A method of controlling the conditioning of a fuel feed to a power generating system comprising a gas turbine, and a related gas turbine auxiliary system for feed conditioning

Abstract

A power generating system is disclosed. The power generating system includes a gas turbine and an auxiliary system for feed conditioning, utilizing hydrogen-containing substances. The auxiliary system comprises feed inlet lines with valves, feed decomposition reactors that produce a hydrogen-rich gas mixture, and outlet lines connecting the reactors to the gas turbine through a inlet line with a valve. A control system adjusts the operation of the valves and reactors based on the gas turbine's parameters. Additional features include feed by-pass lines, separation means for dividing high-value and low-value gas mixtures, and a heat recovery system to utilize exhaust gas heat. The system can also include a blending apparatus for mixing gas mixtures and storage apparatus for gases. Methods for controlling the system's operation involve determining gas mixture amounts and compositions based on various parameters and controlling valve operations accordingly.

Description

A method of controlling the conditioning of a fuel feed to a power generating system comprising a gas turbine, and a related gas turbine auxiliary system for feed conditioningDescriptionTECHNICAL FIELD

[0001] The present disclosure concerns a system for generating power using a gas turbine, wherein the system comprises a device for conditioning the feed before directing it to the gas turbine. Embodiments disclosed herein specifically concern a power generating system comprising a gas turbine and a gas turbine auxiliary system for feed conditioning, wherein one or more feed decomposition reactors process an input stream of a hydrogen containing feed in order to realize a product gas stream that allows operating the gas turbine in every condition. In particular, embodiments disclosed herein concern a gas turbine auxiliary system for feed conditioning through decomposition of one or more hydrogen containing substances into a decomposition gas mixture containing at least one high-value gas mixture, rich in hydrogen.BACKGROUND ART

[0002] Gas turbines are commonly used to generate power at power stations by combusting fuel therein. In particular, the basic operation of a gas turbine is a Brayton cycle with air as the working fluid: atmospheric air flows through a compressor that brings it to a higher pressure; energy is then added by injecting fuel into the air in a combustion chamber and igniting it so that a combustion generates a high-temperature flow; this high-temperature pressurized gas enters a turbine, producing a shaft work output in the process, used to drive the compressor; the unused energy comes out in - the exhaust gases that can be repurposed for external work, such as directly producing thrust in a turboj et engine, or rotating a second, independent turbine (known as a power turbine) that can be connected to a fan, propeller, or electrical generator. The purpose of the gas turbine determines the design so that the most desirable split of energy between the thrust and the shaft work is achieved. The fourth step of the Brayton cycle (cooling of the working fluid) is omitted, as gas turbines are open systems that do not reuse the same air.

[0003] Commonly used fuels include natural gas, propane, diesel, biogas and biodiesel. One of the main problems associated with combusting fuels such as these in gas turbines is the resultant production of carbon dioxide (CO2) gas. Increased CO2 levels in the atmosphere are detrimental to the environment and are a known cause of global warming. As such, there is a need to provide fuels for use in gas turbines which do not generate CO2 upon combustion, or from which CO2 must be removed prior to combustion.

[0004] Carbon-free fuels include ammonia and hydrogen. However, both ammonia and hydrogen have some problems associated with their direct use as fuel in a gas turbine. The main problem associated with the direct use of ammonia as fuel in gas turbines is that during the combustion process ammonia is oxidized to nitrogen oxides NOX, a polluting agent contributing to acid rain and global warming. Additionally, due to the low heat content and low reactivity of ammonia with oxygen, the ammonia combustion within the gas turbine presents stability issues (blow-out) over the entire range of the gas turbine operating conditions. On the other hand, even if the combustion of hydrogen still produces NOXpolluting agents, stability issues (blowout) disappear. Nevertheless, a number of problems is associated with the use of hydrogen as fuel, including storage problems and the fact that hydrogen is an extremely flammable gas. The availability of N2 as inert within the combustion process could help to reduce NOXemissions depending on the type of flame realized in the gas turbine combustor.SUMMARY

[0005] In one aspect, the subject matter disclosed herein is directed to a method for controlling the operation of the power generating system, the method comprising the steps of decomposing at least part of a feed consisting in one or more hydrogen containing substances into a decomposition gas mixture comprising at least one high- value gas mixture, rich in hydrogen; determining the amount of high-value gas mixture delivered to the gas turbine and the amount of feed stream delivered to the decomposition unit, respectively, based on various parameters such as combustion, emissions, and gas turbine parameters. The method also includes adjusting the operation of feed inlet and gas turbine inlet valves to control the flow of gas mixtures in accordance with the determined parameters.

