JPH1151380A - Hot air heater - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure good combustion using a rotation speed control type motor in an FF type hot air heater. The number of revolutions of a burner fan motor for driving an air supply fan is controlled in accordance with the temperature of air supply detected by an air supply temperature sensor. By increasing the number of revolutions as the supply air temperature increases, the amount of combustion air is kept constant. The temperature of the air supply supplied by the pre-purge before ignition is detected, and the number of revolutions at the time of the ignition operation is set. Further, during the combustion whose capacity is controlled, the supply air temperature is detected at regular intervals, and the number of revolutions is corrected according to the detected supply air temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced air supply / discharge type hot air heater.

[0002]

2. Description of the Related Art Usually, a forced air supply / exhaust type hot air heater called an FF type has a supply or exhaust port facing the outside using a wall or a window. And the hot air heater main body are connected by an air supply pipe and an exhaust pipe. Then, the air for combustion is forcibly supplied using the air supply fan to the combustion chamber sealed from the chamber through the air supply pipe through the air supply pipe, and is blown out from the nozzle of the burner incorporated in the combustion chamber. The fuel gas and the air for combustion are burned, and the combustion exhaust gas is discharged to the outside through an exhaust port.

[0003] A convection fan forcibly blows cool air in the room around a heat exchanger interposed between the combustion chamber and the exhaust pipe and around the combustion chamber heated by combustion heat.
The air is converted into warm air to increase the indoor temperature.

[0004]

In order to obtain a good combustion state, there is an optimum amount of combustion air with respect to the amount of combustion gas. Conventionally, a condenser motor has been frequently used as an air supply fan for supplying combustion air, but this condenser motor has autonomy with respect to various load fluctuation factors.

For example, when the atmospheric pressure decreases due to the arrival of a low pressure or an increase in the outdoor temperature, the air density decreases, and the load on the blower decreases, the condenser motor autonomously increases the rotation speed accordingly. To increase the air flow,
The amount of combustion air is kept substantially constant. In contrast, a DC motor controlled by an electronic motor, which has been widely used in recent years, cannot expect such autonomy. Therefore, even if the air density decreases due to a rise in temperature or the like, the blower is operated at the same air volume, and a constant volume of air is continuously supplied. For this reason, the substantial amount of air is reduced by an amount corresponding to the decrease in the air density, and an optimum amount of combustion air may not be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a warm air heater capable of ensuring good combustion by using a rotation speed control type motor.

[0007]

According to a first aspect of the present invention, there is provided a hot air heater in which a mixture of fuel gas and combustion air is burned in a combustion chamber. In the hot air heater, an air supply fan for forcibly supplying combustion air to the combustion chamber, a DC motor for driving the air supply fan, and a supply air for detecting a temperature of the air supply supplied as combustion air. An air temperature detecting means and a control means for controlling the number of rotations of the DC motor in accordance with the temperature of the air supply detected by the air supply temperature detecting means are provided.

In this configuration, the amount of air supplied is adjusted in accordance with the temperature of the supplied air, whereby an optimum amount of air for combustion is always obtained, so that a good combustion state can be obtained. According to a second aspect of the present invention, in the hot air heater according to the first aspect, the control unit detects the temperature of the supply air supplied by the scavenging operation before the ignition by the supply air temperature detection unit, and detects the temperature during the ignition operation. It is characterized in that the number of rotations of the DC motor is set.

With this configuration, an optimal air volume at the time of ignition can be set according to the temperature of the supply air detected during the scavenging operation before the ignition, and reliable ignition can be performed. Note that the scavenging operation before ignition is a so-called prepurge, in which a gas supply fan is operated before ignition to discharge gas remaining in the vaporization chamber or the combustion chamber. The hot-air heater of the invention according to claim 3 is the method according to claim 1 or 2, wherein during the combustion,
The control means sets the number of revolutions of the DC motor in accordance with the temperature of the air supply detected by the air supply temperature detection means at predetermined time intervals.

[0010] Even during heating, by adjusting the amount of air supply in accordance with the change in the temperature of the air supply, an optimal amount of combustion air can always be ensured. The hot air heater according to claim 4 further comprises an air pressure detecting means for detecting the air pressure at the installation location according to claim 1, 2, or 3, wherein the control means responds to the air pressure detected by the air pressure detecting means. D
It is characterized in that the number of rotations of the C motor is controlled.

