The present invention concerns a heat exchanger optimized to promote the heat exchange in a fluid that flows inside it, for example a cooling fluid. In particular, a possible application of the present invention is for heat exchangers with the function of evaporating a cooling fluid, used, for example, in refrigeration circuits.

BACKGROUND OF THE INVENTION

Heat exchangers with the function of evaporating a fluid, for example a coolant, flowing inside them, are known, and are used for example in refrigeration circuits or plants.

These known heat exchangers comprise a first conduit into which the fluid is introduced, fluidically connected to a first manifold, in turn connected to a heat exchange battery, downstream of which a second manifold is disposed, fluidically connected to a second conduit.

In turn, the heat exchange battery comprises a plurality of circulation elements, such as tubes or channels, having an oblong development, disposed parallel to each other and connected, with their respective opposite ends, on one side to the first manifolds and on the other side to the second manifolds.

Normally, heat exchange fins are attached between adjacent circulation tubes, which, in the case of an evaporator, promote the evaporation of the coolant that is inside the circulation tubes.

Heat exchangers known in the state of the art are described, for example, in the patent documents DE-A1-102017109313, US-A 1-2016/054077 and US-A1- 2015/075204.

According to the spatial disposition of the circulation elements, known exchangers are divided into exchangers with horizontal tubes or exchangers with vertical tubes. Further examples of heat exchangers with horizontal tubes of a known type are described in the patent documents US-A1 -2020/333090, WO- Al-2009/022575, EP-A2- 1.884.733 and FR-A1-2855254, while other examples of heat exchangers with vertical tubes are described in patent documents WO- A2-2009/I520I5, US-A-5.619.861 and EP-A2- 1106952.

The first conduit and the second conduit, in turn, are connected to an external hydraulic circuit, in which the fluid is recirculated and subjected to predefined thermodynamic cycles. The hydraulic circuit generally comprises, upstream of the first conduit, a compressor, or a pump.

In this way, the compressor, or pump, can modulate the parameters for feeding the fluid, for example the pressure, or the flow rate, according to the performance required of the heat exchanger.

The consequent modulation can generate pressure waves in the fluid that can be transmitted to the latter with a certain frequency. The amplitude and frequency of the pressure waves as above normally depend on the feed parameters such as the pressure and the flow rate, and on the type of feed fluid.

One very important aspect of these known heat exchangers is that the fluid, for example coolant, which circulates inside them consists of both a component in the liquid state, or liquid component, and also a component in the gaseous state, or gaseous component.

In fact, it is known that, inside the fluid, in addition to the component in the liquid state, parts in the gaseous state remain or are formed, which can affect, even very significantly, the performance of the heat exchangers, considerably reducing their capacity for heat exchange.

It is also known that in order to maximize the performance of the fluid it is better if the latter is, as much as possible, in the liquid state, before it flows into the circulation elements, where the evaporation occurs. The presence of any gaseous component therefore leads to a reduction in the performance of the fluid and consequently in the performance of the heat exchanger itself.

Another disadvantage related to the presence of any gaseous component is the possible formation of vibrations triggered by any possible resonance phenomena between the flow of the fluid and the structure of the heat exchanger. These vibrations can be transient and appear only during the modulation of the feed parameters, or they can be stationary and occur even when the latter remain constant over time.

Furthermore, the vibrations can also be transferred to the hydraulic circuit outside the heat exchanger, but connected to it, and can lead to malfunctions, mechanical or structural problems, or to the generation of noise and therefore of noise pollution. In addition, the deterioration in the performance can also lead to an energy inefficiency of the heat exchanger itself, as well as to a reduction in the life span of the heat exchanger.

The problem therefore arises of eliminating the gaseous component of the fluid, even minimal, before the fluid begins to perform its refrigerant function.

There is therefore a need to provide a heat exchanger which has the purpose of overcoming this problem known in the state of the art and consequently solving at least one of the disadvantages deriving from it.

Another purpose of the present invention is to provide a heat exchanger which does not generate vibrations, or which reduces them to a minimum.

Another purpose of the present invention is to provide a heat exchanger which can prevent breakages due to possible vibrations from occurring.

Another purpose of the present invention is to provide a heat exchanger which can reduce the generation of noise and therefore of noise pollution to a minimum.

Another purpose of the present invention is to provide a heat exchanger which avoids the deterioration of its thermo-fluid dynamic performance.

Another purpose of the present invention is to provide a heat exchanger, in particular of the “micro-channel” type, which is highly efficient from the energy point of view, improving the performance of the fluid, for example a cooling fluid, and which is also reliable for a long time.

Yet another purpose of the present invention is to provide a heat exchanger which is very versatile, which is highly efficient both when used as an evaporator and also when used as a condenser.

