JP2019027629A - Infrared radiation heater - Google Patents

Abstract

To suppress oscillatory burning, in an infrared radiation heater configured to radiate infrared ray from a radiation pipe.SOLUTION: An infrared radiation heater comprises: a combustor configured to combust air-fuel mixture obtained by mixing fuel and air, to emit heat; a cylindrical combustion chamber having a combustion space for combusting the combustor; a radiation pipe having a space connected to the combustion chamber and communicating with the combustion space, and configured to radiate far-infrared ray with heat emitted from the combustor; and a pressure fluctuation resolution unit provided at a connection portion of the combustion chamber and the radiation pipe, and configured to circulate air inside the combustion chamber or radiation pipe to the outside.SELECTED DRAWING: Figure 10

Description

  The present invention relates to an infrared radiation heater.

  There is known an infrared radiation heater including a burner that burns a mixture of fuel and air in a combustion chamber, and a bypass-shaped radiation circuit (radiation tube) that is connected to one of the combustion chambers to emit infrared rays. (For example, refer to Patent Document 1).

  As another type of infrared radiation heater, there is known a radiation type heater having a combustion cylinder in which one end is connected to a radiation unit including a plurality of radiation tubes for heat radiation and arranged in a zigzag manner, and the other end is provided with a burner. (For example, refer to Patent Document 2).

JP-A-5-39924 JP 2008-64409 A

  By the way, in the infrared radiation heater, there is a problem of so-called vibration combustion in which the combustion state of the burner becomes unstable immediately after ignition at start-up, and the internal pressure of the combustion chamber and the radiating portion fluctuates to cause pulsation. Vibratory combustion appears remarkably when the temperature when starting the infrared radiation heater is low or when it is used in a high altitude where the air is thin.

  However, even the conventional infrared radiation heater such as Patent Document 1 or Patent Document 2 has not solved the problem of vibration combustion.

  In addition, it is conceivable to suppress the pulsation by controlling the combustion state of the burner at the time of ignition for such a problem of vibration combustion. was difficult.

  An object of the present invention is to suppress vibration combustion in an infrared radiation heater that radiates infrared rays from a radiation tube.

  The present invention relates to a combustion device that generates heat by burning an air-fuel mixture in which fuel and air are mixed, a cylindrical combustion chamber having a combustion space for combusting the combustion device, and a combustion chamber connected to the combustion chamber. Pressure that allows the air inside the combustion chamber or the radiation tube to circulate to the outside, provided in a connecting portion between the radiation tube that radiates far infrared rays by heat generated by the combustion device and the combustion chamber and the radiation tube A fluctuation elimination unit.

  Further, in the present invention, the pressure fluctuation eliminating portion may be a gap at a connection portion between the combustion chamber and the radiation tube.

  Further, in the present invention, the pressure fluctuation eliminating portion may be formed by a difference in tube diameter of a connection portion between the combustion chamber and the radiation tube.

  In the present invention, the combustion chamber may have a protrusion on the peripheral wall of the connection portion with the radiation tube.

  In the present invention, the protrusion may form the pressure fluctuation eliminating portion.

  Also, the present invention provides an ignition unit in which the combustion device is supplied with fuel and air and ignites the fuel, and a control unit that controls the amount of fuel and air supplied to the ignition unit to control the combustion state of the ignition unit. A first control mode in which the control unit supplies fuel and air to the ignition unit with a predetermined supply amount, and a second control for supplying fuel and air to the ignition unit with a smaller supply amount than in the first control mode The combustion state of the ignition part may be controlled in the second control mode for an arbitrary time after the ignition part is ignited.

  Further, according to the present invention, the control unit includes an air control unit that controls an air supply amount to the ignition unit, and the air control unit supplies the air to the ignition unit with a predetermined supply amount. Mode and a second air supply amount mode for supplying air to the ignition unit with a supply amount smaller than that of the first air supply amount mode, and can be switched for the first predetermined time before ignition of the ignition unit. Air may be supplied to the ignition unit in the air supply amount mode, and air may be supplied to the ignition unit in the second air supply amount mode for a second predetermined time after ignition of the ignition unit.

  In the present invention, the air control unit may supply air to the ignition unit in the first air supply amount mode after supplying air to the ignition unit in the second air supply amount mode.

  Further, according to the present invention, the control unit includes a fuel control unit that controls a supply amount of fuel to the ignition unit, and the fuel control unit supplies air to the ignition unit in the second air supply amount mode. The fuel may be supplied to the ignition unit after a third predetermined time later.

  Further, according to the present invention, the fuel control unit supplies the fuel to the ignition unit with a first fuel supply amount mode in which the fuel is supplied to the ignition unit with a predetermined supply amount, and a supply amount smaller than the first fuel supply amount mode. The second fuel supply amount mode can be switched, and after the third predetermined time has elapsed, the fuel is supplied in the second fuel supply amount mode, and after the fuel is supplied in the second fuel supply amount mode, the fuel is supplied for the fourth predetermined time. After the elapse, fuel may be supplied in the first fuel supply amount mode.

