IT202300001368A1 - VEHICLE THERMAL CONTROL SYSTEM - Google Patents

Description

DESCRIPTION of the industrial invention entitled: "Thermal control system for vehicle"

DESCRIPTION

The present invention relates to a thermal control system for the thermal control of a (at least partially) electrically powered vehicle, i.e. a vehicle having a traction system with an electric motor and a power system with a battery pack capable of powering the electric motor, and related thermal control methods that make use of such a multi-modal thermal control system.

Multi-mode thermal control systems for the thermal control of a vehicle are known in the common art.

For example, US 9,758,011 B2 shows a thermal control system for an electrically powered vehicle, comprising a battery thermal control circuit thermally coupled to a battery pack of the vehicle, a traction system thermal control circuit thermally coupled to an electric motor of the vehicle, and a passenger compartment thermal control circuit thermally coupled to the passenger compartment of the vehicle. Due to the connection method between the three different circuits, in the prior art the ways in which thermal control systems can be used are very limited. In particular, vehicles are generally equipped with an air-fluid heat exchanger for heat exchange arranged frontally in front of the radiator and capable of functioning as both a condenser and an evaporator depending on the contingent thermal needs of the vehicle, and this component constitutes both a structural constraint for the rest of the thermal control system architecture and an efficiency limit for the thermal control system itself.

The object of the present invention is to provide a thermal control system for a vehicle having an electric motor and a battery pack that powers it which does not suffer from the disadvantages of the prior art, and which can, therefore, be used in a plurality of different modes of use depending on the heating or cooling requirements of the various components of the vehicle.

This and other objects are fully achieved according to the present invention thanks to a thermal control system as defined in the appended independent claim 1.

Advantageous embodiments of the thermal control system according to the invention are specified in the dependent claims, the content of which is to be understood as an integral part of the following description.

In summary, the invention is based on the idea of providing a multi-mode thermal control system for a vehicle having a traction system with an electric motor and a power system with a battery pack suitable for powering said electric motor,

the thermal control system comprising:

a battery thermal control circuit, including a first circulation pump and a first fluid-refrigerant heat exchanger, wherein said first circulation pump is adapted to circulate heat exchange fluid within said battery thermal control circuit and through said first fluid-refrigerant heat exchanger, and wherein said battery thermal control circuit is thermally coupled to said vehicle battery pack;

a traction system thermal control circuit comprising a second circulation pump and a second fluid-refrigerant heat exchanger, wherein said second circulation pump is adapted to circulate heat exchange fluid within said traction system thermal control circuit and through said second fluid-refrigerant heat exchanger, wherein said traction system thermal control circuit is thermally coupled to said vehicle electric motor;

a refrigerant circuit in which a refrigerant is circulated, and comprising a compressor, an evaporator, a first expansion valve adapted to couple said evaporator to said refrigerant circuit, said compressor being adapted to circulate the refrigerant within said refrigerant circuit and through said first fluid-refrigerant heat exchanger and said second fluid-refrigerant heat exchanger; the refrigerant circuit further comprising a second expansion valve adapted to regulate by lamination the flow, or the rate, of refrigerant flowing through the first fluid-refrigerant heat exchanger and a third expansion valve adapted to regulate by lamination the flow, or the rate, of refrigerant flowing through the second fluid-refrigerant heat exchanger.

Preferably, the battery thermal control circuit and the traction system thermal control circuit are arranged in parallel to each other, i.e. the heat exchange fluid flow rate flowing in one circuit does not also flow in the other circuit.

Preferably, the thermal control system according to an embodiment of the invention further comprises a condenser coupled to the refrigerant circuit and associated with the evaporator for thermal control of a vehicle passenger compartment.

Preferably, in the thermal control system according to an embodiment of the invention, the thermal control circuit of the traction system further comprises a radiator, in which the heat exchange fluid flows, and which is associated with a fan. In this case, even more preferably, the thermal control circuit of the traction system further comprises a by-pass valve configurable in a first mode and in a second mode, wherein when the by-pass valve is configured in the first mode, it allows the heat exchange fluid circulating within the thermal control circuit of the traction system to pass into the radiator, and wherein when the by-pass valve is configured in the second mode, it allows the heat exchange fluid circulating within the thermal control circuit of the traction system to by-pass the radiator.