[0006] In another aspect, the subject matter disclosed herein is directed to a power generating system that includes a gas turbine and an auxiliary system for feed conditioning, wherein the feed is a hydrogen containing fuel. The system comprises feed inlet lines with valves, feed decomposition reactors that produce a high-value hydrogen-rich gas mixture, outlet lines with respective valves for the gas mixture connected to the gas turbine through respective inlet lines, and a control system that adjusts the operation based on the gas turbine's parameters, plant requirements, such as user requirements and / or operative requirements, law regulations, also comprising emission requirements, combustion dynamics, environmental conditions, such as ambient temperature and / or pressure, humidity, altitude.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A more complete appreciation of the disclosed embodiments of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:Fig. l illustrates a schematic of a power generating system using a gas turbine and comprising a feed conditioning device according to a first embodiment;Fig.2 illustrates a schematic of a power generating system using a gas turbine and comprising a feed conditioning device according to a second embodiment;Fig.3 illustrates a schematic of a power generating system using a gas turbine and comprising a feed conditioning device according to a third embodiment;Fig.4 illustrates a schematic of a power generating system using a gas turbine and comprising a feed conditioning device according to a fourth embodiment;Fig.5 illustrates a schematic of a power generating system using a gas turbine and comprising a feed conditioning device according to a fifth embodiment; andFig.6 illustrates a block diagram of the control architecture of the power generating system using a gas turbine and comprising a feed conditioning device of Fig. 3.DETAILED DESCRIPTION OF EMBODIMENTS

[0008] According to one aspect, the present subject matter is directed to a power generating system comprising a gas turbine and a gas turbine auxiliary system for feedconditioning, said feed consisting in one or more hydrogen containing substances and / or hydrogen carriers, herein after referred to as a whole as hydrogen containing feeds, wherein the gas turbine auxiliary system for feed conditioning comprises one or more feed inlet lines, each connected to one or more sources of a same or different feed, each with a respective feed inlet flow valve, one or more feed decomposition reactors, each feed decomposition reactor being configured to decompose one or more hydrogen containing feeds into a decomposition gas mixture comprising at least one high-value gas mixture, rich in hydrogen,- one or more high-value gas mixture outlet lines of each feed decomposition reactor, the high-value gas mixture outlet lines being provided with respective high value gas mixture flow valves and connecting the feed decomposition reactors to the gas turbine through a first gas turbine inlet line, and- a control system configured to adjust the operation of the feed inlet valves, the feed decomposition reactors and the high value gas mixture flow valve as a function of the set parameters of the gas turbine.The power generating system can also comprise one or more feed by-pass lines with respective feed by-pass flow valves, connecting said one or more feed inlet lines to the gas turbine through the first gas turbine inlet line or a different gas turbine inlet line, the control system being configured to adjust the operation of the feed by-pass flow valves as a function of the set parameters of the gas turbine. In particular, at least one feed decomposition reactor can be configured to decompose said one or more hydrogen containing feeds into at least one high-value gas mixture, rich in hydrogen, and at least one low- value gas mixture.

[0009] In one aspect, the power generating system can further comprise separating means of the at least one feed decomposition reactor, the separating means being configured to separate the at least one high-value gas mixture from the at least one low-value gas mixture, the low-value gas mixture also including any unreacted hydrogen containing feed, one or more high-value gas mixture outlet lines, downstream of the separating means of each feed decomposition reactor, and one or more low-value gas mixture outlet lines, downstream of the separatingmeans of each feed decomposition reactor, the control system being configured to additionally control the operation of the separating means as a function of the set parameters of the gas turbine.In particular, the low-value gas mixture outlet lines can be provided with a low-value gas mixture flow valve and can be configured to connect the feed decomposition reactors to the gas turbine through a second gas turbine inlet line, the control system being configured to additionally control the operation of the low-value gas mixture flow valve as a function of the set parameters of the gas turbine. Alternatively, the bypass line is configured to connect the high-value gas mixture outlet line to the second gas turbine inlet line or to connect the low-value gas mixture outlet line to the first gas turbine inlet line. A blending apparatus can be connected downstream of the high- value gas mixture outlet line and the low-value gas mixture outlet line and upstream of the first gas turbine inlet line and the second gas turbine inlet line, to blend the high- value gas mixture and the low-value gas mixture.

[0010] In another aspect, the subject matter disclosed herein concerns a method for controlling operation of the above defined power generating system, the method comprising the following steps: determining the amount of the high value gas mixture, fed to the gas turbine through the high value gas mixture outlet line and the first gas turbine inlet line, as a function of the gas turbine parameters; determining the amount of the feed stream, delivered to the decomposition unit through one or more feed inlet lines as a function of the decomposition parameters; determining the volumetric composition of the high value gas mixture in the high value gas mixture outlet line as a function of the combustion parameters, emission requirements, determining the operation of one or more of the feed inlet flow valves controlling the amount of the feed inlet stream in the respective feed inlet lines as a function of the combustion parameters, emission requirements; and / or determining the operation of the high value gas mixture flow valve controlling the amount of the high value gas mixture stream flowing inside the first gas turbine inlet line as a function of the gas turbine parameters.

[0011] According to one aspect, the method can also comprise the following steps: determining the amount of the low value gas mixture, fed to the gas turbine through the low value gas mixture outlet line and the second gas turbine inlet line, as a function of the gas turbine parameters and determining the operation of the low value gas mixture flow valve controlling the amount of low value gas mixture stream flowing inside the low value gas mixture outlet line as a function of the gas turbine parameters.