In this configuration, by adjusting the amount of supply air in accordance with a change in the atmospheric pressure, an optimal amount of combustion air can always be ensured. According to a fifth aspect of the present invention, there is provided a warm air heater according to the first, second or third aspect, further comprising: means for setting installation conditions related to air supply efficiency, wherein the control means is based on the set installation conditions. It is characterized in that the number of rotations of the DC motor is controlled.

In this configuration, if the installation conditions related to the air supply efficiency are set in advance at the time of installation using the means for setting the air supply efficiency, the air volume of the air supply is adjusted according to the set installation conditions. As a result, an optimal amount of combustion air can always be ensured. Here, the installation condition related to the air supply efficiency is a factor that affects the supply efficiency of the combustion air to the combustion chamber. For example, the altitude that affects the air pressure, the length of the supply and exhaust pipe that affects the air supply resistance, and the like. Etc. are included.

[0013]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic view showing a forced air supply / exhaust type hot air heater as one embodiment of the present invention. Referring to FIG. 1, the warm air heater draws in cold air in the room from a suction grill 2 disposed below front surface 1 a of warm air heater main body 1, and receives the front air 1 a of warm air heater main body 1. The hot air is blown out from the blow-off grill 3 arranged at the upper part of the table.

A combustion chamber 4 for burning gasified liquid fuel is provided inside the warm air heater main body 1. A burner 5 is arranged below the combustion chamber 4, and a combustion part 6 of the burner 5 formed of a cylindrical wire mesh is incorporated in the combustion chamber 4. Further, in the casing of the burner 5, a vaporization chamber 7, a fan chamber 8, and a motor chamber 9 which are communicated with the combustion chamber 4 through the combustion section 6 are defined (see FIG. 2).

Referring to FIG. 2, a vaporizer 10 is constituted by a portion of a casing that partitions vaporizing chamber 7 and a stirring blade arranged in vaporizing chamber 7. A vaporizer temperature sensor 11 composed of a thermistor for detecting the vaporizer temperature is disposed on a wall surface of the vaporizer 10 or the like. The liquid fuel pressurized and supplied by the electromagnetic pump 12 through the oil feed pipe 13 is injected to the rotary cone 14, atomized by centrifugal force generated by the rotation of the rotary cone 14, and then pre-evaporated by the vaporizer heater 15. The stirring blade 1 in the heated vaporization chamber 7
The mixture is stirred and gasified by 6.

The fan chamber 8 houses an air supply fan 17 for supplying air supplied from outside to the combustion chamber 4 as combustion air. The motor chamber 9 accommodates a burner fan motor 18 composed of a DC motor for driving the air supply fan 17 and an air supply temperature sensor 19 for detecting the temperature of the air supply. Referring to FIG. 1, a heat exchanger 20 communicated with combustion chamber 4 is arranged above combustion chamber 4. A convection fan 21 is provided below the combustion chamber 4 for blowing cold air in the room sucked from the suction grill 2 to the combustion chamber 4 and the heat exchanger 20 and convection into the room through the blow grill 3. . The convection fan 21 is driven by a convection fan motor 22.

Referring to FIGS. 1 and 2, reference numeral 23 denotes an ignition electrode plug disposed close to a flame port 24 of the combustion section 6. A voltage is applied. Reference numeral 26 denotes a flame rod type flame sensor. An oil leveler 27 is connected to a fuel tank (not shown) installed outdoors or the like via a pipe 28 and an oil filter 29. Above the oil leveler 27, the above-described electromagnetic pump 12 is arranged.

Reference numeral 30 denotes a room temperature sensor disposed in the hot air heater main body 1 at a position near the suction grill 2. 31
Is an overheat prevention thermometer disposed near the combustion chamber 4 in the warm air heater main body 1. Reference numerals 32 and 33 denote rotation speed sensors that detect the rotation speeds of the burner fan motor 18 and the convection fan motor 22, respectively, and are configured using, for example, a Hall element.

