JPH1089769A - Combustion controller for hot-water supplier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion controller for a hot-water supplier, which is capable of preventing an air-fuel ratio from being deviated largely from the optimum air-fuel ratio in the transient period of initial period of starting hot-water supplying operation, in a hot-water supplier, in which the supplying amount of fuel is controlled through feed-forward(FF) control and feedback(FB) control while the amount of ventilation is controlled through FF control. SOLUTION: A combustion controller for a hot-water supplier is provided with a burner 20, a fuel supplying means, a ventilating means, a heat exchanger 11, an input water temperature sensor 42, an input water flow rate sensor 41 and an output hot-water temperature sensor 52 while a necessary combustion heat amount is operated from a set output hot-water temperature, an input water temperature and an input water flow rate to control the amount of supplying fuel, supplied by the fuel supplying means, and the amount of ventilation, effected by the ventilating means, through FF control. On the other hand, the fuel supplying amount is controlled from a difference between the set output hot-water temperature and an output hot-water temperature, detected by the output hot-water temperature sensor 52, through FB control. The combustion controller for a hot-water supplier is provided with a controller 60, controlling the supplying amount of fuel through only the FF control in a period from the starting of hot-water supplying operation until the output hot-water temperature, detected by the output hot-water temperature sensor 52, enters within a given range with respect to the set output hot-water temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a combustion control device for a water heater.

[0002]

2. Description of the Related Art Conventionally, for example, in a water heater using a return-nozzle type gun-type proportional control burner, when the water heater is operated at a predetermined number, a fuel supply amount is determined by a feedforward (hereinafter referred to as "feed forward") of the water heater. FF + FB control is performed based on the control number + feedback (hereinafter referred to as FB) control number, and FF control is performed on the amount of blown air based on the FF control number of the water heater. The reason is that if the fuel supply varies,
Even if the fuel supply amount is FF + FB controlled based on the FF control number of the water heater + FB control number, the actual fuel supply amount is close to the actual FF control value.
This is because, if the control is performed by + FB control, the air-fuel ratio between the blown air amount and the fuel supply amount actually deviates from the optimum air-fuel ratio by the amount of the FB control of the blown air amount.

[0003]

However, as described above, the fuel supply amount is controlled by FF + FB control, and
In the water heater controlled by the F control, the difference between the set hot water temperature and the detected hot water temperature in a transitional period from the start of operation to the initial rise is large, so that the FB control value of the fuel supply amount increases. On the other hand, the air flow is only FF control, and as a result, there is a problem that the air-fuel ratio largely deviates from the optimum air-fuel ratio in a transitional period at the beginning of operation. Also, the fuel supply amount is controlled by FF + FB control, and
In a water heater controlled by the F control, there are errors detected by a water inlet temperature sensor, a water outlet temperature sensor, a flow rate sensor, or errors in can body efficiency. The FF control number of the water heater calculated based on the flow rate includes an error. Therefore, if the error in the value detected by the sensor is large, a large error occurs between the calculated FF control number and the really required FF control number.
As a result, the influence of the error on the FB control number becomes very large, and in the relationship between the fuel supply amount controlled by the FF + FB control number and the air flow rate controlled by only the FF control number,
There is a problem that the air-fuel ratio greatly deviates from the optimum air-fuel ratio.

Accordingly, the present invention solves the above-mentioned conventional problems, and in a water heater in which the fuel supply amount is controlled by FF + FB control and the air supply amount is controlled by FF control, the water supply is evacuated during the initial transition period of the hot water supply operation. The fuel ratio is prevented from greatly deviating from the optimum air-fuel ratio, and the fuel supply amount is set to FF + F.
In a water heater controlled by B control and the amount of blown air is controlled by FF control, it is possible to prevent the air-fuel ratio from largely deviating from the optimum air-fuel ratio due to a detection error of a sensor or the like. It is an object to provide a combustion control device.

