System for humidifying and cooling an air flow and method for cleaning an evaporation panel of such a system

Abstract

The invention relates to a humidification and cooling system (10) for an airflow comprising: - a frame (12), - porous evaporation panels (14) mounted on the frame (12), - water dispersion elements (18) arranged above the panels, - a supply device (22) comprising a control unit (24) configured to supply water to the dispersion elements (18). The control unit (24) comprises control elements (57) controllable independently of each other between an evaporation configuration in which the water supply flow rate is equal to the water flow rate evaporated by the associated porous evaporation panel (14), and a cleaning configuration in which the water supply flow rate is greater than the water flow rate evaporated by the porous evaporation panel (14) to generate a water flow.

Description

[0001] The present invention lies in the field of systems for humidifying and cooling an air flow.

[0002] This type of humidification and cooling system allows water to evaporate through an adiabatic process. By passing through the porous evaporation panels impregnated with water, the airflow causes the water present in the evaporation panels to evaporate without the need for an external energy source. The heat required for the water to vaporize is provided directly by the air. The airflow is thus cooled and its humidity level increases.

[0003] The water supply device makes it possible to control the water supply to the evaporation panels according to a setpoint, so as, for example, to maintain a substantially constant humidity level, increase or reduce the humidity level in the room where the humidification and cooling system is located. Controlling the humidity level results in maintaining, increasing or reducing the total exchange surface area of ​​the system.

[0004] The position of the interface between the impregnated portion and the dry portion of each of the evaporation panels varies during operation of the system.

[0005] Even if it is deionized or reverse osmosis, the water dispersed on the evaporation panels always contains a fraction of minerals. The evaporation mechanism causes the deposition of these minerals on the evaporation panels and more particularly at the interface between the impregnated portion and the dry portion of each of the panels. This accumulation of minerals damages the evaporation panels by reducing the porosity of the panels thus reducing their efficiency.

[0006] EP 3 271 660 A1 describes a humidification apparatus comprising a water tank configured to store water, a filter assembly configured to filter water stored in the water tank, a humidification assembly configured to perform humidification by absorbing and vaporizing water filtered by the filter assembly, and a drainage flow passage located at a lower surface of the humidification assembly, wherein residual water remaining in the humidification assembly after absorption is recovered into the water tank via the drainage flow passage. The apparatus further comprises a guide rib configured to guide the recovered residual water into the water tank.

[0007] KR 2019 0069202 A describes a vaporizing humidifier embedded in a ceiling. The humidifier comprises: a humidifier body embedded in a ceiling, a humidification induction part, a water tank. A support plate for supporting both sides of the humidification induction part is installed in an internal space of the humidifier body.

[0008] An object of the invention is to provide a humidification and cooling system which allows regular cleaning of the evaporation panels while maintaining control of the humidification and cooling level during these cleaning phases.

[0009] For this purpose, the invention relates to a humidification and cooling system according to claim 1.

[0010] Thus, the dispersion members can be fed independently of each other depending on the total exchange surface required. In the evaporation configuration, the feed flow generates a flow out of the evaporation panel, at the lower part of the panel, carrying by gravity the minerals deposited on the evaporation panel. This flow does not modify the evaporation conditions of the evaporation panel and thus allows cleaning of the evaporation panel. Thus, by controlling the configuration of the different control members independently of each other, it is then possible to clean the different porous evaporation panels while ensuring precise control of the humidity level of the ambient air.

[0011] According to different or complementary embodiments, the humidification and cooling system further comprises one or more of the features of claims 2 to 6.

[0012] According to a second aspect, the invention relates to a cleaning method according to claim 7.

[0013] According to different or complementary embodiments, the method further comprises one or more of the characteristics of claims 8 to 10.

[0014] Other aspects and advantages of the invention will appear on reading the following description, given by way of example and with reference to the appended figures, among which: there figure 1 is a schematic representation of a humidification and cooling system according to the invention, the figure 2 is a schematic cross-section of the system of the figure 1 , THE figures 3 to 5are schematic representations of the humidification and cooling system of the figure 1 for three distinct operating states.

