JP2016095117A - Pot type combustion unit and method for controlling the pot type combustion unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pot type combustion unit capable of preventing occurrence of deflagration due to abnormal detection operation of a combustion fan.SOLUTION: A pot type combustion unit comprises: a heater 7 arranged at a bottom part of a pot burner 1 to perform preheating and ignition; a combustion fan 18 for supplying air to the pot burner 1; and abnormality detection means 32a for detecting abnormality caused at the combustion fan 18. Control means 32 performs control in such a way that normal combustion at the pot burner 1 is started after turning ON the heater 7 and after pre-heating for driving the combustion fan 18 at low rotation speed, a fuel oil supply part 11 is driven to supply the fuel oil to start ignition with the heater 7, and after pre-combustion for performing combustion for a prescribed time, the combustion is shifted to the normal combustion. When the abnormality detection means 32a detects abnormality of the combustion fan 18 during a period from the start of the drive of the combustion fan 18 to a shift to the normal combustion, the combustion is stopped and at the same time only a convection fan 300 is driven to start cooling the pot burner 1.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a pot type combustor suitable for use in a pot burner type heating apparatus and a method for controlling the pot type combustor.

  An example of a pot burner type heater is disclosed in Patent Document 1. In this type of heater, fuel oil is gradually supplied to a bottomed cylindrical pot burner by an electromagnetic pump or the like. And the supplied fuel oil is vaporized and combusted by being heated with a heater. Moreover, in this kind of heating appliance, in order not to pollute indoor air, a sealed type is frequently used. That is, the pot burner is connected to an intake / exhaust duct extending to the outside so that the exhaust is not discharged indoors. Further, the intake duct incorporates a combustion fan that supplies air to the pot burner. The combustion fan continuously supplies air into the pot burner during combustion of the fuel oil, and continues to supply air for a predetermined time to cool the pot burner while replacing the air in the pot burner even after extinguishing the fire. It has become.

JP 2002-257338 A

By the way, when an abnormality occurs in the combustion fan in the heating appliance described above, the electromagnetic pump is forcibly stopped, and the pot burner is extinguished when the fuel oil remaining in the pot burner is burned out. However, depending on the degree of abnormality of the combustion fan, the fire may be extinguished due to lack of oxygen even though the fuel oil remains in the pot burner. In this case, since the temperature in the pot burner is high, the fuel oil continues to vaporize even after the fire is extinguished. At this time, since the vaporized fuel oil is not discharged unless the combustion fan is rotating, the high-concentration vaporized fuel oil continues to accumulate in the pot burner. When the heating fan stops due to an abnormality in the combustion fan, restarting the combustion fan to cool the inside of the pot burner may ignite high-concentration vaporized fuel oil and cause deflagration.
This invention is made | formed in view of the situation mentioned above, and aims at providing the control method of the pot type combustor which can suppress deflagration, and a pot type combustor.

In order to solve the above problems, the present invention has the following configuration.
In the pot type combustor according to claim 1, provided in the bottom of the pot burner, a pot burner formed in a bottomed cylindrical shape, a fuel supply part for supplying fuel to the pot burner, A heater that performs preheating and ignition, a combustion fan that supplies combustion air to the pot burner, a convection fan that supplies indoor air for cooling and warm air to the pot burner, and the combustion fan An abnormality detection means for detecting an abnormality in the rotational speed is provided, and the main combustion start of the pot burner is performed by preheating the heater and turning on the combustion fan at a low rotation, and then driving the fuel supply section to supply the fuel oil. In this case, the control means controls so as to shift to the main combustion after the preliminary combustion that is ignited by the heater and combusts for a predetermined time. When the abnormality detecting means detects an abnormality of the combustion fan before the transition to, the combustion is stopped and only the convection fan is driven to start the cooling of the pot burner. .

  According to a second aspect of the present invention, when the abnormality detection of the combustion fan by the abnormality detecting means is after the transition to the main combustion, the combustion is stopped and only the combustion fan is rotated at a high speed to start the cooling of the pot hana. It is a thing.

