JP7083211B1 - Combustion device and combustion system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion device and a combustion system in which the usage rate of ammonia as a fuel is increased. SOLUTION: A combustion device 100 has a combustion space forming unit 1 forming a first combustion space S1 for burning ammonia as a first fuel or a second fuel different from the fuel as a fuel, and a combustion space forming unit 1. A fuel supply unit 2 for supplying fuel, an ammonia supply unit 3 for supplying ammonia to the fuel supply unit 2, and a second fuel supply unit 4 for supplying a second fuel to the fuel supply unit are provided, and the ammonia supply unit 3 is provided. Has a heat exchange unit 30 for heating ammonia, and supplies the ammonia heated by the heat exchange unit 30 to the fuel supply unit 2. [Selection diagram] Fig. 1

Description

The present invention relates to a combustion device and a combustion system.

Patent Document 1 states that precautions should be taken to prevent fires and explosions during transportation because there is a potential for fires and explosions on the transport vessels during the transportation of hydrocarbon products by marine vessels. , It is stated that the SOLAS Convention requires ships such as tankers to be equipped with an inert gas system. It also states that the exhaust gas from a diesel engine may be washed and the washed gas may be used as an inert gas. Also, although cleaned gas is an inexpensive inert gas source, cleaning systems may not be completely effective in removing carbon dioxide, nitrogen oxides, and sulfur oxides, and carbon dioxide in the cleaned gas. It is pointed out that carbon can lead to corrosion of the tank.

Patent Document 2 describes a coal combustion device capable of co-firing ammonia. The coal combustion device includes a tubular furnace body and a burner connected to the end of the tubular furnace body 1. The burner is provided with an air-fuel mixture flow path having a double-tube structure, and an ammonia flow path for sending ammonia as fuel is provided in the center of the air-fuel mixture flow path. A pulverized coal flow path for sending pulverized coal as fuel is provided outside the ammonia channel, and a pulverized coal supply path for transporting pulverized coal and primary air to the pulverized coal channel is connected to the pulverized coal channel. .. A two-stage combustion air supply means for supplying air for two-stage combustion is provided on the wake side of the furnace body. Compared to hydrogen and other hydrocarbon-based fuels, ammonia is harder to ignite and has the problem of slower combustion speed. It can be used as part of the fuel. When pulverized coal and ammonia are used as fuels, it is stated that ammonia is used, for example, at a calorific value ratio of 20%.

Non-Patent Document 1 describes an inert gas device that produces a gas having a low oxygen concentration as an inert gas. As an inert gas device, a device that produces an inert gas using the exhaust gas of a boiler, or a device that independently burns fuel to produce an inert gas can produce a cleaner inert gas. The device is described. It is exemplified that the Inactive gas produced by these Inactive gas devices is used to prevent ignition explosion in the cargo tank of a tanker carrying flammable dangerous goods such as crude oil.

Japanese Unexamined Patent Publication No. 2010-269788 Japanese Unexamined Patent Publication No. 2018-96680

Inert gas device, Kashiwa Tech Co., Ltd., [Searched on January 18, 3rd year of Reiwa], Internet <https://kashiwa-tech.co.jp/inert-gas/>

For the purpose of reducing greenhouse gas emissions such as carbon dioxide (so-called carbon neutral), it is desired to reduce the amount of fossil fuel used in various combustion devices. In addition, reduction of carbon dioxide emissions is desired from the viewpoint of use as an inert gas generator for ships. As an example of a fuel that replaces fossil fuel in a combustion device, for example, as described in Patent Document 2, a technique of mixing fossil fuel and ammonia and burning them is known. However, in the prior art, the usage rate of ammonia as a fuel (for example, the calorific value ratio) could not be sufficiently increased, and the reduction of carbon dioxide emissions was not sufficient. Therefore, it is desired to provide a combustion device having a high ammonia usage rate.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a combustion device and a combustion system in which the usage rate of ammonia as a fuel is increased.

The combustion device according to the present invention for achieving the above object is
A combustion space forming unit that forms a first combustion space for burning ammonia as a first fuel or a second fuel different from the ammonia as a fuel.
A fuel supply unit that supplies the fuel to the combustion space forming unit,
An ammonia supply unit that supplies the ammonia to the fuel supply unit,
A second fuel supply unit that supplies the second fuel to the fuel supply unit is provided.
The ammonia supply unit
It has a heat exchange unit that heats the ammonia.
The ammonia heated in the heat exchange section is supplied to the fuel supply section.

The combustion system according to the present invention for achieving the above object is
With the above-mentioned combustion device,
It is equipped with a combustion vessel to which the combustion device is attached and forms a second combustion space.
The combustion container accommodates the combustion space forming portion in the second combustion space.

It is possible to provide a combustion device and a combustion system in which the usage rate of ammonia as a fuel is increased.

It is explanatory drawing of the structure of the combustion system of 1st Embodiment. It is explanatory drawing of the structure of the combustion system of the modification 1 of 1st Embodiment. It is explanatory drawing of the structure of the combustion system of the modification 2 of 1st Embodiment. It is explanatory drawing of the structure of the combustion system of 2nd Embodiment.

A combustion apparatus and a combustion system according to an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment)
(Explanation of outline)
FIG. 1 shows an explanatory diagram of the configuration of the combustion system 200 according to the present embodiment.

The combustion system 200 includes a combustion device 100 and a combustion container 9 in which the combustion device 100 is mounted.

The combustion device 100 supplies fuel to the combustion space forming unit 1 forming the first combustion space S1 for burning ammonia as the first fuel or a second fuel different from the ammonia as the fuel, and the combustion space forming unit 1. It includes a fuel supply unit 2, an ammonia supply unit 3 that supplies ammonia to the fuel supply unit 2, and a second fuel supply unit 4 that supplies a second fuel to the fuel supply unit 2.

