Combustion system

Abstract

A combustion system 1 comprises: an ammonia tank 14 in which ammonia is stored in a liquid state; a combustor 13 having a combustion chamber 13a and an injection valve 13b facing the combustion chamber 13a, the injection valve 13b being connected to the ammonia tank 14 via a flow passage L3 for ammonia and the injection valve 13b being supplied with ammonia in a liquid state; a temperature adjustment device 100 that adjusts the temperature of the ammonia supplied to the injection valve 13b; and a control device 16 that, on the basis of information relating to the pressure of the ammonia in the injection valve 13b, controls the temperature adjustment device 100 so that the temperature of the ammonia supplied to the injection valve 13b will be equal to or lower than the saturation temperature of the ammonia in the injection valve 13b.

Description

Combustion System

[0001] This application claims the benefit of priority from Japanese Patent Application No. 2023-194123, filed on November 15, 2023, the contents of which are incorporated herein by reference.

[0002] A gas turbine system or the like is used as a combustion system for burning fuel in a combustor. In a combustion system such as a gas turbine system, ammonia may be used as a fuel, as disclosed in, for example, Patent Document 1. Using ammonia as a fuel reduces carbon dioxide emissions.

[0003] Japanese Patent Application Laid-Open No. 2016-191507

[0004] There is a combustion system in which liquid ammonia is supplied to a combustion chamber without being vaporized. Such a combustion system offers various advantages, such as reduced equipment costs, by eliminating the need for a vaporizer. Therefore, a new proposal is desired for such a combustion system to improve efficiency while suppressing the vaporization of ammonia.

[0005] An object of the present disclosure is to provide a combustion system that can improve the efficiency of the combustion system.

[0006] In order to solve the above problems, the combustion system of the present disclosure includes a combustor having an ammonia tank in which ammonia is stored in a liquid state, a combustion chamber, and an injector facing the combustion chamber, the injector being connected to the ammonia tank via an ammonia flow path and ammonia being supplied to the injector in a liquid state, a temperature adjustment device that adjusts the temperature of the ammonia supplied to the injector, and a control device that controls the temperature adjustment device based on information about the pressure of ammonia in the injector so that the temperature of the ammonia supplied to the injector is equal to or lower than the saturation temperature of ammonia in the injector.

[0007] The flow paths include a first flow path and a second flow path that merge at a junction upstream of the injection valve, and the temperature of the ammonia flowing into the junction from the first flow path is different from the temperature of the ammonia flowing into the junction from the second flow path, and the temperature adjustment device may include a flow rate ratio adjustment device that adjusts a flow rate ratio that is the ratio between the flow rate of the ammonia flowing into the junction from the first flow path and the flow rate of the ammonia flowing into the junction from the second flow path.

[0008] The temperature adjustment device may include a preheater that preheats the ammonia flowing through one of the first flow path and the second flow path.

[0009] The temperature adjustment device may include a first preheater that preheats the ammonia flowing through the first flow path, and a second preheater that preheats the ammonia flowing through the second flow path.

[0010] The flow paths may not have a joining portion upstream of the injection valve, and the temperature adjustment device may include a preheater that preheats the ammonia flowing through the flow paths.

[0011] The information may include parameters that affect the pressure, and the control device may use a map showing the correspondence between the parameters and the saturation temperature to identify the saturation temperature based on the parameters, and control the temperature adjustment device based on the identified saturation temperature.

[0012] The information may include parameters that affect the pressure, and the control device may use a map showing the correspondence between the parameters and the control targets of the temperature adjustment device to identify the control targets based on the parameters, and control the temperature adjustment device based on the identified control targets.

[0013] The information may include parameters that affect the pressure, and the control device may calculate the pressure based on the parameters, and control the temperature adjustment device based on the calculated pressure.

[0014] The information may include a pressure measurement, and the controller may control the temperature adjustment device based on the measurement.

[0015] The present disclosure allows for improved efficiency of combustion systems.

[0016] FIG. 1 is a schematic diagram showing the configuration of a combustion system according to an embodiment of the present disclosure. FIG. 2 is a flowchart showing a first example of a processing flow performed by a control device according to an embodiment of the present disclosure. FIG. 3 is a flowchart showing a second example of a processing flow performed by a control device according to an embodiment of the present disclosure. FIG. 4 is a flowchart showing a third example of a processing flow performed by a control device according to an embodiment of the present disclosure. FIG. 5 is a flowchart showing a fourth example of a processing flow performed by a control device according to an embodiment of the present disclosure. FIG. 6 is a schematic diagram showing the configuration of a combustion system according to a first modified example. FIG. 7 is a schematic diagram showing the configuration of a combustion system according to a second modified example. FIG. 8 is a schematic diagram showing the configuration of a combustion system according to a third modified example.

[0017] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for ease of understanding and, unless otherwise specified, do not limit the present disclosure. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present disclosure are not shown.

[0018] Fig. 1 is a schematic diagram showing the configuration of a combustion system 1 according to this embodiment. The combustion system 1 is a gas turbine system that obtains power from combustion gas. As shown in Fig. 1, the combustion system 1 includes a compressor 11, a turbine 12, a combustor 13, an ammonia tank 14, a pump 15, a control device 16, and a temperature adjustment device 100.

[0019] The compressor 11 and the turbine 12 rotate as a unit and are connected to each other by a shaft.

[0020] The compressor 11 is provided in an intake air flow path L1 connected to the combustor 13. Air to be supplied to the combustor 13 flows through the intake air flow path L1. An intake port (not shown) through which air is taken in from the outside is provided at the upstream end of the intake air flow path L1. The air taken in through the intake port passes through the compressor 11 and is sent to the combustor 13. The compressor 11 compresses the air and discharges it downstream.

[0021] The turbine 12 is provided in an exhaust flow path L2 connected to the combustor 13. Exhaust gas discharged from the combustor 13 flows through the exhaust flow path L2. The exhaust gas discharged from the combustor 13 passes through the turbine 12 and is sent to a portion of the exhaust flow path L2 downstream of the turbine 12. The turbine 12 is rotated by the exhaust gas to generate rotational power.

[0022] A generator (not shown) is connected to a shaft connecting the compressor 11 and the turbine 12. The rotational power transmitted from the turbine 12 to the shaft is used to generate electricity by the generator.

[0023] The combustor 13 is supplied with air compressed by the compressor 11 through the intake air flow path L1, and with ammonia in a liquid state as fuel. Combustion is performed in the combustor 13 using the ammonia as fuel. Exhaust gas generated in the combustor 13 is discharged to the exhaust flow path L2.