[0005]

In order to achieve the above object, a combustion control apparatus for a water heater according to the present invention comprises a burner, a means for supplying fuel to the burner and a means for blowing air, and the inside of which is heated by combustion heat of the burner. A heat exchanger for heating and passing hot water through the water, an incoming water temperature sensor and an incoming water flow sensor provided on an inlet pipe upstream of the heat exchanger, and a hot water temperature provided on a outlet pipe downstream of the heat exchanger. And a sensor for calculating the required amount of combustion heat from the set tapping temperature, incoming water temperature, and incoming water flow rate, and performs FF control of the fuel supply amount by the fuel supply means and the blown amount by the blower means. In the combustion control device of the water heater, wherein the fuel supply amount is FB-controlled based on a difference between a temperature and a tapping temperature by the tapping temperature sensor, the tapping temperature by the tapping temperature sensor from the start of the tapping operation. Setting tapping period until fall within a certain range with respect to temperature is in the first, comprising a controller for controlling the fuel supply amount in the FF control only. In addition, the combustion control device for a water heater according to the present invention includes a burner, a fuel supply unit and a blowing unit for the burner, a heat exchanger that heats water passing therethrough by the heat of combustion of the burner, and outputs hot water. An inlet water temperature sensor and an incoming water flow rate sensor provided on an inlet pipe on the upstream side of the exchanger, and a hot water temperature sensor provided on a outlet pipe on the downstream side of the heat exchanger,
The required amount of combustion heat is calculated from the set tap water temperature, the incoming water temperature, and the incoming water flow rate, and the FF control of the fuel supply amount by the fuel supply means and the blast amount by the blower means is performed. When the difference between the set hot water temperature and the hot water temperature detected by the hot water temperature sensor is less than a certain temperature in the combustion control device of the hot water supply device that performs FB control of the fuel supply amount based on the deviation from the hot water temperature due to Has a second feature that it has a controller that controls the fuel supply amount only by FF control.

According to the first aspect of the present invention, during the transitional period of the initial stage of the hot water supply operation from the start of the hot water supply operation to the time when the tapping temperature rises to a certain range with respect to the set tapping temperature, the air flow rate is reduced. The control of the fuel supply amount as well as the control is only the FF control. Therefore, in the transient period, a large value of the FB control amount due to a large difference between the set hot water temperature and the detected hot water temperature is added to the fuel supply amount, and the deviation of the air-fuel ratio due to the excessive fuel supply amount becomes large. According to this, the FB control amount does not add to the fuel amount supply, so that it is possible to prevent the air-fuel ratio based on the fuel supply amount and the air flow amount from largely deviating from the optimum air-fuel ratio. In the first feature, the period from the start of hot water supply operation to the time when the tapping temperature detected by the tapping temperature sensor falls within a certain range with respect to the set tapping temperature is
In the period from the start of combustion by the start of hot water supply operation to the time when the tapping temperature rises to within a certain temperature range with respect to the set tapping temperature, the tapping temperature rises to within a certain temperature range with respect to the set tapping temperature. This means that the FB control amount of the fuel supply amount due to the difference between the hot water temperature and the hot water temperature rises to a temperature at which the air-fuel ratio significantly deviates from the optimal air-fuel ratio and no longer appears significantly. Therefore, a temperature difference that can keep the deviation of the air-fuel ratio from the optimum air-fuel ratio within a certain range may be determined in advance by experiments as a certain temperature range. The fixed temperature range may be, for example, a set tapping temperature −5 ° C. Furthermore, it can be set to the set tapping temperature-(2 to 5 ° C). A wider range can be set hot water temperature ± (2-5 ° C.). According to the second feature, when the difference between the set hot water temperature and the incoming water temperature by the incoming water temperature sensor is less than a certain temperature, the control of the fuel supply amount is performed only by the FF control. If the difference between the set hot water temperature and the incoming water temperature by the incoming water temperature sensor is less than a certain temperature, the F
The error of the F control value (for example, the number of FF control numbers) increases,
As a result, the FB control value of the fuel supply amount to be subjected to FB control becomes large, and the air-fuel ratio with the air flow rate controlled only by the FF control amount largely deviates from the optimum air-fuel ratio. However, when the difference between the set outlet temperature and the incoming water temperature by the incoming water temperature sensor is less than a certain temperature, the fuel supply amount is also controlled only by the FF control amount, so that the air-fuel ratio largely deviates from the optimal air-fuel ratio. Can be prevented. In the second feature, when the difference between the set hot water temperature and the incoming water temperature by the incoming water temperature sensor is less than a certain temperature, the constant temperature as a condition can be set to an appropriate value in advance by experiments.

