JP3857816B2 - Combustion equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion device that vaporizes and burns liquid fuel, such as a fan heater, a hot oil heater, or a heat source of a hot water heater.
[0002]
[Prior art]
This kind of combustion equipment, when used in a dilute (low oxygen concentration) environment such as high altitudes, the predetermined combustion air necessary for combustion cannot be taken into the burner, it becomes red fire combustion due to collapse of the air-fuel ratio, Soot and harmful components may be generated.
[0003]
Therefore, in high-altitude combustion equipment, the amount of liquid fuel supplied to the burner is reduced from its normal value, and the fuel efficiency is corrected so that an optimal air-fuel ratio can be secured in accordance with the amount of air supplied. It has been broken. FIG. 5 shows an example of conventional processing related to the operation frequency control of the electromagnetic pump that controls the supply of liquid fuel. The operation frequency calculation processing based on the rotational speed of the burner motor shown in the drawing, the center frequency adjustment processing, The high altitude correction process such as the frequency correction process according to the air temperature corresponds to this.
[0004]
Conventionally, the high altitude correction is automatically corrected by a microcomputer (hereinafter referred to as a microcomputer) or manually switched between normal use and high altitude use by a switch (or jumper switching) provided on a control board. Etc.
[0005]
The automatic correction is a method of setting the combustion to the larger flame current in the combustion at the rated time (normal use) and the combustion when the fuel supply amount is decreased by −10%, and the manual correction is the high altitude. This is a method of fixing the fuel supply amount to -10% reduction during use.
[0006]
[Problems to be solved by the invention]
However, in the automatic correction, combustion at the rated value is always performed at the start of combustion, so there is a high possibility of red fire combustion. Moreover, since the air-fuel ratio correction width is as large as 10%, it takes time to control the combustion width by the microcomputer, and during this time, there is a problem that the red fire combustion changes to extinguishment. In addition, if there is variation in the combustion state of the equipment, it cannot be corrected and stable combustion cannot be obtained.
[0007]
In manual correction, since the operator performs correction operation while observing the flame state, the combustion state varies depending on the operator's feeling, and the correction range of the air-fuel ratio is too large as in the case of the automatic correction. For this reason, there is a problem that it is difficult to obtain suitable combustion.
[0008]
The present invention has been made in view of the above problems, and provides a combustion device capable of obtaining stable combustion even when used at high altitudes.
[0009]
[Means for Solving the Problems]
That is, the present invention according to claim 1 includes a burner, a frame rod that detects the flame of the burner, an electromagnetic pump that supplies liquid fuel to the burner, and a control device that controls the operation of the electromagnetic pump. Further, the control device includes a manual switching means for manually switching the operation frequency of the electromagnetic pump in several stages , a reference frame current value at the operation frequency set by the manual switching means, and a predetermined amount of the operation frequency. The corrected frame current value at the operating frequency increased and decreased by a predetermined amount is saved in the memory area, and the saved frame current values are compared, and the corrected frame current value exceeds the reference frame current value by a certain amount or more. When the operation frequency of the electromagnetic pump is a corrected frequency, and the corrected frame current value is equal to or less than the reference frame current value, Which is configured by providing the automatic correction means for the frequency before correcting the operating frequency of the electromagnetic pump.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a schematic configuration of a burner portion of a heat source unit of a hot water heater to which the present invention is applied, FIG. 2 is a block diagram showing a schematic configuration of a control device of the heat source unit, and FIGS. It is a flowchart which shows operation | movement of a control apparatus.
[0012]
As shown in FIG. 1, the combustion device 1 according to the present invention has a vaporizer 2 as a burner body, and a preheater heater 3 is attached around the vaporizer 2. A burner head 5 is placed on the upper part of the vaporizer 2, and an ignition plug 7 for ignition and a flame rod 6 for flame detection are arranged above the burner head 5. Further, a burner blower 9 for supplying combustion air to the vaporizer 2 is attached to the vaporizer 2, and a fuel tank 12 is connected via an oil feed pipe 10 having an electromagnetic pump 8 disposed therebetween. Further, reference numeral 4 in FIG. 1 denotes burner sensors 4 and 11 for detecting the temperature of the vaporizer 2, and reference numeral 11 denotes a hot water temperature sensor 11 for detecting a hot water temperature in a hot water circulation path (not shown).
[0013]
By the way, the control apparatus 13 for the combustion control shown in FIG. In FIG. 2, 14 is a microcomputer that collectively controls the combustion control. The microcomputer 14 is mounted on the board of the control device 13 in addition to the burner sensor 4, the hot water temperature sensor 11, the frame rod 6, the electromagnetic pump 8, the burner blower 9, the spark plug 7, and the preheater heater 3. Are connected to a later-described high altitude correction switch 17 and operation frequency adjustment volumes 18 and 19, a temperature setting unit 15 on a not-shown operation panel (remote control panel), a display 16 and the like.
