JPH0221123A - Control device for hot water supply equipment - Google Patents

Abstract

PURPOSE:To improve the next ignition performance by driving a fuel supply control device based on signals transmitted from a fuel decision device, changing the values between the upper limit and the lower limit in an effort to look for a proper ignition point, then igniting, and storing the data obtained during ignition. CONSTITUTION:When flowing water is detected by a control device 15 or another control device 18, a fan 10 is adapted to rotate once at the highest rotary speed for about 2min, then the rotary speed of the fan is controlled so that it may be slower and the most suitable for ignition. When a timer is then started, an attempt is made to discharge from an ignition plug 12 by another control device 17. After that, a gas solenoid valve 7 is opened, and a gas proportional valve 8 is driven by manipulating a gas proportional valve drive means 16 so as to obtain a gas volume which stands between the upper limit value and the lower limit value in terms of a ratio of theoretical air and gas. The control device 17 is adapted to store the quantity of gas at that time based on signals transmitted from a flame rod 13 so that the discharge of the ignition plug may come to a halt, thereby carrying out the combustion continuously. This construction makes it possible to change the density of gas during ignition so to obtain the density of gas required for the nest ignition, and hence ignite definitely in short time.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a control device for a water heater that obtains hot water.

Conventional technology As an example of the conventional technology, a gas instantaneous water heater will be explained.

In FIG. 4, water is supplied from a water inlet 1, passes through a water quantity detection device 2 and a water constant quantity device 3, absorbs heat in a heat exchanger 4, and is supplied from a tap water outlet 5. Gas is supplied by a gas solenoid valve 7 and a gas proportional valve 8 which is a fuel supply amount control device from a gas population 6.
is guided to burner 9 and burned. Air necessary for combustion is supplied by a fan 10 as a combustion blower, and exhaust gas is discharged from an exhaust port 11. The burner 9 is equipped with a spark plug 12 as an ignition device and a flame rod 13 as a combustion detection device.

Each of the above devices is controlled by a control device 14.

FIG. 5 shows an outline of a conventional flowchart of the sequence up to ignition.

The control device 14 detects whether or not water is flowing based on the signal from the water amount detection device 2 (Sl), and if the water is not flowing, it waits until the water amount detection device 2 detects the amount of water. When it is detected that water has flowed, the fan 10 is rotated once at the maximum rotation speed for about 2 seconds (S2), and then the fan 10 is rotated at a slow ignition rotation speed to obtain the amount of air necessary for ignition (S3). .

Then start the timer (S4) and spark plug 1
2 is discharged (S5), and after about one second, the gas solenoid valve is opened (S6), and at the same time, the gas proportional valve 8 is operated to supply an amount of gas suitable for ignition (S7). Then, it is determined whether or not combustion is occurring using the flame rod 13.
8) If there is combustion, stop the discharge of the spark plug 12 (S
9) Continue combustion (S10).

In addition, if the flame rod 13 does not determine that combustion is occurring, it is necessary to determine whether the approximately 5-second timer has expired (5t1), and if the timer has not terminated, the flame rod 13 confirms combustion. Until then.

Also, if the timer has finished, gas solenoid valve 7
512), and stop the gas supply to the gas proportional valve (S1, stop the discharge of the 1 spark plug (12) (S14).
), rotate the engine 10 at maximum speed (S15),
The timer is restarted (S10), the fan 10 is rotated at the maximum rotation speed for about 10 seconds, and it is determined whether the timer has ended (617), and if it has ended, the fan is stopped (518).

Problems to be Solved by the Invention However, when applied to ultra-compact water heaters, the conventional technology
It may not ignite. This is due to the following reasons.

Since the amount of gas consumed by ultra-small water heaters is the same as that of conventional water heaters, the amount of air required is also the same. Since the burner 9 is also extremely small, the speed of the fuel and air passing through the medium area of the burner 9 is high, and it is quite difficult to set the ratio of fuel and air at the ignition part to a value suitable for ignition. .

Also, considering the variation in the ratio of fuel and air, it is quite possible that ignition will not occur.