[0015] There figure 1 schematically represents a humidification and cooling system 10 according to the invention.

[0016] The system 10 comprises a frame 12, a plurality of porous evaporation panels 14 mounted on the frame 12, a plurality of water dispersion members 18 and a feeder 22 comprising a control unit 24 configured to feed each of the water dispersion members with a corresponding feed rate. Preferably, the feeder 22 further comprises a water recovery receptacle 26 disposed beneath the evaporation panels 14.

[0017] As visible on the figure 2, the frame 12 delimits an inlet 28, an outlet 30 and a passage 32 between the inlet 28 and the outlet 30. Preferably, the inlet 28 extends in a first elevation plane and the outlet 30 extends in a second elevation plane substantially parallel to the first elevation plane. During operation of the system 10, the first elevation plane and the second elevation plane are substantially parallel to a vertical plane. The surface of the inlet 28 and the surface of the outlet 30 are preferably substantially identical. The inlet 28 and the outlet 30 have, for example, a substantially rectangular shape. The frame 12 is, for example, made of steel.

[0018] The number of porous evaporation panels 14 is for example between two and twenty, for example five as illustrated in the figures 1 to 5 . In particular, in the example of the figures 1 to 5, the system 10 comprises a first porous evaporation panel 29, a second porous evaporation panel 31, a third porous evaporation panel 34, a fourth porous evaporation panel 36 and a fifth porous evaporation panel 38.

[0019] The porous evaporation panels 14 are preferably aligned next to each other in a direction substantially perpendicular to an elevation direction. The elevation direction is substantially the same as a vertical direction when the system 10 according to the invention is in operation.

[0020] Alternatively (not shown), the porous evaporation panels 14 are aligned along the elevation direction.

[0021] As a further variant (not shown), the system 10 comprises a first row of porous evaporation panels 14 extending in a first direction substantially perpendicular to the elevation direction, and a second row of porous evaporation panels 14 extending in a second direction substantially parallel to the first direction, the first direction and the second direction extending in the same elevation plane.

[0022] Each porous evaporation panel 14 extends mainly in an elongation direction substantially parallel to the elevation direction.

[0023] Preferably, the porous evaporation panels 14 are identical to each other.

[0024] Each porous evaporation panel is mounted on the frame 12 within the passage 32, between the inlet 28 and the outlet 30.

[0025] Preferably, the porous evaporation panels 14 are mounted on the frame 12 in a removable manner, that is to say that the porous evaporation panels 14 can be detached from the frame 12 and extracted from the passage 32, for example during installation operations. The porous evaporation panels 14 are, for example, extracted from the frame 12 in an extraction direction substantially parallel to the first and second planes. Alternatively, the porous evaporation panels 14 are extracted in an extraction direction substantially perpendicular to the first plane and to the second plane.

[0026] Thus, an air flow F which enters through the inlet 28 of the frame 12, located upstream of the passage 32, crosses the passage 32 by passing through the porous evaporation panels 14 to exit through the outlet 30, located downstream of the passage 32, having evaporated a quantity of water present in the porous evaporation panel(s) 14, as we will see in more detail later in the description. The air flow F thus crosses the porous evaporation panels 14 in a direction substantially perpendicular to the main direction of elongation of the porous evaporation panels 14.

[0027] The porous evaporation panels 14 are mounted on the frame 12 so that the air flow F which passes through the passage 32 necessarily passes through one of the porous evaporation panels 14.

[0028] Each porous evaporation panel 14 has, for example, a substantially parallelepiped shape. Each panel 14 comprises two lateral surfaces 40 opposite each other, an upper surface 42, a lower surface 44 opposite the upper surface 42, both connected to the lateral surfaces 40. The lateral surfaces 40 extend in a plane substantially parallel to the first plane and the second plane. The upper surface 42 and the lower surface 44 extend in planes substantially perpendicular to the first plane and the second plane.