Yet another purpose of the present invention is to provide a heat exchanger which allows to easily adjust the proportions between the liquid and gaseous component of the fluid, by controlling the pressure of the fluid.

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 claim. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea. In accordance with the above purposes, a heat exchanger configured to make a fluid having a liquid component and a gaseous component circulate inside it, according to the present invention, which overcomes the limits of the state of the art and eliminates the defects present therein, comprises a first manifold comprising a chamber configured to at least partly receive the liquid component, a second manifold comprising a respective chamber configured to receive the gaseous component, and a heat exchange battery disposed between the first manifold and the second manifold and comprising a plurality of circulation elements for circulating the fluid.

The heat exchanger also comprises a separator element disposed in one of either the first manifold or the second manifold, configured to separate a respective one of the chambers into a first part and into a second part which are communicating with each other.

The heat exchanger also comprises a bypass connection fluidically connecting the first manifold to the second manifold in parallel with respect to the heat exchange battery and configured to allow the gaseous component to enter, or exit from, the second manifold, and also comprises means for regulating the pressure of the gaseous component in order to regulate the height of the liquid component.

The regulation means comprise one or more narrowing elements configured to at least partly obstruct the passage cross-section for the gaseous component.

The regulation means comprise at least one first regulation valve interposed between the first manifold and the bypass connection.

The regulation means also comprise at least one second regulation valve interposed between the bypass connection and the second manifold.

The heat exchanger comprises a first conduit and a second conduit configured respectively to selectively allow the fluid to enter, or exit from, the heat exchanger, or vice versa.

The first conduit has its own longitudinal axis that defines the direction of the flow of the fluid, and is disposed in such a way that the longitudinal axis forms an angle of impact with a wall of the heat exchanger configured to be impacted by the fluid exiting from the first conduit which is comprised between 45° and 90°, so as to induce one or several vortex motions which, possibly in combination with other effects, cause the separation of the liquid component from the gaseous component.

According to some embodiments, the separator element is disposed in the first manifold to separate the chamber into a first part fluidically connected to the first conduit, and into a second part fluidically connected to the plurality of circulation elements, wherein the first part and the second part are communicating with each other. The narrowing elements are disposed in the bypass connection in order to regulate the height of the liquid component present in the first part.

In these embodiments, the wall of the heat exchanger configured to be impacted by the fluid exiting from the first conduit consists of the separator element, which is disposed at a determinate distance from the first conduit. The latter has a substantially circular cross-section with a determinate internal diameter, such that the ratio between such internal diameter and the determinate distance is comprised between 0.4 and 0.7.

In these embodiments, the plurality of elements for circulating the fluid and the bypass connection are substantially horizontal, and the separator element is disposed substantially vertically.

According to other embodiments of the present invention, the separator element is disposed in the second manifold in order to separate the chamber into a first part and into a second part which are communicating with each other, and the narrowing elements are disposed in the first part of the second manifold to regulate the height of the liquid component present in the bypass connection.

In these embodiments, the wall of the heat exchanger configured to be impacted by the fluid exiting from the first conduit consists of an internal wall of the bypass connection, which is disposed at a determinate distance from the first conduit. The latter has a substantially circular cross-section with a determinate internal diameter, such that the ratio between the internal diameter and the determinate distance is comprised between 0.4 and 0.7.

In these embodiments, the plurality of elements for the circulation of the fluid and the bypass connection are substantially vertical, the separator element is disposed substantially horizontally, and the narrowing elements are disposed in the first part of the chamber of the second manifold.

According to another aspect of the present invention, there is described a use of a heat exchanger as described above as an evaporator, wherein it is provided to make the fluid enter and exit the heat exchanger respectively from the first conduit connected to the first manifold and from the second conduit connected to the second manifold.

According to another aspect of the present invention, there is described a use of a heat exchanger as described above as a condenser, wherein it is provided to make the fluid enter and exit the heat exchanger respectively from the second conduit connected to the second manifold and from the first conduit connected to the first manifold.

Therefore, the heat exchanger according to the present invention, due to its particular and innovative configuration, can function both as an evaporator and also as a condenser, as a function of the path that the fluid follows inside it.

According to another aspect of the present invention, there is provided a heat exchanger to make a fluid having a liquid component and a gaseous component circulate inside it, comprising at least one first conduit, a heat exchange battery, which in turn comprises a plurality of elements for circulating the fluid, and at least one first manifold, interposed between the at least one conduit and the heat exchange coil.

In accordance with one aspect of the present invention, the first manifold is divided, by means of at least one separator element or mean, into a first part, fluidically connected to the at least one conduit, and into a second part, fluidically connected to the plurality of circulation elements, wherein the first part and the second part are communicating with each other.

In accordance with one aspect of the present invention, the at least one separator element is configured to be impacted by the fluid, exiting from the at least one first conduit, so as to induce one or several vortex motions which, possibly in combination with other effects, cause the separation of the liquid component from the gaseous component of the fluid, in the first part.