[0014]
Next, the general operation of the control device 13 will be described. At the start of operation, the microcomputer 14 turns on the preheating heater 3 to preheat the vaporizer 2. The microcomputer 14 monitors the temperature rise of the vaporizer 2 by the preheating heater 3 from the detection output of the burner sensor 4 (for example, the thermistor element). When the temperature of the carburetor 2 reaches the combustion start temperature, the burner blower 9 is driven to execute pre-purge. After the pre-purge is completed, the electromagnetic pump 8 and the spark plug 7 are operated to start the burner combustion operation. That is, when the electromagnetic pump 8 is operated, the liquid fuel (kerosene) in the fuel tank 12 is ejected into the carburetor 2 through the oil feeding pipe 10 and is vaporized by preheating of the carburetor 2. The vaporized gas is mixed with the combustion air supplied from the burner blower 9 to become a mixed gas, and is ejected from the burner head 5. The jetted mixed gas is ignited by the discharge spark of the spark plug 7, and the combustion operation is started. The microcomputer 14 compares the detected temperature of the hot water temperature sensor 11 with the set temperature from the temperature setter 15 even after ignition, and determines the oil feed amount of the electromagnetic pump 8 and the blower fan 9 according to the temperature difference. The amount of combustion is controlled to adjust, and the hot water temperature is always maintained at the set temperature.
[0015]
The control device 13 also includes means for automatically correcting the air-fuel ratio by controlling the operating frequency of the electromagnetic pump 8 when the device is used in a lean environment such as highland.
[0016]
The operation of the automatic correction means will be described below with reference to FIGS. 3 and 4. The high altitude automatic correction process in FIG. 3 corresponds to this. This process is obtained by adding the above-described automatic high altitude correction process to the conventional process shown in FIG. However, in the present embodiment, the correction range of the air-fuel ratio in high altitude correction (that is, the variable width of the operating frequency Fp of the electromagnetic pump 8) can be manually switched more finely than in the past.
[0017]
That is, in this embodiment, the high altitude correction switch 17 shown in FIG. 2 is used as the manual switching means for the operating frequency Fp. The high altitude correction switch 17 is a four-stage switching slide switch, for example, 500 m (−5% correction), 1000 m (−10% correction), 1500 m (− The correction value can be set with a correction width of 15% correction.
[0018]
When using the high altitude, first, a rough altitude is selected and set by the high altitude correction switch 17, and then the correction value is finely adjusted based on the set value by the following high altitude automatic correction processing. That is, during the combustion operation period, the microcomputer 14 determines the combustion state from the current value (frame current value FL) of the frame rod 6, in other words, the excess or deficiency of the fuel supply amount by the electromagnetic pump 8, and operates the electromagnetic pump 8. Adjust the frequency.
[0019]
FIG. 4 shows an embodiment of the high altitude automatic correction process. However, when the standard ground (500 m or less) is set, the high altitude automatic correction is not performed.
[0020]
According to FIG. 4, the microcomputer 14 performs an operation frequency corresponding to a rough correction value selected and set in advance by the high altitude correction switch 17 for example, 1000 m (−10% correction) for 5 minutes after the ignition is detected. Combustion is continued at Fp. During this time, the flame current is detected, and the average value is saved as a reference flame current value FLzr in a predetermined memory area (not shown) (process (1) in FIG. 4).
[0021]
Next, the operation frequency of the electromagnetic pump 8 is lowered by 5% from the initial frequency Fp, combustion is continued at this air-fuel ratio for 5 seconds, and the average value of the frame current detected during this period is stored in the memory as the corrected frame current value FLdw. Evacuate (Process (2)).
[0022]
Next, the operating frequency is increased by 5% from the initial frequency Fp, and the corrected frame current value FLup is obtained and saved in the memory in the same procedure as the above process (2) (process (3)).
[0023]
Next, the reference frame current value FLzr obtained in the process (1) and the corrected frame current values FLdw and FLup obtained in the processes (2) and (3) are individually compared, and the following procedure ( An optimum automatic correction value is determined based on a), (b), and (c) (Process (4)).
(A) When FLdw <FLzr × 1.2 and FLup <FLzr × 1.2, that is, when improvement in combustion is not seen even when the operating frequency Fp is changed by ± 5%, the automatic correction value is set to 0 To do.
