14 January 2021

WO 2022/130325 PCT/IB2021/061935

- 1 -

THERMODYNAMIC CYCLE REVERSING GROUP FOR REFRIGERATION CIRCUITS WITH REVERSIBLE THERMODYNAMIC CYCLE AND REFRIGERATION CIRCUIT WITH REVERSIBLE THERMODYNAMIC CYCLE COMPRISING SUCH REVERSING GROUP.

DESCRIPTION

The invention relates to a thermodynamic cycle reversing group for refrigeration circuits with reversible thermodynamic cycle, as well as to a refrigeration circuit with reversible thermodynamic cycle comprising such a reversing group.

Refrigeration circuits with reversible thermodynamic cycle, such as air conditioning systems with a heat pump, generally comprise two heat exchangers, an expansion valve on a first line connecting the two heat exchangers, a compressor on a second line connecting the same two heat exchangers, and a thermodynamic cycle reversing group interposed between the compressor and the two heat exchangers.

This thermodynamic cycle reversing group typically comprises a four-way valve, which is connected by means of a first line to the compressor inlet, by means of a second line to the compressor outlet, by means of a third line to a first heat exchanger and by means of a fourth line to a second heat exchanger. In refrigeration circuits, the four-way valve, which reverses the thermodynamic cycle, switches the passage of the refrigerant fluid leaving the compressor from one heat exchanger to another of the refrigerating machine, reversing the direction of the flow of the refrigerant fluid inside these heat exchangers, the thermodynamics inside them and the cooling effect in the environment in which they are located.

As is known, the heat exchanger that receives the refrigerant fluid in the gaseous phase at the outlet of the compressor is called the condenser, while the other heat exchanger is called the evaporator.

The reversing valve is used for refrigeration machines or the heat pump air conditioners which allow to cool or heat the rooms by activating the reversing valve.

To date, the most common reversing valves are the ‘slide’ type.

In such ‘slide’ type valves, which are operated by means of a pressure piston, the command can take place by means of a small solenoid valve called “pilot”, which diverts high and low pressure to move the piston connected to the selection slide.

The operating passage from heating to cooling and vice versa takes place through the movement of the slide, whose position forces the passage of the refrigerant either in a first line directed to a first heat exchanger, or in the second line directed to the second heat exchanger.

The position of this selection slide is determined by the coil, whether or not it is energized by an electrical control signal, the one that controls the reversal of the hot-cold cycle; the solenoid valve then indirectly activates the movement of the slide.

The two positions correspond to the two different operating modes, ‘hot’ and ‘cold’ of the refrigeration circuit.

In order to guarantee the movement of the slide of the slide valve, a minimum pressure difference AP is required between the two flows passing through the valve, i.e. a first flow line in which cold fluid flows at low pressure, and a second flow line in which hot fluid flows at high pressure, otherwise the movement of the slide could be partial or totally absent, with the relative consequences.

Such a four-way valve of the slide type, although well-known and appreciated, has some limitations and drawbacks.

A first drawback of these slide valves of known type is that they do not guarantee the perfect sealing of the refrigerant fluid, with consequent leakage of the same refrigerant fluid towards other elements of the circuit such as exchangers and compressor, with consequent losses in efficiency and reliability and with the risk of premature failure of the compressor.

A second important drawback and limitation is linked to the fact that the operation of the slide-type valves on the market depends on the difference in pressure between the two lines of fluid passing through them, and on the fact that there is no feed-back signal informing the user of the correct positioning of the valve slide itself; there is therefore a difficulty in monitoring the actual position of the valve slide in real time.

In addition, another limitation of slide valves of known type is that these slide valves have many reciprocal moving parts and therefore many friction zones, with an equal risk of seizure of the moving components; there is therefore a low reliability rate due to the complex mechanisms of which the slide valve is composed. The task of the present invention is to develop a thermodynamic cycle reversing group for refrigeration circuits with reversible thermodynamic cycle capable of overcoming the aforementioned drawbacks and limitations of the prior art.

