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

Abstract

A method for supplying fuel to at least one combustion chamber (2) of a gas turbine, comprising: the admission of a hydrocarbon-hydrogen mixture into a feed line (3) connected to at least one combustion chamber (2), the separation of the hydrocarbon-hydrogen mixture in a bypass circuit (8) connected to the feed line (3) for the production of hydrogen and hydrocarbon, and the selective supply of hydrogen, hydrocarbon, or hydrocarbon-hydrogen mixture to the combustion chamber (2) depending on the operating mode of the gas turbine. Figure for the abstract: Fig 1

Description

Title of the invention: Method for supplying fuel to at least one gas turbine combustion chamber and associated supply system

[0001] The present invention relates, in general, to the supply of fuel to a gas turbine combustion chamber and, more specifically, to the separation of a mixture of hydrocarbon and hydrogen intended to supply a gas turbine combustion chamber.

[0002] More particularly, the invention relates to a method for supplying fuel to at least one gas turbine combustion chamber, and to an associated supply system, allowing the separation of a mixture of hydrocarbon and hydrogen intended to supply the combustion chamber.

[0003] In recent years, there has been increasing interest and activity in the development of energy sources derived from non-fossil fuels, such as electricity generated from solar or wind energy and electricity generated from hydrogen.

[0004] This development has led to the production of hydrogen from surplus renewable energy for injection into gas pipelines.

[0005] Indeed, Directive 2003 / 55 / EC of the European Union opened access to the existing natural gas transport and distribution network, with the possibility of co-transporting hydrogen, mixed with natural gas.

[0006] The resulting natural gas and hydrogen mixture makes it possible to reduce the carbon intensity of the hydrocarbons present.

[0007] Furthermore, the use of hydrogen in the combustion system is advantageous because it does not produce compounds considered harmful to the environment, such as S, CO2, CO, particles and unburned hydrocarbons.

[0008] Typically, the initial mixture contains approximately 1% hydrogen but can reach up to 20%.

[0009] However, hydrogen can lead to various operating risks when used in a gas turbine: explosion, flame retention, etc. In particular, when starting the gas turbine with a fuel mixture comprising a percentage of hydrogen greater than 5%, and in the event of a disturbance in the starting step, a volume of gas incorporating hydrogen may be found in the internal cavities of the turbine, downstream of the combustion and up to the exhaust. The fraction of hydrogen then present in the internal cavities of the turbine can, at high temperature, generate an explosion and cause overpressure. by deflagration. Thus it is necessary to ensure the start-up of a gas turbine by eliminating the risks incurred during combustion using a high percentage of hydrogen in the combustible mixture.

[0010] The invention therefore aims to remedy these drawbacks and to propose a method for supplying the combustion chamber of a gas turbine with hydrocarbon free of hydrogen, in particular when this makes it possible to limit the risks associated with its use, from a mixture of hydrocarbon and hydrogen conveyed to the gas turbine by an industrial, transport or distribution network.

[0011] Hydrogen can be separated from the mixture by a physical process that involves diffusing the hydrogen through a membrane that can be made of polymer, metal, ceramic, or even in liquid form. However, when separation uses this technology, it must be considered that it generally has difficulty tolerating certain molecules, particularly acids, hexanes, and sulfites. These molecules tend to degrade the polymeric structure of the membranes. Furthermore, molecules with large carbon chains condense easily and clog the filters, thus reducing the efficiency of the membrane.

[0012] A method of supplying fuel to at least one gas turbine combustion chamber is therefore proposed, comprising:

[0013] the admission of a mixture of hydrocarbon and hydrogen into a supply line connected to the combustion chamber,

[0014] the separation of the mixture of hydrocarbon and hydrogen in a bypass circuit connected to the supply line for obtaining hydrogen on the one hand and on the other hand obtaining hydrocarbon, and

[0015] selectively supplying the combustion chamber with hydrogen, hydrocarbon or a mixture of hydrocarbon and hydrogen depending on the operating mode of the gas turbine.

[0016] Advantageously, the bypass circuit may comprise at least one hydrocarbon reservoir, the method comprising:

[0017] determining a quantity of hydrocarbon in the hydrocarbon reservoir,

[0018] comparing the determined quantity of hydrocarbon with a predetermined hydrocarbon threshold value,

[0019] the admission, when the determined quantity of hydrocarbon is less than the predetermined hydrocarbon threshold value, of mixture of hydrocarbon and hydrogen into the supply line,

[0020] the separation of the mixture of hydrocarbon and hydrogen in the bypass circuit to obtain hydrocarbon, during operation of the gas turbine or when the gas turbine is stopped, and

[0021] storing the obtained hydrocarbon in the hydrocarbon reservoir until a quantity of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold value is obtained.

