JPH05322162A - Hot air heater - Google Patents

Abstract

PURPOSE:To shorten a post purge time and prevent cold air from being blowing out by a method wherein as an operation of heat generating source is stopped, the number of revolution of a blower is decreased as a time elapses from the operation stopped state. CONSTITUTION:An operation control part 41 sends out an instruction of stopping operation S to a post purge control part 45 as an operation switch SW is turned off, opens solenoid valves 24 and 25 so as to extinguish a gas burner. The post purge is started at an initial number of revolution of a convection fan set in correspondence with the level of heating power just before turning-of of the operation switch SW and an energizing current for an AC motor 32 is controlled to be gradually decreased in such a manner that the number of revolutions of the convection fan is decreased as the time elapses and then the electrical energization is stopped at the time of completion of the post purge period. With such an arrangement, the post purge time can be shortened and at the same time a blowing of cold air easily occurring as the post purge time elapses can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot air heater for performing post-purge.

[0002]

2. Description of the Related Art In a hot-air heater, a post-purge for continuously operating a blower even after the operation of the heat source is stopped in order to lower the heat source in the casing, etc., every time the heating operation is stopped. I'm doing it.

[0003]

However, the above-mentioned conventional techniques have the following drawbacks. The temperature of the heat generating source and the body such as the main body case is high immediately after the combustion is stopped, but becomes low over time. Therefore, as the post-purging time elapses, the post-purging is performed at a relatively low constant rotation speed in order to prevent the user from feeling cold air. For this reason, when the combustion is stopped, the amount of heat generated by the heat source is large, or the temperature in the casing is high, the post-purging time becomes long. If the post-purging time is long,
Even if the user tries to go out and turns off the operation switch, the fan and the blower do not stop immediately, so he or she may go out waiting for it to stop or go out, worrying about whether or not it will stop, which is inconvenient. An object of the present invention is to provide a warm air heater that can cool down the casing and the heat source without causing the user to feel cold air after the operation of the heat source is stopped and can shorten the post-purge time.

[0004]

[Means for Solving the Problems] In order to solve the above problems,
The present invention has the following configurations. (1) A casing having an outlet for blowing warm air into a room, a heat source arranged in the casing, and air arranged in the casing and heated by the heat source as the warm air. In a warm air heater comprising a blower directed to an outlet and a post-purge control unit that continues energizing the blower even after the heat source stops operating, the post-purge control unit causes the heat source to operate. When stopped, the blower rotation speed will be lowered with the lapse of time after the operation is stopped. (2) A casing having an outlet for blowing warm air into the room, a heat source arranged in the casing, and air arranged in the casing and heated by the heat source as the warm air. In a warm air heater including a blower directed to an outlet and a post-purge control unit that continues to energize the blower even after the operation of the heat source is stopped, a temperature detector that detects the temperature in the casing is provided. The post-purge control means controls the blower rotation speed so that the detected temperature does not drop below a predetermined temperature when the heat source stops operating. (3) A casing having an outlet for blowing hot air into the room, a heat source arranged in the casing, and air arranged in the casing and heated by the heat source as the hot air. In a warm air heater comprising a blower directed to an outlet and a post-purge control means for continuing to energize the blower even after the operation of the heat source is stopped, a temperature sensor for detecting the temperature of the heat source is provided. In addition, the post-purge control means reduces the blower rotation speed according to the degree of decrease in the detected temperature when the heat source stops operating.

[0005]

[Operation and effect of the invention]

[Claim 1] Immediately after the heat source stops operating, the temperature of the casing and the heat source is high, so the blower is operated at a high rotational speed to strongly lower the temperature. Since the cooling of the casing and the heat source progresses with the lapse of time after the heat source stops operating, the number of revolutions of the blower is reduced so that the air blown from the outlet does not become cold air. For this reason, the post-purge time can be shortened, and cold air can be prevented from blowing out easily as the post-purge time elapses, which is excellent in usability. [Claim 2] Since the temperature inside the casing detected by the temperature detector is high immediately after the operation of the heat source is stopped, the blower is operated at a high rotation speed to strongly lower the temperature. Although the temperature inside the casing decreases with the lapse of time after the heat source stops operating, the post-purge control means controls the rotation speed of the blower so that the temperature inside the casing detected by the temperature detector does not drop below a predetermined temperature. As it is lowered, the wind blown from the outlet does not become cold. For this reason, the post-purge time can be shortened, and cold air can be prevented from blowing out easily as the post-purge time elapses, which is excellent in usability. [Claim 3] Immediately after the heat source stops operating, the temperature of the heat source detected by the temperature sensor is high, so the blower is operated at a high rotational speed to strongly lower the temperature. Although the temperature of the heat source goes down over time after the heat source stops operating,
The post-purge control means reduces the rotation speed of the blower as the temperature of the heat source detected by the temperature detector decreases, so that the air blown from the air outlet is not cold. For this reason, the post-purge time can be shortened, and cold air can be prevented from blowing out easily as the post-purge time elapses, which is excellent in usability.

