JP3763953B2 - Combustion equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to combustion equipment such as a water heater.
[0002]
[Prior art]
FIG. 4 is a model diagram showing an example of a high-efficiency heat exchange type combustion device under development, which the applicant of the present application is studying as a prototype. This combustion device (equipment) is a water heater, and as shown in the figure, a combustion chamber 2 is provided in the appliance case 1, and a burner 3 is provided in the combustion chamber 2.
[0003]
A gas supply passage 4 for introducing fuel gas to the burner 3 is provided. The gas supply passage 4 controls the on-off valves 5 and 6 for opening and closing the passage and the amount of gas supplied to the burner 3 by the valve opening degree. A proportional valve 7 is interposed. The fuel gas introduced from the fuel gas supply source through the gas supply passage 4 is supplied to the burner 3 through the gas nozzle holder 8, and the burner 3 burns the supplied fuel gas.
[0004]
A combustion fan 10 for supplying air to the burner combustion is provided, and an exhaust passage 11 for discharging exhaust gas generated by the combustion of the burner 3 to the outside is communicated with the combustion chamber 2 above. Air is supplied to the burner 3 by driving the fan 10, and exhaust gas is discharged to the outside through the exhaust passage 11.
[0005]
A heat exchanger is provided above the burner 3. In the appliance shown in this figure, the heat exchanger is provided on the exhaust side of the main heat exchanger 12 and the main heat exchanger 12 (provided in the exhaust passage 11 in the appliance shown in this figure). The recovery heat exchanger 13 is connected to the inlet side of the main heat exchanger 12 and the outlet side of the latent heat recovery heat exchanger 13 is connected to the inlet side of the latent heat recovery heat exchanger 13. A water supply passage 14 for leading water from a supply source is connected. One end side of the hot water supply passage 15 is connected to the outlet side of the main heat exchanger 12, and the other end side of the hot water supply passage 15 is led to a hot water supply place such as a shower in a kitchen or a washroom.
[0006]
Most of the heat generated by the combustion of the burner 3 is absorbed by the main heat exchanger 12 (for example, about 80% of the heat generated by the burner 3 is absorbed by the main heat exchanger 12), and further heat exchange for latent heat recovery The heat absorption is performed by the heat exchanger 13, and a high-efficiency heat exchange is achieved that can absorb about 95% or more of the heat generated by the burner 3 into the water flow of the heat exchanger. is doing.
[0007]
By the way, since the water supplied from the water supply passage 14 enters the latent heat recovery heat exchanger 13, the surface temperature of the water pipe of the latent heat recovery heat exchanger 13 is low, and therefore, in the exhaust gas generated by the combustion of the burner 3. The water vapor component adheres to the surface of the water tube of the latent heat recovery heat exchanger 13 due to the dew condensation phenomenon. In this way, the amount of water droplets (drain) adhering to the latent heat recovery heat exchanger 13 due to the dew condensation phenomenon increases with the passage of time, and when the gravity applied to the drain becomes larger than the surface tension of the drain, the latent heat Most of the drain adhering to the recovery heat exchanger 13 falls from the latent heat recovery heat exchanger 13. A rain return 16 is provided to receive the fallen drain.
[0008]
The drain received at the rain return 16 is discharged to the outside through the drain receiver 17 and the drain discharge passage 18 in order, and the drain received at the rain return 16 is smoothly guided to the drain receiver 17. The rain return 16 is inclined downward toward the drain receiver 17.
[0009]
Further, since the drain adhering to the latent heat recovery heat exchanger 13 is exposed to the exhaust gas, acidic components such as NOx in the exhaust gas are contained in the drain, and the acidic concentration of the drain is, for example, ph2-3. It is extremely high, and discharging the drain having a high acid concentration in this state causes a problem of environmental pollution. Therefore, the neutralization treatment means 20 for neutralizing the drain is provided with the drain discharge passage 18. The drain that has been neutralized is discharged from the drain discharge passage 18 to the outside.
[0010]
In the figure, 21 indicates a water temperature sensor for detecting the temperature of water in the water supply passage 14, 22 indicates a water amount sensor for detecting the flow rate of water flowing through the water supply passage 14, and 23 indicates hot water supplied from the hot water supply passage 15. The hot water temperature sensor for detecting the hot water temperature is shown.
