IT201800005082A1 - A new thermodynamic arrangement having combined power generation and refrigeration circuits with a shared heat sink and a shared working fluid - Google Patents

Description

A NEW THERMODYNAMIC ARRANGEMENT WITH COMBINED POWER GENERATION AND REFRIGERATION CIRCUITS WITH A SHARED HEAT WELL AND A SHARED WORKING FLUID

Description

Technical Field

[0001] The sector is generally concerned with thermodynamic arrangements for air conditioning and refrigeration / freezing systems in vehicles, and more specifically a new (sealed) thermodynamic arrangement that combines refrigeration and power generation circuits using a heat sink shared and shared working fluid, to improve the energy efficiency and emissions of vehicles equipped with cooling systems, such as air conditioning systems and refrigeration / freezing compartments.

Front Art

Vehicles, for the transport of people or things, frequently require power to cool a passenger compartment (air conditioning system) or a cooled storage area (refrigeration / freezing). However, vehicle air conditioning systems and vehicle refrigeration / freezing systems have separate and often different working fluids that operate at different pressures and temperatures. These systems are driven by different electric motors, which in turn are powered with electrical power generated by an electric generator, which is driven by an internal combustion engine which also provides mechanical power to drive the vehicle and / or by a combustion engine. separate on-board interior, which does not provide mechanical power to drive the vehicle. In some cases the refrigeration compressor is mechanically connected to the motor shaft by means of a clutch which is engaged when refrigeration is required.

In many applications, the vehicle can be provided with a refrigerated area. For example, refrigerated trucks are equipped with compartments that are kept at a temperature below ambient for the transport of perishable goods. Relatively low temperatures are sometimes required, for example around -20 ° C or -30 ° C, for the transport of frozen food.

[0004] Vessels are sometimes provided with large compartments for storing food, to store large quantities of food. This is the case, for example, with large cruise ships.

[0005] Fishing boats or refrigerated vessels are known which are equipped with fishing and freezing equipment for freezing freshly caught fish.

[0006] The cooling of a refrigeration or freezing compartment is usually achieved by means of a refrigeration circuit, in which a working fluid undergoes cyclic thermodynamic transformations to remove heat from the freezing or cooled area and discharge heat into the environment. The working fluid is processed through a compressor, a condenser and an expansion device, such as a Joule-Thomson valve. The compressor is rotated by mechanical power generated by an electric motor. The latter is powered by electricity generated by an internal combustion engine. In some cases the compressor is driven directly or indirectly by the motor shaft, for example through a gearbox and / or a clutch, such as a disengageable clutch.

[0007] Therefore, the on-board vehicle refrigeration systems described above burn high quality fuel, which can have negative effects on the overall efficiency of the vehicle and / or its range.

There is therefore a need to improve the energy efficiency of these vehicles.

While low temperature heat is available in vehicles, in the form of heat waste from a heat engine, in other systems an engine may not be available as a low temperature heat source. However, other low temperature heat sources, such as solar energy, may be available. It would be advantageous to efficiently exploit this heat source to promote or improve the efficiency of cooling systems or the like.

More generally, it would be advantageous in terms of reducing energy consumption and reducing harmful emissions to efficiently exploit low temperature heat available in thermodynamic arrangements.

Summary

A new thermodynamic arrangement combines a power generating circuit and a refrigeration circuit using a shared heat sink and a shared working fluid. The power generation circuit is in fluid coupling with the shared heat sink. As described below, the heat source may be an engine or other vehicle component or system, which generates heat, or a low temperature heat source, such as a solar type heat collector. The power generation circuit is adapted to circulate a first flow of the shared working fluid and to convert heat transferred into the working fluid shared by the first heat exchanger into mechanical power. An expander, such as a turboexpander, receives and expands the first flow of the shared working fluid from a first pressure and a first temperature to a second pressure and a second temperature to generate mechanical power. The shared working fluid flows from the expander outlet to the shared heat sink, which removes heat from the shared working fluid at a second pressure to lower the second temperature to a third temperature. A refrigeration circuit coupled to the shared heat well comprises a compressor driven by mechanical power and adapted to circulate a second flow of the shared working fluid in the refrigeration circuit. The expander is adapted to be mechanically coupled to the compressor to move the compressor with mechanical power generated by the expander. Depending on the embodiment, the expander and the compressor can be coupled with an electric machine.

The electric machine can be selectively operated in an engine mode and in a generator mode, depending on the operating mode and operating conditions of the thermodynamic cycle. Therefore, mechanical power generated by the expander can be used in part or completely to move the compressor. If no refrigeration is required by the refrigeration cycle, of which the compressor is a part, the expander can operate the electrical machine, which is operated in generator mode, to convert additional mechanical power into electrical power, which can be used or stored. If the refrigeration cycle requires more power than is available from the expander, the electric machine can be activated in motor mode to convert electrical power into mechanical power to move the compressor, either alone or in combination with the expander.

A method for operating a thermodynamic arrangement as described above is also disclosed.

Brief description of the drawings

[0014] A more complete understanding of the illustrated embodiments of the invention and the many advantages achieved will be obtained when the aforementioned invention will be better understood with reference to the detailed description that follows in combination with the attached drawings, in which:

Fig.1 illustrates exemplary embodiments of vehicles which may comprise a thermodynamic arrangement according to the present description;

Fig.2 illustrates a diagram of a first embodiment of a thermodynamic arrangement according to the present description;

Fig.3 illustrates a diagram of a second embodiment of a thermodynamic arrangement according to the present description;

Fig.4 illustrates a diagram of a further embodiment of a thermodynamic arrangement according to the present description;

Fig.5 illustrates a flow chart summarizing the methods described here; and Fig.6 illustrates a further flow chart summarizing a method for installing a kit.

Detailed description of embodiments

A vehicle comprises at least one air conditioning system or a cooled area (chilled or frozen). The vehicle comprises at least one heat source (defined further below, but illustratively may be an engine used to drive the vehicle and / or a solar heat collector coupled to the vehicle). The heat source generates or supplies heat, sometimes referred to here as "thermal waste". The heat from the vehicle's heat source can be used both to efficiently generate electrical power and to cool the cooled area (s) of the vehicle more efficiently and at lower temperatures than previously possible. This is accomplished by using a combined thermodynamic cycle which circulates a single shared working fluid in two circuits which are connected by a shared heat sink, and further using an electric machine which can be mechanically coupled to an expander or compressor of the system. combined thermodynamic, or both to the expander and to the compressor.

The electric machine can convert mechanical power generated by the expander into electric power, or it can convert electric power into mechanical power to drive the compressor, as needed. As will be clear from the description of detailed embodiments, the combination of the electric machine with the fluid machines (expander and compressor) of the combined thermodynamic system improves the flexibility and energy efficiency of the system.

