METHOD AND APPARATUS FOR RECOVERING ENERGY FROM DRIVING ENGINES

Abstract

rgy from engines (20), characterized in that it comprises the following steps: operating the engine (20) by means of a pressurised fluid (A1,A2); recovering the operating fluid (A1,A2) of the engine (20); supplying the recovered pressurised fluid to at least one tank (120) containing water; pressuring the water in said tank (120) by means of said pressurised fluid; supplying said pressurised water to a turbine (140) operating a secondary shaft (2); recovering the outlet water from the turbine (140); supplying the outlet water from the turbine (140) to the said at least one tank (120) for pressurisation; repetition of the cycle.

Description

[0001]The present invention relates to a method and an associated apparatus for recovering energy from engines.

[0002]It is known that, in the various technical sectors where the operation of devices of various kinds is required, there is an increasingly frequent need to optimize the efficiency levels of the various engines in order to reduce the costs associated with the consumption of energy, whatever the form used, (electricity, gas, oil), and in order to limit the environmental impact and pollution of the surrounding environment.

[0003]It is also known that various efforts have been made in this connection, namely with the introduction of energy recovery apparatus into the various operating cycles, but without the effective energy gain achieved being such as to justify the use of said recovery apparatus on a large scale.

[0004]The technical problem which is posed, therefore, is that of providing an apparatus and a method for recovering energy from engines for devices of various kinds, which results in an adequate and effective energy gain at the end of the operating cycle.

[0005]In connection with this problem it is also required that this device should have small dimensions, be easy and inexpensive to produce and assemble and be able to be easily installed at any user premises and also in combination with already existing engines.

[0006]These results are achieved according to the present invention by a method for recovering energy from engines according to the characteristic features of claim 1 and an apparatus for implementing the method according to the characteristic features of claim 9.

[0007]Further details may be obtained from the following description of a non-limiting example of embodiment of the subject of the present invention provided with reference to the accompanying drawings in which:

[0008]FIG. 1 shows a schematic diagram of a first embodiment of the energy recovery apparatus according to the present invention; and

[0009]FIG. 2 shows a schematic diagram of a second embodiment of the energy recovery apparatus according to the present invention.

[0010]As shown in FIG. 1, an engine 20 operates a primary shaft 1, which in the example according to the figure is rotating, but may be also be operated displaceably. The engine 20 in the example shown consists of a pneumatic engine comprising a pair of cylinders 21 which house movably inside them a respective piston 22 moved by compressed air A1 supplied by a primary energy source 10 comprising a compressor 11 and a tank 12.

[0011]By suitably determining the time lag between the two pistons 22 it is possible to produce an alternating thrust/return movement thereof such as to cause, in a conventional manner, operation of the primary shaft 1 during the thrust phase and an action on the compressed air A2, present inside each cylinder 21 after the thrust phase of the pistons 22, so that said air A2 can be conveyed into a line 110 for supplying an energy recovery apparatus 100 according to the present invention.

[0012]According to a preferred embodiment it is envisaged that a storage tank 23 (shown in broken lines in the figure) is arranged between the line 110 and the cylinders 21 of the engine 20, said tank being supplied by means of pipes 23a connected to the respective cylinders 21.

[0013]In greater detail, said recovery apparatus 100 comprises at least one tank 120 (three in the example shown) containing water; each tank 120 has an inlet 121 for the pressurised air supplied by the line 110, at least one inlet 126 for the water and at least one, outlet 122 for the water which is pressurised by the air supplied to the tank.

[0014]The pressurised air inlet 121 is regulated by a controlled intercept valve 121a.

[0015]Preferably an outlet valve 124 for the pressurised air contained inside the tank 120 is also arranged in the region of the air inlet valve 121, said air being in turn also able to be recovered and, for example, being stored in a tank 124a for subsequent use, resulting in further energy recovery.

[0016]The pressurised water from each tank 120 is supplied to a line 130 for supplying a turbine 140 situated at a higher level than the tank 120 so that, when there is no thrust due to the pressurised air A2, the water head is in equilibrium with the free surface being positioned in the vicinity of the inlet to the turbine 140.

[0017]It is envisaged, moreover, that the outlet of the tanks 120 is in turn regulated by a controlled valve 122a.

