A gas turbine apparatus equipped with an ammonia decomposer, a power plant equipped with the same, and a method for operating the gas turbine apparatus.
The gas turbine system efficiently decomposes ammonia into hydrogen and nitrogen using internal heat sources, improving efficiency and maintaining steam generation capabilities by reusing compressed air and decomposed hydrogen heat.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SIEMENS ENERGY GLOBAL GMBH & CO KG
- Filing Date
- 2024-03-28
- Publication Date
- 2026-04-27
AI Technical Summary
Existing gas turbines face challenges in efficiently decomposing ammonia into hydrogen and nitrogen for combustion due to high nitrogen oxide generation and ignition delay, requiring external heat sources which reduce exhaust gas temperature for steam generation.
A gas turbine system with an ammonia decomposer utilizing compressed air and decomposed hydrogen heat to maintain exhaust gas temperature, integrating a fuel heat exchanger and ammonia evaporator to reuse heat efficiently, and using decomposed hydrogen as a fuel source.
Enhances gas turbine efficiency by reusing internal heat sources, minimizing external energy use, and maintaining exhaust gas temperature for steam generation.
Smart Images
Figure 2026513484000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a gas turbine device including an ammonia decomposer. A gas turbine generally includes a compressor, a combustion section, and an expansion turbine. The ammonia decomposer is used to decompose ammonia into a mixture of hydrogen and nitrogen, and hydrogen can be combusted in the combustion section of the gas turbine.
Background Art
[0002] Conventionally, natural gas has been used as fuel in most gas turbines. To reduce carbon dioxide emissions, it is preferable to use hydrogen as fuel for gas turbines. The supply and storage of hydrogen are costly and raise safety concerns. Therefore, ammonia is a preferable medium for storing hydrogen and transporting it from the production site to the power plant.
[0003] Directly combusting ammonia in a gas turbine as fuel is impossible because an unacceptable amount of nitrogen oxides (NOx) is generated. Furthermore, ammonia has ignition delay characteristics, making it difficult to combust directly. Therefore, it is necessary to decompose at least part of the ammonia into hydrogen and nitrogen before combusting it in the combustion chamber of the gas turbine.
[0004] High temperatures are required for ammonia decomposition. For this reason, various different technologies are used to obtain the required heat in the ammonia decomposer.
[0005] Generally, it is desirable to operate a power plant including ammonia decomposition and gas turbine operation as efficiently as possible while minimizing energy waste. Furthermore, it is desirable not to require an external heat source or energy source for ammonia decomposition.
[0006] Exemplary solutions for enabling the combustion of ammonia are disclosed in EP3314166B1, EP3377745B1, and EP3417205B1. In each case, a portion of the ammonia is supplied to an ammonia decomposer, and the resulting hydrogen and nitrogen are further supplied to a combustor of a gas turbine. Preferably, the heat of the exhaust gas from the gas turbine is used to heat the ammonia decomposer.
[0007] When exhaust gas from a gas turbine is used in a steam generator to produce steam for another steam turbine, the usable temperature in the steam generator decreases because a considerable amount of heat has already been used in the ammonia decomposer.
[0008] [Overview of the prefecture] The object of this invention is to develop an alternative solution for ammonia decomposers installed in gas turbine systems without substantially reducing the exhaust gas temperature (and thus enabling the exhaust gas to be used in the steam generator). Another object is to avoid the use of external heat sources or external energy sources as much as possible.
[0009] This problem is solved by the gas turbine apparatus of the present invention as described in claim 1. A method for operating the gas turbine apparatus equipped with an ammonia decomposer is provided in claim 6. Advantageous embodiments are provided in the dependent claims.
[0010] The gas turbine system includes a compressor, a combustor, and an expansion turbine. During operation of the gas turbine, combustion air is compressed in the compressor, at least a portion of the combustion air is supplied from the compressor outlet to the combustor, and exhaust gas from the combustor is supplied to the expansion turbine.
[0011] To enable the combustion of ammonia, an ammonia decomposer is required, which includes a heater, a decomposer air passage, and a decomposer reaction passage. Furthermore, the apparatus includes a fuel heat exchanger having an exchanger fuel passage and an exchanger ammonia passage. The inlet of the exchanger ammonia passage must be connected to an ammonia supply source, and the outlet of the exchanger ammonia passage is connected to the inlet of the decomposer reaction passage.
[0012] Efficiency can be improved by providing a high-temperature air pipe connecting the compressor outlet to the inlet of the decomposer air passage and a low-temperature air pipe connecting the decomposer air passage outlet to the combustor. Furthermore, the first fuel pipe connects the outlet of the decomposer reaction passage to the inlet of the exchanger fuel passage, and the second fuel pipe connects the outlet of the exchanger fuel passage to the combustor (03).
