ITMI20112383A1 - RANKINE CYCLE INTEGRATED MACHINE - Google Patents

Description

"RANKINE CYCLE INTEGRATED MACHINE"

DESCRIPTION

The present invention relates to a closed-cycle and integrated machine for generating an electrical power source using the recovery and conversion of heat by means of a Rankine cycle.

Furthermore, said machine must be made to be able to operate in total autonomy for long periods, it must not require any maintenance for a long time and must be intrinsically separated and protected from external agents or bodies.

It is known that heat sources are widely available, particularly at low / medium temperatures, which are currently dispersed in the environment, and therefore wasted, since their conversion into electrical energy results, with the means and procedures of recovery and conversion currently available, excessively expensive in relation to the energy produced, and therefore, even if they are used in a limited way for professional purposes, they find little use among the general public, and in particular in the home environment, but not only in this.

The most common heat sources, and referred to herein preferentially, are available both as a derivative of human activity and in nature.

The sources of human origin are eg. the heat contained in industrial waste products or resulting, and the heat contained in the bio-masses if this is combusted.

The heat available in nature is mainly solar heat, which can be intercepted, collected, converted and conveyed by countless means well known to the state of the art.

Numerous applications of the Rankine cycle are known for the recovery of the thermal energy existing in a body and for the subsequent production of electrical energy; the preferred embodiment consists in the use, as expansion chamber, of a turbine of a per se known type.

However, this solution has some constraints and drawbacks, which are well known to those skilled in the art, and which are:

- high cost of the turbine and related control bodies,

- need for a fairly frequent maintenance, with consequent charges of various kinds,

- but above all the greatest limit for a turbine is constituted by the fact that its maximum efficiency is obtained at a very precise flow rate of the expanding fluid and with a defined rotation speed, where if the rotation speed varies even slightly from said optimal value, the turbine efficiency is dramatically reduced.

This limitation is normally unacceptable when thermal sources are used whose thermal output is widely variable, as in the cases illustrated above.

To overcome this drawback, it is well known to use, as an expansion chamber, a common cylinder in which a respective sealed piston slides, said piston being connected to a relative rod or connecting rod from which the converted power is taken by mechanical means.

This mode of implementation of a Rankine cycle is advantageous in particular if the machine which carries out the Rankine cycle itself is associated, or integrated, with another machine which uses the motive power supplied.

For example, from US patent 4,720,978 it is known to use solar heat by means of a Rankine cycle to create a machine for pumping liquids, especially water or oil, in areas where electricity is not available, or where Continuous supervision of the electricity generation stations is impracticable.

The pumping machine described therein is particularly advantageous since it uses a cylinder equipped with a double-acting piston as the expansion chamber of the Rankine cycle, in which the free end of the same driving shaft of the piston is applied to a second piston of a second cylinder which is connected and works as a pump.

This solution is particularly simple and advantageous, also because it occurs in an integrated way between some fundamental organs; however it makes use of the mechanical analogy and the connection between the two cylinders, and cannot be advantageously used when it is desired to create a source of electrical energy.

From US patent 5,088,284 it is known to produce a compressor obtained by integrating a Stìrling engine with a machine that uses the Rankine cycle, which is in turn powered by a heat source of a generic nature, and preferably by solar heat.

This solution is also completely advantageous and practicable, and is also considerably compact; however also in this case it is limited to the only function produced, that is to the operation of a gas compressor.

From US patent 4,571,946 an endothermic engine equipped with a rotation shaft and transmission shaft for the produced driving force is known, in which the heat contained in the engine exhaust gases are recovered by a rotating element operated according to a Rankine cycle; said rotating element is connected and acts on the main rotation shaft, so as to increase its torque and therefore ultimately increase the energy efficiency of the whole engine.

However, even this solution is optimized for the particular use, and cannot be transferred simply and directly for electricity generation.

From US patent 4,901,531 an integrated Diesel-Rankine system is known in which a Diesel engine is equipped with several cylinders that work in the conventional way.

At least one of the cylinders is not used for the Diesel cycle, but is used as an expansion chamber for a fluid that is previously vaporized with the recovery of the heat of the exhaust gases of the other cylinders that work according to the Diesel cycle.

This solution, suggested in particular when the Diesel engine runs at full load, is therefore particularly advantageous for increasing engine efficiency, but also in this case the result obtained is not particularly targeted or advantageous for electricity generation.