[0018]During the operating cycle, the turbine 140 starts to move as a result of the thrusting action of the pressurised water and in turn causes rotation of a secondary shaft 2 which may be used to operate auxiliary devices of various kinds.

[0019]In the example shown it is envisaged that the shaft 2 operates an air pump 40 able to pump pressurised air either to the primary tank 12 or directly to the pneumatic engine 20 by means of a duct 41 which, as shown in broken lines, may also be connected to the inlet pipe 110 of the first tank 120.

[0020]In a bypassing arrangement or in parallel, the secondary shaft 2 may also operate an electric motor 50, the shaft 51 of which may be connected to various user devices.

[0021]The turbine operating water, once all of its potential energy has been used up, is discharged via pipes 141 either directly into the tank 120 or, in a preferred embodiment as shown, into a tank 150 provided with outlets 151 for the return of the water to the tank(s) 120.

[0022]In both cases the presence of a normally closed valve 125 situated between the water return pipes and the tank 120 is envisaged, said valve being able to open the delivery for the time need to restore the level of water inside the tank 120 itself.

[0023]It is envisaged, moreover, that all the sequences of the operating cycle of the apparatus and the primary engine, as well as the intercept and regulating valves, are controlled by an associated control unit 1000 able to determine the sequences and actuation of valves and servomechanisms for controlling and operating the various auxiliary parts of the apparatus, which parts, being conventional per se, are not described in detail. In particular, the sequences and the opening/closing times of the valves 121a, 122a and 125 will be synchronized both with each other and with the cycle time of the pistons 21 so that, during the thrust phase of the piston, the air inlet valve 121a is closed and the air discharge valve 124 and in sequence the inlet valve 125 for the water which could not enter with the tank still under pressure are opened.

[0024]As shown in FIG. 2 it is also envisaged being able to achieve further energy recovery by means of an apparatus according to the invention with a dual stage. In this configuration it is envisaged duplicating the recovery apparatus 100 by connecting via a pipe 1110 the breather valve 124 of the first stage to the inlet valve 121a of the pipe 121 supplying the compressed air to the first tank 120.

[0025]In this way the compressed air recovered from the first stage can be used to operate a second shaft 2 of a second turbine 140, operation of which constitutes a total gain since it is obtained only by components with operation by means of recovery from the first stage.

[0026]It is envisaged moreover being able to increase further the number of stages in cascade so as to obtain further energy recovery and that the return pipe 41 from the pump 40 may be connected by means of an extension 1041 to the pipe 1110 supplying the second stage 100.

[0027]According to the invention it is envisaged moreover providing a method for recovering energy from engines 20, comprising the following steps: [0028]operating the engine 20 by means of a pressurised fluid A1,A2; [0029]recovering the operating fluid A1,A2 of the engine 20; [0030]supplying the recovered pressurised fluid to at least one tank 120 containing water; [0031]pressurising the water in said tank 120 by means of said recovered fluid; [0032]supplying said pressurised water to a turbine 140 operating a secondary shaft 2; [0033]recovering the outlet water from the turbine 140; [0034]supplying the recovered water from the turbine 140 to the said at least one tank 120 for pressurisation; [0035]repetition of the cycle.

[0036]It is envisaged moreover that: [0037]the outlet water from the turbine 140 may be stored inside a central tank 150 forming a buffer for supplying the water to the pressurisation tank 120; [0038]the secondary shaft 2 is used to operate auxiliary devices such as a pump 40 able to re-pressurise the operating fluid to be sent to the engine 20.

[0039]In the case of the pneumatic engine illustrated, the pump 40 is an air pump which sends compressed air either to the cylinders 21 or to the storage tank 12 supplying them.

[0040]In addition to this it is envisaged that the secondary shaft 2 may operate an electric motor 50 bypassing or in parallel with the pump 40, in keeping with the values of the residual energy available.

[0041]It is therefore clear how operation of the secondary shaft 2 is obtained by means of free recovery of energy resulting from the reuse of the pressurised operating fluid of the engine 20; consequently the energy delivered from the turbine 140 to the shaft 2 may be regarded as total gain in the operating cycle.