[0011]
This water heater is provided with a control device 25 for controlling a hot water supply operation, and a remote control 26 provided in a kitchen or a washroom is signal-connected to the control device 25. The remote control 26 is provided with hot water supply temperature setting means for setting the hot water supply temperature.
[0012]
The control device 25 controls the hot water supply operation as follows, for example. When a hot-water tap (not shown) provided at the front end side of the hot water supply passage 15 is opened and the water amount sensor 22 detects water flow through the water supply passage 14, the on-off valves 5 and 6 are opened and the gas supply passage 4 is opened. While supplying the fuel gas to the burner 3, the combustion fan 10 is rotationally driven to supply air to the burner 3 to start combustion of the burner 3.
[0013]
Then, the combustion heat amount of the burner 3 is controlled so that the hot water supply set temperature set in the remote controller 26 is reached, that is, the valve opening of the proportional valve 7 is controlled by the proportional valve drive current, and the fuel gas to the burner 3 is controlled. The supply amount is controlled, and the water flowing through the water supply passage 14 is heated by the combustion heat of the burner 3 through the latent heat recovery heat exchanger 13 and the main heat exchanger 12 in order to produce hot water. Hot water is supplied to a desired hot water supply place through the hot water supply passage 15. Thereafter, when the hot-water tap is closed and the water flow stoppage of the water supply passage 14 is detected by the water amount sensor 22, the on-off valve 6 is closed to stop the combustion of the burner 3, and the rotation drive of the combustion fan 10 is stopped. Prepare for the next hot water operation.
[0014]
[Problems to be solved by the invention]
By the way, it is desirable that the burner combustion is performed with a predetermined air-fuel ratio (ratio of the amount of fuel gas supplied to the burner 3 and the amount of air) for the burner 3 to perform complete combustion. Thus, the combustion heat amount control as described above is performed, and the rotation control of the combustion fan 10 for supplying air suitable for the combustion heat amount to the burner 3 is performed in order to perform complete combustion. For example, the relationship data between the amount of combustion heat for complete combustion and the rotational speed of the combustion fan 10 is obtained in advance based on the air-fuel ratio, and the combustion fan corresponding to the amount of combustion heat of the burner 3 during combustion. The rotational speed of 10 is detected based on the relational data, and the rotational drive of the combustion fan 10 is controlled so as to be the detected rotational speed.
[0015]
However, as shown in FIG. 4, in the appliance having the latent heat recovery heat exchanger 13, when the rotation control of the combustion fan 10 is performed by the rotation speed control, the combustion state of the burner 3 is as follows. The problem of fluctuating due to various reasons occurs.
[0016]
The cause of the fluctuation of the combustion state is that the amount of drain adhering to the surface of the water tube of the latent heat recovery heat exchanger 13 fluctuates with time during combustion. 5 and 6 show a part of the latent heat recovery heat exchanger 13 extracted and enlarged. As shown in FIG. 5, during the combustion, the drain that has started to adhere to the surface of the water tube of the latent heat recovery heat exchanger 13 increases as time passes, and as shown in FIG. When the gravitational force increases, almost all of the drain adhering to the surface of the water tube of the latent heat recovery heat exchanger 13 falls, and then the drain begins to adhere to the surface of the water tube of the latent heat recovery heat exchanger 13 again. As described above, the drain is repeatedly attached and dropped on the surface of the water tube of the latent heat recovery heat exchanger 13, and the amount of the drain adhering to the surface of the water tube of the latent heat recovery heat exchanger 13 varies with time. .
[0017]
Since the latent heat recovery heat exchanger 13 is disposed in the exhaust passage 11, the drain adhering to the latent heat recovery heat exchanger 13 becomes exhaust load resistance (exhaust resistance). Since the amount changes with the passage of time, the exhaust resistance changes with the passage of time.