  According to the present invention, vibration combustion can be suppressed in an infrared radiation heater that emits infrared light from a radiation tube.

It is a perspective view which shows the infrared radiation heater which concerns on embodiment of this invention. It is a front view of the infrared radiation heater of FIG. It is a right view of the infrared radiation heater of FIG. It is a schematic diagram which shows the internal structure of the infrared radiation heater of FIG. It is a schematic diagram which shows the combustion chamber of the infrared radiation heater of FIG. 1, a radiation | emission part, and a discharge pipe. It is a schematic diagram which shows the U-shaped radiation tube of the infrared radiation heater of FIG. It is a schematic diagram which shows the functional structure of the radiation | emission part and discharge pipe of an infrared radiation heater. It is a front view which shows the combustion chamber of an infrared radiation heater. (A) The left view which shows the combustion chamber of an infrared radiation heater, (B) The right view which shows the structure of the combustion chamber of an infrared radiation heater. It is a schematic diagram which shows the connection part of the combustion chamber and radiation | emission part of an infrared radiation heater. It is a schematic diagram which shows the combustion apparatus of an infrared radiation heater. It is a sequence diagram which shows control and operation | movement before and behind ignition of an infrared radiation heater.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Configuration of infrared radiation heater]
FIG. 1 is a perspective view showing an infrared radiation heater 1 according to an embodiment of the present invention. FIG. 2 is a front view of the infrared radiation heater 1. As shown in FIGS. 1 and 2, the infrared radiation heater 1 includes a frame 2, a panel 3, a mesh portion 4, a caster 5, a switch 6, and a fuel tank 7 as components exposed to the outside. And a chimney 8.

  In the following description, a surface on which the mesh portion 4 of the infrared radiation heater 1 is provided is a front surface, and a surface opposite to the front surface (a surface viewed from the back surface direction of the paper in FIG. 1) is a back surface. The surface facing the installation surface of the infrared radiation heater 1, that is, the surface on which the casters 5 and the fuel tank 7 are provided is defined as the bottom surface.

  The infrared radiation heater 1 has a substantially rectangular parallelepiped shape. The infrared radiation heater 1 has a substantially rectangular shape in which the length in the vertical direction (height direction) is shorter than the length in the horizontal direction when viewed from the front.

  FIG. 3 is a side view of the infrared radiation heater 1. As shown in FIG. 3, the infrared radiation heater 1 has a substantially rectangular shape in which the length in the horizontal direction (depth direction) is shorter than the length in the vertical direction in a side view.

  The frame 2 accommodates main components of the infrared radiation heater 1 such as a combustion device, a combustion chamber, and a radiation tube. The frame 2 forms a substantially rectangular parallelepiped outer shape of the infrared radiation heater 1. The frame 2 is made of a metal material that is resistant to high temperatures and that is suitable for housing components that become hot when the infrared radiation heater 1 is used, such as a combustion chamber or a radiation tube.

  The panel 3 covers the internal structure of the infrared radiation heater 1 from the outside. The panel 3 is made of, for example, a metal plate-like member in order to withstand heat from a combustion chamber and a radiation tube described later.

  As shown in FIG. 2, the mesh part 4 is a mesh-like opening provided in a part of the panel 3 in order to radiate infrared rays from the radiation part 11 to the outside, for example.

  The casters 5 are attached near the four corners of the bottom of the frame 2. Since the caster 5 is provided with wheels, the infrared radiation heater 1 can be easily moved by being manually pushed by the user. In the infrared radiation heater 1, the leg portion for supporting the apparatus on the installation surface may have no wheel instead of the caster 5 with the wheel.

  The switch 6 accepts operations of the infrared radiation heater 1 such as ON / OFF of operation, combustion intensity and temperature setting from the user. The switch 6 includes a control unit that controls the operation of the infrared radiation heater 1 according to the accepted operation. The operation of the control unit will be described later. The switch 6 is desirably provided at a position where the user can easily operate, for example, an upper position on the panel 3.

  As shown in FIG. 4, the fuel tank 7 is provided below the combustion device 9, the combustion chamber 10, and the radiation unit 11, that is, at the bottom of the infrared radiation heater 1. The fuel tank 7 stores fuel for the infrared radiation heater 1 such as kerosene. The fuel tank 7 has a shape in which the direction along the bottom surface of the frame 2 that is long in the horizontal direction in the front view is the longitudinal direction.

  A cap 72 is attached to the fuel tank 7 at the fuel filler opening. The cap 72 is exposed to the outside from an oil supply opening 71 provided on the right side of the frame 2. When fuel is supplied to the fuel tank 7, fuel is injected from the fuel filler port from which the cap 72 is removed.

