JP4405497B2 - Wood pellet combustion equipment - Google Patents

Description

  The present invention relates to a combustion apparatus such as a heater using wood pellets as fuel.

  In recent years, wood pellets that are cleaner than fossil fuels such as oil and coal and that can be used more effectively than wood have been known, and combustion devices such as heaters that use wood pellets as fuel have been reviewed. It is.

Conventionally, this type of combustion apparatus is provided with a combustion part that burns wood pellets as a burner, and the combustion part is provided with a grate at its lower end and burns the wood pellets loaded on the grate. (For example, refer to Patent Document 1). Further, since the ash is accumulated on the grate due to the burning of the wood pellets, an ash treatment section for treating the ash is provided below the combustion section. Ash processing unit is Haikaki member for scraping off ashes on the grate is provided from between the plurality of slits forming plate constituting the grate.

During the burning of the wood pellets, the ash scraping member is operated every predetermined time, and the ash deposited on the grate is efficiently discharged from the combustion section by the operation of the ash scraping member.
JP 2006-200825 A

  However, the amount of ash deposited on the grate due to the burning of wood pellets does not become a constant amount depending on the combustion state of the wood pellets and the type of wood pellets, for example, the amount of ash was relatively small If the ash from the grate is excessively scraped, the combustion is performed in the vicinity of the ash treatment unit. When combustion is performed in the vicinity of the ash treatment unit, the grate and the ash treatment unit are excessively heated, and the parts such as the ash scraping member provided in the grate and the ash treatment unit are relatively early. Has the disadvantage of causing corrosion.

  An object of the present invention is to provide a wood pellet combustion apparatus that can eliminate such inconvenience and prevent the combustion in the vicinity of the ash treatment part and improve the durability of the grate and the ash treatment part. .

In order to achieve such an object, the present invention provides a combustion section for burning wood pellets, a wood pellet supply means for supplying wood pellets to the combustion section, and a wood pellet supply means provided at the lower end of the combustion section. A grate composed of a plurality of slit forming plates arranged with a predetermined gap in the horizontal direction so as to load the wood pellets supplied from the inside of the combustion part, and below the combustion part via the grate An ash treatment unit that removes ash generated on the grate by combustion of the wood pellets, and combustion control means for controlling the supply and combustion of the wood pellets, the ash treatment unit comprising the grate in wood pellet combustion apparatus comprising a metallic Haikaki member for scraping off the ashes from the gap of each slit forming plate, it is provided in the combustion unit, when a predetermined amount of ash in the fire on the grid is deposited, the ash Combustion section temperature detection means for detecting the temperature in the combustion section at a position corresponding to the upper end, ash processing section temperature detection means for detecting the temperature in the ash processing section provided in the ash processing section, and the combustion section temperature detection When the detected temperature of the means is equal to or lower than the first preset temperature set in advance, the ash scraping operation by the ash scraping member is started, and the detected temperature of the ash treatment unit internal temperature detecting means is set in advance during the ash scraping operation Ash treatment control means for stopping the ash scraping operation when the temperature becomes equal to or higher than the second set temperature is provided.

  As the combustion of the wood pellets in the combustion section proceeds, the wood pellets supplied to the combustion section become ash, and this ash accumulates on the grate. When the ash deposited on the grate exceeds the predetermined amount, the temperature detected by the in-combustion-part temperature detecting means is lowered by the heat insulating action of the ash. From this, the temperature when the temperature detected by the in-combustion section temperature detecting means is subjected to the heat insulation of ash is set to the first set temperature, so that the detected temperature of the in-combustion section temperature detecting means is equal to or lower than the first set temperature. At some point, it can be confirmed that the ash deposited on the grate has exceeded the predetermined amount. Therefore, the ash treatment control means starts the ash scraping operation by the ash scraping member when the temperature detected by the in-combustion temperature detecting means is not higher than the first set temperature. As a result, it is possible to accurately detect that the amount of ash deposited on the grate exceeds the predetermined amount, and it is possible to smoothly discharge a large amount of ash deposited in the combustion section.

