Combustor with gas turbine for generating a flame for a heat generating system

Abstract

A burner (1) for generating a flame for a heat generating system, comprising a fuel supply line (3) and at least one combustion-supporting agent intake system, both operatively connected to a combustion head (2) for supplying a fuel flow and a combustion-supporting agent flow, respectively, to said burner (1). The burner (1) comprises a turbogas unit having an auxiliary combustion chamber (6) in which combustion takes place and for generating and downstream conveying a flow of fumes, and a turbine (7) activated by the fumes generated by the auxiliary combustion chamber (6). In particular, the turbine (7) is operatively active to at least partially contribute to the movement of the fuel in said combustion-supporting agent supply system (4).

Description

[0001] Field of the application

[0002] The present application relates to a burner for generating a flame for a heat production system, wherein the burner comprises a gas turbine.

[0003] In particular, by "burner" it is meant an operating machine of a combustion plant, in which fuel and combustion agent are mixed, and subsequently a combustion reaction is initiated by ignition, usually accompanied by the production of a visible flame.

[0004] For the present application, this means that the burner is configured to be applied to a heat production system (water or steam boiler, furnace, incinerator, smoke gas boosting combustion chamber, etc.). In particular, the burner is applied to a combustion chamber, into which the flame produced extends.

[0005] The present application is not intended to produce significant thrust, and therefore is not intended to be applied in the field of jet propellers of aircraft (excluded field).

[0006] The fuel used can be gaseous (natural gas, liquefied petroleum gas (LPG), biogas, and in general mixtures containing methane and / or hydrogen), liquid (for example diesel, naphtha, ethanol, kerosene) or solid (for example wood or coal powder). State of the art

[0007] In general, from a structural point of view, burners can be divided into premixed burners, suction gas or air burners and forced draft burners.

[0008] The first two are generally used for civil purposes (wall-hung boilers, stoves, relatively small generators for the production of hot water or steam), and comprise a supply duct whose cross section narrows at the point where the fuel or combustion agent is introduced. In this way, for low powers, the air is naturally sucked in by the fuel due to the Venturi effect, usually exploiting the pressure of the main gas ("atmospheric" or "Bunsen" type burners); or for higher powers, the fuel is sucked in by the combustion air driven by a fan, in the same way, driven by an electric motor located downstream of the gas valve with Venturi tube ("premixed" burners).

[0009] On the contrary, forced draft burners force the introduction of air and gas. In this case, the air is introduced by means of a fan placed upstream of the combustion head, and the gas is introduced by exploiting the main pressure of the gas itself (in the case of liquid or solid fuel by means of a pressurized circuit or pump).

[0010] This type of burners is mainly used for industrial applications (steam generators, hot air generators, industrial furnaces) and civil applications (hot water boilers for domestic and district heating).

[0011] Unfortunately, forced-draught burners require a high-lift fan to deliver air to the combustion head to maintain an effective pressure value, guaranteeing good mixing and suitable flame stability. This implies the use of an electric motor, which usually has a three-phase power supply, a relatively large size and significant power consumption, especially when it is not equipped with energy-saving devices such as inverters.

[0012] Object of the present invention

[0013] The technical task of the present invention is therefore to provide a burner for a combustion system which is able to overcome the drawbacks already emerged in the prior art.

[0014] The object of the present invention is therefore to create a burner which is not subject to the limitations of the use of a fan, with reduced or zero power supply requirements.

[0015] The stated technical task and objects are substantially achieved by a burner comprising the technical characteristics as set out in one or more of the attached claims.

[0016] Brief description of the attached drawings

[0017] Further characteristics and advantages of the present invention will become better apparent from the following detailed description of a preferred but non-exclusive embodiment of a burner for a combustion system, illustrated by way of non-limiting example in the accompanying drawings, in which:

[0018] - Figure 1a is a schematic view of a first embodiment (called "Turbine Jet") of a burner according to the present invention;

[0019] - Figure 1b is a schematic view of a variant of the first embodiment of a burner according to the present invention;

[0020] - Figure 2a is a schematic view of a second embodiment (called "Turbine Shaft") of a burner according to the present invention;

[0021] - Figure 2b is a schematic view of a variant of the second embodiment of a burner according to the present invention;

[0022] - Figure 3a is a schematic view of a third embodiment (called "Turbine Fan") of a burner according to the present invention;

[0023] - Figure 3b is a schematic view of a variant of the third embodiment of a burner according to the present invention.

[0024] Description of one or more preferred embodiments according to the present invention

[0025] With reference to the drawings, the burner is indicated in its entirety with the reference number 1, which is referred to herein as burner 1.

[0026] In particular, the drawings show three embodiments of the present application (two possible variants for each embodiment), which will be described in greater detail below. The common features of the three embodiments will first be described in general terms below.

[0027] The drawings show a burner 1 comprising a combustion head 2, in which the mixing of fuel and combustion air takes place, and subsequently the combustion reaction.

[0028] In particular, the burner 1 is a forced draft burner. Therefore, to effectively carry out the combustion reaction, a forced flow of combustion air is required on the combustion head 2.

[0029] The burner 1 comprises a fuel supply line 3 and a combustion air supply system, both operatively connected to the combustion head 2, for supplying a fuel flow and a combustion air flow, respectively, to the burner 1 (as will be better seen below, according to the embodiment, the combustion air preferably comprises the combustion fumes at the outlet of the turbine plus any secondary air, or the combustion air consists of a forced air draft that sucks in the combustion fumes at the outlet of the turbine).

[0030] The combustion head 2 is arranged to generate a continuous flame at least when the burner 1 is operating, and is configured to be connected to the combustion chamber of a heat production system.

[0031] The fuel supply line 3 is connected to a fuel source, for example a delivery pipe of pressurized fuel.

[0032] It should be noted that the fuel supply source delivers said fuel along the fuel supply line 3, which is then divided into a first branch 3a and a second branch 3b.