[0012] According to one aspect, the method for controlling operation of the power generating system of the present disclosure allows to control the composition of the low value gas mixture and / or the composition of the high value gas mixture fed to the gas turbine by mixing the low value gas mixture and the high value gas mixture upstream of the gas turbine. In particular, the method for controlling operation of the power generating system can comprise the following steps: determining the volumetric composition of the low value gas mixture in the low value gas mixture outlet line, as a function of the combustion parameters, emission requirements;- determining the operation of a bypass gas flow valve controlling the amount of high value gas mixture stream flowing from the high-value gas mixture outlet line to the second gas turbine inlet line as a function of the gas turbine parameters; or, alternatively, the following steps: determining the volumetric composition of the high value gas mixture in the high value gas mixture outlet line, as a function of the combustion parameters, emission requirements;- determining the operation of a bypass gas flow valve controlling the amount of low value gas mixture stream flowing from the low value gas mixture outlet line to the first gas turbine inlet line as a function of the gas turbine parameters.

[0013] Alternatively, the method for controlling operation of the power generating system in accordance with the present disclosure can further comprise the steps of:- mixing a first amount of high value gas mixture and a first amount of the low value gas mixture, to obtain a blended gas mixture;- determining the amount of the blended gas mixture to be fed to the gas turbine through the first gas turbine inlet line, as a function of the gas turbine parametersand- determining the volumetric composition of the blended gas mixture in the first gas turbine inlet line, as a function of the combustion parameters and emission requirements;- determining the operation of the high value gas mixture flow valve, controlling the amount of high value gas mixture and of the high value gas mixture flow valve controlling the amount of the low value gas mixture, as a function of the gas turbine parameters.

[0014] Reference now will be made in detail to embodiments of the disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the disclosure, not limitation of the disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. Reference throughout the specification to “one embodiment” or “an embodiment” or “some embodiments” means that the particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrase “in one embodiment” or “in an embodiment” or “in some embodiments” in various places throughout the specification is not necessarily referring to the same embodiment s). Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0015] When introducing elements of various embodiments the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0016] Referring now to the drawings, Fig.l shows a schematic of an exemplary power generating system comprising a gas turbine 100. The gas turbine 100 comprises a compressor, a combustion chamber and an expander. The power generating system comprises a feed inlet line 1, connected to a source of a feed consisting in one or more hydrogen containing substances. More in general, the inlet line can be connected to different sources of the same or different hydrogen containing feeds and can switch from one source to another. Moreover, the power generating system can comprise aplurality of feed inlet lines 1, each feed inlet line 1 being connected to one or more sources of a same or different feed. Exemplary hydrogen containing feeds include ammonia, natural gas (methane), methanol, propane, diesel, biogas and biodiesel. Exemplary hydrogen containing feeds can also include water. Moreover, in the context of the present disclosure, the definition hydrogen containing feed can also refer to hydrogen carriers, in particular hydrogen organic carriers. A feed inlet flow valve 11 is provided for the feed inlet line 1, and in general for each feed inlet line 1. The feed inlet line 1 directs the feed to a feed decomposition reactor 200, more in general to one or more feed decomposition reactors 200, wherein the feed is decomposed into a decomposition gas mixture containing at least one high-value gas mixture, rich in hydrogen. The high-value gas mixture exits from the decomposition reactor 200 through a high-value gas mixture outlet line 2 connecting the feed decomposition reactor 200 to the gas turbine 100 through a first gas turbine inlet line 2’. A high value gas mixture flow valve 21 is provided along the high-value gas mixture outlet line 2. The operation of the power generating system of Fig. 1 is controlled by a control system configured to adjust the operation of the feed inlet valve 11, the feed decomposition reactor 200 and the high value gas mixture flow valve 21 as a function of the set parameters of the gas turbine 100. In particular, the set parameters of the gas turbine 100 can comprise one or more of the following: plant requirements, such as user requirements and / or operative requirements, law regulations, also comprising emission requirements, combustion dynamics, environmental conditions, such as ambient temperature and / or pressure, humidity, altitude.

[0017] According to an exemplary embodiment shown in Fig.l, the feed decomposition reactor 200 can be a catalytic or thermal reactor, configured to process the feed and dissociate it into a decomposition gas mixture containing at least one high- value gas mixture, rich in hydrogen, in presence of a catalyst or under temperature control. In an alternative embodiment, wherein the hydrogen containing substance of the feed is water, the feed decomposition reactor 200 can be an electrolyzer or hydrolizer, configured to dissociate the feed into hydrogen and oxygen. Hydrogen is then fed to the gas turbine, while oxygen is directed to external users. Delivery of the oxygen to the gas turbine is not provided. An emergency system (not shown) is arranged along the gas turbine inlet line 2 and includes a vent and emergency valves to prevent overpressure. A storage drum (not shown) can optionally be arranged alongthe high value gas mixture outlet line 2. In some embodiments the control system can be, for example, a computer or programmable logic controller (PLC).