[0013] [Detailed description of the invention] A typical gas turbine system comprises a gas turbine and an ammonia decomposer. The gas turbine comprises a compressor, at least one combustor, and an expansion turbine.
[0014] A compressor has a compressor inlet, multiple compression stages, and a compressor outlet. During operation of a gas turbine, combustion air (usually filtered outside air) flows into the compressor inlet, is compressed, and supplied from the compressor outlet. As a result, the temperature of the compressed combustion air at the compressor outlet increases due to the compression process.
[0015] Various types of combustion configurations can be used for the solution of the present invention. For example, an annular combustion chamber with multiple burners arranged around the central axis of a gas turbine can be used. Alternatively, a silo-type combustion system or multiple can-type combustors (usually each having one burner and one combustion chamber) arranged around the central axis can be used. In any case, compressed combustion air is supplied (directly or indirectly) from the compressor outlet to one or more combustors, at least in part. Furthermore, during operation of the gas turbine, fuel must be supplied to at least one burner of at least one combustor.
[0016] The expansion turbine is located downstream of at least one combustor and is driven by the flow of hot exhaust gases during gas turbine operation. After the exhaust gases expand within the expansion turbine, they are discharged from the gas turbine outlet at a reduced temperature.
[0017] A typical ammonia decomposer is necessary to break down ammonia into hydrogen and nitrogen. Therefore, an ammonia decomposer has a decomposer reaction channel that runs through the decomposer from inlet to outlet.
[0018] The ammonia supplied from its source is likely to be at a lower temperature than the temperature required in the ammonia decomposer. On the other hand, the fuel gas containing hydrogen and nitrogen exiting the ammonia decomposer is at a high temperature due to the heating required for the decomposition process. Therefore, it is advantageous to reuse the heat from this fuel gas to heat the ammonia supplied to the ammonia decomposer.
[0019] The gas turbine apparatus of the present invention includes a fuel heat exchanger. Preferably, the fuel heat exchanger has an exchanger ammonia passage and an exchanger fuel passage. When the gas turbine apparatus is in use, the inlet of the exchanger ammonia passage must be connected to an ammonia supply source, and the outlet of the exchanger ammonia passage of the fuel heat exchanger must be connected to the inlet of the decomposer reaction passage of the ammonia decomposer.
[0020] To enable heat transfer, a first fuel pipe is required, which connects the outlet of the decomposer reaction passage to the inlet of the fuel exchanger fuel passage of the fuel heat exchanger. Clearly, in embodiments of the present invention, the fuel flow (first as ammonia, then as a fuel gas containing hydrogen and nitrogen) passes through the fuel heat exchanger twice.
[0021] Furthermore, a second fuel pipe is required, which connects the outlet of the fuel passage of the fuel heat exchanger to at least one combustor. If several burners are provided, it is obviously preferable that the second fuel pipe branches to all the burners to which it is installed.
[0022] To make the decomposition process feasible, it is necessary to operate the ammonia decomposer at the required temperature. To achieve the desired efficiency and avoid utilizing the heat of the exhaust gas discharged from the gas turbine, this invention requires that at least a portion of the compressed air be used in the ammonia decomposer to introduce the heat necessary for the decomposition process. During operation of the gas turbine system, the temperature of the compressed air at the compressor outlet is usually lower than that of the exhaust gas downstream of the combustor. However, this temperature is much higher than the normal ambient temperature.
[0023] To make use of the heat from compressed air, the ammonia decomposer is further equipped with a decomposer air channel that allows compressed air to flow through the ammonia decomposer from inlet to outlet.
[0024] The gas turbine system includes a high-temperature air piping that connects the compressor outlet to the inlet of the decomposer air passage of the ammonia decomposer. Furthermore, a low-temperature air piping is required that connects the outlet of the decomposer air passage to at least one combustor, thereby enabling the flow of combustion air for burning fuel in the combustor. During operation of the gas turbine system, the "low-temperature air piping" is still hotter than the outside air but cooler than the "high-temperature air piping".
[0025] A typical ammonia decomposer includes a heater to heat ammonia to the temperature required to decompose it into hydrogen and nitrogen.
[0026] By utilizing the heat from compressed air and further heating with a heater, the efficiency of the gas turbine system can be increased. As a result, the high-temperature exhaust gas discharged from the gas turbine can be used to continue operating the steam generator.
