JPH0445732B2 - - Google Patents

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; Conventionally, in a warm air heater having an indoor air circulation path for exchanging heat between the air and the indoor air,
The combustion blower, which sucks in and exhausts air in the combustion air circulation path, is variable steplessly by an amplifier circuit in response to the oxygen supply status of the flame, and the combustion blower, which sucks in and exhausts air in the indoor air circulation path, is variable steplessly according to the oxygen supply state of the flame. The blower was regulated by switching a relay according to the amount of heat generated by the flame, and by changing the resistance value of the energizing circuit to the convection blower in several stages.

[Problems to be Solved by the Invention] In the conventional technology shown above, the air flow rate of the convection blower is controlled in several stages using a plurality of relays. This increases the potential failure probability due to an increase in the number of parts, increases production costs due to an increase in the number of parts,
There were problems such as rapid changes in the temperature of the hot air due to the stepwise control of the convection blower.

An object of the present invention is to provide a hot air heater that can reduce the number of parts for controlling a convection blower and a combustion blower, and that can continuously variable control the rotation speed of the convection blower.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a combustion blower that supplies combustion air to a burner, a convection blower that blows out the heat of the burner as hot air, and a convection blower that blows out the heat of the burner as hot air. A combustion detection sensor facing the burner and detecting the oxygen supply state to the combustion flame, and a rotation speed control circuit that sends out an electrical output according to the output of the combustion detection sensor.
The present invention includes a combustion blower energization circuit and a convection blower energization circuit that vary the amount of electricity supplied to each blower based on the electrical output and continuously variable control the rotation speed of each blower.

[Functions and Effects of the Invention] The hot air heater having the above configuration has the following effects.

(Function) The rotation speed control circuit sends out an electrical output according to the output of the combustion detection sensor.

The combustion blower energizing circuit is based on this electrical output.
The number of rotations of the combustion blower is continuously variably controlled by varying the amount of electricity supplied to the combustion blower so that an amount of combustion air suitable for combustion is supplied to the burner.

As the output of the combustion detection sensor increases, the convection blower tends to require a higher rotation speed, but convection blowers and combustion blowers have different structures and functions, so they cannot be electrically connected directly to the combustion blower. However, since a convection blower energization circuit is provided, the electrical output is converted by the circuit to be suitable for continuously variable convection blower.

(Effects) A) Since the rotation speed control circuit can be used in common, the number of parts can be reduced. Therefore, the production cost of the hot air heater is kept low and the probability of failure is reduced.

b) The rotation speed of the convection blower can be varied steplessly. Therefore, the temperature of the hot air discharged from 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 are FF type gas hot air that mixes outdoor air introduced from outside with gas, burns it, exchanges heat with the combustion gas with indoor air, and discharges the combustion gas outdoors again. A configuration diagram and a circuit diagram of the device are shown.

The FF type gas hot air device consists of a combustion air circulation path 1 that combusts air introduced from outside and discharges it outside again, a gas introduction path 2 that supplies gas into the combustion air circulation path 1, and an indoor an indoor air circulation path 3 that exchanges air with the combustion gas in the combustion air circulation path 1 and discharges it again as warm air; driving and controlling the combustion air circulation path 1, the gas introduction path 2, and the indoor air circulation path 3; It consists of an electronic control circuit 4 that performs the operation.

The combustion air circulation path 1 includes an outdoor air introduction path 101 that introduces air from outside, and the outdoor air introduction path 10.
A combustion blower 102 sucks outdoor air from the combustion air circulation path 1 and flows the air and combustion gas in the combustion air circulation path 1, and a gas jet nozzle 103 blows gas into the air sucked by the combustion blower 102.
, a ceramic gas burner 104 that performs combustion of gas mixture air, and a heat exchanger 105 that performs heat exchange between the combustion gas combusted by the gas burner 104 and the indoor air circulated through the indoor air circulation path 3.
and an exhaust path 106 that guides the combustion gas after heat exchange with the heat exchanger 105 to the outside.

