JPH04366358A - Hot air heater - Google Patents

Abstract

PURPOSE:To improve comfortableness and safety by a method wherein an abnormal heating at a combustion part or a heat exchanging part can be prevented without giving any uncomfortable cold feeling to a user at the beginning of operation. CONSTITUTION:A micro-computer 17 makes the rotation al epeed of a fan motor 5M lower than that corresponding to the combustion amount when a temperature detected through a temperature sensor 15 located at a heat exchanger or thereabout is low. In turn, when the detected temperature is higher than that, the rotation al epeed of the fan motor 5M is higher than that corresponding to the combustion amount.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to hot air heaters such as oil fan heaters and gas fan heaters.

0002

BACKGROUND OF THE INVENTION For example, a hot air heater such as an oil fan heater has a combustion section, a heat exchange section to which combustion gas is supplied from the combustion section, and It has an air blower that blows indoor air out through the heat exchanger.

[0003] The air volume control by the blower described above is generally performed by controlling the phase of the AC motor for driving the blower.
Depending on the amount of combustion in the combustion section, the phase cut angle (off time in each half cycle of AC power supply, e.g. 50H)
z, set between 0 and 10 ms) and control the phase of the voltage applied to the AC motor using this phase cut angle,
There are known devices that detect the rotational speed of an AC motor and increase or decrease the phase cut angle so that the rotational speed corresponds to the amount of combustion.

0004

[Problems to be Solved by the Invention] However, in systems that control the phase of the blower drive motor so as to obtain an air volume commensurate with the amount of combustion, there is a concern that cold air will blow out at the beginning of operation, causing discomfort to the user. was there. In addition, for those using a rotation speed detector, a photocoupler or Hall IC
etc., which had the disadvantage of increasing costs.

Of course, blowing out cold air can be prevented by controlling the air volume of the blower according to the blowing temperature, but
On the other hand, there was a concern that the combustion section and the heat exchange section would be abnormally heated due to a delay in response of the temperature sensor that detects the temperature of the blast, causing damage to these sections.

[0006] This invention was made in view of the above-mentioned facts, and aims to prevent abnormal heating of the combustion section and heat exchange section without giving the user a feeling of cold air at the beginning of operation. The purpose of this is to enable accurate air volume control without using an expensive rotation speed detector.

[0007]

[Means for Solving the Problems] In this invention, a combustion section,
In a hot air heater that has a heat exchange part and a blower to which combustion gas is supplied from the combustion part, and the blower blows out indoor air through the heat exchange part, the hot air heater is provided at or near the heat exchange part. This configuration includes a temperature sensor, and a control means that operates the blower at an air volume that is determined according to the amount of combustion in the combustion section and is corrected according to the temperature detected by the temperature sensor.

[0008] Furthermore, the present invention includes a combustion section, a heat exchange section to which combustion gas is supplied from the combustion section, and a blower,
In a hot air heater in which indoor air is blown out through a heat exchanger by a blower, a temperature sensor installed in or near the heat exchanger and a central phase cut angle corresponding to the amount of combustion in the combustion part are used. and control means for controlling the phase of an AC motor for driving the blower at a target phase angle in which a target air temperature is determined and a center phase angle is corrected according to a deviation between the temperature detected by the temperature sensor and the target air temperature. The configuration is as follows.

Furthermore, in the hot air heater according to claim 2, the correction amount according to the deviation between the temperature detected by the temperature sensor and the target blast temperature is increased or decreased by a complementary value of the center phase angle. There is.

0010

[Function] In the device according to claim 1, since the air volume of the blower is determined according to the amount of combustion, not only is there no need to worry about abnormal heating of the combustion part, but also the temperature detected by the temperature sensor (blow temperature) Since the air volume is corrected accordingly, it is possible to minimize the feeling of cold air given to the user at the beginning of operation or when the load fluctuates.

[0011] Furthermore, in the second aspect of the present invention, the air volume control described above is performed using an inexpensive AC motor (for example, a shaded motor).
Furthermore, according to the third aspect of the present invention, such phase control can be performed with high accuracy without using a rotation speed detector.

0012

[Embodiment] Hereinafter, an embodiment in which the present invention is applied to a petroleum fan heater will be described.

In FIGS. 2 and 3, reference numeral 1 denotes an exterior case of a kerosene fan heater, and an air inlet 3 having an air filter 2 is provided on the back of the exterior case 1, and a hot air outlet 4 is provided on the front. It is being Inside the exterior case C, a warm air blower 5 facing the air suction port 3 is provided, as well as a cartridge tank 6, an oil tank 7,
Fuel pump 8, combustion blower 9, burner (combustion part) 10
, a combustion tube (combustion section and heat exchange section) 11, an air guide case 12 (heat exchange section), a control device 13, etc. are provided.

A high limit switch (excessive temperature detector) 14 and a case temperature sensor 15 made of a thermistor are mounted on the air guide case 12 in close proximity to each other. Further, 16 is an operation panel provided on the upper surface of the outer case 1.

