TECHNICAL FIELD

The invention relates to the technical sector of systems for generating heat and mechanical energy.

BACKGROUND ART

As is known, stoves, fireplaces, boilers etc. give out heat during processes of combustion, which take place in a relative combustion chamber.

In general, co-generation systems are known which use a part of the heat energy produced internally of the combustion chamber for producing electrical energy; these systems comprise a turbine functionally connected to the discharge conduit of the combustion chamber for receiving the discharge fumes as an operating fluid to draw the activating shaft of an electrical generator in rotation.

SUMMARY OF THE INVENTION

The aim of the present invention consists in providing an innovative system for generation of heat and mechanical energy which enables efficient exploitation of a part of the heat energy produced internally of the relative combustion chamber for generating mechanical or electrical energy.

The aim is attained with a system for generating heat and mechanical energy, comprising: a combustion chamber, a discharge conduit for fumes produced internally of the combustion chamber; a first turbine, connected to the discharge conduit, which receives the fumes as an operating fluid for activating a drive shaft; characterised in that it comprises: a compressor moved by the drive shaft, which compressor receives external air and compresses it; a first valve arranged along the discharge conduit for regulating the obstruction of the discharge conduit and thus increasing the pressure and temperature in the combustion chamber; a first heat exchanger arranged on the external part of a portion of the discharge conduit, for heating the compressed air coming from the compressor; a first conduit for supplying the compressed and heated air coming from the first heat exchanger to a first inlet of the combustion chamber; a compressed-air injection command arranged along the first conduit, for enabling regulation of the quantity of air injected into the combustion chamber; a control unit acting on the first valve and on the injection command for optimising system heat and mechanical performance.

The presence of the first valve and the injection command advantageously guarantee, in any operating system and via the control unit, a better heat and mechanical performance.

Further advantageous embodiments are defined in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific embodiments of the invention, and advantageous technical-functional characteristics correlated to the embodiments which are only in part deducible from the above description, will now be described in detail in the following, in accordance with what is set out in the claims and with the aid of the accompanying figures of the drawings, in which:

figure 1 is a simplified lateral view of a system for generation heat and mechanical energy according to the invention;

figure 2 is a schematic representation of the system of claim 1. BEST MODE FOR CARRYING OUT THE INVENTION

With reference to the accompanying figures of the drawings, the system comprises: a combustion chamber C, for example a combustion chamber of a stove, a fireplace, a boiler, which combustion chamber C can be supplied with wood, gas, biomasses and combustibles in general; a discharge conduit 12 of the fumes produced internally of the combustion chamber C; a first turbine 11 , connected to the discharge conduit 12, for receiving the fumes as an operating fluid and activating a drive shaft 13; a compressor 8 moved by the activating shaft 13, which compressor 8 receives external air and compresses it; a first valve 6 arranged along the discharge conduit 12 for regulating the obstruction of the discharge conduit 12 and thus increasing the pressure and temperature in the combustion chamber C; a first heat exchanger 9 constructed on an external part of a portion of the discharge conduit 12, for heating the compressed air coming from the compressor 8; a first conduit 18 for supplying the compressed and heated air coming from the first heat exchanger 9 to a first inlet 19 of the combustion chamber C; an injection command 10 of the compressed and heated air arranged along the first conduit 18 for enabling regulation of the quantity of air injected into the combustion chamber C; a control unit 7 acting on the first valve 6 and on the injection command 10 for optimising the heat and mechanical performance of the system.

Via the injection command 10, the control unit 7 optimises and regulates the temperature and pressures of the combustion chamber C; the quantity of air injected into the combustion chamber C is thus regulated by the control unit 7.

The hot air optimises the combustion, the temperature and the pressure of the combustion chamber C.

The first turbine 11 and the compressor 8 are both mounted on the drive shaft 13.

The system further comprises: a third conduit 22 connected to the outlet of the fumes from the first turbine 11 , communicating with a discharge 16; a second conduit 20 branched from the third conduit 22 for conveying a part of the fumes in outlet from the first turbine 11 to a second inlet 21 of the combustion chamber C, and means 14, 15, 7 for regulating the quantity of fumes circulating along the second conduit 20 and destined to be re-injected into the combustion chamber C.

The regulating means 14, 15, 7 of the quantity of fumes comprise, in particular: a recycling valve 14 acting along the second conduit 20 for selecting a quantity of fumes to be re-injected into the combustion chamber C; a fume recycling command 15 located along the second conduit 20, for enabling re-injection of the still-hot fumes into the combustion chamber C; and the control unit 7, acting on the recycling valve 14 and on the recycling command 15.

Further, the system comprises: a second heat exchanger 1 for producing water vapour, which second heat exchanger 1 is positioned at the hottest point of the combustion chamber 1 in order to receive heat therefrom, i.e. it is positioned behind, above and about the heart of the combustion hot-point; an electrical or mechanical pump 42 (illustrated only in figure 2) suitable for loading the water, which moves the steam received from the second heat exchanger 1 along a tube 3 which forms a closed circuit; a second turbine 4 connected to the tube 3, for receiving the steam under pressure and heated by the second exchanger 1 as an operating fluid and activating the drive shaft 13.

The exhausted steam which has pushed the blades of the second turbine 4 returns via the tube 3 to the second heat exchanger 1. The steam exchange, transfer and recycling cycle is continuously performed.

The system is configured such that the first turbine 11 , the compressor 8 and the second turbine 4 are all mounted on the drive shaft 13.

The system comprises an electricity generator 5 which is drawn in rotation by the drive shaft 13.

The drive shaft 13 is the common drive shaft of the second turbine 4, the compressor 8, the first turbine 11 and the electricity generator 5. In other words, the shafts of the second turbine 4 of the compressor 8, the first turbine 11 and the electricity generator 5 are coaxial and connected to one another in order to form the common drive shaft 13.

The system of the invention further comprises a third heat exchanger 2 for producing hot water destined for heat and sanitary appliances, which third heat exchanger 2 is positioned in the hottest point of the combustion chamber C in order to receive heat therefrom, i.e. it is positioned behind, above and about the hottest point of the combustion chamber.

A lambda sensor 17 is located along the third conduit 22 and downstream of the branch-off point of the third conduit 22 with the second conduit 20.

The control unit 7 performs calculations on the acquired information such as temperature, pressure and air ratio it receives via the injection command and the lambda sensor 17; using this information, the control unit 7 acts on the first valve 6, performing continuous variations on the level of occlusion of the discharge conduit 12 in order to be able to guarantee optimal head and electrical performance of the system under any operating condition.

The fumes transfer the pressure acquired by the combustion to the blades of the first turbine 11 which activates the drive shaft 13; the compressor 8, on the other hand, is drawn by the drive shaft 13 in order to compress the air.

The discharge fumes in outlet from the first turbine 11 are intercepted by the recycling valve 14 located on the second discharge conduit 20; the recycling valve 14, controlled by the control unit 7, selects a quantity of fumes to be reinjected into the combustion chamber C through the second inlet 21. The fumes are newly injected into the combustion chamber C through the recycling command 15.

The quantity of fumes which are re-introduced into the combustion chamber C and the moment they are re-injected into the combustion chamber C are established by means of the control unit 7. The fumes re-injected into the combustion chamber C are still rich in heat and pressure energy when reinjected into the said chamber C.

The foregoing has been described by way of non-limiting example, and any constructional variants are considered to fall within the ambit of protection of the present technical solution, as claimed herein below.