[0007]

FIG. 1 is an overall view of a water heater according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating a first control example by the combustion control device for a water heater according to the present invention. FIG. 3 is a flowchart illustrating a second control example by the combustion control device for a water heater according to the present invention.

Referring to FIG. 1, the water heater includes an instantaneous heat exchanger 11 in a heat exchange can body 10, and a return nozzle type gun as a fuel supply means is provided to the heat exchange can body 10. A type proportional control burner 20 is provided, and a blower 30 is provided as a means for blowing air used for combustion. Petroleum fuel is supplied to the gun type proportional control burner 20, and a part of the burner is returned without being injected from the nozzle, so that the spray amount is adjusted. An inlet pipe 40 and a tapping pipe 50 are respectively connected to the instantaneous heat exchanger 11, and water from the inlet pipe 40 is heated while passing through the instantaneous heat exchanger 11 of the heat exchange can 10, and Then, hot water is supplied to the hot water supply pipe 50, and hot water is supplied from the hot water supply curan 51 or the like. The inlet pipe 40
Is provided with an incoming water flow sensor 41 and an incoming water temperature sensor 42,
The tapping tube 50 is provided with a tapping temperature sensor 52.

The controller 60 controls the entire water heater, inputs a command from a remote controller 70, and controls the flow rate of incoming water detected by the incoming water flow sensor 41, the incoming water temperature detected by the incoming water temperature sensor 42, and the outgoing water temperature sensor. Hot water temperature detected by 52, information from each sensor provided in the other water heater is input, and the amount of fuel supplied from the burner 20 is controlled and the amount of air supplied by the blower 30 is controlled. It controls members such as pumps and valves provided in other water heaters. Now, the set tapping temperature is determined by the remote controller 70, the hot water supply curran 51 and the like are opened, and when the flow rate equal to or more than the minimum working water amount flows through the water inlet pipe 40, the combustion by the burner 20 is started. The tapping temperature control by the controller 60 is performed by FF control and FB control in principle, and accordingly, the fuel supply amount is controlled by FF control and FB control in principle.
On the other hand, the blowing amount is controlled only by the FF control. That is, when the hot water supply is started, the controller 60 calculates the FF from the set hot water temperature, the detected incoming water temperature, and the detected incoming water flow rate by the following equation 1.
The control number is calculated, and the burner 20 is controlled so that the FF control fuel supply amount corresponds to the FF control number. Similarly F
The blower 30 is controlled so that the FF control air flow amount corresponding to the F control number is obtained. The FF control fuel supply amount and the FF control air supply amount are set to have a relationship that provides an optimum air-fuel ratio.

FF control number = (set hot water temperature-detected incoming water temperature) ÷ 25 x detected incoming water flow rate formula 1

Here, the number 1 is the amount of heat for raising 1 liter of water by 25 ° C. per minute.

Next, the temperature of the hot water discharged from the hot water by the FF control is detected by a hot water temperature sensor 52, and the detected hot water temperature is used as the detected hot water temperature. Equation 3 calculates the number of FB control numbers.