Preferably, in the thermal control system according to an embodiment of the invention, the thermal control circuit of the traction system further comprises a first branch thermally coupled to the vehicle's electric motor and a second branch, arranged in parallel to the first branch, in which the entire flow rate of heat exchange fluid flowing through the second fluid-refrigerant heat exchanger flows.

Preferably, in the thermal control system according to one embodiment of the invention, each of the first and second fluid-refrigerant heat exchangers is a plate exchanger and comprises:

- a first plurality of plates, through which the heat exchange fluid flows;

- a second plurality of plates, arranged interspersed with the first plates and thermally coupled to the first plates, in which the refrigerant flows through the plurality of second plates; and

- a first and a second non-return valve, adapted to be controlled jointly and oppositely from each other to regulate the flow, or the rate of flow, of refrigerant in the second plates so that when the first non-return valve is open, and then the second non-return valve is closed, the flow, or the rate of flow, of refrigerant flows in a first direction inside the second plates, and when the second non-return valve is open, and then the first non-return valve is closed, the flow, or the rate of flow, of refrigerant flows in a second direction, opposite to the first, inside the second plates. In this case, even more preferably, the configuration of the plurality of second plates of each fluid-refrigerant heat exchanger is made so that when the refrigerant flow flows in said first direction the refrigerant flow flows in all of the second plates and that when the refrigerant flow flows in said second direction the refrigerant flow flows through a maximum of two-thirds of the second plates and is then tapped.

Clearly, the invention also includes a vehicle comprising a traction system with at least one electric motor and a power system with a battery pack capable of powering the traction system, and further comprising a thermal control system according to the first aspect of the invention.

Further features and advantages of the present invention will become clearer from the detailed description that follows, given purely by way of non-limiting example with reference to the attached drawings, in which:

Figure 1 is a schematic view of the thermal control system according to an embodiment of the invention;

Figure 2 is a schematic view of the coolant circuit of the thermal control system of Figure 1;

Figure 3 is a schematic view of the coolant circuit of the thermal control system in a further embodiment of the invention;

Figure 4 is a schematic view of the refrigerant circuit of Figure 2 in a first mode of use, i.e. in the battery pack cooling mode;

Figure 5 is a schematic view of the refrigerant circuit of Figure 2 in a second mode of use, i.e. in the battery pack heating mode;

Figure 6 is a schematic view of the refrigerant circuit of Figure 2 in a third mode of use, i.e. in the passenger compartment cooling mode;

Figure 7 is a schematic view of the refrigerant circuit of Figure 2 in a fourth mode of use, i.e. in the passenger compartment heating mode; and

Figure 8a and Figure 8b are schematic views of the first refrigerant-fluid heat exchanger and the second refrigerant-fluid heat exchanger, essentially the same as each other, shown in Figure 8a in a condition where they function as condensers and in Figure 8b in a condition where they function as evaporators.

With reference to the figures, the thermal control system according to the invention is generally indicated by 10. The thermal control system 10 is a multimodal system, that is, it is a system that can be configured in a plurality of different modes of use, depending on the type of use required (cooling, heating, or neither) with respect to a plurality of components (electric motor, batteries, passenger compartment, and others) that are thermally coupled to the system and that require thermal control.

The thermal control system 10 is used for the thermal control of a vehicle, in particular of a vehicle having a traction system D, with an electric motor M, and a power system S, with a battery pack B, suitable for powering said electric motor M. Preferably, the vehicle is a fully electric powered vehicle. As is evident, the traction system D can also comprise a greater number of electric motors M, and the battery pack B can comprise one or more batteries or cells suitable for powering said one or more electric motors M, but the description and the attached claims will always refer to a single electric motor M and a single battery pack B only for simplicity and brevity and in a purely exemplifying and non-limiting manner.

The thermal control system 10 comprises a battery thermal control circuit 12 and a traction system thermal control circuit 14, within each of which a heat exchange fluid circulates, and a refrigerant circuit 16, within which a refrigerant fluid circulates. The thermal control system 10 may also be associated with a passenger compartment thermal control circuit or system.

