ES2882068T3 - Cooling apparatus - Google Patents

Abstract

Cooling apparatus (10) comprising: - a support structure (11) comprising a support surface (12); - a microchannel heat exchanger (15) arranged vertically on the support surface (12), the heat exchanger comprising a plurality of microchannel tubes (25) arranged horizontally for the flow of a fluid and transverse air passages (26 ) between the microchannel tubes, where the heat exchanger is curved along a circular perimeter line to define an upper circular opening (27) for the passage of air and a circular surface on the support surface (12) delimited through the heat exchanger (15); - a fan (19) arranged in the upper opening of the air passage (27), and - an air flow guide element (40) comprising a guide body (40a) having a generally frustoconical shape, arranged in a shape centered on the circular surface around a central axis (A).

Description

DESCRIPTION

cooling apparatus

The present invention relates to a cooling apparatus comprising a microchannel heat exchanger, according to claim 1.

Microchannel heat exchangers have long been used in the automotive industry, replacing mechanical copper-aluminum condensers. In recent years, however, interest in microchannel heat exchangers has increased, replacing traditional tube-flange heat exchangers in industrial processes to cool or condense a working fluid, using heat exchange with air. to reduce fluid temperature. Among the devices that use a microchannel heat exchanger, the dry cooler and the remote condenser take advantage of the outside air as the secondary fluid, while the liquid, for example, water, an aqueous solution containing ethylene glycol or a refrigerant, flows in tubes of microchannels and is brought from a first temperature to a second temperature, lower than the first. In the following description, cooling apparatus indicates an apparatus for cooling a fluid medium, gas or liquid, preferably a liquid.

Microchannel cooling equipment is also currently used in the field of HVAC air conditioning, cogeneration and refrigeration, for example as air condensers.

By "microchannel" is generally meant a channel with a hydraulic diameter (ie, for the passage of a liquid flow) less than about 3 mm, normally between 1 mm and 2 mm in equipment for industrial use.

Microchannel cooling equipment in industrial process cooling systems is equipped with fans and is often installed outdoors, for example on the roof of a building. In view of the fact that a plurality of heat exchangers are often needed to cool the working fluids, modular solutions can be advantageous to reduce the size of the cooling system.

Normally, the microchannel heat exchanger has a substantially flat shape in which a main direction of extension can be defined. The applicant has observed that, if the heat exchanger has a shape that assumes a closed or almost closed circular shape, the compactness of the apparatus for cooling or condensing a fluid, for example, a dry cooler or a condenser, increases while remaining the same. thermal performance.

Document WO 2008/136916 A1 shows a cooling apparatus comprising a support structure comprising a support surface, a microchannel heat exchanger arranged vertically on the support surface, the heat exchanger comprising a plurality of microchannel tubes and a fan.

The Applicant has considered a cooling apparatus comprising a microchannel heat exchanger which is circularly curved to form a circular upper air outlet opening on which a fan is arranged. In a volume enclosed by the circularly curved heat exchanger, the inlet or outlet air entering/leaving the lower area of the heat exchanger has a lower velocity than the velocity of the air entering or leaving the upper part of the heat exchanger , which is closer to the fan.

The Applicant has understood that providing an airflow guide element with a generally frustoconical shape within the volume allows a substantially homogeneous distribution of the air over the entire surface of the heat exchanger, from bottom to top. This allows for a higher overall heat capacity of the heat exchanger and thus of the cooling apparatus.

In accordance with the present invention, there is provided a cooling apparatus comprising:

- a support structure comprising a support surface;

- a microchannel heat exchanger arranged vertically on the support surface, the heat exchanger comprising a plurality of microchannel tubes arranged horizontally for the flow of a fluid and transverse air passages between the microchannel tubes, wherein the heat exchanger heat is curved along a circular perimeter line to define an upper circular opening for the passage of air and a circular surface on the support surface delimited by the heat exchanger (ie by the circular perimeter line);

- a fan arranged in the upper opening of the air passage, and

- an airflow guide element comprising a guide body having a generally frustoconical shape arranged centrally on the circular surface about a central axis.