[0029] For example, each panel 14 comprises a plurality of corrugated sheets of non-organic fibers, for example glass fibers, assembled together to form circulation channels for the air flow F. Preferably, the thickness of each of the corrugated sheets is between 0.1 mm and 0.6 mm, for example 0.3 mm. The corrugation period of the channels is preferably between 3 mm and 25 mm, for example 10 mm. The height of the corrugations is preferably between 2 mm and 10 mm, for example 5 mm.

[0030] Each water dispersion member 18 is arranged above a respective porous evaporation panel 14 in the elevation direction.

[0031] Generally, the system 10 comprises as many water dispersion members 18 as there are porous evaporation panels 14. Thus, in the example illustrated by the figures 1 to 5, the system 10 comprises five water dispersion members 18, respectively a first dispersion member 43, a second dispersion member 45, a third dispersion member 46, a fourth dispersion member 48 and a fifth dispersion member 50, arranged above each of the five porous evaporation panels 14.

[0032] Each dispersion member 18 is adapted to disperse a volume of water on the corresponding evaporation panel 14 so as to impregnate at least a portion 54 of said evaporation panel 14 with the volume of water ( Figure 3 to 5). In particular, the water dispersion member 18 disperses the volume of water on the upper surface 42 of the evaporation panel 14. The volume of water impregnates the evaporation panel 14 from an upper portion of the panel 14 to a lower portion of the panel 14 by gravity. The evaporation panel 14 then comprises a dry portion 52 and an impregnated portion 54 separated by an interface 56, as seen in particular in the figure 3 The position of the interface 56 depends in particular on the volume of water dispersed by the water dispersion member 18, and more particularly on the feed flow rate which feeds the dispersion member 18, and on the evaporation conditions, that is to say the temperature and ambient humidity around the system.

[0033] The volume of water in the impregnated portion 54 of the porous evaporation panel 14 is intended to be evaporated by the passage of the air flow F through the porous evaporation panel 14. The air flow F is then cooled and humidified.

[0034] The impregnated portion 54 comprises at least one exchange surface 55 in contact with the air flow F allowing the evaporation of the volume of water.

[0035] A total exchange surface 53 of the system is formed by the sum of the exchange surfaces of each of the impregnated portions 54 of each of the evaporation panels 14.

[0036] Preferably, each water dispersion member 18 is formed by a dispersion ramp extending mainly in a direction substantially perpendicular to the main direction of extension of the evaporation panel 14, so as to disperse the water uniformly on the upper surface 42 of the evaporation panel 14.

[0037] In the illustrated example, the control unit 24 is configured to supply water to the first dispersion member 43 with a first supply flow rate, the second dispersion member 45 with a second supply flow rate, the third dispersion member 46 with a third supply flow rate, the fourth dispersion member 48 with a fourth supply flow rate and the fifth dispersion member 50 with a fifth supply flow rate.

[0038] According to the invention, the control unit 24 comprises a plurality of control members 57 configured to respectively control each of the water supply flow rates. The control members 57 are controllable independently of one another. In other words, the control unit 24, by means of the control members 57, can control the different supply flow rates independently of one another.

[0039] Each control member 57 is for example a control valve. The ratio between the minimum flow rate of the valve and the maximum flow rate of the valve is very high, generally greater than 30.

[0040] In the example of the figures 1 to 5 , the control unit 24 comprises a first control member 58, a second control member 60, a third control member 62, a fourth control member 64 and a fifth control member 66.

[0041] Each of the control members 57 is controllable between at least one evaporation configuration in which the water supply flow rate is substantially equal to a flow rate of water evaporated by the associated porous evaporation panel 14, and a cleaning configuration in which the water supply flow rate is greater than a flow rate of water evaporated by the associated porous evaporation panel 14 fully impregnated so as to generate a flow of water 59 out of the associated porous evaporation panel 14.

[0042] Preferably, each control member 57 is further controllable between the evaporation configuration, the cleaning configuration, and a closed configuration in which the feed flow rate is zero.