As shown in figure 1, preferably the thermal control circuit of the battery 12 and the thermal control circuit of the traction system 14 are arranged in parallel with each other, i.e. there is no exchange of heat exchange fluid flow between these two circuits.

The heat exchange fluid may be composed of water or a mixture of water and glycol, in variable proportions depending on the application. The refrigerant fluid may, by way of example and not limitation, include the refrigerant fluid R-1234y (according to the denominative standard of the American Society of Heating, Refrigerating and Air-Conditioning Engineers), or even other types of refrigerant fluid (such as carbon dioxide, the refrigerant fluid R-290 and/or the refrigerant fluid R-134a according to the same standard just mentioned).

The battery thermal control circuit 12 is thermally coupled to the battery pack B of the vehicle, i.e., the relative arrangement and configuration of the battery pack B and the battery thermal control circuit 12 are such as to permit the exchange of thermal energy between the battery thermal control circuit 12 and the battery pack B in both directions, to permit controlled heating or cooling of the battery pack B. In some embodiments of the invention, the battery thermal control circuit 12 may also be thermally coupled to a vehicle electronic system, i.e., a system comprising processing and/or memory units configured to control one or more components, systems or functions of the vehicle, i.e., the relative arrangement and configuration of the electronic system and the battery thermal control circuit 12 are such as to permit the exchange of thermal energy between the battery thermal control circuit 12 and the electronic system in both directions, to permit controlled heating or cooling of the electronic system.

The thermal control circuit of the battery 12 comprises a first circulation pump 18 and a first fluid-refrigerant heat exchanger 20. The first circulation pump 18 is adapted to circulate heat exchange fluid within the thermal control circuit of the battery 12, and therefore also through the first fluid-refrigerant heat exchanger 20 in a manner known per se. The first fluid-refrigerant heat exchanger 20 is adapted to allow heat exchange between the thermal control circuit of the battery 12 and the refrigerant circuit 16.

In one embodiment of the invention, the battery thermal control circuit 12 may further comprise an electrical battery heating device (not shown, known per se), adapted to provide heat to the heat exchange fluid circulating in the battery thermal control circuit 12 when activated.

The thermal control circuit of the traction system 14 is thermally coupled to the traction system D, and in particular to the electric motor M of the vehicle, i.e. the arrangement and relative configuration of the electric motor M and the thermal control circuit of the traction system 14 are such as to allow the exchange of thermal energy between the thermal control circuit of the traction system 14 and the electric motor M in both directions, to allow the controlled heating or cooling of the electric motor M. In some embodiments of the invention, the thermal control circuit of the traction system 14 may also be thermally coupled to the electronic system of the vehicle, i.e. the arrangement and relative configuration of the electronic system and the thermal control circuit of the traction system 14 are such as to allow the exchange of thermal energy between the thermal control circuit of the traction system 14 and the electronic system in both directions, to allow the controlled heating or cooling of the electronic system. Clearly, the thermal control circuit of the traction system 14 may It can also be thermally coupled to other components of the traction system D that require thermal control, in a manner known per se.

The thermal control circuit of the traction system 14 further comprises a second circulation pump 26 and a second fluid-refrigerant heat exchanger 21, wherein the second circulation pump 26 is preferably arranged upstream or directly upstream of the second fluid-refrigerant heat exchanger 21. The second circulation pump 26 is adapted to circulate heat exchange fluid within the thermal control circuit of the traction system 14 and therefore also through the second fluid-refrigerant heat exchanger 21, in a manner known per se. Advantageously, the thermal control circuit of the traction system 14 may further comprise a radiator 28, which is arranged so as to be associated with a fan 31. In this case, preferably, according to an embodiment not shown in the figure but nevertheless part of the invention, said radiator 28 is arranged in such a way as to be associated with a fan 31. arranged on a bypassable branch of the thermal control circuit of the traction system 14. In this case, the thermal control circuit of the traction system 14 comprises a by-pass valve (not shown, known per se), configurable in a first mode and in a second mode. When this by-pass valve is configured in the first mode, it allows the passage of the heat exchange fluid circulating inside the thermal control circuit of the traction system 14 in the radiator 28. On the contrary, when the by-pass valve is configured in the first mode, it allows the passage of the heat exchange fluid circulating inside the thermal control circuit of the traction system 14 in the radiator 28. configured in the second mode, this allows the heat exchange fluid circulating inside the thermal control circuit of the traction system 14 to bypass said radiator 28, that is, it diverts the flow of the heat exchange fluid circulating in the thermal control circuit of the traction system 14 onto a branch that bypasses the radiator 28, and therefore allows the heat exchange fluid to exchange heat with the second fluid-refrigerant heat exchanger 21. In a manner per se known, this bypass valve can be provided as a three-way valve, or as a selection valve that allows to control which of the two output branches the flow of incoming heat exchange fluid is directed to. In a manner per se known, this radiator 28 can be associated with an expansion vessel (not shown, known per se) into which the heat exchange fluid circulating in the thermal control circuit of the traction system 14 flows.