In particular, an object of the invention is to develop a refrigeration circuit with reversible thermodynamic cycle comprising such a reversing group.

A further object of the invention is to develop a reversing group capable of a better sealing against the refrigerant than the slide valves of known type.

A further object of the invention is to develop a reversing group which does not exceed the size of the valve of known type.

Still, an object of the invention is to develop a reversing group which allows to limit the friction and seizure problems of the moving components.

The above-mentioned task as well as the above-mentioned purposes are achieved by a thermodynamic cycle reversing group for refrigeration circuits with reversible thermodynamic cycle according to claim 1 , as well as by a refrigeration circuit with reversible thermodynamic cycle comprising said reversing group according to claim 11 .

Further characteristics of the reversing group according to claim 1 are described in the dependent claims.

The aforesaid task and objects, together with the advantages that will be mentioned hereinafter, are highlighted by the description of four embodiments of the invention, which are given, by way of non-limiting example, with reference to the attached drawing tables, where:

- Figure 1 represents a schematic view of a reversing group according to the invention and of a refrigeration circuit according to the invention, in a first embodiment;

- Figure 2 schematically represents a reversing group according to the invention;

- Figure 3 shows the reversing group and the refrigeration circuit of Figures 1 and 2 in a first operating arrangement;

- Figure 4 represents the reversing group and the refrigeration circuit of Figures 1 , 2 and 3 in a second operating arrangement;

- Figure 5 represents a schematic view of a reversing group according to the invention and of a refrigeration circuit according to the invention in a second embodiment and in a first operating arrangement; - Figure 6 represents the same view as Figure 5 with the reversing group in a second operating arrangement;

- Figure 7 represents a schematic view of a reversing group according to the invention and of a refrigeration circuit according to the invention in a third embodiment and in a first operating arrangement;

- Figure 8 represents the same view as Figure 7 with the reversing group in a second operating arrangement;

- Figure 9 represents a schematic side view of a reversing group according to the invention in a fourth embodiment;

- Figure 10 schematically represents the reversing group of Figure 9 in a first operating arrangement;

- Figure 11 schematically represents the reversing group of Figures 9 and 10 in a second operating arrangement.

With reference to the aforementioned figures, a thermodynamic cycle reversing group for refrigeration circuits with reversible cycle according to the invention is indicated as a whole of a first embodiment thereof with the numeral 10.

This thermodynamic cycle reversing group 10 for refrigeration circuits with reversible cycle comprises:

- two ball valves 11 and 12 of at least three-way type, e.g. of the three-way type, a first ball valve 11 comprising a first side fitting 11a, a second side fitting 11b, opposite the first side fitting 11a, and a third central fitting 11c, and a second ball valve 12 comprising a first side fitting 12a, a second side fitting 12b, opposite the first side fitting 12a, and a third central fitting 12c;

- an actuator 13 configured to simultaneously rotate by an angle of rotation A a first ball 14 of the first ball valve 11 and a second ball 15 of said second ball valve 12, between a first operating arrangement and a second operating arrangement.

The reversing group 10 also comprises at least two side manifolds 16 and 17.

A manifold is defined as a hollow body comprising:

- a tubular cavity in its inside,

- three connection mouths for the connection between the tubular cavity and the outside of the manifold.

These side manifolds 16 and 17 are of the three-way type.

A first side manifold is configured to connect:

- a first side fitting of a first ball valve, - with a fitting chosen between a first side fitting, a second side fitting and a third central fitting of the second ball valve.

A second side manifold is configured to connect:

- one chosen between the second side fitting or the third central fitting of the first ball valve,

- with one of the two fittings of the second ball valve which are not connected with the first side manifold.

