BE1021395B1 - AIR CONDITIONER - Google Patents

Abstract

The present invention relates to an air conditioning device comprising an air-conditioned primary air intake duct (1) connected to the inlet of a first venturi-type device, the suction of which communicates with a first air duct. secondary air intake (9), the outlet of the first venturi-type device communicating with the inlet of a second venturi-type device, the intake of which is connected to a second secondary air intake duct (11) comprising a main heat exchanger (8).

Description

air-conditioner

OBJECT OF THE INVENTION [0001] The present invention relates to an air conditioning device, and to an air conditioning method of a confined environment.

STATE OF THE ART [0002] The air conditioning devices integrated in the ceiling of confined rooms are well known. Among these devices, a first type relates to the static type of cold beams, in which the air passes through a cooled exchanger, the air flow being generated by simple convection.

A second type of cold beams is dynamic cold beams in which a flow of fresh air from outside the confined space is mixed with secondary air from the room to be air-conditioned. In this type of device, the primary air is injected at high pressure into nozzles, inducing a secondary air suction by venturi effect. This type of device has many advantages. A first advantage is that the injection of fresh air allows a renewal of the air of the confined environment. The primary fresh air can be further dried to prevent condensation. Finally, the secondary air passes through a cooled heat exchanger before mixing, which increases the cooling capacity of the complete device.

However, these dynamic cold beams have other disadvantages that the present invention will seek to reduce. Of these, this type of device is usually noisy. Indeed, for optimum operation, the ratio between the supply of primary fresh air and secondary air recirculation should be about 7: 1. However, to obtain such a ratio by simple venturi effect, the pressure of the primary air, and its speed in the nozzles induce a noise difficult to withstand continuously. Also, these dynamic beams generally operate with a secondary air / secondary air ratio lower than the optimum, generally between 2: 1 and 6: 1. This low ratio implies a renewal of air in the environment above what is necessary, implying an energy consumption higher than what is strictly necessary.

OBJECT OF THE INVENTION [0005] The present invention aims at proposing a dynamic cold-beam cooling device having a reduced noise while offering a ratio of primary air / secondary air (recirculated) improved.

According to certain preferred embodiments of the invention, it also aims to improve the thermal comfort associated with the use of the device of the invention. SUMMARY OF THE INVENTION [0007] The present invention relates to an air conditioning device comprising a primary air inlet duct (chamber) connected to the inlet of a first venturi type device (inductor ) whose suction communicates with a first duct (chamber) for secondary air intake, the outlet of the first venturi-type device communicating with the inlet of a second device venturi type (inductor) whose suction is connected to a second secondary air intake duct (chamber) comprising a first heat exchanger.

The output of this device communicates directly or indirectly with the room to be air-conditioned.

[0009] Preferably, the first device of the venturi type comprises a primary air inlet nozzle comprising a diameter restriction at its free end, said free end opening into a suction chamber communicating with the first duct. secondary air inlet, said suction chamber comprising an outlet port facing the outlet of said inlet nozzle, said outlet port communicating with the inlet of the second venturi type device.

Advantageously, the second device of the venturi type comprises a plate pierced with orifices said plate separating an inlet chamber communicating with the outlet of the first mixing device and a mixing chamber communicating with the second inlet duct of secondary air, said orifices producing, in use, a venturi effect sucking the secondary air.

Preferably, the device of the invention comprises a valve or adjustable valve for injecting primary air directly to the inlet of the second device venturi type, downstream of the first venturi device, so as to be able to regulate the total mixing ratio between primary and secondary air.

Advantageously, the first secondary air intake duct comprises a second heat exchanger allowing in use to cool the secondary air.

Preferably, the heat exchanger (s) comprise vertical fins, and a condensate removal device at the bottom thereof.

A second aspect of the invention relates to a facade, a facade element or an element allowing access to the facade of a building comprising an air conditioning device according to any one of the preceding claims.

Advantageously, the facade of the invention comprises two walls separated by a ventilation space, the first and second secondary air intake ducts communicating with said ventilation space.

The second wall may be of the curtain or helioscreen type, or, preferably, the facade will be the active facade type.

A third aspect of the invention relates to an air conditioning method of a confined space comprising the following steps: a. withdrawing outside air, called primary air, and bringing it to a predetermined pressure; b. injecting said primary air into a venturi-type device, sucking and mixing air from the confined space, called secondary air, to the primary air, the secondary air passing, before mixing, into a first heat exchanger regulated at a temperature setpoint thus obtaining a first air mixture; vs. injecting the first air mixture into a second suction-type venturi device and mixing secondary air to said first air mixture, the secondary air passing, before mixing, into a second controlled heat exchanger at a set temperature; d. reinject the air mixture obtained in the confined space.

