FR2874421A1 - Conditioned air distributing installation`s fresh air supply regulating method for building, involves positively and/or negatively moderating fresh air in upstream of damper by heat exchange with part of air extracted from enclosed space - Google Patents

Abstract

The method involves providing a damper (6) to ensure a mixture of fresh and recycled air. A heating and/or cooling unit heats and/or cools the air mixture. A blowing unit (3) blows the air mixture after heating and/or cooling at an enclosed space to be conditioned. The fresh air in upstream of the damper is positively or negatively moderated by heat exchange with part of the air (5) extracted from the space. An independent claim is also included for an installation to distribute conditioned air within an enclosed space implementing a fresh air supply regulating method.

Description

METHOD FOR CONTROLLING THE NEW AIR SUPPLY OF A FACILITY

  AIR CONDITIONING OF AN ENCLOSURE AND INSTALLATION IMPLEMENTING SAID METHOD

  The invention relates to a method for regulating the fresh air supply of a conditioned air distribution installation, and more particularly to allow the fresh air thus introduced into a chamber to be tempered in a positive or negative manner. , which we want to condition the ambient air. It also relates to an installation of the type in question implementing such a method.

  For conditioned air supply is meant in the sense of the invention the various ventilation systems for either to cool or to heat the air to be treated.

  Such installations traditionally comprise a heating or cooling unit, at which an air supply terminates. This air, after being heated, or otherwise cooled, is then blown by a blowing unit within the enclosure to be conditioned. At least part of this air is made up of fresh air taken from outside said enclosure in order to meet standards imposing the admission of a determined quantity of fresh air, in particular for industrial applications. and / or commercial. In fresh air, we mean the air taken outside the enclosure to be conditioned and in order to ensure a renewal of the ambient air.

  However, another part of the treated air consists of recycled air from said enclosure.

  These two sources respectively of fresh air and recycled air traditionally end at a register, that is to say a set of adjustable flaps for fixing at the level of the mixture undergoing heating or cooling, the desired ratio of fresh air.

  The objective sought by the present invention is to recover at least some of the calories or the contrary frigories from recycled air, and transfer these calories or frigories to the fresh air and thus corollary allow the realization of an economy significant energy, especially when the temperature variation to be printed is important.

  For this purpose, the method of the invention, implemented to ensure the conditioning of an enclosure by means of an installation comprising: a supply of fresh air taken outside the chamber to be conditioned; a recycled air supply, taken from said enclosure to be conditioned; a controlled opening damper, at which the two previous supplies end, intended to ensure a mixture of a desired proportion of fresh air and recycled air; a unit for heating and / or cooling the air mixture coming from the register; a blowing unit of said mixture after heating and / or cooling at the enclosure to be conditioned; is to temper positive or negative fresh air upstream of said register by heat exchange with at least part of the air extracted from the enclosure to be conditioned.

  The installation of the type in question, implementing this method, comprises in fact upstream of said register an exchanger, for example of the plate type, at which the fresh air and part of the air extracted from the pregnant, without coming into contact with each other.

  In doing so, depending on the characteristics of the exchanger, and in addition of the difference between the respective temperatures of the fresh air and the recycled air, that is to say of the set temperature of the conditioning of the enclosure, it is possible to achieve a warming of the fresh air or on the contrary to its cooling, and therefore, to reduce the energy consumption of the heating or cooling unit located downstream of the controlled opening register .

  According to the invention, the heat exchanger and the exchange zone are integrated within a module that can be adapted to traditional or specific air conditioning installations, in particular those referred to as "roof". top .

  The manner in which the invention can be realized and the advantages which result therefrom will emerge more clearly from the exemplary embodiment which follows, given by way of indication and not limitation, in support of the appended figures.

  Figures 1 and 2 illustrate a schematic representation of the operating principle of an installation according to the prior art, respectively for a vertical connection and for a horizontal connection with the enclosure to be packaged.

  Figures 3 and 4 are figures similar to Figures 1 and 2 of the installation according to the invention implementing the claimed method.

  There is shown a conditioned air distribution installation according to the prior art in FIGS. 1 and 2, in the form of modules associated with each other. Conventionally, an enclosure may comprise a plurality of these modules, depending of course on its dimensions, the actual volume it contains and the desired efficiency of this installation.