The first ball of the first ball valve and the second ball of the second ball valve are configured such that: in a first operating arrangement:

- in the first ball valve, the first ball connects, i.e. is configured to connect, the fitting of the first ball valve, which is connected to the first side manifold, with the fitting of the first ball valve, which is not connected to the second side manifold,

- and in the second ball valve, the second ball connects, i.e. is configured to connect, the fitting of the second ball valve, which is connected to the second side manifold, with the fitting of the second ball valve, which is not connected to the first side manifold; and in a second operating arrangement:

- in the first ball valve, the first ball connects the fitting of the first ball valve, which is connected to the second side manifold, with the fitting of the first ball valve, which is not connected to the first side manifold,

- and in the second ball valve, the second ball connects the fitting of the second ball valve, which is connected to the first side manifold, with the fitting of the second ball valve, which is not connected to the second side manifold.

In the first embodiment of the invention, schematically shown in Figures 3 and

4, the reversing group 10 comprises:

- two side manifolds of the three-way type 16 and 17; a first side manifold 16, comprising three fittings 16a, 16b, 16c, is connected with a first fitting thereof 16a to a first side fitting 11a of a first ball valve 11, and with a second fitting thereof 16b to a first side fitting 12a of the second ball valve 12; a second side manifold 17, comprising three fittings 17a, 17b, 17c, is connected with a first fitting thereof 17a to a second side fitting 12b of said second ball valve 12, and with a second fitting thereof 17b to a second side fitting 11 b of said first ball valve 11.

The two balls 14 and 15 are configured such that:

- in a first operating arrangement, clearly visible in Figure 3, in the first ball valve 11, the first ball 14 connects the first side fitting 11a with the third central fitting 11c, and in the second ball valve 12, the second ball 15 connects said second side fitting 12b with said third central fitting 12c;

- in a second operating arrangement, clearly visible in Figure 4, in the first ball valve 11, the first ball 14 connects said second side fitting 11b with the third central fitting 11c, and in said second ball valve 12, the second ball 15 connects the first side fitting 12a with the third central fitting 12c.

Like also in all embodiments described below, the first ball 14 and the second ball 15 are rigidly connected to a single rotation shaft 20, which rotation shaft 20 is rotated by the actuator 13.

Preferably, but not exclusively, the two ball valves 11 and 12 are integrated into a single two-ball, six-way valve 21, as exemplified in Figure 1.

The actuator 13, as well as the actuator 313 mentioned below, is of the electric type.

In this first embodiment of the invention, the actuator 13 is positioned above, or alternatively below, said two-ball, six-way valve 21.

In this first embodiment of the invention, each of the two side manifolds 16 and 17 is substantially ‘F’-shaped.

At least one between said first ball 14 and said second ball 15 has a T-shaped hole.

In particular, in the first embodiment of the reversing group 10, both the first ball 14 and the second ball 15 have a T-shaped hole.

The invention also relates to a refrigeration circuit 30, of the reversible thermodynamic cycle type, comprising two heat exchangers 31 and 32, an expansion valve 33 on a first line 34 connecting the two heat exchangers 31 and 32, a compressor 35 on a second line 36 connecting the same two heat exchangers 31 and 32, and a thermodynamic cycle reversing group 10 interposed, on the second line 16, between the compressor 35 and the two heat exchangers 31 and 32.

The peculiarity of the refrigeration circuit 30 according to the invention lies in the fact that it comprises a thermodynamic cycle reversing group 10 as described above. In particular, in such a refrigeration circuit 30 the reversing group 10 is connected to the second line 36 in such a way that:

- the third fitting 16c of the first manifold 16 is connected to a first heat exchanger 31 by means of a section 36a of the second line 36;

- the third fitting 17c of the second manifold 17 is connected to a second heat exchanger 32 by means of a section 36b of the second line 36;

- the third central fitting 11c of the first ball valve 11 is connected to the discharge of the compressor 35 by means of a section 36c of the second line 36;

- the third central fitting 12c of the second ball valve 12 is connected to the intake of the compressor 35 by means of a section 36d of the second line 36

The refrigeration circuit 30 according to the invention, comprising the reversing group 10 according to the invention, may operate as described below.

