OA19984A - Heat machine configured for realizing heat cycles and method for realizing heat cycles by means of such heat machine. - Google Patents

Abstract

A heat machine (121) for realizing a heat cycle, the heat machine operating with a thermal fluid and comprising a drive unit (1) provided with a first rotor (4) and a second rotor (5), each having three pistons (7a, 7b,7c; 9a,9b,9c) that are slidable in an annular chamber (12), wherein the pistons delimit six variable-volume chambers (13', 13", 13"'; 14',14",14"'). The drive unit comprises a transmission configured to convert the rotary motion with respective first and second periodically variable angular velocities (w1, w2) of said first and second rotor (4, 5), offset from each other, into a rotary motion at a constant angular velocity. The heat machine further comprises a compensation tank (44), configured to accumulate the compressed thermal fluid from the drive unit, a regenerator (42) configured to preheat the thermal fluid, a heater (41) configured to superheat the thermal fluid circulating in the serpentine coil, a burner (40), configured to supply the necessary thermal energy to the heater (41); wherein the regenerator (42), in fluid communication with the drive unit (1), is further configured to acquire energy-heat from the exhausted thermal fluid and use it to preheat the thermal fluid to be sent to the heater (41). The invention further relates to a method for realizing a heat cycle by means of said heat machine.

Description

Field ofthe Invention

The présent invention relates to a “heat machine”, comprising a rotary drive unit provided with a motion transmission System, and some spécifie functional configurations thereof, and which, despite having JouleEricsson heat cycles as its original reference, suppléments and improves them, achieving an innovative combined heat cycle, operating with a mixture of air and aqueous vapour, in order to obtain a greater unit power, a considérable increase in bverall efficiency and an efficient lubrication of the cylinder in which the pistons rotate. The présent invention further relates to a method for realizing heat cycles.

In particular, the présent invention can hâve application in the production of electrical energy from renewable sources, in the field of the combined génération of electrical energy and heat, in the field of transport and in the automotive sector in general.

Background ofthe invention

Some historical considérations concerning thermodynamic cycles were already set forth in the description of the patent application published with the number WO2015/114602A1 in the name of the same Applicant, and it is therefore deemed useful to mention in the following only the most significant parts tied to the subject matter of the présent invention and regarding use as a heat machine characterized by a new “pulsating heat cycle”, whose origin lies in Joule-Ericsson cycles.

Historical notes on the Ericsson engine

The first design and production of the Ericsson “hot air” engine took place in 1826, initially without régénération and with a modest overall efficiency.

In 1833, a new Ericsson engine was built, provided with valves and a heat recuperator, and a considérable increase in overall efficiency was obtained.

In 1853 an Ericsson hot air” engine was built, which was used on a ship; it was able to generate 220 kW of power with an overall efficiency of 13.3%.

In subséquent years, several thousand Ericsson engines were produced and used on ships and in industrial laboratories in the United States.

Between 1855 and 1860 nearly 3,000 low-power (600 W) Ericsson engines were built. They were sold and used in the United States, Germany, France and Sweden.

These engines possessed high reliability and robustness, so much so that one engine installed in a lighthouse remained in operation for over 30 years after being put into service.

For reasons that hâve not yet been wholly clarified, the Ericsson engine was then first supplanted by conventional steam engines and then by internai combustion engines, more powerful and compact in size. Schematic représentation ofthe closed-circuit Ericsson cycle

The Ericsson cycle, characterized by the use of a reciprocating motion engine operating in a closed circuit, is schematically represented! in figure 4, and is composed ofthe following main components: E_ expansion cylinder;

E1 -E2_ expansion cylinder inlet-discharge valves;

R_ heat exchanger/recuperator;

K_ heat exchanger/sink;

C_ compression cylinder;

C1-C2_compression cylinder inlet-discharge valves;

H_ “thermal fluid” heater.

With reference to said figure 4, the Ericsson engine Works in the following manner;

Jn cylinder C, as a resuit of the downward movement of the piston, the thermal fluid (at température T1), passing through the valve C1, is first suctioned and then, as a resuit of the upward movement of the piston, is compressed until reaching the maximum value corresponding to the predetermined ratio;

_the compressed thermal fluid then passes through the valve C2 and exits from the cylinder C (at température T2);

_the thermal fluid then passes into the recuperator R, where it receives heat and heats up (to température T2’);

Jhe thermal fluid then passes into the heater H, where it receives heat and heats up further (to température T3);

_the thermal fluid then passes through the valve E1 and enfers the cylinder E where, by expanding, it brings aboutthe downward movementofthe piston, producing useful work.

Jhe already expanded thermal fluid, as a resuit of the upward movement of the piston, is then discharged from the cylinder and (at a reduced température T4) passes through the valve E2;

Jhe thermal fluid then passes through the recuperator R, where it surrenders heat (until reaching a reduced température T4 j;

Jhe thermal fluid then passes through the sink K, where it surrenders further heat (until reaching température T1) and from where a new cycle cambegin, perfectly identical to the previous one.

Schematic représentation ofthe Joule closed cycle

The Joule cycle, characterized by the use of a turbo-machine with continuous rotary motion, operating in a closed circuit, is schematically represented in figure 5, and is composed of the following main components:

E_ expansion turbine;

R_ heat exchanger/recuperator;

K_ heat exchanger/sink;

C_ compression turbine;

H_ “thermal fluid” heater.

With reference to said figure 5, the turbo-machine of Joule opérâtes in the following manner:

_as a resuit of the fast rotary movement of the turbine C, the thermal fluid (at température T1) is suctioned and compressed to the maximum predetermined value;

Jhe compressed thermal fluid then exits from the turbine C (at température T2);

_the thermal fluid then passes into the recuperator R, where it receives heat and heats up (to température T2’);

Jhe thermal fluid then passes into the heater H, where it receives heat and heats up further (to température T3);

_the thermal fluid then enters the turbine E, where, by expanding, it brings about the rotary movement of the turbine itself, producing useful work.

_the already expanded thermal fluid¹ is then discharged from the turbine E and (at a reduced température T4); Jhe thermal fluid then passes through the recuperator R, where it surrenders heat (until reaching a reduced température T4’);

Jhe thermal fluid then passes through the sink K, where it surrenders further heat (until reaching température T1 ), concluding the cycle.

General considérations

Overall, various heat machines functioning with diversified thermodynamic cycles hâve been developed and others are still at an experimental stage.

However, the Applicant has found that even already industrialized solutions hâve many limitations. This applies, in particular for the engines used to drive small and medium power autonomous electric generators (below 50 KWh).

Today, in practice, the following drive units are customarily used to drive electric generators: _reciprocating internai combustion engines, which are mechanically complicated, noisy, are particularly polluting and require a great deal of maintenance;

.Stirling engines, which, though less polluting, must operate at low speed (limitation imposed by the use of an alternating flow regenerator) in order to hâve a good overall efficiency and are therefore very heavy and cumbersome.

_gas turbines, which besides being particularly polluting, are not economically compétitive in small-scale applications.

_expanders using the Rankine or Rankine-Hirn cycle, which, given the need to use a steam generator of a certain size, can be strongly compétitive only in fixed cogénération applications and require further technological innovations in orderto be profitably used also in small-scale mobile applications.

In general, ail of the prior art solutions, in addition to the problems of pollution, low efficiency, mechanical complexity and high maintenance costs, are also characterized by a cost-benefit ratio that is not particularly satisfactory, which has! greatly limited the dissémination of cogénération in the market of multioccupancy buildings and residential dwellings.

The Applicant has also observed that if one wishes to extend the use of such heat machines to vehicles and micro cogénération in a domestic setting, compactness and overall efficiency are fundamental. Innovative solution proposée! by the Applicant.

In this context, the Applicant has set the objective of proposing a new heat machine capable of operating with an innovative combined heat cycle using hot air and aqueous vapour, whereby it is possible to exploit greater energy by recovering it during the stages of the cycle itself, with a considérable increase in the unit power and overall efficiency, also solving the large problem of lubricating the cylinder where the pistons of the known drive unit slide.

In particular, compared to Ericsson and Joule cycles, the innovations introduced with the présent invention can be identified in three different possible operating configurations of the heat cycle.

In the first configuration, which comprises solely the injection of water downstream of the régénération, the following results are obtained:

Jubrication of the cylinder¹ of the drive unit, with a réduction in friction and wear and conséquent increase in mechanical efficiency;

Jncrease in the unit power, due to the increase in the flow rate and molecular weight of the thermal fluid that is expanded in the cylinder;

_no increase in négative compression work, since the water introduced is condensed and separated from the air before the suctioning thereof;

-Slight decrease in overall efficiency, since the amount of heat absorbed by évaporation is very high per unit of mass.

In the second configuration, which comprises the injection of saturated vapour obtained with a recovery of energy downstream of the régénération, the following results are obtained:

Jubrication of the cylinder of the drive unit, with a réduction in friction and wear and conséquent increase in mechanical efficiency;

Jncrease in the unit power,i due to the increase in the flow rate and molecular weight of the thermal fluid that is expanded in the cylinder;

_no increase in négative compression work, since the water introduced is condensed and separated from the air before the suctioning thereof;

Jncrease in the overall efficiency, since the amount of heat absorbed by évaporation is compensated for by the recovery of energy achieved with the evaporator.

In the third configuration, which comprises the injection of superheated vapour obtained with a recovery of energy downstream of the régénération and the recovery of energy from the combustion fumes, the following results are obtained:

_lubrication of the cylinder of the drive unit, with a réduction in friction and wear and conséquent increase in mechanical efficiency;

Jurther increase in the unit power, due to the increase in the flow rate, molecular weight and enthalpy of the thermal fluid that is expanded in the cylinder;

_no increase in négative compression work, since the water introduced is condensed and separated from the air before the suctioning thereof;

Jurther increase in the overall efficiency, since the amount of heat absorbed by évaporation is compensated for by the recovery of energy achieved with the evaporator and the increase in enthalpy obtained with the superheating.

Therefore, the object at the basis of the présent invention, in the various aspects and/or embodiments thereof, is to remedy one or more of'the drawbacks of the prior art solutions by providing a new heat machine capable of using multiple heat sources and capable of generating a great deal of mechanical energy (work), being able to be used in any place and for any purpose, but preferably for the production of electrical energy.

A further object of the présent invention is to provide a new heat machine characterized by high thermodynamic efficiency and an excellent power-to-weight ratio.

A further object of the présent invention is to propose a new “heat machine” provided with a drive unit characterized by a mechanical structure that is simple and can be easily built.

A further object of the présent invention is to be able to produce a new heat machine characterized by a reduced cost of production.

These objects, and any others that will become more apparent in the course of the following description, are substantially achieved by a new heat machine that relies on a “drive unit” characterized by a sériés of particular aspects.

In one aspect, the présent invention relates to a heat machine for realizing a heat cycle, the heat machine operating with a thermal fluid and comprising:

- a drive unit comprising:

- a casing delimiting therein an annular chamber and having appropriately dimensioned inlet or discharge openings in fluid communication with conduits external to the annular chamber, wherein each inlet or discharge opening is angularly spaced from the adjacent inlet and discharge openings so as to define an expansion/compression path for a working fluid in the annular chamber;

- a first rotor and a second rotor rotatably installed in said casing ; wherein each one of the two rotors has three pistons that are slidable in the annular chamber; wherein the pistons of one of the rotors are angularly alternated with the pistons of the other rotor; wherein angularly adjacent pistons delimit six variable-volume chambers;

- a primary shaft operatively connected to said first and second rotor;

- a transmission that is operatively interposed between said first and second rotor and the primary shaft and configured to couvert the rotary motion with respective first and second periodically variable angular velocities of said first and second rotor that are offset relative to each other into a rotary motion having a constant angular velocity of the primary shaft; wherein the transmission is configured to confer, on the periodically variable angular velocity of each of the rotors, six periods of variation for each complété révolution of the primary shaft.

In one aspect, said drive unit is a rotary volumétrie expander operating with said thermal fluid.

In one aspect, the heat machine comprises a first section of the drive unit where, following the movement of the two pistons away from each other, the thermal fluid, passing through the inlet opening, is suctioned into the chamber.

In one aspect, the heat machine comprises a second section of said drive unit, where, following the movement of the two pistons towards each other, the previously suctioned thermal fluid is compressed in the chamber and then, on passing through the discharge opening, a pipe and a check valve, it is conveyed into a compensation tank.

In one aspect, the heat machine comprises said compensation tank, configured to accumulate the compressed thermal fluid to make it available, via spécifie pipes and the check valve, for subséquent use thereof, in a continuous mode.

In one aspect, the heat machine comprises a regenerator, in fluid communication via spécifie pipes and configured to preheat the thermal fluid prior to its entry into a heater.

