US20080118877A1

US20080118877A1 - System and Control Method of Oil Burner's Suitable Burning Ratio Using Air Pressure Sensor

Info

Publication number: US20080118877A1
Application number: US11/795,911
Authority: US
Inventors: Tae-Sik Min
Original assignee: Kyungdong Network Co Ltd
Current assignee: Kyungdong Network Co Ltd
Priority date: 2005-01-28
Filing date: 2006-01-11
Publication date: 2008-05-22
Also published as: EP1846696A4; JP2008528925A; KR20060087071A; CN101115955A; WO2006095960A1; EP1846696A1

Abstract

Disclosed are a system and a method for precisely controlling an air fuel ratio of an oil burner, which is extensively used in a household boiler, an industrial boiler, or a heater, using an air pressure sensor. The system includes a power supplying part, a fan for supplying air required for combustion of the oil burner by receiving driving voltage from the power supplying part, a fan driving part serving as a controller which drives the fan, an air pressure sensor, which is installed at a side of a flow path of air supplied from the fan so as to detect an amount of the supplied air, and a control part for outputting an optimum RPM of the fan to the fan driving part by comparing a signal detected by the air pressure sensor with preset data related to an optimum amount of air. The method includes the steps of detecting an amount of air being supplied through a fan using the air pressure sensor, calculating an optimum RPM of the fan using a controller by comparing a signal about the amount of the air with preset data related to an optimum amount of air, outputting the RPM calculated by means of the controller to a fan driving part, and rotating the fan according to the calculated RPM input into the fan driving part.

Description

TECHNICAL FIELD

The present invention relates to a system for controlling an air fuel ratio of an oil burner and a method thereof, and more particularly to a system and a method for precisely controlling an air fuel ratio of an oil burner, which is extensively used in a household boiler, an industrial boiler, or a heater, using an air pressure sensor.

BACKGROUND ART

In general, boilers used for heating rooms or halls are classified into an oil boiler, a gas boiler, and an electric boiler according to kinds of fuel supplied to the boilers. The boilers have been variously developed and used corresponding to a size of a room or a hall or their installation purpose. An oil boiler from among such boilers and a heater using oil as fuel thereof include an oil burner.
In particular, it is very important for the oil burner to precisely control an air fuel ratio. Recently, the control of the air fuel ratio in the oil burner becomes the most important issue.
Hereinafter, detailed description about the conventional oil burner will be given with reference to FIG. 1.
The oil burner 2 includes a blower 4 for supplying air to the oil burner 2, an oil pump 6 for supplying oil to the oil burner 2 by pumping the oil from an oil tank, a nozzle (not shown) for spraying the oil in a droplet state such that the oil can be burned, a flame holder (not shown) for enabling the air to be mixed and burned together with the oil, an ignition transformer 8 and a spark plug 10 performing discharge ignition with respect to a mixer for mixing oil and air, and a flame detection unit 12 for detecting flames.
Since oil burners having the above structure represent different air load resistances according to kinds or sizes of heat-exchange media (a heat exchanger in a case of a boiler, or an air tube in a case of a tube heater) even though the oil burners have the same output (or the same fuel consumption), the oil burners must be equipped with a damper 14, which is an air regulator, at an air feeding port in order to supply an optimum amount of air required for a combustion process. In general, such a damper 14 is regulated when it is manufactured or installed, and it is difficult to actually control an air fuel ratio because the damper 14 is manually regulated.
Hereinafter, a method for regulating an amount of air of the conventional oil burner will be described with reference to FIGS. 1 and 2.
As shown in FIG. 2, on the assumption that load of the heat exchanger becomes L1 when an optimum amount of air required for combustion of a burner is Q1, the damper 14 installed at the air feeding port 16 of the blower 4 is suitably controlled so as to supply the amount (Q1) of air. On the assumption that load of the heat exchanger is L2 when the same burner is employed in another heat exchanger, if the damper 14 is not controlled, an amount of air becomes Q2, so that an amount of air greater than the optimum amount of air is supplied, thereby causing an abnormal combustion state. Accordingly, in this case, the damper 14 must be controlled in such a manner that the amount (Q1) of air can be supplied. However, the conventional oil burner has the following problems.
First, after installing the oil burner, resistance of an internal flow path of the heat exchanger may be changed due to soot generated when the oil burner is turned on/off.
Second, the resistance of a blower may be changed according to the length of an exhaust funnel if the damper is regulated in a manufacturing process.
Third, the resistance of the blower may frequently be changed due to a wind even if the same exhaust funnel is employed.
As a result, it frequently happens that an amount of air supplied to the oil burner deviates from an optimum amount of air required for combustion of the oil burner, so that the combustion of the oil burner becomes unstable.

