JPH04155120A - Pilot burner ignition control device - Google Patents

Abstract

PURPOSE:To eliminate troublesomeness during test by a method wherein a test time is selected as the discharge time of an igniter during a time in which an initial ignition confirmation signal is outputted, an ordinary value is selected after output of the initial ignition confirmation signal, and a selected value is fed to an igniter discharge control means. CONSTITUTION:When a power source is turned ON and operation to generate a combustion command signal (opening of a hot water feed faucet 14 and turning ON of an additional burning switch) is carried out, a gas feed valve 13 to a pilot burner 7 is opened, and an igniter 8, simultaneously, is discharged. In this case, a discharge time in which ignition is first detected is TT and longer than an ordinary discharge time TN, and set to, for example, approximate 30 seconds. Thus, quantities of air gathering in a gas piping can be discharged through one action of ignition operation, and there is no need to repeat ignition operation through opening and closing of the hot water feed faucet 14 times to discharge air. When, after discharge of air, gas is fed and ignition is effected, next and following discharge times are switched to the ordinary discharge time TN.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition control device for a pilot burner provided for igniting a main burner of a bathtub, water heater, or the like.

[Prior Art] As an example of a device equipped with a pilot burner,
A bathtub with a hot water supply function shown in the figure is known.

In this figure, 1 is an appliance case, 2 is a bathtub, 3 is a hot water heat exchanger, 4 is a reheating heat exchanger, 5 is a hot water burner, 6
is the reheating burner, 7 is the hot water supply burner 5 or reheating burner 6
8 is an igniter that generates a spark discharge to ignite the pilot burner 7; 9 is a pyro; a flame rod (flame detector) that detects whether the burner 7 is ignited; 10 is a main Gas solenoid valve, 11 hot water supply gas solenoid valve, 12 reheating gas solenoid valve, 13
is the pilot gas solenoid valve.

Further, the outlet side of the hot water supply heat exchanger 3 is connected to a hot water outlet pipe 15 and a water outlet 16 via a hot water tap 14, and the inlet side of the heat exchanger 3 is connected to a water supply pipe 17. Also, 1
Reference numeral 8 designates a water flow switch that is turned on when water flows through the water supply pipe 17, reference numeral 19 designates an empty heating prevention detector that detects whether or not there is more than a predetermined amount of water in the bathtub 2, and reference numeral 20 an exhaust duct. A control device (as shown) is provided to control the solenoid valves, igniters, etc. based on signals from each switch and detector.

This bathtub operates as follows by the action of the control device.

First, when the hot water tap 14 is operated, water is supplied from the water supply pipe 17, passes through the water flow switch 18, the hot water supply heat exchanger 3, and the hot water tap 14, and is discharged from the hot water tap 15 or the shower 16. At this time, the water flow causes the water flow switch 18 to turn ON, and in response, the main gas solenoid valve 10 and the pilot gas solenoid valve 13 open, and gas flows out from the pilot burner 7. At the same time, the igniter 8 generates a spark discharge and ignites the pilot burner 7.

When the pilot burner 7 is lit, the flame rod 9 detects the flame, and in response, the spark discharge of the igniter 8 is stopped, the hot water gas solenoid valve 11 is opened, and gas flows out from the hot water burner 5. Then, the hot water supply bar 5 is ignited by the pilot burner 7, and the hot water heated by the hot water supply burner 5 is discharged from the hot water tap 15 or the shower 16.

Note that in the above operation, if the pilot burner 7 does not ignite, the spark discharge continues for a predetermined period of time, then the discharge is stopped, and at the same time, the gas supply to the pilot burner 7 is stopped. Therefore, - the hot water tap 14 is closed, and then the tap 14 is opened again to repeat the ignition operation.

In addition to hot water supply, when the reheating switch is turned on, the dry heating prevention detector 19 detects that there is water in the bathtub.
The ignition operation of the pilot burner 7 is performed in the same manner as described above. When the flame rod 9 detects the ignition of the pilot burner 7, the reheating gas ira valve 12 opens, the reheating burner 6 is ignited, and reheating is performed.