[0027] Instead of using an external energy source for the ammonia decomposer's heater, it is advantageous to use the decomposed hydrogen as fuel for the heater. By burning the hydrogen decomposed in the ammonia decomposer in the heater, the efficiency of the gas turbine system can be further improved.
[0028] In the startup process, it is clear that hydrogen required for additional heating in the ammonia decomposer needs to be supplied from the outside. However, in principle, during normal operation of the gas turbine device, it is desirable to configure the hydrogen required for the operation of the heater to be supplied by branching off from a part of the flow of hydrogen and nitrogen discharged from the fuel outlet of the ammonia decomposer.
[0029] Theoretically, it is also possible to install an independent combustion system for burning hydrogen in the ammonia decomposer. However, it is more advantageous to directly burn hydrogen in the air flow path inside the ammonia decomposer. This simplifies the installation work and improves efficiency.
[0030] In order to supply a part of the decomposed ammonia to the heater of the ammonia decomposer, it is possible to connect the heater to the first fuel pipe between the outlet of the decomposer reaction flow path and the inlet of the exchanger ammonia passage. Alternatively, the heater can also be connected to the second fuel pipe between the outlet of the exchanger ammonia passage and the combustor.
[0031] It is also possible to supply ammonia in a gaseous state from an ammonia supply source.
[0032] When the ammonia supply source supplies ammonia in liquid form, it is further desirable to use an ammonia evaporator. The ammonia evaporator should include a fluid passage and an evaporation passage. In terms of configuration, the input side of the evaporation passage of the ammonia evaporator is connected to the fuel supply source, and the outlet side of the ammonia evaporator is connected to the inlet of the exchanger ammonia passage.
[0033] In this case, it is necessary to supply a heated medium to the fluid passage of the ammonia evaporator.
[0034] The gas turbine device according to a preferred embodiment of the present invention includes a steam generator disposed downstream of the expansion turbine. A plurality of heat exchangers for transferring the heat of the exhaust gas to the generation of steam are required inside the steam generator.
[0035] By combining it with a suitable ammonia evaporator, it is advantageous to utilize the heat from the exhaust gas not only for steam generation but also for ammonia preheating. Two different solutions are proposed here.
[0036] In the first embodiment, the fluid passage of the ammonia evaporator is connected to both the outlet and input sides of at least one heat exchanger installed in the steam generator.
[0037] In the second embodiment, a portion of the steam generator constitutes an ammonia evaporator, the evaporation passage is provided as a heat exchanger within the steam generator, and the passage through which the exhaust gas flows is the fluid passage of the ammonia evaporator.
[0038] In either case, the heat exchanger connected to the ammonia evaporator, or the ammonia evaporator as part of a steam generator, should be located at the downstream end of the steam generator. This allows the heat from the exhaust gas to be preferentially used for steam generation. [Brief explanation of the drawing]
[0039] [Figure 1] The figure schematically shows an exemplary embodiment of the gas turbine apparatus 01 of the present invention.
[0040] The gas turbine system 01 comprises a gas turbine having a compressor 02, a combustor 03, and an expansion turbine 04. The steam generator 05 is located downstream of the expansion turbine 04.
[0041] Multiple heat exchangers (not shown) are installed inside the steam generator 05, and at least one of these heat exchangers is connected to the steam turbine 06.
[0042] Compressed combustion air is typically supplied from the compressor 02 to the combustor 03, and the exhaust gas produced in the combustor 03 is supplied to the expansion turbine 04 to drive the gas turbine rotor.
[0043] Here, it is necessary to branch off at least a portion of the compressed combustion air and supply it to the ammonia decomposer 11. The decomposer air passage allows the compressed air to flow through the ammonia decomposer 11. Therefore, the inlet of the decomposer air passage is connected to the compressor outlet, and the outlet of the decomposer air passage is connected to the combustor 03. As a result, at least a portion of the compressed combustion air flows into the combustor 03 after passing through the ammonia decomposer 11.
[0044] The ammonia decomposer 11 contains a decomposition reaction passage and a heater 15. Gaseous ammonia is supplied to the inlet of the decomposition reaction passage, and a mixture of hydrogen and nitrogen is supplied from the outlet of the decomposition reaction passage. The heat in the decomposition reaction passage enables the decomposition of ammonia, with some of the heat supplied by compressed air and some by the heater 15.
[0045] The inlet and outlet of the decomposition reaction passage are both connected to the fuel heat exchanger 12. Therefore, the fuel heat exchanger 12 is equipped with an ammonia passage and a fuel passage.
