JPH10300198A - One-can two-channel-type combustion device and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a user from being hurt by running high temperature hot water when starting running hot water and at the same time to prevent undershooting from being generated by operating a pump continuously when the temperature of hot water in the heat-receiving pipe of hot-water-supply piping is higher than a specific temperature for operating the pump. SOLUTION: After a program is started, a control unit 50 judges whether an automatic hot-water supply is being operated while temperature is being preserved or not. When it is judged that the automatic hot-water supply is not operated while temperature is being preserved, the control unit 50 judges whether a reheating SW is turned on or not. Then, when hot-water is not being supplied when the reheating SW is turned on, a pump 24 is started and at the same time reheating combustion is started by a burner 1. Then, when the temperature of hot-water supply is higher than a setting temperature TPo for turning the pump on, at the same time, the temperature of hot water in a bathtub is higher than the setting temperature, and further the temperature of residence water is higher than the TPo, the combustion of the burner 1 is stopped. Also, a pump 24 is operated continuously with the combustion being tuned off until the temperature of hot water being discharged from a heat- receiving pipe 11 becomes lower than that for turning on reheating/combustion switch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a one-can, two-channel water heater.

[0002]

2. Description of the Related Art Generally, in a one-can, two-channel hot water supply system, one burner and a heat exchanger are commonly used for a hot water supply piping system and a reheating piping system. Therefore, there are advantages that the entire device can be reduced in size and that it can be manufactured at low cost.

[0003] On the other hand, in the one-can two-channel water heater, since one heat exchanger is shared by the hot water supply piping system and the additional heating piping system, there are various problems. For example,
During the reburning combustion, the water retained in the hot water supply pipe (heat receiving pipe) of the hot water supply piping system installed in the heat exchanger is heated to a high temperature. Therefore, when using the hot water supply piping system, high-temperature hot water is discharged from the hot water tap immediately after the start of use, which may cause pain to the user. Therefore, in the apparatus described in Japanese Patent Application Laid-Open No. 6-272954, after the reheating is completed, the bath water is circulated for a predetermined time by operating with a recirculating pump of a reheating pipe system (post pump), and the accumulated water in the hot water supply pipe. To lower the temperature.

[0004]

However, there is a problem which has not yet been solved in the one-can, two-channel water heater. For example, if the hot water supply pipe system is used again immediately after stopping the use of the hot water supply pipe system, the hot water in the hot water supply pipe that has become hot due to the after-boiling phenomenon is discharged from the hot water tap, which may cause pain to the user. However, such a situation cannot be solved by the method described in the above publication.
Also, after the user opens the hot water tap, the hot water supply device starts burning, and until the hot water becomes hot water due to the combustion heat,
The so-called undershoot, in which hot water lower than the set temperature is discharged, occurs. To prevent this, it is necessary to secure hot water in a predetermined temperature range in the heat exchanger. If such hot water cannot be ensured, an undershoot will occur, giving the user discomfort. Further, if the post-pump is performed when the re-heating is stopped by the user immediately after the re-heating is started, the cold water in the bath circulates, so that the heat exchanger is cooled and dew condensation occurs. Furthermore, during reburning combustion,
If the hot water tap 14 is erroneously opened to such an extent that the flow sensor cannot detect the amount of water flowing through the hot water supply piping system, the combustion heat for reheating is increased even though the combustion amount of the burner does not increase. Since it is spent on the hot water supply side, a situation occurs in which the reburning combustion does not end.

[0005]

Means for Solving the Problems To solve the above problems, the invention according to claim 1 is commonly used for a hot water supply piping system and a supplementary heating piping system, and is connected to a heat receiving pipe of the hot water supply piping system. A heat exchange unit provided with a heat receiving pipe of a heating piping system, a heat generating unit for heating the heat exchange unit, and a control for controlling operation of a pump for circulating water in a bathtub connected to the additional heating piping system. And a control unit, wherein the control unit keeps the pump operating when the temperature of hot water in the heat receiving pipe of the hot water supply piping system is higher than a predetermined pump operating temperature. I have.