The ammonia supply unit 3 has a heat exchange unit 30 for heating ammonia, and supplies the ammonia heated by the heat exchange unit 30 to the fuel supply unit 2.

The combustion container 9 to which the combustion device 100 is mounted forms an in-furnace space S. The combustion container 9 accommodates the combustion space forming portion 1 of the combustion device 100 in the furnace space S.

The combustion device 100 and the combustion system 200 including the combustion device 100 can realize combustion with an increased usage rate of ammonia as a fuel. For example, not only the mixed combustion of ammonia and the second fuel is possible, but also the combustion of ammonia alone can be performed.

(Explanation of each part)
As described above, the combustion device 100 includes a combustion space forming unit 1, a fuel supply unit 2 that supplies fuel and oxygen transport gas to the combustion space forming unit 1, an ammonia supply unit 3, and a second fuel supply unit 4. Further, an oxygen transport gas supply unit 20 for supplying oxygen transport gas to the fuel supply unit 2 and a return path 5 for supplying combustion exhaust gas to the fuel supply unit 2 are provided. The combustion device 100 is a burner that burns ammonia as a first fuel or a second fuel different from the ammonia as a fuel. An example of the second fuel is a fossil fuel, for example, a petroleum fuel such as heavy oil A (hereinafter, simply referred to as heavy oil), or a hydrocarbon gas fuel such as natural gas or propane gas. In the following, a case where the second fuel is heavy oil will be described as an example.

The combustion system 200 supplies oxygen transport gas to the combustion device 100, the ammonia supply system system 6 that supplies ammonia to the combustion device 100, the second fuel supply system 7 that supplies heavy oil to the combustion device 100, and the combustion device 100. It includes an oxygen transport gas supply system 8 to be supplied, a combustion container 9 to which a combustion device 100 is mounted, and a control unit C for controlling the operation of each unit. The oxygen transport gas is a gas that transports oxygen for combustion (that is, a gas that contains oxygen), and is air as an example in the present embodiment. In the following, a case where the oxygen transport gas is air will be described as an example.

The control unit C is a functional unit that is a central control mechanism of the combustion system 200 that controls the operation of the combustion system 200. The control unit C receives information related to the operation status and the detection status from each unit of the combustion system 200 and each sensor, and sends an operation command to each unit to control their operation.

The control unit C is realized by hardware or software by a CPU or a program (software) that causes the CPU to control the combustion system 200. In the present embodiment, the control unit C is realized by a computer such as a personal computer or a PLC and control software stored in the storage unit thereof. The control unit C is communicably connected to each unit of the combustion system 200 via a communication path including a port, a bus, a wired or wireless network (including an Internet line), and the like. As the storage unit, a storage device or a storage medium that can be used in a computer or the like, such as a flash memory such as a so-called USB memory, a hard disk, an optical disk such as an SSD or a CDROM, can be generally used.

The combustion container 9 is a container that forms a space (hereinafter, referred to as a furnace space S) for combustion by the combustion device 100. The combustion container 9 is formed in the shape of a bottomed cylinder as an example. FIG. 1 shows a case where the combustion container 9 has a bottom wall 91 of a bottomed cylinder and a tubular cylinder wall portion 90, and the combustion device 100 is fixed to the bottom wall 91. The combustion container 9 may have a temperature sensor 99 that measures the temperature of the combustion exhaust gas. The combustion space forming portion 1 of the combustion device 100 is fixed to the inside of the cylinder of the combustion container 9 in the bottom wall 91 and is housed in the furnace space S. The fuel supply unit 2 is fixed on the side of the bottom wall 91 opposite to the side on which the combustion space forming portion 1 is fixed. In the following description, the flow direction of the supply of fuel and oxygen transport gas from the fuel supply unit 2 to the combustion space forming unit 1 and the direction along the flow direction may be simply referred to as a flow direction. Further, the downstream side of the flow of fuel or oxygen transport gas is simply referred to as the downstream side, and the upstream side of the flow is simply referred to as the upstream side. That is, the combustion space forming unit 1 is on the downstream side when viewed from the fuel supply unit 2. On the contrary, the fuel supply unit 2 is on the upstream side when viewed from the combustion space forming unit 1.

The temperature of the combustion exhaust gas in the combustion container 9 can reach 1200 ° C. to 1500 ° C. in the combustion state of the heavy oil alone. The temperature of the combustion exhaust gas in the combustion container 9 can reach around 800 ° C. in the mixed combustion state of heavy oil and ammonia. The temperature of the combustion exhaust gas in the combustion container 9 can reach 600 ° C. to 800 ° C. in the combustion state of ammonia alone.

The combustion space forming portion 1 has a tubular portion 10 and a pilot burner 19 fixed to the tubular portion 10.

The tubular portion 10 is a wall member that partitions the first combustion space S1 for burning fuel in the furnace space S. The tubular portion 10 is a so-called burner cone. The internal space of the cylinder of the tubular portion 10 is the first combustion space S1. Fuel and air are supplied from the fuel supply unit 2 to the first combustion space S1 of the tubular portion 10. The tubular portion 10 has a circular cross section in the axial direction of the cylinder, that is, along the flow direction. The tubular portion 10 may have a trumpet-shaped shape in which the inner diameter increases from the upstream side to the downstream side in a cross section along the flow direction.

The pilot burner 19 is an ignition device that ignites and burns a pilot fire in the first combustion space S1 at the start of combustion of the combustion device 100. When the combustion device 100 starts combustion, the pilot burner 19 ignites the fuel supplied from the fuel supply unit 2 to the tubular portion 10 by the pilot fire, and realizes the combustion start by the combustion device 100. After ignition by the pilot burner 19, the combustion device 100 can continue combustion without a pilot fire by the pilot burner 19 due to the fuel and air continuously supplied to the tubular portion 10.

