Method for supplying fuel to at least one gas turbine combustion chamber and associated fuel supply system

Abstract

Method for supplying fuel to at least one gas turbine combustion chamber (2), comprising: introducing hydrocarbon with hydrogen into a fuel feed line (3) connected to at least one combustion chamber (2), separating the mixture of hydrocarbon and hydrogen in a bypass circuit (8) connected to the fuel feed line (3) to obtain separated hydrogen and hydrocarbon, and selectively supplying hydrogen, hydrocarbon or a mixture of hydrocarbon and hydrogen to the combustion chamber (2) depending on the operating mode of the gas turbine

Description

The present invention relates generally to the fuel supply to a combustor of a gas turbine, and more particularly to the separation of a mixture of hydrocarbon and hydrogen intended to supply a combustor in a gas turbine.In particular, the invention relates to a method for supplying fuel into at least one combustion chamber of a gas turbine and to an associated fuel supply system which enables a mixture of hydrocarbon and hydrogen intended for supplying the combustion chamber to be separated.In recent years, interest and activities have been increasing in the field of development of non-fossil fuel-based power sources, for example, in power generation from solar or wind energy or in power generation from hydrogen.This development has led to the production of hydrogen from excess renewable energy for feeding to natural gas pipelines.In fact, European Union 2003 / 55 / EG guideline opened up access to the existing natural gas transport and distribution network and allowed the joint transport of hydrogen mixed with natural gas.The resulting mixture of natural gas and hydrogen reduces the carbon intensity of the hydrocarbons.In addition, the use of hydrogen in the combustion system is advantageous since no compounds are formed which are considered to be environmentally harmful, such as: S, CO 2, CO, fine dust and unburned hydrocarbons.Typically, the initial mixture could contain about 1% hydrogen, but the proportion can reach up to 20%.However, hydrogen can lead to various operating risks when used in a gas turbine, for example, explosions, flame backpressure, etc. In particular, when starting a gas turbine with a fuel mixture having a hydrogen content of more than 5%, and in the event of faults in the starting phase, a quantity of hydrogen-containing gas can be present in the inner cavities of the turbine, subsequent to the combustion and up to the exhaust. The hydrogen content then present in the inner cavities of the turbine can trigger an explosion in conjunction with high temperatures and cause an overpressure due to buffer. Therefore, it is necessary to ensure start-up of a gas turbine by eliminating the risks involved in high hydrogen content combustion in the fuel mixture.The purpose of the invention is therefore to eliminate these disadvantages and to propose a method for supplying the combustion chamber of a gas turbine with hydrocarbons free of hydrogen, in particular if this makes it possible to limit the risks associated with its use, namely from a mixture of hydrocarbon and hydrogen which is fed to the gas turbine via an industrial gas network, a transport or distribution plant.Hydrogen can be separated from the mixture by a physical process in which hydrogen diffuses through a membrane which can be made of polymer, metal, ceramic or even in liquid form. However, in separating with this technology, it must be taken into account that it generally has difficulties in compatibility with certain molecules, in particular acids, hexanes and sulfites.These molecules tend to destroy the polymer structure of membranes. In addition, molecules with large carbon chains readily condense and plug the filters, thereby lowering the efficiency of the membrane.Therefore, a method of supplying at least one gas turbine combustor is proposed, including:receiving a mixture of hydrocarbon and hydrogen in a supply line connected to the combustion chamber,separating the mixture of hydrocarbon and hydrogen in a bypass circuit connected to the feed line for the separate recovery of hydrogen and hydrocarbon,and selectively supplying the combustor with hydrogen, hydrocarbon or a mixture of hydrocarbon and hydrogen depending on the mode of operation of the gas turbine.Advantageously, the bypass circuit may include at least one hydrocarbon tank, the method comprising:determining an amount of hydrocarbon in the hydrocarbon tank,comparing the determined amount of hydrocarbon with a predetermined hydrocarbon threshold,introducing a mixture of hydrocarbon and hydrogen into the feed line when the determined amount of hydrocarbon is less than the predetermined hydrocarbon threshold value,separating the hydrocarbon-hydrogen mixture in the bypass circuit to produce hydrocarbon during operation of the gas turbine or at standstill of the gas turbine; andstoring the obtained hydrocarbon in the hydrocarbon tank until an amount of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold is reached.The predefined threshold value is preferably assigned to an amount of hydrocarbon required for the operation of the gas turbine during at least one transition phase.Advantageously, the transition phase may be one of the following: ignition, start-up, stop and a change in the combustion mode of the gas turbine or even an increase or decrease in the load in response to an event in the power grid to which it is connected.Advantageously, the method comprises supplying hydrocarbon through the supply to at least one combustor previously separated from the hydrocarbon-hydrogen mixture in the bypass cycle for operation of the gas turbine during a transition phase.Preferably, the method includes measuring the hydrogen content in the hydrocarbon previously separated from the hydrocarbon-hydrogen mixture by the bypass circuit.Advantageously, the method may include an additional separation step if the measured hydrogen content is above a predetermined hydrogen threshold, for example in the event of membrane fouling.Preferably, the bypass circuit comprises at least one hydrogen tank, the method comprising storing hydrogen recovered after separation of the mixture of hydrocarbon and hydrogen in the hydrogen tank.Preferably, the bypass circuit includes at least one hydrocarbon tank, the method comprising:storing hydrocarbon recovered after separating the hydrocarbon-hydrogen mixture in the hydrocarbon tank;obtaining a mixture of hydrocarbon and hydrogen in which the hydrocarbon and hydrogen contents are controlled from hydrocarbon stored in the hydrocarbon tank and hydrogen stored in the hydrogen tank; andsupplying the combustor with a mixture of hydrocarbon and hydrogen in controlled proportions.For example, the feed process may comprise recovering a mixture of hydrocarbon and hydrogen at controlled proportions which are either enriched with hydrogen or low in hydrogen compared to the mixture of hydrocarbon and hydrogen in the industrial, remote or gas distribution network.The invention also relates to a fuel supply system for at least one combustion chamber in a gas turbine, having:a feed line for supplying at least one combustion chamber with a mixture of hydrocarbon and hydrogen, comprising:an intake section to be connected to an industrial, remote line or gas distribution network supplying a mixture of hydrocarbon and hydrogen,a separation section adjacent to the suction section connected to a hydrocarbon-hydrogen mixture inlet in a bypass circuit and having at least one hydrocarbon-hydrogen mixture separator DS1,an injection portion adjacent to the separation portion connected to a hydrocarbon outlet and a hydrogen outlet of the bypass circuit; anda supply portion adjacent to the injection portion and connected to at least one combustor of the gas turbine; anda plurality of valves each disposed between the suction portion and the separation portion, between the separation portion and the injection portion, between the injection portion and the supply portion, between the separation portion of the supply line and the inlet of the mixture of hydrocarbon and hydrogen in the bypass circuit, between the hydrocarbon outlet of the bypass circuit and the supply portion of the supply line, and between the hydrogen outlet of the bypass circuit and the injection portion of the supply line.Preferably, the bypass circuit comprises a hydrocarbon tank arranged downstream of the hydrocarbon-hydrogen mixture separator and having a capacity greater than or equal to a predetermined hydrocarbon threshold.Preferably, the fuel supply system comprises a management computer configured to arrange when the amount of hydrocarbon in the hydrocarbon tank is below a predetermined hydrocarbon threshold:receiving a mixture of hydrocarbon and hydrogen into the fuel supply system,separating the mixture of hydrocarbon and hydrogen in the bypass circuit to obtain hydrocarbon; andstoring the recovered hydrocarbon in the hydrocarbon tank until an amount of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold is reached.Advantageously, the fuel supply system may include at least one gas analyzer located downstream of the hydrocarbon-hydrogen mixture separator and configured to measure the hydrogen content in the hydrocarbon recovered downstream of the hydrocarbon-hydrogen mixture separator. This makes it possible to check the efficiency of the separation process and compare the hydrogen content with a predefined expected hydrogen level.Advantageously, the bypass circuit may include an additional separator for the mixture of hydrocarbon and hydrogen, arranged downstream of the separator. It is particularly advantageous to have an additional separating device to increase the efficiency of the separating process.Preferably, the bypass circuit includes at least one hydrogen tank for storing hydrogen previously separated from the hydrocarbon by the separator or the additional separator.Further purposes, advantages and characteristics are shown in the following description, which is for illustrative