In accordance with one aspect of the present invention, the at least one first conduit, at least in a zone in which it enters the first manifold, has its own longitudinal axis that defines the direction of the flow of the fluid. Furthermore, the at least one first conduit is disposed so that the longitudinal axis forms an angle of impact with the at least one separator element preferably comprised between 45° and 90°. In accordance with other embodiments, the heat exchanger can comprise two or more feed conduits, each having a respective longitudinal axis defining the direction of the flow of the fluid. Preferably, the two or more feed conduits are all parallel to each other.

In accordance with another aspect of the present invention, the heat exchanger also comprises a second manifold and at least one bypass connection; the first manifold and the second manifold each comprise upper walls and are fluidically connected to each other by means of the bypass tube, in correspondence with the upper walls.

In accordance with another aspect of the present invention, the at least one bypass connection is connected to the first part of the first manifold and to the second manifold, in respective connection zones, so that the at least one bypass connection is able to allow only the passage of the gaseous component of the fluid, from the first manifold to the second manifold.

According to other embodiments, the heat exchanger can comprise two or more bypass connections which put the first manifold in connection with the second manifold, all being configured so that the gaseous component can travel through them.

In accordance with another aspect of the present invention, the at least one separator element is disposed at a determinate distance from the lateral wall of the first manifold, fluidically connected to the at least one first conduit.

In accordance with another aspect of the present invention, the at least one first conduit has a substantially circular cross-section with a determinate internal diameter. Furthermore, the ratio between the internal diameter and the distance is comprised, for example, between 0.4 and 0.7.

In accordance with another aspect of the present invention, regulation means for regulating the pressure of the gaseous component of the fluid are associated with the bypass connection, in order to regulate the height of the liquid component of the fluid inside the first part of the first manifold.

In accordance with another aspect of the present invention, the regulation means comprise one or more narrowing elements disposed inside the bypass connection in order to reduce the cross-section of the latter.

In accordance with another aspect of the present invention, the regulation - O - means comprise at least one regulation valve disposed in correspondence with the connection zones.

In accordance with another aspect of the present invention, there is provided a heat exchanger configured to make a fluid having a liquid component and a gaseous component circulate inside it, and comprising a first manifold disposed in a lower part thereof, a second manifold disposed in an upper part thereof and a heat exchange battery disposed between the first manifold and the second manifold. The heat exchange battery in turn comprises a plurality of elements circulating the fluid, disposed vertically and fluidically connecting the first manifold and the second manifold to each other.

In accordance with one aspect of the present invention, the heat exchanger also comprises a bypass connection disposed substantially parallel to the fluid circulation elements and fluidically connecting the first manifold to the second manifold. Furthermore, the second manifold is divided into a first part, fluidically connected to an upper part of the bypass connection, and into a second part, fluidically connected to the plurality of circulation elements, wherein the first part and the second part are fluidically communicating with each other.

In accordance with another aspect of the present invention, the bypass connection is disposed substantially parallel to the fluid circulation elements; moreover, a first conduit is connected to an external walls thereof to selectively allow the entry or exit of the fluid into/from the heat exchanger.

In accordance with another aspect of the present invention, the first conduit is configured to allow the fluid to enter the heat exchanger. Furthermore, the bypass connection comprises an internal wall which is configured to be impacted by the fluid exiting from the first conduit in such a way as to induce one or several vortex motions which, possibly in combination with other effects, cause the separation of the liquid component from the gaseous component of the fluid in the bypass connection.

In accordance with another aspect of the present invention, the first conduit, at least in a zone in which it enters the bypass connection, has its own longitudinal axis which defines the direction of the flow of the fluid. Furthermore, the first conduit is disposed in such a way that the longitudinal axis forms an angle of impact with the internal wall comprised between about 45° and about 90°. In accordance with another aspect of the present invention, the second manifold is provided with at least one substantially horizontal separator element or mean, which divides the first part from the second part.

In accordance with one aspect of the present invention, the heat exchanger also comprises a second conduit, fluidically connected to the second manifold in order to selectively allow the fluid to exit from or enter the heat exchanger.

In accordance with another aspect of the present invention, the external wall and the internal wall of the bypass connection are disposed at a determinate reciprocal distance; furthermore, the first conduit has a substantially circular cross-section with a determinate internal diameter and the ratio between this internal diameter and this distance is comprised between about 0.4 and about 0.7.

In accordance with another aspect of the present invention, the heat exchanger also comprises means for regulating the pressure of the gaseous component of the fluid which are associated with the upper part of the bypass connection or with the first part of the second manifold, in order to regulate the height of the liquid component of the fluid inside the bypass connection.