Actual number of outgoing hot water = (detected hot water temperature-detected incoming water temperature) ÷ 25 x detected incoming water flow rate formula 2

FB control number = FF control number-actual hot water number

When the FB control number is calculated by the equation 3, the fuel supply amount corresponding to the FB control number is added to the FF control fuel supply amount as the FB control fuel supply amount, and
20 is controlled. On the other hand, even if the FB control number is calculated,
With respect to the blowing amount, the blower 30 is continuously controlled by the FF control blowing amount. The reason why the blast amount is controlled only by the FF control is that the control of the blast amount is not so problematic even if it is not so accurate as compared with the fuel supply amount, and when the blast amount is also controlled by the FF control + FB control, When the fuel supply amount varies, the actual control number of the water heater is FF even if the fuel supply amount is controlled by the FF control number + FB control number.
Since the value is close to the control number, if the air flow rate is controlled by the FF control number + FB control number, the air-fuel ratio between the air flow rate and the fuel supply amount is actually optimal for the FB control number of the air flow rate This is because it will deviate from the air-fuel ratio.

Next, a first embodiment of the control of the fuel supply amount of the burner 20 and the blower amount of the blower 30 by the controller 60 in the water heater combustion control apparatus of the present invention will be described with reference to FIG.
It is explained along. That is, in the first embodiment, when the hot water supply operation switch (not shown) is turned on by the remote controller 70 and the like, and the incoming water flow rate sensor 41 detects the minimum operating water amount or more by opening the hot water supply curan 51 or the like, the combustion of the burner 20 is stopped. Then, the hot water supply operation is started. When the hot water supply operation is started (Yes in step S11), the controller 60 calculates the required number of hot water from the set hot water temperature, the detected hot water temperature, and the detected hot water flow rate set by the remote controller 70 using the above equation 1, This will be referred to as the number of FF control outlets. The controller 60 calculates the FF control fuel supply amount of the fuel supply amount corresponding to the FF control hot water supply number and the FF control air supply amount of the air supply amount, and calculates the FF control fuel supply amount and the FF control air supply amount. Control of the burner 20 and the blower 30 is started. When the control of the burner 20 and the blower 30 is started in accordance with the start of the hot water supply operation, the hot water temperature sensor is
The detected tapping temperature detected by 52 is monitored, and it is monitored whether the detected tapping temperature is within a certain temperature range with respect to the set tapping temperature (step S12). The rise from the start of operation to the time when the detected hot water temperature falls within a certain temperature range with respect to the set hot water temperature (No in step S12) is the time when the control of the fuel supply amount and the air blowing amount is performed by the FF control number. FF control is performed with the FF control value based on (step S13). On the other hand, in step S12, when the detected hot water temperature falls within a certain temperature range with respect to the set hot water temperature (Yes in step S12), the controller 60 determines the fuel supply amount of the burner 20 in addition to the FF control. The FB control is also started, and thereafter, the fuel supply amount is controlled by the FF + FB control and the air flow rate is controlled by the FF control to enter a principle state (step S14).

In the first embodiment of the control of the amount of fuel supplied and the amount of air blown by the controller 60, the initial operation of the hot water supply operation from the start of the hot water supply operation until the tapping temperature rises to a certain range with respect to the set tapping temperature. In the rising period of the normal temperature, there is usually a large temperature difference between the set hot water temperature and the detected hot water temperature. Therefore, when FB control is combined, a large FB is generated based on the temperature difference between the set hot water temperature and the detected hot water temperature. The control number is calculated, which results in a large FB control fuel supply amount. When the large FB control fuel supply amount is added to the FF control fuel supply amount, the air-fuel ratio of the fuel supply amount with respect to the air supply amount of only the FF control air supply amount largely deviates from the optimal air-fuel ratio.
In the first embodiment, during the initial rising period of the hot water supply operation from the start of the hot water supply operation until the tapping temperature rises to a certain range with respect to the set tapping temperature, the FB
Since the control amount is not added to the fuel supply amount, it is possible to prevent the air-fuel ratio based on the fuel supply amount and the blowing amount from largely deviating from the optimum air-fuel ratio.