The flame generated in the combustion space forming portion 1 burns in the combustion vessel 9, that is, in the furnace space S. A part of the combustion exhaust gas generated in the combustion container 9 is returned to the fuel supply unit 2 as described later. The other combustion exhaust gas is discharged from the combustion container 9 and then discharged to the outside of the combustion system 200. The combustion exhaust gas discharged from the combustion system 200 is purified as necessary and used as an inert gas for ships and the like. Further, the combustion exhaust gas discharged from the combustion system 200 is used as a heat source as needed.

Ammonia supply unit 3, a second fuel supply unit 4 for supplying heavy oil, an oxygen transport gas supply unit 20, and a return path 5 are connected to the fuel supply unit 2, and ammonia, heavy oil, air, and combustion are connected. Exhaust gas can be supplied. The fuel supply unit 2 supplies the supplied ammonia or a mixed gas of heavy oil and air to the combustion space forming unit 1. The ammonia supply unit 3, the second fuel supply unit 4, and the oxygen transfer gas supply unit 20 are charged with ammonia and heavy oil from the ammonia supply system system 6, the second fuel supply system 7, and the oxygen transfer gas supply system 8, which will be described later, respectively. And air is supplied.

The fuel supply unit 2 has a mixing mechanism for mixing ammonia or heavy oil, air, and combustion exhaust gas to form a mixed gas. FIG. 1 illustrates a case where the mixing mechanism is an ejector mechanism that mixes air with heavy oil or ammonia by the energy of the air flow of air supplied from the oxygen transport gas supply system 8 and sends the mixed gas to the combustion space forming portion 1. Is shown.

The fuel supply unit 2 is a diffuser unit that communicates and connects the suction chamber 22, the nozzle portion 21 for blowing air into the suction chamber 22, the downstream side of the suction chamber 22, and the upstream side of the cylindrical portion 10 as the above-mentioned ejector mechanism. 23 and.

The suction chamber 22 is a container that forms a space where air, fuel, and the like meet. The nozzle portion 21 has a nozzle shape in which the tip side from which air is ejected is narrowed down, and the tip of the nozzle is housed in the suction chamber 22. An oxygen transport gas supply unit 20 is connected to the nozzle unit 21, so that pressurized air is supplied.

In the present embodiment, the diffuser portion 23 is an opening formed in the suction chamber 22 that communicates the inside of the suction chamber 22 and the inside of the cylinder of the tubular portion 10, and is downstream of the nozzle portion 21 in the air injection direction. It is placed on the side. The opening diameter of the diffuser portion 23 is larger than the opening diameter of the nozzle tip of the nozzle portion 21.

In the fuel supply unit 2, a venturi effect is generated by the nozzle unit 21, the suction chamber 22, the diffuser unit 23, and the air flow of the pressurized air, and the fluid in the suction chamber 22 passes through the diffuser unit 23 to form a cylinder. While being attracted to the shape portion 10, it is dispersed and mixed to form a mixed gas (gas-like mixed gas or gas-liquid mixed phase flow of atomized heavy oil and air). Further, due to this attraction, the inside of the suction chamber 22 becomes negative pressure.

In addition to the nozzle section 21, the suction chamber 22 is connected to the ammonia supply section 3, the second fuel supply section 4 for supplying heavy oil, and the return path 5, and is connected to air, ammonia, and heavy oil. , And combustion exhaust gas can be supplied. In the suction chamber 22 and the diffuser portion 23, air, ammonia, heavy oil, and combustion exhaust gas are mixed by the energy of the air flow of air blown into the suction chamber 22 from the nozzle portion 21. In the present embodiment, as will be described later, a return path 5 is directly connected to the suction chamber 22, an ammonia supply section 3 and a second fuel supply section 4 are connected to the return path 5, and ammonia and heavy oil are returned. It is supplied to the suction chamber 22 via the road 5.

The return path 5 is a tubular piping member that supplies combustion exhaust gas to the fuel supply unit 2. In the return path 5, one end of the suction port for sucking the combustion exhaust gas is arranged in the combustion container 9 and communicates with the furnace space S. The other end of the return path 5 with respect to the suction port is connected to the suction chamber 22 and communicates with the space inside the suction chamber 22. The suction port of the return path 5 may be arranged, for example, on the downstream side of the tubular portion 10 and at a position adjacent to the tubular portion 10. As a result, the combustion device 100 can be miniaturized.

As described above, since the suction chamber 22 has a negative pressure, the return path 5 can suck the combustion exhaust gas from the combustion vessel 9 and supply it to the suction chamber 22 due to the pressure difference from the inside of the combustion vessel 9. In the following, the combustion exhaust gas supplied in the combustion container 9 or the suction chamber 22 may be simply referred to as a return gas. Further, the effect of sucking the return path 5 by the negative pressure of the suction chamber 22 in the ejector mechanism may be referred to as a suction effect. The return passage 5 may be provided with a flow rate adjusting valve 51 (so-called damper) such as a slide valve or a butterfly valve that adjusts the opening degree of the valve to adjust the flow rate of the return gas. The return passage 5 may have a temperature sensor 59 for measuring the temperature of the return gas on the upstream side of the flow rate adjusting valve 51.

The ammonia supply unit 3 is a mechanism for supplying the heated ammonia gas to the fuel supply unit 2. The ammonia supply unit 3 supplies the heat exchange unit 30 that heats the ammonia supplied from the ammonia supply system system 6 by heat exchange in the combustion vessel 9 and the ammonia heated by the heat exchange unit 30 to the fuel supply unit 2. It has an ammonia pipe 31 to be used.

