JPH0752013B2 - Hot air heater security device - Google Patents

Description

TECHNICAL FIELD The present invention prevents abnormal operation of a warm air heater having a rotary burner that vaporizes liquid fuel such as white kerosene and burns it after mixing with air. The configuration of the security device to be obtained.

(Prior Art) A rotary burner in which an oil pump, a fan, and a burner motor are directly connected coaxially is connected to a combustion chamber of a heat exchanger so that combustion gas generated by the rotary burner, that is, vaporized fuel and air are mixed. A device for heating air by the combustion heat obtained when the combustible gas is burned in the combustion chamber is called a warm air heater, and is widely used for commercial and household purposes.

This type of hot air heater is different from the one in which combustion debris is mixed in the room air by utilizing natural convection of air, and forcibly sends air around the heat exchanger by a convection fan to heat the heat exchanger. The heat exchange between the combustion gas and the air is performed via the heat transfer wall, and the convection fan simultaneously supplies air to the rotary burner and the combustion chamber.

By the way, it is not desirable that stable combustion cannot be performed over a wide temperature range due to the effect of a substantial change in the supply air amount due to room temperature fluctuations. As shown in Japanese Laid-Open Publication No. 61-161528,
The rotary burner motor is made up of a motor whose torque increases or decreases according to the applied voltage or current, and the torque is increased when the room temperature is low and the air specific gravity is large. Conversely, the room temperature is high and the air specific gravity is high. When the torque of the convection fan is small, the torque is reduced.On the other hand, the motor of the convection fan is of a variable speed type.When the torque of the motor of the rotary burner is large, the rotation speed of the convection fan is reduced to feed the rotary burner. There is provided a device in which the amount of air is reduced, and conversely, when the torque is small, the rotation speed of the convection fan is increased to increase the amount of air supplied to the rotary burner.

(Problems to be Solved by the Invention) The hot-air heater having the above-described structure can secure an appropriate amount of air supply without being affected by changes in air temperature, and is always efficient and stable over a wide temperature range. It is excellent in that it can perform combustion operation, but this warm air heater is called CF type, and when it is used in a method that takes in indoor air and exhausts the exhaust gas after combustion to the outside with a chimney, There are such problems.

That is, when the air filter is left clogged, torque control and air supply amount control are performed against external factors such as changes in the draft head of the chimney, ventilation from the chimney, and increase in room negative pressure due to operation of the ventilation fan. It is not possible to properly follow the operation, backfire phenomenon, gas leakage occurs, lift disappears or CO generation occurs, and there are safety problems.

The present invention has been made in view of such problems, and it is dangerous to accurately detect an abnormal phenomenon based on the relationship between the torque limit value of the burner motor and the speed limit value of the convection fan motor. It is an object of the present invention to provide a device that enhances safety by stopping the combustion operation before it becomes a stable state.

(Means for Solving the Problem) However, as is apparent from the drawings showing the embodiments, the present invention includes a heat exchanger (1) including a combustion chamber (7) connected to an exhaust passage (24) such as a chimney; The oil pump (8) and the burner fan (9) are axially connected to the burner motor (10) of the variable torque type, and the vaporized fuel ejected by the oil pump (8) and the burner fan (9) are blown from the air suction port (12). A rotary burner (2) that generates a combustion gas that mixes with the sucked air and sends the combustion gas to the combustion chamber (7) and a low or high change in the rotational speed corresponding to the high or low torque of the burner motor (10). A convection fan (3) which is connected to a variable speed type fan motor (11) for supplying air to the air suction port (12) to promote air suction at the air suction port (12). Burner motor (10) in a hot air heater equipped with Abnormality detection means for detecting torque and outputting a deceleration signal when the detected value is larger than the upper limit set torque and smaller than the lower limit set torque with respect to the upper limit set torque and the lower limit set torque, respectively. (32) and the signal from the abnormality detecting means (32), to the fan motor (11),
The speed change means (33) for giving a deceleration output for decreasing the speed by the deceleration signal and the acceleration output for increasing the speed by the acceleration signal, and the deceleration signal when the fan motor (11) has reached the lower limit set speed. Is output, and when the upper limit set speed is reached and the speed-up signal is output, the safety device is configured by the abnormal stop means (34) for generating a stop output for stopping the combustion operation. Characterize.