In order to solve the above problems, the present invention changes the ratio of air and fuel at the time of ignition to facilitate ignition, stores the fuel conditions at the time of ignition, and uses those conditions next time. The aim is to improve ignition performance by changing the air-to-fuel ratio.

Means for Solving the Problems In order to achieve the above object, the water heater control device of the present invention includes an ignition device that ignites fuel, a combustion determination device that determines combustion, and a fuel supply amount that controls the amount of fuel. a control device; a combustion blower that supplies the air necessary to burn the fuel and discharges the combustion exhaust gas generated by the combustion to the outside;
The fuel supply control device is driven by a signal from the combustion determination device, and the ignition is performed by changing the air-fuel mixture ratio between an upper limit value and a lower limit value at the time of ignition, and data at this time is stored. The configuration includes a fuel supply amount control device driving means that changes the mixture ratio based on the data to enable ignition from the next time onwards.

According to the above-described configuration, the combustion blower operates to keep the amount of air suitable for ignition constant at the time of ignition, and uses the fuel supply amount control device driving means to supply air that is theoretically mellow. Ignition is performed by changing the fuel ratio between the upper limit value and the lower limit value. Then, the amount of fuel supplied when the combustion determining device determines combustion is stored. When igniting the next time, the theoretical air-to-fuel ratio is varied between the upper and lower limits, centering on the previously memorized fuel supply amount.
Let it ignite, and repeat this process to make sure it ignites and to ignite it in a short time.

Example FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, water is supplied from a water inlet 1, passes through a water quantity detection device 2 and a constant water quantity device 3, absorbs heat in a heat exchanger 4, and is supplied from a tap water outlet 5. Gas is supplied from a gas port 6, passes through a gas electromagnetic valve 7 and a gas proportional valve 8, which is a fuel supply amount control device, and is burned in a burner 9. The air necessary for this combustion is supplied by a fan 10 as a combustion blower.

Exhaust gas is exhausted from the exhaust port 11. The burner 9 is provided with a spark plug 12 as an ignition device and a flame rod 13 as a combustion detection device at a location where ignition and combustion detection can be easily performed. Also, a side control device 1 that controls each of the devices described above.
Reference numeral 5 includes a gas proportional valve drive means 16 as a fuel supply amount control device drive means and other control devices 17. Here, the operation of each device will be explained using a flowchart of the ignition sequence shown in FIG.

The other control device 17 in the control device 15 determines whether or not water is flowing depending on whether there is a signal from the water amount detection device 2 (519), and if water is not flowing, the water amount detection device 2 Wait until the water level is detected. When the other control device 18 of the control device 15 detects that water has flowed, the fan 10 changes completely and rotates at the maximum rotation speed for about 2 seconds (S20), and then slowly ignites the fan so that the rotation speed is suitable for ignition. Set the rotation speed (521). Then, the timer is started (S27), and the other control devices 1
7, the spark plug 12 discharges (S23).

Thereafter, the gas solenoid valve 7 is opened and the gas proportional valve 8 is driven using the gas proportional valve driving means 16 to bring the amount of gas between the upper and lower limits of the theoretical air-to-gas ratio. (S25). And frame lot 12
The other control device 17 determines whether ignition has occurred based on the signal from 526), and if ignition has occurred, stores the amount of gas at that time (Si27) and stops discharging the spark plug (52B); The combustion is continued (529), and if the slap 26 does not ignite, the gas proportional valve driving means 16 is operated to increase the gas amount (S30), and the other control device 17 determines whether or not to ignite (
)31). If ignited, the same steps are performed from step (927). If the other control device 17 does not detect ignition in step (531), the gas proportional valve driving means 16 is operated to reduce the gas amount (S32).
), the other control device 17 determines whether or not to ignite (933'').

If ignited, do the same thing as before step (527). If the fire is not ignited, the other control device 17 determines whether or not the timer has ended (934
), if the timer has not ended (N), repeat the same steps as before step (S25). Step (
! If the timer ends (Y) at step 534), the gas solenoid valve 7 is closed (535), the gas proportional valve 8 is closed (S36), and the discharge of the spark plug 12 is stopped (S37). ) Rotate the fan 10 at the maximum rotation speed (53
B) Release the gas that is thought to remain inside the container to the outside of the container. For this, set a timer for about 10 seconds539)
, and determines the end (540), and stops the fan 10 (541).