  On the other hand, by performing the ash scraping operation by the ash scraping member, the amount of ash deposited on the grate gradually decreases. In the combustion part, since a flame is formed from the upper layer part of the deposited ash, the distance between the grate and the flame becomes smaller as the amount of ash decreases, and the ash treatment part located below the grate and the grate Temperature rises. The ash treatment control unit stops the ash scraping operation when the temperature detected by the ash treatment unit internal temperature detection unit becomes equal to or higher than a second set temperature during the ash scraping operation. Thereby, it can prevent that each component of ash processing parts, such as a grate and an ash scraping member, is heated excessively, and can improve durability of each component of a grate and an ash processing part.

  Also, in the present invention, the ash treatment control means is configured such that the detected temperature of the combustion section internal temperature detection means is higher than the first set temperature and the detected temperature of the ash treatment section internal temperature detection means is the second set temperature. When the temperature is equal to or higher than the temperature, the ash scraping operation by the ash scraping member is not performed, the detection temperature of the combustion section internal temperature detection means is higher than the first set temperature, and the detection temperature of the ash treatment section internal temperature detection means is When the temperature is lower than the second set temperature, the ash scraping member is controlled to perform a predetermined ash scraping operation.

  When the temperature detected by the in-combustion-part temperature detecting means is higher than a preset first set temperature, the position of the flame in the in-combustion part is low, and the ash deposited on the grate is less than a predetermined amount. I can confirm that. Therefore, at this time, if the temperature detected by the ash treatment section internal temperature detecting means is equal to or higher than the second preset temperature, the ash scraping operation may cause excessive ash scraping. Therefore, in this case, the ash treatment control means can reliably prevent adverse effects due to heat on the grate and the ash treatment unit by controlling so as not to perform the ash scraping operation. On the other hand, even if the detected temperature of the in-combustion-part temperature detecting means is higher than the first set temperature, the detected temperature of the in-ash processing part temperature detecting means is lower than the second set temperature. Since the heat effect of the ash deposited on the grate is less affected by the heat to the grate and the ash treatment unit, the ash in the combustion unit can be discharged by performing the ash scraping operation.

  Further, in the present invention, the ash treatment control means starts the ash scraping operation by the ash scraping member when the detected temperature of the combustion section internal temperature detection means is equal to or lower than the first set temperature, and this ash scraping operation The detected temperature of the ash treatment unit temperature detection means is lower than the second set temperature, and the detection temperature of the combustion unit temperature detection means is preset to a temperature lower than the first set temperature in advance. When the temperature is equal to or lower than a preset temperature of 3, control is performed so as to stop combustion via the combustion control means.

  When the detected temperature of the combustion section temperature detection means becomes equal to or lower than the third set temperature during the ash scraping operation, the combustion section temperature detection is performed even though the amount of ash deposited on the grate is reduced. The detected temperature of the means is extremely low. In this case, it is considered that the wood pellets are not burned well, so that the temperature detected by the ash treatment unit temperature detection means is lower than the second set temperature, and is deposited on the grate. The ash treatment control means stops the combustion through the combustion control means even in a state where the heat effect on the grate and the ash treatment part is small due to the heat insulation action of the ash. Thereby, combustion operation can be stopped quickly and combustion abnormality can be prevented.

  An embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the wood pellet combustion apparatus 1 of the present embodiment is a heater including a rectangular parallelepiped casing 2, and a fuel storage chamber in which the wood pellets 3 are stored in the lower part of the casing 2. 4 and a combustion chamber 5 is provided above the fuel storage chamber 4. A burner section 6 (combustion section) for burning the wood pellets 3 as fuel is provided at the lower part of the combustion chamber 5, and the wood pellets 3 are placed on the back side of the fuel storage chamber 4 and the combustion chamber 5 of the housing 2. Fuel supply means 7 for supplying to the burner section 6 is provided.

