EP3794290B1

EP3794290B1 - Air handling unit

Info

Publication number: EP3794290B1
Application number: EP18742592.1A
Authority: EP
Inventors: Patrice BASTIAND
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 2018-05-15
Filing date: 2018-05-15
Publication date: 2022-09-14
Anticipated expiration: 2038-05-15
Also published as: CN112136009A; WO2019220165A1; US20210222908A1; EP3794290A1

Description

The present invention concerns an air handling unit.
Air handling units are adapted to treat the air: filtering, depolluting, humidifying, drying, heating, cooling, or the like. Some air handling units adapted to produce cooled air for air conditioning comprise heat exchangers which may cause condensation of the humidity in treated air. In air conditioning applications, it is known to place a condensate tray below the heat exchanger to drain condensate outside the enclosure. Such condensate tray cannot be removed or cleaned. State-of-the art air handling units comprise a recuperator placed below the heat exchanger to recuperate the condensate, and a removable tray adapted to receive the condensate coming from the recuperator thanks to a slight slope of the recuperator.
However, the standard shape of the recuperator which comprises a vertical wall provided with holes is not totally satisfying, as the condensate often drips along an exterior face of the recuperator due to capillarity. This results in condensate droplets falling outside the tray.
US 2007/169493 A1 discloses a shield for an evaporator assembly comprising the features of the preamble of claim 1, which is configured to be attachable to a coil slab of a multi-poise coil without requiring the use of any fasteners. The shield comprises a first extension member, a second extension member, a bottom member disposed between the first and second extension members, and a lip member extending from the extension member. The first extension member is configured to be positioned on an inner surface of the coil slab. The lip member is configured to be positioned on an outer surface of the coil slab.
The aim of the invention is to provide a new air handling unit, in which the recuperation of condensate is improved.
To this end, the invention concerns an air handling unit comprising:

an enclosure;
at least one heat exchanger mounted in the enclosure;
a condensate recuperator placed under the at least one heat exchanger;
a condensate tray adapted to receive condensate flowing from the recuperator;

Thanks to the invention, the falling of liquid droplets outside the tray is prevented.
According to further aspects of the invention which are advantageous but not compulsory, such an air handling unit may incorporate one or several of the following features:

The lateral portions are formed by folded parts that are welded to the first and second side walls of the recuperator.
The inclined lip has an inclination angle comprised between 10° and 80°.
The inclination angle of the inclined lip is equal to 25°.

The invention will now be explained in reference to the annexed drawings, as an illustrative example. In the annexed drawings:

Figure 1 is a perspective view of an air handling unit on which a lateral panel is omitted, and in which a heat exchanger is being inserted;
figures 2, 3 and 4 represents three sectional views of various parts of a state-of-the-art air handling unit;
figure 5 is a perspective view of a heat exchanger, a condensate recuperator and a condensate tray of the air handling unit of figure 1;
figure 6 is a perspective view of the heat exchanger, the condensate recuperator and the condensate tray of figure 5, from a different angle;
figure 7 is an exploded view corresponding to figure 5;
figure 8 is a sectional view of the heat exchanger, the condensate recuperator and the condensate tray of figure 5;
figure 9 is a view at a larger scale of detail IX on figure 8;
figure 10 is a front view of a condensate recuperator of figure 5;
figure 11 is a perspective view of a lateral portion of an open side of the recuperator of figure 10 during a manufacturing step;
figure 12 is a view similar to figure 11, after a welding step;
figure 13 is a view at a larger scale of detail XIII on figure8;
figure 14 is a perspective view of the heat exchanger, the condensate recuperator and the condensate tray of figure 5, the heat exchanger being raised from the recuperator;
figure 15 is a perspective view of a stop member of the air handling unit of figure 1;
figure 16 is a perspective view of a support member of the air handling unit of figure 1;
figures 17, 18 and 19 are lateral view of three steps of introducing a removable condensate tray in the support member of figure 16.

