JPH1194357A - Combustion type heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regulate combustion of a combustion burner for switching a sub- heat exchanger between conductive state and nonconductive state accurately by determining a sub-combustion depending on the conduction conditions for a liquid being heated by the sub-heat exchanger. SOLUTION: A hot water supply unit with additional burning function for bath comprises a burner 2 for burning fuel gas being supplied into a combustion chamber 1 on the inside of a casing CA, and two tin-tybe type heat exchangers N1, N2 for supplying or interrupting supply of hot water, i.e., the liquid being heated through the combustion burner 2, individually and freely. The fuel gas supply passage G to the combustion burner 2 is provided with a main gas solenoid valve 25, a main gas valve 27 for switching fuel gas supply state for the combustion burner 2, and a gas proportional valve 26 for regulating fuel gas supply. Heating conditions of the heat exchanger N1 for supplying hot water can be differentiated between a state where the heat exchangers N1, N2 are arranged in the gas channel and hot water flows through the heat exchanger N2 for additional burning and a state where the hot water flow is interrupted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a main heat exchanger and a sub heat exchanger, each of which allows the flow of a liquid to be heated to be intermittently intermittently arranged, in a combustion gas passage of a combustion burner. In the flow state in which the liquid to be heated flows and the flow stop state in which the flow is stopped, provided in a state where the heating state of the main heat exchanger changes,
Combustion control means for controlling the combustion state of the combustion burner,
During the simultaneous operation in which the liquid to be heated flows through both the main heat exchanger and the slave heat exchanger, detection information of temperature detection means for detecting the temperature of the liquid to be heated flowing through the main heat exchanger The main combustion amount required to heat the liquid to be heated to the target temperature is determined based on the total combustion amount obtained by adding the main combustion amount and the auxiliary combustion amount for heating the auxiliary heat exchanger. And a combustion type heating device configured to burn the combustion burner.

[0002]

2. Description of the Related Art In the above-mentioned combustion type heating apparatus, when the main heat exchanger in which the liquid to be heated flows only through the main heat exchanger is operated alone, the secondary heat exchanger is switched to the flowing state, During the simultaneous operation in which the liquid to be heated flows through both the heat exchanger and the sub-heat exchanger, when the sub-heat exchanger is switched to the flow stop state, the combustion amount of the combustion burner is switched to the state. If not adjusted properly, the liquid to be heated flowing through the main heat exchanger may pass through the main heat exchanger before being heated to the target temperature, or as the liquid passes through the main heat exchanger. Since there is a problem of being heated to a temperature exceeding the target temperature, during the simultaneous operation, the main combustion amount required to heat the liquid to be heated flowing through the main heat exchanger to the target temperature is determined. , Its main combustion amount and secondary combustion to heat the secondary heat exchanger Preparative at total combustion amount plus those configured to burn a combustion burner. In such a combustion type heating device, conventionally, as described in, for example, JP-A-8-320149, the auxiliary combustion amount is regarded as a fixed amount set in advance, and during simultaneous operation, Is configured to burn the combustion burner at a total combustion amount obtained by adding the fixed auxiliary combustion amount and the main combustion amount.

[0003]

However, the actual amount of sub-combustion depends on the temperature difference between the temperature of the combustion gas and the liquid to be heated flowing through the sub-heat exchanger, the scale generation state in the sub-heat exchanger, and the like. It depends on the flow conditions of the liquid to be heated, such as the flow rate of the liquid to be heated flowing through the slave heat exchanger, and if the amount of sub combustion is regarded as a fixed amount as described above, depending on the flow conditions, There is a disadvantage that the combustion amount of the combustion burner corresponding to the switching of the heat exchanger to the flow state or the flow stop state cannot be accurately adjusted. The present invention has been made in view of the above-described circumstances, and switches the state of a slave heat exchanger to a flow state or a flow stop state in accordance with a flow condition of a liquid to be heated flowing through the slave heat exchanger. It is an object of the present invention to accurately adjust the combustion amount of a combustion burner corresponding to the above.

