JPS61225548A - Hot air flow space heater - Google Patents

Abstract

PURPOSE:To prevent a noise from generating and the quantity of air flow from abruptly varying without increasing the number of pieces of parts by setting the rotational speed of a convection blower at a value so that it may not become more than a set value or less than the same. CONSTITUTION:An electronic control unit 4 comprises a convection blower changeover circuit 46 for carrying out setting of the lowest rotational speed of a convection blower 303 in accordance with the output of a thermocouple amplifier circuit 42, and carrying out the control of a high rotation zone. The changeover circuit 46 consists of first and second output discriminating circuits 46A and 46B. The convection blower 303 is continuously varied of its power feed quantity in a stepless manner in accordance with the outputs from the thermocouple amplifier circuit 42, a rotational speed indicating circuit 43, and a rotational speed compensating circuit 44, and thus is continuously varied of its rotational speed. Further, since the output of the amplifier circuit 42 is made more than a second set value A2, a relay switch RS2 is connected to a power feed circuit via a resistor R50. Hence, the quantity of power supply is made constant irrespective of the output of the amplifier circuit 42, and the rotational speed is made constant. As a result, the rotational speed can be continuously varied in accordance with the output signal of a thermocouple 402.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a hot air heater that heats a room by exchanging heat generated by combustion with room air.

[Prior art] A combustion air circulation path that introduces outdoor air from outside, mixes it with fuel such as gas or kerosene, burns it, and releases the combustion gas outdoors again, and a combustion air circulation path that Conventionally, in hot air heaters that have an indoor air circulation path that exchanges heat from the combustion air with indoor air, the combustion blower that sucks in and discharges air from the combustion air circulation path has a combustion detection system facing the burner. The convection blower, which is continuously variably adjusted by the rotation control circuit according to the output signal of the sensor, takes in and discharges air from the indoor air circulation path, and switches the relay according to the amount of heat generated by the flame, It was adjusted by switching the resistance value of the energizing circuit to the blower into several levels.

[Problems to be Solved by the Invention] In the conventional technology shown above, the air flow rate of the convection blower is switched and controlled in several stages using a plurality of relays. There were problems such as sudden changes in the temperature of the hot air and sudden changes in the air pressure. Therefore, it has been proposed that the convection blower, like the combustion blower, be continuously variably adjusted by a rotation control circuit according to the output of the combustion detection sensor. Providing a sensor and a rotation control circuit has problems such as an increase in the probability of potential failure due to an increase in the number of parts, and an increase in production costs due to an increase in the number of parts. Furthermore, when a combustion blower and a convection blower are controlled by one combustion detection sensor and rotation control circuit, the combustion blower has a wider input voltage range than the combustion blower, so the combustion blower has a wider input voltage range. When the rotation control (energization control) corresponding to the rotation speed is performed, the convection blower has problems such as generation of noise due to wind noise of the blower IiI fan at the upper limit of the rotation speed, and a decrease in air flow 1 at the upper limit. Was.

An object of the present invention is to provide a hot air heater that can solve the above problems without increasing the number of parts.

[Means for Solving the Problems] In order to solve the above problems, the hot air heater of the present invention includes a combustion blower that supplies combustion air to the burner, and a combustion blower that supplies combustion air to the burner, and uses the heat generated by the barb as hot air. A temperature control device comprising a convection blower for blowing air, and an electronic control device having a rotation speed control circuit for controlling the rotation speeds of the combustion blower and the convection blower based on an output signal from a combustion detection sensor placed in front of the burner. In the wind heater, the electronic control device is configured to set at least one of the rotational speeds of the convection blower not to exceed a certain set value or to not exceed a certain set value.

[Operations and Effects of the Invention] The hot air heater of the present invention having the above-mentioned configuration allows the rotational speeds of the combustion blower and the convection blower to be varied steplessly based on the output signal of the combustion detection sensor adjacent to the burner, and By setting at least one of the high rotational speed and the minimum rotational speed of the convection blower, the number of parts can be set without increasing the number of parts, and without causing inconveniences such as noise and air volume at the upper and lower limits of the convection blower. Both the combustion blower and the convection blower can be controlled steplessly. Furthermore, since the rotational speed of the convection blower can be varied steplessly, the temperature of the hot air discharged by the hot air heater can be gently varied or maintained at a constant temperature.