  A stalker 8 that can be pulled out is provided in the upper part of the fuel storage chamber 4, and the wood pellet 3 is supplied into the fuel storage chamber 4 through the stalker 8 that is pulled out. A coil-shaped fuel agitating member 9 and an agitating motor 10 for rotating the fuel agitating member 9 are provided in the fuel storage chamber 4, and the wood pellet 3 is transferred to the fuel supply means 7 by the rotation of the fuel agitating member 9. It is designed to feed smoothly.

  The fuel supply means 7 includes a fuel supply cylinder 11 installed in the vertical direction at the center on the back side in the housing 2, and a screw 12 that rotates within the fuel supply cylinder 11. The screw 12 is rotationally driven by a driving motor 13 to convey the wood pellet 3 toward the upper side of the fuel supply cylinder 11. The wood pellets 3 conveyed to the upper part of the fuel supply cylinder 11 by the screw 12 are guided to an input cylinder 14 provided continuously to the fuel supply cylinder 11 and are input to the burner section 6.

  1 is a sensor for detecting the presence or absence of the wood pellet 3 in the vicinity of the tip of the fuel agitating member 9, and what is denoted by the reference numeral 16 in FIG. It is a sensor to detect.

  The wood pellet 3 is a cylinder having a diameter of about 6 to 8 mm and a length of about 15 mm using a molding machine after pulverizing small pieces of wood and bark, which are raw materials, to a uniform particle size and drying the moisture content to 8 to 12%. It is a solid fuel molded and solidified into a shape. In the present embodiment, a bark-based pellet (bark pellet) is used as the wood pellet 3, but a wood part pellet (white pellet) or a wood pellet may be used.

  A transparent heat-resistant glass 18 is attached to a part of the front side of the combustion chamber 5 so that the flame 17 when the wood pellet 3 is burned by the burner portion 6 can be seen from the outside. A plurality of heat radiating pipes 19 are arranged in the upper part of the combustion chamber 5. An exhaust chamber 20 communicating with the combustion chamber 5 is provided above the heat radiating pipe 19. An exhaust cylinder 21 for exhausting exhaust gas from the combustion chamber 5 is connected to the exhaust chamber 20. Although not shown, the exhaust pipe 21 is connected to an exhaust path provided in an air supply / exhaust pipe extending outside the room.

  The upper surface, the rear surface, and the left and right side surfaces of the combustion chamber 5 and the exhaust chamber 20 are surrounded by a heat insulating plate 22, and a space formed between the combustion chamber 5 and the exhaust chamber 20 and the heat insulating plate 22 is a hot air passage 23. A convection fan 24 is provided outside the back surface of the combustion chamber 5. The convection fan 24 forms convection in the warm air passage 23 by driving the convection motor 25, and blows out the warm air heated by the combustion chamber 5 and the exhaust chamber 20 on the front side of the housing 2. To send out. The outlet 26 is provided with a plurality of louvers 27 that adjust the direction of the warm air.

  Further, as shown in FIG. 2, a convection temperature sensor 28 for detecting the temperature of the hot air in the hot air passage 23 is provided on the inner surface of the side portion of the heat insulating plate 22. An exhaust gas temperature sensor 29 for detecting the above is provided. Further, as shown in FIG. 1, a room temperature sensor 30 for detecting the room temperature is provided on the back surface of the housing 2.

  As shown in FIGS. 3 and 5, the burner unit 6 is provided continuously above the box-shaped burner case 31, the rectangular cylinder-shaped combustion cylinder 32 housed in the burner case 31, and the combustion cylinder 32. And a hopper 33 for taking in the wood pellet 3 supplied from the charging cylinder 14 of the fuel supply means 7 from above. An air passage 34 is provided between the burner case 31 and the combustion cylinder 32 and the hopper 33, and a plurality of vent holes 35 communicating with the air passage 34 are formed in the combustion cylinder 32 and the hopper 33. The air passage 34 is connected to an air supply pipe 36 (see FIGS. 1 and 5) extending to the back side of the burner case 31, and combustion air sent from the air supply pipe 36 is transferred to the combustion cylinder 32 through the vent hole 35. Supply. Further, as shown in FIGS. 1 and 5, a ventilating cylinder 37 communicating with the air passage 34 is connected to the front side of the burner case 31. The ventilation tube 37 guides air to the back surface of the heat-resistant glass 21 attached to the front surface of the combustion chamber 5.