  A tank cover 73 that covers the fuel tank 7 from the bottom and protects the fuel tank 7 is provided at the bottom of the infrared radiation heater 1. The tank cover 73 is formed by molding a hard plate member such as a steel plate by bonding or pressing. The tank cover 73 is formed in a trapezoidal shape in a side view with a portion corresponding to a substantially columnar lower bottom surface opened.

[Infrared radiation heater internal structure]
Next, the internal structure of the infrared radiation heater 1 will be described.

  FIG. 4 is a schematic diagram showing the internal structure of the infrared radiation heater 1. As shown in FIG. 4, the infrared radiation heater 1 includes a combustion device 9, a combustion chamber 10, a radiation portion 11, and a discharge pipe 12 inside a frame 2.

  The combustion device 9 is disposed below the frame 2 of the infrared radiation heater 1. The combustion device 9 includes a nozzle, a fan, a fuel pump, and the like, which will be described later, and sends and mixes fuel such as kerosene and air into the combustion chamber 10 and burns the mixture in the combustion chamber 10.

  The combustion chamber 10 is formed in a cylindrical shape using a material that can withstand a temperature of about 800 ° C., stainless steel (for example, SUS302B) having a thickness of about 0.8 mm, and the like. The combustion chamber 10 has a combustion space for burning the air-fuel mixture inside the combustion chamber 10 such as a substantially cylindrical shape formed hollow. The combustion space inside the combustion chamber 10 has a temperature of about 800 ° C. when the combustion device 9 is burned.

  FIG. 5 is a schematic diagram showing the combustion chamber 10, the radiating portion 11, and the exhaust pipe 12 of the infrared radiation heater 1. As shown in FIG. 5, the radiating portion 11 is a tubular member having a space inside the tube wall. One end of the radiating unit 11 is connected to the combustion chamber 10. The radiating unit 11 has an internal space communicating with a combustion space inside the combustion chamber 10. The radiating portion 11 is formed using a material that can withstand a temperature of at least about 600 ° C., stainless steel (for example, SUS304) having a plate thickness of about 0.3 mm, as in the combustion chamber 10.

  FIG. 6 is a schematic diagram showing the U-shaped radiation tube 14 constituting the radiation unit 11. As shown in FIG. 6, the U-shaped radiation tube 14 has a bellows portion 141 and a straight tube portion 142. The radiation part 11 is configured by using the bellows part 141 and the straight pipe part 142 of the two U-shaped radiation tubes 14 in combination with each other. The inner diameter D of the U-shaped radiation tube 14 is, for example, 100 mm. The length L of the straight portion of the U-shaped radiation tube 14 is, for example, 835 mm. The U-shaped radiation tube 14 includes a bellows portion 141 and a straight tube portion 142 that are integrally formed. Note that the bellows portion 141 and the straight pipe portion 142 may be formed individually and then integrally formed by welding or the like.

  The bellows portion 141 is a substantially U-shaped tube having a space inside. The bellows portion 141 can be adjusted in the degree of bending of a substantially U shape to improve assemblability and the like. The straight pipe part 142 is a cylindrical pipe having a space communicating with the bellows part 141.

  The tube wall of the radiating unit 11 is heated by transferring heat generated by the combustion device 9 inside the combustion chamber 10. As a result, infrared rays are radiated from the tube wall of the radiation portion 11 to the outside of the infrared radiation heater 1.

  One end of the discharge pipe 12 is connected to the other end of the radiating section 11 opposite to the side connected to the combustion chamber 10. The discharge pipe 12 has a space communicating with the radiating portion 11. The exhaust pipe 12 is formed using a material that can withstand a temperature of at least about 600 ° C., for example, stainless steel (SUS304), like the combustion chamber 10 and the radiating portion 11. The inner diameter of the discharge pipe 12 is, for example, 100 mm, similar to the inner diameter of the U-shaped radiation pipe 14.

[Configuration of radiation section and discharge pipe]
Next, the functional configuration of the radiation section 11 and the discharge pipe 12 of the infrared radiation heater 1 will be described.

  FIG. 7 is a schematic diagram showing a functional configuration of the radiation section 11 and the discharge pipe 12 of the infrared radiation heater 1. As described above, the radiating unit 11 is configured by combining two U-shaped radiating tubes 14, but in the following description, depending on the temperature at the time of heating the radiating unit 11, the wavelength of emitted infrared rays, and the like. The parts of the radiation part 11 are classified as follows.