  These modules are traditionally positioned on the roof of the enclosure, hence the traditional name of such an installation in English rooftop.

  One of these modules firstly comprises a feed zone (1) mixed with air both recycled (9) and fresh air (11), that is to say air taken outside the enclosure to be conditioned. This fresh air mixture (11) / air conditioning (9) is achieved by means of a register (6) providing such a mixture. This register is well known to those skilled in the art, and consists in particular of a set of flaps, each of said flaps being rotatably mounted relative to an axis, these different axes being parallel to each other. The respective opening or closing of the shutters makes it possible to adjust the fresh air (11) / recirculated air mixture according to the wishes of the user and in accordance with the standards in force.

  The mixture thus obtained is then heated or otherwise cooled at a heating or cooling unit (2), before being blown by a fan (3) within the enclosure to be conditioned. The arrow (4) represents the air thus blown within the enclosure and controlled by conventional temperature devices.

  As a corollary, part of the air (5) of the enclosure is recycled. To do this, it is sucked by means of a fan or extractor (7), conveying a portion (9) of the air thus recycled at the register (6), and evacuating the other portion (8) to the outside the enclosure, by an outlet (10). This evacuation of part of the air contained in the enclosure is dictated by the concern not to create excess pressure within it, inherent in the continuous introduction of fresh air (11).

  Figure 2 is based on a completely identical operating system, with the exception of the implementation of the modules. Indeed, if in Figure 1, the various modules are located on the roof of the enclosure, explaining the vertical paths of the air (4) introduced into the enclosure and extracted (5) out of it, on these modules are for example located at the lateral level with respect to the walls of the enclosure, explaining the horizontal paths of the respective air flows.

  The invention is more particularly described in relation with FIGS. 3 and 4.

  It is basically based on the same principle as previously described, except that it has an additional portion (12) upstream of the controlled opening register (6).

  Within this zone or part (12) is set up a plate heat exchanger (13), for example of the type marketed by the company DELTA AIR PLUS or the company HEATEX. In the example described, this exchanger is made of aluminum plates of 750 mm of raw aluminum with a thickness varying from 600 to 1675 mm depending on the dimensions of the caissons constituting the installation of the invention. The inter-plate pitch is 9 or 12 mm. In addition, each exchanger is equipped with an integrated bypass. Within this plate heat exchanger, and as symbolized, the heat exchange is carried out between the fresh air (11) and a portion (8) of the recycled air (5). The function of the bypass is, on the one hand, to cancel the exchange in the phases where the internal and external temperatures do not justify it (phase called under the British expression free-cooling: new air temperature lower than that of indoor air with cold demand on the air conditioner). On the other hand, it allows the exchanger to be defrosted by the hot air extracted at periodic intervals, when the fresh air of negative temperature induces through the plates the setting in ice of the humidity coming out of the building.

  If the described example uses a plate heat exchanger, the invention is able to operate in the same way by means of a wheel type exchanger. The exchange principle is similar to that previously described, except that the exchanger consists of a porous wheel rotating at the same time in the two air flows (fresh air and incoming fresh air) and installed in a box cloisonne separating the extracted air and the fresh air.

  The opening or outlet (10) of the module of the prior art, instead of communicating directly with the outside, communicates with this zone (12) to allow the transport of this recycled air at the level of the exchanger (13). ).

  In doing so, and as will be understood, when it is desired to heat the enclosure to be conditioned, and therefore the outside air or fresh air (11) is cooler or cold, it is partially tempered by a portion of the recycled air (5) at this exchanger (13). Therefore, the energy consumed at the unit (2) to heat the mixture from the register (6) is reduced.

  As a corollary, when it is desired to cool the enclosure to be conditioned, the outside or new air (11), thus a priori warmer, is partially cooled by a portion (8) of the recycled air (5), already at lower temperature due to its previous passage through the unit (2), again allowing to reduce the amount of energy of said cooling unit (2) to reach the set temperature.

  The laws of thermodynamics specify that the efficiency of this exchanger (13) is increased when the temperature variation between the fresh air (11) and the recycled air (5) is high.