[0004]

According to a first aspect of the present invention, there is provided a combustion-type heating apparatus in which the auxiliary heat exchanger is switched to a flow stop state, and the main heat exchanger only flows through the main heat exchanger. During the stand-alone operation, the combustion burner is burned at the main combustion amount required to heat the liquid to be heated to the target temperature, and the auxiliary heat exchanger is switched to the flowing state, and the main heat exchanger and the auxiliary heat exchanger are connected. During the simultaneous operation in which the liquid to be heated flows to both the heat exchanger and the secondary heat exchanger, the secondary combustion amount in consideration of the flow conditions is estimated based on the operation information of the secondary heat exchanger, and the estimated secondary combustion is calculated. The combustion burner is burned at a total combustion amount obtained by adding the amount and the main combustion amount. Therefore, a secondary combustion amount is determined according to the flow conditions of the liquid to be heated flowing through the secondary heat exchanger, and the combustion of the combustion burner corresponding to the switching of the secondary heat exchanger to the flow state or the flow stop state. The amount can be adjusted precisely. In the combustion-type heating device according to the second aspect, the amount of subordinate combustion is proportional to the product of the flow rate and the temperature difference between the outgoing side detection temperature and the inflow side detection temperature of the liquid to be heated. The auxiliary combustion amount is estimated based on the flow rate of the flowing liquid to be heated, the inlet-side detected temperature, and the outlet-side detected temperature. Therefore, the temperature difference between the temperature of the combustion gas and the liquid to be heated flowing through the sub heat exchanger, the scale generation state in the sub heat exchanger, the flow rate of the liquid to be heated flowing through the sub heat exchanger, etc. It is possible to estimate an appropriate secondary combustion amount that is considered. The combustion-type heating device according to claim 3, wherein the auxiliary heat exchanger is used based on the combustion amount of the combustion burner, the inlet-side detected temperature, and the outlet-side detected temperature during the single operation in which the flow passes only to the slave heat exchanger. The flow rate of the liquid to be heated flowing through the heater is determined. In other words, the amount of heat obtained when the liquid to be heated passes through the secondary heat exchanger can be expressed as the product of the temperature difference between the detected temperature on the outgoing side and the detected temperature on the incoming side and the flow rate, and Since it is proportional to the amount of combustion, the amount of combustion of the combustion burner and the temperature detected on the inflow side and the temperature on the exit side of the liquid to be heated are used in the isolated operation in which the flow only to the slave heat exchanger is performed. An appropriate flow rate can be determined in consideration of the length of the flow path of the liquid to be heated connected to the heat exchanger, a change in flow resistance due to scale generation, and the like. In the combustion type heating device according to the fourth aspect, when switching from the single operation flowing only to the slave heat exchanger to the simultaneous operation, the flow rate obtained in the single operation before the switching and the simultaneous flow after the switching are obtained. The secondary combustion amount is estimated based on the detected entrance side detected temperature and the detected exit side detected temperature. Therefore, using the accurate flow rate before switching to the simultaneous operation, it is possible to estimate an appropriate auxiliary combustion amount corresponding to the flow rate. In the combustion type heating device according to the fifth aspect, when the total combustion amount exceeds the maximum combustion amount of the combustion burner during the simultaneous operation, a part of the required main combustion amount is used to heat the secondary heat exchanger. Therefore, the amount of combustion for heating the liquid to be heated flowing through the main heat exchanger to the target temperature is insufficient, so that the flow rate of the liquid to be heated flowing through the main heat exchanger is reduced. By reducing it, the required main combustion amount is reduced. Therefore, during the simultaneous operation, it is possible to control the liquid to be heated passed through the main heat exchanger to the target temperature while burning the combustion burner at the maximum combustion amount.
In the combustion type heating device according to the sixth aspect, the hot water for hot water supply is heated to the target temperature in the main heat exchanger, and the circulating liquid to be heated is heated in the secondary heat exchanger. It is possible to prevent hot water supplied at a temperature lower than the target temperature or hot water supplied at a temperature higher than the target temperature from causing a danger due to the switching of the container to the flow state or the flow stop state. . In the combustion type heating device according to the seventh aspect, since the main heat exchanger and the sub heat exchanger are constituted by fin tube type heat exchangers sharing heat transfer fins, combustion of the combustion burner is achieved. The heat generated by the heat transfer is easily transmitted to both the main heat exchanger and the sub heat exchanger by the heat transfer fins, thereby improving the heat efficiency and suppressing the fuel consumption of the combustion burner to a small amount.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] Hereinafter, a hot water supply device having a bath reheating function as an example of a combustion type heating device according to the present invention will be described with reference to the drawings. As shown in FIG. 1, a combustion burner 2 for burning supplied fuel gas is provided in a combustion chamber 1 provided inside a casing CA, and hot and cold water as a liquid to be heated which is heated by combustion of the combustion burner 2. Two fin tube type heat exchangers N whose flow can be interrupted separately
1, N2, and a motor-driven fan 4 for ventilating combustion air to the combustion burner 2 at a lower portion of the combustion chamber 1; An ignition igniter 5 for igniting and a frame rod 6 for detecting whether or not ignition has occurred are provided. The fuel gas supply path G to the combustion burner 2 is provided with an original gas solenoid valve 25, a main gas valve 27 for switching the fuel gas supply state to the combustion burner 2, and a gas proportional valve 26 for changing and adjusting the fuel gas supply amount. ing.