The heat exchange unit 30 is a member having a heat exchanger or the like. The heat exchange unit 30 may have, for example, a heat exchanger in which a metal tube through which ammonia can flow is wound in a coil shape. The heat exchange unit 30 is arranged, for example, on the downstream side of the flow of the combustion exhaust gas generated in the combustion space forming unit 1, and heat exchanges with the combustion exhaust gas, that is, takes in the heat of the combustion exhaust gas and heats the ammonia. The heat exchange unit 30 may be arranged immediately after the downstream side of the combustion space forming unit 1, for example, and may be directly exposed to the flame ejected from the combustion space forming unit 1 into the furnace space S. With such an arrangement, the heat exchange unit 30 can efficiently heat ammonia. The heat exchange unit 30 may be arranged at a position where it is not directly exposed to the flame ejected from the combustion space forming unit 1 into the furnace space S, and may exchange heat with the combustion exhaust gas. By doing so, the life of the heat exchange unit 30 may be extended.

As described above, in the present embodiment, the ammonia supply unit 3 is connected to the return path 5, and ammonia is supplied to the fuel supply unit 2 via the return path 5. In FIG. 1, as an example, an ammonia supply port 32 of an ammonia pipe 31 is connected between a suction chamber 22 and a flow rate adjusting valve 51 in the return passage 5, and ammonia is supplied from the ammonia pipe 31 to the return passage 5. Shows the case. Further, FIG. 1 illustrates a case where a temperature sensor 39 for measuring the temperature of ammonia is provided between the ammonia supply port 32 and the heat exchange unit 30 in the ammonia pipe 31.

The ammonia supply unit 3 heats the ammonia to a high temperature by the heat exchange unit 30, thereby facilitating the combustion of the ammonia in the combustion space forming unit 1 and enabling the combustion of the ammonia alone. In the heat exchange unit 30, ammonia is heated from 400 ° C. to 800 ° C. Ammonia is preferably heated to 500 ° C. or higher. When ammonia is heated to 500 ° C. or higher, the combustion stability during combustion of ammonia alone is improved.

The second fuel supply unit 4 is a mechanism for supplying heated heavy oil to the fuel supply unit 2. The second fuel supply unit 4 heats the heavy oil supplied from the second fuel supply system 7 with the combustion exhaust gas and supplies it to the fuel supply unit 2.

As described above, in the present embodiment, the second fuel supply section 4 is connected to the return path 5, and heavy oil is supplied to the fuel supply section 2 via the return path 5. In FIG. 1, as an example, a heavy oil supply port 41 as a second fuel supply unit 4 is connected between the suction chamber 22 and the ammonia supply port 32 in the return path 5, and the return path is from the second fuel supply unit 4. 5 shows a case where heavy oil is supplied.

By supplying the heavy oil to the return passage 5, the second fuel supply unit 4 can heat the heavy oil by exchanging heat between the return gas as the combustion exhaust gas and the heavy oil. When the heavy oil is heated, its viscosity decreases and it becomes easy to atomize, and it vaporizes to improve the mixing property with air or the like in the fuel supply unit 2. As a result, the supply of heavy oil to the combustion space forming unit 1 in the fuel supply unit 2 is stable, and the combustion of heavy oil in the combustion space forming unit 1 is stable.

Hereinafter, the operation of the combustion system 200 will be described. The operation of the combustion system 200 is realized by the control of the control unit C in this embodiment. Unless otherwise specified, the operation of each part in the following description shall be performed based on the operation command of the control unit C, and the description of the operation command of the control unit C will be omitted as appropriate.

In the combustion system 200, when the combustion of the combustion device 100 is started, first, the pilot burner 19 ignites the pilot fire, and the fuel supply and the air supply from the fuel supply unit 2 are started. An igniter can be used to ignite the pilot fire in the pilot burner 19. Heavy oil or flammable gas may be used as the fuel for the pilot fire ignited by the pilot burner 19. The present embodiment shows a case where the pilot burner 19 burns a pilot fire using heavy oil as fuel. The fuel supply unit 2 may supply only heavy oil as fuel to the combustion space forming unit 1 at the start of combustion of the combustion device 100 and immediately after the start of combustion.

In the present embodiment, the heavy oil is supplied by supplying the heavy oil from the second fuel supply system 7 to the second fuel supply unit 4 based on the operation command of the control unit C. That is, the control unit C starts combustion of the combustion device 100 using heavy oil. The control unit C is, for example, the output of the flow sensor 73 provided in the heavy oil supply pipe 71 connected to the second fuel tank 70 as the heavy oil tank and the second fuel supply unit 4 of the second fuel supply system 7. Based on the signal, the output of the pump 72 provided in the supply pipe 71 is adjusted, and the supply amount of heavy oil supplied from the second fuel tank 70 to the second fuel supply unit 4 is adjusted. As the pump 72, a turbine pump, a diaphragm pump, or the like can be adopted. The output of the pump 72 may be adjusted by adjusting the rotation speed and the number of pistons. In the case of a turbine pump, a valve body may be provided on the downstream side, and the output may be adjusted by the valve opening while keeping the turbine rotation speed constant.

In the present embodiment, the air is supplied by supplying air from the oxygen transport gas supply system 8 to the oxygen transport gas supply unit 20 based on the operation command of the control unit C. The control unit C is, for example, an output signal of a flow rate sensor 83 or a pressure sensor 84 provided in a blower pipe 81 connected to a blower 80 such as a fan or a blower of the oxygen transfer gas supply system 8 and an oxygen transfer gas supply unit 20. Based on the above, the opening degree of the valve of the air volume adjusting valve 82 provided in the blower pipe 81 or the output of the blower 80 is adjusted, and the supply amount of air supplied from the blower 80 to the oxygen transport gas supply unit 20 is adjusted. The air volume adjusting valve 82 is an opening degree adjusting valve (damper) such as a butterfly valve.

When the supply of air to the fuel supply unit 2 is started, the inside of the combustion container 9 is sucked through the return path 5 by the suction effect of the ejector mechanism of the fuel supply unit 2, and the return gas is started to be returned. In the combustion state of heavy oil alone, the preferable flow rate of the return gas is 0.05 or more and 1.0 or less when the flow rate of the air supplied to the fuel supply unit 2 is 1.

