JP2007218468A - Ignition method of biomass fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition method of biomass fuel capable of preventing generation of smoke in igniting biomass fuel, in particular, improving accuracy in controlling hot water in a biomass fuel water heater. <P>SOLUTION: The biomass fuel water heater 1 as a biomass fuel device burns the biomass fuel such as chaff, sawdust and woody pellet in a combustion chamber 11 of a combustion portion 3. A temperature of a combustion pan 10 of the combustion portion 3 is detected before the biomass fuel is ignited, so that the igniting operation is performed without change when the temperature of the combustion pan 10 is within an ignition proper temperature range, the igniting operation is performed after the combustion pan 10 is heated to the ignition proper temperature range (60°C or more and less than 150°C) by a burner 15 as a heating means when the temperature of the combustion pan 10 is lower than the ignition proper temperature range, and the igniting operation is performed after the temperature of the combustion pan 10 is lowered to the ignition proper temperature range by introducing the outside air by a combustion fan 13 or a suction fan 22 as a cooling means, when the temperature of the combustion pan 10 is higher than the proper temperature range. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel tank for storing biomass fuel such as rice husk, large sawdust or wood pellet, a combustion section for burning biomass fuel, and a biomass combustion apparatus for supplying biomass fuel from the fuel tank to the combustion section for combustion. The present invention relates to a method for igniting biomass fuel that has improved ignitability by eliminating smoke and reducing ignition time.

  An ignition method of a combustion apparatus for burning wood pellet fuel, and a method of igniting after preheating the combustion part at the time of ignition is disclosed in Japanese Patent Application Laid-Open No. 2004-191016, and an apparatus for preheating combustion means at the time of re-ignition in a combustor, Japanese Patent Application Laid-Open No. 10-160157 discloses a pot-type combustor equipped with a preheating heater. Japanese Patent Application Laid-Open No. 2001-99424 discloses a method for preheating a catalytic combustion unit in a catalytic combustion apparatus. Moreover, the method of preheating a vaporizer and heating a combustion chamber in an oil-fired hot water boiler is described in JP-A-6-2950.

JP 2004-191016 A Japanese Patent Laid-Open No. 10-160157 JP 2001-99424 A JP 2003-28403 A JP-A-6-2950

  Biomass fuel such as wood pellets generates a large amount of smoke when ignited, extinguished, and reignited after extinguishing. It is not necessarily a suitable fuel for hot water heaters and the like, but the current situation is that heating devices and water heaters that use biomass fuel are preventing their spread.

  By the way, it is conventionally known that the amount of smoke generated when the biomass fuel is ignited is due to the low temperature of the biomass fuel. Therefore, various means for igniting after increasing the temperature of the biomass fuel are taken. It has been. However, according to the knowledge of the present inventor, it has been clarified that a large amount of smoke is generated even when the temperature of the biomass fuel is high, suppressing the generation of smoke when the biomass fuel is ignited and shortening the ignition time. Therefore, it has been found that a method of igniting the biomass fuel after adjusting the temperature of the biomass fuel within an appropriate ignition temperature range is suitable.

  Therefore, the present invention controls the temperature of the combustion section that burns the biomass fuel, so that the biomass accompanying the control of heating, hot water temperature, etc. from the time of ignition to the biomass fuel at the start of combustion until the stable combustion state is achieved. An object of the present invention is to provide a method for igniting biomass fuel that eliminates the generation of smoke during re-ignition due to intermittent combustion of fuel, and that can achieve high accuracy in hot water control particularly in a biomass fuel water heater.

  In order to achieve the above object, the present invention provides a biomass fuel ignition method according to claims 1 to 5. That is, a method for igniting a biomass fuel according to claim 1 includes a fuel tank for storing biomass fuel, a combustion section for burning biomass fuel, and a biomass combustion apparatus for supplying biomass fuel from the fuel tank to the combustion section for combustion. Prior to ignition, the temperature of the combustion part is detected, and when the temperature of the combustion part is within the appropriate ignition temperature range, the ignition operation is started as it is, and when the temperature of the combustion part is lower than the appropriate ignition temperature range, heating is performed by heating means. The temperature is raised to the above range and the ignition operation is started. When the temperature of the combustion section is higher than the proper temperature range, the temperature is lowered to the proper ignition temperature range by the cooling means and the ignition operation is started.

