JP3323024B2 - Combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a combustion device such as a water heater or a bath kettle.

[0002]

2. Description of the Related Art For example, a water heater can be operated by a controller having a built-in sequence program for controlling the hot water operation. In order to increase the incoming water temperature of the water heater to a predetermined set temperature, the amount of heat to be supplied is calculated every moment. The gas supply amount is controlled in accordance with the combustion capacity of the required heat quantity, and the air flow rate corresponding to the combustion capacity is controlled by controlling the number of revolutions of the combustion fan in accordance with the required heat quantity. Air is supplied to the burner. The control of the air volume is performed based on an air volume detection sensor. Based on the sensor output detected by the airflow detection sensor, the difference between the required airflow and the airflow actually detected by the airflow detection sensor is determined, and the fan speed of the combustion fan is controlled in a direction to correct the deviation. As a result, an optimum air flow corresponding to the combustion amount is supplied.

By the way, while a water heater is generally used for a long period of time, fins and the like of a heat exchanger of a water heater are
Clogging of garbage and dust occurs. As the clogging progresses gradually, the airflow resistance gradually increases, and finally the air flow required for burner combustion cannot be obtained, so that the life of the water heater becomes longer.

[0004]

Conventionally, the life of such a water heater is determined based on the characteristics of the sensor output of the air flow sensor and the fan speed of the combustion fan. However, when the life is determined by self-diagnosis of the combustion equipment when the burner is not burning, the conventionally used air flow detection sensor uses the sensor output of the air flow detection sensor and the fan rotation of the combustion fan that performs air supply and exhaust. Because the relationship between numbers is affected by changes in the outside air temperature,
Not constant. In other words, the relationship between the change in the sensor output and the change in the fan rotation speed is linear, but when the outside air temperature (also called the system temperature or the ambient temperature) changes when the sensor output is fixed, the sensor output becomes constant. Despite this, the fan speed changes. For example, when the sensor output is constant, the outside air temperature is, for example, 0 ° C. to 30 ° C.
When the temperature rises to ° C., the fan rotation speed shifts by about 450 rpm even though the sensor output is constant.

As described above, when judging the life of the water heater during non-combustion, the influence of the change in the outside air temperature on the fan rotation speed depends on the characteristic relationship between the fan rotation speed of the combustion fan and the sensor output of the air volume detection sensor. Therefore, there is a problem that it is not possible to accurately determine the life of the water heater from the characteristic relationship between the fan rotation speed and the sensor output.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a combustion apparatus that can reliably determine the life of a combustion device.

[0007]

According to the first aspect of the present invention, there is provided a burner, a combustion fan for supplying and exhausting air, a rotation speed detection sensor for detecting a rotation speed of the combustion fan, and a burner. The airflow detection sensor detects the amount of air flowing through the air flow path from the air supply unit to the exhaust unit, and the sensor output of the airflow detection sensor is used to determine the life of the combustion device when the burner is not burning. The upper limit rotation speed of the combustion fan obtained by raising the rotation speed of the combustion fan by a predetermined rotation speed based on the characteristic of the change in the rotation speed of the combustion fan with respect to the change in the outside air temperature obtained in a constant state in advance And a control unit that outputs a life signal of the combustion device when the rotation speed obtained from the actual rotation speed detection sensor reaches the value of (1). In the invention of claim 2, preferably, the outside air temperature corresponds to a nozzle holder temperature of the burner. The above object is achieved according to a third aspect of the present invention, in which a burner, a combustion fan for supplying and exhausting air,
A rotation speed detection sensor that detects the rotation speed of the combustion fan, an air flow detection sensor that detects the amount of air flowing in the air circulation path from the air supply unit to the burner to the exhaust unit, and the life of the combustion device when the burner is not burning When trying to determine
When the characteristic of the change of the sensor output of the air flow detection sensor with respect to the change of the outside air temperature obtained in advance with the rotation speed of the combustion fan being constant is increased when the rotation speed of the combustion fan increases by the predetermined rotation speed, And a control unit for outputting a life signal of the device. In the invention according to claim 4, preferably, the outside air temperature corresponds to a nozzle holder temperature of the burner.

