Air conditioner

Abstract

Disclosed is an air conditioner, including an air compressor intended to compress the air to cool, an air-liquid thermal exchanger designed to transfer heat from the compressed air to a liquid placed in a tank, an air-to-air thermal exchanger designed to further lower the temperature of the air to be cooled which, at this stage, is still kept in the compressed air state, a compressed air engine to provide an expansion of the compressed air, which naturally lowers its temperature and provides cooled air, and an envelope, with good thermal insulation properties and intended to contain all the constituent elements of the air conditioner; it will then not be necessary to provide for a hot air evacuation as on most air conditioners known in the state of the art.

Claims

1. An air conditioner, comprising: an air compressor that compresses air to be cooled; an engine that drives said air compressor; a liquid tank containing an air-liquid heat exchanger in contact with a liquid and connected to an outlet of the air compressor by a first duct; an air-to-air heat exchanger connected to said air-liquid heat exchanger by a second duct; a compressed air engine connected to an outlet of the air-to-air heat exchanger by a third duct; and a thermally insulated housing configured to contain at least the air compressor, the liquid tank, the air-to-air heat exchanger, and the compressed air engine, and having an opening allowing introduction of air that supplies the air compressor, wherein the first, second and third ducts are configured to withstand pressure provided by the air compressor and configured to allow passage of compressed air with a low pressure drop, wherein said air-liquid heat exchanger is configured to transfer heat from the air to be cooled compressed by the air compressor to the liquid located in said liquid tank, and configured to allow passage of compressed air with a low pressure drop, wherein said air-to-air heat exchanger is configured to further lower the temperature of compressed air at an outlet of the air-to-liquid heat exchanger, and configured to allow passage of compressed air with a low pressure drop, the air that cools said air-to-air heat exchanger being ambient air, wherein said compressed air engine provides an expansion of compressed air recovered at the outlet of the air-to-air heat exchanger, said expansion lowering the temperature of the air and providing cooled air while producing reusable mechanical energy, and wherein a motor shaft of said compressed air engine is connected to a drive shaft of the air compressor by a mechanical connection for recovering mechanical energy provided by the compressed air engine.

2. The air conditioner according to claim 1, further comprising: a steam engine; a fourth duct connecting said steam engine to said liquid tank, the liquid tank being configured to allow an increase in a pressure of the liquid contained therein and thus allow boiling of said liquid, while said steam engine causes a lowering of a temperature and pressure of steam that passes through the steam engine; a vapor-air heat exchanger; a fifth duct connecting an outlet of the steam engine to the vapor-air heat exchanger that allows condensation of steam and to return to liquid state, cooling air used by the vapor-air heat exchanger being derived from the ambient air; a sixth duct connecting the opening in the housing to the vapor-air heat exchanger in order to lower the temperature of the steam; a seventh duct connecting the opening in the housing to the air-to-air heat exchanger to preheat air absorbed by the air compressor located inside said housing, while lowering the temperature of the compressed air at the outlet of the air-to-liquid heat exchanger; a liquid compressor; an eighth duct connecting an outlet of the vapor-air heat exchanger to said liquid compressor; a ninth duct connecting said liquid compressor to said liquid tank, said liquid compressor reintroducing liquid obtained by condensation of the vapor which takes place in the vapor-air heat exchanger to the liquid tank which is then under pressure due to the boiling of the liquid therein; and an engine shaft of said steam engine mechanically connected to the drive shaft of the air compressor and a drive shaft of the compressed air engine.

3. The air conditioner according to claim 2, wherein said air conditioner is configured for driving an electricity generator that recovers, by a mechanical connection, mechanical energy returned by the steam engine and the compressed air engine during operation phases of the air conditioner where a sum of combined mechanical energies provided by the steam engine and the compressed air engine becomes greater than a mechanical energy required to drive the air compressor so that the air conditioner supplies electrical energy to other electrical appliances or returns the electrical energy to an electrical supply network.

4. The air conditioner according to claim 3, wherein the motor to drive the air compressor is an electric motor.

5. The air conditioner according to claim 4, wherein the electricity generator is the electric motor used to drive the air compressor.

6. The air conditioner according to claim 5, wherein said steam engine is a vane motor type.

7. The air conditioner according to claim 5, wherein said air compressor is an air vane compressor.

8. The air conditioner according to claim 5, wherein said compressed air engine is an air vane motor.

9. A set, comprising: an electricity generator; and an air conditioner according to claim 4 and adapted to drive the electricity generator.

