WO1997005431A1

WO1997005431A1 - Air-conditioning device for rooms

Info

Publication number: WO1997005431A1
Application number: PCT/EP1995/003051
Authority: WO
Inventors: Heinrich Klemt
Original assignee: Wenzel, Herta
Priority date: 1995-07-31
Filing date: 1995-07-31
Publication date: 1997-02-13
Also published as: AU3254795A

Abstract

The invention concerns an air-conditioning device for rooms, said device comprising an air heat-exchanger (8) through which the air of the room flows in order to be treated. There is further provided a water heat-exchanger (6) to which water is fed from outside the room to be cooled, the water then being expelled from this room again. Disposed between the water heat-exchanger (6) and the air heat-exchanger (8) are thermoelectric elements (10) which, under the effect of an electric voltage, remove heat from the air flowing through the air heat-exchanger (8), this heat then being fed to the water flowing through the water heat-exchanger (6). The device preferably takes the form of a flat, cuboid unit covered by a natural stone plate, in particular a marble slab (2) which can support a heating element (4) which is used to heat the room via the marble slab (2) in cold weather.

Description

Device for air conditioning rooms

The present invention relates to a device for air conditioning rooms. The invention relates in particular, but not exclusively, to a device with which rooms can be both cooled and heated.

Devices for cooling rooms, usually referred to as air conditioning units or air conditioning systems, are known in the prior art in a large number of variations.

Stationary air conditioning systems are most commonly used, which are used centrally or decentrally and in which the air used for cooling is cooled via a piston compressor cooling circuit and supplied to the rooms. If air conditioning systems are arranged centrally, this means that a system for cooling several rooms is provided, considerable expenditure for ventilation ducts etc. to the individual rooms is required. Such central air conditioning systems can therefore only be used practically if they are already included in the planning when planning the new building. In addition, central air conditioning systems have the disadvantage that they are very complex and therefore also very expensive to design. Decentralized air conditioning systems of this type are e.g. B. built directly into the outer walls of the room to be cooled and also cool the air with a piston compressor refrigeration cycle. The disadvantage of these systems is, on the one hand, the relatively high expenditure on equipment and, on the other hand, the development of noise, which makes the operation of such systems such. B. usually excludes at night. The systems also have the disadvantage that they cannot generally be used to heat rooms.

In recent years, portable, usually mobile, air conditioners have become increasingly widespread. A piston-compressor refrigeration cycle is also used in these devices, the heat generated being dissipated via the air through a hose to the outside. The devices can also be used for heating in some designs. However, these devices have the disadvantage of a relatively high water consumption, which forces the user to fill in water regularly and, on the other hand, the quite high noise level.

The present invention has for its object to provide a device for air conditioning rooms, which avoids the disadvantages of the prior art shown above and which is also suitable for retrofitting.

This object is achieved by the subject matter of claim 1. Preferred developments of the invention are the subject of the dependent claims. The cooling device according to the invention has thermoelectric elements which, when a suitable electrical voltage is supplied, extract heat from the surroundings on a first surface and in turn emit them to the surroundings on a second surface. The thermoelectric elements thus cause heat transfer, for. B. from one surface of an element to the opposite surface. The elements can thus be used for both heating and cooling. Such thermoelectric elements, which are usually produced on a semiconductor basis, are known in the prior art and are mostly referred to as Peltier elements. For the sake of simplicity, the term Peltier element is used throughout in the following. However, it should be noted that the term Peltier element is in no way to be taken as a limitation and is intended to include all electrical elements that are capable of transferring heat from a first surface, which has a lower temperature, to a second surface, which has higher temperature to transport. Peltier elements can therefore not only be used for cooling, but also for heating in the same way.

The device according to the invention has an air heat exchanger device through which the ambient air flows and via which these Peltier elements extract the heat from the ambient air.

The device also has a water heat exchanger, via which these Peltier elements give off heat to the water flowing through the heat exchanger. This water is preferably fed to a heat exchanger which is arranged outside the space to be cooled. In a preferred embodiment of the invention, the air heat exchanger and the water heat exchanger are designed in the broad sense of a plate, so that the cooling device has the overall dimensions of a thicker plate. This thicker plate is preferably designed in the form of a cuboid, which is arranged in the space to be cooled such that two opposite side walls of the cuboid are parallel to the floor level of the space. In this case, a crossflow fan is preferably arranged on the lower side wall of the cuboid facing the floor, through which room air is drawn in and guided through the air heat exchanger. The cooled air exits at the top of the cuboid element. This design has the particular advantage that the volume of the air movement is very low, so that the operation of the cooling device is not perceived as disruptive.