[0008]

According to the above construction, in the first aspect of the invention, when the control unit attempts to determine the life of the combustion device when the burner is not burning, the control unit keeps the sensor output of the air volume detection sensor constant. The characteristic of the upper limit rotation speed of the combustion fan obtained by increasing the rotation speed of the combustion fan by a predetermined rotation speed based on the characteristic of the change of the rotation speed of the combustion fan with respect to the change of the outside air temperature obtained in advance is actually When the actual rotation speed obtained from the rotation speed detection sensor has reached, the control unit outputs a life signal of the combustion device. Thus, the life of the combustion device can be determined regardless of a change in the outside air temperature. According to the second aspect of the present invention, the outside air temperature can be easily obtained from the nozzle holder temperature of the burner during non-combustion. According to the third aspect of the present invention, when the control unit attempts to determine the life of the combustion device when the burner is not burning, the control unit determines the change in the outside air temperature obtained in advance with the rotation speed of the combustion fan kept constant. When the characteristic of the change in the sensor output of the air volume detection sensor is obtained when the rotation speed of the combustion fan is increased by a predetermined rotation speed, the control unit outputs a life signal of the combustion device. Thus, the life of the combustion device can be determined regardless of a change in the outside air temperature. According to the fourth aspect of the invention, the outside air temperature can be easily obtained from the temperature of the nozzle holder of the burner during non-combustion.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are
Since it is a preferred specific example of the present invention, various technically preferred limitations are added, but the scope of the present invention is limited to the following description unless otherwise specified to limit the present invention.
It is not limited to these embodiments.

Embodiment 1 FIG. 1 shows a configuration of a water heater system which is an embodiment of a combustion apparatus according to the present invention. In FIG. 1, a burner 2 is installed below a combustion chamber 1 of a water heater. A combustion fan 3 for supplying and exhausting air is provided below the burner 2.
Is provided. The combustion fan 3 is provided with a rotation speed detection sensor 28. On the upper side of the combustion chamber 1,
A hot water supply heat exchanger 4 is provided between the combustion chamber 1 and the exhaust passage 19, and the hot water supply heat exchanger 4 has fins 9. A water absorption pipe 5 is connected to the inlet side of the hot water supply heat exchanger 4,
The water intake pipe 5 is provided with an incoming water temperature sensor 6 such as a thermistor for detecting the incoming water temperature and a water amount sensor 7 for detecting the incoming water flow rate. A hot water supply pipe 8 is connected to the outlet side of the hot water supply heat exchanger 4. The hot water supply pipe 8 is provided with a hot water temperature detection sensor 10 such as a thermistor for detecting the hot water temperature from the hot water supply heat exchanger 4, and a water flow control valve 11 for controlling the hot water flow rate. Gas supply passage 12 of burner 2
Has a solenoid valve 13 and a proportional valve 14 for controlling a gas supply amount.
Is provided.

The air volume detection sensor is also called a differential pressure sensor.
This is indicated by reference numeral 16. The air volume detection sensor 16 is arranged to detect a pressure difference between the upper and lower sides of the burner 2. That is, one air introduction pipe 1 of the air volume detection sensor 16
6a is connected to an air supply section to the burner 2 between the burner 2 and the combustion fan 3, and the other air introduction pipe 16b is connected to an air exhaust section between the burner 2 and the hot water supply heat exchanger 4. I have. In FIG. 1, the control unit 15 is connected to the air volume detection sensor 16, the rotation speed detection sensor 28 of the combustion fan 3, and the like. As a result, the control unit 15 controls the sensor output S1 from the air volume detection sensor 16 and the rotation speed detection sensor 2
8 can receive a rotation speed detection signal S2 of the combustion fan 3.