10. The air conditioner according to claim 3, wherein said air compressor is an air vane compressor.

11. The air conditioner according to claim 3, wherein said compressed air engine is an air vane motor.

12. The air conditioner according to claim 2, wherein said steam engine is a vane motor type.

13. The air conditioner according to claim 2, further comprising: a second housing that surrounds the first housing and provides a space for air circulation between the housing and the second housing, said second housing having an opening that allows introduction of the ambient air to circulate between the housing and the second housing before entering the housing.

14. The air conditioner according to claim 2, wherein said air compressor is an air vane compressor.

15. The air conditioner according to claim 2, wherein said compressed air engine is an air vane motor.

16. The air conditioner according to claim 1, further comprising: a second housing that surrounds the housing and provides a space for air circulation between the housing and the second housing, said second housing having an opening that allows introduction of the ambient air to circulate between the housing and the second housing before entering the housing.

17. The air conditioner according to claim 16, wherein said air compressor is an air vane compressor.

18. The air conditioner according to claim 16, wherein said compressed air engine is an air vane motor.

19. The air conditioner according to claim 1, wherein said air compressor is an air vane compressor.

20. The air conditioner according to claim 1, wherein said compressed air engine is an air vane motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other purposes and advantages of the present invention will appear in the description that follows, relating to embodiments of the device proposed by the invention, by way of non-limiting examples and whose understanding will be made easier by referring to the attached drawings, which constitute schematic representations of the air conditioner proposed by the invention:

(2) FIG. 1: representation of the air conditioner consisting of an air compressor (1), an air-liquid heat exchanger (3), an air-to-air heat exchanger (5) and a compressed air engine (7).

(3) FIG. 2: representation of the air conditioner described above with the variant of the liquid tank (9) allowing a boiling of said liquid and the production of steam used to power a steam engine (11) which will contribute to drive of the air compressor (1).

(4) FIG. 3: representation of the air conditioner described above with the housing (17) intended to confine the constituent elements of it.