[Example] Next, a hot air heater of the present invention will be described based on an example shown in the drawings.

Figures 1, 2, and 3 show FF type gas hot air that mixes outdoor air introduced from outside with gas and burns it, exchanges heat with the combustion gas with indoor air, and discharges the combustion gas outdoors again. A configuration diagram and an electronic circuit diagram of the device are shown.

The FF type gas hot air device includes a combustion air V'M path 1 for combusting air introduced from outside and then discharging it outside again, and a gas introduction path 2 for supplying gas into the combustion air circulation path 1.
an indoor air circulation path 3 that exchanges indoor air with combustion gas in the combustion air circulation path 1 and discharges it again as warm air; and driving of the combustion air circulation path 1, the gas introduction path 2, and the indoor air circulation path 3; It consists of an electronic control device 4 that performs control.

The combustion air circulation path 1 includes an outdoor air introduction path 101 that introduces air from outside the room, and a combustion air introduction path 101 that sucks outdoor air from the outdoor air introduction path 101 to flow the air and combustion gas in the combustion air circulation path 1. The blower 102 and the combustion blower Jli
A gas ejection nozzle 103 that ejects gas into the air sucked in by l102, a gas burner 104 made of ceramic that burns the gas mixture air, and the gas burner 10.
A heat exchanger 105 performs heat exchange between the combustion gas combusted by 4 and the indoor air circulated by the indoor air circulation path 3, and the combustion gas after heat exchange with the heat exchanger 105 is guided outside.
dll airway 106.

The gas introduction path 2 is provided on the upstream side of the gas combustion supply pipe 201 that supplies gas to the gas ejection nozzle 103, and includes a first main valve 202 that is opened and closed by energization and de-energization, and a first main valve 202 that is opened and closed by energization and de-energization. A second valve is provided downstream and is opened and closed by energization control similarly to the first main valve 202.
A main valve 203 and a constant flow valve 2 provided downstream of the second main valve 203 and regulating the pressure of the gas flow rate.
04, a proportional control valve 205 which is provided downstream of the constant flow valve 204 and whose opening degree is variable depending on the amount of electricity supplied, and a gas jet nozzle 103 from upstream of the proportional control valve 205 regardless of the open/closed state of the proportional control valve 205. A gas bypass 207 with a regulating orifice 206 that allows a constant amount of gas to flow out
It consists of

The indoor air circulation path 3 includes an indoor air inlet 302 having an air filter 301 that introduces indoor air into the FF type gas wetting device, and an indoor air inlet 302 that sucks indoor air through the indoor air inlet 302 and circulates the indoor air. a convection blower 303 that flows air in the passage 3; and a heat exchanger 1 in the combustion air circulation passage 1;
05 and a hot air outlet 304 for discharging high temperature air after heat exchange.

The electronic control device 4 includes a spark electrode 401 that ignites a flame in the gas barb 104, a thermocouple 40 that controls the rotational speed of the combustion blower 102, and the convection blower 303.
2. Combustion feeder 102 of the combustion air circulation path 1
, the first main valve 202, the second main valve 203, the proportional control valve 205 of the gas introduction path 2, the convection blower 303 of the indoor air circulation path 3, etc. are driven and controlled.