FIG. 1 shows the basic configuration of the control device 13 described above. In FIG. 1, reference numeral 17 is a microcomputer (hereinafter referred to as microcomputer) with a built-in A/D converter, and an operation switch 18 is on the input side of the microcomputer 17.
, a temperature setting device 19, a room temperature sensor 20, a burner temperature sensor 21 that detects the temperature of the vaporization part of the burner 10, and a flame detector F.
L, high limit switch 14 and case temperature sensor 1
5 is connected.

Furthermore, a burner 1 is connected to the input side of the microcomputer 17.
An electric heater 22 that heats the vaporization part of the engine 0, an igniter 23, a burner motor 9M that drives the combustion blower 9, a fuel pump 8, a fan motor 5M that drives the hot air blower 5, and a digital display 24 are connected. . A rotation speed detector 25 detects the rotation speed of the burner motor 9M, and a rotation speed signal from the rotation speed detector 25 is input to the microcomputer 17. Note that the operation switch 18, temperature setting device 19, and digital display 24 are provided on the operation panel 16. Furthermore, AC motors such as shaded motors are used for the fan motor 5M and the burner motor 9M.

When the operation switch 18 is turned on, the microcomputer 17 first energizes the electric heater 22 to heat the vaporization section of the burner 10. Then, when the temperature detected by the burner temperature sensor 21 reaches a temperature suitable for vaporizing kerosene and preheating is completed, the microcomputer 16 operates the burner motor 9M to pre-purge the burner 10, as shown in FIGS. 4 and 5. . When the prepurge is completed, the microcomputer 17 waits for a predetermined time T.
A. Activate the igniter 23 and turn on the hot air blower 5
The fan motor 5M that drives the engine and the fuel pump 8 are started.

The rotation speed of the fan heater 5M is maintained for a certain period TB, which includes at least the activation time TA (several seconds) of the igniter 23.
, the rotation speed is forcibly maintained at a predetermined rotation speed (an intermediate rotation speed between the maximum rotation speed and the minimum rotation speed, or the minimum rotation speed). this is,
While trying to minimize the feeling of cold air to the user when igniting,
This is to prevent a large amount of gas from accumulating in the combustion tube 11 and to prevent explosive ignition even if an ignition error occurs and ignition is repeated.

When combustion air and fuel (kerosene) are thus supplied to the burner 10, the fuel is vaporized, mixed with the combustion air, and then ignited by the igniter 23. When the microcomputer 17 determines that ignition has occurred based on the signal from the flame detector FL, it performs the following combustion control and hot air volume control.

First, as shown in FIG.
The combustion amount Q is determined according to the deviation ΔT between the set temperature TS set by the room temperature sensor 20 and the room temperature TI detected by the room temperature sensor 20. Then, in order to obtain this combustion amount Q, the driving frequency of the fuel pump (electromagnetic pump) 8 is controlled, and
The burner motor 9M and fan motor 5M are phase controlled.

[0021] In the phase control of the burner motor 9M, a target rotation speed NS1 commensurate with the combustion amount Q is determined in advance.
The actual rotation speed N1 of the burner motor 9M is detected by the signal from the rotation speed detector 25, and the phase angle of the applied voltage to the burner motor 9M is increased or decreased so that this rotation speed N1 becomes the target rotation speed NS1. . Therefore, the amount of combustion air in the combustion blower 9 is controlled accurately in accordance with the amount of fuel supplied by the fuel pump 8.

In the phase control of the fan motor 5M, as shown in FIG. 7, the central phase angle ts of the voltage applied to the fan motor 5M and the target air blowing temperature are determined with respect to the rotational speed N1 of the burner motor 9M corresponding to the combustion amount Q. HS is established. A bending point P in the center phase cut angle ts characteristic of the applied voltage of the fan motor 5M with respect to the burner motor rotation speed N1 in FIG.
The reason why is provided is to match the characteristics of the burner motor rotation speed N1 with respect to the phase cut angle of the applied voltage of the burner motor 9M (see FIG. 8).

Now, assuming that the burner motor rotational speed N1 is N1x, the microcomputer 17 determines the corresponding center phase angle tsx and target blowing temperature HSx. In addition, the deviation ΔH between the target air blowing temperature HSx and the temperature (air blowing temperature) H detected by the case temperature sensor 15 is determined, and the complementary value of the center phase cut angle tsx, for example, when the AC power frequency is 50 Hz, is determined.
For (10.00-tsx), for 60Hz, (
8.33-tsx) is determined, a target phase angle t is set as shown in Equations 1 and 2, and the phase of the fan motor 5M is controlled using this phase angle t.

[0024]

[Math 1]

[0025]

[Math 2]

As is clear from the above equation, the base set air volume is determined according to the combustion amount Q, and this set air volume is calculated by combining the target air temperature HS and the temperature detected by the case temperature sensor 15 (
Since the air volume of the hot air blower 5 is controlled so that the air volume is corrected according to the deviation ΔH from the air blowing temperature) H, for example, at the beginning of the heating operation, the case temperature sensor 15
Even if there is a delay in response to It can be prevented from operating.

