JPH109675A - Composite water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent vapor condensation of a reheating heat exchanger due to a decrease in combustion heat quantity of a bath burner caused by simultaneous combustion of a hot water supply burner and the bath burner in a composition water heater having a common proportional valve for both the supply burner and the bath burner. SOLUTION: A pump intermittent operation controller 50 is provided in a control apparatus 56. A data storage unit 52 stores a pump-off temperature TOFF of an output side of a reheating heat exchanger corresponding to a temperature immediately before generation of vapor condensation of the exchanger and a higher pump-on temperature TON than the temperature TOFF. The controller 50 turns off a circulation pump 23 while keeping a bath burner burning when it is judged that the detected hot water temperature of an output side temperature sensor 44 of the exchanger is the TOFF or less, at the time when the pump 23 is turned on in simultaneous combustion, and turns on the pump 23 when it is judged that the detected hot water temperature is the TON or more for its pump-off period. It prevents the temperature drop of the exchanger to avoid the occurrence of vapor condensation of the exchanger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined water heater having a hot water supply burner and a bath burner.

[0002]

2. Description of the Related Art FIG. 7 shows an example of a system configuration of a combined water heater (apparatus). In FIG. 1, a hot water supply combustion chamber 3 and a bath combustion chamber 4
The hot water supply combustion chamber 3 is provided with a hot water supply burner 5, and the bath combustion chamber 4 is provided with a bath burner 6.

[0003] The hot water supply burner 5 and the bath burner 6 are arranged side by side through a partition portion 2.
An original solenoid valve 37 and a proportional valve 38 are provided in a gas supply passage 36 communicating with the gas nozzle holders 12 and 13, respectively, and a gas supply passage 36 downstream of the proportional valve 38 is branched. The gas serving as fuel is guided to the gas nozzle holders 12 and 13 via the hot water supply gas switching valve 39 and the bath gas switching valve 40, respectively. A common air chamber (air chamber) 7 is provided below the hot water supply burner 5 and the bath burner 6, and a combustion fan 8 for supplying and exhausting air is connected to the bottom of the air chamber 7. The combustion fan 8 is provided with a fan speed sensor 17 for detecting the fan speed.

In the hot water supply combustion chamber 3, a hot water supply heat exchanger 15 is provided above the hot water supply burner 5, and the hot water supply heat exchanger 15 is supplied from a water supply source such as tap water through a water supply passage 19. The introduced water is heated by the combustion flame of the hot water supply burner 5 to produce hot water at a set temperature, and this hot water is supplied to the hot water supply heat exchanger 15.
The hot water is supplied to a desired hot water supply place such as a kitchen or a bathroom via a hot water supply passage 20 connected to the outlet side of the hot water supply. In the drawing, reference numeral 30 denotes an incoming water temperature sensor, 31 denotes an outgoing water temperature sensor, and these sensors detect the incoming water temperature to the hot water supply heat exchanger 15 and the outgoing water temperature from the hot water supply heat exchanger 15, respectively. . Reference numeral 41 denotes a flow rate sensor that detects the flow rate of water supplied from the water supply source to the hot water supply heat exchanger 15.

In the bath combustion chamber 4, a reheating heat exchanger 16 is installed above the bath burner 6, and one end of a pipe 22 is connected to the inlet side of the reheating heat exchanger 16. The other end of the conduit 22 is connected to the discharge side of the circulation pump 23. The conduit 22 is provided with a bath temperature sensor (entrance temperature sensor) 24 such as a thermistor for detecting the temperature of water flowing in the inlet side of the reheating heat exchanger 16.

A return pipe 26 is connected to the suction side of the circulation pump 23, and a return port side (inlet side) of the return pipe 26 is connected to a side wall of the bathtub 21 via a circulation fitting 27. This return pipe
26 is provided with a flowing water detection sensor 28 that is configured by a flow sensor, a flowing water switch, or the like that detects the passage of water and outputs an ON signal. The outlet side of the reheating heat exchanger 16 is connected to the inlet side of the outgoing pipe 29, and the outlet side of the outgoing pipe 29 is connected to the circulation fitting 27.
Is connected to the side wall of the bathtub 21 via the. Return pipe 26
The pipe 22 and the reheating heat exchanger 16 and the outgoing pipe 29 constitute a reheating circuit 25 for circulating hot and cold water in the bathtub 21 via a circulation fitting 27, and the reheating heat exchanger 16 is provided from the bathtub. The circulating hot and cold water is introduced and heated by the combustion flame of the bath burner 6, and the heated hot water is returned to the bathtub 21 to reheat the bath. Both the bath combustion chamber 4 and the hot water supply combustion chamber 3 communicate with a common exhaust port 42 so that the exhaust gas of the hot water supply burner 5 and the exhaust gas of the bath burner 6 are discharged from the common exhaust port 42. It has become.

The hot water supply passage 20 is branched from a hot water filling pipe 32 and connected to the pipe line 22.
A pouring valve 35 as a pouring control valve and a pressure sensor 34 as a water level detecting sensor for detecting a bathtub water level are provided.

In the drawing, reference numeral 44 denotes an outlet temperature sensor which is an outlet temperature sensor for the reheating heat exchanger for detecting the outlet hot water temperature of the reheating heat exchanger 16, and reference numeral 45 denotes a fan air volume of the combustion fan 8. 2 shows a fan airflow detection sensor for detecting the airflow.

A control device 56 for controlling the combustion of a hot water supply burner and the combustion of a bath burner is provided in this type of combined water heater, and a remote controller 55 is connected to the control device 56. Signals from various sensors such as the flow rate sensor 41 and information from the remote controller 55 are added to the control device 56.For example, the control device 56 may be connected to a hot water supply place such as a kitchen where the hot water supply passage 20 is guided. When a hot water tap (not shown) provided is opened and water is introduced into the water supply passage 19 from a water supply source such as a tap water, the control device 56 receives a water input signal from the flow rate sensor 41 and controls the combustion fan 8. Rotate the gas supply passage 36 of the original solenoid valve
37, the proportional valve 38 and the hot water supply side gas opening / closing valve 39 are opened. In this state, the hot water supply burner 5 is ignited, and after detecting the flame, the hot water temperature detected by the hot water temperature sensor 31 is set by the remote controller 55. The hot water supply operation in the hot water supply mode is controlled so as to reach a set temperature.

In controlling the hot water supply operation, the control device
The combustion capacity at the time of minimum combustion of hot water supply combustion (minimum combustion capacity) and the combustion capacity at the time of maximum combustion (maximum combustion capacity) are given to 56 in advance. The amount of gas supplied from the gas supply passage 36 to the hot water supply burner 5, that is, the opening amount of the proportional valve 38 (proportional valve current amount), so that hot water supply burner combustion is performed within the range up to the combustion capacity.
The amount of air supplied from the combustion fan 8 to the hot water supply burner 5 is controlled so that hot water at a stable set temperature is supplied from the hot water supply heat exchanger 15 via the hot water supply passage 20 to a desired hot water supply place. I have.