purposes only and is made with reference to the accompanying drawing, in which: FIG. 1 is an illustration of a gas turbine combustor fuel supply system according to an embodiment of the invention.In the following, the term "at least one" used in this description is synonymous with the term "one or more".FIG. 1 shows a fuel supply system 1 which serves to supply fuel to at least one combustion chamber 2 in a gas turbine.The fuel supply system 1 comprises a fuel feed line 3 for the combustion chamber 2.Via the fuel feed line 3 of the fuel supply system 1, it is likely that a plurality of combustion chambers 2 of the gas turbine can be supplied with fuel.The fuel supply pipe 3 is composed of an intake portion 4, a partition portion 5, an injection portion 6, and a supply portion 7.The suction section 4 is intended for connection to an industrial, transport or gas distribution network supplying a mixture of hydrocarbon and hydrogen, outside the fuel supply system 1, and allows a mixture of hydrocarbon and hydrogen to be sucked into the fuel supply line 3.The network may be an industrial, trunking and / or gas distribution network that carries a mixture of hydrocarbon and hydrogen.In the example shown, the gas network that provides the mixture of hydrocarbon and hydrogen is a gas distribution network.The mixture transported and then distributed over the industrial, trunking or gas distribution network may contain one or more hydrocarbons of different types.The hydrogen content in the mixture of hydrocarbon and hydrogen distributed over the industrial, trunking or gas distribution network may be between 0 and 20%.In the present invention, the terms "upstream" and "downstream" are considered with respect to the flow direction of the fuel flow in the gas turbine, in particular between the intake section 4 and the combustion chamber 2 of the gas turbine.The separating portion 5 is disposed downstream of and adjacent to the suction portion 4.The separation portion 5 is connected to an inlet E 1 of a bypass circuit 8 to introduce a mixture of hydrocarbon and hydrogen into the bypass circuit 8.The bypass circuit 8 connected to the separating section 5 is arranged parallel to the fuel feed line 3.The bypass circuit 8 must comprise at least one separator DS1 for a mixture of hydrocarbon and hydrogen in order to separate the hydrocarbon and hydrogen from the mixture into two separate streams with a certain efficiency. Preferably, the separator is a membrane of the polymer, metal, ceramic or even liquid type.The injection section 6 is arranged downstream of the separating section 5 and adjacent thereto.Moreover, the injection portion 6 is connected to a hydrocarbon outlet SHC 1 and a hydrogen outlet SH 2 of the bypass circuit 8.The supply portion 7 is adjacent to the injection portion 6 and is connected to the combustor of the gas turbine.In an embodiment in which the fuel supply line 3 is connected to a plurality of combustion chambers, the supply section 7 opens into each of these combustion chambers.Moreover, the fuel supply system 1 includes a plurality of valves for selectively controlling fluid communication between various adjacent parts of the fuel supply system 1.A valve V 1 is arranged between the intake section 4 and the separation section 5.A valve V 2 is arranged between the separating section 5 and the injection section 6.Between the injection section 6 and the feed section 7 a valve V 3 is arranged.A first section 9 of the bypass circuit 8 extends between the inlet E 1 for the mixture of hydrocarbon and hydrogen connected to the intake section 4 of the fuel feed line 3 and the separation device DS 1.A valve V4 is arranged at the first section 9 between the separation section 5 of the fuel supply line 3 and the inlet E1 for the mixture of hydrocarbon and hydrogen in the bypass circuit 8 in order to control the passage of the mixture of hydrocarbon and hydrogen into the bypass circuit 8.A second section 10 of the bypass circuit 8 extends from the separator DS 1 and is connected to the injection section 6 of the fuel supply line 3 via the hydrocarbon outlet SHC 1.A valve V 5 is arranged at the second portion 10 of the bypass circuit 8 between the hydrocarbon outlet SHC 1 of the bypass circuit 8 and the injection portion 6 of the fuel supply line 3.In addition, a valve V 6 is arranged between the hydrogen outlet SH 2 of the bypass circuit 8 and the injection section 6 of the fuel feed line 3.Advantageously, a valve (not shown) may be arranged between the industrial, trunk or gas distribution network providing a mixture of hydrocarbon and hydrogen and the suction section 4 to control the suction of the fuel into the fuel feed line 3.Preferably, the bypass circuit 8 includes a hydrocarbon tank RHC arranged downstream of the hydrocarbon-hydrogen mixture separator DS 1 in the second section 10 of the bypass circuit 8. The hydrocarbon tank RHC enables storing hydrocarbon previously separated from hydrogen in the separator DS 1 with a predetermined efficiency.It is to be understood that the bypass