In the preferable embodiment of the invention, as shown in Figure 1, the thermal control circuit of the traction system 14 further comprises a first branch 15 and a second branch 17, arranged in parallel to each other, i.e. in such a way that a part of the flow rate of heat exchange fluid flowing in the thermal control circuit 14 flows in the first branch 15 and another part flows in the second branch 17. In this embodiment, the electric motor M is thermally coupled to the first branch 15, while the second fluid-refrigerant heat exchanger 21 is thermally coupled to the second branch 17, i.e. the flow rate of heat exchange fluid flowing in the second branch 17 also flows through the second fluid-refrigerant heat exchanger 21. In this embodiment, even more preferably, the thermal control circuit of the traction system 14 also comprises a third pump 27 suitable for circulating heat exchange fluid within the thermal control circuit of the traction system 14 and arranged on the first branch 15, preferably arranged upstream or directly upstream of the electric motor M.

The refrigerant circuit 16 comprises a compressor 36, an evaporator 38 (exposed to a flow of air represented in figures 1 to 7 with three small arrows), a first expansion valve 40, a second expansion valve 42, and a third expansion valve 44. Preferably, one, two or all of the first expansion valve 40, the second expansion valve 42 and the third expansion valve 44 can be electronically controlled, even in a coordinated manner, by the same electronic control unit (not shown, known per se). Preferably, the refrigerant circuit 16 can also comprise a condenser 30 arranged so as to be thermally coupled with the passenger compartment of the vehicle, and therefore designed for thermal control of the passenger compartment.

The compressor 36, in a manner known per se, is adapted to circulate the refrigerant within the refrigerant circuit 16, and therefore in particular also through the first fluid-refrigerant heat exchanger 20 and the second fluid-refrigerant heat exchanger 21.

The evaporator 38 is arranged to be thermally coupled to the passenger compartment of the vehicle, and is therefore designed to control the temperature of the passenger compartment. The first expansion valve 40 is adapted to, and arranged to, couple the evaporator 38 to the refrigerant circuit 16.

The second expansion valve 42, instead, is designed to couple the first fluid-refrigerant heat exchanger 20 of the thermal control circuit of the battery 12 to the refrigerant circuit 16, so as to allow heat exchange between the refrigerant flowing through the first fluid-refrigerant heat exchanger 20 and the heat exchange fluid circulating in the thermal control circuit of the battery 12 and through the first fluid-refrigerant heat exchanger 20. In particular, the second expansion valve 42 is designed to regulate, by means of lamination, the flow of refrigerant flowing through the first fluid-refrigerant heat exchanger 20.

Similarly, the third expansion valve 44 is adapted to couple the second fluid-refrigerant heat exchanger 21 of the thermal control circuit of the traction system 14 to the refrigerant circuit 16, so as to allow heat exchange between the refrigerant flowing through the second fluid-refrigerant heat exchanger 21 and the heat exchange fluid circulating in the thermal control circuit of the traction system 14 and through the second fluid-refrigerant heat exchanger 21. In particular, the third expansion valve 44 is adapted to regulate, by means of lamination, the flow, or the rate of flow, of refrigerant flowing through the second fluid-refrigerant heat exchanger 21.