The electronic control device 4 includes a power supply circuit 41 that converts 100 volt alternating current distributed to general households into constant voltage direct current, and a thermocouple amplifier circuit 42 that enhances the output of a thermocouple 402 facing the burner 104. , a rotational speed instruction circuit 43 that detects the oxygen supply state based on the output of the thermocouple amplifier circuit 42 and sets the rotational speed of the combustion blower 102 and the convection blower 303; and a rotational speed instruction circuit 43 that corrects the output of the rotational speed instruction circuit 43. Rotational speed correction circuit 44
Then, the combustion blower 102 is energized by the output of the rotational speed correction circuit 44, and the convection blower @ 303
A convection air blower @ 303 according to the output of the blower drive circuit 45 and the thermocouple amplifier circuit 42 that energizes the
A convection blower switching circuit 4G sets the minimum rotation speed and controls the high rotation range, and a combustion blower ll1 at the time of ignition.
Ignition rotation speed setting circuit 4 that sets the rotation speed of 102
7, and the combustion blower 10 from the rotational speed correction circuit 44.
a combustion blower rotation detection circuit 48 that detects the rotation of No. 2;
The combustion blower rotation detection circuit 48 is connected to the combustion blower 102.
The spark electrode 40 is rotated by the rotational speed of the spark electrode 40.
1, a sparker drive circuit 49 that performs ignition; and a spark detection circuit 5 that detects the spark state of the spark electrode 401.
0, the combustion blower rotation detection circuit 48 detects that the combustion blower 102 blows air in the combustion air circulation path 1 for a predetermined period of time during startup, and the spark detection circuit 50
After detecting a spark, the first main valve 202 and the second main valve 203 are energized to open the gas combustion supply pipe 20.
1, an ignition determination circuit 52 that detects a flame based on the output of the thermocouple amplifier circuit 42 and detects the ignition state; and an ignition determination circuit 52 that detects a flame. , a timer circuit 53 operates the proportional valve control circuit 54 described above for a certain set time, and the output of the timer circuit 53 is received to increase the opening degree of the proportional control valve 205 for a certain period of time, and also increases the opening degree of the proportional control valve 205 to a reference value obtained by a temperature setting device. A standard obtained by a proportional valve control circuit 54 that controls the energization amount of the proportional control valve 205 by comparing the output signal from the temperature sensing element that detects the room temperature and the temperature setting device of the proportional valve control circuit 54. When the difference between the value and the output signal of the temperature sensing element reaches a certain value or more, the first main valve 20
2 and the second main valve 203 to stop combustion of the gas; a flame initial check circuit 56 that sets the length of the ignition determination circuit 52 based on the output of the ignition determination circuit 52; A high-cut circuit 5 that detects abnormal combustion based on the output of the thermocouple amplifier circuit 42
7, and the output of the high-cut circuit 57 causes the combustion blower 102, the first main valve 202, and the spark electrode 401
an abnormality lock circuit 58 that generates an output that de-energizes;
An ignition sequence circuit 59 that controls the above circuit, a good morning timer circuit 60 that automatically starts operation after an arbitrarily set time has elapsed, and stops operation when three hours have elapsed, and a certain predetermined good morning timer circuit 60 A save circuit 61 controls the proportional valve control circuit 54 to lower the set temperature by, for example, 1° C. after a predetermined time has elapsed, and further lowers the set temperature by, for example, 1° C. after a predetermined period of time has elapsed to perform a save operation.

FIG. 3 shows that even if the output signal of the thermocouple facing the burner 104 is below a certain set output, the convection air blower n 3
An example of an electric circuit showing the thermocouple amplifier circuit 42, the blower drive circuit 45, and the convection blower switching circuit 46 for maintaining the rotational speed of the motor 03 at a predetermined speed is shown.

The thermocouple amplifier circuit 42 is a thermocouple 402
operational amplifier OP that compares and amplifies the output of
Consists of 1 to R3.

The rotational speed instruction circuit 43 is provided to variably set the rotational speeds of the combustion blower 102 and the convection blower 303 in accordance with the output signal of the operational amplifier OP of the thermocouple amplifier circuit 42.

The rotational speed correction circuit 44 is controlled by the rotational speed instruction circuit 43 and the frequency generator, amplifies the output by the power transistor Trl, and controls the energization of the combustion air blower 102 and the convection air blower 303.

The blower drive circuit 45 includes a diode bridge 45A whose energization m is varied by changing the potential of the power transistor Trl of the rotational speed correction circuit 44, and a convection blower switching circuit that sets the minimum speed of the convection blower 303 of the present invention. 46, and switches the convection blower 303 of the combustion blower 102 and the convection blower 303 connected in parallel to a current-carrying circuit via the resistor R4 or a current-carrying circuit connected to the diode bridge 45A. Like the relay switch Rsl, the convection blower switching circuit 46 controls the convection blower J!
The relay switch Rs2 connects the machine 303 to the diode bridge 45A via the diode bridge 45A or the resistor R5, and the combustion blower 1102 and the convection blower 303 to absorb noise generated and block external noise. 45C is a power transistor T of the blower drive circuit 45.
This varistor is disposed between r1 and the diode bridge 45A, and absorbs and removes noise, surge, and the like.