[0018] The control method allows to change the amount of the high value gas mixture to the gas turbine 100 by determining the operation (E) of the high value gas mixture flow valve 21 controlling the amount of the high value gas mixture flowing inside the high value gas mixture outlet line 2 and the first gas turbine inlet line 2’ as a function of the gas turbine parameters: E=f(m2+m3)=f (GT param). Additionally, the control method allows to change the composition of the high value gas mixture to the gas turbine 100 by controlling the operation A of the feed decomposition reactor 200 as a function of the volumetric composition of the gas (A=f(x2i; X3i)), wherein X2i is the volumetric composition of the high-value gas mixture in the first gas turbine inlet line 2’ and X3i is the volumetric composition of the low-value gas mixture in the second gas turbine inlet line 3’, to increase or decrease the reaction conversion rate, i.e. by reducing the amount of products and consequently increasing the amount of unreacted feed, or vice versa. In particular, when the feed decomposition reactor 200 is a electrolyzer or hydrolyzer, configured to dissociate water into hydrogen and oxygen, then the operation A of the feed decomposition reactor 200 is a function of the temperature inside the feed decomposition reactor 200 and / or the intensity of current in the electrodes of the electrolyzer or of the hydrolyzer. In addition, when the feed inlet line 1 is configured for being connected to different sources of different feeds, then the control method allows to select and / or to switch from one type of feed to another. In addition, when a plurality of feed inlet lines 1 is present and connected to sources of different feeds, then the control method allows to change the composition of the gas mixture to the gas turbine 100 by controlling the operation of the feed inlet valve 11 of each feed inlet line 1, in order to vary the composition of the feed mixture directed to the decomposition reactor 200. In particular, in case multiple sources of hydrogen containing feed (e.g. CEU, NH3, CEhOH, other HC; or water) are available, the operation V of the valves 11 controlling the inlet of the selected sources to the decomposition reactors 200 is determined as a function of gas turbine parameters, combustion parameters and plant requirements: V=f(GT param; Comb param, plant requirements). Moreover, in case multiple reactor units are present, e.g. with different catalysts, depending from the selected sources of feed, the status Z of the selected decomposition reactor or reactors 200 is determined as a function of gas turbineparameters, combustion parameters and plant requirements: Z=f(GT param; Comb param, plant requirements).

[0019] With continuing reference to Fig. l, further embodiments of a power generating system are shown in Figs. 2, 3, 4 and 5. The same reference numbers designate the same or corresponding parts, elements or components already illustrated in Fig.l and described above, and which will not be described again. In particular, according to the embodiment shown in Fig.2, a feed by-pass line 4 with respective feed by-pass flow valve 41 connects the feed inlet line 1 to the gas turbine through the first gas turbine inlet line 2’, the control system being configured to adjust the operation B of the feed by-pass flow valve 41 as a function of the set parameters of the gas turbine: B=f(GT param). In particular, through the by-pass line 4 it is possible to operate a control of the composition of the gas mixture to the gas turbine 100 by controlling the amount of unreacted feed in a faster way with respect to the one shown with reference to Fig. 1. In particular, in case a plurality of feed inlet lines 1 is present, each of them can be associated to a respective by-pass line 4.

[0020] With continuing reference to Figs 1 and 2, a further embodiment of a power generating system is shown in Fig.3. The same reference numbers designate the same or corresponding parts, elements or components already illustrated in Figs.1 and 2 and described above, and which will not be described again. The power generating system of Fig.3 differs from the power generating system of Fig.2 mainly in that the feed decomposition reactor 200 is configured to decompose the hydrogen containing feed into at least one high-value gas mixture, rich in hydrogen, and at least one low-value gas mixture and in that it further comprises separating means of the feed decomposition reactor 200, to separate the at least one high-value gas mixture from the at least one low-value gas mixture, the at least one low-value gas mixture also containing unreacted hydrogen containing feed. A high-value gas mixture outlet line 2 and a low-value gas mixture outlet line 3 are present downstream of the separating means of the feed decomposition reactor 200, the high-value gas mixture outlet line 2 being connected to the first gas turbine inlet line 2’ and the low-value gas mixture outlet line 3 being connected to the second gas turbine inlet line 3’ and being provided with a low value gas mixture flow valve 31. When the separating means are present, the control system can control operation of the power generating system by additionally controlling the operation C of the separating means as a function of theset parameters of the gas turbine 100: C=f(GT param). Additionally, the control system controls the operation E of the high value gas mixture flow valve 21 and the operation F of the low value gas mixture flow valve 31 as a function of the set parameters of the gas turbine 100:E=f (GT param)=f(m2+m3)F=f (GT param)=f(m2 / (m2+m3)).