According to preferred embodiments of the invention, the air conditioning method of the invention further comprises one or a suitable combination of several of the following characteristics: said predetermined pressure is between 100 and 1000 Pa, preferably between 300 and 300; and 500 Pa; The ratio between the intake of primary air and secondary air in the first mixing device is between 0.7 and 2.5, preferably between 0.9 and 1.5; The flow ratio between the admission of the first mixture of air and secondary air in the second mixing device is between 2 and 4; The pressure of the first air mixture at the inlet of the second venturi device is between 50 and 200 Pa, preferably between 70 and 150 Pa; The secondary air circulates in a ventilated space between two walls of an active facade before being admitted into the first and second mixing chambers; the primary air taken in step (a) is brought to a predetermined temperature; before being injected into said first venturi device.

Brief Description of the Figures [0019] Figure 1 shows a broken view of an example of an air conditioning device according to the invention.

Figure 2 shows a side view in section along the plane AA "of Figure 1.

Figure 3 shows a side view in section along the plane BB 'of Figure 1.

Figure 4 shows a side view in section along the plane BB 'of Figure 1, the device comprising a valve "bypass" in the open position.

DETAILED DESCRIPTION OF THE INVENTION [0023] The present invention relates to an air conditioning device 10 of the dynamic cold beam type comprising a double induction module for secondary air, allowing, in use, to increase the ratio between the primary air flow 18,22 outside injected into the room to be conditioned, and the recirculated secondary air flow 16,17. The use of two induction modules of the Venturi type, arranged in series, makes it possible to reduce the noise, without increasing the necessary primary air pressure, while making it possible to increase the secondary air flow rate for an air flow rate. given primary.

By venturi-type device or induction device is meant any type of device in which a first air flow is accelerated by a section restriction of the fluid path inducing suction of a second air flow. by venturi effect. It is typically a device of the ejector or eductor type, either in the form of nozzles, diaphragms, or more complex devices comprising an inlet nozzle, a suction chamber and an outlet nozzle. By inlet of a venturi device is meant the entry of the first air flow.

Preferably the first venturi device, in which is injected air conditioning 18 from an external air conditioning battery comprises an injection nozzle 3 comprising a restriction at its free end. This nozzle opens into a suction chamber 2 communicating with a secondary air duct 9 (from the room to be air-conditioned). The suction chamber 2 also comprises an outlet orifice 15 facing the outlet of the injection nozzle 3. This orifice 15 will advantageously be extended by a streamlined ejection nozzle, so as to reduce turbulence and the noise generated by these turbulence.

Preferably, the first venturi device is dimensioned so that the flow ratio between the primary air 18 and the air induced by the first venturi device is between 0.7 and 1.5.

The temperature of the primary air 18 will preferably be between 14 and 18 ° C depending on the cooling power required. This primary air 18 will also have a humidity controlled to reduce the relative humidity of the room, so as to avoid any condensation phenomenon. Finally, the pressure of the primary air 18 will preferably be between 300 and 500 Pa, ideally around 400 Pa.

The second induction device will preferably be in the form of a wall 14 (plate) separating a first mixing chamber 4 in which opens the outlet 15 of the first venturi device of a second mixing chamber 6 in which opens a second secondary air intake duct 11. This second intake duct comprises a main heat exchanger 8 for effectively cooling the secondary air flow 16 induced by the second venturi device.

The wall 14 will include orifices 5 communicating between the first mixing chamber 4 and the second mixing chamber 6. These orifices 5 will be either in the form of simple diaphragms or in the form of nozzles inducing an increase in the speed of air, and thereby a venturi effect sucking the secondary air 16 through the main heat exchanger 8.

The pressure in the first mixing chamber 4 is preferably between 50 and 100 Pa, so as to reduce the noise generated by the device.

The flow ratio between the secondary air inlet 16 of the second venturi device and the outlet 19 of the first induction device is preferably between 2 and 4, bringing the total ratio between primary air and air induced by both venturi devices to a value greater than about 4, preferably greater than 6, and even more preferably greater than 7.

