Multi-fuel fuel supply device and fuel supply method therefor

Abstract

The present invention provides a multi-fuel combustion fuel supply device equipped with a fuel supply system with a bypass fuel supply pipe, which is capable of easily adjusting the fuel flow rate while maintaining the calorific value ratio of each fuel at a set calorific value ratio for each fuel, and a fuel supply method for the multi-fuel combustion fuel supply device. [Solution] The multi-fuel fuel supply device (30) of the embodiment comprises: a hydrogen supply system (40) that supplies hydrogen gas to a combustion device (200), including a main fuel supply pipe (41) with a flow control valve (45) and a bypass fuel supply pipe (42) that has a flow control valve (46) and is connected to the main fuel supply pipe (41) bypassing the flow control valve (45); a city gas supply system (70) that supplies city gas to the combustion device (200), including a main fuel supply pipe (71) with a flow control valve (75) and a bypass fuel supply pipe (72) that has a flow control valve (76) and is connected to the main fuel supply pipe (71) bypassing the flow control valve (75); and a control device (90) for adjusting the flow rates of the hydrogen gas and the city gas.

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a multi-fuel combustion fuel supply device and a fuel supply method in the multi-fuel combustion fuel supply device. [Background technology]

[0002] Among conventional combustion devices, there is a multi-fuel combustion device that burns multiple different fuels. The ratio of the calorific values ​​of the fuels burned in this multi-fuel combustion device is indicated as a calorific value ratio. The calorific value ratio for each fuel is arbitrarily set in advance as a set calorific value ratio. When hydrogen and city gas are used as fuels, the set calorific value ratio is set taking into consideration, for example, NOx and CO2 emissions, misfire conditions, etc. Then, the flow rates of each fuel supplied to the multi-fuel combustion device are adjusted to achieve the set calorific value ratio.

[0003] A multi-fuel combustion system is supplied with each fuel by a multi-fuel fuel supply system. In the multi-fuel fuel supply system, the flow rate of each fuel is generally adjusted by a valve. Electric valves such as electric ball valves and electric butterfly valves are widely used as these valves.

[0004] The fuel supply system in a dual-fuel fuel supply system includes a fuel supply system with a bypass fuel supply pipe, which includes a main fuel supply pipe equipped with an electric valve and a bypass fuel supply pipe provided to bypass the electric valve of the main fuel supply pipe. The bypass fuel supply pipe is also equipped with an electric valve. In this case, for example, the bypass fuel supply pipe is used as a supply system that supplies fuel at a smaller flow rate than the main fuel supply pipe. Therefore, the motor-operated valve provided in the bypass fuel supply pipe is a small-flow motor-operated valve suitable for adjusting a small flow rate. On the other hand, the motor-operated valve provided in the main fuel supply pipe is a large-flow motor-operated valve suitable for adjusting a large flow rate.

[0005] In such a fuel supply system with a bypass fuel supply pipe, when the fuel flow rate is low, the large flow rate motor-operated valve is closed and the fuel flow rate is adjusted only by the small flow rate motor-operated valve.

[0006] On the other hand, when the fuel flow rate is high, for example, the small flow rate motor valve is closed and the fuel flow rate is regulated only by the large flow rate motor valve, and when the fuel flow rate is high, for example, the small flow rate motor valve is fully opened and the fuel flow rate is regulated only by the large flow rate motor valve.

[0007] FIG. 8 is a diagram illustrating the inherent flow rate characteristic showing the relationship between valve opening and flow rate in a typical motor-operated valve. Here, the inherent flow rate characteristics of motor-operated valve 300A and motor-operated valve 300B are illustrated. As shown in FIG. 8, the flow rate does not change linearly with respect to the valve opening, but changes in a curve. Note that such inherent flow rate characteristic is a typical characteristic of a motor-operated valve.

[0008] Specifically, the inherent flow rate characteristic of motor-operated valve 300A is such that when the valve opening is small, the change in flow rate is small, and as the valve opening becomes larger, the change in flow rate becomes larger, as shown by curve A in Figure 8. On the other hand, the inherent flow rate characteristic of motor-operated valve 300B is such that when the valve opening is small, the change in flow rate is large, and as the valve opening becomes larger, the change in flow rate becomes smaller. For this reason, in a fuel supply system equipped with a motor-operated valve, the inherent flow rate characteristic of the motor-operated valve as described above is understood before flow rate control is performed.

[0009] Here, in the case of motor-operated valves 300A and 300B, where the flow rate changes in a curved manner relative to the valve opening, it is possible to adjust the valve opening by controlling the current input as a control signal to motor-operated valves 300A and 300B, for example, and to change the flow rate linearly relative to the valve opening, as shown by dashed line C in Figure 8.

[0010] In the multi-fuel fuel supply system, the flow rate of each fuel is adjusted based on the inherent flow rate characteristics of the motor-operated valves as described above in order to set the calorific value ratio of each fuel to a set calorific value ratio. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-87190 Summary of the Invention [Problem to be solved by the invention]

[0012] As described above, the inherent flow rate characteristic of the motor-operated valve changes in a curve with respect to the valve opening, as shown in Fig. 8. Here, Fig. 9 is a diagram illustrating the relationship between the output of a conventional multi-fuel combustion system and the fuel flow rate in a fuel supply system with a bypass fuel supply pipe. In Fig. 9, the output refers to the total amount of heat generated by the combustion of each fuel in the multi-fuel combustion system. Also, the fuel flow rate refers to the fuel flow rate of a certain type of fuel in a fuel supply system with a bypass fuel supply pipe.

[0013] In Fig. 9, when the output is equal to or less than H1, the large flow rate motor-operated valve is closed and the fuel flow rate is adjusted by the small flow rate motor-operated valve. When the output is greater than H1, the small flow rate motor-operated valve is closed and the fuel flow rate is adjusted by the large flow rate motor-operated valve. Fig. 9 also shows an example in which the valve opening is adjusted by controlling the control current to the small flow rate motor-operated valve and the large flow rate motor-operated valve, and the flow rate is changed linearly with the valve opening, as shown by dashed line C in Fig. 8.

[0014] As shown in Figure 9, even when the small flow rate motor-operated valve and the large flow rate motor-operated valve are controlled to change the flow rate linearly with the valve opening, when the motor-operated valve that adjusts the flow rate is switched (at output H1), the change in flow rate relative to the output may exhibit a bending characteristic. That is, there is a point (bending point 310) where the slope of the line of the flow rate relative to the output changes.

[0015] Such a bending point 310 also occurs in the relationship between the fuel flow rate in a fuel supply system with a bypass fuel supply pipe for other fuels and the output of a multi-fuel combustion system. The output at which the bending point 310 occurs differs for each fuel.

[0016] Furthermore, the change characteristics of the flow rate with respect to the output shown in Figure 9 can be obtained similarly when the small flow rate motor-operated valve is fully opened and the fuel flow rate is adjusted by the large flow rate motor-operated valve on the side where the output is greater than H1.

[0017] In a multi-fuel combustion system, control is executed to increase or decrease the output while maintaining the calorific value ratio of each fuel at a set calorific value ratio for each fuel. In this case, with the change characteristic of the flow rate relative to the output as shown in Figure 9, the control to increase or decrease the output while maintaining a constant calorific value ratio is more complicated than with a characteristic (linear characteristic) in which the total flow rate changes along a straight line relative to the output.

[0018] FIG. 10 is a diagram illustrating the relationship between the output of a conventional multi-fuel combustion combustion system and the fuel flow rate in a fuel supply system with a bypass fuel supply pipe for a first fuel and a fuel supply system with a bypass fuel supply pipe for a second fuel.

[0019] Here, H2 and H3 on the horizontal axis of FIG. 10 are inputs when, for example, flow rate regulation by the small flow rate motor-operated valve is switched to flow rate regulation by the large flow rate motor-operated valve.

[0020] 10, for the first fuel, the slope of the line showing the flow rate of the first fuel relative to the output changes at input H3, and for the second fuel, the slope of the line showing the flow rate of the second fuel relative to the output changes at input H2.

[0021] When the output is equal to or lower than H2, the flow rate of the first fuel and the flow rate of the second fuel change with respect to the output, while the calorific value ratio of each fuel is maintained at the set calorific value ratio for each fuel.

[0022] On the other hand, when the slope of the straight line is greater than the input H2, the calorific value ratio of each fuel does not maintain the set calorific value ratio for each fuel when the flow rate of the first fuel and the flow rate of the second fuel are changed relative to the output. In this case, in order to maintain the calorific value ratio at the set calorific value ratio, complicated adjustment of the flow rate of the first fuel and the flow rate of the second fuel is required.

[0023] An object of the present invention is to provide a multi-fuel combustion fuel supply system equipped with a fuel supply system with a bypass fuel supply pipe, which is capable of easily adjusting the fuel flow rate while maintaining the calorific value ratio of each fuel at a set calorific value ratio for each fuel, and a fuel supply method for the multi-fuel combustion fuel supply system. [Means for solving the problem]

[0024] A multi-fuel fuel supply system according to an embodiment supplies fuel to a combustion device capable of multi-fuel combustion. The multi-fuel fuel supply system includes a first fuel supply system that supplies a first fuel, a second fuel supply system that supplies a second fuel, and a control device that adjusts the flow rates of the first fuel and the second fuel.

[0025] The first fuel supply system includes: a first main fuel supply pipe equipped with a first flow rate adjustment valve that adjusts the flow rate of the first fuel; a first bypass fuel supply pipe equipped with a second flow rate adjustment valve that adjusts the flow rate of the first fuel and connected to the first main fuel supply pipe while bypassing the first flow rate adjustment valve; and a first heat amount ratio adjustment valve that is provided in the first main fuel supply pipe between the combustion device and a first connecting portion of a connecting portion between the first bypass fuel supply pipe and the first main fuel supply pipe that is on the combustion device side, and the first heat amount ratio adjustment valve, the valve opening of which is set based on a preset set heat amount ratio that indicates the ratio of the heat amounts of the fuels in the combustion device.

[0026] The second fuel supply system includes: a second main fuel supply pipe equipped with a third flow rate control valve that adjusts the flow rate of the second fuel; a second bypass fuel supply pipe equipped with a fourth flow rate control valve that adjusts the flow rate of the second fuel and connected to the second main fuel supply pipe while bypassing the third flow rate control valve; and a second heat amount ratio control valve that is provided in the second main fuel supply pipe between the combustion device and a second connecting portion of the connecting portion between the second bypass fuel supply pipe and the second main fuel supply pipe that is on the combustion device side, and the second heat amount ratio control valve, the valve opening of which is set based on the set heat amount ratio.