The control device 56 opens the pouring valve 35 such as an electromagnetic valve to drop hot water produced on the hot water supply heat exchanger 15 side into the bathtub 21 via the heating circulation circuit 25 to fill the bathtub. It has a running operation function in the hot water filling mode. This automatic filling operation is performed by a command from the remote controller 55 or the like.
When the water level of the hot water reaches the set water level set by the remote controller 55 or the like by the pressure sensor 34, the pouring valve 35 is closed to stop the hot water filling, and then the circulation pump 23 is started to reheat the water. The operation in the mode is performed.

At the time of this reheating operation, the controller 56
First, the circulation pump 23 of the reheating circuit 25 is rotated to circulate the hot water in the bathtub 21 through the reheating circuit 25. Then, when the flowing water detection sensor 28 detects the flow of hot and cold water, the control device 56 rotates the combustion fan 8, opens the bath-side gas on-off valve 40, burns the bath burner 6 by spot ignition, and reheats heat. The circulating hot water passing through the vessel 16 is heated to reheat the hot water in the bathtub 21.

In this reheating independent operation control,
Normally, a value of the maximum combustion capacity is given to the control device 56, and the combustion fan 8 is rotated at a fan rotation speed corresponding to the maximum combustion capacity, and the burner combustion of the bath burner 6 is performed. Make sure that reheating is done.
Then, when the bath temperature detected by the bath temperature sensor 24 reaches the bath set temperature (boiling temperature) set by the remote controller 55, the reheating operation is stopped.

In this type of combined water heater, the system shifts to the heat retention mode for a predetermined time (for example, 4 hours) from the end of the reheating operation, and in this heat retention mode, the circulation pump 23 is turned on at a time interval of, for example, 30 minutes. When the bath is started and the bath water is recirculated through the recirculating circuit 25, the bath temperature sensor 24
When the temperature of the bath water detected in the step (b) is lower than a predetermined temperature with respect to the bath set temperature, the bath burner 6 is burned to raise the temperature of the bath water to the set temperature and the like. Keep warm. In this warming operation, in the case of a bath apparatus having a water level maintaining function, during the warming mode, the bathtub water level is constantly monitored by the water level detection signal of the pressure sensor 34, and the bathtub water level is set within an allowable range from the set water level. When the water level falls below the predetermined value, the pouring valve 35 is opened, a shortage of water up to the set water level is added from the hot water supply heat exchanger 15 side, and the operation in the water retention mode for maintaining the bathtub water level at the set water level is performed.

[0015]

As shown in FIG. 7, a combined water heater having a hot water supply burner 5 and a bath burner 6 and a proportional valve 38 common to the hot water supply burner 5 and the bath burner 6 is provided. Normally, when both a hot water supply burner for hot water supply to a kitchen or a shower and a bath burner for hot water reheating and heat retention are performed together, the proportional valve 38 is opened by giving priority to the hot water supply side. Valve amount (proportional valve current amount) control is performed to prevent hot water from flowing into the kitchen, shower, or the like, thereby avoiding the danger of injuring the body of a user of the hot water.

As described above, when the hot water supply burner combustion and the bath burner combustion are performed by the priority control on the hot water supply side (at the time of simultaneous combustion of the hot water supply burner and the bath burner), for example,
When the opening amount of the proportional valve 38 is reduced in the direction in which the combustion capacity of the hot water supply burner 5 decreases, the combustion capacity of the bath burner 6 necessarily decreases. Even if the combustion capacity of the bath burner 6 is reduced in this way, a constant flow of hot and cold water flows through the reheating heat exchanger 16 as in the case of the maximum combustion of the bath burner 6 by driving the circulation pump 23. In addition, the bath burner 6 cannot sufficiently heat the water flowing through the reheating heat exchanger 16 due to insufficient combustion heat, and the temperature of the water flowing through the reheating heat exchanger 16 becomes difficult to increase, and the reheating heat exchange becomes difficult. The temperature of the water pipe surface of the heat exchanger 16 decreases, and the steam generated by the combustion of the bath burner 6 is easily dew-condensed on the water pipe surface of the reheater 16. When such dew condensation phenomenon of the reheating heat exchanger 16 occurs repeatedly, adverse effects such as corrosion of the reheating heat exchanger 16 occur.

In order to prevent the dew condensation from occurring in the reheating heat exchanger 16, Japanese Utility Model Laid-Open No. 2-124442 discloses that when the combustion capacity of the bath burner 6 falls below a set value, the driving amount of the circulation pump 23 is reduced. (Capacity) reduced reheating heat exchanger
The water flow rate of the reheater 16 is reduced by a certain amount to raise the outlet hot water temperature of the reheater 16, that is, the surface temperature of the water pipe of the reheater 16 is increased, and the dew condensation of the reheater 16 is performed. Means for preventing occurrence have been proposed.

However, as is well known, a circulating pump
The drive control of the 23 is performed by a phase angle control method using a triac or the like, and the circuit configuration for variably controlling the continuous flow rate of the circulation pump 23 using the pump drive control method such as the phase angle is complicated. Problem. Also, in general, instruments shipped with orifices or the like in the circulation path may be removed or replaced with a pump having a high circulation capacity according to the situation at the site. In order to variably control the flow rate, a complicated continuous flow rate variable control circuit corresponding to each setting and type (capacity) of the circulating pump 23 must be manufactured, thereby increasing the cost of the circuit. There is also. Also,
In the phase angle control, when the pump capacity is reduced, a torsional motion tends to occur in the appliance itself around the pump mounting portion, and this torsional motion becomes a source of vibration (noise) of the appliance. A reduction in pump capacity for preventing dew condensation tends to cause new vibration (noise).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to reduce the combustion capacity of a bath burner due to simultaneous combustion of a hot water supply burner and a bath burner, and to cause condensation in a reheating heat exchanger. When it becomes a state just before the occurrence, it is possible to prevent dew condensation from occurring in the reheating heat exchanger without variably controlling the continuous flow rate of the reheating circulation pump, and
An object of the present invention is to provide a combined water heater having a dew condensation preventing function of a reheating heat exchanger capable of simplifying a circuit configuration of a control circuit.

[0020]

In order to achieve the above object, the present invention has the following structure to solve the above-mentioned problems. That is, the first invention provides a hot water supply burner for performing heating and combustion of a hot water supply heat exchanger, a bath burner for performing heating and combustion of a follow-up heat exchanger, and an amount of fuel to be supplied to the hot water supply burner and the bath burner. A common proportional valve controlled by a circulating pump that recirculates the hot water of the bath and recirculates through a heat exchanger during reheating for performing bath burner combustion,
A control device for controlling the opening amount of the proportional valve and controlling the pump drive, and when both hot water burner combustion and bath burner combustion are performed, a combined hot water supply device that prioritizes the hot water supply side and controls the opening amount of the proportional valve A reheating heat exchanger outlet temperature sensor for detecting the temperature of hot water at the outlet of the reheating heat exchanger; and an outlet of the reheating heat exchanger corresponding to the temperature immediately before the dew condensation occurs in the reheating heat exchanger. A data storage unit for storing the pump-off temperature of the pump and the pump-on temperature of the outlet side of the reheating heat exchanger which is higher than the pump-off temperature by a preset temperature; when the simultaneous combustion of the hot water supply burner and the bath burner is performed Comparing the detected hot water temperature at the outlet of the heat exchanger detected by the reheating heat exchanger outlet temperature sensor with the temperature data stored in the data storage unit, the detected hot water temperature at the outlet of the heat exchanger is set to the pump temperature. When it is determined that the temperature is below the temperature, a pump-off signal is output and the circulation pump is turned off while the combustion of the bath burner is continued. When it is determined that the above is the case, a pump-on signal is output, and a pump intermittent operation control unit for performing an on-off intermittent operation of the circulating pump is provided as means for solving the above problem.