In a first arrangement schematically shown in Figure 3, in the first ball valve 11, the first ball 14 connects the first side fitting 11a with the third central fitting 11c, and in the second ball valve 12 said second ball 15 connects said second side fitting 12b with said third central fitting 12c; in this way, the discharge of the compressor 35 is connected, by means of the first side manifold 16, to the first heat exchanger 31, which operates as a condenser, while the second heat exchanger 32 operates as an evaporator, this second heat exchanger 32 being connected, by means of the second side manifold 17, to the intake of the compressor 35.

By operating the actuator 13, a rotation of the rotation shaft 20 is made by a 180° angle A, until the balls 14 and 15 of the first 11 and second 12 ball valves reach the second arrangement of Figure 4.

In the second arrangement, schematically shown in Figure 4, in the first ball valve 11, the first ball 14 connects the second side fitting 11b with the third central fitting 11c, and in the second ball valve 12 the second ball 15 connects the first side fitting 12a with the third central fitting 12c; in this way, the discharge of the compressor 35 is connected, by means of the second side manifold 17, to the second heat exchanger 32, which operates as a condenser, while the first heat exchanger 31 operates as an evaporator, this first heat exchanger 31 being connected, by means of the first side manifold 16, to the intake of the compressor 35. Advantageously, the first 11 and the second 12 ball valves have, on the respective valve body, at a free zone not affected by any fitting, at least one sensor 40 chosen between a pressure sensor and a temperature sensor.

The electric-type actuator 13 and 313 is configured in such a way as to be able to acquire the signals from these sensors 40 installed on the valve body.

In a second embodiment of the invention, schematically shown in Figures 5 and 6, a reversing group 110 comprises:

- two ball valves 111 and 112 of at least three-way type, e.g. three-way, a first ball valve 111 comprising a first side fitting 111b, a second side fitting 111a, opposite the first side fitting 111b, and a third central fitting 111c, and a second ball valve 112 comprising a first side fitting 112b, a second side fitting 112a, opposite the first side fitting 112b, and a third central fitting 112c;

- an actuator 13 configured to simultaneously rotate by an angle of rotation A a first ball 114 of the first ball valve 111 and a second ball 115 of the second ball valve 112, between a first operating arrangement and a second operating arrangement;

- two side manifolds 116 and 117, of which:

- a first side manifold 116 is configured to connect:

- a first side fitting 111 b of a first ball valve 111,

- with a first side fitting 112b of the second ball valve 112;

- a second side manifold 117 is configured to connect:

- the third central fitting 111c of the first ball valve 111,

- with the second side fitting 112a of the second ball valve 112.

In such a second embodiment of the reversing group 110, the first ball 114 of the first ball valve 111 and the second ball 115 of the second ball valve 112 are configured such that: in a first operating arrangement, schematically shown in Figure 5:

- in the first ball valve 111, the first ball 114 connects, i.e. is configured to connect, the first side fitting 111b of the first ball valve 111, which is connected to the first side manifold 116, with the second fitting 111a of the first ball valve 111, which is not connected to the second side manifold 117,

- and in the second ball valve 112, said second ball 115 connects, i.e. is configured to connect, the second side fitting 112a of the second ball valve 112, which is connected to the second side manifold 117, with the third fitting 112c of the second ball valve 112, which is not connected to the first side manifold 116; and in a second operating arrangement, schematically shown in Figure 6:

- in the first ball valve 111, the first ball 114 connects the third central fitting 111c of the first ball valve 111, which is connected to the second side manifold 117, with the second side fitting 111a of the first ball valve 111, which is not connected to the first side manifold 116,

- and in the second ball valve 112, the second ball 115 connects the first side fitting 112b of the second ball valve 112, which is connected to said first side manifold 116, with the third central fitting 112c of the second ball valve 112, which is not connected to the second side manifold 117.

At least one between said first ball 114 and said second ball 115 has an ‘L’-shaped hole.

In particular, in this second embodiment of the reversing group 110, the first ball 114 has a T-shaped hole, and the second ball 115 has an ‘L’-shaped hole.

Similarly to what has been described above for the first embodiment of a refrigeration circuit 10 according to the invention, a refrigeration circuit 130 according to the invention comprises a thermodynamic cycle reversing group 110 as described above.