  The method for igniting biomass fuel according to claim 2 is the method for igniting biomass fuel according to claim 1, wherein the suitable temperature range for ignition is set to 60 ° C. or higher and lower than 150 ° C.

  The biomass fuel ignition method according to claim 3 is the biomass fuel ignition method according to claim 1 or 2, wherein the heating means is composed of a liquid fuel combustion device, a gaseous fuel combustion device or an electric heating device, and the cooling means is It is characterized by comprising an air temperature blower.

  A method for igniting a biomass fuel according to claim 4 is characterized in that, in the method for igniting a biomass fuel according to claim 1, 2 or 3, 10 to 30 minutes after the extinction of normal combustion is regarded as an appropriate temperature range for ignition. is there.

  The biomass fuel ignition method according to claim 5 is the biomass fuel ignition method according to claim 1, 2, or 3, wherein the biomass combustion device constitutes a hot water heater for heating the stored water in the hot water tank. The water temperature sensor of the tank extinguishes when the water temperature reaches a preset temperature, and detects whether or not the temperature of the combustion part is within a suitable ignition temperature range upon re-ignition.

  According to the method for igniting a biomass fuel according to the present invention, by controlling the temperature of the combustion section that burns the biomass fuel, from the time of ignition to the biomass fuel at the start of combustion until the stable combustion state is reached, heating or Smoke is not generated at the time of re-ignition due to intermittent combustion of the biomass fuel accompanying the control of the hot water temperature and the like, and in particular, an effect of improving the accuracy of the hot water control in the biomass fuel water heater can be obtained.

  FIG. 1 is a cross-sectional view showing a configuration of a biomass fuel water heater as an example of a biomass combustion apparatus according to the present invention, FIG. 2 is a flowchart showing a determination operation of an ignitable region in the biomass fuel water heater shown in FIG. 1, and FIG. FIG. 3 is a partial cross-sectional view showing another embodiment shown in FIG.

  As shown in FIG. 1, a biomass fuel water heater 1 according to the present invention includes a fuel tank 2 that stores biomass fuel such as rice husk, large sawdust or wood pellets, a combustion unit 3 that burns biomass fuel, and a fuel tank 2. Fuel supply device 4 that supplies biomass fuel to the combustion unit 3, a hot water tank 8 having an upper water temperature sensor 5, a middle water temperature sensor 6, and a lower water temperature sensor 7, and heat between the combustion unit 3 and the hot water tank 8 The combustion section 3 includes a combustion chamber 11 provided with a combustion dish 10 for burning the biomass fuel supplied from the fuel tank 2 by the fuel supply device 4, and a combustion dish along with the combustion of the biomass fuel. 10 includes an ash collecting portion 12 that collects ash generated on the combustion chamber 11, and a combustion fan 13 and the like for supplying combustion air to the combustion chamber 11 are all provided in an integrated exterior case 14. That. The combustion fan 13 and the suction fan 22 supply outside air from the lower part of the combustion dish 10 into the combustion chamber 11.

  The combustion chamber 11 of the combustion section 3 is provided with a burner (liquid fuel combustion device) 15 that uses kerosene as fuel for preheating. The burner 15 for preheating can be constituted by a gaseous fuel combustion apparatus using gas as fuel. The burner 15 also serves as an ignition burner for biomass fuel. In addition, as a preheating structure of the combustion dish 10, it can comprise with the electric heating apparatus which embed | buried the electric heater 16 as shown in FIG.

  The fuel supply device 4 includes a screw conveyor 17 provided along a bottom portion in the fuel tank 2, and a lower inclined portion of the screw conveyor 17 is open to a bottom portion of the fuel tank 2, and a combustion chamber 11 is provided on the upper inclined portion. A supply chute 18 for supplying biomass fuel is connected to the inner combustion dish 10.