The two heat exchangers N1 and N2 are provided with a heat exchanger N1 as a main heat exchanger for heating the water supplied from the water supply channel 7 and supplying the hot water to the hot water channel 8; A reheating furnace N2 as a secondary heat exchanger for heating hot water in a supplied bathtub 18 (an example of a heated portion) and flowing it out to the outlet Lo.
N2 is arranged in the combustion gas passage S of the combustion burner 2 in the longitudinal direction of the combustion gas, and the reheating heat exchanger N2 is set in a flow state in which hot and cold water flows and a flow stop state in which the flow is stopped. The hot water supply heat exchanger N1 is provided in a state where the heating state changes.

More specifically, as shown in FIG. 2 and FIG. 3, which is a cross-sectional view in the same direction as FIG.
Is provided with nine heat-absorbing pipes 12 connected to each other by U-shaped pipes 11 on both lateral sides.
2 is similarly provided with five heat absorption pipes 13. Then, the heat transfer fins 14 are connected to these heat absorbing pipes 1.
2 and 13, and each of the heat absorption pipes 13 constituting the additional heat exchanger N2 is connected to five of the nine heat absorption pipes 12 constituting the hot water supply heat exchanger N1. The hot water in the heat exchanger N1 for hot water supply and the hot water in the heat exchanger N2 for additional heating are easily conducted to each other by arranging the pipes and the pipes so as to contact each other along the longitudinal direction.

The bathtub 18 is connected to a bath return pipe 9 for flowing hot water from the bathtub 18 and a bath going pipe 10 for flowing hot water into the bathtub 18. The bath return pipe 9 is connected to the entrance Li. While connecting via the return joint 3a,
The bath outgoing pipe 10 and the outgoing line Lo are connected via the outgoing joint 3b, and are heated while circulating the hot water in the bath tub 18 over the bath tub 18 and the additional heat exchanger N2 by driving the circulation pump 28. A reheating circuit is configured.

The hot water supply path 8 is provided with a bypass path 15 for bypassing and supplying water from the water supply path 7, and a mixing ratio between a hot water supply amount from the hot water supply heat exchanger N 1 and a water bypass amount from the bypass path 15. The hot and cold water mixed after being mixed by the mixing valve 16 is supplied through a hot water supply passage 17 from a hot water tap (not shown), or the hot water is supplied to a bathtub 18. Or to be configured.

On the upstream side of the connection point of the water supply passage 7 with the bypass passage 15, the hot water supply heat exchanger N 1
An inlet water temperature thermistor 19 as a temperature detecting means for detecting the temperature of hot water flowing through the water, and a water amount sensor 20 for detecting the amount of flowing water are provided.
An outlet hot water thermistor 21 for detecting the temperature of the hot water from the hot water outlet is provided. The hot water supply path 17 has a hot water supply temperature thermistor 22 for detecting the temperature of the hot and cold water mixed by the mixing valve 16, and a water proportion for suppressing the hot water supply when the total hot water supply exceeds the heating capacity of the combustion burner 2. A valve 23, an interrupt sensor 24 for detecting whether or not the amount of water passing through the hot water tap is greater than or equal to a set amount for detecting that the hot water tap is opened while hot water is being supplied to the bathtub 18 are provided. .

A constant discharge type circulating pump 28 for circulating hot and cold water, a water flow switch 29 which is turned on when it detects that there is more water than a set amount,
Entry-side hot water temperature thermistor 30 for detecting the temperature of hot and cold water in the inside as entry-side detected temperature Tfi, bath two-way valve 31, bathtub 18
Water level sensor 32 for detecting the water level of the
The outlet o is provided with an outlet-side hot water temperature thermistor 34 that detects the temperature of the hot water in the outlet Lo after being heated by the additional heat exchanger N2 as the outlet-side detected temperature Tfo.

The hot water supply path 17 is branched downstream of the water proportional valve 23 into a general hot water supply path 17a for supplying hot water to the hot water tap and a hot water supply path 17b for supplying hot water to the bathtub 18 side. Reference numeral 17b is connected to the entrance Li via a hot water filling electromagnetic valve 36, a hopper 37 for preventing backflow, and a check valve 38, and is provided with a drainage electromagnetic valve 39 for discharging remaining hot water in the hopper 37. .

