JP2549581B2 - Combustion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a combustion apparatus in which combustion control is performed using a fuel flow rate sensor.

[Conventional technology]

Some combustion devices are provided with a fuel flow rate sensor for detecting the flow rate of fuel such as gas, and control the supply of fuel based on the detected value to perform combustion control.

Further, the gas appliances for general household use have a structure in which the cock is fully opened at the time of ignition and the fuel flow rate is maximized (100%) to perform ignition.

[Problems to be Solved by the Invention]

When the combustion control is performed based on the detection value of the fuel flow rate sensor, the measurement accuracy of the fuel flow rate sensor becomes a problem. If the accuracy is poor, the control will not be performed smoothly and a safety problem will occur.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a fuel device that performs a span check to improve the measurement accuracy of a fuel flow sensor.

[Means for solving the problem]

The correction means of the combustion apparatus according to the present invention compares the fuel flow rate detection value detected by the fuel flow rate sensor at the time of ignition with the stored fuel flow rate value, and maximizes the detection value of the fuel flow rate sensor according to the comparison result. The correction is performed by replacing with the fuel flow rate value.

[Action]

Every time ignition is performed, the span check of the fuel flow rate sensor is performed, and the detected value at the time of ignition is corrected to the constant fuel flow rate required at the time of ignition.

〔Example〕

An embodiment in which the present invention is applied to a combustion control device that keeps safety when a person leaves the combustion device will be described with reference to the drawings.

In FIG. 1, reference numeral 1 is a fuel device for cooking provided on the upper surface of the range 2 and has two combustors 1a and 1b. Reference numeral 3 is a pipe for supplying combustion, for example, gas to the combustion appliance 1, 4 is a shutoff valve provided in the middle of the pipe 3, 5 is a fuel flow rate sensor such as a microflow sensor for detecting the flow rate of fuel flowing through the pipe 3, 6,
7 is an ignition valve for the combustors 1a, 1b, 8 and 9 are operation detection switches for the ignition valves 6 and 7, 10 is a selection switch for selecting the type of cooking, 11 is a ventilation hood disposed above the combustion appliance 1. A ventilation fan (not shown) is provided in the ventilation hood 11.

Reference numeral 12 is a human body detection sensor provided in the ventilation fan 11 so as to detect the presence or absence of the human body 13 during cooking. As the human body detection sensor 12, for example, a spatial filter using a polyhedral mirror, a pyroelectric human body detection sensor in combination with a pyroelectric infrared sensor that detects a wavelength in the infrared region, or the like is used. A flame size sensor 15 detects the size of the fire in the combustors 1a and 1b.

Reference numeral 14 denotes a controller. The controller 14 has a start signal from the ignition valves 6 and 7, a fuel flow rate detected by the fuel flow rate sensor 5, a cooking signal selected by the selection switch 10, a human body detection sensor 12 and a flame size sensor 15. Output signals are respectively supplied. In addition, the controller 14 allows the human body 13 to move away from the combustion appliance 1 based on the flow rate of fuel supplied to the combustion appliance 1 and the type of cooking, and the value of a constant fuel flow rate required for ignition. In addition, a memory (not shown) for storing necessary data in advance and a timer (not shown) which is activated by receiving an output signal of no human body from the human body detection sensor when the combustion instrument 1 is used are provided.

Figure 2 shows the above allowable time (h) and fuel flow rate Q (/ h)
The curve A shows the case of cooking which is dangerous if there is no person who uses oil like tempura, and when the person leaves the place of the burning appliance 1 and time t ₁ elapses, A shutoff signal for closing the shutoff valve 4 is output from the controller 14. Further, the curve B shows the case of other cooking such as cooking because it is oily, and since the degree of danger is lower than the above case, the allowance from when the person leaves the place of the burner 1 until the cutoff signal is output is shown. When the time is long and time t ₂ has passed, the controller 14 outputs a cutoff signal.

Next, the operation of the above embodiment will be described with reference to the flow chart shown in FIG. First, when the combustors 1a, 1b are ignited, the ignition valves 6, 7 are fully opened, and the output signal of the human body detection switch 12, the cooking signal selected by the selection switch 10, the ignition valve
Input the detection signals of the operation detection switches 8 and 9 of 6,7, measure the fuel flow rate flowing at this time with the fuel flow rate sensor 5, and compare it with the stored rated value of each combustor 1a, 1b. Check and correct the span (steps ST3-1 to ST3-
5).

When the combustor 1a or 1b is being used and the human body 13 moves away from the combustion device 1, the human body detection switch
An output signal without human body is input to the controller 14 from 12.

Based on the fuel flow rate detected by the fuel flow rate sensor 5 and the type of cooking selected by the selection switch 10, the controller 14 obtains from the memory the permissible time period during which the human body 13 is allowed to move away from the combustion appliance 1. At the same time, the presence / absence of the human body 13 is determined (step ST3-6). If yes, this determination is repeated, and if not, the timer is started (step ST3-7). Then, after the timer is started, it is determined whether or not the above allowable time has elapsed (step ST3−
8) In case of YES, shut off the shutoff valve 4 and combustor 1a or 1b
To stop fuel supply to extinguish fire (step ST3−
9).