[0024] Specifically, the combustor 13 has a combustion chamber 13a and an injection valve 13b. Ammonia, which is a fuel, is combusted in the combustion chamber 13a. The injection valve 13b injects the ammonia, which is a fuel, into the combustion chamber 13a. The injection valve 13b has an injection port 13b1. Ammonia is injected from the injection port 13b1. The injection valve 13b faces the combustion chamber 13a. Specifically, the injection port 13b1 of the injection valve 13b faces the combustion chamber 13a. The injection valve 13b is connected to the ammonia tank 14 via an ammonia flow path L3. Ammonia is supplied in a liquid state from the ammonia tank 14 to the injection valve 13b.

[0025] Ammonia is stored in a liquid state in the ammonia tank 14. In the ammonia tank 14, the ammonia is maintained in a liquid state, for example, at atmospheric pressure and −33° C. As described above, the ammonia tank 14 is connected to the injector 13b of the combustor 13 via the ammonia flow path L3. Ammonia flows in a liquid state through the flow path L3. A pump 15 is provided in the flow path L3 downstream of the ammonia tank 14. The pump 15 sends the ammonia supplied from the ammonia tank 14 to the downstream side.

[0026] The flow path L3 branches into a first flow path L3a and a second flow path L3b at a branching point P1 downstream of the ammonia tank 14 and joins at a joining point P2 upstream of the injection valve 13b. In this way, the flow path L3 includes the first flow path L3a and the second flow path L3b that join at the joining point P2 upstream of the injection valve 13b. The ammonia that has passed through the pump 15 is sent to the first flow path L3a and the second flow path L3b, respectively, at the branching point P1.

[0027] The combustion system 1 is provided with a temperature adjustment device 100 that adjusts the temperature of the ammonia supplied to the injector 13b. The temperature adjustment device 100 includes a flow rate ratio adjustment device 110 and a preheater 120. As described below, the flow rate ratio adjustment device 110 adjusts a flow rate ratio, which is the ratio between the flow rate of ammonia flowing from the first flow path L3a to the junction P2 and the flow rate of ammonia flowing from the second flow path L3b to the junction P2. As described below, the preheater 120 can make the temperature of the ammonia flowing from the first flow path L3a to the junction P2 different from the temperature of the ammonia flowing from the second flow path L3b to the junction P2. Therefore, the flow rate ratio adjustment device 110 and the preheater 120 realize the function of adjusting the temperature of the ammonia supplied to the injector 13b.

[0028] The flow ratio adjusting device 110 includes a first flow control valve 111 and a second flow control valve 112 .

[0029] The first flow control valve 111 is provided in the first flow path L3a. The first flow control valve 111 adjusts the flow rate of ammonia flowing from the first flow path L3a to the junction P2 through the first flow control valve 111. For example, the flow rate of ammonia flowing from the first flow path L3a to the junction P2 is adjusted by adjusting the opening degree of the first flow control valve 111.

[0030] The second flow control valve 112 is provided in the second flow path L3b. The second flow control valve 112 adjusts the flow rate of ammonia flowing from the second flow path L3b to the junction P2 through the second flow control valve 112. For example, the flow rate of ammonia flowing from the second flow path L3b to the junction P2 is adjusted by adjusting the opening degree of the second flow control valve 112.

[0031] The preheater 120 preheats the ammonia flowing through the second flow path L3b. For example, the preheater 120 is provided in the second flow path L3b downstream of the second flow control valve 112. The second flow path L3b and the heat medium flow path L4 each pass through the preheater 120. A heat medium having a higher temperature than the ammonia flowing through the second flow path L3b flows through the heat medium flow path L4. The heat medium flowing through the heat medium flow path L4 is, for example, steam generated in the combustion system 1, exhaust gas generated in the combustion system 1, seawater, etc.

[0032] In the preheater 120, heat exchange occurs between the ammonia flowing through the second flow path L3b and the heat medium flowing through the heat medium flow path L4. As a result, in the preheater 120, the ammonia flowing through the second flow path L3b is preheated by the heat medium flowing through the heat medium flow path L4.

[0033] As described above, the ammonia flowing through the second flow path L3b flows into the junction P2 after being preheated by the preheater 120. On the other hand, the ammonia flowing through the first flow path L3a flows into the junction P2 without being preheated. Therefore, the temperature of the ammonia flowing from the second flow path L3b into the junction P2 is higher than the temperature of the ammonia flowing from the first flow path L3a into the junction P2.

[0034] A first temperature sensor T1 is provided in the first flow path L3a downstream of the first flow control valve 111. The first temperature sensor T1 detects the temperature of the ammonia flowing from the first flow path L3a to the junction P2. A second temperature sensor T2 is provided in the second flow path L3b downstream of the preheater 120. The second temperature sensor T2 detects the temperature of the ammonia flowing from the second flow path L3b to the junction P2.

[0035] The control device 16 includes, for example, a processor 16a and a memory 16b. The processor 16a includes, for example, a central processing unit (CPU). The memory 16b includes, for example, a ROM in which programs and the like are stored, and a RAM as a work area. The functions of the control device 16 are realized, for example, by the processor 16a executing a program stored in the memory 16b.

[0036] The control device 16 controls the entire combustion system 1. For example, the control device 16 controls the temperature of the ammonia supplied to the injector 13b by controlling the temperature adjustment device 100. In the example of Fig. 1, the control device 16 controls the temperature of the ammonia supplied to the injector 13b by controlling the flow ratio adjustment device 110 including the first flow control valve 111 and the second flow control valve 112 of the temperature adjustment device 100. The control device 16 can also acquire detection results from various sensors such as the first temperature sensor T1 and the second temperature sensor T2.

[0037] In the combustion system 1, the control device 16 controls the temperature adjustment device 100 based on information related to the pressure of ammonia in the injector 13b so that the temperature of the ammonia supplied to the injector 13b is equal to or lower than the saturation temperature of the ammonia in the injector 13b. As a result, as will be described later, it is possible to improve the efficiency of the combustion system 1. Below, a first example, a second example, a third example, and a fourth example will be described in order as examples of processing performed by the control device 16.

[0038] The pressure and saturation temperature of ammonia in the injector 13b refer to, for example, the pressure and saturation temperature of ammonia at the upstream end of the injector 13b, but may also refer to the pressure and saturation temperature of ammonia at a position in the injector 13b that is shifted from the upstream end.

[0039] 2 is a flowchart showing a first example of the flow of processing performed by the control device 16 according to this embodiment. The processing flow shown in FIG. 2 is executed repeatedly at preset time intervals, for example.