Preferably, the guide body of the guide element has a lateral surface with a concave parabolic profile.

The applicant has observed that a concave parabolic profile of the lateral surface of the frustoconical guide body can further improve the airflow entering or leaving the lower part of the airflow volume and that it is subject to a considerable reduction in the flow velocity, since it is farther from the point of suction or push. Preferably, the fan is arranged at the opening of the upper air passage, in order to close this opening. The space enclosed by the support structure, in particular by the resting surface, the circularly curved heat exchanger and adjacent to the fan is substantially cylindrical in shape and will be referred to hereinafter as the airflow volume.

Preferably, the guide body of the guide element is hollow.

The frustoconical guide body has a circular upper surface having an outer diameter. Preferably, the upper surface is perpendicular to the central axis.

Preferably, the fan is an axial fan comprising a plurality of blades and a motor housed in a motor body centrally arranged in the opening of the upper air passage, the motor body having a (maximum) width in a direction parallel to the plane comprising the upper surface of the guide body. The generally frustoconical guide body is arranged such that its upper surface is disposed below and on the motor body, the upper surface having an outer diameter greater than or equal to the width of the motor body. Said configuration, in particular if the guide body has a concave parabolic side profile, allows the air flow to be transmitted directly to the fan wing profile, avoiding or reducing the air turbulence present in the area in front and to the side of the fan. fan motor body.

Especially in cooling systems that are installed outdoors, relatively high ambient temperatures, for example above 30°C, decrease the effectiveness of air cooling.

Preferably, the cooling apparatus comprises a nebulizer device for evaporative cooling of the surface of the heat exchanger. Preferably, the guide body is hollow and has an upper opening concentric to the central axis, the nebulizer device comprising:

- a distribution duct that extends inside the hollow body of the guide element along the central axis and passes through the upper opening of the hollow guide body, where the distribution duct has an inlet that can be connected to a pressurized cooling liquid source and outlet, and

- at least one diffusion conduit in fluid communication with the outlet of the distribution conduit, wherein the at least one diffusion conduit is placed radially outside the guide body and comprises a plurality of spray nozzles arranged in line along the at least one diffusion duct and oriented to spray nebulized cooling liquid towards the heat exchanger.

In some embodiments, the guide element also comprises a tray to collect any excess water mist. The collection tray is arranged on the support surface of the support structure, in a radially external position with respect to the frustoconical body and comprises a raised edge along its perimeter. Preferably, the collection tray surrounds the guide body and is in contact with the lower end of the side wall of the guide body. Preferably, the heat exchanger is mounted on the collection tray along an inner circular line concentric with the edge of the tray. In this embodiment, the annular collection tray has an outer diameter greater than the diameter of the surface defined by the outer circular curvature line of the heat exchanger.

In a preferred embodiment, the guide body is hollow, the collection tray has an annular shape, and the guide body and the collection tray are made in one piece.

Preferably, the fluid flowing within the microchannel tubes of the heat exchanger is a liquid. In some embodiments, the cooling device is a dry cooler for cooling a liquid.

Brief description of the figures

Other features and advantages of the present invention will become more apparent from the following description of some preferred embodiments thereof made with reference to the accompanying drawings. In said drawings, Figure 1 is a perspective view of a first embodiment of a cooling apparatus according to the present invention;

Figure 2 shows the cooling apparatus of Figure 1, in which the fan and the fixing elements to the support structure are omitted for clarity;

figure 3 is a perspective view of figure 2, partially in section, to show the volume enclosed by the heat exchanger and the fan;

- figure 4 shows the guide element and the nebulizer device of the cooling apparatus of figures 1-3, with several elements of the support structure omitted for clarity;

figure 5 shows a partial section of the apparatus of the previous figures along a plane B-B indicated in figure 1;

Figure 6 is a schematic plan view of a parallel flow microchannel heat exchanger; Figure 6A is an enlarged part of the insert C of Figure 6, schematically showing the microchannel structure.