[0006]

The first embodiment of the present invention (corresponding to claim 1) is as follows.
A description will be given based on FIGS. 1 to 4. The gas hot air heater A shown in FIG. 1 includes a housing 1, a gas burner 2 and a convection fan 3 arranged in the housing 1, and a controller 4 for controlling combustion of the gas burner 2 and the convection fan 3. Become.

The metal housing 1 has inlets 11 and 12 for the indoor air 10 used for mixing and combustion at the upper part of the rear surface, and an outlet 14 for blowing warm air 13 into the room at the lower part of the front surface. There is. A filter 15 (made of resin cotton) for removing dust in the room is detachably arranged in the suction ports 11 and 12, and a louver 16 for changing the blowing direction of the warm air 13 is attached to the blowing port 14. .. In addition, 17 is a duct that connects the suction port 11 and the air outlet 14, and 18 is an air guide path that guides the indoor air 10 to the gas burner 2.

The gas burner 2 includes a gas ejected from a nozzle 20 disposed downstream of the air guide passage 18 and the air guide passage 18
Mixing chamber 21 for mixing with the indoor air 10 induced by
And a combustion plate 22 made of ceramic, and a combustion cylinder 23 having an ignition electrode 231 and a thermocouple 232 arranged therein. The nozzle 20 is formed at the tip of a gas pipe g in which electromagnetic valves 24, 25 and a proportional valve 26 are sequentially arranged.

The convection fan 3 has an impeller 31 pivotally mounted in a duct 17 downstream of the gas burner 2 and an impeller 31.
And an AC motor 32 for driving.

As shown in FIG. 2, the controller 4 includes an operation control section 41 for controlling the ignition and extinguishing of the gas burner 2 based on the operation of the operation switch SW, and a temperature control section 42 for determining the combustion level. A proportional valve drive circuit 43 for controlling the current supplied to the proportional valve 26, a fan drive circuit 44 for controlling the amount of power supplied to the AC motor 32, a memory 451, a post-purge fan rotational speed gradual reduction circuit 452, and a timer T. And a post-purge control unit 45 having
The operation is performed based on the sequence (steps s1 to s7) shown in FIG.

The operation control unit 41 energizes the ignition electrode 231 for a predetermined time after the operation switch SW has been turned on for 4 seconds, and opens the solenoid valves 24 and 25 to ignite the gas burner 2. To do. Also, the operation switch S
When W is turned off, an operation stop signal S is sent to the post-purge control unit 45, the solenoid valves 24 and 25 are closed, and the gas burner 2 is extinguished. When the output voltage of the thermocouple 232 becomes less than a predetermined value during combustion of the gas burner 2, the solenoid valves 24 and 25 are closed to extinguish the gas burner 2.

The temperature control section 42 operates after the forced strong combustion operation period (heating capacity during this period is level 8) for performing strong combustion for a predetermined time in order to improve the rise of room temperature, and the temperature setting device 421 is used. The heating capacity (level 1 to level 8) is determined based on the temperature difference between the set temperature set and the detected room temperature detected by the thermistor 422 arranged in the air guide passage 18 near the suction port 12.

The proportional valve drive circuit 43 energizes the proportional valve 26 with a current (1-8 stages) according to the heating capacity determined by the temperature control unit 42 during the temperature control operation.

The fan drive circuit 44 of the present embodiment applies a current to the AC motor 32 to obtain a predetermined fan rotation speed until the forced strong combustion operation period ends, and during the temperature adjustment operation, the temperature adjustment control section. When a current that provides a fan rotation speed suitable for the heating capacity determined in 42 is supplied to the AC motor 32 and the operation switch SW is turned off during the temperature control operation, the heating capacity immediately before the operation switch SW is turned off is changed. Level (Level 1-
8), the post-purge is started with the initial rotation speed N ₀ {shown in FIG. 4 (b)}, and the convection fan rotation speed N changes with time as shown in FIG. 4 (a). The energizing current to the AC motor 32 is controlled to decrease gradually, and energization is stopped at the end of the post-purge period (for example, 50 seconds). The degree of gradual decrease in the number of rotations of the convection fan 3 is set in advance so that the air blown out from the air outlet 14 has a minimum temperature at which a feeling of cold air is not felt.

