Gas turbine

Abstract

To make the concentration of nitrogen oxides (NOx) meet emission standards without enlarging the size of an exhaust denitrification device and improve thermal efficiency of a gas turbine that uses ammonia as fuel on a gas turbine.SOLUTION: A gas turbine that comprises at least a compressor, a combustor, and a turbine, and combusts ammonia as fuel in the combustor, the gas turbine further comprising a reducing agent supply device that supplies a reducing agent for reducing a nitrogen oxide in the combustion gas to a combustion gas flow passage between the combustor and the turbine.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to gas turbines. This application claims priority based on PCT / JP2020 / 019693, filed in Japan on May 18, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] The following Patent Document 1 discloses a combustion device and a gas turbine system that mix and burn natural gas and ammonia in a combustor. This combustion device etc. mixes and burns gaseous ammonia as ammonia for combustion in the combustor, and also reduces nitrogen oxides (NO x In order to reduce the oxidized carbon dioxide (CO2), ammonia is supplied downstream of the turbine and upstream of the reduction catalyst chamber. In addition, the following Patent Document 2 describes a method for burning ammonia as the only fuel in the main combustor (single-fuel combustion) and supplying it to a reheater to reduce nitrogen oxides (NO x A reheat type ammonia gas turbine that reduces the concentration of NOx is disclosed. In this gas turbine, exhaust gas from a reheater is supplied to the reheat gas turbine through a denitration catalyst. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-162752 [Patent Document 2] Japanese Patent Application Publication No. 2015-031215 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned gas turbines, the nitrogen oxide concentration in the combustion gas or exhaust gas is reduced using a reduction catalyst chamber or a denitration catalyst. However, since ammonia is burned as fuel, nitrogen oxides (NOx In other words, a large exhaust denitrification device is indispensable for ammonia-burning gas turbines.

[0005] However, the increase in size of the exhaust gas denitration device leads to various problems such as cost, space, a decrease in overall efficiency, and a deterioration in load fluctuation follow-up. x ) needs to be reduced.

[0006] In addition, ammonia does not emit carbon dioxide (CO2) when burned, but since the production volume of CO2-free ammonia derived from renewable energy is limited, it is necessary to use it efficiently, i.e., to improve its thermal efficiency. The larger the gas turbine, the easier it is to improve its thermal efficiency, but the larger the gas turbine, the greater the amount of ammonia used, so large gas turbines that consume large amounts of CO2-free ammonia, which is produced in limited quantities, are difficult to adapt. Therefore, measures to improve the thermal efficiency of small and medium-sized gas turbines that take advantage of the characteristics of ammonia combustion are needed.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and has the following objectives. (1) Reduces nitrogen oxides (NO x ) concentration to comply with emission standards. (2) Improve the thermal efficiency of gas turbines that use ammonia as fuel. [Means for solving the problem]

[0008] The gas turbine of the first aspect of the present disclosure is a gas turbine that includes at least a compressor, a combustor, and a turbine, and burns ammonia as fuel in the combustor, and includes a water vapor circulation means that recovers water vapor generated by the combustion of ammonia and circulates and supplies the water vapor to the combustor.

[0009] In the gas turbine of the first aspect of the present disclosure, the water vapor circulation means may include a recovery device that recovers water vapor contained in the exhaust gas of the turbine as water, and a water vapor supply device that vaporizes the water and supplies it to the combustor, and the water vapor may be condensed and the water vaporized by heat exchange between the exhaust gas and the water.

[0010] In the gas turbine of the first aspect of the present disclosure, the recovery device may include a heat exchanger that exchanges heat between the exhaust gas and water, and a gas-liquid separator that separates the water output from the heat exchanger and the residual gas of the exhaust gas into gas and liquid, and the water vapor supply device may include a water pump that supplies the water output from the gas-liquid separator to the heat exchanger, and the heat exchanger.

[0011] The gas turbine according to the first aspect of the present disclosure may further include a first mixing means for mixing at least a portion of the steam supplied to the combustor by the steam supply device with the ammonia before the ammonia is supplied to the combustor as fuel.

[0012] The gas turbine according to the first aspect of the present disclosure may further include a second mixing means for mixing at least a portion of the ammonia before being supplied to the combustor as fuel with the water recovered by the recovery device.