As the combustion by the combustion space forming unit 1 continues, the temperature of the combustion exhaust gas in the combustion container 9 gradually rises. When the temperature of the return gas rises with the temperature rise of the combustion exhaust gas, the heavy oil is heated in the return path 5 by the return gas. When the temperature of the combustion exhaust gas reaches a predetermined value (for example, 800 ° C. or higher), the atomization and vaporization of heavy oil in the fuel supply unit 2 becomes good, and the combustion flame in the combustion space forming unit 1 becomes stable. Reach.

When the temperature of the combustion exhaust gas reaches a predetermined temperature or higher (for example, 800 degrees or higher) after the combustion is started in the combustion device 100, the control unit C supplies the ammonia to the fuel supply unit 2 by the ammonia supply unit 3. Start. That is, when the temperature of the combustion exhaust gas reaches a predetermined temperature or higher, the control unit C starts combustion of ammonia in the combustion device 100 and switches the combustion device 100 to a mixed combustion state of ammonia and heavy oil. The control unit C detects that the temperature of the combustion exhaust gas exceeds a predetermined temperature based on the output signal of the temperature sensor 99 provided in the combustion container 9 or the temperature sensor 59 provided in the return path 5, for example. The supply of ammonia to the fuel supply unit 2 by the ammonia supply unit 3 can be started. Ammonia supplied to the fuel supply unit 2 is supplied to the combustion space forming unit 1 and burns.

In the present embodiment, the supply of ammonia is performed by supplying ammonia from the ammonia supply system system 6 to the ammonia supply unit 3 based on the operation command of the control unit C. The control unit C, for example, adjusts the flow rate provided in the ammonia supply pipe 61 based on the output signal of the flow sensor 63 provided in the ammonia supply pipe 61 connected to the ammonia cylinder 60 and the ammonia supply unit 3. The opening degree of the valve of the valve 62 is adjusted to adjust the supply amount of ammonia supplied from the ammonia cylinder 60 to the ammonia supply unit 3. The flow rate adjusting valve 62 is an opening degree adjusting valve such as a diaphragm valve or a needle valve, which can adjust the opening degree of the valve to adjust the flow rate.

The control unit C adjusts the supply amounts of air, heavy oil, and ammonia to an appropriate ratio based on the temperature of the combustion exhaust gas or the temperature of the ammonia flowing through the ammonia pipe 31. The control unit C switches the combustion in the combustion space forming unit 1 to the combustion of ammonia alone, if necessary, or based on the operator or a predetermined operation program.

For example, when the temperature of the combustion exhaust gas reaches a predetermined temperature or higher after the combustion is started in the combustion device 100, the control unit C starts supplying ammonia while continuing the supply of heavy oil, and causes the combustion device 100 to use heavy oil and ammonia. It is in a mixed combustion state with. After that, the supply amount of ammonia is increased while reducing the supply amount of heavy oil, and the ratio of ammonia in the calorific value ratio is gradually increased. At this time, the control unit C monitors (maintains) the calorific value ratio so that the temperature of the combustion exhaust gas does not drop below a predetermined temperature (for example, does not fall below 600 ° C.) by the temperature sensor 99 or the temperature sensor 59. Increase the ratio of ammonia. In addition, the temperature sensor 39 increases the ratio of ammonia to the calorific value ratio while monitoring (maintaining) so that the temperature of ammonia does not drop below a predetermined temperature (for example, not to fall below 400 ° C.), and ammonia alone. To the burning state of. When the control unit C detects that the temperature of the combustion exhaust gas has dropped below the predetermined temperature by the temperature sensor 99 or the temperature sensor 59, or detects that the temperature of ammonia has dropped below the predetermined temperature by the temperature sensor 39. May stop increasing the proportion of ammonia in the calorie ratio and may temporarily reduce the proportion of ammonia in the calorie ratio. As a result, it is possible to prevent the temperature of the combustion exhaust gas and the temperature of ammonia from further decreasing, and to recover the temperature to a predetermined temperature or higher.

The control unit C continues to monitor the temperature of any one or more of the temperature sensors 39, 59, 99 as necessary even after the combustion device 100 shifts to the combustion state of ammonia alone, and the fuel supply unit 2 The supply of ammonia, the supply of air or the supply of heavy oil to the fuel oil may be adjusted. For example, when the temperature of the combustion exhaust gas drops extremely or the temperature of ammonia drops below a predetermined value, the supply of heavy oil may be started again to bring the heavy oil and ammonia into a mixed combustion state. Further, the control unit C may continue the mixed combustion state of ammonia and heavy oil depending on the use of the combustion device 100 or the combustion system 200.

The control unit C may adjust the supply amount of the return gas from the return path 5 as necessary. By such adjustment control, the turndown ratio of the combustion device 100 can be increased. For example, in the combustion state of ammonia alone, the flow rate adjusting valve 51 may be closed to stop the supply of the return gas. By stopping the supply of the return gas, the turndown ratio in the combustion state of ammonia alone can be increased.

In the present embodiment, since the heavy oil supply port 41 and the ammonia supply port 32 are connected to the return path 5, when the supply of ammonia is started, the return amount of the return gas naturally decreases. The oxygen concentration of the mixed gas supplied to the combustion space forming unit 1 rises and is automatically adjusted to a state suitable for combustion of ammonia. When the supply of ammonia is started, the amount of returned gas returned naturally decreases because the ratio of ammonia in the fluid sucked from the return path 5 due to the suction effect in the ejector mechanism of the fuel supply unit 2 is relative. This is because the ratio of returned gas decreases accordingly. That is, by connecting the heavy oil supply port 41 and the ammonia supply port 32 to the return path 5, the turndown ratio of the combustion device 100, that is, the turndown ratio of the combustion system 200 can be increased.