circuit 8 includes a plurality of hydrocarbon tanks.Advantageously, the capacity of the hydrocarbon tank RHC is greater than or equal to a predetermined hydrocarbon threshold.Preferably, the bypass circuit 8 of the fuel supply system 1 also comprises a hydrogen tank RH 2 for storing hydrogen which has been previously separated from the hydrocarbon with a certain efficiency by the separation device DS 1.It is to be understood that the bypass circuit 8 includes a plurality of hydrogen tanks.Preferably, the bypass circuit 8 comprises an additional hydrocarbon outlet SHC2 to the injection section 6 of the fuel supply line 3.The additional hydrocarbon outlet SHC 2 is located at a third section 11 of the bypass circuit 8, which connects the separator DS 1 to the injection section 6 of the fuel feed line 3.The additional hydrocarbon outlet SHC2 is arranged downstream of the separator DS1 and upstream of the hydrocarbon tank RHC, in order to allow the suction of hydrocarbon into the fuel feed line 3 directly after its separation from the hydrocarbon-hydrogen mixture.The valves V 7 and V 8 may be advantageously respectively arranged at the second and third portions of the bypass circuit 8 between the separator DS 1 and the hydrocarbon tank RHC and between the separator DS 1 and the injection portion 6.The valves V 7 and V 8 are for controlling the passage to the hydrocarbon injection portion 6 immediately after being separated by the separator DS 1 via the hydrocarbon outlet SHC 2 or previously stored hydrocarbon via the hydrocarbon outlet SHC 1.The fuel supply system 1 may include a compressor disposed downstream of the valve V 8 at the additional hydrocarbon outlet SHC 2 to achieve a gas pressure similar to or close to the gas pressure before separation.Advantageously, the fuel supply system 1 may comprise at least one analyzer for the hydrogen content.An analyzer A1 disposed downstream of the separator DS1 is configured to measure the possible hydrogen content in the hydrocarbon obtained after separation by the separator DS1.In the example shown, the analyzer A1 is arranged to measure the hydrogen content of the hydrocarbon stored in the hydrocarbon tank RHC.In the example shown, the fuel supply system 1 comprises an additional analyzer A 2 arranged at the intake section 4 of the fuel feed line 3 and a further additional analyzer A 3 arranged at the injection section 6 downstream of the outlets for hydrocarbon SHC 1 and for hydrogen SH 2 of the bypass circuit 8.The additional analyzer A2 is advantageous for measuring the hydrogen content of the mixture of hydrocarbon and hydrogen distributed over the industrial or transport gas network.The additional analyzer A3 is advantageous for measuring the hydrogen content of the hydrocarbon and hydrogen mixture in the injection section 6, which directs it directly into the combustion chamber 2 via the valve V3.Preferably, the bypass circuit 8 advantageously includes an additional separator DS2, which in the example shown is arranged downstream of the separator DS1 and upstream of the hydrocarbon tank RHC.The additional separator DS 2 allows additional separation of the hydrogen contained in the hydrocarbon previously separated by the separator DS 1, depending on the hydrogen content measured by the analyzer A 1 downstream of the separator DS 1, i.e., when an improvement in separation performance is required.A fourth section 12 of the bypass circuit 8 connects the isolation device DS 1 and the further isolation device DS 2.Expediently, a valve V 10 is arranged between the separating device DS 1 and the further separating device DS 2.A fifth section 13 of the bypass circuit 8 connects the additional separator DS2 and the second section 10 of the bypass circuit 8 upstream of the hydrocarbon tank RHC, preferably between the valves V7 and V9.The hydrogen separated by the separator DS1 is supplied to the hydrogen tank RH 2 through a sixth section 14 in the bypass circuit 8.The hydrogen separated by the additional separator DS 2 is supplied to the hydrogen tank RH 2 through a seventh portion 15 of the bypass circuit 8. An eighth section 16 connects the hydrogen tank RH 2 to the injection section 6 of the fuel supply pipe 3 for injecting hydrogen previously separated from the hydrocarbon or a mixture of hydrocarbon and hydrogen into the combustor, the amounts being controllable depending on the operation supply mode required by the gas turbine.Advantageously, check valves are arranged on the sixth, seventh, eighth sections 14, 15 and 16 and on the second section 10 downstream of the hydrocarbon tank RHC.Preferably, a vent 17, 18 is attached to each of the hydrocarbon tank RHC and the hydrogen tank RH 2 respectively.In addition, a vent 19 can also be attached to the eighth section 16 of the bypass circuit 8, downstream of the valve V 6.Preferably, a vent 20 is also arranged on the injection section 6 downstream of the fuel feed line 3, downstream of the bypass circuit 8. The opening and closing of the vent 20 is controlled by a valve V 12 to flush the