In accordance with another aspect of the present invention, the regulation means comprise a regulation valve disposed in the upper part of the bypass connection, or in a zone of connection between the bypass connection and the second manifold.

In accordance with another aspect of the present invention, the regulation means comprise one or more narrowing elements disposed inside the first part of the second manifold so as to at least partly reduce the passage cross-section thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, characteristics and advantages 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, section, lateral view of a heat exchanger according to a first embodiment of the present invention;

- fig. 2 is a schematic, section, lateral view of a variant of the heat exchanger of fig. 1; i v -

- fig. 3 is a schematic, section, lateral view of a heat exchanger according to another embodiment of the present invention;

- fig. 4 is a section view of a detail of fig. 3, in accordance with one variant.

We must clarify that in the present description and in the claims the terms upper and lower, with their declinations, have the sole function of better illustrating the present invention with reference to the drawings and must not be in any way used to limit the scope of the invention itself, or the field of protection defined by the claims.

Furthermore, the person of skill in the art will recognize that certain sizes, or characteristics, in the drawings may have been enlarged, deformed, or shown in an unconventional or non-proportional manner in order to achieve a version of the present invention that is easier to understand.

When sizes and/or values are specified in the following description, the sizes and/or values are given for illustrative purposes only and must not be understood as limiting the scope of protection of the present invention, unless such sizes and/or values are present in the attached claims.

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 combined or incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

With reference to figs. 1 and 2, a heat exchanger 10 according to the present invention can be used for the evaporation or condensation of a fluid, in particular of a cooling fluid, having a liquid component and a gaseous component and formed by a mixture of known substances commonly used in heat exchangers with this function, such as for example the fluids R-134a or R410A.

The heat exchanger 10 comprises a first manifold 11 and a second manifold 12, fluidically connected to each other by means of a heat exchange battery 13. The heat exchange battery 13 comprises a plurality of circulation elements, or circulation tubes 14, parallel to each other and substantially perpendicular to the two manifolds 11 and 12.

On the external surfaces of the circulation tubes 14 there are attached fins 15 with the function of increasing the useful heat exchange surface of the circulation tubes 14. The presence of the fins 15 therefore promotes the evaporation or condensation inside the heat exchange battery 13.

In the example shown in figs. 1 and 2, the circulation tubes 14 are disposed substantially horizontally so that the heat exchange coil 13 is of the type with horizontal tubes.

It should be noted that, in some embodiments, the circulation tubes 14 have a very small passage section, configuring the heat exchange battery 13 as a so- called “micro-channel” core.

Furthermore, the first manifold 11 and the second manifold 12 are fluidically connected to each other also by at least one bypass connection 16, disposed in parallel with the heat exchange battery 13 and in particular higher than the latter.

In other variants, not shown in the drawings, the bypass connection 16 can be integrated in the heat exchange battery 13, extending, for example, immediately above the pack of circulation tubes 14.

Both the first manifold 11 and also the second manifold 12 can have a cylindrical shape, or the shape of a prism that has any polygonal base whatsoever.

In particular, the first manifold 11 comprises at least one lateral wall 18, 19, one upper wall 20 and one lower wall 21, which define a cavity, or chamber 22. Similarly, the second manifold 12 comprises at least one lateral wall 25, 26, one upper wall 27 and one lower wall 28, which in turn define a cavity, or chamber 29.

The first manifold 11 and the second manifold 12 can be either cylindrical or parallelepiped in shape. For the sake of clarity, the lateral wall(s) of the first manifold 11 has/have been indicated with reference numbers 18 and 19, which respectively indicate the wall into which the first conduit 31 leads, and the wall from which the circulation tubes 14 branch off. Similarly, the lateral wall(s) of the second manifold 12 has/have been indicated with reference numbers 25 and 26, which respectively indicate the wall into which the circulation tubes 14 are inserted, and the wall from which a second conduit 32 branches off.

The chamber 22 of the first manifold 11 is divided into a first part 23 and a second part 24 by means of a partition 30, which acts as a separator element and i - which will be described in detail below. The first part 23 and the second part 24 of the chamber 22 are communicating with each other in the lower zone thereof.

A first conduit 31 is fluidically connected to the lateral wall 18 of the first manifold 11 in correspondence with an upper zone of the first part 23, in order to introduce inside it the fluid coming from an external hydraulic circuit, of a known type or which will be developed in the future, connected to the heat exchanger 10 and not shown in the drawings.

The first conduit 31, at least in the zone in which it enters the first manifold 11, has its own longitudinal axis X, which defines the direction of the flow of the fluid entering the latter.

In the embodiment shown here, the longitudinal axis X forms an angle of impact a of 90° with the partition 30, it being understood that it can have an amplitude comprised in a range between about 35° and about 90°, preferably between about 45° and about 90°.

Furthermore, the first feed conduit preferably has a circular cross-section, with a determinate internal diameter D, preferably comprised between 12 mm and 42 mm.