The gas introduction path 2 supplies the gas to the gas ejection nozzle 1.
A main valve 202 is provided on the upstream side of the gas combustion supply pipe 201 that supplies gas to the gas combustion supply pipe 201 and is opened and closed by energization and de-energization, and a safety valve is provided downstream of the main valve 202 and is opened and closed by energization control like the main valve 202. 203, a constant flow valve 204 that is provided downstream of the safety valve 203 and adjusts the pressure of the gas flow rate, and a proportional control valve 205 that is provided downstream of the constant flow valve 204 and whose opening degree varies depending on the amount of energization. and the proportional control valve 2
A gas bypass 207 has a flow rate adjustment screw 206 that allows a fixed amount of gas to flow out from upstream of the proportional control valve 205 to the gas jet nozzle 103 regardless of whether the proportional control valve 205 is open or closed, and It consists of a gas rich burner passage 209 which is a bypass that flows out a certain amount of gas to a small vent 208 for oxygen deficiency provided at the site.

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 warm air device, and the indoor air inlet 30.
A convection blower 303 sucks indoor air from 2 and flows the air in the indoor air circulation path 3, and discharges the high temperature air after heat exchange with the heat exchanger 105 of the combustion air circulation path 1. It consists of a hot air discharge port 304.

The electronic control circuit 4 includes a spark electrode 401 that ignites a flame in the gas burner 104, and a spark electrode 401 that ignites a flame in the gas burner 104.
A flame rod 402 that detects flames on the surface, a thermocouple 403 that controls the rotation speed of the combustion blower 102, and a combustion blower 1 in the combustion air circulation path 1.
02, main valve 202 of the gas introduction path 2,
It drives and controls the safety valve 203, the proportional control valve 205, the convection blower 303 of the indoor air circulation path 3, and the like.

The electronic control circuit 4 has 100
A power supply circuit 41 that converts volt alternating current to constant voltage direct current, and an ignition rotation speed setting circuit 42 that sets the rotation speed of the combustion blower 102 at the time of ignition.
, a thermocouple amplifier circuit 43 that increases the output of the thermocouple 403 that controls the rotational speed of the combustion blower 102, and the ignition rotational speed setting circuit 4.
2, a rotation speed control circuit 44 that receives the output of the thermocouple amplifier circuit 43, detects the oxygen supply state based on the output of the thermocouple amplifier circuit 43, and controls the rotation speed of the combustion blower 102 during gas combustion; the combustion blower 102 and the convection blower 303; a combustion blower energization circuit 46 that drives the combustion blower 102 by the output of the ignition rotation speed setting circuit 42; and a convection blower by the output of the ignition rotation speed setting circuit 42. 303; a combustion blower rotation detection circuit 48 that detects the rotation of the combustion blower 102 from the blower drive circuit 45; and a spark detection circuit 49 that detects the spark state of the spark electrode 401. , the combustion blower rotation detection circuit 4
At step 8, it is detected that the combustion blower 102 blows air inside the combustion air circulation path 1 for a certain period of time during startup, and after the spark detection circuit 49 detects a sputter, the main valve 202 is energized to supply combustion gas. a solenoid valve drive circuit 50 that opens the piping 201;
A flame detection circuit 51 detects a flame with a flame rod 402 installed above the gas burner 104 and detects an ignition state;
a timer circuit 52 which is started by detecting a flame, de-energizes the convection blower 303 for a certain set time, and operates a proportional control circuit 53 described below for a certain fixed time; and the timer circuit 52.
The opening degree of the proportional control valve 205 is increased for a certain period of time in response to the output of A proportional control circuit 53 that controls the amount, and the proportional control circuit 5
a temperature control determination circuit 54 that controls the energization circuit to the safety valve 203 to stop gas combustion when the difference between the reference value obtained by the temperature setting device 3 and the output signal of the temperature sensing element reaches a certain value or more; , a backfire detection circuit 55 that detects backfire based on the output of the thermocouple amplifier circuit 43; and a combustion blower 102 and the main valve 20 based on the output of the backfire detection circuit 55.
2. An abnormality circuit 56 that generates an output that causes the spark electrode 401 to be de-energized, and a combustion blower 102 and a main valve 202 that receive the respective outputs of the flame detection circuit 51, temperature control determination circuit 54, and abnormality circuit 56. , a convection blower 303, an ignition sequence circuit 57 that controls energization of the spark electrode 401, and the like.

Next, one embodiment of the combustion blower energization circuit 46 and the convection blower energization circuit 47 which are controlled by the rotation speed control circuit 44 will be described.

The rotational speed control circuit 44 is provided to variably determine the rotational speed of the combustion blower in response to the outputs from the ignition rotational speed setting circuit 42 and the thermocouple amplifier circuit 43 as described above, and the blower drive circuit 45 includes a frequency generator and the like. The combustion blower energization circuit 46 outputs to the combustion blower energization circuit 46 and the convection blower energization circuit 47 via the blower drive circuit 45.
an amplifying section 46A consisting of a transistor Tr1 and a resistor R1 that amplifies the output from the amplifying section 4;
A control unit 46 consisting of a transistor Tr2 and a resistor R2 that receives an output of 6A and changes the voltage value.
B, a diode bridge 46C whose energization amount is variable depending on the voltage change of the control unit 46B, and capacitors C1, C2 for absorbing noise generated by the combustion blower 102 and the convection blower 303 or for blocking external noise. C3 and coil L1,
It consists of a filter part 46D consisting of L2, and 4
6E is a control section 46B and a diode bridge 46C.
This is a varistor that is placed between the two and absorbs and removes noise, surge, etc.

Like the combustion blower energizing circuit 46, the convection blower energizing circuit 47 includes an amplifying section 47A comprising a transistor Tr3 and a resistor R3 that amplify the output from the blower drive circuit 45, and a voltage value upon receiving the output of the amplifying section 47A. Transistor that changes the
A control section 47B consisting of Tr4 and resistor R4;
It consists of a diode bridge 47C whose energization amount is variable depending on the voltage change of the control section 47B, and a diode bridge 47D.
47E is a varistor disposed between the control unit 47B and the diode bridge 47C to absorb and remove noise and surges, and 47E is the above-mentioned timer circuit 5.
Convection blower 3 is activated for a certain period of time during startup due to the operation of 2.
This is a normally closed contact that stops the rotation of 03.

As described above, in the combustion blower energizing circuit 46, the amplification section 46A continuously increases and decreases the output from the rotation speed control circuit 44 and the blower drive circuit 45, and the voltage value is varied steplessly, and the resistance value is set in the transistor Tr2. The amount of current supplied to the diode bridge 46C is varied, and the amount of current supplied to the combustion blower 102 is thereby continuously increased or decreased.
is continuously variable. Similar to the combustion blower energizing circuit 46, the convection blower energizing circuit 47 has an amplifying section 47A that continuously increases/decreases the output voltage of the rotation speed control circuit 44 and the blower drive circuit 45 to vary the resistance value of the transistor Tr4. In order to continuously control the amount of electricity supplied to the bridge 47C, the convection blower 303 is also continuously varied steplessly. Generally, the convection blower 303 is the combustion blower 102.
Since a larger air flow rate is required, a damper for variable air flow rate is provided in the indoor air circulation path 3, and the air flow rate can be finely adjusted by adjusting the position of the damper, or a combustion blower energizing circuit 46, Amplifying sections 46A and 47A of convection blower energizing circuit 47
The amplification value may be changed and provided.

[Brief explanation of drawings]

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 electronic control circuit, and FIG. 3 is a diagram of the combustion blower energization circuit shown in FIG. FIG. 3 is an electronic circuit diagram of a convection transmitter energization circuit. In the figure, 44... rotation speed control circuit, 46... combustion blower energization circuit, 47... convection blower energization circuit, 104... gas burner (burner), 102...
...Blower for combustion, 303...Blower for convection, 40
3...Thermocouple (combustion detection sensor).

Claims (1)

[Scope of Claims] 1. A combustion blower that supplies combustion air to the burner; a convection blower that blows out the heat of the burner as warm air; and a combustion blower that faces the burner and detects the state of oxygen supply to the combustion flame. a detection sensor; a rotation speed control circuit that sends out an electrical output according to the output of the combustion detection sensor; and a stepless variable control of the rotation speed of each blower by varying the amount of electricity supplied to each blower based on the electric output. do,
A hot air heater comprising a combustion blower energizing circuit and a convection blower energizing circuit.