FIG. 2 shows an example of a connection relationship between the control unit 15 of FIG. 1, the air volume detection sensor 16, the rotation speed detection sensor 28 of the combustion fan 3, the burner 2, the combustion fan 3, and the like.
The control unit 15 includes a situation determination and rotation speed increasing unit 22, a memory 23, a combustion stopping unit 24, a fan restart unit 25, a life determining unit 26, and a timer 27.

When the control unit 15 attempts to determine the life of the water heater when the burner 2 is not burning, the air volume detection sensor 1
6, the number of revolutions of the combustion fan 3 is determined by a predetermined number of revolutions (for example, 520 rpm) based on a characteristic of a change in the number of revolutions of the combustion fan with respect to a change in the outside air temperature obtained in advance with the sensor output kept constant. The characteristics of the upper limit rotation speed of the combustion fan obtained by raising the
When the actual number of rotations obtained from 8 has reached, the life signal SL of the water heater is output. That is, when the actual rotation speed of the combustion fan 3 reaches the characteristic of the predetermined upper limit rotation speed, the control unit 15 gives the life signal SL of the water heater to the life display unit 50 and the life warning unit 52.

An air volume detection sensor 16 and a rotation detection sensor 28 are connected to the condition determination and rotation speed increasing unit 22 of the control unit 15. The condition determination and rotation speed increasing unit 22 is connected to the memory 23. The condition determination and rotation speed increasing unit 22 obtains a signal S3 indicating whether the combustion stopping unit 24 has stopped burning the burner 2, and determines whether the burner 2 is not burning.

The memory 23 is used to determine the life of the water heater when the burner 2 is not burning.
The characteristic of the change in the number of revolutions of the combustion fan with respect to the change in the outside air temperature, which is obtained in advance with the sensor output of the air volume detection sensor 16 illustrated in FIG. Have been. That is, the memory 23 stores the burner 2 corresponding to the outside air temperature as illustrated in FIG.
The characteristic relationship between the nozzle holder temperature and the fan rotation speed of the combustion fan 3 is stored. The relationship between the nozzle holder temperature (° C.) and the fan rotation speed shown in FIG. 3 is, for example, at the time of normal combustion, the fan rotation speed R = 5T + 1930 which is represented by Expression 1.
(Rpm) (the straight line L1 in FIG. 3). On the other hand, when determining the life of the water heater when the burner 2 is not burning, the condition determination of the control unit 15 and the rotation speed increasing unit 22 determine the rotation of the combustion fan 3 described above with respect to the equation (1). The number is set to a predetermined number of revolutions (for example, 520 rpm).
m)) Formula 2 obtained by increasing the fan rotation speed R = 5T
+ (1930 + rotational speed increase R1) (rpm) (straight line L2 in FIG. 3). For example, when the outside air temperature is 30 ° C.,
20 rpm, and the upper limit of the fan rotation speed for determining the life in this case is about 2600 rpm from the equation (2).
It is. Further, if the rotation speed increase R1 is 970 rpm, the fan rotation speed upper limit threshold at the time of self-determination is 2900 rpm at 30 ° C.

After a predetermined time, for example, 4 to 6 hours, has passed since the signal S5 was given to the timer 27 when the combustion stopping section 24 stopped the burner 2, the timer 27 sends a water heater to the life determining section 26. A signal S4 for determining the life of the camera is sent. Fan restart unit 25
Is a restarting unit for rotating the combustion fan 3 when determining the life of the water heater when the combustion stopping unit 24 is not burning the burner 2. For example, a liquid crystal display unit can be used as the life display unit 50, and a buzzer can be used as the life warning unit 52. The life display unit 50 and the life warning unit 52 are operated based on the life signal SL obtained from the life judgment unit 26.

