FIELD OF THE INVENTION

The present invention preferably concerns a cooling apparatus and a corresponding method to improve the efficiency of a heat exchanger for plants for conditioning and/or refrigerating spaces and not only.

The invention also concerns a heat exchanger provided with the cooling apparatus.

BACKGROUND OF THE INVENTION

It is known that a sector that uses significant quantities of electrical energy is that of industrial air conditioning and refrigeration.

The high demand for electrical energy, especially in the summer period, is mainly due to the high thermal load to which heat exchangers are subjected.

Another reason is the difficulty that heat exchangers have in transferring heat to the air that transits to the outside.

This situation is exacerbated in the presence of high external temperatures which make heat dissipation difficult.

It is known that heat exchangers generally consist of a plurality of pipes, inside which a heat-carrying fluid circulates, connected together and cooperating with specific aluminum fins.

Both heat exchangers are known in which the pipe/fm assembly is hit by a stream of air that has a temperature lower than that of the heat-carrying fluid, so as to cool the latter, and also heat exchangers in which the heat-carrying fluid which circulates in the pipes acts by means of the pipe/fin assembly on the stream of air, cooling the latter.

It is known that the lower the temperature of the stream of air that passes through the exchanger, the greater the thermal power that the exchanger is able to transmit to the air in transit, heating it. This is the case of heat exchangers for air conditioning plants with heat pump.

Similarly, and alternatively, the more heat removal capacity the air has, the more heat is removed from the heat-carrying fluid that flows in the pipes of the heat exchanger. This is the case of heat exchangers which are used to reduce the temperature of the heat-carrying fluid.

In the warm months, the simultaneous functioning of a large number of plants, which often function in extreme conditions, determines a considerable general increase in consumption and absorption of electrical energy.

In the processing industry, where there are several applications that use a heat carrying fluid as a cooling fluid, for example hydroglycolic mixtures with temperatures above 25°C, during the summer period the plants have to use a chiller device to cool the fluid, since the external temperatures are too high to use dry coolers, with a consequent increase in consumption and waste of energy.

It is known that many heat exchangers currently have devices able to lower the temperature of the air entering the finned pack, causing water to evaporate directly into the incoming stream of air.

To achieve the purpose, for example, specific packs are used consisting of layers of suitable material, positioned at the entrance of the heat exchanger, which are sprayed with water.

There are also devices that use nozzles that nebulize water at low or high pressure on the layers of material as above.

The above mentioned devices, however, have some disadvantages:

- in the case of layers of material sprayed with water, mold and algae are easily formed;

- in the case of devices with low pressure spraying nozzles, the formation of excessively large droplets of water is not able to guarantee the complete evaporation thereof, with consequent lower effectiveness of the evaporative action and greater water consumption;

- in the case of devices with high pressure spraying nozzles, the non uniformity of the evaporative action and the flow rate control of the on/off type create discontinuity in the amount of water used, which proves to not be proportionate to the amount of heat that it has to subtract.

These known devices also entail significant additional costs in terms of energy consumption.

US-A-2008/0022709 describes a system for cooling a stream of water with an inlet stream of air to produce a cooled stream of water usable with a cooling coil to produce chilled water for a system with ground well. The solution described in this document provides to nebulize droplets of water toward an evaporation mean located in a cooling zone upstream of an exchanger. The presence of the evaporation means does not allow to have a real and direct control of the nebulization, due to the hysteresis produced by the vapor residues present on the evaporation means themselves. The solution described in US-A-2008/0022709 does not allow to optimize energy consumption and at the same time guarantee effective cooling of the heat exchanger. Furthermore, since not all the nebulized water is evaporated, stagnations and mold can be created with the disadvantages described above.

WO-A-2004/085946 describes a plate heat exchanger for exchanging heat between a first and a second stream of air, which comprises a plurality of plates that limit exchange chambers disposed in series in a transverse direction with respect to the plates.

One purpose of the present invention is to provide a cooling apparatus and to devise a method for improving the efficiency of an air heat exchanger for cooling any heat-carrying fluid whatsoever circulating inside it, or for cooling the air.

One purpose of the present invention, in particular, is to perfect the heat exchange system of the air entering a heat exchanger.

One purpose of the present invention is also to provide an air cooling apparatus, applicable to an air exchanger, which is simple and economic at least in terms of consumption.

Another purpose of the present invention is to provide a cooling apparatus able to subcool the heat-carrying fluid circulating in a heat exchanger in the phase in which the heat-carrying fluid is in the liquid state.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

The improvements that allow to achieve the purposes above and other advantages which will become clearer hereafter are obtained by a cooling apparatus according to the invention.

The cooling apparatus in particular is based on an adiabatic cooling system and can be applied to any type of air exchanger whatsoever.

The cooling apparatus is generally applicable to an air heat exchanger equipped with pipes in which a heat-carrying fluid flows, which cooperate with heat dissipation fins to cool the transiting heat-carrying fluid.