  A meandering cylinder 19 passing through the hot water tank 8 is connected to the upper part of the combustion chamber 11 of the combusting part 3, and the meandering cylinder 19 constitutes a heat exchanging part 9. The connecting cylinder 21 is connected to the cyclone 20 constituting the part 12. A suction fan 22 is interposed near the cyclone 20 of the connecting cylinder 21 so that exhaust gas containing ash generated in the combustion chamber 11 by the outside air taken in from the combustion fan 13 is sucked and sent to the cyclone 20. It has become. A ash collection chamber 23 is provided in the lower part of the cyclone 20. Reference numeral 24 denotes an exhaust temperature sensor.

  The hot water tank 8 is provided with a water supply port 25 at the lower portion and a hot water outlet 26 at the upper portion, and a water supply valve 27 is interposed between the water supply port 25 and a water supply source (water supply, not shown). It is.

  Reference numeral 28 denotes a control panel, which is an upper water temperature sensor 5, a middle water temperature sensor 6, a lower water temperature sensor 7, an exhaust temperature sensor 24, a screw conveyor 17, a combustion fan 13, a suction fan 22, a burner 15, and not shown. In addition, a temperature sensor for measuring the temperature of the combustion dish 10 may be connected, and the control panel 28 performs necessary control such as biomass fuel supply, burner combustion, exhaust, feed water, and hot water delivery in a concentrated manner. It is configured.

  The biomass fuel water heater 1 configured as described above operates as illustrated in FIGS. 2 and 3. That is, when a start operation for starting combustion is performed on the control panel 28, the temperature of the combustion dish 10 is first detected. When the temperature of the combustion dish 10 is cold (less than 60 ° C.), it is warm (60 ° C. or more and less than 150 ° C.). A temperature range when hot (above 150 ° C.) is detected. And when it is cold, before supplying biomass fuel onto the combustion dish 10, the burner 15 of the liquid fuel combustion apparatus is operated to preheat the combustion dish 10 to the temperature range when it is warm to the ignition suitable temperature range, and then onto the combustion dish 10. Supply biomass fuel and ignite. When the combustion dish 10 is warm, the biomass fuel is supplied as it is to ignite. In addition, when the combustion dish 10 is hot, the combustion fan 13 and the suction fan 22 are operated to introduce the outside air to circulate in the vicinity of the combustion dish 10, and the combustion dish 10 is heated to a temperature range that is warm within a suitable ignition temperature range. The fuel is ignited by supplying biomass fuel.

  As described above, the state when the combustion dish 10 is cold is when the biomass combustion apparatus is initially ignited, the state when it is hot is immediately after extinguishing the biomass combustion apparatus, and the state when it is warm is when a certain time has elapsed after the fire extinguishing of the biomass combustion apparatus. In the case where the biomass combustion apparatus is the biomass fuel water heater 1 as shown in the figure, the fire is automatically extinguished when the lower water temperature sensor 7 of the hot water tank 8 reaches the set temperature, and then set from the hot water outlet 26. When the hot water heated to the temperature is used as hot water for a bath or kitchen, water is automatically supplied from the water supply port 25 into the hot water tank 8 by the pressure of the water supply, whereby the water temperature in the hot water tank 8 is increased. When the temperature falls below the set temperature of the middle water temperature sensor 6, it is automatically re-ignited and the combustion is continued until the set temperature of the lower water temperature sensor 7 is reached.

  When a large amount of hot water is discharged from the hot water outlet 26, such as when a large amount of hot water is consumed in a bath or kitchen, since the time has not elapsed since the previous combustion, the combustion dish 10 is in a hot state. Therefore, prior to re-ignition, the combustion fan 13 or the suction fan 22 is actuated to introduce outside air, and the biomass fuel is re-ignited in a state where the temperature of the combustion dish 10 is lowered to a warm temperature that is an appropriate ignition temperature range. Be started. (See FIG. 2).