An air handling unit 1 is shown on figure 1. The air handling unit 1 comprises an enclosure 3 extending along a longitudinal axis X. The enclosure 3 is delimited by panels comprising an entry panel 30 and an exit panel 32, each provided with an opening 300 and 320. In this example, an air flow enters the enclosure 3 through the opening 300 along arrow A1, and exits through the opening 320 along arrow A2. The air flow circulates along a flow direction corresponding to the longitudinal axis X. The invention is not limited to this type of air path, and various other air paths can be used, including double flow in some air handling units.
The enclosure 3 also comprises longitudinal panels comprising a bottom panel 34, a rear panel 36 and a top panel 38, that extend parallel to the longitudinal axis X. The enclosure 3 also comprises a front panel which is omitted to show the inner side of the enclosure 3.
The air handling unit 1 comprises at least one heat exchanger 5 mounted in the enclosure 3. The heat exchanger 5 extends transversally to the air flow direction X. As an example, the heat exchanger 5 may be an evaporator, with refrigerant flowing inside the heat exchanger to cool the air. The heat exchanger 5 may also be a water heat exchanger, with cooled water flowing inside, or any other type.
Figures 2 to 4 show a portion of an air handling unit 1' according to the prior art. Depending on temperature conditions and relative humidity of the cooled air, condensate may form in the heat exchanger 5 as an adverse side effect. This condensate has to be drained from the enclosure 3. The air handling unit therefore comprises a condensate recuperator 7, formed by a slightly sloped plate with folded side walls. The recuperator 7 is placed under the heat exchanger 5 to collect condensate. A side wall 70 of the recuperator 7 comprises holes 70a provided above a condensate tray 9, provided to receive the condensate coming from the recuperator 7.
Due to the geometry of the holes 70a, condensate often drips through the holes 70a and continues its path along a bottom face 72 of the recuperator 7 due to capillarity, and often drops outside the tray 9.
The recuperator 7 comprises a side wall 74 oriented towards the entry panel 30. The side wall 74 comprises a folded end 74a. The recuperator 7 is supported by a holding structure 10. The tray 9 is put on a support member 11 that comprises a side wall 110 oriented towards the entry panel 30. The side wall 110 comprises a folded end 110a with a shape complementary to the shape of the folded end 74 of the recuperator. The heat exchanger 5 is mounted on the recuperator 7, and the weight of the heat exchanger 5 is supported by the recuperator 7 and transmitted to the holding structure 10.
During transportation of the air handling unit 1', the heat exchanger 5 may move with respect to the recuperator 7 along the longitudinal direction X, which may cause damages to or break the welding lines that connect the side walls of the recuperator 7 resulting in leakage.
In the present example, as shown on Fig. 5, the air handling unit 1 comprises a support member 13, a condensate recuperator 15, and a condensate tray 17. The condensate recuperator 15 is held in place by a holding structure 19 fixed to the support member 13, shown on figure 6 and similar to the holding structure 10. The support member 13 is fixed to the bottom panel 34 by non-shown fastening means. The holding structure 19 is also fixed to the bottom panel 34. The holding structure 19 may be fixed to the bottom panel 34 with non-shown fastening means passing through the support member 13. According to a non-shown variant, the holding structure 19 and the support member 13 may be a unitary element. For example, the holding structure 19 may be formed by a portion of the support member 13.
The holding structure 19 has also the function of supporting the weight of the heat exchanger 5 when the air handling unit 1 is in static position.
As represented on figures 8 to 11, the recuperator 15 has an open side 150 oriented towards the tray 17 and reaching over the tray 17. This open side 150 has an inclined lip 152 guiding the condensate towards the tray 17. The lip 152 comprises lateral portions 152a and 152b that are bent inwards.
The lip 152 and its inclined shape ensure a correct flow of condensate into the tray 17 and prevent drops of liquid from falling outside the tray 17. The inwardly bent shape of the portions 152a and 152b helps in guiding the condensate flow towards a central area of the tray 17.
According to an embodiment, the inclined lip 152 has an inclination angle α with respect to a bottom wall 154 of the recuperator 15, comprised between 10° and 80°, preferably equal to 25°.
According to an embodiment, the lateral portions 152a and 152b are formed by folded parts that are welded to side walls 156 and 157 of the recuperator 15. As shown on figures 11 and 12, the lateral portions 152a and 152b have a triangular shape connected by one edge to a central portion of the lip 152. The lateral portions 152a and 152b are manufactured with an initial continuous planar shape with the lip 152, then folded to abut against the side walls 156 and 157. By way of welding the portions 152a and 152b are then connected to the side walls 156 and 157 respectively.
In order to improve the tightness of the recuperator 15, the mechanical structure of the recuperator 15 is changed. The recuperator 15 does not comprise any folded end 74. The air handling unit 1 comprises a stop member 21 attached to the heat exchanger 5. The stop member 21 may be attached to the heat exchanger 5 by any means, such as screws, rivets or the like.
The stop member 21 comprises sliding means 210 interfacing with sliding means 132 of the support member 13 so that the ensemble formed by the heat exchanger 5 and the stop member 21 can slide with respect to the support member 13, in a direction transversal to the air flow. The stop member 21 acts as a sliding guide, and holds in position the heat exchanger with respect to the support member 13 along the air flow direction X. The cooperation of the sliding means 132 and 210 transmits the weight of the heat exchanger 5 to the support member 13.
The ensemble formed by the heat exchanger 5 and the stop member 21 is mounted in the recuperator 15, with a bottom portion 50 of the heat exchanger 5 resting against the bottom wall 154 of the recuperator 15. The recuperator 15 rests against the holding structure 19 by planar contact allowing sliding transversal movement of the recuperator 15 with respect to the holding structure 19 and the support member 13.
The ensemble formed by the heat exchanger 5, the stop member 21 and the recuperator 15 is therefore able to slide transversally with respect to the support member 13.
In case during transportation the heat exchanger 5 slides longitudinally to the air flow axis X, the stop member 21 cooperates with a portion of the support member 13, namely the sliding means 132, to block the ensemble formed by the heat exchanger 5 and the recuperator 15 with respect to the support member 13 along the longitudinal air flow direction X. The cooperation of the sliding means 132 and 210 transmits the weight of the heat exchanger 5 to the support member 13. The recuperator 15 does not therefore bear anymore the weight of the heat exchanger 5. The risk of shocks against the side walls of the recuperator 15 and the risk of damage to the tightness of the recuperator 15 are therefore reduced.
The recuperator 15 and the heat exchanger 5 forming a sliding ensemble also facilitate the mounting of this ensemble within the enclosure 3.
Making the support member 13 bear the weight of the heat exchanger 5 does not raise tightness issues as the support member 13 does not need to be watertight.
The support member 13 comprises a portion 130 extending transversal to the air flow direction X, and on which the sliding means 132 are formed. The stop member 21 is formed by a part extending transversally to the flow direction X and attached to the foot portion 50 of the heat exchanger 5. The stop member 21 comprises an attachment portion 212 suitable for planar contact with the bottom portion 50 and attachment to the bottom portion 50.
According to an embodiment, the stop member 21 may be made of folded sheet metal.
The sliding means 210 and the sliding means 132 have transversal sections of complementary shape. According to an example, the sliding means 210 and the sliding means 132 may have transversal sections of "V" shape, with a surface of contact SC formed by one of the branches of the "V" and represented on figure 13. Any other shape adapted to transmit the mechanical stress in the longitudinal direction X while at the same time allowing a sliding movement transversal to the longitudinal direction X can be provided, such as rounded shapes, square shapes or other polygonal shapes, or the like.
On the represented example, a side wall 158 of the recuperator 15, located on the side of the stop member 21, extends between the side wall 130 of the tray 13 and the stop member 21.
According to an embodiment, there may be no mechanical attachment between the heat exchanger 5 and the recuperator 15, the bottom portion 50 of the heat exchanger 5 being simply placed on the bottom face 154.
According to an optional embodiment, the support member 13 comprises a cut-out 134 allowing removable insertion of the condensed liquid tray 17. The tray 17 is removable for purpose of cleaning. The cut out 134 is formed by a reduced dimension of a lateral side wall 136 of the support member 13 with respect to an opposed lateral side wall 138.
When mounting the tray 17, the tray 17 is positioned vertically in front of the open side 150 of the recuperator 15, as represented on figure 17. Then as represented on figure 18, the tray 17 is moved along the arrow A3 towards the heat exchanger 5, so that the lip 152 is engaged with the internal volume of the tray 17. Finally, the tray 17 is rotated along the arrow A4, towards its horizontal position. This rotation is permitted by the cut-out 134.
The technical features of the embodiments described here-above can be combined to form new embodiments, as long as within the scope of the invention as defined in the appended claims.