[0027] The control device is set based on the types of the first fuel and the second fuel, the set calorific value ratio, inherent flow characteristics indicating the relationship between valve opening and flow rate in the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve, and opening characteristics indicating the relationship between command valve opening and control valve opening in the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve, and valve control data for controlling the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve so that the flow rate of the first fuel relative to an output corresponding to a calorific value in the combustion device and the flow rate of the second fuel relative to the output are changed while maintaining the set calorific value ratio. a valve control data selection unit that selects corresponding data from the valve control data based on the types of the first fuel and the second fuel, the set calorific value ratio, and the types of the first flow rate adjustment valve, the second flow rate adjustment valve, the third flow rate adjustment valve, and the fourth flow rate adjustment valve; a temperature determination unit that determines whether the temperature of the combustion exhaust gas discharged from the combustion device is at a preset set temperature; and a valve control unit that, when the temperature determination unit determines that the temperature of the combustion exhaust gas is not at the set temperature, controls the first flow rate adjustment valve, the second flow rate adjustment valve, the third flow rate adjustment valve, and the fourth flow rate adjustment valve based on the data selected by the valve control data selection unit to adjust the temperature of the combustion exhaust gas to the set temperature.

[0028] In addition, in a fuel supply method of a multi-fuel fuel supply device that supplies fuel to a combustion device capable of multi-fuel combustion of a plurality of fuels according to an embodiment, the multi-fuel fuel supply device includes a first fuel supply system that supplies a first fuel, a second fuel supply system that supplies a second fuel, and a control device that adjusts the flow rates of the first fuel and the second fuel.

[0029] The first fuel supply system includes: a first main fuel supply pipe equipped with a first flow rate adjustment valve that adjusts the flow rate of the first fuel; a first bypass fuel supply pipe equipped with a second flow rate adjustment valve that adjusts the flow rate of the first fuel and connected to the first main fuel supply pipe while bypassing the first flow rate adjustment valve; and a first heat amount ratio adjustment valve that is provided in the first main fuel supply pipe between the combustion device and a first connecting portion of a connecting portion between the first bypass fuel supply pipe and the first main fuel supply pipe that is on the combustion device side, and the first heat amount ratio adjustment valve, the valve opening of which is set based on a preset set heat amount ratio that indicates the ratio of the heat amounts of the fuels in the combustion device.

[0030] The second fuel supply system includes: a second main fuel supply pipe equipped with a third flow rate control valve that adjusts the flow rate of the second fuel; a second bypass fuel supply pipe equipped with a fourth flow rate control valve that adjusts the flow rate of the second fuel and connected to the second main fuel supply pipe while bypassing the third flow rate control valve; and a second heat amount ratio control valve that is provided in the second main fuel supply pipe between the combustion device and a second connecting portion of the connecting portion between the second bypass fuel supply pipe and the second main fuel supply pipe that is on the combustion device side, and the second heat amount ratio control valve, the valve opening of which is set based on the set heat amount ratio.

[0031] The control device is set based on the types of the first fuel and the second fuel, the set calorific value ratio, inherent flow characteristics indicating the relationship between valve opening and flow rate in the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve, and opening characteristics indicating the relationship between command valve opening and control valve opening in the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve, and controls the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve so that the flow rate of the first fuel relative to an output corresponding to a calorific value in the combustion device and the flow rate of the second fuel relative to the output change while maintaining the set calorific value ratio. the control device stores valve control data for adjusting the temperature of the combustion exhaust gas based on the types of the first fuel and the second fuel, the set calorific value ratio, and the types of the first flow rate adjustment valve, the second flow rate adjustment valve, the third flow rate adjustment valve, and the fourth flow rate adjustment valve; the control device determines whether the temperature of the combustion exhaust gas discharged from the combustion device is at a preset set temperature; and if it determines that the temperature of the combustion exhaust gas is not at the set temperature, the control device controls the first flow rate adjustment valve, the second flow rate adjustment valve, the third flow rate adjustment valve, and the fourth flow rate adjustment valve based on the data selected from the valve control data to adjust the temperature of the combustion exhaust gas to the set temperature. [Effects of the Invention]

[0032] According to the multi-fuel combustion fuel supply device and the fuel supply method for the multi-fuel combustion fuel supply device of the present invention, in a multi-fuel combustion fuel supply device equipped with a fuel supply system with a bypass fuel supply pipe, it is possible to easily adjust the fuel flow rate while maintaining the calorific value ratio of each fuel at a set calorific value ratio for each fuel. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a diagram showing a schematic configuration of a combustion system including a multi-fuel combustion fuel supply device according to an embodiment; [Figure 2]2 is a block diagram showing the configuration of a control device in the multi-fuel combustion fuel supply device according to the embodiment; FIG. [Figure 3] FIG. 3 is a diagram showing an example of inherent flow rate characteristics showing the relationship between the valve opening and flow rate in a flow rate adjustment valve provided in the multi-fuel combustion fuel supply device of the embodiment. [Figure 4] 3 is a diagram showing an example of opening characteristics showing the relationship between a command valve opening and a regulating valve opening in a flow rate regulating valve provided in the multi-fuel combustion fuel supply device of the embodiment. FIG. [Figure 5] FIG. 3 is a diagram showing an example of the relationship between the output of a combustion device and the flow rate of each fuel in the multi-fuel combustion fuel supply device according to the embodiment. [Figure 6] 4 is a flowchart for explaining a fuel supply method of the multi-fuel combustion fuel supply device according to the embodiment. [Figure 7] 4 is a flowchart for explaining processing relating to a calorific value ratio in a fuel supply method of a multi-fuel combustion fuel supply device according to an embodiment. [Figure 8] FIG. 1 is a diagram illustrating an example of inherent flow rate characteristics showing the relationship between valve opening and flow rate in a typical motor-operated valve. [Figure 9] FIG. 10 is a diagram illustrating the relationship between the output of a conventional multi-fuel combustion combustion system and the fuel flow rate in a fuel supply system with a bypass fuel supply pipe. [Figure 10] FIG. 10 is a diagram illustrating the relationship between the output of a conventional multi-fuel combustion combustion system and the fuel flow rate in a fuel supply system with a bypass fuel supply pipe for a first fuel and a fuel supply system with a bypass fuel supply pipe for a second fuel. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0035] FIG. 1 is a diagram showing a schematic configuration of a combustion system 1 equipped with a multi-fuel combustion fuel supply device 30 according to an embodiment.

[0036] As shown in FIG. 1, the combustion device system 1 includes a multi-fuel combustion oxidant supply device 10, a multi-fuel combustion fuel supply device 30, and a combustion device 200.

[0037] (Combustion device 200) First, the combustion device 200 will be described.

[0038] The combustion device 200 is a multi-fuel combustion device capable of mixing and burning a plurality of fuels. Here, the combustion device 200 will be described by taking as an example a diffusion combustion type combustor that separately injects two types of fuel and an oxidizer into the combustion chamber 210. However, the combustion type of the combustion device 200 is not limited to this, and other combustion types such as premixed combustion may also be used.

[0039] The combustion device 200 includes a combustion chamber 210, a first fuel ejection unit 220, a second fuel ejection unit 221, an oxidizer ejection unit 230, a combustion exhaust gas return system 270, and a temperature detector 240. The combustion device 200 may also include, for example, a pilot burner 250.

[0040] The combustion chamber 210 is a cylindrical body in which fuel and oxidizer are combusted. A flame is formed within the combustion chamber 210.

[0041] The first fuel ejection part 220 ejects the first fuel into the combustion chamber 210. The first fuel ejection part 220 is formed of, for example, a tubular member. The first fuel ejection part 220 is provided at one end of the combustion chamber 210, for example.

[0042] The oxidant ejection part 230 ejects an oxidant into the combustion chamber 210. The oxidant ejection part 230 is configured, for example, by an annular flow path between a tubular member that configures the first fuel ejection part 220 and a tubular member that surrounds the outer periphery of the oxidant ejection part 230. The tubular member that surrounds the outer periphery of the first fuel ejection part 220 is provided, for example, at one end of the combustion chamber 210.

[0043] The second fuel ejection part 221 ejects the second fuel into the combustion chamber 210. The second fuel ejection part 221 is configured, for example, by an annular flow path between a tubular member that configures the oxidizer ejection part 230 and a tubular member that surrounds the outer periphery of the second fuel ejection part 221. The tubular member that surrounds the outer periphery of the oxidizer ejection part 230 is provided, for example, at one end of the combustion chamber 210.

[0044] The arrangement of the first fuel ejection part 220, the second fuel ejection part 221, and the oxidant ejection part 230 is not limited to these, and may be changed appropriately depending on the application. The first fuel ejection part 220, the second fuel ejection part 221, and the oxidant ejection part 230 configure a main burner 235.

[0045] Here, the fuel supplied to the first fuel ejection part 220 and the second fuel ejection part 221 is in a gaseous state. For example, hydrogen is used as the first fuel, and a gas containing methane as a main component is used as the second fuel. Here, an example is shown in which hydrogen is used as the first fuel and city gas is used as the second fuel. However, the first fuel and the second fuel are not limited to these. The first fuel and the second fuel can be appropriately selected and combined from widely used fuel gases depending on the purpose. For example, the first fuel and the second fuel may be combined with hydrogen and a hydrocarbon gas, or with a hydrocarbon gas different from the hydrocarbon gas.

[0046] Although air is used as an oxidizing agent in this example, oxygen or the like may also be used.

[0047] The outlet of the combustion chamber 210 and the combustion gas utilization section 290 that utilizes the combustion gas are connected by a combustion gas exhaust pipe 260. The combustion gas exhaust pipe 260 is equipped with a blower 261 such as a fan. The blower 261 guides the combustion exhaust gas from the combustion chamber 210 to the combustion gas utilization section 290 via the combustion gas exhaust pipe 260. The blower 261 is configured by, for example, a sirocco fan or a turbo fan.

[0048] The combustion exhaust gas return system 270 has a function of extracting a portion of the combustion exhaust gas used in the combustion gas utilization section 290, and mixing the extracted combustion exhaust gas with air and returning it to the combustion chamber 210. Specifically, the combustion exhaust gas return system 270 includes a return pipe 271 and an atmosphere introduction pipe 272.

[0049] The return pipe 271 returns a portion of the combustion exhaust gas after being used in the combustion gas utilization section 290 into the combustion chamber 210. One end of the return pipe 271 is provided so as to communicate with the space in the combustion gas utilization section 290 where the combustion exhaust gas is utilized. The other end of the return pipe 271 is connected to the inside of the combustion chamber 210. The other end of the return pipe 271 is provided at a position that does not interfere with the combustion reaction in the main burner 235.

[0050] An atmosphere introduction pipe 272 is connected to the other end of the return pipe 271. One end of the atmosphere introduction pipe 272 is open to the atmosphere. The atmosphere introduction pipe 272 is a pipe for introducing atmosphere (air) into the combustion exhaust gas that is returned from the combustion gas utilization section 290 to the combustion chamber 210 via the return pipe 271. In other words, the atmosphere is sucked in from the end of the atmosphere introduction pipe 272 that is open to the atmosphere, and introduced into the return pipe 271.

[0051] The atmospheric air introduction pipe 272 is provided with a flow rate adjustment unit 273 for adjusting the flow rate of air introduced into the return pipe 271. This flow rate adjustment unit 273 is configured with, for example, a damper. The opening degree of the damper is adjusted, for example, so that a constant flow rate of air is introduced into 271.

