JP3259424B2 - Combustion control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control device for detecting a state of a flame port temperature of a burner block in which NOx is reduced mainly by lean combustion.

[0002]

2. Description of the Related Art Conventionally, there is a combustion control apparatus of this kind as shown in FIG. That is, a burner body 2 having a flame port 1 made of a ceramic material forming a lean flame.
And a fan 3 provided on the upstream side thereof, and a gas supply unit 4 attached to a discharge port of the fan 3 and adjusting a gas supply amount. The control unit 6 controls the fan 3 and the gas supply unit 4 based on the output of the temperature sensor 5 mounted near the flame outlet 1.

[0003]

However, in the above-described conventional configuration, the lean flame has a limited stable combustion region, so that the responsiveness of the fan 3 is taken into consideration and control is restricted.
That is, when the air becomes insufficient, the flame port 1 is abnormally heated by the lean flame. However, since the flame port is made of ceramic, there is a time margin for performing the correction control before the flashback occurs. is there. Conversely, when the air becomes excessive, the lean flame has a characteristic that the fire is easily extinguished because it is close to the flammable limit of the lean combustion. Therefore, in order to maintain stable combustion, the setting of combustion must be controlled on the side of insufficient air, that is, a low excess air ratio. Therefore, the flame outlet 1 is always hot,
The generation of NOx increases as compared with the case where the air amount is large. In addition, there is no means for detecting the state of change with time even if the flame outlet 1 is deteriorated, or for notifying the same. Further, since the ceramic flame port 1 has a large heat capacity, the output of the temperature sensor 5 is not stable for a while at the time of ignition, so that control becomes difficult.

The present invention has been made to solve the above problems, and has a low N
The primary purpose is to monitor the temperature of the flame that forms a lean flame that becomes Ox, to reliably grasp the durable deterioration of the flame, to predict the life of the equipment, and to take necessary measures such as maintenance. And

A second object is to provide notification so that necessary treatment can be performed based on the temperature information of the flame outlet.

[0006]

SUMMARY OF THE INVENTION In order to attain the first object, the present invention provides a flame port for forming a lean flame, a temperature sensor for detecting the temperature of the flame port, When the temperature is equal to or higher than the temperature, the apparatus includes a temperature determining unit that outputs an emergency signal and an integrating unit that integrates and stores the output time of the emergency signal.

In order to achieve the second object, the present invention provides a flame port for forming a lean flame, a temperature sensor for detecting the temperature of the flame port, Has a temperature determining means for outputting an emergency signal, and a notifying means for making a notification or display based on the output of the emergency signal.

[0008]

According to the present invention, when the flame sensor temperature exceeds a predetermined temperature by the temperature sensor, an emergency signal is output from the temperature judging means, and the flame temperature rises above the predetermined temperature by the integrating means. Store the cumulative time.

An emergency signal generated when the flame port temperature exceeds a predetermined temperature is received by a temperature sensor, and a display or a notification is made by a notification means according to the situation.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the burner and the control. A light burner 9 for forming a lean flame 8 on a light flame port 7 having a large number of small diameter holes and formed in a shape protruding downstream.
And a rich burner 1 for forming a rich flame 11 on the rich flame port 10
2 are alternately provided in parallel to form a burner block 13. A fan 14 for supplying combustion air is mounted on the upstream side of the burner block 13. Each of the light burners 9 and the dense burners 12 is provided with a nozzle 17 for ejecting and supplying fuel supplied through an electromagnetic valve 15 and a proportional valve 16, respectively. A temperature sensor 18 is provided adjacent to the burner block 13 on the upstream side of the specific light flame port 7. Further, a mixture ratio sensor 19 for detecting a mixture ratio is provided near the specific light flame port 7.

The combustion control unit 20 includes a mixture ratio detection unit 21 for detecting a signal of the mixture ratio sensor 19, a correction unit 22 for correcting a detection response delay of the mixture ratio sensor 19, and a mixture ratio sensor 19 in an optimum combustion state. State setting means 23 for setting a target value of temperature, and a temperature detecting section 2 for detecting a signal of the temperature sensor 18.
4, temperature determination means 25 for determining the flame port temperature and outputting an emergency signal, integration means 26 for integrating and storing the output time of the emergency signal, and combustion amount setting for setting the combustion amount calculated from the usage status Means 27, a proportional valve driver circuit 28 for controlling the voltage or current value applied to the proportional valve 18 in accordance with the combustion amount setting signal, and the output of the correcting means 22 and the set value of the state setting means 23 are compared. Control means 29 for outputting a control signal corresponding to the deviation, and a fan driver circuit 30 for controlling the drive of the fan 14 in accordance with the signal of the control means 29
It consists of.