  As shown in FIG. 2, the air supply pipe 36 is connected to a blower 38 installed on the back side in the housing 2, and is sucked from an intake cylinder 39 by driving the blower 38. The intake cylinder 39 is connected to an intake passage provided in the above-described supply / exhaust cylinder, and takes outside air from the outside through the supply / exhaust cylinder. As shown in FIG. 5, an ignition heater 40 for igniting the wood pellet 3 is provided on the front side of the combustion cylinder 32.

As shown in FIG. 5, a grate 41 is provided at the lower end of the combustion cylinder 32. The grate 41 includes a plurality of slit-forming plates 42 arranged with a predetermined gap in the horizontal direction, and loads the wood pellets 3 introduced through the hopper 33 into the combustion cylinder 32. The wood pellets 3 loaded on the grate 41 are ignited and burned by the ignition heater 40 in the combustion cylinder 32.

  As shown in FIG. 3, an ash treatment means 43 (ash treatment unit) is provided below the combustion cylinder 32 to remove the ash accumulated on the grate 41 by the combustion of the wood pellets 3. As shown in FIG. 3, the ash treatment means 43 is provided below a plurality of (two in this example) ash scraping members 44 spaced apart from each other in the horizontal direction and the ash scraping member 44. The same number (two in this example) of auxiliary ash scraping members 45 are provided. The ash scraping member 44 is accommodated in a substantially upper half portion in a frame 46 surrounding the grate 41 at the lower part of the combustion cylinder 32, and the auxiliary ash scraping member 45 is an upper surface opening provided below the bottom of the burner case 31. Is housed in an ash treatment box 47.

As shown in FIGS. 3 to 5, the ash scraping member 44 includes a rotating shaft 48 that is rotatably attached to the frame body 46, and a plurality of undulations that are connected and supported by the rotating shaft 48 and have a plurality of irregularities on the outer periphery. And a metal vane plate 49. Each blade 49 of the ash scraping member 44 is located between the slit forming plates 42 of the grate 41, and the adjacent blades 49 of both ash scraping members 44 are inserted alternately.

  As shown in FIGS. 4 and 5, the two ash scraping members 44 are connected by gears 50 attached to one end side of the rotary shaft 48, and the ash treatment motor 51 is connected to one rotary shaft 48. ing. When one ash scraping member 44 is rotated by the ash treatment motor 51, the other ash scraping member 44 is rotated via the gear 50. The ash treatment motor 51 can be rotated in the forward and reverse directions, thereby moving the two ash scraping members 44 in an inward direction in which the opposite side moves from top to bottom and the opposite side from bottom to top. It can be selectively rotated in the outward direction of the direction to be performed.

The ash scraping member 44 is rotated at a predetermined timing by the ash processing motor 51 during combustion of the wood pellets 3 loaded on the grate 41 and is inserted between the slit forming plates 42 of the grate 41. The ash collected on the grate 41 is scraped off into the ash processing box 47.

  As shown in FIGS. 3 and 5, the auxiliary ash scraping member 45 is provided between a rotary shaft 52 rotatably attached to the ash treatment box 47 and a pair of disks 53 fixed to both ends of the rotary shaft 52. And a plurality of blades 54 passed to each other. A V-shaped groove is formed between the blades 54, and the convex portion of the blade plate 49 of the ash scraping member 44 enters and engages with the groove. Thereby, when the two ash scraping members 44 rotate, the auxiliary ash scraping member 45 rotates following the rotation.