In one operating mode, when the compressor 36 is activated, the refrigerant fluid is compressed by it and then passes inside the condenser 30. In a manner known per se, a first phase change occurs inside the condenser 30, whereby the refrigerant fluid, due to the heat exchange with the air flow to which the condenser 30 is exposed, passes from the gaseous state to the liquid state. The refrigerant, now liquid, is then subcooled in this way, and is made available via the first expansion valve 40, the second expansion valve 42, and the third expansion valve 44, which regulate the flow of refrigerant to the evaporator 38, the first refrigerant-fluid heat exchanger 20, and the second refrigerant-fluid heat exchanger 21, respectively. At this point, the refrigerant, passing through the evaporator 38, undergoes a second phase change, evaporating due to the heat exchanged with the outside air, via the evaporator 38. The refrigerant exiting the evaporator is finally returned to the compressor 36, from where the cycle just described can begin again from the beginning.

As visible in figure 1, through a first line 16a, the compressor 36 pushes a fraction of the refrigerant flow rate in gaseous form also directly towards the second fluid-refrigerant heat exchanger 21. Thanks to a valve assembly 23, it is also possible to control which part of this fraction of the refrigerant flow rate flows directly towards the second fluid-refrigerant heat exchanger 21 through a second line 16b, and which part, instead, is returned directly upstream of the compressor 36 through a third line 16c.

Similarly, via a fourth line 16d, the compressor 36 pushes a fraction of the refrigerant flow rate in gaseous form also directly towards the first fluid-refrigerant heat exchanger 20. Thanks to a valve assembly 25, it is also possible to control which part of this fraction of the refrigerant flow rate flows directly towards the first fluid-refrigerant heat exchanger 20 via a fifth line 16e, and which part, instead, is returned directly upstream of the compressor 36 via a sixth line 16f.

In an advantageous embodiment of the invention, the refrigerant circuit 16 also comprises an accumulator 22 suitable for accumulating the refrigerant fluid in gaseous form and therefore arranged immediately upstream of the compressor 36. In an alternative but equivalent embodiment, the refrigerant circuit comprises, instead, in place of or in addition to the accumulator 22, a tank 22b, suitable for accumulating the refrigerant fluid in liquid form and therefore arranged downstream of the compressor 36, for example downstream of the condenser 38 or downstream of the first fluid-refrigerant heat exchanger 20.

The first fluid-refrigerant heat exchanger 20 and the second fluid-refrigerant heat exchanger 21 are essentially equal or equivalent to each other at least in the characteristics described below and functionally essential.

As shown in Figures 8a and 8b, each of which shows the first fluid-refrigerant heat exchanger 20 or the second fluid-refrigerant heat exchanger 21, which are essentially the same as mentioned, in the configuration in which they function as condensers (Figure 8a) or as evaporators (Figure 8b), each of the two essentially comprises a plurality of first plates 24 and a plurality of second plates 34, which are, in each heat exchanger, thermally coupled to each other to allow heat exchange between the refrigerant and the heat exchange fluid. In particular, the first plates 24 and the second plates 34 are arranged alternately, or the second plates 34 are arranged interspersed with the first plates, so that each first plate 24 is in contact with a second plate 34 in a stacked manner.

The first plates 24 of the first fluid-refrigerant heat exchanger 20 are connected to the thermal control circuit of the battery 12 so that all or part of the flow of heat exchange fluid circulating within the thermal control circuit of the battery 12 flows through them. Similarly, the first plates 24 of the second fluid-refrigerant heat exchanger 21 are connected to the thermal control circuit of the traction system 14 so that all or part of the flow of heat exchange fluid circulating within the thermal control circuit of the traction system 14 flows through them.

The second plates 34 of the first fluid-refrigerant heat exchanger 20 and the second plates 34 of the second fluid-refrigerant heat exchanger 21 are connected to the refrigerant circuit 16 so that all or part of the refrigerant flow circulating within the refrigerant circuit 16 flows through them.

Each fluid-refrigerant heat exchanger 20 and 21 further comprises a first non-return valve 46 and a second non-return valve 48. The first non-return valve 46 and the second non-return valve 48 are configured so as to be controlled jointly and oppositely to each other, i.e. when the first non-return valve 46 is open then the second non-return valve 48 is closed and vice versa. For this purpose, the first non-return valve 46 and the second non-return valve 48 can be connected to each other mechanically, or by means of a hydraulic control, or even be controlled electronically in a coordinated manner by the same electronic control unit (not shown, known per se).