  In the biomass fuel water heater 1 according to the present invention, the temperature of the combustion dish 10 of the combustion unit 3 is detected prior to ignition, and when the temperature of the combustion dish 10 is within the ignition suitable temperature range, the ignition operation is started as it is. When the temperature is lower than the appropriate temperature range for ignition, the burner 15 is heated to raise the temperature to the appropriate temperature range for ignition (60 ° C. or higher and lower than 150 ° C.), and then the ignition operation is started. When the temperature is high, outside air is introduced by the combustion fan 13 or the suction fan 22 serving as a cooling means, and the temperature is lowered to an appropriate ignition temperature range and then the ignition operation is started. Therefore, from when the biomass fuel is ignited at the start of combustion until stable combustion is achieved. During this period, smoke is not generated at the time of re-ignition due to intermittent combustion of biomass fuel due to control of heating, hot water temperature, etc., especially hot water in a biomass fuel water heater It is possible to control the high accuracy, it is possible to improve the ignitability by shortening the smokeless and ignition time for ignition.

  At the time of re-ignition due to intermittent combustion of biomass fuel accompanying control of heating, hot water temperature, etc., the range from 10 minutes to 30 minutes after extinction of normal combustion is often the optimum temperature range for ignition, so 10 to 30 minutes after extinction of normal combustion Even if the range of minutes is regarded as the optimum ignition temperature range, there is substantially no problem, and the control operation can be simplified.

It is sectional drawing which shows the structure of a biomass fuel water heater as an example of the biomass combustion apparatus which concerns on this invention. It is a flowchart which shows the determination operation | movement of the ignition possible area | region in the biomass fuel water heater shown in FIG. It is a fragmentary sectional view which shows other embodiment of what is shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Biomass fuel water heater 2 Fuel tank 3 Combustion part 4 Fuel supply apparatus 5 Upper water temperature sensor 6 Middle water temperature sensor 7 Lower water temperature sensor 8 Hot water tank 9 Heat exchange part 10 Combustion dish 11 Combustion chamber 12 Ash collecting part 13 Combustion fan 14 Exterior Case 15 Burner 16 Electric heater 17 Screw conveyor 18 Supply chute 19 Meander cylinder 20 Cyclone 21 Connection cylinder 22 Suction fan 23 Ash collecting chamber 24 Exhaust temperature sensor 25 Water supply port 26 Hot water supply outlet 27 Water supply valve 28 Control panel

Claims (5)

In a fuel tank for storing biomass fuel, a combustion unit for burning biomass fuel, and a biomass combustion apparatus for supplying biomass fuel from the fuel tank to the combustion unit for combustion,
Prior to ignition, the temperature of the combustion part is detected,
When the temperature of the combustion section is within the appropriate ignition temperature range, the ignition operation is started as it is, and when the temperature of the combustion section is lower than the appropriate ignition temperature range, it is heated by the heating means to reach the proper ignition temperature range, and then enters the ignition operation. A method for igniting a biomass fuel, characterized in that when the temperature of the section is higher than an appropriate temperature range, the temperature is lowered to an appropriate ignition temperature range by a cooling means and then an ignition operation is started.   The method for igniting a biomass fuel according to claim 1, wherein the suitable temperature range for ignition is set to 60 ° C or higher and lower than 150 ° C.   The method for igniting biomass fuel according to claim 1 or 2, wherein the heating means is constituted by a liquid fuel combustion device, a gaseous fuel combustion device or an electric heating device, and the cooling means is constituted by an air blowing device having an outside air temperature. .   The method for igniting biomass fuel according to claim 1, 2 or 3, wherein 10 to 30 minutes after the extinction of normal combustion is regarded as an appropriate ignition temperature range. The biomass combustion device constitutes a water heater that heats the water stored in the hot water tank. The water temperature sensor in the hot water tank extinguishes when the water temperature reaches the preset temperature, and the temperature of the combustion section is within the appropriate ignition temperature range during re-ignition. 4. The method for igniting biomass fuel according to claim 1, 2, or 3, wherein:

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