According to a second aspect of the present invention, there is provided a hot water supply burner for heating and burning a hot water supply heat exchanger, a bath burner for heating and burning a reheating heat exchanger, and opening a fuel amount supplied to the hot water supply burner and the bath burner. A common proportional valve controlled by the amount, a circulating pump that circulates the hot water of the bath through a heat exchanger during reheating for performing bath burner combustion, and controls a valve opening amount control and a pump drive of the proportional valve. With a control device,
When both the hot water supply burner combustion and the bath burner combustion are performed, in a combined water heater that gives priority to the hot water supply side and controls the valve opening amount of the proportional valve, the reheating heat exchange that detects the temperature of the water on the outlet side of the reheating heat exchanger The outlet temperature sensor and the pump-off temperature on the outlet side of the reheating heat exchanger corresponding to the temperature immediately before the dew condensation of the reheating heat exchanger and the pump-on temperature on the outlet side of the reheating heat exchanger higher than the pump-off temperature A data storage portion to be stored; a detected reheating heat exchanger outlet hot water temperature detected by a reheating heat exchanger outlet temperature sensor during simultaneous combustion of a hot water supply burner and a bath burner; and the data storage portion. Compares the temperature data stored in the water heater and outputs a pump-off signal when it is determined that the hot water temperature at the outlet of the detected reheating heat exchanger is lower than the pump-off temperature, and keeps the bath burner burning. Turns off the ring pump, outputs a pump-on signal when it is determined that the temperature of the hot water at the outlet of the reheating heat exchanger is higher than the pump-on temperature during the off-period of the circulation pump, and intermittently turns the circulation pump on and off. A pump intermittent operation control unit to be performed; a reheating heat amount detecting unit for detecting a reheating heat amount of the bath burner combustion; a pump-on temperature as the reheating heat amount increases based on the reheating heat amount detected by the reheating heat amount detection unit. A pump-on temperature automatic updating unit that variably sets the pump-on temperature in the direction of decreasing the pump-on temperature and automatically updates the pump-on temperature stored in the data storage unit.

According to a third aspect of the present invention, the output period of the pump-on signal output from the intermittent operation control section of the first or second aspect is given in advance by time, and the intermittent operation control section outputs the pump-on signal. The output is continuously output until the output period elapses, and the output is switched from the pump-on signal to the pump-off signal when the output period elapses.

In a fourth aspect of the present invention, in addition to the configuration of the third aspect of the present invention, there is provided a reheating heat amount detecting section for detecting a reheating heat amount of the bath burner combustion, and a reheating heat amount detected by the reheating heat amount detecting section. Means for solving the above-mentioned problem with a configuration having a pump-on signal output period automatic updating unit that variably sets the output period of the pump-on signal in a direction to lengthen the output period of the pump-on signal as the amount of reheating heat increases based on And

According to a fifth aspect of the present invention, in addition to the configuration of any one of the first to fourth aspects of the invention, a flowing water detection sensor for detecting flowing water of the reheating heat exchanger driven by a circulating pump, A bath burner combustion stop unit that stops the combustion of the bath burner when the detection sensor detects running water off, and the running water detection sensor detects running water off when the pump intermittent operation is turned off by the pump intermittent operation control unit. The present invention also provides a means for solving the above-mentioned problem with a configuration in which a combustion stop operation preventing unit for preventing a bath burner combustion stop operation of the bath burner combustion stop unit is provided.

In the invention having the above structure, for example, during simultaneous combustion of the hot water supply burner and the bath burner, the pump intermittent operation control unit detects the additional heating heat exchanger outlet hot water temperature detected by the additional heating heat exchanger outlet temperature sensor. And the temperature data (pump-on temperature and pump-off temperature) stored in the data storage unit.
When the circulation pump is turned on, when it is determined that the detected hot-water heat exchanger outlet hot water temperature is equal to or lower than the pump-off temperature, it is determined that the heat-up heat exchanger is in a state immediately before the occurrence of dew condensation. , A pump-off signal is output, and the circulation pump is turned off while the bath burner is burning.

The hot water staying in the reheating heat exchanger during the off period of the circulation pump is heated by the heat of the combustion of the bath burner, and the hot water temperature rises. The pump intermittent operation control unit outputs a pump-on signal when the hot water temperature detected by the reheating heat exchanger outlet temperature sensor is equal to or higher than the pump-on temperature, and turns on the circulation pump. Make the pump intermittently operate on and off.

As described above, at the time of simultaneous combustion of the hot water supply burner and the bath burner, the combustion capacity of the bath burner is reduced, the water temperature of the additional heat exchanger is lowered, and the surface temperature of the water pipe of the additional heat exchanger is reduced. When dew condensation easily occurs on the water pipe surface of the reheating heat exchanger, that is, the temperature of the hot water detected by the temperature sensor on the outlet side of the reheating heat exchanger has fallen below the pump-off temperature corresponding to the temperature immediately before the occurrence of dew condensation. When the circulation pump is turned off while the combustion of the bath burner is continued, hot water stays in the reheating heat exchanger, and the accumulated hot water is heated by the heat of the combustion of the bath burner. The temperature of the hot and cold water in the vessel rises, and the temperature of the water pipe surface of the reheating heat exchanger is prevented from lowering, and the occurrence of dew condensation in the reheating heat exchanger is avoided.

In the case where the combined water heater having a function of stopping the combustion of the bath burner when the running water detection sensor detects the running water off of the reheating heat exchanger is provided with the intermittent operation control section of the pump, the combustion is stopped. By providing the operation prevention unit, even if the running water detection sensor detects running water off when the pump intermittent operation control unit turns off the pump intermittent operation, the combustion stop operation preventing unit prevents the bath burner from stopping the combustion. The intermittent operation of the pump is performed without stopping the combustion of the burner, and as described above, the occurrence of dew condensation in the reheating heat exchanger is avoided.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. The combined water heater of each embodiment described below is directed to the combined water heater having the system configuration shown in FIG. 7, and the description thereof will not be repeated.

FIG. 1 shows, by solid lines, a control structure for performing the dew condensation preventing function of the reheating type heat exchanger which is characteristic in the first embodiment. This control is performed by the control device 56. I have. The control device 56 includes a combustion control unit 48, a pump intermittent operation control unit 50, and a data storage unit 52.