[0018]
Thus, the exhaust resistance varies with time. For example, as shown in FIG. 5, when the amount of drain adhering to the latent heat recovery heat exchanger 13 is small, the exhaust resistance is small. Although air suitable for the amount of combustion heat can be supplied to the burner 3 with the fan air volume Fm shown, the exhaust resistance increases with the increase of the drain adhering to the latent heat recovery heat exchanger 13, and at a constant rotational speed. Thus, when the combustion fan 10 is driven to rotate, as shown in FIG. 7, the fan air amount supplied to the burner 3 is lower than the fan air amount Fm suitable for the combustion heat amount.
[0019]
Thereafter, when the drain adhering to the latent heat recovery heat exchanger 13 falls, the exhaust resistance is reduced, and the fan air volume is recovered to the fan air volume Fm suitable for the combustion heat quantity. As described above, when the combustion fan 10 is controlled by the rotational speed control, the air flow of the fan fluctuates with the passage of time due to the fluctuation of the amount of drain adhering to the latent heat recovery heat exchanger 13, so that the burner 3 is completely The combustion state fluctuates by repeating combustion and incomplete combustion due to air shortage.
[0020]
When the combustion state fluctuates in this way, various problems occur. For example, the burner 3 cannot perform complete combustion stably and performs incomplete combustion. Therefore, when complete combustion is performed, the CO gas generated by the combustion is, for example, 70 ppm. When combustion is performed, the amount of CO gas generated by combustion is, for example, 2000 ppm. For example, the amount of CO gas generated at the time of incomplete combustion greatly increases, or abnormal noise is generated at the time of incomplete combustion. There is a concern about the adverse effects on the human body.
[0021]
Further, since the combustion efficiency is lower at the time of incomplete combustion than at the time of complete combustion, the combustion efficiency fluctuates when repeating complete combustion and incomplete combustion as described above. From this, as shown in FIG. The temperature of the hot spring water fluctuates, and it is impossible to stably supply hot water at a set temperature of the hot water supply.
[0022]
In addition, as described above, the complete content and the incomplete combustion are repeated, so that the content rate of the acidic component in the exhaust gas varies. Therefore, the amount of the acidic component contained in the drain also varies, and the acidic concentration of the drain varies. Fluctuate. Thus, when the acidic concentration of the drain fluctuates with time, there arises a problem that it is very difficult to stably neutralize the drain by the neutralization treatment means 20.
[0023]
The present invention has been made to solve the above-described problems, and its purpose is to stably perform a complete combustion state regardless of temporal fluctuations of the amount of drain adhering to the latent heat recovery heat exchanger. The object is to provide a high efficiency heat exchange type combustion device.
[0024]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration as means for solving the above problems. That is, Book The invention includes a burner that burns fuel using air supplied by rotation driving of a combustion fan, and a heat exchanger that heats water using heat generated by combustion of the burner, The heat exchanger comprises a main heat exchanger and a heat exchanger for recovering latent heat disposed on the exhaust side of the main heat exchanger. The heat generated by the burner combustion is absorbed by the main heat exchanger, and further the latent heat A high-efficiency heat exchange type combustion device that improves thermal efficiency by absorbing heat with a recovery heat exchanger, and an air volume detecting means for detecting the air volume supplied to the burner; and the air volume supplied to the burner and the burner A target air volume detection unit for obtaining a target air volume corresponding to the required combustion heat quantity based on the relation data given in advance with relation data with the combustion heat quantity; an air volume detected by the air volume detecting means is the target air volume detection And fan air volume control unit for controlling the rotation of the combustion fan so that the target air amount obtained by; is provided Furthermore, the load resistance fluctuation of the exhaust due to the driving of the combustion fan is monitored. When the load resistance fluctuation amount fluctuates beyond a predetermined threshold, the rotation amount of the combustion fan is increased and the fan air volume is instantaneously increased. It is equipped with a configuration that blows away water droplets that adhere to the heat exchanger for latent heat recovery due to condensation. The configuration serves as means for solving the above-described problems.
[0026]
In the invention of the above configuration, fan air volume data for supplying air for performing complete combustion to the burner is given in correspondence with the combustion heat volume, and during combustion, the target air volume detector is based on the above data. The target air volume corresponding to the required amount of combustion heat is detected, and the fan air volume control unit controls the rotational drive of the combustion fan so that the air volume detected by the air volume detecting means becomes the target air volume.