The water heated in the heat exchanger can preferably be used to heat domestic water by means of a heat pump installed in a supply room, for example in a basement. In this way, the overall efficiency of the system is particularly favorable.

In a further preferred embodiment, the system is combined with a heating device. It is particularly preferred to use a heating device which works on the radiant heat principle and has a plate which is made of a material with low thermal conductivity, in particular natural stone, such as. B. marble or the like. In the following, this slab is called a marble slab for simplicity. However, it is to be understood that the term "marble" is not intended to be a limitation to this Material is to be understood, but that the term "marble" is intended to include any slab which is characterized by low thermal conductivity, for example slabs made of other natural stones, artificial stones and any other material with the desired thermal properties.

A heating foil is arranged on the back of this plate, as described, for example, in application WO 93/23969.

In this embodiment, the heating device and cooling device are combined to form a common component, the marble plate being arranged facing the room and the cooling device being concealed behind the marble plate.

This design, which is particularly preferred by the present invention, creates a cooling-heating device which is visually appealing, which can be easily installed in existing rooms and which provides both heating and cooling of the respective room with good efficiency. Due to the cross flow fan used, the system for cooling is very quiet, so that the system can be operated in summer without sacrificing comfort. In heating mode, the system works completely silently.

Further advantages, features and possible uses of the present invention result from the following description of an exemplary embodiment in connection with the drawing. In it show: 1 shows a cross section through an embodiment of the device according to the invention, here a cooling device is combined with a heating device, along the line II in Fig. 2;

Figure 2 is a front view of the embodiment of FIG. 1;

Figure 3 is a rear view of the embodiment of FIG. 1;

Figure 4 is a top view;

Figure 5 is a schematic representation of the arrangement of the

Peltier elements in the exemplary embodiment according to FIG. 1;

Figure 6 is a perspective view of a

Heat exchange blocks, as used in the embodiment shown in FIG. 1.

The shown as an embodiment

Air conditioning device is a combined heating and cooling device. However, it is expressly pointed out that the device can also be used without a heating device, otherwise it is a pure cooling device.

The heating-cooling device, designated overall by 1, has a marble slab 2, which is cuboid in shape and which faces the room when installed. The Marble slab 2 is additionally thermally insulated on the side edges by PU foam 3.

Attached to the marble slab is a heating element 4 which is sandwiched from a first plastic film facing the marble slab, a heating device which e.g. are designed as flat, meandering electrical conductor tracks with corresponding electrical resistance, a second plastic film or plate placed thereon and possibly a metal film arranged thereon for reflecting the heat radiation. With regard to the structure of the heating element, reference is made to the description of W093 / 23969, which is thus made the subject of the disclosure of this application.

An insulating layer 5, for example made of polyurethane foam, is arranged on the heating element 4 and isolates the heating element from a water heat exchanger 6. The water heat exchanger is, as can be seen in FIG. 5, constructed as a flat cuboid and is flowed through by water which is supplied and discharged through a water connection 7. A large number of Peltier elements 10 are arranged on the water heat exchanger in such a way that their heat-emitting surface is in direct contact with the water heat exchanger. The heat-absorbing surface, ie the cool surface, is in contact with an air heat exchanger 8, which is also constructed as a flat cuboid with regard to its outer dimensions. Between the air heat exchanger and water heat exchanger is a z. B. also made of polyurethane foam insulating layer 12 is provided. The surface 6a of the water heat exchanger is thus arranged adjacent to the surface 8a of the air heat exchanger. The water heat exchanger 6 is made up of individual

Heat exchanger blocks 20 assembled, one of which is shown in FIG. 6. The heat exchanger blocks 20 are cuboidal and consist of a good heat-conducting material, preferably aluminum or copper. In this metal block two bores 21, 22 are arranged, which run parallel to the longer edge of the heat exchanger block. In the exemplary embodiment, the dimensions of the heat exchanger block are approx. 8x6 cm.

A Peltier element 10 is arranged on the heat exchanger block 20 and, as stated, consists of a semiconductor with thermoelectric properties. The dimensions of the Peltier element are approx. 4x4 cm in the exemplary embodiment, however, as with the heat exchanger block, different dimensions can be used.