  As shown in FIG. 3, the ash treatment box 47 includes a peripheral wall having a substantially W-shaped cross section, and an ash discharge port 55 is formed in a part of the peripheral wall. As shown in FIG. 1, an ash collection container 56 that stores ash discharged from the discharge port 55 is provided below the ash treatment box 47 so as to be removable from the housing 2. Referring to FIG. 3, when the ash scraping member 44 rotates during the ash treatment, the auxiliary ash scraping member 45 is also driven to rotate by this rotation. At this time, the ash in the combustion cylinder 32 scraped off from the grate 41 by the ash scraping member 44 is received between the blades 54 of the auxiliary ash scraping member 45, and further, the ash treatment is performed by the rotation of the auxiliary ash scraping member 45. The ash in the box 47 is forcibly discharged to the ash collection container 56 from the discharge port 55 at the bottom.

  Further, as shown in FIGS. 3 and 5, when the ash accumulated on the grate 41 at a position near the upper end of the combustion cylinder 32 reaches a predetermined height in the combustion cylinder 32, A burner section temperature sensor 57 (combustion section internal temperature detection means) is provided at a corresponding position (in the present embodiment, a portion in the vicinity of the boundary between the combustion cylinder 32 and the hopper 33). Further, an ash processing unit temperature sensor 58 (ash processing unit internal temperature detection unit) is provided on the side wall of the ash processing box 47 of the ash processing unit 43.

  And the control means 59 which controls the driving | operation of the wood pellet combustion apparatus 1 is provided as shown in FIG. The control means 59 is constituted by a microcomputer, and includes a combustion control section 60 that controls the combustion operation of the wood pellets 3 and an ash treatment control section 61 that controls the processing operation of ash generated by the combustion of the wood pellets 3 (ash treatment control means). ).

  When an operation switch (not shown) is turned on by the user, the combustion control unit 60 first starts preheating operation by the ignition heater 40 and supply of the wood pellet 3 to the burner unit 6. A preliminary combustion operation is performed through the ignition operation. In addition, since the wood pellet combustion apparatus 1 uses the wood pellet 3 as a fuel, for example, compared with the case where oil is used as a fuel, an immediate ignition cannot be expected. Therefore, the combustion control unit 60 performs a preliminary combustion operation prior to the main combustion that is the heating operation. Moreover, since the ash of the wood pellet 3 combusted in the preliminary combustion operation accumulates on the grate 41, the combustion control unit 60 instructs the ash processing control unit 61 to perform the ash processing operation for the preliminary combustion operation. . The ash treatment control unit 61 performs ash treatment according to a procedure set in advance as an ash treatment operation during the preliminary combustion operation. In the present embodiment, the ash treatment motor 51 is driven to drive two ash scraping members. 44 are rotated around each other (in FIG. 3, the left ash scraping member 44 is rotated counterclockwise and the right ash scraping member 44 is rotated clockwise) for 4 seconds, and the wood pellets 3 supplied onto the grate 41 are Disperses and homogenizes and scrapes ash.

  Next, the combustion control unit 60 performs the main combustion operation after performing the preliminary combustion operation. In the main combustion operation, the combustion control unit 60 controls the operation of the motors and the like based on the information from the temperature sensors and the like, and maintains a good combustion state in the burner unit 6 for efficient heating operation. Do.

  As shown in FIG. 6, when performing the heating operation, the combustion control unit 60 is set with six control levels from control level 1 (minimum level) to 6 (maximum level) from weak operation to strong operation. . The control level 1 is a control level at the time of the minimum weak operation, and becomes a control level at the time of the medium to strong operation as the level increases, and the control level 6 is a control level at the time of the maximum strong operation. Therefore, at the control level 1 (minimum level), the blower 38 (BM) and the drive motor 13 (PM) for the screw 12 are rotationally driven at the minimum rotational speed, and at the control level 6 (maximum level), the blower 38 (BM). ) And the drive motor 13 (PM) for the screw 12 are driven to rotate at the maximum rotational speed. That is, the supply amount of combustion air and the supply amount of wood pellets 3 at the control level 1 are minimized, and the supply amount of combustion air and the supply amount of wood pellets 3 at the control level 6 are maximized.

  During the main combustion, a large amount of ash is generated by the combustion of the wood pellets 3, and thus it is necessary to perform a process for efficiently discharging the generated ash from the burner unit 6 in order to perform the main combustion continuously. Therefore, as will be described in detail later, the ash processing operation during the main combustion is performed by the ash processing control unit 61.