The second part 24 of the chamber 22 is fluidically connected to the inlet ends of the circulation tubes 14.

The second conduit 32 is fluidically connected to the lateral wall 26 of the second manifold 12 to make the gaseous component of the fluid exit from it, as will be described in detail below. The second conduit 32 is connected to the hydraulic circuit as above, outside the heat exchanger 10. In accordance with possible variants, not shown, the heat exchanger can comprise two or more of such conduits, which preferably extend along directrices that are all parallel to each other.

In the example provided here, the partition 30 consists of an intermediate wall, parallel to the lateral walls 18 and 19 and for example substantially equidistant therefrom. In particular, the partition 30 is disposed at a determinate distance L from the lateral wall 18 to which the first conduit 31 is connected.

This disposition is very important for the purposes of the separation effect between the liquid and gaseous components of the fluid to be obtained. In fact, the partition 30 is configured to be impacted by the fluid exiting from the first conduit 31 so as to induce one or more vortex motions inside the fluid itself which, in combination with other effects that will be described below, cause the separation of the liquid component from the gaseous component of the fluid.

The ratio between the internal diameter D of the first conduit 31 and the distance L between the partition 30 and the lateral wall 18 into which the first conduit 31 leads is preferably comprised between 0.2 and 0.9, more preferably between 0.3 and 0.8, even more preferably between 0.4 and 0.7. This ratio is appropriately chosen also taking into consideration the speed and pressure of the fluid entering the first manifold 11.

In other embodiments, not shown in the drawings, the division of the first manifold 11 into the two parts 23 and 24 can also be obtained without inserting a separator element, such as the partition 30, but by modifying the very shape of the first manifold 11 , for example conforming it into a U shape, so as to define in any case two parts communicating with each other in the lower zone, such as two communicating vessels, so as to maintain the same separation effect that is to be obtained on the components of the fluid in the chamber 22.

It should be noted that in addition to the contribution of the vortex motions that are generated by the impact of the flow of the fluid on the partition 30, the separation of the liquid component from the gaseous component of the fluid is due, at least partly, to at least one of the following effects:

- contribution of the force of gravity, which promotes the downward precipitation of the liquid component of the fluid;

- amplitude of the angle of impact a, which can promote the formation of vortex motions of such an extent as to facilitate the separation of the liquid and gaseous components of the fluid;

- ratio between the internal diameter D of the first conduit 31 and the distance L between the partition 30 and the lateral wall 18 of the first manifold 11;

- flow rate and therefore associated speed of the fluid at exit from the first conduit 31 ;

- vapor quality, that is, the concentration, expressed in physical or chemical units, of the gaseous component in the fluid.

The bypass connection 16 is fluidically connected to the upper zone of the first part 23 of the chamber 22 in a connection zone 33, and is fluidically connected to 1 H- - the upper wall 26 of the second manifold 12 in correspondence with a respective connection zone 35.

In this way, the bypass connection 16 is configured to allow only the passage of the gaseous component of the fluid from the first manifold 11 to the second manifold 12.

With the bypass connection 16 there are associated one or more regulation elements, or members, for regulating the pressure of the gaseous component of the fluid, so that the height H of the liquid component of the fluid inside the first part 23 of the first manifold 11 can be regulated.

For example, the regulation elements for regulating the pressure of the gaseous component of the fluid comprise one or more narrowing elements 36, preferably disposed at intervals with respect to each other in order to locally reduce the cross-section of the bypass connection 16 and thus create localized pressure drops.

The shape and number of the narrowing elements 36 are chosen as a function of the pressure drops to be created in the bypass connection 16, so as to obtain a determinate height H of the liquid component of the fluid inside the first part 23 of the first manifold 11.

According to some variants not shown in the drawings, the regulation elements for regulating the pressure of the gaseous component of the fluid can comprise walls, or partitions, either solid or possibly provided with apertures, preferably disposed transversely inside the bypass connection 16 so as to partly obstruct its passage section.

In one variant shown in fig. 2, in addition to the narrowing elements 36, there is provided the presence of other pressure regulation members, consisting for example of a first and a second regulation valve 37, 38 of a known type, or which will be developed in the future, which are disposed, for example, in the connection zones indicated with reference numbers 33 and 35.

In this case, by means of the regulation valves 37, 38 it is possible to modify the pressure of the gaseous component of the fluid, increasing or decreasing it, in order to regulate the height H of the liquid component of the fluid inside the first part 23 of the first manifold 11.

By way of example, the regulation valves 37, 38 can be configured as one-way valves, or non-return valves, which allow the gaseous component of the fluid to travel through the bypass connection 16 between the connection zones 33 and 35, and prevent it from flowing in the opposite direction.