[0013] In the gas turbine according to the first aspect of the present disclosure, a reducing agent supplying means may be provided for supplying a portion of ammonia before it is supplied to the combustor as fuel to the turbine as a reducing agent for reducing nitrogen oxides in the combustion gas.

[0014] A gas turbine according to a second aspect of the present disclosure is a gas turbine including at least a compressor, a combustor, and a turbine, and combusts ammonia as fuel in the combustor, and is provided with a reducing agent supplying device that supplies a reducing agent for reducing nitrogen oxides in the combustion gas to a combustion gas flow passage between the combustor and the turbine and / or the turbine.

[0015] In the gas turbine of the second aspect of the present disclosure, the turbine is a multi-stage turbine in which a plurality of individual turbines are combined, and the reducing agent supply device may supply the reducing agent to the individual turbine of a stage in which a denitrification effect is expected and / or to an individual combustion gas flow path connecting the individual turbines.

[0016] The gas turbine according to the second aspect of the present disclosure may further include a cooling fluid supply device that supplies a cooling fluid to the turbine, and the reducing agent may be mixed with the cooling fluid and supplied.

[0017] In the gas turbine of the second aspect of the present disclosure, the reducing agent may be ammonia. Effect of the Invention

[0018] According to the present disclosure, it is possible to reduce nitrogen oxides (NO x ) concentrations can be made to comply with emission standards. Furthermore, according to the present disclosure, it is possible to improve the thermal efficiency of a gas turbine that uses ammonia as fuel. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a system configuration diagram showing an overall configuration of a gas turbine according to a first embodiment of the present disclosure. [Figure 2A] FIG. 2 is a first schematic diagram showing a turbine configuration and a reducing agent injection location in the first embodiment of the present disclosure. [Figure 2B] FIG. 4 is a second schematic diagram showing a turbine configuration and a reducing agent injection location in the first embodiment of the present disclosure. [Diagram 3] 4 is a graph showing a simulation result of a denitration rate in the first embodiment of the present disclosure. [Figure 4] FIG. 4 is a system configuration diagram showing an overall configuration of a gas turbine according to a second embodiment of the present disclosure. [Diagram 5] FIG. 11 is a system configuration diagram showing an overall configuration of a gas turbine according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [First embodiment] First, a first embodiment of the present disclosure will be described with reference to Fig. 1 to Fig. 3. As shown in Fig. 1, a gas turbine A according to the first embodiment includes a compressor 1, a combustor 2, a turbine 3, a fuel supply device 4, a cooling air supply device 5, a reducing agent supply device 6, a heat recovery boiler 7, and an exhaust gas denitrification device 8. This gas turbine A is an ammonia mono-fuel type gas turbine that combusts (mono-fuels) ammonia supplied from the fuel supply device 4 as the only fuel X3 in the combustor 2.

[0021] The compressor 1 is, for example, an axial flow compressor equipped with rotor blades and stator blades arranged alternately in multiple stages along a rotating shaft, and pressurizes air X1 taken in from the atmosphere to a predetermined pressure and supplies it to a combustor 2. The rotating shaft of this compressor 1 is axially coupled to the rotating shaft of a turbine 3, and is rotationally driven by the turbine 3.

[0022] The combustor 2 includes a burner that injects compressed air X2 supplied from the compressor 1 and fuel X3 supplied from a fuel supply device 4 into a chamber, and burns the fuel X3 using the compressed air X2 as an oxidizer. The combustor 2 supplies high-temperature and high-pressure combustion gas X4 generated by the combustion reaction of the fuel X3 to the turbine 3 as a driving fluid.

[0023] The turbine 3 is, for example, an axial flow turbine equipped with rotor blades and stator blades arranged alternately in multiple stages along a rotating shaft, and is a prime mover that converts the kinetic energy of the combustion gas X4 (driving fluid) into power. The turbine 3 uses the power it generates to rotate the compressor 1 to which the rotating shaft is connected. The turbine 3 also has an output shaft connected to a load, and rotates the load.