(Function) By providing the above-mentioned safety device, for example, when a large ventilation fan is operated, resulting in negative pressure in the room, or when there is a back wind from the chimney, the cover is provided within the air flow adjustment range of the convection fan. If it becomes impossible, the abnormal stop means (3
4) is activated to stop the combustion operation, resulting in high safety.

EXAMPLES Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is a schematic view showing the structure of a warm air heater according to an example of the present invention, in which a suction port (5) is opened in the lower front portion, and a blowout port (6) is opened in the upper front portion and the front intermediate portion. Inside the casing (4), a heat exchanger (1), a rotary burner (hereinafter referred to as a burner) (2), a convection fan (3) are arranged from above.
The burner (2) has a plurality of flame openings provided at the upper end of the burner head (16).
Is disposed so as to penetrate the bottom wall of the heat exchanger (1) and face the combustion chamber (7) in the heat exchanger (1).

In the warm air heater, the convection fan (3) is energized and the burner (2) burns to operate the burner (2).
The combustion gas generated in 1. heats the peripheral wall of the heat exchanger (1) that has burned at the flame mouth in the combustion chamber (7), and then the exhaust passage (24)
Exhausted through the chimney, which is a convection fan (3)
The indoor air guided by the suction port (5) into the casing (4) is partially sent to the air suction port (12) of the burner (2) for the purpose of promoting suction, and at the same time, a large amount of the air is discharged. After being heated while flowing along the outer peripheral heat transfer wall of the heat exchanger (1) to become warm air, the both outlets (6),
It is sent out from the room (6) to the room, thus heating the room.

The burner (2) has a structure shown in FIG. 3, and has a combustion part, a vaporization part, a fan part and a pump part in this order from the upper part to the lower part.

The combustion section has a burner head (16) having a flame port (19) and an ignition plug (20) provided at a position in contact with a flame formed on the burner head (16).

The vaporization part has a vaporizer (15), a vaporization heater (17), and a diffusion blade (18).

The fan part has an air inlet (12) with a damper (21).
It has a fan (9) for sending the combustion air introduced from (1) to the carburetor, and the fan (9) is connected to one shaft of the burner motor (10).

The pump part has a filling port (2
2) and the drain plug (23), and the nozzle (1
A double-cylinder structure having an oil pump (8) formed by opening 3) downward and a concentric inner cylinder having an upper part formed in the pump chamber (14), The shaft of (3) is connected to the other shaft of the burner motor (10).

The burner (2) having such a structure is called a synchro-gasification burner which has an oil pump (8) and a fan (9) coaxially and integrally. First, in the fuel system, a fuel is supplied from an oil tank or the like through a constant oil leveler or the like. Is introduced into the pump chamber (14) and the oil level is maintained at a constant level.

The fuel whose pressure is increased by the oil pump (8) by the rotation of the burner motor (10) is converted into a constant amount of oil by the nozzle (13), and passes through an oil passage provided in the shaft of the burner motor (10) to diffuse the vanes (1).
8), where radiation is scattered by centrifugal action.

The scattered oil particles collide with the wall of the vaporizer (15) whose temperature is raised by the vaporization heater (17) (at 260 to 290 ° C.) and vaporize.

On the other hand, in the combustion air system, the fan (9) rotates to flow from the damper (21), the pressure is increased, and the gas is directed into the carburetor (15).

In this case, about 70% is supplied as primary air and about 30% is supplied as secondary air.

The primary air introduced into the vaporizer (15) is transferred to the diffusion blade (1
While being mixed with the fuel atomized and vaporized by 8), it is emitted from the slit of the flame port (19) and ignited by the spark plug (20) to continue combustion.

The combustion operation control of the warm air heater having the above structure will be described with reference to FIGS. 1 to 4.

The burner motor (10), which is the drive source of the burner (2), is a variable torque type motor. For example, a direct current motor, a condenser motor, or the like having a characteristic that the torque increases or decreases depending on the level of the applied voltage is used. The fan motor (11), which is the drive source of (3), uses a variable-speed motor, for example, a single-phase induction motor capable of stepless speed switching between high rotation and low rotation and any rotation therebetween. The burner motor (10) performs constant-speed operation control, and the fan motor (11) performs variable operation control by a control circuit shown as a block in the figure.