The combustion control unit 48 controls the operation of appliances such as a hot water supply mode, a hot water filling mode, a reheating mode, and a heat retention mode. Since the control configuration has been described above, a duplicate description thereof will be omitted.

The data storage section 52 is constituted by a storage device.
The pump- _off temperature T _OFF (for example, 40 ° C.) on the outlet side of the reheating heat exchanger 16 corresponding to the temperature immediately before the occurrence of dew condensation, and the output of the reheating heat exchanger 16 higher than the pump-off temperature by a preset temperature. Side pump-on temperature T _ON (for example, 55
° C) is stored in advance as an optimum value obtained by experiments, calculations, or the like.

The pump intermittent operation control section 50 is a sampling section.
It comprises a 62, a comparison / determination unit 63 and a signal output unit 64. The sampling unit 62 has a timer (not shown) built therein, and is determined in advance after detecting from the information on the control operation of the combustion control unit 48 that the hot water supply burner 5 and the bath burner 6 are performing simultaneous combustion. Sampling time interval (for example, 1
Every second), the outlet-side temperature sensor 44 samples the reheating heat exchanger outlet-side hot water temperature T _OUT and outputs it to the comparison / determination unit 63.

When the hot water supply burner 5 and the bath burner 6 burn simultaneously, the comparison judging section 63 reads out the temperature data (pump- _off temperature T _OFF and pump-on temperature T _ON ) stored in the data storage section 52 and reads out the sampling section. Each time the detected outlet water temperature T _OUT is received from 62, the outlet water temperature T _OUT is compared with the temperature data. When the circulation pump 23 is driven by the control operation of the combustion control unit 48, the detected outlet hot water temperature T _OUT is equal to or lower than the pump _off temperature T _OFF (T _OUT ≦
T _OFF ), the combustion performance of the bath burner 6 caused by simultaneous combustion of the hot water supply burner 5 and the bath burner 6 causes the water temperature of the reheating heat exchanger 16 to drop, and the water pipe of the reheating heat exchanger 16 The surface temperature is lowered, and the reheating heat exchanger 16 determines that the water pipe surface is in a state immediately before dew condensation occurs, and sends a signal to the signal output unit 64 to the pump-off signal to the circulation pump 23 and to the combustion control unit 48. Is output, and the circulation pump 23 is turned off (stopped) while the combustion of the bath burner is continued.

During the off-period of the circulation pump 23, the hot water staying in the reheating heat exchanger 16 is heated by the heat of the combustion of the bath burner and the hot water temperature rises. During the OFF period of 23, the outlet water temperature T _OUT detected by the outlet temperature sensor 44 is equal to or higher than the pump-on temperature T _ON (T
_OUT ≧ T _ON ), the surface temperature of the water pipe of the reheating heat exchanger 16 rises with the rise of the retained hot water temperature of the reheating heat exchanger 16, and the dew condensation of the reheating heat exchanger 16 is avoided. Then, the signal output unit 64 outputs a pump-on signal to the circulation pump 23 to activate the circulation pump 23.

As described above, the pump intermittent operation control unit 50
During the simultaneous combustion of the hot water supply burner 5 and the bath burner 6, the combustion capacity of the bath burner 6 decreases, and the hot water temperature T _{OUT at} the outlet side of the reheating heat exchanger 16 becomes the temperature just before the dew condensation of the reheating heat exchanger 16 occurs. When it is determined that the temperature is below the corresponding pump- _off temperature T _OFF , the circulation pump is maintained while the bath burner combustion is continued.
When the circulation pump 23 is turned off, the outlet hot water temperature T _OUT of the reheating heat exchanger 16 becomes the pump on temperature T _ON during the off period of the circulation pump 23.
When it is determined that the above is the case, the circulation pump 23 is turned on. During the ON period of the circulation pump 23, as described above, the hot water temperature T _{OUT at} the outlet side of the reheating heat exchanger 16 becomes the pump off temperature T
When it is determined to be _OFF or less, the circulation pump 23 is turned off again, such as turning off the circulation pump 23 again while the bath burner combustion is continued, and the water pipe surface of the reheating heat exchanger 16 is operated. This prevents the temperature from dropping and avoids the occurrence of dew condensation on the reheating heat exchanger 16.

The intermittent operation control unit having the above-described structure will be described below.
The operation example of 50 will be briefly described based on the flowchart of FIG. First, in step 101, when simultaneous combustion of the hot water supply burner 5 and the bath burner 6 is started, the pump intermittent operation control unit is started.
The sampling section 62 of 50 takes in the _output temperature T _OUT detected by the output temperature sensor 44, and in step 102, the comparison judgment section 63
Determines whether the detected outlet water temperature T _OUT is equal to or lower than the pump- _off temperature T _OFF stored in the data storage unit 52. When it is determined that the detected outlet-side hot water temperature T _OUT is equal to or lower than the pump- _off temperature T _{OFF, the} reburning heat exchanger 16 is in a state immediately before the occurrence of dew condensation. Therefore, in step 103, the combustion of the bath burner 6 is continued. The circulation pump 23 is stopped, and the temperature of the hot water in the reheating heat exchanger 16 is raised to avoid a drop in the water pipe surface temperature of the reheating heat exchanger 16.

In step 104, the sampling section 62 takes in the next detected outlet water temperature T _OUT , and the comparison judging section 63 outputs the detected pump water temperature T _OUT stored in the data storage section 52. It is determined whether or not the temperature is higher than _{ON. If} the detected outlet water temperature T _OUT is lower than the pump-on temperature T _ON , the stop state of the circulation pump 23 is continued in step 106, and the determination operation in step 104 is performed again. Do.

When it is determined that the detected outlet-side hot water temperature T _OUT is equal to or higher than the pump-on temperature T _ON , the occurrence of dew condensation in the reheating steam exchanger 16 has been avoided.
The circulation pump 23 is started, and the operations after the step 102 are repeated to reliably prevent the dew condensation heat exchanger 16 from dew formation.

According to this embodiment, the hot water supply burner 5
When it is determined that the outlet water temperature T _OUT detected by the outlet temperature sensor 44 is equal to or lower than the pump- _off temperature T _OFF during the simultaneous combustion of the bath burner 6 and the bath burner 6, the circulation pump 23 is turned off while the combustion of the bath burner 6 is continued. In the off-period of the circulating pump 23, when it is determined that the detected outlet hot water temperature T _OUT is equal to or higher than the pump-on temperature T _ON , the circulating pump 23 is turned on and the intermittent operation of the circulating pump 23 is performed. Therefore, when the water pipe surface temperature of the reheating heat exchanger 16 was reduced to a temperature immediately before the occurrence of dew condensation due to a decrease in the combustion capacity of the bath burner 6 during simultaneous combustion of the hot water supply burner 5 and the bath burner 6, As described above, since the circulation pump 23 is turned off while the combustion of the bath burner 6 continues, the hot water stays in the reheating heat exchanger 16, and the retained hot water is heated by the heat of the combustion of the bath burner 6. Fired heat exchanger The temperature of the retained hot water in 16 rises,
Accordingly, the temperature of the water pipe surface of the reheating heat exchanger 16 also increases, and the occurrence of dew condensation on the reheating heat exchanger 16 can be prevented.