[0040] When the process flow shown in FIG. 2 starts, in step S101, the control device 16 acquires parameters that affect the pressure of ammonia in the injection valve 13b.

[0041] The saturation temperature, which is the temperature at which liquid ammonia vaporizes, depends on the pressure of the ammonia. Specifically, the higher the ammonia pressure, the higher the saturation temperature of the ammonia. As will be described later, in the first example of FIG. 2, the saturation temperature that depends on the ammonia pressure is determined using the above parameters.

[0042] The pressure of ammonia in injector 13b (specifically, the pressure of ammonia at the upstream end of injector 13b) corresponds to a value obtained by adding the pressure loss in injector 13b to the pressure of ammonia at injection port 13b1 of injector 13b. Therefore, the above parameters may include, for example, various information for estimating the pressure of ammonia at injection port 13b1 (for example, information on the pressure of combustion chamber 13a, information on the rotation speed of turbine 12, information on the open / close state of the bleed valve provided in intake flow path L1, information on the discharge pressure of compressor 11, etc.). Furthermore, the above parameters may include, for example, various information for estimating the pressure loss in injector 13b (for example, information on the total flow rate of ammonia supplied to injector 13b, information on the power generation load, etc.).

[0043] In step S101, the control device 16 may acquire the above parameters based on input operations by the user, may acquire the above parameters from another control device, or may acquire the above parameters based on the detection results of various sensors.

[0044] Next, in step S102, the control device 16 identifies the saturation temperature of the ammonia in the injector 13b using the saturation temperature map.

[0045] The saturation temperature map is a map showing the correspondence relationship between the parameters acquired in step S101 and the saturation temperature of ammonia in the injector 13b. Specifically, in the saturation temperature map, the parameters acquired in step S101 are associated with the saturation temperature corresponding to the pressure of ammonia in the injector 13b estimated from the parameters. The saturation temperature map is stored in advance in the memory 16b of the control device 16, for example.

[0046] In step S102, the control device 16 identifies the saturation temperature associated with the parameter acquired in step S101 in the saturation temperature map as the saturation temperature of ammonia in the injector 13b.

[0047] For example, the higher the pressure of the combustion chamber 13a, the higher the pressure of ammonia at the injection port 13b1, and therefore the higher the pressure of ammonia in the injector 13b. Therefore, in the saturation temperature map, for example, the higher the pressure of the combustion chamber 13a, the higher the saturation temperature of ammonia in the injector 13b. Also, for example, the greater the total flow rate of ammonia supplied to the injector 13b, the greater the pressure loss in the injector 13b, and therefore the higher the pressure of ammonia in the injector 13b. Therefore, in the saturation temperature map, for example, the greater the total flow rate of ammonia supplied to the injector 13b, the higher the saturation temperature of ammonia in the injector 13b. The saturation temperature map is a function that, when parameters including, for example, the pressure of the combustion chamber 13a and the total flow rate of ammonia supplied to the injector 13b are input, outputs a saturation temperature corresponding to the input parameters. However, the input parameters are not limited to this example.

[0048] Next, in step S103, the control device 16 determines a target flow rate ratio, which is a target value of the flow rate ratio, which is the ratio between the flow rate of ammonia flowing from the first flow path L3a to the confluence P2 and the flow rate of ammonia flowing from the second flow path L3b to the confluence P2.

[0049] In step S103, the control device 16 determines, as the target flow rate ratio, for example, a flow rate ratio such that the temperature of the ammonia supplied to the injection valve 13b is a predetermined temperature (for example, several degrees Celsius to several tens of degrees Celsius) lower than the saturation temperature identified in step S102.

[0050] In the combustion system 1, the temperature of the ammonia flowing from the first flow path L3a to the junction P2 and the temperature of the ammonia flowing from the second flow path L3b to the junction P2 are each controlled to be constant. For example, the flow rate of the heat medium flowing through the heat medium flow path L4 is adjusted according to the flow rate of the ammonia flowing through the second flow path L3b, thereby realizing the temperature of the ammonia flowing from the second flow path L3b to the junction P2 to be constant. Therefore, by changing the above flow rate ratio, the temperature of the ammonia supplied to the injector 13b can be changed.

[0051] The temperature of the ammonia flowing from the first flow path L3a to the junction P2 and the temperature of the ammonia flowing from the second flow path L3b to the junction P2 do not have to be controlled to be constant. In this case, the control device 16 determines the target flow rate ratio taking into account the detection results of the first temperature sensor T1 and the second temperature sensor T2.

[0052] Next, in step S104, the control device 16 adjusts the aperture of each flow control valve of the flow ratio adjusting device 110 so that the flow ratio, which is the ratio between the flow rate of ammonia flowing from the first flow path L3a to the flow rate of ammonia flowing from the second flow path L3b to the junction P2, becomes the target flow rate ratio, and the processing flow shown in FIG. 2 ends.

[0053] In step S104, the control device 16 can control the above flow rate ratio to the above target flow rate ratio by adjusting the aperture of the first flow control valve 111 and the aperture of the second flow control valve 112. As a result, the temperature of the ammonia supplied to the injector 13b becomes a temperature that is lower by a predetermined temperature (for example, several degrees Celsius to several tens of degrees Celsius) than the saturation temperature identified in step S102. Therefore, it is possible to bring the temperature of the ammonia supplied to the injector 13b closer to the saturation temperature while suppressing the temperature of the ammonia supplied to the injector 13b from exceeding the saturation temperature and causing vaporization of the ammonia.

[0054] In step S104, the control device 16 controls the aperture of the first flow control valve 111 and the aperture of the second flow control valve 112 so that the total flow rate of ammonia supplied to the injector 13b becomes the target value. This makes it possible to control the above-mentioned flow rate ratio to the above-mentioned target flow rate ratio while controlling the total flow rate of ammonia supplied to the injector 13b to the target value.