The hot water supply apparatus includes a remote controller R having an operation switch for instructing operation, and a remote controller R
And a control unit H for controlling the operation of each unit of the water heater based on the command information input from the control unit. As the command information, there are a hot water filling operation for supplying hot water to the bathtub 18, a bath reheating operation, a test operation operation command, and a temperature command such as a target hot water supply temperature. The control unit H is provided with a microcomputer, and receives detection information of the thermistors and sensors, and sends the detection information and the remote control R
The control unit H controls the operation of the combustion state of the combustion burner 2, the valves for adjusting the water flow, the mixing valve 16, the circulation pump 28, and the like based on the command information from the combustion burner 2. 2 functions as combustion control means for controlling the combustion state. Further, the control unit H rewritably stores the circulation amount Qf of the hot and cold water circulating in the additional heating circulation path, the number of times of the additional heating operation, and the like, which are the flow rates passed through the additional heating heat exchanger N2. A non-volatile memory 33 is provided;
In this memory 33, a circulation amount Qf corresponding to a standard installation state of the water heater is stored as an initial value.

Next, the control operation of the control unit H will be described with reference to the flowchart of FIG. When the operation switch of the remote controller R is not turned on,
The operation stop processing is executed (# 1, 9), and the operation switch is set to O
If the N operation has been performed, it is determined whether or not it is necessary to operate the hot water supply device (# 2). If it is determined that the hot water supply device does not need to be operated, the operation stop processing is executed (#).
9). In the operation stop processing, when the combustion burner 2 is burning, the original gas solenoid valve 25, the main gas valve 27,
After closing the supply of the fuel gas to the combustion burner 2 by closing each of the gas proportional valves 26, the ventilation by the fan 4 is stopped, and when the circulation pump 28 is driven, the driving thereof is stopped. Then, when the water flow rate exceeding the set water flow rate is detected by the water flow rate sensor 20, or when the operation command of the hot water filling operation, the additional heating operation, or the test operation is input, it is necessary to operate the hot water supply device. When it is determined that the test operation command is input, the operation in the test operation mode is executed (# 3, 10). When the test operation command is not input, hot water is supplied from the hot water tap. It is determined which one of the hot water supply operation mode, the hot water supply operation mode, the additional heating operation mode, and the general hot water supply and additional heating simultaneous operation mode is to be executed (# 4,
5). That is, when a water flow rate exceeding the set water flow rate is detected by the water flow sensor 20 in a state where the operation command of the hot water filling operation is not input, and when the operation instruction of the additional heating operation is input, the normal hot water supply operation is performed. An operation is performed in the general hot water supply and additional heating simultaneous operation mode in which the additional water heating operation is performed simultaneously (# 11), and when the operation command of the hot water filling operation and the additional heating operation is not input, the amount of water flowing exceeds the set amount of water flowing. If the interrupt sensor 24 detects that the water amount sensor 20 has been operated or that the hot water tap has been opened during the operation in the hot water filling operation mode, the operation in the general hot water supply operation mode is executed (# 6). When the operation command of the filling operation is input while the operation in the general hot water supply operation mode is not executed, the operation in the filling operation mode is executed (# 7), and the filling is performed. When the operation command reheating operation is inputted in a state where the operation command of the operation is not input, executes the operation by reheating operation mode (#
8).

In the test operation mode, the thermistors, sensors and the like,
Combustion burner 2, valves for water flow control, mixing valve 1
6. This is executed to check the operation of each part such as the circulation pump 28.

In the operation in the general hot water supply operation mode,
When the combustion burner 2 is not ignited, after the burner ignition process is executed, the detected kettle outlet temperature Toa detected by the outlet hot water temperature thermistor 21 is set to a preset target kettle outlet temperature Ts.
In addition to controlling the amount of combustion of the combustion burner 2 so as to achieve a, the mixing valve 16 is operated so as to reach the target hot water supply temperature instructed by the remote controller R. When the detection is stopped, the operation in the general hot water supply operation mode ends. In the burner ignition process, the ventilation by the fan 4 is started to open the source gas solenoid valve 25, the main gas valve 27, and the gas proportional valve 26 to supply the fuel gas to the combustion burner 2 and the igniter 5 Igniting the combustion burner 2 by the ignition of the combustion burner 2. When the ignition is confirmed by the flame rod 6, the ignition operation of the igniter 5 is stopped.

In operation in this general hot water supply operation mode, the incoming water temperature thermistor 19 and the outlet hot water thermistor 21
Of combustion (fuel supply amount) I of the combustion burner 2 required to heat the water to the target kettle outlet temperature Tsa based on the detection information of
Pa is determined, and the combustion burner 2 is burned using the combustion amount IPa as a target combustion amount. More specifically, as shown in the following [Equation 1], the target shuttle discharge temperature Tsa
And a control amount Kpa, Kia for feedback control, and a combustion amount IPa for feedback control is determined so that the detected cooker exit temperature Toa becomes the target cooker exit temperature Tsa. , Its combustion amount IPa
Is set as the target combustion amount to burn the combustion burner 2.