Preferably, the second non-return valve 48 of the first fluid-refrigerant heat exchanger 20 is arranged between this exchanger and the second expansion valve 42, while the second non-return valve 48 of the second fluid-refrigerant heat exchanger 21 is arranged between this exchanger and the third expansion valve 44.

The first and second check valves 46 and 48 are arranged to regulate the flow, or rate of flow, of refrigerant into the plurality of second plates 34, so that when the first check valve 46 is open and therefore the second check valve 48 is closed the flow of refrigerant flows in a first direction (figure 8a) within the second plates 34, and so that when the second check valve 48 is open and therefore the first check valve 46 is closed the flow of refrigerant flows in a second direction, opposite to the first, within the second plates 34 (figure 8b). This is clearly visible in the comparison between figures 8a and 8b where the arrows indicate the presence and direction of flow of refrigerant within the second plates 34.

In particular, as regards the first fluid-refrigerant heat exchanger 20, when this functions as a condenser (figure 8a), the first non-return valve 46 is open and the refrigerant flow arrives from the fifth line 16e to flow in the first direction through the second plates 34 and exit from an outlet 20a. On the contrary, when the first fluid-refrigerant heat exchanger 20 functions as an evaporator (figure 8b), the first non-return valve 46 is closed and the refrigerant flow arrives from an inlet 20b to flow in the second direction through the second plates 34 and exit from the fifth line 16e.

Similarly, as regards the second fluid-refrigerant heat exchanger 21, when this functions as a condenser (figure 8a), the first check valve 46 is open and the refrigerant flow arrives from the second line 16b to flow in the first direction through the second plates 34 and exit from an outlet 21a. Conversely, when the second fluid-refrigerant heat exchanger 21 functions as an evaporator (figure 8b), the first check valve 46 is closed and the refrigerant flow arrives from an inlet 21b to flow in the second direction through the second plates 34 and exit from the second line 16b.

As also visible in figures 8a and 8b, in the most preferable embodiment of the invention, the configuration of the plurality of second plates 34 of each of the first and second fluid-refrigerant heat exchangers 20 and 21 is made in such a way that when the refrigerant flow flows in the first direction, i.e. when the heat exchanger functions as a condenser, the flow flows through all the second plates 34, while when the refrigerant flow flows in the second direction, i.e. when the heat exchanger functions as an evaporator, the refrigerant flow flows for a maximum of three quarters, even more preferably a maximum of two thirds, of the second plates, and is then tapped.

The thermal control system 10 according to the invention can operate in different ways, i.e. can be controlled according to different control methods, depending on the type of thermal control (heating, cooling, or neither) that is required for the different components of the vehicle that are thermally coupled to the thermal control system 10 (passenger compartment, battery pack B, traction system D, etc.). Some of these control methods, i.e. modes of operation, will be described with reference to the thermal control system 10 according to the embodiment shown in Figure 1.

A first operating mode, called the "battery pack cooling mode", is shown in Figure 4. In this operating mode, the first refrigerant heat exchanger 20 functions as an evaporator, i.e. the refrigerant flows into the second plates 34 of the first refrigerant-fluid heat exchanger 20 in the second direction of flow, while the second refrigerant-fluid heat exchanger 21 functions as a condenser, i.e. the refrigerant flows into the second plates 34 of the second refrigerant-fluid heat exchanger 21 in the first direction of flow. At the same time, both the condenser 30 and the evaporator 38 do not receive any refrigerant flow. As can be seen in Figure 4, in fact, no refrigerant flow circulates in the third line 16c. In this mode, the battery pack B is cooled by the radiator 28.

In an alternative mode of the first operating mode, called the "battery pack cooling and passenger compartment cooling mode", not shown in the figures, all components are in the same configuration as in the first operating mode, with the exception of the evaporator 38 through which a flow of refrigerant circulates. In this mode, the battery pack B and the passenger compartment are cooled by the radiator 28.