The time chart of the hot water supply ignition operation described above is shown in Figure 5 (
The ignition operation for reheating is the same as for hot water supply, so it is omitted here.) 11 of this time chart] 1? C. This shows a case in which the pilot bar 7 does not ignite even after turning on the hot water tap 14 for one turn, does not ignite even after turning on the hot water tap 14 for one more turn, and finally ignites after repeating the ignition operation several more times.

As can be seen in this example, the discharge time of the igniter 7 is managed to be a constant short time. This is to prevent explosion and ignition due to gas filling inside the case l. Conventionally, this discharge time is usually set to approximately 5 seconds. Therefore, if ignition is not confirmed even after 5 seconds of continuous discharge, the same operation will be repeated after the tap 14 is closed once.

By the way, after installing such a bathtub and performing gas piping work, a test operation is generally performed. In this case, air is trapped in the gas pipe after construction, and until all of it is released, no matter how many times you try to ignite the pyro or tovarna, it will not ignite. In particular, the amount of gas flowing out from the pilot burner is very small, so if the gas piping is long, it may be necessary to repeat the ignition operation more than ten times before the gas comes out and a fire is lit. This ignition operation actually involves opening the hot water tap, waiting a few seconds, and then closing it, so it was extremely troublesome to repeat this over and over again.

[Problems to be Solved by the Invention] As mentioned above, in conventional devices, the discharge time of the igniter is uniformly set to about 5 degrees, so when performing a test drive, very troublesome work is forced. It had been.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pilot burner ignition control device that can eliminate the troubles during testing as described above.

[Means for Solving the Problems] In order to solve the above problems, the pilot burner ignition control device of the present invention, as shown in the functional block diagram of FIG. 1, includes (a) a pilot burner 31; (b) an igniter 32 that ignites the pilot burner 31 by generating a spark discharge; (c) a flame rod 33 that detects ignition of the pilot burner 31; (d) a means 34 that generates a combustion command signal; ) An igniter discharge control means 35 which causes the igniter 32 to discharge a spark in response to a combustion command signal, and if no ignition is detected, causes the igniter 32 to discharge a spark for a preset time T and then stops the discharge.
(f) In response to the combustion command signal, the gas supply valve to the pyro burner 31 is opened, and even though the igniter 32 has finished spark discharge for time T, 7L/- Murorad 33 is ignited during that time. and a pilot burner gas supply control means 36 that closes the gas supply valve when the gas supply valve is not detected, further comprising (g) a normal value T as the discharge time T of the igniter 32 and a test value T longer than that. (h) means 38 for outputting an initial ignition confirmation signal when the flame rod 33 detects ignition for the first time after the power is turned on; (i) the discharge time T of the igniter 32 is set to The test value TT is selected until the first ignition confirmation signal is output, and the normal value TN is selected after the first ignition confirmation signal is output, and the selected value is applied to the igniter discharge control means 35.
The present invention is characterized in that it is provided with a discharge time selection means 39 for supplying a discharge time to the discharge time.

[Function] In the ignition control device of the present invention, when the power is turned on and an operation to generate a combustion command signal (opening the hot water tap or turning on the reheating switch) is performed, gas is supplied to the pyro-nodburner. The supply valve opens and the igniter discharges at the same time. At this time, the discharge time until the first ignition is detected is Ta, which is set longer than the conventional normal discharge times T and l. For example, it is set to about 30 seconds. Therefore, much of the air accumulated in the gas pipe can be discharged with -1 ignition operation, and there is no need to repeat the ignition operation by opening and closing the hot water tap many times in order to discharge the air.

Then, after the air is released, gas comes out and ignites, and the next discharge time is switched to the normal discharge time TN.

[Example code] An embodiment of the present invention will be described below.

In the apparatus of this embodiment, the equipment connected to the control apparatus is the same as that shown in FIG. 6, except for the function of the control apparatus. Therefore, only the contents of the control device will be explained with reference to FIG. 6 for the equipment.