From patents JP10252558, JP 10252557, and JP 10259966 various technical solutions are known which use the Rankine cycle for various purposes, or different combinations of manufacturing machines for optimizing the Rankine cycle; however none of the proposed solutions is particularly advantageous for electricity generation, in particular if the supply of thermal energy occurs with a widely variable regime.

It would therefore be desirable, and it is the main object of the present invention, to realize a type of Rankine cycle machine which uses a heat source of a general nature and with a high variability of heat output, and which constitutes a source of electrical power, the which is capable of operating for long periods without the need for any maintenance and which constitutes a highly integrated and compact unit.

This and other objects are achieved by a machine operating according to the Rankine cycle integrated with an electric generator manufactured and operating according to the attached claims.

Characteristics and advantages of the invention will become evident from the following description, by way of non-limiting example, with reference to the attached drawings, in which:

Figure 1 shows a perspective and exploded view of a machine according to the invention;

the fìg. 2 shows a median section view along two main axes "X" and "Z" of the machine of Figure 1, in a precise instant of operation, with the piston 2 close to the top dead center;

fig. 3 shows a second view similar to Figure 2, but with the same piston 2 at the bottom dead center;

fig. 4 shows a partially cut-away perspective view of a subassembly with some fundamental components of the machine of the invention, in the state of fig. 2;

the fìg. 5 shows a perspective view as in fig. 4, but in the state of fig. 3, and with the addition of a component (the body 17);

the fìg. 6 shows a view similar to the two previous figures, but with a view from the outside of the components previously observed in cut-away;

fig. 7 shows a perspective view of a specific component included in fig. 5; the fìg. 8 shows a median sectional and perspective view of the component of fig. 7;

the fìg. 9 shows a schematic diagram of a connection for the preferred use of the machine of the invention;

Figures 9A, 9B, 9C and 9D show respective connection diagrams of the machine of the invention, connected to different types of heat sources and to different types of cooling sources symbolically represented.

With ref. in Figures 1 to 8, a Rankine cycle machine according to the invention comprises:

- a cylinder 1 in which a piston 2 sliding hermetically in said cylinder is housed, and which defines with said piston a substantially hermetic internal chamber 12,

- a connecting rod 3 connected to one of its ends by means of a suitable pin

4, to said piston 2,

- a main shaft 5, formed with "gooseneck 6" portions on one of which the other end of said connecting rod 3 is applied in a known way,

- an electric generator equipped with a rotor 7 and a relative stator 8.

On the head 9 of said cylinder 1 there are two distinct through holes 10, 11, (Figures 2 and 3) which put said internal chamber 12 in communication with the outside of the cylinder 1, by means which are described further on.

The fluid which can be used for said Rankine cycle machine, and which fills said internal chamber 12, being then expelled from it, is a thermodynamic fluid of a per se known type, and preferably an organic fluid of the ORC type (ORGANIC RANKINE CYCLE).

A body 17 equipped with a cylindrical cavity in which a rotary valve 13 is housed, whose axis of rotation "Y" is arranged in a direction orthogonal to the axis "X" of cylinder 1, is arranged in correspondence with said head 9.

Said rotary valve 13 is equipped with two internal through channels, an intake channel 14 and an exhaust channel 15.

Said intake channel 14 is so shaped that its intake opening 14A facing the cylinder 1, with a certain and pre-defined position of rotation of said valve 13, is arranged in front of said inlet opening 10.

The opposite opening 14B of the channel 14, in this same position as the valve 13, enters, through a hole 18A, into a conduit 18 arranged inside another body, which can advantageously be constituted by a suitable portion of said same. body 17.

Said conduit 18 opens to the outside with a respective hole 18B.

Therefore, in said position of rotation of the valve 13 (Fig. 2 and 5), the internal chamber 12 of the cylinder 1 is put in communication with the outside, so that a flow of gas coming from the outside can enter, crossing in succession said hole 18B, said duct 18, said hole 18A, said opening 14B, said intake duct 14 and relative opening 14A, said through duct 16, said opening 16A and said opening 10 of the cylinder head, inside said internal chamber 12.

As regards the gas outlet path, from the inside of the chamber 12 to the outside, an analogous solution can of course be realized.

The discharge channel 15, from which the gas is expelled from said internal cavity 12 comes

equipped with a respective discharge mouth 15A which, at a precise and predefined position of rotation of said valve 15, is positioned in front of said discharge opening 11.

However, for reasons which will be explained further on, it is preferred that said exhaust channel 15 has an opposite opening 15B which flows directly outside the cylinder, without therefore passing through said body 17, as shown in Figure 3.

