METHOD AND DEVICE FOR PREPARING AIR TO BE SUPPLIED TO A ROOM TO A DESIRED TEMPERATURE AND A DESIRED HUMIDITY
The air to be supplied to a room is brought to a desired temperature and a desired humidity through the following process steps: making outside air flow as a first air stream through a first line (20) and making a first portion of exhaust air coming from the room flow as a second air stream through a second line (21), wherein moisture is exchanged between the first air stream and the second air stream by means of a device for exchanging humidity, condensing, by means of a dehumidifying and cooling device (19), moisture in the form of water from the first air stream and/or from the second air stream and/or inside the device for exchanging humidity, and making a second portion of the exhaust air flow as a third air stream through another line (32) comprising another dehumidifying and cooling device (33) and returning said second portion back to the room, wherein in the other dehumidifying and cooling device (33) moisture is condensed from the third air stream in the form of water.
The invention relates to a method and a device for preparing air to be supplied to a room, which is designated in technical language as supply air, to a desired temperature and a desired humidity, wherein moisture and heat are exchanged with the exhaust air to be removed from the room.
BACKGROUND OF THE INVENTIONKnown from U.S. Pat. No. 6,178,966 is a dehumidifying device, in which fresh outside air to be supplied to a room and exhaust air to be removed from the room are passed through two cavities separated by a water-vapor-permeable membrane in order to transfer both moisture and also heat between the two air streams. Known from EP 1521040 and EP 1748260 are devices in which the outside air and the exhaust air are passed through two separate humidity exchangers, wherein a third intermediary air stream transports moisture from one humidity exchanger to the other humidity exchanger. The third air stream makes it possible to regulate the moisture exchange. These devices are used in winter to transfer moisture and heat contained in the exhaust air to the outside air to be prepared and in summer to transfer cold contained in the exhaust air to the outside air to be prepared and moisture contained in the outside air to be prepared to the exhaust air in order to bring, with the lowest possible energy, the outside air to a desired temperature and a desired humidity, which is perceived as pleasant by persons residing in the room.
BRIEF DESCRIPTION OF THE INVENTIONIt is the object of the invention to improve the preparation of the supply air.
The said object is solved according to the invention by the features of claims 1 and 6. Advantageous embodiments are obtained from the dependent claims.
The invention relates to a method for the preparation of supply air to a desired temperature and a desired humidity, wherein the supply air comprises prepared outside air and a portion of prepared exhaust air=prepared circulating air, and wherein moisture and heat are exchanged between the outside air and the exhaust air. The method comprises the steps:
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- making outside air flow as a first air stream through a first line and making a first portion of exhaust air coming from the room as a second air stream flow through a second line, wherein moisture is exchanged between the first air stream and the second air stream by means of a device for exchanging humidity, e.g., by means of a single humidity exchanger or by means of coupled humidity exchangers, e.g. by means of two humidity exchangers coupled through a closed air circuit or liquid circuit,
- condensing, by means of a dehumidifying and cooling device, moisture in the form of water from the first air stream and/or from the second air stream and/or inside the device for exchanging humidity, and
- making a second portion of the exhaust air flow as a third air stream through another line comprising another dehumidifying and cooling device, and returning said second portion back to the room, wherein moisture is condensed from the third air stream in the form of water in the other dehumidifying and cooling device.
In this context, the third air stream is designated in technical terminology as circulating air.
The dehumidification and cooling of the air stream flowing through one of the necessary dehumidifying and cooling devices is preferably accomplished by means of Peltier elements.
The dehumidification and cooling of the air stream flowing through one such dehumidifying and cooling device can alternatively take place by condensing this air stream by means of a compressor, whereby the air stream is heated to a temperature above the ambient temperature so that the air stream can release heat to the surroundings, and by relaxing the condensed air stream by means of a turbine, wherein the condensed air stream is cooled to a temperature below the dew point so that moisture is separated as water.
The dehumidification and cooling of the air stream flowing through such a dehumidifying and cooling device can take place according to a further alternative, whereby the second air stream is condensed by means of a compressor and is separated into a warm and a cold air stream by means of a vortex tube, wherein the temperature of the cold air stream lies below the dew point so that moisture is separated as water.