[0022] Preferably, the predetermined threshold value is associated with a quantity of hydrocarbon required for the operation of the gas turbine during at least one transient phase.

[0023] Advantageously, the transient phase can be one of: ignition, start-up, shutdown, and a change in combustion mode of the gas turbine, or even an increase or decrease in the load in response to a network event to which it is connected.

[0024] Advantageously, the method comprises supplying, via the supply line of the at least one combustion chamber, hydrocarbon previously separated from the mixture of hydrocarbon and hydrogen in the bypass circuit, for the operation of the gas turbine during a transient phase.

[0025] Preferably, the method comprises measuring the hydrogen level in the hydrocarbon previously separated from the mixture of hydrocarbon and hydrogen by the bypass circuit.

[0026] Advantageously, the method may comprise an additional separation step when the measured hydrogen level is higher than a predetermined hydrogen threshold value, for example in the event of fouling of a membrane.

[0027] Preferably, the bypass circuit comprises at least one hydrogen tank, the method comprising storing hydrogen obtained after separation of the hydrocarbon and hydrogen mixture in the hydrogen tank.

[0028] Preferably, the bypass circuit comprises at least one hydrocarbon reservoir, the method comprising:

[0029] the storage of hydrocarbon obtained after separation of the mixture of hydrocarbon and hydrogen in the hydrocarbon tank;

[0030] obtaining a mixture of hydrocarbon and hydrogen whose hydrocarbon and hydrogen fractions are controlled, from hydrocarbon stored in the hydrocarbon tank and hydrogen stored in the hydrogen tank; and

[0031] supplying the combustion chamber with a mixture of hydrocarbon and hydrogen in controlled fractions.

[0032] According to one example, the supply method may comprise obtaining a mixture of hydrocarbon and hydrogen with controlled fractions enriched or depleted in hydrogen relative to the mixture of hydrocarbon and hydrogen coming from the industrial, transport or distribution network.

[0033] The invention also relates to a system for supplying fuel to at least one gas turbine combustion chamber, comprising:

[0034] a line for supplying the at least one combustion chamber with a mixture of hydrocarbon and hydrogen comprising:

[0035] an intake section intended to be connected to an industrial, transport or distribution network for a mixture of hydrocarbon and hydrogen,

[0036] a separation section adjacent to the intake section and connected to a hydrocarbon and hydrogen mixture inlet of a bypass circuit comprising at least one hydrocarbon and hydrogen mixture separation device DSI,

[0037] an injection section adjacent to the separation section connected to a hydrocarbon outlet and to a hydrogen outlet of the bypass circuit, and

[0038] a feed section adjacent to the injection section and connected to the at least one combustion chamber of the gas turbine; and

[0039] a plurality of valves each respectively positioned between the intake section and the separation section, between the separation section and the injection section, between the injection section and the feed section, between the separation section of the feed line and the hydrocarbon and hydrogen mixture inlet of the bypass circuit, between the hydrocarbon outlet of the bypass circuit and the injection section of the feed line, and between the hydrogen outlet of the bypass circuit and the injection section of the feed line.

[0040] Preferably, the bypass circuit comprises a hydrocarbon reservoir positioned downstream of the device for separating the hydrocarbon and hydrogen mixture and having a capacity greater than or equal to a predetermined hydrocarbon threshold value.

[0041] Preferably, the supply system comprises a management computer configured to order, when the quantity of hydrocarbon in the hydrocarbon tank is less than a predetermined hydrocarbon threshold value:

[0042] the admission of hydrocarbon and hydrogen mixture into the feed line,

[0043] the separation of the hydrocarbon and hydrogen mixture by the bypass circuit to obtain hydrocarbon, and

[0044] storing the obtained hydrocarbon in the hydrocarbon reservoir until a quantity of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold value is obtained.

[0045] Advantageously, the feed system may comprise at least one analyzer positioned downstream of the hydrocarbon and hydrogen mixture separation device and configured to measure the hydrogen level in the hydrocarbon obtained after separation by the hydrocarbon and hydrogen mixture separation device. This makes it possible to verify the effectiveness of the separation process and to compare the hydrogen level with a previously defined expected hydrogen level.

[0046] Advantageously, the bypass circuit may comprise an additional device for separating the hydrocarbon and hydrogen mixture positioned downstream. of the separation device. The presence of an additional separation device is particularly advantageous in order to increase the efficiency of the separation process.

[0047] Preferably, the bypass circuit comprises at least one hydrogen tank, for storing hydrogen previously separated from the hydrocarbon by the separation device or by the additional separation device.

[0048] Other aims, advantages and characteristics will emerge from the description which follows, given purely for illustrative purposes and with reference to the attached drawing in which:

[0049] [Fig-1] is a schematic representation of a power supply system in com fuel of a gas turbine combustion chamber according to one embodiment of the invention.