[0024] 2A and 2B, such a turbine 3 includes a plurality of (four) individual turbines 3a-3d and five combustion gas flow paths 3e-3i, and is a multi-stage turbine that combines the individual turbines 3a-3d and the combustion gas flow paths 3e-3i. This turbine 3 discharges exhaust gas X5 after power recovery in the individual turbines 3a-3d of each stage to a heat recovery boiler 7.

[0025] Of the four individual turbines 3a to 3d, the individual turbine 3a is a first stage turbine located at the most upstream position in the flow direction of the combustion gas X4. The inlet of the individual turbine 3a for the combustion gas X4 is connected to the outlet of the combustor 2 via a combustion gas passage 3e. Moreover, the outlet of the individual turbine 3a for the combustion gas X4 is connected to the inlet of the individual turbine 3b via a combustion gas passage 3f.

[0026] The individual turbine 3b is a second stage turbine located second from the upstream in the flow direction of the combustion gas X4. The inlet of the individual turbine 3b for the combustion gas X4 is connected to the outlet of the individual turbine 3a via a combustion gas passage 3f. The outlet of the individual turbine 3b for the combustion gas X4 is connected to the inlet of the individual turbine 3c via a combustion gas passage 3g.

[0027] The individual turbine 3c is a third stage turbine located third from the upstream in the flow direction of the combustion gas X4. The inlet of the individual turbine 3c for the combustion gas X4 is connected to the outlet of the individual turbine 3b via a combustion gas passage 3g. The outlet of the individual turbine 3c for the combustion gas X4 is connected to the inlet of the individual turbine 3d via a combustion gas passage 3h.

[0028] The individual turbine 3d is a fourth-stage turbine located at the most downstream position in the flow direction of the combustion gas X4. The inlet of the combustion gas X4 of the individual turbine 3d is connected to the outlet of the individual turbine 3c via a combustion gas passage 3h. The outlet of the combustion gas X4 of the individual turbine 3d is connected to the inlet of the heat recovery steam generator 7 via a combustion gas passage 3i.

[0029] The fuel supply device 4 includes at least a fuel tank and a fuel pump, and supplies a predetermined flow rate of fuel X3 to the combustor 2. More specifically, the fuel supply device 4 supplies ammonia as the sole fuel X3 to the combustor 2. As is well known, ammonia is generally distributed as a liquefied gas. The fuel supply device 4 receives such ammonia as fuel X3 from the outside and supplies it to the combustor 2.

[0030] The cooling air supply device 5 includes at least an air compressor, and supplies cooling air X6 as a cooling fluid to the turbine 3. This cooling air X6 is supplied to the inside of the moving blades, stationary blades, etc. that constitute the turbine 3, and by flowing out from the inside to the outside, it suppresses fatigue deterioration of the turbine 3 that is exposed to high-temperature combustion gas. Such a cooling air supply device 5 corresponds to the cooling fluid supply device of the present disclosure.

[0031] The reducing agent supply device 6 includes at least a reducing agent tank and a reducing agent pump, and supplies a predetermined flow rate of a reducing agent X7 to the turbine 3 and the exhaust denitrification device 8. The reducing agent X7 is used to reduce nitrogen oxides (NO x ) is a substance that can be expected to have a reducing effect, such as ammonia. More specifically, the reducing agent supply device 6 selectively supplies the reducing agent X7 to any one of the individual turbines 3a to 3d and / or the combustion gas passages 3e to 3i.

[0032] That is, the reducing agent supplying device 6 supplies the reducing agent X7 to the combustion gas flow path between the combustor 2 and the turbine 3 and / or to an individual turbine and / or an individual combustion gas flow path of a stage where a denitrification effect is expected, among the turbine 3. Such a reducing agent supplying device 6 corresponds to the reducing agent supplying device of the present disclosure.

[0033] The heat recovery boiler 7 is a steam generator that includes at least a gas flow pipe through which the exhaust gas X5 flows and a water flow pipe through which water flows, and generates steam using the exhaust gas X5 supplied from the turbine 3 as a heat source. The heat recovery boiler 7 discharges the exhaust gas X8 after exhaust heat recovery to the exhaust denitrification device 8.

[0034] The exhaust gas denitration device 8 includes at least a catalyst chamber filled with a denitration catalyst and a sprayer that sprays a reducing agent X7 in front of the denitration catalyst. The exhaust gas X8 is passed through the denitration catalyst together with the reducing agent X7 to reduce nitrogen oxides (NO x The exhaust denitrification device 8 releases exhaust gas X9, in which the concentration of nitrogen oxides has been reduced to the environmental standard, into the atmosphere.