[0043] In the evaporation configuration, the feed flow rate is controllable so as to increase or reduce the exchange surface 55 of the porous evaporation panel 14, i.e. to increase or reduce the volume of the impregnated portion 54 of the evaporation panel 14. In the evaporation configuration, the feed flow rate is for example between 1 l / h and 50 l / h.

[0044] In the evaporation configuration, the evaporation panel 14 always comprises at least one portion 54 impregnated with water.

[0045] In the cleaning configuration, the water supply flow rate generates a flow of water 59 by gravity at the lower part of the evaporation panel 14. This flow 59 carries with it the minerals deposited on the evaporation panel 14.

[0046] Preferably, in the cleaning configuration, the water supply flow rate is 1.5 times to 2.5 times greater than the flow rate of water evaporated by the associated evaporation panel. In the cleaning configuration, the evaporation panel 14 is completely impregnated with water. The exchange surface 55 is maximum.

[0047] The water dispersed by the dispersion members 18 is, for example, mains water, osmosis water or deionized water. The conductivity of the osmosis water is, for example, between 1 µS / cm and 50 µS / cm. The conductivity of the deionized water is typically between 0.1 µS / cm and 1 µS / cm.

[0048] The supply device 22 comprises a plurality of water supply lines 68. Each supply line 68 is fluidically connected to a corresponding water dispersion member 18. The supply device thus comprises as many supply lines 68 as there are dispersion members 18. In the illustrated example, the supply device 22 comprises five supply lines 68, respectively a first supply line 70, a second supply line 72, a third supply line 74, a fourth supply line 76 and a fifth supply line 78, connected respectively to the first dispersion member 43, second dispersion member 45, third dispersion member 46, fourth dispersion member 48 and fifth dispersion member 50.

[0049] Each control member 57 is connected to a respective supply line 68 so as to control the supply flow rate provided by the water supply line 68.

[0050] Each of the supply lines 68 is fluidically connected to a fluid source 80, preferably a single fluid source, for example formed by a water supply network or a reservoir. Each of the control members 57 is thus arranged between the fluid source 80 and the corresponding water dispersion member on the corresponding supply line 68.

[0051] The control unit 24 is advantageously configured to control each of the water supply flow rates according to a setpoint value. Preferably, the control unit 24 is slaved to the setpoint value. Thus, the system 10 according to the invention makes it possible, for example, to maintain a constant humidity level and / or a substantially constant temperature over time in the room in which the system is located.

[0052] The humidity level and / or the temperature are controlled by the total exchange surface 53 of the evaporation panels 14, that is to say by the total volume of the portions of panels 14 impregnated with water in contact with the air. Depending on the conditions external to the system 10, maintaining the setpoint requires maintaining, increasing or decreasing the total exchange surface 53.

[0053] The water recovery receptacle 26 is arranged under the porous evaporation panels 14 and makes it possible to collect the water flow(s) 59 coming from the lower surface 44 of the evaporation panels 14. The receptacle 26 is for example fluidically connected to a discharge line 82 configured to discharge the collected water and minerals.

[0054] A method of cleaning at least one porous evaporation panel 14 of a system 10 for humidifying and cooling an air flow F as described above will now be described with reference to figures 3 to 5 .

[0055] The method firstly comprises a step of supplying water to the first dispersion member 43 of the first evaporation panel 29 so as to impregnate at least a portion of the first evaporation panel 29. The first control member 58 is then in the evaporation configuration.

[0056] When maintaining the setpoint requires an increase in the total exchange surface area 53, the first feed rate is increased to increase the volume of the impregnated portion 54 of the first evaporation panel 29 until the entire first evaporation panel 29 is impregnated. At this stage, the other control members 60, 62, 64, 66 are in the closed configuration, i.e. the other dispersion members 45, 46, 48, 50 are not supplied with water.

[0057] If necessary, that is to say if maintaining the setpoint requires that the total exchange surface 53 increases further, when the first evaporation panel 29 is completely impregnated, the second dispersion member 45 is supplied with water. The second control member 60 is then in the evaporation configuration. A portion of the second panel 29 is impregnated.