As described above, in order to prevent dew condensation in the reheating heat exchanger 16, it is only necessary to turn on and off the circulation pump 23, and the on / off control of the circulation pump 23 is simple. It is possible to simplify the circuit configuration of the pump intermittent operation control unit 50 that controls the on / off intermittent operation of the circulation pump 23. Further, it is not necessary to prepare a circuit of the pump intermittent operation control unit 50 corresponding to each capacity of the circulation pump 23, and a pump- _off temperature T _OFF corresponding to the temperature immediately before the dew condensation of the reheating heat exchanger 16 and this pump- _off temperature By merely storing the pump-on temperature T _ON higher than the temperature in the data storage unit 52, it is possible to perform the intermittent operation of the pump for preventing dew condensation in the reheating heat exchanger 16, so that the pump of each of the multi-capacity types can be pumped. The circuit of the intermittent operation control unit 50 does not have to be manufactured, and the cost of the circuit can be reduced.

Hereinafter, a second embodiment will be described. The feature of the second embodiment different from that of the first embodiment is that, as shown by the solid line in FIG. the provided variably set for lowering according Reheating heat bath burner combusting Ponpuon temperature T _oN (combustion capability of the bath burner 6) increases, automatically updates Ponpuon temperature T _oN stored in the data storage unit 52 The other configuration is the same as that of the first embodiment, and the description thereof will not be repeated.

In FIG. 3, the combustion control unit 48 and
The illustration of the sampling unit 62, the comparison judgment unit 63, and the signal output unit 64 of the pump intermittent operation control unit 50 is omitted.

By the way, the circulation pump 23 normally takes about one minute, for example, from the time it is started to the time when it rises to the normal flow rate. The hot water flow is very gentle. Therefore, even if the pump intermittent operation control unit 50 determines that the hot water temperature T _OUT on the outlet side of the reheating heat exchanger 16 has reached the pump-on temperature T _ON and starts the circulation pump 23, as described above, the circulation pump 23 does not rise instantaneously, the flow of hot water in the reheating heat exchanger 16 is very gentle, and the temperature of the hot water in the reheating heat exchanger 16 becomes considerably higher than the pump-on temperature T _ON by the heat of the combustion of the bath burner 6. The pump _ON temperature T _ON
The rise in hot water temperature increases as the amount of reheating heat increases, and if the pump-on temperature T _ON is set higher, very hot water may be produced in the reheating heat exchanger 16. The hot water may flow into the bathtub 21 and, if there is a bather, the bather may be burned.

Therefore, in this embodiment, as described above, the control unit 56 is provided with the additional heating amount detecting unit 51 and the automatic pump-on temperature updating unit 53, and the pump-on temperature T _ON is decreased as the additional heating amount increases. And automatically updates the pump-on temperature T _ON stored in the data storage unit 52 to prevent hot water from being injected into the bathtub 21 when the intermittent operation of the circulating pump 23 is performed by the intermittent operation control unit 50. And

As is well known, the amount of gas supplied to the bath burner is controlled by the opening amount of the proportional valve 38 to control the amount of reheating of the bath burner combustion. Based on the proportional valve current), it is possible to indirectly detect the amount of reheating of the bath burner combustion. From this, during the simultaneous combustion of the hot water supply burner 5 and the bath burner 6, the additional heating calorie detection unit 51 detects the proportional valve current from the proportional valve drive unit 46 at every predetermined sampling time interval (for example, every 1 second). Then, the detected proportional valve current is detected as the amount of reheating of the bath burner combustion, and is output to the pump-on temperature automatic updating unit 53. In addition, a timer (not shown) for setting a sampling time interval is built in the reheating calorie detection unit 51.

The data storage unit 52, T _ON detection data indicating the relationship between the reheating heat and Ponpuon temperature T _ON bath burner combustion are stored determined by experiment, calculation or the like, the T _ON detection data It is formed of graph data, arithmetic expression data, table data, and the like shown in FIGS. In addition, as shown in FIG. 4A, the pump-on temperature T _ON may be continuously given to the reheating heat quantity,
As shown in FIG. 4B, the pump-on temperature T _ON may be given in a stepwise manner with respect to the amount of reheating heat.

When the hot water supply burner 5 and the bath burner 6 are simultaneously burned, the pump-on temperature automatic updating unit 58 receives the additional heating heat amount (proportional valve current) detected by the additional heating heat amount detection unit 51 every time the additional heating is performed. Calorific value and the data storage unit 52
On the basis of the stored and are T _ON detection data to a variable set for lowering the Ponpuon temperature T _ON according Reheating heat increases, to automatically update the Ponpuon temperature T _ON of the data storage unit 52.

According to this embodiment, in addition to the configuration of the first embodiment, the pump-on temperature T _ON is variably set as the reheating heat amount of the bath burner combustion increases, and the data storage unit 52 Since the configuration is such that the pump-on temperature T _ON is automatically updated, when the circulation pump 23 is activated by the pump intermittent operation control unit 50 in a state where the bath burner is burning, the reheating pump 16 Regardless of the size of the calorific value of the hot water flowing out,
It is possible to keep the temperature of the hot water at a substantially constant temperature while avoiding the ejection of the hot water to the bathtub 21, and it is possible to prevent the hot water from being ejected to the bathtub 21. In addition, the larger the reheating heat, the higher the exhaust temperature.However, the higher the exhaust temperature, the more difficult it is for the temperature of the hot water flowing out of the same reheating heat exchanger 16 to dew. It is preferable to change the pump T _ON by using the above method.

Hereinafter, a third embodiment will be described. What is characteristic in this embodiment is that a timer 58 is provided in the control device 56 as shown by a dotted line in FIGS.
The output time of the pump-on signal output from the pump intermittent operation control unit 50 is determined by time using the timer 58, and the pump intermittent operation control unit 50 continuously outputs the pump-on signal until a predetermined output period has elapsed, When the output period has elapsed, the pump-on signal is switched to the pump-off signal. Other configurations are the same as those of the above-described embodiments, and the description thereof will not be repeated.

By the way, as described above, at the time of simultaneous combustion of the hot water supply burner 5 and the bath burner 6, priority is given to combustion of the hot water supply burner, and the opening control of the proportional valve 38 is performed.
When the opening amount of the proportional valve 38 is reduced in a direction to decrease the combustion capacity of the bath, the combustion capacity (reheating heat) of the bath burner 6 necessarily decreases. In this state, the pump intermittent operation control unit 50
When the intermittent operation of the pump is performed, the circulation pump 23 is turned on and the time elapses even if the hot water temperature in the reheater 16 rises during the off period of the circulation pump 23 by the intermittent operation control unit 50. Then, the temperature of the hot water in the reheater 16 gradually decreases.