[0027]
Since the combustion fan is driven and controlled based on the fan air volume as described above, the target air volume corresponding to the combustion heat quantity can be continuously supplied to the burner even if the amount of drain adhering to the latent heat recovery heat exchanger fluctuates. In other words, since air capable of complete combustion can be stably supplied to the burner, fluctuations in the combustion state in which incomplete combustion and complete combustion are repeated can be prevented. Since the complete combustion state can be continued in this way, problems due to fluctuations in the combustion state are avoided, and the above-described problem is solved.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the drawings.
[0029]
One of the combustion devices according to the present invention The embodiment has a configuration substantially similar to the system configuration shown in FIG. e 4, an air volume sensor 27 (for example, an AF sensor (wind speed sensor)) capable of detecting a fan air volume by rotational driving of the combustion fan 10 is provided, and the fan detected by the air volume sensor 27 is provided. Provided with a control structure for performing rotational drive control of the combustion fan 10 using the air volume Have The In addition, in description of this embodiment, the duplication description of the part which is common in the water heater shown in the said FIG. 4 is abbreviate | omitted.
[0030]
In FIG. this Example embodiment The control configuration is It is shown. As shown by the solid line in FIG. 1, the control device 25 shown in this embodiment includes a combustion heat amount detection unit 30, a target air amount detection unit 31, a data storage unit 32, and a fan air amount control unit 33. It is configured.
[0031]
Combustion heat detection The unit 30 takes in various sensor outputs such as the incoming water temperature sensor 21 and information on the hot water set temperature set in the remote control 26, and detects the combustion heat amount of the burner 3 for supplying hot water at the hot water set temperature. To do. For example, the feedforward heat amount required to increase the water flow rate detected by the water amount sensor 22 from the incoming water temperature detected by the incoming water temperature sensor 21 to the hot water supply set temperature set in the remote control 26 with respect to the hot water supply set temperature. The amount of combustion heat of the burner 3 is detected in consideration of the amount of feedback heat for correcting the deviation of the temperature of the hot water detected by the hot water temperature sensor 23.
[0032]
There are various detection methods other than those described above for detecting the combustion heat quantity of the burner for supplying hot water at a hot water supply set temperature, and other combustion heat quantity detection techniques may be employed. Description of these detection methods is omitted.
[0033]
The target air volume detection data as shown in FIG. This target air volume detection data is data in which air volume data that can supply the burner 3 with an air volume capable of complete combustion is given in correspondence with the amount of combustion heat. Is obtained by the data storage unit 32. The target air volume detection data may be given as graph data as shown in FIG. 2, or may be given in a data format such as arithmetic expression data or table data.
[0034]
The combustion heat quantity detection unit 30 outputs information on the combustion heat quantity obtained as described above to the target air volume detection unit 31, and the target air volume detection unit 31 uses the combustion heat quantity applied from the target air volume detection unit 31 in the data storage unit 32. A target air volume corresponding to the detected amount of combustion heat is obtained in light of the target air volume detection data. In this way, the target air volume detection unit 31 outputs the obtained target air volume information to the fan air volume control unit 33.
[0035]
The fan air volume control unit 33 takes in the fan air volume detected by the air volume sensor 27 every moment and rotates the combustion fan 10 so that the detected fan air volume becomes the target air volume applied from the target air volume detecting unit 31. Control the drive. For example, when the detected fan air volume of the air volume sensor 27 is smaller than the target air volume, the power supplied to the combustion fan 10 is increased (increasing the rotation control amount) to increase the fan air volume toward the target air volume, and conversely When the detected fan air volume of the air volume sensor 27 is larger than the target air volume, the power supplied to the combustion fan 10 is decreased (decreasing the rotation control amount) to decrease the fan air volume toward the target air volume.
[0036]
According to this embodiment, since the rotational drive control of the combustion fan 10 is performed by the fan air volume control, the fan air volume for performing complete combustion regardless of the fluctuation of the amount of drain adhering to the latent heat recovery heat exchanger 13. Can be stably supplied to the burner 3, that is, the air suitable for the amount of combustion heat capable of complete combustion can be stably supplied to the burner 3, so that complete combustion can be stably performed.