The shared heat sink of combined thermodynamic systems is common to both the power generation circuit and the refrigeration circuit. In this way, a single working fluid can simultaneously circulate both in the power generation circuit and in the refrigeration circuit. This simple arrangement means that the power generation circuit and the refrigeration circuit can be designed, manufactured and assembled as a single sealed combination system.

The new combined thermodynamic system works by flowing the shared working fluid in the first place: through a first heat exchanger, which is adapted to transfer thermal waste from a heat source into the shared working fluid; subsequently through an expander, which converts heat into mechanical power; and then through the shared heat sink, which extracts heat from the shared working fluid, thereby reducing its temperature. Thereafter, the cooled shared working fluid stream is split into two paths. A path (power generation) returns a portion of the shared working fluid to circulate again through the power generation circuit. A second path (refrigeration) circulates the remaining portion of the shared working fluid through the refrigeration circuit, where it is compressed and then circulated (recirculated) back through the heat sink.

This combined thermodynamic system, and the combination of the electric machine, expander and compressor, can increase the fuel efficiency of engines that drive coolers / freezers, regardless of whether such engines also serve to drive a vehicle. In some embodiments, the thermodynamic arrangement improves the energy efficiency of cooling or refrigeration systems by exploiting one or more low temperature heat sources.

[0020] Embodiments of the new thermodynamic arrangement can be applied to vehicles of any type and can be used to create new cooled areas (chilled or frozen) according to the wishes of the users, but which up to now it has not been possible to realize and / or that they were too expensive to implement. It can be used in the production of new vehicles and also for retrofitting existing vehicles, or refrigeration systems and systems. It can be used to cool one or more cooled areas (compartments or containers) associated with a vehicle, aboard a motorized vehicle and / or aboard another vehicle (such as a refrigerated container or trailer) coupled to the driven vehicle. The cooled area of the vehicle can be fixedly or removably coupled to the refrigeration circuit and / or to the vehicle itself.

While the use of a combined thermodynamic system and an electric machine has proved particularly advantageous when used in combination with a vehicle drive heat engine, some advantages can also be achieved in stationary refrigeration or cooling arrangements, which use a different heat source than a traction heat engine. In the following detailed description, embodiments of a thermodynamic arrangement are described in combination with both motor-driven vehicles and stationary cooling or refrigeration systems and installations, in order to improve overall energy efficiency and flexibility of operation.

Cooling can be understood as cooling of air for air conditioning purposes. However, in particularly advantageous embodiments, cooling can also be understood as reducing the temperature in a closed compartment for the purpose of preserving food or other perishable goods, including freezing cooling purposes. The exploitation of waste heat generated by a vehicle propulsion engine, or heat from low-temperature heat sources, for the purpose of storing perishable goods results in efficient use of energy and therefore in improved thermodynamic efficiency.

Specifically, the thermodynamic arrangement comprises a heat source, which receives or collects heat waste from a vehicle propulsion engine, as well as a thermodynamic system which includes a power generation circuit adapted to convert heat waste generated as a by-product from the vehicle propulsion engine, in additional mechanical power (non-propulsive). The thermodynamic arrangement further includes a refrigeration circuit, which is driven by mechanical power generated by the power generation circuit. The refrigeration circuit is used for example for air conditioning of a vehicle and / or for cooling purposes. In embodiments described herein, the refrigeration circuit can be used to freeze food or other goods, or to store food or other perishable goods during transport. In general, the refrigeration circuit is in functional relationship with a vehicle refrigeration system, to remove low temperature heat from the refrigeration system and discharge heat at higher temperatures, for example at room temperature.

[0024] The use of a refrigeration circuit employing a compressor, a condenser and an expander, allows to reach particularly low temperatures, in the range of -20 ° C or lower, for example -30 ° C or lower, also around or below -40 ° C. Such low temperatures cannot currently be achieved with currently known absorption refrigeration cycles which are used today, such as lithium bromide cycles. The combination of the thermodynamic system and the vehicle's propulsion engine results in an efficient generation of cold. Due to the very low temperatures that can thus be reached on the cold side of the refrigeration circuit, the refrigeration circuit can be efficiently used for freezing purposes.

While the refrigeration system does not require freezing temperatures, nevertheless the low temperatures achievable by the refrigeration circuit are advantageous, since cooling to milder temperatures can be achieved by using heat exchangers that are more compact than those required for Traditional absorption refrigeration cycles, which is particularly important when an embodiment of the refrigeration circuit described here is installed on the vehicle, for example small trucks, scooters, motorcycles or automobiles.

By using the same working fluid in the power generation circuit and in the refrigeration circuit, a completely sealed system can be designed. This avoids leaking working fluid into the environment and avoids the need for a sealing system, such as oil seals or dry gas seals, which consume a buffer fluid or cause continuous leaks which in turn require topping up. Furthermore, some of the stationary equipment (especially the shared heat sink) can be shared by the two circuits of the thermodynamic system. The result is an efficient and easy-to-design system.

The electric machine combined with the power generation circuit expander and the refrigeration circuit compressor maximizes energy savings under varying vehicle operating conditions and at the same time ensures proper cooling as required.

The power generation circuit can use a Rankine cycle. In some embodiments the Rankine cycle may be an organic Rankine cycle (ORC).

[0029] In the sense used here, the term "engine" and specifically the term "heat engine" includes any machine capable of producing mechanical power through a thermodynamic cycle between a first higher temperature (heat source) and a second lower temperature (heat sink). Engines in the sense here understood can therefore be internal combustion engines with positive ignition or diesel, both reciprocating and rotary (Wankel engines for example), external combustion engines, such as Stirling engines, or gas turbine engines, steam turbines. water, or other steam turbines using a Rankine cycle or other closed thermodynamic cycles or the like. The nature and type of engine may depend for example on the type of vehicle.

While internal combustion engines, such as reciprocating internal combustion engines, or gas turbine engines, provide a better source of waste heat for the operation of the combined thermodynamic system, in some embodiments heat waste can be provided by a different heat engine, such as a steam turbine engine. Thermal waste can be fed from the condenser of a steam turbine engine arrangement, which can be driven by, for example, fossil fuel or nuclear power.

[0031] While typically engines generate heat waste which can be absorbed and transferred from the first heat exchanger to the shared working fluid, which circulates in the power generation circuit, other heat waste can be generated, for example in the engine cooling system , in the lubrication system, in the vehicle brakes and the like. Therefore, it is considered that the principles described herein include adapting the power generation circuit (specifically at least the first heat exchanger) to receive and transfer heat waste recovered from these heat sources.