In accordance with some embodiments, the cooling apparatus comprises a source of a cooling liquid, for example water, nebulizing nozzles configured to supply the cooling liquid suitable to dispose of the required heat from each heat exchanger, feed means suitable to feed the cooling fluid from the source to the nozzles and possible control means to adjust the quantity and flow rate of the fluid fed.

According to some embodiments, the nebulizing nozzles are disposed according to a matrix, ordered into rows and columns.

According to some embodiments, the nebulizing nozzles are located one with respect to the other at a distance such as to provide, in cooperation with each other, a substantially uniform stream of cooling liquid on a plane parallel to the respective outlet mouths.

According to some embodiments, the feed means comprise a pump of the type suitable to feed high pressure water to the nebulizing nozzles, so as to obtain droplets of very small sizes even at the minimum functioning pressure. In this way, all the water fed is nebulized even at partial loads.

According to variants, it can be provided to increase the number of nebulizing nozzles, and to reduce the flow rate and/or the pressure of the cooling liquid supplied by the feed means. The Applicant, by means of experimental tests, has verified that it is possible to obtain good results even with low pressures, starting from 1 bar. In this case, the use of a pump may also not be necessary, with a consequent increase in the efficiency of the apparatus and reduction of the energy consumption associated with it.

According to possible variants, the feed means comprise a plurality of valves, in particular electronically commandable electro valves, which can be divided into parts, that is, the passage section thereof can be modulated in order to increase or decrease the flow rate and pressure of the cooling liquid according to requirements.

The present invention, if applied in a capillary manner, considering the capability to increase the efficiency of air exchangers, both newly built and also existing ones, allows to reduce the absorption of electrical energy necessary for their functioning, preventing the occurrence of peaks of electric current absorption, in particular during the summer months. This device also allows to significantly reduce emissions of carbon dioxide C0 ₂ into the environment.

The capillarity of the distribution of the cooling liquid allows to optimize its distribution, avoiding possible waste.

Since it is able to lower the temperature of the air sucked in by the ventilation device by about 10°C, the apparatus according to the invention allows to prevent the activation of the chiller devices even with ambient air temperatures in the range of 35 °C, with considerable energy savings when the heat-carrying fluid has to circulate at 25 °C.

The apparatus according to the invention can also be advantageously applied to condensers of refrigerator units that use different types of synthetic (HFC, HFO, etc.) or natural (ammonia, propane and isobutane mixtures, etc.) refrigerants. In this case, since it is able to cool the air sucked in by the condensers by about 10 °C, it allows to lower the compression ratio of the refrigeration compressors, with a consequent increase in the efficiency of the system.

The apparatus according to the invention, therefore, by increasing the energy efficiency of the exchanger, is able to increase both the energy efficiency ratio (EER) thereof, and also the seasonal energy efficiency ratio (SEER).

Furthermore, the vapor of the cooling liquid is immediately sucked in by the heat exchanger, without having the time to generate bacterial formations or mold, making the apparatus according to the invention hygienic and suitable to be applied in any environment whatsoever.

According to some embodiments, the apparatus comprises control devices configured to feed the stream of cooling liquid between a delivery circuit and a suction circuit of the pump.

In particular, the apparatus comprises a control and command unit configured to receive data relating to the environmental conditions, detected by detection devices, process them in real time and command the functioning of the feed means of the apparatus as a function of the data received, in order to increase the efficiency of the heat exchanger and reduce energy consumptions. In other words, the flow rate of the nebulized water can be modulated in real time as a function of the thermal load disposed, such as to modify the temperature at entry of the air entering the exchanger as a function of the thermal power required by the exchanger itself.

According to another embodiment, the apparatus comprises interception devices configured to divide into parts the surface affected by the nebulizing nozzles.

According to other embodiments, the cooling apparatus according to the invention, in the event the heat-carrying fluid is a gas, allows to subcool the latter during the phase in which it is in a liquid state, so as to increase the useful enthalpy effect for the same electrical energy required, improving the efficiency of the heat exchanger.

According to other embodiments, the cooling apparatus comprises a wet bulb detection device, configured to measure temperature and/or humidity in the proximity of an external surface of the heat exchanger. The control and command unit can be configured to determine the wet bulb temperature at the environmental conditions measured by the detection devices and to activate/deactivate the feed means in order to guarantee that the wet bulb temperature of the humid air that affects the surface of the heat exchanger is always kept higher than the wet bulb value determined - even by only a few tenths of a degree. In this way, limescale is prevented from accumulating on the surface of the heat exchanger, where dust and dirt normally deposit, due to water evaporated in contact with it.

These embodiments allow to preserve the surface of the heat exchanger, and also prevent having to carry out accessory processes such as demineralizing the water, or osmotizing the water used as a cooling liquid, which entail significant costs both as regards the initial economic investment, and also routine maintenance.