[0035] Such an exhaust gas denitration device 8 has a property that the size of the device increases depending on the flow rate of the exhaust gas X8 and / or the concentration of nitrogen oxides contained in the exhaust gas X8. That is, when the flow rate of the exhaust gas X8 increases, the size of the device of the exhaust gas denitration device 8 increases in order to make the exhaust gas X9 conform to the environmental standards, and when the concentration of nitrogen oxides in the exhaust gas X8 increases, the size of the device increases in order to make the exhaust gas X9 conform to the environmental standards.

[0036] Therefore, in order to prevent the exhaust gas denitration device 8 from becoming large, it is necessary to sufficiently reduce the concentration of nitrogen oxides upstream of the exhaust gas denitration device 8, that is, between the combustor 2 through which the combustion gas X4 or the exhaust gases X5, X8, and X9 flow and the exhaust heat recovery boiler 7.

[0037] Next, the operation of the gas turbine A according to the first embodiment will be described in detail with reference to FIG.

[0038] 3 shows the results of a simulation of the change in denitrification rate with respect to the temperature (K) and pressure (bar) in the presence (reduction) field of the reducing agent X7 for the combustion gas X4 generated in the combustor 2 when ammonia (fuel X3) is exclusively burned. In FIG. 3, the solid line indicates the case where the pressure is 1 bar, the dotted line indicates the case where the pressure is 10 bar, and the dashed line indicates the case where the pressure is 20 bar.

[0039] More specifically, the combustion gas X4 is a mixed gas containing 17% oxygen (O2), 6% water vapor (H2O), and 500 ppm of nitric oxide (NO) in nitrogen (N2). In this simulation, the change in the denitrification rate was obtained when 500 ppm of ammonia (NH3), which is the same amount as nitric oxide (NO), was converted into the combustion gas X4. As is well known, 1 bar is 0.1 MPa (megapascal).

[0040] The simulation results show that the higher the pressure, the higher the denitration rate, and that the denitration rate takes a positive value in a certain temperature range and a negative value in a temperature range beyond that range. In other words, the simulation results show that the nitrogen oxide concentration decreases in the temperature range from about 1100°C to about 1500°C, but increases in the temperature range above about 1500°C.

[0041] The gas turbine A according to the first embodiment has been developed in consideration of such simulation results, and as shown in FIGS. 2A and 2B, the reducing agent supply device 6 supplies the reducing agent X7 to a portion in the turbine 3 where the denitrification rate can have a positive value.

[0042] 2A shows a case where the gas turbine A according to the first embodiment is applied to a relatively large gas turbine. In this case, the properties of the combustion gas X4 at the outlet of the combustor 2 are pressure: 20 bar, temperature: 1673 K, and nitrogen oxide concentration: 500 ppm. In addition, when the turbine expansion coefficient of each of the individual turbines 3a to 3d is 1.7, the pressure, temperature, and nitrogen oxide concentration at the inlet and outlet of each of the individual turbines 3a to 3d are as shown in the three rows, one above the other.

[0043] That is, the pressure at the inlet of the first stage individual turbine 3a is 20 bar, the temperature is 1673 K, and the nitrogen oxide concentration is 500 ppm, similar to the outlet of the combustor 2, and the pressure at the outlet of the first stage individual turbine 3a and the inlet of the second stage individual turbine 3b is 11.8 bar and the temperature is 1480 K.

[0044] Furthermore, the pressure at the outlet of the second stage individual turbine 3b and the inlet of the third stage individual turbine 3c is 6.9 bar and 1310 K, the pressure at the outlet of the third stage individual turbine 3c and the inlet of the fourth stage individual turbine 3d is 4.1 bar and 1159 K, and the pressure at the outlet of the fourth stage individual turbine 3d is 2.4 bar and 1025 K.

[0045] Among the pressures and temperatures at the inlets and outlets of each of these individual turbines 3a to 3d, the locations which satisfy the condition that the denitrification rate takes a positive value are the outlet of the second stage individual turbine 3b and the inlet of the third stage individual turbine 3c, as well as the outlet of the third stage individual turbine 3c and the inlet of the fourth stage individual turbine 3d.