[0032] In the sense herein understood, a vehicle is any convoy in or through which people or things are transported, that is, any means in which or through which a person can travel or something can be transported or conveyed. The term vehicle in the sense understood here can therefore include land transport vehicles, such as cars, trucks, buses, caravans, campers, recreational vehicles, trains and the like. The broad definition of vehicle in the sense understood here also includes sea vehicles and air or spacecraft vehicles. In some embodiments, a vehicle may be a two-wheeled or three-wheeled land vehicle, such as motorcycles and scooters.

In the sense herein understood, a vehicle refrigeration system is any system that requires removal of heat therefrom to reach a temperature below ambient temperature. Therefore, according to some embodiments, a refrigeration plant can be a refrigerated or cooled compartment. The refrigeration system can also be an air conditioning system.

[0034] Coming now to the attached figures, in Fig.1 the reference numbers 100, 200, 300 and 400 indicate types of vehicles, illustrative and not limiting, which can be equipped with embodiments of the new thermodynamic arrangement. Illustratively, the vehicles can be land vehicles, such as a refrigerated truck, refrigerated truck 100, bus 200, or automobile 300, recreational vehicles (so-called RVs), caravans, campers, or other two or three-wheeled vehicles. , such as motorcycles or scooters, which may include or be associated with refrigerated volumes or compartments. In other embodiments, the vehicles may be marine vehicles or fishing vessels 400, such as cruise ships, freezer fishing vessels or the like. In other embodiments, the vehicle may be an air vehicle. The vehicle can also be a rail vehicle powered by an internal combustion engine, rather than electric motors, or a rail vehicle powered by electric motors, which receive their electrical power from one or more generators driven by one or more motors. diesel.

In general, each vehicle has a vehicle propulsion engine 2, which represents a heat source for the thermodynamic arrangement.

In the diagram of Fig.1, the vehicle 100 is a refrigerated truck or van, comprising a vehicle chassis 101, a driver's cab 103 and at least one refrigeration arrangement. The latter can comprise a cooled area 105, or an air conditioning system 104, for example arranged in the driver's cab 103, or both. The cooled area 105 can be at any suitable temperature usually below ambient temperature. The temperature inside the cooled area 105 can be selected according to the nature of the goods to be transported. For example, freezing temperatures around -30 ° C can be used to transport frozen food. Milder temperatures, around 0 ° C can be used for transporting meat or similar.

[0037] The vehicle 100 is provided with a propulsion engine 2 of the vehicle, for example a diesel engine or a positive ignition engine. The vehicle 100 also comprises a thermodynamic arrangement which comprises a first heat exchanger 7 (Fig. 2), adapted to receive heat waste from the engine 2, and a combined thermodynamic system 1, with which the heat waste generated by the propulsion engine 2 of the vehicle is partially converted into mechanical power. Therefore, the propulsion engine 2 of the vehicle is, or forms part of, a heat source for the combined thermodynamic system. Therefore, in the following description of embodiments of the combined thermodynamic system 1, the propulsion engine 2 of the vehicle will also be referred to as the heat source 2, which supplies thermal energy (heat) to the combined thermodynamic system 1.

[0038] The mechanical power generated by the combined thermodynamic system 1 is in turn exploited to operate a refrigeration circuit forming part of the thermodynamic system 1 and which cools the interior of the cooled area 105 (which can be a refrigeration compartment or container or freezing). As further explained with reference to Fig. 2, the same thermodynamic system 1 can be used to remove heat from the air conditioning system 104.

[0039] The structure and operation of the combined thermodynamic system 1 will be described later with reference to Figs. 2 and 3.

[0040] The vehicle 200 is a bus having a vehicle propulsion engine, again indicated with 2, and a thermodynamic system 1. The bus 200 can be equipped with an air conditioning system 104, from which cooling power it is supplied by the thermodynamic system 1, which still uses the motor 2 as a source of thermal waste.

The vehicle 300 is an automobile having at least one heat source 2, which may or may include the vehicle's propulsion engine, and an air conditioning system 104 and / or a cooled area 106, in wherein the cooling power of the air conditioning system 104, or of the cooled area 106, or both, is provided by the combined thermodynamic system 1, which exploits thermal waste from the at least one heat source 2.

[0042] The vehicle 400 is a watercraft, for example a cruise ship or a fishing vessel. Schematically, the vessel comprises a propulsion engine, for example a diesel engine, or a gas turbine engine, which functions as a heat source for one or more combined thermodynamic systems 1 which can be associated with the heat source 2. By way of example , in the diagram of Fig.1 a combined thermodynamic system 1 is provided in combination with the heat source 2 to convert the thermal waste generated by the heat source 2 into useful mechanical power, which can in turn be used in a refrigeration circuit for cool at least one refrigeration system. The refrigeration plant may comprise an air conditioning system 104, or a cooled area 106 (compartment or container, such as one or more refrigerated or frozen storage compartments), where perishable goods, such as food, can be stored, or both.

The vessel may be an LNG transport vessel, which may use thermal waste from a vessel propulsion engine to maintain the LNG (Liquefied Natural Gas) at the required temperature, which can be as low as -160 ° C.

As mentioned above, the principles, arrangements and embodiments of the new combined thermodynamic system 1 can be conceptually similar for the various applications; Exemplary embodiments of the combined thermodynamic system 1 are shown in Figs. 2 and 3 and will be described below in greater detail.

Fig.2 illustrates a diagram of a first embodiment of a thermodynamic arrangement comprising a first heat exchanger 7 (also referred to below as "heater 7") and a combined thermodynamic system 1.

The heater 7 may comprise an additional heat exchanger.

[0047] The heater 7 is adapted to receive thermal waste from the heat source 2 (for example the propulsion engine of the vehicle) and to supply heat to the thermodynamic system 1. Specifically, the heater 7 is able to transfer heat from the heat source 2 to the shared working fluid, which circulates in the thermodynamic system 1 as described in greater detail below. In the embodiment of Fig. 1 the thermodynamic system 1 comprises a power generation circuit 3 and a refrigeration circuit 5, which are connected together by a common shared heat sink 13, which forms part of the power generation circuit 3 and of the refrigeration circuit 5, or which is in heat exchange relationship with them. A shared working fluid circulates in the power generation circuit 3 and receives heat from the heater 7, and also circulates in the refrigeration circuit 5 and receives heat from (e.g. it is configured to be a heat sink for) one or more separate sources heat (such as an air conditioner 104 or cooled areas 105, 106). The arrow FP represents a first flow of shared working fluid, which circulates in the power generation circuit 3; the arrow FR represents a second flow of shared working fluid, which circulates in the refrigeration circuit 5. The arrow F represents the sum of the first flow FR and the second flow FP of the working fluid, which circulates in the shared heat sink 13.