In the above description, the period from the start of the hot water supply operation to the time when the tapping temperature detected by the tapping temperature sensor falls within a certain range with respect to the set tapping temperature is defined as the time from the start of combustion at the start of the hot water supply operation to the setting of the tapping temperature. In the period until the temperature rises to within a certain temperature range, the tapping temperature rises to within a certain temperature range with respect to the set tapping temperature, that is, the fuel supply amount due to the difference between the set tapping temperature and the tapping temperature. This means that the FB control amount becomes a large deviation from the optimal air-fuel ratio in the air-fuel ratio and rises to a temperature at which the FB control amount does not appear significantly. Therefore, the temperature difference that can keep the deviation of the air-fuel ratio from the optimum air-fuel ratio within a certain range may be determined in advance by experiments as a certain temperature range.
The fixed temperature range may be, for example, a set tapping temperature −5 ° C. Furthermore, it can be set to the set tapping temperature-(2 to 5 ° C). A wider range can be set hot water temperature ± (2-5 ° C.).

Next, a second embodiment of the control of the fuel supply amount of the burner 20 and the blower amount of the blower 30 by the controller 60 in the combustion control apparatus for a water heater of the present invention will be described with reference to FIG.
It is explained along. That is, in the second embodiment, when the hot water supply operation switch (not shown) is turned on by the remote controller 70 or the like and the incoming water flow rate sensor 41 detects the minimum operating water amount or more due to the opening of the hot water supply curan 51 or the like, the combustion of the burner 20 is stopped. Then, the hot water supply operation is started. During the hot water supply operation (Yes in step S21), the controller 60
Calculates the required hot water number from the set hot water temperature, the detected hot water temperature, and the detected hot water flow rate set by the remote controller 70 to obtain the FF control number, and the difference between the detected temperature and the detected hot water temperature is a constant temperature. It is monitored whether it becomes less than (Step S22)
I do. If the temperature difference is not less than the predetermined temperature (NO in step S22), the controller 60 sets the fuel supply amount to the FF corresponding to the FF control number in principle.
FF + FB control is performed by the combination of the control fuel supply amount and the FB control fuel supply amount corresponding to the FB control number, and the air flow rate is determined by the FF control air flow rate corresponding to the FF control number.
F control is performed (step S23). On the other hand, when the temperature difference is less than the certain temperature (in the case of YES in step S22), the controller 60 stops the above-mentioned principle during that time, and also adjusts the fuel supply amount to the FF control fuel supply amount corresponding to the FF control number. The FF control is performed, and the FF control is performed with the FF control air flow corresponding to the FF control number as before (step S24).

When the set hot water temperature is determined in the water heater,
The required FF control number is calculated from the set hot water temperature, the detected incoming water temperature, and the detected incoming water flow rate as the required amount of combustion heat by the above equation 1, and based on this, the FF control fuel supply amount is determined, and the FF control fuel supply amount is determined. The air flow is determined and the operation is performed.
However, since the value of the detected incoming water temperature includes the detection error of the incoming water temperature sensor 42, and the value of the detected incoming water flow rate includes the detection error of the incoming water flow rate sensor 41, it is calculated using the detected incoming water temperature value. The above-mentioned FF control number (hereinafter referred to as operation FF control number) includes an error with respect to the already required FF control number (hereinafter referred to as true FF control number). Therefore, when the error between the true FF control number and the arithmetic FF control number is large, the FB control number becomes large, and as a result, the fuel supply amount and the FF that also perform the FB control
The air-fuel ratio with the amount of air to be controlled only greatly deviates from the optimum air-fuel ratio. The error between the true FF control number and the calculation FF control number can be calculated by Expression 5 using Expression 1 and Expression 4 below.

True FF control number = (Detected hot water temperature−True water temperature) ÷ 25 × True water flow ... Equation 4 Here, True water temperature: Real water temperature True water flow: Real water flow

FF control number error = | (true FF control number−operation FF control number) | ÷ true FF control number ・ ・ ・ Equation 5

The errors affecting the FF control number error are an error in the detected incoming water temperature and an error in the detected incoming water flow rate. And, among them, the FF due to the error of the detected inlet water temperature
It was found that the effect of the control number error greatly changed depending on the difference between the set hot water temperature and the detected hot water temperature. That is, in the above formula 5, if the error of the detected incoming water flow rate is excluded from consideration, the FF control number error can be expressed by the following formula 6.