The convection blower switching circuit 46 is a first output determination circuit 46A.
and a second output determination circuit 46B, the first output determination circuit 46A inputs the output signal of the operational amplifier OP of the thermocouple amplifier circuit 42, and determines that the output of the operational amplifier OP is equal to or higher than a first set value. a comparator CP1 whose output is high, and a transistor rr whose ON/OFF control is controlled by the output signal of the comparator CP1.
2, transistor lr3, which is provided in the ignition sequence circuit 59 and is controlled to be turned on and off by the output of a de-energization timer that is turned off at power-on and setting time B (for example, during blip-purging), and transistors Tr2 and rr3 are both turned on. The blower drive circuit 45 is energized by
It consists of a relay coil RCI that connects the relay switch Rsl provided in the diode bridge 45A,
R6-R8 are resistors for setting the reference voltage of comparator CP1, R9 and R10 are resistors for voltage control, and Dl
is a diode. The second output determination circuit 46B inputs the output signal of the operational amplifier OP of the thermocouple amplifier circuit 42, and outputs a high output signal from the operational amplifier OP when the output of the operational amplifier OP exceeds a second set value.
ON/OFF by the output signal of P2 and the comparator CP2.
It consists of a transistor Tr4 which is turned off, and a relay coil Rc2 which is energized when the transistor rr4 is turned on and connects a relay switch Rs2 provided in the blower drive circuit 45 with a resistor R5.
1 to R13 are resistors for setting the reference voltage of comparator CP2, R14 and R15 are resistors for voltage control, and D
2 is a diode. Further, C5 is a capacitor that absorbs fluctuations in the output of the operational amplifier OP and stabilizes the output of the comparator CP1.

The operation of the electric circuit shown above will be explained using FIGS. 4 and 5. The combustion blower 102 is a two-pole synchro motor whose rated input can withstand the voltage due to pre-purge, and the convection blower @303 is a four-pole synchro motor whose rated input is half that of the combustion blower 102. A first set value that causes a high output is set as A1, and a second set value that causes a high output of the comparator CP2 is set as A2.

After the power is turned on and before the burner 104 is ignited, the combustion blower 10
2 is the ignition sequence circuit 59 and the rotation speed instruction circuit 4
The operation in step 3 replaces the air in the combustion chamber (pre-purge). At this time, since the convection blower 303 has not yet ignited the burner 104, the thermocouple 402 is not heated, and the output of the thermocouple amplifier circuit 42 is set to the first set value A.
Since it is less than 1, the comparator CP1 of the convection blower switching circuit 46 is set to a low output, and the relay coil Rcl is de-energized to turn off the transistor Tr2.
Although the relay switch R3I is connected to the resistor R5, it does not operate because the normally bimetallic fan switch FS is in the closed position. In addition, after the power is turned off, the thermocouple 402 is heated when the power is turned on, such as when the power is turned on again before the combustion chamber etc. are cooled down, and the output of the operational amplifier OP becomes equal to or higher than the first set value A1. Even if CP1 is a high output, the transistor Tr3 is turned off for a predetermined time after the power is turned on due to the operation of the de-energization timer provided in the ignition sequence circuit 59.
Since it is in the F state, the convection blower 303 is connected to the resistor R4 via the relay switch R31.