[0021] Optionally, the separating means can also be configured to separate a stream of unreacted feed to be recycled to the decomposition reactor through a recirculation line (not shown). Additionally, part of the exhaust gas 101 from the gas turbine 100 is routed to an exhaust gas stream line 102’, from which a portion of the exhaust gas stream is split through an exhaust gas heat recovery line 102, which is routed to the decomposition reactor 200. A heat recovery flow valve 112 is arranged on the exhaust gas heat recovery line 102 in order to control the portion of the exhaust gas from the gas turbine 100 that is directed to the decomposition reactor 200.

[0022] Finally, Fig.3 shows a bypass line 5, with a bypass gas flow valve 51 and connecting the high-value gas mixture outlet line 2 to the low-value gas mixture outlet line 3 and the second gas turbine inlet line 3’, allowing a further control of the operation of the power generating system. In fact, based on the volumetric composition of the low value gas mixture in the second gas turbine inlet line 3’, the control system can determine the operation G of the bypass gas flow valve 51 controlling the amount of high value gas mixture stream flowing through the bypass line 5, from the high- value gas mixture outlet line 2 to the low-value gas mixture outlet line 3 and the second gas turbine inlet line 3’.

[0023] With continuing reference to Figs 1, 2 and 3, a further embodiment of a power generating system is shown in Fig.4. The same reference numbers designate the same or corresponding parts, elements or components already illustrated in Figs. l, 2 and 3 and described above, and which will not be described again. The power generating system of Fig.4 differs from the power generating system of Fig.3 mainly in that a bypass line 6, with a bypass gas flow valve 61, and connecting the low-value gas mixture outlet line 3 to the high-value gas mixture outlet line 2 and the first gas turbine inlet line 2’ is present instead of the bypass line 5, with a bypass gas flow valve 51 and connecting the high-value gas mixture outlet line 2 to the low-value gas mixture outletline 3 and the second gas turbine inlet lines 3’. According to this configuration, the control system can control the operation of the power generating system in accordance with the volumetric composition X2i of the high-value gas mixture in the first gas turbine inlet line 2’ , by determining the operation G’ of the bypass gas flow valve 61 controlling the amount of low-value gas mixture stream flowing from the low-value gas mixture outlet line 3 to the high value gas mixture outlet line 2 and the first gas turbine inlet line 2’ .

[0024] With continuing reference to Figs 1, 2, 3 and 4, a further embodiment of a power generating system is shown in Fig.5. The same reference numbers designate the same or corresponding parts, elements or components already illustrated in Figs. l, 2, 3 and 4 and described above, and which will not be described again. The power generating system of Fig.5 differs from the power generating system of Fig.3 mainly in that a blending apparatus 300 is connected downstream of the high-value gas mixture outlet line 2 and the low-value gas mixture outlet line 3 and upstream of the first gas turbine inlet line 2’ and the second gas turbine inlet line 3’, the blending apparatus 300 being configured to blend the high-value gas mixture and the low-value gas mixture. A flow valve 21’ of the first gas turbine inlet line 2’ and a flow valve 31 of the second gas turbine inlet line 3’ are also present to control the amount mb 2 of the blended gas mixture to be fed to the gas turbine 100 through the first gas turbine inlet line 2’ and the amount mb3 of the blended gas mixture to be fed to the gas turbine 100 through the second gas turbine inlet line 3’. In accordance with this embodiment, the control system can operate by mixing a first amount m2 of high value gas mixture and a first amount m3 of the low value gas mixture, to obtain a blended gas mixture; determining the amount mb2 of the blended gas mixture to be fed to the gas turbine 100 through the first gas turbine inlet line 2’ and the amount mb3 of the blended gas mixture to be fed to the gas turbine 100 through the second gas turbine inlet line 3’, as a function of the gas turbine parameters: mb2=f(GT param), and- determining the volumetric composition Xb2i of the blended gas mixture in the first gas turbine inlet line 2’, as a function of the combustion parameters and plant requirements, in particular emission requirements: Xb2i=f(Comb param; Emiss req);determining the operation E of the high value gas mixture flow valve (21), controlling the amount of high value gas mixture and the operation F of the low value gas mixture flow valve (31) controlling the amount of the low value gas mixture, as a function of the gas turbine parameters.

[0025] With continuing reference to Figs. 1-5, Fig. 6 illustrates a block diagram of the control architecture of the power generating system using a gas turbine and comprising a feed conditioning device according to the embodiment of Fig. 3.

[0026] In particular, the blocks of the block diagram are identified by letters, corresponding to the control elements listed in the following table land to the control outputs listed in the following table 2.Table 1. Control elementsTable 2. Control outputs