[0037]
As described above, since the complete combustion state can be continued, various problems due to the change in the combustion state in which the complete combustion state and the incomplete combustion state are repeated can be avoided. That is, it is possible to prevent the problem of increase in the amount of CO gas generated during incomplete combustion, the problem of abnormal noise generation, and the problem of hydrocarbon generation.
[0038]
In addition, since the problem of fluctuations in combustion efficiency can be avoided, the problem of fluctuations in hot water temperature caused by fluctuations in combustion efficiency can also be avoided. It is possible to provide comfortable use of hot water to users of hot water.
[0039]
Further, since the combustion state can be stabilized as described above, the content of the acidic component in the exhaust gas generated by the combustion of the burner 3 is substantially determined, whereby the drain adhering to the latent heat recovery heat exchanger 13 is determined. Since the acid concentration of the liquid becomes substantially constant and the acid concentration of the drain can be obtained in advance, the neutralization treatment of the drain by the neutralization treatment means 20 is facilitated, and the neutralized drain is reliably discharged to the outside. Can do.
[0040]
further, What is characteristic in this embodiment is that The configuration In addition, a control configuration is provided in which the amount of fan air generated by driving the combustion fan 10 is instantaneously increased to blow away the drain adhering to the latent heat recovery heat exchanger 13.
[0041]
That means In addition to the control configuration shown by the solid line in FIG. 1, the control device 25 shown in this embodiment is provided with a load resistance fluctuation monitoring unit 34 and a drain blowing command unit 35 shown by the dotted line in FIG.
[0042]
The load resistance fluctuation monitoring unit 34 monitors fluctuations in exhaust load resistance (exhaust resistance) due to temporal fluctuations in the amount of drain adhering to the latent heat recovery heat exchanger 13. For example, when the fan air volume is to be kept constant, the combustion fan 10 is controlled in the direction of increasing the rotational speed by the control of the fan air volume controller 33 as the exhaust resistance increases, and when the exhaust resistance decreases, the combustion fan 10 Since the rotational speed of the combustion fan 10 fluctuates with the fluctuation of the exhaust resistance, such that the rotational speed of the combustion fan 10 is monitored. Variations can be monitored.
[0043]
Therefore, a fan rotation speed detection sensor for detecting the rotation speed of the combustion fan 10 is provided, and the load resistance fluctuation monitoring unit 34 takes in the rotation speed of the combustion fan 10 detected by the fan rotation speed detection sensor every moment. Changes in the rotational speed of the combustion fan 10 are monitored as fluctuations in exhaust resistance.
[0044]
Alternatively, when trying to keep the fan air volume constant, the power consumption consumed by the combustion fan 10 increases as the exhaust resistance increases, and the power consumption of the combustion fan 10 decreases as the exhaust resistance decreases. In addition, since the power consumption of the combustion fan 10 varies with the variation of the exhaust resistance, the variation of the exhaust resistance can be monitored by monitoring the variation of the power consumption of the combustion fan 10.
[0045]
From the above, power consumption detection means for detecting the power consumed by the combustion fan 10 is provided, and the load resistance fluctuation monitoring unit 34 changes the power consumption of the combustion fan 10 detected by the power consumption detection means from moment to moment. It is also possible to monitor the fluctuation of the power consumption of the combustion fan 10 as the fluctuation of the exhaust resistance.
[0046]
Incidentally, as shown in FIG. 6, when the amount of drain adhering to the latent heat recovery heat exchanger 13 becomes very large, the exhaust passage 11 is almost blocked by the drain, and the above state is reached. like Even if the rotation control of the combustion fan 10 is performed so that the fan air volume control unit 33 reaches the target air volume, the fan air volume cannot be increased to the target air volume. There is a risk of incomplete combustion.
[0047]
Example of this embodiment Then, in order to avoid the above problem, before the exhaust passage 11 is blocked by the drain, the fan air volume is instantaneously increased to blow away the drain adhering to the latent heat recovery heat exchanger 13. It was.