After the power is turned on, the de-energization timer turns off the transistor Tr3.
When a flame is generated in the burner 104 after a predetermined period of time has elapsed, the thermocouple amplifier circuit 42 and the rotation speed indicating circuit 4
3. The current value of the diode bridge 45A of the blower drive circuit 45 is varied steplessly according to the output of the rotational speed correction circuit 44, and the amount of current flowing through the combustion blower 102 is continuously changed as shown by the solid line N1 in FIG. The combustion blower 102 is increased or decreased.
The rotational speed of is continuously varied steplessly as shown by the solid line N2 in FIG. Until the output of the operational amplifier OP of the thermocouple amplifier circuit 42 is set to the first set value A1 by the flame generated in the burner 104, the comparator CP1 is operated as described above.
is a low output, transistor Tr2 is set to F,
Since the relay switch Rs1 is connected to the resistor R4 to de-energize the relay coil Rc1, the convection blower 3
030 energization amount is constant regardless of the output of the thermocouple amplifier circuit 42, as shown by the broken line -1a1 in FIG. 4, and the rotational speed of the convection blower 303 is kept constant as shown by the broken line Ta2 in FIG. . Tsuji-Mocouple amplifier circuit 42
Since the output of ff1A1 is set to be higher than the first setting ff1A1, the comparator CP1 of the convection blower switching circuit 46 becomes a high output, and in response to this output, the transistor rr2
is turned on. At this time, the transistor Tr3 is turned on because a predetermined time has elapsed since the power was turned on, the relay coil Rc1 is energized, and the relay switch Rsl is connected to the diode bridge 45A. This allows the convection blower I
Similar to the combustion blower 102, the energization amount of the combustion blower 303 is continuously and steplessly varied as shown by the broken line Tb1 in FIG. As a result, the rotational speed is the fifth
It is continuously variable as shown by the broken line Tb2 in the figure. Furthermore, as the output of the thermocouple amplifier circuit 42 becomes equal to or higher than the second set value A2, the output of the comparator CP2 of the second output determination circuit 46B becomes high, and this output turns on the transistor Tr4 and turns on the relay coil RC2. Electricity is applied, and relay switch R, s2 is connected to resistor R5. As a result, the convection feed mm303 is adjusted by the broken line Tc1 in FIG.
The amount of current is as shown in Figure 5, and the rotational speed is as shown by the broken line TC in Figure 5.
It is controlled as shown in 2. Note that the resistor R4 in the above example
When the output of the thermocouple amplifier circuit 42 is at the first setting value A1, the energization circuit via the diode bridge 45A
The voltage is set to be equivalent to the voltage supplied from the

FIG. 6 is an electrical circuit diagram showing another embodiment of the present invention.

In this embodiment, the relay switch Rs2 is the relay coil Rc
2 is connected to the current-carrying circuit via the resistor R50 when energized, and when the output of the thermocouple amplifier circuit 42 is at the second set value A2, the current-carrying circuit via the resistor R50 is The voltage is set to be equivalent to the voltage supplied from the bridge 45A.

The relay switch R32 is activated when the output of the thermocouple amplifier circuit 42 is set at or above the second set value A2.
is connected to the energizing circuit via the resistor R50, the amount of energization of the convection blower 303 is constant regardless of the output of the thermocouple amplifier circuit 42, as shown by the broken line d1 in FIG. The rotational speed of the convection blower 303 is constant as indicated by the broken line "d2" in FIG. .

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a gas combustion hot air heater to which the present invention is applied, Fig. 2 is a block diagram of an electronically controlled device, and Fig. 3 is a block diagram of an electronically controlled device.
4 and 5 are graphs for explaining the operation of the embodiment. FIG. 6 is an electronic circuit diagram showing another embodiment of the invention. 7 and 8 are graphs for explaining the operation of other embodiments. In the diagram: 1...Combustion air circulation path 2...Gas introduction path 3
...Indoor air circulation path 4...Electronic control device 42.
... Thermocouple amplifier circuit 43 ... Rotation speed indication circuit 44 ... Rotation speed correction circuit 45 ... Blower drive circuit 46 ... Convection blower switching circuit 102 ...
・Combustion blower 104... Gas burner 303...
Convection feed ff1l 402...Thermocouple

Claims (1)

[Claims] 1) A combustion blower that supplies combustion air to the burner, a convection blower that blows out the heat generated by the burner as warm air, and an output signal from a combustion detection sensor facing the burner. In the hot air heater, the electronic control device includes a rotation speed control circuit that controls the rotation speed of the combustion blower and the convection blower, wherein the electronic control device controls the rotation speed of the convection blower. A hot air heater characterized in that at least one of the values is set so that the temperature does not exceed a set value or fall below a certain set value. 2) The hot air heater according to claim 1, wherein the set value of the rotational speed of the convection blower is set based on an output signal of the combustion detection sensor.