FR3028635A1 - COMPUTER TOOL FOR AIDING THE BALANCING OF A VENTILATION NETWORK ON SITE - Google Patents

Abstract

The invention relates to a method for balancing an extraction ventilation network or air insufflation, characterized in that it consists in using a portable computer tool for assisting the balancing of a network extraction ventilation or air insufflation on site, once the ventilation network installed.

Description

The invention relates to a computer tool for assisting the balancing of an exhaust ventilation ventilation network or air insufflation, on the site. It is known to use a flow regulator for a ventilation plant, in particular a regulator also called a damper disposed within a coupling sleeve for use in a controlled mechanical ventilation unit. Such a regulator may include automatic flow limiting means. During an increase in the suction caused by a depression prevailing downstream of the regulator, this means obstructs a portion of the passage of the sleeve. These types of regulators are relatively complex and expensive and their implementation is complicated because their adjustment is adapted to a precise network dimensioning. Another solution consists in using a rigid passage restriction member consisting of a sleeve equipped with a pre-calibrated orifice in the laboratory according to a determined pressure drop giving a certain flow rate for a determined length of sheath. However, if on-site the connected sheaths are in fact of different length from the predetermined reference value in the laboratory, which is very common, the calibration and the predefined flow rates for this restriction member are not respected. The invention solves these problems by providing a computer tool for balancing an on-site ventilation network, once the ventilation network installed, particularly simple use. To do this, the invention thus proposes a method for balancing an exhaust ventilation or air blowing network, characterized in that it consists of using a portable computer tool to assist the balancing of an extraction ventilation network or air insufflation on site, once the ventilation network installed. The invention also proposes a portable computer tool for assisting the balancing of an exhaust ventilation or air insufflation network, on site, once the ventilation network has been installed, for the implementation of the invention. of this method, comprising at least one computer means for calculating the air passage surface to be applied to each branch Bi of the network. The installer can use this computer tool in situ, during the adjustment of the already installed ventilation network with regard to his suction or insufflation unit and his ducts, and he can then install on the ducts surface suitable for balancing the installation. This tool can be installed on a laptop, tablet or smart phone. According to a preferred embodiment of the invention, this portable computer tool for assisting the balancing of an exhaust ventilation or air insufflation network, on site, comprises at least one means of manual input of the architecture of the network, for example octopus and / or linear, manual input means of the number N of branches of said network and the parameters of each branch Bi, i being between 1 and 25 and N and N being greater than or equal to 2, a means for manually entering the desired flow rate in each branch Bi, a computer means for calculating the pressure losses of each said branch Bi and said computing means for calculating the area of passage of air 3028635 3 to apply to each branch B ,. The algorithm applied by this computer tool is particularly simple. More complex networks than linear or octopus networks can also be managed, the computer tool according to the invention then having a suitable input interface. Preferably, said parameters are the type of sheath, its shape, its aeraulic equivalent passage diameter, its length and its number of bends. Said type of sheath is advantageously defined by its flexibility or rigidity. The tool may also comprise a computer means for determining the branch Bn having the greatest pressure drop and a computer means for calculating the difference of said greater pressure drop and the pressure drop of each branch. B. It may also comprise a computing means for calculating an opening percentage to be applied to each branch Bi, a percentage of opening of 100% being applied to said branch Bn.

The invention also relates to a method of use on site of such a computer tool, characterized in that it consists in installing a breakthrough orifice restriction member on each said branch Bi, said orifice being cut to said surface of passage. Finally, the invention relates to a method of use on site of such a computer tool, characterized in that it consists in installing a passage restriction member breakable orifice on each said branch Bi, except on said branch Bn, said orifice being cut to said opening percentage. This method may include installing a passage restricting member having adjustable indexing indicia of a passage surface or aperture percentage, said member being set to indexing provided by the computer tool. . The invention is described below in more detail with the aid of figures illustrating only preferred embodiments of the invention.

FIG. 1 represents an example of an algorithm applied by a computer tool according to the invention, in the case of a network of radiating ducts or commonly called octopus network. Figure 2 is a perspective view of an exemplary passage restriction member according to the invention.