In one aspect, the heat machine comprises said heater, configured to superheat the thermal fluid circulating in the serpentine coil (i.e. in the pipe placed around the combustion chamber and defining the heater), using the thermal energy produced by a burner.

In one aspect, the heat machine comprises said burner with a combustion chamber attached thereto, said burner being configured to operate with various types of fuel and being capable of supplying the necessary thermal energy to the heater.

In one aspect, the heat machine comprises a third section of said drive unit, in fluid communication with said heater, via spécifie pipes, and configured to receive, via the inlet openings, the thermal fluid heated to a high température under pressure in the heater so as to hâve it expand in the chambers, which are delimited by the pistons, respectively, for the purpose of having said pistons rotate and produce work.

In one aspect, the heat machine comprises a fourth section of said drive unit, in fluid communication with the regenerator through the discharge openings and spécifie pipes, and wherein, due to the réduction in volume of the two chambers brought about by the movement of the two pairs of pistons towards each other, the exhausted thermal fluid is forcedly expelled.

In one aspect, said regenerator, in fluid communication with said drive unit, is configured to acquire heat-energy from the exhausted thermal fluid and to use it to preheat the thermal fluid to be sent to the heater.

In one aspect (see the schematic représentation in figure 6), the first section of the drive unit is in fluid connection with the external environment via a spécifie pipe, so that the ambient air can be suctioned into the chamber.

In one aspect (see the schematic représentation in figure 6), the heat machine comprises a metering pump in fluid connection with a distilled water tank and arranged so as to enable a predefined amount of distilled water to be injected in the air circuit by means of an injector, said predefined amount being capable of increasing the unit power of the drive unit and of ensuring lubrication of the cylinder.

In one aspect (see the schematic représentation in figure 7), the heat machine comprises a cooler operatively interposed between the low température outlet of the regenerator and the inlet of the heater.

In one aspect (see the schematic représentation in figure 7), the thermal fluid, exiting from the cooler at température T1, passes into a spécifie pipe, passes through a condensate trap, where the water in the thermal fluid is condensed and separated from the air, passes into a further spécifie pipe at température T1 ’, passes through the suctioning opening and following the movement of the two pistons away from each other, is suctioned into the chamber of said first section.

In one aspect (see the schematic représentation in figure 7), pushed by a high-pressure pump, the condensate water previously extracted from the air by the trap travels through spécifie pipes and reaches an injector arranged so as to inject, in the air circuit, a predefined amount of condensate water, which is capable of increasing the unit power of the drive unit and of ensuring lubrication of the cylinder.

In one aspect (see the schematic représentation in figure 8), the heat machine comprises a cooler that is operatively interposed between the low température outlet of the regenerator and the inlet of the heater, and the thermal fluid, exiting from the cooler at température T1, passes into a pipe, passes through a condensate trap, where the water in the thermal fluid is condensed and separated from the air, passes into a further pipe at température T1’, passes through the suctioning opening and following the movement of the two pistons away from each other, is suctioned into the chamber of said first section and, pushed by a high-pressure pump, the condensate water previously extracted from the air by the trap travels through spécifie pipes and reaches an evaporator that is configured to heat and vaporize the condensate water and send it to an injector arranged so 7 as to inject, in the air circuit, a ipredefined amount of vaporized condensate water, which is capable of increasing the unit power of the drive unit and of ensuring lubrication of the cylinder..

In one aspect (see the schematic représentation in figure 8), the evaporator is operatively interposed, with its high température side, between said high pressure pump and said injector, and the evaporator is configured to receive as incoming fluid, on its low température side, the exhausted thermal fluid expelled from the outlet of the drive unit, so as to acquire residual heat-energy from this exhausted thermal fluid and to use it to preheat the thermal fluid to be sent to the heater.

In one aspect (see the schematic représentation in figure 11), the heat machine comprises a cooler, which is operatively interposed between the low température outlet of the regenerator and the inlet of the heater, and the thermal fluid, exiting from the cooler at température T1, passes into a pipe, passes through a condensate trap, where the water ih the thermal fluid is condensed and separated from the air, passes into a pipe at température T1’, passes through the suctioning opening and, following the movement of the two pistons away from each other, is suctioned into the chamber of said first section and, pushed by a highpressure pump, the condensate water previously extracted from the air by the trap travels through the pipes and reaches an evaporator, configured to heat and vaporize the condensate water and send it to a superheater, which, by extracting energy from the hot combustion fumes downstream of the burner, is configured to superheat the saturated vapour exiting from the evaporator, so as to supply energy thereto.

In one aspect (see the schematic représentation in figure 11), the superheater is configured to send the vaporized and superheated condensate water to an injector, which is arranged so as to enable injection, in the air circuit, of a predefined amount of said superheated and vaporized condensate water, which is capable of further increasing the unit power of the drive unit and of ensuring lubrication of the cylinder.

In one aspect (see the schematic représentation in figure 11), the evaporator is operatively interposed, with its high température side, between said high pressure pump and said superheater, and the evaporator is configured to receive as incoming fluid, on its low température side, the exhausted thermal fluid expelled from the outlet of the drive unit, so as to acquire residual heat-energy from this exhausted thermal fluid and to use it to preheat the thermal fluid to be sent to the heater.

In one aspect (see the schematic représentation in figure 12), the heat machine is provided with a cooling circuit comprising:

- a first recuperator, located upstream of the burner, where combustion air is drawn from the environment;

- a cooling unit (or interspace) associated with the drive unit;

- a second recuperator, located downstream of the burner and of the heater, and preferably downstream of said superheater, along the exit path of the hot combustion fumes;

- a plurality of cooling pipes connecting in sériés said first recuperator, said cooling unit and said second recuperator, so as to form a circular path, and bearing an amount of cooling fluid (preferably water);

- a cooling pump, located in said circuit and that is operatively active on one pipe of said plurality of cooling pipes so as to bring about circulation of said cooling fluid in the cooling circuit.

In one aspect (see the schematic représentation in figure 12), the first recuperator is configured to cool said cooling fluid by surrendering heat-energy to said combustion air, the cooling unit is configured to cool the 5 drive unit by transfer of heat-energy from the drive unit to the cooling fluid, which undergoes an increase in température, and the second recuperator is configured to heat said cooling fluid by acquiring heat-energy from the hot combustion fumes.

In one aspect (see the schematic représentations in figures 6, 7, 8, 11, 12), the heat machine comprises an auxiliary hydraulic circuit. In one aspect the auxiliary hydraulic circuit comprises:

- an auxiliary recuperator, located downstream of the burner and of the heater, and preferably downstream of the superheater, along the exit path of the hot combustion fumes;

- a plurality of auxiliary pipes configured to pass through said auxiliary recuperator and to be connected with one or more auxiliary uses, preferably devices for space heating and/or production units for domestic hot water;

- an auxiliary pump, located in said circuit and that is operatively active on one pipe of said plurality of auxiliary pipes so as to bring about circulation in said auxiliary circuit.

In one aspect the auxiliary recuperator is configured to recover as much energy as possible from the combustion fumes and to transmit it to the fluid circulating in said auxiliary circuit, said energy thus being available for said auxiliary uses.

^{20 ln one} aspect, the heat machine comprises a fan upstream of the burner and configured to draw combustion air from the environment and to send it forcedly to said burner to feed the combustion process.

In one aspect, the heat machine comprises one or more check vales located along the pipes of the heat machine and configured to facilitate circulation of the thermal fluid in a unidirectional manner and prevent the outflow of the thermal fluid in the opposite direction.

^{25 ln an} independent aspect thereof, the présent invention relates to a method for realizing a heat cycle, the method operating with a thermal fluid and comprising the steps of:

- arranging a heat machine;

- carrying out a plurality of steps.

In one aspect, said plurality of steps comprises:

- setting the primary shaft into motion and the transmission of the drive unit, setting the six pistons into motion;

- activating the burner and starting ,up the combustion process;

- when the thermal fluid circulating in the heat machine has reached a pre-established minimum operating state, the drive unit produces the work needed to be able to turn independently;

- following the movement of the two pistons away from each other, the thermal fluid is suctioned into the chamberthrough the suctioning opening;

- following the movement of the two pistons towards each other, the previously suctioned thermal fluid is compressed in the chamber, undergoes an increase in température from TT to T2, passes through the discharge opening and reaches the compensation tank;

- with the intermittency determined by the rotation of the pistons and the resulting opening/closing of the inlet openings, the thermal fluid flows out from the tank and passes through the regenerator, where it undergoes an increase in température from T2 to T2’;

- the thermal fluid passes through the heater, where it receives heat-energy and increases in température from T2” to T3;

- rotating in the annular cylinder, when the pistons open the inlet openings, the superheated thermal fluid is admitted into the expansion chambers where it expands, with a decrease in its température from T3 to T4 and, as it makes the pistons rotate, it produces useful work.

In one aspect, in said step of arranging a heat machine, said heat machine is in accordance with a combination of one or more of the présents aspects and/or one or more of the accompanying daims.

In one aspect (see the schematic représentation in figure 6), following the movement of the pistons towards each other, the chambers diminish in volume, the exhausted thermal fluid is expelled from the drive unit, passes through the discharge openings, and passes through the regenerator, where it surrenders part of the heat-energy still possessed and undergoes a decrease in température from T4 to T4’.

In one aspect (see the schematic représentation in figure 6), in the step of suctioning the thermal fluid into the chamber, said thermal fluid is air suctioned from the environment at température TT.

In one aspect (see the schematic représentation in figure 6), the method comprises the steps of: - drawing distilled water from the tank;

- activating the metering pump and introducing a given amount of distilled water into the circuit by means of the injector, thereby bringing about a decrease in the température of the resulting thermal fluid from T2’ to T2”;

- following the step of passing through the regenerator, the exhausted thermal fluid is discharged into the atmosphère.

In one aspect (see the schematic représentation in figure 7), the method further comprises the following steps:

- the thermal fluid, exiting from the cooler at température T1, passes into a pipe, passes through a condensate trap, where the water in the thermal fluid is condensed and separated from the air, passes into a pipe at température TT, passes through the| suctioning opening and, following the movement of the two pistons away from each other, is suctioned into the chamber of said first section;

- pushed by a high-pressure pump; the condensate water previously extracted from the air by the trap travels through the pipes and reaches an injector arranged so as to enable injection, in the air circuit, of a predefined amount of condensate water, which is capable of increasing the unit power of the drive unit and of ensuring lubrication of the cylinder.

In one aspect (see the schematic représentation in figure 8), the method further comprises the following steps:

- the thermal fluid, exiting from the cooler at température T1, passes into a pipe, passes through a condensate trap, where the water in the thermal fluid is condensed and separated from the air, passes into a pipe at température ΤΓ, passes through the suctioning opening and, following the movement of the two pistons away from each other, is suctioned into the chamber of said first section;

- pushed by a high-pressure pump, the condensate water previously extracted from the air by the trap travels through the pipes and reaches an evaporator, configured to heat and vaporize the condensate water and send to an injector arranged so as to enable injection, in the air circuit, of a predefined amount of condensate water, which is capable of increasing the unit power of the drive unit and of ensuring lubrication of the cylinder;

wherein said evaporator is configured to receive as incoming fluid, on its low température side, the exhausted thermal fluid expelled from the outlet of the drive unit, so as to acquire residual heat-energy from this exhausted thermal fluid and to use it to preheat the thermal fluid to be sent to the heater.

In one aspect (see the schematic représentation in figure 11), the method further comprises the following steps:

- the thermal fluid, exiting from the cooler at température T1, passes into a pipe, passes through a condensate trap, where the water in the thermal fluid is condensed and separated from the air, passes into a pipe at température ΤΓ, passes through the suctioning opening and, following the movement of the two pistons away from each other, is suctioned into the chamber of said first section;

- pushed by a high-pressure pump, the condensate water previously extracted from the air by the trap travels through the pipes and reaches an evaporator that is configured to heat and vaporize the condensate water and send it to a superheater, which, by extracting energy from the hot combustion fumes downstream of the burner, is configured to superheat the saturated vapour exiting from the evaporator, so as to supply energy thereto;

wherein said superheater is configured to send the superheated and vaporized condensate water to an injector, which is arranged so as to enable injection, in the air circuit, of a predefined amount of said superheated and vaporized condensate water, which is capable of further increasing the unit power of the drive unit, of increasing the overall efficiency and of ensuring lubrication of the cylinder, il and wherein said evaporator is configured to receive as incoming fluid, on its low température side, the exhausted thermal fluid expelled from the outlet of the drive unit, so as to acquire residual heat-energy from this exhausted thermal fluid and to use it to preheat the thermal fluid to be sent to the heater.

In one aspect (see the schematic représentation in figure 12), the method further comprises the following steps:

- arranging a cooling circuit comprising:

- a first recuperator, upstream of the burner, where combustion air is drawn from the environment;

- a cooling unit (or interspace) associated with the drive unit;

- a second recuperator, located downstream of the burner and of the heater, and preferably downstream of said superheater, along the exit path of the hot combustion fumes;

- a plurality of cooling pipes connecting in sériés said first recuperator, said cooling unit (or interspace) and said second recuperator, so as to form a circular path, and bearing an amount of cooling fluid (preferably water);

- a cooling pump, located in said circuit and that is operatively active on one pipe of said plurality of cooling pipes so as to bring about circulation of said cooling fluid in the cooling circuit;

- carrying out the following steps:

- cooling the cooling fluid by means of said first recuperator by surrendering heat-energy to said combustion air;

- cooling, by means of said cooling unit, the drive unit by transfer of heat-energy from the drive unit to the cooling fluid, which undergoes an increase in température;

- heating, by means of said second recuperator, said cooling fluid by acquiring heat-energy from the hot combustion fumes.

In one aspect (see the schematic représentations in figures 6, 7, 8, 11, 12), the method further comprises the following steps:

- arranging an auxiliary hydraulic circuit comprising:

- an auxiliary recuperator, located downstream of the burner and of the heater, and preferably downstream of said superheater, along the exit path of the hot combustion fumes;

- a plurality of auxiliary pipes configured to pass through said auxiliary recuperator and to be connected with one or more auxiliary uses, preferably devices for space heating and/or production units for domestic hot water;

- an auxiliary pump, located in said circuit and that is operatively active on one pipe of said plurality of auxiliary pipes so as to bring about circulation in said auxiliary circuit;

- carrying out the following steps:

- recovering as much energy as possible from the combustion fumes, by means of said auxiliary recuperator;

- transmitting said energy to the fluid circulating in said auxiliary circuit;

- providing said energy for auxiliary uses.

In one aspect, the drive unit is substantially composed of:

- an engine block formed by a casing provided with an internai cavity defining a toroidal cylinder (or annular cylinder);

- two triads of pistons rotatably housed inside the toroidal cylinder (or annular cylinder), each triad being connected to a respective driving rotor, with the pistons of the two triads alternating with each other;

- a three-shaft transmission a with a train of four three-lobe gears housed in a spécifie case, configured and designed to transmit motion from and/or to the two triads of pistons, the transmission comprising a primary shaft (or drive shaft), a first secondary shaft and a second secondary shaft, each secondary shaft being connected, via driving rotors to a respective triad of piston;

- a first rotor and a second rotor connected respectively to a first and a second auxiliary shaft and rotatably installed in the casing; wherein each of the two rotors is mechanically intégral with three pistons which are angularly offset from each other by 120° and slidable in the annular chamber; wherein the pistons of one of the rotors are angularly alternated with the pistons of the other rotor so that the angularly adjacent pistons form and delimit each of the six variable-volume chambers that are created.

In one aspect, the annular chamber has a rectangular or square cross section and the pistons, being of mating shape, are respectively rectangular or square.

In one aspect, the annular chamber has a circular cross section (extending toroidally) and the pistons, being of mating shape, hâve a circular cross section (extending toroidally).

In one aspect, the toroidal cylinder (or annular cylinder) is provided with a number of mutually distinct inlet openings for the entry of a high-temperature thermal fluid into the cylinder and a number of mutually distinct discharge openings for evacuating the exhausted thermal fluid.

In one aspect, each of the six chambers expands three times and contracts three times per each complété révolution (360°) of the primary shaft.

In one aspect, ail of the inlet/discharge openings, used for the passage of the thermal fluid, are fashioned on the casing of the toroidal (or annular) cylinder.

In one aspect the toroidal cylinder (or annular cylinder) is provided with one or more inlet openings for the entry of the cooled thermal fluid into the cylinder and one or more discharge openings for evacuating the compressed thermal fluid in the compensation tank.

In one aspect, by means of a manual or automatic angular rotation of the case containing the transmission, relative to the inlet/discharge openings, it is possible to time the phases of the heat cycle to corne earlier or later in order to optimize thermodynamic efficiency.

In one aspect, by means of a manual or automatic angular rotation of the case containing the 5 transmission, relative to the inlet/discharge openings, it is possible to time the phases of the heat cycle to corne earlier or later in order to enable autonomous starting of the engine apparatus.

In one aspect, the first triad of pistons is an intégral part of a first rotor and the second triad of pistons is an intégral part of a second rotor.

In one aspect, the three pistons of each of the two rotors are angularly équidistant from one another.

¹⁰ In one aspect, the three pistons of each of the rotors are rigidly connected together so as to rotate integrally with one another.

In one aspect, the first secondary shaft is solid and integrally joined at one end with a first three-lobe gear and at the opposite end with the first rotor.

In one aspect, the second secondary shaft is hollow and integrally joined at one end with a respective 15 second three-lobe gear and at the opposite end with the second rotor.

In one aspect, the primary shaft (or drive shaft) is integrally joined with a first and a second three-lobe gear, positioned at 60° from each other.

In one aspect, the transmission of the drive unit comprises:

- a first auxiliary shaft on which the first rotor is mounted;

- a second auxiliary shaft on which the second rotor is mounted;

- a first three-lobe gear and a second three-lobe gear keyed onto the primary shaft and angularly offset from each other by an angle of 60°;

- a third three-lobe gear, keyed onto the first auxiliary shaft;

- a fourth three-lobe gear, keyed onto the second auxiliary shaft;

wherein the first three-lobe gear is functionally operating with the third three-lobe gear and the second threelobe gear is functionally operating with the fourth three-lobe gear.

In one aspect, the first auxiliary shaft is coaxially inserted in the second auxiliary shaft or vice versa.

In one aspect, the axis of the primary shaft is parallel to and appropriately distanced from the axis of the first shaft and second shaft.

^{30 ln one} aspect, each three-lobe gear has concave and/or fiat and/or convex connecting portions between its lobes.

In one aspect, each three-lobe gear, as may be inferred from the définition thereof, has a substantially triangular profile.

In ail aspects, a rotation having a constant angular velocity of the primary shaft (or drive shaft) brings about a periodic variation in the angular velocity of rotation of the two secondary shafts.

In ail aspects, the primary shaft (or drive shaft) brings about a periodic cyclical variation of the angular velocity of the first and second secondary shafts and of the corresponding triads of pistons rotating inside the toroidal cylinder (or annular cylinder), enabling the création of six distinct rotating chambers with a variable volume and ratio.

In one aspect, the transmission of motion between the pistons and the primary shaft (or drive shaft) is obtained with the train of three-lobe gears which connects the first and second secondary shafts to the primary shaft, characterized in that while the primary shaft (or drive shaft) rotâtes with a constant angular velocity, the two secondary shafts rotate with an angular velocity that is periodically higher than, equal to or lower than the primary shaft.

In one aspect, without préjudice to the inventive idea, the drive unit can be provided with any System whatsoever for transmitting motion between the two triads of pistons and the primary shaft (such as, for example, the one claimed in patents US5147191, EP0554227A1 and TW1296023B), it being possible to adopt any mechanism able to transform the rotary motion of the primary shaft, which has a constant angular velocity, into a rotary motion with a periodically variable angular velocity of the two secondary shafts, functionally connected to the two triads of pistons.

In ail aspects, the drive unit can be configured, by means of suitable thermal fluid conveying conduits, in such a way that the varions components and varions sections can be operatively connected with the corresponding inlet/discharge openings of the drive unit.

In one aspect, the drive unit is completely devoid of inlet/discharge valves and the associated mechanisms, since the triads of pistons, by moving in the toroidal cylinder (or annular cylinder), themselves bring about the opening and the closing of the inlet/discharge openings for the thermal fluid.

In one aspect, the heat machine which uses the drive unit can be provided with check valves appropriately positioned in the thermal fluid conveying conduits, in such a way as to optimize the heat cycle by aiding the work of the pistons in the function of opening-closing the inlet/discharge openings.

In one aspect, the heat machine which uses the drive unit can comprise one or more thermal fluid heaters and/or recuperators configured in such a way as to be able to provide ail the maximum energy serving to produce the useful work, while recovering as much as possible of ail the energy that would otherwise be lost.

In one aspect, the drive unit is connected to a generator capable of producing electrical energy utilizable for any purpose.

In one aspect, the drive unit is capable of producing mechanical energy utilizable for any purpose.

ln one aspect, the heat machine which uses the drive unit comprises a heat energy regulating System, configured to regulate the delivery pressure and/or température of the thermal fluid in the various stages of the process.

In one aspect, the drive unit can be configured so as to function with an original Joule-Ericsson 5 operating cycle, as the drive unit càn perform functions of compressing and expanding the thermal fluid.

In one aspect, the heat machine which uses the drive unit is configured to function with a new pulsating heat cycle” using hot air and aqueous vapour, featuring unidirectional continuous motion of the thermal fluid.

ln one aspect, the drive unit is suitable for being employed as an apparatus capable of producing 10 mechanical energy using flows of thermal fluid heated with any source of heat.

In one aspect, the heating of the circulating thermal fluid can be achieved using a fuel burner (for example a gas burner) or any other external source of heat, such as, for example: solar energy, biomass, unrefined fuel, high-temperature industrial waste, or another source suitable for heating the thermal fluid itself to the minimum necessary température.

¹⁵ Additional features will become more apparent from the following detailed description of the heat machine of the présent invention and of some preferred embodiments of the use thereof, regarding, respectively:

_a first functional configuration (see figure 6) regarding the new “open” operating cycle, wherein the thermal fluid (normally air) is supplemented with an injection of non-recyclable distilled water whose primary purpose is 20 lubrication of the cylinder where the pistons slide and an increase in the unit power of the drive unit;

- ^a second functional configuration (see figure 7) regarding the new “closed” operating cycle, wherein the thermal fluid (normally air) is supplemented with an injection of condensed water, whose primary purpose is lubrication of the cylinder where the pistons slide and an increase in the unit power of the drive unit;

_a third functional configuration (see figure 8) regarding the new “closed” operating cycle, wherein the thermal 25 fluid (normally air) is supplemented with an injection of saturated aqueous vapour, which, in addition to lubrication of the cylinder where the pistons slide and an increase in the unit power of the drive unit, also enables an improvement in the overall efficiency of the heat cycle;

_a fourth functional configuration (see figure 11) regarding the new “closed” operating cycle, wherein the thermal fluid (normally air) is supplemented with an injection of aqueous superheated vapour, which, in 30 addition to lubrication of the cylinder where the pistons slide and a significant increase in the unit power of the drive unit, also enables a major improvement in the overall efficiency of the heat cycle;

_a fifth functional configuration (seei figure 12) regarding the new “closed” operating cycle, where the thermal fluid (normally air) is supplemented with an injection of aqueous superheated vapour which, in addition to lubrication of the cylinder where the Ipistons slide and a significant increase in the unit power of the drive unit, enables a major improvement in the overall efficiency of the heat cycle and also enables complété heat-energy recovery of the fluids in circulation.

It should be noted first of ail that the gas preferably used as a thermal fluid is common “air”; however, without préjudice to the inventive idea, any other gas that is better suited and more compatible with aqueous vapour can be used, as is presented and described below.

It is also useful to point out that, in the rest condition, the thermal fluids used (normally air and water) are at the same température as the surrounding environment and that in closed-circuit solutions, inside the cylinder and pipes, a pressure other than atmospheric pressure could also be chosen where appropriate.

In its completeness, the new heat cycle is carried out, in a continuous mode, in a number of steps of thermodynamic variation of the fluid: introduction, compression, heating, vaporization, superheating, expansion (which produces useful work), expulsion, and condensation, as described below for the five main configurations of the heat machine 'according to the présent invention, which are given by way of non-limiting example.

The most complété functional configuration of the heat machine, represented in figure 12, relates to a heat machine (121), comprising a drive unit (1) in accordance with one or more of the preceding aspects, configured to realize a new thermodynamic cycle, conventionally defined as a pulsating heat cycle, characterized by the use of a thermal fluid, preferably composed of air and distilled water, suitably heated, vaporized and superheated before of its expansion in the drive unit 1, in order to obtain a considérable increase in the unit power, a considérable increase in the overall efficiency and an efficient lubrication of the cylinder/piston System with aqueous vapour.

In this configuration, where the start of the cycle is made to coïncide with the suction of cooled air, the heat machine comprises:

- a cooler (43), adapted to extract heat from the thermal fluid in circulation, in order to cool it and increase the mass of air that will then be suctioned/compressed in the unit (1);

- a four- or six-piston drive unit (1), having functions of “compressing” and “expanding” the circulating thermal fluid;

- a compensation tank” (44) provided with suitable check valves, adopted to optimize the “pulsating” circulation of the compressed thermal fluid;

- a “regenerator” (42), adapted to extract heat from the exhausted thermal fluid which is expelled from the unit (1) to preheat the thermal fluid, which will then be heated;

- an “evaporator” (95), adapted to transform the condensed water in vapour, extracting further energy from the exhausted thermal fluid which has already passed through the regenerator (42);

_ a “superheater” (96) which, by extracting energy from the hot combustion fumes, is capable of superheating the saturated vapour exiting from the “evaporator” (95) so as to provide it with energy, with a considérable advantage for the heat cycle;

- a “heater” (41), which has the purpose of heating the circulating thermal fluid so as to provide it with the thermal energy necessary for the subséquent active expansion step, which produces work;

- a discharger/separator (93), adapted to condense the aqueous vapour in circulation, so as to be able to reuse it in a continuous mode;

- a high pressure pump (94), adapted to recirculate the condensed water;

- an “injector” (97), adapted to bring about the best conditions for the introduction of the superheated vapour into the circuit;

_an “exchanger” (98), a pump (99), a first “recuperator” (100), a second recuperator (101), adapted to maintain the drive unit (1) at an idéal operating température and to recover further energy from the combustion fumes, prior to their discharge into the atmosphère.

In particular, the motion of the circulating fluid in the heat machine is conditioned by the rotary movement of the pistons, which, by bringing about the opening/closing of the inlet/discharge openings, generate the very particular high-frequency pulsating effect that characterizes this new heat cycle. For example, a rotation speed of 1,000 rpm of the primary shaft corresponds to exactly 100 puises per second of the circulating thermal fluid).

Description ofthe diagrams and drawings

With reference to the accompanying diagrams and drawings, it is noted that the same are provided solely by way of illustration and not by way of limitation; in them:

figure 1 shows a schematic front view of a drive unit utilizable in the présent invention;

figure 2a illustrâtes a side sectional view of the central body of the drive unit of figure 1 ;

figure 2b is a side sectional view bf a variant of the central body of the drive unit of figure 1, with a section of the motion transmission System;

figure 3 illustrâtes a front view of the train of three-lobe gears forming part of the motion transmission System of the drive unit of figure 1 ;

figure 4 illustrâtes the operating diagram of the closed-circuit Ericsson cycle carried out with an engine provided with pistons with reciprocating motion;

figure 5 illustrâtes the operating diagram of a heat machine with a closed-circuit Joule cycle carried out with a single-shaft turbine;

figure 6 schematically illustrâtes a first possible embodiment of a heat machine according to the présent invention in an “open-circuit” configuration characterized by the use of a thermal fluid composed of air with the injection of water;

figure 7 schematically illustrâtes a second possible embodiment of a heat machine according to the présent invention, in a “closed-circuit” configuration, characterized by the use of a thermal fluid composed of air with the injection of condensate of aqueous vapour;

figure 8 schematically illustrâtes a third possible embodiment of a heat machine according to the présent invention, in a “closed-circuit” configuration, characterized by the use of a thermal fluid composed of air with the injection of saturated aqueous vapour;

figure 9 illustrâtes a functional diagram that shows the energy recovery obtainable through the vaporization of condensed water;

figure 10 illustrâtes a functional diagram that shows the increase in energy obtainable through the vaporization of condensed water and with the use of superheated aqueous vapour in the cycle;

figure 11 schematically illustrâtes a fourth possible embodiment of a heat machine according to the présent invention, in a “closed-circuit” configuration, characterized by the use of a thermal fluid composed of air with the injection of superheated aqueous vapour;

figure 12 schematically illustrâtes a fifth possible embodiment of a heat machine according to the présent invention, in a “closed-circuit” configuration, characterized by the use of a thermal fluid composed of air with the injection of superheated aqueous vapour and provided with an energy recovery System with thermal stabilization ofthe drive unit;

figure 13 shows an enlargement of a portion of the heat machine according to the présent invention; this portion is identical for the configurations shown in figures 6, 7, 8,11 and 12.

Detailed description ofthe drive unit employed in the heat machine

With reference to figures 1, 2a, 2b, 3, (1) dénotés in its entirety the “drive unit” employed as “compressor/expander” in a new “pulsating heat cycle” operating preferably with hot air and aqueous vapour.

The drive unit 1 comprises a casing 2 which internally delimits a seat 3.

In the non-limiting embodiment illustrated, the casing 2 is made up of two half-parts 2a, 2b joined together.

Housed in the seat 3 there is a first rotor 4 and a second rotor 5, which rotate around a same axis “XX.

The first rotor 4 has a first cylindrical body 6 and three first éléments 7a, 7b, 7c which extend radially from the first cylindrical body 6 and are rigidly connected or intégral therewith.

The second rotor 5 has a second cylindrical body 8 and three second éléments 9a, 9b, 9c which extend radially from the second cylindrical body 8 and are rigidly connected or intégral therewith.

The éléments 7a, 7b, 7c of the rotor 4 are angularly équidistant from one another, i.e. each element is spaced apart from the adjacent element on average by an angle “a” of 120° (measured between the planes of symmetry of each element).

The éléments 9a, 9b, 9c of the rotor 5 are angularly équidistant from one another, i.e. each element is spaced apart from the adjacent element on average by an angle “a” of 120° (measured between the planes of symmetry of each element).

The first and second cylindrical bodies 6, 8 are set side by side at respective bases 10, 11 and are coaxial.

The three first éléments 7a, 7b, 7c of the first rotor 4 moreover extend along an axial direction and hâve a projecting portion disposed in a position that is radially external to the second cylindrical body 8 of the second rotor 5.

The three second éléments 9a, 9b, 9c of the second rotor 5 moreover extend along an axial direction and hâve a projecting portion disposed in a position that is radially external to the first cylindrical body 6 of the first rotor4.

The three first éléments 7a, 7b, 7c are alternated with the three second éléments 9a, 9b, 9c along the circumferential extent of the annular chamber 12.

Each of the first and second éléments 7a, 7b, 7c, 9a, 9b, 9c has, in a radial section (figure 1), a substantially trapézoïdal profile which converges toward the rotation axis X-X and, in a axial section (figure 2a,2b), a substantially circular or rectangular profile.

Each of the first and second éléments 7a, 7b, 7c, 9a, 9b, 9c has an angular size, given purely by way of approximation and not by way of limitation, of about 38°.

Peripheral surfaces that are radially external to the first and second cylindrical bodies 6, 8 delimit, together with an inner surface of the seat 3, an annular chamber 12.

The annular chamber 12 is therefore divided into variable-volume rotating chambers 13', 13, 13', 14', 14, 14' by the first and second éléments 7a, 7b, 7c, 9a, 9b, 9c. In particular, each variable-volume rotating chamber is delimited (besides by the surface radially internai to the casing 2 and the surface radially external to the cylindrical bodies 6, 8) by one of the first éléments 7a, 7b, 7c and one of the second éléments 9a, 9b, 9c.

In the first figure 2a, each of the first and second éléments 7a, 7b, 7c, 9a, 9b, 9c has, in an axial section thereof, a substantially circular profile and the annular chamber 12 likewise has a circular cross section defined as “toroidal”.

In the variant in figure 2b, each of the first and second éléments 7a, 7b, 7c, 9a, 9b, 9c has, in a axial section thereof, a rectangular (or square) profile and the annular chamber 12 likewise has a rectangular (or square) cross section.

Between inner walls of the annular chamber 12 and each of the aforesaid first and second éléments 7a, 7b, 7c, 9a, 9b, 9c there remains an interspace such as to permit the rotary movement of the pistons 4, 5 and sliding of the éléments 7a, 7b, 7c, 9a, 9b, 9c in the chamber 12 itself.

The first and second éléments 7a, 7b, 7c, 9a, 9b, 9c are the pistons of the drive unit 1 illustrated and the variable-volume rotating chambers 13', 13, 13', 14', 14, 14' are the chambers for the compression and/or expansion of the working fluid of said drive unit 1.

The inlet or discharge openings 15', 16', 15, 16, 15', 16' (of suitable size and shape) are fashioned in a wall radially external to the casing 2; they open into the annular chamber 12 and are in fluid communication with conduits external to the annular chamber 12, illustrated further below.

Each inlet or discharge opening 15', 16', 15, 16, 15', 16' is angularly spaced in an appropriate way so as to adapt to the requirements of each different individual functional configuration of the drive unit 1.

The drive unit 1 further comprises a primary shaft 17 parallel to and distanced from the rotation axis X-X and rotatably mounted on the casing 2 and a transmission 18 mechanically interposed between the primary shaft 17 and the rotors 4, 5.

The transmission 18 comprises a first auxiliary shaft 19 onto which the first rotor 4 is keyed and a second auxiliary shaft 20 onto which the second rotor 5 is keyed. The first and second auxiliary shafts 19, 20 are coaxial with the rotation axis X-X. The second auxiliary shaft 20 is tubular and houses within it a portion of the first auxiliary shaft 19. The first auxiliary shaft 19 can rotate in the second auxiliary shaft 20 and the second auxiliary shaft 20 can rotate in the casing 2.

A first three-lobe gear 23 is keyed onto the primary shaft 17. A second three-lobe gear 24 is keyed onto the primary shaft 17 next to the first. The second three-lobe gear 24 is mounted on the primary shaft 17 angularly offset relative to the first three-lobe gear 23 by an angle Δ of 60°. The two three-lobe gears 23 and 24 rotate together jointly with the primary shaft 17.

A third three-lobe gear 25 is keyed onto the first auxiliary shaft 19 (so as to rotate integrally therewith) and the teeth thereof precisely enmesh with the teeth of the first three-lobe gear 23.

A fourth three-lobe gear 26 is keyed onto the second auxiliary shaft 20 (so as to rotate integrally therewith) and the teeth thereof precisely enmesh with the teeth of the second three-lobe gear 24.

Each of the above-mentioned three-lobe gears 23, 24, 25, 26 has approximately the profile of an équilatéral triangle with rounded vertices 27 and connecting portions 28, interposed between the vertices 27, which can be concave, fiat or convex.

Changing the shape of the vertices 27 and connecting portions 28 of the gears makes it possible to pre-establish the value of the angular periodic movement of the auxiliary shafts 19, 20 during their rotary motion.

The structure of the transmission 18 is such that during a complété révolution of the primary shaft 17 the two rotors 4, 5 also carry out a complété révolution, but with periodically variable angular velocities, offset from each other, which induce the adjacent pistons 7a, 9a; 7b, 9b; 7c, 9c to move away and toward one another three times during a complété 360° révolution. Therefore, each of the six variable-volume chambers

13', 13, 13', 14', 14, 14' expands three times and contracts three times at each complété révolution of the primary shaft 17.

In others words, pairs of adjacent pistons of the six pistons 7a, 7b, 7c; 9a, 9b, 9c are movable, during their rotation at a periodically variable angular velocity in the annular chamber 12, between a first position, in which the two faces of the adjacent pistons lie substantially next to each other, and a second position, in which the same faces are angularly spaced apart by the maximum allowed. Purely by way of example, in the first position the two faces of the adjacent pistons are angularly spaced apart from each other by about 1 °, whereas in the second position the two same faces are angularly spaced apart from each other by about 81°.

The six variable-volume chambers 13', 13, 13', 14', 14, 14' are made up of a first group of three chambers 13', 13, 13' and a second group of three chambers 14’, 14”, 14”’. When the three chambers 13', 13, 13' of the first group hâve the minimum volume (pistons next to each other at the minimum reciprocal distance) the other three chambers 14', 14, 14' (of the second group) hâve the maximum volume (pistons at the maximum reciprocal distance).

For the purpose of better clarifying and highlighting the innovative aspects of the présent invention, the five main functional configurations will be described below in a précisé and detailed manner.

In order to describe the operation of the new heat machine (121), configured to operate with a “pulsating heat cycle according to the présent invention, it is necessary to start off by noting that in the drive unit (1), in each of the six periodically variable-volume chambers (13',13,13',14',14,14'), each delimited by the two pistons adjacent to each other and rotating inside the annular cylinder, the diversified suction, compression, expansion and expulsion functions are performed periodically.

Figure 13 shows an enlargement of a portion of the heat machine according to the présent invention; this portion relates to the drive unit émployed, identically, in the five configurations that are shown in figures 6, 7, 8, 11 and 12, and are the subject matter of the following five descriptions (A, B, C, D, E). The reference numbers included in figure 13, used to identify éléments of the drive unit 1 and its connection to the components of the heat machine 121, are applicable to the corresponding éléments shown in figures 6, 7, 8, 11 and 12.

For the sake of simplicity, in the following five descriptions (A, B, C, D, E), the path followed by the thermal fluid in the different sections of the heat engine (121) will be explained as if a single complété heat cycle were involved. In reality, for each révolution of the drive shaft (corresponding to a révolution angle of 360°) no fewer than six complété heat cycles are carried out.

A. Detailed description of the heat machine 121 operating according to the functional configuration represented in the figure 6.

Compared to the Joule-Ericsson cycles on their own and the sole drive unit”, the novelty introduced with this configuration regards the realization of a combined” operating cycle, where the thermal fluid is a mixture of air and water (transformed into vapour); this ensures the lubrication of the cylinder (where the pistons slide) and enables a higher unit power to be obtained, albeit with a slight decrease in overall efficiency.

With reference to figure 6, in the position where the pistons are located, the following main steps of the cycle can be identified:

A1_Setting into motion.

Noting first of ail that ail control and regulating devices are powered via a spécifie auxiliary electric line (not represented), the start-up of the heat machine 121 takes place in the following manner:

Jhe primary shaft 17 (visible in figure 2b) and the whole transmission System that moves the six pistons 7a,7b,7c,9a,9b,9c are set in rotation via the starter motor, thus creating the preliminary condition for start-up of the cycle;

Jhe metering pump for metering distilled water 97b is activated;

Jhe fan 92 is activated;

Jhe burner is activated by acting on the régulation valve 91 (which contrais the injection of fuel F) 40 and the combustion process is started;

_when the circulating thermal fluid has reached the predetermined minimum operating condition, the drive unit 1 will be capable of producing the work necessary in order to be able to run autonomously.

A2_Start ofthe cycle, sterling from the step ofsuctioning ambient air.

The air suctioned from the environment at température TT, passes into the pipe 93, passes through the suctioning opening 15' and, following the movement of the two pistons 9c-7c away from each other, it is suctioned into the chamber 13'.

A3_Step of compression and recovery ofthe suctioned air.

Following the movement of the two pistons 7c-9a towards each other, the previously suctioned air is compressed in the chamber 14”' (up to the limit, which is normally preset with a minimum ratio of 1:4 and a maximum ratio of 1:20), undergoes an increase in température from TT to T2, passes through the discharge opening 16', the pipe 44' and the check valve 44a and ends up in the compensation tank 44, where it remains available for immédiate use.

A4_Step of preheating the compressed thermal fluid.

With the intermittency determined by the rotation of the pistons and the resulting opening/closing of the inlet openings 15 J 5”, the air flows out from the tank 44, passes through the pipe 44” and the check valve 44b, travels through the pipe 44”’, and passes into the regenerator 42 (where it undergoes an increase in température from T2 to T2j.

A5_Step of injecting distilled water into the air conduit.

The air, exiting from the regenerator 42, travels through the pipe 42’, passes through the check valve 42a and passes into the pipe 42’”.

The distilled water is drawn from the tank 97a, travels through the pipe 97”, is brought to a high pressure in the metering pump 97b and, at température Te, is conveyed into the pipe 97”’ and, by means of the injector 97, it is introduced into the pipe 42”’ where, as a resuit of mixing, the mixture thus formed undergoes a decrease in température from T2' to T2”.

A6_Step of superheating the circulating thermal fluid.

The mixed thermal fluid travels through the pipe 97’, passes through the heater 41 (adjacent to the combustion chamber 40A and provided with the multi-fuel burner 40), where it receives heat-energy and increases in température from T2” to T3.

A7_Step of expanding the superheated thermal fluid andproducing useful work.

When the pistons 7a-7b, by rotating in the annular cylinder in the direction of motion indicated by the arrows, open the inlet openings 15’-15”, the superheated thermal fluid flowing through the pipes 4Τ-4Γ-4Τ is introduced into the expansion chambers 13' and 13”, where it is expanded (decreasing in température from T3 to T4) and, by making the pistons rotate, produces useful work.

A8_Step of expulsion and ofrecovering energy from the exhausted thermal fluid.

Following the movement of the pistons 7a-9b and 7b-9c towards each other, the chambers 14’ and 14 diminish in volume, the exhausted thermal fluid (already expanded in the previous cycle) is expelled from the drive unit 1, passes through the two discharge openings 16-16, flows through the pipes 45'-45-45’”, passes through the regenerator 42 (where it surrenders part of the energy-heat still possessed and undergoes a decrease in température from T4 to T4’) and then, on passing through the pipe 42”, is discharged into the atmosphère, the heat cycle thus being concluded.

A9_Recovery of energy with a réduction in the température ofthe combustion fumes.

Given that the function envisaged for the heat machine is also to provide energy-heat to be destined to auxiliary uses (space heating and/or production of domestic hot water, etc.), before the hot fumes are discharged into the atmosphère (through the conduit 102), ail their residual energy is recovered by reducing their température as much as possible (it also being possible to recover further energy through their possible condensation). To achieve this purpose, use is made of a spécifie hydraulic circuit, where the following mode of conveyance is adopted: the incoming thermal fluid (normally water) from the auxiliary uses 103 passes into the pipe 103’ and, pushed by the circulation pump 104, passes into the pipe 104’, reaches the recuperator 101 at the low température Tf and then, on passing through it, thanks to the réduction in the température of the fumes S from Th7 to Th2, acquires energy-heat and heats up to the higher température Tg, so as to be made available, via the pipe 101’, for the auxiliary uses 130, and for the intended purpose.

B. Detailed description of the heat machine 121 operating according to the functional configuration represented in figure 7.

Compared to the Joule-Ericsson cycles on their own and the sole “drive unit”, the novelty introduced with this configuration regards the realization of a “combined” operating cycle, where the thermal fluid is a mixture of air and water (transformed into vapour); this ensures the lubrication of the cylinder (where the pistons slide) and enables a higher unit power to be obtained, albeit with a slight decrease in overall efficiency.

With reference to figure 7, in the position where the pistons are located, the following main steps of the cycle can be identified:

B1_Setting into motion the heat machine 121.

Noting first of ail that ail cohtrol and regulating devices are powered via a spécifie auxiliary electric line (not represented), the start-up of the heat machine 121 takes place in the following manner:

_the primary shaft 17 (visible in figure 2b) and the whole transmission System that moves the six pistons 7a,7b,7c,9a,9b,9c are set in rotation via the starter motor, thus creating the preliminary condition for start-up of the cycle;

_the condensate water pump 94 is activated;

_the fan 92 is activated;

_the burner 40 is activated by acting on the régulation valve 91 (which contrais the injection of fuel F) and the combustion process is started;

_when the circulating thermal fluid has reached the predetermined minimum operating condition, the drive unit 1 will be capable of producing the work necessary in order to be able to run autonomously.

B2_Start of the cycle, starting from the step ofsuctioning the cooled thermal fluid.

The thermal fluid, exiting from the cooler 43 at température T1, passes into the pipe 43', passes through the condensate trap 93 (where the water in the thermal fluid is condensed and separated from the air), passes into the pipe 93’ at température TT, passes through the suctioning opening 15' and, following the movement of the two pistons 9c-7c away from each other, is suctioned into the chamber 13'.

B3_Step of compression and recovery ofthe suctioned thermal fluid.

Following the movement of the two pistons 7c-9a towards each other, the previously suctioned air is compressed in the chamber 14'” (up to the limit, which is normally preset with a minimum ratio of 1:4 and a maximum ratio of 1:20), undergoes an increase in température from TT to T2, passes through the discharge opening 16', the pipe 44' and the check valve 44a and ends up in the compensation tank 44, where it remains available for immédiate use.

B4_Step of preheating the compressed thermal fluid.

With the intermittency determined by the rotation of the pistons and the resulting opening/closing of the inlet openings 15’,15”, the air flows out from the tank 44, passes through the pipe 44” and the check valve 44b, travels through the pipe 44'”, and passes into the regenerator 42 (where it undergoes an increase in température from T2 to T2’).

B5_Step ofdrawing condensate water.

Pushed by the high pressure pump 94, the condensate water previousiy extracted from the air by the trap 93, flows through the pipes 93” and 94’ (at température T1 ”).

B6_Step ofinjecting the condensate water into the air conduit.

The air, exiting from the regenerator 42, travels through the pipe 42’, passes through the check valve

42a and passes into the pipe 42’” where, via the injector 97, the condensate water is introduced. As a resuit of the mixing of the air with the condensate water, the mixture undergoes a decrease in température from T2’ to T2”.

B7_Step of superheating the circulating thermal fluid.

¹⁰ The mixed thermal fluid travels through the pipe 97, passes through the heater 41 (adjacent to the combustion chamber 40A and provided with the multi-fuel burner 40), where it receives heat-energy and increases in température from T2” to T3.

B8_Step of expanding the superheated thermal fluid and producing useful work.

When the pistons 7a-7b, by rotating in the annular cylinder in the direction of motion indicated by the 15 arrows, open the inlet openings 15’-15”, the superheated thermal fluid flowing through the pipes 4T-41-4T is introduced into the expansion chambers 13' and 13”, where it is expanded (decreasing in température from T3 to T4) and, by making the pistons rotate, produces useful work.

B9_Step of expulsion and of recovèring energy from the exhausted thermal fluid.

Following the movement ofthe pistons 7a-9b and 7b-9c towards each other, the chambers 14' and 14 20 diminish in volume, the exhausted thermal fluid (already expanded in the previous cycle) is expelled from the drive unit 1, passes through the two discharge openings 16-16, flows through the pipes 45'-45-45’”, passes through the regenerator 42 (where it surrenders part of the energy-heat still possessed and undergoes a first decrease in température from T4 to T4’).

B10_Conclusion ofthe cycle with further cooling ofthe exhausted thermal fluid.

²⁵ The thermal fluid passes into the pipe 42” and reaches the cooler 43, from where the cycle can continue and repeat itself in a continuous mode.

B11_Recovery of energy with the optimization ofthe process ofpreheating the combustion air.

The combustion air drawn from the environment is pushed by the fan 92 and passes into the cooler 43, where it acquires energy and increases in température from Th1 to Th3, thus facilitating the combustion 30 process.

B12_Recovery of energy with a réduction in the température ofthe combustion fumes.

Given that the function envi^aged for the heat machine is also to provide energy-heat to be destined to auxiliary uses (space heating and/or production of domestic hot water, etc.), before the hot fumes are discharged into the atmosphère (through the conduit 102), ail their residual energy is recovered by reducing their température as much as possible (it also being possible to recover further energy through their possible condensation). To achieve this purpose, use is made of a spécifie hydraulic circuit, where the following mode of conveyance is adopted: the incoming thermal fluid (normally water) from the auxiliary uses 103 passes into the pipe 103’ and, pushed by the circulation pump 104, passes into the pipe 104’, reaches the recuperator 101 at the low température Tf and then, on passing through it, thanks to the réduction in the température of the fumes S from Th7 to Th2, acquires energy-heat and heats up to the higher température Tg, so as to be made available, via the pipe 101’, for the auxiliary uses 130, and for the intended purpose.

C. Detailed description of the heat machine 121 operating according to the functional configuration represented in figure 8.

Compared to the Joule-Ericsson cycles on their own and the sole “drive unit”, the novelty introduced with this configuration regards the realization of a “combined” operating cycle, where the thermal fluid is a mixture of air and water (transformed into vapour); this ensures the lubrication of the cylinder (where the pistons slide) and enables a higher unit power to be obtained and an improvement in the overall efficiency.

With reference to figure 8, in the position where the pistons are located, the following main steps of the cycle can be identified:

C1_Setting into motion the heat machine 121.

Noting first of ail that ail control and regulating devices are powered via a spécifie auxiliary electric line (not represented), the start-up of the heat machine 121 takes place in the following manner:

_the primary shaft 17 (visible in figure 2b) and the whole transmission System that moves the six pistons 7a,7b,7c,9a,9b,9c are set in rotationl via the starter motor, thus creating the preliminary condition for start-up of the cycle;

_ the condensate water pump 94 is activated;

_thefan 92 is activated;

_the burner 40 is activated by acting on the régulation valve 91 (which contrais the injection of fuel F) and the combustion process is started;

_when the circulating thermal fluid has reached the predetermined minimum operating condition, the drive unit 1 will be capable of producing the work necessary in order to be able to run autonomously.

C2_Start of the cycle, starting from the step ofsuctioning the cooled thermal fluid.

The thermal fluid, exiting from the cooler 43 at température T1, passes into the pipe 43', passes through the condensate trap 93 (where the water in the thermal fluid is condensed and separated from the air), passes into the pipe 93’ at température T1’, passes through the suctioning opening 15¹ and, following the movement of the two pistons 9c-7c away from each other, is suctioned into the chamber 13’.

C3_Step of compression and recovery ofthe suctioned thermal fluid.

Following the movement of the two pistons 7c-9a towards each other, the previously suctioned air is compressed in the chamber 14”’ (up to the limit, which is normally preset with a minimum ratio of 1:4 and a maximum ratio of 1:20), undergoes an increase in température from TT to T2, passes through the discharge opening 16', the pipe 44' and the check valve 44a and ends up in the compensation tank 44, where it remains available for immédiate use.

C4_Step ofpreheating the compressed thermal fluid.

With the intermittency determined by the rotation of the pistons and the resulting opening/closing of the inlet openings 15’, 15”, the air flows out from the tank 44, passes through the pipe 44” and the check valve 44b, travels through the pipe 44”’, and passes into the regenerator 42 (where it undergoes an increase in température from T2 to T2’).

C5_Step of vaporizing/superheating the condensate water.

Pushed by the high pressure pump 94, the condensate water previously extracted from the air by the trap 93, flows through the pipes 93” and 94’, passes through the evaporator 95, where it is heated/vaporized (changing in State from a liquid to a vapour, with an increase in température from T1” to Ta).

C6_Step of injecting the saturated vapour into the air conduit.

The air, exiting from the regenerator 42, travels through the pipe 42’, passes through the check valve 42a and passes into the pipe 42’” where, via the injector 97, the saturated vapour conveyed in the pipe 95’ is introduced. As a resuit of the mixing of the air with the saturated vapour, the thermal fluid undergoes an increase in mass and decrease in température from T2' to T2”.

C7_Step of superheating the circulating thermal fluid.

The mixed thermal fluid travels through the pipe 97', passes through the heater 41 (adjacent to the combustion chamber 40A and provided with the multi-fuel burner 40), where it receives heat-energy and increases in température from T2” to T3.

C8_Step of expanding the superheated thermal fluid and producing useful work.

When the pistons 7a-7b, by rotating in the annular cylinder in the direction of motion indicated by the arrows, open the inlet openings 15’-15”, the superheated thermal fluid flowing through the pipes 4Τ-4Γ-4Τ is introduced into the expansion chambers 13' and 13”, where it is expanded (decreasing in température from T3 to T4) and, by making the pistons rotate, produces useful work.

C9_Step of expulsion and ofrecovering energy from the exhausted thermal fluid.

Following the movement of the pistons 7a-9b and 7b-9c towards each other, the chambers 14' and 14 diminish in volume, the exhausted thermal fluid (already expanded in the previous cycle) is expelled from the drive unit 1, passes through the two discharge openings 16'-16, flows through the pipes 45'-45-45’”, passes through the regenerator 42 (where it surrenders part of the energy-heat still possessed and undergoes a first decrease in température from T4 to T4'), then passes into the pipe 42”, passes through the evaporator 95, where it again surrenders part of the energy-heat possessed and undergoes a second decrease in température from T4’ to T4”, enabling the recovery of useful energy, which is schematically represented in the area Q95 in figure 9.

C10_Conclusion of the cycle with further cooling of the exhausted thermal fluid.

The thermal fluid passes into the pipe 95” and reaches the cooler 43, from where the cycle can continue and repeat itself in a continuous mode.

C11 _Recovery of energy with the optimization ofthe process ofpreheating the combustion air.

The combustion air drawn from the environment is pushed by the fan 92 and passes into the cooler 43, where it acquires energy and increases in température from Th1 to Th3, thus facilitating the combustion process.

C12_Recovery of energy with a réduction in the température ofthe combustion fumes.

Given that the function envisaged for the heat machine is also to provide energy-heat to be destined to auxiliary uses (space heating and/or production of domestic hot water, etc.), before the hot fumes are discharged into the atmosphère (through the conduit 102), ail their residual energy is recovered by reducing their température as much as possible (it also being possible to recover further energy through their possible condensation). To achieve this purpose, use is made of a spécifie hydraulic circuit, where the following mode of conveyance is adopted: the incoming thermal fluid (normally water) from the auxiliary uses 103 passes into the pipe 103’ and, pushed by the circulation pump 104, passes into the pipe 104’, reaches the recuperator 101 at the low température Tf and then, on passing through it, thanks to the réduction in the température of the fumes S from Th7 to Th2, acquires energy-heat and heats up to the higher température Tg, so as to be made available, via the pipe 101’, for the auxiliary uses 130, and for the intended purpose.

D. Detailed description of the heat machine 121 operating according to the functional configuration represented in figure 11.

Compared to the Joule-EricSson cycles on their own and the sole “drive unit”, the novelty introduced with this configuration regards the realization of a “combined” operating cycle, where the thermal fluid is a mixture of air and water (transformed into superheated vapour); this ensures the lubrication of the cylinder (where the pistons slide) and enables a higher unit power to be obtained and an improvement in the overall efficiency.

With reference to figure 11, in the position where the pistons are located, the following main steps of the cycle can be identified:

D1_Setting into motion the heat machine 121.

Noting first of ail that ail control and regulating devices are powered via a spécifie auxiliary electric line (not represented), the start-up of thefteat machine 121 takes place in the following manner:

Jhe primary shaft 17 (visible in figure 2b) and the whole transmission System that moves the six pistons 7a,7b,7c,9a,9b,9c are set in rotation via the starter motor, thus creating the preliminary condition for start-up of the cycle;

Jhe condensate water pump 94 is activated;

Jhe fan 92 is activated;

Jhe burner 40 is activated by acting on the régulation valve 91 (which contrais the injection of fuel F) and the combustion process is started;

_when the circulating thermal fluid has reached the predetermined minimum operating condition, the drive unit 1 will be capable of producing the work necessary in order to be able to run autonomously.

D2_Start of the cycle, starting from the step of suctioning the cooled thermal fluid.

The thermal fluid, exiting from the cooler 43 at température T1, passes into the pipe 43', passes through the condensate trap 93 (where the water in the thermal fluid is condensed and separated from the air), passes into the pipe 93’ at température TT, passes through the suctioning opening 15' and, following the movement of the two pistons 9c-7c away from each other, is suctioned into the chamber 13'.

D3_Step of compression and recovery ofthe suctioned thermal fluid.

Following the movement of the two pistons 7c-9a towards each other, the previously suctioned air is compressed in the chamber 14'” (up to the limit, which is normally preset with a minimum ratio of 1:4 and a maximum ratio of 1:20), undergoes an increase in température from TT to T2, passes through the discharge opening 16', the pipe 44' and the check valve 44a and ends up in the compensation tank 44, where it remains available for immédiate use.

D4_Step ofpreheating the compressed thermal fluid.

With the intermittency determined by the rotation of the pistons and the resulting opening/closing of the inlet openings 15’,15”, the air flows out from the tank 44, passes through the pipe 44” and the check valve 44b, travels through the pipe 44’”, and passes into the regenerator 42 (where it undergoes an increase in température from T2 to T2’).

D5_Step of vaporizing/superheating the condensate water.

Pushed by the high pressure pump 94, the condensate water previously extracted from the air by the trap 93, flows through the pipes 93” and 94’, passes through the evaporator 95, where it is heated/vaporized (changing in state from a liquid to a vapour, with an increase in température from T1” to Ta), travels through the pipe 95', passes through the superheater 96 (where acquires further energy and increases in température from Ta to Tb).

D6_Step ofinjecting the superheated vapour into the air conduit.

The air, exiting from the regenerator 42, travels through the pipe 42', passes through the check valve 42a and passes into the pipe 42’” where, via the injector 97, the superheated vapour conveyed in the pipe 96’ is introduced. As a resuit of the mixing of the air with the superheated vapour, the thermal fluid undergoes an increase in energy and increases in température from T2' to T2”, enabling the recovery of useful energy, which is schematically represented in the area Q96 in figure 10.

D7_Step of superheating the circulating thermal fluid.

The mixed thermal fluid travels through the pipe 97’, passes through the heater 41 (adjacent to the combustion chamber 40A and provided with the multi-fuel burner 40), where it receives heat-energy and increases in température from T2” to T3.

D8_Step of expanding the superheated thermal fluid and producing useful work.

When the pistons 7a-7b, by rotating in the annular cylinder in the direction of motion indicated by the arrows, open the inlet openings 15’-15”, the superheated thermal fluid flowing through the pipes 4T-41 -4T is introduced into the expansion chambers 13' and 13”, where it is expanded (decreasing in température from T3 to T4) and, by making the pistons rotate, produces useful work.

D9_Step of expulsion and ofrecovering energy from the exhausted thermal fluid.

Following the movement of the pistons 7a-9b and 7b-9c towards each other, the chambers 14' and 14 diminish in volume, the exhausted thermal fluid (already expanded in the previous cycle) is expelled from the drive unit 1, passes through the two discharge openings 16-16, flows through the pipes 45'-45-45’”, passes through the regenerator 42 (where it surrenders part of the energy-heat still possessed and undergoes a first decrease in température from T4 to T4’), then passes into the pipe 42”, passes through the evaporator 95, where it again surrenders part of the energy-heat possessed and undergoes a second decrease in température from T4’ to T4”, enabling the recovery of useful energy, which is schematically represented in the area Q95 in figure 10.

D10_Conclusion of the cycle with further cooling of the exhausted thermal fluid.

The thermal fluid passes into the pipe 95” and reaches the cooler 43, from where the cycle can continue and repeat itself in a continuous mode.

D11 _Recovery of energy with the optimization ofthe process ofpreheating the combustion air.

The combustion air drawn from the environment is pushed by the fan 92 and passes into the cooler 43, where it acquires energy and increases in température from Th1 to Th3, thus facilitating the combustion process.

D12_Recovery of energy with a réduction in the température ofthe combustion fumes.

Given that the function envisaged for the heat machine is also to provide energy-heat to be destined to auxiliary uses (space heating and/or production of domestic hot water, etc.), before the hot fumes are discharged into the atmosphère (through the conduit 102), they are first made to pass through the superheater 96 (where their température is reduced from Th7 to Th6) and then ail their residual energy is recovered by reducing their température as much 'as possible (it also being possible to recover further energy through their possible condensation). To achieve this purpose, use is made of a spécifie hydraulic circuit, where the following mode of conveyance is adopted: the incoming thermal fluid (normally water) from the auxiliary uses 103 passes into the pipe 103’ and, pushed by the circulation pump 104, passes into the pipe 104’, reaches the recuperator 101 at the low température Tf and then, on passing through it, thanks to the réduction in the température of the fumes S from Th6 to Th2, acquires energy-heat and heats up to the higher température Tg, so as to be made available, via the pipe 101 ’, for the auxiliary uses 130, and for the intended purpose.

E. Detailed description of the heat machine 121 operating according to the most complété functional configuration, represented in figure 12.

Compared to the Joule-Ericsson cycles on their own and the sole “drive unit”, the novelty introduced with this configuration regards the realization of a “combined” operating cycle, where the thermal fluid is a mixture of air and water (transformed into superheated vapour); this ensures the lubrication of the cylinder (where the pistons slide) and enables a higher unit power to be obtained and a considérable improvement in the overall efficiency.

With reference to figure 12, in the position where the pistons are located, the following main steps of the cycle can be identified:

E1_Setting into motion the heat machine 121.

Noting first of ail that ail control and regulating devices are powered via a spécifie auxiliary electric line (not represented), the start-up of the heat machine 121 takes place in the following manner:

Jhe primary shaft 17 (visible in figure 2b) and the whole transmission System that moves the six pistons 7a,7b,7c,9a,9b,9c are set in rotation via the starter motor, thus creating the preliminary condition for start-up of the cycle;

_the condensate water pump 94 is activated;

Jhe water pump 99 is electrically powered up;

Jhe fan 92 is activated;

Jhe burner 40 is activated by acting on the régulation valve 91 (which contrais the injection of fuel F) and the combustion process is started;

_when the circulating thermal fluid has reached the predetermined minimum operating condition, the drive unit 1 will be capable of producing the work necessary in order to be able to run autonomously.

E2_Start of the cycle, starting from the step ofsuctioning the cooled thermal fluid.

The thermal fluid, exiting from the cooler 43 (at température T1), passes into the pipe 43', passes through the condensate trap 93 (where the water in the thermal fluid is condensed and separated from the air), passes into the pipe 93’ at température TT, passes through the suctioning opening 15' and, following the movement of the two pistons 9c-7c away from each other, is suctioned into the chamber 13'.

E3_Step of compression and recovery ofthe suctioned thermal fluid.

Following the movement of the two pistons 7c-9a towards each other, the previously suctioned air is compressed in the chamber 14”' (up to the limit, which is normally preset with a minimum ratio of 1:4 and a maximum ratio of 1:20), undergoes an increase in température from TT to T2, passes through the discharge opening 16', the pipe 44' and the check valve 44a and ends up in the compensation tank 44, where it remains available for immédiate use.

E4_Step of preheating the compressed thermal fluid.

With the intermittency determined by the rotation of the pistons and the resulting opening/closing of the inlet openings 15’,15”, the air flows out from the tank 44, passes through the pipe 44” and the check valve 44b, travels through the pipe 44”’, and passes into the regenerator 42 (where it undergoes an increase in température from T2 to T2’).

E5_Step of vaporizing/superheating the condensate water.

Pushed by the high pressure pump 94, the condensate water previously extracted from the air by the trap 93, flows through the pipes 93” and 94’ at température T1 ”, passes through the evaporator 95, where it is heated/vaporized (changing in State from a liquid to a vapour, with an increase in température from T1” to Ta), travels through the pipe 95”, passes through the superheater 96 (where it acquires further energy and undergoes an increase in température from Ta to Tb).

E6_Step of injection of the superheated vapour in the air conduit.

The air, exiting from the regenerator 42, travels through the pipe 42’, passes through the check valve 42a and passes into the pipe 42”' where, via the injector 97, the superheated vapour conveyed in the pipe 96’ is introduced. As a resuit of the mixing of the air with the superheated vapour, the thermal fluid undergoes an increase in energy and its température increases from T2’ to T2”, enabling the recovery of useful energy, which is schematically represented in the area Q96 in figure 10.

E7_Step of superheating the circulating thermal fluid.

The mixed thermal fluid travels through the pipe 97’, passes through the heater 41 (adjacent to the combustion chamber 40A, provided with the multi-fuel burner 40), where it receives heat-energy and increases in température from T2” to T3.

E8_Step of expanding the superheated thermal fluid and producing useful work.

When the pistons 7a-7b, by rotating in the annular cylinder in the direction of motion indicated by the arrows, open the inlet openings 15’-15”, the superheated thermal fluid flowing through the pipes 4Î-4T-4T is introduced into the expansion chambers 13' and 13”, where it is expanded (decreasing in température from T3 to T4) and, by making the pistons rotate, produces useful work.

E9_Step of expulsion and ofrecovering energy from the exhausted thermal fluid.

Following the movement of the pistons 7a-9b and 7b-9c towards each other, the chambers 14' and 14 diminish in volume, the exhausted thermal fluid (already expanded in the previous cycle) is expelled from the drive unit 1, passes through the two discharge openings 16-16, flows through the pipes 45'-45-45’”, passes through the regenerator 42 (where it surrenders part of the energy-heat still possessed and undergoes a first decrease in température from T4 to T4’), then passes into the pipe 42”, passes through the evaporator 95, where it again surrenders part of the energy-heat possessed and undergoes a second decrease in température from T4’ to T4”, enabling the recovery of useful energy, which is schematically represented in the area Q95 in figure 10.

E10_Conclusion ofthe cycle with further cooling ofthe exhausted thermal fluid.

The thermal fluid passes into the pipe 95’ and reaches the coder 43, from where the cycle can continue and repeat itself in a continuous mode.

E11_Optimized cooling ofthe drive'unit 1, with recovery of energy.

The water cooled in the recuperator 98 (at température Te) is constantly maintained in circulation by the pump 99, flows through the pipes 98’-99’, passes through a spécifie interspace 2R formed in the drive unit 1, (where, by performing a cooling action, it undergoes an increase in température from Te to Td), travels through the pipe 2’, passes through the recuperator 100 (where it acquires heat-energy, increasing in température from Td to Te), travels through the pipe 100’ and, finally, arrives at the recuperator 98, where its path ends. The interspace 2R constitutes a cooling unit for the drive unit 1. The pipes 2’, 98’, 99’ and 100’ constitute cooling pipes. The interspace 2R (or cooling unit) of the first recuperator 98, the second recuperator 100, the cooling pump 99 and the cooling pipes together constitute a cooling circuit of the heat machine. E12_Recovery of energy with the optimization ofthe process ofpreheating the combustion air.

The combustion air drawn from the environment at température Th1 is pushed by the fan 92 and passes into the cooler 43 (where it acquires energy and increases in température to Th3), passes into the recuperator 98 (where it acquires further energy and increases in température to Th5).

The preheated air is mixed in the burner 40 with the fuel conveyed through the régulation valve 91 and is introduced into the combustion chamber 40A, where the gas, mixed at a high température, can undergo optimal combustion, thus reducing harmful émissions.

E13_Recovery of energy with a réduction in the température ofthe combustion fumes.

The hot fumes produced by combustion at température Th7 are first cooled to température Th6 (passing through the superheater 96), then further cooled to température Th4 (passing through the recuperator 100) and then, given that the function envisaged for the heat machine is also to provide energy-heat to be destined to auxiliary uses (space heating and/or production of domestic hot water, etc.), before the hot fumes are discharged into the atmosphère (through the conduit 102), ail their residual energy is recovered by reducing their température as much as possible (it also being possible to recover further energy through their possible condensation). To achieve this purpose, use is made of a spécifie hydraulic circuit, where the following mode of conveyance is adopted: the incoming thermal fluid (normally water) from the auxiliary uses . . . r

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103 passes into the pipe 103’ and,i pushed by the circulation pump 104, passes into the pipe 104’,'feaches the recuperator 101 at the low température Tf and then, on passing throughit, thanks to the réduction in the “ température of the fumes from Th4 to Th2, it acquires energy-heat and heats up to the higher température Tg, so as to be made available, via the pipe 10Γ, for the auxiliary uses 130, and for the intended purpose.

The pipes 101’, 103’ and 104’ constitute auxiliary pipes. The auxiliary recuperator 101, the auxiliary pump 104 and the auxiliary pipes together constitute a cooling circuit of the heat machine 121.

The invention thus conceived is susceptible of numerous modifications and variants, ail falling within the scope of the inventive concept, and the components mentioned may be replaced by other technically équivalent éléments.

^{10 The} invention achieves important advantages. First of ail, the invention enables at least some of the drawbacks of the prior art to be overcome.

Furthermore, the heat machine and the associated method according to the présent invention are capable of using a variety of heat sources and of generating mechanical energy (work), as they can be employed in any place and for any Use, but preferably for the production of electrical energy.

¹⁵ Furthermore, the heat machine according to the présent invention is characterized by a high thermodynamic efficiency and an excellent weight-power ratio.

In addition, the heat machine according to the présent invention is characterized by a simple, easy to produce structure.

Furthermore, the heat machine according to the présent invention is characterized by a reduced production cost.

The invention is not limited to the embodiment/s illustrated in the drawings. Accordingly it should be understood that where features mentioned in the appended daims are followed by reference signs, such signs are included solely for the purpose of enhancing the intelligibility of the daims and are in no way limiting on the 25 scope of the daims

Claims (15)

1. A heat machine (121) for realizing a heat cycle, the heat machine operating with a thermal fluid and configured to function with a combined heat cycle using hot air and aqueous vapour, featuring unidirectional continuous motion of the thermal fluid, the heat machine comprising:

5 - a drive unit (1) comprising:

- a casing (2) delimiting therein an annular chamber (12) and having inlet or discharge openings (15', 16', 15, 16, 15', 16') in fluid communication with conduits external to the annular chamber (12), wherein each inlet or discharge opening (15', 16', 15, 16, 15', 16') is angularly spaced from the adjacent inlet and discharge openings so as to define an expansion/compression path for a working 10 fluid in the annular chamber (12);

- a first rotor (4) and a second rotor (5) rotatably installed in said casing (2); wherein each one of the two rotors (4, 5) has three pistons (7a, 7b,7c; 9a, 9b, 9c) that are slidable in the annular chamber (12); wherein the pistons (7a, 7b, 7c) of one (4) of the rotors (4, 5) are angularly alternated with the pistons (9a, 9b, 9c) of the other rotor (5); wherein angularly adjacent pistons (7a, 9a; 7b, 9b; 7c, 9c) delimit six 15 variable-volume chambers (13', 13, 13'; 14', 14, 14');

- a primary shaft (17) operatively connected to said first and second rotor (4, 5);

- a transmission (18) that is operatively interposed between said first and second rotor (4, 5) and the primary shaft (17) and configured to convert the rotational motion with respective first and second periodically variable angular velocities (ω1, ω2) of said first and second rotor (4, 5) that are offset 20 relative to each other into a rotational motion having a constant angular velocity of the primary shaft (17); wherein the transmission (18) is configured to confer, on the periodically variable angular velocity (ω1, ω2) of each of the rotors (4, 5), six periods of variation for each complété révolution ofthe primary shaft (17);

wherein said drive unit is a rotary volumétrie expander operating with said thermal fluid;

25 - a first section of the drive unit (1), where, following the movement of the two pistons (9c, 7c) away from each other, the thermal fluid, passing through the inlet opening (15'), is suctioned into the chamber (13');

- a second section of said drive unit (1), where, following the movement of the two pistons (7c, 9a) towards each other, the previously suctioned thermal fluid is compressed in the chamber (14') and then, on passing through the discharge opening (16'), a pipe (44') and a check valve (44a), it is conveyed into a compensation 30 tank (44);

- a compensation tank (44) configured to accumulate the compressed thermal fluid to make it available, via spécifie pipes (44,42') and the check valve (44b), for subséquent use thereof, in a continuous mode;

- a regenerator (42), in fluid communication via spécifie pipes (42-97') with said drive unit (1) and configured to preheat the thermal fluid prior to its entry in a heater (41);

35 - a heater (41) configured to superheat the thermal fluid circulating in a serpentine coil, using the thermal energy produced by a burner (40)';

•3

- a bumer (40) with â combustion chamber (40A) attachée! thereto, said bumer (40) being apt for operating with various types of fuel and being capable of supplying the necessary thermal energy to the heater (41);

- a third section of said drive unit (1), in fluid communication with said heater (41), via spécifie pipes (4T, 41, 41 j, and capable of receiving, via the inlet openings (15', 15), the thermal fluid heated to a high température 5 under pressure in the heater (41) so as to hâve it expand in the chambers (13', 13), which are delimited by the pistons (9a,7a-9b-7b), respectively, for the purpose of having said pistons rotate and produce work;

- a fourth section of said drive unit (1), in fluid communication with the regenerator (42) through the discharge openings (16', 16) and spécifie pipes (45', 45, 46), and wherein, due to the réduction in volume ofthe two chambers (14', 14) brought about by the movement of the two pairs of pistons (7a, 9b - 7b, 9c) towards each 10 other, the exhausted thermal fluid is forcedly expelled;

- wherein said regenerator (42), lin fluid communication with said drive unit (1), is further configured to acquire heat-energy from the exhausted'thermal fluid and to use it to preheat the thermal fluid to be sent to the heater (41).

15

2. The heat machine (121) according to claim 1, wherein the first section of the drive unit (1) is in fluid connection with the external environment via a pipe (93), so that the ambient air can be suctioned into the chamber (13'), and wherein the lheat machine (121) comprises a metering pump (97b) in fluid connection with a distilled water tank (97a) and arranged so as to enable a predefined amount of distilled water to be injected in an air circuit (42”’) by means of an injector (97), said predefined amount being capable of increasing the 20 unit powerofthe drive unit (1) and ofensuring lubrication ofthe cylinder.

3. The heat machine (121) according to claim 1, comprising:

- a cooler (43) that is operatively interposed between the low température outlet of the regenerator and the inlet of the heater (41 ),

25 wherein the thermal fluid, exiting from the cooler (43) at température T1, passes into a pipe (43j, passes through a condensate trap (93), where the water in the thermal fluid is condensed and separated from the air, passes into a pipe (93 j at température TT, passes through the suctioning opening (15’”) and following the movement of the two pistons (9c-7c) away from each other, is suctioned into the chamber (13”’) of said first section, and wherein, pushed by a high-pressure pump (94), the condensate water previously extracted from 30 the air by the trap (93) travels through spécifie pipes (93”, 94’) and reaches an injector (97) arranged so as to inject, in an air circuit (42’”), a predefined amount of condensate water, which is capable of increasing the unit power of the drive unit (1) and of ensuring lubrication of the cylinder.

4. The heat machine (121) according to claim 1, comprising:

³⁵ - ^a cooler (43) that is operatively interposed between the low température outlet of the regenerator and the inlet of the heater (41);

J <.·>Μ?*ψ.ΛΓ*.'< ΎΓΛΜ'^Χ.’ΓίΜ îæsa&æswti wherein the thermal fluid, exiting from the cooler (43) at température T1, passes into a pipe (43’), passes through a condensate trap (93), where the water in the thermal fluid is condensed and separated from the air, passes into a pipe (93’) at température TT, passes through the suctioning opening (15’”) and following the movement of the two pistons (9c-7c) away from each other, is suctioned into the chamber (13’”) of said first section, and wherein, pushed by a high-pressure pump (94), the condensate water previously extracted from the air by the trap (93) travels through the pipes (93”, 94’) and reaches an evaporator (95) that is configured to heat and vaporize the condensate water and send it to an injector (97) arranged so as to inject, in an air circuit (42”’), a predefined amount of aqueous vapour, which is capable of increasing the unit power of the drive unit (1) and of ensuring lubrication of the cylinder, wherein said evaporator (95) is operatively interposed, with its high température side, between said high pressure pump (94) and said injector (97), and wherein said evaporator (95) is configured to receive as incoming fluid, on its low température side, the exhausted thermal fluid expelled from the outlet of the drive unit (1), so as to acquire residual heat-energy from this exhausted thermal fluid and to use it to preheat the thermal fluid to be sent to the heater.

5. The heat machine (121) according to claim 1, comprising:

- a cooler (43) that is operatively interposed between the low température outlet of the regenerator and the inlet of the heater (41);

wherein the thermal fluid, exiting from the cooler (43) at température T1, passes into a pipe (43j, passes through a condensate trap (93), where the water in the thermal fluid is condensed and separated from the air, passes into a pipe (93’) at température TT, passes through the suctioning opening (15’”) and following the movement of the two pistons (9g-7c) away from each other, is suctioned into the chamber (13’”) of said first section, and wherein, pushed by a high-pressure pump (94), the condensate water previously extracted from the air by the trap (93) travels through the pipes (93, 94’) and reaches an evaporator (95) that is configured to heat and vaporize the condensate water and send it to a superheater (96), which, by extracting energy from the hot combustion fumes downstream of the burner (40), is configured to superheat the saturated vapour exiting from the evaporator (95), so as to supply energy thereto;

wherein said superheater (96) is configured to send the vaporized and superheated condensate water to an injector (97), which is arranged so as to enable injection, in an air circuit (42”’), of a predefined amount of superheated aqueous vapour, which is capable of further increasing the unit power of the drive unit (1) and of ensuring lubrication of the cylinder, wherein said evaporator (95) is operatively interposed, with its high température side, between said high pressure pump (94) and said superheater (96), and wherein said evaporator (95) is configured to receive as incoming fluid, on its low température side, the exhausted thermal fluid expelledl from the outlet of the drive unit (1), so as to acquire residual heat-energy from this exhausted thermal fluid and to use it to preheat the thermal fluid to be sent to the heater.

6. The heat machine (121) according to claim 5, and provided with a cooling circuit comprising:

- a first recuperator (98), located upstream of the burner (40), where combustion air is drawn from the environment;

- a cooling unit (interspace 2R) associated with the drive unit (1);

- a second recuperator (100), located downstream of the burner (40) and the heater (41), along the exit path of the hot combustion fumes;

- a plurality of cooling pipes (2', 98', 99’, 100’) connecting in sériés said first recuperator (98), said cooling unit (2R) and said second recuperator (100), so as to form a circular path, and bearing an amount of cooling fluid;

- a cooling pump (99) located in said circuit and that is operatively active on one pipe of said plurality of cooling pipes so as to bring about circulation of said cooling fluid in the cooling circuit;

wherein:

- said first recuperator (98) is configured to cool said cooling fluid by surrendering heat-energy to said combustion air;

- said cooling unit (2R) is configured to cool the drive unit (1) by transfer of heat-energy from the drive unit to the cooling fluid, which undergoes an increase in température;

- said second recuperator (100) is configured to heat said cooling fluid by acquiring heat-energy from the hot combustion fumes.

7. The heat machine (121) according to any one of the preceding daims and equipped with an auxiliary hydraulic circuit comprising:

- an auxiliary recuperator (101), located downstream of the burner (40) and the heater (41), along the exit path of the hot combustion fumes;

- a plurality of auxiliary pipes (101’, 103’, 104’) configured to pass through said auxiliary recuperator and to be connected with one or more auxiliary uses, preferably devices for space heating and/or production units for domestic hot water;

- an auxiliary pump (104), located in said circuit and that is operatively active on one pipe of said plurality of auxiliary pipes so as to bring about circulation in said auxiliary circuit;

wherein said auxiliary recuperator (101) is configured to recover energy from the combustion fumes and to transmit it to the fluid circulating in said auxiliary circuit, said energy thus being available for said auxiliary uses (103).

8. The heat machine (121) according to any one ofthe preceding daims, further comprising:

- a fan (92) located upstream of the burner (40) and configured to draw combustion air from the environment and to send it forcedly to said burner (40) to feed the combustion process; and/or >9

- one or more check vales (44a, 44b, 42a) located along the pipes of the heat machine and configured to facilitate circulation of the thermal fluid in a unidirectional manner and prevent the outflow of the thermal fluid in the opposite direction.

5

9. A method for realizing a heat cycle, the method operating with a thermal fluid and being configured to function with a combined heat cycle using hot air and aqueous vapour, featuring unidirectional continuous motion of the thermal fluid, the method comprising the steps of:

- arranging a heat machine (121), according to one or more of daims 1 to 8;

- carrying out the following steps:

10 - starting up the primary shaft (17) and the transmission (18) of the drive unit (1), setting the pistons (7a, 7b, 7c, 9a, 9b, 9c) into motion;

- activating the burner (40) and starting up the combustion process;

- when the thermal fluid circulating in the heat machine has reached a pre-established minimum i operating State, the drive unit (1) produces the work needed to be able to turn independently;

15 - following the movement of the two pistons (9c-7c) away from each other, the thermal fluid is suctioned into the chamber (13') through the suctioning opening (15’);

- following the movement of the two pistons (7c-9a) towards each other, the previously suctioned thermal fluid is compressed in the chamber (14”'), undergoes an increase in température from TT to T2, passes through the discharge opening (16') and reaches the compensation tank (44);

20 - with the intermittency determined by the rotation of the pistons and the resulting opening/closing of the inlet openings (15', 15), the thermal fluid flows out from the tank (44) and passes through the regenerator (42), where it undergoes an increase in température from T2 to T2’;

- the thermal fluid passes through the heater (41), where it receives heat-energy and increases in température from T2” to T3;

25 - rotating in the annular cylinder, when the pistons (7a-7b) open the inlet openings (15-15), the superheated thermal fluid is admitted into the expansion chambers (13’, 13”) where it expands, with a decrease in its température from T3 to T4 and, as it makes the pistons rotate, it produces useful work;

- following the movement of the pistons towards each other (7a-9b; 7b-9c), the chambers (14', 14”) 30 diminish in volume, the exhausted thermal fluid is expelled from the drive unit (1 ), passes through the discharge openings (16’-16”), and through the regenerator (42), where it surrenders part of the heatenergy still possessed and undergoes a decrease in température from T4 to T4’.

10. The method according to claim 9, wherein in the step of suctioning the thermal fluid into the chamber

35 (13’), said thermal fluid is air siictioned from the environment at température ΤΓ, and wherein the method comprises the steps of:

- drawing distilled water from the^tank (97a);

- activating the metering pump (97b) and introducing a given amount of distilled water into the circuit by means of the injector (97), thereby bringing about a decrease in the température of the resulting thermal fluid from T2’ to T2”;

and wherein, following the step of passing through the regenerator (42), the exhausted thermal fluid is discharged into the atmosphère.¹

11. The method according to claim 9, further comprising the following steps:

- the thermal fluid, exiting from the cooler (43) at température T1, passes into a pipe (43’), passes through a condensate trap (93), where the water in the thermal fluid is condensed and separated from the air, passes into a pipe (93’) at température T1 ’, passes through the suctioning opening (15’) and following the movement of the two pistons (9c-7c) away from each other, is suctioned into the chamber (13’”) of said first section;

- pushed by a high-pressure pump (94), the condensate water previously extracted from the air by the trap (93) travels through pipes (93, 94’) and reaches an injector (97) arranged so as to enable injection, in an air circuit (42’”), of a predefined amount of condensate water, which is capable of increasing the unit power of the drive unit (1) and ofensuring lubrication ofthe cylinder.

12. The method according to claim 9, further comprising the following steps:

- the thermal fluid, exiting from the cooler (43) at température T1, passes into a pipe (43’), passes through a condensate trap (93), where the water in the thermal fluid is condensed and separated from the air, passes into a pipe (93’) at température T1 ’, passes through the suctioning opening (15’) and following the movement of the two pistons (9c-7c) away from each other, is suctioned into the chamber (13”’) of said first section;

- pushed by a high-pressure pump (94), the condensate water previously extracted from the air by the trap (93) travels through the pipes (93”, 94’) and reaches an evaporator (95) that is configured to heat and vaporize the condensate water and to send it to an injector (97) arranged so as to enable injection, in an air circuit (42’”), of a predefined amount of aqueous vapour, which is capable of increasing the unit power of the drive unit (1) and ofensuring lubrication ofthe cylinder;

wherein said evaporator (95) is configured to receive as incoming fluid, on its low température side, the exhausted thermal fluid expelled from the outlet of the drive unit (1), so as to acquire residual heat-energy from this exhausted thermal fluid 'and to use it to preheat the thermal fluid to be sent to the heater.

13. The method according to claim 9, further comprising the following steps: :

- the thermal fluid, exiting from the cooler (43) at température T1, passes into a pipe (43’), passes through a condensate trap (93), where the water in the thermal fluid is condensed and separated from the air, passes into a pipe (93’) at température TT, passes through the suctioning opening (15”’) and following the movement of the two pistons (9c-7c) away from each other, is suctioned into the chamber (13’”) of said first section;

- pushed by a high-pressure pump (94), the condensate water previously extracted from the air by the trap (93) travels through the pipes ^f(93”, 94') and reaches an evaporator (95) that is configured to heat and vaporize the condensate water and to send it to a superheater (96), which, by extracting energy from the hot combustion fumes downstream of the burner (40), is configured to superheat the saturated vapour exiting from the evaporator (95), so as to supply energy thereto;

wherein said superheater (96) is configured to send the superheated aqueous vapour to an injector (97), which is arranged so as to enable injection, in an air circuit (42’”), of a predefined amount of said superheated aqueous vapour, which is capable of further increasing the unit power of the drive unit (1), of increasing the overall yield and of ensuring lubrication ofthe cylinder, and wherein said evaporator (95) is configured to receive as incoming fluid, on its low température side, the exhausted thermal fluid expelled from the outlet of the drive unit (1), so as to acquire residual heat-energy from this exhausted thermal fluid and to use it to preheat the thermal fluid to be sent to the heater.

14. The method according to claim 13, further comprising the following steps:

- arranging a cooling circuit, comprising:

- a first recuperator (98), located upstream ofthe burner (40), where combustion airis drawn from the environment;

- a cooling unit (interspace 2R) associated with the drive unit (1);

- a second recuperator (100), located downstream of the burner (40) and the heater (41), along the exit path of the hot combustion fumes;

- a plurality of cooling pipes (2', 98’, 99', 100’) connecting in sériés said first recuperator (98), said cooling unit (2R) and said second recuperator (100), so as to form a circular path, and bearing an amount of cooling fluid;

- a cooling pump (99) located in said circuit and that is operatively active on one pipe of said plurality of cooling pipes so as to bring about circulation of said cooling fluid in the cooling circuit;

- carrying out the following steps:

- cooling the cooling fluid by means of said first recuperator (98) by surrendering heat-energy to said combustion air;

i

- cooling, by means of said cooling unit (2R), the drive unit (1) by transfer of heat-energy from the drive unit to the cooling fluid, which undergoes an increase in température;

- heating, by means of said second recuperator (100), said cooling fluid by acquiring heat-energy from the hot combustion fumes.

15. The method according to any one of claims 9 to 14, further comprising the following steps:

- arranging an auxiliary hydraulic circuit, comprising:

- an auxiliary recuperator (101), located downstream ofthe burner (40) and the heater(41), along the exit path of the hot combustion fumes;

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- a plurality of auxiliary pipes (101 ’, 103’, 104’) configurée! to pass through said auxiliary recuperator and to be connected with one or more auxiliary uses, preferably devices for space heating and/or production units for domestic hot water;

- an auxiliary pump (104), located in said circuit and that is operatively active on one pipe of said

5 plurality of auxiliary pipes so as to bring about circulation in said auxiliary circuit;

- carrying out the following steps: —

- recovering energy from the combustion fumes, by means of said auxiliary recuperator (191);

- transmitting said energy to the fluid circulating in said auxiliary circuit;

- making said energy available for auxiliary uses (103).