[0033] In particular, the fuel supply line 3 can supply different types of fuel (for example gaseous or liquid), preferably natural gas or a mixture of natural gas and hydrogen, to the combustion head 2 and to the auxiliary combustion chamber 6.

[0034] In a variant of the embodiment disclosed and not represented in the drawings, if two different fuels are used, the branch 3a and the branch 3b can be independent.

[0035] Advantageously, the fuel supply line 3 comprises fuel flow regulation and safety devices, indicated in its entirety with the reference number 70 in the drawings. The regulation and safety devices 70 are independent for the first branch 3a and for the second branch 3b; for each branch, the regulation and safety devices 70 comprise a "normally closed" on / off safety valve 70a, a stable proportional pressure regulator 70b and electrically operated regulation valves 70c, 70d.

[0036] The regulating and safety devices 70 arranged along the first branch 3a and the second branch 3b of the fuel supply line 3 will be of a suitably different type depending on the type of fuel used (for example liquid fuel or a specific fuel).

[0037] Moreover, in order to guarantee the operation of the turbine, it is preferable to have a high working pressure, therefore the fuel pressure at the burners of the auxiliary combustion chamber 6 cannot be neglected. Without the help of an intermediate pressure jump, high working pressure values can not be reached. For this purpose, it can be necessary to use a small booster with accumulator, compressor and stable proportional pressure regulator, indicated as a whole with 70e. In the attached figures, the booster 70e is arranged in the branch 3b, upstream of the unit comprising the on-off safety valve 70a, the stable proportional pressure regulator 70b and the regulating valve 70d and downstream of the fuel supply source.

[0038] As already disclosed, the supply line 3 supplies fuel to the combustion heads of the burners through the branch 3a, while the branch 3b supplies fuel to the burners in the auxiliary combustion chamber 6 of the turbine unit.

[0039] According to the present application, the burner 1 comprises a compressor 15, an auxiliary combustion chamber 6 and a turbine 7.

[0040] The auxiliary combustion chamber 6 is configured to receive the flow rate supplied by the compressor 15 in order to be able to generate a high pressure flow of fumes suitable for driving the turbine 7. The drive shaft 16 to which the compressor 15 and the turbine 7 are keyed is the same and the turbine unit operates with a Brayton-Joule thermodynamic cycle.

[0041] The turbine unit comprises at least the compressor 15, the auxiliary combustion chamber 6 and the turbine 7 and their dimensions are suitably determined according to the working requirements and the specific embodiments better described below.

[0042] The turbine 7 is configured to generate a total outlet pressure comprised between 0 and 600 millibar (60 kPa) with a mass flow rate less than 70 kg / s.

[0043] In the "turbine jet" embodiment ( Figure 1a and Figure 1b ) the turbine unit is sized so as to guarantee that the fumes at the outlet have a relatively high enthalpy content, so as to be able to exploit the high flow rate of the expanded gas at high temperature and suitable pressure.

[0044] In the "turbine shaft" embodiment ( Figure 2a and Figure 2b ) the turbine unit is sized so as to guarantee that the motor torque at the drive shaft 16 is suitable for driving the impeller and provides a sufficient pressure head at the combustion head 2.

[0045] In the "turbine fan" embodiment (Figure 3a and Figure 3b ) in which the size of the turbogas unit is appropriate to ensure that the enthalpy content of the fumes at the outlet of the first expansion stage is sufficiently high to enable the use of the residual energy to expand in the second stage turbine 20 in order to provide sufficient motor torque to drive the impeller and to ensure a suitable pressure head at the combustion head 2.

[0046] In all the above embodiments, the turbogas unit can have a plurality of expansion 7 compression stages 15, based on the design characteristics. Moreover, mainly for the "turbine shaft" and "turbine fan" embodiments, in the case where it is necessary to include two independent turbine-compressor units, the turbogas unit is provided with two coaxial drive shafts (not shown in the figures) for high and low pressure.

[0047] It should also be noted that any of the embodiments of the auxiliary combustion chamber 6 can be provided with various burners supplied in parallel, for example for high energy (the annular auxiliary combustion chamber can be provided with various burners for dispersing and aligning the flame energy in the available volume).

[0048] The high pressure fumes generated by the auxiliary combustion chamber 6 and directed towards the turbine 7 through the manifold 60 are started by the turbine 7.

[0049] The auxiliary combustion chamber 6 is connected to the fuel supply line 3 through a branch 3b (defining a discharge duct) which is arranged to be drawn from the fuel supply line 3.

[0050] In other words, the auxiliary combustion chamber 6 receives as a supply a portion of the fuel flow drawn from the fuel supply line 3.

[0051] In particular, the fuel flow regulation and safety device 70 is also configured to separate the fuel flow directed to the auxiliary combustion chamber 6 by means of the electrically powered regulation valve 70d.

[0052] The turbine 7 is operatively active to at least partially promote the movement of the fuel towards the combustion head 2.

[0053] In particular, in the "turbine jet" embodiment, the jet of fumes at the outlet of the turbine 7 is directed towards the combustion head 2. In the "turbine shaft" and "turbine fan" embodiments, the fans 9b and 21 push the combustion air towards the combustion head 2, thus sucking the fumes ejected from the turbines 7, 20.

[0054] In the "turbine jet" embodiment, the auxiliary combustion air is preferably introduced into the combustion head 2 via the line 4 by means of the Venturi effect. In the "turbine shaft" and "turbine fan" embodiments, the combustion air (in this case necessary rather than auxiliary) is driven by the fans 9b and 21.

[0055] Generally, the fan 9b or 21 is configured to supply the combustion head (2) with combustion air only. In particular, such a fan 9b or 21 can be arranged at or spaced from the combustion head 2 but configured to deliver a flow thereto (e.g. through an air delivery system).