On the other hand, if the determination in step ST3-8 is NO, the presence or absence of the human body 13 at the combustion appliance 1 is determined (step ST3
-10), if yes, return to step ST3-6 to perform the above operation. If none, the output signal X indicating the size of the flame such as a frying pan from the flame size sensor 15 is input (step ST3-11), and the memory (not shown) is stored in advance.
It is determined whether X> X ₀ by comparing with the reference value X ₀ stored in (STEP ST3-12). If NO, the process returns to ST3-10 to perform the above operation. In the case of YES, the fuel supply is shut off (step ST3-13), the ventilation fan is set to maximum rotation (step ST3-14), and a warning is displayed (step ST3-15).

In step ST3-4, when the fuel flow rate signal is input from the fuel flow rate sensor 5, the combustor 1a or
Based on whether 1b is used or not, it is judged whether there is a fuel leak (step ST3-16), and if NO, step ST3-4
Return to and repeat the above operation. If YES, the fuel supply is cut off (step ST3-17), the ventilation fan is set to maximum rotation (step ST3-18), and the fuel leak warning display is performed (step ST3-19).

In step ST3-4, the required air volume of the ventilation fan is calculated based on the fuel flow rate input from the fuel flow rate sensor 5 (step ST3-20), and the rotation speed of the ventilation fan is changed according to the calculation result. (Step ST3
-21).

Next, span cooking (span check) in step ST3-5 will be described.

The span check is performed every time the combustor 1a or 1b is ignited in order to improve the measurement accuracy of the fuel flow rate sensor 5. As mentioned above, the combustors 1a and 1b are 100% when ignited.
Is required to be stored in the memory of the controller 14 in advance as a constant fuel flow rate.

FIG. 4 shows a flowchart for performing a span check using the above-mentioned constant fuel flow rate. First, in step ST4-1, the number of ignited combustors is checked, and it is determined in step ST4-2 whether or not the number of combustors is one. For example, when the combustor 1a is ignited, the start signal is sent from the operation detection switch 8 to the controller 14. When only one combustor 1a is ignited, the process proceeds to step ST4-3, where the value of the constant fuel flow rate required at the time of ignition of the combustor 1a is read out, and this value and the fuel flow rate sensor 5 are read. The detected values of the actual flow rate indicated by the fuel flow rate signal from are compared. Then, a correction coefficient is obtained according to the difference between the two, and the detected value is corrected so as to match the value of the constant fuel flow rate. After that, the detection value is corrected by the correction coefficient until ignition is performed again and the correction is performed. In addition, step
When both combustors 1a and 1b are ignited in ST4-2, or when it is determined that none of them are ignited, the span check is not performed and the process is completed.

According to the above, in the case of a normal household, the combustor 1a, 1
Although there is a time when two b's are not used, after that, the span check is performed by using the first ignited combustor 1a or 1b, so that the span check can be performed several times a day.

The correction coefficient may be temperature-corrected according to the ambient temperature. In addition to the start signal of the combustor 1a or 1b, a digital signal indicating the constant fuel flow rate or an analog signal as a voltage drop due to a change in fixed resistance due to the operation of the ignition valves 6 and 7 may be sent to the controller 14.

〔The invention's effect〕

According to the present invention, the fuel flow rate detected by the fuel flow rate sensor at the time of ignition is compared with the constant fuel flow rate required at the time of ignition, which is stored in advance, and the fuel flow rate sensor is corrected according to the comparison result. Therefore, the flow rate becomes constant at the time of ignition, and span check and span correction can be performed accurately. Further, at the time of ignition, the maximum fuel flow rate of 100% is supplied, and at this time, the ignition valve is in the fully open state, and it is difficult to receive a slight fluctuation in the current that controls this ignition valve.
Therefore, a constant flow rate is obtained, the flow rate detected by the fuel flow rate sensor is stable, and the comparison with the stored maximum fuel flow rate value can be performed accurately. As a result, it is possible to obtain the effect that the span correction amount can be obtained with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a combustion control device to which a combustion device according to an embodiment of the present invention is applied, FIG. 2 is a characteristic diagram of permissible time versus fuel flow rate according to the type of cooking, and FIG. FIG. 4 is a flowchart for performing span check. 1a and 1b are combustors, 5 is a fuel flow sensor, 6 and 7 are ignition valves, 8 and
9 is a motion detection switch, 14 is a controller.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasuji Morita 1-12-2 Kawana, Fujisawa-shi, Kanagawa Yamatake Honeywell Co., Ltd. Fujisawa factory (72) Inventor Go Watanabe 1-12-2 Kawana, Fujisawa, Kanagawa No. Takeshi Yamawell, Fujisawa Co., Ltd. (56) References JP-A-62-138622 (JP, A)

Claims (1)

(57) [Claims] 1. A combustor that requires a maximum fuel flow rate at ignition, a storage unit that stores the maximum fuel flow rate value, and a fuel flow rate sensor that detects a fuel flow rate supplied to the combustor.
In a combustion device including a correction unit that performs span correction of the fuel flow rate sensor based on a detection value from the fuel flow rate sensor, the correction unit detects the fuel flow rate detected by the fuel flow rate sensor at the time of ignition. A combustion device, wherein a value is compared with the stored maximum fuel flow rate value, and correction is performed to replace the detected value with the maximum fuel flow rate value according to the comparison result.