The post-purge control unit 45 of this embodiment stores a memory 451 that stores the level of the heating capacity immediately before the operation switch SW is turned off based on the operation stop signal S, and a memory when the operation stop signal S is input. The initial speed N ₀ is determined based on the level of the heating capacity stored in 451;
The convection fan 3 rotates at the initial rotation speed N ₀ , and the post-purge fan rotation speed gradual reduction circuit 452 sends a signal to the fan drive circuit 44 such that the convection fan rotation speed N decreases with the passage of time, and 50 seconds. And a timer T that sets the post-purge time of the above.

Next, the advantages of this embodiment will be described. Driving
Immediately after the switch SW is turned off and the gas burner 2 has stopped burning
Is a housing 1, a duct 17, and a combustion plate 2 which is a heat source.
The temperature of 2 is high, but the initial speed N is large. ₀So convection
Since the fan 3 rotates, the temperature can be lowered efficiently,
The post-purge time can be shortened (50 seconds). Well
Also, with the passage of time since the combustion of the gas burner 2 stopped
Lowers the temperature of the housing 1, duct 17, and combustion plate 22
Proceed, but as shown in Fig. 4 (a), the rotation speed of the convection fan 3
Will decrease as the post-purge time elapses.
The wind blown from the outlet 14 does not become cold air. still,
The level of heating capacity immediately before the operation switch SW is turned off
The larger the size, the initial speed N₀Is higher,
To the level of heating capacity immediately before turning off the operation switch SW
Irrespective of, blow from the outlet 14 during post purge
The temperature of the blown wind can be made uniform.

Next, a second embodiment of the present invention (corresponding to claim 2) will be described with reference to FIGS. 1, 5, 6, and 7. Since the basic structure of the gas warm air heater B is the same as that of the gas warm air heater A, only the differences will be described. In the gas warm air heater B shown in FIGS. 1 and 5, a thermistor Th for detecting the temperature in the duct 17 is arranged in an appropriate place in the duct 17 (not shown in FIG. 1). In addition, the post-purge control unit 45 of the gas warm air heater B determines the duct internal temperature Td and the reference value Ts.
When a comparison circuit 453 for comparing (for example, 30 ° C.) and an operation stop signal S are input, the convection fan rotation speed during post-purging is determined based on the difference between the duct internal temperature Td and the reference value Ts (FIG. 6) and a post-purge fan rotation speed determination circuit 454 that terminates the post-purge when the rotation speed of the convection fan 3 becomes equal to or lower than a predetermined value, and the controller 4 performs the sequence shown in FIG. The operation is performed based on S1 to S6).

The fan drive circuit 44 of the present embodiment causes a current to obtain a predetermined fan rotation speed to flow through the AC motor 32 until the forced strong combustion operation period ends, and the temperature adjustment control unit 42 during the temperature adjustment operation. When a current that provides a fan rotation speed suitable for the heating capacity determined in step S2 is passed through the AC motor 32 and the operation switch SW is turned off during the temperature control operation, the post-purge fan rotation speed determination circuit 454 determines the rotation speed. A control signal is sent to the fan drive circuit 44 so that the convection fan 3 rotates at the post-purge fan rotation speed (shown in FIG. 6).

Next, the advantages of this embodiment will be described. When the operation switch SW is turned off, the duct internal temperature Td and the reference value T
Since the rotation speed of the convection fan 3 is controlled based on the difference with s, it is possible to rotate the convection fan 3 with a large rotation speed of the convection fan immediately after the combustion of the gas burner 2 is stopped. The temperature Td in the duct decreases. Then, as the temperature inside the duct Td decreases with the lapse of time after the combustion of the gas burner 2 is stopped, the convection fan rotation speed decreases as shown in FIG. Therefore, as the time of post-purging elapses, the noise can be reduced without making the user feel cold air.

Next, a third embodiment of the present invention (corresponding to claim 3) will be described with reference to FIGS. 1, 8, 9 and 10. Since the basic structure of the gas warm air heater C is the same as that of the gas warm air heater A, only the differences will be described. The gas warm air heater C shown in FIGS. 1 and 8 has a combustion plate temperature Tb of the gas burner 2.
The thermistor T _H for detecting is disposed at a predetermined position (not shown in FIG. 1) of the gas burner 2. Further, the post-purge control unit 45 of the gas warm air heater C determines that the operation stop signal S
Is input, the convection fan rotation speed is determined based on the combustion plate temperature Tb (as shown in FIG. 9), and the post purge is ended when Tb ≦ predetermined value (for example, 50 ° C.). The fan rotation speed determination circuit 450 is included and the sequence shown in FIG. 10 (steps St1 to St) is performed.
The operation is performed based on 6).

