JP2007247933A - Water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high heat efficiency by effectively utilizing the retained residual heat of a combustion chamber. <P>SOLUTION: When an automatic switch of a hot water supply remote controller or a bath remote controller is pressed in S1, a bath/hot water supply solenoid valve is opened to allow the water to flow to an appliance, and a hot water supply burner is burned in S2. Thus the water heated by the hot water supply heat exchanger is supplied to a bathtub. When a detected accumulated amount of hot water reaches a set hot water amount on the basis of discrimination in S3, a gas cock solenoid valve is closed, and the combustion of the hot water supply burner is stopped first in S4, and then the bath/hot water supply solenoid valve is closed thereafter to stop the water flow into the appliance in S5. The retained residual heat of the combustion chamber can be taken out during from the stop of combustion of the hot water supply burner to the stop of water flow. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus having an automatic hot water supply function.

The hot water supply device includes a heat exchanger in which a water supply pipe and a hot water discharge pipe are connected, and a burner for heating the heat exchanger, and the hot water tap connected to the hot water discharge pipe is opened and passed through the apparatus. When water is supplied, a controller serving as a control means causes the burner to perform a combustion operation to heat the water passing through the heat exchanger and discharge the hot water from the hot water discharge pipe.
In such a hot water supply apparatus, the branch pipe branched from the hot water discharge pipe is connected to the bathtub, and the branch pipe is provided with an electromagnetic valve (open / close valve) so that the controller automatically fills the bathtub with hot water or adds hot water. There is something like that. This automatic hot water supply function is provided in the branch pipe by pressing the automatic switch provided in the bath remote control etc., the controller opens the solenoid valve and starts burning of the burner, supplying hot water from the branch pipe to the bathtub. When the accumulated amount of hot water detected by the flow sensor reaches a predetermined amount, the controller closes the solenoid valve to automatically stop hot water supply (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-316047

  In this automatic hot water supply function, the closing of the solenoid valve and the extinguishing of the burner when the predetermined amount is reached are performed almost simultaneously or at a timing when the extinguishing of the burner is slightly delayed after the closing of the solenoid valve. The retained residual heat is generated in the combustion chamber after stopping. Since this retained residual heat is radiated to the atmosphere without being exchanged as it is, it leads to energy loss.

  In view of the above, an object of the present invention is to provide a hot water supply apparatus that can effectively use the residual heat retained in a combustion chamber and that can obtain high thermal efficiency.

In order to achieve the above object, according to the first aspect of the present invention, when the control means terminates the automatic hot water supply upon reaching a predetermined amount or a predetermined water level to the hot water tank, after the combustion of the burner is stopped. The on-off valve is closed.
In order to achieve the above object, according to the second aspect of the present invention, the branch pipe branched from the hot water pipe is connected to the hot water storage tank, and the control means is based on the arrival of a predetermined amount or a predetermined water level in the hot water storage tank. When ending automatic hot water supply, check whether hot water is supplied to the hot water outlet side, and if hot water is not supplied to the hot water outlet side, the burner is stopped and the on-off valve is closed. On the other hand, when hot water is supplied to the outlet pipe side, only the on-off valve is closed without stopping the combustion of the burner.
In addition to the object of the first or second aspect, the invention according to the third aspect does not impair the usability of the user on the hot water tank side, and further enables improvement of thermal efficiency. When the on-off valve is closed after combustion of the burner is stopped, the amount of discharged hot water is gradually increased by the water-flow control means between the stop of combustion of the burner and the closing of the on-off valve. It is intended to decrease.
In addition, the hot water storage tank as used in the present invention refers to all containers that can store heated hot water at a predetermined amount or a predetermined water level, such as a bathtub in a hot water supply device with a bath or a hot water storage tank in a hot water storage type hot water heater.