(Modification 1 of the first embodiment)
In the first embodiment, the oxygen transport gas is used to increase the turndown ratio of the combustion system 200, improve the combustion state in the combustion vessel 9, and reduce the oxygen concentration in the combustion exhaust gas. In addition to the air as the oxygen transport gas supplied to the supply unit 20, the combustion vessel 9 may supply the secondary air as the secondary oxygen transport gas to the furnace space S.

FIG. 2 shows the configuration of the combustion system 200 in the case where the secondary air is supplied to the second combustion space S2 which is the outer space of the first combustion space S1 in the combustion vessel 9, that is, the space S in the furnace. An explanatory diagram is shown.

In this modification, the combustion container 9 is provided in the combustion container 9 and the secondary air supply port 95 for introducing the secondary air into the combustion container 9, and the secondary air is connected to the secondary air supply port 95. The case of having a supply container 96 is shown. The secondary air supply port 95 is formed as, for example, a through hole penetrating the cylinder wall portion 90. The secondary air supply container 96 is supplied with secondary air from the secondary air supply port 95.

The secondary air supply container 96 may have, for example, a tubular secondary air nozzle portion 97 that accommodates the tubular portion 10 of the combustion space forming portion 1. The secondary air supply container 96 is an opening of the secondary air nozzle portion 97 located on the downstream side of the combustion space forming portion 1 by the secondary air nozzle portion 97, and is a cylinder wall of the secondary air nozzle portion 97. Secondary air may be supplied into the combustion vessel 9 through a gap with the secondary air nozzle portion 97. The secondary air may be supplied to the secondary air supply port 95 via, for example, a second blower pipe 85 branched from the blower pipe 81. The second air flow pipe 85 may be provided with a flow rate sensor 86 and a second air volume adjusting valve 87, and the control unit C adjusts the opening degree of the valve of the second air volume adjusting valve 87 based on the output signal of the flow rate sensor 86. Then, the supply amount of secondary air may be adjusted.

By enabling the supply of secondary air into the combustion vessel 9, the turndown ratio of the combustion system 200 can be increased, the combustion state in the combustion vessel 9 can be improved, or the oxygen concentration in the combustion exhaust gas can be reduced. It may be possible to reduce it.

(Modification 2 of the first embodiment)
In the first embodiment, the combustion vessel 9 is used in order to increase the turndown ratio of the combustion system 200, improve the combustion state in the combustion vessel 9, and reduce the oxygen concentration in the combustion exhaust gas. In addition to the ammonia supplied to the oxygen transport gas supply unit 20, ammonia may be supplied to the furnace space S as a secondary fuel.

FIG. 3 shows an explanatory diagram of a configuration in which ammonia can be further supplied into the furnace space S as a secondary fuel for the combustion system 200 of the first modification. In this modification 2, the second supply pipe 64 branched from the supply pipe 61 is connected to the downstream side of the flow rate sensor 86 and the second air volume adjusting valve 87 in the second blower pipe 85. The combustion vessel 9 can supply ammonia into the furnace space S via the secondary air supply port 95 and the secondary air supply vessel 96.

The second supply pipe 64 may be provided with a flow rate sensor 66 and a second flow rate adjusting valve 65. The control unit C can adjust the opening degree of the valve of the second flow rate adjusting valve 65 based on the output signal of the flow rate sensor 66, and can adjust the supply amount of ammonia supplied to the secondary air supply container 96. The second flow rate adjusting valve 65 is an opening degree adjusting valve such as a diaphragm valve or a needle valve.

By making it possible to supply ammonia as a secondary fuel in the combustion vessel 9, the turndown ratio of the combustion system 200 can be increased, the combustion state in the combustion vessel 9 can be improved, or the oxygen concentration in the combustion exhaust gas can be increased. May be possible to reduce.

(Second embodiment)
In the first embodiment, the case where the second fuel is heavy oil has been illustrated and described. In the second embodiment, the second fuel is propane gas instead of heavy oil, and as shown in FIG. 4, the second fuel supply unit 4 and the second fuel supply system 7 are suitable for supplying propane gas. Further, the combustion device 100 is different from the first embodiment in that it does not have the return path 5 (see FIG. 1 and the like) shown in the first embodiment, and the others are the same. Hereinafter, the differences from the first embodiment will be mainly described.

In the present embodiment, the ammonia supply port 32 of the ammonia pipe 31 is directly connected to the suction chamber 22, and ammonia is directly supplied from the ammonia supply unit 3 to the suction chamber 22.

Further, the gas fuel supply port 45 as the second fuel supply unit 4 is connected to the suction chamber 22, and propane gas is directly supplied from the second fuel supply unit 4 to the suction chamber 22. The gas fuel supply port 45 may be connected to the oxygen transport gas supply unit 20 so that the propane gas is supplied to the suction chamber 22 together with the air.

The propane gas is supplied by supplying the propane gas from the second fuel supply system 7 to the second fuel supply unit 4 based on the operation command of the control unit C. The control unit C is, for example, a flow sensor 73 provided in the propane gas supply pipe 71 connected to the second fuel cylinder 79 as the propane gas cylinder and the second fuel supply unit 4 of the second fuel supply system 7. Based on the output signal, the opening degree of the flow control valve 74 provided in the supply pipe 71 is controlled, and the supply amount of propane gas supplied from the second fuel cylinder 79 to the second fuel supply unit 4 is adjusted. .. The flow rate adjusting valve 74 is an opening degree adjusting valve such as a diaphragm valve or a needle valve.

The pilot burner 19 may burn a pilot fire using propane gas as fuel.

In the present embodiment, a combustion state of propane gas alone, a mixed combustion state of propane gas and ammonia, and a combustion state of ammonia alone are possible.

Natural gas may be used as the second fuel instead of propane gas.