[0052] That is, the combustion exhaust gas discharged from the combustion chamber 210 to the combustion gas exhaust pipe 260 is a mixture of the combustion gas produced by the combustion of fuel and oxidizer in the combustion chamber 210 and the combustion exhaust gas containing the air that is returned to the combustion chamber 210 from the return pipe 271.

[0053] Here, the blower 261 provided in the combustion gas exhaust pipe 260 has the function of introducing combustion exhaust gas from the combustion chamber 210 to the combustion gas utilization section 290 via the combustion gas exhaust pipe 260, and the function of returning the combustion exhaust gas from the combustion gas utilization section 290 to the combustion chamber 210 via the return pipe 271.

[0054] The temperature detector 240 detects the temperature of the combustion exhaust gas at the outlet of the combustion chamber 210. The temperature detector 240 is provided, for example, at the entrance of the combustion gas exhaust pipe 260, which is the outlet of the combustion chamber 210. The temperature detector 240 detects the temperature of the mixed gas consisting of the above-mentioned combustion gas and the combustion exhaust gas containing the air.

[0055] The pilot burner 250 is used, for example, when igniting the main burner 235. For example, a mixed fuel of a first fuel and a second fuel, and an oxidizer are supplied to the pilot burner 250. The fuel ejected from the pilot burner 250 is ignited by an ignition device such as an igniter (not shown). An ignition device may be provided in the main burner 235 without providing the pilot burner 250. (Oxidizer supply device for mixed combustion 10) Next, the multi-fuel combustion oxidant supply device 10 will be described.

[0056] The multi-fuel combustion oxidizer supply device 10 supplies oxidizer to the combustion device 200. The multi-fuel combustion oxidizer supply device 10 includes a main burner oxidizer supply pipe 11, an oxidizer supply source 13, and flow control valves 14 and 15. When the pilot burner 250 is included, the multi-fuel combustion oxidizer supply device 10 also includes a pilot oxidizer supply pipe 12 and a flow control valve 16.

[0057] The main burner oxidizer supply pipe 11 supplies oxidizer to the main burner 235. One end of the main burner oxidizer supply pipe 11 is connected to the oxidizer jetting section 230, and the other end of the main burner oxidizer supply pipe 11 is connected to an oxidizer supply source 13. The main burner oxidizer supply pipe 11 is provided with flow control valves 14 and 15 that adjust the flow rate of the oxidizer.

[0058] The pilot oxidizer supply pipe 12 supplies oxidizer to the pilot burner 250. One end of the pilot oxidizer supply pipe 12 is connected to the pilot burner 250. The other end of the pilot oxidizer supply pipe 12 is connected to the main burner oxidizer supply pipe 11 between the oxidizer supply source 13 and a flow control valve 15 on the oxidizer supply source 13 side. The pilot oxidizer supply pipe 12 is provided with a flow control valve 16 that adjusts the flow rate of the oxidizer.

[0059] The oxidant supply source 13 is composed of, for example, a fan, a blower, a compressor, etc. When the oxidant is oxygen, the oxidant supply source 13 is composed of, for example, an oxygen cylinder that stores high-pressure oxygen.

[0060] (Fuel supply device for mixed combustion 30) Next, the multi-fuel combustion fuel supply device 30 will be described.

[0061] Here, a case where hydrogen gas (H2) is used as the first fuel and city gas (13A) is used as the second fuel will be described as an example.

[0062] The multi-fuel combustion fuel supply device 30 is a fuel supply device that can supply a plurality of types of fuel to the multi-fuel combustion type combustion device 200. In this example, the multi-fuel combustion fuel supply device 30 supplies hydrogen gas and city gas to the combustion device 200.

[0063] The multi-fuel combustion fuel supply system 30 includes a hydrogen supply system 40, a city gas supply system 70, and a control device 90. The hydrogen supply system 40 functions as a first fuel supply system, and the city gas supply system 70 functions as a second fuel supply system.

[0064] (Hydrogen supply system 40) First, the hydrogen supply system 40 will be described.

[0065] The hydrogen supply system 40 supplies hydrogen gas to the combustion device 200. The hydrogen supply system 40 includes a main fuel supply pipe 41, a bypass fuel supply pipe 42, and a hydrogen supply source 49. The main fuel supply pipe 41 functions as a first main fuel supply pipe, and the bypass fuel supply pipe 42 functions as a first bypass fuel supply pipe.

[0066] When the pilot burner 250 is provided, the hydrogen supply system 40 includes a pilot fuel supply pipe 55. Furthermore, the hydrogen supply system 40 may include a purge gas supply pipe 60 that supplies purge gas to the combustion device 200, and a nitrogen gas supply source 61.

[0067] Here, the configuration for supplying purge gas to the combustion device 200 is preferably applied when using a fuel such as hydrogen that has a high combustion speed and is prone to causing flame flashback, for example, when shutting off the fuel. Note that when using a fuel that does not have the problem of flashback, the configuration for supplying purge gas to the combustion device 200 does not need to be provided.

[0068] One end of the main fuel supply pipe 41 is connected to the first fuel ejection part 220, and the other end of the main fuel supply pipe 41 is connected to a hydrogen supply source 49. The main fuel supply pipe 41 is provided with, in this order from the hydrogen supply source 49 side, a flow detector 48, a governor 47, a shutoff valve 44, a flow control valve 45, and a heat ratio control valve 43.

[0069] The flow rate detector 48 detects the flow rate of hydrogen gas supplied to the combustion device 200. When the pilot burner 250 is provided, the flow rate detected by the flow rate detector 48 is the flow rate supplied to the main burner 235 and the pilot burner 250.

[0070] The governor 47 adjusts the pressure of the hydrogen gas supplied from the hydrogen supply source 49, and allows the hydrogen gas to flow at a predetermined pressure toward the combustion device 200. The shutoff valve 44 opens and closes to allow or block the flow of hydrogen gas.

[0071] The flow rate control valve 45 adjusts the flow rate of hydrogen gas supplied to the first fuel ejection part 220 through the main fuel supply pipe 41. An electric valve such as an electric ball valve or an electric butterfly valve is used as the flow rate control valve 45. The flow rate control valve 45 functions as a first flow rate control valve.

[0072] The calorific value ratio adjustment valve 43 passes hydrogen gas at a flow rate that satisfies the set calorific value ratio for the hydrogen gas. Here, the set calorific value ratio indicates a preset ratio of the calorific values ​​of the respective fuels in the combustion device 200. The valve opening degree of the calorific value ratio adjustment valve 43 is set based on the set calorific value ratio for the hydrogen gas. As a result, the flow rate of the hydrogen gas supplied to the combustion device 200 becomes a flow rate that satisfies the set calorific value ratio for the hydrogen gas. In other words, the calorific value generated by the combustion of the hydrogen gas that has passed through the calorific value ratio adjustment valve 43 becomes the set calorific value ratio for the hydrogen gas. The calorific value ratio adjustment valve 43 functions as a first calorific value ratio adjustment valve.

[0073] The bypass fuel supply pipe 42 bypasses the flow rate adjustment valve 45 and is connected to the main fuel supply pipe 41. Specifically, one end of the bypass fuel supply pipe 42 is connected to the main fuel supply pipe 41 between the shutoff valve 44 and the flow rate adjustment valve 45 at a connection part C1, and the other end of the bypass fuel supply pipe 42 is connected to the main fuel supply pipe 41 between the heat ratio adjustment valve 43 and the flow rate adjustment valve 45 at a connection part C2.

[0074] The bypass fuel supply pipe 42 is equipped with a flow rate adjustment valve 46. The flow rate adjustment valve 46 adjusts the flow rate of hydrogen gas that passes through the bypass fuel supply pipe 42 and the main fuel supply pipe 41 and is supplied to the first fuel ejection part 220. An electric valve such as an electric ball valve or an electric butterfly valve is used as the flow rate adjustment valve 46. The flow rate adjustment valve 46 functions as a second flow rate adjustment valve.

[0075] Here, for example, the bypass fuel supply pipe 42 is used as a supply system that allows a smaller flow rate of fuel to flow than the main fuel supply pipe 41. Therefore, a small flow rate motor-operated valve suitable for adjusting a small flow rate is used as the flow rate control valve 46 provided in the bypass fuel supply pipe 42. On the other hand, a large flow rate motor-operated valve suitable for adjusting a large flow rate is used as the flow rate control valve 45 provided in the main fuel supply pipe 41.

[0076] In this embodiment, the fuel flow rate is adjusted by controlling the valve openings of both the flow rate adjustment valve 45 and the flow rate adjustment valve 46, regardless of the fuel flow rate. As will be described in detail later, this results in a relationship between the output and the fuel flow rate in the combustion device 200 that changes on a predetermined straight line.

[0077] Furthermore, for example, by configuring the flow rate control valve 46 as a small flow rate motor-operated valve and the flow rate control valve 45 as a large flow rate motor-operated valve, the fuel flow rate can be adjusted over a range from small to large flow rates, and a wide turndown ratio (TDR) can be obtained. The turndown ratio (TDR) is the ratio between the minimum controllable flow rate and the maximum controllable flow rate.

[0078] The pilot fuel supply pipe 55 supplies a portion of the hydrogen gas flowing through the main fuel supply pipe 41 to a pilot mixed fuel supply pipe 58, which supplies mixed fuel to the pilot burner 250. One end of the pilot fuel supply pipe 55 is connected to the main fuel supply pipe 41 between the governor 47 and the shutoff valve 44. The other end of the pilot fuel supply pipe 55 is connected to the pilot mixed fuel supply pipe 58.

[0079] Pilot fuel supply pipe 55 is equipped with a shutoff valve 56 and a flow rate adjustment valve 57. Shutoff valve 56 allows or blocks the flow of hydrogen gas by opening and closing the valve. Flow rate adjustment valve 57 adjusts the flow rate of hydrogen gas supplied to pilot mixed fuel supply pipe 58 through pilot fuel supply pipe 55.

[0080] Although an example is shown here in which hydrogen gas and city gas are mixed in the pilot mixed fuel supply pipe 58 and supplied to the pilot burner 250, the configuration is not limited to this. Hydrogen gas may be supplied directly to the pilot burner 250 via the pilot fuel supply pipe 55. Furthermore, city gas may be supplied directly to the pilot burner 250 via a pilot fuel supply pipe 80, which will be described later.

[0081] The purge gas supply pipe 60 supplies an inert gas to the hydrogen supply system 40 to prevent flame backfire, for example, when stopping the supply of hydrogen gas to the first fuel ejection part 220. Examples of inert gas that can be used include nitrogen gas, argon gas, and helium gas. Here, an example is shown in which nitrogen gas is used as the inert gas.

[0082] One end of the purge gas supply pipe 60 is connected to a nitrogen gas supply source 61. The other end of the purge gas supply pipe 60 branches into a purge gas supply pipe 62 for the main burner and a purge gas supply pipe 63 for the pilot burner.