[0046] That is, the reducing agent supply device 6 in the first embodiment supplies the reducing agent X7 to the outlet of the second-stage individual turbine 3b and the outlet of the third-stage individual turbine 3c as shown in the figure. As a result, the nitrogen oxide concentration at the inlet of the third-stage individual turbine 3c decreases to 240 ppm, and the nitrogen oxide concentration at the inlet of the fourth-stage individual turbine 3d decreases to 154 ppm.

[0047] According to the first embodiment, it is possible to ensure a total denitration rate of about 69% for a relatively large gas turbine, and the nitrogen oxide concentration of 154 ppm is a level that can be treated by a normal-scale exhaust denitration device 8. Therefore, according to the first embodiment, it is possible to reduce nitrogen oxides (NO x ) concentrations can be made to comply with emission standards.

[0048] 2B shows a case where the gas turbine A according to the first embodiment is applied to a small to medium-sized gas turbine. In this case, the properties of the combustion gas X4 at the outlet of the combustor 2 are pressure: 20 bar, temperature: 1373 K, and nitrogen oxide concentration: 500 ppm. If the turbine expansion coefficient of each of the individual turbines 3a to 3d is 1.7, the pressure, temperature, and nitrogen oxide concentration at the inlet and outlet of each of the individual turbines 3a to 3d are as shown in the three rows, one above the other.

[0049] That is, the pressure at the inlet of the first stage individual turbine 3a is 20 bar, the temperature is 1373 K, and the nitrogen oxide concentration is 500 ppm, similar to the outlet of the combustor 2, and the pressure at the outlet of the first stage individual turbine 3a and the inlet of the second stage individual turbine 3b is 11.8 bar and the temperature is 1215 K.

[0050] Furthermore, the pressure at the outlet of the second stage individual turbine 3b and the inlet of the third stage individual turbine 3c is 6.9 bar and 1075 K, the pressure at the outlet of the third stage individual turbine 3c and the inlet of the fourth stage individual turbine 3d is 4.1 bar and 951 K, and the pressure at the outlet of the fourth stage individual turbine 3d is 2.4 bar and 841 K.

[0051] Among the pressures and temperatures at the inlets and outlets of each of these individual turbines 3a to 3d, the locations that satisfy the condition that the denitrification rate takes a positive value are the outlet of the combustor 2 and the inlet of the first-stage individual turbine 3a, as well as the outlet of the first-stage individual turbine 3a and the inlet of the second-stage individual turbine 3b.

[0052] Therefore, the reducing agent supply device 6 supplies the reducing agent X7 to the outlet of the combustor 2 and the outlet of the first stage individual turbine 3a as shown in the figure. As a result, the nitrogen oxide concentration at the inlet of the first stage individual turbine 3a decreases to 276 ppm, and the nitrogen oxide concentration at the inlet of the second stage individual turbine 3b decreases to 132 ppm.

[0053] According to the first embodiment, it is possible to ensure a total denitration rate of about 74% for small and medium-sized gas turbines, and the nitrogen oxide concentration of 132 ppm is a level that can be treated by a normal-sized exhaust denitration device 8. Therefore, according to the first embodiment, even for small and medium-sized gas turbines, it is possible to reduce nitrogen oxides (NO x ) concentrations can be made to comply with emission standards.

[0054] According to the first embodiment, ammonia can be used both as the fuel X3 and the reducing agent X7, so that the device configuration can be simplified. Also, ammonia, which has excellent cooling capacity, is supplied to the turbine 3 as the reducing agent X7, so that the cooling capacity of the turbine 3 can be improved.

[0055] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to FIG. In FIG. 4, the same functional components as those in FIG. 1 are denoted by the same reference numerals.

[0056] 4, the gas turbine B according to the second embodiment includes a heat exchanger 12, a gas-liquid separator 13, and a water pump 14 in addition to the compressor 1, the combustor 2, the turbine 3, and the fuel supply device 4. The fuel supply device 4 includes a fuel tank 10 and a fuel pump 11. The heat exchanger 12, the gas-liquid separator 13, and the water pump 14, which are new functional components, configure the water vapor circulation means of the present disclosure, and recover water vapor generated by combustion of ammonia, which is the fuel X3, and circulate and supply the water vapor to the combustor 2.

