JP2019184179A - Combustion apparatus for fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion device capable of stably continuing combustion of a flame-retardant fuel. A fuel combustion device (2) according to the present invention includes a combustion cylinder (4), a fuel injector (6) for feeding a mixed gas fuel into the combustion cylinder (4) as a swirling air flow, and an ignition unit (32) in the combustion cylinder (4). An igniter 10 including an igniter 10, an ion detector 12 including a detector 40 in the combustion cylinder 4, and a controller 14 capable of adjusting a fuel mixture ratio according to a detection result of the ion detector 12. Preferably the fuel is ammonia. Preferably, the detection unit 40 is located near the ignition unit 32. [Selection diagram] Figure 1

Description

  The present invention relates to a fuel combustion apparatus. In detail, it is related with the combustion apparatus of flame-retardant fuels, such as ammonia.

  With increasing demand for carbon dioxide emission reduction, there is an increasing expectation for ammonia as a fuel to replace carbon-based fuels. Ammonia does not contain carbon, so it does not emit carbon dioxide when burned. Ammonia is already widely used as a fertilizer, is inexpensive and can be stably supplied. Ammonia has the same liquefaction pressure as LPG and can be stored at room temperature. Ammonia has many advantages as an alternative to carbon-based fuels.

  On the other hand, ammonia is flame retardant. The ignition energy of carbon-based fuel is about 80 mJ to 120 mJ, whereas ammonia requires an ignition energy of about 400 mJ to 600 mJ. Also, the laminar burning rate of ammonia is about 7 times slower than the laminar burning rate of carbon-based fuel. A study on an internal combustion engine using this flame-retardant ammonia as a fuel is reported in Japanese Patent Application Laid-Open No. 2010-159705.

JP 2010-159705 A

  However, in the case of burning a flame-retardant fuel such as ammonia fuel, compared with the case of burning a carbon-based fuel that is currently widely used, the difficulty of initial ignition, the difficulty of stabilization of combustion, etc. Many issues remain. In particular, in order to put a combustion apparatus using a flame-retardant fuel into practical use in various fields, it is an important issue to continue stable combustion.

  An object of the present invention is to provide a combustion apparatus capable of stably continuing the combustion of a flame-retardant fuel.

  A fuel combustion apparatus according to the present invention includes a combustion cylinder, a fuel injector that feeds mixed gas fuel into the combustion cylinder as a swirling airflow, an igniter that includes an ignition unit in the combustion cylinder, and the combustion cylinder And an ion detector including a detector, and a controller capable of adjusting a mixture ratio of the mixed gas fuel according to a detection result of the ion detector.

  Preferably, the fuel is ammonia.

  Preferably, the detection unit is located in the vicinity of the ignition unit. The detection unit may be common to the ignition unit.

  Preferably, the ignition unit includes a discharge electrode and a first ground electrode, and the detection unit includes an application electrode and a second ground electrode, and the first ground electrode and the second ground electrode are common. .

  Preferably, the ignition part is located in a region where the mixed gas fuel stays in the combustion cylinder.

  Preferably, the combustion cylinder includes a cylindrical body portion and a lower lid portion that covers the end of the body portion, and an input port through which the mixed gas fuel is fed is provided in the lower lid portion. The ignition part and the detection part are arranged on the lower lid part.

  Preferably, the detection unit is disposed in the lower lid part and the body part.

  Preferably, the charging port has an annular shape, and the ignition unit and the detection unit are arranged in a region of the lower lid portion surrounded by the charging port.

  The charging port may have a circular shape, and the ignition unit and the detection unit may be arranged around the charging port in the lower lid.

  One or a plurality of the igniters are present, and at least one of the igniters is located in a region where the mixed gas fuel does not stay in the combustion cylinder.

  Preferably, the ignition part is disposed on the lower lid part and the body part.

  The fuel combustion method according to the present invention includes a combustion step of continuously burning fuel. In the combustion step, the mixed gas fuel containing fuel is fed into the combustion cylinder as a swirling airflow, the mixed gas fuel is ignited, ions generated by the combustion are detected, and the detection result is used to determine the mixing ratio of the fuel. adjust.

  Preferably, the combustion method further includes a step of measuring a correlation between a parameter representing the combustion state of the fuel and an ion detection result and setting a reference range of the ion detection result before the combustion step. In the adjustment of the fuel mixture ratio, the ion detection result is adjusted to fall within the reference range.

  Preferably, the parameter representing the combustion state of the fuel includes an oxide emission amount during combustion.

  In the fuel combustion apparatus according to the present invention, since the ion current detector is provided in the combustion cylinder, it is possible to grasp the combustion state of the mixed gas fuel introduced into the combustion cylinder. In addition, since the apparatus also includes a controller that adjusts the air-fuel ratio of the mixed gas fuel, it is possible to perform appropriate air-fuel ratio control based on the grasped combustion state.

  In this combustion apparatus, since the mixed gas fuel is fed into the combustion cylinder as a swirling airflow, a “region where the mixed gas stays” is generated in the combustion cylinder. When an igniter and an ion detector are arranged in this staying region, the combustion state of the region where energy is effectively supplied is reflected in the ion current in this combustion device, so that the state of the flame kernel can be grasped. It becomes possible. Further, since the apparatus includes a controller that adjusts the air-fuel ratio of the mixed gas fuel, air-fuel ratio control based on the state of the flame kernel can be realized.