The invention relates on the other hand to a device suitable for carrying out the method according to the invention. Such a device comprises
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- a first line having an inlet via which outside air can be drawn in and an outlet via which supply air can be delivered to the room,
- a second line having an inlet via which exhaust air can be drawn in and an outlet via which outgoing air can be released to the surroundings,
- a device for exchanging humidity between a first air stream flowing in the first line and a second air stream flowing in the second line,
- a dehumidifying and cooling device, which is disposed either in the first line or in the second line or inside said device for exchanging humidity between the first and the second air stream, and
- another line having an inlet to which exhaust air can be supplied from the room, and an outlet which opens into the room or into the first line upstream of the outlet thereof, and
- another dehumidifying and cooling device, which is disposed in the other line.
The device advantageously comprises another line or other lines through which outside air can be passed to one or both dehumidifying and cooling devices and then back (as outgoing air) to the surroundings, in order to remove heat accumulating in the corresponding dehumidifying and cooling device. If necessary, these lines contain a separate fan.
The device for exchanging humidity between the first air stream flowing through the first line and the second air stream flowing through the second line is, for example, a single humidity exchanger, advantageously an air-air humidity exchanger, which has two cavities which are separated by a water-vapor-permeable membrane, wherein the two air streams can flow through the two cavities. However, it can also comprise a first and a second humidity exchanger, wherein the first humidity exchanger comprises a first cavity disposed in the first line, which is separated from a second cavity by a water-vapor-permeable membrane, wherein the second humidity exchanger comprises a third cavity disposed in the second line, which is separated from a fourth cavity by a water-vapor-permeable membrane, and wherein the second and the fourth cavity are disposed in a closed air circuit in which an air stream can circulate or in a closed liquid circuit. In this case, a dehumidifying and cooling device can be disposed in this closed air circuit or liquid circuit.
A water-vapor-permeable membrane is to be understood as any structure which is permeable for water molecules but not for air.
The invention is explained in detail hereinafter with reference to exemplary embodiments and with reference to the drawing. The figures are schematic and are not drawn to scale.
In the first exemplary embodiment shown in
In the second exemplary embodiment shown in
In the exemplary embodiments shown in
The first line 20 and the second line 21 are a part of the device, as shown in the figures, on the other hand they are connected to the surroundings or the room by means of additional external lines.
The devices according to
According to the invention, in all the exemplary embodiments, as illustrated for the exemplary embodiment in
According to the invention, such a circulating air stream is also provided in the exemplary embodiments according to
A plurality of fans are required for conveying the various air streams. The number of the fans and their arrangement inside the device 1 can vary according to the specific design. The devices 1 presented are suitable for carrying out the method according to the invention. They are to be understood as exemplary embodiments which can be modified within the scope of the technical knowledge of a person skilled in the art.
The humidity exchangers shown in
The devices 1 described are switchable between two operating modes, which are designated as winter operation and summer operation. These two operating modes are now explained in detail.
Winter OperationThe device 1 transfers moisture and heat contained in the exhaust air to the outside air. The first fan 6 conveys outside air into the room and the second fan 7 conveys exhaust air out from the room. The first fan 6 can be disposed anywhere in the first line 20, the second fan 7 can be disposed anywhere in the second line 21. The third fan 23 circulates the air stream in the closed air circuit 22. The dehumidifying and cooling device 19 is switched off, i.e. the air flows through the dehumidifying and cooling device 19 without releasing moisture or heat.
Summer OperationThe device 1 transfers a portion of the moisture contained in the outside air to the exhaust air and transfers a portion of the heat of the outside air to the exhaust air, i.e. the cooler exhaust air is used to cool the warmer outside air. The transfer of the moisture from the outside air to the exhaust air is accomplished by means of the two humidity exchangers 11 and 15 which are interconnected via the closed air circuit 22. Since the exhaust air cannot absorb as much moisture as is necessary, in the exemplary embodiment according to
The first fan 6 conveys outside air into the room and the second fan 7 conveys exhaust air out from the room. The dehumidifying and cooling device 19 is operating so that the air at the outlet of the dehumidifying and cooling device 19 is drier and cooler than the air at the inlet of the dehumidifying and cooling device 19. Air circulates in the closed air circuit 22, which, depending on the design of the dehumidifying and cooling device 19, is made to flow either by the third fan 23 or by the dehumidifying and cooling device 19.
In addition, that portion of the exhaust air which flows as circulating air through the fourth line 32, is cooled and/or dehumidified by means of the dehumidifying and cooling device 33 and then returned to the room. The circulating air and the outside air are prepared so that together they supply air of the desired temperature and humidity to the room.
In the example shown in
A particularly advantageous embodiment is shown in
In winter operation, the dehumidifying and cooling device 19 is usually not operating since the outside air is relatively dry and does not need to be dehumidified. The Peltier elements 39 provided in this example can, however, be used to heat the air stream flowing through the dehumidifying and cooling device 19. The current flowing through the Peltier elements 39 then flows in the reverse direction so that the wall 40 is now heated and the wall 41 is cooled.