[0058] The first dispersion member 43 is then supplied with a first supply flow rate greater than a flow rate of water evaporated by the first porous evaporation panel 29 which is completely impregnated. In other words, the first control member 58 is in the cleaning configuration. This generates a flow of water 59 at the lower part of the first panel 29 carrying with it the minerals deposited on the first panel 29. The flow 59 and the minerals are collected in the recovery receptacle 26. The other control members, i.e. the third control member 62, the fourth control member 64 and the fifth control member 66 are in the closed configuration.

[0059] This state is illustrated by the figure 3Maintaining the setpoint requires that the total exchange surface 53 be greater than 20% of the maximum total exchange surface, i.e. more than one evaporation panel must be completely impregnated.

[0060] Still if necessary, the total exchange surface 53 is increased by controlling the second feed flow rate until the entire second evaporation panel 31 is impregnated. Then when the second evaporation panel 31 is completely impregnated, the third dispersion member 46 is supplied with water by positioning the third control member 62 in the evaporation configuration.

[0061] The second dispersion member 45 is then supplied with water with a second supply flow rate greater than a flow rate of water evaporated by the second porous evaporation panel 31 which is completely impregnated so as to generate a flow of water 59 out of the second evaporation panel 31. The second control member 60 is then in the cleaning configuration.

[0062] At this stage, as illustrated in the figure 4 , the first and second control members 58, 60 are in the cleaning configuration allowing cleaning of the first and second evaporation panels 29, 31. The third control member 46 allows adjustment of the total exchange surface 53 ( figure 4 ) of system 10.

[0063] Generally, to increase the total exchange surface 53 of the system 10, the dispersion members 18 are fed successively one after the other as soon as an evaporation panel 14 is completely impregnated. Each time an evaporation panel 14 is completely impregnated, the corresponding control member 57 is switched into the cleaning configuration to allow cleaning of the associated panel 14.

[0064] Back to the state illustrated by the figure 4 , if maintaining the setpoint value requires a reduction in the total exchange surface 53, the first feed flow rate is controlled so that the first evaporation panel 29 is partially impregnated. In other words, the first control member 58 is moved into the evaporation configuration. The second control member 60 is maintained in the cleaning configuration allowing the cleaning of the second evaporation panel 31 to continue.

[0065] If necessary, if it is necessary to further reduce the total exchange surface 53, for example so that it represents less than 40% of the maximum total exchange surface as illustrated in the Figure 5 , we end up no longer supplying the first water dispersion member 43. The first control member 58 is in the closed configuration.

[0066] If it is again necessary to increase the total exchange surface 53, preferably, the third feed rate is controlled until, if necessary, the third evaporation panel 34 is completely impregnated. When the third evaporation panel 34 is completely impregnated, the fourth evaporation panel 36 is supplied with water. The third control member 62 is in the cleaning configuration allowing cleaning of the third panel 34. The fourth control member 64 is in the evaporation configuration.

[0067] It is then understood that during operation of the system 10 according to the invention, it is possible to clean the various porous evaporation panels 14 of the system 10 while maintaining precise control of the humidity level and the temperature.

Claims

1. A system (10) for humidifying and cooling an air flow (F), said system (10) comprising: - a frame (12) delimiting an inlet (28), an outlet (30) and a passage (32) between the inlet (28) and the outlet (30), the air flow (F) being intended to pass through the passage (32), - a plurality of porous evaporation panels (14) mounted on the frame (12) and arranged in the passage (32), each porous evaporation panel (14) extending mainly in a substantially vertical direction, - a plurality of water dispersing elements (18), each dispersing element (18) being positioned over a corresponding porous evaporation panel (14), each of the dispersing elements (18) being suitable for dispersing a volume of water over the corresponding porous evaporation panel (14) so as to soak at least one portion (54) of said porous evaporation panel (14) with a volume of water, the soaked portion (54) comprising at least one exchange surface area (55) intended to be in contact with the air flow (F) and to allow the volume of water to evaporate, a total exchange surface area (53) being formed by the sum of the exchange surface areas of each of the evaporation panels (14), - a supply system (22) comprising a control unit (24) configured to supply water to the dispersing elements (18) with corresponding supply flow-rates, characterized in that the control unit (24) comprises a plurality of control elements (57) configured to control each of the supply flow-rates, correspondingly, where the control elements (57) can be controlled independently of each other, at least one evaporation configuration wherein the water supply flow-rate is substantially equal to a flow-rate of the water evaporated through the associated porous evaporation panel (14), and a cleaning configuration wherein the water supply flow-rate is greater than a flow-rate of the water evaporated through the associated completely soaked porous evaporation panel (14) so that a water flow (59) is created outside said associated porous evaporation panel (14), wherein the supply system (22) comprises a plurality of water supply lines (68), each supply line (68) being fluidically connected to a corresponding dispersing element (18), each control element (57) being connected to a corresponding supply line (68).