Therefore, in this embodiment, taking into account the drop in the hot water temperature, the pump-on signal is output during the output period after the circulation pump 23 is started, for example, by reheating heat exchange. The hot water temperature at the outlet side of the vessel 16 is set by time (for example, 5 minutes) so as not to be lower than the pump-off temperature (temperature immediately before the occurrence of dew condensation) T _OFF , and is given to the timer 58.

The timer 58 is configured to output a time-up signal to the pump intermittent operation control unit 50 when the above-mentioned output period has elapsed since the timer was driven.

The pump intermittent operation control unit 50 starts the timer 58 when the pump-on signal is output, and continues the pump-on signal until the output period of the pump-on signal elapses, that is, until the time-up signal is received from the timer 58. And outputs a pump-up signal at the same time as receiving a time-up signal.

According to this embodiment, excellent effects such as prevention of dew condensation on the reheating heat exchanger 16 can be obtained as in the above embodiments.

The fourth embodiment will be described below. The characteristic feature of the fourth embodiment different from that of the third embodiment is that, as shown in FIG. 5, the reheating heat amount detection unit 51 and the output period of the pump-on signal output period automatic update unit are used. An automatic updating section 54 is provided to automatically set and update the output period of the pump-on signal variably in a direction in which the output period of the pump-on signal is lengthened as the amount of reheating increases, and other configurations are the same as those of the third embodiment. This is the same as the example, and the overlapping description is omitted. Also, in FIG. 5, components (parts of the sampling unit 6 shown in FIG.
2, comparison judgment section 63, signal output section 64, combustion control section 48, FIG.
The illustration of the pump-on temperature automatic updating unit 53) shown in FIG.

The reheating heat amount detecting section 51 has the same configuration as the reheating heat amount detecting section 51 shown in the second embodiment, and the pump-on temperature T _ON is the same as in the second embodiment. When the reheating heat amount detection unit 51 is provided for variably setting and automatically updating, the output period of the pump-on signal shown in FIG. 5 is changed separately from the reheating heat amount detection unit 51 for setting the pump-on temperature variable. It is not necessary to provide the additional heating amount detection unit 51 for setting.

By the way, as described above, the hot water supply burner 5
When the combustion performance of the bath burner 6 is reduced due to the simultaneous combustion of the bath burner 6 and the bath burner 6, the water temperature of the reheating heat exchanger 16 decreases with time. In the present embodiment, since the amount of reheating increases, the on-period of the circulation pump 23 can be extended to prevent condensation from occurring in the reheating heat exchanger 16 because the amount of reheating increases gradually. In view of the above, as described above, the configuration is such that the output period of the pump-on signal is variably set to be longer as the amount of reheating heat increases, and is automatically updated.

In the data storage section 52, output period detection data indicating the relationship between the output period of the pump-on signal and the amount of additional heating (proportional valve current) is obtained and stored in advance by experiments, calculations, and the like. The output period detection data is formed of graph data, arithmetic expression data, table data, and the like shown in FIGS. The output period may be continuously given to the reheating heat amount as shown in FIG. 8A, or the output period may be set to be stepwise relative to the reheating heat amount as shown in FIG. 8B. May be given.

The automatic output period updating unit 54 receives the reheating heat amount of the bath burner combustion sent from the reheating heat amount detection unit 51 when the hot water supply burner 5 and the bath burner 6 simultaneously burn, and detects the detected reheating heat amount. The output period of the pump-on signal is variably set based on the output period detection data stored in the data storage unit 52, and the output period of the timer 58 is automatically updated.

According to this embodiment, in addition to the configuration of each of the above embodiments, the output period of the pump-on signal is variably set and automatically updated as the amount of reheating heat increases. The same advantageous effects as those of the embodiment can be obtained, and the following effects can be obtained.

As shown in the third embodiment,
Regardless of the magnitude of the reheating heat, when a constant pump-on signal output period is given, even if the reheating heat is large and the circulation pump 23 is turned on for longer than the constant output period, dew condensation of the reheating heat exchanger 16 is prevented. Can be achieved,
Since the circulation pump 23 is turned off early and wasteful reheating of the bath is interrupted early, it takes a long time for the bath to boil, but as shown in this embodiment, By variably setting the output period of the pump-on signal in accordance with the amount of heating heat, it is possible to prevent dew condensation in the reheating heat exchanger 16 as well as to circulate as the amount of reheating heat increases. When the on-period of the pump 23 is long and the amount of reheating heat is large, the bath can be boiled faster than when the amount of reheating heat is small, and the reheating can be performed efficiently.

Hereinafter, a fifth embodiment will be described.
In the fifth embodiment, when the flowing water detection sensor 28 of the reheating circulation circuit 25 stops detecting the flowing water during the reheating of the bath, the combustion of the bath burner 6 is stopped to prevent the empty heating. It is applied to a combined water heater with a fire prevention function. Combined water heater (apparatus) with the above-mentioned function to prevent empty heating
In trying to perform the pump intermittent operation to prevent dew condensation of the reheating heat exchanger 16 as in each of the embodiments,
When the intermittent operation is turned off, the flowing water detection sensor 28 does not detect flowing water, the function for preventing empty burning is activated, and the combustion of the bath burner 6 is stopped, so that the intermittent operation of the circulation pump 23 cannot be performed smoothly.

Therefore, the present embodiment is characterized in that a control device for smoothly performing the intermittent operation of the circulating pump 23 is provided even with the appliance having the above-mentioned function of preventing the empty heating. An example is shown in FIG. This control device
56 is a pump intermittent operation control unit 50 and a bath burner combustion stop unit 60
And a combustion stop operation preventing unit 61. The other configuration is the same as that of each of the above-described embodiments, and the overlapping description will be omitted.

The bath burner combustion stop section 60 is provided when the output of the flowing water ON signal of the flowing water detection sensor 28 is stopped during reheating of the bath (while the bath burner 6 is burning), that is, when the flowing water detection sensor 28 is turned off. Is detected, the bath-side gas on / off valve 40 or the original solenoid valve 37 is closed to stop the gas supply to the bath burner 6 and stop the combustion of the bath burner 6, thereby preventing the empty burning. ing.

The pump intermittent operation control unit 50 includes the hot water supply burner 5
During the simultaneous combustion of the bath burner 6 and the bath burner 6, when the pump-off signal and the pump-on signal are alternately output to the circulation pump 23 as described in the above embodiments, the pump intermittent operation signal is output together with the output of these signals. Combustion stop operation prevention section
It has a configuration to output to 61.

The output configuration of the pump-off signal and the pump-on signal output from the pump intermittent operation control section 50 may be any of the configurations shown in the first to fourth embodiments. The description is omitted.

The intermittent operation stop unit 61 is provided for smoothly performing the intermittent operation of the circulation pump 23 by the intermittent operation control unit 50 while receiving the intermittent operation signal of the intermittent operation control unit 50. The operation of stopping the combustion of the bath burner 6 of the bath burner combustion stopping section 60 is prevented.