Example 2In this example shown in
In the example shown in
Claims
1. Method for the preparation of supply air to be supplied to a room to a desired temperature and a desired humidity, comprising the steps:
- making outside air flow as a first air stream through a first line (20) and making a first portion of exhaust air coming from the room flow as a second air stream through a second line (21), wherein moisture is exchanged between the first air stream and the second air stream by means of a device for exchanging humidity,
- condensing, by means of a dehumidifying and cooling device (19), moisture in the form of water from the first air stream and/or from the second air stream and/or inside the device for exchanging humidity, and
- making a second portion of the exhaust air flow as a third air stream through another line (32) comprising another dehumidifying and cooling device (33) and returning said second portion back to the room, wherein in the other dehumidifying and cooling device (33) moisture is condensed from the third air stream in the form of water.
2. Method according to claim 1, characterized in that the dehumidification and cooling of the air stream flowing through the dehumidifying and cooling device (19) and/or through the other dehumidifying and cooling device (33) is accomplished by means of at least one Peltier element (39).
3. Method according to claim 1, characterized in that the dehumidification and cooling of the air stream flowing through the dehumidifying and cooling device (19) and/or through the other dehumidifying and cooling device (33) takes place through the steps:
- condensing the air stream by means of a compressor (46), whereby the air stream is heated,
- passing an outside air stream through a heat exchanger and releasing heat of the condensed air stream to this outside air stream by means of the heat exchanger, and
- relaxing the condensed air stream by means of a turbine (48), whereby the condensed air stream is cooled to a temperature below the dew point so that moisture is separated as water.
4. Method according to claim 1, characterized in that the dehumidification and cooling of the air stream flowing through the dehumidifying and cooling device (19) and/or through the other dehumidifying and cooling device (33) takes place in that this air stream is condensed by means of a compressor (46) and is separated into a warm and a cold air stream by means of a vortex tube (53), wherein the temperature of the cold air stream lies below the dew point so that moisture is separated as water.
5. Method according to any of claims 1 to 4, characterized in that the exchange of moisture in said device for exchanging humidity takes place by means of at least one air-air humidity exchanger.
6. Device for the preparation of supply air to be supplied to a room to a desired temperature and a desired humidity, comprising:
- a first line (20) having an inlet (2) via which outside air can be drawn in and an outlet (3) via which supply air can be delivered to the room,
- a second line (21) having an inlet (4) via which exhaust air can be drawn in from the room and an outlet (5) via which outgoing air can be released to the surroundings,
- a device for exchanging humidity between a first air stream flowing in the first line (20) and a second air stream flowing in the second line (21),
- a first dehumidifying and cooling device (19), which is disposed either in the first line (20) or in the second line (21) or inside the said device for exchanging humidity,
- another line (32) having an inlet to which exhaust air can be supplied from the room, and an outlet which opens into the room or into the first line (20) upstream of the outlet (3) thereof, and
- another dehumidifying and cooling device (33), which is disposed in the other line (32).
7. Device according to claim 6, characterized by another line (26) through which outside air can be passed to the dehumidifying and cooling device (19) and/or to the other dehumidifying and cooling device (33) and then back to the surroundings, in order to remove heat accumulating in the corresponding dehumidifying and cooling device (19; 33).
8. Device according to claim 6 or 7, characterized in that at least one of the dehumidifying and cooling devices contains a Peltier element (39) in order to cool the temperature of the air flowing through the dehumidifying and cooling device below the dew point.
9. Device according to claim 6 or 7, characterized in that at least one of the dehumidifying and cooling devices contains a compressor (46) in order to condense the air and a turbine (48) in order to relax the condensed air and thereby cool the temperature of the air to a temperature below the dew point.
10. Device according to claim 6 or 7, characterized in that at least one of the dehumidifying and cooling devices contains a compressor (46) and a vortex tube (53).
11. Device according to any of claims 6 to 10, characterized in that the device for exchanging humidity comprises at least one air-air humidity exchanger, which has two cavities (29, 30) which are separated by a water-vapor-permeable membrane (31).
Type: Application
Filed: Jul 8, 2009
Publication Date: Aug 4, 2011
Applicant: MENTUS HODING AG (Cham)
Inventors: Reto Holzner (Zurich), Gustav Hans Weber (Freienstein), Urs A. Weidmann (Zug)
Application Number: 13/054,771
International Classification: F24F 3/147 (20060101);