this way, the water exiting the bypass channel 34 can flow in the direction away from the filter 30.

Due to the splitting of the seal 31 , one side of the evaporator 20 is partially exposed in a region in which the bypass channel 34 extends, so that the evaporator 20 likewise forms a part of a wall of the bypass channel 34.

Consequently, the bypass channel 34 is formed as soon as the evaporator 20, with the seal 31 , is fitted in the housing 12.

In an alternative embodiment, it is possible for the seal 31 not to be split. In this case, merely the seal 31 and not the evaporator 20 forms a wall of the bypass channel 34. - 9 -

If, in the region of the bypass channel 34, no seal is arranged on the evaporator 20, it is possible for the protuberance 40 to directly adjoin the evaporator 20, so that the evaporator 20 forms a wall of the bypass channel 34.

If the fan 24 is operated at a high rotational speed, owing to the flow conditions prevailing in the housing 12, it may be the case that there is a higher air pressure in the region of the base trough 18 and in particular in the region of the outlet 36 of the bypass channel 34 than in the region of the inlet 38 of the bypass channel 34.

In order to avoid a situation in which, due to the high air pressure in the region of the base trough 18, water present in the bypass channel 34 is forced upwards, the bypass channel 34 is dimensioned in such a way that a hydrostatic pressure in the bypass channel 34 is high enough for the air pressure prevailing at the outlet 36 to be resisted in any operating state of the heating, ventilation and/or air- conditioning unit 10. In particular, forcing of water upwards through the inlet 38 is to be avoided.

This is achieved in that a vertical height of the bypass channel 34 and a maximum fan power are matched to one another in such a way that, at maximum fan rotational speed, water present in the bypass channel 34 remains below the inlet 38 of the bypass channel 34 owing to the hydrostatic pressure.

Particularly preferably, the bypass channel 34 is designed in such a way that the hydrostatic pressure at the outlet 36 of the bypass channel 34 is high enough for the air pressure prevailing at the outlet to be overcome, so that the water can flow from the bypass channel 34 to the condensation-water outflow 32.

In order to achieve the largest possible hydrostatic pressure, the bypass channel 34 must be completely filled with water. However, even if the bypass channel 34 is only partially filled with water, it is reliably ensured that water present in the bypass channel 34 remains below the inlet 38, since the air pressure in the bypass channel 34 decreases in the upward direction.

In the exemplary embodiment, the bypass channel 34 extends over more than half of the vertical height of the evaporator 20, in particular over more than 3/4 of the vertical height of the evaporator 20.

For example, a height of the bypass channel 34 is at least 10 cm. 10

A cross section of the bypass channel 34 is for example between 1 cm² and 3 cm².

Claims

11

Patent claims

1 . Heating, ventilation and/or air-conditioning unit (10), having a housing (12) which has a base trough (18) in which a condensation-water outflow (32) is formed, having an evaporator (20) and having a fresh-air inlet (22), wherein an air guide for air sucked in through the fresh-air inlet (22) extends from the fresh-air inlet (22) through the housing (12) to the evaporator (20), and from the evaporator (20) to an air outlet (28), and wherein provision is made of a bypass channel (34) to the evaporator (20), which, after the fresh-air inlet (22), branches off from the air guide and, further downstream of the fresh-air inlet (22) and downstream of the evaporator (20), opens out directly into the base trough (18).

2. Heating, ventilation and/or air-conditioning unit (10) according to Claim 1 , characterized in that the heating, ventilation and/or air-conditioning unit (10) comprises a fan (24), and an inlet (38) of the bypass channel (34) is situated below the level of the fan (24).

3. Heating, ventilation and/or air-conditioning unit (10) according to Claim 2, characterized in that the inlet (38) of the bypass channel (34) is arranged upstream of the fan (24).

4. Heating, ventilation and/or air-conditioning unit (10) according to one of the preceding claims, characterized in that the bypass channel (34) is formed by a protuberance (40) in the housing (12), which protuberance directly adjoins the evaporator (20) and/or a seal (31) arranged on the evaporator (20).

5. Heating, ventilation and/or air-conditioning unit (10) according to one of the preceding claims, characterized in that the heating, ventilation and/or air- conditioning unit (10) comprises a filter (30) which is arranged upstream of the evaporator (20), and the opening of the bypass channel (34) into the base trough (18) is situated downstream of the filter (30).

6. Heating, ventilation and/or air-conditioning unit (10) according to one of the preceding claims, characterized in that the bypass channel (34) extends over more than half of the vertical height of the evaporator (20).

7. Heating, ventilation and/or air-conditioning unit (10) according to one of the preceding claims, characterized in that the vertical height of the bypass channel 12

(34) and the maximum fan power are matched to one another in such a way that, at maximum fan rotational speed, water present in the bypass channel (34) remains below the inlet (38) of the bypass channel (34) owing to the hydrostatic pressure. 8. Heating, ventilation and/or air-conditioning unit (10) according to one of the preceding claims, characterized in that the bypass channel (34) extends along one side of the evaporator (20), and at least one wall of the bypass channel (34) is formed by the evaporator (20) and/or by a seal (31) arranged on the evaporator (20). 9. Heating, ventilation and/or air-conditioning unit (10) according to Claim 8, characterized in that a seal (31) arranged on the evaporator (20) is split in the region of the bypass channel (34) in such a way that a part of the bypass channel (34) extends in the seal (31).

10. Heating, ventilation and/or air-conditioning unit (10) according to one of the preceding claims, characterized in that the bypass channel (34) at least sectionally narrows in the direction of its outlet (36).

11. Heating, ventilation and/or air-conditioning unit (10) according to one of the preceding claims, characterized in that a housing wall of the housing (12), downstream of the fresh-air inlet (22), slopes down towards the inlet (38) of the bypass channel (34).