The first flow FP of the shared working fluid circulates through the power generation circuit 3 and is subjected to a sequence of thermodynamic transformations of a thermodynamic cycle. The thermodynamic cycle comprises an expansion phase in an expander 9, for example a turboexpander, through which mechanical power is generated by converting part of the heat supplied by the heater 7 into mechanical power.

In some embodiments, the thermodynamic cycle is a Rankine cycle. In currently preferred embodiments, the thermodynamic cycle is an organic Rankine cycle, also briefly referred to herein as ORC. The shared working fluid circulating in the power generation circuit 3 can therefore be an organic fluid. In embodiments described herein, the working fluid can comprise, for example but without limitation: pentane, cyclopentane, hydrofluorocarbon (HFC), propane, isopropane, butane, isobutane, CO2, liquefied natural gas, ammonia.

The shared working fluid, which circulates in the power generation circuit 3, flows through the heater 7 and receives thermal waste Q1 from the exhausted combustion gas of the heat source 2. In some embodiments, further thermal waste can be recovered from the engine refrigeration circuit, from other parts of the vehicle, from a low temperature heat source, and / or from the lubrication circuit, for example.

[0051] Reference 8 schematically indicates an exhaust gas duct. In some embodiments, specifically when the vehicle is an automobile 300, a catalytic converter 10 can be provided along the exhaust pipe of the exhausted gas. The heater 7 can be arranged downstream of the catalytic converter 10. In other embodiments, the heater 7 can be integrally or partially integrated into the catalytic converter 10, as shown in dashed lines in Fig.2.

[0052] The power generator circuit 3 may further comprise a power generation circuit section, comprising at least a first expander 9, in which the first flow FP of the shared working fluid is expanded. In some embodiments the expander 9 may be a turboexpander. The turboexpander 9 can be a single stage or multistage turboexpander.

Observing the power generation path in Fig.2, starting from the heater 7, during operation the heater 7 transfers heat at a first pressure P1 and at a first temperature T1 to the first flow FP of the shared working fluid. Subsequently the first flow FP of the shared (heated) working fluid enters the turboexpander 9 at a pressure P1 and a temperature T1, expands into the turboexpander 9 and is discharged by the turboexpander 9 at a pressure P2 and a temperature T2. The enthalpy jump through the turboexpander 9 generates mechanical power which is available on a shaft 11 of the turboexpander. As known, enthalpy is defined as a thermodynamic quantity equivalent to the total heat content of a system. It is equal to the internal energy of the system added to the product of the pressure and the volume. Thereafter, the FP expanded shared working fluid flows to the shared heat sink 13.

The shared heat sink 13 is adapted to receive the first flow FP of shared working fluid from the expander 9 and to remove heat from said first flow FP of shared working fluid. Heat Q2 is discharged into the shared heat sink 13 from the expanded shared working fluid.

The shared heat sink 13 may comprise one or more heat exchangers and may be configured to condense the shared working fluid circulating therethrough.

[0056] Continuing its path, the first flow FP of shared working fluid in a liquid state at the pressure P2 and at the temperature T3, leaves the shared heat exchanger 13 and is fed to a suction side of a pump 15 arranged in the power generation circuit 3. Pump 15 increases the pressure of the first condensed FP flow (hour) of the shared working fluid from pressure P2 to pressure P1 and pumps the shared working fluid to heater 7, where the first FP flow of fluid of shared work is vaporized and can be overheated, before being expanded again in the turboexpander 9.

The refrigeration circuit 5 comprises a shared heat sink 13, coupled to an expansion arrangement 21, for example a JouleThomson valve or an expander. The expansion device 21 is coupled to a second heat exchanger 19, having a cold side 19C and a hot side 19H. The second heat exchanger 19 is coupled to the suction side of a compressor 17. The discharge side of the compressor 17 is coupled to the inlet of the shared heat sink 13. The second flow FR of shared working fluid flows from the sink. heat 13, through the expansion device 21, the second heat exchanger 19 and the compressor 17.

[0058] Starting from the left side of Fig.2, in general terms, the refrigeration circuit 5 is in a heat exchange ratio with the low temperature heat source (s) (104, 105, 106), from which heat is supplied to the second condensed and expanded flow FR of the shared working fluid, which circulates in the refrigeration circuit 5 at a pressure P4. The second flow FR of working fluid is then compressed by the compressor 17 to a pressure P2 and a temperature T6 and fed to the heat sink 13, where heat is removed from the shared working fluid compressed to a pressure P2.

The temperature of the shared heat sink 13 is higher than the temperature of the low temperature heat source (s) (104, 105, 106), so that mechanical work is required to transfer heat from the low temperature heat source (s) to the shared heat sink 13. The refrigeration circuit 5 therefore includes the compressor 17 mechanically coupled to the expander 9 of the power generator circuit 3. The mechanical power generated by the expander 9 and which drives the compressor 17 is then used to "pump "the heat from the low temperature source (s) (104, 105, 106) to the high temperature shared heat sink 13 for its removal.

The compressor 17 can be a centrifugal compressor or an axial compressor, or a combined axial-centrifugal compressor. In other embodiments, the compressor 17 may be a volumetric compressor, such as a reciprocating compressor or a screw compressor. The compressor 17 can be a single-stage or multistage compressor.

The suction side, i.e. the low pressure side, of the compressor 17 is in fluid coupling with the second heat exchanger 19. The second flow FR of shared working fluid circulates through a cold side 19C of the second heat exchanger heat 19, while a flow of a fluid to be cooled circulates in a hot side 19H of the second heat exchanger 19. The second heat exchanger 19 therefore functions to transfer heat from one or more low-temperature sources (104, 105, 106) to the second flow FR of shared working fluid which circulates in the refrigeration circuit 5. The discharge side of the compressor 17 is in fluid coupling with the inlet of the shared heat sink 13.

The cold side 19C of the second heat exchanger 19 can be a vaporizer. The cold side 19C of the second exchanger 19 can be in functional relationship with an air conditioner and / or with a vehicle cooler / freezer, on which the combined thermodynamic system 1 and the heat source 2 are arranged.

An operating cycle of the chiller circuit is now described in greater detail. Starting from point 14 in Fig. 2, the second flow FR of shared working fluid condensed at pressure P2 and temperature T3 exits from the outlet side of the shared heat sink 13 and is expanded through the expansion device 21 at a pressure P4 and at a temperature T4, below the pressure P2 and the temperature T3 at the outlet side of the shared heat sink 13. Depending on the system design, the temperature T4 can be as low as -45 ° C or even lower.

The low temperature, low pressure FR flow of shared working fluid is then heated to a temperature T5 in the second (refrigeration) heat exchanger 19 by heat Q3 removed from the fluid flow circulating in the hot side 19H of the second heat exchanger 19. The heated shared working fluid then exits the outlet of the second heat exchanger 19 and is fed to the suction side of the compressor 17.