  Thereafter, when an operation switch (not shown) is turned off by the user or the combustion control unit 60 detects an abnormality in combustion, the combustion control unit 60 performs a fire extinguishing operation. In the fire extinguishing operation, the supply of the wood pellets 3 is stopped from the state of the main combustion, the unburned wood pellets 3 remaining in the combustion cylinder 32 are completely burned, the ash is recovered, and the operation is stopped. .

  Next, the ash processing operation by the ash processing control unit 61 during the main combustion will be described in detail. As shown in FIG. 7, when the main combustion is started in STEP 1, the ash treatment control unit 61 starts measuring the main combustion time T in STEP 2 and proceeds to STEP 3. The main combustion time T is measured by a clock built in the control means 59. In STEP3, when the main combustion time T reaches a predetermined time t set in advance (T ≧ t), the process proceeds to STEP4. As shown in FIG. 6, the predetermined time t is an interval time of an ash treatment cycle that is determined in advance according to the control level. For example, the time t is set to 4 minutes at the minimum control level 1 during weak operation. Has been. In addition, although the ash processing period (t) shown in FIG. 6 has shown the ash processing period at the time of using a bark-type pellet (bark pellet), the ash processing period (t) is set for every kind of the wood pellet 3 It is what is done.

  Next, in STEP 4 in FIG. 7, the measurement of the main combustion time T is stopped, and the process proceeds to STEP 5. In STEP5, when the detected temperature of the burner part temperature sensor 57 (BTH1) is higher than the first set temperature, the process proceeds to STEP6. The first set temperature in the burner temperature sensor 57 (BTH1) is predetermined according to the control level as shown in FIG. The case where the detected temperature of the burner part temperature sensor 57 is higher than the first set temperature is a state in which the burner part temperature sensor 57 is heated by the flame in the combustion cylinder 32, and the normal combustion state is assumed. Show.

  In STEP 6 in FIG. 7, when the temperature detected by the ash treatment unit temperature sensor 58 (BTH2) is lower than the second set temperature, the process proceeds to STEP 7. The second set temperature in the ash treatment unit temperature sensor 58 (BTH2) is predetermined according to the control level as shown in FIG. When the detected temperature of the ash treatment unit temperature sensor 58 is lower than the second set temperature, the ash treatment unit temperature sensor 58 is caused by the flame in the combustion cylinder 32 due to the heat insulating action of the ash accumulated in the combustion cylinder 32. It shows a state where the heating is not received and the influence of heat on the ash treatment means 43 is small.

  Next, in STEP 7 in FIG. 7, a first ash treatment operation is performed. In the present embodiment, as shown in FIG. 8, the first ash processing operation is performed by first turning the ash scraping members 44 outwardly by switching the rotation direction of the ash processing motor 51 (right ash scraping in FIG. 3). Rotate the member 44 to the right, rotate the left ash scraping member 44 to the left) for 5 seconds (STEP 7-1), then rotate the ash scraping member 44 inwardly for 7 seconds (STEP 7-2), then ash scraping member 44 are rotated outward for 5 seconds (STEP 7-3), and finally the ash scraping member 44 is rotated inward for 7 seconds (STEP 7-4) to perform an ash scraping operation for a total of 24 seconds. The ash scraped off from the grate 41 by the ash scraping member 44 is forcibly transferred to the discharge port 55 of the ash treatment box 47 by the auxiliary ash scraping member 45 and discharged from the discharge port 55 to the ash collection container 56. .