Embodiments described here also concern a method to cool a heat exchanger, 7 which provides to spray a cooling liquid by means of nebulizing nozzles disposed in a matrix order on a surface of a heat exchanger, and nebulize the cooling liquid in a homogeneous and uniform manner on an area corresponding to a surface of the heat exchanger to be cooled, so as to decrease the temperature of a stream of air incident on the surface and cool the heat exchanger by adiabatic evaporation.

According to other embodiments, the cooling method provides to determine a wet bulb temperature value in the proximity of the surface of the heat exchanger and to adjust the flow rate of the cooling liquid so that the temperature measured by a wet bulb detection device in the proximity of the surface of the heat0 exchanger always remains at least a few tenths of a degree higher than the wet bulb temperature value determined.

Other embodiments concern a heat exchanger comprising a cooling apparatus according to the invention.

ILLUSTRATION OF THE DRAWINGS

5 These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is a schematic front view of a heat exchanger provided with a cooling apparatus according to embodiments described here;

0 - fig. 2 is a schematic lateral view of a cooling apparatus applied to a heat exchanger according to one embodiment;

- fig. 3 is a schematic lateral view of a cooling apparatus applied to a heat exchanger according to a variant;

- fig. 3 a is a schematic lateral view of a detail of a cooling apparatus according to5 another variant;

- fig. 4 is a schematic front view of a part of a cooling apparatus applied to a heat exchanger according to a further variant;

- fig. 5 is a schematic lateral view of a cooling apparatus according to the invention according to a variant applied to two heat exchangers;

0 - fig. 6 is a schematic front view of a part of a cooling apparatus applied to a heat exchanger according to a further variant;

- fig. 7 is a schematic front view of a cooling apparatus according to the invention according to a variant; - fig. 7a shows a detail of fig. 7 according to a variant;

- fig. 8 is a schematic front view of a cooling apparatus according to the invention according to a variant, applied to two heat exchangers;

- fig. 9 is a graph showing the curve of the air that comes into contact with the heat exchanger as atmospheric conditions vary.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DESCRIPTION OF EMBODIMENTS

We will now refer in detail to the various embodiments of the invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

Embodiments described here concern an apparatus 10 configured to cool a heat exchanger 11 so as to improve the heat exchange efficiency thereof.

The heat exchanger 11 to which the apparatus 10 according to the invention can be applied can be any air heat exchanger whatsoever, newly built or already existing. In the first case, the apparatus 10 makes the heat exchangers 11 better performing than the original, in particular if they are sized for climatic conditions different from the current ones, that is, for lower external temperatures.

The heat exchanger 11 comprises pipes 12 which develop between an inlet conduit 13 and an outlet conduit 14, in which a heat-carrying fluid is able to flow. The pipes 12 can define a condenser of a cooling circuit.

The heat-carrying fluid enters the heat exchanger 11 through the inlet conduit 13 and exits, cooled, from the outlet conduit 14.

The heat exchanger 11 comprises, in a known manner, a plurality of dissipating fins 15, cooperating with the pipes 12 and configured to increase the heat-exchange surface and facilitate the dissipation of the heat and, therefore, the cooling of the heat-carrying fluid circulating inside. According to some embodiments, the exchanger 11 also comprises one or more ventilation devices 16 configured to generate a stream of air forced through the fins 15 and the pipes 12 in order to increase the removal of heat from them.

According to some embodiments, the direction of the stream of air F, indicated for example by the arrows in fig. 2, is substantially orthogonal to a lateral heat- exchange surface of the heat exchanger 11 and axial with respect to the ventilation devices 16.

The direction of the stream of air F in the heat exchanger 11 defines an entry side 22 and an exit side 23 thereof.

According to some embodiments, the cooling apparatus 10 comprises a hydraulic circuit 17 connected, during use, to a source 18 that feeds a cooling liquid, and configured to allow the latter to flow inside it.

According to some embodiments, the cooling liquid is water.

The feed source 18 can be a tank comprised in the apparatus 10, or it can be a hydraulic network, domestic or industrial.

According to some embodiments, the cooling apparatus 10 comprises a plurality of nebulizing nozzles 19 configured to nebulize the cooling liquid fed along the hydraulic circuit 17.

According to some embodiments, the nebulizing nozzles 19 are disposed in a matrix order on respective feed conduits 20, each fed by the cooling liquid circulating in the hydraulic circuit 17.

The feed conduits 20 can be disposed parallel to each other and equidistant along a collector 21 defining a terminal segment of the hydraulic circuit 17.

According to some embodiments, the nebulizing nozzles 19 are disposed equally distanced with respect to each other along lines and/or columns.

The extension area of the collector 21 and the distribution area of the nebulizing nozzles 19 substantially corresponds to a surface 24 to be cooled of the heat exchanger 11.