injection portion 6.The opening and closing of the respective vent 17, 18, 19 and 20 is advantageously controlled by special valves.Preferably, the fuel supply system 1 additionally includes a controller or management computer 21 configured to control the opening and closing of all valves in the fuel supply system 1.Preferably, the management computer is configured to request when the amount of hydrocarbon in the hydrocarbon tank RHC is below a hydrocarbon threshold value set as follows:sucking a mixture of hydrocarbon and hydrogen into the fuel feed line 3,separating the mixture of hydrocarbon and hydrogen through the bypass circuit 8 to produce hydrocarbon andstoring the recovered hydrocarbon in the hydrocarbon tank RHC until an amount of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold is reached.The invention also relates to a method for supplying fuel to the gas turbine combustion chamber 2.A plurality of combustion chambers 2 can be supplied with fuel. The supply method includes a first step of aspirating a mixture of hydrocarbon and hydrogen from the industrial, trunking or gas distribution network into the fuel supply line 3.In a second step, in the bypass circuit 8 connected to the fuel feed line 3, a separation of the mixture of hydrocarbon and hydrogen is carried out in order to obtain hydrogen on the one hand and hydrocarbon on the other hand.In a third step, the combustion chamber 2 is optionally supplied with either hydrogen or with hydrocarbon previously separated in the second stage, or also with a mixture of hydrocarbon and hydrogen which has not been separated by the bypass circuit 8.Selective supply of hydrocarbon, hydrogen or a controlled hydrocarbon mixture to the combustor can be readily achieved depending on the mode of operation or need for the transition modes of the gas turbine.The fuel supply system 1 is a simple system that allows the supply of fuel to at least one combustion chamber via a single fuel supply line 3 made of a mixture of hydrocarbon and hydrogen distributed over an industrial, trunked or general gas distribution network, regardless of the mode of operation of the gas turbine.In particular, it is thus possible to supply the combustion chamber with hydrocarbon which has been at least partially separated from hydrogen, preferably until a predetermined threshold value of the hydrogen content in the separated hydrocarbon is reached, in order to enable the operation of the gas turbine without risks associated with the presence of hydrogen, in particular during transition phases in which flame loss occurs, such as during starting or stopping of the gas turbine.The method preferably comprises feeding hydrocarbon from the combustion chamber 2 to the feed line 3 of the previously separated mixture of hydrocarbon and hydrogen in the bypass circuit 8 for the operation of the gas turbine during a transition phase.The hydrogen content of the hydrocarbon separated from the hydrocarbon-hydrogen mixture may be below a predetermined threshold value, below which risks associated with hydrogen present in the internal cavities of the gas turbine, such as explosion, are eliminated.According to one example, the predetermined threshold value of the amount of hydrogen in the hydrocarbon separated by the separator DS 1 may be 5%.Advantageously, the supplying method includes determining an amount of hydrocarbon in the hydrocarbon tank RHC, preferably before a transition phase.The determined hydrocarbon quantity is then compared with a predefined hydrocarbon threshold value.When the indicated amount of hydrocarbon is below the predetermined hydrocarbon threshold, a mixture of hydrocarbon and hydrogen is introduced into the fuel supply line 3.The mixture of hydrocarbon and hydrogen introduced into the fuel supply line 3 is then separated in the bypass circuit 8 to recover hydrocarbon.The recovered hydrocarbon is then stored in the hydrocarbon tank RHC until an amount of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold is reached.In one embodiment, the separation of the mixture of hydrocarbon and hydrogen and the storage of the resulting hydrocarbon are performed when the gas turbine is stopped, and preferably before a transition phase. Separating and storing hydrocarbon prior to starting up the gas turbine is particularly advantageous in order to ensure that sufficient amounts of hydrocarbon without at least partial hydrogen are supplied to the combustion chamber.In another embodiment, the separating of the mixture of hydrocarbon and hydrogen and the storing of the recovered hydrocarbon are performed during operation of the gas turbine. The separation and storage during the gas turbine operation is advantageous in particular for setting up or refilling the hydrocarbon tank RHC if it contains hydrocarbon which has not been separated, or no longer sufficiently separated.The predefined threshold value is preferably assigned to an amount of hydrocarbon required for the operation of the gas turbine during at least one transition phase. By separating the mixture of