As shown in FIG. 5, the heat exchanger blocks 20 are assembled to form the heat exchanger 6, the bores 21, 22 being designed in such a way that the water flows through all the blocks 20. In the exemplary embodiment, a matrix of six heat exchanger blocks arranged side by side and three one above the other, i.e. a total of 18 heat exchanger blocks and 18 Peltier elements used.

The Peltier elements are suitably electrically connected to one another and to the power supply 30. Furthermore, the water guides are designed overall so that the supplied water is fed through a water collecting line 26, enters the two bores of the heat exchanger blocks from below and via one Water collecting line 25 is again led out of the heat exchanger 6 from above. The water collecting line 26 is arranged perpendicular to the bores 21, 22 at the lower section of the heat exchanger 6 and is connected to all corresponding bores 21 and 22.

This above-described modular construction of the heat exchanger by means of individual heat exchanger blocks has a number of advantages. Since a relatively large number of identical heat exchanger blocks are used, the manufacturing costs per block are reduced. Furthermore, it is easily possible to replace a Peltier element in which the respective heat exchanger block is exchanged. Finally, the design allows the simple construction of cooling devices of different sizes in the modular system, since only additional heat exchanger blocks have to be provided in order to enlarge the heat exchanger area.

Room air is supplied to the air heat exchanger via an electrically operated cross-flow fan 15 arranged on its lower side wall and exits the air heat exchanger via an outlet grill 17.

A plurality of cooling fins 40 are provided in the air heat exchanger and are in contact with the Peltier elements with a side edge. The cooling fins are also made of a highly thermally conductive material, such as aluminum or copper or another metal, so that they assume a temperature that corresponds to the temperature of the Peltier elements on their (when used as a cooling device) colder side. As can be seen in FIG. 1, a ventilation grille 16 is arranged in front of the cross-flow fan 15 and lies in one plane with the marble slab 2. The ventilation grille 16 can be a simple ventilation grille, ie it only has slots or openings which prevent larger objects from entering the cross-flow fan and in particular prevent the cross-flow fan from being touched by hand during operation. However, a design of the grille 16 in connection with a filter mat is particularly preferred, which allows the sucked-in air to be filtered at the same time. The filter can be constructed as a simple dust removal filter, that is to say that it has an appropriate mesh size which is small enough to retain dust particles, but a germicidal filter can also be used, for example an active carbon filter.

3, the cross-flow fan comprises the largest part of the width of the cooling device, the length of the cross-flow fan essentially corresponding to the length of the heat exchanger 6, measured in a direction perpendicular to the bores 21, 22. This design has the advantage that there is a very large air inlet opening, which allows working with low air speeds.

As can further be seen from the design according to FIG. 1, the air is only slightly impeded by the deflection by 90 ° from the horizontal inflow to the vertical throughflow of the air heat exchanger. All edges are rounded and the available cross-section is relatively large. As a result, the air speed can also be relative within the air heat exchanger kept low and thus the speed of the cross-flow fan and its power consumption are reduced. Overall, these measures contribute to the fact that the ventilation is unusually quiet and can usually no longer be perceived in a room.

In an experiment it was found that the volume was only 35 dB at a blower output of 550 m / h.

In the air heat exchanger, parallel to the cross-flow fan, water collecting channels 17 are provided, the condensed water, which runs downward on the inner surfaces of the heat exchanger, is collected. Since the flow direction of the water caused by gravity is opposite to the flow direction of the air, a large part of the water is carried along by the air flow and enters the room. This prevents the dehumidification of the cooled air, which is often perceived as uncomfortable.

As can be seen from FIG. 3, a first switch box 30 is arranged on the rear wall of the device, which, as stated, contains the power supply for the Peltier elements and the cross-flow fan, and a second switch box 31, which is used for control. In the first switch box 30, a transformer and a rectifier are provided, which have an output voltage of e.g. 28 V for the operation of the Peltier elements. Of course, other supply voltages are also possible and conceivable.

The switch box 31 contains switches 32 accessible from above, with which the device is switched on and off and the desired one Temperature can be adjusted. Furthermore, the control box 31 contains a control device with which it is checked to what extent the room temperature deviates from the set target temperature and which, in conjunction with conventional control electronics, causes the heating device or the cooling device to be controlled in a corresponding manner in order to achieve the desired target temperature . The control box 31 is connected in a conventional manner via a line 33 to the power grid.