[0046] Ammonia is supplied to the inlet of the ammonia passage in the fuel heat exchanger 12. As the ammonia passes through the ammonia passage of the fuel heat exchanger 12, it is heated using the heat generated when a mixture of hydrogen and nitrogen passes through the exchanger fuel passage. This allows for the efficient reuse of the heat required in the ammonia decomposer 11.
[0047] The outlet of the fuel passage of the fuel heat exchanger 12 is connected to the combustor 03, thereby allowing the fuel, consisting of a mixture of hydrogen and nitrogen, to be used in the combustion process within the gas turbine.
[0048] A portion of the generated hydrogen is diverted and supplied to the heater 15 in the ammonia decomposer 11 to achieve the temperature required for the decomposition process. In this embodiment, the heater 15 is connected to a second fuel pipe between the outlet of the exchanger fuel passage and the combustor 03. However, in an alternative configuration, the heater may also be connected to a first fuel passage located between the outlet of the decomposer reaction channel of the ammonia decomposer 11 and the inlet of the exchanger ammonia passage of the heat exchanger 12.
[0049] An ammonia evaporator 13 is installed between the ammonia source 14 and the fuel heat exchanger 12 to enable the use of liquid ammonia from the ammonia source 14. Inside the ammonia evaporator 13, ammonia changes state from liquid to gas through heat transfer.
[0050] Therefore, the ammonia evaporator 13 is connected to the heat exchanger installed inside the steam generator 05.
Claims
1. A gas turbine device (01), - A gas turbine having a compressor (02), a combustor (03), and an expansion turbine (04), wherein, during operation of the gas turbine, combustion air is compressed in the compressor (02), at least a portion of the combustion air is supplied from the outlet of the compressor (02) to the combustor (03), and exhaust gas is supplied from the combustor (03) to the expansion turbine (04) during operation of the gas turbine, - An ammonia decomposer (11) having a heater (15), a decomposer air channel, and a decomposer reaction channel, - A fuel heat exchanger (12) having an exchanger fuel passage and an exchanger ammonia passage, Equipped with, When the gas turbine device (01) is in use, the inlet of the ammonia passage of the fuel heat exchanger is structurally connected to the ammonia supply source (14), and the outlet of the ammonia passage of the fuel heat exchanger is connected to the inlet of the decomposer reaction channel. The first fuel pipe connects the outlet of the decomposer passage to the inlet of the exchanger fuel passage, and the second fuel pipe connects the outlet of the exchanger fuel passage to the combustor (03). The high-temperature air piping connects the compressor outlet to the inlet of the decomposer air passage, and the low-temperature air piping connects the outlet of the decomposer air passage to the combustor (03). A gas turbine device (01) characterized by the following features.
2. The gas turbine apparatus (01) according to claim 1, wherein the second fuel pipe branches off to a heater pipe extending to the heater (15).
3. The gas turbine apparatus (01) according to claim 2, wherein the heater (15) is configured to burn hydrogen in the air passage.
4. The ammonia evaporator (13) further comprises an evaporator fluid passage and an evaporator ammonia passage. The gas turbine apparatus (01) according to any one of claims 1 to 3, wherein the inlet of the evaporator ammonia passage is configured to be connected to the ammonia supply source (14), and the outlet of the evaporator ammonia passage is connected to the inlet of the exchanger ammonia passage.
5. The steam generator (05) is further equipped, The steam generator (05) is located downstream of the expansion turbine (04) and has a plurality of heat exchangers. The gas turbine apparatus (01) according to claim 4, wherein the ammonia evaporator (13) is connected to at least one of the heat exchangers, or the ammonia evaporator (13) is arranged as one of the heat exchangers within the steam generator (05).
6. A method for operating a gas turbine device (01), - At least a portion of the compressed air is supplied to the ammonia decomposer (11), - In the ammonia decomposer (11), additional heat is introduced by the heater (15), - Ammonia is supplied from the ammonia source (14) to the fuel heat exchanger (12), and is guided from the fuel heat exchanger (12) to the ammonia decomposer (11) through the ammonia passage of the exchanger. - Ammonia is heated in the decomposition reactor reaction channel, thereby decomposing into a fuel gas containing hydrogen and nitrogen. - The decomposed fuel gas is supplied from the ammonia decomposer (11) to the fuel heat exchanger (12), guided through the exchanger fuel passage, and heat is transferred to the ammonia in the exchanger ammonia passage. - The fuel gas is supplied from the fuel heat exchanger (12) to the combustor (03). A method for operating a gas turbine device (01) having the gas turbine device (01) according to any one of the above claims.
7. The method according to claim 6, wherein a portion of the fuel gas is branched from the second fuel pipe and supplied to the heater (15) and burned in the ammonia decomposer (11).