According to some embodiments, the number and the reciprocal distance between the nebulizing nozzles 19 depends on the extension of the surface area that has to be cooled. For example, the number and distance of the nozzles 19 can be defined as a function of the type of heat exchanger 11 to which they are to be applied. The positioning of the nebulizing nozzles 19 and of the feed conduits 20 is defined so as to guarantee an adequate and uniform release of water vapor onto the entire surface 24 of the heat exchanger 11 in a capillary manner, without any insufficiency or waste of vapor, so as to obtain a maximum level of efficiency.

In this way, thanks to the capillarity of nebulization of the cooling liquid, it is possible to effectively and uniformly cool substantially the entire surface 24 of the heat exchanger 11 facing the inlet side 22.

According to embodiments described with reference to figs. 1-3 and 5, the nebulizing nozzles 19 are oriented, during use, in a direction substantially orthogonal to the surface 24 to be cooled of the fins 15.

According to some embodiments, the nebulizing nozzles 19 can be configured to nebulize the cooling liquid with a jet having a certain aperture cone, so as to supply, in cooperation with the other nebulizing nozzles 19, a substantially uniform flow onto a plane P parallel to the respective outlet mouths 19a, located at a distance D from the latter.

For example, the inclination of the cone of nebulized water can be comprised between about 60° and 80°.

By way of example, the nebulizing nozzles 19 can be configured to nebulize the cooling liquid with a cone having a diameter of about 90- 150mm, and in any case dependent on the outlet pressure and the speed of the air in transit, on the plane P.

By way of example, the distance D can be comprised between about 10cm and about 30cm. According to some embodiments, for example described with reference to fig. 3, during use, the nebulizing nozzles 19 are positioned with their outlet mouths 19a facing toward the heat exchanger 11, on the opposite side with respect to the ventilation device(s) 16.

In this way, the liquid nebulized by the nozzles 19 is delivered directly onto the surface 24 of the inlet side 22 of the heat exchanger 11, in a direction concordant with the stream of air generated by the ventilation device 16.

This solution can be implemented, for example, when the space available between the outlet mouths 19a and the heat exchanger 11 is greater than or equal to the distance D, and therefore such as to guarantee a uniform nebulization of the cooling liquid on the entire surface. 24. According to possible variants, for example described with reference to figs. 2 and 4, during use, the nebulizing nozzles 19 are positioned with their outlet mouths 19a facing in an opposite direction with respect to the heat exchanger 11 and the stream of air F entering the heat exchanger 11.

The delivery of the cooling fluid in the opposite direction to the exchanger 11, in combination with the action of the stream of air F, allows to capture the whole cone of cooling liquid nebulized by the nebulizing nozzles 19, so as to obtain a uniform distribution on the surface 24 to be cooled.

This embodiment is particularly advantageous when the space between the collector 21 or the feed conduits 20 and the exchanger 11 is limited.

According to embodiments described with reference to fig. 4, the nebulizing nozzles 19 are oriented, during use, along a direction substantially parallel to the surface 24 to be cooled of the fins 15.

According to this embodiment, it can be provided that the nebulizing nozzles 19 on adjacent feed conduits 20 are disposed offset with respect to each other, with the delivery mouths 19a of one feed conduit 20 facing toward an adjacent feed conduit 20.

In this way, during use, a curtain of water vapor is created through which the stream of air transits, which is therefore cooled.

Also according to this solution, it can be provided that the cone of nebulized water is comprised between about 60° and about 80°.

According to further variants, for example described with reference to fig. 3a, the nebulizing nozzles 19 can have a quadrangular shape, comprising two or more outlet mouths 19a positioned angled with respect to each other. Also in this case, however, the resulting flow can have a uniform distribution on a plane P parallel to the surface 24 to be cooled.

According to some embodiments, the apparatus 10 comprises feed means 43 configured to feed the cooling liquid from the feed source 18 to the feed conduits.

According to some embodiments, for example described with reference to fig. 1 , the feed means 43 comprise a pump 25 configured to suck in the cooling liquid from the feed source 18 and supply it to the feed conduits 20 with defined pressure and flow rate.

According to some embodiments, the pump 25 is disposed along the hydraulic circuit 17, between a suction branch 17a connected to the feed source 18 and a delivery branch 17b connected to the feed conduits 20.

According to some embodiments, the pump 25 is a high pressure pump, for example able to supply pressures comprised between 25 and lOObar.

Preferably, the pump 25 is such as to allow the cooling liquid to exit from the nebulizing nozzles 19 with pressures between 25 and lOObar, preferably around 70bar or greater.

According to some embodiments, the outlet mouths 19a of the nebulizing nozzles 19 can have a passage hole comprised between 150 and 1000 pm. In this way, droplets of water steam are obtained with sizes much smaller than those of traditional spray systems, and therefore, with pressures of 25bar, all the water, that is, the cooling liquid, is nebulized, even at partial loads.