As shown in FIG. 2, signals from the running water switch 18, the dry firing prevention detector 19, the additional firing switch 41, and the frame rod 9 are input to the control device 40. Then, the control device 40 controls the igniter 8 based on these input signals.
, the main gas solenoid valve 10, the pilot gas solenoid valve 13, the hot water supply gas solenoid valve 11, and the reheating gas solenoid valve 12.

This control device 40 is mainly composed of a microcomputer, and has an input/output device, A if necessary.
/D converter, an igniter 8, and a drive circuit for electromagnetic valves 10 to 13. The control device 40 is characterized in that a microcomputer executes processing according to the procedure shown in FIG. The operation of the control device 40 will be described below with reference to the flowchart shown in FIG.

When the power is turned on, initial settings are performed in the first step 101. This initial setting includes resetting a flag for initial ignition confirmation, which will be described later. Then, step 102
It is determined whether the combustion command has changed from "absent" to "present". In this example, when the running water switch 18 is ON, or when the reheating switch is ON and the empty heating prevention detector 19 detects that the bathtub is not empty, the combustion command is in the "Yes" state. .

Therefore, if there is no combustion command, or if the "present" state continues (this will be explained later as it has meaning in the second and subsequent processes), step 102
The judgment becomes No, and the combustion command changes from "No" to "Yes"
Wait until.

When the combustion command becomes "Yes", that is, for example, when the closed hot water tap 14 is opened, the judgment in step 102 becomes YES, and the process proceeds to step 103, where the main gas solenoid valve 10, the pyromagnetic valve, and the pyromagnetic valve 13 is opened, and at the same time, the igniter 103 starts discharging.

Next, in step 104, the state of the first ignition confirmation flag is checked, and if the flag is 0, step 1 is checked.
Proceed to step 05 to detect ignition, that is, frame rod 9 is ON.
Judge whether it is L or not. If ignition is not confirmed, this state is continued for 30 seconds (step 106).

If ignition is not confirmed within 30 seconds, the process proceeds to step 107, closes the main gas solenoid valve 10 and the pilot gas solenoid valve 13, simultaneously stops the discharge of the igniter 8, and returns to step 102.

At this stage, the hot water tap 14 remains open and the combustion command remains in the "present" state.
Close. and by reopening step 102
If the judgment is YES, the process proceeds to the next step, step 103.

Thereafter, the above operations are repeated by opening and closing the tap 14 unless ignition is confirmed.

If it is confirmed that the pilot burner 7 is ignited during the above 30 seconds of discharge time, step 1
05 or YES, proceed to step 108,
A flag indicating that the first ignition has been confirmed is set to "1", and the process proceeds to step 109. Then, the hot water supply gas solenoid valve 11 or the prostitute gas solenoid valve 12 is opened to ignite the hot water supply burner 5 or the reheating burner 6. At the same time, the discharge of the igniter 8 that is no longer needed is stopped, and the process proceeds to step 110.

If the combustion command disappears from the state of main burner combustion, that is, if the tap 14 is closed, the judgment in step 110 is YES, and the process proceeds to step 111, where all gas solenoid valves 10 to 13 are closed. So, step 10
Return to 2.

As described above, from the time the power is turned on until the first ignition is confirmed, a maximum of 30 seconds of discharge is performed for each ignition operation. Then, when the first ignition is confirmed, set the flag to "1"
to complete the ignition combustion test.

From the next time onwards, the process will be as follows. First, when you open the hot water tap 14, the combustion command is "Yes".
The state is reached, the judgment in step 102 becomes YES, and the process advances to step 103.

Here, similarly to the above, the main gas solenoid valve 10 and the pyro,
At the same time as opening the togasumi magnetic valve 13, the igniter 8 starts discharging. Then, the process proceeds to step 104.

Here, the flag indicating that the first ignition has been confirmed is "
1", the judgment is YES and the process proceeds to step 112. Here, ignition is detected, that is, it is determined whether the flame rod 9 is active or not. If ignition is not confirmed, the state continues for 5 seconds (Step 113). If ignition is not confirmed within 5 seconds, proceed to step 114, close the main gas solenoid valve 1o and the pilot gas solenoid valve 13, and at the same time close the igniter 8.
The discharge is stopped and the process returns to step 102.