(B) When FLdw ≧ FLup, that is, when combustion is improved when the operating frequency Fp is lowered by 5%, the automatic correction value is set to −5%.
(C) When FLdw <FLup, that is, when combustion is improved when the operating frequency Fp is increased by 5%, the automatic correction value is set to + 5%.
[0024]
As described above, according to the present embodiment, when the high altitude correction is performed, first, a rough air-fuel ratio corresponding to the installation altitude of the device is set manually, and thereafter, the air-fuel ratio depends on the combustion state. Therefore, it is possible to obtain fine combustion that conforms to the conditions of use by absorbing variations in the combustion state of the equipment. Further, since the fine adjustment width is small and the time required for the combustion control is short, the red fire / extinguishing phenomenon during fuel efficiency correction as in the conventional control can be prevented.
[0025]
【The invention's effect】
As described above, according to the first aspect of the present invention, the manual switching means for manually switching the operation frequency of the electromagnetic pump in several stages, and the operation frequency set by the manual switching means are adjusted by a predetermined amount. When the corrected frame current value exceeds the reference frame current value by a certain amount or more, the operation frequency of the electromagnetic pump is set as a corrected frequency, and the corrected frame current value is compared with the corrected frame current value. When the current value is less than or equal to the reference frame current value , high altitude correction is performed with automatic correction means that sets the operation frequency of the electromagnetic pump to the frequency before correction, so that finer and finer qualification in a shorter time than conventional control. Correction can be performed, and more suitable combustion can be obtained in accordance with the actual situation by absorbing the variation of the equipment.
In addition, the automatic correction is performed when a certain improvement effect occurs (for example, in the above-described embodiment, the correction is effective only when the frame current value is increased by 20% or more). The fuel consumption fluctuation is suppressed, and stable and suitable combustion can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a heat source machine to which the present invention is applied.
FIG. 2 is a block diagram showing a schematic configuration of a control device for a heat source machine.
FIG. 3 is a flowchart showing the operation of the control device.
FIG. 4 is a flowchart different from FIG. 3 showing the operation of the control device.
FIG. 5 is a flowchart showing the operation of a conventional control device.
[Explanation of symbols]
2 Burner (vaporizer)
6 Frame rod 8 Electromagnetic pump 13 Control device 17 Manual switching means (high altitude correction switch)
Fp Electromagnetic pump operating frequency FLzr Reference frame current value FLdw, FLup Corrected frame current value

Claims (3)

A burner, a flame rod that detects the flame of the burner, an electromagnetic pump that supplies liquid fuel to the burner, and a control device that controls the operation of the electromagnetic pump;
Further, the control device includes a manual switching means for manually switching the operation frequency of the electromagnetic pump in several stages , a reference frame current value at the operation frequency set by the manual switching means, and an increase in the operation frequency by a predetermined amount. In addition, the corrected frame current value at the operation frequency reduced by a predetermined amount is saved in the memory area, and the saved frame current values are compared, and the corrected frame current value exceeds the reference frame current value by a certain amount or more. Automatic correction means for setting the operation frequency of the electromagnetic pump to a frequency after correction and setting the operation frequency of the electromagnetic pump to a frequency before correction when the correction frame current value is equal to or less than the reference frame current value. Combustion equipment characterized by comprising. A burner, a flame rod that detects the flame of the burner, an electromagnetic pump that supplies liquid fuel to the burner, and a control device that controls the operation of the electromagnetic pump;
Further, the control device includes a manual switching means for manually switching the operation frequency of the electromagnetic pump in several stages, a reference frame current value at the operation frequency set by the manual switching means, and a predetermined amount of the operation frequency. When the corrected frame current value exceeds the reference frame current value, the operation frequency of the electromagnetic pump is set as a corrected frequency, and the corrected frame current value is Combustion equipment comprising an automatic correction means for setting the operation frequency of the electromagnetic pump to a frequency before correction when the current is less than the reference frame current value. A burner, a flame rod that detects the flame of the burner, an electromagnetic pump that supplies liquid fuel to the burner, and a control device that controls the operation of the electromagnetic pump;
Further, the control device includes a manual switching means for manually switching the operation frequency of the electromagnetic pump in several stages, a reference frame current value at the operation frequency set by the manual switching means, and a predetermined amount of the operation frequency. When the corrected frame current value exceeds the reference frame current value by a certain amount or more, the operation frequency of the electromagnetic pump is set as a corrected frequency, and the corrected frame current value is compared with the corrected frame current value. Combustion equipment comprising automatic correction means for setting the operation frequency of the electromagnetic pump to a frequency before correction when the current value is equal to or less than the reference frame current value.

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