  Thus, according to the first aspect of the present invention, when an abnormality of the combustion fan is detected during the pre-combustion from the preheating of the pot burner that may cause deflagration, the combustion is stopped and only the convection fan is detected. Since the pot burner is cooled in this way, it is possible to reliably prevent the deflagration caused by driving the combustion fan for cooling, and to cool the pot burner in the heated state during preparation for the main combustion. It is surely performed by a fan and can be used with confidence.

  According to the second aspect of the present invention, when the abnormality detection of the combustion fan by the abnormality detection means is after the transition to the main combustion, the combustion is stopped and only the combustion fan is rotated at a high speed to start the cooling of the pothana. Therefore, if an abnormality of the combustion fan is detected after the transition to the main combustion of the pot burner without fear of deflagration, the combustion fan can be driven again after the combustion is stopped to cool the pot burner more reliably. is there.

It is a schematic block diagram of the principal part of the heating appliance of one Embodiment of this invention. It is a block diagram of the control circuit of this heating appliance. 4 is a flowchart of an on operation processing routine stored in a ROM. Normal combustion sequence until the same combustion. Combustion sequence when an abnormality is detected in the combustion fan during the preliminary combustion Combustion sequence when a combustion fan abnormality is detected during combustion

[Outline configuration]
The details of the pot burner type heater according to one embodiment of the present invention will be described.
The pot burner type heating appliance includes a pot type combustor 100 (see FIG. 1) that burns fuel oil to generate combustion gas, a combustion cylinder 200 that performs radiant heating by burning a metal cylinder with the combustion gas, and a combustion cylinder It has a convection fan 300 that exchanges heat between the exhausted gas and the air in the room.
As shown in FIG. 1, the pot-type combustor 100 includes a pot burner 1 formed in a bottomed cylindrical shape, an electromagnetic pump 11 serving as a fuel oil supply unit that supplies fuel oil to the pot burner 1, and a supply pipe 12. And an injection pipe 13, an ignition heater (heater) 7 for preheating and igniting the fuel oil, and a combustion fan 18 for supplying air to the pot burner 1.

  In FIG. 1, a pot burner 1 is formed in a bottomed cylindrical shape, and a plurality of primary air holes 2 and secondary air holes 3 which are circular through holes are formed in a peripheral wall thereof. The outer periphery of the pot burner 1 is surrounded by an outer cylinder 5, and an air chamber 4 is formed between them. The flame adjusting cylinder 6 is fixed to the center part in the pot burner 1 and promotes mixing of vaporized gas and combustion air. The vaporized mesh 8 is formed by folding a heat-resistant stainless steel fine wire so as to generate a capillary phenomenon, and is fixed to the bottom center portion of the pot burner 1.

  The ignition heater 7 is composed of a rod-shaped ceramic heater, and protrudes from the peripheral wall of the pot burner 1 toward the upper side of the vaporization chamber 8. The ignition heater 7 has both a function of preheating and vaporizing the fuel oil and a function of igniting the vaporized fuel oil. The injection pipe 13 is configured by a small-diameter pipe inclined downward toward the inside of the pot burner 1, and when the fuel oil is supplied, the fuel oil is injected toward the vaporization chamber 8. The protective cylinder 14 is formed in a cylindrical shape that covers the periphery of the injection pipe 13. One end of the protective cylinder 14 is fixed to the outer cylinder 5, and the other end penetrates the side wall of the pot burner 1 and is exposed inside.

  When fuel oil is supplied from a fuel tank (not shown), the oil leveler 9 maintains its oil level at a certain level. The upper lid 10 covers the upper surface of the oil leveler 9. The electromagnetic pump 11 is fixed to the upper lid 10 and supplies the fuel oil in the oil leveler 9 into the pot burner 1 through the supply pipe 12 and the injection pipe 13. The suction pump 15 is fixed on the upper lid 10 in parallel with the electromagnetic pump 11, and is interposed between the electromagnetic pump 11 and the supply pipe 12. The suction pump 15 sucks the fuel oil remaining in the supply pipe 12 and the injection pipe 13 and returns it to the oil leveler 9 in order to shorten the fire extinguishing time during fire extinguishing.