According to the first and second aspects of the invention, by previously stopping the combustion of the burner, it is possible to effectively use the residual heat retained in the combustion chamber that has been conventionally released into the atmosphere, and to improve the thermal efficiency. it can. In particular, according to the second aspect of the present invention, when hot water is supplied on the side of the hot water discharge pipe, combustion of the burner is not stopped, so that hot water supply is continued on the side of the hot water discharge pipe without being affected even if automatic hot water supply ends. Can be used and does not impair usability.
According to the third aspect of the present invention, in addition to the effect of the first or second aspect, by adopting the water flow control means, it is possible to suppress the lowering of the hot water temperature until the plug is closed and to stop the combustion of the burner first. In addition, temperature unevenness does not occur on the hot water tank side, and the user does not feel uncomfortable. Further, the retained heat can be sufficiently transferred to the heat transfer tube of the heat exchanger, and further improvement in thermal efficiency can be expected.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of a hot water heater provided with the hot water supply apparatus of the present invention. The hot water heater 1 is configured to exchange hot water with the hot water burners 3, 3... Serving as a burner and a heat exchanger according to the present invention. The hot water supply circuit 2 is provided with a heater 7 for heating and discharging tap water, and the heating burners 5 and 5, the heating heat exchanger 26 and the bath heat exchanger 40 are used for floor heating and bathing. And a bath / heating circuit 4.
First, in the hot water supply circuit 2, 6 is a water supply pipe for supplying water from the water pipe to the hot water supply heat exchanger 7, 8 is a hot water discharge pipe for discharging hot water heated by the hot water supply heat exchanger 7, and 9 is a hot water supply burner 3. A gas pipe that supplies gas, a hot water supply amount sensor 10 is provided in the water supply pipe 6, a hot water supply thermistor 11 is provided in the hot water discharge pipe 8, and a gas source solenoid valve 12, A hot water supply switching solenoid valve 14, 14,... Is provided for each branch pipe to the hot water supply gas proportional control valve 13 and each hot water supply burner 3.

Further, a hot water supply fan 16 is provided below the hot water combustion chamber 15 that accommodates the hot water burners 3, 3..., And combustion air can be supplied to each hot water burner 3. Above the hot water supply combustion chamber 15, an exhaust passage 17 that leads combustion gas generated by the combustion of the hot water supply burner 3 to the exhaust port 18 is connected.
Further, a drop pipe 19 as a branch pipe connected to a return pipe 38 to a bathtub 39 serving as a hot water storage tank is branched and connected to the hot water discharge pipe 8, and a bath hot water solenoid valve 20 as an on-off valve provided in the drop pipe 19. , 20 can be opened to supply hot water heated by the hot water supply heat exchanger 7 to the bathtub 39.

  21 is a controller as control means, 22 is a hot water remote controller, 23 is a bath remote controller, and normal hot water supply is performed as follows. First, when water flow in the appliance due to opening of the hot-water tap 24 provided in the hot water discharge pipe 8 is detected by the hot-water supply amount sensor 10, the controller 21 starts with the hot-water supply fan 16 and the heating fan 31 of the bath / heating circuit 4 described later. And the combustion gas stored in the hot water supply combustion chamber 15 and the heating combustion chamber 30 are discharged (pre-purge). Thereafter, the gas source solenoid valve 12 of the gas pipe 9 and each hot water supply switching solenoid valve 14 are opened, the hot water supply gas proportional control valve 13 is opened at a predetermined opening, and gas is supplied to each hot water burner 3, The igniter 25 is continuously discharged to ignite the hot water supply burners 3, 3. Next, the controller 21 monitors the hot water temperature with the hot water supply thermistor 11 provided in the hot water discharge pipe 8, and the hot water supply switching solenoid valve 14 so that the hot water temperature becomes the set temperature indicated by the hot water remote controller 22 or the bath remote controller 23. And the opening degree of the hot water supply gas proportional control valve 13 are adjusted, and the air amount is continuously changed by controlling the rotational speed of the hot water supply fan 16.

  On the other hand, in the bath / heating circuit 4, a branch gas pipe 27 branched from the gas pipe 9 of the hot water supply circuit 2 is connected to the heating burner 5 of the heating heat exchanger 26, and the heating gas is connected to the branch gas pipe 27. Heating switching electromagnetic valves 29 and 29 are provided for the proportional control valve 28 and the branch pipes to the respective heating burners 5. A heating fan 31 that supplies combustion air to the heating burner 5 is also provided below the heating combustion chamber 30 that houses the heating burner 5. Above the heating combustion chamber 30, an exhaust passage 32 is provided which continuously joins the combustion gas generated by the combustion of the heating burner 5 with the exhaust passage 17 on the hot water combustion chamber 15 side and discharges it from the same exhaust port 18.