[0056] In Figure 3a and Figure 3b the embodiment shown ("turbine fan"), the fan 21 is preferably but not necessarily arranged downstream of the turbines 7 and 20 according to the direction of movement of the combustion air towards the combustion head 2, so as to supply the combustion head 2 directly with combustion air.

[0057] It is noted that the overall combustion air intake system to the combustion head 2 is formed by the line 4 and / or by the flue gas portion at the outlet of the turbine 7. In the "turbine jet" embodiment, the intake of combustion air can also be guaranteed only by the flue gas portion at the outlet of the turbine 7, without the line 4 being activated or even not present at all in some cases. In fact, for such a configuration, the flue gas portion, having a higher pressure and a higher flow rate and a high residual value of O2 (about 16%), can itself be sufficient to guarantee the amount of combustion air required for correct combustion. Generally, according to the embodiment, additional combustion air is drawn in by an injector system located at the exhaust nozzle of the turbine 7 Figure 1a and Figure 1b ); while the necessary combustion air is mechanically forced to be introduced by a fan Figure 2a and Figure 2b , and Figure 3a and Figure 3b .

[0058] Thanks to the regulating member 100b, any additional ambient air (21% O2) from the line 100a can be proportionally distributed.

[0059] The turbine gas unit operates with the highest possible dilution ratio (BPR), preferably 0.5:1 to 1.5:1 for the turbine jet embodiment with intake flow, and preferably 2.5:1 to 12:1 for the turbine shaft and turbine fan embodiments.

[0060] The turbine 7 and the compressor 5 are preferably made of a metal alloy so as to withstand the high inertias of movement, mechanical strains and thermal stresses coming from the thermodynamic cycle.

[0061] According to alternative embodiments, the turbine 7 can comprise portions made of superalloys and / or made using advanced metal processing techniques (e.g. directional solidification or single crystal structure generation) to guarantee high performance levels under particularly high temperature conditions.

[0062] Generally, the burner 1 also comprises a fan 9 arranged in the pre-ventilation and post-ventilation line 120 of the compressor 4.

[0063] Two upstream branches flow into said pre-ventilation and post-ventilation lines 120, said branches being indicated with reference numerals 120a and 120b, respectively, suitable for the entry of air, preferably through the inlet 100. The fan 9 or 9a is arranged along the branch 120a.

[0064] It should be noted that the two branches 120a and 120b can be activated alternatively by means of the respective valves 121 and 122.

[0065] According to the embodiment illustrated in Figure 1, the fan 9 can be powered by means of an electric power source external to the burner, but alternatively it can be powered by means of a battery connected to the burner itself, which is charged during operation, as will be better disclosed below.

[0066] In particular, the fan 9 can be activated or deactivated by means of controllable activation means.

[0067] Advantageously, based on the type of application and in the embodiments not having multiple compression stages, the compressor 15 can have a compression ratio between 1.5 / 1 and 5 / 1, preferably between 1.5 / 1 and 3.5 / 1, and a low compression ratio guarantees a relatively controlled rotation mechanism, for example less than 50,000 RPM.

[0068] In the embodiment of Figure 1, the turbogas unit is designed to supply a flow of fumes which guarantees a characteristic flow / pressure curve suitable for supplying the combustion head of the burner, instead of using a traditional centrifugal fan.

[0069] In the other embodiments illustrated and described, the turbogas unit is designed to guarantee that the drive shaft 16 has sufficient motor torque to drive a fan which can provide a suitable flow and pressure to supply the combustion head 2 of the burner 1, or to provide sufficient enthalpy from the first expansion stage to complete the expansion of the gas in the second stage, thus driving a fan which can provide a suitable flow and pressure to supply the combustion head 2 of the burner 1.

[0070] In particular, the compressor 15 receives the flow of combustion-supporting agent at the inlet through the duct 120 and supplies the auxiliary combustion chamber 6 through the supply duct 130. The flow of combustion-supporting agent is preferably sucked through the inlet 100 described above.

[0071] During the start-up step of the burner 1, the fan 9 pushes air into the duct 120 to enable the turbogas unit to rotate and generate a flow of combustion-supporting agent towards the auxiliary combustion chamber 6. After the start-up step, the fan 9 can be deactivated, since the compressor 15 independently promotes the movement of the flow of combustion-supporting agent towards the auxiliary combustion chamber 6. During the deactivation step, the fan 9 can be reactivated to cool the turbogas unit and ventilate air into the combustion chamber of the heat production system in which the burner 1 is installed.

[0072] The burner 1 can comprise an electric unit 10 equipped with a battery 12 for powering a plurality of devices (for example electric motors) to guarantee the rotation of the turbogas unit up to the cycle self-supporting point (in this way instead of starting by means of the fan 9, or starting by means of the support of auxiliary lines (valve coils, flame control devices, servo motors, sensors, etc.).

[0073] Advantageously, the electric unit 10 can also comprise an alternator 13 (which in some technical variants can also act as a motor) keyed to the turbogas shaft so as to be able to charge the battery 12.

[0074] Furthermore, the electric unit 10 is configured so as to enable the turbogas unit to be turned on and / or off. In this regard, the drive shaft 16 is connected to the alternator 13 by means of a mechanical connection 50 (50b in the case of the "turbine shaft" embodiment).

[0075] This mechanical connection 50 (or 50b) can be configured to switch between an engaged condition, in which the drive shaft 16 drives the alternator 13 (for example when the turbogas unit is running at a steady speed), and a disengaged condition, in which the alternator 13 is disconnected from the drive shaft 16 (for example during the brief initial start-up of the turbogas unit).

[0076] Alternatively, mechanical starting of the turbogas unit is possible, in which the mechanical connection 50 (or 50b) is in the engaged condition and the electric motor 13 actively drives the drive shaft 16 until starting has taken place. It should be noted that in the figures the reference 13 is used to identify a single device which acts as an alternator or as a motor depending on the operating condition.