Also, if it is confirmed that the pilot burner 7 is ignited during the 5 seconds of discharge time, the ST.

If the judgment in block 112 is YES, the above step 109
I'm on my way to.

The above operation is shown in the time chart of FIG. In this example, since ignition was not confirmed during the first ignition operation, the hot water tap 14 was closed again. Then, ignition was confirmed. Up to this point, the discharge time is a maximum of 30 seconds for each ignition operation. After that, if you open the hot water tap 14,
The discharge time is 5 seconds.

In this way, during testing, a maximum discharge time of 30 seconds is ensured for each ignition operation. Therefore, when the tap 14 is opened once, much of the air accumulated in the gas pipe can be discharged during that time, and the first ignition can be confirmed with a small number of ignition operations. Furthermore, after the first ignition, the discharge time changes to a maximum of 5 seconds. Therefore, the same safety as before is ensured for use after the test.

Note that in the above embodiment, the discharge time is set to 30 seconds and 5 seconds, but of course the discharge time is not limited to this. Furthermore, the discharge time during testing can also be made variable.

[Effects of the Invention] As explained above, according to the pilot burner ignition control device of the present invention, during test operation, the pilot burner can be ignited with a small number of ignition operations, and the tap can be opened and closed many times. It is possible to eliminate such troubles. Therefore, testing work becomes much easier. Also,
- Once ignition is detected, the discharge time is switched to the normal short discharge time, so safety against explosive ignition can be maintained as in the conventional case.

[Brief explanation of the drawing]

Fig. 1 is a block diagram corresponding to the claims of the present invention, Fig. 2 is a block diagram corresponding to the claims of the present invention;
Fig. 3 is a block diagram of a control system according to an embodiment of the present invention, Fig. 3 is a flowchart showing the control operation of the embodiment, Fig. 4 is a time chart of the control operation of the embodiment, and Fig. 5 is a diagram of the conventional device. The time chart of the control operation, FIG. 6, is a configuration diagram of a bathtub with a hot water supply function shown as an example of a device equipped with a pilot burner. 5-...Hot water burner, 6...Prostitute burner, 7
．． 31...pyro y), burner, s, 32...
・・・Igniter, 9.33・・Frame rod, 1
0... Main gas solenoid valve, 11... Hot water supply gas solenoid valve, 12... Prostitute gas solenoid valve, 13 Pyro, Togasumi solenoid valve, 14. Hot water tap, 15. Hot water tap,
16.../Yawaa, 18...Water switch, 3
4 Combustion command signal generation means, 35 - Igniter discharge control means, 36... Pilot burner gas supply al1 means, 37...TN'T pre-memory main storage means--
- Initial ignition confirmation signal output means, 39 - Discharge time selection means, 40...control device.

Claims (1)

[Claims] (a) a pilot burner; (b) an igniter that ignites the pilot burner by generating a spark discharge; (c) a flame rod that detects ignition of the pilot burner; (d) combustion. (e) causing the igniter to discharge a spark in response to the combustion command signal, and if the flame rod does not detect ignition, causing the spark to discharge for a preset time T and then stopping the discharge; igniter discharge control means; (f) in response to a combustion command signal, the gas supply valve to the pilot burner is opened, and even though the igniter has finished spark discharge for time T, the flame rod does not detect ignition during that time; is a pilot burner gas supply control means that closes the gas supply valve; (g) the discharge time T of the igniter is a normal value T_
(h) means for outputting an initial ignition confirmation signal when the flame rod detects ignition for the first time after power is turned on; (i) igniter discharge time; As T, a test value T_r is selected until the first ignition confirmation signal is output, and after the first ignition confirmation signal is output, a normal value T_N is selected, and the selected value is supplied to the igniter discharge control means. A pilot burner ignition control device comprising: a discharge time selection means for selecting a discharge time.