The notifying means 31 receives a signal from the integrating means 26 and determines a necessary treatment method in accordance with the level of the accumulated time. A display unit 33 for displaying the deterioration state, and a communication unit 34 for communicating with a service center or the like by means of communication means.
And a valve control unit 35 that outputs a closing signal of the solenoid valve 15.

The combustion and control operations in the above configuration will be described. From each nozzle 17, fuel whose flow rate has been adjusted by the proportional valve 16 is jetted in a predetermined amount,
In the light burner 9 and the rich burner 12. Here, in the light burner 9, a light mixture having a ratio equal to or less than the equivalent ratio is blown out from the light flame port 7 to form a light flame 8. Similarly, in the rich burner 12, a rich mixture having a ratio equal to or higher than the equivalent ratio is blown out from the rich flame port 10 to form a rich flame 11.
Therefore, in the entire burner block 13, the light flame 8 and the rich flame 1
1 are alternately formed.
x combustion is achieved.

Here, the limit state in the combustion control will be described in advance with reference to FIG. When the set combustion amount changes, the optimum mixing ratio of the lean flame 8 and the rich flame 11 in consideration of the combustion limit also changes. Therefore, burner block 1
3. The excess air ratio m of the whole is determined by the curve J as the combustion amount changes.
Is controlled to the value indicated by. When the amount of combustion decreases, the light flame 8 comes closer to the light flame port 7, and when the amount of air further decreases, the flame temperature rises.
Is in a state where it starts to glow in response to abnormal heating, and a red-hot glow region as shown in FIG. 2 is generated. On the other hand, if the amount of air is too large, the light flame 8 becomes leaner and extinguishes from blowing away, or the rich flame 11 similarly extinguishes when the air amount further increases, so that the fire extinguishing zone shown in FIG. Become.

A control operation for ensuring a stable combustion state in the presence of such a combustion limit will be described. The required combustion amount is determined by the combustion amount setting means 27, and the proportional valve 16 and the fan 14 are controlled by the proportional valve driver circuit 28 and the fan driver circuit 30 to set the flow rates of fuel and air, and the combustion amount is determined. It is set to point A, which is the optimum combustion set point corresponding to this. Here, the operation of the combustion device when the supply / exhaust amount changes due to disturbance factors such as wind will be described with reference to FIG.

When the exhaust resistance increases due to the breeze at time t1, the combustion set point starts to move from point A toward point B (FIG. 2), and the output 35 of the mixture ratio sensor 19 by the mixture ratio sensor 19 becomes the combustion amount. Accordingly, the mixture ratio detection unit 21 detects that it has started to deviate from the preset value 37 determined in advance. Here, the control means 29 compares the output value of the correction means 22 with the set value of the state setting means 23, and outputs a proportional control signal of the fan 14 so that the deviation between the two becomes small. Accordingly, the correction means 22 outputs a correction value taking into account this change in consideration of the response delay of the mixture ratio sensor 19. Then, the control unit 29 compares the set value 37 of the state setting unit 23 and increases the fan rotation speed 38 because a positive deviation has occurred, and controls the fan driver circuit 30 so that the deviation becomes zero. As a result, the combustion set point returns from point B to point A again. When the breeze stops at the time t2, the above-described operation is performed in the same manner, and a negative deviation is generated. Therefore, immediately after the breeze stops, it moves from point A to point C temporarily, but again at point A
Is returned to.

When the exhaust resistance increases greatly due to the strong wind at time t3, the combustion set point moves from point A toward point D (FIG. 2) in the red hot region of the light flame port 7. In this case, the deviation of the mixture ratio sensor output 36 is also large, and
The correction value output from the controller also increases, and the fan rotation speed 38 is greatly increased.

The temperature sensor output 39 detected by the temperature sensor 18 and output from the temperature detector 24 rises with a slightly large time delay under the influence of the heat capacity of the light flame port 9. Then, at time t4, the temperature determining means 25 detects that the temperature of the light flame port 7 has exceeded the predetermined value 40, and outputs an emergency signal to the integrating means 26. The time T1 that temporarily exceeds the predetermined value 40 from the time t4 to the time t5 to escape from the light flame red heat region is stored in the integrating means 26. When the fan rotation speed 38 increases and the deviation of the mixture ratio sensor output 36 becomes zero, the combustion set point returns to the point A again.