[0077] As shown in the attached figures, the drive shaft 16 on which the compressor 15 and the turbine 7 are keyed is supported by a fluid-dynamically supported sliding member 17 (essentially by an oil bushing or oil bearing or air bearing) having a liquid or gas passage. In the two particular cases of defining the two above-mentioned embodiments for each of the three embodiments, the fluid distribution mechanical configuration varies.

[0078] In the case of oil distribution (for example Figure 1b ), the pump 90 of the circuit is activated at the start of the starter motor (or fan). Typically, the circuit will be provided with a filter 91, a tank 95, a pressure regulator 92 with overflow valve, a heat exchanger 93 and monitoring / safety devices for pressure (PSH, PSL) and temperature (T) values. In the case of air distribution (for example Figure 1a), the pressure at the bearing 17 can be provided before starting, for example by advancing the timing circuit of the on / off valve 17a. The flow of air is guaranteed by the tank 95 under pressure, which according to the layout will be "boosted" by the compressor 96 according to the pressure drop detected by a pressure switch (PSL). Downstream of the tank, a stable pressure regulator 17b will be provided for keeping the pressure on the bearing 17 constant.

[0079] In steady operation, when the pressure detected by appropriate sensors, not shown, reaches a value sufficient to trigger the on / off switching valves 24 and 17a on the circuit (valve 17a closed and valve 24 open) so as to bypass the air flow from the compressor 96 support line to the operating compressor 15 of the turbogas unit, support to the bearing can be guaranteed by this compressor 15.

[0080] The burner 1 can comprise an energy recovery device 33 arranged upstream of the compressor 15 and a heat recovery device 19 arranged downstream of the turbine 7 or of the second stage turbine 20.

[0081] The heat recovery device 19 is configured to recover a portion of the thermal energy from the flue gas stream coming from the turbine 7 or 20. For example, the heat recovery device can comprise a heat exchanger and / or a Seebeck effect energy converter.

[0082] As regards the energy recovery device 33 arranged upstream of the compressor 15, it advantageously comprises the alternator 13 already described, which is keyed (by means of a breakable mechanical connection 50) to the turbogas shaft, so as to achieve the purpose of being able to charge the battery 12 for the storage of electrical energy and / or mainly for the exchange of any excess electrical energy.

[0083] The attached drawings show three different embodiments, in which:

[0084] - the first embodiment (called "turbine jet") is shown in Figure 1a and 1b respectively with a variant with air bearings ( Figure 1a ) and with oil bushings or oil bearings ( Figure 1b );

[0085] - the second embodiment (called "turbine shaft") is shown in Figure 2a and 2b respectively with a variant with air bearings ( Figure 2a ) and with oil bushings or oil bearings ( Figure 2b );

[0086] - the third embodiment (called "turbine fan") is shown in Figure 3a and 3b respectively with a variant with air bearings ( Figure 3a ) and with oil bushings or oil bearings (Figure 3b The variant of ) is shown.

[0087] The first embodiment (“turbine jet”) shows a burner 1 including a burner head 2 in which fuel and combustion accelerant are mixed and then a combustion reaction occurs.

[0088] The turbine gas unit is appropriately sized to ensure that the flue gas flow at the outlet has a suitable flow rate and pressure head to supply the burner head 2 and draw in additional combustion air flow through the Venturi effect.

[0089] The burner 1 includes the aforementioned fan 9 arranged along the duct 120 and specifically on branch 120a. The fan 9 can be powered by an external power source or by a battery 12 charged by an alternator 13.

[0090] Specifically, the fan 9 can be started or stopped by the starting device.

[0091] In addition, the compressor 15 receives the combustion-supporting agent flow at the inlet through the pipe 120 and supplies it to the auxiliary combustion chamber 6 through the supply pipe 130.

[0092] During the start-up phase of burner 2, fan 9 starts and supplies air into duct 120 to trigger the rotation of the turbine gas unit and generate a flow of oxidizer toward auxiliary combustion chamber 6. After the start-up phase, fan 9 (if present) can be shut off because the turbine gas unit is self-sustaining and compressor 15 independently promotes the flow of oxidizer toward auxiliary combustion chamber 6.

[0093] In addition, the burner 1 includes an electrical unit 10 equipped with a battery 12 to power multiple users (e.g., electric motors) to ensure that the unit rotates until the cycle self-support point, thereby replacing starting by the fan 9 and / or starting by the support of auxiliary lines (valve coil, flame control device, servo motor, etc.).

[0094] In other words, the electrical unit 10 is configured to enable the turbine gas unit to be turned on and / or off.

[0095] Advantageously, the electrical unit 10 also includes an alternator 13 (which acts as or includes a starter motor unit), which is keyed to the turbine gas shaft to enable charging of the battery 12.

[0096] Specifically, the drive shaft 16 is connected to the alternator 13 via a mechanical connection 50.

[0097] This mechanical connection 50 can be configured to switch between an engaged condition, in which the drive shaft 16 drives the alternator 13 (for example when the turbogas unit is running at full speed), and a disengaged condition, in which the alternator 13 is disconnected from the drive shaft 16 (for example during the brief initial start-up of the turbogas unit).

[0098] Alternatively, a mechanical start-up of the turbogas unit is possible, in which the mechanical connection 50 is in the engaged condition and the motor / alternator 13 actively drives the drive shaft 16 until the start-up has taken place.

[0099] The system is equipped with a regulation member 100b for the introduction of the secondary combustion air sucked in by the injectors 8a in Figure 1a and 1b , or of the primary combustion air sucked in by the fan 9b in Figure 2a and 2b and by the fan 21 in Figure 3a and 3b . In all variants, the primary or secondary combustion air can take away heat from the hot components through a convective motion, thus improving the thermal performance of the machine.