  In addition, when the igniter and the ion detector are arranged in a region away from the staying region, the combustion state of the combustion device is reflected in the ion current in the region flowing at a relatively high speed. Can be grasped. In addition, since the apparatus includes a controller that adjusts the air-fuel ratio of the mixed gas fuel, air-fuel ratio control that contributes to stabilization of combustion can be realized.

FIG. 1 is a conceptual diagram illustrating a combustion apparatus according to an embodiment of the present invention. FIG. 2 is a view of a part of the combustion apparatus of FIG. 1 as viewed from above. FIG. 3 is a connection diagram showing a part of the combustion apparatus of FIG. FIG. 4 is a circuit diagram showing an example of an ion detection circuit of the combustion apparatus of FIG. FIG. 5 is a graph showing the relationship between the mixing ratio, the ionic current, and the oxide emission when the fuel is burned by the combustion apparatus of FIG. FIG. 6 is a graph showing the relationship between the flow rate of the fuel and the ionic current when the fuel is burned by the combustion apparatus of FIG. FIG. 7 is a conceptual diagram illustrating a combustion apparatus according to another embodiment of the present invention. FIG. 8 is a view of a part of a combustion apparatus according to still another embodiment of the present invention as viewed from above.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 is a conceptual diagram showing a fuel combustion apparatus 2 according to an embodiment of the present invention. In this figure, a part of the device is shown in cross section. The combustion apparatus 2 includes a combustion cylinder 4, a fuel injector 6, a fuel mixer 8, an igniter 10, an ion detector 12, and a controller 14. In this specification, the direction indicated by the arrow X in FIG. 1 is the lower side of the combustion device 2, and the opposite direction is the upper side. The direction in which the fuel injector 6 is located is downward.

  The combustion cylinder 4 has a cylindrical shape. In this embodiment, the combustion cylinder 4 is cylindrical. In FIG. 1, the cross section of the combustion cylinder 4 is shown. The combustion cylinder 4 includes a body portion 16, a lower lid portion 18, and an upper lid portion 20. The body portion 16 forms the side surface of the combustion cylinder 4. The trunk | drum 16 is extended in the up-down direction. The lower lid portion 18 is put on the lower end of the trunk portion 16. An input port 22 is provided in the lower lid portion 18. A mixed gas containing fuel (mixed gas fuel) is fed from the inlet 22. FIG. 2 is a view of the lower lid portion 18 as viewed from above to below. As shown in the drawing, in this embodiment, the inlet 22 has an annular shape. The upper lid portion 20 is put on the upper end of the trunk portion 16. An output port 23 through which a flame is ejected is provided at the center of the upper lid portion 20. In this embodiment, the material of the combustion cylinder 4 is heat resistant glass.

  As shown in FIG. 1, the fuel injector 6 is located below the lower lid portion 18 of the combustion cylinder 4. The fuel injector 6 includes a housing 24 and a swirler 26. The casing 24 has an annular shape when viewed from below. The inside of the housing 24 is hollow. The swirler 26 is located inside the housing 24. The swirler 26 is located below the charging port 22. In FIG. 2, the swirler 26 located below the insertion port 22 is visible. The swirler 26 includes a plurality of inclined blades. The mixed gas fuel fed into the housing 24 passes through the swirler 26 and becomes an airflow (swirl airflow) with a rotating vortex (swirl flow). The mixed gas fuel is fed into the combustion cylinder 4 as a swirling airflow. The material of the swirler 26 is typically steel.

  Although not shown, the fuel injector 6 may further include a drive unit that rotates the swirler 26. By rotating the swirler 26, the mixed gas fuel may be fed into the combustion cylinder 4 as a swirling airflow.

  The fuel mixer 8 includes a fuel tank 28 and a valve 30. In this embodiment, the fuel mixer 8 has a first valve 30a and a second valve 30b. The fuel tank 28 stores flame-retardant fuel that is the main fuel of the combustion device 2. In this embodiment, the fuel tank 28 stores liquefied ammonia. This liquefied ammonia is vaporized and sent to the fuel injector 6. A first valve 30 a is connected to the fuel tank 28. The first valve 30a adjusts the amount of fuel in the mixed gas fuel. The second valve 30b adjusts the amount of air in the mixed gas fuel.

  The fuel mixer 8 may further include a fuel tank storing auxiliary fuel and a third valve connected to the fuel tank. At this time, in the fuel mixer 8, two types of fuel and air are mixed. This secondary fuel is more combustible than the main fuel. That is, the ignition energy of the auxiliary fuel is smaller than the ignition energy of the main fuel, and the laminar combustion speed of the auxiliary fuel is larger than the laminar combustion speed of the main fuel. By mixing the highly combustible auxiliary fuel, the mixed gas fuel can be easily ignited. A typical secondary fuel is exemplified by methane. The combustion apparatus 2 may include three or more fuel tanks.

  FIG. 3 is a connection diagram showing connections of the igniter 10, the ion detector 12, and the controller 14. As shown in FIG.

  The igniter 10 ignites the mixed gas fuel. As shown in FIG. 3, the igniter 10 includes an igniter 32 and a voltage generator. FIG. 1 shows the ignition unit 32 among these. In FIG. 1, two ignition parts 32 are shown.