[0083] The branched end of the main burner purge gas supply pipe 62 is connected to the main fuel supply pipe 41 at a connecting part C1. The main burner purge gas supply pipe 62 is equipped with a shutoff valve 64 and a flow rate adjustment valve 65. The shutoff valve 64 allows or stops the flow of nitrogen gas by opening and closing the valve. The flow rate adjustment valve 65 adjusts the flow rate of nitrogen gas supplied to the first fuel jetting part 220 via the main burner purge gas supply pipe 62 and the main fuel supply pipe 41, or via the main burner purge gas supply pipe 62, the bypass fuel supply pipe 42, and the main fuel supply pipe 41.

[0084] The branched pilot burner purge gas supply pipe 63 is connected to the pilot fuel supply pipe 55 between the shutoff valve 56 and the flow rate adjustment valve 57. The pilot burner purge gas supply pipe 63 is equipped with a shutoff valve 66 and a flow rate adjustment valve 67. The shutoff valve 66 allows or blocks the flow of nitrogen gas by opening and closing the valve. The flow rate adjustment valve 67 adjusts the flow rate of nitrogen gas supplied to the pilot burner 250 via the pilot burner purge gas supply pipe 63 and the pilot mixed fuel supply pipe 58.

[0085] (City gas supply system 70) Next, the city gas supply system 70 will be described.

[0086] The city gas supply system 70 supplies city gas to the combustion device 200. The city gas supply system 70 includes a main fuel supply pipe 71, a bypass fuel supply pipe 72, and a city gas supply source 78. The main fuel supply pipe 71 functions as a second main fuel supply pipe, and the bypass fuel supply pipe 72 functions as a second bypass fuel supply pipe.

[0087] Furthermore, when the pilot burner 250 is provided, the city gas supply system 70 is provided with a pilot fuel supply pipe 80 .

[0088] One end of main fuel supply pipe 71 is connected to second fuel ejection part 221, and the other end of main fuel supply pipe 71 is connected to city gas supply source 78. Main fuel supply pipe 71 is equipped with, in this order from the city gas supply source 78 side, a flow detector 77, a shutoff valve 74, a flow control valve 75, and a heat ratio control valve 73.

[0089] The flow rate detector 77 detects the flow rate of the city gas supplied to the combustion device 200. When the pilot burner 250 is provided, the flow rate detected by the flow rate detector 77 is the flow rate supplied to the main burner 235 and the pilot burner 250.

[0090] The shutoff valve 74 allows or blocks the flow of city gas by opening and closing the valve.

[0091] The flow rate control valve 75 adjusts the flow rate of city gas supplied to the second fuel injection part 221 through the main fuel supply pipe 71. An electric valve such as an electric ball valve or an electric butterfly valve is used as the flow rate control valve 75. The flow rate control valve 75 functions as a third flow rate control valve.

[0092] Here, for example, bypass fuel supply pipe 72 is used as a supply system that allows fuel to flow at a smaller flow rate than main fuel supply pipe 71. Therefore, a small flow rate motor-operated valve suitable for adjusting a small flow rate is used as flow rate control valve 76 provided in bypass fuel supply pipe 72. On the other hand, a large flow rate motor-operated valve suitable for adjusting a large flow rate is used as flow rate control valve 75 provided in main fuel supply pipe 71.

[0093] In this embodiment, the fuel flow rate is adjusted by controlling the valve openings of both the flow rate adjustment valve 75 and the flow rate adjustment valve 76, regardless of the fuel flow rate. As will be described in detail later, this results in a relationship between the output and fuel flow rate in the combustion device 200 that changes on a predetermined straight line.

[0094] Furthermore, for example, by configuring the flow rate control valve 76 as a small flow rate motor-operated valve and the flow rate control valve 75 as a large flow rate motor-operated valve, it becomes possible to adjust the fuel flow rate in a range from small flow rate to large flow rate, and a wide turndown ratio (TDR) can be obtained.

[0095] The calorific value ratio adjustment valve 73 passes city gas at a flow rate that satisfies the set calorific value ratio for the city gas. The valve opening of the calorific value ratio adjustment valve 73 is set based on the set calorific value ratio for the city gas. As a result, the flow rate of the city gas supplied to the combustion device 200 becomes a flow rate that satisfies the set calorific value ratio for the city gas. In other words, the amount of heat generated by the combustion of the city gas that has passed through the calorific value ratio adjustment valve 73 becomes the set calorific value ratio for the city gas. The calorific value ratio adjustment valve 73 functions as a second calorific value ratio adjustment valve.

[0096] The bypass fuel supply pipe 72 bypasses the flow rate adjustment valve 75 and is connected to the main fuel supply pipe 71. Specifically, one end of the bypass fuel supply pipe 72 is connected to the main fuel supply pipe 71 between the shutoff valve 74 and the flow rate adjustment valve 75 at a connection part C3, and the other end of the bypass fuel supply pipe 72 is connected to the main fuel supply pipe 71 between the heat ratio adjustment valve 73 and the flow rate adjustment valve 75 at a connection part C4.

[0097] The bypass fuel supply pipe 72 is equipped with a flow rate adjustment valve 76. The flow rate adjustment valve 76 adjusts the flow rate of city gas that passes through the bypass fuel supply pipe 72 and the main fuel supply pipe 71 and is supplied to the second fuel ejection part 221. An electric valve such as an electric ball valve or an electric butterfly valve is used as the flow rate adjustment valve 76. The flow rate adjustment valve 76 functions as a fourth flow rate adjustment valve.

[0098] The pilot fuel supply pipe 80 supplies a portion of the city gas flowing through the main fuel supply pipe 71 to the pilot mixed fuel supply pipe 58, which supplies mixed fuel to the pilot burner 250. One end of the pilot fuel supply pipe 80 is connected to the main fuel supply pipe 71 between the flow detector 77 and the shutoff valve 74. The other end of the pilot fuel supply pipe 80 is connected to the pilot mixed fuel supply pipe 58.

[0099] Pilot fuel supply pipe 80 is equipped with a shutoff valve 81 and a flow rate adjustment valve 82. Shutoff valve 81 allows or blocks the flow of city gas by opening and closing the valve. Flow rate adjustment valve 82 adjusts the flow rate of city gas supplied to pilot mixed fuel supply pipe 58 through pilot fuel supply pipe 80.

[0100] (Control device 90) Next, the control device 90 will be described.

[0101] The control device 90 executes control to adjust the flow rates of hydrogen gas and city gas supplied to the combustion device 200. Here, Fig. 2 is a block diagram showing the configuration of the control device 90 in the multi-combustion fuel supply device 30 of the embodiment.

[0102] As shown in FIG. 2, the control device 90 includes an input unit 100, a storage unit 110, a calculation unit 120, and an output unit .

[0103] The input unit 100 receives input signals from external input means such as a control panel or input terminal used as input means by users of the multi-fuel combustion fuel supply device 30, as well as detection signals from various detectors. For example, the input unit 100 receives information from external input means, such as the type and characteristics of fuel, the set calorific value ratio for each fuel, and the type of flow control valve. The input unit 100 also receives detection signals from the temperature detector 240, flow detector 48, flow detector 77, etc.

[0104] The storage unit 110 is realized by, for example, a hard disk drive, a nonvolatile memory, etc. The storage unit 110 stores fuel type input data 111, heat ratio input data 112, valve type input data 113, combustion exhaust gas temperature data 114, valve control data 115, etc.

[0105] The fuel type input data 111 is data relating to the type and characteristics of the fuel supplied to the combustion device 200. Here, the fuel type input data 111 stores, for example, data relating to hydrogen gas, which is the first fuel, and city gas, which is the second fuel. Note that data relating to the type and characteristics of the fuel input by external input means is input by the input unit 100 and stored as the fuel type input data 111 by the storage unit 110. Examples of data relating to the characteristics of the fuel include data relating to fuel characteristics such as the higher heating value and lower heating value of each fuel.

[0106] The calorific value ratio input data 112 is data relating to the set calorific value ratio of each fuel supplied to the combustion device 200. Here, the calorific value ratio input data 112 stores, for example, data relating to the set calorific value ratio of hydrogen gas, which is the first fuel, and the set calorific value ratio of city gas, which is the second fuel. As the calorific value ratio input data 112, for example, a set calorific value ratio of 40% for hydrogen gas and a set calorific value ratio of 60% for city gas are set. As the calorific value ratio input data 112, various ratio combinations can be set. As the set calorific value ratio, for example, a set calorific value ratio of 0% for hydrogen gas and a set calorific value ratio of 100% for city gas, or a set calorific value ratio of 100% for hydrogen gas and a set calorific value ratio of 0% for city gas, etc., are also possible. In other words, as the calorific value ratio input data 112, the set calorific value ratios of hydrogen gas and city gas can be set in the range of 0-100%.

[0107] The data relating to the set calorific value ratio of each fuel input by the external input means is input by the input unit 100 and stored as calorific value ratio input data 112 by the storage unit 110 .

[0108] The calorific value ratio input data 112 also stores, for example, data on the fuel flow rate ratio of each fuel corresponding to the set calorific value ratio of each fuel. Specifically, for a combination of hydrogen gas and city gas, the fuel flow rate ratio of hydrogen gas to city gas is stored so that the set calorific value ratio of hydrogen gas is 40% and the set calorific value ratio of city gas is 60%, for example.

[0109] The valve type input data 113 is data relating to the type of flow control valves and the like provided in the multi-fuel combustion fuel supply device 30. As the valve type input data 113, for example, data relating to valve types such as flow control valves 45, 46, 75, 76 and calorie ratio control valves 43, 73 is stored. As the data relating to valve types, for example, data relating to specifications such as the valve manufacturer and valve model is stored. As the data relating to valve types, at least information that can identify the valve is stored. Note that the data relating to valve types input by external input means is input by the input unit 100 and stored as the valve type input data 113 by the memory unit 110.

[0110] The combustion exhaust gas temperature data 114 is data relating to the set temperature of the combustion exhaust gas discharged from the combustion chamber 210 of the combustion device 200. That is, the temperature of the combustion exhaust gas required at the outlet of the combustion chamber 210 is stored as the set temperature as the combustion exhaust gas temperature data 114. Note that data relating to the set temperature of the combustion exhaust gas input by external input means is input by the input unit 100 and stored as the combustion exhaust gas temperature data 114 by the memory unit 110.

[0111] The valve control data 115 is set in advance based on the types of the first fuel and the second fuel, the set calorific value ratio, inherent flow characteristics indicating the relationship between the valve opening and flow rate of the flow control valves 45, 46, 75, and 76, and opening characteristics indicating the relationship between the command valve opening and control valve opening of the flow control valves 45, 46, 75, and 76. The valve control data 115 stores data for controlling the flow control valves 45, 46, 75, and 76 so that the flow rate of the first fuel relative to the output of the combustion device 200 and the flow rate of the second fuel relative to the output of the combustion device 200 change while maintaining the set calorific value ratio. The output of the combustion device 200 corresponds to the heat value of the combustion device 200. The output of the combustion device 200 will hereinafter be simply referred to as "output."

[0112] Here, the valve control data 115 is exemplified as data for controlling the flow control valves 45, 46, 75 and 76 so that the flow rate of hydrogen gas relative to the output and the flow rate of city gas relative to the output change while maintaining the set calorific value ratio.