[0057] As shown in the following formula (1), the combustion gas X4 generated by the combustion reaction of ammonia contains a large amount of moisture. The gas turbine B according to the second embodiment utilizes such a feature of the combustion reaction of ammonia to improve thermal efficiency. 4NH4+3O2→2N2+6H2O (1)

[0058] The heat exchanger 12 selectively condenses the water vapor contained in the exhaust gas X5 to generate gas-liquid mixed water X10 and vaporizes the water X11 to generate water vapor X13 by exchanging heat between the exhaust gas X5 supplied from the turbine 3 and the water X11 supplied from the water pump 14. The heat exchanger 12 supplies the gas-liquid mixed water X10 to the gas-liquid separator 13 and supplies the water vapor X13 to the combustor 2.

[0059] The gas-liquid separator 13 separates the gas-liquid mixed water X10 into gas and liquid, thereby separating the water X11 and the remaining gas X12 other than the water X11 in the gas-liquid mixed water X10. The gas-liquid separator 13 supplies the water X11 to a water pump 14, and discharges the remaining gas X12 to a downstream exhaust heat recovery boiler or exhaust denitrification device (not shown).

[0060] That is, the heat exchanger 12 and the gas-liquid separator 13 constitute the recovery device of the present disclosure, and recover water vapor contained in the exhaust gas X5 of the turbine 3, that is, water vapor generated by the combustion of ammonia, as water X11.

[0061] The water pump 14 pressurizes the water X11 supplied from the gas-liquid separator 13 and supplies it to the heat exchanger 12. This water X11 is heated in the heat exchanger 12 and vaporized to become water vapor X13, which is supplied to the combustor 2. That is, the heat exchanger 12 and the water pump 14 constitute a water vapor supply device of the present disclosure, which vaporizes the water X11 and supplies it to the combustor 2.

[0062] When gas turbine B configured in this way is applied to a small to medium-sized gas turbine with an output of 11 MW, the total thermal efficiency is calculated by simulation to be 35.7%. The conditions in this simulation are as follows:

[0063] (1) Fuel X3 (ammonia) supply: 123 kmol / h (2) Fuel (ammonia) supply temperature: Room temperature (3) Fuel (ammonia) supply pressure: 10 atm (4) Turbine 3 inlet temperature: 1100°C (5) Turbine 3 inlet pressure: 20 atm

[0064] In addition, the simulation results, together with the above-mentioned thermal efficiency (35.7%), are as follows: power of the fuel supply device 4 (supply pump power) is 1 kW, power of the water pump 14 is 6 kW, power of the compressor 1 is 2281 kW (air flow rate: 600 kmol / h), output of the turbine 3 is 6156 kW, and net output is 3867 kW.

[0065] From these simulation results, when the heat exchanger 12, the gas-liquid separator 13, and the water pump 14, i.e., the steam circulation means of the present disclosure, are removed from the gas turbine B, and a heat exchanger that exchanges heat between the exhaust gas X5 and the fuel X3 (ammonia) is added, the thermal efficiency is calculated to be 29.0%. The simulation conditions in this case are substantially the same as those in the case of the gas turbine B described above, but the inlet temperature of the turbine 3 is 1400°C.

[0066] In addition, the simulation results, together with the above-mentioned thermal efficiency (29.0%), are as follows: power of the fuel supply device 4 (supply pump power) is 1 kW, power of the compressor 1 is 4068 kW (air flow rate: 1070 kmol / h), output of the turbine 3 is 7207 kW, and net output is 3138 kW.

[0067] That is, according to the gas turbine B of the second embodiment, water vapor generated by combustion of the fuel X3 (ammonia) is recovered and circulated and supplied to the combustor 2, so that it is possible to improve the thermal efficiency when ammonia is used as the fuel X3.

[0068] Moreover, according to this gas turbine B, since the steam X13 is supplied to the combustor 2, it is possible to lower the temperature of the combustion gas X4, and therefore it is possible to suppress the corrosion of the turbine 3. Moreover, according to this gas turbine B, since the steam X13 is also supplied to the combustor 2, it is possible to reduce the amount of air supplied to the combustor 2, and therefore it is possible to reduce the power of the compressor 1.