FF control number error = | (detected incoming water temperature−true incoming water temperature) | ÷ (set outgoing water temperature−true incoming water temperature) = (detected incoming water temperature−true incoming water temperature) ÷ ｛set outgoing water temperature− (detected incoming water temperature) −Δt)｝ = Δt / (ΔT + Δt) ≒ Δt / ΔT Expression 6 where Δt: error of detected incoming water temperature with respect to true incoming water temperature ΔT: set outgoing water temperature−detected incoming water temperature

As is apparent from Equation 6, the FF control number error is ΔT, ie, the difference between the set hot water temperature and the detected hot water temperature,
It can be seen that it is greatly affected by For example, when the detection error of the incoming water temperature sensor 42 is set as an error Δt of the detected incoming water temperature, for example, when Δt = 1 ° C., the above set outlet water temperature is
If the detected inlet water temperature is 65 ° C and the detected inlet water temperature is 15 ° C, the FF control number error is 2% at 1 / (65-15) = 0.02, the set outlet temperature is 40 ° C, and the detected inlet water temperature is 15 ° C. In that case, FF
The control number error is 4% at 1 / (40−15) = 0.04. If the set tap water temperature is 40 ° C and the detected inlet water temperature is 30 ° C, the FF control number error is 1 / (40−30) = 0.10 and 10%
Also.

The error of the FF control number is determined by the input water temperature sensor 42.
Increases due to the detection error of the incoming water flow rate sensor 41 as well as the detection error of. The error in the FF control number is directly reflected on the FB control number, and the detection error of the sensors also affects the calculation of the FB control number. Therefore, for example, when the range of the number error exerted on the FB control number becomes a certain value or more, it may be preferable to not perform the control based on the FB control number. When the FB control fuel supply amount is calculated based on the FB control number based on the large number error, and the fuel supply is performed, the air-fuel ratio with the air flow rate not performing the FB control greatly deviates from the optimum air-fuel ratio. Now, if the allowable error of the number that the FB control number is not performed any more is determined, based on the error,
The total allowable error in the F control number is determined, and the allowable error of the FF control number based on the detection error of the incoming water temperature sensor 42 is further determined with respect to the total allowable error of the FF control number. now,
Assuming that the permissible error of the FF control number based on the detection error of the incoming water temperature sensor 42 is, for example, 8%, the detection error Δt becomes 1
In the case of using the incoming water temperature sensor 42 which is
From, the allowable temperature difference between the set tap water temperature and the detected inlet water temperature is 12.5 ° C, and when the temperature difference is less than 12.5 ° C,
The tolerance of the number of FF control numbers exceeds 8%. Therefore, in this case, the FB control of the fuel supply amount is not performed.

An experiment must be performed in advance to determine whether the difference between the set hot water temperature and the detected hot water temperature is less than how many times the fuel supply control should be performed only with the FF control in the same way as the air flow rate control. Then, the FB control is allowed until the error of the number of FF control numbers becomes large, or the error of the number of FF control numbers due to the detection error of the input water temperature sensor 42 is determined based on the allowable FF control number error. It is determined whether or not the FB control is allowed up to, and is determined by Expression 6.