According to possible variants, the pump 25 is of the low/medium pressure type, suitable to supply pressures comprised between 1 and 25bar. According to these embodiments, a higher number of nebulizing nozzles 19 can be provided than that used in the case of high pressure pumps 25 (see for example fig. 6), so as to guarantee in any case effective cooling of the heat exchanger 11.

According to further embodiments, the pump 25 has an adjustable flow rate and is provided with an inverter device, not shown, incorporated or connected to it, able to be driven in order to modify the power supply and consequently modulate the functioning flow rate.

This allows to significantly reduce energy consumption, since the energy absorption of the pump 25 decreases as the flow rate decreases.

According to further embodiments, for example described with reference to figs. 7 and 8, the feed means 43 comprise valves, or valve devices 44, disposed along the hydraulic circuit 17 and able to be driven to allow the passage of the cooling liquid toward the nebulizing nozzles 19.

According to some embodiments, the valve devices 44 are of the type that can be divided into parts, that is, provided with a variable and modifiable passage section to adjust the flow rate and possibly the pressure of the cooling liquid.

Fig. 7 shows, by way of example, a configuration of an apparatus 10 suitable to be applied to a heat exchanger 11 configured to dispose of a not very high thermal power, indicatively up to about 100 Kw. 13

In this case, the feed means 43 comprise a first modulating valve 46 disposed along the hydraulic circuit 17 between the source and the collector 21, which can be commanded by a control and command unit 34 in order to increase or decrease the passage section of the cooling liquid.

5 The feed means 43 can also comprise a feed valve 47, for example a solenoid valve, disposed downstream of the feed source 18, and able to be selectively driven to open/close the hydraulic circuit 17.

Along the circuit 17, upstream of the collector 21, a modulating valve 46 can also be present, by means of which the flow rate of the cooling liquid can be0 adjusted.

According to some embodiments, moreover, there can be provided collectors 48a, 48b configured to connect respective ends of the feed conduits 20 opposite the collector 21, and substantially define two closed circuits. This expedient allows to guarantee a greater uniformity of pressure to all the nebulizing nozzles5 19.

In the event that the apparatus 10 according to the embodiment of fig. 7 is applied to two or more heat exchangers 11, the feed means 43 can comprise a pump 25 in addition to, or in replacement of, the modulating valve 46, as shown in fig. 7a.

0 Fig. 8 is used to describe an apparatus 10 suitable to be applied to one or more heat exchangers 11 configured to dispose of a high thermal power, indicatively comprised between 100 and 200 kW, or even higher.

Since the nebulizing nozzles 19 are unable, if they are fed at low pressure, to feed water at a flow rate equal to 25% of the nominal one, as required in these5 exchangers 11, two collectors 21, 48 can be provided, each connected to a respective group of feed conduits 20, 20a, disposed alternately with respect to those of the other group 20a, 20.

According to these solutions, two modulating valves 46, 50 can be present respectively connected between the hydraulic circuit 17 and one of the collectors0 21, 48. In this way, each collector 21, 48 feeds one part of the feed conduits 20, substantially forming two independent circuits.

When a nebulization equal to 50% of the total is required, there can be provided a complete opening of a single modulating valve 46 or 50, while the 14 other will be completely closed. When a nebulization equal to 25% is required, the open valve can be modulated up to the required minimum, adjusting the opening section.

According to some embodiments, the apparatus 10 can comprise return valves

5 51, 52 located along respective connection circuits between the collectors 21, 48, 48a, 48b and the feed source 18, in order to allow the automatic emptying of the feed conduits 20 and of the collectors 21, 48, 48a, 48b.

According to some embodiments, the apparatus 10 comprises interception devices 26 configured to divide into parts the surface affected by the nebulizing0 nozzles 19.

According to some embodiments, the interception devices 26 can comprise at least one choke valve 27 disposed along the collector 21 and able to be selectively driven to prevent the transit of the cooling liquid toward one or more of the feed conduits 20.

5 According to some embodiments, the choke valve 27 divides the feed conduits 20 into two groups, which can have the same or a different number of feed conduits 20.

According to some embodiments, in the case of a heat exchanger 11 in which the heat-carrying fluid is a phase-change fluid, the choke valve 27 is located in an0 intermediate position such as to divide the feed conduits 20 and therefore the nebulizing nozzles 19 into two sub-groups, one of which is suitable to cooperate with the portion of exchanger 11 in which the heat-carrying fluid is in the gaseous state, and a second suitable to cooperate with the portion of the exchanger 11 in which the heat-carrying fluid is in the liquid state.

5 In the event the sub-groups are connected substantially in a closed ring (fig. 7), when the choke valve 27 is in the open position all the nebulizing nozzles 19 are active and there is a single closed ring circuit, while when the choke valve 27 is in the closed position only the nebulizing nozzles 19 upstream of it are active and fed in a closed ring.