[0113] Furthermore, data for controlling the flow rate control valves 45, 46, 75, and 76 is stored as valve control data 115 so that the flow rate of the first fuel relative to the output and the flow rate of the second fuel relative to the output change linearly.

[0114] Here, the expression "the fuel flow rate changes linearly with respect to the output" means that the relationship between the output and the fuel flow rate satisfies a linear function. In other words, the expression "the fuel flow rate changes linearly with respect to the output" means that when the fuel flow rate is plotted against the output, the locus of the fuel flow rate with respect to the output becomes a straight line.

[0115] In addition, data for controlling the valve opening degree of valves other than the flow control valves 45, 46, 75, and 76 (hereinafter referred to as other valves) based on the types of the first fuel and the second fuel, the set calorific value ratio, the temperature of the combustion exhaust gas, etc. is also stored as valve control data 115.

[0116] The valve control data 115 is set assuming that the pressure and temperature of the hydrogen gas immediately downstream of the governor 47 in the hydrogen supply system 40 are the predetermined conditions. The valve control data 115 is set assuming that the pressure and temperature of the city gas immediately downstream of the flow detector 77 in the city gas supply system 70 are the predetermined conditions. The predetermined conditions in the hydrogen supply system 40 may be the same as or different from the predetermined conditions in the city gas supply system 70.

[0117] Here, the valve control data 115 will be described in detail.

[0118] 3 is a diagram showing an example of inherent flow rate characteristics showing the relationship between the valve opening and flow rate of the flow rate control valves 45, 46, 75, and 76 provided in the multi-fuel combustion fuel supply device 30 of the embodiment. Note that each flow rate control valve has different inherent flow rate characteristics depending on the specifications of the flow rate control valve, etc.

[0119] Fig. 4 is a diagram showing an example of opening characteristics showing the relationship between the command valve opening and the regulating valve opening in the flow control valves 45, 46, 75, and 76 provided in the multi-fuel combustion fuel supply device 30 of the embodiment. The opening characteristics shown in Fig. 4 are an example of the opening characteristics of one flow control valve. Note that each flow control valve has a different opening characteristic depending on the specifications of the flow control valve, etc.

[0120] 5 is a diagram showing an example of the relationship between the output and the flow rate of each fuel in the multi-fuel combustion fuel supply device 30 according to the embodiment. Note that Fig. 5 shows the relationship at a predetermined set calorific value ratio.

[0121] As shown in Figure 3, the flow rate in a flow control valve does not change linearly but changes curvilinearly with respect to the valve opening. Shown here is an example of inherent flow rate characteristic 1, where the flow rate characteristic with respect to the valve opening is convex downward, and an example of inherent flow rate characteristic 2, where the flow rate characteristic with respect to the valve opening is convex upward.

[0122] Intrinsic flow characteristic 1 shows a small change in flow rate when the valve opening is small, and a large change in flow rate as the valve opening becomes larger. Intrinsic flow characteristic 2 shows a large change in flow rate when the valve opening is small, and a small change in flow rate as the valve opening becomes larger.

[0123] Now, FIG. 4 will be described.

[0124] The command valve opening on the horizontal axis of Fig. 4 is the valve opening corresponding to the valve opening on the horizontal axis of Fig. 3, and is the valve opening for a flow rate determined based on the inherent flow rate characteristic of the flow control valve. For example, in a flow control valve having inherent flow rate characteristic 1 in Fig. 3, the valve opening is set to 50% for a required flow rate F1. Also, in a flow control valve having inherent flow rate characteristic 2 in Fig. 3, the valve opening is set to 50% for a required flow rate F2. These valve openings correspond to the command valve openings in Fig. 4.

[0125] The regulating valve opening on the vertical axis of Fig. 4 is the valve opening for correcting the flow characteristics that change curvilinearly with respect to the valve opening as shown in Fig. 3 into flow characteristics that change linearly. As shown in Fig. 4, one flow regulating valve has multiple correction valve opening patterns for linearizing the flow characteristics with respect to the command valve opening. In other words, the relationship between the command valve opening and the regulating valve opening for linearizing the flow characteristics is the opening characteristic. Fig. 4 shows 10 types of opening characteristics, from opening characteristic A to opening characteristic J, as examples. Note that the number of opening characteristics is not limited to 10.

[0126] In the example shown in FIG. 4, for example, if the command valve opening is 50%, there are 10 multiple correction valve opening patterns for linearizing the flow characteristics. For example, if the command valve opening is 50%, by applying a correction to opening characteristic A, the valve opening is adjusted to a control valve opening of 92%. In this case, by adjusting the valve opening to the control valve opening, a flow rate greater than the flow rate at the command valve opening is allowed to flow. Also, for example, if the command valve opening is 50%, by applying a correction to opening characteristic J, the valve opening is adjusted to a control valve opening of 8%. In this case, by adjusting the valve opening to the control valve opening, a flow rate less than the flow rate at the command valve opening is allowed to flow.

[0127] Here, for example, by applying a correction to the opening characteristic C in Figure 4 to a flow control valve having a downwardly convex inherent flow characteristic 1 in Figure 3, a flow rate greater than the flow rate at the command valve opening will be allowed to flow. In this way, by applying a correction to the downwardly convex inherent flow characteristic 1 in the upwardly convex opening characteristic C, the flow rate characteristic can be linearized as shown by the dashed dotted line in Figure 3. Note that linearizing the flow rate characteristic means linearly changing the fuel flow rate relative to the output, as described above.

[0128] For example, for a flow control valve having inherent flow rate characteristics 2 that are convex upward in Fig. 3, applying a correction to the opening characteristic G in Fig. 4 will result in a flow rate that is less than the flow rate at the command valve opening. In this way, by applying a correction to the inherent flow rate characteristics 2 that are convex upward in the opening characteristic G that is convex downward, the flow rate characteristics can be linearized as shown by the dashed dotted line in Fig. 3.

[0129] Valve control data 115 stores data for adjusting the flow characteristics of flow control valves 45 and 46 in hydrogen supply system 40 and the flow characteristics of flow control valves 75 and 76 in city gas supply system 70 based on the inherent flow characteristics and opening characteristics as described above, thereby controlling flow control valves 45, 46, 75 and 76 so that, for example, the flow rate of hydrogen gas relative to output and the flow rate of city gas relative to output change linearly while maintaining the set calorific value ratio.

[0130] As data for controlling the flow control valves 45, 46, 75 and 76, for example, control data for setting the valve opening degrees of the flow control valves 45, 46, 75 and 76 to the adjustment valve opening degrees corresponding to the output is stored.

[0131] Here, by controlling flow rate adjustment valve 45, flow rate adjustment valve 46, flow rate adjustment valve 75, and flow rate adjustment valve 76 based on the control data stored as valve control data 115, it is possible to linearly change the flow rate of hydrogen gas relative to the output and the flow rate of city gas relative to the output while maintaining the set calorific value ratio, for example, as shown in FIG. 5.

[0132] Here, the data for controlling the flow rate adjustment valves 45, 46, 75, and 76 stored in the valve control data 115 differs depending on the type of fuel, the set calorific value ratio, the inherent flow rate characteristics of each flow rate adjustment valve, and the opening characteristics of each flow rate adjustment valve. Therefore, the valve control data 115 includes a plurality of data for each combination of the type of fuel, the set calorific value ratio, and the type of flow rate adjustment valve.

[0133] Therefore, by setting the type of fuel (fuel type) (here, hydrogen gas and city gas) to be supplied to the combustion device 200, the set calorific value ratio for each fuel, and the type of flow control valve (valve type), corresponding data is selected from the preset valve control data 115. In other words, by setting the type of fuel (here, hydrogen gas and city gas) to be supplied to the combustion device 200, the set calorific value ratio for each fuel, and the type of flow control valve (valve type), it is possible to obtain preset control data for the flow control valves 45, 46, 75, and 76, which allows the flow rate of hydrogen gas relative to the output and the flow rate of city gas relative to the output to be changed linearly while maintaining the set calorific value ratio.

[0134] Here, the data stored in valve control data 115 is based on data obtained by adjusting the flow characteristics of flow control valves 45 and 46 in hydrogen supply system 40 and the flow characteristics of flow control valves 75 and 76 in city gas supply system 70 based on the inherent flow characteristics and opening characteristics for all combinations of fuel type, set calorific value ratio, and valve type, and by obtaining in advance the valve opening of each flow control valve that allows the hydrogen gas flow rate relative to output and the city gas flow rate relative to output to be changed linearly while maintaining the set calorific value ratio.

[0135] The fuel type, set calorific value ratio, and valve type that are preset to configure the valve control data 115 are set, for example, based on the fuel type, set calorific value ratio, and valve type that are expected to be used.

[0136] Here, the storage unit 110 may further store various programs and various data for operating the multi-fuel combustion fuel supply device 30 in addition to the above-mentioned data.

[0137] The calculation unit 120 executes various calculation processes and determination processes using, for example, programs and data stored in the storage unit 110. The calculation unit 120 includes a valve control data selection unit 121, a temperature determination unit 122, a heat ratio determination unit 123, and a valve control unit 124.

[0138] The valve control data selection unit 121 selects corresponding data from the valve control data 115 based on the types of the first and second fuels, the set calorific value ratio, and the types of the flow control valves 45, 46, 75, and 76. The valve control data selection unit 121, for example, references the fuel type input data 111 to obtain information on the types of the first and second fuels (hydrogen gas and city gas). The valve control data selection unit 121 also references the calorific value ratio input data 112 to obtain information on the set calorific value ratios of each fuel. The valve control data selection unit 121 references the valve type input data 113 to obtain information on each flow control valve. Then, based on the obtained information, the valve control data selection unit 121 selects data that satisfies all of this information from the preset valve control data 115. The valve control data selection unit 121 outputs information related to the selected data to the valve control unit 124.

[0139] Furthermore, the valve control data selection unit 121 selects data for controlling the valve opening degree of other valves from the valve control data 115 based on the types of the first fuel and the second fuel, the set calorific value ratio, the temperature of the combustion exhaust gas, and the like.

[0140] The temperature determination unit 122 determines whether the temperature of the combustion exhaust gas discharged from the combustion chamber 210 of the combustion device 200 is at a preset temperature based on the detection signal from the temperature detector 240 and the set temperature stored in the combustion exhaust gas temperature data 114. Specifically, the temperature determination unit 122 determines whether the temperature of the combustion exhaust gas is lower than the set temperature, whether the temperature of the combustion exhaust gas is higher than the set temperature, etc.