  The ignition unit 32 is disposed in the “region where the mixed gas fuel stays”. In FIG. 1, the flow of the swirling airflow of the mixed gas fuel is indicated by arrows. The main flow (the thick dotted line in FIG. 2) of the swirling airflow that has flowed from the inlet 22 proceeds upward while spreading along the inner peripheral surface of the combustion cylinder 4 while swirling. Since the atmospheric pressure is low in the portion where the main flow flows, the mixed gas fuel in the central portion of the combustion cylinder 4 is pulled by this flow. In the central portion, a spiral flow (thin dotted line in FIG. 2) is generated. A region where the spiral flow is generated is a “region where the mixed gas fuel stays (residence region)”. In this staying region, an air flow having a lower speed than the main flow of the swirling air flows continuously. In this portion, the mixed gas fuel flows in a spiral shape, and flows from the lower side to the upper side at a speed slower than the main flow of the swirling airflow as a whole. In the staying region, the mixed gas fuel is swirled, so that the mixed gas fuel is repeatedly guided to the ignition unit 32. The mixed gas fuel repeatedly passes in the vicinity of the ignition unit 32.

  As a typical staying region, a vicinity 39 a of the region 38 of the lower lid portion 18 surrounded by the annular inlet 22 can be cited. Similarly, the vicinity 39b outside the charging port 22 is also a staying region. As shown in FIG. 1, a staying region also exists in the mainstream inner side 39 c at the center in the vertical direction of the combustion cylinder 4. These staying areas can be examined, for example, by putting colored smoke into the combustion cylinder 4 at the same speed as the mixed gas fuel. The staying region can be examined by simulation.

  In this embodiment, the ignition part 32 is located in the lower lid part 18. The ignition unit 32 is located inside the combustion cylinder 4. A plurality of ignition parts 32 are arranged in a region 38 of the lower lid part 18 surrounded by the annular charging port 22. These ignition parts 32 are located in the staying region. As shown in FIG. 2, in this embodiment, the region 38 surrounded by the inlet 22 is circular. In FIG. 2, it is hidden by the ion detector 12 and cannot be seen, but a plurality of ignition parts 32 are arranged concentrically in this region 38 below the ion detector 12. These ignition parts 32 are arranged so as to form a single circle on a concentric circle in a region 38 surrounded by the inlet 22. The ignition unit 32 may be arranged so as to form a plurality of circles on the concentric circle of the region 38. The position where the ignition parts 32 are arranged is not limited to the concentric circle of the region 38 surrounded by the charging port 22. A plurality of ignition parts 32 may be arranged in a spiral shape in this region 38. The number of ignition parts 32 may be one.

  The lower lid part 18 where the ignition part 32 is located is located upstream of the flow of the mixed gas fuel. In the combustion apparatus 2, the ignition unit 32 is located upstream of the flow of the mixed gas fuel in order to sufficiently burn the fuel. The vertical distance between the position where the ignition unit 32 ignites (the tip of the ignition unit 32) and the insertion port 22 is preferably 50% or less, more preferably 25% or less of the vertical length of the body portion 16.

  As shown in FIG. 1, in this embodiment, the ignition unit 32 includes a discharge electrode 34 and a first ground electrode 36. The discharge electrode 34 and the first ground electrode 36 have a bowl shape formed by bending a rod. The discharge electrode 34 and the first ground electrode 36 protrude from the lower lid portion 18 to the inside. Although not shown, the lower lid portion 18 is provided with a grounded terminal. The first ground electrode 36 is grounded by being in contact with this terminal. The discharge electrode 34 is electrically connected to the voltage generator. A high voltage is applied to the discharge electrode 34 from the voltage generator. As a result, a spark is generated between the tip of the discharge electrode 34 and the tip of the first ground electrode 36. Thereby, the mixed gas fuel is ignited. The ignition unit 32 is a spark plug. The ignition part 32 may not be a spark plug. The ignition part 32 may be comprised from the plasma jet ignition plug.

  The voltage generator generates a high voltage according to a signal from the controller 14. Although not shown, the voltage generator includes a primary coil and a secondary coil. By repeatedly cutting and conducting the current of the primary coil, a high voltage is intermittently generated on the secondary coil side.

  The ion detector 12 detects ions in the combustion cylinder 4. As shown in FIG. 3, the ion detector 12 includes a detection unit 40 and a detection circuit unit. Of these, FIGS. 1 and 2 show the detector 40. In this embodiment, the detection unit 40 includes a saddle type detection unit 40a and a ring type detection unit 40b.

  As shown in FIGS. 1 and 2, the saddle-shaped detection unit 40 a is located in the lower lid unit 18. As shown in FIG. 2, the plurality of detection units 40 a are arranged on concentric circles in a region 38 surrounded by the insertion port 22. Each saddle-shaped detection unit 40 a includes an application electrode 42 and a second ground electrode 44. The application electrode 42 and the second ground electrode 44 of the bowl-shaped detection unit 40a have a bowl shape formed by bending a rod. The application electrode 42 and the second ground electrode 44 protrude from the lower lid portion 18 to the inside. In the embodiment of FIG. 1, the second ground electrode 44 is common with the first ground electrode 36. The second ground electrode 44 may not be common with the first ground electrode 36. The application electrode 42 is electrically connected to the detection circuit unit.

  Although not shown, the application electrode 42 may be common with the discharge electrode 34 of the ignition unit 32. The application electrode 42 may be common with the discharge electrode 34, and the second ground electrode 44 may be common with the first ground electrode 36. That is, the detection unit 40a and the ignition unit 32 may be common. Furthermore, a circuit in which the detection circuit unit and the voltage generation unit are integrated may be used. In this case, each igniter performs ignition by discharge and ion detection.