0 According to variants, a plurality of valves can be provided, each associated with a feed conduit 20, and able to be selectively activated independently from the others.

According to some embodiments, the apparatus 10 comprises devices 28 for detecting the temperature of the fluid configured to detect the temperature of the heat-carrying fluid to be cooled circulating in the heat exchanger 11.

According to some embodiments, the devices 28 for detecting the temperature of the fluid comprise an inlet sensor 29 associated, during use, with the inlet conduit 13 and an outlet sensor 30 associated, during use, with the outlet conduit 14.

According to some embodiments, the apparatus 10 can also comprise devices 31 for detecting the environmental conditions, including an ambient temperature sensor 32 for detecting the temperature and a humidity sensor 33 for detecting the humidity of the surrounding air.

The devices 31 for detecting the environmental conditions can be integrated in a single component or made as separate elements.

According to some embodiments, the apparatus 10 also comprises a control and command unit 34 configured to control the functioning of the apparatus 10 as a function at least of the temperature of the heat-carrying fluid and/or the environmental conditions detected by the respective detection devices 28, 31.

According to some embodiments, the control and command unit 34 is connected to the detection devices 28, 31 in order to receive from them information relating to the detections carried out, and is configured to command at least the feed means 43 and/or the interception devices 26 as a function of the information received, in order to increase the efficiency of the heat exchanger 11.

According to some embodiments, the control and command unit 34 is configured to activate the cooling apparatus 10 when the heat exchanger 11 is in operation and determinate environmental conditions occur. In this way, the cooling apparatus 10 is used only when its functioning is advantageous in terms of energy consumption, and therefore avoiding wastes of cooling liquid when not useful and unnecessary.

According to some embodiments, the control and command unit 34 can also automatically deactivate the apparatus 10 when the conditions detected by the detection devices 28, 31 do not make it advantageous.

According to some embodiments, the control and command unit 34, in order to verify whether the heat exchanger 11 is functioning, can process the data detected by the devices 28 for detecting the temperature of the fluid. 16

For example, the control and command unit 34 can compare the outlet temperature and the inlet temperature of the heat-carrying fluid detected by the inlet 29 and outlet 30 sensors and can activate the apparatus 10 when the outlet temperature is lower than the inlet one.

According to some embodiments, the control and command unit 34 can regulate the functioning of the pump 25, for example acting on an inverter device connected to it, in order to modulate its flow rate as a function of the data detected by the devices 32 for detecting the environmental conditions and of the temperature of the heat-carrying fluid detected by the outlet sensor 30.

0 In particular, the control and command unit 34 adjusts the flow rate of the pump 25 in such a way as to maintain the temperature of the heat-carrying fluid in the outlet conduit 14 within the range of a predefined value using the least possible quantity of cooling fluid. In this way, the energy consumption of the pump 25 is reduced, and at the same time a waste of cooling liquid is prevented.5 In particular, the control and command unit 34 can decrease or increase the flow rate of the pump 25 as a function of the difference between the temperature of the heat-carrying fluid at exit and the predefined value. The predefined value can be pre-set and/or stored in a memory unit 40 integrated, or connected, to the control and command unit 34, or it can be a value set by a user, for example by0 means of a command interface 41.

If there is no pump 25, the control and command unit 34 can adjust the flow rate of the cooling liquid as a function of the data detected by the detection devices 28, 31, acting on the valve devices 44.

According to further embodiments, the apparatus 10 comprises a wet bulb5 detection device 45 positioned, during use, in the proximity of the surface 24 of the heat exchanger 11 and configured to measure the wet bulb temperature of the surface 24.

According to some embodiments, the wet bulb detection device 45 is connected to the control and command unit 34 and the latter is configured to0 command the feed means 43 so as to always maintain the temperature of the air entering the exchanger 11, or incident on its surface 24, at a higher temperature than the wet bulb temperature, regardless of the environmental conditions.

In other words, the control and command unit 34, on the basis of the ambient temperature and pressure conditions provided by the detection devices 31, can calculate the corresponding wet bulb temperature, and can consequently command the feed means 43 to reduce (or possibly increase) the flow rate of the cooling liquid, so that the temperature of the air measured by the wet bulb detection device 45 remains above the calculated temperature value, for example by a few tenths of a degree.

For example, the control and command unit 34 can calculate the wet bulb temperature corresponding to a determinate ambient temperature and pressure, on the basis of a graph of the type shown in fig. 9, and command the feed means 43 to maintain the temperature of the air in correspondence with the surface 24 corresponding to that indicated by the line T.

According to some embodiments, the wet bulb detection device 45 comprises a temperature probe, and the control and command unit 34 implements a mathematical function to calculate the wet bulb temperature.