A second operating mode, called the "battery pack heating mode", is shown in Figure 5. In this operating mode, the first refrigerant-fluid heat exchanger 20 functions as a condenser, i.e. the refrigerant flows into the second plates 34 of the first refrigerant-fluid heat exchanger 20 in the first direction of flow, while the second refrigerant-fluid heat exchanger 21 functions as an evaporator, i.e. the refrigerant flows into the second plates 34 of the second refrigerant-fluid heat exchanger 21 in the second direction of flow. At the same time, both the condenser 30 and the evaporator 38 do not receive any refrigerant flow. As can be seen in Figure 5, in fact, no refrigerant flow circulates in the first line 16a. In this mode, the battery pack B is heated by the excess heat of the electric motor M, and electricity consumption is reduced.

In an alternative mode of the second operating mode, called the "battery pack heating and passenger compartment heating mode", not shown in the figures, all components are in the same configuration as in the second operating mode, with the exception of the condenser 30 through which a refrigerant flow circulates. In this mode, the battery pack B and the passenger compartment of the vehicle are heated by the excess heat of the electric motor M.

A third operating mode, called the "cabin cooling mode", is shown in Figure 6. In this operating mode, the second refrigerant-fluid heat exchanger 21 functions as a condenser, i.e. the refrigerant flows in the second plates 34 of the second refrigerant-fluid heat exchanger 21 in the first direction of flow, while the first refrigerant-fluid heat exchanger 20 does not receive any refrigerant flow. At the same time, the condenser 30 does not receive any refrigerant flow, while the evaporator 38 does. As can be seen in Figure 6, in fact, no refrigerant flow circulates in the third line 16c or in the fourth line 16d. In this mode, the passenger compartment of the vehicle is cooled.

A fourth operating mode, called the "cabin heating mode", is shown in Figure 7. In this operating mode, the second refrigerant-fluid heat exchanger 21 functions as an evaporator, i.e. the refrigerant flows in the second plates 34 of the second refrigerant-fluid heat exchanger 21 in the second direction of flow, while the first refrigerant-fluid heat exchanger 20 does not receive any refrigerant flow. At the same time, the evaporator 38 does not receive any refrigerant flow, while the condenser 30 does. As can be seen in Figure 7, in fact, no refrigerant flow circulates in the first line 16a nor in the fifth and sixth lines 16e and 16f. In this mode, the passenger compartment of the vehicle is heated, or kept at room temperature, also by means of the excess heat of the electric motor M, and electricity consumption is reduced.

In an alternative mode of the fourth operating mode, called the "defogging or defrosting mode", not shown in the figures, all components are in the same configuration as in the fourth operating mode, with the exception of the evaporator 38 through which a flow of refrigerant circulates.

Clearly, as is evident to the person skilled in the art, the control methods for controlling a thermal control system 10 according to the invention are numerous and, even if not all have been explicitly described, these can be easily deduced by the person skilled in the art starting from the description of the thermal control system 10 and from the thermal control methods described by way of example in a non-limiting manner.

Clearly, the application of the thermal control system 10 according to the invention to a vehicle comprising a traction system D with at least one electric motor M and a power supply system S with a battery pack B suitable for powering said traction system D also forms part of the invention.

As is evident to the person skilled in the art, the invention has several advantages over the known art.

In particular, thanks to the relative configuration of the refrigerant circuit and of the first and second fluid-refrigerant heat exchangers, it is possible to obtain a plurality of operating modes alternative to that of the known art or more energy efficient.

In particular, differently from the known art, thanks to the use of proportional mechanical valves, or controllable expansion valves, multimodal thermal control does not only work in the modes previously described in an exemplifying and non-limiting manner, but also in a series of intermediate modes, which can be managed through thermal sensors arranged in the circuit and on the individual components in order to guarantee maximum energy efficiency and the correct functioning of the systems in relation to their functional specifications.

Naturally, without prejudice to the principle of the invention, the embodiments and details of construction may be varied widely with respect to what has been described and illustrated purely by way of non-limiting example, without thereby departing from the scope of the invention as defined in the attached claims.