[0027] In particular, according to the block diagram of the control architecture of the power generating system shown in fig. 3, the flow valves 21, 31 and 51 and the heat recovery flow valve 112 are operated as follows. A gas turbine control unit D such as, for example, a computer or programmable logic controller (PLC), receives the following input parameters: gas turbine parameters M, combustion parameters N and plant requirements O. In particular, the gas turbine parameters M are dependent from the gas turbine technology. In some embodiments, the gas turbine parameters M comprise the gas turbine generated power, the gas turbine speed, the gas turbine exhaust gas temperature. The combustion parameters N are dependent from the combustion technology adopted by the gas turbine. In some embodiments, the combustion parameters N comprise fuel-to-air-ratio in specific zones of the combustor and distribution of the thermal load along the combustor. Plant requirements O comprise pollutant emissions in the exhaust stream downstream the gas turbine 100, user requirements, law regulations, combustion dynamics and environmental conditions, such as ambient temperature, pressure, humidity and altitude. The total amount R of gas fed to the gas turbine as the sum of the high value gas mixture and the low value gas mixture, respectively through the high-value gas mixture outlet line 2(indicated with m2) and the low-value gas mixture outlet line 3 (m3) are a function of the above gas turbine parameters:R = m2 + m3 = f(GT param)The volumetric composition of the high value gas mixture in the high-value gas mixture outlet line 2 (indicated by the reference letter U in Fig. 6), the volumetric composition P of the low value gas mixture in the low-value gas mixture outlet line 3; the ratio Q of the high value gas mixture mass flow through the high-value gas mixture outlet line 2 (m2) and the total mass flow (m2+m3) of the high value gas mixture and the low value gas mixture fed to the gas turbine 100 are a function of the above combustion parameters and plant requirements:U = X2i = flcombustion parameters; plant requirements)P = X3i = flcombustion parameters; plant requirements)Q = m2 / (m2 + m3) = flcombustion parameters; plant requirements)These parameters (P, Q, R, U), together with the current feed decomposition reactor parameter status T (as measured through measurement devices) and, in case multiple sources of hydrogen containing feed (e.g. CH4, NH3, CEFOH, other HC) are available, the status V of the valves (11) controlling the inlet of the selected sources to the decomposition reactor, determined as already described with reference to Fig.l, and also, in case multiple reactor units are present, e.g. with different catalysts, depending from the selected source or sources, the status Z of the selected decomposition reactor or reactors, determined as already described with reference to Fig. l, are the input(s) to the auxiliary control unit S such as, for example, a computer or programmable logic controller (PLC), configured to control the operation of the flow valves 21, 31 and 51, of the heat recovery flow valve 112 and the feed decomposition system parameters according to the following relations. The operation E of the gas flow valve 21 controlling the amount m2 of high value gas mixture flowing inside high-value gas mixture outlet line 2, is a function of the sum of the amount of the high value gas mixture m2 and the low value gas mixture m3 :E = f(m2 + m3) = f (GT param)The operation F of the gas flow valve 31 controlling the amount m3 of low value gas mixture flowing inside the low-value gas mixture outlet line 3 and the second gas turbine inlet line 3’ is a function of the ratio of the high value gas mixture mass flow m2 through the high-value gas mixture outlet line 2 and the sum of the mass flow of the high value gas mixture m2 and the low value gas mixture m3 :F = f(m2 / (m2 + m3)) = f (GT param)Finally, the operation G of the bypass gas flow valve (51) controlling the amount of high value gas mixture flowing from the high-value gas mixture outlet line (2) to thelow-value gas mixture outlet line 3 and the second gas turbine inlet line (3’), the operation H of the heat recovery flow valve 112 and the operation A of the feed decomposition reactor are a function of the volumetric composition of the gas:G = f(x2i; x3i) H = f(x2i; X3i)A = f(x2i; X30The above described control method allows to change the composition of the fuel to the gas turbine and inject high value gas mixture, in particular hydrogen, in any ratio according to any eventual combustor and gas turbine requirements (these requirements not being part of the present disclosure).

[0028] While aspects of the invention have been described in terms of various specific embodiments, it will be apparent to those of ordinary skill in the art that many modifications, changes, and omissions are possible without departing from the spirt and scope of the claims.

Claims

A method of controlling the conditioning of a fuel feed to a power generating system comprising a gas turbine, and a related gas turbine auxiliary system for feed conditioningCLAIMS1. A method for controlling operation of a power generating system, the power generating system comprising a gas turbine (100) and a gas turbine auxiliary system for feed conditioning, said feed consisting in one or more hydrogen containing substances, wherein the gas turbine auxiliary system for feed conditioning comprises one or more feed inlet lines (1), each connected to one or more sources of a same or different feed, each with a respective feed inlet flow valve (11), one or more feed decomposition reactors (200), each feed decomposition reactor (200) being configured to decompose one or more hydrogen containing substances into a decomposition gas mixture containing at least one high-value gas mixture, rich in hydrogen, each of said one or more feed decomposition reactors (200) being connected downstream of at least one of said one or more feed inlet lines (1),- one or more high-value gas mixture outlet lines (2) of each feed decomposition reactor (200), the high-value gas mixture outlet lines (2) connecting the feed decomposition reactors (200) to the gas turbine (100) through a first gas turbine inlet line (2’), the high-value gas mixture outlet lines (2) being provided with a high value gas mixture flow valve (21), and a control system configured to adjust the operation of the feed inlet valves (11), the feed decomposition reactors (200) and the high value gas mixture flow valve (21) as a function of the set parameters of the gas turbine (100), the method comprising the following steps: delivering a feed to the decomposition unit (200), the feed comprising one or more hydrogen containing substances; decomposing at least part of the feed into a decomposition gas mixture comprising at least one high-value gas mixture, rich in hydrogen,determining the amount (m2) of the high value gas mixture, fed to the gas turbine (100) through the high value gas mixture outlet line (2) and the first gas turbine inlet line (2’), as a function of the gas turbine parameters: m2 = f(GT param); determining the amount (ml) of the feed stream, delivered to the decomposition unit (200) through one or more feed inlet lines (1) as a function of the decomposition parameters: ml=f(decomp param); determining the volumetric composition (x2i) of the high value gas mixture in the high value gas mixture outlet line (2) as a function of the combustion parameters, emission requirements: X2i=f(Comb param; Emiss req), determining the operation (V) of one or more of the feed inlet flow valves (11) controlling the amount of the feed inlet stream in the respective feed inlet lines (1) as a function of the gas turbine parameters, the combustion parameters, plant requirements: V=f(GT param; Comb param, plant requirements); and / or- determining the operation (E) of the high value gas mixture flow valve (21) controlling the amount of the high value gas mixture flowing inside the high value gas mixture outlet line (2) and the first gas turbine inlet line (2’) as a function of the gas turbine parameters: E=f (GT param).