  The heating heat exchanger 26 forms a heating water circulation path together with the expansion tank 33, the low-temperature radiator 34 and the high-temperature radiator 35 for floor heating, and a heating circulation pump 36 is provided in the circulation path. It has been. Part of the piping of this circulation path passes through the bath heat exchanger 40 connected to the bathtub 39 by the forward piping 37 and the return piping 38, and is heated by the heating heat exchanger 26 to circulate through the circulation path. The bath circulating water passing through the bath heat exchanger 40 can be heated by the heating water. 41 is a bath heat valve that sends heating water to the bath heat exchanger 40, 42 is a bath circulation pump that circulates bath circulating water between the bathtub 39 and the bath heat exchanger 40, and 43 is a hot water outlet of the heating heat exchanger 26. A heating high temperature thermistor 44 that detects the temperature is a heating low temperature thermistor that detects the temperature of the heating water in the expansion tank 33.

  The additional cooking of the bath in the bath / heating circuit 4 is performed as follows. The return pipe 38 is provided with a bath return thermistor 45 that detects the hot water temperature of the bath, and when the detected bath return temperature falls below the set temperature, the bath thermal valve 41 is opened to open the heating circulation pump. 36 rotates, the heating burner 5 is ignited, and the bath circulation pump 42 also rotates. Therefore, the bath circulating water that circulates between the bath heat exchanger 40 and the bathtub 39 is heat-exchanged in the bath heat exchanger 40 with the heating water heated by the heating heat exchanger 26 and heated to the set temperature. When the set temperature is reached, combustion of the heating burner 5 is stopped, the heating circulation pump 36 and the bath circulation pump 42 are stopped, and the bath heat valve 41 is closed.

  On the other hand, the heating operation is performed as follows. When the controller 21 obtains an ON signal of the floor heating switch, the heating circulation pump 36 is rotated. Here, if the temperature of the heating water obtained from the heating high temperature thermistor 43 or the heating low temperature thermistor 44 is equal to or lower than the specified value, the controller 21 rotates the heating fan 31 and the hot water supply fan 16 by pre-purge rotation, and then the heating switching electromagnetic valve 29. Is opened, the heating gas proportional control valve 28 is opened at a predetermined opening, gas is supplied to the heating burner 5, and the igniter is continuously discharged to ignite the heating burner 5. The heating water pressurized by the heating circulation pump 36 branches to the low-temperature radiator 34 side and the heating heat exchanger 26 side, and the heating operation is performed by circulating through the circulation path. The controller 21 monitors the temperature from the heating high temperature thermistor 43 or the heating low temperature thermistor 44 and maintains the set temperature by adjusting the opening degree of the heating gas proportional control valve 28.

  Then, when the automatic switch is pressed in the hot water remote controller 22 or the bath remote controller 23 or the controller 21 detects that the water level of the bathtub 39 is equal to or lower than the set value by the water level sensor, the controller 21 executes the automatic hot water control to fill the hot water. Or add water. FIG. 2 is a flowchart of automatic hot water supply control in the case of hot water filling. First, when the automatic switch of the hot water remote controller 22 or the bath remote controller 23 is pressed in S1, the bath hot water solenoid valves 20 and 20 of the drop pipe 19 are opened in S2. At the same time, the hot water supply burner 3 is combusted because the bath circulation pump 42 operates to pass water through the appliance. Therefore, the hot water heated by the hot water supply heat exchanger 7 is supplied to the bathtub 39 through the dropping pipe 19 and the return pipe 38. When the accumulated hot water amount detected by the bath water amount sensor 46 provided in the dropping pipe 19 reaches a predetermined amount in the determination of S3, the controller 21 closes the gas source solenoid valve 12 in S4 and first turns on the hot water supply burner 3. After stopping the combustion, the bath hot water solenoid valves 20 and 20 are closed in S5, the bath circulation pump 42 is stopped, and the water flow in the appliance is stopped.

The timing of extinguishing the hot water supply burner 3 is, for example, the extinguishing time when the set temperature can be set by the maximum amount of gas input of the appliance (for example, 60 ° C.) (from extinguishing the hot water burner 3 to the bath hot water solenoid valve 20 (T1> T2), and the fire extinguishing time at the lowest temperature (for example, 38 ° C.) at which the set temperature can be set with the minimum amount of gas input is T2 seconds (T1> T2). In the actual automatic hot water supply, the fire extinguishing time may be obtained by equally dividing the difference between the times T1 and T2 in accordance with the gas input at that time and the set temperature to obtain an equal distribution.
According to this control, as shown in FIG. 3A, the amount of hot water indicated by the dotted line does not change until the closing time, whereas the temperature of the hot water indicated by the solid line gradually decreases from the time of extinction. Therefore, the retained residual heat in the hot water supply combustion chamber 15 can be taken out during the fire extinguishing time T from this fire extinguishing time to the closing time. Therefore, when the automatic hot water supply is terminated, there is no retained residual heat in the hot water combustion chamber 15, so that the post purge by the hot water supply fan 16 becomes unnecessary.
In addition, the automatic hot water supply control in the case of additional hot water is the same processing as FIG. 2 except for determining whether or not the water level of the bathtub 39 has become equal to or lower than the set value in S1.