[0100] It should be noted that the introduction of the secondary combustion air can take place through a single inlet or through several inlets. In this regard, for the sake of completeness of the disclosure and only by way of example, the 1stembodiment shown in Figure 1a and 1b has two inlets 100a, while the other embodiments shown in the other figures show only one inlet 100a. In any case, it should be understood that each embodiment of the present invention can indifferently have one or more air inlets 100a.

[0101] Furthermore, the drive shaft 16 on which the compressor and the turbine are keyed is supported by fluid-dynamically supported sliding members (essentially by oil bushings or oil bearings or air bearings) having a liquid or gaseous passage. In two particular cases, the mechanical configuration of the fluid distribution will be different.

[0102] In the case of oil distribution (for example Figure 1b ), the pump 90 of the circuit is started at the start-up of the starter motor (or fan). Typically, the circuit is provided with a filter 91, a tank 95, a pressure regulator 92 with overflow valve, a heat exchanger 93 and monitoring / safety devices for the pressure (PSH, PSL) and temperature (T) values. In the case of air distribution (for example Figure 1a), the pressure at the bearings 17 can be provided before starting, for example by advancing the timing circuit of the on / off valve 17a. The flow of air is guaranteed by the tank 95 under pressure, which according to the layout will be "boosted" by the compressor 96 according to the pressure drop detected by the pressure switch (PSL). Downstream of the tank 95 a stable pressure regulator 17b will be provided, for keeping the pressure on the bearings 17 constant. When the pressure reaches a value sufficient to trigger the on / off switching valves 24 and 17a on the circuit (valve 17a closed and valve 24 open) in order to bypass the air flow from the compressor 96 support line to the operating compressor of the turbine gas unit, the air support to the bearings 17 is guaranteed by the compressor 15.

[0103] The burner 2 comprises an energy recovery device 33 arranged upstream of the compressor and a heat recovery device 19 arranged downstream of the turbine 7.

[0104] The heat recovery device 19 is configured to recover a portion of the thermal energy from the flue gas stream coming from the turbine 7 or 20. For example, the heat recovery device can comprise a heat exchanger and / or a Seebeck effect energy converter.

[0105] The energy recovery device 33 comprises, for example, the above-mentioned alternator 13 and the energy storage battery 12.

[0106] The embodiment of figure 2 ("turbine shaft") shows a burner 1 comprising a combustion head 2 in which the mixing of the fuel and the combustion agent takes place and subsequently the combustion reaction.

[0107] The turbine gas unit is dimensioned so as to ensure that the driving shaft 16 has sufficient torque to be able to drive the fan 9b to provide a sufficient head of combustion agent flow for the correct mixing in the combustion head 2. To this end, the compressor 15 and possibly the turbine 7 can be multi-stage, or the turbine gas unit can be composed of two independent turbine-compressor units for high and low pressure.

[0108] In this embodiment, in addition to the fan 9a, which is also present in the other embodiments, there is a fan 9b, which can be driven in rotation by the turbine 7.

[0109] The fan 9a is arranged along the branch 120a and can be activated by the supply of the electric power outside the burner 1 and / or of the electric unit 10 comprising the alternator / motor 13 and the battery 12.

[0110] In other words, the burner 1 comprises an electric unit 10 equipped with an electric motor for activating the turbine gas unit as an alternative to the fan 9a. This fan 9a can in any case be used in the step of pre-ventilation or post-ventilation.

[0111] The fan 9b is preferably configured to supply the combustion head 2 with the combustion agent only. In particular, such a fan 9b can be arranged at the combustion head 2 or spaced therefrom but configured to deliver a flow thereto (e.g. through an air delivery system).

[0112] Furthermore, the fan 9b is connected to the turbogas unit through a mechanical connection 50a.

[0113] The mechanical connection 50a can be configured to switch between an engaged condition and a disengaged condition. In the disengaged condition, the fan 9b is disconnected from the drive shaft of the demultipler 80, for example during the ignition step of the burner 1; and in the engaged condition, the fan 9b is connected to the drive shaft of the demultipler 80 to facilitate the direct flow of the combustion agent to the combustion head 2 and through the path 8, for example during the full operation step of the turbogas unit.

[0114] In particular, in order to be able to trigger the rotation of the fan in the most gradual manner possible and to prevent backlashes on the drive shaft 10 and upstream of the turbogas unit, the mechanical connection 50a can comprise a viscous coupling (Ferguson type) as well as a synchronous mechanical coupling.

[0115] In particular, the demultipler 80 enables the fan 9b to rotate at an angular speed lower with respect to the angular speed of the turbogas drive shaft 16.

[0116] For the preceding embodiment, the electric unit 10 is equipped with a battery 12 for storing the current supplied by the alternator and for powering the electric motor 13.

[0117] In fact, advantageously, the electric unit 10 comprises an alternator 13 connected to the turbogas unit for storing at least part of the mechanical energy of the turbine 7 in the battery 12.

[0118] In this way, the electric unit 10 is able to generate electric energy to guarantee the supply to a plurality of users.

[0119] Furthermore, the burner 1 comprises starting means to enable the opening and / or closing of the fan 9a.

[0120] The burner 1 comprises a compressor 15 adapted to supply the auxiliary combustion chamber 6 with a flow of combustion agent at the inlet.

[0121] And in this case, the drive shaft 16 is connected to the alternator 13 through a mechanical connection 50b.

[0122] Such a mechanical connection 50b can be configured to switch between an engaged condition, in which the drive shaft 16 drives the alternator 13 (for example when the turbogas unit is running at full speed), and a disengaged condition, in which the alternator 13 is disconnected from the drive shaft 16 (for example during the brief initial start-up of the turbogas unit).