[0018]

## EQU1 ## IPa = Kpa.multidot. (Tsa-Toa) + Kia
・ ∫ (Tsa-Toa) dt

In the operation in the bath filling operation mode, each of the bath filling solenoid valve 36 and the bath two-way valve 31 is opened.
When the water flow rate sensor 20 detects a water flow rate exceeding the set water flow rate, the burner ignition process is executed when the combustion burner 2 is not ignited, and then the detected tank outlet temperature Toa detected by the outlet hot water temperature thermistor 21 is used. The combustion amount of the combustion burner 2 is controlled so as to reach a preset target discharge temperature Tsa, and the mixing valve 16 is operated so as to reach the target filling temperature instructed by the remote control operation unit R. Hot water of the tension temperature is supplied to the entrance Li from the bath hot water supply path 17b. The hot and cold water supplied to the entrance Li is supplied from the bath return pipe 9 to the bathtub 18 through the circulation pump 28 and the bath two-way valve 31, and is supplied to the bath pipe 10 through the additional heat exchanger N2. When the water level of the bathtub 18 detected by the water level sensor 32 reaches the target water level, the hot water filling solenoid valve 36 and the bath two-way valve 31 are closed, and the hot water filling operation mode is started. End the operation. In the operation in the hot water filling operation mode, the combustion burner 2 is configured to burn the combustion amount IPa obtained in the same manner as in the general hot water supply operation mode as a target combustion amount.

In the reheating operation mode, as shown in the flow chart of FIG. 5, the hot water in the bathtub 18 such as the opening of the bath two-way valve 31, the driving of the circulation pump 28, and the amount of combustion of the combustion burner 2 is measured. The control necessary for heating is executed in the reheating operation processing (# 20), and when a set time from the start of the reheating operation to the time when the combustion state is stabilized elapses (# 21), at that time, A circulation amount calculation process for obtaining a circulation amount Qf of the hot and cold water circulating through the additional heating circulation path is performed (# 22), and the circulation amount Q stored in the memory 33 is obtained.
f is updated to the obtained circulation amount Qf (# 23).

In the reheating operation, the bath two-way valve 31 is used.
To drive the circulation pump 28 with a constant driving force,
When the water flow switch 29 is turned on when the circulation of hot water in the bathtub 18 is started, the burner ignition process is executed when the combustion burner 2 is not ignited, and then the heat is supplied from the bath return pipe 9 to the additional heat exchanger N2. The target reheating temperature Ts for hot water
The amount of combustion of the combustion burner 2 is controlled so as to heat to the temperature c, and when the entrance-side detected temperature Tfi exceeds the target reheating temperature Tsc, the drive of the circulation pump 28 is stopped. In the reheating operation process, the combustion burner 2 necessary for heating the hot water in the bathtub 18 to the target reheating temperature Tsc in the reheating heat exchanger N2 based on the circulation amount Qf stored in the memory 33. Of combustion (fuel supply amount) IPc of the fuel cell, and the combustion amount IPc
Is set as the target combustion amount to burn the combustion burner 2. More specifically, as shown in the following [Equation 2], the target reheating temperature Tsc set by the remote control operation unit R is set.
A combustion amount IPc for feedback control is determined such that the output side detected temperature Tfo becomes the target reheating temperature Tsc based on a deviation between the output side detected temperature Tfo and the control constants Kpc and Kic for feedback control.

[0022]

## EQU2 ## IPc = Kpc. (Tsc-Tfo) + Kic
・ ∫ (Tsc-Tfo) dt

In the circulation amount calculation process, the detected temperature Tfi on the entrance side and the detected temperature Tfo on the exit side at that time, the combustion amount IPc obtained by the above [Equation 2], and the heat exchanger N for reheating.
Based on the proportionality constant Cc experimentally obtained in advance in consideration of the thermal efficiency and the like of No. 2, as shown in the following [Equation 3],
The circulation amount Qf is calculated.