The geometric configuration, the architecture and the dimensions of the components just described are such that, when at a first position of the rotary valve 13 said channel 14 communicates the outside with the internal chamber 12, (pipes 14 and 18), then the rotary valve also closes the discharge passage from the internal chamber 12 to the outside since said rotary valve 13 also blocks the passage from said discharge opening 11 to the discharge channel 15 inside the same valve. (Fig. 2) And of course vice versa, as exemplified in fig. 3.

Moreover, the operating modes of the rotary valves to feed the inside of a cylinder in which a piston alternately slides is known per se, and therefore for the sake of brevity will not be explained in great detail.

There are also disposed means for controlling the rotation of the rotary valve, which will be more detailed hereinafter, such that these, combined with the configuration, dimensions and geometry of the elements described, are capable of causing that, with each complete rotation of the main shaft 5, said through hole 14A rotates for a short interval, including in the same complete rotation, in front of said opening 10 so as to put the internal chamber 12 of the cylinder in permanent communication with the outside through said channel 14 and said duct 18, and the relative openings at the respective ends.

In a subsequent interval of the same rotation, said valve 13 closes the access to said inlet opening 10, and puts said internal chamber 12 in communication with the outside of the cylinder.

In practice, said internal chamber 12 is alternately put in communication with the two ducts 14 and 15 for the inlet and discharge, according to a sequence synchronized with the movement and position of the piston 2, and this sequence of opening / closing of the opening of input 10, and opening / closing of the other opening 11 are controlled by and included in the same single rotation of the main shaft 5.

Therefore the introduction of a gas with an adequate pressure, and with the methods explained above, inside said internal chamber 12, an alternating movement of said piston 2 inside the cylinder 1 is obtained; this alternating movement, due to the effect of the gooseneck portion 6, transforms this alternating movement into a rotary movement of said shaft, which can be used to drive a general-type electric rotary motor consisting of a rotor 7, keyed on said shaft main shaft 5, and a stator 8, known per se.

Said electric rotary motor therefore generates one or more electrical voltages suitable for powering, by means of suitable electrical connections, not shown, the user devices which can take on an extreme variety of forms, uses and nature. Therefore, if a thermodynamic fluid is introduced, preferably of the well-known ORC type, coming from an evaporator medium and at an adequate pressure, as it is heated by a general type heat source, a machine is obtained which uses the Rankine cycle in a manner particularly efficient.

As regards the recovery of the gas discharged from the cylinder 1 through the opening 11 and the rotary valve, this aspect will be detailed below.

The advantage of the solution just described consists in the fact that the rotary valve has some undoubted and remarkable advantages over the usual valve stem distribution, which are:

- very high reliability,

- no consumption of the parts involved or wear, and therefore very limited maintenance needs,

- essentially no need for "registration",

- reduced energy absorption, since only rotary movement is produced and used,

- furthermore, and this is another substantial element to prefer the rotary valve, please note that the solution that uses traditional stem valves, with tappets, camshaft etc. It is preferred when the gases to be transferred are at a high temperature; in fact, the rotary valve is intrinsically vulnerable to other temperatures, since the gas that inevitably leaks between the valve itself and the relative openings on the cylinder head comes into contact with the lubricant used, destroying it in a short time.

On the contrary, in the Rankine cycle described, when fluids heated to low or medium temperature, at most to 250 ° C are used, this drawback is completely eliminated.

And therefore the use of the rotary valve no longer finds any counter-indication and can be adopted without any risk, exploiting its advantages.

The solution just described can be effectively improved by some advantageous improvements and variants of embodiments:

1) with reference to Figures 3, 4 and 5, it is necessary that the rotary valve 13 can rotate in synchrony with the movement of the piston, so that the inlet opening 10 can always open in a predetermined position thereof, typically when it reaches angles - anticipated or retarded - with respect to the top dead center which depend on the relationship between the operating pressures, and is closed after a fraction of a pre-defined period, before the piston reaches the bottom dead center; a similar situation, albeit naturally reversed, must also be respected as regards the opening and closing of the discharge opening 11.

For this purpose, said main shaft is connected to said rotary valve 13 by means of an assembly 27 of kinematic elements, comprising gears, pinions, idle wheels, adapted to act on the rotation shaft 19 of the rotary valve 13, preferably housed in part on said same. body 17, so as to ensure the conditions described above.