By the way, the DC motor and the condenser motor can change the torque and the speed by changing the applied voltage.

Now, in the feedback control that detects the motor speed and keeps the motor speed constant, if the load applied to the motor increases, the voltage applied to the motor will increase to maintain a predetermined value so as not to decrease the speed, and conversely The applied voltage decreases as the value decreases.

That is, since the voltage applied to the motor changes depending on the load, it is possible to know the magnitude of the load by detecting the voltage applied to the motor.

The control circuit shown in FIG. 1 controls the burner motor (10) to maintain a constant rotation speed by the feedback control circuit (25) irrespective of the fluctuation of the load (air amount), while controlling the speed of the fan motor (11). It is a circuit configuration for performing control by a circuit (26) to shift to a high rotation upper limit set speed, a low rotation lower limit set speed, and a stepless arbitrary speed between them.

Feedback control circuit (25) is a burner motor (10)
The motor speed control circuit (27) that outputs a voltage for rotating the motor at a predetermined rotation speed and the speed detection unit (28) that detects the rotation speed of the burner motor (10) are elements, and the speed detection unit (28 The motor speed control circuit (27) is configured to generate a voltage output that is feedback-controlled so that the rotation speed detected in (1) matches a predetermined rotation speed.

In the motor speed control circuit (27), the upper limit value and the lower limit value of the torque are set to define the torque adjustment range, and it is formed so that torque outside the range is not generated.

On the other hand, the speed control circuit (26) includes a voltage detection unit (29) that detects the voltage applied to the burner motor (10) as a torque conversion value, a torque value of the burner motor (10), and air suction promotion of the convection fan (3). Detection of the fan rotation speed storage circuit (30) in which the value of the fan rotation speed corresponding to the torque value that is set as an appropriate value by measurement in advance from the relationship with the action is readably written, and the detection of the voltage detection unit (29) Based on a signal, a speed switching circuit (31) which outputs a switching output so as to operate at a fan rotation speed read from a predetermined address of the storage circuit (30) is used as an element, the room temperature is high, and the burner motor ( When 10) is a light load operation, the fan motor (11) is operated at a high speed, and when the room temperature is low and the load is high, the fan motor (11) is operated at a low speed.

The speed control circuit (26) is further provided with a security circuit, and the security circuit is composed of an abnormality detecting means (32), a speed changing means (33) and an abnormal stopping means (34).

The abnormality detecting means (32) receives the detection signal of the voltage detecting section (29) and causes the upper limit setting torque and the lower limit setting torque to be compared. When the detected torque value is larger than the upper limit setting torque, deceleration is performed. A signal is output, and when the torque is smaller than the lower limit set torque, an acceleration signal is output.

On the other hand, the speed changing means (33) receives the output signal of the abnormality detecting means (32) and gives a deceleration output for further reducing the speed to the fan motor (11) by the deceleration signal and further increases the speed by the acceleration signal. The speed increase output to increase is given to forcibly increase or decrease the speed.

Further, the abnormal stop means (34) receives the output signal of the abnormality detection means (32) and the speed signal of the fan motor (11), and the fan motor (11) has decreased to the lower limit set speed,
Moreover, combustion operation such as stopping the burner motor (10) is performed when the deceleration signal is output, when the fan motor (11) is rising to the upper limit set speed, and when the acceleration signal is output. It is formed so as to generate a stop output for stopping.

The operation of the warm air heater having the above-described configuration will be briefly described.

In the hot air heater, when the amount of air sent to the burner head (16) by the burner motor (10) is reduced due to the light specific gravity when the room temperature rises, that is, the burner motor load is reduced and the motor current or motor applied voltage is reduced. At times, by increasing the motor speed of the convection fan (3), the internal pressure (P) (see FIG. 2) increases and the air amount increases.

On the contrary, when the specific gravity of the air increases and the motor load increases as the room temperature decreases, the motor speed of the convection fan (3) is reduced to lower the internal pressure (P) and reduce the air amount.

Thus, the combustion can be stabilized by supplying an appropriate amount of combustion air regardless of the change in the load on the burner motor (10).