FIG. 3 represents an example of an algorithm applied by a computer tool according to the invention, in the case of an array of ducts arranged linearly in parallel. According to FIG. 1, an octopus array consists of sheaths of circular cross-section referred to as radiating sections, all of which originate from a suction or central blower system and have an air inlet or outlet end. A portable computer tool for assisting the balancing of an exhaust ventilation ventilation or air insufflation ventilation system on site, in accordance with the invention, comprises: a means 1 for manual entry the number N of branches of the network and the parameters of each branch B, which is the type of sheath, preferably its flexibility or rigidity, its shape, its passage diameter, its length and number of elbows, and the desired flow rate in each branch B ,, i being between 1 and N and N being greater than or equal to 2, - a computer means 2 for calculating the pressure losses of each branch B, comprising a linear part corresponding to the sheath lengths and a singular part corresponding to the elbows and a computer means for determining the branch B, having the greatest loss of load which is the branch No. 3 according to the example shown, and a means 3 for calculating the difference in this bigger 5 pressure loss and the pressure drop of each branch Bi and - a computer means 4 for calculating the air passage surface to be applied to each branch Bi and its diameter, the sheaths being of circular section with a diameter of 125 mm according to the illustrated example.

We will start from the formula Qv '/ Qv = S' / S * V (dP '/ dP) and for the same flow rate, the ratio S7S will vary as the ratio V (dP / dP') Qv being the flow rate, S la restriction surface, dP the pressure gradient and the symbol "*" means a multiplication. With Qv being the desired flow rate of the branch Bi and Qv 'the flow rate of the reference branch namely B' S being the passage area of the branch Bi and S 'that of the branch Bn, dP being the PdC of branch Bi and dP that branch Bn. In the case of a circumferential restriction device with a circular section, the formula flow = 3600 * air velocity * Surface 25 with air velocity = V (2 * dP / p) and surface = n * 02 / 4. This diameter of passage area or restriction diameter is therefore defined by: ## EQU1 ## where p is the density of the air, ie: ## EQU1 ## equal to 1.2 kg / m3, the flow rate in m3 / h, the air velocity in m / s, the area in m2, the delta Pressure in Pascal and the diameter (I) of restriction in meters. The tool may also comprise a means for calculating a percentage of opening to be applied to each branch Bi, a percentage of opening of 100% being applied to said branch Bn, namely branch No. 3 according to the illustrated example. which is intended to be left free without passing restrictor Each of the other branches will have an aperture percentage calculated according to the formula: Percentage of aperture = 100% V (maximum PdC of Bi / PdC), with maximum PdC being the loss of load of the branch Bn. According to one embodiment, the method of use on site of such a computer tool consists of to move a breakable orifice surface restricting member 15 on each branch Bi, except on said branch Bn, said orifice being cut at the opening percentage. This member may be installed anywhere in the branch but preferably is installed at the outlet of the ventilation system at the head of each duct or at the inlet or outlet mouth of each branch on the side of the building part. ventilated. An example of a surface restriction member 100 is shown in FIG. 2. It consists of a cylinder 100A provided with breakable staggered concentric plates 10B in order to shape the desired opening section. The installer can then be equipped with an abacus 25 giving a relationship between the restriction diameter and the blade (s) 100B to be removed from each surface restriction member 100. The passage restricting member 100 may have setting indexes representative of a passage surface or a percentage of opening, the member being set to the indexing provided by the computer tool.

Alternatively, the ducts may be equipped with a register consisting of an indexed swivel blade, instead of such a breakable passage restriction member, and in this case, it is provided to the installer the angle of inclination of this blade to be applied according to the passage area calculated by the computer tool. Other types of restriction members may also be integrated, for example an iris or guillotine damper. The invention is here described considering sheaths of circular section, but it can be applied to any shape of sheath section.