  The ring-shaped detection unit 40 b is located on the trunk unit 16. FIG. 1 shows two ring-shaped detection units 40b. Each annular detection unit 40 b includes an application electrode 42 and a second ground electrode 44. The application electrode 42 and the second ground electrode 44 are annular. The application electrode 42 and the second ground electrode 44 are attached to the inner surface of the cylindrical body 16. The application electrode 42 is electrically connected to the detection circuit unit. Although not shown, the trunk portion 16 is provided with a grounded terminal. The second ground electrode 44 is grounded by being in contact with this terminal.

  FIG. 4 shows a circuit example of the ion detector 12. As shown in FIG. 4, the detection circuit unit includes a power source E, a resistor R, and a voltage measurement unit. The power source E applies a voltage to the application electrode 42 of the detection unit 40 through the resistor R. In this embodiment, a negative voltage is applied. For example, the voltage of the power source E is -200V. When ions are present around the detection unit 40, the ions are attracted to the application electrode 42, and a current (ion current) flows. The more ions that are present, the greater the ion current that flows. The voltage measuring unit detects and amplifies a potential difference generated at both ends of the resistor R due to the ionic current. The voltage measuring unit detects a voltage proportional to the ion current. From this voltage, an ionic current is obtained. In the ion detector 12, an ion current is obtained as a result of ion detection.

  The power source E may apply a positive voltage to the application electrode 42. For example, the voltage of the power supply E may be 200V. When electrons generated together with ions exist around the detection unit 40, the electrons are attracted to the application electrode 42 and an ion current flows. The greater the number of ions present, that is, the greater the number of electrons, the greater the ion current that flows. By measuring the voltage across the resistor R, the ionic current is measured.

  Ions are heavier than electrons. Ions are less mobile than electrons. When a negative voltage is applied to the application electrode 42, ions in the vicinity of the application electrode 42 are attracted. This method is suitable for detecting the amount of ions in the vicinity of the application electrode 42. Since electrons easily move, when a positive voltage is applied to the application electrode 42, electrons are attracted from a wider range than when a negative voltage is applied. This method is suitable for detecting the amount of ions in a wider range around the application electrode 42. Which of the positive and negative voltages is applied to the application electrode 42 is appropriately selected depending on the application and design concept of the combustion apparatus.

  The configuration of the detection circuit unit is not limited to FIG. The voltage measuring unit and the resistor may be provided in parallel with the power source between the power source and the application electrode 42. Instead of the power supply E in FIG. 4, a capacitor and a charging circuit that charges the capacitor may be included. In this configuration, a current flows between the capacitor and the application electrode 42. Further, the detection circuit unit and the voltage generation unit of the igniter 10 may be configured integrally. For example, when the voltage generator applies a high voltage to the discharge electrode 34, the voltage generator may simultaneously charge the capacitance of the detection circuit unit.

  The controller 14 is connected to the igniter 10, the ion detector 12 and the fuel mixer 8. A symbol P in FIG. 1 represents a connection line with the igniter 10, and a symbol I represents a connection line with the ion detector 12. As shown in FIG. 3, the controller 14 includes an ion analyzer, a valve controller, and an ignition controller. The detection results from all the ion detectors 12 are analyzed by the ion analyzer. From this result, the valve control unit controls the valve 30 of the fuel mixer 8. As a result, the fuel mixture ratio is changed. From the analysis result of the ion analysis unit, the ignition control unit controls the ignition timing of each igniter 10. The ignition timing of the igniter 10 is adjusted.

  The controller 14 is typically realized by a microcomputer. In this case, the circuit of the ion analysis part of FIG. 3, a valve | bulb control part, and an ignition control part does not exist separately. These functions are realized by a microcomputer and software. The controller 14 may have dedicated circuits for the ion analyzer, the valve controller, and the ignition controller.

  In combustion using the apparatus shown in FIGS. 1-4, at the start of combustion, the controller 14 opens the first valve 30a and the second valve 30b, and the mixed gas of fuel and air has a predetermined flow rate. Is sent to the fuel injector 6. In this embodiment, a mixed gas fuel of ammonia and air is sent to the fuel injector 6. The mixed gas fuel passes through the swirler 26 of the fuel injector 6 and is sent into the combustion cylinder 4 as a swirling airflow. The controller 14 drives the igniter 10 to ignite the mixed gas fuel. At this time, the plurality of igniters 10 are driven simultaneously. Thereby, mixed gas fuel combusts. The ion detector 12 detects ions in the combustion cylinder 4 generated by this combustion as an ion current.

The combustion method according to the present invention comprises:
(1) a reference range setting step for setting a reference range of ion current; and (2) a combustion step for continuously burning fuel.

  In the step (1), the correlation between the ion current and the parameter indicating the combustion state is measured. A straight line a in FIG. 5 is called a relationship (λ−Iz function) between the mixing ratio of fuel (ammonia) and air (air-fuel ratio λ) and the ionic current Iz under a predetermined mixed gas fuel flow velocity. Is shown). FIG. 5 shows that the ion current Iz increases as the air-fuel ratio λ increases. A curve d in FIG. 5 represents the relationship between the air-fuel ratio λ at this time and the amount of oxide (nitrogen oxide NOx) discharged when the fuel burns. The amount of nitrogen oxide has a peak at a specific air / fuel ratio λ. From the value of the air-fuel ratio λ at this time, the amount of nitrogen oxides decreases as the air-fuel ratio λ increases or decreases. In the step (1), data representing the λ-Iz function is acquired as map data. A plurality of map data is acquired by the temperature and pressure in the combustion cylinder. Further, the reference range of the ionic current is set in consideration of stable continuity of combustion, fuel efficiency, and oxide emission. FIG. 5 shows an example of this reference range. These map data and reference range are stored in a memory circuit (not shown) of the control unit.