2. The system (10) according to claim 1, wherein each control element (57) is further controllable between the evaporation configuration, the cleaning configuration and a closed configuration wherein the supply flow-rate is zero.

3. The system (10) according to claim 1 or 2, wherein, in the evaporation configuration, the supply flow-rate is controllable so as to increase or decrease the exchange surface area (55) of the porous evaporation panel (14).

4. The system according to any of claims 1 to 3, wherein, in the cleaning configuration, the water supply flow-rate is 1.5 times to 2.5 times greater than the flow-rate of the water evaporated through the associated evaporation panel (14).

5. The system (10) according to any of claims 1 to 4, wherein the control unit (24) is configured to control the water supply flow-rates according to a setpoint.

6. The system (10) according to any of claims 1 to 5, wherein the supply system (22) further comprises a water collection recipient (26) placed under the porous evaporation panels (14) intended to collect the water flow (59).

7. A method for cleaning at least one porous evaporation panel (14) of a system (10) for humidifying and cooling an air flow (F) according to any of claims 1 to 7, the system (10) comprising at least a first and a second porous evaporation panel (29, 31), a first and a second water dispersing element (43, 45), and a first and a second control element (58, 60), the method comprising the following steps: - supplying water to the first dispersing element (43), the first control element (58) being in the evaporation configuration, the first evaporation panel (29) being partially soaked, - increasing the total exchange surface area (53) by controlling the first supply flow-rate until the first evaporation panel (29) is completely soaked, - when the first porous evaporation panel (29) is completely soaked, supplying water to the second dispersing element (45), the second control element (60) being in the evaporation configuration, - supplying water to the first dispersing element (43) with a first supply flow-rate greater than a flow-rate of the water evaporated through the first completely soaked porous evaporation panel (29) so as to create a water flow (59) outside said porous evaporation panel (29), the first actuator (58) being in the cleaning configuration.

8. The cleaning method according to claim 7, the system comprising at least a third panel (34), a third water dispersing element (46), and a third control element (62), the method comprising the following steps: - increasing the total exchange surface area (53) by controlling the second supply flow-rate until completely soaking the second evaporation panel (31), - when the second porous evaporation panel (31) is completely soaked, supplying water to the third dispersing element (46), the third control element (62) being in the evaporation configuration, - supplying water to the second dispersing element (45) with a second supply flow-rate greater than a flow-rate of the water evaporated through the completely soaked second porous evaporation panel (31) so as to create a water flow (59) outside said porous evaporation panel (31), the second control element (60) being in the cleaning configuration.

9. The cleaning method according to claim 8, comprising the following step: - reducing the total exchange surface area (53) by controlling the water supply flow-rate to the first dispersing element (43) so as to reduce the exchange surface area (55) of the first evaporation panel (29).

10. The cleaning method according to claim 9, the system (10) comprising at least a fourth panel (36), a fourth water dispersing element (48), and a fourth control element (64), the process comprising the following steps: - stopping the water supply to the first dispersing element (43), the first control element (58) being in the closed position, - increasing the total exchange surface area (53) by supplying the fourth water dispersing element (48) with water, the fourth control element (64) being in the evaporation configuration.

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