The exhaust pipe 3 connected to the heat exchanger 20
4, and an air supply pipe 35 connected to the motor chamber 9 of the burner 5 are led out of the hot air heater main body 1, and are both connected to a supply / exhaust cylinder 36 (also referred to as a supply / exhaust cylinder top). I have. The supply / exhaust cylinder 36 is formed of a double cylinder attached to a wall surface. The inside of the inner cylinder is an exhaust passage 37, and the annular passage between the inner cylinder and the outer cylinder is an air supply passage 38.

In the hot air heater having such a configuration, the fuel supplied by the electromagnetic pump 12 and vaporized is supplied to the vaporizing chamber 7 through the air supply passage 38 and the air supply pipe 35 of the air supply / exhaust cylinder 36.
The combustion air supplied to the inside is mixed, and the air-fuel mixture is burned at the flame port 24 of the combustion unit 6. The combustion waste gas is supplied to the heat exchanger 20, the exhaust pipe 34, and the exhaust passage 37 of the supply / exhaust pipe 36.
It is discharged outside through.

An operation panel 40 provided with various operation switches 39 is disposed below the blow grill 3 on the front surface 1a of the warm air heater main body 1, and on the back side of the operation panel 40, various operation switches 39 are provided. An operation board 42 including a circuit related to setting of operation conditions and a circuit related to display of the display unit 41 on the operation panel 40 is arranged. On the other hand, the operation board 42 and various sensors 11, 19, 26, 30, 31, 32, 3
A control board 43 including a control circuit and the like for controlling the operations of the electromagnetic pump 12, the burner fan motor 18, and the convection fan motor 22 in response to signals from 3,.

Next, with reference to FIG. 3, a description will be given of a main electric configuration of the warm air heater. CPU 46, RA
A control circuit 49 configured by a microcomputer including an M47, a ROM 48, and the like and mounted on the control board 43 includes a vaporizer temperature sensor 11, an air supply temperature sensor 1, and the like.
9, room temperature sensor 30, flame sensor 26, thermostat 3
1, a rotation speed sensor 32, a current sensor 44, a rotation speed sensor 33, and a current sensor 45 are connected, and signals from these sensors are input. Reference numerals 44 and 45 denote current sensors for detecting load currents of the burner fan motor 18 and the convection fan motor 21, respectively.

The control circuit 49 includes the electromagnetic pump 1
2. The carburetor heater 15, the igniter transformer 25, the burner fan motor 18, and the convection fan motor 22 are connected, and a signal is output to these. Signals are exchanged between the control circuit 49 and the operation / display circuit 50 mounted on the operation board 42. The operation / display circuit 50 inputs signals from various operation switches 39 and outputs signals for display to the display unit 41.

The control circuit 49 includes an installation condition setting switch 51 for setting installation conditions such as altitude.
52 and 53 are connected. As shown in FIG. 4, these setting condition setting switches 51, 52, 53
3 is implemented by a combination of ON and OFF of each of the switches 51, 52 and 53.
A plurality of setting levels 1 to 6 can be set according to the altitude. When the on / off state of each of the switches 51, 52 and 53 is indicated by 1 and the off by 0, the set level of the altitude is (0, 0, 0): set level 1 (corresponding to the standard altitude) (1, 0, 0): Setting level 2 (corresponding to an altitude of 300 M) (0,1,0): Setting level 3 (corresponding to an altitude of 600 M) (1,1,0): Setting level 4 (corresponding to an elevation of 900 M) (0,0,1) : Set level 5 (corresponding to an altitude of 1200 M) (1, 0, 1): Set level 6 (corresponding to an altitude of 1500 M). It should be noted that the combination is not described above (0, 1,
1) and (1,1,1) are set to the set level 1.

When installing the hot air heater, the installation operator sets the installation condition setting switches 51 to 51 on the control board 43.
By operating 53, a setting level relating to altitude is set. According to the set level, the higher the set level (the higher the altitude), the higher the number of revolutions of the burner fan motor 18 during the ignition operation and the normal combustion operation (at the time of capacity control). .

Burner fan motor 1 for set level
The data of the number of rotations 8 may be stored in the ROM 48 as a table, or an arithmetic expression may be stored and the number of rotations according to the set level may be obtained using the arithmetic expression. . When storing as the above table, it is preferable to store as a table in which the number of revolutions of the burner fan motor 18 is set according to the setting level of the installation condition and the supply air temperature. This is because the rotation speed can be set most efficiently by determining the rotation speed using the supply air temperature and the air pressure that both affect the air density as parameters.