[0050] In the following, the expression “at least one” used in the present description is equivalent to the expression “one or more”.

[0051] [Fig.l] illustrates a supply system 1 intended to supply fuel to at least one combustion chamber 2 of a gas turbine.

[0052] The supply system 1 comprises a supply line 3 for fuel to the combustion chamber 2.

[0053] It may be provided that the supply line 3 of the supply system 1 supplies fuel to a plurality of combustion chambers 2 of the gas turbine.

[0054] The feed line 3 comprises an intake section 4, a separation section 5, an injection section 6 and a feed section 7.

[0055] The intake section 4 is intended to be connected to an industrial, transport or distribution network for a mixture of hydrocarbon and hydrogen, external to the supply system 1, and allows the admission of a mixture of hydrocarbon and hydrogen into the supply line 3.

[0056] The network may be an industrial network, a transport network and / or a distribution network carrying a mixture of hydrocarbon and hydrogen.

[0057] In the example illustrated, the network transporting the mixture of hydrocarbon and hydrogen is a distribution network.

[0058] The mixture transported and then distributed by the industrial, transport or distribution network may comprise a hydrocarbon or a plurality of hydrocarbons of different natures.

[0059] The quantity of hydrogen in the mixture of hydrocarbon and hydrogen distributed by the industrial, transport or distribution network can be between 0 and 20%.

[0060] In the present invention, the terms "upstream" and "downstream" are considered relative to the flow direction of the fuel stream in the gas turbine, in particular between the intake section 4 and the combustion chamber 2 of the gas turbine.

[0061] The separation section 5 is positioned downstream of the intake section 4 and adjacent to the latter.

[0062] The separation section 5 is connected to an inlet E1 of a bypass circuit 8 for the admission of a mixture of hydrocarbon and hydrogen into the bypass circuit 8.

[0063] The branch circuit 8, connected to the separation section 5, is positioned in parallel with the supply line 3.

[0064] The bypass circuit 8 comprises at least one device DSI for separating a mixture of hydrocarbons and hydrogen, making it possible to separate the hydrocarbons and hydrogen from the mixture into two separate flows with a given efficiency. Preferably, the separation device is a membrane of the following type: polymer, metal, ceramic, or even in liquid form.

[0065] The injection section 6 is positioned downstream of the separation section 5 and adjacent to the latter.

[0066] Furthermore, the injection section 6 is connected to a hydrocarbon outlet SHC1 and to a hydrogen outlet SH2 of the bypass circuit 8.

[0067] The feed section 7 adjacent to the injection section and connected to the combustion chamber of the gas turbine.

[0068] In an embodiment in which the supply line 3 is connected to several combustion chambers, the supply section 7 opens into each of them.

[0069] In addition, the supply system 1 comprises a plurality of valves for selectively controlling fluid communication between various adjacent portions of the supply system 1.

[0070] A valve V1 is positioned between the intake section 4 and the separation section 5.

[0071] A valve V2 is positioned between the separation section 5 and the injection section 6.

[0072] A valve V3 is positioned between the injection section 6 and the supply section 7.

[0073] A first portion 9 of the bypass circuit 8 extends between the hydrocarbon and hydrogen mixture inlet E1 connected to the inlet section 4 of the supply line 3 and the separation device DSL

[0074] A valve V4 is positioned on the first portion 9, between the separation section 5 of the supply line 3 and the inlet E1 of the hydrocarbon and hydrogen mixture of the bypass circuit 8, in order to control the passage of the hydrocarbon and hydrogen mixture of hydrogen in the bypass circuit 8.

[0075] A second portion 10 of the bypass circuit 8 extends from the separation device DSI and is connected to the injection section 6 of the supply line 3 by the hydrocarbon outlet SHC1.

[0076] A valve V5 is positioned on the second portion 10 of the bypass circuit 8, between the hydrocarbon outlet SHC1 of the bypass circuit 8 and the injection section 6 of the supply line 3.

[0077] In addition, a valve V6 is positioned between the hydrogen outlet SH2 of the bypass circuit 8 and the injection section 6 of the supply line 3.

[0078] Advantageously, a valve (not shown) can be positioned between the industrial, transport or distribution network for the mixture of hydrocarbon and hydrogen and the intake section 4 in order to control the intake of fuel into the supply line 3.

[0079] Preferably, the bypass circuit 8 comprises a hydrocarbon reservoir RHC, positioned downstream of the device DSI for separating a mixture of hydrocarbon and hydrogen, on the second portion 10 of the bypass circuit 8. The hydrocarbon reservoir RHC allows the storage of hydrocarbon previously separated from the hydrogen, according to a given efficiency, by the separation device DSI.

[0080] It may be provided that the bypass circuit 8 comprises several hydrocarbon tanks.