2. The method for controlling operation of a power generating system in accordance to claim 1, further comprising the following step:- by-passing to the gas turbine (100) an amount of the feed as a function of the set parameters of the gas turbine (100).

3. The method for con trolling operation of a power generating system in accordance to claim 1 or 2, wherein the decomposition gas mixture of the step of decomposing the feed also comprises a low-value gas mixture.

4. The method for controlling operation of a power generating system in accordance to claim 3, further comprising the following steps: separating the at least one high-value gas mixture from the at least one low-value gas mixture, the at least one low-value gas mixture also including any unreacted hydrogen containing feed;- feeding part of the low-value gas mixture to the gas turbine (100) through a low- value gas mixture outlet line (3) with a low-value gas mixture flow valves (31)and a second gas turbine inlet line (3’); and controlling the operation of the separating means as a function of the set parameters of the gas turbine (100).

5. The method for controlling operation of a power generating system in accordance to claim 4, further comprising the following steps: determining the amount (m3) of the low value gas mixture, fed to the gas turbine (100) through the low value gas mixture outlet line (3) and the second gas turbine inlet line (3’), as a function of the gas turbine parameters: m3=f(GT param); and- determining the operation (F) of the low value gas mixture flow valve (31) controlling the amount of low value gas mixture stream flowing inside the low value gas mixture outlet line (3) and the second gas turbine inlet line (3’) as a function of the gas turbine parameters: F=f (GT param).

6. The method for controlling operation of a power generating system in accordance to claim 5, further comprising the steps of: determining the volumetric composition (x3i) of the low value gas mixture in the low value gas mixture outlet line (3), as a function of the combustion parameters, emission requirements: X3i=f(Comb param; Emiss req);- determining the operation (G) of a bypass gas flow valve (51) controlling the amount (m5) of high value gas mixture stream flowing through a by-pass line (5) from the high-value gas mixture outlet line (2) to the low-value gas mixture outlet line (3) and the second gas turbine inlet line (3’) as a function of the gas turbine parameters: G=f(GT param).

7. The method for controlling operation of a power generating system in accordance to claim 5, further comprising the steps of: determining the volumetric composition (x2i) of the high value gas mixture in the high value gas mixture outlet line (2), as a function of the combustion parameters, emission requirements: X2i=f(Comb param; Emiss req);- determining the operation (G’) of a bypass gas flow valve (61) controlling the amount of low value gas mixture stream flowing through a by-pass line (6) from the low value gas mixture outlet line (3) to the first gas turbine inlet line (2’) as a function of the gas turbine parameters: G’=f(GT param).

8. The method for controlling operation of a power generating system in accordance to one or more of claims 4-7, further comprising the steps of:- mixing a first amount (m2) of high value gas mixture and a first amount (m3) of the low value gas mixture, to obtain a blended gas mixture;- determining the amount (mb2) of the blended gas mixture to be fed to the gas turbine (100) through the first gas turbine inlet line (2’), as a function of the gas turbine parameters: mb2=f(GT param) and- determining the volumetric composition (xb2i) of the blended gas mixture in the first gas turbine inlet line (2’), as a function of the combustion parameters and emission requirements: Xb2i=f(Comb param; Emiss req);- determining the operation (E, F) of the high value gas mixture flow valve (21), controlling the amount of high value gas mixture and of the low value gas mixture flow valve (31) controlling the amount of the low value gas mixture, as a function of the gas turbine parameters: E=f (GT param); F=f (GT param).