  In FIG. 7, when the detected temperature of the burner temperature sensor 57 (BTH1) is equal to or lower than the first set temperature in STEP5, the process proceeds to STEP8. The case where the detected temperature of the burner part temperature sensor 57 is equal to or lower than the first set temperature means that the burner part temperature sensor 57 is not heated by the flame in the combustion cylinder 32 even though the main combustion is being performed. Is shown. This state is considered to be a state in which the heat insulating action of the ash accumulated in the combustion cylinder 32 is generated, the ash accumulation in the combustion cylinder 32 becomes excessive, and the height of the ash is determined by the burner temperature sensor 57. It seems that it was higher than the position. Then, it progresses to STEP8 and performs 2nd ash processing operation. In the second ash treatment operation, the ash treatment operation is performed for a longer time than the first ash treatment operation. In the present embodiment, as shown in FIG. 9, the second ash treatment operation is performed by turning the ash scraping members 44 inwardly (in FIG. 3, the right ash scraping member 44 is rotated counterclockwise and the left ash scraping member 44 is rotated to the right. Rotation) for 40 seconds to perform ash scraping operation.

  That is, as shown in FIG. 9, when the internal rotation of the ash scraping member 44 is started in STEP 8-1, the process proceeds to STEP 8-2 and time measurement by a 40-second timer is started. The timer uses a clock built in the control means. Next, the process proceeds to STEP 8-3, and when the temperature detected by the ash treatment unit temperature sensor 58 (BTH2) is lower than the second set temperature, the process proceeds to STEP 8-4. At this time, when the temperature detected by the ash treatment unit temperature sensor 58 (BTH2) is lower than the second set temperature, the heat effect on the ash treatment means 43 is small due to the heat insulation action of the ash accumulated in the combustion cylinder 32. Indicates the state. In STEP 8-4, if the detected temperature of the burner temperature sensor 57 (BTH1) is higher than the third set temperature, the process proceeds to STEP 8-5, and STEP 8-3 and STEP 8-4 until the 40-second timer reaches time-up. And repeat. As shown in FIG. 6, the third set temperature in the burner temperature sensor 57 (BTH1) is set lower than the first set temperature in the burner temperature sensor 57 (BTH1), and is predetermined according to the control level. It has been. The case where the detected temperature of the burner part temperature sensor 57 is higher than the third set temperature is a state in which the burner part temperature sensor 57 is heated by the flame in the combustion cylinder 32, and the ash scraping operation is normal. It shows the process where the amount of ash accumulation decreases. In FIG. 7, when the 40-second timer expires in STEP 8-5, the process proceeds to STEP 8-6, where the rotation of the ash scraping member 44 is stopped, and the second ash treatment operation is terminated.

  If the detected temperature of the ash treatment unit temperature sensor 58 (BTH2) is equal to or higher than the second set temperature in STEP8-3, the process proceeds to STEP8-6, and the second time is not waited for the 40 second timer to expire. The ash processing operation is terminated. The case where the temperature detected by the ash treatment unit temperature sensor 58 (BTH2) is higher than the second set temperature indicates a state in which the heat insulating action of the ash accumulated in the combustion cylinder 32 is reduced, and the ash scraping is further performed. If the operation is continued, the influence of heat on the grate 41 and the ash treatment means 43 may be increased. Therefore, by immediately ending the second ash treatment operation, it is possible to prevent the ash treatment means 43 from being heated excessively, and to the components of the ash treatment means 43 such as the ash scraping member 44 and the auxiliary ash scraping member 45. The bad influence by overheating can be prevented beforehand.

  If the detected temperature of the burner temperature sensor 57 (BTH1) is lower than the third set temperature in STEP8-4, the process proceeds to STEP8-7 and STEP8-8. At this time, the case where the temperature detected by the burner temperature sensor 57 (BTH1) is lower than the third set temperature indicates that the temperature in the combustion cylinder 32 is extremely low. That is, the burner temperature sensor 57 is heated by the flame in the combustion cylinder 32 even though the ash scraping operation in the second ash treatment operation is started (or the ash scraping operation is being performed). It is conceivable that the combustion state in the combustion cylinder 32 is not maintained. Then, after proceeding to STEP8-7 and STEP8-8 to stop the rotation of the ash scraping member 44, the combustion operation is stopped (terminated).