Advantageously, a "by-pass" valve 20,21 between a primary air distribution pipe 12 and the first mixing chamber 4, so as to increase the primary air injection 22 (ratio air primary / secondary air), for example when an unusual number of occupants are in the room. Figure 4 shows the operation of the device when the valve 21 is in the open position. In this case, a primary air flow 22 is admitted directly into the inlet chamber 4. In this case, preferably, the first secondary air intake duct will comprise a non-return device (not shown), for example in the form of a valve preventing a reverse flow of primary air.

A secondary heat exchanger 7 may advantageously be placed on the fluid path of the secondary air flow 17 upstream of the suction of the first venturi type device. This secondary heat exchanger 7 makes it possible on the one hand to increase the total power of the device, and on the other hand to regulate the humidity of the mixture in the first mixing chamber 4.

Preferably, the set temperature of the heat exchangers 7.8 will be maintained at a temperature between 14 and 20 ° C, so as to avoid condensation while providing sufficient cooling power. This setpoint temperature will be adapted according to the power required and the relative humidity of the secondary air.

Preferably, the air conditioning module (device) of the invention is integrated in front, above the windows, so as to induce a secondary air flow in front of the hot zone induced by the glazing of the building. This hot zone can advantageously be optimized by the use of devices simulating an active facade, such as curtains or helioscreens.

Advantageously, the air conditioning module of the invention is integrated with an active facade comprising a ventilated space between two walls, the intake ducts 9, 11 of secondary air being connected to said ventilated space. In this case, the conditioned air circulation between the two walls makes it possible to cool the internal wall, and thereby improve the comfort of the air-conditioned room, the walls of the room having a lowered temperature, which improves the comfort.

The arrangement on the front allows the use of vertical exchangers, which allows a collection and easy evacuation of the possible condensation on the fins of these exchangers.

The integration of the air conditioning module of the invention in front also reduces congestion, the primary air ducts and cold water can easily be integrated into said facade, avoiding having to integrate the beams in the ceilings, posing difficulties of installation and maintenance.

The device of the invention may advantageously integrate one or more carbon filters. In addition, the internal surfaces of the mixing chambers and venturis may be covered with catalytic paint comprising Ag ions or titanium oxide photocatalytic paints allowing the use of UV light sources to reduce the volatile organic compounds present. in the room.

The primary fresh air can also be taken directly to the front by means of a fan, the humidity control is then directly along the heat exchangers, by means of condensate tray placed under the heat exchangers.

EXAMPLE [0041] An embodiment of a device 10 according to the invention is shown in FIGS. 1 to 4. This device is integrated into an active façade in which the air is heated by the action of the sun in a ventilated space. between 2 windows. The air in the ventilated space communicates with the room to be conditioned by the bottom of the active window, so as to increase the natural convection through the device, thus further improving the secondary air flow.

In this device, a distribution duct 12 placed in front, brings conditioned primary air. The air in this duct is maintained at a pressure of 410 Pa and a temperature of about 14 ° C. The humidity of this primary air is about 90%. This air is conditioned by means of a first centralized battery for the whole building. The energy consumption of this first battery, per air conditioning module is around 283W for an outside temperature of 32 ° C and a relative humidity of 50%.

This air-conditioned primary air 18 is fed through a distribution chamber 1 to a nozzle 3 opening into the first suction chamber 2. The air-conditioned primary air flow in each facade module is 25m3 / h.

The air-conditioned primary air flow at the outlet of the nozzle 3 sucks through an orifice 13 of the secondary air 17. This secondary air from the intake duct 9 passes through a heat exchanger 7 before The cooling water temperature in this exchanger is 12 ° C inlet and 14 ° C outlet. The power consumed by this battery is around 146W. The secondary air 17 comes from an active facade, and enters the heat exchanger at a temperature of 34 ° C and 36% relative humidity. The secondary air flow rate 17 in this first heat exchanger 7, induced by the primary air flow is 25m3 / h.

The mixture 19 of primary air 18 and secondary 17 induced by the first venturi, is injected into a chamber 4 defined by a wall 14 pierced with openings 5 opening on a second suction chamber 6. Air secondary 16 enters the second suction chamber 6 through a second heat exchanger 8. The secondary air sucked by the conduit 11 comes again from the active facade and has the same input characteristics as the intake air through the duct 9. The secondary air flow induced in this second venturi is about 150m3 / h.

Thus, at the outlet of the device, an air flow rate of 200m3 / h is obtained, for a primary air flow rate of 25m3 / h, ie a multiplicative factor of 8 (or a ratio of 7: 1). The air output in this example is 18 ° C, for an ambient temperature of 26 ° C. This air conditioning is ejected through the orifice 23.