hydrocarbon and hydrogen and storing the recovered hydrocarbon, a sufficient amount of separated hydrocarbon is available to the gas turbine for operation during a transition phase.Advantageously, the transition phase may be one of: ignition, starting, stopping, or a change in the combustion mode of the gas turbine.Preferably, the supply method comprises measuring the hydrogen content in the hydrocarbon previously separated from the mixture of hydrocarbon and hydrogen in the bypass circuit 8.In the example shown, the measurement is carried out by the gas analyzer A1 in the hydrocarbon tank RHC.In one embodiment, the predetermined threshold hydrogen content in the hydrocarbon after the simple separation by the separator DS 1 may be 5%.Moreover, the supply method may comprise an additional separation step if the measured hydrogen content is above a predetermined hydrogen threshold.The performance of the double separation can be controlled manually or automatically by the management computer 21.For example, when the hydrogen content in the hydrocarbon after a single separation by the separator DS 1 is greater than or equal to 5%, a double separation can be performed together with the separators DS 1 and the additional separator DS 2.Preferably, the hydrogen content at the beginning of the separation step is measured by the separator DS 1 and the hydrocarbon tank storage step RHC by the gas analyzer A 1 to quickly correct the hydrogen content of the hydrocarbon to be stored in the hydrocarbon tank RHC.According to another embodiment, the second separation by the separation device DS 2 may be performed after the completion of storage of the hydrocarbon separated by the separation device DS 1.In the example shown, the hydrocarbon tank RHC is filled when the gas turbine is stopped, i.e. before starting up.In a simple separation, the valves V1, V4, V9 and V7 are opened, preferably controlled by the management computer 21, The mixture of hydrocarbon and hydrogen is introduced into the suction section 4 of the fuel supply line 3 and then into the separation section 5 and reaches the first section 9 of the bypass circuit 8, where it is separated by the separation device DS1.After separation, the separated hydrocarbon is conveyed through the second section 10 to the hydrocarbon tank RHC to fill the hydrocarbon tank RHC to the predetermined threshold required for operation of the gas turbine during one or more transition phases.In the case of a double separation, the valve V9 is closed and the valves V1, V4, V10, V7 and V11 are opened, preferably on command from the controller 21, the mixture of hydrocarbon and hydrogen is introduced into the suction section 4 of the fuel feed line 3 and then into the separation section 5 and reaches the first section 9 of the bypass circuit 8 in order to be separated there by the separation device DS1 and then by the additional separation device DS2, the hydrocarbon separated by the separation device DS1 reaches the fourth section 12 of the bypass circuit 8.After the double separation, the separated hydrocarbon is sent to the hydrocarbon tank RHC through the fifth section 13 and the second section 10 to fill the hydrocarbon tank RHC up to the predetermined threshold value.The hydrogen separated by the separator DS 1 is supplied to the hydrogen tank RH 2 through the sixth portion 14 of the bypass circuit 8.The hydrogen separated by the additional separator DS 2 is supplied to the hydrogen tank RH 2 through the seventh portion 15 of the bypass circuit 8.In one embodiment, the fuel supply system 1 may include an auxiliary boiler or other steam device connected to the hydrogen tank RH 2. In this way, the auxiliary boiler can use the hydrogen H 2 stored in the hydrogen tank RH 2 for its operation.The auxiliary boiler or other steam device may be arranged downstream of the gas turbine.In one embodiment, the fuel supply system 1 may include a methane pyrolysis device to produce hydrogen and carbon from a methane source. The pyrolysis device may be provided either for connection to the fuel supply line 3 in the suction section 4 or to the hydrocarbon tank RHC.In this embodiment, the hydrocarbon stored in the hydrocarbon tank RHC is therefore methane. If the mixture introduced into the intake section 4 of the fuel supply line 3 consists only of methane hydrocarbon, the connection of the pyrolysis device to the fuel supply line 3 is particularly advantageous in order to be able to separate the hydrogen from the mixture via the bypass circuit 8 before pyrolysis.Moreover, the mixture of hydrocarbon and hydrogen fed into the fuel supply system may contain mercaptan, a molecule to which the fuel is to be odourd.The mercaptan can be filtered out and retained by the separating apparatus DS 1. It may therefore be necessary to add mercaptan again to the hydrocarbon after the hydrogen has been removed.In this regard, it may be provided that the supplying method includes a step of adding mercaptan to the previously separated hydrocarbon downstream of the separator DS 1 or the