According to the combustion system 200 of the second embodiment, since the return gas is not supplied to the combustion space forming portion 1, it is easy to increase the turndown ratio of the combustion device 100.

The combustion device 100 and the combustion system 200 including the above-described combustion device 100 are widely used as fuel for current ships, for example, heavy oil that can be easily procured in ships, and heavy oil that will be replaced as fuel for ships in the future. It is possible to burn hydrocarbon gas such as propane gas and natural gas, which are low carbon fuels that may be used, and ammonia, which is expected as a next-generation fuel that does not emit carbon dioxide, especially for ships. Suitable for mounting applications. The combustion device 100 and the combustion system 200 including the combustion device 100 are excellent not only for general heat sources such as boilers but also for inert gas production devices mounted on ships because they generate a small amount of carbon dioxide. ..

As described above, it is possible to provide a combustion device and a combustion system in which the usage rate of ammonia as a fuel is increased.

[Another Embodiment]
(1) In the above embodiment, when the temperature of the combustion exhaust gas reaches a predetermined temperature or higher after the combustion is started in the combustion device 100, the control unit C supplies the ammonia to the fuel supply unit 2 by the ammonia supply unit 3. The case to start was explained. Further, the control unit C detects that the temperature of the combustion exhaust gas exceeds a predetermined temperature based on, for example, the output signal of the temperature sensor 99 provided in the combustion container 9 or the temperature sensor 59 provided in the return path 5. Then, it was explained that the supply of ammonia to the fuel supply unit 2 by the ammonia supply unit 3 can be started.

However, instead of starting the supply of ammonia to the fuel supply unit 2 based on the temperature of the combustion exhaust gas, the control unit C has the ammonia to the fuel supply unit 2 based on the flame state of the combustion space forming unit 1. It is also possible to start the supply of. In this case, the combustion device 100 may include a frame sensor for detecting the state of the flame of the combustion space forming unit 1, and supplies ammonia to the fuel supply unit 2 based on the state of the flame detected by the frame sensor. You may start. As the frame sensor, a sensor that determines the state of the flame based on the light emitted by the flame (for example, ultraviolet rays or visible light) or a sensor that determines the state of the flame based on the conductivity of the flame may be used. That is, the control unit C can also start supplying ammonia to the fuel supply unit 2 by the ammonia supply unit 3 when the flame reaches a predetermined combustion state after the combustion starts in the combustion device 100. ..

(2) In the above embodiment, the control unit C monitors the temperature of any one or more of the temperature sensors 39, 59, 99 as necessary even after the combustion device 100 shifts to the combustion state of ammonia alone. It was explained that the supply amount of ammonia, the supply amount of air, or the supply amount of heavy oil to the fuel supply unit 2 may be adjusted.
did.

However, instead of monitoring the temperature of any one or more of the temperature sensors 39, 59, 99, the control unit C supplies the amount of ammonia to the fuel supply unit 2 based on the flame state of the combustion space forming unit 1. , Air supply or heavy oil supply may be adjusted. In this case, the combustion device 100 may include a frame sensor for detecting the state of the flame of the combustion space forming unit 1, and the amount of ammonia supplied to the fuel supply unit 2 based on the state of the flame detected by the frame sensor. , Air supply or heavy oil supply may be adjusted. As the frame sensor, the same one as described above may be used.

The configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

The present invention can be applied to a combustion device and a combustion system.

1: Combustion space forming part 10: Cylindrical part 100: Combustion device 19: Pilot burner 2: Fuel supply part 20: Oxygen transport gas supply part 200: Combustion system 21: Nozzle part 22: Suction chamber 23: Diffuser part 3: Ammonia Supply unit 30: Heat exchange unit 31: Ammonia pipe 32: Ammonia supply port 39: Temperature sensor 4: Second fuel supply unit 41: Heavy oil supply port 45: Gas fuel supply port 5: Return path 51: Flow control valve 59: Temperature Sensor 6: Ammonia supply system 60: Ammonia bomb 61: Supply pipe 62: Flow control valve 63: Flow sensor 64: Second supply pipe 65: Second flow control valve 66: Flow sensor 7: Second fuel supply system 70: No. (Ii) Fuel tank 71: Supply pipe 72: Fuel pump 73: Flow sensor 74: Flow control valve 79: Second fuel bomb 8: Oxygen transfer gas supply system 80: Blower 81: Blower pipe 82: Air volume control valve 83: Flow sensor 84 : Pressure sensor 85: Second blower pipe (second oxygen transfer gas path)
86: Flow sensor 87: Second air volume control valve 9: Combustion container 90: Cylinder wall 91: Bottom wall 95: Secondary air supply port 96: Secondary air supply container 97: Secondary air nozzle 99: Temperature sensor C : Control unit S: In-furnace space S1: First combustion space S2: Second combustion space

Claims (22)