[0055] As described above, the control device 16 of the combustion system 1 according to this embodiment controls the temperature adjustment device 100 based on information about the pressure of ammonia in the injector 13b (in the above example, a parameter affecting the pressure of ammonia in the injector 13b) so that the temperature of the ammonia supplied to the injector 13b is equal to or lower than the saturation temperature of ammonia in the injector 13b. This allows the temperature of the ammonia supplied to the injector 13b to be adjusted to be equal to or lower than the saturation temperature of ammonia in the injector 13b, taking into account the pressure of ammonia in the injector 13b. Therefore, the temperature of the ammonia supplied to the injector 13b can be brought closer to the saturation temperature while preventing the temperature of the ammonia supplied to the injector 13b from exceeding the saturation temperature and causing the ammonia to vaporize. This prevents an increase in pressure loss due to an increase in the volume of ammonia caused by the partial vaporization of ammonia, and an oscillation phenomenon caused by the cycle of ammonia vaporization and recondensation. Furthermore, compared to when the temperature of the ammonia supplied to the injector 13b is excessively low relative to the saturation temperature, the energy consumed for burning the ammonia in the combustor 13 can be reduced (for example, the amount of energy recovered in the preheater 120 can be reduced). Therefore, the efficiency of the combustion system 1 can be improved while suppressing the vaporization of ammonia.

[0056] 2 , the information about the pressure of ammonia in injector 13b includes parameters that affect the pressure of ammonia in injector 13b. Using a map (a saturation temperature map in the above example) showing the correspondence between the parameters and the saturation temperature of ammonia in injector 13b, control device 16 identifies the saturation temperature based on the parameters, and controls temperature adjustment device 100 (flow ratio adjustment device 110 in the above example) based on the identification result of the saturation temperature. This appropriately realizes the temperature of ammonia supplied to injector 13b being adjusted to be equal to or lower than the saturation temperature of ammonia in injector 13b, taking into account the pressure of ammonia in injector 13b. In particular, because temperature adjustment device 100 is controlled using the map, the process of calculating the pressure of ammonia in injector 13b can be omitted, reducing the calculation load.

[0057] In particular, in the combustion system 1 according to this embodiment, the flow path L3 includes a first flow path L3a and a second flow path L3b that merge at a junction P2 upstream of the injector 13b. The temperature of the ammonia flowing from the first flow path L3a to the junction P2 is different from the temperature of the ammonia flowing from the second flow path L3b to the junction P2. The temperature control device 100 includes a flow rate ratio adjustment device 110 that adjusts the flow rate ratio between the flow rate of the ammonia flowing from the first flow path L3a to the junction P2 and the flow rate of the ammonia flowing from the second flow path L3b to the junction P2. This allows the temperature of the ammonia supplied to the injector 13b to be appropriately adjusted by adjusting the flow rate ratio. In particular, the temperature of the ammonia supplied to the injector 13b can be changed more quickly than in a combustion system 1B according to a second modified example described below, in which one of the first flow path L3a and the second flow path L3b is omitted.

[0058] In particular, in the combustion system 1 according to this embodiment, the temperature adjustment device 100 includes a preheater (in the above example, the preheater 120) that preheats the ammonia flowing through one of the first flow path L3a and the second flow path L3b. This appropriately makes it possible to differentiate the temperature of the ammonia flowing from the first flow path L3a to the junction P2 from the temperature of the ammonia flowing from the second flow path L3b to the junction P2.

[0059] 3 is a flowchart showing a second example of the flow of processing performed by the control device 16 according to this embodiment. The processing flow shown in FIG. 3 is executed repeatedly at preset time intervals, for example.

[0060] 3 starts, the control device 16 acquires parameters that affect the pressure of ammonia in the injector 13b in step S201. The processing in step S201 is similar to step S101 in FIG. 2 described above.

[0061] Next, in step S202, the control device 16 uses the target flow rate ratio map to identify a target flow rate ratio, which is a target value of the flow rate ratio, which is the ratio between the flow rate of ammonia flowing from the first flow path L3a to the confluence P2 and the flow rate of ammonia flowing from the second flow path L3b to the confluence P2.

[0062] The target flow rate ratio map is a map showing the correspondence relationship between the parameters acquired in step S201 and the target flow rate ratio. Specifically, in the target flow rate ratio map, the parameters acquired in step S201 are associated with flow rate ratios such that the temperature of the ammonia supplied to the injector 13b is a temperature that is lower by a predetermined temperature (for example, several degrees Celsius to several tens of degrees Celsius) than the saturation temperature corresponding to the pressure of ammonia in the injector 13b estimated from the parameters. The target flow rate ratio map is stored in advance in, for example, the memory 16b of the control device 16.

[0063] In step S202, the control device 16 specifies the flow rate ratio associated with the parameter acquired in step S201 in the target flow rate ratio map as the target flow rate ratio.

[0064] For example, the higher the pressure of combustion chamber 13a, the higher the pressure of ammonia at injection port 13b1, and therefore the higher the pressure of ammonia in injector 13b and the higher the saturation temperature of ammonia in injector 13b. Therefore, in the target flow rate ratio map, the flow rate ratio is set such that, for example, the higher the pressure of combustion chamber 13a, the higher the temperature of ammonia supplied to injector 13b. Also, for example, the greater the total flow rate of ammonia supplied to injector 13b, the greater the pressure loss in injector 13b, and therefore the higher the pressure of ammonia in injector 13b and the higher the saturation temperature of ammonia in injector 13b. Therefore, in the target flow rate ratio map, the flow rate ratio is set such that, for example, the greater the total flow rate of ammonia supplied to injector 13b, the higher the temperature of ammonia supplied to injector 13b. The target flow rate ratio map is a function that, when parameters including, for example, the pressure of combustion chamber 13a and the total flow rate of ammonia supplied to injector 13b are input, outputs a flow rate ratio corresponding to the input parameters. However, the input parameters are not limited to this example.

[0065] When the temperature of the ammonia flowing from the first flow path L3a to the junction P2 and the temperature of the ammonia flowing from the second flow path L3b to the junction P2 are controlled to be constant, the target flow ratio map is generated taking into account the above-mentioned known temperatures. On the other hand, when the temperature of the ammonia flowing from the first flow path L3a to the junction P2 and the temperature of the ammonia flowing from the second flow path L3b to the junction P2 are not controlled to be constant, the detection results of the first temperature sensor T1 and the detection results of the second temperature sensor T2 are additionally set as input parameters in the target flow ratio map.

[0066] Next, in step S203, the control device 16 adjusts the aperture of each flow control valve of the flow ratio adjusting device 110 so that the flow ratio, which is the ratio of the flow rate of ammonia flowing from the first flow path L3a to the flow rate of ammonia flowing from the second flow path L3b to the junction P2, becomes the target flow rate ratio, and the processing flow shown in Fig. 3 ends. The processing in step S203 is similar to step S104 in Fig. 2 described above.

[0067] In the second example of Fig. 3, similar to the first example of Fig. 2 described above, the control device 16 controls the temperature adjustment device 100 based on information relating to the pressure of ammonia in the injector 13b (in the above example, a parameter affecting the pressure of ammonia in the injector 13b) so that the temperature of the ammonia supplied to the injector 13b is equal to or lower than the saturation temperature of ammonia in the injector 13b. This makes it possible to improve the efficiency of the combustion system 1, similar to the first example of Fig. 2 described above.