  In the step (2), the igniter 10 is driven at regular time intervals while the mixed gas fuel is continuously sent to the combustion cylinder 4. Thereby, mixed gas fuel burns continuously. The ion detector 12 detects the ions in the combustion cylinder 4 at this time as an ion current. The controller 14 specifies the air-fuel ratio λ from the detected ion current and the λ-Iz function. The controller 14 adjusts the first valve 30a and the second valve 30 so that the ion current falls within the reference range set in (1) above. The air-fuel ratio λ is adjusted so that the ion current falls within the reference range set in (1) above.

  In the above-described embodiment, the λ-Iz function (that is, the straight line a) under a predetermined mixed gas fuel flow rate is used to specify the air-fuel ratio λ. In practice, the flow rate of the mixed gas fuel can vary. As another embodiment of this combustion method, correction processing by fluctuations in flow velocity may be performed so that the air-fuel ratio λ can be specified more accurately. In the following, this method will be described.

  FIG. 6 shows the relationship between the flow velocity v and the ion current Iz (referred to as the v-Iz function) at the reference air-fuel ratio λ. As shown in FIG. 6, the ion current Iz tends to increase as the flow velocity v increases. In this embodiment, this v-Iz function is also acquired as map data in the step (1). FIG. 5 shows only the v-Iz function at the reference air-fuel ratio λ, but this map data is acquired for a plurality of air-fuel ratios λ. These map data are stored in the memory circuit of the control unit.

  A broken line b in FIG. 5 indicates the λ-Iz function in a high speed state where the flow velocity is increased. A broken line c indicates the λ-Iz function in a low speed state where the flow velocity is low. In the step (1), these data are also acquired as map data. These map data are stored in the memory circuit of the control unit. In FIG. 5, the λ-Iz function at three different flow rates is shown, but the λ-Iz function may be acquired at more flow rates.

  In this embodiment, in specifying the air-fuel ratio λ in the step (2), the control unit 14 specifies the flow velocity v from the detection result by the ion detector 12 using the map data of the v-Iz function. . At this time, the map data at the air-heat ratio λ specified in the process before this process is used. Thereby, the control part 14 specifies that a combustion state is a high speed state, for example. At this time, the control unit 14 specifies the air-fuel ratio λ from the λ-Iz function in the high speed state of FIG. When the map data of FIG. 6 is used next, the map data at this air-fuel ratio λ is used. Using this, the flow velocity v is specified. This process is repeated.

  Below, the effect of this invention is demonstrated.

  In the fuel combustion apparatus 2 according to the present invention, a mixed gas fuel containing fuel is fed into the combustion cylinder 4 as a swirling airflow. In this mixed gas fuel, there is a portion that flows in a spiral shape and flows at a slower speed than the main flow of the swirling airflow as a whole. In the combustion apparatus 2, flame-retardant fuel having a slow laminar combustion speed can be burned.

  The ignition unit 32 of the igniter 10 of the combustion apparatus 2 is located in a region where the mixed gas fuel stays in the combustion cylinder 4. A spiral mixed gas fuel having a lower speed than the main flow of the swirling airflow continuously flows into this staying region. For this reason, the mixed gas fuel is repeatedly guided to the ignition unit 32. The mixed gas fuel repeatedly passes in the vicinity of the ignition unit 32. Thereby, the ignition part 32 can give big energy to mixed gas fuel. In this apparatus, sufficient energy for ignition can be given even to fuel with high ignition energy.

  The combustion apparatus 2 includes a detection unit 40 of the ionizer 12 in the combustion cylinder 4. The detection unit 40 detects the ions generated by the combustion, whereby the combustion state of the mixed gas fuel can be grasped. Since this combustion apparatus 2 includes a controller 14 that adjusts the fuel mixture ratio based on the detection result, appropriate air-fuel ratio control based on the grasped combustion state is possible. This contributes to continued stable combustion. In this combustion device, the combustion of the flame retardant fuel can be stably continued.

  As shown in FIG. 1, it is preferable that there is a detection unit 40 located in the vicinity of the ignition unit 32. The ignition unit 32 is located in the staying area. In the detection unit 40 in the vicinity of the ignition unit 32, the combustion state of the region where energy is effectively supplied is reflected in the detected ionic current, so that the state of the flame kernel can be grasped. In this device, air-fuel ratio control based on the state of the flame kernel and control of the ignition timing of the igniter 60 can be realized. In this combustion apparatus 2, flame-retardant fuel can be combusted stably and efficiently.

  The fuel mixing ratio affects the amount of oxide produced. Adjustment of the mixing ratio of the fuel can contribute to the reduction of oxide generation. In the combustion apparatus 2, the discharge of oxides can be suppressed while continuing the stable combustion of the flame-retardant fuel.

  A combustion method using this apparatus includes a step of measuring a correlation between a parameter representing a combustion state of fuel and an ion current to set a reference range of the ion current. In the step of continuously burning the fuel, by setting the ion current value detected by the ion detector 12 within this reference range, an appropriate combustion state can be maintained.

  The parameter representing the combustion state preferably includes the amount of oxides emitted. Thereby, the combustion which suppressed the discharge | emission of an oxide more effectively can be implement | achieved. In this combustion method, emission of oxides can be suppressed while stably burning a flame-retardant fuel.

  When the ignition unit 32 includes the discharge electrode 34 and the first ground electrode 36, and the detection unit 40 includes the application electrode 42 and the second ground electrode 44, the first ground electrode 36 and the second ground electrode 44 are common. Preferably it is done. By doing in this way, it is suppressed that these ground electrodes prevent efficient combustion.