Claims

Air handling unit (1) comprising:
- an enclosure (3);

- at least one heat exchanger (5) mounted in the enclosure (3);

- a condensate recuperator (15) placed under the at least one heat exchanger (5);

- a condensate tray (17) adapted to receive condensate flowing from the recuperator (15),
wherein the recuperator (15) comprises a first side wall (156), a second side wall (157), a bottom wall (154) interconnecting to each other said first and second side walls (156, 157), and an open end side (150) oriented towards the tray (17) and overlooking the tray (17), characterized in that the recuperator (15) further comprises, at said open end side (150), a lip (152) which protrudes from the bottom wall (154) and is inclined downwardly towards the tray (17) guiding the liquids towards the tray (17), and wherein lateral end portions (152a, 152b) of the lip (152) are bent inwards so to help in guiding the condensate flow towards a central area of the tray (17).
Air handling unit according to claim 1, wherein the lateral portions (152a, 152b) are formed by folded parts that are welded to said first and second side walls (156, 157) of the recuperator (15).
Air handling unit according to any preceding claim, wherein the inclined lip (152) has an inclination angle (α) with respect to the bottom wall (154) of the recuperator (15) comprised between 10° and 80°.
Air handling unit according to claim 3, wherein the inclination angle (α) of the inclined lip (152) is equal to 25°.