additional separator DS 2.The addition of mercaptan can advantageously take place in the hydrocarbon tank RHC.In addition, it is possible for the fuel supply system 1 to comprise a device for separating heavy portions of the hydrocarbon previously separated from the hydrogen.For example, hydrocarbon may contain a mixture of methane, ethane and propane. The fuel supply system 1 may include a separation device for separating heavy components such as ethane and propane from methane.Advantageously, the device for separating heavy fractions of the hydrocarbon previously separated from the hydrogen can be arranged downstream of the separation device DS 1 or downstream of the additional separation device DS 2 and upstream of the hydrocarbon tank RHC.Preferably, during a first phase of the pre-ignition of the gas turbine, venting of the injection section 6 is performed using the vent 20 located downstream of the bypass circuit 8. Valves V1, V2, V3, V4, V7, V8, V10 are closed and valve V12 is open.Preferably, during a second ignition phase of the gas turbine, the venting valve V 12 is closed, the valves V 3 and V 5 are opened, the hydrocarbon stored in the tank RHC is introduced into the injection section 6 of the fuel feed line 3 and supplies the combustion chamber 2 with a mixture of air and hydrocarbon, which has been previously separated from the hydrogen and comes from the hydrocarbon tank RHC, as shown in the example, during an attempt to ignite. The supply takes place until the fuel mixture in the combustion chamber 2 actually ignites. The ignition test can be carried out via a spark plug. Ignition may be confirmed by a flame detector.Thus, when the ignition transition phase of the gas turbine is completed, the combustor 2 is ignited. Subsequently, a supply changeover of the injection section 6 takes place. the combustible gas supply is changed over by the bypass circuit 8 via the valve V 5 to a supply by the hydrocarbon mixture and hydrogen from the industrial, trunk line or gas distribution network without the hydrogen being separated off beforehand. The valve V5 gradually closes while the valves V1 and V2 gradually open to feed the injection portion 6.An acceleration phase of the gas turbine then follows.In one embodiment, it is possible to supply the combustion chamber 2 with hydrogen previously stored in the hydrogen tank RH 2 with single or double separation.The valves V 3 and V 6 and the valve downstream of the valve V 6 in the direction of the injection section 6 are opened in order to introduce hydrogen into the injection section 6 of the fuel feed line 3 guided through the eighth section 16 and to feed the combustion chamber 2.The hydrogen content of the fuel gas composition introduced into the combustion chamber 2 may be variable, preferably from 0 to 20% or from 5 to 20% hydrogen, the theoretical hydrogen variation being estimated to be, for example, 0 to 30% per minute.In this case, the rate of hydrocarbon supplied by the injection section 6 of the fuel supply system 1, e.g. methane, and hydrogen, may be adjusted to ensure a constant composition for the transition phases, e.g. to ensure a response to the power grid with a 10% increase in its rated load, e.g. in 30 seconds.Thus, in order to maintain controlled proportions of hydrocarbon and hydrogen, e.g., methane, and a constant hydrogen content during transient operation, the fuel supply system 1 may provide:adjusting the hydrogen rate upward by injecting more hydrogen from the hydrogen tank RH 2, orAdjustment for reducing the hydrogen rate, either by adding hydrocarbon, for example methane, from the hydrocarbon tank RHC or by injecting hydrocarbon, for example methane, directly downstream of the bypass circuit 8 without it passing through the hydrocarbon tank RHC.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 2003 / 55

[0005]

Claims

A method of supplying fuel to at least one gas turbine combustor, comprising: aspirating a mixture of hydrocarbon and hydrogen into a feed line connected to at least one combustor (2); separating the mixture of hydrocarbon and hydrogen into a bypass circuit (8) connected to the feed line (3) for recovering hydrogen and recovering hydrocarbon; and selectively supplying hydrogen, hydrocarbon or a mixture of hydrocarbon and hydrogen to the combustor depending on the mode of operation of the gas turbine.The method of claim 1, wherein the bypass circuit (8) comprises at least one hydrocarbon tank (RHC), the method comprising: determining an amount of hydrocarbon in the hydrocarbon tank (RHC), comparing the determined amount of hydrocarbon to a predetermined hydrocarbon threshold, drawing a mixture of hydrocarbon and hydrogen into the feed line (3) when the determined amount of hydrocarbon is less than the predetermined hydrocarbon threshold, separating the mixture of hydrocarbon and hydrogen in the bypass circuit (8) to recover hydrocarbon during operation of the gas turbine or at standstill of the gas turbine, and storing the recovered hydrocarbon in the hydrocarbon tank (RHC) until an amount