JPS61147021A - Combustion device - Google Patents

Abstract

PURPOSE:To provide a device indicating the operation condition even in case of immediate start of re-operation after fire-cut by installing a controller which put out trouble indicating signal when a output signal from flame detector is beyond the specified limit before ignition time after a certain time elasped since operation is started. CONSTITUTION:The required time for cutting off completely flames on the burner is experimentally determined and designated as a specified time ta. After that time elapsed, flame resistance Rf is compared to the resistance RH at trouble time. In case of Rf<RH, the device judges the outbreak of trouble and stops operation after indicating. In case of Rf>=RH, the device judges whether or not thermister temperature T is beyond the pre-heat finished temperature T1 within the time tb. After beyond that time, the device puts in timer 5 at zero point, pump circuit 14 at ON, relay 16 at ON, and igniter 12 at ON. The controlling circuit receives information from flame detector 1 and operates igniter 12 etc. and in case of abnormal condition, stops operation immediately after indication by indicating device 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a combustion device such as a 7 unheater or a hot air heater.

<Prior Art> In conventional combustion devices, a flame detector (flame rod) or the like is generally used to check the ignition and combustion state of a part of a burner that burns fuel. In this flame detector 1, a bar alloy wire is placed on a burner, a voltage is applied between the bar alloy wire and the burner as bipolar poles, and the presence or absence of a flame is detected by the flame current appearing at both poles. In the flame detector with the above configuration, if an abnormality such as a foreign object (such as carbon) is present between the flame detector's bar alloy wire and the burner electrodes before the ignition operation, or if an abnormality such as a wiring short circuit occurs, the flame resistance will decrease. The ignition level would be reached at the same time as the ignition operation, causing problems such as the igniter not discharging when it was determined that ignition was complete, and fuel spouting out without ignition.

Therefore, there is a system that checks the resistance value in advance during preheating of the carburetor or before ignition operation, and when this value is below a set value (failure level), the operation is stopped and a failure message is displayed. . In this way, the problem caused by the fuel spewing mentioned above was solved, and an abnormality in the flame detector could be confirmed in advance.

However, if you try to relight the flame immediately after extinguishing it, there may still be a small amount of flame remaining on the burner, or even if there is no flame, there may be a sufficient flow of electrons between the burner and the bar alloy wire immediately after the flame is extinguished. If so, the flame current between the bar alloy wire and the burner will be above a certain level. That is, it is possible that the flame resistance becomes less than the set value.

FIG. 4 shows an example of a conventional flame detection control state. If the flame resistance is below the failure level RH from the start of operation (when the operation switch is turned ON and preheating starts) to the opening of the ignition operation, it is determined that there is a failure.

Figure 5 shows the relationship between flame resistance and time after extinguishing. When the fire is extinguished, the flame resistance increases rapidly, but it takes t seconds for it to reach this set value, depending on the set resistance value of the failure level. If the re-ignition operation is performed within one second after extinguishing the fire, the flame resistance is less than the set value of the failure level RH, so it is identified as a failure.

If this happens, it may be determined that there is a failure even if it is not a failure, and a failure indication will be displayed, possibly causing an unnecessary service request.

<Purpose> In view of the above, an object of the present invention is to provide a combustion device that can display a normal operation display even when restarted immediately after extinguishing a fire.

<Examples> Examples of the present invention will be described below based on the drawings. 1.
The combustion apparatus according to the present invention includes a flame detector 1 for detecting combustion flame.
and a control device 3 that outputs a display signal as a display wave e2 based on the output of the flame detector 1, and the control device 3 detects the flame after a certain period of time has elapsed from the start of operation and before the ignition operation. The detector 1 is configured to output a failure indication signal when the output signal of the detector 1 is outside the set range.

As shown in FIG. 2, the control device 3 compares and processes the output signal (flame resistance Rf) of the flame detector 1 and the failure level resistance RH, and determines whether the flame resistance Rf is smaller than the failure level resistance RH. It consists of a control circuit 4 that sometimes outputs a signal to the display device 2, and a timer 5 controlled by a clock signal from the control circuit 4. The control circuit 4 consists of a general chip microcomputer, and the power supply circuit 3A
It also has input terminals for inputting signals from a room temperature setting device 6, a room temperature thermistor 7, an xizer thermistor 8, and an operation switch 9.