[0141] The calorific value ratio determination unit 123 determines whether the calorific value ratio of each fuel is the set calorific value ratio for that fuel based on the set calorific value ratio and the detection signals from the flow rate detector 48 and the flow rate detector 77. Specifically, the calorific value ratio determination unit 123 determines, for example, whether the calorific value ratio for hydrogen gas is below the set calorific value ratio for hydrogen gas or whether the calorific value ratio for hydrogen gas exceeds the set calorific value ratio for hydrogen gas. Alternatively, the calorific value ratio determination unit 123 determines, for example, whether the calorific value ratio for city gas is below the set calorific value ratio for city gas or whether the calorific value ratio for city gas exceeds the set calorific value ratio for city gas. The calorific value ratio determination unit 123 calculates the calorific value ratio of each fuel generated in the combustion device 200 based on data related to fuel characteristics in the fuel type input data 111 and the detection signals from the flow rate detector 48 and the flow rate detector 77.

[0142] Here, the calorie ratio determining unit 123 calculates the calorie ratio of each fuel based on, for example, the flow rate of each fuel.

[0143] The valve control unit 124 controls the flow control valve 45, the flow control valve 46, the flow control valve 75, the flow control valve 76, and other valves, for example, based on data selected from the valve control data 115 by the valve control data selection unit 121, in order to start or stop combustion in the combustion device 200 or to perform combustion under predetermined conditions in the combustion device 200.

[0144] For example, when the temperature determination unit 122 determines that the temperature of the combustion exhaust gas is not the set temperature, the valve control unit 124 executes control to adjust the flow rate of the hydrogen gas and the flow rate of the city gas in order to adjust the output corresponding to the heat generation amount in the combustion device 200. That is, the valve control unit 124 adjusts the flow rate of the fuel to be combusted in the combustion chamber 210 in order to adjust the temperature of the combustion exhaust gas. Note that the equivalence ratio calculated based on the flow rate of the fuel and the flow rate of the oxidizer supplied to the combustion chamber 210 is kept constant when adjusting the output. Note that the equivalence ratio is calculated by dividing the fuel-air ratio by the stoichiometric fuel-air ratio.

[0145] Specifically, when the temperature determination unit 122 determines that the temperature of the combustion exhaust gas is lower than the set temperature, the valve control unit 124 outputs control signals to increase the flow rate of hydrogen gas and the flow rate of city gas to the flow rate control valves 45, 46, 75, and 76 via the output unit 130 based on the valve control data 115. At this time, in the multi-fuel combustion oxidizer supply device 10, control is performed to increase the flow rate of the oxidizer in accordance with the increased fuel flow rate in order to maintain a constant equivalence ratio. This control to increase the flow rate of the oxidizer may be performed by the valve control unit 124.

[0146] Furthermore, when the temperature determination unit 122 determines that the temperature of the combustion exhaust gas is higher than the set temperature, the valve control unit 124 outputs control signals to the flow rate control valves 45, 46, 75, and 76 via the output unit 130 to reduce the flow rates of the hydrogen gas and the city gas, based on the valve control data 115. At this time, in the multi-fuel combustion oxidizer supply device 10, control is performed to reduce the flow rate of the oxidizer in accordance with the reduced fuel flow rate in order to maintain a constant equivalence ratio. This control to reduce the flow rate of the oxidizer may be performed by the valve control unit 124.

[0147] Furthermore, when the calorific value ratio determination unit 123 determines that the calorific value ratio of each fuel is not the set calorific value ratio of each fuel, the valve control unit 124 executes control to adjust the flow rate ratio of each fuel supplied to the combustion device 200 so that the calorific value ratio of each fuel becomes the set calorific value ratio of each fuel. The valve control unit 124 adjusts the valve opening of the calorific value ratio adjustment valve 43 or the calorific value ratio adjustment valve 73 to adjust the flow rate ratio of each fuel.

[0148] As described above, data on the fuel flow rate ratio of each fuel corresponding to the set calorific value ratio of each fuel is stored in the calorific value ratio input data 112. Based on this data, for example, a set flow rate of each fuel that satisfies the set calorific value ratio and fuel flow rate ratio of each fuel can be obtained.

[0149] For example, if the calorific value ratio determination unit 123 determines that the calorific value ratio of hydrogen gas is lower than the set calorific value ratio for hydrogen gas, the valve control unit 124 outputs a control signal to the calorific value ratio adjustment valve 43 via the output unit 130 based on the calorific value ratio input data 112, for example, to increase the flow rate ratio of hydrogen gas to city gas.

[0150] For example, if the calorific value ratio determination unit 123 determines that the calorific value ratio of hydrogen gas exceeds the set calorific value ratio for hydrogen gas, the valve control unit 124 outputs a control signal to the calorific value ratio adjustment valve 43 via the output unit 130 based on the calorific value ratio input data 112, for example, to reduce the flow rate ratio of hydrogen gas to city gas.

[0151] Note that by adjusting the calorific value ratio of hydrogen gas to the set calorific value ratio for hydrogen gas, the calorific value ratio of city gas also becomes the set calorific value ratio for city gas. While an example of adjusting the calorific value ratio of hydrogen gas to the set calorific value ratio for hydrogen gas has been shown here, the calorific value ratio adjustment valve 73 may be controlled to adjust the calorific value ratio of city gas to the set calorific value ratio for city gas. That is, the valve control unit 124 may output a control signal to the calorific value ratio adjustment valve 73 via the output unit 130, for example, to increase or decrease the flow rate ratio of city gas to hydrogen gas, based on the calorific value ratio input data 112.

[0152] The output unit 130 outputs control signals from the valve control unit 124 to the flow rate adjustment valves 45, 46, 75, 76, the heat ratio adjustment valves 43, 73, and the like, for example.

[0153] Here, the processing executed by the control device 90 described above is realized by, for example, a computer device.

[0154] (Operation of the entire combustion device system 1) Next, an overview of the overall operation of the combustion device system 1 will be described with reference to Fig. 1. Note that the description here will be given for a case in which the pilot burner 250 is provided. The operation of the multi-fuel combustion fuel supply device 30 will be described in detail later.

[0155] When the combustion device system 1 starts operating, the oxidant supply source 13 and the blower 261 are driven.

[0156] Hydrogen gas is supplied from a hydrogen supply source 49 to a pilot mixed fuel supply pipe 58 via a pilot fuel supply pipe 55. City gas is supplied from a city gas supply source 78 to a pilot mixed fuel supply pipe 58 via a pilot fuel supply pipe 80. The mixed fuel of hydrogen gas and city gas is then supplied from the pilot mixed fuel supply pipe 58 to a pilot burner 250.

[0157] Air is supplied from an oxidizer supply source 13 to a pilot burner 250 via a pilot oxidizer supply pipe 12 .

[0158] The premixed fuel and air ejected from the pilot burner 250 is ignited by an ignition device (not shown) to form a pilot flame.

[0159] Next, in accordance with a predetermined set calorific value ratio, hydrogen gas is supplied from hydrogen supply source 49 to first fuel ejection section 220 via main fuel supply pipe 41 and bypass fuel supply pipe 42, and city gas is supplied from city gas supply system 70 to second fuel ejection section 221 via main fuel supply pipe 71 and bypass fuel supply pipe 72.

[0160] Air is supplied from the oxidizer supply source 13 to the oxidizer jetting portion 230 via the oxidizer supply pipe 11 for the main burner.

[0161] The fuel gas injected into the combustion chamber 210 from the first fuel injection part 220 and the second fuel injection part 221 mixes with the oxidizer injected from the oxidizer injection part 230 to form an air-fuel mixture. The air-fuel mixture is ignited by the pilot flame, and a main flame is formed.

[0162] After combustion in the main burner 235 starts, the supply of fuel and air to the pilot burner 250 may be cut off.

[0163] Here, when the fuel supply to the pilot burner 250 is cut off, for example, the flow rate of fuel is reduced and nitrogen gas is supplied from the nitrogen gas supply source 61 to the pilot mixed fuel supply pipe 58 via the pilot burner purge gas supply pipe 63. This makes it possible to prevent the flame from flashing back into the pilot burner 250.

[0164] When combustion begins in the combustion chamber 210, the combustion gas in the combustion chamber 210 is sucked into the combustion gas exhaust pipe 260 by the suction of the blower 261. In addition, a portion of the combustion exhaust gas that has been introduced into the combustion gas utilization section 290 and utilized is returned to the combustion chamber 210 via the return pipe 271. At this time, a predetermined amount of air is introduced into the return pipe 271 via the atmosphere introduction pipe 272 and is led to the combustion chamber 210 together with the combustion exhaust gas. The combustion exhaust gas containing this air is also sucked into the combustion gas exhaust pipe 260 together with the combustion gas generated by combustion.

[0165] Here, the combustion exhaust gas in the combustion chamber 210 is sucked in by the blower 261, so the pressure in the combustion chamber 210 becomes lower than the pressure in the combustion gas utilization space of the combustion gas utilization section 290. Therefore, the combustion exhaust gas in the combustion gas utilization space is guided to the combustion chamber 210 through the return pipe 271.

[0166] The combustion exhaust gas drawn into the combustion gas exhaust pipe 260 is then guided to the combustion gas utilization section 290 .

[0167] When the fuel supply to the main burner 235 is cut off, for example, the flow rate of fuel is reduced and nitrogen gas is supplied from the nitrogen gas supply source 61 to the main fuel supply pipe 41 and the bypass fuel supply pipe 42 via the main burner purge gas supply pipe 62. This makes it possible to prevent backfire of the flame into the first fuel ejection part 220 of the main burner 235.

[0168] (Action of the multi-fuel fuel supply device 30) Next, the operation of the multi-fuel combustion fuel supply device 30 will be described.

[0169] FIG. 6 is a flowchart for explaining the fuel supply method of the multi-fuel combustion fuel supply device 30 according to the embodiment.

[0170] As shown in FIG. 6, the storage unit 110 of the control device 90 sets and stores information about each type of fuel (fuel type) input from the external input means via the input unit 100 as fuel type input data 111 (step S10).

[0171] The storage unit 110 sets and stores information about the set calorific value ratio of each fuel input from the external input means, which is input by the input unit 100, as calorific value ratio input data 112 (step S11).

[0172] The storage unit 110 sets and stores information relating to the valve type of each flow rate adjustment valve input from the external input means via the input unit 100 as valve type input data 113 (step S12).

[0173] The storage unit 110 sets and stores information relating to the set temperature of the combustion exhaust gas at the outlet of the combustion chamber 210 input from the external input means by the input unit 100 as combustion exhaust gas temperature data 114 (step S13).

[0174] Here, the processing of steps S10 to S13 is not limited to being performed in the order described above, as long as the processing of steps S10 to S13 is performed.

[0175] Next, based on the information set in steps S10 to S13, the valve control data selection unit 121 selects data that satisfies all of the information set in steps S10 to S13 from the preset valve control data 115 (step S14). Also, based on the information set in steps S10 to S13, the valve control data selection unit 121 selects data for controlling other valves from the valve control data 115. Then, the valve control data selection unit 121 outputs information related to the selected data to the valve control unit 124.

[0176] The processing of step S14 enables combustion in the main burner 235 and the pilot burner 250. After the processing of step S14, as described above, combustion starts in the pilot burner 250 and the main burner 235, and the combustion device system 1 enters an operating state (step S15).

[0177] After combustion starts, the temperature determination unit 122 determines whether the temperature of the combustion exhaust gas is higher than the set temperature based on the detection signal from the temperature detector 240 and the set temperature stored in the combustion exhaust gas temperature data 114 (step S16).