[0069] Third Embodiment Next, a third embodiment of the present disclosure will be described with reference to FIG. In FIG. 5, the same functional components as those in FIG. 4 are denoted by the same reference numerals.

[0070] As shown in Fig. 5, the gas turbine C according to the third embodiment includes a compressor 1, a combustor 2, a turbine 3, a fuel supply device 4, a heat exchanger 12, a gas-liquid separator 13, and a water pump 14, as well as a first mixing pipe 21, a second mixing pipe 22, and a reducing agent supply pipe 23. The first mixing pipe 21, the second mixing pipe 22, and the reducing agent supply pipe 23, which are new functional components, may be added individually to the gas turbine B of Fig. 4 described above. That is, only the first mixing pipe 21 may be added to the gas turbine B of Fig. 4. Also, only the second mixing pipe 22 may be added to the gas turbine B of Fig. 4. Also, only the reducing agent supply pipe 23 may be added to the gas turbine B of Fig. 4.

[0071] The first mixing pipe 21 is a branch pipe branched from the steam supply pipe 31 connecting the heat exchanger 12 and the combustor 2, and connected to the fuel supply pipe 32 connecting the fuel pump 11 and the combustor 2. The first mixing pipe 21 and the steam supply pipe 31 are provided with flow rate control valves 21a, 31a capable of adjusting the distribution amount of the steam between 0 and 100% according to various loads of the gas turbine C. This first mixing pipe 21 corresponds to the first mixing means of the present disclosure, which mixes at least a part of the steam supplied by the steam supply device to the combustor 2 with ammonia before it is supplied to the combustor 2 as the fuel X3.

[0072] The second mixing pipe 22 is a branch pipe branched from the fuel supply pipe 32 connecting the fuel pump 11 and the combustor 2, and connected to the water supply pipe 33 connecting the water pump 14 and the heat exchanger 12. The second mixing pipe 22 and the fuel supply pipe 32 are provided with flow rate control valves 22a, 32a that can adjust the distribution amount of ammonia between 0 and 100% according to various loads of the gas turbine C. This second mixing pipe 22 corresponds to the second mixing means of the present disclosure, which mixes at least a portion of the ammonia before it is supplied to the combustor 2 as the fuel X3 with the water recovered by the recovery device.

[0073] The reducing agent supply pipe 23 is a branch pipe branched from the fuel supply pipe 32 that connects the fuel pump 11 and the combustor 2, and connected to the turbine 3. The reducing agent supply pipe 23 is provided with a flow rate adjustment valve 23a that can adjust the flow rate of ammonia. The connecting position of the reducing agent supply pipe 23 to the turbine 3 may be the same as the connecting position of the reducing agent supply device 6 to the turbine 3 in the above-mentioned first embodiment. This reducing agent supply pipe 23 corresponds to the reducing agent supply means of the present disclosure, which supplies a part of the ammonia before it is supplied to the combustor 2 as the fuel X3 to the turbine 3 as a reducing agent that reduces nitrogen oxides in the combustion gas.

[0074] According to the first mixing pipe 21, liquid ammonia to be the fuel X3 and the recovered water vapor can be mixed, and the liquid ammonia that has absorbed the water vapor can be supplied to the combustor 2. Since ammonia mixes very well with water, the liquid ammonia and the recovered water vapor can be mixed. Since the liquid ammonia to be the fuel X3 contains water, the calorific value is reduced, and the local flame temperature is reduced during combustion in the combustor 2. As a result, the NOx emission in the combustor 2, which is an issue in the combustion of ammonia, is reduced. x The generation of can be reduced. In addition, by mixing the liquid ammonia that becomes fuel X3 with the recovered steam, heat of dissolution is generated, which serves as preheating for fuel X3. This improves the thermal efficiency of gas turbine C.