[0081] The capacity of the RHC hydrocarbon reservoir is, advantageously, greater than or equal to a predetermined hydrocarbon threshold value.

[0082] Preferably, the bypass circuit 8 of the supply system 1 also comprises a hydrogen tank RH2, for the storage of hydrogen previously separated from the hydrocarbon, according to a given efficiency, by the separation device DSL

[0083] It may be provided that the branch circuit 8 comprises several hydrogen tanks.

[0084] Preferably, the bypass circuit 8 comprises an additional hydrocarbon outlet SHC2 opening into the injection section 6 of the supply line 3.

[0085] The additional hydrocarbon outlet SHC2 is arranged on a third portion 11 of the bypass circuit connecting the separation device DSI to the injection section 6 of the supply line 3.

[0086] The additional hydrocarbon outlet SHC2 is positioned downstream of the separation device DSI and upstream of the hydrocarbon tank RHC, so as to allow admission into the hydrocarbon supply line 3 directly after its separation from the mixture of hydrocarbon and hydrogen.

[0087] Valves V7 and V8 can advantageously be arranged, respectively, on the second and third portions of the bypass circuit 8, between the DSI separation device and the RHC hydrocarbon tank and between the DSI separation device and the injection section 6.

[0088] Valves V7 and V8 make it possible to control the passage to the hydrocarbon injection section 6 directly after separation by the separation device DSI via the hydrocarbon outlet SHC2 or previously stored hydrocarbon via the hydrocarbon outlet SHC1.

[0089] It may be provided that the supply system 1 comprises a compressor positioned downstream of the valve V8 on the additional hydrocarbon outlet SHC2 in order to be able to find a gas pressure similar to or close to the gas pressure before separation.

[0090] Advantageously, the supply system 1 can comprise at least one hydrogen level analyzer.

[0091] An analyzer Al, positioned downstream of the DSI separation device, is configured to measure the possible level of hydrogen in the hydrocarbon obtained after separation by the DSI separation device.

[0092] In the example illustrated, the analyzer A1 is positioned so as to measure the level of hydrogen present in the hydrocarbon stored in the hydrocarbon tank RHC.

[0093] In the example illustrated, the supply system 1 further comprises an additional analyzer A2 positioned on the intake section 4 of the supply line 3 and an additional analyzer A3 positioned on the injection section 6 downstream of the hydrocarbon outlets SHC1 and SH2 of the hydrogen outlets of the bypass circuit 8.

[0094] The additional analyzer A2 is advantageous for measuring the hydrogen content of the mixture of hydrocarbon and hydrogen distributed by the industrial, transport or distribution network and which is admitted into the supply system 1.

[0095] The additional analyzer A3 is advantageous for measuring the hydrogen content of the hydrocarbon and hydrogen mixture in the injection section 6, directly admitted into the combustion chamber 2 via the valve V3.

[0096] Preferably, the bypass circuit 8 advantageously comprises an additional separation device DS2 arranged, in the example illustrated, downstream of the separation device DSI and upstream of the hydrocarbon reservoir RHC.

[0097] The additional separation device DS2 makes it possible to carry out an additional separation of the hydrogen present in the hydrocarbon, previously separated by the separation device DSI, as a function of the hydrogen level measured by the analyzer Al downstream of the separation device DSI, in other words, when an improvement in the efficiency of the separation is necessary.

[0098] A fourth portion 12 of the branch circuit 8 connects the se- DSI separation and the additional DS2 separation device.

[0099] A VIO valve is advantageously arranged between the separation device DSI and the additional separation device DS2.

[0100] A fifth portion 13 of the bypass circuit 8 connects the additional separation device DS2 and the second portion 10 of the bypass circuit 8, upstream of the hydrocarbon tank RHC, preferably between the valves V7 and V9.

[0101] The hydrogen separated by the separation device DSI is conveyed to the hydrogen tank RH2 by a sixth portion 14 of the bypass circuit 8.

[0102] The hydrogen separated by the additional separation device DS2 is conveyed to the hydrogen tank RH2 by a seventh portion 15 of the bypass circuit 8.

[0103] An eighth portion 16 connects the hydrogen tank RH2 to the injection section 6 of the supply line 3 for the injection of hydrogen previously separated from the hydrocarbon into the combustion chamber or of a new mixture of hydrocarbon and hydrogen whose rates can be controlled, depending on the operating mode of the gas turbine.

[0104] Advantageously, non-return valves are positioned on the sixth, seventh, eighth portions 14, 15 and 16, as well as on the second portion 10, downstream of the RHC hydrocarbon tank.

[0105] Preferably, a vent 17, 18 is arranged on the hydrocarbon RHC and hydrogen RH2 tanks.

[0106] In addition, a vent 19 can also be arranged on the eighth portion 16 of the bypass circuit 8, downstream of the valve V6.