Detailed description

With reference to figures 1 to 5, a cooling apparatus 10 comprises a support structure 11 comprising an upper support surface 12, on which it is mounted vertically, that is, substantially perpendicular to the support surface 12 (z axis). in the figures), a microchannel heat exchanger 15. For example, the heat exchanger is fixed to the support surface 12 with bolts.

The heat exchanger 15 has a circular curve, along a circular perimeter line, to delimit a circular surface on the support surface 12 and define an upper circular opening 27 for the passage of air (figure 2).

The microchannel heat exchanger 15 comprises: a first collector 20, arranged vertically with respect to the support surface 12, to receive an inlet fluid, and a second collector 21, arranged in parallel with the first collector 20 (and vertically with with respect to the support surface), to drain the fluid, a plurality of microchannel tubes arranged horizontally and in fluid communication with both the first and the second collector. The microchannel tubes are spaced vertically apart from one another to have a plurality of transverse air passages disposed between adjacent microchannel tubes. The microchannel tubes and transverse air passages are not clearly visible in Figures 1-3 and 5. The plurality of microchannel tubes with interposed air passages define a heat exchange region 14 that extends horizontally between the first and the second collector.

The heat exchanger has a length L of maximum vertical extension (z axis) from the bearing surface 12. The heat exchange region 14 defines an interior heat exchange surface, which extends vertically around the circular surface.

The cooling apparatus 10 further comprises a fan 19 arranged in the upper opening of the air passage 27, to close this opening. The space enclosed by the support structure 11, in particular by the support surface 12, by the circularly curved heat exchanger 15 and by the fan 19 has a substantially cylindrical shape and is indicated in the present description with the volume of the flow of air, in which the air, entering through the air ducts between the microchannel tubes, is sucked into the fan.

In the embodiment of the figures, a protection grid 49 is provided, arranged on the fan 19.

Figure 5 shows a partial section of the cooling apparatus 10 along a transverse median plane B-B indicated in Figure 1. The fan 19 is shown schematically, partially in section.

The fan 19 may be of the conventional type and comprises a plurality of blades 47 and a motor (not shown) for driving the blades, the motor being housed in a motor body 46. In the usual way, the plurality of blades are connected to the motor body 46 rotating about the impeller shaft. The motor body 46 is centrally located in the upper opening of the air passage 27.

The fan 19 is mounted on a spacer element 18 comprising a frame 18a of substantially cylindrical shape. Preferably, the spacer element 18 comprises a support grid for the motor body fixed to the frame 18a, the support grid being configured, of a conventional type, to facilitate the transport of air towards the blades (support grid, inside the frame 18a , not shown in Figure 5 for clarity Spacer element 18, in particular frame 18a, is mounted on heat exchanger 15. Preferably, frame 18a has a diameter substantially equal to the diameter of the air passage opening top 27.

The spacer element 18, i.e. the frame 18a on which the fan 19 is mounted, has such a height that it circularly encloses the motor body 46 and the blades 47 and ensures that these elements are arranged above the air exchange region. heat 14. In this way, the motor body 46, which often extends below the blades, avoids being located in a part of the airflow volume affected by heat exchange. Preferably, the motor body 46 and more preferably also the blades 47 are placed at a height greater than the vertical extension length L (in the figures along the z axis) of the heat exchanger 15.

In this embodiment, the substantially cylindrical-shaped airflow volume is the space enclosed horizontally by the support surface 12 and by the fan 19 and vertically by the heat exchanger of circular shape 15 and by the frame 18a of the spacer element.

Preferably, the fan 19 is an axial fan, with which the air is drawn in and sent in the same direction. The airflow is vertical, i.e. parallel to the impeller axis (i.e. z-axis), and the air entering from the transverse air passages is conveyed outside by the fan through the air passage opening 27. The applicant has realized that the apparatus according to the present invention can function effectively also in a mode in which the fan 19 is configured to push air into the volume of the air flow, the air being transported to the outside through the transverse air passages between the microchannel tubes. Depending on the mode of operation, the circular opening 27 is an opening for air outlet or air inlet. In known ways, the fan 19 can be configured to push air into or out of the airflow volume by adjusting the direction of rotation of the impeller and hence the blades (motor tuning).