A combustion space forming unit that forms a first combustion space for burning ammonia as a first fuel or a second fuel different from the ammonia as a fuel.
A fuel supply unit that supplies the fuel to the combustion space forming unit,
An ammonia supply unit that supplies the ammonia to the fuel supply unit,
A second fuel supply unit that supplies the second fuel to the fuel supply unit ,
The fuel supply unit is provided with a return path for supplying the combustion exhaust gas generated in the combustion space forming unit .
The ammonia supply unit
It has a heat exchange unit that heats the ammonia.
The ammonia heated in the heat exchange section is supplied to the fuel supply section, and the ammonia is supplied to the fuel supply section.
The fuel supply unit
It is supplied with oxygen carrier gas and
It has a mixing mechanism that mixes the ammonia or the second fuel and the oxygen transport gas to form a mixed gas.
The mixed gas is supplied to the combustion space forming portion, and the mixture gas is supplied to the combustion space forming portion.
The mixing mechanism is an ejector mechanism that mixes the oxygen transport gas with the second fuel or the ammonia by the energy of the air flow of the oxygen transport gas, and sends the mixed gas to the combustion space forming portion.
The ejector mechanism is
A suction chamber to which the ammonia is supplied from the ammonia supply unit, and
A nozzle portion that blows the oxygen transport gas into the suction chamber,
It has a diffuser portion that is communicated and connected to the downstream side of the suction chamber.
The return path is a combustion device that is connected to the suction chamber in communication . The combustion device according to claim 1 , wherein the second fuel supply unit supplies the second fuel to the fuel supply unit via the return path. The combustion device according to claim 1 or 2 , wherein the ammonia supply unit supplies the ammonia to the fuel supply unit via the return path. The combustion device according to any one of claims 1 to 3 , wherein the return path has a flow rate adjusting valve for adjusting the flow rate of the combustion exhaust gas. The combustion device according to any one of claims 1 to 4 , wherein the second fuel supply unit supplies the second fuel together with the oxygen transport gas to the suction chamber via the nozzle unit. The combustion apparatus according to any one of claims 1 to 5 , further comprising an oxygen transport gas supply unit for supplying the oxygen transport gas to the fuel supply unit. The one according to any one of claims 1 to 6 , wherein the heat exchange section is arranged on the downstream side of the flow of the combustion exhaust gas generated in the combustion space forming section, and heat exchange between the combustion exhaust gas and the ammonia is performed. Combustion device. The combustion device according to any one of claims 1 to 7 .
A combustion vessel equipped with the combustion device and forming a space inside the furnace is provided.
The combustion container is a combustion system in which the combustion space forming portion is housed in the furnace space. The combustion system according to claim 8 , wherein the combustion container is in the space inside the furnace and supplies the secondary oxygen transport gas to the space outside the first combustion space. The combustion system according to claim 8 or 9 , wherein the combustion container is inside the furnace space and supplies ammonia as a second fuel to the external space of the first combustion space. Further equipped with a control unit
The control unit determines the amount of the fuel supplied to the fuel supply unit based on the temperature of the combustion exhaust gas generated in the combustion vessel, the temperature of the ammonia heated by the heat exchange unit, or the state of the flame. The combustion system according to any one of claims 8 to 10 , wherein the ratio to the supply amount of the second fuel to the fuel supply unit is adjusted. The control unit
The combustion device is started to burn with the second fuel, and the combustion device is started to burn.
When the temperature of the combustion exhaust gas reaches a predetermined temperature or higher, the combustion device is switched to a mixed combustion state of the ammonia and the second fuel, and then the combustion state is shifted to the combustion state of the ammonia alone.
When switching from the mixed combustion state to the combustion state of the ammonia alone, the ratio of the ammonia in the mixed combustion state is increased while keeping the temperature of the ammonia heated in the heat exchange unit above a predetermined value. The combustion system according to claim 11 , wherein the combustion system shifts to the combustion state of ammonia alone. A combustion space forming unit that forms a first combustion space for burning ammonia as a first fuel or a second fuel different from the ammonia as a fuel.
A fuel supply unit that supplies the fuel to the combustion space forming unit,
An ammonia supply unit that supplies the ammonia to the fuel supply unit,
A second fuel supply unit that supplies the second fuel to the fuel supply unit is provided.
The ammonia supply unit
It has a heat exchange unit that heats the ammonia.
A combustion device that supplies the ammonia heated in the heat exchange unit to the fuel supply unit, and
A combustion vessel to which the combustion device is attached to form a space inside the furnace, and
With a control unit ,
The combustion container accommodates the combustion space forming portion in the furnace space .
The control unit determines the amount of the ammonia supplied to the fuel supply unit based on the temperature of the combustion exhaust gas generated in the combustion vessel, the temperature of the ammonia heated in the heat exchange unit, or the state of the flame. A combustion system that adjusts the ratio of the second fuel to the fuel supply unit . The combustion system according to claim 13, wherein the combustion container is inside the furnace space and supplies the secondary oxygen transport gas to the external space of the first combustion space. The combustion system according to claim 13 or 14, wherein the combustion container is inside the furnace space and supplies ammonia as a second fuel to the external space of the first combustion space. The control unit
The combustion device is started to burn with the second fuel, and the combustion device is started to burn.
When the temperature of the combustion exhaust gas reaches a predetermined temperature or higher, the combustion device is switched to a mixed combustion state of the ammonia and the second fuel, and then the combustion state is shifted to the combustion state of the ammonia alone.
When switching from the mixed combustion state to the combustion state of the ammonia alone, the ratio of the ammonia in the mixed combustion state is increased while keeping the temperature of the ammonia heated in the heat exchange unit above a predetermined value. The combustion system according to any one of claims 13 to 15, wherein the combustion system shifts to the combustion state of ammonia alone. The fuel supply unit
It is supplied with oxygen carrier gas and
It has a mixing mechanism that mixes the ammonia or the second fuel and the oxygen transport gas to form a mixed gas.
The combustion system according to any one of claims 13 to 16, wherein the mixed gas is supplied to the combustion space forming portion. 17. The 17th claim, wherein the mixing mechanism is an ejector mechanism that mixes the oxygen transport gas with the second fuel or the ammonia by the energy of the air flow of the oxygen transport gas, and sends the mixed gas to the combustion space forming portion. Combustion system The ejector mechanism is
A suction chamber to which the ammonia is supplied from the ammonia supply unit, and
A nozzle portion that blows the oxygen transport gas into the suction chamber,
The combustion system according to claim 18, further comprising a diffuser portion communicated and connected to the downstream side of the suction chamber. The combustion system according to claim 19, wherein the second fuel supply unit supplies the second fuel together with the oxygen transport gas to the suction chamber via the nozzle unit. The combustion system according to any one of claims 17 to 20, further comprising an oxygen transport gas supply unit for supplying the oxygen transport gas to the fuel supply unit. 13. Combustion system.

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