[0068] 3 , the information about the pressure of ammonia in the injector 13b includes parameters that affect the pressure of ammonia in the injector 13b. The control device 16 identifies the control target based on the parameters using a map (a target flow ratio map in the above example) that shows the correspondence between the parameters and the control target of the temperature control device 100 (the target flow ratio in the above example), and controls the temperature control device 100 (the flow ratio control device 110 in the above example) based on the identification result of the control target. This appropriately realizes the adjustment of the temperature of the ammonia supplied to the injector 13b to be equal to or lower than the saturation temperature of the ammonia in the injector 13b, taking into account the pressure of ammonia in the injector 13b. In particular, because the temperature control device 100 is controlled using the map, the process of calculating the pressure of ammonia in the injector 13b can be omitted, reducing the calculation load.

[0069] 4 is a flowchart showing a third example of the flow of processing performed by the control device 16 according to this embodiment. The processing flow shown in FIG. 4 is executed repeatedly at preset time intervals, for example.

[0070] 4 starts, the control device 16 acquires parameters that affect the pressure of ammonia in the injector 13b in step S301. The processing in step S301 is similar to step S101 in FIG. 2 described above.

[0071] Next, in step S302, the control device 16 calculates the pressure of ammonia in the injection valve 13b.

[0072] In step S302, the control device 16 calculates the pressure of ammonia in the injector 13b using the parameters acquired in step S301. As described above, the pressure of ammonia in the injector 13b (specifically, the pressure of ammonia at the upstream end of the injector 13b) corresponds to the value obtained by adding the pressure loss in the injector 13b to the pressure of ammonia at the injection port 13b1 of the injector 13b. For example, the pressure P10 of ammonia at the upstream end of the injector 13b is expressed by the following equation (1), where the pressure of ammonia at the injection port 13b1 is P20 and the pressure loss is ΔP.

[0073] P10=P20+ΔP...(1)

[0074] The pressure loss ΔP is expressed by, for example, the following equation (2), where ρ is the density of ammonia and U is the flow rate of ammonia.

[0075] ΔP=(ρU^2) / 2...(2)

[0076] For example, the control device 16 calculates the pressure loss ΔP using the above formula (2). Note that the density ρ of ammonia depends on the temperature. Therefore, the control device 16 may obtain information on the temperature of ammonia at the upstream end of the injector 13b and change the density ρ according to the information. However, the density ρ may also be a fixed value. For example, the control device 16 may specify the flow velocity U by detecting the flow velocity of ammonia at the upstream end of the injector 13b using a sensor. Note that a correction coefficient may be further added to the right side of the above formula (2).

[0077] Then, the control device 16 can calculate the ammonia pressure P10 at the upstream end of the injection valve 13b by, for example, regarding the pressure of the combustion chamber 13a as the ammonia pressure P20 at the injection port 13b1 and substituting this into the above equation (1), and by substituting the pressure loss ΔP calculated by the above equation (2) into the above equation (1).

[0078] Next, in step S303, the control device 16 determines a target flow rate ratio, which is a target value of the flow rate ratio, which is the ratio between the flow rate of ammonia flowing from the first flow path L3a to the confluence P2 and the flow rate of ammonia flowing from the second flow path L3b to the confluence P2.

[0079] In step S303, the control device 16 determines, as the target flow rate ratio, for example, a flow rate ratio such that the temperature of the ammonia supplied to the injector 13b is a predetermined temperature (for example, several degrees Celsius to several tens of degrees Celsius) lower than the saturation temperature corresponding to the pressure of ammonia inside the injector 13b identified in step S302.

[0080] Next, in step S304, the control device 16 adjusts the aperture of each flow control valve of the flow ratio adjusting device 110 so that the flow ratio, which is the ratio of the flow rate of ammonia flowing from the first flow path L3a to the flow rate of ammonia flowing from the second flow path L3b to the junction P2, becomes the target flow rate ratio, and the processing flow shown in Fig. 4 ends. The processing in step S304 is similar to step S104 in Fig. 2 described above.

[0081] In the third example of Fig. 4, similarly to the first example of Fig. 2 described above, the control device 16 controls the temperature adjustment device 100 based on information relating to the pressure of ammonia in the injector 13b (in the above example, a parameter affecting the pressure of ammonia in the injector 13b) so that the temperature of the ammonia supplied to the injector 13b is equal to or lower than the saturation temperature of ammonia in the injector 13b. This makes it possible to improve the efficiency of the combustion system 1, similarly to the first example of Fig. 2 described above.

[0082] In particular, in the third example of Fig. 4, the information related to the pressure of ammonia in injector 13b includes parameters that affect the pressure of ammonia in injector 13b. Control device 16 calculates the pressure based on the parameters, and controls temperature adjustment device 100 (flow ratio adjustment device 110 in the example) based on the calculation result of the pressure. This makes it possible to appropriately adjust the temperature of ammonia supplied to injector 13b to be equal to or lower than the saturation temperature of ammonia in injector 13b, taking into account the pressure of ammonia in injector 13b. In particular, since the pressure of ammonia in injector 13b is calculated in accordance with the laws of physics, the pressure can be determined with greater accuracy.

[0083] 5 is a flowchart showing a fourth example of the flow of processing performed by the control device 16 according to this embodiment. The processing flow shown in FIG. 5 is executed repeatedly at preset time intervals, for example.

[0084] When the process flow shown in FIG. 5 starts, in step S401, the control device 16 acquires a measured value of the pressure of ammonia in the injection valve 13b.

[0085] In a fourth example, a sensor measuring the pressure of the ammonia in the injector 13b is added to the combustion system 1. The control device 16 can obtain said pressure measurement from such a sensor.

[0086] Next, in step S402, the control device 16 determines a target flow rate ratio, which is a target value of the flow rate ratio, which is the ratio between the flow rate of ammonia flowing from the first flow path L3a to the confluence P2 and the flow rate of ammonia flowing from the second flow path L3b to the confluence P2.

[0087] In step S402, the control device 16 determines, as the target flow rate ratio, for example, a flow rate ratio such that the temperature of the ammonia supplied to the injector 13b is a predetermined temperature (for example, several degrees Celsius to several tens of degrees Celsius) lower than the saturation temperature corresponding to the measured value of the ammonia pressure inside the injector 13b acquired in step S401.