  As shown in FIG. 1, it is preferable that a detection unit 40 is provided on the inner surface of the body portion 16 from the lower lid portion 18 side toward the opposite side. By doing so, the combustion state at a position above the fuel inlet 22 can be detected. This contributes to setting an appropriate fuel mixture ratio and setting the ignition timing of the igniter 10. In the combustion apparatus 2, the emission of oxides can be suppressed while burning the flame-retardant fuel stably and efficiently.

  As described above, the ignition part 32 is preferably disposed in the region 38 of the lower lid part 18 surrounded by the annular inlet 22. Inside the annular inlet 22, the flow of the mixed gas fuel stays. By disposing the ignition part 32 of the igniter 10 in this region 38, the mixed gas fuel that is a spiral flow is repeatedly guided to the ignition part 32. The mixed gas fuel repeatedly passes in the vicinity of the ignition unit 32. For this reason, in this apparatus 2, sufficient energy for ignition can be given also to a flame-retardant fuel. Moreover, these ignition parts 32 are located upstream of the flow of the mixed gas fuel. As a result, stable ignition and combustion can be realized even for flame-retardant fuel.

  As described above, the igniter 32 is preferably disposed on a concentric circle of the region 38 when the region 38 surrounded by the inlet 22 is circular. By doing so, the mixed gas fuel can be ignited uniformly around the charging port 22. Thereby, the mixed gas fuel can be ignited stably.

  Although not shown, the combustion device 2 may have a temperature sensor that measures the temperature in the combustion cylinder 4. This temperature sensor is connected to the controller 14, and the temperature measurement result is sent to the controller 14. In general, the fuel easily burns when the temperature in the combustion cylinder 4 increases. As the temperature of ammonia also increases, the combustibility improves, and the amount of nitrogen oxide NOx that is discharged decreases. In this combustion apparatus 2, the controller 14 adjusts the fuel mixture ratio based on the temperature measurement result. Based on the temperature measurement result, the controller 14 controls the ignition timing of the igniter 10. These contribute to the continuation of stable combustion. In this combustion apparatus 2, stable combustion can be continued.

  Although not shown, the combustion device 2 may have a pressure sensor that measures the pressure in the combustion cylinder 4. The pressure sensor is connected to the controller 14, and the pressure measurement result is sent to the controller 14. In general, the fuel easily burns when the pressure in the combustion cylinder 4 increases. As the pressure of ammonia also increases, the combustibility improves and the amount of nitrogen oxide NOx discharged decreases. In the combustion apparatus 2, the controller 14 adjusts the fuel mixture ratio based on the pressure measurement result. The controller 14 controls the ignition timing of the igniter 10 based on the pressure measurement result. These contribute to the continuation of stable combustion. In this combustion apparatus 2, stable combustion can be continued.

  Although not shown, the combustion apparatus 2 may have a drive mechanism that controls the angle of the blades of the swirler 26. This drive mechanism is connected to the controller 14. The controller 14 adjusts the swirl ratio of the swirling airflow by controlling the angle of the blade through the drive mechanism. Based on the measurement results of the ion current, temperature, and pressure, the controller 14 adjusts the blade angle. These contribute to the continuation of stable combustion. In this combustion apparatus 2, stable combustion can be continued.

  FIG. 7 is a conceptual diagram showing a fuel combustion apparatus 52 according to another embodiment of the present invention. In this figure, a part of the device is shown in cross section. The combustion device 52 includes a combustion cylinder 54, a fuel injector 56, a fuel mixer 58, an igniter 60, an ion detector 62, and a controller 64. In this embodiment, the material of the combustion cylinder 54 is steel. The fuel injector 56, the fuel mixer 58, and the controller 64 of the combustion device 52 are the same as those devices of the combustion device 2 of FIG. The direction indicated by the arrow X in FIG. 7 is the lower side of the combustion device 52, and the opposite direction is the upper side.

  The igniter 60 includes an igniter 66 and a voltage generator. FIG. 7 shows the ignition unit 66 among them. As shown in FIG. 7, in this embodiment, the ignition part 66 is located in the lower lid part 68 and the trunk part 70. A plurality of ignition parts 66 are positioned on the lower lid part 68 and the body part 70. The ignition part 66 located in the lower lid part 68 is located in the staying area, like the ignition part 32 in FIG. In the ignition part 66 located in the trunk | drum 70, the ignition part 66 located in the area | region where mixed gas fuel does not stay exists. For example, there is an ignition unit 66 located at a place where the main flow of the swirling airflow flows. In this embodiment, the igniter 66 located in the stay region and the igniter 66 located in a region away from the stay region coexist. Although not shown, the voltage generator of this embodiment is the same as the voltage generator of FIG.

  The ignition part 66 located in the lower lid part 68 includes a discharge electrode 72 and a first ground electrode 74. The first ground electrode 74 is grounded by contacting the grounded lower lid portion 68. The configuration of the discharge electrode 72 is the same as that of the discharge electrode 34 of FIG.

  The ignition part 66 located in the trunk | drum 70 is located in a line from the lower cover part 68 side toward the opposite side. Each ignition unit 66 includes a discharge electrode 72 and a first ground electrode 74. The discharge electrode 72 and the first ground electrode 74 have a bowl shape formed by bending a rod. The discharge electrode 72 and the first ground electrode 74 of the ignition unit 66 located on the body part 70 protrude from the inner surface of the body part 70 to the inside. The first ground electrode 74 is grounded by contacting the grounded body part 70. The discharge electrode 72 is electrically connected to the voltage generator. A high voltage is applied to the discharge electrode 72 from the voltage generator. As a result, a spark is generated between the tip of the discharge electrode 72 and the tip of the first ground electrode 74. Thereby, the mixed gas fuel is ignited.