Since the main shaft performs a complete revolution with the double descent and ascent stroke of the piston, it will be sufficient to realize these kinematic mechanisms so that one revolution of the main shaft corresponds to only one revolution of the rotary valve, which causes both an opening and closing of the inlet path through opening 10, and a subsequent opening and closing of the discharge path through discharge opening 11.

Naturally, different solutions can be identified, such as those that provide for a valve rotating according to a rotation axis parallel to the "X" axis of the cylinder, or two distinct rotary valves, but their choice and synchronization are perfectly within the reach of the expert in the field, and therefore a detailed description thereof is omitted.

The solution with a rotary valve 13 whose rotation axis "Y" is orthogonal to the axis "X" of the cylinder is therefore preferred, and has been described and illustrated, for ease of transmission of the rotation motion from the shaft. main 5.

2) A second improvement is carried out as follows; with reference to Figures 1, 4 and 5, all the parts just described, namely said cylinder 1, said rotary valve 13, said kinematic mechanisms 27 and said electric generator 7, 8 are introduced and encapsulated in a suitable hermetic container 20, inside which are supported and secured by suitable locking means, such as brackets 21, brackets etc. The reason for the choice of this solution is threefold:

- first of all, the circumstance that a rotating valve is used implies a slight loss of gas in the environment outside the valve itself and cylinder 1. To recover this loss, it is therefore essential to "enclose" all the cylinder and the connected parts in a casing , naturally sealed, which includes inside both the gas inlet and the exhaust members.

This solution can of course be achieved by using the described hermetic container 20.

The choice then to include in said container 20 also the mechanical part, that is the connecting rod 3, the main shaft 5 and the electric generator including rotor and stator comes as a practically obligatory solution, given that a choice would be extremely more difficult and costly. different, that is to isolate the organs just listed from the outside of said container 20.

- Secondly, it must be considered that the gas expelled from the internal chamber 12 of the cylinder 1, due to the rising action in its stroke towards the cylinder head, if it were conveyed directly to the outside, would carry with it the parts of oil which are always inevitably included in the thermodynamic gas, which would prevent said oil from separating from the fluid itself, and ultimately in the long run compromising the characteristics of the fluid itself.

Thirdly, it must also be considered that the electric generator, comprising the rotor 7 and the stator 8, logically tends to heat up in operation, and therefore to avoid excessive overheating it must be suitably cooled.

In order to avoid both of the drawbacks explained above, advantageously the discharge duct 15 of the rotary valve 13 enters directly into the internal volume of the container 20, as symbolically represented in fig. 2, instead of being connected directly to the outside through the same body 17, as is the case for the intake duct 14 of the same valve 13.

Hence the discharge opening 11 is not accompanied by a corresponding discharge conduit which carries the gas discharged from the piston directly outside the container 20; on the contrary, after having passed through said discharge opening 11, and of course the duct 15 in the rotary valve 13, the gas immediately enters the hermetic container 20, from which it then exits in a regular manner by means of a suitable outlet 22, which introduces the gas into a suitable return pipe.

The gas then expands within the internal volume of the container 20, and therefore the twofold result can be achieved that the oil in the gas can spontaneously fall back into the bottom of said container, and therefore separate from the gas, and furthermore it functions effectively as a cooling fluid. for the electric generator containing in the same container 20.

Finally, last but not least, said container 20 constitutes the ideal means to contain the whole machine of the invention, since its nature as a hermetically closed casing prevents it from presenting accessible mechanical or electrical parts, and because inside it the functional organs can be arranged and positioned in a stable and definitive way, without the risk of tampering from the outside.

A machine is therefore created that appears on the outside as a single hermetically sealed container, and equipped only with the inevitable connection connections, that is, the two inlet and exhaust pipes of the thermodynamic gas, and the electrical connections that transfer the electrical power. delivered.

It will now be clear that said inlet 18B, cited above, is mounted in the wall of said container 20 so that through this the thermodynamic fluid can flow to said inlet channel 14 in the rotary valve 13 and to the relative outlet mouth 14A, and finally, through said inlet opening 10, into the internal chamber 12 of cylinder 1.

The operation of the described machine is as follows, and will have already been imagined by the reader: with reference to figure 9, the hot tank 101 (which in principle can be any thermal source) heats a boiler 102, also called evaporator, which contains the thermodynamic fluid used for the Rankine cycle. This fluid is heated until it evaporates, simultaneously increasing its pressure and passes through a delivery duct 103 from which said into the container 20 is introduced through the inlet 18 (previously mentioned) placed on the wall of the container 20 and in particular through the duct 18, the duct 14 in the rotary valve 13, said inlet duct 15, and said through opening 10, inside said chamber 12, into which it expands thanks to its greater pressure.