Next, the operation of the first embodiment shown in FIGS. 1 to 3 will be described. The combustion stopping unit 24 of the control unit 15 stops the combustion in the burner 2 and stops the combustion state of the water heater. That is,
When the user closes the water amount control valve 11 of FIG. 1, the water amount sensor 7 is turned off, the solenoid valve 13 and the proportional valve 14 are closed by the signal of the combustion stop unit 24 of the control unit 15, and the combustion fan 3 is set to the moderate ignition air volume. And the combustion fan 3 is turned off, and the control unit 15
Opens the water amount control valve 11 fully. At this point, the combustion stopping unit 24 supplies a signal S5 to the timer 27. On the basis of the signal S5, the timer 27 counts a predetermined time, preferably 4 hours, from the time when the combustion in the burner 2 is stopped to the time when the combustion is not performed. When the timer 27 counts for 4 hours, the timer 27 sends a life determination start signal S4 to the life determination unit 26.
give. The reason for waiting for the elapse of 4 hours is that the nozzle holder temperature is stabilized substantially corresponding to the outside air temperature. Thereby, the combustion fan 3 is rotated, for example, for 10 seconds in order to perform a self-diagnosis of the water heater.

The condition determination and rotation speed increasing unit 22 fetches the formula 1 from the memory 23 indicating the fan rotation speed at the time of normal combustion shown in FIG. 3, and further adds a predetermined rotation speed increase R1 to the formula 1. The situation is determined based on Equation 2 which is a target rotational speed calculation equation at the time of the added self-diagnosis. For example, when the outside air temperature is 30 ° C., the life determination at the time of non-combustion is performed by Expression 2 in FIG. When the outside air temperature T is 30 ° C., if T = 30 is substituted into the calculation formula (Equation 2) of the fan rotation speed at the time of life determination during non-combustion and the rotation speed increase R1 is set to 520 rpm, the fan rotation speed R is
It becomes 2600 rpm. This 2600 rpm corresponds to the rotation speed when the closing ratio of the exhaust passage is about 60% when the fins 9 and the like of the hot water supply heat exchanger 4 in FIG. 1 are clogged with dust and the like. Therefore, the rotation speed detection signal S obtained from the rotation speed detection sensor 28 in the rotation speed increasing section 22 in this state determination and rotation speed increasing section 22.
If the value of 2 has reached about 2600 rpm, the life determining unit 26 determines that the water heater has reached the end of its life. When the life determining unit 26 determines that the life of the water heater is reached, the life signal SL is displayed on the life display unit 50 and the life warning unit 5.
2 given. The life display unit 50 displays, for example, the characters "life", and the life warning unit 52 sounds a buzzer to notify the user.

As described above, in the first embodiment shown in FIGS. 1 to 3, the fan speed of the combustion fan 3 and the
When determining the life of the water heater from the characteristic relationship of the sensor output of the above, the status determination of the control unit 15 and the rotation speed increasing unit 22
Expression 2 representing the upper limit value of the fan rotation speed at the time of self-diagnosis is obtained using the fan rotation speed calculation formula 1 for determining the life during non-combustion shown in FIG. Then, the life determination unit 26 of the control unit 15 determines the rotation speed upper limit value of the expression 2 and the rotation detection sensor 28.
And if the actual fan speed from the speed sensor 28 is equal to or exceeds the upper limit of the fan speed, the life determining unit 26 It can be determined that the life of the vessel has expired. Thus, when determining the life of the water heater, the life of the water heater can be accurately determined without being affected by changes in the outside air temperature.

Embodiment 2 FIGS. 4 and 5 show Embodiment 2 of the present invention. The second embodiment of FIG. 4 is different from the first embodiment of FIG.
Is different from the information stored in the system and the method of situation determination and determination in the rotation speed increasing unit 122. The memory 23 in the embodiment of FIG. 4 stores the characteristic relationship between the nozzle holder temperature as the outside air temperature and the sensor output of the air volume detection sensor 16 illustrated in FIG. The characteristic relationship between the nozzle holder temperature and the sensor output recorded in the memory 23 is a characteristic when the rotational speed obtained from the rotational speed detection signal S2 of the rotational speed detection sensor 28 of the combustion fan is 2100 rpm, which is a normal combustion characteristic. It is the rotation speed at the time.