  The ion detector 62 includes a detection unit 76 and a detection circuit unit. FIG. 7 shows the detection unit 76 among them. As shown in FIG. 7, the detection unit 76 is located in the lower lid unit 68 and the body unit 70. A plurality of detectors 76 are located on the lower lid 68 and the body 70. In this embodiment, all the detection units 76 are bowl-shaped. The configuration of the detection unit 76 located in the lower lid 68 is the same as that of the detection unit 40 in FIG. Although not shown, the detection circuit unit of this embodiment is the same as the detection circuit unit of FIG.

  The detection parts 76 located in the trunk | drum 70 are located in a line from the lower cover part 68 side toward the opposite side. Each detection unit 76 includes an application electrode 78 and a second ground electrode 80. The application electrode 78 and the second ground electrode 80 have a bowl shape formed by bending a rod. The application electrode 78 and the second ground electrode 80 located on the body part 70 protrude from the inner surface of the body part 70 to the inside. The detection unit 76 is located in the vicinity of the ignition unit 66 located in the trunk unit 70. In the embodiment of FIG. 7, the second ground electrode 80 is the same as the first ground electrode 74 of the ignition unit 66 located in the body unit 70. The second ground electrode 80 may not be common with the first ground electrode 74. The application electrode 78 is electrically connected to the detection circuit unit.

  In the present combustion device 52, the ignition part 66 of the igniter 60 is located in the body part 70 in addition to the lower lid part 68. These ignition parts 66 are arranged from the lower lid part 68 side toward the opposite side. In the combustion device 52, the fuel can be ignited also at the center and above the trunk portion 70. In the combustion device 52, the fuel can be burned in a well-balanced manner throughout the combustion cylinder 54. Thereby, stable ignition and combustion are realized even for flame-retardant fuel.

  In the combustion device 52, the detection unit 76 of the ion detector 62 is located in the vicinity of the ignition unit 66 of the lower lid unit 68 and in the vicinity of the ignition unit 66 of the trunk unit 70. That is, the detection unit 76 is located in the vicinity of the ignition unit 66 located in the stay region and in the vicinity of the ignition unit 66 located in a region away from the stay region. The detection unit 76 in the vicinity of the ignition unit 66 located in the staying region reflects the combustion state of the region where energy is effectively supplied in the detected ion current, so that the state of the flame kernel can be grasped. Become. In this device, air-fuel ratio control based on the state of the flame kernel and control of the ignition timing of the igniter 60 can be realized. This contributes to the formation of a stable flame kernel. In this combustion device 52, stable combustion can be continued.

  In the detection unit 76 in the vicinity of the ignition unit 66 located in a region away from the staying region, the combustion state of the region where the fuel flows at a relatively high speed is reflected in the detected ion current, so that the state of combustion stability is grasped. It becomes possible to do. In this device, air-fuel ratio control based on the degree of combustion stability and control of the ignition timing of the igniter 60 can be realized. This contributes to stabilization of combustion.

  Although not shown, the combustion device 52 may have a plurality of temperature sensors arranged from the lower lid side in the combustion cylinder 54 toward the opposite side. These temperature sensors measure the temperature distribution in the combustion cylinder 54. In the combustion device 52, the controller 64 controls the ignition timing of each igniter 60 based on the measurement results of these temperatures. An appropriate ignition timing of the igniter 60 can be realized depending on the location where the ignition unit 66 is located. These contribute to the continuation of stable combustion. In this combustion device 52, stable combustion can be continued.

  Although not shown, the combustion device 52 may have a plurality of pressure sensors arranged from the lower lid side in the combustion cylinder 54 toward the opposite side. These pressure sensors measure the pressure distribution in the combustion cylinder 54. In the combustion device 52, the controller 64 controls the ignition timing of each igniter 60 based on the measurement results of these pressures. An appropriate ignition timing of the igniter 60 can be realized depending on the location where the ignition unit 66 is located. These contribute to the continuation of stable combustion. In this combustion device 52, stable combustion can be continued.

  FIG. 8 is a view of a lower lid portion 94 of the fuel combustion apparatus 92 according to still another embodiment of the present invention as viewed from above to below. The combustion apparatus 92 is the same as the combustion apparatus 2 of FIGS. 1 and 2 except for the lower lid portion 94, the fuel injector 96, the igniter, and the ion detector 98.

  As shown in FIG. 8, a charging port 100 is provided in the lower lid portion 94 of the combustion device 92. A mixed gas fuel containing fuel is fed from the charging port 100. In this embodiment, the input port 100 has a circular shape.

  The fuel injector 96 is located below the lower lid portion 94 of the combustion cylinder. The fuel injector 96 includes a swirler 102. In FIG. 8, the swirler 102 located below the insertion port 100 is visible. The mixed gas fuel passes through the swirler 102 and becomes a swirling airflow. The mixed gas fuel is fed into the combustion cylinder as a swirling airflow. The material of the swirler 102 is typically steel.