Further, the target phase cut angle t is increased or decreased according to the deviation ΔH(α), and the air blowing temperature H is lower than the target air blowing temperature HS.
When H is low, the target phase cut angle t becomes larger than the center phase cut angle ts, which reduces the air volume and prevents the user from feeling cold air.On the other hand, when H is higher than HS, t becomes larger than the center phase cut angle ts. ts, the air volume increases, and the temperature rise inside the exterior case 1 can be suppressed.

Further, the correction amount based on this deviation ΔH(α) has a small complementary value when the rotational speed of the fan motor 5M is in a low range, and its value also becomes small. Conversely, when the rotation speed of fan motor 5M is in a high range, the complementary value is large;
Its value also increases. Therefore, whether the rotation speed of the fan motor 5M is high or low, the correction amount by ΔH (α) can be made the same, and the characteristics of the fan motor rotation speed with respect to the phase cut angle of the applied voltage of the fan motor 5M. (Refer to FIG. 8) It is possible to perform phase control suitable for this, and it is possible to perform highly accurate air volume control based on the combustion amount Q and the air blowing temperature H without using a rotation speed detector.

During the heating operation described above, the microcomputer 16 monitors the temperature H detected by the case temperature sensor 15 and the signal from the high limit switch 14. And air filter 3
The air volume decreases due to clogging of the case temperature sensor 1.
When the detected temperature H of 5 becomes equal to or higher than the first predetermined temperature HL, the digital display 24, which usually displays temperature and time, displays, for example, "E1" to notify the user that the air filter 3 is clogged. and urges the air filter 3 to be cleaned. Further, when the high limit switch 14 provided near the case temperature sensor 15 detects a temperature equal to or higher than the second predetermined temperature HH and turns off, the combustion in the burner 10 is stopped and the digital display 24 displays " E2” is displayed,
The user is notified that combustion has been stopped due to abnormal heating due to clogging of the air filter 3, etc.

[0030]

[Effects of the Invention] Since the present invention is constructed as described above, the air volume of the blower is determined according to the amount of combustion, and it is possible to prevent abnormal heating of the combustion part and the heat exchange part due to extremely insufficient air volume. Not only that, the air volume of the blower is corrected according to the air temperature, so when the air temperature is low at the beginning of operation or due to load fluctuations, the air volume decreases so that the user does not feel cold air, and vice versa. When the temperature rises, the air volume increases and the temperature rise inside the hot air heater can be suppressed, making it possible to achieve comfortable hot air heating and also being excellent in safety.

Further, in the second aspect of the present invention, the above-mentioned hot air control can be realized by phase control of an inexpensive AC motor such as a shaded motor, and in the third aspect of the invention, such phase control can be realized by This can be done with high precision without using an expensive rotation speed detector.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control device for an oil fan heater (warm air heater) to which the present invention is applied.

FIG. 2 is a perspective view of the oil fan heater.

FIG. 3 is an explanatory diagram of the internal structure of the oil fan heater.

[Figure 4] Microcomputer of control device (control means)
2 is a time chart for explaining the operation.

FIG. 5 is a flowchart as well.

FIG. 6 is an explanatory diagram showing combustion control characteristics of a microcomputer.

FIG. 7 is a diagram for explaining control characteristics of a fan motor by a microcomputer.

FIG. 8 is an explanatory diagram showing the characteristics of the rotation speed with respect to the phase cut angle of the burner motor (or fan motor).

[Explanation of symbols]

3 Air filter 5 Hot air blower 5M Fan motor (AC motor) 10 Burner (combustion section) 11 Combustion tube (combustion section and heat exchange section) 12 Air blow guide case (heat exchange section) 14 High limit switch (excess temperature detection container) 15
case temperature sensor

Claims (3)

[Claims] Claim 1: A hot air heater comprising a combustion section, a heat exchange section to which combustion gas is supplied from the combustion section, and a blower, and the blower blows out room air through the heat exchange section. A temperature sensor installed at or near the combustion section, and a control means for operating the blower at an air flow rate determined according to the amount of combustion in the combustion section corrected according to the temperature detected by the temperature sensor. Features a warm air heater. 2. A hot air heater comprising a combustion section, a heat exchange section to which combustion gas is supplied from the combustion section, and a blower, the blower blowing out indoor air through the heat exchange section. A center phase cut angle and a target blast temperature are determined according to a temperature sensor installed at or near the temperature sensor and the combustion amount in the combustion part, and the center phase cut angle is determined based on the temperature detected by the temperature sensor and the target blast temperature. 1. A hot-air heater comprising: control means for controlling the phase of an AC motor for driving a blower at a target phase angle corrected according to a deviation of the AC motor. 3. The hot air heating according to claim 1, wherein the correction amount according to the deviation between the temperature detected by the temperature sensor and the target air blowing temperature is increased or decreased by a complementary value of the center phase cut angle. Machine.