However, when the fins and the like of the hot water supply heat exchanger as shown in FIG. 1 are clogged with dust and the amount of passing air is reduced, the sensor output of the air volume detection sensor 16 as shown in FIG. 5 is obtained. To do so, it is necessary to increase the fan rotation speed to 2620 rpm, for example. That is, in the relationship between the nozzle holder temperature and the sensor output as shown in FIG.
When the actual rotation number detection signal S2 of 2620 rpm is received from the rotation detection sensor 28 instead of m, a signal is given to the life determination unit 26. Thus, the life determining unit 26 provides the life signal SL to the life display unit 50 and the life warning unit 52. The other components and the structure of the water heater in the second embodiment of FIG. 4 are the same as the configuration of the control unit 15 and the structure of the water heater of the first embodiment shown in FIGS.

Next, the operation of the second embodiment shown in FIGS. 4 and 5 will be described. The combustion stopping unit 24 of the control unit 15 stops the combustion in the burner 2 and stops the combustion state of the water heater. That is,
When the user closes the water amount control valve 11 of FIG. 1, the water amount sensor 7 is turned off, the solenoid valve 13 and the proportional valve 14 are closed by the signal of the combustion stop unit 24 of the control unit 15, and the combustion fan 3 is set to the moderate ignition air volume. And the combustion fan 3 is turned off, and the control unit 15
Opens the water amount control valve 11 fully. At this point, the combustion stopping unit 24 supplies a signal S5 to the timer 27. On the basis of the signal S5, the timer 27 counts a predetermined time, preferably 4 hours, from the time when the combustion in the burner 2 is stopped to the time when the combustion is not performed. When the timer 27 counts for 4 hours, the timer 27 sends a life determination start signal S4 to the life determination unit 26.
give. The reason for waiting for the elapse of 4 hours is that the nozzle holder temperature is stabilized substantially corresponding to the outside air temperature. Thereby, the combustion fan 3 is rotated, for example, for 10 seconds in order to perform a self-diagnosis of the water heater.

Then, the life determining unit 26 of the control unit 15
When the life of the water heater is to be determined when the burner 2 is not burning, the air flow rate detection sensor 16 for the change in the nozzle holder temperature, which is the outside air temperature, obtained in advance with the rotation speed of the combustion fan 3 constant. Is obtained when the rotation speed of the combustion fan 3 is increased by a predetermined rotation speed (for example, 520 rpm).
The life determining unit 26 outputs the life signal SL of the water heater. When the life determining unit 26 determines that the life of the water heater is reached, the life signal SL is displayed on the life display unit 50 and the life warning unit 5.
2 given. The life display unit 50 displays, for example, the characters "life", and the life warning unit 52 sounds a buzzer to notify the user. As described above, in the relationship between the nozzle holder temperature and the sensor output as shown in FIG. 5, the situation determination and the rotation speed increasing unit 122 output the actual rotation speed detection signal S2 of 2620 rpm from the rotation speed detection sensor 28 instead of 2100 rpm. When it is received, the life determining unit 26
, It is possible to accurately determine the life of the water heater without being affected by a change in the outside air temperature.

The present invention is not limited to the above embodiment. In the embodiment described above, for example, a burner other than the two-stage or three-stage combustion switching system, the multi-stage combustion switching system, or the non-combustion switching system can be adopted as the burner 2. Further, the air volume detection sensor 16 is configured to detect a differential pressure between a section on the upstream side and a section on the downstream side of the burner 2 so as to sandwich the burner 2 by using, for example, a differential pressure sensor. However, not limited to this, burner 2
It is only necessary to detect a differential pressure between an arbitrary upstream and downstream path section in the air flow path from the air supply section to the exhaust path to the exhaust path. In other words, the differential pressure between the air supply port of the combustion fan and the section of the combustion chamber, the differential pressure between the air outlet side of the combustion fan and the section of the combustion chamber, or the air pressure difference between the air supply port and the air outlet of the combustion fan and the hot water supply Various changes can be made as needed, such as the differential pressure between the upper exhaust top section and the differential section between the combustion chamber and the exhaust top section. If the air volume detection sensor 16 is arranged with the burner 2 interposed therebetween as in the above-described embodiment, since the clogging of the burner 2 with dust or the like hardly occurs, the air resistance passing through the burner 2 hardly changes with time. Thus, the amount of air sent from the combustion fan 3 can be accurately detected by the differential pressure. Therefore, from this point, a method of detecting the differential pressure of air in the air path section sandwiching the burner 2 is desirable. Although a differential pressure sensor is used as the air volume detection sensor, for example, a hot wire heater type or Karman vortex type air volume sensor may be used instead. Alternatively, a propeller rotating type air flow meter that directly detects the air flow may be used.