  In FIG. 8, although hidden behind the detection unit 104 and not visible, a plurality of ignition units are located below the detection unit 104. A plurality of ignition parts are arranged in the lower lid part 94 so as to surround the periphery of the circular inlet 100. The area around the inlet 100 is a staying area. A spiral mixed gas fuel having a slower speed than the main flow of the swirling airflow continuously flows into the staying region. For this reason, the mixed gas fuel is repeatedly guided to the ignition unit. The mixed gas fuel repeatedly passes in the vicinity of the ignition part. Thereby, the ignition part 32 can give big energy to mixed gas fuel. In this apparatus, sufficient energy for ignition can be given even to fuel with high ignition energy.

  In this embodiment, a plurality of ignition parts are arranged on a concentric circle of the circular inlet 100. These ignition parts are arranged so as to form one circle on the concentric circle of the inlet 100. By doing so, the mixed gas fuel can be ignited uniformly around the charging port 100. Thereby, the mixed gas fuel can be ignited stably.

  Although not shown, these ignition parts may be arranged on the concentric circle of the inlet 100 so as to form multiple circles. These ignition parts may be arranged in a spiral shape so as to surround the periphery of the charging port 100. By doing so, the mixed gas fuel can be ignited uniformly around the charging port 100. Thereby, the mixed gas fuel can be ignited stably.

  The detection unit 104 of the ion detector 98 is disposed on the lower lid unit 94. The detection unit 104 is a saddle type. As shown in FIG. 8, the detection unit 104 is arranged on a concentric circle of the circular insertion port 100. The detection unit 104 is located in the vicinity of the ignition unit. In the detection unit 104, the detected ion current reflects the combustion state of the region where energy is effectively supplied, so that the state of the flame kernel can be grasped. In this device, air-fuel ratio control based on the state of the flame kernel and control of the ignition timing of the igniter can be realized.

  In the combustion apparatus shown in the above embodiment, the fuel was continuously sent to the combustion apparatus. This combustion apparatus can also be applied to an internal combustion engine such as an automobile. In this case, the fuel is fed into the combustion cylinder and the fuel is ignited as one cycle, and this is repeated.

  As described above, according to the present invention, it is possible to realize a combustion apparatus that can stably continue combustion of a flame-retardant fuel. From this, the superiority of the present invention is clear.

  The fuel combustion apparatus described above is used in various devices.

2, 52, 92 ... Combustion device 4, 54 ... Combustion cylinder 6, 56 ... Fuel injector 8, 58 ... Fuel mixer 10, 60 ... Igniter 12, 62, 98 .... Ion detectors 14, 64 ... Controllers 16, 70 ... Trunk parts 18, 68, 94 ... Lower lid part 20 ... Bottom part 22, 100 ... Input port 24 ... Housing Body 26, 102 ... Swirler 28 ... Fuel tank 30 ... Valve 30a ... First valve 30b ... Second valve 32, 66 ... Ignition part 34, 72 ... Discharge electrode 36 , 74... First ground electrode 38... Area 40, 76... Detection section 40 a... Bowl-shaped detection section 40 b. 104 ... Applied electrode 44, 80 ... Second ground electrode

Claims (15)

  A combustion cylinder, a fuel injector that feeds mixed gas fuel into the combustion cylinder as a swirling airflow, an igniter that includes an ignition section in the combustion cylinder, and an ion detector that includes a detection section in the combustion cylinder; A fuel combustion apparatus comprising: a controller capable of adjusting a mixture ratio of the mixed gas fuel according to a detection result of the ion detector.   The combustion apparatus according to claim 1, wherein the fuel is ammonia.   The combustion apparatus according to claim 1, wherein the detection unit is located in the vicinity of the ignition unit.   The combustion apparatus according to claim 1, wherein the detection unit is common to the ignition unit.   2. The ignition unit includes a discharge electrode and a first ground electrode, the detection unit includes an application electrode and a second ground electrode, and the first ground electrode and the second ground electrode are common. To 4. The combustion apparatus according to any one of 1 to 4.   The combustion device according to any one of claims 1 to 5, wherein the ignition unit is located in a region where the mixed gas fuel stays in the combustion cylinder. The combustion cylinder includes a cylindrical body portion and a lower lid portion that covers the end of the body portion;
The lower lid portion is provided with an inlet into which the mixed gas fuel is fed,
The combustion apparatus according to claim 6, wherein the ignition unit and the detection unit are disposed on the lower lid unit.   The combustion device according to claim 7, wherein the detection unit is disposed in the lower lid part and the body part. The inlet has an annular shape,
The combustion apparatus according to claim 7 or 8, wherein the ignition unit and the detection unit are disposed in a region of the lower lid portion surrounded by the charging port. The inlet has a circular shape;
The combustion apparatus according to claim 7 or 8, wherein the ignition unit and the detection unit are arranged around a charging port in the lower lid unit.   11. The igniter is provided in one or more, and at least one of the igniters is located in a region where the mixed gas fuel does not stay in the combustion cylinder. Combustion equipment.   The combustion device according to claim 11, wherein the ignition unit is disposed in the lower lid part and the body part. Comprising a combustion step of burning the fuel continuously;
In the combustion step, the mixed gas fuel is ignited while being sent as a swirling air flow into the combustion cylinder, the ions generated by the combustion are detected, and the detection result adjusts the mixing ratio of the mixed gas fuel. To burn the fuel. Before the combustion step, further comprising the step of measuring the correlation between the parameter representing the combustion state of the mixed gas fuel and the detection result of ions to set a reference range of the ion detection result,
The fuel combustion method according to claim 13, wherein the adjustment of the mixture ratio of the mixed gas fuel is adjusted so that an ion detection result falls within the reference range.   15. The fuel combustion method according to claim 14, wherein the parameter representing the combustion state of the mixed gas fuel includes an oxide emission amount during combustion.

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