(5) FIG. 4: representation of the air conditioner described above with a variant proposing a double housing consisting of a first housing (17) surrounding the constituent elements of the air conditioner and a second housing (20) surrounding the first housing (17).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) The example of an embodiment of the air conditioner proposed by the present invention consists of (FIG. 1): an air compressor (1) intended to compress the air to be cooled; said air compressor (1) will be of the “vane” type well known in the state of the art, for the needs of this example of an embodiment, without this constituting any limitation in the use of other types of compressors also known in the state of the art; an air-liquid heat exchanger (3) known in the state of the art and intended to transfer the heat from the air thus compressed to a liquid placed in a liquid tank (9); an air-to-air heat exchanger (5) known in the state of the art and intended to further lower the temperature of the compressed air at the outlet of the air-liquid exchanger (3) above; a compressed air engine (7), known in the state of the art, which will have the function of obtaining an expansion of the compressed air with a natural lowering of its temperature, which is the purpose sought for the air conditioner proposed by the invention, while allowing to recover a reusable mechanical energy to contribute to the drive of the air compressor (1), remarkable for the fact that: said air compressor (1) will be driven mechanically by an electric motor or by any other type of motor known in the state of the art, not shown in the attached figure; the pressure delivered by the air compressor (1) may be of the order of ten bars for the needs of this non-limiting example, so as to raise the temperature of the air thus compressed to a value significantly higher than 100° C. In this way, a heat transfer can be carried out through the air-liquid heat exchanger (3), from the compressed air to the liquid, which will consist of water in this example, with the effect of a possible boiling of this water. A duct (2) capable of withstanding the pressure supplied by the air compressor (1) will be provided between said air compressor (1) and the air-liquid heat exchanger (3). The duct (2) and the air-liquid heat exchanger (3) will be sized in such a way as to allow the passage of compressed air with a low pressure drop, which the one skilled in the art will be able to achieve easily, so that the pressure of the compressed air remains practically constant and equal to the pressure value provided by the air compressor (1). said air-to-air heat exchanger (5), of design known in the state of the art, is arranged in series with the air-liquid heat exchanger (3) described above, to which it is connected by a duct (4) having characteristics similar to the duct (2) described above. The air used for cooling said air-to-air heat exchanger (5) will simply be the ambient air in which the air conditioner object of the invention is located. In addition, the said air-to-air heat exchanger (5) will be sized in such a way as to allow the passage of compressed air with a low pressure drop, which the one skilled in the art will be able to achieve easily, so that the pressure of the compressed air remains practically constant, as in the case of the air-liquid heat exchanger (3). said compressed air engine (7) shall consist simply of a vane air compressor mounted so that the circulation of the air flow is in the opposite direction of the direction usually used for operation in air compressor mode; this arrangement makes it possible to expand the compressed air in the air compressor and consequently allows to recover mechanical energy, which corresponds to the operation of an engine. This provision constitutes a preferential choice of an embodiment, without this being any limitation in the use of other types of compressed air engines also known in the state of the art; said compressed air engine (7) will use the compressed air recovered at the outlet of the air-to-air heat exchanger (5) described above, to which it is connected by a duct (6), having characteristics similar to those of the duct (2) and the duct (4). The function of said compressed air engine (7) being to expand the compressed air brought by the duct (6) so as to lower its temperature significantly and evacuate to the outside of the air conditioner the expanded air thus cooled, via a duct (8) connected to the air outlet of the compressed air engine (7); in addition, the mechanical work provided by the compressed air engine (7) will be partly transmitted to the air compressor (1). For this purpose, it is provided a mechanical connection between the motor shaft of the compressed air engine (7) and the drive shaft of the air compressor (1), of the transmission belt type, chain, gears, transmission shaft, or any other mechanical connection, well known in the state of the art and not shown in the figure attached here. said liquid tank (9) in which the air-liquid heat exchanger (3) described above is located will be intended to recover the enthalpy—or heat—from the compressed air at the outlet of the air compressor (1). Said liquid being constituted by water in this example and contained in said liquid tank (9) will naturally see its temperature increase during the operation of the air conditioner. When the temperature of this water becomes too high, in the vicinity of 100° C., it will be necessary to replace it with cooler water. To avoid this water replacement operation, it will be enough to connect the liquid tank (9) to a water circuit which is continuously renewed or that directs the heated water to a hot water tank. These solutions will not be described here because they can be easily implemented by the one skilled in the art and also they have the disadvantage of requiring hydraulic connections between the air conditioner and the water pipes located nearby. a variant of the liquid tank (9) (FIG. 2), consists in designing it to allow an increase in the pressure of the liquid it contains and thus allow the boiling of said liquid. In this configuration, the liquid tank (9) will be able to contain boiling water as well as part of this water in the vapor phase. A duct (10) will direct water in the vapor phase to a steam engine (11) of any type known in the state of the art. For the purposes of the example of a preferred embodiment, said steam engine (11) will be constituted as the compressed air engine (7), and will be of the “vane” type. The steam recovered downstream of the steam engine (11), of lower temperature and pressure than upstream of the steam engine (11), will be directed by means of a duct (12) to a vapor-air heat exchanger (13) which will allow the condensation of said steam and a return to the liquid state. The cooling air used by the vapor-air heat exchanger (13) will simply come from the ambient air in which the said air conditioner is located. A liquid compressor (15) connected to the outlet of the vapor-air heat exchanger (13) by a duct (14), and connected to the liquid tank (9) by a duct (16), will make it possible to reintroduce the water obtained by condensation inside the vapor-air heat exchanger (13) to the liquid tank (9) which is then under pressure due to the boiling of the water there. Said liquid compressor (15) will be driven by an electric motor or by one or more of the other rotating elements in said air conditioner: air compressor (1), compressed air engine (7), steam engine (11). The engine shaft of the said steam engine (11) shall be mechanically connected to the engine shafts of the air compressor (1) and the compressed air engine (7) described above. The mechanical connection not described here may be of any kind known in the state of the art, such as a belt, a chain, gears or simply a transmission shaft common to the three elements concerned above, which constitutes a preferential solution because of its easy implementation. This arrangement will make it possible to recover in the form of mechanical work, part of the enthalpy that the compressed air will have lost in the air-liquid heat exchanger (3). a housing (17) (FIG. 3), having good thermal insulation properties is intended to constitute an enclosure containing all the constituent elements of the air conditioner described above. This housing (17) has an opening allowing the introduction of air that will be used to supply the air compressor (1) described above. The flow of air entering the housing (17) will be partly directed to the air-to-air heat exchanger (5) by means of a duct (19) and partly to the vapor-air heat exchanger (13) by means of a duct (18). The purpose of that provision is to confine all the constituent elements of the air conditioner to an almost adiabatic environment, which has very little heat exchanges with the outside, thanks to the good thermal insulation provided by that housing (17). In this way, the ambient air in which the air conditioner is located will not be heated unnecessarily, and moreover, the air absorbed by the air compressor (1) which is located inside the said housing (17), will be preheated by the heat exchanges produced by the air-to-air heat exchanger (5) and by the vapor-air heat exchanger (13) as well as by the heat losses of the other elements located in the housing (17), so that the enthalpy thus recovered by the air introduced into the air compressor (1) will be partly recovered by the air-liquid heat exchanger (3) described above. a variant of the housing constituting the enclosure containing all the constituent elements of the air conditioner described above will be to provide a double housing constituted as follows (FIG. 4): a first housing (17) contains all the constituent elements of the air conditioner as described above. This first housing (17) has an opening allowing the introduction of air that will be used to supply the air compressor (1) described above. A second housing (20) will surround the first housing (17), and will be arranged so that a space for air circulation (22) is provided between these two housings, so that said air circulation takes place with as much contact as possible with the first housing (17); the said second housing (20) will have an opening (21) allowing the introduction of the ambient air in which the air conditioner is located, so that the ambient air flow which will be introduced into the air conditioner first circulates between the first housing (17) and the second housing (20) before entering the said first housing (17). This arrangement makes it possible to use the ambient air circulating between the two housings described above as a thermal insulation between, on the one hand, the constituent elements of the air conditioner which are at a relatively high temperature and, on the other hand, the ambient air of the room where the said air conditioner is located, the temperature of which is sought to be lowered.