In one variant of this embodiment, not shown in the drawings, the regulation elements can only comprise the valves 37, 38; since they are without the narrowing elements 36.

Hereafter we describe how the heat exchanger 10 previously described with reference to figs. 1 and 2 functions as an evaporator.

The fluid coming from the previously mentioned external hydraulic circuit is introduced into the first manifold 11 by means of the first conduit 31.

The fluid, due to the impact against the partition 30, possibly in combination with the other effects described above, is divided and its liquid component is disposed in the lower zone of the first part 23 of the chamber 22, up to the height H, while above it there is disposed only the gaseous component of the fluid, which, due to its pressure, reaches the second manifold 12 through the bypass connection 16.

In the second part 24 of the chamber 22, on the other hand, only the liquid component of the fluid is present, which passes int the circulation tubes 14, inside which, through the known phenomena of heat exchange with an external fluid, for example air, the evaporation of the liquid component of the internal fluid circulating in the circulation tubes 14 occurs.

In this way, only the gaseous component of the fluid is collected in the second manifold 12, which is then recirculated in the hydraulic circuit outside the heat exchanger 10, by means of the second conduit 32.

When, on the other hand, the heat exchanger 10 described above with particular reference to fig. 2 operates as a condenser, its functioning is as follows. In this case, the fluid reaches the second manifold 12 by means of the second conduit 32. From here, it enters the circulation tubes 14, passing through them from right to left as the fluid condenses, and reaches the first manifold 11, in which it is completely in the liquid state, to then leave the exchanger 10 by means of the first conduit 31. It is evident that in this functioning mode, unlike what is shown in figs. 1 and 2, the liquid component of the fluid substantially fills the entire first manifold 11, at least until it reaches the mouth of the first i o - conduit 31. It should be noted that in this functioning mode the valves 37, 38 prevent the cooling fluid from entering the bypass connection 16, which in this case is not used.

With reference to fig. 3, a heat exchanger 110 according to the present invention can be selectively used for the evaporation, or for the condensation, of a fluid having a liquid component and a gaseous component. For example, the fluid as above can be formed by a mixture of known substances commonly used in heat exchangers, such as the fluids R-134a or R410A.

The heat exchanger 110 comprises a first manifold 111 and a second manifold 112, fluidically connected to each other by means of a heat exchange battery 113, which in turn comprises a plurality of circulation elements, or circulation tubes 114, parallel to each other and substantially perpendicular to the two manifolds 111 and 112.

On the external surfaces of the circulation tubes 114 there are attached fms 115 with the function of increasing the useful heat exchange surface of the circulation tubes 114. The presence of the fins 115 therefore promotes the evaporation or condensation inside the heat exchange battery 113.

In the embodiment described here with reference to fig. 3, the circulation tubes 114 are disposed vertically, so that the heat exchange battery 113 is of the type with vertical tubes.

In particular, the first manifold 111 is disposed below the heat exchange

In some embodiments of the present invention, the circulation tubes 114 can have a very small passage section, so that the heat exchange battery 113 can be defined as a so-called “micro-channel” core.

Furthermore, the first manifold 111 and the second manifold 112 are fluidically connected to each other by means of a connection member or conduit, which defines a bypass connection 116, substantially parallel to the circulation tubes 114 and which, in the example provided here, is disposed outside the heat exchange battery 113.

In other embodiments of the present invention, not shown in the drawings, the bypass connection 116 can be integrated in the heat exchange battery 113, extending, for example, immediately on one side of the pack of circulation tubes 114.

The bypass connection 116 can be a simple oblong element with a tubular shape, for example with a circular, square or rectangular cross-section and comprises an external wall 139 and an internal wall 140, for example parallel to the external wall 139 and closer to the heat exchange battery 113.

A first conduit 131 is fluidically connected to the external wall 139, the first conduit 131 in turn being connected to a suitable external hydraulic circuit, of a known type, or which will be developed in the future, and not shown in the drawings.

The zone in which the first conduit 131 is fluidically connected to the bypass connection 116 divides the latter into an upper part and a lower part thereof, indicated with reference numbers 135 and 133 respectively, the function of which will be described later.

For example, the first conduit 131 has a circular cross-section, with a determinate internal diameter D preferably comprised between about 12 mm and about 42 mm.

A second conduit 132 is fluidically connected to the second manifold 112, the second conduit 132, as the first conduit 131, being connected to the external hydraulic circuit as above.

In particular, when the heat exchanger 110 is made to function as an evaporator, the first conduit 131 acts as an inlet conduit for the fluid and the second conduit 132 acts as an outlet conduit for the fluid as above. Conversely, when the heat exchanger 110 is made to function as a condenser, the first conduit 131 acts as an outlet conduit for the fluid and the second conduit 132 acts as an inlet conduit for the fluid as above.

Both the first manifold 111 and also the second manifold 112 have an oblong shape having a circular or polygonal cross-section.