Claims (8)

1. Thermal control system (10) for a vehicle having a traction system (D) with an electric motor (M) and a power system (S) with a battery pack (B) capable of powering said electric motor (M), the thermal control system (10) comprising: a battery thermal control circuit (12), comprising a first circulation pump (18) and a first fluid-refrigerant heat exchanger (20), wherein said first circulation pump (18) is adapted to circulate heat exchange fluid within said battery thermal control circuit (12) and through said first fluid-refrigerant heat exchanger (20), and wherein said battery thermal control circuit (12) is thermally coupled to said vehicle battery pack (B); a traction system thermal control circuit (14) comprising a second circulation pump (26) and a second fluid-refrigerant heat exchanger (21), wherein said second circulation pump (26) is adapted to circulate heat exchange fluid within said traction system thermal control circuit (14) and through said second fluid-refrigerant heat exchanger (21), wherein said traction system thermal control circuit (14) is thermally coupled to said electric motor (M) of the vehicle; a refrigerant circuit (16) in which a refrigerant is circulated, and comprising a compressor (36), an evaporator (38), a first expansion valve (40) adapted to couple said evaporator (38) to said refrigerant circuit (16), wherein said compressor (36) is adapted to circulate the refrigerant within said refrigerant circuit (16) and through said first fluid-refrigerant heat exchanger (20) and said second fluid-refrigerant heat exchanger (21); the refrigerant circuit (16) further comprising a second expansion valve (42) adapted to regulate by lamination the flow rate of refrigerant flowing through the first fluid-refrigerant heat exchanger (20) and a third expansion valve (44) adapted to regulate by lamination the flow rate of refrigerant flowing through the second fluid-refrigerant heat exchanger (21). 2. A thermal control system according to claim 1, further comprising a condenser (30) coupled to the refrigerant circuit (16) and associated with said evaporator (38) for thermal control of a vehicle passenger compartment. 3. Thermal control system according to claim 1 or claim 2, wherein the thermal control circuit of the traction system (14) comprises a radiator (28) in which at least a portion of the flow rate of said heat exchange liquid circulating in the thermal control circuit of the traction system (14) flows, and which is associated with a fan (31). 4. Thermal control system according to claim 3, wherein the thermal control circuit of the traction system (14) further comprises a by-pass valve configurable in a first mode and in a second mode, wherein when the by-pass valve is configured in the first mode, it allows the passage of the heat exchange fluid circulating within said thermal control circuit of the traction system (14) into said radiator (28), and wherein when the by-pass valve is configured in the second mode, it allows the heat exchange fluid circulating within said thermal control circuit of the traction system (14) to by-pass said radiator (28). 5. Thermal control system according to any of the preceding claims, wherein the thermal control circuit of the traction system (14) further comprises a first branch (15) thermally coupled to the electric motor (M) of the vehicle and a second branch (17), arranged in parallel to the first branch (15), in which the entire flow rate of heat exchange fluid flowing through the second fluid-coolant heat exchanger (21) flows. 6. Thermal control system according to any of the preceding claims, wherein each of the first and second fluid-refrigerant heat exchangers (20; 21) is a plate heat exchanger and comprises: - a plurality of first plates (24), through which the heat exchange fluid flows; - a plurality of second plates (34), arranged interspersed with the first plates (24) and thermally coupled to the first plates (24), in which the refrigerant flows through the plurality of second plates (34); and - a first and a second non-return valve (46; 48), adapted to be controlled jointly and oppositely from each other to regulate the flow of refrigerant through the second plates (34) so that when the first non-return valve (46) is open and therefore the second non-return valve (48) is closed the flow of refrigerant flows in a first direction inside the second plates (34), and when the second non-return valve (48) is open and therefore the first non-return valve (46) is closed the flow of refrigerant flows in a second direction, opposite to the first, inside the second plates (34). 7. Thermal control system according to claim 6, wherein the configuration of the plurality of second plates (34) of each fluid-refrigerant heat exchanger (20; 21) is made such that when the refrigerant flow flows in said first towards the refrigerant flow flows through all of the second plates (34) and that when the refrigerant flow flows in said second towards the refrigerant flow flows through at most two-thirds of the second plates (34) and is then tapped. 8. Vehicle comprising a traction system (D) with at least one electric motor (M) and a power system (S) with a battery pack (B) suitable for powering said traction system (D), further comprising a thermal control system (10) according to any of the preceding claims.