[0048]
FIG. 3 shows an example of temporal variation of the exhaust resistance. As shown in FIG. 5, from the exhaust resistance Rmn when the amount of drain adhering to the latent heat recovery heat exchanger 13 is small, the exhaust resistance increases as time passes due to the increase in adhering drain, and the latent heat recovery heat exchanger 13 When the drain falls from the above, the exhaust resistance decreases to the exhaust resistance Rmn. Since the relationship between the increased fluctuation amount of the exhaust resistance and the amount of drain adhering to the latent heat recovery heat exchanger 13 is determined in advance, the relationship can be obtained in advance by experiments, calculations, and the like. Based on an appropriate predetermined attached drain amount for avoiding a problem caused by the blockage state, a fluctuation amount of the exhaust resistance for determining the timing of blowing the drain is obtained, and the obtained fluctuation amount (for example, in FIG. 3 ΔRst) is stored in the data storage unit 32 as a threshold value.
[0049]
The drain blow command unit 35 takes in the monitoring information of the load resistance fluctuation monitoring unit 34 every moment, and based on this monitoring information, the threshold value ΔRst in which the fluctuation amount of the exhaust resistance is stored in the data storage unit 32. Is exceeded, a drain blow command is output to the fan air volume control unit 33.
[0050]
When the fan air volume control unit 33 receives the drain blow command, the fan air volume control unit 33 instantaneously increases the rotation control amount of the combustion fan 10 to temporarily increase the fan air volume, and the drain adhering to the latent heat recovery heat exchanger 13. Blow away. Of course, in this case, the drain is blown off with a fan air volume that can prevent the combustion flame of the burner 3 from being blown out.
[0051]
In this example embodiment According to the latent heat recovery heat exchanger 13 has a configuration to blow off the drain adhering to So drain As a result, the drain adhering to the latent heat recovery heat exchanger 13 can be blown off before the exhaust passage 11 is closed, thereby reliably preventing incomplete combustion of the burner due to the blockage of the exhaust passage 11. be able to.
[0052]
In addition, this invention is Example of the above embodiment The present invention is not limited to this, and various embodiments can be adopted. For example, Example of the above embodiment 4 has been described by taking the hot water heater shown in FIG. 4 as an example, but a burner that burns fuel by using air supplied by the rotational drive of a combustion fan, a main heat exchanger, and an exhaust gas that is more exhausted than the main heat exchanger. The present invention can be applied to any combustion device of a high efficiency heat exchange type provided with a heat exchanger for latent heat recovery provided on the side, and can be applied to a combustion device such as a bath device or a heater other than a water heater. May be.
[0053]
Also, Example of the above embodiment In the above description, a hot water heater that uses a fuel gas such as city gas as an example has been described. However, the present invention can also be applied to a combustion device that uses a liquid fuel such as kerosene or heavy oil.
[0054]
further, Example of the above embodiment In this embodiment, a wind speed sensor is used as the air volume sensor 27. For example, a differential pressure sensor that detects a differential pressure detected using a diaphragm or the like as an air volume, a pressure sensor that detects an air volume using the wind pressure, or the like is used. 27 may be used.
[0055]
further, Example of the above embodiment Then, as shown by the chain line in FIG. 4, the air volume sensor 27 is interposed in the air diversion passage that diverts and takes in the air before being supplied to the burner, but is supplied to the main heat exchanger 12, for example. (For example, a bypass passage connecting the combustion chamber on the burner side and the combustion chamber on the exhaust side with respect to the main heat exchanger 12 is provided, and an air flow sensor is provided in the bypass passage. Alternatively, the air volume supplied to the latent heat recovery heat exchanger 13 may be detected, and the air volume sensor 27 may be provided at a position where the air volume on the exhaust side of the burner 3 can be detected. The air volume on the exhaust side of the burner 3 may be detected as the air volume supplied to the burner 1.
[0056]
further, Example of the above embodiment However, the fan air volume is controlled by controlling the rotation control amount of the combustion fan 10, but an air volume damper for controlling the fan air volume is provided, and the fan air volume is controlled by controlling the air volume damper. May be.
