KR960016352B1 - Exhaust gas safe combustion control device in a boiler - Google Patents

Abstract

The control device detects the degree of clogging of the conduit using revolution number of exhaust/suction fan to stop combustion at a safety point where waste gas is drastically generated. The control device includes : a revolution number reading unit(101) for exhaust/suction fan(23); a command unit(102) outputting boiler operating signal; a function parts operation unit(103) for driving the fan(23), a gas valve(1) and a sparker(25) selectively; a normal revolution number memory(104); and a comparator(106) for controlling such as the fan(23).

Description

Safe combustion control device for waste gas discharge from boiler

1 is a block diagram of a boiler control unit for explaining the apparatus of the present invention.

2 is a schematic configuration diagram of a gas boiler to which the apparatus of the present invention is applied.

3 is a flowchart for explaining the operation of the apparatus of the present invention.

4 is a graph showing the exhaust resistance and the rotational speed of the exhaust fan for explaining the operating state of the present invention.

Figure 5 (a) is a partial configuration of the boiler showing a state in which the exhaust fan is installed in the lower portion of the conventional boiler.

(B) is a part of the boiler showing the state where the exhaust fan is installed in the lower part of the boiler.

Figure 6 is a graph showing the exhaust resistance and the generation value of the waste gas and the rotation speed of the exhaust fan in the conventional boiler.

* Explanation of symbols for main parts of the drawings

1 gas valve 2 rotation speed detection unit

3: oscillator 10: control unit

10 ': Micom 23: ship (class) fan

11: manual operation device 25: sparker

101: rotation speed reading unit 102: driving execution command unit

103: functional part drive unit 104: normal rotation speed memory

105: timer 106: double speed fan comparison unit

According to the present invention, when carbon monoxide is generated due to a blockage of the heat exchanger or the flue of a boiler, the degree of blockage is detected by the number of revolutions of the exhaust fan. The present invention relates to a safety combustion control device for discharging waste gas from a boiler to stop combustion and prevent a safety accident caused by generation of waste gas in advance.

In general, in a boiler adopting a forced exhaust method (FE method) or forced exhaust method (FF method), in order to supply a predetermined amount of oxygen required for combustion of gas during combustion, the combustion chamber of the boiler as shown in FIG. (I.e., heat exchanger) by installing a fan motor for supplying or exhausting the lower part or the upper part as shown in (b) of FIG. 5, it is configured to supply an appropriate amount of air by driving the fan motor. It was possible to carry out safe combustion which limits the amount of waste gas to within safe values.

By the way, the waste gas is generated during the combustion of the gas, regardless of whether it is the FE method or the FF method or CF method (natural exhaust method), it is always generated during the combustion of the gas and is discharged in the state contained in the exhaust gas components. Is greatly changed by the amount of oxygen supplied.

Therefore, the air supply to the combustor is the most important factor that determines the safe value discharge of the waste gas value.

However, after the boiler is installed, a problem occurs in the boiler itself or inadequate supply of air (ie, lack of an adequate air supply amount) during gas combustion in the boiler due to inadequate boiler installation.

For example, in the case of the FE or FF type boiler which burns gas using the air supply or exhaust fan, the combustion rate of the air is adjusted properly by adjusting the rotation speed of the exhaust fan according to the gas supply amount. Set the waste gas value during combustion to the following value during safe discharge.

By the way, during the installation and use of the boiler, defects in the boiler itself, problems in installation work, and changes in the external environment may cause problems between the fins in the boiler heat exchanger or the flue of the boiler.

For example, if the input is excessive and the amount of circulating water in the primary heat exchanger is small, the fins in the primary heat exchanger are oxidized to form an oxidized cornea over time, so that the space between the fins and the fins is blocked, or the installation of flue is performed. If rainwater flows along the flue during combustion and falls on the fin part of the heat exchanger due to a defect, sulfur salts are generated during combustion, which causes the black soot to block between the fins so that the air supplied from the air supply fan or the exhaust fan is discharged by the angle of view and soot. There was a lot of resistance, reducing the air supply to the heat exchanger.