The heated shared working fluid is processed by the compressor 17 and fed to the discharge side of the compressor 17 at a temperature T6 and pressure P2 higher than the temperature T5 and pressure P4 and is then fed (i.e. circulated back) to the shared heat sink 13, where the second stream FR of shared working fluid is cooled and condensed by removing heat Q4.

The compressor 17 is mechanically coupled to the turboexpander 9 through a shaft 11 and is driven by mechanical power generated by the turboexpander 9. In some embodiments, the compressor 17 and the turboexpander 9 rotate at the same speed, and there is no gearbox along the shaft line connecting the compressor 17 to the turboexpander 9, so that a more compact and more reliable arrangement is obtained.

As described in general above, and referring now to Fig. 2, the shared heat sink 13 is common to the power generator circuit 3 and the refrigeration circuit 5. Therefore, the same shared working fluid circulates in both the power generation 3 and refrigeration 5 circuits, so that the circuits can be designed as a sealed combined system. A total working fluid flow F flows through the shared heat sink 13 and is made available at the outlet (point 14) of the shared heat sink 13. At point 14 the total working fluid flow F is split into the first flow of working fluid FP, which circulates in the power generation circuit 3, and in the second flow of working fluid FR, which circulates in the refrigeration circuit 5.

The hot side 19H of the second (refrigeration) heat exchanger 19 can be part of any closed or open circuit of a flow of fluid to be cooled or cooled. In some embodiments, the hot side 19H may be an open air circuit. For example, the hot side 19H can be an open air duct of an air conditioning system 104 of a vehicle 100, 200, 300, 400. Air can circulate in the hot side 19H of the second heat exchanger 19 to exchange heat towards the work flow circulating in the cold side 19C of the second heat exchanger 19. Heat Q3 from the circulating air vaporizes the working fluid in the cold side 19C of the second heat exchanger.

[0069] In some embodiments the cold side 19C of the second heat exchanger 19 can be arranged directly in a closed cooled area 105 or 106. In Fig.2, for example, the cold side 19C of the second exchanger 19 is positioned directly in the cooled area 105 of the refrigerated truck or van 100. Heat Q3 is then absorbed by the cold side 19C of the second heat exchanger 19 directly by the cooled area 105, 106.

In other embodiments, Q3 heat can be transferred from one or more types of cooling systems to the second heat exchanger 19 through one or more intermediate heat transfer circuits 20. For example, a heat transfer circuit can be provided to transfer heat from an air conditioning system 104 to the second (refrigeration) heat exchanger 19 and the same or a different heat transfer circuit can be used to transfer heat from a cooled area 105, 106 to the second heat exchanger 19.

[0071] In still further embodiments, the second (refrigeration) heat exchanger 19 may comprise one or more vaporizers or vaporizing sections, which form the cold side 19C of the second heat exchanger 19, which are in a ratio of heat exchange with different multiple systems, such as one or more air conditioning systems 104 and / or cooled areas (105, 106) (for example refrigerated or frozen compartments or containers of a vehicle). Furthermore, different cooled areas can be placed at different temperature levels. For example, on a large cruise ship there may be a refrigeration compartment for the storage of perishable food at around 2-6 ° C in combination with freezing compartments for the storage of frozen goods, around -30 ° C. The flow rate of the working fluid shared in the different vaporizers or vaporization sections can be controlled as a function of the amount of heat to be removed from each type of cooling systems (air conditioning, refrigeration or freezing).

[0072] An electric machine 22 can be mechanically coupled to the turboexpander 9 through one or more couplings 24, 25. For example, the electric machine 22 can be a reversible electric machine adapted to function selectively in an electric generator mode and in a motor mode electric. In some embodiments, the electric machine 22 can be arranged on the same shaft 11, which mechanically connects the turboexpander 9 and the compressor 17.

[0073] In preferred embodiments, a common shaft line is provided, which connects the rotating machines 9, 17, 22. The electric machine 22 then rotates at the same speed of rotation as the turboexpander 9 and the compressor 17. An actuator variable frequency (VFD) 26 can be used to connect the electric machine 22 to an electric power distribution network 28. A first clutch 24 can be provided along the shaft line 24. The clutch 24 is a disengageable clutch, which it can be adapted to disconnect the electric machine 22 and the turboexpander 9 from the compressor 17, for example if no refrigeration is required. In some embodiments, a second clutch 25 can be arranged between the turboexpander 9 and the electric machine 22. The clutch 25 can be a disengageable clutch, which can be adapted to disconnect the electric machine 22 from the turboexpander 9. Disconnecting the clutch 25 the compressor 17 can be operated by electric power supplied by the electric power distribution network 28, for example fed by an accumulation battery. This can happen, for example, when the motor 3 is not running and / or if it supplies an insufficient quantity of thermal waste.

[0074] The clutch 24 and / or the clutch 25 can be electromagnetically controlled clutches. In some embodiments, the clutch 25 can also be a freewheel clutch or a so-called synchro-self shifting clutch.

[0075] The turboexpander 9, the electric machine 22 and the compressor 17 can be arranged in a common box, schematically indicated at 27, which can be sealed. This avoids leakage of working fluid to the environment and removes the need for seals, for example dry gas seal, on the rotating shaft 11. In some embodiments, the turboexpander 9 and / or the electric machine 22 and / or the compressor 17 can be housed in two or three separate boxes. For example, the turboexpander 9 and the electric machine 22 can be housed in a first box, and the compressor 17 can be housed in a second box. In order to avoid leaks around the rotating shaft that connects the electric machine 22 and the compressor 17, a magnetic coupling 24 can be provided, which is partially housed in the first box and partially housed in the second box. The torque can thus be transmitted from the electric machine 22 to the compressor 17 through the magnetic action of the clutch 24, without the passage of a mechanical shaft through the first and second casing.

[0076] In other embodiments, the turboexpander 9 can be housed in a first box, while a second box contains the compressor 17 and the electric machine 22. The clutch 25 can be housed partly in the first box and partly in the second box, so that torque can be magnetically transmitted from the turboexpander 9 to the electric machine 22 without the need for a shaft coming out of the boxes.

[0077] In still further embodiments, three boxes can be provided, for the compressor 17, for the electric machine 22 and for the turboexpander 9, respectively. Two magnetic clutches 24, 25 can be provided. An element of the clutch 25 and an element of the clutch 24 are housed in the intermediate case where the machine is housed. The second element of the clutch 25 is housed in the case of the turboexpander 9 and the second element of the clutch 24 is housed in the case of the compressor 17.