9. A power generating system configured to be operated according to the method of claims 1-8, the power generating system comprising a gas turbine (100) and a gas turbine auxiliary system for feed conditioning, said feed consisting in one or more hydrogen containing substances, wherein the gas turbine auxiliary system for feed conditioning comprises one or more feed inlet lines (1), each connected to one or more sources of a same or different feed, each with a respective feed inlet flow valve (11), one or more feed decomposition reactors (200), each feed decomposition reactor (200) being configured to decompose one or more hydrogen containing substances into a decomposition gas mixture containing at least one high-value gas mixture, rich in hydrogen,- one or more high-value gas mixture outlet lines (2) of each feed decomposition reactor (200), the high-value gas mixture outlet lines (2) connecting the feed decomposition reactors (200) to the gas turbine (100) through a first gas turbine inlet line (2’), the high-value gas mixture outlet line (2) being provided with a high value gas mixture flow valve (21), and- a control system configured to adjust the operation of the feed inlet valves (11), the feed decomposition reactors (200) and the high value gas mixture flow valve(21) as a function of the set parameters of the gas turbine (100).

10. The power generating system of claim 9, configured to be operated also according to at least claim 2, the power generating system further comprising one or more feed by-pass lines (4) with respective feed by-pass flow valves (41) connecting said one or more feed inlet lines (1) to the gas turbine (100) through the first gas turbine inlet line (2’) or a different gas turbine inlet line, the control system being configured to adjust the operation of the feed by-pass flow valves (41) as a function of the set parameters of the gas turbine (100).

11. The power generating system of claim 9 or 10, wherein at least one feed decomposition reactor (200) is configured to decompose said one or more hydrogen containing feeds into at least one high-value gas mixture, rich in hydrogen, and at least one low- value gas mixture.

12. The power generating system of claim 11, further comprising separating means of said at least one feed decomposition reactor (200), the separating means being configured to separate the at least one high-value gas mixture from the at least one low-value gas mixture, the at least one low-value gas mixture also including any unreacted hydrogen containing feed, one or more high-value gas mixture outlet lines (2), downstream of the separating means of each feed decomposition reactor (200), one or more low-value gas mixture outlet line (3), downstream of the separating means of each feed decomposition reactor (200),- the control system being configured to additionally control the operation of the separating means as a function of the set parameters of the gas turbine (100).

13. The power generating system of claim 12, configured to be operated also according to at least claim 4, wherein the one or more low-value gas mixture outlet lines (3), with respective low-value gas mixture flow valves (31), are configured to connect the feed decomposition reactors (200) to the gas turbine (100) through a second gas turbine inlet line (3’), the control system being configured to additionally control the operation of the low-value gas mixture flow valves (31) as a function of the set parameters of the gas turbine (100).

14. The power generating system of claim 12 or 13, wherein a bypassline (5) is configured to connect said high-value gas mixture outlet line (2) to said low- value gas mixture outlet line (3).

15. The power generating system of claim 12 or 13, wherein a bypass line (6) is configured to connect said low-value gas mixture outlet line (3) to said high- value gas mixture outlet line (2).

16. The power generating system of claim 13, wherein a blending apparatus (300) is connected downstream of the high-value gas mixture outlet line (2) and the low-value gas mixture outlet line (3) and upstream of the first gas turbine inlet line (2’) and the second gas turbine inlet line (3’), the blending apparatus (300) being configured to blend the high-value gas mixture and the low-value gas mixture.

17. The power generating system of one or more of claims 12-16, wherein a gas storage apparatus is arranged along the high-value gas mixture outlet line (2) and / or along the low-value gas mixture outlet line (3).

18. The power generating system of one or more of claims 9-17, also comprising a heat recovery system configured to recover at least part of the heat of an exhaust gas stream from the gas turbine (100), the heat recovery system comprising a heat recovery sub-line (102’), configured to convey a portion (102) of the exhaust gas stream to the decomposition reactor (200).

19. The power generating system of claim 18, also comprising at least one heat recovery flow valve (112), the control system being configured to additionally control the operation of the heat recovery flow valve (112).

20. The power generating system of claim 13 and one or more of claims 12 and 14-19, wherein the first gas turbine inlet line (2’) is connected to a primary stage of the gas turbine (100) and the second gas turbine inlet line (3’) is connected to a secondary stage of the gas turbine (100).

21. The power generating system of claim 13 and one or more of claims 12 and 14-19, wherein the first gas turbine inlet line (2’) is connected to a secondary stage of the gas turbine (100) and the second gas turbine inlet line (3’) is connected to a primary stage of the gas turbine (100).

22. The power generating system of one or more of claims 9-21 , wherein said one or more feed decomposition reactors (200) comprise at least one feed decomposition reactor (200).

23. The power generating system of one or more of claims 9-22, wherein said hydrogen containing substances are chosen amongst ammonia, methane and mixtures thereof.

24. The power generating system of one or more of claims 9-22, wherein said hydrogen containing substance is water.

25. The power generating system of one or more of claims 9-24, wherein the set parameters of the gas turbine (100) comprise one or more of the following: plant requirements, such as user requirements and / or operative requirements, law regulations, also comprising emission requirements, combustion dynamics, environmental conditions, such as ambient temperature and / or pressure, humidity, altitude.

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