[0042]Tests carried out on pneumatic engines, according to the example illustrated, i.e. engines which have a normal average efficiency of around 0.5 to 0.6%, have confirmed overall efficiency levels of the engine which are increased up to 0.8 to 0.9% in the condition where the engine forms a closed loop with the energy recovery apparatus 100 according to the invention operating an air pump 40 according to the diagram shown.

[0043]With reference to FIG. 2 it is also envisaged being able to obtain further energy recovery by means of a method applied to an apparatus according to the invention with a dual stage.

[0044]In such a case it is envisaged duplicating the recovery apparatus 100 by connecting via a pipe 1110 the breather valve 124 of the first stage to the inlet valve 121a of the pipe 121 for supplying the compressed air to the first tank 120.

[0045]Consequently the method comprises a further step consisting in: [0046]recovery of compressed air from the first tank 120 of the first stage and supplying thereof to the first tank of the second stage; [0047]repetition of the basic cycle so as to operate a second shaft 2 of a second turbine 140, operation of which represents a total gain since it is obtained only by components with operation by means of recovery from the first stage, which allows a considerable increase in the overall efficiency of the apparatus.

[0048]Further energy recovery is possible by means of a pipe leading from the pump 40 and extended with the section 1041 to the inlet of the first tank of the second stage.

[0049]Although illustrated in relation to a pneumatic engine, it is also within the scope of the person skilled in the art to use the energy recovery apparatus according to the present invention also in combination with different engines operating with pressurised fluid which may be recovered in order to pressurise the water in the tanks and cause operation of the turbine 140 of the secondary shaft 2.

[0050]Although the invention has been described in the context of a number of embodiments and a number of preferred examples, the persons skilled in the art will understand that the present invention also extends beyond the embodiments described in a specific manner, according to the scope of protection determined by the claims which follow.

Claims

1. Method for recovering energy from engines (20), characterized in that it comprises the following steps:operating the engine (20) by means of a pressurised fluid (A1,A2);recovering the operating fluid (A1,A2) of the engine (20);supplying the recovered pressurised fluid to at least one tank (120) containing water;pressuring the water in said tank (120) by means of said pressurised fluid;supplying said pressurised water to a turbine (140) operating a secondary shaft (2);recovering the outlet water from the turbine (140);supplying the outlet water from the turbine (140) to the said at least one tank (120) for pressurisation;repetition of the cycle.

2. Method according to claim 1, characterized in thatthe step for recovering and supplying the pressurised fluid (A1;A2) of the engine (20) is performed by the same means (21, 22) for operating the primary shaft (1) of the engine.

3. Method according to claim 1, characterized in that it envisages a step for storing the outlet water from the turbine (140) inside a tank (150) before supplying thereof to the at least one water pressurisation tank (120).

4. Method according to claim 1, characterized in that it envisages a step involving operation by the secondary shaft (2) of a pump (40) able to pressurise the operating fluid of the engine (20).

5. Method according to claim 4, characterized in that the secondary shaft (2) operates an auxiliary electric motor (50) bypassing or in parallel with the pump (40).

6. Method according to claim 1, characterized in that the engine (20) is a pneumatic engine operating a primary shaft (1).

7. Method according to claim 6, characterized in that the pneumatic engine (20) is operated by a compressor (11).

8. Method according to claim 4, characterized in that supplying of the pneumatic engine (20) is performed via a storage tank (12) arranged between the compressor (11) and the engine itself.

9. Method according to claim 1, characterized in that the recovery cycle is a multi-stage cycle.

10. Method according to claim 9, characterized in that it comprises a step (124, 1110) for recovering the pressurised fluid from the at least one tank (120) of a first stage and supplying said recovered fluid to at least one second tank (120) of at least one second stage (100) connected to a second turbine (140).

11. Method according to claim 4, characterized in that said pump (40) has an outlet pipe (41) connected to the inlet of the first tank (120) of the first stage.

12. Method according to claim 4, characterized in that said pump (40) has an outlet pipe (41) connected to the inlet of the second tank (1041) of the second stage.