According to this embodiment, an empty heating prevention function is provided to stop the combustion of the bath burner 6 when the flowing water detection sensor 28 of the additional heating circulation path 25 detects that the flowing water is off during the additional heating of the bath. The intermittent operation control unit 50 is provided on the appliance, and the intermittent operation of the circulating pump 23 by the intermittent operation control unit 50 of the pump is used to prevent dew condensation from occurring in the reheating heat exchanger 16 and to provide the combustion stop operation preventing unit 61. Circulation pump 23
When the intermittent operation is turned off, the combustion stop operation of the bath burner 6 is prevented. Therefore, when the intermittent operation of the circulation pump 23 is performed, the running water detection sensor 28 detects the running water off when the intermittent operation is turned off. However, the combustion of the bath burner 6 does not stop, and the intermittent operation of the circulation pump 23 can be performed smoothly.

The present invention is not limited to the above embodiments, but can adopt various embodiments. For example, a reheating calorie detecting unit shown in each of the above embodiments.
51 detects the proportional valve current as a reheating heat amount. For example, as the gas flow rate of the gas supply passage 36 increases, the combustion capacity (reheating heat amount) of the bath burner 6 increases. Since the gas flow rate of 36 corresponds to the combustion capacity of the bath burner 6, the gas supply passage
A gas flow rate detection sensor for detecting a gas flow rate may be provided at 36, and the gas flow rate detected by the gas flow rate detection sensor may be detected as a reheating heat quantity, or when the combustion capacity of the bath burner 6 increases, the combustion capacity Since the airflow to the bath burner 6 is controlled to increase so as to match the rotation speed, the rotation speed and the fan airflow of the combustion fan 8 correspond to the combustion capacity of the bath burner 6, so that the fan rotation speed detection sensor 17 The sensor output of the fan air volume detection sensor 45 may be detected as the reheating heat amount, the information on the reheating heat amount may be directly taken in from the combustion control unit 48, or the input side of the reheating heat exchanger 16 may be detected. Based on the following equation (1), based on the input water temperature T _IN , the outlet hot water temperature T _OUT , the flow rate of the reheating heat exchanger 16 (a predetermined flow rate of the circulation pump 23) Q,
The amount of heat J received by the reheating heat exchanger 16 through the combustion of the bath burner 6, that is, the amount of reheating heat may be directly calculated and detected.

J = (T _OUT −T _IN ) · Q · C (1)

Here, C shown in the above equation (1) is a constant, and the specific heat of water is given.

[0073] entrance side of the above equation (1) the detection hot water temperature of the delivery temperature sensor 44 for detecting the output side hot water temperature of the reheating heat exchanger 16 to a T _OUT shown in, follow the T _IN fired heat exchanger 16 Substituting heat can be detected by substituting the detected hot water temperature of the bath temperature sensor 24 for detecting the hot water temperature and the predetermined flow rate of the circulation pump 23 into Q, and performing the calculation according to the equation (1).

As described above, in the case where something other than the proportional valve current is indirectly detected as the reheating heat amount, or when the reheating heat amount is directly detected, T _ON shown in the second embodiment is used. The detection data is constituted by relation data indicating the relation between the reheating heat amount and the pump-on temperature instead of the proportional valve current, and the output period detection data shown in the fourth embodiment replaces the proportional valve current. It consists of relational data indicating the relation between the reheating heat quantity and the output period of the pump-on signal.

In each of the above embodiments, the hot water supply burner 5 and the bath burner 6
However, for example, a hot water supply burner is provided by using a frame rod electrode (not shown) disposed above each combustion surface of the hot water supply burner 5 and the bath burner 6 to detect a combustion flame. The simultaneous combustion of the bath 5 and the bath burner 6 may be detected.

Further, the reheating heat detecting section 51 shown in each of the above embodiments detects the proportional valve current and outputs it as information on the reheating heat to the pump-on temperature automatic updating section 53 or the output period automatic updating section 54. However, the sampling unit 62 of the pump intermittent operation control unit 50 may detect the proportional valve current and output the detected proportional valve current to the pump-on temperature automatic updating unit 53 or the output period automatic updating unit 54. The detection unit 51 can be omitted.

Further, in each of the above embodiments, the combined hot water supply apparatus shown in FIG. 7 has been described as an example. However, the present invention has the hot water supply burner 5 and the bath burner 6, and the hot water supply burner 5 and the bath burner 6
However, the present invention is not limited to the composite water heater having the configuration shown in FIG.

[0078]

According to the present invention, the intermittent operation control unit for the pump is provided, and the intermittent operation control unit for the pump adjusts the temperature of the hot water at the outlet of the reheating heat exchanger at the time of simultaneous combustion of the hot water supply burner and the bath burner. When it is determined that the temperature is lower than the pump-off temperature corresponding to the temperature immediately before the occurrence of dew condensation in the exchanger, the circulation pump is turned off while the bath burner combustion continues, and the reheated heat exchanger is turned off during the off-period of the circulation pump. The circulation pump is turned on when it is determined that the outlet hot water temperature is equal to or higher than the pump-on temperature.Therefore, the combustion capacity of the bath burner decreases due to the simultaneous combustion of the hot water supply burner and the bath burner, and the discharge of the reheater heat exchanger occurs. When the temperature of the hot water drops to the pump-off temperature, the circulation pump is turned off while the bath burner continues to burn, and hot water stays in the reheating heat exchanger. During the period, the temperature of the hot water staying in the post-heating heat exchanger rises due to the heat of the bath burner combustion, the water pipe surface temperature of the post-heating heat exchanger rises, and the dew condensation of the post-heating heat exchanger is prevented. Can be.

Then, after the hot water of the reheating heat exchanger reaches the pump-on temperature, the circulation pump is turned on, the hot water is returned from the reheating heat exchanger to the bathtub, and the bath is reheated.
During the ON period of the circulation pump, for example, as described above,
When the temperature of the hot water at the outlet of the reheating heat exchanger drops again below the pump-off temperature due to the insufficient combustion capacity of the bath burner, the circulation pump is turned off again. In this way, by performing the on / off intermittent operation of the circulation pump while the bath burner combustion is continued, it is possible to reheat the bath while preventing dew condensation in the reheating heat exchanger.

Further, as described above, the present invention has a configuration in which the intermittent operation of the pump is performed to prevent the occurrence of dew condensation in the reheating heat exchanger. Since the on / off control can be easily performed, the circuit configuration of the pump intermittent operation control unit can be simplified. Further, it is not necessary to prepare a circuit of a pump intermittent operation control unit corresponding to each capacity of the pump, and it is possible to perform the intermittent pump operation only by storing the pump off temperature and the pump on temperature in the data storage unit. It is not necessary to manufacture a circuit of the pump intermittent operation control unit for each pump of the capability type, and the cost of the circuit can be reduced.

In the configuration in which the pump-on temperature is variably set in the direction of decreasing the pump-on temperature as the reheating heat increases, the pump-on temperature in the data storage unit is automatically updated. When the circulation pump is turned on, the temperature of the hot water spouting into the bathtub can be kept at a substantially constant temperature while avoiding hot water spouting into the bathtub, and hot water spouts into the bathtub when the intermittent pump is turned on. Can be prevented, and the danger caused by the ejection of hot water can be reliably avoided.