The function of this exemplary embodiment is now as follows:

The device is attached to an inner wall of the room to be cooled, with the marble slab facing the room. The device is connected to a water supply, through which the water is supplied at a temperature which is suitable for absorbing heat from the Peltier elements. Usually, the water circuit will be connected to a heat exchanger, which is arranged outside the room to be cooled. It is particularly advisable to use a suitable heat exchanger, e.g. to install in the basement of the building and use this heat exchanger to heat domestic water. But you can also e.g. Water from a swimming pool or the like use for cooling the Peltier elements. Since such heat exchangers are known in the prior art, the design is not discussed further here.

When operating as a cooling device, no current is supplied to the heating device and water is led through the water heat exchanger 6. The Peltier elements are supplied with direct current and are heated by the water heat exchanger facing side and cool down on the side facing the air heat exchanger. The cross-flow fan 15 draws air from the room and guides it through the air heat exchanger, which then emerges at the top parallel to the wall of the room. When the air flows through the air heat exchanger, it is cooled so that the exiting air is at a lower temperature than the entering air.

The cooling capacity can be regulated in different ways:

In a first variant, the control is carried out with two-point control, as is customary with heaters. This means that the cooling device as a whole switches off as soon as the desired temperature is reached and switches on again as soon as the setpoint is exceeded by a certain limit.

According to a second variant, the cooling is carried out at full power until the target temperature is reached, and the cooling power is then reduced by either reducing the supply voltage of the Peltier elements or switching off individual Peltier elements.

In this variant, it is also possible to use a divided cross-flow fan, ie a cross-flow fan that is, for example, only arranged over half of the area of the air heat exchanger. Although this increases the outlay on equipment, it has the advantage that, with reduced cooling capacity, only one of the two fans then present and, accordingly, only half of the fans Peltier elements is supplied, which improves the efficiency and the noise emission is further reduced.

It is also possible to regulate the speed of the cross-flow fan, which can be done in a particularly simple manner if it is also supplied with direct current.

If the device is required for heating, in a first embodiment variant the Peltier elements and the cross-flow fan 15 are not supplied with current, but instead the heating element 4 is supplied with current. The heating element 4 heats up and gives off the heat to the marble plate 2. A heat transfer to the water heat exchanger 6 is largely prevented by the metal foil placed on it, which covers the heating element towards the water heat exchanger, and by the applied insulation 5. The marble slab 2 heats up and emits the heat to the room through radiation. In this context, it should be pointed out that the radiant heat creates a particularly pleasant living climate and causes a pleasant feeling of warmth even with cooler outer walls. The all-round heat insulation 3, which covers the side edges of the marble slab, also has the effect that the heat radiation occurs practically exclusively towards the front in the direction of the room.

If the material for the slab is marble or another material with low thermal conductivity, such as some types of natural stone, artificial stone, cement, concrete, sand-lime brick, chamotte or the like. there is no risk of burns if the plate is touched briefly. According to a second variant of the device it can be provided that the heating of the room is supported with radiant heat by also switching on the Peltier elements in the heat recovery process. In this case, care must be taken to ensure that the water supplied is at a higher temperature than the temperature on the cool surface of the Peltier elements. The Peltier elements are then charged with the opposite polarity (compared to the cooling process) with direct current and have the effect that heat is extracted from the water in the water heat exchanger, which heat is supplied to the air in the air heat exchanger. In this embodiment, the cross-flow fan 15 is also kept in operation, so that warm air then flows into the room in addition to the radiant heat. The circuit is preferably selected so that this convective heat generation by the Peltier elements is only maintained until a predetermined room temperature is reached.

In a third variant of the exemplary embodiment described here, the heating element 4 is omitted. The device is then essentially only intended for cooling. However, as in the variant described above, the cooling process can also be reversed by operating the Peltier elements with reversed polarity, so that heat is transferred from the water heat exchanger to the air heat exchanger. In this case, the heat exchanger, which is arranged outside the space to be cooled or heated, serves to bring the water cooled by the Peltier elements back to a higher temperature. In the third embodiment variant described last, in which radiation heating by the heating element 4 is dispensed with, the marble slab can also be designed differently. There is then no longer a need to use a material with special thermal properties, but a material is preferably used that adapts to the decorative requirements of the room. For example, instead of the marble slab 2, a color coating can be applied to the insulation 4 to the water heat exchanger, a covering with wood, fabric, plastic or the like.