  As shown in FIG. 7, in the infrared radiation heater 1, the function of radiating infrared rays in the radiation unit 11 is classified into a first curved tube 111 and a radiation tube 112. The radiation tube 112 is classified into a first tubular portion 113, a second curved tube 114, and a second tubular portion 121 for each function of emitting infrared rays. The first curved tube 111 and the first cylindrical portion 113 correspond to one of the two U-shaped radiation tubes 14, and the second curved tube 114 and the second cylindrical portion 121 correspond to the other U-shaped radiation tube 14. Corresponding to

  The first curved pipe 111 is connected to the combustion chamber 10 and communicates with the combustion space of the combustion chamber 10. The first curved tube 111 is closer to the combustion chamber 10 than the radiation tube 112. Therefore, the first bent tube 111 is heated at about 500 ° C., which is higher than that of the radiation tube 112. Near infrared rays having a shorter wavelength than far infrared rays (3 to 10 μm) are radiated from the first bent tube 111 heated at about 500 ° C. to the outside.

  The first cylindrical portion 113 is arranged in a substantially horizontal direction above the combustion chamber 10 in the vertical direction, and is connected to the first curved pipe 111. The first tubular portion 113 is a straight pipe having a space communicating with the first curved pipe 111. The first tubular portion 113 is heated to approximately 300 to 400 ° C., which is a lower temperature than the first curved tube 111, due to heat transmitted from the first curved tube 111. The first cylindrical portion 113 heated to approximately 300 to 400 ° C. radiates far infrared rays having a wavelength of 3 to 10 μm to the outside of the tube mainly by heat transmitted from the first curved tube 111.

  As shown in FIG. 6, for example, the first tubular portion 113 has a straight portion having a length L of approximately 835 mm. As described above, the first tubular portion 113 is formed of a cylindrical tube having an inner diameter D of approximately 100 mm.

For this reason, as for the 1st cylindrical part 113 in the radiation tube 112, the internal diameter D of a pipe | tube and the length L of the linear part of a pipe | tube become the relationship of the following formula | equation.
L / D = 8.35

  Here, in the infrared radiation heater 1, the cylindrical radiation part 11 is heated by the heat of the combustion chamber 10 connected to one end of the radiation part 11 in the axial direction to emit infrared rays. For this reason, in the infrared radiation heater 1, when the axial distance from the combustion chamber 10 increases, the surface temperature of the radiation section 11 decreases. That is, in the radiating portion 11 of the infrared radiation heater 1, the position of the region heated to 300 to 400 ° C. that irradiates far infrared rays is determined by the axial distance from the combustion chamber 10. Moreover, in order to increase the area | region which irradiates a far infrared ray, the surface area of the radiation | emission part 11 of the area | region which can irradiate a far infrared ray is important.

  And in the infrared radiation heater 1, when the ratio of the length of L and D has the above relationship, the 1st cylindrical part 113 can increase the area heated to about 300-400 degreeC. . When the ratio of the lengths of L and D is in such a relationship, the first cylindrical portion 113 can efficiently radiate far infrared rays mainly having a wavelength of 3 to 10 μm to the outside of the tube.

In consideration of the above conditions, the relationship between the length ratios of L and D is
L / D = 6.2 to 8.4
It is desirable to be within the range.

  The second curved tube 114 is a substantially U-shaped tube that connects the first tubular portion 113 and the second tubular portion 121. The second curved pipe 114 has a space communicating with the first cylindrical portion 113 and the second cylindrical portion 121. The second bent tube 114 is heated to a temperature lower than that of the first tubular portion 113 by heat transmitted from the first tubular portion 113. The second curved tube 114 radiates far infrared rays having a wavelength of mainly 3 to 10 μm to the outside of the tube by heat transmitted from the first cylindrical portion 113.

  The second tubular portion 121 is arranged in a substantially horizontal direction in the vertical direction above the first tubular portion 113 and is connected to the first tubular portion 113. The second cylindrical portion 121 is a straight pipe having a space communicating with the second curved pipe 114. The second tubular portion 121 is heated to approximately 200 ° C., which is a lower temperature than the second curved tube 114, by the heat transmitted from the second curved tube 114.

  The discharge pipe 12 has a space that communicates with the radiation pipe 112. The discharge pipe 12 discharges air (hot air) that has passed through the radiating unit 11 to the outside. As shown in FIG. 4, the other end of the discharge pipe 12 is provided with a chimney 8 for discharging warm air to the outside. From the discharge pipe 12, infrared rays due to heat passing through the radiation pipe 112 are also emitted. The discharge pipe 12 includes a bent portion 122 and a flow rate limiting portion 13.

  The bent portion 122 is provided above the first bent tube 111 in the vertical direction, and is bent from a substantially horizontal direction to a substantially vertical direction. The inner diameter of the bent portion 122 is, for example, 100 mm, similar to the inner diameter D of the U-shaped radiation tube 14 used for the radiation portion 11 and the discharge tube 12.