In this case, it is desirable to set the pump operating temperature to a temperature lower than the reheating combustion ON temperature determined for reheating the heat generating section. In addition, the control unit sets the pump to an operating state when the temperature of the hot water in the heat receiving pipe of the hot water supply pipe system is higher than a predetermined pump operating temperature during the reheating combustion, and the temperature of the hot water is equal to or lower than the pump operating temperature. , It is desirable to stop the pump. Furthermore, a second control unit for controlling the heat generation unit is further provided, and the second control unit sets the temperature of the hot water in the heat receiving pipe of the hot water supply piping system to the pump operating temperature for a predetermined time during the reheating combustion. When the temperature does not reach even after the elapse, or when the temperature falls below the pump operating temperature, it is desirable to stop the reburning combustion.

The invention according to claim 5 is used commonly for the hot water supply piping system and the reheating piping system, and is provided with a heat exchange pipe provided with a heat receiving pipe of the hot water supply piping system and a heat receiving pipe of the reheating heating piping system. And a heat generating unit that heats the heat exchange unit. In a one-can, two-channel water heater that is provided with a pump that circulates water from a bathtub in the reheating pipe system, the heat receiving pipe system receives heat. When the temperature of the hot water in the pipe is higher than a predetermined pump operating temperature, the pump is continuously operated.

In this case, it is preferable that the pump operating temperature is set to a temperature lower than the reheating combustion ON temperature set for reheating the heat generating portion.
Further, during the reheating combustion, the pump is set to the operating state when the temperature of the hot water in the heat receiving pipe of the hot water supply pipe system is higher than a predetermined pump operating temperature, and when the temperature of the hot water is equal to or lower than the pump operating temperature, the pump is operated. Is desirably in a stopped state. Further, during the reheating combustion, when the temperature of the hot water in the heat receiving pipe of the hot water supply pipe system does not reach the pump operating temperature for a predetermined time, or when the temperature drops below the pump operating temperature, the reheating combustion is performed. It is desirable to stop it.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a schematic configuration of a one-can two-channel gas hot water supply apparatus according to the present invention. The hot water supply apparatus has one can (not shown) and a gas burner (heat pump) housed under the can. Generating unit) 1;
It has a heat exchange unit 2 housed in the upper part of the can and a fan (not shown) for supplying combustion air to the gas burner 1. Means for supplying gas to the burner 1 includes a gas pipe 3
And a main solenoid on-off valve 4 provided on each of the gas pipes 3.
And an electromagnetic proportional valve 5. In addition, an ignition mechanism (shown) is arranged near the burner 1.

The gas burner 1 and the heat exchange section 2 are commonly used for both the hot water supply piping system 10 and the additional heating piping system 20. That is, the heat exchange section 2 has a large number of thin fin plates 2a, and the fin plates 2a have a hot water supply pipe 11 as a heat receiving pipe of the hot water supply piping system 10,
A reheating water pipe 21 as a heat receiving pipe of the reheating piping system 20 is disposed in a penetrating state.

First, the hot water supply pipe system 10 will be described. A water supply pipe 12 of the hot water supply pipe system 10 is connected to an inlet end of the heat receiving pipe 11, and a hot water supply pipe 13 is connected to an outlet end thereof. A hot water tap 14 is provided at the end of the hot water supply pipe 13. Two bypass pipes 15 and 16 are provided between the water supply pipe 12 and the hot water supply pipe 13 in parallel with the heat receiving pipe 11. In FIG. 1, connection points between the bypass pipe 15 and the water supply pipe 12 and the hot water supply pipe 13 are indicated by reference numerals P1 and P2, respectively, and the bypass pipe 16 and the water supply pipe 12 and the hot water supply pipe 13 are shown.
Are indicated by reference numerals P3 and P4, respectively.

The bypass pipe 15 closer to the heat exchange section 2 is not provided with a valve or the like, and water flowing in the water supply pipe 12 always flows to the heat receiving pipe 11 side and the bypass pipe 12 side at the connection point P1. Parting at a fixed ratio (for example, 70:30). Then, they merge again at the connection point P2.