In the above-described embodiment, a single-purpose water heater (a water heater having only a hot water supply function) is described as an example of the combustion apparatus of the present invention. However, the present invention relates to a combined water heater having both functions of hot water supply and post-heating, or both hot water supply and hot water heating, as well as burners for various devices such as bath kettles and heaters, air conditioners and air conditioners, and air conditioners. The present invention can be applied to a combustion apparatus that requires. Further, in the above-described embodiment, the temperature of the nozzle holder is adopted as the temperature representing the outside air temperature, but the temperature is not limited to this, and the temperature of other parts can be applied. 2 and 4, the life indicator 5
It is sufficient that at least one of 0 and the life warning unit 52 is provided.

[0026]

As described above, according to the present invention, the life of the combustion equipment can be reliably determined without being affected by the outside air temperature.

[Brief description of the drawings]

FIG. 1 is a diagram showing a water heater that is Embodiment 1 of a combustion device of the present invention.

FIG. 2 is a diagram showing a connection relationship between a control device of a water heater and a peripheral element thereof according to the first embodiment in FIG. 1;

FIG. 3 is a diagram illustrating an example of a relationship between a nozzle holder temperature (outside air temperature) and a fan rotation speed of a combustion fan stored in a control unit according to the first embodiment.

FIG. 4 is a diagram showing a connection relationship between a control unit of a water heater, which is Embodiment 2 of the combustion apparatus of the present invention, and peripheral elements.

FIG. 5 is a diagram showing an example of a relationship between an outside air temperature (nozzle holder temperature) and a sensor output stored in a memory according to the second embodiment in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 Burner 3 Combustion fan 4 Hot water supply heat exchanger 15 Control part 16 Air volume detection sensor 28 Revolution number detection sensor of combustion fan

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-14545 (JP, A) JP-A-8-121753 (JP, A) JP-A-8-68533 (JP, A) 8038 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F23N 5/18 101 F23N 5/24 104 F23N 5/26 101

Claims (4)

(57) [Claims] 1. A burner, a combustion fan for supplying and exhausting air, a rotation speed detection sensor for detecting a rotation speed of the combustion fan, and a flow rate of air flowing in an air flow path from an air supply section to the burner to an exhaust section. When trying to determine the life of the combustion device when the burner is not burning, the combustion fan detects the change in the outside air temperature that is obtained in advance with the sensor output of the air flow detection sensor kept constant. The rotation speed obtained from the actual rotation speed detection sensor has reached the value of the upper limit rotation speed of the combustion fan obtained by increasing the rotation speed of the combustion fan by a predetermined rotation speed based on the characteristic of the change in the rotation speed. And a control unit for outputting a life signal of the combustion device. 2. The combustion apparatus according to claim 1, wherein the outside air temperature corresponds to a nozzle holder temperature of the burner. 3. A burner, a combustion fan for supplying and exhausting air, a rotation speed detection sensor for detecting a rotation speed of the combustion fan, and a flow rate of air flowing through an air flow path from an air supply section to the burner to an exhaust section. When trying to determine the life of the combustion device when the burner is not burning, the air flow detection sensor detects the change in the outside air temperature obtained in advance with the combustion fan rotating at a constant speed. A combustion device comprising: a control unit that outputs a life signal of a combustion device when a characteristic of a change in a sensor output increases a rotation speed of a combustion fan by a predetermined rotation speed. 4. The combustion apparatus according to claim 3, wherein the outside air temperature corresponds to a nozzle holder temperature of the burner.