  Then, as shown in FIG. 7, when the first ash processing operation of STEP 7 or the second ash processing operation of STEP 8 is completed, the process returns to STEP 2 and starts measuring the main combustion time T. In this embodiment, after stopping the counting of the combustion time T in STEP4, the first ash processing operation or the second ash processing operation is performed, and then returning to STEP2 to start counting the main combustion time T. In addition to that, although not shown, for example, after measuring the combustion time T in STEP 4, the measurement of the main combustion time T is started between STEP 4 and STEP 5. After the ash processing operation or the second ash processing operation of STEP8 is completed, the process may return to STEP3. Accordingly, the operation time of the first ash processing operation of STEP 7 or the second ash processing operation of STEP 8 can be included in the interval time of the ash processing cycle.

The schematic sectional drawing which looked at the wood pellet combustion apparatus of one embodiment of the present invention from the side. The schematic sectional drawing which looked at the device of Drawing 1 from the front. The schematic sectional drawing which looked at the ash processing means installed in the apparatus of FIG. 1 from the front. FIG. 4 is a schematic plan view of the ash treatment means of FIG. 3. The schematic side view of the ash processing means of FIG. The figure which shows an example of the setting value which concerns on the ash process set in the control means. The flowchart which shows the ash process control in this combustion. The flowchart which shows 1st ash processing operation. The flowchart which shows 2nd ash processing operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wood pellet combustion apparatus, 3 ... Wood pellet, 6 ... Burner part (combustion part), 41 ... Grate, 42 ... Slit formation board , 43 ... Ash processing means (ash processing part), 44 ... Ash scraping member, 57 ... Burner part temperature sensor (combustion part temperature detection means), 58 ... Ash treatment part temperature sensor (ash treatment part temperature detection means), 60 ... Combustion control part (combustion control means), 61 ... Ash treatment control part (ash treatment) Control means).

Claims (3)

Combustion section for burning wood pellets, wood pellet supply means for supplying wood pellets to the combustion section, and wood pellets provided from the wood pellet supply means provided at the lower end of the combustion section are loaded inside the combustion section a grate consisting of a plurality of slits forming plate which are arranged with a predetermined gap therebetween in the horizontal direction in order to provided below the combustion section through the該火grid, grate by the combustion of the wood pellets An ash treatment unit that removes the ash generated above, and combustion control means that controls the supply and combustion of the wood pellets, and the ash treatment unit scrapes the ash from the gaps between the slit forming plates of the grate. In the wood pellet combustion apparatus provided with a metal ash scraping member to be dropped,
Combustion unit temperature detection means that is provided in the combustion unit and detects the temperature in the combustion unit at a position corresponding to the upper end of the ash when a predetermined amount of ash is deposited on the grate,
Provided in the ash processing unit, ash processing unit temperature detection means for detecting the temperature in the ash processing unit,
When the temperature detected by the combustion section internal temperature detection means is equal to or lower than a first preset temperature set in advance, an ash scraping operation by the ash scraping member is started, and during the ash scraping operation, the ash processing section internal temperature detection means A wood pellet combustion apparatus, comprising: an ash treatment control means for stopping an ash scraping operation when the detected temperature is equal to or higher than a second preset temperature set in advance.   The ash treatment control means is configured such that the detected temperature of the combustion section internal temperature detection means is higher than the first set temperature and the detected temperature of the ash treatment section internal temperature detection means is equal to or higher than the second set temperature. The ash scraping operation by the ash scraping member is not performed, the detection temperature of the combustion section internal temperature detection means is higher than the first set temperature, and the detection temperature of the ash treatment section internal temperature detection means is the second set temperature. 2. The wood pellet combustion apparatus according to claim 1, wherein when it is smaller, the ash scraping member is controlled to perform a predetermined ash scraping operation. 3.   The ash treatment control means starts the ash scraping operation by the ash scraping member when the temperature detected by the combustion section internal temperature detection means is equal to or lower than the first set temperature, and during the ash scraping operation, The detected temperature of the temperature detecting means is lower than the second set temperature, and the detected temperature of the in-combustion temperature detecting means is equal to or lower than a third set temperature set in advance to a temperature lower than the first set temperature. 3. The wood pellet combustion apparatus according to claim 1, wherein control is performed such that combustion is stopped via the combustion control means.

Images