DISCLOSURE OF INVENTION

Technical Problem

Therefore, the present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a system and a method for controlling an air fuel ratio of an oil burner using an air pressure sensor (APS), which can control an RPM of a fan by detecting an amount of air using the air pressure sensor (APS) and then comparing the detected air with data about an optimum amount of air.

Technical Solution

To accomplish the above object, there is provided a system for controlling an optimum air fuel ratio of an oil burner using an air pressure sensor, the system including a power supplying part, a fan for supplying air required for combustion of the oil burner by receiving driving voltage from the power supplying part, a fan driving part serving as a controller which drives the fan, an air pressure sensor, which is installed at a side of a flow path of air supplied from the fan so as to detect an amount of the supplied air, and a control part for outputting an optimum RPM of the fan to the fan driving part by comparing a signal detected by the air pressure sensor with preset data related to about an optimum amount of air.
In addition, the control part includes a PID controller, which maintains an optimum air fuel ratio by changing proportionally an RPM of the fan.
Furthermore, the oil burner is selectively employed for a household boiler, an industrial boiler, or a heater.
According to an aspect of the present invention, there is provided a method for controlling an air fuel ratio of an oil burner using an air pressure sensor, the method including the steps of detecting an amount of air being supplied through a fan using the air pressure sensor, calculating an optimum RPM of the fan using a controller by comparing a signal about the amount of the air with preset data related to an optimum amount of air, outputting the RPM calculated by means of the controller to a fan driving part, and rotating the fan according to the calculated RPM input into the fan driving part.
In addition, steps from the air amount detection step to the fan driving step are achieved through a closed loop scheme such that an optimum amount of air is supplied to the oil burner even though external disturbance exists.

ADVANTAGEOUS EFFECTS

As described above, although a control system according to the present invention may be subject to external disturbance after the control system has been installed or during the control system is being used, since a fan is proportionally rotated based on a detection signal of an air pressure sensor, it is possible to supply an amount of air suitable for the oil burner.
Accordingly, it is possible to stably control an air fuel ratio of the oil burner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating a structure of the conventional oil burner;

FIG. 2 is a graph for explaining a method for regulating an amount of air using a damper in the conventional oil burner;

FIG. 3 is a block diagram illustrating a structure of a system for controlling an air fuel ratio by an air pressure sensor according to the present invention;

FIG. 4 is a block diagram illustrating a procedure for controlling an optimum air fuel ratio of an oil burner according to the present invention; and