  The flow rate limiting unit 13 is provided at the other end of the discharge pipe 12, that is, at the end of the discharge pipe 12 on the chimney 8 side. The flow rate limiting unit 13 is provided inside the discharge pipe 12. The flow rate limiting unit 13 is provided with a plurality of holes in the tube wall of a tube having an inner diameter smaller than the inner diameter of the discharge tube 12. The flow rate restriction unit 13 restricts the flow rate of the discharged air by an inner diameter smaller than that of the discharge pipe 12. Moreover, the flow velocity limiting unit 13 obtains a silencing effect by the tube wall and the hole in the tube wall. For this reason, the flow velocity limiting unit 13 functions as a silencer.

[Composition of combustion chamber]
Next, the structure of the combustion chamber 10 of the infrared radiation heater 1 will be described.

  FIG. 8 is a front view showing the combustion chamber 10 of the infrared radiation heater 1. FIG. 9A is a left side view showing the combustion chamber 10, and FIG. 9B is a right side view showing the configuration of the combustion chamber 10. As shown in FIGS. 8 and 9, the combustion chamber 10 includes a combustion chamber main body 101, a first partition wall 102, a second partition wall 103, a first opening 104, a second opening 105, and a second opening peripheral wall 106. And a protrusion 107.

  The combustion chamber body 101 defines the general shape of the cylindrical combustion chamber 10. The combustion chamber main body 101 is formed using a material that can withstand a temperature of about 800 ° C., stainless steel (for example, SUS302B) having a thickness of about 0.8 mm, and the like. The combustion chamber main body 101 is formed in a hollow shape, and forms a combustion space for burning the air-fuel mixture inside the combustion chamber 10 therein.

  The first partition wall 102 is provided between the combustion device 9 and the combustion chamber 10. The first partition wall 102 forms a partition wall between the combustion device 9 and the combustion chamber 10. The first partition wall 102 is formed using a material that can withstand a temperature of about 800 ° C., like the combustion chamber body 101. The first partition wall 102 is provided with a rib that protrudes axially outward from the first partition wall 102.

  The second partition wall 103 is provided between the combustion chamber 10 and the radiating unit 11. The second partition 103 forms a partition between the combustion chamber 10 and the radiating portion 11. The second partition wall 103 is formed using a material that can withstand a temperature of about 800 ° C., like the combustion chamber body 101. The second partition wall 103 is provided with a rib that protrudes axially outward from the second partition wall 103.

  The first opening 104 is provided at a rib position of the first partition wall 102. The first opening 104 is an opening for allowing the flame and air from the combustion device 9 to flow through the combustion space of the combustion chamber 10.

  The second opening 105 is provided at the rib position of the second partition wall 103. The second opening 105 is an opening for allowing the air inside the combustion chamber 10 to flow inside the radiating portion 11. A second opening peripheral wall 106 facing the tube wall inside the radiating portion 11 is provided outside the rib of the second opening 105 in the radial direction.

  The protrusion 107 is provided on a connection portion between the combustion chamber 10 and the radiating portion 11, specifically, on the second opening peripheral wall 106 of the second opening 105. The protrusion 107 is provided on the surface of the second opening peripheral wall 106 so as to protrude outward in the radial direction from the central axis of the combustion chamber 10.

  FIG. 10 is a schematic diagram showing a connection portion between the combustion chamber 10 and the radiation portion 11 of the infrared radiation heater 1. As shown in FIG. 10, the protrusion 107 functions as a member that forms a pressure fluctuation eliminating portion that allows the air inside the combustion chamber 10 or the radiating portion 11 to flow outside. Here, there is a difference in the tube diameter of the connecting portion between the combustion chamber 10 and the radiating portion 11. Specifically, the inner diameter of the U-shaped radiation tube 14 of the radiating portion 11 is larger than the outer diameter of the second opening peripheral wall 106 of the combustion chamber 10. In other words, the pressure fluctuation eliminating portion is a gap formed by a difference in tube diameter at the connection portion between the combustion chamber 10 and the radiating portion 11.

  By providing the pressure fluctuation eliminating section, the infrared radiation heater 1 can release the air due to the pressure fluctuation in the combustion chamber 10 and the radiation section 11 due to vibration combustion that occurs immediately after the combustion device 9 ignites. Thereby, in the infrared radiation heater 1, even if the pulsation by the pressure fluctuation inside the combustion chamber 10 and the radiation part 11 which causes vibration combustion after ignition occurs, the influence can be suppressed. For this reason, according to the infrared radiation heater 1, the malfunction by vibration combustion can be eliminated.

  As shown in FIG. 9A, four protrusions 107 are provided evenly every 90 ° along the peripheral surface of the second opening peripheral wall 106 of the substantially circular second opening 105. By providing the protrusions 107 at a plurality of locations on the second opening peripheral wall 106 in this way, the dimensions and positions of the gaps that function as the pressure fluctuation eliminating portion can be made uniform. The protrusions 107 may be provided at uneven intervals as long as they are provided on the peripheral surface of the second opening peripheral wall 106. Further, the number of the protrusions 107 is not particularly limited. Further, the shape of the protrusion 107 is not particularly limited as long as a gap can be formed between the second opening 105 of the combustion chamber 10 and the radiating portion 11.