[0088] Next, in step S403, the control device 16 adjusts the aperture of each flow control valve of the flow ratio adjusting device 110 so that the flow ratio, which is the ratio of the flow rate of ammonia flowing from the first flow path L3a to the flow rate of ammonia flowing from the second flow path L3b to the junction P2, becomes the target flow rate ratio, and the processing flow shown in Fig. 5 ends. The processing in step S403 is similar to that in step S104 in Fig. 2 described above.

[0089] In the fourth example of Fig. 5, similarly to the first example of Fig. 2 described above, the control device 16 controls the temperature adjustment device 100 based on information related to the pressure of ammonia in the injector 13b (in the above example, the measured value of the pressure of ammonia in the injector 13b) so that the temperature of the ammonia supplied to the injector 13b is equal to or lower than the saturation temperature of ammonia in the injector 13b. This makes it possible to improve the efficiency of the combustion system 1, similarly to the first example of Fig. 2 described above.

[0090] 5 , the information related to the pressure of ammonia in injector 13b includes a measured value of the pressure of ammonia in injector 13b. Control device 16 controls temperature adjustment device 100 (flow ratio adjustment device 110 in the above example) based on the above measured value. This makes it possible to appropriately adjust the temperature of ammonia supplied to injector 13b to be equal to or lower than the saturation temperature of ammonia in injector 13b, taking into account the pressure of ammonia in injector 13b. In particular, since the pressure of ammonia in injector 13b is directly detected, the pressure can be determined with greater accuracy.

[0091] The combustion system 1 according to this embodiment has been described above. However, various modifications may be made to the above example.

[0092] For example, a flow control valve may be added to the flow path L3 upstream of the branch point P1. In this case, for example, the total flow rate of ammonia supplied to the injection valve 13b may be adjusted by the aperture of the above-mentioned flow control valve, and a flow rate ratio, which is the ratio of the flow rate of ammonia flowing from the first flow path L3a to the junction point P2 and the flow rate of ammonia flowing from the second flow path L3b to the junction point P2, may be adjusted by the apertures of the first flow control valve 111 and the second flow control valve 112.

[0093] For example, when a flow control valve is added to flow path L3 upstream of branch point P1, a shutoff valve may be provided near the flow control valve. Also, a shutoff valve may be provided near first flow control valve 111. In this case, the shutoff valve can be used to quickly stop the inflow of ammonia from first flow path L3a to junction P2. Also, a shutoff valve may be provided near second flow control valve 112. In this case, the shutoff valve can be used to quickly stop the inflow of ammonia from second flow path L3b to junction P2.

[0094] For example, in the above example, the control device 16 controls the flow rate ratio adjusting device 110 so that the flow rate ratio, which is the ratio between the flow rate of ammonia flowing from the first flow path L3a to the junction P2 and the flow rate of ammonia flowing from the second flow path L3b to the junction P2, becomes a target flow rate ratio. However, the control device 16 may also control the flow rate ratio adjusting device 110 so that the measured value of the temperature of the ammonia supplied to the injector 13b becomes a target temperature. This allows for more accurate control of the temperature of the ammonia supplied to the injector 13b. For example, if a temperature sensor is provided in the flow path L3 downstream of the junction P2, the control device 16 can obtain the measured value of the temperature of the ammonia supplied to the injector 13b based on the detection result of the temperature sensor. Furthermore, for example, the control device 16 uses a temperature that is lower by a predetermined temperature (e.g., several degrees Celsius to several tens of degrees Celsius) than the saturation temperature of the ammonia in the injector 13b as the target temperature.

[0095] For example, a mixer for mixing ammonia may be added to the junction P2 of the flow path L3. This allows the ammonia flowing into the junction P2 from the first flow path L3a and the ammonia flowing into the junction P2 from the second flow path L3b to be mixed by the mixer, thereby preventing the temperature of the ammonia supplied to the injector 13b from becoming non-uniform.

[0096] For example, in the above example, the number of injectors 13b to which ammonia is supplied is one. However, the number of injectors 13b to which ammonia is supplied may be multiple. In this case, one pair of the first flow path L3a through which low-temperature ammonia flows and the second flow path L3b through which high-temperature ammonia flows may be provided for each injector 13b, or only one pair may be provided for all injectors 13b.

[0097] For example, in the above example, there is one pair of the first flow path L3a through which low-temperature ammonia flows and the second flow path L3b through which high-temperature ammonia flows. However, there may be more than one pair. That is, multiple first flow paths L3a and multiple second flow paths L3b may be provided in the flow path L3. In this case, the first flow control valve 111 of each first flow path L3a and the second flow control valve 112 of each second flow path L3b may be replaced with a shut-off valve. In this case, the temperature of the ammonia supplied to the injection valve 13b can be quickly changed by switching the open / close state of each shut-off valve. Furthermore, the use of a shut-off valve can reduce equipment costs.

[0098] Fig. 6 is a schematic diagram showing the configuration of a combustion system 1A according to a first modification. As shown in Fig. 6, the combustion system 1A differs from the above-described combustion system 1 in that a preheater 130 is added. The temperature adjustment device 100A of the combustion system 1A further includes the preheater 130 in addition to the flow ratio adjustment device 110 and the preheater 120.

[0099] The preheater 130 preheats the ammonia flowing through the first flow path L3a. For example, the preheater 130 is provided in the first flow path L3a downstream of the first flow control valve 111. The first flow path L3a and the heat medium flow path L5 each pass through the preheater 130. A heat medium having a higher temperature than the ammonia flowing through the first flow path L3a flows through the heat medium flow path L5. The heat medium flowing through the heat medium flow path L5 is, like the heat medium flowing through the heat medium flow path L4, for example, steam generated in the combustion system 1, exhaust gas generated in the combustion system 1, seawater, etc.

[0100] In the preheater 130, heat exchange occurs between the ammonia flowing through the first flow path L3a and the heat medium flowing through the heat medium flow path L5. As a result, in the preheater 130, the ammonia flowing through the first flow path L3a is preheated by the heat medium flowing through the heat medium flow path L5. In the combustion system 1A, the first temperature sensor T1 is provided in the first flow path L3a downstream of the preheater 130.

[0101] In the combustion system 1A, the ammonia flowing through the first flow path L3a flows into the junction P2 after being preheated by the preheater 130. However, the thermal energy applied to the ammonia in the preheater 130 is less than the thermal energy applied to the ammonia in the preheater 120. Therefore, the temperature of the ammonia flowing from the second flow path L3b into the junction P2 is higher than the temperature of the ammonia flowing from the first flow path L3a into the junction P2.