On the other hand, a first flow control valve GM2 is provided in the bypass pipe 16 remote from the heat exchange section 2.
As the flow control valve GM2, for example, a gear motor drive type configured as follows is used. That is,
The gear motor-driven flow control valve includes an annular valve seat provided in a pipe, a valve body movable with respect to the valve seat, a shaft having one end fixed to the valve body, and a shaft. A motor connected to the end via a reduction gear train. The shaft is screwed to the valve case.
Therefore, when the motor rotates, the shaft moves in the axial direction, whereby the opening between the valve body and the valve seat can be changed. Therefore, the amount of water flowing from the connection point P3 to the hot water supply pipe 11 side and the bypass pipe 1
The ratio with the amount of water flowing to the 6 side can be changed as appropriate. Note that a flow control valve GM1 configured similarly to the flow control valve GM2 is also provided on the hot water supply pipe 13 between the connection points P2 and P4.

The hot water supply piping system 10 is provided with first and second two flow sensors FL1 and FL2. The first flow sensor FL1 is disposed in the water supply pipe 12 between the connection points P1 and P3, and the second flow sensor FL2
Is disposed on the hot water supply pipe 13 between the connection point P4 and the hot water tap 14.

Further, the hot water supply piping system 10 is provided with four temperature sensors TH _IN , TH _Z , TH _OUT , and TH _MIX . The temperature sensor TH _IN is arranged in the water supply pipe 12 on the upstream side of the connection point P3, and detects the temperature of the water supply. Temperature sensor TH _Z is disposed on a bend portion of the hot water pipe 11, for detecting the temperature of the water hot water pipe 11. The temperature sensor TH _OUT is also provided with a hot water supply pipe 13 near the outlet of the hot water supply pipe 11 and detects the temperature of hot water flowing out of the hot water supply pipe 11. The temperature sensor TH _MIX is arranged in the hot water supply pipe 13 downstream of the connection point P4, and detects the temperature of hot water coming out of the water tap 14.

On the other hand, in the reheating pipe system 20, a return pipe 22 is connected between the inlet end of the reheating water pipe 21 and the bathtub 6, and the return pipe 22 is connected between the outlet end of the reheating water pipe 21 and the bathtub 6. An outgoing pipe 23 is connected between them. The return pipe 22 has a pump 2
4. A temperature sensor TH _HR and a flow switch FS are provided. The temperature sensor TH _HR is connected to the return pipe 22 from the bathtub 6.
Detects the temperature of hot water (or water) flowing into the system. Therefore, the temperature sensor TH _HR is substantially detects the temperature of the hot water in the bathtub 6. The running water switch FS is for detecting whether hot water is flowing in the return pipe 22 or not.
When hot water is flowing in the return pipe 22, the hot water is ON, and when hot water is not flowing, the hot water is OFF. When the flowing water switch FS is in the OFF state, the burner 1 is not ignited even if a reheating switch described later is turned ON.

Between the hot water supply pipe 13 of the hot water supply pipe system 10 and the return pipe 22 of the additional heating pipe system 20, a pouring pipe 30 for filling the bathtub 6 with hot water is provided. The connection points between 30 and the hot water supply pipe 13 and the return pipe 22 are indicated by reference numerals P5 and P6. The pouring pipe 30 is provided with a pouring valve 31 composed of an electromagnetic on-off valve.

The hot water supply apparatus further includes a control unit 5
0 and a remote controller 60. Detection signals from various detection units are input to the control unit 50. Here, temperature sensors TH _IN , TH _Z , T
H _OUT , TH _MIX , TH _HR , flow sensor FL1, FL2
And the detection signal of the flowing water switch FS is input.
In the following, it is assumed that the same reference numerals as those of the detecting means are used for the detection signals of the detecting means. Control unit 50, based on each detection signal, the control main electromagnetic switching valve 4 and the proportional solenoid valve 5 of the gas supply means, the ignition mechanism, a fan, the flow control valve GM _1, GM _2, a pump 24 and hot-water pouring valve 31 I do. On the other hand, the remote controller 60 includes an operation switch, an automatic bath operation switch, a reheating switch, a temperature setting unit, and a display unit (none of which are shown), and outputs ON / OFF information and set temperature information of these switches. The information is output to the control unit 50 and the information is displayed on the display unit. As described later, the display unit also displays error information from the control unit 50.