In the detailed description that follows, for the sake of brevity only, reference will be made primarily to a configuration in which the fan is configured to allow air to flow out.

In the circularly curved heat exchanger, the first header 20 is adjacent to the second header 21 (FIG. 2). In the embodiment shown in the figures, the first and second collectors are arranged at a distance from each other, preferably between 2 cm and 10 cm, defining a longitudinal opening that extends along the collectors. Preferably, there is no contact between the two collectors to avoid heat exchange between the fluid flowing in the first collector 20 and the fluid flowing in the second collector 21, normally at a lower temperature.

Preferably, a cover element 13 is arranged above the first and second collectors 20, 21, which extends along the collectors and covers the longitudinal opening (FIG. 1). The cover element 13 serves to close the longitudinal opening between the collectors to circularly close the volume of air flow and make the suction of air towards the fan 19 more efficient.

With reference to figures 1 and 5, the heat exchanger 15 and the fan 19 mounted on the spacer element 18 are attached to each other and to the support structure 11 by means of fixing elements 16, 17 (more clearly visible in figure one). In particular, a plurality of tie rod fixings 16, for example by means of fixing screws, the heat exchanger to the support structure 11 and a respective plurality of connection plates 17 fix the heat exchanger 15 to the spacer element 18, in particular to the frame 18a, for example, by means of fixing screws. In the non-limiting example of figure 1, the connection plates 17 are plates for orthogonal transversal connection, transversally to a lower flange of the frame 18a of the spacer element 18 and orthogonally to a respective brace 16 for fixing to the support structure 11 The connection plates 17 can be equipped with a free vertical part comprising a through hole for hanging and transporting the cooling apparatus. It is understood that the present invention is not limited to a particular attachment configuration.

The construction of the microchannel heat exchanger may be of the conventional type. Preferably, the heat exchanger has a parallel flow configuration. Figure 6 schematically shows a typical construction of a parallel flow microchannel heat exchanger. Figure 6A is an enlarged portion of insert C of Figure 6, schematically showing the microchannel structure. The heat exchanger 15 comprises a plurality of microchannel tubes 25, each tube 25 having two ends (not shown) connected, respectively, to the first and second headers 20, 21 to be in fluid communication with the first and second headers. 20, 21.

Typically, in conventional microchannel heat exchangers, the maximum thickness of the heat exchanger along a direction perpendicular to the main extension is about 2 cm to 10 cm, and is often defined by the cross section of the distribution manifolds. of the circulating fluid.

The microchannel tubes 25 are arranged horizontally, substantially parallel to each other. The first and second manifolds 20, 21 are arranged parallel to each other and substantially perpendicular to the microchannel tubes 25. Each microchannel tube comprises a plurality of microchannels, within which fluid flows. Preferably, the microchannel tubes are flat, eg about 3mm thick, each comprising a plurality of microchannels with a cross-flow width of 1mm to 6mm. Tubes can be welded to manifolds by brazing or casting.

Preferably, the heat exchanger 15 comprises a plurality of tabs 26, which are arranged in the air passages between and in contact with the adjacent tubes 25. Preferably, each flange 26 extends parallel to the microchannel tubes, substantially covering the length of the microchannel tubes. The tabs are preferably welded between the microchannel tubes by brazing. In one embodiment, the tabs 26 are louver-type tabs.

Referring again to figures 1-5, the first collector 20 has an inlet opening 22 for the entry of a fluid and a first plurality of outlet openings (not visible) arranged along its length, in the first ends of the microchannel tubes to place the first collector in fluid communication with the microchannels of each tube of the plurality of tubes. The fluid flows along the microchannels along parallel flow paths. The second collector 21 has an outlet opening 23 for draining the fluid and a second plurality of inlet openings (not visible) respectively to the first plurality of outlet openings, arranged along its length, at the second ends of the microchannel tubes.