[0102] As described above, in the combustion system 1A according to the first modified example, the temperature adjustment device 100A includes a first preheater (preheater 130 in the above example) that preheats the ammonia flowing through the first flow path L3a and a second preheater (preheater 120 in the above example) that preheats the ammonia flowing through the second flow path L3b. This allows the first preheater to adjust the temperature of the ammonia flowing from the first flow path L3a to the junction P2. For example, the temperature or flow rate of the heat medium flowing through the heat medium flow path L5 can be adjusted to adjust the temperature of the ammonia flowing from the first flow path L3a to the junction P2. This further improves the controllability of the temperature of the ammonia supplied to the injector 13b.

[0103] In the combustion system 1A, similarly to the above-described combustion system 1, the control device 16 controls the temperature adjustment device 100 based on information related to the pressure of ammonia in the injector 13b so that the temperature of the ammonia supplied to the injector 13b is equal to or lower than the saturation temperature of the ammonia in the injector 13b. For example, in the combustion system 1A, the processing performed by the control device 16 may be similar to that in the first, second, third, and fourth examples described above.

[0104] Furthermore, the various modifications that can be made to the combustion system 1 described above may also be made to the combustion system 1A.

[0105] 7 is a schematic diagram showing the configuration of a combustion system 1B according to a second modification. As shown in FIG. 7, the combustion system 1B differs from the combustion system 1 described above in that the first flow path L3a is omitted. The temperature adjustment device 100B of the combustion system 1B includes a second flow control valve 112 and a preheater 120.

[0106] In the combustion system 1B, the flow path L3 does not branch, and the ammonia that has passed through the preheater 120 is sent directly to the injector 13b. The control device 16 can adjust the temperature of the ammonia sent from the preheater 120 to the injector 13b, for example, by adjusting the temperature or flow rate of the heat medium flowing through the heat medium flow path L4. That is, in the combustion system 1B, the temperature of the ammonia supplied to the injector 13b is adjusted using the preheater 120.

[0107] As described above, in the combustion system 1B according to the second modification, the flow path L3 does not have a junction upstream of the injector 13b, and the temperature adjustment device 100B includes a preheater 120 that preheats the ammonia flowing through the flow path L3. This eliminates the need for the first flow path L3a and the devices provided in the first flow path L3a, thereby reducing equipment costs compared to the combustion system 1 described above. Furthermore, since the ammonia that has passed through the preheater 120 is sent directly to the injector 13b without being mixed with lower-temperature ammonia, the temperature of the ammonia that has passed through the preheater 120 can be lowered. This prevents the temperature of the ammonia that has passed through the preheater 120 from becoming excessively high, which would otherwise cause the ammonia to vaporize.

[0108] In the combustion system 1B, similarly to the combustion system 1 described above, the control device 16 controls the temperature adjustment device 100 based on information relating to the pressure of ammonia in the injector 13b so that the temperature of the ammonia supplied to the injector 13b is equal to or lower than the saturation temperature of ammonia in the injector 13b.

[0109] For example, in the combustion system 1B, the control device 16 may use a map showing the correspondence relationship between parameters affecting the pressure of ammonia in the injector 13b and the saturation temperature of ammonia in the injector 13b to identify the saturation temperature based on the parameters, as in the first example described above, and control the temperature adjustment device 100B based on the identification result of the saturation temperature. In this case, the control device 16 controls, for example, the temperature or flow rate of the heat medium flowing through the heat medium flow path L4 so that the temperature of the ammonia sent from the preheater 120 to the injector 13b becomes a temperature that is lower by a predetermined temperature (for example, several degrees Celsius to several tens of degrees Celsius) than the identified saturation temperature.

[0110] For example, in the combustion system 1B, as in the second example described above, the control device 16 may use a map showing the correspondence between parameters affecting the pressure of ammonia in the injector 13b and a control target of the temperature adjustment device 100B (e.g., a target value such as the temperature or flow rate of the heat medium flowing through the heat medium flow path L4) to identify the control target based on the parameters, and control the temperature adjustment device 100B based on the identified control target. In this case, the control device 16 may use the map, for example, to identify a control target such that the temperature of the ammonia sent from the preheater 120 to the injector 13b is a temperature that is lower than the saturation temperature by a predetermined temperature (e.g., several degrees Celsius to several tens of degrees Celsius). Then, the control device 16 controls the temperature adjustment device 100B so that the temperature or flow rate of the heat medium flowing through the heat medium flow path L4 becomes the control target.

[0111] For example, in the combustion system 1B, the control device 16 may calculate the pressure based on parameters that affect the pressure of ammonia in the injector 13b, as in the third example described above, and control the temperature adjustment device 100B based on the calculation result of the pressure. In this case, the control device 16 controls the temperature, flow rate, etc. of the heat medium flowing through the heat medium flow path L4 so that the temperature of the ammonia sent from the preheater 120 to the injector 13b becomes a temperature that is lower by a predetermined temperature (for example, several degrees Celsius to several tens of degrees Celsius) than the saturation temperature corresponding to the specified pressure.

[0112] For example, in the combustion system 1B, the control device 16 may control the temperature adjustment device 100B based on the measured value of the pressure of ammonia in the injector 13b, as in the fourth example described above. In this case, the control device 16 controls, for example, the temperature or flow rate of the heat medium flowing through the heat medium flow path L4 so that the temperature of the ammonia sent from the preheater 120 to the injector 13b becomes a temperature that is lower by a predetermined temperature (for example, several degrees Celsius to several tens of degrees Celsius) than the saturation temperature corresponding to the measured value of the pressure.

[0113] Moreover, the various modifications that can be made to the combustion system 1 described above may also be made to the combustion system 1B.

[0114] Fig. 8 is a schematic diagram showing the configuration of a combustion system 1C according to a third modification. As shown in Fig. 8, the combustion system 1C differs from the above-described combustion system 1 in that the ammonia tank 14 is replaced with a pressurized ammonia tank 17. The temperature adjustment device 100C of the combustion system 1C includes a flow ratio adjustment device 110 and a preheater 120, similar to the above-described temperature adjustment device 100.

[0115] Ammonia is stored in a liquid state in the ammonia tank 17. Unlike the above-described ammonia tank 14, the ammonia in the ammonia tank 17 is maintained in a liquid state at a pressure higher than atmospheric pressure and at a temperature approximately equal to the ambient temperature. The ammonia tank 17 is connected to the injection valve 13b of the combustor 13 via an ammonia flow path L3. A pump 15 is provided in the flow path L3 downstream of the ammonia tank 17.