[0024]

## EQU3 ## Qf = Cc.IPc / (Tfo-Tfi)

In the operation in the general hot water / supplementary heating simultaneous operation mode, the bath two-way valve 31 is opened and the circulation pump 2 is opened.
8 is driven with a constant driving force, and when the combustion burner 2 is not ignited, a burner ignition process is executed, and then the detected cooker outlet temperature Toa is heated so as to be a preset target cooker outlet temperature Tsa, and , Additional heat exchanger N
Burner 2 so as to heat the hot and cold water flowing through
And the mixing valve 16 is operated so that the target hot water supply temperature instructed by the remote controller R is attained. Then, when the flow rate exceeding the set flow rate is not detected by the flow rate sensor 20, the operation shifts to the operation in the additional heating operation mode, and the flow rate exceeding the set flow rate is detected by the flow rate sensor 20. Entry side detected temperature Tfi
If the temperature exceeds the target additional heating temperature Ts, the driving of the circulation pump 28 is stopped and the operation shifts to the operation in the general hot water supply operation mode.

In the operation in the general hot water supply / supplementary heating simultaneous operation mode, the water from the water supply passage 7 obtained in the same manner as in the general hot water supply operation mode is supplied to the hot water supply heat exchanger N1.
Combustion burner 2 required to heat to the target pot discharge temperature Tsa
The target combustion amount (fuel supply amount) IPa is set as the main combustion amount, and the entry-side detection temperature Tfi and the exit-side detection temperature Tfo, which are the operation information of the additional heating heat exchanger N2, are stored in the memory 33. Based on the circulating amount Qf, the combustion amount IPb required to heat the additional heating heat exchanger N2 is estimated as the auxiliary combustion amount, and the total obtained by adding the estimated auxiliary combustion amount IPb and the main combustion amount IPa. Combustion amount IPs (IPa + IP
It is configured to burn the combustion burner 2 with b) as a target combustion amount.

The secondary combustion amount IPb, as shown in the following [Equation 4], takes into account the circulation amount Qf, the inlet-side detected temperature Tfi, the outlet-side detected temperature Tfo, the thermal efficiency of the additional heat exchanger N2, and the like. And the proportional constant Cb, which is experimentally determined in advance
And is estimated based on

[0028]

## EQU4 ## IPb = Cb. (Tfo-Tfi) .Qf

Therefore, when the operation shifts from the operation in the general hot water supply operation mode to the operation in the general hot water supply and additional heating simultaneous operation mode, the target combustion amount is changed from IPa to IPs.
When shifting from the operation in the general hot water supply / reheating operation mode to the operation in the general hot water supply operation mode, the target combustion amount is changed from IPs to IPa, and the operation in the reheating operation mode is changed to the general hot water / reheating operation mode. When the operation shifts to the operation, the target combustion amount is changed from IPc to IPs, and when the operation shifts from the operation in the general hot water supply and additional heating simultaneous operation mode to the operation in the additional heating operation mode, the target combustion amount IP changes from IPs to IPc. Be changed.

When the total combustion amount IPs exceeds the maximum combustion amount IPmax that can be burned by the combustion burner 2 and the water from the water supply passage 7 cannot be heated to the target tank discharge temperature Tsa, the combustion burner 2 Is the maximum combustion amount IPmax
The maximum water flow Qm of the hot water supply heat exchanger N1 that can be heated to the target kettle outlet temperature Tsa by the combustion is determined, and the water flow Qa detected by the water flow sensor 20 decreases to the maximum water flow Qm. Thus, the water proportional valve 23 is squeezed so as to heat it to the target shuttle outlet temperature Tsa.
As shown in the following [Equation 5], the maximum water flow rate Qm is a proportional value previously experimentally determined in consideration of the target hot water supply temperature Tsa and the incoming water temperature Tia, the thermal efficiency of the hot water supply heat exchanger N1, and the like. It is determined based on the constant Ca.

[0031]

## EQU5 ## Qm = Ca. (IPmax-IPb) / (Tsa
-Tia)

[Second Embodiment] In the first embodiment,
Although the circulation amount Qf is obtained and updated every time the operation is performed in the reheating operation mode, in addition to checking the operation of each part during the operation in the test operation mode executed at the time of installation of the water heater, etc. , A circulation amount updating process for obtaining and updating the circulation amount Qf may be performed. In this circulation amount update process, the combustion amount (fuel supply amount) IPt for the test operation for obtaining the circulation amount Qf is stored in the memory 33, the flow of water to the hot water supply heat exchanger N1 is stopped, and The operation is performed in a state where a predetermined amount of hot water is filled in the bathtub 18. That is, as shown in the flowchart of FIG. 6, after the bath two-way valve 31 is opened (# 3
0), the circulation pump 28 is driven with a constant driving force (# 3
1) The water flow switch 29 is turned on when the circulation of hot water starts
Then (# 32), a burner ignition process for igniting the combustion burner 2 is executed, and the combustion burner 2 is fired in the test combustion mode in which the combustion burner 2 is burned at the test operation combustion amount IPt stored in the memory 33 in advance. The combustion amount is controlled (# 33). Then, when the set time until the combustion state becomes stable (# 34), the entrance-side detected temperature T at that time is set.
Based on fi, the outgoing-side detected temperature Tfo, the combustion amount IPt for the test operation, and the proportionality constant Cc experimentally determined in advance in consideration of the thermal efficiency and the like of the additional heat exchanger N2. As shown in [Equation 6], a circulation amount calculation process for calculating the circulation amount Qf is executed (# 35), and the circulation amount Qf stored in the memory 33 is updated to the obtained circulation amount Qf (# 36). ).