(7) More generally, the present invention provides an air conditioner, comprising an air compressor (1) for compressing the air to be cooled, an air-liquid heat exchanger (3) for transferring heat from the air thus compressed to a liquid placed in a liquid tank (9), an air-to-air heat exchanger (5) for further lowering the temperature of the air to be cooled which, at this stage, is still kept in the state of compressed air, a compressed air engine (7) to obtain an expansion of the compressed air, which naturally lowers its temperature and provides cooled air, while producing reusable mechanical energy to contribute to the drive of the air compressor (1), characterized by the fact that: said air compressor (1), of design known in the state of the art, is mechanically driven by an electric motor or by any other type of motor known in the state of the art; said air-liquid heat exchanger (3), of design known in the state of the art, is connected to the outlet of the air compressor (1) by a duct (2) capable of withstanding the pressure provided by the air compressor (1), said air-liquid heat exchanger (3) and said duct (2) being sized so as to allow the passage of compressed air with a low pressure drop; said air-to-air heat exchanger (5), of design known in the state of the art and intended to further lower the temperature of the compressed air at the outlet of the air-liquid heat exchanger (3), is connected to said air-liquid heat exchanger (3) by a duct (4) having characteristics similar to the duct (2), while said air-to-air heat exchanger (5) is sized so as to allow the passage of compressed air with a low pressure drop; moreover, the air used for cooling said air-to-air heat exchanger (5) is the ambient air in which the air conditioner object of the invention is located; said compressed air engine (7), of design known in the state of the art and using compressed air recovered at the outlet of the air-to-air heat exchanger (5), to which it is connected by a duct (6) with characteristics similar to those of the duct (2) and the duct (4), contributes to the drive of the air compressor (1) by a mechanical connection between the engine shaft of the said compressed air engine (7) and the drive shaft of the air compressor (1), said mechanical connection being of any type known in the state of the art; said liquid tank (9) in which the air-liquid heat exchanger (3) is located is intended to recover the enthalpy from the compressed air at the outlet of the air compressor (1); a housing (17), having good thermal insulation properties is intended to contain all the constituent elements of the air conditioner proposed by the invention, while an opening in said housing (17) allows the introduction of air used to supply the air compressor (1); moreover, the flow of air entering the housing (17) is partly directed to the air-to-air heat exchanger (5) by means of a duct (19) and partly directed to the vapor-air heat exchanger (13) by means of a duct (18);

(8) According to a particular arrangement of that air conditioner, which may be taken in combination with those defined above, said air conditioner shall be used as an electric generator during phases where the temperature of the liquid located in the liquid tank (9) is significantly higher than the boiling temperature of the said liquid under atmospheric pressure conditions, and that, consequently, the resulting vapor pressure is significantly higher than atmospheric pressure.