Preferably, the inlet opening 22 for fluid inflow and the outlet opening 23 for fluid outflow are arranged at one end of the respective manifold 20, 21. In the embodiment shown in figures 1-5 (more clearly visible in figure 3, showing the heat exchanger in partial section), the support structure 11 comprises a first and a second through opening 28a and 28b for the insertion of the lower end of the respective collector 20, 21 comprising the respective opening 22 , 2. 3.

In the case of cooling a working fluid and in air condensers for HVAC, the heat exchanger is normally with an open circuit flow. However, the present invention envisions that the heat exchanger may be a closed loop flow.

In operating mode, the first collector 20 is connected, through the inlet opening 22, with an inlet conduit for the inlet of fluid and the second collector 21 is connected, through the outlet opening 23, with a conduit. outlet for fluid outlet (inlet and outlet ducts not shown in the figures).

The fluid may be a liquid, eg hot water, which must be cooled. In that case, the cooling apparatus, eg dry cooler, may be part of a cooling or temperature control system for industrial processes where water is cooled by airflow. For example, high temperature water enters the first conduit 20 of the heat exchanger and leaves the second conduit 21 at a lower temperature.

If the fluid is a liquid refrigerant, the cooling apparatus 10 may function as an air condenser. Air enters from the outside through the flaps 26 and, with the fan motor on, is conveyed to the outlet, i.e. the opening of the upper air passage 27, through the blades 47 of the fan 19.

Preferably, microchannel tubes 25, barbs 26, and more preferably manifolds 20 and 21 are made entirely of aluminum.

Microchannel heat exchangers usually have a planar configuration, that is, they have a main direction of extension arranged in a plane, as shown in the example in figure 6. To obtain a circular configuration, the planar microchannel heat exchanger it is circularly bent, along a circumferential line to bend the plurality of microchannel tubes, approaching the first collector 20 to the second collector 21. When the exchanger is mounted on the support surface 12, the circumferential bending line defines the perimeter of the circular surface of the generally cylindrical airflow volume.

In accordance with the present invention, the cooling apparatus 10 comprises an airflow guide element 40 disposed in the airflow volume and configured to guide air into or out of interposed spaces (preferably with tabs). between the microchannel tubes, towards the ventilator or coming from the ventilator.

The airflow guide element has the general function of optimizing the outflow/inflow of outflow/inflow air between the microchannel tubes.

The guide element 40 comprises a guide body 40a in the shape of a generally truncated cone, preferably with a circular base. The truncated cone body is arranged on the support surface 12, substantially in the center with respect to the circular surface delimited by the heat exchanger, around a central axis A (along the z axis). Preferably, the truncated-cone guide body 40a has a rotational side surface 40b having a concave parabolic profile. The concave parabolic profile is in relation to a cross section in the yz plane perpendicular to the support surface 12 and passing through the central axis A. The concave parabolic profile has a progressive increase in cross section in a yz plane of the body 40a. from an upper end of the lateral surface 40b to its lower end, at the base of the guide body 40a.

The parabolic profile of the surface of the side guide body is concave with respect to the air flow entering (or leaving) through the air passages of the heat exchanger.

Preferably, the frustoconical guide body 40a has a substantially circular upper surface and a substantially circular lower surface, concentric to the upper surface.

Preferably, the axis of the fan impeller 19 is on the central axis A, and therefore the motor body 46 is approximately centered on the central axis A. In a plane passing through the motor body and perpendicular to the central axis A, the motor body occupies a centrally arranged motor area at the upper air passage opening 27. The motor area of the motor body can be represented by the width of the motor body 46 on a direction perpendicular to the central axis A. Width means the maximum width of the motor body.

Preferably, the guide body 40a is arranged so that the upper surface of the guide body is arranged below and in the engine area of the engine body. In this way, the airflow towards the fan continues upwards along the concave parabolic surface and, unobstructed by the air turbulence created by the motor body in action, reaches the profile of the fan's wing. This also applies if the fan motor is operated to push air into the airflow volume.

Preferably, the upper surface of the guide body has an outer diameter greater than or equal to the width of the motor body in a direction that is in a plane parallel to the upper surface, in the embodiment of the figures in a direction perpendicular to the axis A. In some embodiments, the outside diameter of the top surface is approximately equal to the width of the motor body.