In particular, in such a refrigeration circuit 130 the reversing group 110 is connected to the second line 36 in such a way that:

- the third fitting 116c of the first manifold 116 is connected to a first heat exchanger 31 by means of a section 36a of the second line 36;

- the third fitting 117c of the second manifold 117 is connected to a second heat exchanger 32 by means of a section 36b of the second line 36;

- the second side fitting 111a of the first ball valve 111 is connected to the intake of the compressor 35 by means of a section 36d of the second line 36;

- the third central fitting 112c of the second ball valve 112 is connected to the discharge of the compressor 35 by means of a section 36c of the second line 36.

In such a second embodiment of the invention, the angle of rotation A, in order to pass from a first operating arrangement to a second operating arrangement, is at 90°. The operation of the refrigeration circuit 130 according to the invention in its second embodiment is analogous to the operation described above for the refrigeration circuit 30 in its first embodiment.

A third embodiment of a reversing group according to the invention and a third embodiment of a refrigeration circuit according to the invention are schematically shown in Figures 7 and 8, and indicated therein by the numbers 210 and 230, respectively.

In such a third embodiment of the reversing group 210 according to the invention, a first ball valve 211 is of the four-way type.

In this embodiment, the second ball valve 212 is also of the four-way type.

This reversing group 210 therefore comprises:

- two ball valves 211 and 212 of the four-way type, a first ball valve 211 comprising a first side fitting 211a, a second side fitting 211b opposite the first side fitting 211a, a third central fitting 211c, and a fourth central fitting 211d opposite the third central fitting 211c, and a second ball valve 212 comprising a first side fitting 212a, a second side fitting 212b opposite the first side fitting 212a, a third central fitting 212c, and a fourth central fitting 212d opposite the third central fitting 212c;

- an actuator 13 configured to simultaneously rotate by an angle of rotation A a first ball 214 of the first ball valve 211 and a second ball 215 of said second ball valve 212, between a first operating arrangement and a second operating arrangement;

- a first three-way side manifold 216 configured to connect a side fitting of a first ball valve 211, for example the second side fitting 211b, with a fitting chosen between the first side fitting 212a, the second side fitting 212b, the third central fitting 212c and the fourth central fitting 212d of said second ball valve 212, for example the second side fitting 212b;

- two second three-way side manifolds 217a and 217b, one for each of the first 211 and second 212 ball valves, each of these second side manifolds 217a and 217b being configured and shaped to connect the side fitting 211a and 212a, respectively of the first 211 and second 212 ball valve, which is opposite the side fitting 211b and 212b connected to the first manifold 216, with one of the two central fittings, 211c or 211 d for the first ball valve 211, and 212c or 212d for the second ball valve 212, of the same first 211 or second 212 ball valve. The first ball 214 of said first ball valve 211 and the second ball 215 of the second ball valve 212 are configured such that: in a first operating arrangement, schematically shown in Figure 7:

- in the first ball valve 211, the first ball 214 connects the two opposite central fittings 211c and 211 d, where one of these two central fittings is connected to the second side manifold 217a,

- and in the second ball valve 212, the second ball 215 connects the second side fitting 212b of the second ball valve 212, which is connected to the first side manifold 216, with the opposite first side fitting 212a of the second ball valve 212, which is connected to the second side manifold 217b; and in a second operating arrangement, schematically shown in Figure 8:

- in the first ball valve 211, the first ball 214 connects the second side fitting 211b of the first ball valve 211, which is connected to the first side manifold 216, with the opposite first side fitting 212a of the first ball valve 211, which is connected to the second side manifold 217a,

- and in said second ball valve 212, the second ball 215 connects the two opposite central fittings 212c and 212d, where one of these two central fittings is connected to the second side manifold 217b.

In this third embodiment of the invention, the first 214 and second 215 balls have a linear, i.e. , rectilinear, through hole.

In this third embodiment of the invention, the angle of rotation A, in order to pass from a first operating arrangement to a second operating arrangement, is at 90°.