In particular, the first manifold 111 comprises two lateral walls 118 and 119, an upper wall 120 and a lower wall 121, which define a chamber 122.

Similarly, the second manifold 112 comprises two lateral walls 125 and 126, an upper wall 127 and a lower wall 128, which define a chamber 129.

Furthermore, in accordance with one aspect of the present invention, the chamber 129 of the second manifold 112 is divided by a substantially horizontal separator element, or partition, 130 into a first part 123 and a second part 124, disposed below the latter, the functions of which will be described later. The first part 123 and the second part 124 of the chamber 129 are communicating with each other in a zone adjacent to the lateral wall 126 of the latter (on the right in the attached drawing).

The circulation tubes 114 of the heat exchange battery 113 have their lower ends fluidically connected to the upper wall 120 of the first manifold 111 and their upper ends fluidically connected to the lower wall 128 of the second manifold 112 and therefore to the second part 124 of the chamber 129 of the latter.

The lateral wall 118 (on the left in the attached drawing) of the first manifold 111 is connected to the connection member 116 in correspondence with its lower part 133, while the corresponding lateral wall 125 (also on the left in the attached drawing) of the second manifold 112, in correspondence with the first part 123 of the chamber 129 of the latter, is connected to the connection member 116 in correspondence with its upper part 135. The lateral wall 126 (on the right in the attached drawing) of the second manifold 112 is instead connected to the second conduit 132.

In other embodiments of the present invention, not shown in the drawings, the division of the second manifold 112 into the two parts 123 and 124 can also be achieved without the insertion of a separator element, such as the partition 130, shaping it in the shape of a U, so as to define in any case two parts communicating with each other in the zone adjacent to the bypass connection 116.

The first conduit 131, at least in its part which is in contact with the external wall 139 of the bypass connection 116, has its own longitudinal axis X, which defines the direction of the flow of the fluid entering the same bypass connection 116, when the heat exchanger 110 is made to function as an evaporator.

In the embodiment shown here, the longitudinal axis X forms an angle of impact a of 90° with the internal wall 140, it being understood that it can have an amplitude comprised in a range between about 35° and about 90°, preferably between about 45° and about 90°. In the event that the heat exchanger 110 is made to function as an evaporator, the fluidic connection between the first conduit 131 and the bypass connection 116 has the function of separating the gaseous component from the liquid component of the fluid. In fact, the first conduit 131 is configured to direct the fluid so as to impact the internal wall 140 of the bypass connection 116 in a zone close to the connection between the two, in order to induce one or several vortex motions inside the fluid which, in combination with other effects that will be described below, cause the separation of the liquid component from the gaseous component of the fluid.

The ratio between the internal diameter D of the first conduit 131 and the distance L between the external wall 139 of the bypass connection 116, that is, the end part of the first conduit 131, and the internal wall 140 of the bypass connection 116 is preferably comprised between about 0.2 and about 0.9, more preferably between about 0.3 and about 0.8, even more preferably between about 0.4 and about 0.7. This ratio is appropriately chosen also taking into consideration the speed and pressure of the fluid entering the bypass connection 116.

It should be noted that in addition to the contribution of the vortex motions generated by the impact of the flow of the fluid on the internal wall 140 of the bypass connection 116, the separation of the liquid component from the gaseous component of the fluid is due, at least partly, to at least one of the following effects:

- contribution of the force of gravity, which promotes the downward precipitation of the liquid component of the fluid;

- amplitude of the angle of impact a, which can promote the formation of vortex motions of such an extent as to facilitate the separation of the liquid and gaseous components of the fluid;

- ratio between the internal diameter D of the first conduit 131 and the distance L between the external wall 139, that is, the end part of the first conduit 131, and the internal wall 140;

- flow rate and therefore associated speed of the fluid at exit from the first conduit 131;

- vapor quality, that is, the concentration, expressed in physical or chemical units, of the gaseous component inside the fluid.

The liquid component, due to the effect of gravity, accumulates in the lower part 133 of the bypass connection 116, generating a height H of the liquid component, while the gaseous component flows in the upper part 135 of the bypass connection 116.

Associated with the upper part 135 of the bypass connection 116 and with the first part 123 of the chamber 129 are one or more elements, or members, for regulating the pressure of the gaseous component of the fluid, so that the height H of the liquid component of the fluid can be regulated in the lower part 133 of the bypass connection 116.

A first regulation element is a regulation valve 138, preferably of the unidirectional or non-return type, positioned in the upper part 135 of the bypass connection 116 or in any case in the connection zone between the latter and the first part 123 of the chamber 129. The regulation valve 141 has the function of enabling, or not, the passage of the gaseous component of the fluid in the direction of the chamber 129 and prevents its opposite flow, in the opposite direction.