If the ignition sequence is to be performed again after the engine is burned for -degrees, the flow will be as shown by the dotted line (...) in FIG.

Corresponding to step (S25), ignition is started (942) according to the gas amount stored in the gas proportional valve based on the data of the gas proportional valve driving means 16 stored when ignition was detected.

FIG. 3 shows an example of the gas proportional valve driving means 16 as the fuel supply amount control driving means.
, D/A converter 20. It is composed of an amplifying section 21. The microcomputer 18 (hereinafter referred to as microcomputer) includes l1022, CPU23, RAM24, F20
It is composed of M25. The ROM 25 stores data on the upper limit and lower limit of the amount of gas at the time of ignition. When starting the sequence and performing the ignition sequence for the first time, the CPU 23 calculates the midpoint between the upper and lower limit data stored in the ROM 25, and the R
It is stored in AM24. And the data is 1102
2, D/^ converter 20, operational amplifier 26, amplifier 21
The gas proportional valve 8 is operated via the . When the ignition is ignited, the 7-rem rotor detection circuit 19 sends an ignition detection signal to the l1022. When the microcomputer 18 receives a signal indicating that the l 1022 has detected ignition, the microcomputer 18 converts the D/A converter 2
The data output to 0 is stored in the RAM 24, and the next time the ignition is started, the data in the RAM 24 is output, and the data is output to the ROM 2.
Data is output to +1022 so as to vary between the upper limit value and lower limit value stored in 5. The frame lot detection circuit 19 includes the frame lot 13 and FET2.
6 and a transistor 27, and whether or not there is a flame front current depending on the presence or absence of a flame is determined by the FET 26.
The signal is detected by the transistor 27 and sent to the l 1022 of the microcomputer 18.

With the above configuration, the gas concentration at the time of ignition is changed so that the concentration at the time of ignition is the same at the next ignition, and then the gas concentration is changed to ensure ignition in a short time. .

Effects of the Invention As is clear from the above embodiments, the present invention includes an ignition device that ignites combustion, a combustion determination device that determines combustion, a fuel supply control device that controls the amount of fuel, and an ignition device that ignites combustion. a combustion blower that supplies the air necessary for the combustion and discharges the combustion exhaust gas generated by combustion to the outside; and a fuel supply amount control device drive that drives the fuel supply amount control device with a signal from the combustion determination device. By providing a means, the ratio of air amount and fuel at the time of ignition is adjusted to ensure ignition, and the data from the previous ignition is memorized, so that the next time the ignition is started, the ignition will be based on the previous data. can be started and ignited in a short time.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a water heater showing one embodiment of the present invention;
The figure is a flowchart of the same sequence, Figure 3 is a block diagram of the gas proportional valve driving means, Figure 4 is a configuration diagram of the conventional example,
FIG. 5 is a flowchart of a conventional sequence. 8...Gas proportional valve (fuel supply amount control device), 1
0...Fan (combustion blower), 12...
. . . Spark plug (ignition device), 13 . . . Flame rod (combustion detection device), 16 . . . Gas proportional valve drive means (fuel supply amount control device drive means). Names of m persons: Patent attorney Shigetaka Awano and 1 other person 1 Figure 8 - Evening comparison? l*lθ-゛-Fan motor 12-fly, spark plug/3-7 frame a de Is, 17--Separate printing device l"-force base I9+drive means Fig. 2 Fig. Fig. 1q frame One mulloft detection circuit diagram

Claims (1)

[Claims] An ignition device that ignites the fuel, a combustion determination device that determines combustion, a fuel supply amount control device that controls the amount of fuel, and a fuel supply amount control device that supplies the air necessary to burn the fuel and controls the combustion exhaust gas generated by combustion. Drives the fuel supply amount control device with a signal from a combustion blower device that discharges the air to the outside of the device and the combustion determination device, and changes the mixture ratio of air and fuel at the time of ignition between an upper limit value and a lower limit value. control of a water heater equipped with a fuel supply amount control device driving means that allows ignition to occur, stores data at this time, and changes the mixture ratio based on the data for next ignition. Device.