[0107] Preferably, a vent 20 is also arranged on the injection section 6 of the supply line 3, downstream of the bypass circuit 8. The opening and closing of the vent 20 are controlled by a valve V12 in order to purge the injection section 6.

[0108] The opening and closing of each of the vents 17, 18, 19 and 20 are advantageously controlled by their own valve.

[0109] Preferably, the supply system 1 further comprises a management computer 21 configured to control the opening and closing of all the valves of the supply system 1.

[0110] Preferably, the management computer is configured to order, when the quantity of hydrocarbon in the hydrocarbon tank RHC is less than a predetermined hydrocarbon threshold value:

[0111] the admission of hydrocarbon and hydrogen mixture into the supply line 3,

[0112] the separation of the mixture of hydrocarbon and hydrogen by the bypass circuit 8 to obtain hydrocarbon, and

[0113] storing the obtained hydrocarbon in the RHC hydrocarbon reservoir until a quantity of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold value is obtained.

[0114] The invention also relates to a method for supplying fuel to the combustion chamber 2 of the gas turbine.

[0115] It will be possible to provide fuel supply to a plurality of combustion chambers 2.

[0116] The supply method comprises a first step of admitting a mixture of hydrocarbon and hydrogen, coming from the industrial, transport or distribution network, into the supply line 3.

[0117] In a second step, a separation of the admitted hydrocarbon and hydrogen mixture is implemented in the bypass circuit 8, which is connected to the supply line 3, to obtain a part of hydrogen and a part of hydrocarbon.

[0118] During a third step, the combustion chamber 2 is selectively supplied either with hydrogen or with hydrocarbon, previously separated during the second step, or with a mixture of hydrocarbon and hydrogen not separated by the bypass circuit 8.

[0119] A selective supply of hydrocarbon, hydrogen or a controlled mixture of the latter two to the combustion chamber can be easily achieved, depending on the operating mode or the need for transient modes of the gas turbine.

[0120] The supply system 1 is a simple system allowing at least one combustion chamber to be supplied with fuel via a single supply line 3, from a mixture of hydrocarbon and hydrogen distributed by an industrial, transport or general distribution network, regardless of the operating mode of the gas turbine.

[0121] In particular, it is thus possible to supply the combustion chamber with hydrocarbon separated, at least partially, from the hydrogen, preferably until a predetermined threshold value of hydrogen content in the separated hydrocarbon is reached, so as to allow the operation of the gas turbine without risks linked to the presence of hydrogen, in particular during a transient phase subject to loss of flame such as, for example, the starting or stopping of the gas turbine.

[0122] In this regard, the method preferably comprises supplying the combustion chamber 2 via the supply line 3 with hydrocarbon previously separated from the mixture of hydrocarbon and hydrogen in the bypass circuit 8, for the operation of the gas turbine during a transient phase.

[0123] The level of hydrogen present in the hydrocarbon separated from the hydrocarbon mixture and hydrogen may be below a predetermined threshold value below which risks associated with the presence of hydrogen in the internal cavities of the gas turbine, such as explosion, are eliminated.

[0124] According to one example, the predetermined threshold value of the amount of hydrogen in the hydrocarbon separated by the DSI separation device may be 5%.

[0125] Advantageously, the feeding method comprises determining a quantity of hydrocarbon in the RHC hydrocarbon reservoir, preferably prior to a transient phase.

[0126] The comparison of the determined hydrocarbon quantity with a predetermined hydrocarbon threshold value is then implemented.

[0127] When the determined quantity of hydrocarbon is less than the predetermined hydrocarbon threshold value, a mixture of hydrocarbon and hydrogen is admitted into the supply line 3.

[0128] The mixture of hydrocarbon and hydrogen admitted into the supply line 3 is then separated in the bypass circuit 8 to obtain hydrocarbon.

[0129] The hydrocarbon obtained is then stored in the RHC hydrocarbon tank until a quantity of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold value is obtained.

[0130] In one embodiment, the separation of the mixture of hydrocarbon and hydrogen and the storage of the hydrocarbon obtained are carried out when the gas turbine is stopped, and preferably prior to a transient phase. The separation and storage of hydrocarbon prior to the start-up of the gas turbine is particularly advantageous in order to guarantee a supply of the combustion chamber with a sufficient quantity of hydrocarbon free, at least partially of hydrogen, so as to limit the risks linked to the presence of hydrogen during the transient phase of the gas turbine.

[0131] In another embodiment, the separation of the hydrocarbon and hydrogen mixture and the storage of the resulting hydrocarbon are carried out during operation of the gas turbine. The separation and storage during operation of the gas turbine are particularly advantageous for adjusting or refilling the hydrocarbon tank RHC when it does not contain or no longer contains a sufficient quantity of separated hydrocarbon.