[0028]

According to the present invention, there is provided the above construction.
According to the combustion control device of the water heater described in the above, the required amount of combustion heat is calculated from the set hot water temperature, incoming water temperature, and incoming water flow rate,
The fuel supply amount by the fuel supply means and the air supply amount by the blower means are FF-controlled, and the fuel supply amount is calculated based on the difference between the set tapping temperature and the tapping temperature by the tapping temperature sensor.
In the combustion control device of the water heater that performs the B control,
During the period from the start of hot water supply operation to the time when the hot water temperature detected by the hot water temperature sensor falls within a certain range with respect to the set hot water temperature, there is a controller that controls the fuel supply amount only by FF control. During the initial transition period of hot water supply operation until the temperature rises to a certain range with respect to the set hot water temperature, it is possible to prevent the air-fuel ratio due to the fuel supply amount and the air blowing amount from largely deviating from the optimum air-fuel ratio. it can. Also, according to the combustion control apparatus for a water heater according to claim 2, the required amount of combustion heat is calculated from the set outlet temperature, the incoming water temperature, and the incoming water flow rate, and the amount of fuel supplied by the fuel supply means and the amount of air blown by the blowing means are calculated. In the combustion control device of the water heater, the fuel supply amount is FB-controlled based on the difference between the set tapping temperature and the tapping temperature by the tapping temperature sensor. When the difference from the temperature is less than a certain temperature, a controller that controls the fuel supply amount only by the FF control is provided, so that the FB control value of the fuel supply amount to be FB controlled due to a detection error of the sensor increases. Before the FB control of the fuel supply amount is stopped, it is possible to prevent the air-fuel ratio between the fuel supply amount and the blowing amount from largely deviating from the optimum air-fuel ratio.

[Brief description of the drawings]

FIG. 1 is an overall view of a water heater according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a first control example by the water heater combustion control device of the present invention.

FIG. 3 is a flowchart illustrating a second control example by the combustion control device for a water heater according to the present invention.

[Explanation of symbols]

 10 Heat exchange can 11 Instantaneous heat exchanger 20 Gun type proportional control burner 30 Blower 40 Inlet pipe 41 Inlet flow sensor 42 Inlet temperature sensor 50 Outlet pipe 52 Outlet temperature sensor 60 Controller 70 Remote control

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihiko Tanaka 93rd Edocho, Chuo-ku, Kobe-shi, Hyogo Inside Noritz Co., Ltd.

Claims (2)

[Claims] 1. A burner, a fuel supply means and a blowing means to the burner, a heat exchanger for heating water passing through the burner by combustion heat of the burner and discharging hot water, and a heat exchanger upstream of the heat exchanger. It has an incoming water temperature sensor and an incoming water flow sensor provided on the water pipe, and an outgoing water temperature sensor provided on the outgoing water pipe on the downstream side of the heat exchanger, and calculates the required amount of combustion heat from the set outgoing water temperature, incoming water temperature, and incoming water flow rate. The feed amount of the fuel supplied by the fuel supply unit and the amount of air blown by the blowing unit are feed-forward controlled, and the fuel supply amount is fed back based on a difference between the set tap temperature and the tap temperature by the tap temperature sensor. In the combustion control device for a water heater controlled, the period from the start of the hot water supply operation until the tapping temperature detected by the tapping temperature sensor falls within a certain range with respect to the set tapping temperature. A combustion control device for a water heater, comprising a controller for controlling the fuel supply amount only by feedforward control during the interval. 2. A burner, a means for supplying fuel to the burner and a means for blowing air to the burner, a heat exchanger for heating water passing through the interior by the heat of combustion of the burner and discharging hot water, and an inlet upstream of the heat exchanger. It has an incoming water temperature sensor and an incoming water flow sensor provided on the water pipe, and an outgoing water temperature sensor provided on the outgoing water pipe on the downstream side of the heat exchanger, and calculates the required amount of combustion heat from the set outgoing water temperature, incoming water temperature, and incoming water flow rate. Then, the feed amount of the fuel supplied by the fuel supply unit and the amount of air blown by the blowing unit are feedforward controlled, and the fuel supply amount is fed back based on a deviation between the set hot water temperature and the hot water temperature by the hot water temperature sensor. In the combustion control device for a water heater, the fuel supply amount is set when the difference between the set outlet temperature and the inlet temperature detected by the inlet temperature sensor is less than a certain temperature. A combustion control device for a water heater, comprising: a controller that performs the control of (1) only by feedforward control.