[0078] In some embodiments, for example if the electric machine 22 is housed in the same case in which at least one of the compressor 17 and the turboexpander 9 are housed, the fluid processed through the compressor 17 and / or the turboexpander 9 can be used as a cooling fluid for the electric machine 22. Control means or control devices (not shown) may be provided for controlling the flow of cooling fluid through the electric machine 22.

In the sense used herein, a sealed casing can be understood as a casing housing a rotating shaft which must not extend outside the casing, so that seals on the rotating shaft can be avoided. The casing can comprise separate compartments which house the turboexpander 9, the electric machine 22 and the compressor 17, respectively. Each compartment, in particular the turboexpander compartment and the compressor compartment are in fluid coupling with the power generation circuit 3 and with the refrigeration circuit 5, respectively. The seal between these compartments is not critical, since the power generation circuit 3 and the refrigeration circuit 5 use the same working fluid.

[0080] In some embodiments, as shown in Fig.2, the electric machine 22 is arranged between the turboexpander 9 and the compressor 17. With this embodiment the turboexpander 9, and the electric machine 22 can remain connected to the one to the other but disconnected from the compressor 17 by the disconnectable clutch 4. This can be useful, for example, if the refrigeration plant, to which the refrigeration circuit 5 is coupled, is inoperative. In some embodiments, when the refrigeration circuit 5 is used only to operate an air conditioning system 104, the turbo expander 9 and the electric machine 22 can be disconnected from the compressor 17 when air conditioning is not required. . If the refrigeration system includes a refrigerated or cooled compartment for the transport of perishable goods, for example, the compressor 17 can be disconnected when the vehicle is empty and no goods are being transported.

Thermal waste from the motor 2 can still be used in a useful manner to generate electrical power through the electrical machine 22, which can be switched to the generator mode. The electric power can be used to charge a storage battery (not shown in Fig. 2) or to operate other units or systems of the vehicle on which the combined thermodynamic system 1 is arranged.

[0082] In some operating conditions, for example when starting the motor 2, the thermal waste available from the motor 2 may not be sufficient to drive the compressor 17. In this case the electric machine 22 can be switched to the motor mode and supply power additional mechanics to drive the compressor 17. This can be advantageous, for example, to accelerate the cooling effect in order to reach a desired temperature in a shorter time.

[0083] Referring now to Fig.3, continuing to refer to Fig.2, a further embodiment of a new thermodynamic arrangement is described. The new thermodynamic arrangement comprises a first heat exchanger (heater) 7 and a combined thermodynamic system 1. The same reference numerals indicate similar or identical components to those already described in relation to Fig.2 and which will not be described again. The following description will therefore focus mainly on the differences between Figs. 2 and Fig. 3-

[0084] In Fig. 3 thermal waste is recovered from the exhaust gas coming from a heat source 2 (such as an engine), which flows through the exhaust pipe of the exhaust gas 8. Heat is recovered by means of the heater 7 and a further heat exchanger 7A, through an intermediate heat transfer circuit 30. A heat transfer fluid, such as a heat transfer oil, water or any other suitable fluid, preferably a non-flammable fluid, can be used to transfer heat from the heater 7 to the 7A heat exchanger. A circulation pump 31 can be provided to circulate the heat transfer fluid in the heat transfer circuit 30. The second heat exchanger 7A is then configured to transfer heat from the heater 7 and the heat source 2 to the heat generation circuit. power 3 (and to the shared working fluid circulating in it) of the thermodynamic system 1.

This arrangement can be particularly useful for safety reasons, since the intermediate heat transfer circuit 30 prevents contact between the hot exhaust gas duct and the shared organic working fluid circulating in the combined thermodynamic system 1. However, in other embodiments the intermediate heat transfer circuit 30 can be omitted and a direct heat exchange can be provided as shown in Fig.2. Conversely, an intermediate heat transfer circuit 30 with respective first and second heat exchangers 7, 7A can also be used in the embodiment of Fig.2.

According to the embodiment of Fig.3, a storage battery 32 can be electrically coupled to the electrical power distribution network 28, so that electrical energy generated by the electrical machine 22, when operating in generator mode, can be used for recharge the storage battery 32. Conversely, electrical energy stored in the storage battery 32 can be used to power the electric machine 22, when the latter operates in engine mode, for example if no power is available from the turboexpander 9 or if power is available insufficient power.

[0087] The electrical power distribution network 28 can be electrically coupled to a further electric machine 34, which can be combined with the engine 2, for example to provide a hybrid vehicle propulsion system. Mechanical power generated by the electric machine 34 and mechanical power generated by the heat source 2 can be combined through a gearbox 36. An output shaft 38 mechanically couples the gearbox 36 to the wheels or other means of propulsion of the vehicle, such as a propeller of a boat or air vehicle, or the wheels of a car, bus or truck.

[0088] The hybrid propulsion system shown in Fig.3 can also be provided in the embodiment of Fig.2.

In some embodiments, clutch 24 can be disengaged for controlled time intervals while the refrigeration circuit is running, if required. For example, in the case of hybrid vehicles the power required on the output shaft 38 can suddenly increase for short periods of time. This can happen, for example in hybrid cars or other hybrid land vehicles. Battery 32 may not be capable of supplying sufficient electrical power, or may be damaged by sudden current surges. To prevent damage to the battery and / or to increase the electric power available for the electric motor 34, the clutch 24 can be temporarily disconnected, so that mechanical power generated by the turboexpander 9 is temporarily made available for the electric motor 34.

Mechanical power generated by the conversion of waste heat through the turboexpander 9 can be used to drive the compressor 17 of the refrigeration cycle 5. However, if the mechanical power generated by the turboexpander 9 exceeds the power required to drive the compressor 17, the Excess mechanical power can be used for propulsion of the vehicle and / or can be stored for later use, for example if in some operating conditions the mechanical power to the turboexpander becomes insufficient to drive the compressor 17.

According to a further aspect of the present description, the thermodynamic arrangement can be used to cool a cooled area (such as an air-conditioned, refrigerated or frozen compartment) for the storage of perishable goods, in particular for example (but not exclusively ) foods, using different heat sources than a vehicle propulsion engine.

[0092] Fig.4 illustrates an embodiment of a thermodynamic arrangement comprising a combined thermodynamic system 1 in heat exchange ratio with a generic heat source 12, for example a solar plant, such as a concentrating solar plant. The same reference numbers used in Figs.2 and 3 are used in Fig.4 to indicate identical or equivalent parts or elements, which will not be described again.

A concentrating solar power plant can for example provide heat at a sufficiently high temperature to operate a combined thermodynamic system using an organic fluid. Heat Q1 can be extracted from the source 12 directly from the shared working fluid circulating in the power generation circuit 3, or through an intermediate heat transfer circuit, again indicated with 30.