[0132] Preferably, the predetermined threshold value is associated with a quantity of hydrocarbon required for operation of the gas turbine during at least one transient phase. The separation of the mixture of hydrocarbon and hydrogen and the storage of the resulting hydrocarbon thus allowing the gas turbine to have a quantity of separated hydrocarbon sufficient for operation during a transient phase.

[0133] Advantageously, the transient phase can be one of: ignition, start-up, shutdown, or even a change in combustion mode of the gas turbine.

[0134] Preferably, the feeding method comprises measuring the hydrogen level in the hydrocarbon previously separated from the mixture of hydrocarbon and hydrogen by the bypass circuit 8.

[0135] In the example illustrated, the measurement is carried out by the analyzer Al in the hydrocarbon tank RHC.

[0136] In one embodiment, the predetermined threshold value of the hydrogen level in the hydrocarbon after a simple separation by the DSI separation device may be 5%.

[0137] In addition, the feeding method may comprise an additional separation step when the measured hydrogen level is greater than a predetermined hydrogen threshold value.

[0138] The implementation of the double separation can be controlled manually or automatically by the management computer 21.

[0139] According to one example, when the hydrogen content in the hydrocarbon after a single separation by the separation device DSI is greater than or equal to 5%, a double separation can be implemented from the set of separation devices DSI and additional separation device DS2.

[0140] Preferably, the hydrogen level is measured by the analyzer A1 in the first moments of the separation step by the separation device DSI and of the storage step in the hydrocarbon tank RHC so as to quickly rectify the hydrogen level in the hydrocarbon intended to be stored in the hydrocarbon tank RHC.

[0141] According to another embodiment, the second separation by the separation device DS2 can be carried out after complete storage of the hydrocarbon separated by the separation device DSI.

[0142] In the example illustrated, the filling of the RHC hydrocarbon tank is carried out when the gas turbine is stopped, before it is started.

[0143] In the case of a simple separation, the valves VI, V4, V9 and V7 are open, preferably controlled by the management computer 21. A mixture of hydrocarbon and hydrogen is admitted into the inlet section 4 of the supply line 3 then the separation section 5, and goes towards the first portion 9 of the bypass circuit 8 to be separated by the separation device DSI.

[0144] After separation, the separated hydrocarbon is conveyed to the RHC hydrocarbon tank by the second portion 10 for filling the RHC hydrocarbon tank up to the predetermined threshold value necessary for the operation. operation of the gas turbine during one or more transient phases.

[0145] In the case of a double separation, the valve V9 is closed and the valves VI, V4, VIO, V7 and Vil are open, preferably controlled by the management computer 21. A mixture of hydrocarbon and hydrogen is admitted into the inlet section 4 of the supply line 3 then the separation section 5, and goes to the first portion 9 of the bypass circuit 8 to be separated by the separation device DSI, then successively by the additional separation device DS2 that the hydrocarbon separated by the separation device DSI reaches by the fourth portion 12 of the bypass circuit 8. After double separation, the separated hydrocarbon is conveyed to the hydrocarbon tank RHC by the fifth portion 13 and the second portion 10 for filling the hydrocarbon tank RHC up to the predetermined threshold value.

[0146] The hydrogen separated by the separation device DSI is conveyed to the hydrogen tank RH2 via the sixth portion 14 of the bypass circuit 8. The hydrogen separated by the additional separation device DS2 is conveyed to the hydrogen tank RH2 via the seventh portion 15 of the bypass circuit 8.

[0147] In one embodiment, it may be provided that the supply system 1 includes an auxiliary boiler or another steam device connected to the hydrogen tank RH2. In this way, the auxiliary boiler can use hydrogen H2 stored in the hydrogen tank RH2 for its operation.

[0148] The auxiliary boiler or other steam device may be positioned downstream of the gas turbine.

[0149] In one embodiment, it may be provided that the feed system 1 includes a methane pyrolysis device in order to produce hydrogen and carbon from a methane source. It may be provided that the pyrolysis device is connected either to the feed line 3, for example to the intake section 4, or to the hydrocarbon tank RHC. In this embodiment, the hydrocarbon stored in the hydrocarbon tank RHC will therefore be methane. When the mixture admitted into the intake section 4 of the feed line 3 only comprises methane hydrocarbon, the connection of the pyrolysis device to the feed line 3 is particularly advantageous.When the mixture admitted into the inlet section 4 of the supply line 3 comprises hydrogen in methane hydrocarbon, the connection of the pyrolysis device to the hydrocarbon tank RHC of the bypass circuit is particularly advantageous in order to be able to separate, prior to pyrolysis, the hydrogen from the mixture via the bypass circuit 8.

[0150] In addition, the mixture of hydrocarbon and hydrogen admitted into the supply system may contain mercaptan, a molecule intended to odorize the com- combustible.