[0178] If it is determined in step S16 by temperature determination unit 122 that the temperature of the combustion exhaust gas is higher than the set temperature (Yes in step S16), valve control unit 124 performs adjustment to make the temperature of the combustion exhaust gas the set temperature (step S17). Specifically, based on valve control data 115, valve control unit 124 outputs control signals to flow rate adjustment valve 45, flow rate adjustment valve 46, flow rate adjustment valve 75, and flow rate adjustment valve 76 via output unit 130 to reduce the flow rates of hydrogen gas and city gas while maintaining the set calorific value ratios for each fuel. Then, flow rate adjustment valve 45, flow rate adjustment valve 46, flow rate adjustment valve 75, and flow rate adjustment valve 76 adjust their valve opening degrees based on the control signals.

[0179] As a result, the amount of heat generated by combustion decreases by reducing the flow rates of hydrogen gas and city gas, and the temperature of the combustion exhaust gas introduced into the combustion gas exhaust pipe 260 decreases. At this time, in the multi-fuel combustion oxidizer supply device 10, the flow rate of the oxidizer is controlled to decrease in accordance with the decreased fuel flow rate in order to maintain a constant equivalence ratio.

[0180] After the process of step S17, the process from step S16 is repeated.

[0181] If the judgment in step S16 determines that the temperature of the combustion exhaust gas is not higher than the set temperature, in other words, that the temperature of the combustion exhaust gas does not exceed the set temperature (No in step S16), the temperature judgment unit 122 determines whether the temperature of the combustion exhaust gas is lower than the set temperature based on the detection signal from the temperature detector 240 and the set temperature stored in the combustion exhaust gas temperature data 114 (step S18).

[0182] If it is determined in step S18 by temperature determination unit 122 that the temperature of the combustion exhaust gas is lower than the set temperature (Yes in step S18), valve control unit 124 executes adjustment to set the temperature of the combustion exhaust gas to the set temperature (step S19). Specifically, based on valve control data 115, valve control unit 124 outputs control signals to flow rate adjustment valve 45, flow rate adjustment valve 46, flow rate adjustment valve 75, and flow rate adjustment valve 76 via output unit 130 to increase the flow rate of hydrogen gas and the flow rate of city gas while maintaining the set calorific value ratio for each fuel. Then, flow rate adjustment valve 45, flow rate adjustment valve 46, flow rate adjustment valve 75, and flow rate adjustment valve 76 adjust their valve opening degrees based on the control signals.

[0183] As a result, the amount of heat generated by combustion increases by increasing the flow rates of hydrogen gas and city gas, and the temperature of the combustion exhaust gas introduced into the combustion gas exhaust pipe 260 rises. At this time, in the multi-fuel combustion oxidizer supply device 10, the flow rate of the oxidizer is controlled to increase in accordance with the increased fuel flow rate in order to maintain a constant equivalence ratio.

[0184] After the process of step S19, the process is repeated from step S16.

[0185] If the temperature determination unit 122 determines in step S18 that the temperature of the combustion exhaust gas is not lower than the set temperature (No in step S18), the valve control unit 124 determines whether information for stopping the operation of the combustion device system 1 has been input (step S20). The information for stopping the operation is input, for example, by an external input means. The information for stopping the operation is input by the input unit 100.

[0186] If it is determined in step S20 that information for stopping the operation of the combustion device system 1 has not been input (No in step S20), the process from step S10 is executed in the multi-combustion fuel supply device 30. Note that in the process from step S10 when the combustion device system 1 is operating, the process of step S15 is not executed.

[0187] If it is determined in step S20 that information for stopping the operation of the combustion device system 1 has been input (Yes in step S20), the valve control unit 124 outputs a control signal for stopping the operation of the combustion device system 1 to each flow rate control valve and other valves in the combustion device system 1 via the output unit 130 (step S21). By the processing of step S21, the combustion device system 1 is stopped, and the above series of processing ends.

[0188] Furthermore, in the operation of the multi-fuel combustion fuel supply device 30, after the processing of step S15 (after the start of combustion) described above, processing related to the calorific value ratio is executed in addition to the processing related to the temperature of the combustion exhaust gas described above.

[0189] 7 is a flowchart for explaining the process related to the calorific value ratio in the fuel supply method of the multi-fuel combustion fuel supply device 30 according to the embodiment. Note that this example shows an example in which the process related to the calorific value ratio adjusts the calorific value ratio of hydrogen gas to the set calorific value ratio for hydrogen gas, and as a result, the calorific value ratio of city gas is also adjusted to the set calorific value ratio for city gas.

[0190] As shown in FIG. 7, the calorie ratio determining unit 123 receives the detection signals from the flow rate detector 48 and the flow rate detector 77 via the input unit 100 (step S30).

[0191] The calorific value ratio determination unit 123 calculates the calorific value ratio of each fuel generated in the combustion device 200 based on the fuel type input data 111 and detection signals from the flow rate detector 48 and the flow rate detector 77 (step S31). At this time, the calorific value ratio determination unit 123 obtains information such as the type of fuel being used and fuel characteristics based on the fuel type input data 111.

[0192] Next, the calorie ratio determination unit 123 determines whether the calorie ratio of hydrogen gas exceeds the set calorie ratio for hydrogen gas based on the calorie ratio of each fuel calculated in step S31 and the calorie ratio input data 112 (step S32).

[0193] If the calorific value ratio determination unit 123 determines in step S32 that the calorific value ratio of hydrogen gas exceeds the set calorific value ratio for hydrogen gas (Yes in step S32), the valve control unit 124 outputs a control signal to the calorific value ratio adjustment valve 43 via the output unit 130 to reduce the flow rate ratio of hydrogen gas to city gas based on the calorific value ratio input data 112 (step S33). Then, the calorific value ratio adjustment valve 43 adjusts the valve opening based on the control signal. Note that by adjusting the calorific value ratio of hydrogen gas to the set calorific value ratio for hydrogen gas, the calorific value ratio of city gas also becomes the set calorific value ratio for city gas.

[0194] After the process of step S33, the process from step S30 is repeated.

[0195] If it is determined in step S32 that the calorific value ratio of the hydrogen gas does not exceed the set calorific value ratio for the hydrogen gas (No in step S32), the calorific value ratio determination unit 123 determines whether the calorific value ratio of the hydrogen gas is below the set calorific value ratio for the hydrogen gas (step S34).

[0196] If the calorific value ratio determination unit 123 determines in step S34 that the calorific value ratio of hydrogen gas is lower than the set calorific value ratio for hydrogen gas (Yes in step S34), the valve control unit 124 outputs a control signal to the calorific value ratio adjustment valve 43 via the output unit 130 to increase the flow rate ratio of hydrogen gas to city gas based on the calorific value ratio input data 112 (step S35). Then, the calorific value ratio adjustment valve 43 adjusts the valve opening based on the control signal. Note that by adjusting the calorific value ratio of hydrogen gas to the set calorific value ratio for hydrogen gas, the calorific value ratio of city gas also becomes the set calorific value ratio for city gas.

[0197] After the process of step S35, the process from step S30 is repeated.

[0198] If the calorific value ratio determination unit 123 determines in step S34 that the calorific value ratio of hydrogen gas is not below the set calorific value ratio for hydrogen gas (No in step S34), the process related to the calorific value ratio ends. In this case, the multi-combustion fuel supply device 30 may execute the process from step S30 again.

[0199] In the above-described process related to the calorific value ratio, the calorific value ratio of each fuel is adjusted to the set calorific value ratio for that fuel. At this time, the flow rate of the fuel may be increased or decreased by adjusting the calorific value ratio of each fuel. This increase or decrease in the flow rate of the fuel may change the temperature of the combustion exhaust gas discharged from the combustion chamber 210, but the temperature of the combustion exhaust gas is adjusted to the set temperature by the process from step S16, which is the process related to the temperature of the combustion exhaust gas shown in FIG. 6 described above.

[0200] Here, an example has been shown in which, in the process related to the calorific value ratio, the calorific value ratio of hydrogen gas is adjusted to the set calorific value ratio for hydrogen gas, and as a result, the calorific value ratio of city gas is also adjusted to the set calorific value ratio for city gas, but in the process related to the calorific value ratio shown in Figure 7, the calorific value ratio of city gas may be adjusted to the set calorific value ratio for city gas. In other words, by adjusting the calorific value ratio of city gas to the set calorific value ratio for city gas, the calorific value ratio of hydrogen gas may also be adjusted to the set calorific value ratio for hydrogen gas.

[0201] As described above, the multi-fuel combustion fuel supply device 30 of the embodiment is provided with valve control data 115 that stores data for controlling the flow control valves 45, 46, 75, and 76 by adjusting the flow characteristics of the flow control valves 45 and 46 in the hydrogen supply system 40 and the flow characteristics of the flow control valves 75 and 76 in the city gas supply system 70 so that the flow rate of hydrogen gas relative to the output and the flow rate of city gas relative to the output are changed while maintaining the set calorific value ratio.

[0202] In addition, data for controlling flow control valve 45, flow control valve 46, flow control valve 75, and flow control valve 76 is stored as valve control data 115 so that the flow rate of hydrogen gas relative to output and the flow rate of city gas relative to output change linearly.

[0203] Valve control data 115 stores data for controlling each flow control valve so that the flow rate of each fuel relative to the output changes linearly while maintaining the set calorific value ratio for all combinations of fuel type, set calorific value ratio, and type of flow control valve.

[0204] Furthermore, the flow rate of hydrogen gas relative to the output and the flow rate of city gas relative to the output can be changed linearly while maintaining the set calorific value ratio by controlling flow rate adjustment valves 45, 46, 75, and 76 based on valve control data 115. This makes it possible to easily change the flow rate of hydrogen gas and the flow rate of city gas according to the output while maintaining the set calorific value ratio for each fuel at a predetermined ratio.

[0205] In addition, by setting the type of fuel to be supplied to the combustion device 200, the set calorific value ratio for each fuel, and the type of flow control valve, and selecting corresponding data from the pre-set valve control data 115, it is possible to obtain control information for each flow control valve 45, 46, 75, 76 to linearly change the flow rate of hydrogen gas relative to the output and the flow rate of city gas relative to the output while maintaining the set calorific value ratio.

[0206] By adjusting the fuel flow rate by controlling both flow rate adjustment valves 45 and 46 in the hydrogen supply system 40 and both flow rate adjustment valves 75 and 76 in the city gas supply system 70 regardless of the flow rate, it is possible to obtain a relationship in which the relationship between output and fuel flow rate changes along a predetermined straight line. In other words, except when either fuel is shut off, the valve openings of flow rate adjustment valves 45 and 46 and flow rate adjustment valves 75 and 76 are always controlled to adjust the fuel flow rate.

[0207] Furthermore, in the multi-fuel combustion fuel supply device 30, by executing the process related to the temperature of the combustion exhaust gas shown in FIG. 6 as well as the process related to the calorific value ratio shown in FIG. 7, it is possible to maintain the temperature of the combustion exhaust gas at a set temperature while maintaining the calorific value ratio of each fuel at the set calorific value ratio for each fuel.