FIG. 5 is a view illustrating a method for regulating an amount of air by changing an RPM of a fan installed in the oil burner according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention.
FIG. 3 is a block diagram illustrating a structure of a system for controlling an air fuel ratio by an air pressure sensor according to the present invention, FIG. 4 is a view illustrating a procedure for controlling an air fuel ratio of an oil burner according to the present invention, and FIG. 5 is a view illustrating a method for regulating an amount of air by changing an RPM of a fan installed in the oil burner according to the present invention.
Referring to FIG. 3, the system according to the present invention includes a power supplying part 100, which receives electric power, converts the electric power into pre-determined driving voltage, and supplies the driving voltage to the system, a fan 150, which operates as a blower for receiving basic driving power from the power supplying part 100 and then supplying air required for the combustion of the oil burner, a fan driving part 140, which operates as a controller for driving the fan 150, an air pressure sensor 120, which is installed at an air feeding port of the fan 150 so as to detect an amount of the air being supplied, a control part 110, which receives the driving power through the power supplying part 100 and an electrical signal from of the air pressure sensor 120 so as to calculate an optimum RMP of the fan 150 by comparing the electric signal of the air pressure sensor 120 with data related to an optimum amount of air, and outputs an electric signal thereof to the fan driving part 140, and a memory 130, which stores information about all control operations of the control part 110.
The control part 110 proportionally changes the RPM of the fan 150 in such a manner that an optimum amount of air can be maintained and includes a PID controller capable of performing a proportional control.
The fan driving part 140 operates as an RPM controller for directly driving the fan 150 by receiving an output signal (the RPM of the fan 150) of the control part 110.
Herein, the air pressure sensor 120 is not limited to one product, but can be selected from among sensors capable of detecting an amount of air.
It can be understood from FIG. 4 that the control procedure according to the present invention is achieved in a closed loop.
The air pressure sensor 120 detects an amount of air, which is continuously supplied, and applies a corresponding electric signal to the control part 110 including the PID controller.
Then, the control part 110 receives the electrical signal of the air pressure sensor 120, compares the electrical signal with preset data related to an optimum amount of air, and calculates an optimum RPM of the fan 150. If the control part 110 outputs the calculated RPM to the fan driving part 140, the fan driving part 140 drives the fan 150.
Such a control procedure may be repeated due to the characteristic of the closed loop, so it is possible to stably perform the proportional control.
Accordingly, although the proportional control system may be subject to external disturbance after the control system has been installed or during the control system is being used, since the proportional control system supplies a desired amount of air, it is possible to stably maintain the combustion process.
Referring to FIG. 5, if an amount of air supplied to the oil burner is changed due to the change of a load curve of the fan derived from the change of a type of a heat exchanger, the load, the exhaust funnel, and the influence of wind, the air pressure sensor may detect the change of the amount of the air supplied to the oil burner, and the control part, which is a controller of the oil burner, may change an RPM of the fan based on a signal detected by the air pressure sensor so that it is possible to always maintain an optimum amount of air.
While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment and the drawings, but, on the contrary, it is intended to cover various modifications and variations within the spirit and scope of the appended claims.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, an amount of fuel is regulated according to an amount of air supplied to an oil burner extensively used for a household boiler, an industrial boiler, or a heater, so that it is possible to obtain an optimum air fuel ratio.

Claims

1. A system for controlling an optimum air fuel ratio of an oil burner using an air pressure sensor, the system comprising:

a power supplying part;

a fan for supplying air required for combustion of the oil burner by receiving driving voltage from the power supplying part;

a fan driving part serving as a controller which drives the fan;

an air pressure sensor, which is installed at a side of a flow path of air supplied from the fan so as to detect an amount of the supplied air; and

a control part for outputting an optimum RPM of the fan to the fan driving part by comparing a signal detected by the air pressure sensor with preset data related to an optimum amount of air.

2. The control system as claim 1, wherein the control part includes a PID controller, which maintains an optimum air fuel ratio by changing proportionally an RPM of the fan.

3. The control system as claimed in claim 1, wherein the oil burner is selectively employed for a household boiler, an industrial boiler, or a heater.

4. A method for controlling an air fuel ratio of an oil burner using an air pressure sensor, the method comprising the steps of:

detecting an amount of air being supplied through a fan using the air pressure sensor;

calculating an optimum RPM of the fan using a controller by comparing a signal about the amount of the air with present data related to an optimum amount of air;

outputting the RPM calculated by means of the controller to a fan driving part; and

rotating the fan according to the calculated RPM input into the fan driving part.

5. The control method as claimed in claim 4, wherein steps from the air amount detection step to the fan driving step are achieved through a closed loop scheme so that an optimum amount of air is supplied to the oil burner even though external disturbance exists.

6. The control system as claimed in claim 2, wherein the oil burner is selectively employed for a household boiler, an industrial boiler, or a heater.