Instead of considering the diameter of the sheath, it is then necessary to consider the equivalent passage aeraulic diameter. By way of example, according to Chézy's formula, the equivalent aeraulic diameter for a sheath of rectangular section is equal to D = (1 xaxb) / (a + b), where a is the width of the sheath and b is the height. of the sheath. The ASHRAE formulas (acronym for "American Society of Heating, Refrigerating and Air Conditioning Engineers") can also be used. According to FIG. 3, a network consists of sheaths 20 of circular section and said linear, sheath sections A to F being butted and sheath sections or branches No. 1 to No. 6 being arranged in parallel on the formed length. by the preceding sections and having an inlet mouth or air outlet. A portable computer tool for balancing an on-site ventilation network 25 according to the invention comprises: a means for manually entering the number N of branches of the network and the parameters of each section sheath A to F and each branch No. 1 to No. 6, which is the type of sheath, preferably its flexibility or rigidity, its shape, its passage diameter, its length and its number of elbows, and the desired flow rate in each section of sheath and each branch, i being between 1 and N and N being greater than or equal to 2, a computer means 20A for calculating the pressure losses of each duct section A to F and each branch No. 1 to No. 6 isolated, 5 comprising a linear portion corresponding to the sheath lengths and a singular portion corresponding to the elbows, - a computer means 20B for calculating the total pressure losses of each branch No. 1 at n ° 6, taking into account the pressure losses of the sections of associated sheaths, 10 - a computer means 30 for determining the branch Bn having the greatest pressure drop which is the branch No. 6 according to the example shown, and - a computer means for calculating the difference of this greater loss. load and the pressure drop of each branch B1 15 and - a computer means 40 for calculating an opening percentage to be applied to each branch Bi, a percentage of opening of 100% being applied to said branch Bn, that is, branch No. 6 according to the illustrated example which is intended to be left free without a surface restriction member. The method of use on site of such a computer tool consists in installing a surface restriction device with a breakable orifice or with an adjustable passage surface on each branch Bi, except on said branch Bn, said orifice being cut to the percentage 25 opening and the passage surface being set at a position representing the percentage of opening. As illustrated in FIG. 3, this member may be installed anywhere in the branch but preferably is installed at the branch of each branch with the sheath sections A to F connected to or at the level 3028635 of the inlet or outlet mouth. from each branch on the side of the ventilated building room. Although more particularly described in the case of an air-exhaust fan controlled mechanical type ventilation installation, the invention can also be applied to an air blower installation on the same principle obviously for the skilled person. 10

Claims (13)

REVENDICATIONS1. A method of balancing an extraction ventilation network or air insufflation, characterized in that it consists in using a portable computer tool for assisting the balancing of an extraction ventilation network or air blowing on site, once the ventilation network is installed. 2. Portable computer tool for assisting the balancing of an exhaust ventilation or air insufflation network, on site, once the ventilation network has been installed, for the implementation of the process according to the claim 1, comprising at least one computer means for calculating the air passage surface to be applied to each branch B1 of the network. 15 3. Portable computer tool for assisting the balancing of an exhaust ventilation or air blowing network according to claim 2, characterized in that it is installed on a portable microcomputer. 20 4. Portable computer tool for assisting the balancing of an extraction ventilation network or air insufflation according to claim 2, characterized in that it is installed on a computer tablet. 25 5. A portable computer tool for assisting the balancing of a ventilation or exhaust ventilation network according to claim 2, characterized in that it is installed on a smart phone. 3028635 11 6. Portable computer tool for assisting the balancing of an on-site extraction or air supply ventilation network according to one of claims 2 to 5, comprising at least one means of manual input of the architecture of the network, for example octopus and / or linear, -a means (1, 10) of manual entry of the number N of branches of said network and parameters of each branch B ,, i being between 1 and N and N being greater than or equal to 2, a means (1, 10) of manual input of the desired flow rate in each branch Bi, a computer means (2, 20) for calculating the pressure losses of each said branch B, and said computer means for calculating the air passage area to be applied to each branch B. 7. Computer tool according to the preceding claim, characterized in that said parameters are the type of sheath, its shape, its aeraulic equivalent passage diameter, its length and its number of bends. 20 8. Computer tool according to the preceding claim, characterized in that said type of sheath is defined by its flexibility or rigidity. 25 9. Computer tool according to one of claims 2 to 8, characterized in that it also comprises a means (3, 30) computer for determining the branch Bn having the greatest loss of load and a means 3028635 12 (3) Computer calculation of the difference of said largest pressure drop and load loss of each branch B. 5 10. Computer tool according to the preceding claim, characterized in that it also comprises a means (40) computer for calculating a percentage of opening to be applied to each branch B ,, a percentage of opening of 100% being applied. to said branch Bn. 10 11. A method for balancing an extraction ventilation network or air insufflation, on site, once the ventilation network installed, using a computer tool according to one of claims 2 at 10, characterized in that it consists in installing a passage restricting member (100) breakable orifice on each said branch Bi, said orifice being cut to said passage surface. 12.An equilibration method of an extraction ventilation or air blowing system, on site, after the ventilation network has been installed, using a computer tool according to claim 10, characterized in that it consists in installing a breakable surface restriction member (100) on each said branch Bi, except on said branch Bn, said orifice being cut off at said opening percentage. 13. The method of claim 11 or 12, characterized in that it consists in installing a passage restriction member (100) having adjustment indexing representative of a passage surface or a percentage of opening , said member being adjusted to the indexing provided by the computer tool.