[0208] Furthermore, the valve control data 115 stores data for controlling each flow rate control valve for all combinations of fuel type, set calorific value ratio, and type of flow rate control valve. Therefore, even when operating with different combinations of fuel type, set calorific value ratio, and type of flow rate control valve, it is possible to easily adjust the fuel flow rate while maintaining the calorific value ratio for each fuel at the set calorific value ratio for each fuel, while maintaining the above-mentioned effects.

[0209] (Other embodiments) Here, the above-described combustion device system 1 may be configured to utilize exhaust gas recirculation (EGR) in which part of the combustion gas generated in the combustion chamber 210 is mixed with the oxidizer.

[0210] For example, an EGR pipe (not shown) is provided that introduces a portion of the combustion gas in the combustion chamber 210 into the main burner oxidizer supply pipe 11. When exhaust gas recirculation (EGR) is used, in FIG. 1, one end of the EGR pipe opens into the combustion chamber 210, and the other end of the EGR pipe is connected to the main burner oxidizer supply pipe 11. The other end of the EGR pipe is connected to the main burner oxidizer supply pipe 11 between the flow rate adjustment valve 14 and the main burner 235.

[0211] The EGR piping is equipped with a blower for extracting combustion gas from inside the combustion chamber 210 to the oxidizer supply pipe 11 for the main burner, and a flow control valve for adjusting the flow rate of the combustion gas introduced into the oxidizer supply pipe 11 for the main burner.

[0212] It is preferable to use exhaust gas recirculation (EGR) when, for example, air is used as an oxidizer and the set calorific value ratio of hydrogen gas is high during operation of the combustion device system 1. By using exhaust gas recirculation (EGR) under these combustion conditions, it is possible to suppress NOx generated by combustion and reduce the NOx concentration in the combustion gas.

[0213] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0214] 1...Combustion system, 10...Oxidizer supply device for multi-combustion, 11...Oxidizer supply pipe for main burner, 12...Oxidizer supply pipe for pilot, 13...Oxidizer supply source, 14, 15, 16, 45, 46, 57, 65, 67, 75, 76, 82...Flow control valve, 30...Fuel supply device for multi-combustion, 40...Hydrogen supply system, 41...Main fuel supply pipe, 42...Bypass fuel supply pipe, 43, 73...Heat ratio control valve, 44, 56, 6 4, 66, 74, 81...Shut-off valve, 47...Governor, 48...Flow detector, 49...Hydrogen supply source, 55, 80...Pilot fuel supply pipe, 58...Pilot mixed fuel supply pipe, 60...Purge gas supply pipe, 61...Purge gas supply source, 62...Main burner purge gas supply pipe, 63...Pilot burner purge gas supply pipe, 70...City gas supply system, 71...Main fuel supply pipe, 72...Bypass fuel supply pipe, 7 7...flow rate detector, 78...city gas supply source, 90...control device, 100...input section, 110...memory section, 111...fuel type input data, 112...calorific value ratio input data, 113...valve type input data, 114...combustion exhaust gas temperature data, 115...valve control data, 120...calculation section, 121...valve control data selection section, 122...temperature determination section, 123...calorific value ratio determination section, 124...valve control section, 130...output section, 200...fuel Combustion device, 210...combustion chamber, 220...first fuel injection section, 221...second fuel injection section, 230...oxidizer injection section, 235...main burner, 240...temperature detector, 250...pilot burner, 260...combustion gas exhaust pipe, 261...blower, 270...combustion exhaust gas return system, 271...return piping, 272...atmospheric air introduction pipe, 273...flow rate adjustment section, 290...combustion gas utilization section, C1, C2, C3, C4...connecting sections.

Claims

1. A fuel supply device for multi-fuel combustion that supplies fuel to a combustion device capable of multi-fuel combustion, a first fuel supply system that supplies a first fuel; a second fuel supply system that supplies a second fuel; a control device for adjusting the flow rates of the first fuel and the second fuel; Equipped with The first fuel supply system includes: a first main fuel supply pipe provided with a first flow rate regulating valve that regulates the flow rate of the first fuel; a first bypass fuel supply pipe including a second flow rate adjustment valve that adjusts a flow rate of the first fuel, the first bypass fuel supply pipe bypassing the first flow rate adjustment valve and connected to the first main fuel supply pipe; a first heat amount ratio adjustment valve that is provided in the first main fuel supply pipe between the combustion device and a first connecting portion of the connecting portion between the first bypass fuel supply pipe and the first main fuel supply pipe that is on the combustion device side, and the first main fuel supply pipe, and that has a valve opening set based on a preset heat amount ratio that indicates a ratio of the heat amounts of the fuels in the combustion device; Equipped with The second fuel supply system includes: a second main fuel supply pipe provided with a third flow rate regulating valve for regulating the flow rate of the second fuel; a second bypass fuel supply pipe including a fourth flow rate adjustment valve that adjusts a flow rate of the second fuel, the second bypass fuel supply pipe bypassing the third flow rate adjustment valve and connected to the second main fuel supply pipe; a second heat quantity ratio adjustment valve that is provided in the second main fuel supply pipe between the combustion device and a second connecting portion of the connecting portion between the second bypass fuel supply pipe and the second main fuel supply pipe, the second connecting portion being on the combustion device side, and the combustion device, and the second heat quantity ratio adjustment valve has a valve opening degree that is set based on the set heat quantity ratio; Equipped with The control device valve control data that is set based on the types of the first fuel and the second fuel, the set calorific value ratio, inherent flow characteristics that indicate the relationship between valve opening and flow rate in the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve, and opening characteristics that indicate the relationship between command valve opening and control valve opening in the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve, and that is used to control the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve so that the flow rate of the first fuel relative to an output corresponding to a calorific value in the combustion device and the flow rate of the second fuel relative to the output are changed while maintaining the set calorific value ratio; a valve control data selection unit that selects corresponding data from the valve control data based on the types of the first fuel and the second fuel, the set calorific value ratio, and the types of the first flow rate adjustment valve, the second flow rate adjustment valve, the third flow rate adjustment valve, and the fourth flow rate adjustment valve; a temperature determination unit that determines whether the temperature of the combustion exhaust gas discharged from the combustion device is a preset temperature; a valve control unit that, when the temperature determination unit determines that the temperature of the combustion exhaust gas is not the set temperature, controls the first flow rate adjustment valve, the second flow rate adjustment valve, the third flow rate adjustment valve, and the fourth flow rate adjustment valve based on the data selected by the valve control data selection unit to adjust the temperature of the combustion exhaust gas to the set temperature; A multi-fuel fuel supply device comprising:

2. 2. The multi-fuel fuel supply system according to claim 1, wherein the flow rate of the first fuel relative to the output and the flow rate of the second fuel relative to the output change linearly.

3. the multi-combustion fuel supply device further includes a calorific value ratio determination unit that determines whether the calorific value ratio of each fuel is the set calorific value ratio based on the set calorific value ratio, a flow rate of the first fuel and a flow rate of the second fuel supplied to the combustion device, 3. The multi-fuel combustion fuel supply device according to claim 1, wherein, when the calorific value ratio determination unit determines that the calorific value ratio of each fuel is not the set calorific value ratio, the valve control unit controls the first calorific value ratio adjustment valve or the second calorific value ratio adjustment valve to adjust the calorific value ratio of each fuel to the set calorific value ratio for each fuel.

4. A fuel supply method for a multi-fuel fuel supply device that supplies fuel to a combustion device capable of multi-fuel combustion, comprising: The multi-fuel fuel supply device includes: a first fuel supply system that supplies a first fuel; a second fuel supply system that supplies a second fuel; a control device for adjusting the flow rates of the first fuel and the second fuel; Equipped with The first fuel supply system includes: a first main fuel supply pipe provided with a first flow rate regulating valve that regulates the flow rate of the first fuel; a first bypass fuel supply pipe including a second flow rate adjustment valve that adjusts a flow rate of the first fuel, the first bypass fuel supply pipe bypassing the first flow rate adjustment valve and connected to the first main fuel supply pipe; a first heat amount ratio adjustment valve that is provided in the first main fuel supply pipe between the combustion device and a first connecting portion of the connecting portion between the first bypass fuel supply pipe and the first main fuel supply pipe that is on the combustion device side, and the first main fuel supply pipe, and that has a valve opening set based on a preset heat amount ratio that indicates a ratio of the heat amounts of the fuels in the combustion device; Equipped with The second fuel supply system includes: a second main fuel supply pipe provided with a third flow rate regulating valve for regulating the flow rate of the second fuel; a second bypass fuel supply pipe including a fourth flow rate adjustment valve that adjusts a flow rate of the second fuel, the second bypass fuel supply pipe bypassing the third flow rate adjustment valve and connected to the second main fuel supply pipe; a second heat quantity ratio adjustment valve that is provided in the second main fuel supply pipe between the combustion device and a second connecting portion of the connecting portion between the second bypass fuel supply pipe and the second main fuel supply pipe, the second connecting portion being on the combustion device side, and the combustion device, and the second heat quantity ratio adjustment valve has a valve opening degree that is set based on the set heat quantity ratio; Equipped with the control device stores valve control data that is set based on the types of the first fuel and the second fuel, the set calorific value ratio, inherent flow characteristics that indicate the relationship between valve opening and flow rate in the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve, and opening characteristics that indicate the relationship between command valve opening and control valve opening in the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve, and that is used to control the first flow control valve, the second flow control valve, the third flow control valve, and the fourth flow control valve so that the flow rate of the first fuel relative to an output corresponding to a calorific value in the combustion device and the flow rate of the second fuel relative to the output are changed while maintaining the set calorific value ratio; the control device selects corresponding data from the valve control data based on the types of the first fuel and the second fuel, the set calorific value ratio, and the types of the first flow rate adjustment valve, the second flow rate adjustment valve, the third flow rate adjustment valve, and the fourth flow rate adjustment valve; The control device determines whether or not the temperature of the combustion exhaust gas discharged from the combustion device is a preset temperature, a control unit that controls the first flow rate control valve, the second flow rate control valve, the third flow rate control valve, and the fourth flow rate control valve based on data selected from the valve control data, to adjust the temperature of the combustion exhaust gas to the set temperature.

5. 5. The fuel supply method for a multi-fuel combustion fuel supply system according to claim 4, wherein the flow rate of the first fuel relative to the output and the flow rate of the second fuel relative to the output change linearly.

6. the control device determines whether a calorific value ratio of each fuel is the set calorific value ratio based on a flow rate of the first fuel and a flow rate of the second fuel supplied to the combustion device; 6. The fuel supply method in a multi-fuel combustion fuel supply system according to claim 4, wherein, when it is determined that the calorific value ratio of each fuel is not the set calorific value ratio, the control device controls the first calorific value ratio adjustment valve or the second calorific value ratio adjustment valve to adjust the calorific value ratio of each fuel to the set calorific value ratio for each fuel.

Images