The fan drive circuit 44 of the present embodiment sends a current to the AC motor 32 to obtain a predetermined fan rotation speed until the forced strong combustion operation period ends, and during the temperature adjustment operation, the temperature adjustment controller 42. When a current that provides a fan rotation speed suitable for the heating capacity determined in step A is supplied to the AC motor 32 and the operation switch SW is turned off during the temperature control operation, the post-purge fan rotation speed determination circuit 450 determines the rotation speed. A control signal is sent to the fan drive circuit 44 so that the convection fan 3 rotates at the post-purge fan rotation speed (shown in FIG. 9).

Next, the advantages of this embodiment will be described. Immediately after the operation switch SW is turned off and the combustion of the gas burner 2 is stopped, the housing temperature and the combustion plate temperature Tb are high. However, since the convection fan 3 is rotated with a large convection fan rotation speed, the efficiency is good and the temperature is short. The housing temperature and the combustion plate temperature Tb decrease. Then, as the temperature of the housing 1 and the combustion plate 22 is lowered with the lapse of time after the combustion of the gas burner 2 is stopped, the convection fan rotation speed is reduced as shown in FIG. 9, and Tb = 50 ° C. At that point, the post-purging by the convection fan 3 is completed.
Therefore, the post-purge time can be shortened (gas burner 2
(Because of the high rotation speed immediately after the combustion is stopped), the noise can be reduced with the passage of the post-purging time without making the user feel cold air (because the rotation speed is determined by the combustion plate temperature Tb).

The present invention includes the following embodiments in addition to the above embodiments. a. The heat source may be configured using an electric heater, a petroleum burner, or the like. b. The warm air heater may be of a type that takes in combustion air from the outside into the casing and discharges the exhaust to the outside without mixing with the taken indoor air. c. In the gas warm air heater according to claims 2 and 3, the post-purge period may be set by a timer. d. In the gas warm air heater of claim 3, a thermistor Th may be provided in the combustion barrel 23 or the duct 17 to detect the temperature of the heat source instead.

[Brief description of drawings]

FIG. 1 is a structural diagram of a gas warm air heater according to each embodiment of the present invention.

FIG. 2 is a block diagram of the gas warm air heater according to the first embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of the gas warm air heater.

FIG. 4 (b) shows the heating capacity level and initial rotation speed N immediately before the operation switch is turned off in the gas warm air heater.
A graph showing the relationship with ₀ , (a) is a graph showing a gradual decrease state of the convection fan rotation speed for each heating capacity level immediately before the operation switch is turned off.

FIG. 5 is a block diagram of a gas warm air heater according to a second embodiment of the present invention.

FIG. 6 is a graph showing the relationship between the duct temperature and the convection fan rotation speed in the gas hot air heater.

FIG. 7 is a flow chart for explaining the operation of the gas warm air heater.

FIG. 8 is a block diagram of a gas warm air heater according to a third embodiment of the present invention.

FIG. 9 shows a combustion plate temperature Tb in the gas hot air heater.
It is a graph which shows the relationship between a convection fan rotation speed.

FIG. 10 is a flow chart for explaining the operation of the gas warm air heater.

[Explanation of symbols]

1 Housing (Casing) 2 Gas Burner (Heat Source) 3 Convection Fan (Blower) 4 Controller 13 Hot Air 14 Outlet 17 Duct (Casing) 45 Postpurge Control Section (Postpurge Control Means) Th Thermistor (Temperature Detector) T _H thermistor (temperature sensor) A, B, C Hot air heater

Claims (3)

[Claims] 1. A casing having an outlet for blowing warm air into a room, a heat source arranged in the casing, and air arranged in the casing and heated by the heat source as hot air. In a warm air heater comprising a blower directed to the air outlet and a post-purge control unit that continues energizing the blower even after the operation of the heat source is stopped, the post-purge control unit is the heat source. The hot air heater is characterized in that, when the operation stops, the rotation speed of the blower decreases with the lapse of time after the operation stops. 2. A casing having an outlet for blowing hot air into the room, a heat source arranged in the casing, and air arranged in the casing and heated by the heat source as hot air. In a warm air heater comprising a blower directed to the air outlet, and a post-purge control means for continuing to energize the blower even after the operation of the heat source is stopped, temperature detection for detecting the temperature in the casing. A warm air heater, wherein the post-purge control means controls the blower rotation speed so that the detected temperature does not drop below a predetermined temperature when the heat source stops operating. 3. A casing having an outlet for blowing warm air into a room, a heat source arranged in the casing, and air arranged in the casing and heated by the heat source as hot air. In a warm air heater including a blower directed to the air outlet and a post-purge control unit that continues energizing the blower even after the operation of the heat source is stopped, a temperature sensor that detects the temperature of the heat source. And the post-purge control means reduces the blower rotation speed according to the degree of decrease in the detected temperature when the heat source stops operating.