In the embodiment of Fig.4, heat Q3 is removed by means of a second heat exchanger 19 from one or more cooled areas (105 or 106). In the sense herein understood, a cooled area may comprise one or more of: a refrigerator, a freezer, or both, or other similar installations for the storage of perishable goods. An emergency generator 40, for example a diesel generator, can be provided to generate electrical power if insufficient heat is available from the heat source. Electric power generated by the emergency generator 40 can be used to drive the electric machine 22 and therefore the compressor 17 of the refrigeration circuit 5.

A clutch 25 can be arranged along the shaft line, which mechanically couples the compressor 17, the electric machine 22 and the expander 9. The clutch can selectively connect the electric machine 22 and the compressor 17 to the expander 9, or disconnect the latter from the electric machine 22 and from the compressor 17. In this way, if the expander is not in operation, for example if insufficient heat is available from the heat source 12, the expander 9 can be disconnected and the compressor 17 can be operated by the electric machine 22, fed by electric power coming from the electric power distribution network 28.

In some embodiments, a further clutch 24 can be arranged along the shaft line between the compressor 17 and the electrical machine 22. This allows the electrical machine 22 to be disconnected from the compressor 17. In some operating conditions this can be advantageous, for example if cooling is not required and any available mechanical power generated by the mechanical power generation circuit can be used to generate useful electrical power through the electrical machine 22.

While in Fig.4 both the couplings 24 and 25 are shown in combination, in other embodiments only the graft 24 or only the graft 25 may be provided.

[0098] The electric machine 22 and the turbomachinery 9 and 17 can be housed in one or more boxes, as described above in relation to Figs.2 and 3.

In some embodiments, a control system 120 (see Fig.2) may be provided for controlling the temperature in one or more of an air conditioning system 104, a cooled area 105, 106, or both of them. Temperature sensors 122 can detect one or more temperature values in the air conditioning system or in the cooled area (s) and provide a control signal to control the refrigeration circuit 5. A user interface 124 may also be provided. for introducing temperature values for one or more of said air conditioning systems or cooled areas.

[0100] Fig.5 illustrates a flow chart summarizing methods of operation of the thermodynamic arrangement, or of a vehicle comprising a thermodynamic arrangement according to the present description.

[0101] As mentioned above, a thermodynamic arrangement according to the present description can be installed on existing vehicles for retrofitting purposes. Fig.6 illustrates a flow chart summarizing a method for installing a thermodynamic arrangement on a new or existing vehicle. A first heat exchanger 7 of the power generating circuit 3 of the combined thermodynamic system 1 is coupled to the heat source of the vehicle, for example its heat engine. The second heat exchanger 19 of the refrigeration circuit 5 is coupled to at least a cooled area, which may include an air-conditioned area, of the vehicle. The coupling is such that first and second flows FP and FR of a shared working fluid circulating in the power generation circuit 3 and in the refrigeration circuit 5 can convert heat from the heat source into mechanical power and the mechanical power is used to run the refrigeration circuit and extract power from the cooled area. The thermodynamic arrangement also includes the aforementioned electric machine 22, having the purpose of providing a power balance between the two circuits, so that additional mechanical power is generated by the electric machine to operate the refrigeration circuit if the power generation circuit generates power. insufficient or does not generate it. Conversely, useful electrical power is generated using mechanical power from the power generation circuit, if the latter produces more mechanical power than is needed for the refrigeration circuit 5.

While the invention has been described in terms of various specific embodiments, it will be clear to those skilled in the art that many modifications, changes and omissions are possible without departing from the spirit and scope of the claims. Furthermore, unless otherwise indicated, the order or sequence of any process or method step can be varied or rearranged according to alternative embodiments.

Claims (25)