  Advantageously, pressure sensors positioned upstream and downstream of the exchanger (13) are put in place, in order, if necessary, to detect the ice setting of the exchanger on the extracted (hot and humid) air side in case new air treatment below 0 C. Indeed, in such a case, the general operation of the installation is likely to be affected. When these sensors detect an increase in load difference, they induce periodic or cyclic opening over a period of a few minutes of a baffle flap located in parallel with the exchanger on the path of fresh air.

  This deflector flap makes it possible to temporarily divert the fresh air, especially when it is less than 0 C, so that it no longer crosses the exchanger (13). In doing so, is no longer directed on the exchanger (13) that the air extracted, so naturally hot and at least temperate, which is thus transferred to said heat exchanger a hot air stream inducing defrosting.

  As a corollary, the bottom of the zone or part (12) also comprises (not shown) in the lower zone an extractable condensate recovery tank resulting from the condensation phenomena, which may occur during the heat exchange between the fresh air ( 11) and the recycled air (5) at the exchanger (13).

  It is therefore conceivable the whole point of the method and the installation of the present invention.

  First of all, the substantial energy savings that may result from the implementation of such a method and of such an installation will be observed.

  In addition, it will be observed the great simplicity of addition of this accessory constituted by the heat exchanger and by this zone (12), since these are standardized dimensions, perfectly capable of adapting to traditional packaging modules of air for speakers.

  In other words, this accessory has a great modularity, likely to allow its adaptation to any air conditioning installation, including roof top type installations, ie positioned on the roof of 20 speakers to condition.

Claims (1)

7 CLAIMS   1. A method of regulating the fresh air supply of a conditioned air distribution installation, wherein said installation comprises: a fresh air supply (11) taken outside the enclosure to be conditioned; a recycled air supply (8) taken from said enclosure to be conditioned; a damper (6) with controlled opening, at which the two preceding feeds end, and intended to ensure a mixture in a desired proportion of fresh air and recycled air; a heating and / or cooling unit (6) of the air mixture coming from the register (6); a blowing unit (3) of said mixture after heating and / or cooling at the enclosure to be conditioned; characterized in that it consists in tempering positive or negative fresh air (11) upstream of said register (6) by heat exchange with at least part of the air (5) extracted (7) from the enclosure to condition.   2. A conditioned air distribution installation within an enclosure, comprising: a fresh air supply (11) taken outside the enclosure to be packaged; a recirculated air supply (8) taken from said enclosure to be conditioned; a damper (6) with controlled opening, at which the two previous feeds end, and intended to ensure a mixture in a desired proportion of fresh air and recycled air; a heating and / or cooling unit (6) of the air mixture from the register (6); a blowing unit (3) of said mixture after heating and / or cooling at the enclosure to be conditioned; characterized in that it further comprises upstream of the register (6) a heat exchange zone (12) between the fresh air (11) taken outside the chamber 35 and the recycled air (5). ) extracted from the enclosure.   3. Installation for distributing conditioned air within an enclosure according to claim 2, characterized in that the zone (12) incorporates an exchanger (13), at which ends the fresh air (11) and part of the air extracted from the enclosure, and at which there is a thermal exchange between these two flows.   4. Installation for distributing conditioned air within an enclosure according to claim 3, characterized in that the exchanger (13) is plate type or wheel type.   5. Installation for distributing conditioned air in a chamber according to one of claims 3 and 4, characterized in that it further comprises pressure sensors positioned upstream and downstream of the exchanger (13). ), intended to indicate the ice setting of the exchanger by detecting a pressure drop and to induce the cyclic opening of a baffle flap mounted in parallel with the exchanger (13), intended to deflect temporarily the circulation of fresh air outside said exchanger, in order to direct on it only the extracted air, and therefore naturally tempered to lead to the defrosting of said exchanger.   6. Installation for distributing conditioned air in a chamber according to one of claims 3 to 5, characterized in that the zone (12) is provided at its bottom with a removable tray for recovering condensates. resulting from condensation phenomena, likely to occur during the heat exchange between the fresh air (11) and the recycled air (5) at the exchanger (13).   7. Installation for distribution of conditioned air in a chamber according to one of claims 2 to 5, characterized in that the zone (12) is integrated within an additional module, may be integrated in the within an air conditioning installation, including roof-top type.