  Thus, according to the hot water heater of the said form, when terminating the automatic hot water supply when the predetermined amount is reached, the controller 21 stops the water flow in the appliance after stopping the combustion of the hot water burner 3. By doing so, the residual heat retained in the hot water combustion chamber 15 that has been conventionally released into the atmosphere can be used effectively, and the thermal efficiency can be improved.

In the above embodiment, when the accumulated hot water amount reaches a predetermined amount in the determination of S3, the combustion stop of the hot water supply burner 3 and the stop of water flow in the appliance are processed in order, but as shown in FIG. When the accumulated hot water amount reaches the predetermined amount in the determination, it is determined in next S4 whether or not hot water is supplied to the hot water discharge pipe 11 side. If simultaneous hot water supply is not confirmed here, as in FIG. 2, the gas source solenoid valve 12 is closed in S5 and the combustion of the hot water burner 3 is stopped first, and then the bath hot water solenoid valves 20 and 20 in S6. And the bath circulation pump 42 is turned OFF, and the water flow in the appliance is stopped. The presence or absence of hot water supply to the side of the hot water discharge pipe 11 can be confirmed by a change in the amount of hot water detected by the hot water amount sensor 46 (in the case of simultaneous hot water supply, the amount of hot water is small). May be.
On the other hand, if hot water supply to the hot water discharge pipe 11 side is confirmed in S4, the hot water supply solenoid valve 20, 20 and the bath circulation pump 42 are turned off in S7 to stop only the water flow to the drop pipe 19 side, and the hot water supply burner No. 3 combustion, that is, hot water supply to the hot water discharge pipe 11 side is continued. When the hot water tap 24 is closed in S8 and hot water supply on the side of the hot water discharge pipe 11 is stopped, combustion of the hot water supply burner 3 is stopped in S9.

  According to this modified example, the controller 21 confirms whether hot water is supplied to the hot water discharge pipe 11 side when hot water supply is terminated when the predetermined amount is reached, and hot water supply to the hot water discharge pipe 11 side is not performed. In this case, after the hot water supply burner 3 is stopped from burning, the hot water supply solenoid valve 20 is closed, while when hot water supply to the hot water discharge pipe 11 is being performed, the hot water supply burner 3 is stopped from burning. By stopping only the water flow to the dropping pipe 19 side without making it hot, the hot water supply burner 3 does not stop burning when hot water is being supplied on the hot water outlet pipe 11 side, so that the automatic hot water supply ends. However, it is possible to continue hot water supply without affecting other hot water supply points, and it does not impair usability.

In the above embodiment, the fire extinguishing time T is obtained from the relationship between the gas input and the temperature. However, the fire extinguishing time T can always be set to a fixed time, or after the combustion of the burner is stopped, the branch pipe such as the bath return thermistor 45 or the like. It is also possible to close the on-off valve after confirming that the tapping temperature obtained by the temperature detecting means on the side has reached a predetermined temperature. In this case, the calculation of the fire extinguishing time is unnecessary and the configuration is simplified.
Further, in the above embodiment, only the retained residual heat of the hot water combustion chamber 15 is taken out, but the retained residual heat is also generated in the bath side piping by the operation of the bath circulation pump 42 at the time of dropping. The time when the power consumption of the bath circulation pump 42 is the maximum and the minimum is set respectively, and the fire extinguishing time is obtained by adding the time obtained by the proportional calculation with respect to the actual power consumption of the bath circulation pump 42. It may be.