A valve 20, 21 allows the need to bypass the first inductor (venturi), so as to increase the reducing the multiplicative factor of the device. In operation with the open valve 21, the primary air flow rate rises to 50m3 / h, while the secondary air flow induced in the second inductor remains constant at 150m3 / h, passing from a multiplicative factor of 8 to 4 .

Forcing the secondary air forcibly into the ventilated space of the active facade avoids an excessive increase in the temperature of the interior walls of the room, which improves the sensitive comfort of the occupants.

The two heat exchangers 7,8 being contiguous, in practice, we can use a single heat exchanger with a wall separating the two ducts. Nevertheless, it may be advantageous to regulate these two heat exchangers separately, so as to avoid any condensation in the first mixing chamber.

The module dimensions of the example are compatible with the dimensions of windows usually used in the building, in this case, in this example, the width of the second heat exchanger is 1m, and 25cm for the first heat exchanger . The height of the first and second heat exchangers is 29cm, while the total height of the module (including the distribution duct 12 of the primary air) is 60cm.

Claims (12)

1. Air conditioning device (10) comprising a primary air intake duct (1) connected to the inlet of a first venturi device whose suction communicates with a first intake duct secondary air outlet (9), the outlet of the first venturi type device communicating with the inlet of a second venturi type device whose suction is connected to a second secondary air intake duct (11) comprising a main heat exchanger (8), the first venturi type device comprising a primary air inlet nozzle (3) comprising a diameter restriction at its free end, said free end opening into a suction chamber (2 ) communicating with the first secondary air intake duct (9), said suction chamber (2) comprising an outlet orifice (15) facing the outlet of said inlet nozzle, said outlet orifice (15) ) communicating with the entrance of the second disp venturi type ositif, the second venturi type device comprising a plate (14) pierced with orifices (5), said plate separating an inlet chamber (4) communicating with the outlet (15) of the first mixing device and a chamber mixture (6) communicating with the second secondary air intake duct (11), said orifices (5) producing, in use, a venturi effect sucking the secondary air, the device being dimensioned so that, in use, the flow ratio between the admission of the first mixture of air and secondary air in the second mixing device is between 2 and 4. 2. An air conditioning device (10) according to claim 1 wherein the first secondary air intake duct (9) comprises a secondary heat exchanger (7). 3. An air conditioning device (10) according to any one of the preceding claims wherein the heat exchanger (s) comprises vertical fins, and a condensate removal device at the bottom thereof. 4. An air conditioning device (10) according to any one of the preceding claims, wherein an adjustable valve for injecting primary air directly to the inlet of the second venturi device, downstream of the first venturi device, in order to be able to regulate the total mixing ratio between the primary air and the secondary air. Facade comprising an air conditioning device (10) according to any one of the preceding claims. 6. Facade according to claim 7, comprising two walls separated by a ventilation space, the first and second secondary air intake ducts being connected to said ventilation space. 7. Air conditioning method of a confined space including the following steps: a. withdrawing outside air (18), called primary air, and bringing it to a predetermined pressure; b. injecting said primary air (18) in a venturi type device, sucking and mixing air from the confined space, said secondary air (17), to the primary air, the secondary air passing, before mixing, in a first heat exchanger (7) regulated at a set temperature thereby obtaining a first air mixture (19); vs. injecting the first air mixture (19) into a second suction-type venturi device and mixing secondary air (16) with said first air mixture (19), the secondary air passing, before mixing, into a second heat exchanger (8) regulated at a set temperature; d. reinjecting the air mixture obtained in the confined space characterized in that the flow ratio between the admission of the first mixture of air and secondary air in the second mixing device is between 2 and 4. 8. The method of claim 9 wherein said predetermined pressure is between 100 and 1000 Pa. 9. Method according to any one of claims 9 or 10 wherein the ratio between the intake of primary air and secondary air in the first mixing device is between 0.7 and 2.5. 10. Method according to any one of claims 9 to 12 wherein the pressure of the first air mixture at the inlet of the second venturi device is between 50 and 100 Pa. 11. Method according to any one of claims 9 to 13 wherein the secondary air circulates in a ventilated space between two walls of an active facade before being sucked through the heat exchangers (7,8). 12. Method according to any one of claims 9 to 14 wherein the primary air taken in step (a) is brought to a predetermined temperature before being injected into said first venturi type device.