[0151] Mercaptan may be filtered and retained by the DSI separation device. Therefore, it may be necessary to add mercaptan again to the hydrocarbon after hydrogen separation.

[0152] In this regard, it may be provided that the feeding process comprises a step of adding mercaptan to the previously separated hydrocarbon, downstream of the separation device DSI or the additional separation device DS2.

[0153] Advantageously, the addition of mercaptan can be carried out in the RHC hydrocarbon reservoir.

[0154] In addition, it may be provided that the feed system 1 comprises a device for separating heavy fractions of the hydrocarbon previously separated from the hydrogen.

[0155] According to one example, the hydrocarbon may comprise a mixture of methane, ethane and propane. It may be provided that the feed system 1 comprises a separation device for separating heavy fractions such as ethane and propane from the methane.

[0156] Advantageously, the device for separating heavy fractions of the hydrocarbon previously separated from the hydrogen can be positioned downstream of the separation device DSI or downstream of the additional separation device DS2, and upstream of the hydrocarbon reservoir RHC.

[0157] Preferably, during a first pre-ignition step of the gas turbine, venting of the injection section 6 is carried out using the vent 20 arranged downstream of the bypass circuit 8. The valves V1, V2, V3, V4, V7, V8, V10 are closed and the valve V12 is open.

[0158] Preferably, during a second ignition step of the gas turbine, the vent valve V12 is closed, the valves V3 and V5 are open, the hydrocarbon stored in the RHC tank is admitted into the injection section 6 of the supply line 3 and supplies the combustion chamber 2 during an attempt to ignite a mixture of air and hydrocarbon previously separated from the hydrogen and coming, in the example illustrated, from the RHC hydrocarbon tank. The supply is carried out until the actual ignition of the fuel mixture in the combustion chamber 2 is obtained. The ignition attempt can be carried out via a spark plug. The ignition can be confirmed by a flame detector.

[0159] When the transient ignition phase of the gas turbine is complete and the combustion chamber 2 is therefore ignited. A transfer of supply from the injection section 6 is then carried out. The supply of combustible gas by the bypass circuit 8 via the valve V5 is transferred to a supply by the mixture of hydrocarbon and hydrogen coming from the industrial, transport or distribution network. tribution, without prior separation of the hydrogen. Valve V5 closes gradually while valves VI and V2 open gradually to supply injection section 6.

[0160] This is followed by an acceleration phase of the gas turbine.

[0161] In one embodiment, it is possible to supply the combustion chamber 2 from hydrogen previously stored in the hydrogen tank RH2 during the single or double separation.

[0162] The valves V3 and V6 as well as the valve downstream of the valve V6 in the direction of the injection section 6 are open for the admission of hydrogen to the injection section 6 of the supply line 3 conveyed by the eighth portion 16, and the supply of the combustion chamber 2.

[0163] The hydrogen content of the combustible gas composition admitted into the combustion chamber 2 can be variable, preferably from 0 to 20% or from 5 to 20% of hydrogen, with a theoretical hydrogen variation estimated for example between 0 to 30% per minute.

[0164] In this case, the rate of hydrocarbon, for example methane, and hydrogen delivered by the injection section 6 of the supply system 1 may be adjusted in order to ensure a constant composition for the transient phases, for example in order to ensure a response to the network with an increase of 10% of its nominal load for example in 30 seconds.

[0165] Thus, in order to maintain controlled hydrocarbon and hydrogen fractions, for example methane, and constant hydrogen during a transient operation, the supply system 1 may provide:

[0166] - adjusting the hydrogen rate upwards by injecting more hydrogen from the hydrogen tank RH2, or

[0167] - adjusting the hydrogen level downwards, either by adding hydrocarbon, such as than methane, from the RHC hydrocarbon tank, or by an injection of hydrocarbon, such as methane, directly downstream of the bypass circuit 8, without passing through the RHC hydrocarbon tank.

Claims

Claims

1. A method of supplying fuel to at least one gas turbine combustion chamber, comprising: admitting a mixture of hydrocarbon and hydrogen into a supply line connected to the at least one combustion chamber (2), separating the mixture of hydrocarbon and hydrogen in a bypass circuit (8) connected to the supply line (3) for obtaining hydrogen and obtaining hydrocarbon, and selectively supplying the combustion chamber with hydrogen, hydrocarbon or a mixture of hydrocarbon and hydrogen depending on the operating mode of the gas turbine.

2. A method according to claim 1, wherein the bypass circuit (8) comprises at least one hydrocarbon reservoir (RHC), the method comprising: determining a quantity of hydrocarbon in the hydrocarbon reservoir (RHC), comparing the determined quantity of hydrocarbon with a predetermined hydrocarbon threshold value, admitting, when the determined quantity of hydrocarbon is less than the predetermined hydrocarbon threshold value, a mixture of hydrocarbon and hydrogen into the feed line (3), separating the mixture of hydrocarbon and hydrogen in the bypass circuit (8) to obtain hydrocarbon, during operation of the gas turbine or when the gas turbine is stopped, and storing the obtained hydrocarbon in the hydrocarbon reservoir (RHC) until a quantity of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold value is obtained.