If the data in this case is graphed, the ignition operation is as shown in FIG. 5 (a), which is set for the supply air temperature level and the setting levels 1 to 6 of the installation conditions. Burner fan motor 1 during power ignition operation
Eight rotation speeds are associated with each other. Also, during the combustion operation, the state becomes as shown in FIG. 5B, and similarly, the supply air temperature level and the installation condition setting levels 1 to 6 are set.
Is associated with the number of revolutions of the burner fan motor 18 during the combustion operation to be set. In addition, FIG.
Is shown with a capacity of 50%, but data having a similar tendency is set for a plurality of levels of capacity%.

FIG. 6 shows that the control circuit 49 controls the supply air temperature sensor 1.
FIG. 4 is a rotation speed control configuration diagram showing only a configuration for controlling the rotation speed of the burner fan motor 18 by inputting signals from the switch 9 and the installation condition setting switches 51 to 53 in more detail than FIG. Referring to FIG. 6, a target rotation speed is calculated (or retrieved from a table stored in advance) by rotation speed calculation unit 54 based on the detected supply air temperature and the set level of the installation condition, The rotation speed control unit 55 controls the rotation speed so as to approach the target rotation speed. Specifically, the current controller 56 controls the amplifier 5
The number of revolutions is controlled by adjusting the control current value to the burner fan motor 18 via 7, and at this time, feedback is given on the current and the number of revolutions. That is, the load current of the burner fan motor 18 is detected by the current sensor 44, feedback control is performed so that the load current becomes a target current value for realizing the target rotation speed, and the actual rotation speed of the burner fan motor 18 is detected by the rotation speed sensor 32. And the feedback control is performed so as to approach the target rotation speed.

Next, the operation of controlling the number of revolutions of the burner fan motor 18 in the present warm air heater will be described with reference to the flowcharts of FIGS. FIG. 7 shows an operation during ignition control, and FIG. 8 shows an operation during combustion control. Referring to FIG. 7, the carburetor heater 15 is turned on to start preheating (step S1). When the carburetor temperature exceeds a predetermined value (step S2), the burner fan motor 18 is set to the rated rotation speed (step S2). 100%) for a predetermined time (for example, 20 seconds) to perform so-called prepurge,
Clean the interior of the combustion chamber 4 before ignition (steps S3, S
4).

Immediately after the prepurge, the ignition transformer 25
Is turned on (step S5), the supply air temperature is detected, and the number of revolutions of the burner fan motor 18 during the ignition operation is obtained in the manner described above (steps S6 and S7). Then
A predetermined period of time (for example, 3
After waiting for 0 seconds, the electromagnetic pump 12 is turned on to supply fuel and ignite (steps S8 and S9).

On the other hand, referring to FIG. 8, during the combustion operation, the supply air temperature is detected and monitored every predetermined time (for example, every 20 seconds) (steps S11 to S14). Based on the air temperature, the target rotation speed is obtained based on the above table or the arithmetic expression (step S15), and the target rotation speed is controlled to be the target rotation speed. If there is a mode change during monitoring, the mode shifts to another mode (step S16).

In the present embodiment, the amount of air supplied during the ignition operation can be optimally set according to the temperature of the supplied air during the pre-purge (scavenging operation) before the ignition, so that reliable ignition can be achieved. I can do it. In addition, even during the combustion operation, since the supply air volume is adjusted at regular intervals according to the change in the supply air temperature,
Good combustion can be performed by always securing the optimal amount of combustion air.