[0033]

## EQU6 ## Qf = Cc.IPt / (Tfo-Tfi)

Incidentally, while the hot water supply device has been used for a long period of time, scale may be generated in the additional heating circulation path or the performance of the circulation pump 28 may be deteriorated. In addition to the operation in the test operation mode, when the number of executions of the heating operation exceeds the set number, only the circulation amount update process is executed, or in the operation in the additional heating operation mode described in the first embodiment. A configuration for obtaining and updating the circulation amount Qf may be combined.

[Third Embodiment] In the first embodiment, in the general hot water supply / supplementary heating simultaneous operation mode, it is necessary to heat the water from the water supply passage 7 to the target kettle discharge temperature Tsa by the hot water supply heat exchanger N1. Although the combustion is performed with the total combustion amount IPs obtained by adding the secondary combustion amount IPb estimated in [Equation 4] to the main combustion amount IPa, the operation is performed from the reheating operation mode to the general hot water supply / reheating simultaneous operation mode. When the operation shifts to, instead of the secondary combustion amount IPb estimated in [Equation 4], the combustion obtained in [Equation 2] during the operation in the additional heating operation mode before shifting to the operation in the general hot water supply and additional heating simultaneous operation mode The amount IPc may be estimated as a sub-combustion amount, and combustion may be performed at a total combustion amount IPs obtained by adding the sub-combustion amount IPc and the main combustion amount IPa. Other configurations are the same as those of the first embodiment.

[Fourth Embodiment] In the first embodiment, the circulation amount Qf flowing through the additional heat exchanger N2 is determined by the combustion amount IPc of the combustion burner 2, the inlet-side detected temperature Tfi, and the outlet-side detected temperature Tfo. However, a flow rate sensor may be provided in the additional heating circulation path, and the flow rate detected by the flow rate sensor may be used as the circulation amount Qf. Other configurations are the same as those of the first embodiment.

[Fifth Embodiment] In the first embodiment, the auxiliary combustion amount IPb is estimated based on the circulation amount Qf, the entrance-side detected temperature Tfi, the exit-side detected temperature Tfo, and the proportionality constant Cb. Although the configuration has been described, a configuration may be adopted in which the estimation is performed using the target additional heating temperature Tfs instead of the exit-side detected temperature Tfo. Other configurations are the same as those of the first embodiment.

[Other Embodiments] The combustion-type heating device according to the present invention may be provided with a heat exchanger for heating as a main heat exchanger or a sub heat exchanger. 2. In the combustion type heating device according to the present invention, the main heat exchanger and the sub heat exchanger may be provided side by side in a direction crossing the combustion gas flow path. 3. The combustion type heating device according to the present invention is not limited to the one in which the heat transfer fins of the main heat exchanger and the heat transfer fins of the slave heat exchanger are shared. The heat transfer fins of the exchanger may be provided separately. 4. The combustion-type heating device according to the present invention is provided with three or more heat exchangers in a combustion gas passage of a combustion burner,
One of the heat exchangers may be configured to function as a main heat exchanger and the remaining heat exchangers may function as slave heat exchangers. 5. The combustion-type heating device according to the present invention experimentally determines the relationship between the detected inlet side temperature, the detected outlet side temperature of the slave heat exchanger, and the amount of secondary combustion at that time, and stores the determined relationship in the storage element in advance. In this case, the secondary combustion amount corresponding to the entrance-side detected temperature and the exit-side detected temperature detected during the simultaneous operation may be read from the storage element and estimated. 6. The combustion-type heating device according to the present invention may be configured such that each time simultaneous operation is started, the secondary combustion amount is estimated using the circulation amount of the liquid to be heated obtained before the start of the simultaneous operation. 7. The combustion type heating device according to the present invention may be configured to estimate the secondary combustion amount using a preset fixed circulation amount. 8. In the combustion-type heating device according to the present invention, the liquid to be heated is not necessarily required to be hot and cold, and when a heating heat exchanger is provided as a main heat exchanger or a sub heat exchanger, the heating is performed. A liquid heat medium exclusively for heating as a liquid to be heated may be used in the heat exchanger for heating. 9. In the combustion type heating device according to the present invention, the combustion control means controls the combustion state of the combustion burner by setting a combustion amount obtained by adding a combustion amount for feedforward control and a combustion amount for feedback control as a target combustion amount. May be configured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a water heater.