In the preferred embodiments, the guide body 40a of the generally frustoconical guide element 40 is hollow and has an upper opening 43 concentric to the central axis A. The hollow guide body has a lower opening in the bearing surface 12. Preferably , the lower end of the lateral surface 40b delimits the lower opening in the base of the guide body (partially visible in figure 3) which is arranged on the support surface 12. In the embodiment of the figures, the upper and lower surfaces of the hollow guide body 40a are generally ring-shaped.

In one embodiment, the guide body has a height H of 1050 mm, an upper surface with an outer diameter of approximately 160 mm and a lower surface with a diameter of approximately 1080 mm.

Preferably, the guide body 40 has a height H greater than or equal to 0.8 x L, L being the maximum vertical extension of the heat exchanger 15 from the support surface 12. More preferably, the height of the guide element 40 is between 0.8 xL and L. However, it should be understood that, with a suitable size of the spacer element 18, the height of the guide element 40 could be greater than L. In some embodiments, the height H of the guide element is between 0 .8 xL and 1.1 xL.

The Applicant has pointed out that, especially in cooling systems that are installed outdoors, relatively high ambient temperatures, for example above 30 °C, decrease the efficiency of air cooling.

In preferred embodiments, the apparatus comprises a nebulizer device 30 for evaporative cooling of the air within the cylindrical airflow volume through the evaporation of a cooling liquid, preferably water, in contact with the air. In such embodiments, the guide body 40a is hollow. The nebulizer device 30 comprises a distribution duct 39 that extends vertically from the support surface 12 and is arranged substantially in the center of the circular surface delimited by the heat exchanger 15. The distribution duct 39 extends inside the body of hollow guide 40a along the central axis A. The hollow guide body 40a of the guide element 40 is concentric with the distribution duct 39, which passes through the upper opening 43 of the guide body.

The distribution duct 39 has a lower inlet opening 48 (figure 5) for the introduction of pressurized water, which can be at room temperature or refrigerated, from a source (for example, a tank or water mains) external to the appliance. cooling and not shown in the figures. The distribution conduit further comprises an upper outlet opening for pressurized water.

The distribution duct 39 is mounted on a swivel joint 38, to rotate around the central axis A. The swivel joint 38 is in turn mounted on a central through hole (not shown) which from the bearing surface 12 passes through support structure 11. Swivel joint 38 is motorized or activated by water pressure, in known ways.

The distribution conduit is connected to at least one diffusion conduit provided with a plurality of nebulizing nozzles. The at least one diffusion duct is arranged vertically, parallel to and spaced from the distribution duct, in a position radially external to the guide body. The at least one diffusion conduit rotates integrally with the distribution conduit along a circular line while the distribution conduit rotates on itself. Preferably, the at least one diffusion duct is rigidly connected to the distribution duct. Preferably, the at least one diffusion duct is connected to the distribution duct by means of a connecting duct and is suspended from the latter. The circular line of rotation of the at least one diffusion duct is radially external to the lower surface of the guide body and radially internal to the circular line of the perimeter that delimits the volume of air flow on the support surface 12.

In the embodiment of the figures, the distribution duct 39 is connected to a first and a second diffusion duct 32a and 32b, arranged vertically, in parallel with the distribution duct 39, and spaced from it to be arranged radially outside the body of guide 40a. The diffusion ducts 32a, 32b are connected to the distribution duct 39 by means of a cross connection duct 33, preferably arranged horizontally. To facilitate rotation, the diffusion ducts are suspended from the connecting duct 33.

Each diffusion duct comprises a plurality of spray nozzles 35 arranged along the respective diffusion duct and oriented to spray water mist (in droplets normally a few microns in diameter) towards the heat exchanger 15. In particular, water is sprayed misted onto the inner heat exchange surface of heat exchanger 15, which faces and encloses the airflow volume. Preferably, the nebulizer nozzles 35 are arranged in line along the respective diffusion duct 32a, 32b.