In addition, setting levels such as elevation, which are installation conditions related to air supply efficiency, are set in advance at the time of installation, and the amount of air supplied is adjusted in accordance with the set levels. Therefore, it is possible to always ensure an optimal amount of combustion air and perform good combustion. In the above-described embodiment, the altitude related to the atmospheric pressure is determined by setting the installation condition setting switches 51 to 53 including the dip switches of the control board 43.
, The switches 51 to 53 are eliminated, and a pressure sensor 58 for detecting the pressure of the environment in which the warm air heater main body 1 is placed is provided as shown in FIG. The supply air volume can be adjusted according to the air pressure detected by the air pressure sensor 58 and the supply air temperature. In this case, fine control can be performed according to the atmospheric pressure change at any time (for example, every predetermined time). In addition, it is preferable to provide the pressure sensor 58 in a position inside the main body 1 of the warm air heater or on a wall surface of the main body 1 where the air pressure sensor 58 is not affected as much as possible by the convection fan 21 in order to ensure detection accuracy.

The present invention is not limited to the above embodiments. For example, in each of the above embodiments, the dip in which the length of the air supply pipe at the time of installation which affects the air supply efficiency is set as the installation condition at the time of installation. A switch may be provided. In addition, various changes can be made within the scope of the present invention.

[0035]

According to the first aspect of the present invention, the supply air volume is adjusted in accordance with the supply air temperature, so that an optimum combustion air amount is always obtained, so that a good combustion state can be obtained. According to the second aspect of the invention, the amount of supply air at the time of ignition can be optimally set according to the supply air temperature at the time of the scavenging operation before ignition, so that reliable ignition can be performed.

According to the third aspect of the present invention, the optimum amount of combustion air is always ensured and the optimum combustion state is obtained by adjusting the supply air flow according to the change in the supply air temperature even during heating. be able to. According to the fourth aspect of the present invention, the supply air volume is adjusted according to a change in the atmospheric pressure at any time,
Fine combustion control can be achieved.

According to the fifth aspect of the present invention, by setting in advance the installation conditions related to the air supply efficiency, for example, the level such as the altitude, it is possible to secure the optimum combustion state without the influence of the altitude and the like.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an internal configuration of a warm air heater according to one embodiment of the present invention.

FIG. 2 is a schematic sectional view mainly showing a burner.

FIG. 3 is a block diagram showing an electrical configuration of the hot air heater.

FIG. 4 is a front view of a main part of the control board.

FIG. 5 is a graph showing a relationship between a setting level of an installation condition and an air supply temperature, and a rotation speed set correspondingly thereto. (A) is during the ignition operation, and (b) is during the combustion operation.

FIG. 6 is a block diagram illustrating a configuration of rotation speed control.

FIG. 7 is a flowchart showing a control flow at the time of ignition.

FIG. 8 is a flowchart showing a control flow during combustion.

FIG. 9 is a block diagram showing an electrical configuration of a hot air heater according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot-air heater main body 4 Combustion chamber 5 Burner 17 Air supply fan 18 Burner fan motor 43 Control board 49 Control circuit 51, 52, 53 Installation condition setting switch 54 Rotation speed calculation unit 55 Rotation speed control unit 57 Atmospheric pressure sensor

Claims (5)

[Claims] An air-fuel mixture of fuel gas and combustion air is supplied to a combustion chamber.
In the warm air heater that burns in (4), an air supply fan (17) that forcibly supplies combustion air to the combustion chamber (4) and a DC motor (18) that drives the air supply fan (17) ), Air supply temperature detection means (19) for detecting the temperature of air supply supplied as combustion air, and a DC motor according to the air supply temperature detected by the air supply temperature detection means (19). Control means for controlling the rotation speed of (18)
(49) A hot air heater comprising: The control means (49) detects the temperature of the supply air supplied by the scavenging operation before ignition by the supply air temperature detection means (19), and rotates the DC motor (18) during the ignition operation. The hot air heater according to claim 1, wherein the number is set. 3. During combustion, the control means (49) sets the number of revolutions of the DC motor (18) in accordance with the supply air temperature detected by the supply air temperature detection means (19) at predetermined time intervals. The hot air heater according to claim 1 or 2, wherein: 4. An air pressure detecting means (5) for detecting the air pressure at the installation location.
The control means (49) controls the number of revolutions of the DC motor (18) according to the air pressure detected by the air pressure detection means (58). Hot air heater as described. 5. The apparatus further comprises means (51, 52, 53) for setting installation conditions relating to air supply efficiency, wherein said control means (49) controls the DC based on the set installation conditions.
The hot air heater according to claim 1, 2, or 3, wherein the number of rotations of the motor (18) is controlled.