It should be emphasized, however, that regardless of this design variant, the device according to the invention has the overall advantage that it is designed to be extremely flat, so that it can be easily integrated into rooms. If a marble slab or other decorative surface is used, the device is not perceived as a technical device, but on the contrary contributes to the decorative design of the room. There is also the advantage that the device is extremely quiet in cooling mode and completely noiseless in heating mode, so that the disturbance in the room itself is reduced to a minimum.

Claims

claims

1. device for air conditioning rooms,

with an air heat exchanger (8) which has a first opening (16) through which air flows, which is extracted from the room to be cooled, and a second opening (17) through which the air is fed back into the room;

a water heat exchanger (6), to which water is supplied from a source outside the room to be cooled, which flows through this water heat exchanger and is led to a sink which is arranged outside the room to be cooled,

wherein this water heat exchanger (6) and this air heat exchanger (8) each have at least one surface (6a, 8a) which is adjacent to one another, and

at least one thermoelectric element (10) which is arranged between this at least one surface (6a) of the water heat exchanger (6) and this at least one surface (8a) of the air heat exchanger (8) in such a way that under the action of an electrical voltage applied to this thermoelectric Element is created, the heat flowing through the air heat exchanger is extracted, which is supplied to the water flowing through the water heat exchanger.

2. Device according to claim 1, characterized in that this air heat exchanger (8) essentially is constructed in the form of a plate, this at least one surface (8a) which is in contact with these thermoelectric elements (10) being one of the large surfaces of this plate.

3. Device according to claim 1, characterized in that this water heat exchanger (6) is constructed substantially plate-shaped, wherein this at least one surface (6a), which is in contact with these thermoelectric elements (10), is one of the large surfaces of this plate .

4. Apparatus according to claim 2 and claim 3, characterized in that a cover plate (2) is provided which covers the device at least on one of the sides with the larger area.

5. The device according to claim 4, characterized in that a sandwich-like structure is provided, wherein the individual layers are formed by this cover plate, which faces the room, a preferably arranged thereafter thermal insulation (12), the water heat exchanger (6) these thermoelectric elements (10) and this air heat exchanger, a further insulating layer (5) preferably being provided between the water heat exchanger and the air heat exchanger.

6. The device according to claim 4 or 5, characterized in that this cover plate (2) is a plate made of a material with low thermal conductivity.

7. The device according to claim 6, characterized in that this material of this plate with low thermal conductivity is selected from a group of materials containing marble, granite, natural stone, plastic, cement, plaster, concrete, limestone and the like ..

8. The device according to at least one of claims 6 or 7, characterized in that a plate-shaped heating element (4) is arranged between this plate of low thermal conductivity (2) and this heat insulation (12).

9. The device according to at least one of claims 2 to 8, characterized in that the device is designed overall plate-shaped, the larger surfaces of this plate form a rectangle, the lower horizontal edge is arranged substantially parallel to the floor of the room to be air-conditioned.

10. The device according to claim 9, characterized in that this air heat exchanger is connected to a cross-flow fan, the dimension of which corresponds essentially to the longitudinal dimension of this plate-shaped air heat exchanger.

11. The device according to claim 10, characterized in that this cross-flow fan has an air grille (16) which forms the air flow inlet and which is arranged substantially in one plane with this cover plate (2).

12. The device according to claim 9 and at least one of claims 10 or 11, characterized in that this cross-flow fan is arranged below this air heat exchanger (8) and this water heat exchanger (6).

13. The apparatus according to claim 11 or 12, characterized in that this cross-flow fan has a deflection device to deflect the air which enters horizontally through this air grille (16) in a vertical direction in which air flows through the air heat exchanger (8), wherein the air passage cross section essentially does not change during the deflection process and the side surfaces of the flow channel are rounded off in such a way that only a small flow resistance and only little flow noise arise.

14. The device according to at least one of claims 4 to 13, characterized in that the area of this cover plate (2) is larger than the larger area of this water heat exchanger and the larger area of this air heat exchanger and that on this plate adjacent to the water heat exchanger or to the air heat exchanger a control device is provided by which the function of the device is controlled.