The distribution duct 39 has a length greater than the height H of the hollow body 40a in order to have an upper water outlet opening arranged above the guide element 40 for connection with the cross connecting duct 33, and then with the drainage ducts. diffusion 32a, 32b.

In some embodiments, the length of the conduit 39 is less than or equal to the length L of the heat exchanger, preferably between 0.9 x L and L. However, it should be understood that, with a suitable size of the spacer element 18, the length of the distribution duct could be greater than L. In some embodiments, the length of the distribution duct is between 0.9 xL and 1.2 xL and is greater than H (height of the guide body).

Preferably, the diffusion ducts 32a, 32b are arranged radially symmetrically with respect to the distribution duct 39 and, therefore, to the central axis A of rotation. The construction is "carousel style" and the diffusion ducts 32a, 32b, suspended from the connecting duct 33, rotate along a circular line concentric to the distribution duct 39, radially external to the guide element and radially internal to the circular line of the perimeter of the circular surface delimited by the heat exchanger 15.

The length of the diffusion ducts 32a, 32b is preferably selected so that the ducts extend vertically to spray the interior surface of the heat exchange region 14, preferably the entire interior surface.

The pressurized water, for example at a pressure between 1 and 10 bar, is pushed along the distribution duct towards the upper outlet opening to exit the nozzles 35 in the form of nebulized sprays. For example, the distribution line 39 is connected to a compressor (not shown).

In one embodiment, the cooling apparatus has a total height of approximately 1.90 m, the maximum vertical extension length L of the heat exchanger is approximately 1.30 m, and the diameter of the opening of the upper circular air passage (and therefore of the circular support surface delimited by the exchanger) is approximately 1.00 m.

Preferably, the guide element 40 further comprises a collection tray 41 to collect any excess water mist. The collection tray 41 comprises a raised edge 42 along its perimeter and is arranged on the bearing surface 12 of the support structure 11, in a position radially external to the frustoconical guide body 40a. In the embodiment of the figures, the collection tray 41, which is mounted on the support surface, surrounds and is in contact with the lower end of the side wall 40b of the guide body 40a.

In one embodiment, the collection tray is annular in shape. The collection tray 41 comprises a drainage opening (not visible), preferably arranged in an intermediate radial position between the edge 42 and the perimeter of the body 40a. The drain opening is provided in a through opening of the support structure 11 to allow water to drain out of the cooling apparatus.

Preferably, the guide body 40a is hollow and the guide body and the collecting plate 41 are made in one piece, preferably made from a plastic material, for example ABS (acrylonitrile-butadiene styrene). For example, the hollow guide body integrated with the collection tray can be made by thermoforming. In this embodiment, shown in the figures, the collection tray 41 forms the base of the guide body 40a.

Preferably, the heat exchanger is disposed in the collection tray 41, mounted along an inner circular line and concentric with respect to the edge 42 of the collection tray 41. In this embodiment, the collection tray 41 has a diameter greater than the diameter of the surface defined by the outer circular line of curvature of the heat exchanger 15. The collection tray 41 comprises two through holes (not visible in figure 4 because they are hidden by the raised edge 42) in the holes 28a , 28b for the insertion/assembly of the first and second manifolds 20, 21 in the support structure 11.

The nebulizer device can be configured to activate in the event of relatively high ambient temperatures, for example above 30°C, and deactivate when the temperature drops below a threshold value. For this purpose and in a known manner, the activation/deactivation of the nebulizer device can be controlled by a central control unit to which a room temperature detection system is connected.

Naturally, those skilled in the art can make additional modifications and variants to the invention described above in order to meet specific and contingent application needs, variants and modifications in any case falling within the scope of protection defined in the following claims.