of hydrocarbon is reached that is greater than or equal to the predetermined hydrocarbon threshold.The method of claim 2, wherein the predetermined threshold is associated with an amount of hydrocarbon required to operate the gas turbine during at least one transition phase.The method of claim 3, wherein the transition phase is one of: ignition, launch, stop, and change of combustion mode of the gas turbine.Method according to one of the preceding claims, in which, for the operation of the turbine, hydrocarbon is fed through the feed line (3) to at least one combustion chamber (2) which has previously been separated from the mixture of hydrocarbon and hydrogen in the bypass circuit (8).A method according to any preceding claim, comprising measuring the hydrogen content in the hydrocarbon previously separated from the mixture of hydrocarbon and hydrogen by the bypass circuit (8).Method according to claim 6, comprising an additional separation step if the measured hydrogen content is greater than a predetermined hydrogen threshold.Method according to any one of the preceding claims, wherein the bypass circuit (8) comprises at least one hydrogen tank (RH 2) the method comprising storing hydrogen obtained after the separation of the mixture of hydrocarbon and hydrogen in the hydrogen tank (RH 2).The method according to claim 8, wherein the bypass circuit (8) comprises at least one hydrocarbon tank (RHC), the method comprising: storing hydrocarbon obtained after separation of the hydrocarbon-hydrogen mixture in the hydrocarbon tank (RHC); obtaining a mixture of hydrocarbon and hydrogen in which the hydrocarbon and hydrogen fractions are controlled from hydrocarbon stored in the hydrocarbon tank (RHC) and hydrogen stored in the hydrogen tank (RH 2) ; and supplying the combustor with a mixture of hydrocarbon and hydrogen in controlled fractions.A fuel supply system for at least one gas turbine combustor (2) comprising: a fuel supply line (3) for supplying at least one combustor (2) with a mixture of hydrocarbon and hydrogen, comprising: an intake section (4) intended to be connected to an industrial, remote line or gas distribution network providing a mixture of hydrocarbon and hydrogen, a separation section (5) adjacent to the intake section (4) and connected to an inlet (E1) of a mixture of hydrocarbon and hydrogen in a bypass circuit (8) having at least one separation device (DS 1) for a mixture of hydrocarbon and hydrogen, an injection section (6) adjacent to the separation section (5), which is connected to an outlet for hydrocarbon (SHC1) and an outlet for hydrogen (SH2) in the bypass circuit (8), and a feed section (7) which is adjacent to the injection section (6) and is connected to at least one combustion chamber (2) of the gas turbine; and a plurality of valves (V1, V2, V3, V4, V5, V6) which are respectively arranged between the suction section (4) and the separation section (5), between the separation section (5) and the injection section (6), between the injection section (6) and the feed section (7), between the separation section (5) of the feed line (3) and the inlet (E1) of the mixture of hydrocarbon and hydrogen in the bypass circuit (8), between the hydrocarbon outlet (SHC1) of the bypass circuit (8) and the injection section (6) of the feed line (3) and between the hydrogen outlet (SH2) of the bypass circuit (8) and the injection section (6) of the feed line (3).The system according to claim 10, wherein the bypass circuit (8) comprises a hydrocarbon tank (RHC) arranged downstream of the hydrocarbon-hydrogen mixture separator (DS1) and having a capacity greater than or equal to a predetermined hydrocarbon threshold.The system according to claim 11, comprising a management computer (21) configured to arrange, when the amount of hydrocarbon in the hydrocarbon tank (RHC) is less than a predetermined hydrocarbon threshold: aspirating a mixture of hydrocarbon and hydrogen into the feed line (3), separating the mixture of hydrocarbon and hydrogen in the bypass circuit (8) to produce hydrocarbon, and storing the recovered hydrocarbon in the hydrocarbon tank (RHC) until an amount of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold is reached.The system according to any one of claims 10 to 12, comprising at least one gas analyzer (A1) arranged downstream of the hydrocarbon-hydrogen mixture separator (DS1) and configured to measure the hydrogen content in the hydrocarbon obtained after the hydrocarbon-hydrogen mixture is separated by the separator (DS1).System according to any one of claims 10 to 13, wherein the bypass circuit (8) comprises an additional separator (DS2) for the mixture of hydrocarbon and hydrogen, arranged downstream of the separator (DS1).The system according to any one of claims 10 to 14, wherein the bypass circuit (8) comprises at least one hydrogen tank (RH 2), for storing hydrogen previously separated from the hydrocarbon by the separation device (DS1) or by the additional separation device (DS2).

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