During this combustion operation, if the amount of air supply decreases due to, for example, back wind from the chimney, the burner motor load increases, and the torque exceeds the upper limit set value.

As a result, the abnormality detecting means (32) outputs a deceleration signal to detect higher than Banamota applied voltage (V _M) has an upper limit set torque corresponding voltage as in step (b) of FIG. 4 (V _rH) Thus, the speed changing means (33) thus outputs a deceleration output as in step (b) to decelerate the fan motor (11).

Due to this deceleration, the motor speed of the convection fan (3) is lowered to the lower limit set speed, so that combustion is stabilized and at the same time,
If the torque becomes smaller than the upper limit set value, the combustion operation is continued as it is (step (d) (g)),
If the torque is still larger than the upper limit set torque, the abnormal stop means (34) outputs a stop output (step (c)), so that the warm air heater stops the combustion operation (step (h)).

Apart from this, the same is true when the burner motor load decreases due to external factors and the torque falls below the lower limit setting value. As is clear from FIG. 4, in the event of an abnormality, a stop output is issued to start combustion operation. It comes to stop.

By thus operating the safety device, it is possible to prevent flashback (backfire) and gas leakage from the burner.

The fan rotation speed storage circuit (30) and the abnormality detection means (32) can be easily configured in the microcomputer which is the center of the control unit.

(Effects of the Invention) The effects of the present invention are as follows.

If it becomes impossible to maintain a stable combustion state by controlling the air volume of the convection fan (3) due to external factors such as backwind from the exhaust passage (24), indoor negative pressure, etc., the safety device will operate and stop combustion. It is possible to reliably prevent flashback from the engine and leakage of gas from the combustion chamber.In addition, if the draft head in the exhaust passage (24) is too strong and the combustion air volume increases too, the safety device operates in the same way, so the lift disappears. Problems such as CO generation can be prevented in advance.

[Brief description of drawings]

FIG. 1 is a block diagram of a control circuit diagram according to an embodiment of the present invention,
Fig. 2 is a schematic structural diagram of the hot air heater, and Fig. 3 is a schematic diagram
FIG. 4 is a detailed view of the structure of the rotary burner in the figure, and FIG. 4 is a flow chart showing the operation of the safety device in FIG. (1) ...... Heat exchanger, (2) ...... Rotary burner, (3) ...... Convection fan, (7) ...... Combustion chamber, (8) ...... Oil pump, (9) ...... Burner fan, ( 12) …… Air inlet, (24) …… Exhaust passage, (32) …… Abnormality detection means, (33) …… Speed changing means, (34) …… Abnormal stop means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tadamitsu Imai 1-1 No. 1 Nishiichitsuya, Settsu City, Osaka Prefecture Daikin Industries, Ltd. Yodogawa Manufacturing Co., Ltd. (56) Reference JP-A-54-159733 (JP, A) JP-A-SHO 61-15018 (JP, A)

Claims (1)

[Claims] 1. A variable torque burner motor (10) comprising a heat exchanger (1) containing a combustion chamber (7) connected to an exhaust passage (24) such as a chimney, an oil pump (8) and a burner fan (9). ), And a combustion gas is generated by mixing the vaporized fuel ejected by the oil pump (8) with the air sucked from the air suction port (12) by the burner fan (9) to produce the combustion chamber ( 7) is connected to a rotary burner (2) and a variable speed fan motor (11) that changes the rotation speed in accordance with the torque level of the burner motor (10),
A hot air heater provided with a convection fan (3) for promoting air suction at the air suction port (12) by feeding air to the air suction port (12), the torque of a burner motor (10) The abnormality detection means for detecting the detected value and outputting a deceleration signal when the detected value is larger than the upper limit set torque and smaller than the lower limit set torque with respect to the upper limit set torque and the lower limit set torque, respectively. 32) and the signal from the abnormality detecting means (32), the fan motor (1
1), the speed change means (33) for giving a deceleration output for decreasing the speed by the deceleration signal and the acceleration output for increasing the speed by the acceleration signal, and the fan motor (1
1) is a lower limit set speed and the deceleration signal is output, and an upper limit set speed is reached and the speed increase signal is output, an abnormal stop that generates a stop output that stops the combustion operation. A safety device for a hot air heater, comprising: means (34).