[0075] Furthermore, the second mixing pipe 22 allows the liquid ammonia to be the fuel X3 and the recovered water to be mixed, passed through the heat exchanger 12, and supplied to the combustor 2 via the fuel supply pipe 32. Since ammonia mixes very well with water, the liquid ammonia and the recovered water can be mixed. The inclusion of moisture in the liquid ammonia to be the fuel X3 reduces the calorific value, and the local flame temperature during combustion in the combustor 2 decreases. This reduces the NOx emission in the combustor 2, which is an issue when burning ammonia. xThe generation of can be reduced. Furthermore, by mixing the liquid ammonia that becomes the fuel X3 with the recovered water, heat of dissolution is generated, which serves as preheating of the fuel X3. The heat of dissolution by this liquid-liquid mixing is more effective than the heat of dissolution by the gas-liquid mixing described above. Furthermore, by passing the liquid ammonia that becomes the fuel X3 through the heat exchanger 12, the fuel X3 can be preheated and vaporized. As a result, the thermal efficiency of the gas turbine C can be improved.

[0076] Furthermore, the reducing agent supply pipe 23 allows the liquid ammonia to be shared between the fuel X3 and the liquid ammonia to be the reducing agent X7 (denitrification agent) shown in Fig. 1. This eliminates the need to separately install the reducing agent supply device 6, making it possible to prevent the device from becoming large in scale.

[0077] The present disclosure is not limited to the above-described embodiment, and the following modifications are possible. (1) In the above embodiments, the gas turbines A and B are described as being ammonia-only combustion type, but the present disclosure is not limited thereto. The present disclosure is also applicable to an ammonia-mixed combustion type gas turbine in which ammonia is mixed with other fuel.

[0078] (2) In the above embodiments, the applications of the gas turbines A and B were not described, but the gas turbines A and B are used, for example, for power generation. That is, a rotating shaft of a generator is connected to the output shaft of the turbine 3, and the generator is driven by the power of the turbine 3.

[0079] (3) In the above first embodiment, the turbine 3 includes four (four stages) of individual turbines 3a to 3d, but the present disclosure is not limited to this. The number of stages of the individual turbines may be, for example, a two-stage configuration consisting of a high-pressure turbine and a low-pressure turbine.

[0080] (4) In the above first embodiment, the reducing agent X7 and the cooling air X6 (cooling fluid) are supplied separately to the turbine 3, but the present disclosure is not limited thereto. For example, the reducing agent X7 may be mixed with the cooling air X6 and supplied to the turbine 3. In this case, it is possible to use an ejector having a discharge nozzle for the reducing agent X7 in the flow path of the cooling air X6. By using such an ejector, the reducing agent X7 can be supplied to the turbine 3 using the kinetic energy of the cooling air X6, so that it is possible to reduce the power for supplying the reducing agent X7.

[0081] (5) In the first embodiment, ammonia is used as the reducing agent X7, but the present disclosure is not limited to this. Any substance that exhibits a reducing effect on nitrogen oxides may be used other than ammonia.

[0082] (6) In the above second embodiment, the water vapor circulation means including the heat exchanger 12, the gas-liquid separator 13, and the water pump 14 is employed, but the present disclosure is not limited to this. In addition, it is also possible to mix water supplied from a system separate from the water vapor circulation means with a gas (such as ammonia). [Industrial Applicability]

[0083] The present disclosure may be utilized in gas turbines. [Explanation of symbols]

[0084] A, B, C Gas Turbines 1 Compressor 2. Combustor 3. Turbine 3a~3d Individual turbines 3e~3i Combustion gas flow path 4 Fuel supply device 5. Cooling air supply device 6 Reducing agent supply device 7. Waste heat recovery boiler 8 Exhaust denitration equipment 10. Fuel Tank 11 Fuel pump 12 Heat exchanger 13 Gas-liquid separator 14 Water Pump 21 1st mixing pipe 22 2nd mixing pipe 23 Reducing agent supply pipe

Claims

1. A gas turbine including at least a compressor, a combustor, and a turbine, the gas turbine burning ammonia as fuel in the combustor, a reducing agent supply device that supplies a reducing agent for reducing nitrogen oxides in the combustion gas to a combustion gas flow path between the combustor and the turbine, Gas turbine.

2. The present invention further includes a cooling fluid supply device for supplying a cooling fluid to the turbine, and the reducing agent is mixed with the cooling fluid and supplied. The gas turbine of claim 1 .

3. The reducing agent is ammonia. A gas turbine according to claim 1 or 2.

Images