A NEW THERMODYNAMIC ARRANGEMENT WITH COMBINED POWER GENERATION AND REFRIGERATION CIRCUITS WITH A SHARED HEAT WELL AND A SHARED WORKING FLUID CLAIMS 1. A thermodynamic arrangement, comprising: a first heat exchanger (7; 7A); a power generating circuit (3) adapted to circulate a first flow (FP) of a shared working fluid and convert heat from a heat source (2, 12) into mechanical power; wherein the power generating circuit (3) comprises an expander (9) adapted to receive the first flow (FP) of shared working fluid and to expand the first flow (FP) of shared working fluid by a first pressure (P1 ) at a second pressure (P2) and generate mechanical power with it; And a refrigeration circuit (5) comprising a compressor (17) driven by mechanical power generated by the mechanical power generation circuit (3) and adapted to circulate a second flow (FR) of the working fluid shared in the refrigeration circuit; wherein the expander (9) is adapted to be mechanically coupled to the compressor (17) to drive the compressor (17) with mechanical power generated by the expander; and in which the expander (9) and the compressor (17) are adapted to be mechanically coupled to an electric machine (22). The thermodynamic arrangement of claim 1, further comprising a shared heat sink (13) adapted to receive the first flow (FP) of working fluid shared by the expander (9) and the second flow (FR) of fluid working fluid shared by the compressor (17) to remove heat therefrom, and to supply the first flow of cooled fluid (FP) of shared working fluid to the power generator circuit (3) and the second flow (FR) of working fluid shared with the refrigeration circuit (5). The thermodynamic arrangement of claim 2, wherein the first heat exchanger (7; 7A) is adapted to receive the first flow (FP) of working fluid from the shared heat sink (13) and to circulate the first flow ( FP) of working fluid to receive heat from the first heat exchanger (7; 7A). The thermodynamic arrangement of claim 2 or 3, wherein the refrigeration circuit (5) further comprises a second heat exchanger (19) disposed between the shared heat sink (13) and the compressor (17) and in fluid coupling therewith, and able to circulate the second flow (FR) of working fluid shared by the shared heat well (13) in a heat exchange ratio with a fluid to be cooled. The thermodynamic arrangement of claim 4, wherein the refrigeration circuit (5) further comprises an expansion device (21) disposed between the shared heat sink (13) and the second heat exchanger (19), adapted to expand the second stream (FR) of shared working fluid. 6. The thermodynamic arrangement of one or more of the preceding claims, wherein the first heat exchanger (7; 7A) is adapted to receive heat waste from a heat engine (2). 7. The thermodynamic arrangement of one or more of the preceding claims, further comprising at least one refrigeration plant (104, 105, 106) and in which the refrigeration circuit (5) is in functional relationship with the refrigeration plant for remove heat from it. The thermodynamic arrangement of claim 7, wherein the refrigeration plant comprises at least one of an air conditioning system (104); and a cooled area (105; 106). 9. The thermodynamic arrangement of one or more of the preceding claims, wherein the expander (9), the electric machine (22) and the compressor (17) are arranged along a single shaft line (11) and are adapted to rotate at the same rotation speed. The thermodynamic arrangement of claim 9, wherein the electric machine (22) is arranged along the shaft line between the compressor (17) and the expander (9). The thermodynamic arrangement of one or more of the preceding claims, wherein the electric machine (22) is adapted to be selectively connected to and disconnected from the compressor (17). The thermodynamic arrangement of one or more of the preceding claims, wherein the electric machine (22) is adapted to be selectively connected to and disconnected from the expander (9). The thermodynamic arrangement of one or more of the preceding claims, wherein a disengageable clutch (24) is placed between the compressor (17) and the electric machine (22). The thermodynamic arrangement of one or more of the preceding claims, wherein the detachable clutch (25) is disposed between the expander (9) and the electric machine (22). The thermodynamic arrangement of one or more of the preceding claims, wherein the electric machine (22) is adapted to function selectively: in a generator mode to convert at least a part of the mechanical power generated by the expander (9) into electric power; and in a motor mode for providing mechanical power to the compressor (17). 16. The thermodynamic arrangement of one or more of the preceding claims, in which the electric machine (22) is electrically coupled to a storage battery (32). 17. The thermodynamic arrangement of one or more of the preceding claims, wherein the power generating circuit (3) further comprises a pump (15) adapted to circulate the first flow (FP) of working fluid shared therein. 18. The thermodynamic arrangement of one or more of the preceding claims, wherein the shared working fluid is an organic working fluid running an organic Rankine cycle in the power generating circuit (3). 19. A kit comprising a thermodynamic arrangement according to one or more of the preceding claims, configured to be coupled to a heat source (2) and a cooled area (105, 106) of a vehicle (100, 200, 300, 400 ). 20. A vehicle (100, 200, 300, 400) comprising a propulsion heat engine (2) and a thermodynamic arrangement according to one or more of claims 1 to 18, wherein the first heat exchanger (7) of the thermodynamic arrangement is in heat exchange ratio with the propulsion heat engine (2) and is able to receive heat waste generated by the heat engine (2) and feed heat waste to the first flow (FP) of shared working fluid that circulates in the generation circuit of power (3). The vehicle (100, 200, 300, 400) of claim 20, comprising a hybrid propulsion system, adapted to use electric power generated by said electric machine (22) for the propulsion of the vehicle. 22. A method for operating a thermodynamic arrangement, comprising: a first heat exchanger (7; 7A); a power generating circuit (3) adapted to circulate a first flow (FP) of a working fluid shared in it and comprising an expander (9) able to expand the first flow (FP) of working fluid shared by a first pressure (P1) at a second pressure (P2) and generate mechanical power with it; a refrigeration circuit (5) having a compressor (17) adapted to be operated by mechanical power generated by the expander (9) and to circulate a second flow (FR) of said working fluid shared in the refrigeration circuit; the method including the following steps: - converting heat from the heat exchanger (7; 12) into mechanical power pouring the working fluid into the power generation circuit (3); And - mechanically coupling an electric machine (22) selectively to the spantore (9) and to the compressor (17), for: � convert mechanical power generated by the expander (9) into po- electric power with said electric machine (22); or � operate the compressor (17) with the mechanical power generated by the expander (9); or � operate the compressor (17) with the mechanical power generated from the electric machine (22); or � operate the compressor (17) with mechanical power generated in combination by said electric machine (22) and by said expander (9). 23. A method for driving a vehicle comprising an engine (2) adapted to generate propulsion power for the propulsion of said vehicle (100, 200, 300, 400) and to generate thermal waste; wherein the vehicle further comprises: a power generation circuit (3) adapted to circulate in the first flow (FP) of a working fluid shared within it and comprising an expander (9) adapted to expand the first flow (FP) of working fluid from a first pressure (P1) to a second pressure (P2) and generate mechanical power with it; a refrigeration circuit (5) having a compressor (17) adapted to be operated by mechanical power generated by the expander (9) and to circulate a second flow (FR) of said working fluid shared in the refrigeration circuit; the method comprising the following steps: - converting thermal waste generated by the engine (2) during operation into additional mechanical (non-propulsive) power by circulating the first flow (FP) of working fluid in the power generation circuit (3); And - mechanically coupling an electric machine (22) selectively with the spantore (9) and with the compressor (17), for: � convert mechanical power generated by the expander (9) into po- electric power with said electric machine (22); or � operate the compressor (17) with the mechanical power generated by the expander (9); or � operate the compressor (17) with the mechanical power generated from the electric machine (22); or � operate the compressor (17) with mechanical power generated in combination by the electric machine (22) and the expander (9). 24. A method of installing on a vehicle a thermodynamic arrangement having a combined power generation circuit (3) with an expander (9), a refrigeration circuit (5) with a compressor mechanically connectable to the expander, and an electric machine adapted to be engaged to and disengaged from the expander and the compressor; the method including: coupling a first heat exchanger (7) of the power generation circuit (3) to a heat source (2) of the vehicle; And couple a cooled area (105, 10, 104) of the vehicle to a second heat exchanger (19) of the refrigeration circuit (5), so that a shared working fluid can circulate in the power generation circuit (3) and in the circuit (5) to produce mechanical power by heat from the heat source (2) and to drive a refrigeration compressor (17) of the refrigeration circuit (5) with said power. 25. A vehicle (100, 200, 300, 400) comprising: an engine (2) adapted to generate propulsive power for the vehicle and thermal waste; a thermodynamic system (1), comprising: - a first heat exchanger (7) adapted to receive heat from the engine (2); - an expander (9) mechanically coupled to a compressor (17); - a shared heat sink (13), in fluid coupling with a discharge side of the expander (9) and adapted to receive expanded working fluid from the expander (9); the shared heat sink (13) also being in fluid coupling with a discharge side of the compressor (17), and adapted to receive working fluid compressed by the compressor (17); - a cooling circuit section between the shared heat sink (13) and a suction side of the compressor (17); wherein the cooling circuit section comprises a second heat exchanger (19) having a cold side adapted to circulate working fluid from the shared heat sink (13) in heat exchange ratio with a hot side of the second heat exchanger ( 19), said hot side able to circulate a medium in flow, to be cooled by heat exchange with working fluid which circulates in the cold side of the second heat exchanger (19); - a power generation circuit section between the shared heat sink (13) and an inlet of the expander (9); wherein the power generation circuit section comprises a heater (7) adapted to circulate a working fluid from a shared heat sink (13) and receive heat waste from the engine (2); and wherein the heater (7) is in fluid coupling with an inlet of the expander (9); And - an electric machine (22), adapted to be mechanically coupled to the compressor (17) and to the expander (9).