According to one variant, the wet bulb detection device 45 can also comprise a humidity probe. This solution, however, can present the disadvantage that, in the event that a droplet of water forms on it, it continues to indicate a humidity equal to 100%, effectively preventing real-time adjustment of the flow rate of the water, which could be lower than the one required.

According to further embodiments, the apparatus 10 can comprise a safety pressure switch 35 configured to detect the pressure of the cooling liquid in the hydraulic circuit 17 and communicate the data detected to the control and command unit 34.

The apparatus 10 can also comprise a deviation circuit 36, connected between the suction branch 17a and the delivery branch 17b and able to be selectively opened or closed by means of a valve device 37.

According to some embodiments, the valve device 37 can be selectively commanded by the control and command unit 34 as a function of the data detected by the safety pressure switch 35 in order to balance the pressure between the suction branch 17a and the delivery branch 17b when the pump 25 is deactivated.

According to some embodiments, the apparatus 10 can comprise, along the hydraulic circuit 17, for example at the inlet of the suction branch 17a, one or 18 more filter elements 38 suitable to filter the cooling liquid in transit.

According to some embodiments, the apparatus 10 can also comprise anti- limescale devices 39 suitable to remove and retain the possible limescale present in the cooling liquid, so as to prevent possible obstructions of the pipes of the

5 hydraulic circuit 17 and extend their useful life.

According to some embodiments, the apparatus 10 can be used to optimize the efficiency of the heat exchanger 11 when the ambient air temperature is higher than the temperature that is optimal for its functioning. This mode therefore allows to improve the yield of the heat exchanger 11 when the climatic0 conditions, that is, high temperature, compromise its effectiveness.

According to other embodiments, the apparatus 10 can be used to further optimize the efficiency of the heat exchanger 11 even when the ambient air temperature is optimal. This case can occur in particular when the apparatus 10 is applied to a heat exchanger 11 that uses a two-phase fluid as heat-carrying fluid,5 that is, a fluid which is subjected to a phase-change between vapor and liquid and vice versa as a function of pressure and temperature conditions.

The functioning according to the first mode provides to confirm whether the following conditions are verified:

- the heat exchanger 11 is active;

0 - the devices 31 for detecting environmental conditions detect thermo hygrometric conditions such that the activation of the apparatus 10 is advantageous to make the cooling of the heat exchanger 11 more effective.

According to some embodiments, in the event the feed valve 47 is present, it can be provided to open it only if the ambient air temperature detected by the5 detection devices 31 is higher than 2 °C.

According to further embodiments, it can be provided to keep the feed valve 47 closed and to open one or more return valves 51, 52 in order to allow the automatic emptying of the feed conduits 20 and of the collectors 21, 48, 48a, 48b.

The cooling method according to the invention provides to exploit the known0 principle of cooling air by adiabatic evaporation.

The method in particular provides to deliver a cooling fluid by means of nebulizing nozzles 19 positioned in a matrix shape so as to distribute the cooling liquid uniformly and homogeneously on the entire surface 24 of the heat 19 exchanger 11 , in particular on the entire surface 24 facing the air inlet side.

In this way, the evaporation occurs in a capillary manner on the surface 24, making the benefit that the invention is able to guarantee uniform, in order to increase the efficiency of the exchanger 11.

5 According to some embodiments, the cooling liquid is nebulized directly toward the surface 24.

According to other embodiments, the cooling liquid is delivered in the opposite direction to the exchanger 11 and is entrained by the stream of air generated by the ventilation devices 16.

0 The cooling method also provides to analyze the data relating to the environmental conditions and the temperature of the heat-carrying fluid detected by the detection devices 28, 31 in order to regulate the functioning of the feed means 43, for example of the pump 25, and in particular the flow rate thereof, or possibly the division into parts and modulation of the valve devices 44, so as to5 increase the efficiency of the cooling and, at the same time, optimize the consumption of energy and cooling liquid.

By way of a non-limiting example, the thermo-hygrometric conditions suitable for the first functioning mode can provide a temperature comprised between about 30-35 °C and a humidity comprised between about 60% and 90%.

0 When the humidity detected by the humidity sensor 33 is at a value higher than 90%, the control and command unit 34 can decide not to activate the apparatus 10, since in such conditions the cooling liquid nebulized on the surface 24 would not be able to evaporate, and therefore there would be no benefit.

According to some embodiments, the second functioning mode can be applied5 when the environmental conditions, that is, temperature and humidity of the ambient air, are below the values provided for the activation of the first mode.

By way of a non-limiting example, the thermo-hygrometric conditions suitable for the second functioning mode can provide a temperature comprised between about 25-30 °C and a humidity comprised between about 40% and 70%.

0 According to some embodiments, when the control and command unit 34 detects these thermo-hygrometric conditions, it can drive the choke valve 27 so as to allow the delivery of the cooling liquid only through the nebulizing nozzles 19 cooperating with the zone of the heat exchanger 11 in which the heat-carrying 20 fluid is in the liquid state.