In addition, even if there is no abnormality in the fin of the heat exchanger, due to the poor installation of the exhaust flue, a predetermined portion of the exhaust flue is bent downward and the diameter is narrowed, or the flue is crushed and the diameter of the flue flue is narrowed. Even though the rotation speed of the exhaust and air supply fans for air supply is the same, the amount of air actually supplied to the heat exchanger is reduced.

As the amount of air supplied decreases, the combustion rate of the air is broken and the value of waste gas is increased. At this time, the amount of waste gas generated increases the amount of air to a predetermined exhaust resistance as shown in FIG. However, after exceeding a certain exhaust resistance value, it is a general feature that the waste gas value is greatly changed even in the minute supply fluctuation of air.

By the way, in the conventional boiler, if the waste gas value increases due to the exhaust resistance of the fan as described above, wind pressure switch (or differential pressure switch) is installed in the year, and if the displacement is not generated by the exhaust resistance, A, B, C of FIG. In this case, the bar has been used to stop the combustion of the boiler by designing a mechanical structure so that the wind pressure switch or the differential pressure switch is 'off' when one point is selected and becomes higher than the point.

That is, in the conventional boiler, combustion is controlled by a wind pressure switch or a differential pressure switch that is turned on / off by the exhaust force of the fan. In this method, a separate wind pressure and differential pressure switch must be installed, and thus the production cost of the product increases. There was a problem that many requests for after-sales service occur due to poor diaphragm and poor contact due to the durability of the switch itself.

On the other hand, as a conventional technology for solving the above problems, Korean Utility Model Publication No. 91-8506 (Gas Boiler Ventilation Control Device) is already known, which is composed of a general analog device and TTL IC, so accurate ventilation Not only the control is not made, but the circuit configuration is complicated, there was a problem that the production cost of the product increases.

An object of the present invention is to detect the exhaust resistance of the exhaust gas by the rotation speed of the exhaust fan without using a wind pressure switch or a differential pressure switch, and to stop the combustion when it is determined in the digital circuit that the combustor or flue is blocked. Safe combustion control when discharging waste gas from a boiler that can reduce the production cost of the product and eliminate the cause of the increase in after-sales service by adding parts by increasing the accuracy of the method and using the existing exhaust fan. To provide a device.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic configuration diagram of a gas boiler 100 to which the apparatus of the present invention is applied, a control unit 10 in which a manual operation device 11 is installed in a casing 101 connected to the outside to control an overall operation of a boiler. )Wow ; A combustor 20 for combusting gas for warming hot water for heating or hot water supply; A water tank 30 for storing heating circulation water; The secondary heat exchanger 40 having different paths for circulation of hot and cold water is configured by mutually coupling.

In this case, a burner group 22 including a plurality of burners is formed in the casing 21 of the combustor 20, and a primary heat exchanger having a temperature fuse 24 ′ attached thereto at an upper direction thereof to prevent overheating. 24 is installed and the burner group 22 heats the water passing therethrough, and an exhaust fan 23 for supplying combustion air is installed at the bottom of the combustor casing 21. In the vicinity of the burner group 22, a frame rod 27 for detecting the ignition of the sparker plug 26 and the burner group 22 connected to the sparker 25 for igniting the burner group 22 is installed. On the upper surface of the combustor casing 21, an exhaust part 28 for exhausting the exhaust gas is formed through the boiler casing 101.

In addition, a gas pipe 50 for supplying gas is installed below the burner group 22, and there are two electron valves 51 and 52 for passing the gas at the time of energization and a proportional valve for adjusting the gas supply amount. 53 is provided from the upstream of the gas pipe 50 with respect to the gas supply path.