Similarly to what has been described above for the first and second embodiment of a refrigeration circuit according to the invention, a refrigeration circuit 230 according to the invention comprises a thermodynamic cycle reversing group 210 as described above.

In particular, in such a refrigeration circuit 230 the reversing group 210 is connected to the second line 36 in such a way that:

- the third fitting 216c of the first manifold 216 is connected to a first heat exchanger 31 by means of a section 36a of the second line 36;

- the central fittings of the first 211 and second 212 ball valves, which are not connected to the respective second side manifold 217a and 217b, for example the central fittings 211c and 212c respectively, are connected to the second heat exchanger 32 by means of a common section 36b bifurcated into two dedicated sections 36b’ and 36b”, respectively;

- a fitting 217a1 of the second side manifold 217a of the first ball valve 211 is connected to the intake of the compressor 35 by means of a section 36d of the second line 36;

- a fitting 217b1 of the second side manifold 217b of the second ball valve 212 is connected to the discharge of the compressor 35 by means of a section 36c of the second line 36.

Figures 9 to 11 schematically show a fourth embodiment of a reversing group 310 according to the invention.

In such a fourth embodiment of the invention, the actuator 313 is interposed between the first ball valve 311 and the second ball valve 312.

Similarly to what has been described for the first embodiment of the invention, the actuator 313 is configured to simultaneously rotate by an angle of rotation A a first ball 314 of the first ball valve 311 and a second ball 315 of said second ball valve 312, between a first operating arrangement and a second operating arrangement.

The reversing group 310 also comprises two side manifolds 316, 317 as described above for the first embodiment of the reversing group 10.

The first ball 314 and the second ball 315 are also to be understood as described above for the first embodiment of the reversing group 10.

Such a configuration with the actuator 313 interposed between the first ball valve 311 and the second ball valve 312 is obviously to be understood as also applicable to the second embodiment 110 and to the third embodiment 210 of the reversing group according to the invention.

In general, the invention also relates to a refrigerant circuit 30, 130, 230 of the reversible thermodynamic cycle type, comprising two heat exchangers 31 and 32, an expansion valve 33 on a first line 34 connecting the two heat exchangers 31 and 32, a compressor 35 on a second line 36 connecting the same two heat exchangers 31 and 32, and a thermodynamic cycle reversing group interposed between the compressor 35 and the two heat exchangers 31 and 32, characterized by comprising a thermodynamic cycle reversing group 10, 110, 210, 310 as described above.

It has in practice been established that the invention achieves the intended task and objects.

In particular, with the invention, a reversing group capable of better sealing against the refrigerant fluid than the slide valves of the known type has been developed, thanks to the use of ball valves; in fact, the reversing group according to the invention substantially comprises a double shutter, i.e. a shutter with two ball valves, which, when closed, guarantees the perfect sealing of the refrigerant gas.

In particular, thanks to the single two-ball, six-way valve 21, the overall dimensions are more limited with the same cooling capacity compared to known valves, as the cycle reversal action takes place through a double valve residing on the single body and through a single electric actuator.

The actuator 13 allows positioning the balls towards one or the other exchanger by means of a 0-10V signal (or BUS) arriving from a control device.

The actuator 13 is provided with a feed-back device, which allows controlling the position of the balls of the ball valves and the successful reversal; the reversing group according to the invention thus allows real-time monitoring of the actual and real angular position of the balls of the ball valves.

Ball valves are robust devices because they have little movements and therefore little friction between surfaces.

The invention thus conceived is susceptible of numerous modifications and variants, all of which are within the scope of the inventive concept; moreover, all the details may be replaced by other technically equivalent elements.

In practice, the components and materials used, as well as the dimensions and shapes, as long as they are compatible with the specific use, can be any according to requirements and the state of the art.

If the characteristics and techniques mentioned in any claim are followed by reference signs, these reference signs are to be intended for the sole purpose of increasing the intelligibility of the claims and, consequently, such reference signs have no limiting effect on the interpretation of each element identified by way of example by these reference signs.