  In the above description, the protrusion 107 is provided on the second opening peripheral wall 106 which is the tube wall of the connection portion with the radiating portion 11 of the combustion chamber 10. For example, the protrusion 107 is provided on the tube wall of the radiating portion 11. Thus, a pressure fluctuation eliminating portion may be formed. Moreover, the difference in the tube diameter of the connection part of the combustion chamber 10 and the radiation | emission part 11 is not limited to the above-mentioned relationship, For example, the internal diameter of the 2nd opening 105 of the combustion chamber 10 rather than the outer diameter of the U-shaped radiation tube 14 May be large. Further, the pressure fluctuation elimination unit is not limited to the gap as described above, and for example, an opening may be provided at a connection portion between the combustion chamber 10 and the radiating unit 11.

[Combustion device configuration]
Next, the configuration of the combustion device 9 of the infrared radiation heater 1 will be described.

  FIG. 11 is a schematic diagram showing the combustion device 9 of the infrared radiation heater 1. The combustion device 9 includes a nozzle 15, a fan 16, a motor 17, a fuel supply device 20, an igniter 33, an ignition unit 34, a flame detector 35, and a thermostat 36.

  The fan 16 is provided to supply air to the combustion chamber 10. The fan 16 is driven by the motor 17 to rotate.

  The fuel supply device 20 supplies fuel from the fuel tank 7 to the nozzle 15. The fuel tank 7 and the fuel supply device 20 are connected by a pipe 31. A fuel filter 32 is provided at the end of the pipe 31 on the fuel tank 7 side.

  The fuel supply device 20 includes a pump 21 for injecting fuel from the nozzle 15 toward the combustion chamber 10, and a solenoid valve for returning the fuel to the fuel tank 7 from the nozzle 15 at the outlet of the pump 21 to release the residual pressure of the nozzle. 22. The pump 21 can be a general electromagnetic pump.

  The igniter 33 is provided to ignite the fuel sprayed in the ignition unit 34. The ignition unit 34 is a space for igniting and burning the fuel injected from the nozzle 15 by the igniter 33.

  The flame detector 35 detects a flame in the ignition unit 34. The thermostat 36 is a safety device when the inside of the infrared radiation heater 1 is overheated.

  The fan 16, the pump 21 and the electromagnetic valve 22 of the fuel supply device 20, the igniter 33, the flame detector 35, and the thermostat 36 are connected to a control unit inside the switch 6.

  The control unit 60 controls the air supply amount by the fan 16 and the fuel supply amount by the pump 21 in accordance with signals from these connected components. That is, the control unit 60 has a function as an air control unit that controls the amount of air supplied to the ignition unit 34 and a function as a fuel control unit that controls the amount of fuel supplied to the ignition unit 34.

[Operation of control unit]
Next, operation | movement of the control part 60 of the infrared radiation heater 1 is demonstrated.

  The control unit 60 controls the combustion state of the ignition unit 34 by controlling the supply amounts of fuel and air. The controller 60 controls the fuel and air to be supplied to the ignition unit 34 at a predetermined supply amount, and supplies the fuel and air to the ignition unit 34 at a supply amount smaller than that of the first control mode. It is possible to switch between the second control mode to be controlled as described above.

  The control unit 60 can switch the fuel supply amount from the pump 21 and the drive amount (air flow rate) of the fan 16 in order to realize the first control mode and the second control mode. The first control mode is generally referred to as a strong combustion mode. Further, the second control mode is generally referred to as a weak combustion mode.

  In the first control mode, the fan 16 is controlled to supply air to the ignition unit 34 with a predetermined supply amount. In the following description, the air supply amount mode in the first control mode is referred to as a first air supply amount mode. In the first control mode, fuel is supplied to the ignition unit 34 with a predetermined supply amount. In the following description, the fuel supply amount mode in the first control mode is referred to as a first fuel supply amount mode.

  In the second control mode, the fan 16 that supplies air to the ignition unit 34 with a smaller supply amount than in the first air supply amount mode is controlled. In the following description, the air supply amount mode in the second control mode is referred to as a second air supply amount mode. In the second control mode, the fuel is supplied to the ignition unit 34 with a smaller supply amount than in the first fuel supply amount mode. In the following description, the fuel supply amount mode in the second control mode is referred to as a second fuel supply amount mode.

  The control unit 60 can integrally change the air supply amount and the fuel supply amount between the first control mode and the second control mode. Further, the control unit 60 can change the air supply amount and the fuel supply amount individually between the first control mode and the second control mode.