The water tank 30 recovers the float switch 31 for inspecting the quantity of water in the water tank 30, the overflow pipe 32 for discharging the overflowed water, and the heating water rotated on the floor. In the return pipe 33 provided with the filter 33 'and the water supply pipe 34 for supplying water to the primary heat exchanger 24, a circulation pump 35 for adjusting the circulation of water is provided downward. .

On the other hand, the secondary heat exchanger 40 to the freezing prevention heater 42 'and the user by discharging water through the hot water pipe 41 for guiding the hot water flowing from the primary heat exchanger 24 and the tap water. Water flow switch for detecting the presence or absence of the filter 43 'and water flow by injecting cold water from the outside of the gas boiler, the hot water discharge pipe 42 is attached to the warmer 60 to sense the direct tapping temperature of the hot water supplied (43 ") and a direct flow inlet pipe 43 and the return pipe 33 is installed is provided with a mechanical automatic quantity control device 70 to obtain a stable proportional control temperature characteristics by passing a predetermined quantity according to the direct water temperature Auxiliary pipe 46 is installed to return the water circulated through the secondary heat exchanger 40, wherein the water supply pipe 34 is a hot water pipe 41 and the water for heating through the three-way (44) It is connected to the heating hot water supply pipe 45 passed through.

In addition, the water supply pipe 34 passing through the primary heat exchanger 24 is provided with anti-vibration bimetal 34 'and a deamister 34 "measuring the tapping temperature from upstream with respect to the flow of water, respectively. Between the return pipe (33) and the direct inflow pipe (43) is provided with a water supply tank (54) for replenishing water when there is insufficient water in the water tank (30), the heating hot water pipe ( Bypass pipe 55 for preventing boiling when water does not flow to 45 is connected between the return pipe 33 and the heating hot water supply pipe 45, the low-temperature sensing bar metal to sense the outside temperature of the boiler ( 56 is installed on the inner wall of the boiler casing 101.

FIG. 1 is a block diagram of the control unit 10 centered on the microcomputer 10 ', which receives a predetermined output signal from the rotational speed detection unit 2 of the exhaust fan fan 23 and receives a predetermined output signal. In constructing the control unit 10 of the boiler having a microcomputer 10 'for selectively outputting a control signal, a predetermined output signal is output from the rotational speed detection unit 2 coupled to the supply fan fan 23. A rotation speed reading unit 101 which receives the input and reads the rotation speed of the exhaust fan 23; An operation execution command unit 102 for outputting an operation signal of a boiler according to an output signal of the rotation speed reading unit 101 and the manual operation apparatus 11; A functional part driver 103 for selectively driving the exhaust fan fan 23, the gas valve 1, and the sparker 25 according to the output signal of the operation execution command unit 102; Normal rotation speed in which the exhaust speed of the exhaust fan (23) which can be rotated during normal combustion, the rotational speed of each point by the exhaust resistance, and the idle rotation speed due to the exhaust failure are stored. Memory 104; A timer 105 which receives an output signal of the oscillator 3 and counts a predetermined time; The output data of the rotation speed reading unit 101 and predetermined data provided from the normal rotation speed memory 104 are compared with each other, and a predetermined control signal according to the result value is output to the driving execution command unit 102. It is characterized in that the microcomputer 10 'is provided with a doubler fan rotation speed comparator 106 for controlling the driving of the (grade) fan fan 23 and the like.

At this time, the manual control device 11 which outputs a predetermined control signal to the microcomputer and indicates the operating state of the boiler is provided with an operation operator 111, an operation instruction unit 112, an indicator 113, and the like. .

3 is a flowchart of a predetermined control program executed by the microcomputer 10 'according to the present invention, in which the operation switch installed in the manual operation apparatus 11 is' on' and the exhaust fan 23 is If it is rotated, it detects the rotation state of the exhaust fan 23, and if it turns out to be a defective fan, it stops operation. If it turns out to be in normal rotation state, it detects whether the current fan speed is normal. Drive to ensure safe combustion, but if the fan rotation speed is not normal or the safety combustion is in progress, it is continuously detected whether the rotation speed of the exhaust fan 23 reaches the combustion stop value. If the rotation speed of the exhaust fan reaches the combustion stop value for more than a certain time (t1) due to blockage, etc., the combustion is stopped and combustion stops due to the increase of the waste gas value on the indicator 113 of the manual control device 11. Mark is dropped.