[0123] In this way, during the short initial start-up of the turbogas unit, the mechanical connection 50a is in the disengaged condition, so that the fan 9a provides the air required for starting and the fan 9b does not generate any further inertia for starting the turbogas unit. Then, when the turbogas unit has sufficient speed, the mechanical connection 50a can be in the engaged condition, so that the turbogas unit drives the fan 9b to direct the combustion air towards the combustion head 2.

[0124] Alternatively, a mechanical start-up of the turbogas unit is possible, in which the mechanical connection 50b is in the engaged condition and the electric motor 13 actively drives the drive shaft 16 until the start-up has taken place. In this case, for the reasons described above, the connection 50a can be disengaged.

[0125] In particular, the compressor 15 receives the flow of combustion air at the inlet through the duct 120 and then supplies the auxiliary combustion chamber 6 through the supply duct 130.

[0126] In detail, the turbine 7 and the compressor 15 are keyed to the drive shaft 16, which is supported by the gas bearings 17, which are supplied through the auxiliary energy supply line 18 and / or through the connection taken from the compressor 15.

[0127] Alternatively, oil bearings or oil bushes can be provided without changing the inventive concept underlying the present application.

[0128] In the case of oil distribution (for example Figure 2b ), the pump 90 of the circuit is started at the start-up of the starter motor (or fan). Typically, the circuit will be provided with a filter, a tank 95, a pressure regulator 92 with overflow valve, a heat exchanger 93 and monitoring / safety means for the pressure and temperature (T) values. In the case of air distribution (for example Figure 2a ), the pressure can be supplied to the bearings before starting, for example through a timing circuit that opens the on / off valve 17a in advance. The flow of air is guaranteed by the tank 95 under pressure, which according to the layout will be "recharged" by the compressor 96 according to the pressure drop detected by the pressure switch (PSL). Downstream of the tank, a stable pressure regulator 17b will be provided, for keeping the pressure on the bearings 17 constant. When the pressure reaches a value sufficient to trigger the on / off exchange valve 24 and 17a on the circuit (closing valve 17a and opening valve 24) so as to bypass the air flow from the compressor support line to the operating compressor of the turbogas unit, the air support to the bearings can be guaranteed through this compressor 15.

[0129] Figure 3 ("turbine fan") shows the burner 1 comprising the combustion head 2, in which the mixing of fuel and combustion air takes place, and subsequently the combustion reaction.

[0130] The size of the turbogas unit is appropriate to provide sufficient motor torque to the second expansion stage, so as to guarantee, through the fan 21, a sufficient pressure head at the combustion head 2. To this end, the compressor 15 and possibly the turbine 7 can be multi-stage, or the turbogas unit can be composed of two independent turbine-compressor units, for high and low pressure.

[0131] In order to provide the correct excess air at the combustion head 2 in the embodiment of the double expansion stage turbogas fan burner, there is a path 8 for the supply of combustion air, which is introduced through one or more regulating members 100b, also electrically actuated.

[0132] If the turbogas shaft is not directly started by means of electrical devices, the line 120 can activate the turbogas unit by providing the compressor 15 with the necessary amount of air through the fan 9, which has appropriate on-off exchange valves 121, 122. In this case, the fan can have a second function, that of ventilating in a pre-ventilation step and cooling the unit in a post-ventilation step.

[0133] The burner 1 comprises a compressor 15, a combustion chamber 6, a turbine 7 and a two-stage turbine 20.

[0134] The two-stage turbine 20 is arranged to receive the exhaust gases produced by the turbine 7. Preferably, as shown in the attached figures, according to the direction of movement of the combustion agent towards the combustion head 2, the two-stage turbine 20 is arranged downstream of the turbine 7.

[0135] The combustion chamber 6 is configured to receive the air flow processed by the compressor 15, which is processed by the compressor 15 so as to be able to generate a high pressure gas flow suitable for driving the turbine 7, which then leaves the first expansion stage with a high enthalpy and flows in a second stage expansion, to drive the fan 21. The rotation shaft to which the compressor and the turbine are keyed is the same, and the turbogas unit operates with a Brayton-Joule double expansion cycle. The connection shaft 22 of the fan 21 and the two-stage turbine 20 is unconstrained and independent of the turbine of the first stage. The size of the turbogas unit is appropriate to guarantee a sufficient output pressure from the first stage to be able to drive the turbine 20 to start the fan 21, so as to be able to provide a sufficient pressure head of the combustion agent flow for the correct mixing in the combustion head 2.

[0136] The turbine 20 is moved by the exhaust gases with high residual enthalpy from the first expansion stage and provides the mechanical movement of the fan 21 through the driving shaft 22.

[0137] It should be noted that, although the fan 21 is shown arranged downstream of the turbine 20 for simplicity of illustration in the figures, it is preferably arranged upstream of the turbogas unit.

[0138] The first expansion unit supplies the exhaust gases to the second expansion unit through a manifold in which a on / off valve 20a is inserted, which is activated alternatively with a gas injection valve 20b of the first stage, which opens when the second expansion unit is not used. In this way, even when / if the combustion head 2 remains closed, the high-pressure unit can be triggered on a continuous cycle.

[0139] When the valve 20b is closed, any overpressure of the first expansion stage can be relieved by a self-opening valve 20c according to the exceeding of a certain set pressure threshold.

[0140] In other words, the turbine 7 is activated by the high-pressure fumes generated by the auxiliary combustion chamber 6, which are directed towards the turbine 7 through the manifold 60.

[0141] The integration air introduced by the line 100a has the effect of removing heat from the turbine gas unit by convection, simultaneously with the ideal path 8 through the hot elements. In this way, it is possible to reduce the heat dispersion and improve the overall operating energy balance of the machine.

[0142] The regulating device 70 of the fuel flow is also configured to split the fuel flow to be directed to the auxiliary combustion chamber 6.

[0143] The turbine 7 is operatively active to make a substantial contribution to the discharge of high-pressure gases in the second stage driving the fan 21.