[0116] The ammonia in the ammonia tank 17 is sent to the pump 15. In addition to the pressure loss occurring in the piping from the ammonia tank 17 to the pump 15, the ammonia pressure at the inlet of the pump 15 becomes lower than the ammonia pressure in the ammonia tank 17 because the pump 15 sucks in the ammonia. Therefore, from the viewpoint of suppressing the evaporation of the ammonia sent to the pump 15, it is preferable to make the vertical height of the installation position of the ammonia tank 17 as high as possible to obtain a sufficient head pressure.

[0117] A cooler 18 is provided in flow path L3 downstream of the ammonia tank 17 and upstream of the pump 15. The cooler 18 cools the ammonia flowing in flow path L3 downstream of the ammonia tank 17 and upstream of the pump 15. For example, the cooler 18 is a heat pump or the like. Note that the cooler 18 may also be a heat exchanger that uses, as a refrigerant, a portion of the ammonia that has been extracted from the ammonia tank 17, depressurized, and vaporized. In this case, the gaseous ammonia used as the refrigerant is sent to, for example, a denitration device or the like. By cooling the ammonia flowing in flow path L3 upstream of the pump 15 by the cooler 18, it is possible to suppress the evaporation of the ammonia sent to the pump 15.

[0118] A cooler 19 is provided in the first flow path L3a downstream of the branch point P1 and upstream of the first flow control valve 111. The cooler 19 cools the ammonia flowing through the first flow path L3a. The cooler 19 is, for example, a heat pump or the like, similar to the cooler 18. By cooling the ammonia flowing through the first flow path L3a by the cooler 19, it is possible to suppress the evaporation of ammonia in the injector 13b under the condition that the pressure of ammonia in the injector 13b is low.

[0119] However, both the cooler 18 and the cooler 19 may be omitted from the combustion system 1C. Alternatively, one of the cooler 18 and the cooler 19 may be omitted from the combustion system 1C.

[0120] In the combustion system 1C, similarly to the above-described combustion system 1, the control device 16 controls the temperature adjustment device 100 based on information related to the pressure of ammonia in the injector 13b so that the temperature of the ammonia supplied to the injector 13b is equal to or lower than the saturation temperature of the ammonia in the injector 13b. For example, in the combustion system 1C, the processing performed by the control device 16 may be similar to that in the first, second, third, and fourth examples described above.

[0121] Furthermore, the various modifications that can be made to the combustion system 1 described above may also be made to the combustion system 1C.

[0122] The above-described combustion system 1C is an example in which the ammonia tank 14 of the above-described combustion system 1 is replaced with a pressurized ammonia tank 17. However, the ammonia tank 14 of the above-described combustion system 1A may be replaced with a pressurized ammonia tank 17. The ammonia tank 14 of the above-described combustion system 1B may be replaced with a pressurized ammonia tank 17.

[0123] Although the embodiments of the present disclosure have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to such embodiments. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present disclosure.

[0124] In the above, an example has been described in which the rotational power generated by the turbine 12 is used to drive a generator in the combustion systems 1, 1A, 1B, and 1C. However, in the combustion systems 1, 1A, 1B, and 1C, the rotational power generated by the turbine 12 may also be used to drive a moving body such as a ship.

[0125] In the above, an example has been described in which the combustion energy in the combustor 13 is used to rotate the turbine 12 in the combustion systems 1, 1A, 1B, and 1C. However, in the combustion systems 1, 1A, 1B, and 1C, the combustion energy in the combustor 13 may be used for a purpose other than rotating the turbine 12.

[0126] 1: Combustion system 1A: Combustion system 1B: Combustion system 1C: Combustion system 13: Combustor 13a: Combustion chamber 13b: Injector 14: Ammonia tank 16: Control device 17: Ammonia tank 100: Temperature regulator 100A: Temperature regulator 100B: Temperature regulator 100C: Temperature regulator 110: Flow ratio regulator 120: Preheater (second preheater) 130: Preheater (first preheater) L3: Flow path L3a: First flow path L3b: Second flow path P2: Junction

Claims

1. A combustion system comprising: an ammonia tank in which ammonia is stored in a liquid state; a combustor having an ammonia tank and an injector facing the combustion chamber, the injector being connected to the ammonia tank via an ammonia flow path, and the ammonia being supplied in a liquid state to the injector; a temperature adjustment device that adjusts the temperature of the ammonia supplied to the injector; and a control device that controls the temperature adjustment device based on information regarding the pressure of the ammonia in the injector so that the temperature of the ammonia supplied to the injector is equal to or lower than the saturation temperature of the ammonia in the injector.

2. The combustion system described in claim 1, wherein the flow paths include a first flow path and a second flow path which merge at a junction upstream of the injection valve, a temperature of the ammonia flowing into the junction from the first flow path and a temperature of the ammonia flowing into the junction from the second flow path are different from each other, and the temperature control device includes a flow rate ratio adjustment device which adjusts a flow rate ratio which is a ratio between a flow rate of the ammonia flowing into the junction from the first flow path and a flow rate of the ammonia flowing into the junction from the second flow path.

3. The combustion system according to claim 2, wherein the temperature adjustment device includes a preheater that preheats the ammonia flowing through one of the first flow path and the second flow path.

4. The combustion system according to claim 2, wherein the temperature adjustment device includes a first preheater that preheats the ammonia flowing through the first flow path, and a second preheater that preheats the ammonia flowing through the second flow path.

5. The combustion system according to claim 1, wherein the flow passages do not have a joining portion upstream of the injector, and the temperature adjustment device includes a preheater that preheats the ammonia flowing through the flow passages.

6. A combustion system as claimed in any one of claims 1 to 5, wherein the information includes parameters that affect the pressure, and the control device identifies the saturation temperature based on the parameters using a map showing a correspondence between the parameters and the saturation temperature, and controls the temperature adjustment device based on the result of identifying the saturation temperature.

7. A combustion system as claimed in any one of claims 1 to 5, wherein the information includes parameters that affect the pressure, and the control device identifies the control target based on the parameters using a map showing the correspondence between the parameters and control targets of the temperature adjustment device, and controls the temperature adjustment device based on the identified control target.

8. A combustion system according to any one of claims 1 to 5, wherein the information includes parameters that affect the pressure, and the control device calculates the pressure based on the parameters, and controls the temperature adjustment device based on the calculation result of the pressure.

9. A combustion system as claimed in any one of claims 1 to 5, wherein the information includes a measurement value of the pressure, and the control device controls the temperature adjustment device based on the measurement value.

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