When described with reference to Figure 4 the effect of the present invention as follows.

First, when the user 'turns on' the operation switch installed in the operation manipulator 111 of the manual operation apparatus 11, the operation signal is the driving execution command unit 102 in the microcomputer 10 ′ through the operation instruction unit 112. Since the driving execution command unit 102 outputs a predetermined driving signal to the functional supply unit 103 to the supply fan 23, the supply fan 23 rotates a predetermined amount. Driven by numbers.

At this time, the rotation speed of the air supply fan 23 is detected by the gray water storage detector 2 serving as a pulse generator provided on the shaft of the motor.

That is, the rotation speed detection unit 2 continuously outputs a pulse proportional to the rotation speed of the exhaust fan while the exhaust fan is rotated, so that the rotation speed reading unit in the microcomputer 10 'is connected thereto. The rotation speed of the exhauster fan 23 driven by 101 can be accurately read.

By the way, the driving execution command unit 102 outputs a ship fan drive signal, and then determines the drive state of the ship fan that receives a predetermined output signal from the rotational speed readout 101. As a result, if there is no output signal due to a faulty motor (that is, fixed), etc., there is no air supply to the combustor 20, and thus all combustion operations are stopped.

In addition, when the stomach (fan) fan 23 is rotated normally and a predetermined output signal is generated from the rotation speed reading unit 101, the stomach (fan) fan rotation speed comparing unit 106 in the rotation speed reading unit The output data of the 101 and the rotation speed of the normal combustion range stored in the normal rotation speed memory 104, the rotational speed of each point according to the exhaust resistance, and the idling rotational speed (ie, the combustion stop value) data are compared with each other. The result is output to the operation execution command unit 102.

Therefore, the driving execution command unit 102 outputs a predetermined control signal according to the output value of the exhaust fan speed comparison unit 106. When the operation is started for the first time, the exhaust fan 23 It is detected whether the rotational speed of the rotational speed is enough to perform normal combustion.

As a result, when it is at the normal value, the gas valve 1 is opened by generating a predetermined output signal to the functional part driving unit 103, and the sparker 25 is driven to safely burn the gas when the gas is ignited. .

On the other hand, as a result of detecting the rotation speed of the exhaust fan 23, the rotation speed of the exhaust fan 23 stops the combustion while the combustion exhaust fan 23 is above the normal value due to exhaust failure or the safety combustion is being performed. It will continue to detect if it reaches a combustion stop that is at a high enough speed.

As a result, if the rotation speed of the exhaust fan 23 reaches the combustion stop value due to an increase in the exhaust resistance due to clogging of the exhaust flue during initial operation or safe combustion, the exhaust fan speed comparison unit ( In 106, a predetermined output signal is input from the timer 105 under the control of the oscillator 3, and the state (that is, the rotation speed of the exhaust fan is at the combustion stop value) is longer than a predetermined time t1. It continues to detect if it lasts.

That is, the rotation speed of the exhaust fan 23 may be temporarily changed even by a back wind or the like, which flows into the combustor 20 through the exhaust flue. It is to detect whether it lasts longer than t1).

In the above state, if the rotation speed of the exhaust fan is maintained at the combustion stop value for more than a predetermined time t1, the operation execution command unit 102 of each component required for combustion through the functional part driving unit 103 is performed. By blocking the operation, it is possible to prevent a large amount of waste gas discharged due to poor air supply to the combustor 20.

At the same time, the operation execution command unit 102 indicates that the combustion is stopped due to the increase of the waste gas value on the indicator 113 of the manual operation apparatus 11, so that the user can easily know from the perspective that the current exhaust gas is poor. .