[0144] The gases exiting from the turbine 20 and possibly from the valve 20c are drawn towards the combustion head 2 by the air supplied by the fan.

[0145] Also for this embodiment, the drive shaft 16 is connected to the alternator 13 through a mechanical connection 50.

[0146] This mechanical connection 50 can be configured to switch between an engaged condition, in which the drive shaft 16 drives the alternator 13 (for example, when the turbine gas unit is running at full speed), and a disengaged condition, in which the alternator 13 is disconnected from the drive shaft 16 (for example, during the brief initial start-up of the turbine gas unit).

[0147] Furthermore, the drive shaft 16 on which the compressor and the turbine are keyed is supported by a fluid-dynamically supported sliding member (essentially by an oil bushing or oil bearing or air bearing), which has a liquid or gas passage. In the two specific cases, the mechanical configuration of the fluid distribution will be different.

[0148] In the case of oil distribution (for example Figure 3b), the pump 90 of the circuit is started at the start of the starter motor (or fan). Typically, the circuit will be provided with a filter 91, a tank 95, a pressure regulator 92 with overflow valve, a heat exchanger 93 and monitoring / safety means for the pressure and temperature (T) values.

[0149] In the case of air distribution, the pressure at the bearings 17 can be provided before starting, for example by means of a timing circuit which opens the on / off valve 17a in advance. The flow of air is guaranteed by the tank 95 under pressure, which according to the layout will be "recharged" by the compressor 96 according to the pressure drop detected by the pressure switch (PSL). Downstream of the tank, a stable pressure regulator 17b will be provided, for keeping the pressure on the bearings 17 constant. When the pressure reaches a value sufficient to trigger the on / off switching valves 17a and 24 on the circuit in order to bypass the air flow from the compressor 96 support line to the operating compressor of the turbogas unit, the air support to the bearings 17 and 23 can be guaranteed by the compressor 15.

[0150] The combustor 2 can comprise an energy recovery device 33 arranged upstream of the compressor 13 and a heat recovery device 19 arranged downstream of the turbine 7.

[0151] The heat recovery device 19 is configured to recover a portion of the thermal energy from the flue gas stream coming from the turbine 7.

[0152] For example, the heat recovery device can comprise a heat exchanger and / or a Seebeck effect energy converter.

[0153] The present application also relates to a heat production system comprising a combustion chamber (preferably defined by a water or steam boiler, and / or a smelter, and / or an incinerator, and / or a flue gas reheat combustion chamber) and a combustor of the type described above, in which the combustion head 2 is connected to the combustion chamber so that the flame produced extends into said combustion chamber.

[0154] According to another aspect, the present application relates to a method for supplying a combustor, the method comprising the steps of discharging at least a first quantity of fuel from a fuel supply line and supplying at least a second quantity of fuel to a combustion head.

[0155] In other words, the method envisages discharging a portion of fuel from a fuel supply line suitable for supplying a combustor.

[0156] The method also comprises the step of combusting the first quantity of fuel.

[0157] The step is carried out inside a combustion chamber. The method also envisages the step of converting a portion of the energy from the combustion of the discharged fuel into a combustion aid for the combustion head.

[0158] Preferably, the method comprises the step of starting a turbine by means of the flue gas in the combustion chamber described above.

[0159] In particular, the turbine can be connected to a fan, or to a secondary turbine connected to a fan, suitable for promoting the flow of fluid, preferably air, to the combustion head of the burner.

[0160] It can thus be seen that the present application achieves the proposed aim by providing a burner capable of operating with a reduced or zero supply of electricity and of generating an electric current to supply operating equipment and to introduce any surplus into the pipeline.

[0161] The present application achieves the set aim by finding a compact solution with respect to the prior art and providing a single machine that achieves the multiple aims predetermined by the above-mentioned application.

[0162] In particular, the turbine gas unit provides the necessary head of exhaust fumes, thus enabling the operation of the combustion head. Thanks to the gas regulation valve, which can vary the fuel flow of the burner in the auxiliary combustion chamber 6 of the turbine gas unit, the flow of combustion air of the combustion head 2 can also be regulated by increasing or decreasing the rotation speed of the turbine gas unit. Thanks to the electric regulation system, it is also possible to regulate the necessary or secondary quantity of combustion air.

[0163] Advantageously, the post-combustion of the exhaust gases from the turbine 7 or 20 contributes to reducing the content of NOx emissions.

[0164] Advantageously, the flow of combustion air skimming over the surfaces of the hot components improves the thermal balance, thus increasing the performance of the machine.

[0165] Advantageously, the possibility of regulating the flow of gas to the turbine gas boiler, together with the possibility of operating the regulation device of the suction fuel, increases the regulation ratio of the burner 2 with respect to the use of traditional centrifugal ventilators, without the need for inverters used in common burners.

[0166] Advantageously, the system can be configured to produce heat through a recuperator downstream of the turbine gas unit.

[0167] Advantageously, the possibility of generating an electric current for the process, recovering heat and obtaining a flame configures the unit as a trigeneration unit, while achieving the aim of optimizing the process and catering to the trend of increasing efficiency and reducing pollutants, as required by current legislation.

[0168] Advantageously, the present application can be used with fuels containing hydrogen or hydrogenated mixtures, such as hydrogenated methane.

[0169] Advantageously, the present application can be equipped with an electronic regulation system and the flow of fuel and combustion air can be detected by the relevant flow measurement sensors, in order to achieve automation and make the combustion more efficient.