FIG. 2 is a side view of a main part of the heat exchanger.

FIG. 3 is a sectional view of a main part of the heat exchanger.

FIG. 4 is a flowchart showing a control operation of the water heater.

FIG. 5 is a flowchart of an operation in a reheating operation mode.

FIG. 6 is a flowchart of a circulation amount update process;

[Explanation of symbols]

 2 Combustion burner 14 Heat transfer fin 18 Heated portion 19, 21 Temperature detection means H Combustion control means IPa Main combustion amount IPb Secondary combustion amount IPc Combustion amount IPmax Maximum combustion amount IPs Total combustion amount Li Inlet Lo Outlet N1 Main heat exchanger N2 Secondary heat exchanger OPt Combustion amount Qa Flow rate Qf Flow rate S Combustion gas flow path Tfi Incoming side detected temperature Tfo Outgoing side detected temperature Tsa Target temperature

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Daisuke Konishi, 1-15-1 Oka, Minami-shi, Minato-ku, Osaka, Osaka Prefecture Inside Herman Co., Ltd. (72) Masayoshi Hogawa 1-1-1, Oka, Minami-shi, Minato-ku, Osaka, Osaka No. 52 Inside Harman Co., Ltd. (72) Kenji Kanji Office, 1-1-1, Oka, Minami-shi, Minato-ku, Osaka-shi No. 52 Inside Harman Co., Ltd.

Claims (7)

[Claims] 1. A main heat exchanger and a sub heat exchanger, each of which allows the flow of a liquid to be heated to be intermittently connected, through which a liquid to be heated flows through a combustion gas flow path of a combustion burner. The main heat exchanger is provided in a state where the heating state of the main heat exchanger changes between a flowing state in which the main heat exchanger is stopped and a flow stopping state in which the flow is stopped, and the combustion control means for controlling a combustion state of the combustion burner includes: In the simultaneous operation in which the liquid to be heated flows to both the exchanger and the sub heat exchanger, based on the detection information of the temperature detecting means for detecting the temperature of the liquid to be heated flowing to the main heat exchanger. The main combustion amount required to heat the liquid to be heated to the target temperature is determined, and the total combustion amount is obtained by adding the main combustion amount and the secondary combustion amount for heating the secondary heat exchanger. A combustion-type heating device configured to burn a combustion burner, wherein the combustion control unit includes: Wherein said 従燃 sintered amount during simultaneous operation, the 従熱 exchanger operating information Configured combustion type heating device to estimate based on. 2. The combustion control means, comprising: a flow rate of a liquid to be heated flowing through the slave heat exchanger; a temperature detected on an inlet side of the liquid to be heated detected at an inlet of the slave heat exchanger;
The combustion-type heating device according to claim 1, wherein the auxiliary combustion amount is estimated based on an outlet-side detected temperature of the liquid to be heated detected at an outlet of the slave heat exchanger. 3. The combustion control means, based on the combustion amount of the combustion burner, the inlet-side detected temperature, and the outlet-side detected temperature during a single operation in which only the slave heat exchanger flows. 3. The combustion type heating device according to claim 2, wherein the flow rate is determined. 4. When the combustion control means switches from the single operation flowing only to the slave heat exchanger to the simultaneous operation, the combustion flow rate and the simultaneous operation after the switching are determined. 4. The combustion-type heating device according to claim 3, wherein the auxiliary combustion amount is estimated based on the entrance-side detected temperature and the exit-side detected temperature detected at a time. 5. The combustion control means, wherein, during the simultaneous operation, when the total combustion amount exceeds a maximum combustion amount of the combustion burner, a liquid to be heated flowing through the main heat exchanger has a target temperature. The combustion-type heating device according to any one of claims 1 to 4, wherein the flow rate of the liquid to be heated is reduced. 6. The main heat exchanger is configured to heat hot water for hot water supply as a liquid to be heated, and the slave heat exchanger heats a liquid to be heated circulating over a heated portion. The combustion-type heating device according to any one of claims 1 to 5, wherein the heating device is configured as described above. 7. The main heat exchanger and the sub heat exchanger,
The combustion type heating device according to any one of claims 1 to 7, comprising a fin tube type heat exchanger sharing heat transfer fins.