The regulation valve 141 also allows to modify the pressure of the gaseous component of the fluid, increasing or decreasing it, in order to regulate the height H of the liquid component of the fluid in the bypass connection 116.

A second regulation element consists of one or more narrowing elements 136 respect to each other, in order to locally reduce the cross-section of the first part 123 of the chamber 129 and thus create localized pressure drops.

The shape and number of the one or more narrowing elements 136 are chosen as a function of the pressure drops to be created in the first part 123 of the chamber 129, so as to obtain a determinate height H of the liquid component of the fluid in the lower part 133 of the bypass connection 116.

In accordance with one variant, schematically shown in fig. 2, the narrowing elements 136 can be attached both to the upper wall 127 of the second manifold 112 and facing downward, and also to the partition 130 and facing upward. The narrowing elements 136 are suitably sized and distanced from each other, as a function of the pressure drop to be obtained in the first part 123 of the chamber 129 of the second manifold 112.

In other embodiments of the present invention, not shown in the drawings, the elements for regulating the pressure of the gaseous component of the fluid can comprise walls, or partitions, either solid or possibly provided with apertures, preferably disposed transversely inside the first part 123 of the chamber 129, so as to partly obstruct its passage section.

Below, we describe the functioning of the heat exchanger 110 described heretofore, when it functions as an evaporator.

The fluid coming from the external hydraulic circuit as above is introduced into the bypass connection 116 through the first conduit 131.

Due to the impact against the internal wall 140 of the bypass connection 116, possibly in combination with the other effects described above, the fluid is divided and its liquid component is disposed in the lower part 133 of the bypass connection 116, up to the height H, while above it there is disposed only the gaseous component of the fluid, which, due to its pressure, reaches the first part 123 of the chamber 129 of the second manifold 112, through the upper part 135 of the bypass connection 116.

The pressure of the gaseous component of the fluid inside the bypass connection 116 is regulated by the regulation valve 141 and/or by the narrowing elements 136.

In the chamber 122 of the first manifold 111, only the liquid component of the fluid is present, which passes into the circulation tubes 114, inside which, through the known phenomena of heat exchange with an external fluid, for example air, the evaporation of the liquid component of the internal fluid circulating in the circulation tubes 114 occurs.

In the zone of the chamber 129 of the second manifold 112, in which the two parts 123 and 124 are communicating with each other, the union between the gaseous component of the fluid coming from the upper part 135 of the bypass connection 116 and the one coming from the circulation tubes 114 of the heat exchange battery 113 occurs.

In this way, in the second manifold 112 only the gaseous component of the fluid is collected, which is then recirculated in the hydraulic circuit outside the heat exchanger 110, by means of the second conduit 132. - ZZ -

It should be noted that, when functioning as an evaporator, the heat exchanger 110 does not necessarily need the regulation valve 141. In fact, it would be possible to obtain the same result through the exclusive use of other regulation elements among those previously described, such as for example the narrowing elements 136.

When, on the other hand, the heat exchanger 110 described above is made to function as a condenser, its functioning is as follows.

The fluid enters the second manifold 112 by means of the second conduit 132. From here, since the passage toward the bypass connection 116 is blocked by the second regulation valve 138, the fluid enters the circulation tubes 1 14, flows through them from the top downward and condenses. The fluid then reaches the first manifold 111, which is reached completely in the liquid state, to then leave the exchanger 110 through the first conduit 131, passing through the connection member 116.

It is clear that modifications and/or additions of parts may be made to the heat exchanger 10, 110 as described heretofore, without departing from the field and scope of the present invention as defined by the claims.

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 heat exchanger, all coming within the scope of the present invention. protuberance or as a series of successive protuberances, possibly provided with one or more holes, preferably such as to follow, at least partly, the perimeter development of the bypass connection 16 section.

In other embodiments, the regulation elements can be configured as a structural discontinuity in the bypass connection 16 which constitutes a discontinuity in the geometry thereof.

This means, for example, that the regulation elements can comprise portions made of a material different from the one the bypass connection 16 is made of, or portions in which a geometric variation thereof is provided. According to a nonlimiting example, in correspondence with these portions the walls of the bypass tube 16 can have a different thickness, greater or lesser, than the nominal thickness.

In other embodiments, the regulation elements can comprise free or semi-free bodies, for example retained by a cable, with a shape and/or made of materials suitable to impart the desired localized pressure drop to the flow of the fluid. In other embodiments, the regulation elements can comprise at least one flexible membrane, configured to be passed through by the flow of the fluid, for example perforated or micro-perforated, and made of plastic, polymeric, fabric, non-woven fabric or rubber material, or other suitable material.

It should be noted that all the embodiments of the regulation elements are provided by way of a non-limiting example, therefore modifications to the embodiments described and/or their combinations are not excluded.

In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection determined by the specific claims.