[0057]
【The invention's effect】
According to the present invention, there is provided a configuration in which the air volume detecting means supplied to the burner is provided, and the fan air volume is controlled so that the air volume detected by the air volume detecting means becomes a target air volume corresponding to the required combustion heat quantity. Therefore, it is possible to stably supply a fan air volume suitable for the combustion heat quantity to the burner regardless of fluctuations in exhaust resistance caused by fluctuations in the amount of water droplets (drain) adhering to the latent heat recovery heat exchanger due to condensation. Therefore, complete combustion of the burner can be stably performed.
[0058]
As described above, since the complete combustion state can be stably performed, various problems due to fluctuations in the combustion state in which complete combustion and incomplete combustion are repeated can be avoided. That is, there is a problem that the amount of generated CO gas is increased due to incomplete combustion and there is a concern about the adverse effect on the human body, a problem that abnormal noise is generated, and a problem that hydrocarbon is generated. It is possible to reliably avoid the occurrence.
[0059]
In addition, since the complete combustion state is performed stably, the content of acidic components such as NOx in the exhaust gas is determined to be substantially constant, so that the acidic concentration of drain adhering to the latent heat recovery heat exchanger becomes substantially constant. As a result, the neutralization treatment of the drain becomes easy, and the neutralized drain can be discharged to the outside, and the occurrence of environmental pollution problems can be prevented.
[0060]
Furthermore, according to the present invention, It has a structure that blows off water droplets (drain) adhering to the heat exchanger for latent heat recovery by instantaneously increasing the fan air volume by driving the combustion fan. Because Since the drain adhering to the latent heat recovery heat exchanger can be blown before the exhaust blockage state caused by the drain is reached, problems due to the exhaust blockage state can be avoided.
[Brief description of the drawings]
FIG. 1 relates to the present invention. Example embodiment It is a block diagram which shows the characteristic control structure in FIG.
FIG. 2 is a graph showing an example of relationship data between the amount of air supplied to a burner and the amount of combustion heat of the burner.
FIG. 3 is a time chart showing temporal variation of exhaust load resistance caused by temporal variation of the amount of drain adhering to the latent heat recovery heat exchanger.
FIG. 4 is a model diagram showing an example of a high-efficiency heat exchange type combustion device.
FIG. 5 is a model diagram showing an example of the form of water droplet (drain) adhesion on the surface of the water tube of the heat exchanger for recovering latent heat.
FIG. 6 is a model diagram showing an example of water droplet adhesion in the latent heat recovery heat exchanger when the exhaust is closed.
FIG. 7 is a time chart showing the temporal variation of the fan air volume caused by the temporal variation of the amount of drain adhering to the latent heat recovery heat exchanger when the combustion fan is rotationally driven at a constant rotational speed. It is.
FIG. 8 is a time chart showing an example of fluctuations in tapping water temperature due to temporal fluctuations in the amount of drain adhering to the latent heat recovery heat exchanger.
[Explanation of symbols]
3 Burner
10 Combustion fan
12 Main heat exchanger
13 Heat exchanger for latent heat recovery
27 Airflow sensor
31 Target air volume detector
33 Fan air volume control unit

Claims (1)

A burner that burns fuel using air supplied by rotation driving of a combustion fan; and a heat exchanger that heats water using heat generated by the combustion of the burner, the heat exchanger Consists of a main heat exchanger and a latent heat recovery heat exchanger disposed on the exhaust side of the main heat exchanger. The heat generated by the burner combustion is absorbed by the main heat exchanger, and further the latent heat recovery heat A high-efficiency heat exchange type combustion device that improves thermal efficiency by absorbing heat with an exchanger, and an air volume detection means for detecting an air volume supplied to the burner; an air volume supplied to the burner and a combustion heat quantity of the burner; The target air volume detecting unit that obtains the target air volume corresponding to the required amount of combustion heat based on the relation data, and the air volume detected by the air volume detecting means is detected by the target air volume detecting unit. And fan air volume control unit for controlling the rotation drive of the combustion fan so as to fit was the target airflow; is provided, furthermore, monitors the load resistance variation of exhaust gas by driving the combustion fan, the load resistance variation When the air pressure fluctuates beyond a predetermined threshold value, the rotation control amount of the combustion fan is increased to instantaneously increase the fan air volume, and the water droplets adhering to the latent heat recovery heat exchanger due to condensation are blown away. Combustion equipment characterized by comprising .

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