As a result of this expansion, the piston 2 is urged to move in an alternating direction, in a per se known manner, thus rotating said main shaft 5 and ultimately activates said electric generator.

The gas flow is then expelled from the piston through said discharge opening 11, entering the container 20, from which it exits through said outlet mouth.

From here, the same conduit 103, which now functions as a return conduit, conveys the gas into a suitable condenser 104, in which the gas is condensed, often by means of a cold tank 106, and then, through a pump 105, returns in said boiler 102.

Advantageously, said rotation shaft 5 is directly keyed to rotor 7; therefore the axis of rotation "Z" of the shaft 5 is substantially orthogonal to said axis "X" of the cylinder 1, and therefore is also parallel to the axis "Y" of rotation of the rotary valve 13.

The solution of a machine for electricity generation can be advantageously exploited in very different circumstances and environments; with reference to fig. 9A, the hot source "C" can be an industrial drain, while the heat exchanger can use a cold source "F" consisting of eg. from a watercourse, or, as shown in fig. 9B, an ambient air condenser, if conditions permit. Similarly, figures 9C and 9D illustrate similar situations, in which the hot source is instead supplied here by a battery of solar panels "P".

Said figures 9A to 9D also show the presence and connection of an accumulation tank 108, interposed between the condenser 104 and the pump 105; the function of this storage tank is important in the present thermodynamic circuit, since the liquid just condensed in the condenser is at a temperature just below the condensation temperature, and therefore if the pump 105 is a conventional pump , or impeller, the rotation of the blades causes a depression in the suction part of the pump, with a sudden drop in pressure and therefore can evaporate the liquid, which triggers the harmful phenomenon of cavitation.

Precisely to avoid this situation, the accumulation tank 108 is inserted since a quantity of liquid is collected in its bottom, within which the conduit that enters the pump 105 is immersed, and which guarantees a continuous supply of liquid at a sufficient pressure. at the pump inlet 105.

Ultimately it is obtained that the main shaft 5 is set in rotation.

Further aspects of the invention are described below.

Appearance 1. Rankine cycle machine for the conversion of thermal energy into electrical energy, comprising:

- a cylinder (1) in which a relative piston (2) is housed and slides, and an internal chamber with variable volume (12),

- a connecting rod (3) connected to said piston (44) and to which a relative main shaft (5) is associated,

- an electric generator, comprising a rotor (7) and a respective stator (8), and driven by said main shaft,

- characterized in that said cylinder (1) is fed with a flow of thermodynamic fluid through two distinct through openings, respectively for inlet and outlet (10, 11),

- at least one rotary valve (13) equipped with at least,

- a through inlet channel (14) adapted to allow the passage, selectively controllable, through said inlet opening (10) between an inlet duct (18) and the inner chamber (12) of said cylinder (1),

- a second through exhaust channel (15) adapted to allow the passage of the gas from the inside of said chamber (12) to the outside of said cylinder (1) through said exhaust opening (11).

Appearance 2. Machine according to aspect 1, characterized in that said rotary valve (13) is operated by a plurality of motion transmission members (27) connected and activated by said main shaft (5).

Appearance 3. Machine according to aspect 2, characterized in that said main shaft (5) is connected to the rotor (7) of an electric generator adapted to deliver a substantially continuous voltage.

Appearance 4. Machine according to one of the preceding aspects, characterized in that said rotary valve (13) rotates along an axis (Y) substantially orthogonal to the axis (X) of said cylinder (1).

Appearance 5. Machine according to one of the preceding aspects, characterized by the fact that on the head of said cylinder (1) there is a body (17) equipped with an internal cavity able to house said rotary valve (13), and that said body ( 17) is adapted to put said inlet channel (14) in communication with said inlet opening (10) in a defined position of rotation of said rotary valve (13).

Appearance 6. Machine according to aspect, characterized in that said body (17) is adapted to put said discharge channel (15) in communication within said valve (13) with said discharge opening (11), and that said discharge channel (15) outlet (15) opens outside said cylinder (1) without passing through said body (17).

Appearance 7. Machine according to one of the aspects 5 or 6, characterized in that said cylinder, said main shaft, said motion transmission members, said electric generator, said rotary valve are entirely contained in a hermetically sealed container (20).