Claims

1. A heat production system comprising: - a combustion chamber; and - a burner (1) for generating a flame for the heat production system, the burner (1) comprising: - a combustion head (2) arranged to produce a continuous flame at least when the burner (1) is operating, and configured to be connected to the combustion chamber of the heat production system; - a fuel supply line (3) and a combustion air intake system, both operatively connected to the combustion head (2) for supplying a fuel flow and a combustion air flow, respectively, to the burner (1); - an auxiliary combustion chamber (6) of a gas turbine, separate from the combustion head (2) and configured for the combustion of fuel and the production of a flow of fumes; and - a turbine (7) activated by the fumes produced by the auxiliary combustion chamber (6) and operatively operating to at least partially contribute to the movement of the combustion air in the combustion air intake system, wherein the turbine (7) directs an exhaust jet of outlet to the combustion head (2); wherein the combustion head (2) is at least partially inserted into the combustion chamber so that the produced flame extends into the combustion chamber; the combustion chamber being defined by a water or steam boiler and / or a smelter and / or an incinerator. The turbine (7) is configured to produce a total outlet pressure comprised between 0 and 600 mbar, with a mass flow less than 70 kg / s.

2. The heat generating system of claim 1, wherein, The auxiliary combustion chamber (6) is connected to the fuel supply line (3).

3. The heat generating system of claim 1, wherein, 4. The heat production system according to claim 1, wherein the auxiliary combustion chamber (6) is connected to the fuel supply line (3) by means of a discharge duct (3b) arranged as a tapping branch from the fuel supply line. The exhaust jet causes the suction of combustion air from a portion of the combustion air supply line (4) of the combustion air intake system.

5. The heat generating system of claim 1, wherein, The exhaust jet causes the suction of combustion air from a portion of the combustion air supply line (4) of the combustion air intake system by means of a Venturi effect.

6. The heat generating system of claim 1, wherein, 7. The heat production system according to any one of claims 1 to 6, comprising a fan (9b) configured to contribute to the supply of combustion air to the combustion air intake system and rotatably activated by the turbine (7). The fan (9b) is mounted on a drive shaft (16) to which the turbine (7) is keyed.

8. The heat generating system of claim 7, wherein, The fan (9b) is configured to supply combustion air only to the combustion head (2).

9. The heat generating system of claim 8, wherein, The fan (9b) is connected to the drive shaft (16) by means of a mechanical connection (50a) which can be configured to be switched between an engaged condition and a disengaged condition, in which the fan (9b) is disconnected from the drive shaft (16), and in which the fan (9b) is connected to the drive shaft (16) to facilitate the flow of combustion air to the combustion head (2).

10. The heat generating system of claim 8, wherein, According to the direction of movement of the combustion air towards the combustion head (2), the fan (9b) is arranged downstream of the turbine (7) so as to supply combustion air to the combustion head (2).

11. The heat generating system of claim 8, wherein, ​ 12. The heat generating system according to any one of claims 1 to 6, comprising a secondary turbine (20) defining a second expansion stage arranged to receive the exhaust gases produced by the turbine (7); the secondary turbine (20) being arranged downstream of the turbine (7) so as to supply the combustion head (2) with combustion agent, according to the direction of movement of the combustion agent towards the combustion head (2).

13. The heat generating system according to claim 12, comprising an additional fan (21) rotationally activated by a mechanical connection (22) between the additional fan (21) and the secondary turbine (20).

14. The heat generating system according to any one of claims 1 to 6, further comprising a compressor (15) having one or more compression stages, the compressor (15) being configured to supply a flow of combustion agent into the auxiliary combustion chamber (6); the compressor (15) and the turbine (7) being keyed to a drive shaft (16) so as to define a turbogas unit associated with the auxiliary combustion chamber (6).

15. The heat generating system according to claim 14, comprising electric activation means connected to the drive shaft (16) for activating the turbogas unit at least in a start-up step of the burner (1).

16. The heat generating system according to claim 14, comprising a fan (9, 9a) connected to the compressor (15) by an intake duct (120), the fan (9, 9a) being used to activate the turbogas unit at least in a start-up step of the burner (1) and to ventilate the turbogas unit in a pre-start-up step or to cool the turbogas unit in a shut-down step.

17. The heat generating system of claim 16, wherein, The intake duct (120) of the turbogas unit has at least two inlets (100) provided with valves (111, 122) for alternately opening or closing the at least two inlets (100), the at least two inlets (100) being adjustable for regulating the flow of combustion agent entering the intake duct (120) or dividing the flow of combustion agent entering the intake duct (120).

18. The heat generating system according to claim 14, comprising an electric unit (10) equipped with an electric motor (13) for activating the turbogas unit during an initial start-up step; the electric unit (10) being equipped with a battery (12) for powering the electric motor (13).

19. The heat generating system of claim 18, wherein, The electric unit (10) further comprises an alternator (13) connected to the drive shaft (16) for storing at least part of the mechanical energy of the turbine (7) during a running step.

20. The heat generating system according to any one of claims 1 to 6, comprising an energy recovery device (33) in turn comprising a heat recovery device (19) arranged downstream of the turbine (7) and configured to recover thermal energy from the flow of fumes coming from the turbine (7).

21. The heat generating system according to any one of claims 1 to 6, wherein, The turbine (7) is mounted on a drive shaft (16) supported by a gas or air bearing (17) connected to an auxiliary gas or air supply line.

22. A method for generating a flame for a heat generating system according to any one of claims 1 to 21, comprising: - discharging at least a first amount of fuel from a fuel supply line for supplying fuel to a combustion head, the combustion head being arranged to produce the flame and being connectable to a combustion chamber of the heat generating system; - combusting the first amount of fuel in a combustion chamber separate from the combustion head; and - converting part of the energy from the combustion of the discharged fuel into mechanical energy, the mechanical energy being used to supply combustion-supporting agent to the combustion head.

23. The method according to claim 22, comprising the steps of: - arranging a turbine for converting the part of the energy from the combustion of the discharged fuel, the turbine being configured to at least partly contribute to the movement of combustion-supporting agent in the combustion head; and - configuring the turbine to produce a total outlet pressure of between 0 and 600 mbar, wherein the mass flow is less than 70 kg / s.

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