Furthermore, the control circuit 4 has a drive circuit 13 that drives the pump 10, the carburetor heater 11, and the igniter 12, and an output terminal that outputs a signal to the display device 2. In addition, in Fig. 2, 14 is a pump circuit, 15 is a heater circuit, and 16 is a pump circuit.
is the igniter drive relay.

Further, the flame detector 1 is made up of, for example, a burner, a bar alloy wire disposed on the bar at regular intervals, and an electric circuit with the bar alloy wire as a positive electrode and the burner as a negative pole,
It is configured to detect a current (flame current) appearing between both poles by applying a voltage to both poles, and output this to the control circuit 4 as a digital signal.

Further, the display device 2 is composed of display lamps and the like that indicate operation, stop, and failure.

Next, based on the time chart of FIG. 1 and the 70-chart of FIG. 3, the control operation based on the output signal of the flame detector 1 will be explained mainly when the re-ignition operation is performed immediately after extinguishing the fire. First, when the operation switch 9 is turned on, the operation lamp of the display device 2 lights up and the timer 5 starts counting.

Next, the thermistor temperature T and the upper limit temperature TH of the preheating completion temperature are compared, and if T>TH, it is determined that there is a failure, the display is displayed, and the operation is stopped. If T≦TH, the heater circuit is turned on and energization of the heater 11 is started.

Next, a preset time ta, that is, the time for the flame on the burner to completely disappear, is determined as an experimental value, and this is determined as a fixed time t.
a, and after that time the flame resistance Rf and failure level RH
Compare with. At this time, if Rf<RH, it is determined that there is a failure, a display is made, and the operation is stopped. If Rf≧R)I, then it is determined whether the thermistor temperature T exceeds the preheating completion temperature T1 within the time tb, and if the thermistor temperature T exceeds that time, the pump circuit 14 is turned on after setting the timer 5 to zero. After turning the ON state and operating the pump 10, the relay 16 is set to ONa.
the igniter 12. Then, when the flame resistance Rf becomes below the ignition level R1 and reaches the ignition range, the relay 16 is turned off, the igniter 12 is stopped, and combustion is continued while monitoring the thermistor temperature T and flame resistance Rf. >If the state reaches R2, it will be displayed immediately and the operation will be stopped. In this way, the control circuit 4 receives information from the detector 1 and operates the igniter 12 etc. according to the respective state, and if an abnormality occurs, it is immediately displayed on the display device 2 and the operation is stopped. It has become.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

<Effects> As is clear from the above description, the present invention includes a flame detector that detects a combustion flame, and a control device that outputs a display signal to a display device based on the output of the flame detector. The apparatus relates to a combustion apparatus, characterized in that the apparatus is configured to output a failure indication signal when the output signal of the flame detector is outside a set range after a certain period of time has elapsed from the start of operation and before ignition operation. It is.

Therefore, according to the present invention, since failure indications are not identified for a certain period of time after the start of operation, in other words, even if the flame is re-ignited immediately after being extinguished, flame detection is performed with the flame on the burner completely extinguished, so that the normal state is detected. This has the excellent effect of preventing failure indications from occurring.

[Brief explanation of drawings]

FIG. 1 is a control time chart of a combustion device showing one embodiment of the present invention, FIG. 2 is a block diagram of the control device, and FIG.
4 is a conventional control time chart, and FIG. 5 is a diagram showing the relationship between flame resistance and time after extinguishing. 1: Flame detector, 2: Display device, 3: Control device, 4: Control circuit, 5: Timer, 6: Room temperature setting device, 7: Room temperature thermistor, 8: Vaporizer thermistor, 9: Operation switch, 10
: pump, 11: vaporizer heater, 12: igniter.

Claims (1)

[Claims] A flame detector that detects a combustion flame, and a control device that outputs a display signal to a display device based on the output of the flame detector,
The combustion device is characterized in that the control device is configured to output a failure indication signal when the output signal of the flame detector is outside a set range after a certain period of time has elapsed since the start of operation and before the ignition operation. .