In a configuration in which the output period of the pump-on signal output from the pump intermittent operation control section is variably set to be longer as the reheating heat amount increases and automatically updated, the circulation period increases as the reheating heat amount increases. Since the on-period of the pump becomes longer, it is possible to boil the bath more quickly when the reheating heat is large than when the reheating heat is small, while preventing dew condensation in the reheating heat exchanger. Can be.

Further, there is provided a bath burner combustion stopping section for stopping the combustion of the bath burner when the running water detecting sensor detects that the reheating water of the bath is turned off, and a pump intermittent operation control section and a bath burner combustion stopping operation preventing section. When the intermittent operation of the pump is turned off by the pump intermittent operation control unit, the bath burner combustion stop operation preventing unit does not allow the bath burner combustion stop unit to stop the bath burner combustion even if the running water detection sensor detects running water off. Since the operation is prevented, the intermittent operation of the pump can be smoothly performed without stopping the combustion of the bath burner, and the dew condensation of the reheating heat exchanger can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a control device characteristic of a combined water heater according to the present invention.

FIG. 2 is a flowchart showing an example of a dew condensation preventing operation of a reheating heat exchanger in the control device shown in FIG. 1;

FIG. 3 is a block diagram showing a second embodiment.

FIG. 4 is a graph showing an example of a relationship between a pump-on temperature and a reheating heat amount.

FIG. 5 is a block diagram showing a fourth embodiment.

FIG. 6 is a block diagram showing an example of a control configuration for causing a combined water heater having an idle-heating prevention function to perform an intermittent operation of a pump.

FIG. 7 is an explanatory view showing an example of a combined water heater in which a common proportional valve is provided for a hot water supply burner and a bath burner.

FIG. 8 is a graph showing an example of the relationship between the output period of a pump-on signal and the amount of reheating.

[Explanation of symbols]

 1 Equipment 5 Hot water supply burner 6 Bath burner 16 Reheating heat exchanger 23 Circulating pump 28 Flowing water detection sensor 38 Proportional valve 44 Outlet temperature sensor 50 Pump intermittent operation control unit 51 Reheating heat amount detection unit 52 Data storage unit 53 Automatic pump-on temperature update Unit 54 Automatic output period update unit 56 Control unit 60 Bath burner combustion stop unit 61 Burn stop operation prevention unit

Claims (5)

[Claims] 1. A hot water supply burner for performing heating and combustion of a hot water supply heat exchanger, a bath burner for performing heating and combustion of a reheating heat exchanger, and an amount of fuel supplied to the hot water supply burner and the bath burner is controlled by a valve opening amount. A common proportional valve, a circulating pump that circulates the hot water in the bath through a heat exchanger at the time of reheating for performing bath burner combustion, and a control device that controls valve opening amount control and pump driving of the proportional valve. In a combined water heater that gives priority to the hot water supply side and controls the valve opening amount of the proportional valve when both the hot water supply burner combustion and the bath burner combustion are performed, the additional heating that detects the temperature of hot water at the outlet side of the additional heat exchanger A heat exchanger outlet temperature sensor; a pump-off temperature on the outlet side of the reheat heat exchanger corresponding to the temperature immediately before the dew condensation of the reheat heat exchanger, and a reheat that is higher than the pump-off temperature by a preset temperature. A data storage unit for storing the pump-on temperature at the outlet side of the heat exchanger; a reheating heat detected by the outlet temperature sensor of the reheating heat exchanger during simultaneous combustion of the hot water supply burner and the bath burner. The outlet hot water temperature of the exchanger is compared with the temperature data stored in the data storage unit, and when it is determined that the detected hot water heat exchanger outlet hot water temperature is equal to or lower than the pump off temperature, a pump-off signal is output and the bath is output. The circulation pump is turned off while the burner continues to burn, and a pump-on signal is output when the detected reheating heat exchanger outlet hot water temperature is determined to be equal to or higher than the pump-on temperature during the off-period of the circulation pump. And a pump intermittent operation control unit for performing on / off intermittent operation of the water heater. 2. A hot water supply burner for heating and burning the hot water supply heat exchanger, a bath burner for heating and burning the reheating heat exchanger, and an amount of fuel supplied to the hot water supply burner and the bath burner is controlled by a valve opening amount. A common proportional valve, a circulating pump that circulates the hot water in the bath through a heat exchanger at the time of reheating for performing bath burner combustion, and a control device that controls valve opening amount control and pump driving of the proportional valve. In a combined water heater that gives priority to the hot water supply side and controls the valve opening amount of the proportional valve when both the hot water supply burner combustion and the bath burner combustion are performed, the additional heating that detects the temperature of hot water at the outlet side of the additional heat exchanger A heat exchanger outlet temperature sensor; a pump-off temperature on the outlet side of the reheat heat exchanger corresponding to the temperature immediately before the dew condensation of the reheat heat exchanger, and a pump on the outlet side of the reheat heat exchanger higher than the pump-off temperature. A data storage unit for storing a power-on temperature; a detection reheating heat exchanger outlet temperature detected by a reheating heat exchanger outlet temperature sensor when a hot water supply burner and a bath burner are being simultaneously fired; The temperature data stored in the data storage unit is compared, and when it is determined that the temperature of the hot water at the outlet of the detected reheating heat exchanger is lower than the pump-off temperature, a pump-off signal is output to circulate while continuing to burn the bath burner. Turns off the pump, outputs a pump-on signal when it is determined that the temperature of the hot water at the outlet of the reheating heat exchanger is higher than the pump-on temperature during the off-period of the circulation pump, and performs intermittent operation of the circulation pump on / off. An intermittent operation control unit for pumping; a reheating unit for detecting the amount of reheating of the bath burner; and a reheating unit based on the amount of reheating detected by the reheating unit. Ponpuon temperature automatic update unit and for automatically updating the Ponpuon temperature the Ponpuon temperature for lowering the Ponpuon temperature is variably set and stored in the data storage unit as the amount increases; composite water heater having. 3. An output period of a pump-on signal output from the intermittent pump operation control unit is given in advance by time,
2. The pump intermittent operation control section continuously outputs a pump-on signal until the output period elapses, and switches from a pump-on signal to a pump-off signal output when the output period elapses. Or the composite water heater according to claim 2. 4. An output period of a pump-on signal as the reheating heat amount increases based on the reheating heat amount detected by the reheating heat amount detected by the reheating heat amount detected by the reheating heating amount of the bath burner combustion. 4. The combined water heater according to claim 3, further comprising a pump-on signal output period automatic updating section for variably setting an output period of the pump-on signal in a direction to increase the length of the pump-on signal. 5. A running water detection sensor for detecting running water in a reheating heat exchanger driven by a circulation pump, and a bath burner combustion stopping section for stopping combustion of the bath burner when the running water detection sensor detects running water off. A combustion stop operation preventing unit for preventing a bath burner combustion stop operation of the bath burner combustion stop unit even if the running water detection sensor detects running water off when the pump intermittent operation control unit turns off the pump intermittent operation. The combined water heater according to any one of claims 1 to 4, characterized in that: