JPH01159524A - Control device of forced blasting type combustion device - Google Patents

Abstract

PURPOSE:To realize a rapid changeover by carrying out beforehand the selection of a combustion state upon changing over from one burner to two burners by increasing the required combustion amount in a forced blasting type combustion device such as a hot water supplier or the like using two burners. CONSTITUTION:A fan 12 for combustion, a governor proportional valve 23, and a solenoid valve 24 for changeover are controlled in accordance with a set combustion quantity and an adjusted fuel gas is ejected to a first burner 11a and a second burner 11b. When the set combustion quantity is changed at a second combustion in which the solenoid valve 24 for changeover is closed, the combustion quantity is changed by the governor proportional valve 23. However, in a case where the quantity of a change is large and a predetermined combustion quantity is not obtained in the second combustion, a first combustion in which two burners are burnt together is selected. Upon this occasion, the governor proportional valve is immediately adjusted to a slow igniting state, the solenoid valve 24 for changeover is opened to change to the first combustion, and thereafter the governor proportional valve is adjusted to carry out the change of the combustion quantity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used for water heaters, space heaters, etc.
Regarding forced-air combustion equipment that uses two burners (hereinafter simply referred to as "two burners") and supplies combustion air with a blower, it particularly relates to a control device that switches the number of burners used according to the required combustion amount. .

[Prior art] In forced air combustion devices used in water heaters, etc., a combustion device equipped with two burners is used to ensure a large calorific value. In addition to using a burner, in the case of a small calorific value, a single burner or a set of burners (hereinafter simply referred to as "one burner") is used, and a temperature control for setting the hot water temperature, water input temperature, and amount of water input is used. Combustion is performed by switching the number of burners used according to the required calorific value calculated accordingly. Further, in order to easily control the combustion amount, a combustion amount range is provided that overlaps the combustion amount range with one burner and the combustion amount range with two burners.

When the set combustion amount is increased during combustion with one burner, the combustion amount is gradually increased while the single burner is used. If the increased set combustion amount exceeds the combustion capacity of the one burner, the combustion amount is changed to the two burner. The switching is performed.

Switching to two burners is simply opening the solenoid valve installed in the fuel supply path, so if you switch to two burners while the single burner is at its maximum combustion rate, the amount of fuel will increase rapidly. It is very dangerous. In addition, in order to maintain continuity in the change in combustion amount when correcting the combustion amount based on the hot water temperature, after reaching the maximum combustion amount in one burner, the combustion amount is reduced to the combustion amount at -1 ignition, and then Switching to two burners is performed.

[Problems to be Solved by the Invention] However, when there is a request to increase the combustion amount due to changes in the set water temperature, etc. during combustion with only one burner,
If you switch to two burners after reaching the maximum combustion rate with one burner, the increased combustion rate will have to be reduced again before switching, so it will take time for the combustion status to stabilize, and The problem is that no changes can be made.

The present invention provides a forced air combustion system using two burners, in which the required combustion amount increases while one burner is in use.
It is an object of the present invention to provide a control device that can quickly switch to the present burner.

[Means for Solving the Problems] The present invention includes a blower for supplying combustion air, and the fuel is regulated by a proportional valve provided in a fuel supply path.
a first combustion consisting of a first burner supplied via a solenoid valve and a second burner supplied directly; a first combustion in which both the first burner and the second burner are combusted by opening the solenoid valve; The combustion amount set by the combustion amount setting means is configured to include a forced air combustion device that opens the solenoid valve, burns only the second burner, and performs a second combustion having a combustion amount range that overlaps with the first combustion. In the control device, the control device selects the first combustion or the second combustion based on the combustion amount set by the combustion amount setting means at the time of ignition, and slows down the blower and the proportional valve. ignition control, and after ignition, the solenoid valve, the blower, and the proportional valve are controlled according to the set combustion amount, and when the set combustion amount is increased in the second combustion, the combustion amount is increased. A technical means is adopted characterized in that the first combustion or the second combustion is selected in advance based on the amount of combustion, and the solenoid valve is opened when the first combustion is selected.

[Operation] In the forced air combustion device of the present invention, the proportional valve and the solenoid valve are controlled according to the setting state of the combustion amount setting means, and the fuel gas is regulated by the proportional valve and supplied to the first burner and the second burner. and combustion air is supplied by a blower.

When the blower and the proportional valve are ignited, slow ignition control is performed, and fuel gas is supplied according to the energizing current. At this time, the electromagnetic valve is also controlled, and when the set combustion amount is large, it becomes open, and when it is small, it becomes closed.

After ignition, when the setting state of the combustion amount setting means is changed, the blower and the proportional valve are controlled according to the changed setting state, and the solenoid valve is also controlled accordingly.

In the case of second combustion using only the second burner, if the setting state of the combustion amount setting means is changed and the set combustion amount is increased, the second combustion has a combustion amount change range that overlaps with the first combustion.
The combustion state is selected in advance, whether only the second burner continues to burn or both the first burner and the first burner burn.

[Effect of the invention] In the control device for a forced air combustion device according to the present invention.

If there is a change in the setting of the combustion amount during the second combustion and the combustion amount is to be increased, the changed setting combustion amount can be obtained by the second combustion only in the second burner, or the combustion amount in the first burner and the second burner can be increased. It is selected in advance whether the first combustion should be changed to the one that uses both the first combustion and the first combustion.

Therefore, when the set combustion amount cannot be obtained using only the second burner, the first combustion is selected in advance, so that the combustion amount is not excessively changed in the second combustion.

As a result, the combustion amount can be quickly changed to the increased combustion amount.

[Example] Next, a control device for a forced air combustion apparatus of the present invention will be described based on an example shown in the drawings.

The gas combustion type water heater 1 shown in FIG. 2 uses gas such as propane gas as fuel, and is provided with a combustor case 10, inside which a fuel gas supplied through a gas supply pipe 20 is fed. A twin burner 11 for combustion is provided. The two-pass burner 11 has a first
Consisting of a burner 11a and a second burner 11b, there are two combustion states: a first combustion in which combustion is performed in both the first burner Ila and the second burner 11b, and a second combustion in which combustion is performed only in the second burner 11b. can be switched. These first combustion and second combustion are nine combustion states that are set to easily achieve a large combustion amount and a small combustion amount, respectively, as shown by the solid line A and the broken line B in FIG. 3, respectively. In the example, the range of the small combustion amount by the second combustion is set to Q8 so that when there is a change in the set combustion amount in each combustion state, there is no need to change the combustion state if the amount of change is small. to Q, and the range of large combustion amount by the first combustion is set from Q2 to Q4, respectively, so that overlapping combustion amounts can be obtained between Q2 and Q. Combustion air is supplied to the two-pass burner 11 by a combustion fan 12 provided in the combustor case 10 as a blower according to the present invention.

A heat exchanger 13 connected to a water supply pipe (not shown) is provided above the combustor case 10, and the water passing through the interior is heated by the heat generated by the combustion of the two-pass burner 11. Further, a sparker 14 as an ignition device and a flame rod 15 as a flame detection means are provided near the two-pass burner 11 in the combustor case 10.

The gas supply pipe 20 as a fuel supply path includes a source solenoid valve 21 and a main solenoid valve 2 that allow fuel gas to pass through from the upstream side when energized.
2. A governor proportional valve 23 is provided that adjusts the amount of fuel gas supplied by controlling the supply pressure, and a two-way nozzle 16 that injects fuel to the two-way burner 11 is provided at the downstream end of the governor proportional valve 23. .

The two-way nozzle 16 consists of a first nozzle 16a and a second nozzle 16b, which are connected to the first burner 11a and the second nozzle, respectively.
Fuel is injected to the burner 11b. In addition, in this embodiment, in order to change the supply amount of fuel gas in stages according to the usage status of the water heater, the gas supply pipe 20 to the first nozzle 16a is
A switching solenoid valve 24 is provided therein as a solenoid valve of the present invention, and the switching solenoid valve 24 is energized and opened during the first combustion, and is not energized and closed during the second combustion.

The combustion exhaust gas after combustion is exhausted to the outside from the exhaust port 2, but in the second combustion, the combustion exhaust gas is mixed with the combustion air supplied to the first burner 11a and exhausted, so drainage may not occur. few.

Note that on the downstream side of the heat exchanger 13, an outlet hot water temperature thermistor 25 is provided to detect the temperature of the heated water.

As shown in FIG. 4, the control device 30 is composed of the following circuits centered around a microcomputer 40 (hereinafter referred to as CPU 40).

The sparker circuit 31 is a circuit for energizing a high voltage generation circuit for generating a spark discharge in the discharge gap of the sparker 14 via a relay.

The fan circuit 32 drives the combustion fan 12 under control from the CPU 40, and includes a rotation speed detection circuit for detecting the rotation speed of the combustion fan 12.

The proportional valve circuit 33 is a circuit for energizing the governor proportional valve 23 in order to adjust the amount of fuel gas supplied to the dual burner 11, and the energizing current for this purpose is determined by detecting the rotation speed of the fan circuit 32. In this embodiment, from this proportional valve circuit 33, a slow ignition current Ia, which is unrelated to the combustion amount set at the time of ignition, is proportional to the governor. Valve 23 is energized.

The water amount detection circuit 34 detects the amount of water flowing in by detecting the rotation speed of an impeller of a water amount sensor provided in a water supply pipe (not shown) upstream of the heat exchanger 13.

The water valve circuit 35 is a circuit for driving a geared motor of a water flow control valve (not shown) provided in a water supply pipe upstream of the water flow sensor, and the water flow control valve is equipped with a potentiometer for detecting its opening degree. The water flow control valve is controlled to an opening degree according to the control state based on a detection signal from a potentiometer.

The water temperature detection circuit 36 detects the temperature of the water heated by the heat exchanger 13 based on the signal from the above-mentioned outlet water temperature thermistor 25 and the signal from the inlet water temperature thermistor (not shown) provided upstream of the heat exchanger 13. This circuit is for detecting the temperature of water flowing into the heat exchanger 13.

The control circuit 37 is an operation section for controlling the operating state of the gas combustion water heater 1, and includes an operation switch and a temperature setting switch. This control circuit 37
are connected by wire-saving two-wire wiring (not shown) for remote control, and are operated by power supplied from this two-wire wiring.

Then, an operating signal and a temperature setting signal are digitally generated, modulated onto a predetermined carrier wave, and sent out.

The interface circuit 38 is a circuit for transmitting signals between the above-mentioned circuits, the original solenoid valve 21, the main solenoid valve 22, the switching solenoid valve 24, and the frame rod 15, and the CPU 40, which will be described later. The energizing circuit for the valve 21 and the main solenoid valve 22 includes a safety circuit 39 for stopping the fuel when the flame of the dual burner 11 is no longer detected.
is provided.

The CPU 40 comprehensively controls the operating state of each of the circuits described above, and includes a ROM 41 and a RAM 42 as storage devices, and analyzes the operating signal from the control circuit 37 from a carrier wave, depending on the set state such as the set temperature. , ROM in advance
The gas combustion type water heater 1 is operated in the operating order stored in 41.

Further, each of the CPUs 40 has the following functions.

The combustion amount setting function 43 calculates the required combustion amount based on the setting state of the temperature setting etc. by the control circuit 37 and each signal from the water amount detection circuit 34 and the water temperature detection circuit 36, and sets the combustion amount of the dual burner 11. Set.

The combustion state selection function 44 selects the first combustion or the second combustion based on the combustion amount set by the combustion amount setting function 43, and in this embodiment, the switching solenoid valve 24 is in the open state. 2 During combustion, the control circuit 37
When the set combustion amount is changed depending on the set temperature, water supply amount, and inlet water temperature, it is necessary to determine in advance whether the set combustion amount can be obtained while continuing the second combustion, or whether it must be changed to the first combustion. select. As a result, when the first combustion is selected, the current flowing to the governor proportional valve 23 is changed to the second combustion.
It is possible to immediately change to the slow ignition current Ia without increasing the maximum current for combustion. Therefore, if this selection is not made, the current flowing to the governor proportional valve 23 is set to the maximum current value as the set combustion amount increases, and then is set to the slow ignition current Ia, whereas in this embodiment Since the current Ia is quickly changed to the slow ignition current Ia, the combustion amount is quickly changed.

The blower control function 45 controls the combustion fan 12 based on the combustion amount set by the combustion amount setting function 43 and the combustion state selected by the combustion state selection function 44 to supply combustion air to the burner 11. ing. In particular, when transitioning from the second combustion to the first combustion, the rotation speed of the combustion fan 12 is once changed to the rotation speed for slow ignition, and then the switching solenoid valve 24 is energized to be in the open state, and then Controls the rotation speed according to the set combustion amount.

The fuel supply amount control function 46 controls the energizing current of the governor proportional valve 23 and the energizing state of the switching solenoid valve 24 according to the selected combustion state, and controls the energizing state of the combustion fan 1 detected.
The governor proportional valve 23 is controlled according to the rotation speed of the burner 11, and the amount of fuel supplied to the burner 11 is controlled.

In particular, when transitioning from the second combustion to the first combustion, the current flowing to the governor proportional valve 23 is changed to the slow ignition current Ia, similar to the combustion fan 12, and then the switching solenoid valve 24 is changed. It is energized to open it, and then a current corresponding to the set combustion amount is energized to the governor proportional valve 23. This is because in the transition from the first combustion to the second combustion, the amount of combustion can be reliably reduced by simply closing the switching solenoid valve 24, but in the transition from the second combustion to the first combustion. In the case of switching, the first burner 11a will be newly ignited at the time of switching, so ignition will not be performed safely unless appropriate control is performed. supply

Next, the gas combustion water heater 1 of this embodiment having the above configuration
The operation will be explained based on FIG.

When the user turns on the operation switch, the control device 30 is activated by the signal, and operation is started in a predetermined sequence.

The control device 30 calculates the amount of combustion based on the set temperature, inlet water temperature, and amount of inlet water, and sets the amount of combustion. The combustion fan 12, the governor proportional valve 23, and the switching solenoid valve 24 are controlled according to the set combustion amount, and the regulated fuel gas is delivered to the first burner 11a from the first nozzle 16a and the second nozzle 16b, respectively. and is ejected to the second burner 11b. At this time, combustion air is supplied to each burner 11a, 11b by a combustion fan 12.

When the set temperature is changed and the set combustion amount is changed, the current of the governor proportional valve 23 is changed in accordance with the changed amount in each combustion state.

When the set combustion amount cannot be obtained in each combustion state, the switching solenoid valve 24 is changed to change the combustion state.

For example, as shown in FIG. 3, when the current value of the governor proportional valve 23 is Im smaller than the slow ignition current value Ia during the second combustion when the switching solenoid valve 24 is in the closed state, combustion occurs. The quantity is Qm. At this time, if the set combustion amount is drastically changed and the changed combustion amount is Qn, then
In the second combustion shown by the broken line B, the combustion amount Qn cannot be obtained even if the current applied to the governor proportional valve 23 is increased. Therefore, the first combustion is selected by the CPU 40. Then, the current applied to the governor proportional valve 23 is increased to the slow ignition current Ia, and then the switching solenoid valve 24 is energized to be in the open state and the combustion is changed to the first combustion. After that, the governor proportional valve 23
The current is increased to In so that the amount of combustion becomes Qn.

Further, in the second combustion, when the current flowing through the governor proportional valve 23 is Ip larger than the slow ignition current Ia and the combustion amount is Qp, the set combustion amount is changed to Qn as in the above case. In the second combustion, as in the case of
Since the combustion amount Qn cannot be obtained, the first combustion is selected,
The current flowing through the governor proportional valve 23 is reduced to approximately the ignition current Ia. Thereafter, the combustion is changed to the first combustion in the same manner, the current is set to In, and the combustion amount Qn is obtained.

In this way, when changing from the second combustion to the first combustion, the current flowing through the governor proportional valve 23 is immediately changed to the slow ignition current when the first combustion is selected, so the switching solenoid valve 24 is quickly energized, and can be brought into the open state quickly. Therefore, the combustion amount can be changed safely and quickly.

[Brief explanation of the drawing]

Fig. 1 is a functional block diagram for explaining the operation of the gas combustion water heater of this embodiment, Fig. 2 is a schematic configuration diagram showing the gas combustion water heater of this embodiment, and Fig. 3 is a functional block diagram of the gas combustion water heater of this embodiment. FIG. 4 is a characteristic diagram showing a change in the amount of combustion caused by a change in the current value of the governor proportional valve. FIG. 4 is a block diagram showing the configuration of the control device of this embodiment. In the figure, 11a...First burner, 11b...Second burner, 12...Combustion fan (blower), 23...Governor proportional valve (proportional valve), 24...Switching solenoid valve (electromagnetic valve), 30...control device, 40...microcomputer (combustion amount setting means).

Claims (1)

[Claims] 1) A blower for supplying combustion air is provided, and fuel regulated by a proportional valve provided in the fuel supply path is directly supplied to the first burner supplied via a solenoid valve. second to be done
burner, and when the solenoid valve is opened, the first
Forced air blowing that performs first combustion in which both the burner and the second burner are combusted, and second combustion in which only the second burner is combusted with the solenoid valve in a closed state and has a combustion amount range that overlaps with the first combustion. A control device for controlling a combustion device based on a combustion amount set by a combustion amount setting means, wherein the control device controls the first combustion or the first combustion based on the combustion amount set by the combustion amount setting means at the time of ignition. The second combustion is selected to perform slow ignition control on the blower and the proportional valve, and after ignition, the solenoid valve, the blower, and the proportional valve are controlled according to the set combustion amount, and the second combustion When the combustion amount set in is increased, the first combustion amount is determined in advance based on the increased combustion amount.
A control device for a forced air combustion device, characterized in that combustion or the second combustion is selected, and when the first combustion is selected, the solenoid valve is opened. 2) When the first combustion is selected, the control device performs slow ignition control on the blower and the proportional valve to open the solenoid valve. Control device for forced air combustion equipment.