Here, further, a gust is generated to greatly increase the exhaust resistance, and the combustion set point is changed from the point A to the point E (FIG. 2).
A description will be given of a case where the user moves toward. Since the deviation between the mixture ratio sensor output 36 and the set value 37 occurs again, the correction means 22 outputs an increase in the number of rotations of the fan which is further required to return to the point A as a correction value. Will require a rotation speed higher than the limit. The fan motor driver circuit 30 keeps the fan rotation speed set to the limit value 41 to protect the fan motor.
Therefore, the temperature sensor output 39 rises again and exceeds the predetermined value 40 again at time t7. The fan speed 38 is the limit value 4
1, the fan speed 38 can be reduced to the limit value 41 or less after the time t8 when the gust is weakened, and the time T2 until the temperature sensor output 39 becomes the predetermined value 40 or less at the time t9. Is similarly stored in the integrating means 26. Thus, the time during which the temperature sensor output 39 exceeds the predetermined value 40 is accumulated and stored in the integrating means 26.

Next, a case in which the output from the integrating means 26 and the notifying means 31 operate will be described. The integrating means 26 stores the cumulative time when the temperature sensor output 39 has exceeded the predetermined value 40 and outputs a signal of the cumulative time to the determining means 32. The determination means 32 determines the state of deterioration of the combustion device according to the level of the cumulative time, and outputs a signal to take a necessary action when the level reaches a predetermined level. That is, while the cumulative time is small, the determination means 32 activates the display unit 31 and outputs a display signal corresponding to the cumulative time to the remote controller or the display device 42 of the combustion device main body (not shown). When the accumulated time increases and the device needs to be inspected, a display indicating that the device needs to be inspected is transmitted from the display unit 31, and the communication unit 34 sends the signal to a service center (not shown) or the monitoring center 43 via a predetermined communication medium. Sends a communication signal for inspection required. When the cumulative time further increases and reaches a level at which the risk of damage to the device is predicted, the valve control unit 35 is operated to output a close signal to the electromagnetic valve 17 to stop the supply of fuel. At the same time, the end of the life of the combustion device is transmitted to the display unit 33 and the communication unit 34, and a predetermined notification is made. As a result, the user of the combustion apparatus can grasp the deterioration state of the apparatus and take necessary measures such as inspection and replacement of the apparatus.

In the above embodiment, the burner block of the lean burn is described. However, the burner block may be applied to the burner block of the all primary combustion. Also, the case has been described where the mixture ratio sensor 19 and the temperature sensor 18 are also installed one by one on a specific burner, but may be installed on a plurality of burners.

[0022]

According to the combustion apparatus of the present invention as described in the above embodiments, the following effects can be obtained.

According to the present invention, the temperature of a flame forming a lean flame with low NOx is monitored, and durable deterioration is surely grasped to predict the life of the equipment and necessary measures such as maintenance can be taken.

Further, a notification is made so that necessary measures can be taken from the temperature information of the flame outlet. That is, (1) a lean flame of low NOx is formed, but the temperature of the light flame port that easily glows when subjected to disturbance is detected and determined by a temperature sensor, and the accumulated time exceeding a predetermined temperature during use is integrated. Since monitoring is performed by the means, it is possible to reliably grasp the durable deterioration and to predict the life of the device, and to reliably perform necessary measures such as maintenance.

(2) The temperature sensor detects the red-hot state of the light flame outlet, and the notification means performs display and notification according to the deterioration level of the apparatus, and measures such as stopping fuel supply, so that abnormal combustion continues. As a result, safety can be assured, and it is possible to know in advance when to check or replace the device, so that the combustion device can be used systematically.

(3) Since the deterioration level of the apparatus can always be ascertained, the inspector can perform planned and efficient maintenance even if many similar combustion apparatuses are installed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a burner and control of a combustion control device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a combustion limit region and a combustion set point based on a combustion amount and an excess air ratio.

FIG. 3 is a diagram showing a time indicating a response of combustion control by disturbance;

FIG. 4 is an overall sectional view of another conventional combustion control device.

[Explanation of symbols]

 7 Light Flame Port 8 Light Flame 18 Temperature Sensor 25 Temperature Judgment Means 26 Accumulation Means 31 Notification Means

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Junichi Ueda 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-company (72) Inventor Yoichi Kimura 1006 Kadoma, Kazuma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-291414 (JP, A) JP-A-1-19220 (JP, A (58) Fields surveyed (Int.Cl. ⁷ , DB name) F23N 5/14 340 F23N 5/20 103 F23N 5/24 113 F23N 5/26 101

Claims (2)

(57) [Claims] 1. A flame port for forming a lean flame, a temperature sensor for detecting a temperature of the flame port, and a temperature judging means for judging an output signal of the temperature sensor and outputting an emergency signal when the temperature is higher than a predetermined temperature. A combustion control device having an integrating means for integrating and storing the output time of the emergency signal. 2. A flame port for forming a lean flame, a temperature sensor for detecting a temperature of the flame port, and a temperature judging means for judging an output signal of the temperature sensor and outputting an emergency signal when the temperature is higher than a predetermined temperature. And a notifying means for notifying or displaying based on the emergency signal.