  The flame rod 16 is suspended in the pot burner 1 so as to be positioned in the combustion flame at the time of combustion, and detects ignition, misfire, abnormal combustion, and the like. The temperature sensor 17 detects the temperature of the bottom portion of the pot burner 1, is constituted by a thermistor, and is fixed in contact with the bottom rear side of the pot burner 1. The combustion fan 18 supplies air into the pot burner 1 through the air chamber 4 through the primary and secondary air holes 2 and 3. The tachometer 19 measures the rotational speed of the combustion fan 18.

[Control circuit configuration]
Next, the configuration of the control circuit in the present embodiment will be described with reference to FIG.
In FIG. 2, the CPU 32 (control means) controls each unit via the bus 30 based on a program stored in the ROM 34. The RAM 36 is used as a work memory for the CPU 32.
The flash memory 38 functions as a storage unit that stores data to be retained even after the power supply of the heating appliance is turned off. In particular, an error code for specifying the content of the abnormality is written in the flash memory 38 when the heating appliance abnormally stops. The operation unit 40 is provided with an operator for supplying various commands (for example, setting of a target room temperature) to the CPU 32 based on a user operation. In particular, the operation unit 40 is provided with an operation switch 40a that toggles the on / off state of the heating appliance.

  The display unit 42 displays various information to the user. The I / O interface 44 performs various input / output controls under the control of the CPU 32. That is, the I / O interface 44 obtains the combustion state, the bottom temperature of the pot burner 1 and the rotational speed of the combustion fan 18 from the frame rod 16, the temperature sensor 17 and the tachometer 19, and supplies them to the CPU 32. Based on the command, the operations of the ignition heater 7, the electromagnetic pump 11, the suction pump 15, the combustion fan 18, and the convection fan 300 are controlled.

[Operation of the embodiment]
<Normal operation>
Next, the operation of the present embodiment will be described. First, the operation when the heating appliance is normal will be described.
When the user presses the operation switch 40a while the heating appliance is stopped, this is regarded as “ON operation”, and the ON operation processing routine shown in FIG. 3 is started. In FIG. 3, when the process proceeds to step S <b> 2, it is determined whether or not there is an error code written in the flash memory 38 when the heater is stopped last time. If there is no error code, it is determined as “No”, the process proceeds to step S12, and the “combustion start sequence” is executed.

  The combustion start sequence is similar to the sequence from the start of combustion to the main combustion shown in FIG. 4. First, the ignition heater 7 is energized, the combustion fan 18 is driven at a low speed (for example, 1250 rpm), and the pot burner 1 Is gradually raised (preheating). Next, when a predetermined time (120 seconds) elapses after the ignition heater 7 is energized and the temperature detected by the temperature sensor 17 is equal to or higher than a predetermined temperature (for example, 80 ° C. or higher), the driving of the electromagnetic pump 11 is started. The rotational speed of the combustion fan 18 is slightly increased (for example, 1500 rpm). The fuel oil injected from the electromagnetic pump 11 through the injection pipe 13 is vaporized and ignited (ignition) by the vaporization chamber 8 and the ignition heater 7.

  Thereafter, the amount of injected oil of the electromagnetic pump 11 and the rotational speed of the combustion fan 18 are increased to start preliminary combustion for 60 seconds (preliminary combustion A), and further preliminary combustion is being performed, but the injected oil of the electromagnetic pump 11 is maintained for 70 seconds. Although the amount is increased, the rotational speed of the combustion fan 18 is slightly reduced (preliminary combustion B). In this process, when the temperature of the pot burner 1 becomes high, combustion can be continued without energizing the ignition heater 7, so that the ignition heater 7 is turned off. When the combustion start sequence ends, the process proceeds to step S14, and the main combustion process is executed. Here, the main combustion is a state in which the injection oil amount of the electromagnetic pump 11 is automatically controlled according to the current conditions such as the room temperature so that the room temperature designated by the user in the operation unit 40 is realized. .