13. Apparatus for recovering energy from an engine (20) operated by a pressurised fluid (A1,A2), characterized in that it comprises means (110) for recovering and supplying the operating fluid of the engine to at least one tank (120) containing water for pressurisation thereof, means (130) for supplying the pressurised water in said tank (120) to a turbine (140) operating a secondary shaft (2), means (141) for collecting and supplying the outlet water from the turbine (140) to said at least one tank (120) containing the water to be pressurised.

14. Apparatus according to claim 13, characterized in that said operating means of the engine consist of at least one piston (22) movable inside an associated cylinder (21).

15. Apparatus according to claim 14, characterized in that said operating means of the engine consist of at least one pair of pistons (22) movable inside an associated cylinder (21).

16. Apparatus according to claim 15, characterized in the operating means (21, 22) of the engine (20) are time-lagged and able to perform recovery of the pressurised operating fluid (A1;A2) of the said engine (20).

17. Apparatus according to claim 11, characterized in that said means (110) for recovering and supplying the operating fluid of the engine (20) consist of a line connecting together the at least one tank (120) and the operating means (21; 22) of the engine (20).

18. Apparatus according to claim 17, characterized in that a tank (23) supplied via pipes (23a) connected to the respective means (21) is arranged between the line (110) and the operating means (21;22) of the engine (20).

19. Apparatus according to claim 13, characterized in that said at least one tank (120) for pressurising the water has at least one inlet (121) connected to the line (110) supplying the pressurised fluid, at least one inlet (126) and at least one outlet (122) for delivering the pressurised water.

20. Apparatus according to claim 19, characterized in that said water and fluid inlets and outlet (122) are regulated by respective control valves (121a;125;122a).

21. Apparatus according to claim 13, characterized in that said inlet valve (125) of the water tank is normally closed and able to regulate the filling level of the tank in synchronism with the operating means of the engine (20).

22. Apparatus according to claim 13, characterized in that said valve (121a) supplying the pressurised fluid is normally closed and opened in counter-synchronism with the water supply and water delivery valves (125).

23. Apparatus according to claim 12, characterized in that said means (130) for supplying the pressurised water to the turbine (140) consist of a line connected to said outlet (122) of the at least one pressurised water tank.

24. Apparatus according to claim 13, characterized in that said water pressurisation tank (120) comprises a controlled breather valve (124) for the pressurised air.

25. Apparatus according to claim 13, characterized in the said means (141) for collecting and supplying the turbine outlet water consist of direct lines connected to the at least one tank (120).

26. Apparatus according to claim 13, characterized in that it comprises a tank (150) for storing the outlet water from the turbine (140), connected to said at least one water pressurisation tank (120).

27. Apparatus according to claim 13, characterized in that it comprises a pump (40) operated by the turbine (140) and able to pressurise the fluid to be sent to the engine (20).

28. Apparatus according to claim 13, characterized in that the shaft (2) of the turbine (140) operates an auxiliary electric motor (50) bypassing or in parallel with the pump (40).

29. Apparatus according to claim 13, characterized in the engine (20) is a pneumatic engine operating a primary shaft (1).

30. Apparatus according to claim 29, characterized that the pneumatic engine (20) is operated by a compressor (11).

31. Apparatus according to claim 29, characterized in the supplying of the pneumatic engine (20) is performed via a storage tank (12) arranged between the compressor (11) and the engine itself.

32. Apparatus according to claim 13, characterized in that it is a dual-stage apparatus (100).

33. Apparatus according to claim 32, characterized in that it comprises a pipe (1110) connecting together the first tank (120) of the first stage (100) and the first tank (120) of at least one second stage (100).

34. Apparatus according to claim 33, characterized in the said pipe (1110) is arranged between the breather valve (124) of the first tank (120) of the first stage (100) and the inlet valve (121a) of the first tank (120) of the second stage (100).

35. Apparatus according to claim 32, characterized in the said pump (40) has an outlet pipe (41) connected to the inlet of the first tank (120) of the first stage.

36. Apparatus according to claim 32, characterized in said pump (40) has an outlet pipe (41) connected to the inlet of the second tank (1041) of the second stage.

37. Apparatus according to claim 13, characterized in that it comprises a control unit (1000) able to determine the sequences and actuation of valves and servo-mechanisms for controlling and operating the various auxiliary parts of the apparatus.

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