Claims (11)

1. Cooling apparatus (10) comprising: - a support structure (11) comprising a support surface (12); - a microchannel heat exchanger (15) arranged vertically on the support surface (12), the heat exchanger comprising a plurality of microchannel tubes (25) arranged horizontally for the flow of a fluid and transverse air passages (26 ) between the microchannel tubes, where the heat exchanger is curved along a circular perimeter line to define an upper circular opening (27) for the passage of air and a circular surface on the support surface (12) delimited through the heat exchanger (15); - a fan (19) arranged in the upper opening of the air passage (27), and - an airflow guide element (40) comprising a guide body (40a) having a generally frustoconical shape, arranged centrally on the circular surface about a central axis (A). Cooling apparatus (10) according to claim 1, wherein the body (40a) of the guide element (40) has a lateral rotation surface (40b) having a concave parabolic profile. 3. Cooling device (10) according to claims 1 or 2, wherein the body (40a) is hollow and has an upper opening (43) concentric to the central axis (A). 4. Cooling apparatus (10) according to one of the preceding claims, wherein the microchannel heat exchanger (15) comprises: - a first collector (20) arranged vertically to receive an input fluid; - a second collector (21) to drain the fluid, arranged parallel to the first collector (20), where the plurality of microchannel tubes (25) are arranged horizontally between the first (20) and second (21) manifolds and in fluid communication with both the first and second manifolds, the microchannel tubes (25) of the plurality vertically separated from each other, and the microchannel tubes of the plurality of microchannel tubes (25) are curved along the circular perimeter line, and the first collector (20) and the second collector (21) are disposed adjacent to each other. 5. Cooling device (10) according to one of the preceding claims, wherein the microchannel heat exchanger (15) further comprises: - a plurality of tabs (26) arranged in the transverse air passages between adjacent microchannel tubes (25). 6. Cooling device (10) according to one of the preceding claims, wherein: - the fan (19) is an axial fan comprising a plurality of blades (47) and a motor housed in a motor body (46) placed centrally in the circular air passage opening (27), and - the guide body (40a) having a generally frustoconical shape has an upper surface disposed below and on the motor body (46) and having an outer diameter that is greater than or equal to the width of the motor body in one direction parallel to the plane comprising the upper surface. Cooling appliance (10) according to one of the preceding claims, wherein the fan (19) is mounted on a spacer element (18) comprising a substantially cylindrical-shaped frame (18a) arranged on the heat exchanger (15), the frame having a height such that it encloses the motor body (46) and the plurality of blades (47) and places the motor body (46) at a height greater than the maximum extension length of the heat exchanger (15) in the vertical direction. Cooling apparatus (10) according to one of the preceding claims, when dependent on claim 3, further comprising a nebulizer device (30) comprising: - a distribution duct (39) that extends inside the hollow body (40a) of the guide element (40) along the central axis (A) and passes through the upper opening (43) of the hollow body, where the distribution conduit (39) has an inlet that can be connected to a source of pressurized cooling liquid and an outlet, and - at least one diffusion conduit (32a, 32b) in fluid communication with the outlet of the distribution conduit ( 39), where the at least one diffusion duct (32a, 32b) is placed radially outside the guide body (40a) and comprises a plurality of nebulizer nozzles (35) arranged in line along the at least one diffusion duct. diffusion and oriented to spray misted cooling liquid towards the heat exchanger 9. Cooling apparatus (10) according to claim 8, wherein the distribution duct (39) is configured to rotate about the central axis (A) imparting a rotation to the at least one diffusion duct (32a, 32b) along a circular line radially external to the guide body (40a) and radially internal and concentric with respect to the circular perimeter line, the at least one diffusion duct (32a, 32b) being arranged parallel to the distribution duct ( 39). Cooling device (10) according to one of claims 8 or 9, wherein the at least one diffusion duct comprises a first (32a) and a second (32b) diffusion duct, connected to the distribution duct ( 39) and arranged parallel thereto, each diffusion duct comprising a plurality of nebulizing nozzles (35) arranged along the respective diffusion duct and oriented to spray nebulized cooling liquid towards the heat exchanger (15). Cooling apparatus (10) according to claim 10, wherein the first and second diffusion ducts (32a, 32b) are rigidly connected to the distribution duct (39) through a cross connecting duct ( 33) and are arranged suspended from the transverse connection duct (33) radially symmetrical with respect to the distribution duct (39).