  FIG. 12 is a sequence diagram showing control and operation before and after ignition of the infrared radiation heater. In FIG. 12, the code | symbol in the left end of a diagram shows operation | movement of the following components.

Switch operation ON / OFF: SW
Thermostat 36 ON / OFF: TH
Air flow of fan 16: CF
ON / OFF of igniter 33: IG
Fuel supply amount of pump 21: PF
ON / OFF of solenoid valve 22: SO
Whether or not the flame detector 35 detects a flame (ON / OFF): FD

  The sequence before and after ignition of the infrared radiation heater 1 will be described with reference to FIG. In the following description, the operation of the infrared radiation heater 1 is shown in time series with t = 0 when a driving operation ON is received from the switch 6.

  When receiving an ON operation from the switch 6, the control unit 60 turns on the operation of the thermostat 36 indicated by TH and the operation of the fan 16 indicated by CF. At this time, the control unit 60 sets the air supply amount by the fan 16 indicated by CF to the first air supply amount mode (F1) of the strong combustion mode (first control mode). The control unit 60 supplies air to the ignition unit 34 in the first air supply amount mode (F1) for a first predetermined time (t1: for example, 15 seconds) before ignition of the ignition unit 34. During the first predetermined time (t1), as shown by IG, the delay timer of the igniter 33 is operating. For this reason, the ignition operation of the igniter 33 is not performed until the first predetermined time has elapsed. Further, when a flame is detected by the flame detector 35 before the first predetermined time elapses, the control unit 60 determines that the flame (simulated light) detection is an error.

  After the elapse of the first predetermined time (t1), as indicated by IG, the igniter 33 is shifted from the OFF state to the ignition operation (ON state) by the delay timer.

  At the same time that the igniter 33 shifts to the ignition operation (ON state), the control unit 60 changes the blowing amount of the fan 16 from the first air supply amount mode (F1) to the second air supply amount mode (F2) as indicated by CF. Change to The controller 60 continuously supplies air to the ignition unit 34 in the second air supply amount mode (F2) for a second predetermined time (t2) after ignition of the ignition unit 34.

  The control unit 60 turns on the power of the pump 21 as indicated by PF after a lapse of a third predetermined time (t3: 2 seconds, for example) after setting the air flow rate of the fan 16 to the second air supply amount mode. Then, the pump 21 is shifted from the OFF state to the ON state.

  After shifting the pump 21 to the ON state, the control unit 60 controls the combustion state of the ignition unit 34 in the second control mode for a predetermined time after the ignition operation of the ignition unit 34 is started by the igniter 33. Specifically, as indicated by PF, the control unit 60 controls the fuel supply amount of the pump 21 so that fuel is supplied to the ignition unit 34 in the second fuel supply amount mode (P2) during weak combustion. To control the combustion state.

  As indicated by SO, the control unit 60 sets a delay timer for releasing the residual pressure of the nozzle after supplying fuel in the second fuel supply amount mode (P2) (t4-1: for example, 5 seconds). After the elapse of time, the power supply of the solenoid valve 22 is changed from OFF to ON.

  As indicated by FD, the control unit 60 waits for a flame detection determination until a delay timer set time (t4-1) and a flame detection waiting time (t4-2) for releasing the residual pressure of the nozzle have elapsed. . If a flame is detected by the flame detector 35 before the first predetermined time (t1) and the third predetermined time (t3) have elapsed, the control unit 60 determines that the flame (pseudo-light) detection is an error. judge.

  The controller 60 detects the flame by the flame detector 35 after the fourth predetermined time (t4) has elapsed since the fuel was supplied in the second fuel supply amount mode (P2). The operation of the pump 21 is controlled so as to supply fuel in the mode (P1).

  The controller 60 supplies air to the ignition unit 34 for the second predetermined time (t2) in the second air supply amount mode (F2), and then supplies air to the ignition unit 34 in the first air supply amount mode (F1). .

  Here, the timing after the elapse of the second predetermined time (t2) and the timing after the elapse of the fourth predetermined time (t4) are synchronized. That is, the control unit 60 performs the second air supply amount mode (F2) included in the second control mode for an arbitrary time after the ignition of the ignition unit 34 (t2: the same as the second predetermined time in the present embodiment). ) And the second fuel supply amount mode (P2), the air supply amount and the fuel supply amount are controlled. By doing so, the control unit 60 controls the combustion state of the ignition unit 34.

  The controller 60 controls the air supply amount and the fuel supply amount in the first air supply amount mode (F1) and the first fuel supply amount mode (P1) both included in the first control mode.

  After the post-ignition time (t5 = 40 seconds, for example), the control unit 60 changes the power supply of the igniter 33 from the ON state to the OFF state in order to stop the ignition operation of the igniter 33. The control unit 60 performs combustion control according to normal strong combustion (first control mode) and weak combustion (second control mode).