At this time, the exhaust fan 23 has a basic characteristic, and the load of the exhaust fan changes according to the load of the displacement.

That is, the load of the exhaust fan changes as the displacement of the exhaust fan changes depending on the magnitude of the exhaust resistance.

Therefore, if the exhaust resistance is increased due to the blockage of the combustor 20 or the exhaust flue, the exhaust fan 23 has a lower exhaust force (ie, exhaust air volume). Since the fan takes less electrical load, the current value drops while the supply voltage is the same, and the rotation speed of the exhaust fan becomes high.

4 is a graph showing a change in the exhaust resistance and the rotational speed of the exhaust fan 23, and the rotational speed is changed at the same supply voltage by the exhaust resistance of the exhaust fan. It has a gentle change characteristic until it reaches this point.

That is, if the air supply or the exhaust port is narrowed or completely blocked due to any problem in the primary heat exchanger or the exhaust flue or the supply or exhaust, the generation of the waste gas gradually increases due to the lack of oxygen supplied to the combustor, and as shown in FIG. As the exhaust gas starts to increase abruptly and the exhaust gas is excessively discharged, the exhaust load decreases as the fan gradually approaches idling as shown in FIG. 4, so that the rotation speed of the exhaust fan 23 is naturally increased.

Therefore, in the present invention, the normal speed memory 104 stores the exhaust fan speed in the range where normal combustion is possible, the rotation speed for each point due to the exhaust resistance, the idle rotation speed due to the exhaust failure, and the like. The motor motor rotational speed comparator 106 is used for comparison.

That is, when the combustion stop value, which is the rotational speed at which the rotational speed of the exhaust fan 23 is expected to harm the human body due to the sudden increase in the waste gas value, is detected for a predetermined time (t1), the combustion of the boiler is stopped immediately. Hazardous combustion due to increased waste gas levels can be excluded.

As described above, according to the present invention, the exhaust resistance of the exhaust gas is detected as the number of revolutions of the exhaust fan without using the wind pressure switch or the differential pressure switch as in the conventional boiler, and it is determined that the combustor or the flue is blocked. When the combustion is stopped, the accuracy of the detection method can be improved, and the dangerous combustion caused by the increase of the waste gas level can be eliminated, thereby preventing the safety accidents in advance. By using the product as it is, the production cost of the product can be reduced and the cause of the increase in after-sales service by the addition of parts can be prevented, thereby greatly improving the reliability of the product.

Claims (2)

The control unit 10 of the boiler having a microcomputer 10 'which receives a predetermined output signal from the rotational speed detection unit 2 of the ship fan 23 and selectively outputs predetermined control signals to the respective units. In the configuration, the rotation speed reading unit 101 for receiving a predetermined output signal from the rotation speed detection unit 2 to read the rotation speed of the exhaust fan 23; An operation execution command unit 102 for outputting an operation signal of a boiler according to an output signal of the rotation speed reading unit 101 and the manual operation apparatus 11; A functional part driver 103 for selectively driving the exhaust fan fan 23, the gas valve 1, and the sparker 25 according to the output signal of the operation execution command unit 102; A normal rotation speed memory 104 in which data of the exhaust fan speed during normal combustion, rotational speed per point due to exhaust resistance, and idle speed due to exhaust failure are stored; The output data of the rotation speed reading unit 101 and predetermined data provided from the normal rotation speed memory 104 are compared with each other, and a predetermined control signal according to the result value is output to the driving execution command unit 102. Safety combustion control device when discharging waste gas from the boiler, characterized in that the addition of the exhaust fan fan speed comparison unit 106 to control the driving lights of the (grade) fan fan 23 in the microcomputer (10 '). . The apparatus of claim 1, wherein the microcomputer (10 ') is provided with a timer (105) for counting a predetermined time by receiving the output signal of the oscillator (3).