The air entering the heat exchanger 11, and cooled by the action of the nebulizing nozzles 19 in correspondence with the area affected by the heatcarrying fluid in the liquid state, determines an under-cooling of the heat-carrying 5 fluid. Consequently, an increase in the enthalpy effect of the heat-carrying fluid is obtained, which translates into an increase in the cooling capacity, while maintaining the required absorbed power unaltered.

By way of example, the under-cooled liquid heat-carrying fluid can have a temperature comprised between 20 and 22 °C. For example, with an ambient 10 temperature of about 25 °C and a relative humidity of 40%, the apparatus 10 is able to lower the temperature of the air sucked in by the heat exchanger 11 in the portion where the heat-carrying fluid is located in liquid state to about 16.2°.

According to some embodiments, in the second functioning mode, the control and command unit 34 can adjust the flow rate of the pump 25 as a function of the 15 temperature required for the under-cooled liquid in correspondence with the outlet conduit 14.

Fig. 5 is used to describe another embodiment of a cooling apparatus 10, applied in the example case to two heat exchangers 11.

In this case, two or more collectors 21 can be provided, each associated with a 20 respective group of nebulizing nozzles 19 disposed in a matrix order, and positioned at a desired distance from a heat exchange surface 24 of a respective heat exchanger 11.

According to some embodiments, each collector 21 can be selectively able to be connected to the hydraulic circuit 17 by means of respective shut-off valves 25 42, which are able to be activated independently of each other.

According to some embodiments, the control and command unit 34 can regulate the functioning of each group of nebulizing nozzles 19 in a manner correlated to the other groups of nebulizing nozzles 19.

According to possible variants, it can be provided that for each group of 30 nebulizing nozzles 19 and for each heat exchanger 11 there are provided respective devices 28 for detecting the temperature and devices 31 for detecting the environmental conditions.

In this way, it is possible to optimize the functioning of two or more heat exchangers 11 even disposed in different positions, for example one facing to the north, or one to the south, or in more or less sunny or shady areas, and therefore subjected to different environmental conditions.

According to these embodiments, it can also be provided that each group of nebulizing nozzles 19 is fed by its own pump 25, able to be selectively driven by the control and command unit 34.

According to further embodiments, the cooling method provides to determine a wet bulb temperature value and to adjust the flow rate of the cooling fluid so that the temperature measured by a wet bulb detection device always remains at least a few tenths of a degree higher than the wet bulb temperature value determined.

According to some embodiments, the method can provide to calculate the wet bulb temperature correlated to the ambient temperature and pressure detected by the detection devices 31, and regulate the feed means 43 to ensure that the temperature of the air entering the exchanger, measured by the wet bulb detection device 45, remains above the calculated temperature, for example between 0.2 and 0.7 °C higher.

In the case of an apparatus 10 applied to two heat exchangers 11, for example shown in figs. 1 and 8, thanks to this arrangement, the functioning of both exchangers 11 can be optimized in relation to their actual working conditions.

For example, in the case of an exchanger 11 disposed to the north and one to the south, the conditions can be different. Assuming for the exchanger to the north a temperature of 20.0 °C, a relative humidity of 67.75% and a saturation pressure of 2338.80 Pa, with a vapor titer X2 of 9.88 g, a wet bulb temperature equal to 16.22 °C is obtained. In the case of a heat exchanger disposed to the south, assuming a temperature of 25.0 °C, a relative humidity of 50.00% and a saturation pressure of 3169.22 Pa, with a vapor titer XI of 9.88 g, a wet bulb temperature equal to 18.00 °C is obtained. In this case, the air entering the exchanger to the north must not be lower than about 16.5-16.7 °C, while the temperature of the air entering the exchanger to the south must not be lower than about 18.2-18.5 °C.

It is clear that modifications and/or additions of parts or steps may be made to the apparatus 10 and method for cooling a heat exchanger and to the heat exchanger 11 as described heretofore, without departing from the field and scope of the present invention.

In particular, it is clear that the various embodiments of the apparatus 10 described with reference to the attached drawings can be applied to a single heat exchanger 11 or to two or more exchangers 11 , providing respective hydraulic circuits 17 and respective feed means 43 for each one of them.

It can also be provided that, in the case of heat exchangers 11 of different sizes or type, different feed means 43 can be provided to feed the water into the respective hydraulic circuits 17, for example providing a pump 25 in one and valve means 44 in another. In any case, the control and command unit 34 can adjust the feed of the cooling liquid into the respective hydraulic circuit 17 as a function of the operating and functioning conditions of the heat exchanger 11 with which it is associated.

The materials used, provided that they are compatible with the specific use, as well as the contingent shapes and sizes, can be varied according to requirements.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of apparatus 10 and method for cooling a heat exchanger, and corresponding heat exchanger 11, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.