  In addition, if the fire extinguishing time is long, the temperature of the hot water is greatly reduced before the plug is closed, and the temperature of the bathtub may be uneven. Therefore, after the combustion of the hot water supply burner 3 is stopped, the amount of water is gradually reduced by the operation control of the water amount control motor 48 (water flow control means) that operates the bypass control valve 47 provided in the water supply pipe 6. Also good. In this case, as shown in FIG. 3 (B), the temperature of the hot water indicated by the solid line gradually decreases from the time of extinction, and the amount of the hot water indicated by the dotted line also gradually decreases and becomes 0 when the plug is closed. If the amount of water is reduced in this way, a decrease in the temperature of the hot water until closure is suppressed, and even if combustion of the previous burner is stopped, temperature unevenness does not occur on the bathtub side, and the user does not feel uncomfortable. In addition, the retained heat can be sufficiently transmitted to the heat transfer tube of the hot water supply heat exchanger 7, and further improvement in thermal efficiency can be expected.

In addition, although the end of the automatic hot water supply to the bathtub is assumed to reach a predetermined amount in the above form, the water level may be monitored by a water level sensor provided on the hot water tank side, and the automatic hot water supply may be ended when the predetermined water level is reached. .
In addition, it is not essential to have a bath / heating circuit as a hot water supply device, even if there is no bath side or heating side, or both, and there is no hot water supply circuit with a hot water pipe connected directly to the bathtub. The present invention is applicable. Therefore, when there is no bath / heating circuit, ON / OFF of the bath circulation pump is not included in the automatic hot water supply control of the above-described form.
On the other hand, the present invention relates to a hot water supply such as a hot water storage type hot water heater that automatically supplies hot water heated by a heat exchanger to a hot water storage tank as a hot water storage tank at a predetermined amount or a predetermined water level and keeps the hot water at a predetermined temperature. Even an apparatus can be employed with the same control during automatic hot water supply to a hot water storage tank.

It is the schematic of a hot water heater. It is a flowchart of automatic hot-water supply control. It is a graph which shows the relationship between the hot water temperature at the time of completion | finish of automatic hot water supply, the amount of hot water, and time, when (A) does not reduce the amount of hot water gradually, and (B) shows the case where it decreases gradually, respectively. It is a flowchart of the example of a change of automatic hot-water supply control.

Explanation of symbols

1. Hot water heater / heater, 2. Hot water supply circuit, 3. Hot water burner, 4. Bath / heating circuit, 5. Heating burner, 6. Hot water pipe, 7. Hot water heat exchanger, 8. Hot water pipe, 15 ... Hot water combustion chamber, 19 ... Drop pipe, 20 ... Bath hot water solenoid valve, 21 ... Controller, 22 ... Hot water remote control, 23 ... Bath remote control, 37 ... Outward piping, 38 ... Return piping, 39 ... Bathtub, 40 ... Bath heat exchanger, 42 ... Bath circulation pump, 46 ... Bath water sensor, 47 ... Bypass control valve, 48 ... Water control motor.

Claims (3)

A heat exchanger provided in the combustion chamber and capable of heating water to be passed by a burner, a hot water tank connected to the heat exchanger via a hot water discharge pipe and supplied with hot water, and an open / close provided in the hot water discharge pipe And a control means for controlling combustion of the burner, the control means enabling automatic hot water supply of a predetermined amount or a predetermined water level to the hot water storage tank by opening / closing control of the on-off valve and combustion control of the burner. A water heater,
When the automatic hot water supply is terminated when the predetermined amount or the predetermined water level is reached, the control means closes the open / close valve after the combustion of the burner is stopped. A heat exchanger provided in the combustion chamber and capable of heating water to be passed by a burner, a tapping pipe to which hot water heated by the heat exchanger is supplied, a branch from the tapping pipe, and an open / close valve A branch pipe connected to the hot water storage tank, and a control means for controlling the combustion of the burner, the control means to the hot water storage tank by a predetermined amount or a predetermined amount by open / close control of the on-off valve and burner combustion control. A hot water supply device that enables automatic hot water supply at the water level,
When the automatic hot water supply is terminated when the predetermined amount or the predetermined water level is reached, the control means checks whether or not hot water is supplied to the hot water discharge pipe side, and hot water supply to the hot water discharge pipe side is not performed. Is configured to close the on-off valve after stopping the combustion of the burner, while the hot-water supply to the outlet pipe side is performed without stopping the burning of the burner. A hot water supply device characterized in that only the valve is closed. When a water flow control means for controlling the water flow rate to the apparatus is provided to close the on-off valve after the burner has stopped burning, the passage of the burner after the burner has stopped burning until the on-off valve is closed. The hot water supply apparatus according to claim 1 or 2, wherein the amount of hot water is gradually reduced by the water control means.

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