Appearance 8. Machine according to aspect 7, characterized by the fact that said body (17) closes a portion of the external surface of said container (20), and which is equipped with an inlet (18B) which leads into a duct (18) which accesses, in a defined position of said valve (13), to said suction channel (14).

Appearance 9. Machine according to aspect 8, characterized in that said container (20) is equipped with an outlet (22) which communicates the inside of said container with the outside.

Appearance 10. Machine according to any of the preceding aspects, characterized in that the rotation axis (Z) of said rotor (7) is parallel to the rotation axis (Y) of said rotary valve (13).

Claims (10)

CLAIMS 1) Rankine closed cycle machine for the conversion of thermal energy into electrical energy, including: an evaporator (102) configured to heat thermodynamic fluid and to bring the same to vaporization while increasing its pressure, a delivery duct (103) which receives fluid from the evaporator, a cylinder (1) in which a relative piston (2) is housed and slides, and an internal chamber with variable volume (12), a connecting rod (3) connected to said piston (44) and to which a relative main shaft 5) is associated, an electric generator, comprising a rotor (7) and a respective stator (8), and driven by said main shaft, wherein said cylinder (1) has two distinct through openings, respectively for inlet and outlet (10, 11), a rotary valve (13) equipped with at least: a through inlet channel (14) adapted to allow the passage, selectively controllable, through said inlet opening (10) between an inlet duct (18) and the inner chamber (12) of said cylinder (1), a second through exhaust channel (15) adapted to allow the passage of gas from the inside of said chamber (12) to the outside of said cylinder (1) through the exhaust opening (11), a return duct that receives fluid coming out of the discharge opening and conveys it to an condenser and then to the evaporator. 2) Machine according to claim 1, characterized in that said rotary valve 13) is operated by a plurality of motion transmission members (27) connected and activated by said main shaft (5) to synchronize the motion of the valve with the piston motion. 3) Machine according to one of the preceding claims, characterized by the fact that said rotating valve (13) rotates according to an axis (Y) substantially orthogonal to the axis (X) of said cylinder (1) and by the fact that axis of rotation (Z) of said rotor (7) is parallel to the rotation axis Y) of said rotary valve (13). 4) Machine according to one of the preceding claims, characterized in that on the end of said cylinder (1) there is a body (17) equipped with an internal cavity suitable for housing said rotating valve (13), and that said body (17 ) Is adapted to put said inlet channel (14) in communication with said inlet opening (10) in a defined position of rotation of said rotary valve (13), and by the fact that said body (17) is adapted to putting said discharge channel (15) in communication within said valve (13) with said discharge opening (11), and that said loading channel (15) opens outside said cylinder (1) without passing through said body (17). 5) Machine according to one of the preceding claims, characterized in that said cylinder, said main shaft, said motion transmission members, said electric generator, said rotary valve are entirely contained in a hermetically sealed container (20), said container ( 20) receiving fluid introduced from the delivery duct (103) through an inlet port placed on the wall of the container (20) and allowing the exit of the gas coming from the discharge opening (11) through an outlet mouth which enters the return pipe. 6) Machine according to any one of the preceding claims comprising a pump 105) placed on the return duct to pump the return flow to the evaporator. 7) Machine according to claim 6 comprising an accumulation tank (108), placed between the condenser (104) and the pump (105), said accumulation tank having a bottom for collecting a quantity of condensed liquid, within which a quantity of condensed liquid is immersed in the conduit that puts into the pump 105, which guarantees a continuous supply of liquid at a pressure that is unofficial at the inlet of the pump itself. 8) Process for the conversion of thermal energy into electrical energy using a Rankine closed-cycle bank in accordance with any one of the preceding claims, the process comprising the following steps: heat the evaporator until the thermodynamic fluid is led to evaporation at the same time raising its pressure, let the heated fluid flow through the delivery duct to the chamber inside the cylinder, in which the fluid expands and pushes the piston to move in reciprocating motion causing the rotation of the main shaft of the electric generator, convey gas leaving the chamber inside the cylinder through the return pipe in the condenser, return the condensed fluid towards the evaporator. 9) Process according to claim 8 in which the condensed fluid is sent to a storage tank (108), interposed between the condenser (104) and a pump (105) operating on the surrounding duct, said storage tank having a bottom collection of a quantity of corrugated liquid, inside which the pipe that enters the pump is immersed, which guarantees a continuous supply of liquid at a sufficient pressure at the inlet of the pump itself. 10) Process according to claim 9, wherein the fluid is heated to a maximum of 50 ° C.