3. A method according to claim 2, wherein the predetermined threshold value is associated with an amount of hydrocarbon required for operation of the gas turbine during at least one transient phase.

4. The method of claim 3, wherein the transient phase is one of: ignition, start-up, shutdown, a change in combustion mode of the gas turbine.

5. Method according to any one of the preceding claims, comprising supplying via the supply line (3) of the at least one combustion chamber (2) with hydrocarbon previously separated from the mixture of hydrocarbon and hydrogen in the bypass circuit (8), for the operation of the gas turbine during a transient phase.

6. A method according to any preceding claim, comprising measuring the level of hydrogen in the hydrocarbon previously separated from the mixture of hydrocarbon and hydrogen by the bypass circuit (8).

7. A method according to claim 6, comprising an additional separation step when the measured hydrogen level is greater than a predetermined hydrogen threshold value.

8. A method according to any preceding claim, wherein the bypass circuit (8) comprises at least one hydrogen tank (RH2), the method comprising storing hydrogen obtained after separation of the hydrocarbon and hydrogen mixture in the hydrogen tank (RH2).

9. Method according to claim 8, in which the bypass circuit (8) comprises at least one hydrocarbon tank (RHC), the method comprising: storing hydrocarbon obtained after separation of the mixture of hydrocarbon and hydrogen in the hydrocarbon tank (RHC); obtaining a mixture of hydrocarbon and hydrogen whose hydrocarbon and hydrogen fractions are controlled, from hydrocarbon stored in the hydrocarbon tank (RHC) and hydrogen stored in the hydrogen tank (RH2); and supplying the combustion chamber with a mixture of hydrocarbon and hydrogen with controlled fractions.

10. Fuel supply system for at least one combustion chamber (2) of a gas turbine, comprising: a supply line (3) for supplying the at least one combustion chamber (2) with a mixture of hydrocarbon and hydrogen comprising: an intake section (4) intended to be connected to an industrial, transport or distribution network for a mixture of hydrocarbon and hydrogen, a separation section (5) adjacent to the intake section (4) and connected to a hydrocarbon and hydrogen mixture inlet of a bypass circuit (8) comprising at least one separation device (DSI) for a mixture of hydrocarbon and hydrogen, an injection section (6) adjacent to the separation section (5) connected to a hydrocarbon outlet (SHC1) and to an outlet hydrogen (SH2) of the bypass circuit (8), and a supply section (7) adjacent to the injection section (6) and connected to the at least one combustion chamber (2) of the gas turbine; and a plurality of valves (VI, V2, V3, V4, V5, V6) each respectively positioned between the intake 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 hydrocarbon and hydrogen mixture inlet (El) of the bypass circuit (8), between the hydrocarbon outlet (SHC1) of the bypass circuit (8) and the injection section (6) of the feed line, and between the hydrogen outlet (SH2) of the bypass circuit (8) and the injection section (6) of the feed line (3).

11. System according to claim 10, in which the bypass circuit (8) comprises a hydrocarbon reservoir (RHC) positioned downstream of the hydrocarbon and hydrogen mixture separation device (DSI) and with a capacity greater than or equal to a predetermined hydrocarbon threshold value.

12. System according to claim 11, comprising a management computer (21) configured to order, when the quantity of hydrocarbon in the hydrocarbon tank (RHC) is less than a predetermined hydrocarbon threshold value: the admission of a mixture of hydrocarbon and hydrogen into the supply line (3), the separation of the mixture of hydrocarbon and hydrogen by the bypass circuit (8) to obtain hydrocarbon, and the storage of the hydrocarbon obtained in the hydrocarbon tank (RHC) until a quantity of hydrocarbon greater than or equal to the predetermined hydrocarbon threshold value is obtained.

13. System according to any one of claims 10 to 12, comprising at least one analyzer (Al) positioned downstream of the device (DSI) for separating the mixture of hydrocarbon and hydrogen and configured to measure the level of hydrogen in the hydrocarbon obtained after separation by the device (DSI) for separating the mixture of hydrocarbon and hydrogen.

14. A system according to any one of claims 10 to 13, wherein the bypass circuit (8) comprises an additional separation device- additional (DS2) of hydrocarbon and hydrogen mixture positioned downstream of the separation device (DSI).

15. System according to any one of claims 10 to 14, in which the bypass circuit (8) comprises at least one hydrogen tank (RH2), for the storage of hydrogen previously separated from the hydrocarbon by the separation device (DSI) or by the additional separation device (DS2).

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