<Operation when combustion fan 18 is abnormal>
Next, as shown in FIG. 5, the operation in which the combustion fan 18 becomes abnormal during the sequence from the start of operation to the main combustion is shown. The rotation speed of the combustion fan 18 is constantly measured via a tachometer 19. An abnormality is detected in the CPU 32 (control means) when the rotation speed is monitored and the rotation speed becomes a predetermined minimum rotation speed (for example, 300 rpm) or less and the state continues for a predetermined maximum allowable time (for example, 30 seconds). The means 32a (see FIG. 2) detects and the combustion fan error is determined, and the CPU 32 (control means) determines whether this combustion fan error has occurred between the start of operation and the main combustion transition. Since the pre-combustion is in progress, the fuel supply section (11, 12, 13), the heater 7 and the combustion fan 18 are stopped to stop the combustion, and the convection flow is stopped after a predetermined time (30 seconds) from the stop. 300 is driven to cool the pot burner 1 and the combustion cylinder 200, and the cooling of the convection fan 300 is stopped when the pot burner 1 is lowered to a predetermined temperature or a predetermined time has elapsed. It is.

  As described above, when an abnormality of the combustion fan 18 is detected between preheating and pre-combustion of the pot burner 1 that may cause deflagration, the combustion is stopped and the pot burner 1 is cooled only by the convection fan 300. As a result, the deflagration generated by driving the combustion fan 18 for cooling can be reliably prevented, and the convection fan 300 reliably cools the pot burner 1 in the heated state during preparation for the main combustion. It can be used with peace of mind.

  Next, as shown in FIG. 6, when the abnormal rotation of the combustion fan 18 is detected and the combustion fan error is determined by the abnormality detection unit 32a after the main combustion transition, the CPU 32 (control unit) detects the combustion fan error. Since it is determined that the transition to the main combustion has been made and the heater 7 has already been turned off, the fuel supply section (11, 12, 13), the combustion fan 18 and the convection fan 300 are stopped to stop the combustion. The combustion fan 18 is driven after a predetermined time (30 seconds), and the pot burner 1 and the combustion cylinder 200 are cooled by using combustion air from the inside. The burner 1 is lowered to a predetermined temperature or stopped after a predetermined time.

  As described above, when the abnormality detection of the combustion fan 18 by the abnormality detection means 32a is after the transition to the main combustion, the combustion is stopped and only the combustion fan 18 is rotated at a high speed so as to start the cooling of the pothana 1. Therefore, if an abnormality of the combustion fan 18 is detected after the transition to the main combustion of the pot burner 1 without fear of deflagration, the combustion fan 18 is driven again after the combustion is stopped to cool the pot burner 1 more reliably. Is something you can do.

1 Pot burner 7 Ignition heater (heater)
11 Electromagnetic pump (fuel supply part)
12 Supply pipe (fuel supply part)
13 Injection pipe (fuel supply part)
18 Combustion fan 19 Tachometer 32 CPU (control means)
32a Abnormality detection means 100 Pot type combustor 200 Combustion cylinder 300 Convection fan

Claims (2)

A pot burner formed in a bottomed cylindrical shape;
A fuel supply unit for supplying fuel to the pot burner;
A heater provided at the bottom of the pot burner for preheating and ignition;
A combustion fan for supplying combustion air to the pot burner;
A convection fan that supplies indoor air for cooling and warm air to the pot burner;
An abnormality detecting means for detecting an abnormality in the rotational speed generated in the combustion fan,
The main combustion of the pot burner is started after the preliminary combustion in which the heater is turned on and the combustion fan is driven at a low rotation, the fuel oil supply unit is driven to supply the fuel oil, and the heater is ignited and burned for a predetermined time. The control means controls to shift to the main combustion, and the abnormality detection means detects the abnormality of the combustion fan between the start of driving of the combustion fan and the shift to main combustion. In the case, the pot type combustor is characterized in that the combustion is stopped and the cooling of the pot burner is started by driving only the convection fan.   When the abnormality detection of the combustion fan by the abnormality detection means is after the transition to the main combustion, the combustion is stopped and only the combustion fan is rotated at a high speed to start the cooling of the pothana. Item 1. A pot-type combustor according to item 1.

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