[Effect of the embodiment]
According to the infrared radiant heater 1 described above, vibration combustion is provided by a pressure fluctuation canceling portion that is provided at a connection portion between the combustion chamber 10 and the radiating portion 11 and circulates the air inside the combustion chamber 10 or the radiating portion 11 to the outside. Can be suppressed.

  Moreover, according to the infrared radiation heater 1 demonstrated above, the control part 60 can control the fuel supply amount and air supply amount after ignition, and can suppress vibration combustion. Further, according to the infrared radiation heater 1, vibration combustion can be further suppressed by releasing the pressure fluctuation of the air inside the combustion chamber 10 and the radiation part 11 by the pressure fluctuation canceling part and the control by the control part 60.

1: Infrared radiation heater 2: Frame 3: Panel 4: Mesh part 5: Caster 6: Switch 7: Fuel tank 8: Chimney 9: Combustion device 10: Combustion chamber 11: Radiation part 12: Exhaust pipe 13: Flow rate restriction part 14 : U-shaped radiation tube 15: Nozzle 16: Fan 17: Motor 20: Fuel supply device 21: Pump 22: Solenoid valve 31: Pipe 32: Fuel filter 33: Igniter 34: Ignition unit 35: Flame detector 36: Thermostat 60: Control unit 71: Refueling opening 72: Cap 73: Tank cover 101: Combustion chamber body 102: First partition wall 103: Second partition wall 104: First opening 105: Second opening 106: Second opening peripheral wall 107: Protrusion 111: 1st curved pipe 112: Radiation pipe 113: 1st cylindrical part 114: 2nd curved pipe 121: 2nd cylindrical part 122: Bending part 141: Bellows 142: straight pipe section

Claims (10)

A combustion device for generating heat by burning a mixture of fuel and air; and
A cylindrical combustion chamber having a combustion space for burning the combustion device;
A radiation tube that is connected to the combustion chamber and communicates with the combustion space, and radiates far-infrared rays by heat generated by the combustion device;
A pressure fluctuation canceling portion that is provided at a connection portion between the combustion chamber and the radiation tube, and circulates the air inside the combustion chamber or the radiation tube to the outside;
Comprising
Infrared radiation heater. The pressure fluctuation canceling portion is a gap at a connection portion between the combustion chamber and the radiation tube.
The infrared radiation heater according to claim 1. The pressure fluctuation elimination part is formed by a difference in tube diameter of a connection portion between the combustion chamber and the radiation tube.
The infrared radiation heater according to claim 1 or 2. The combustion chamber has a protrusion on a peripheral wall of a connection portion with the radiation tube.
The infrared radiation heater according to any one of claims 1 to 3. The protrusion forms the pressure fluctuation elimination part.
The infrared radiation heater according to claim 4. The combustion device comprises:
An ignition unit that is supplied with fuel and air and ignites the fuel;
A control unit that controls the amount of fuel and air supplied to the ignition unit to control the combustion state of the ignition unit;
Have
The controller is
A first control mode for supplying fuel and air to the ignition unit at a predetermined supply amount;
A second control mode for supplying fuel and air to the ignition unit with a smaller supply amount than the first control mode;
Can be switched,
Controlling the combustion state of the ignition part in the second control mode only for an arbitrary time after the ignition part is ignited;
The infrared radiation heater according to any one of claims 1 to 5. The controller is
An air control unit for controlling the amount of air supplied to the ignition unit;
Have
The air control unit
A first air supply amount mode for supplying air to the ignition unit at a predetermined supply amount;
A second air supply amount mode for supplying air to the ignition unit with a supply amount smaller than the first air supply amount mode;
Can be switched,
Supplying air to the ignition unit in the first air supply amount mode only for a first predetermined time before ignition of the ignition unit;
Supplying air to the ignition unit in the second air supply amount mode only for a second predetermined time after ignition of the ignition unit;
The infrared radiation heater according to claim 6. The air control unit
Supplying air to the ignition unit in the first air supply amount mode after supplying air to the ignition unit in the second air supply amount mode;
The infrared radiation heater according to claim 7. The controller is
A fuel control unit for controlling the amount of fuel supplied to the ignition unit;
Have
The fuel control unit includes:
The air control unit supplies fuel to the ignition unit after a lapse of a third predetermined time after supplying air to the ignition unit in the second air supply amount mode;
The infrared radiation heater according to claim 7 or 8. The fuel control unit includes:
A first fuel supply amount mode for supplying fuel to the ignition unit at a predetermined supply amount;
A second fuel supply amount mode for supplying fuel to the ignition unit with a supply amount smaller than the first fuel supply amount mode;
Can be switched,
After the elapse of the third predetermined time, fuel is supplied in the second fuel supply amount mode,
Supplying fuel in the first fuel supply amount mode after a lapse of a fourth predetermined time after supplying fuel in the second fuel supply amount mode;
The infrared radiation heater according to claim 9.