When hot water supply, additional heating, and automatic hot water filling are performed using the hot water supply device having the above-described configuration, first, when hot water supply is performed, the operation switch of the remote controller 60 is turned off.
The state is set to the N state, and the hot water tap 14 is opened. Then, the control unit 50 controls the electromagnetic proportional control valve 5 and the flow rate control valve GM1, based on the set temperature, the water supply amount FL1, the water supply temperature TH _IN , the tap water temperature TH _OUT and the water supply amount FL2 supplied to the water supply pipe 12. Controls GM2. As a result, hot water having a temperature equal to the set temperature is discharged from the tap 14. The control of the electromagnetic proportional control valve 5 and the like is the same as that of the conventional one, and is not a main part of the present invention. This is the same for the subsequent reheating and automatic hot water filling. If the difference between the water supply amount FL1 and the hot water supply amount FL2 is equal to or larger than a predetermined value, it is determined that there is a water leak in the pipe, the burner is stopped, and the display unit displays an error.

When performing additional heating, the additional heating switch of the remote controller 60 is turned on. Then, first, the pump 24 is started, and the hot water in the bathtub 6 circulates through the return pipe 22 and the outward pipe 23. When the flowing water switch FS detects the flow of the hot water in the return pipe 22, the gas burner 1 is ignited. Thereby, the hot water in the bathtub 6 is heated.
When the detection signal of the temperature sensor TH _HR reaches a set temperature, automatically with the combustion of the burner 1 is stopped, the pump 24 is stopped.

When performing automatic hot water filling, the bath automatic operation switch of the remote controller 60 is turned on. Then, the pouring valve 31 is opened, and the hot water heated in the hot water supply pipe 11 passes through the pouring pipe 30 and is supplied to the bathtub 6 via the return pipe 22 and the forward pipe 23. Of course, control is performed by the control unit 50 so that the temperature of the hot water supplied to the bathtub 6 becomes the set temperature. When a predetermined amount of hot water accumulates in the bathtub 6, the injection valve 31 is closed based on a detection signal of a detecting means (not shown) for detecting the amount of water in the bathtub 6, and the combustion of the burner 1 is stopped. And the hot water is finished.

After the completion of hot water filling, a warming operation for maintaining the hot water in the bath tub at a substantially constant temperature is performed. During the heat retention operation, reheating is performed every predetermined time. That is, when a predetermined time has elapsed after the completion of hot water filling, additional reheating is performed automatically. Reheating at this time is the same as reheating when the reheating switch is turned ON. And the temperature TH _HR of the hot water in the bathtub 6
When the temperature reaches the set temperature, the reheating is stopped, and the burner 1 and the pump 24 are stopped until a predetermined time elapses again.

Here, as described above, the stagnant water in the hot water supply pipe 11 is heated to a high temperature during the additional heating, or stays due to the heat storage of the fins 2a of the heat exchange unit 2 after the additional heating is stopped or the hot water supply is stopped. There is a problem that water is heated to a high temperature. When the reheating switch is turned off immediately after the reheating is started and the post pump is performed, the heat exchange unit 2 is cooled by the cold water in the bathtub, and the fins 2a and the heat receiving tubes 11 and
Dew condensation may occur on the 21. In order to prevent such a problem, the following control is executed by the control unit 50. This control will be described with reference to the flowcharts shown in FIGS.

After the program starts, first, in step S
In step 1, it is determined whether or not the automatic hot water filling operation is being performed. If the warm-up operation is being performed, it is determined in step S2 whether a predetermined standby time has elapsed. If the predetermined standby time has elapsed, it is determined in step S3 whether the frame rod (not shown) of the burner 1 is in the ON state. In this case, the flame rod being in the ON state means that the burner 1 is burning and hot water is being supplied. Therefore, step 3 can be rephrased as determining whether or not hot water is being supplied.

If it is determined in step S2 that the heat retaining operation is not being performed, the process proceeds to step S4 in which the reheating switch is operated.
It is determined whether or not has been turned ON. If the ON operation has not been performed, the process returns to step S1. If the ON operation has been performed, step S3 is executed.

In step 3, the frame rod is
If it is determined that the state is N, that is, if it is determined that hot water is being supplied, the pump 24 is operated intermittently in step 5. The intermittent operation of the pump 4
Flowing a small amount of hot water within the return tube 22, it is for to detect the temperature by the temperature sensor TH _HR. Thereafter, in step 6, based on the temperature TH _{HR of} the hot water in the bathtub 6, the set temperature of the hot water supply and the hot water supply amount, and the opening of the electromagnetic proportional valve 5, it is determined whether or not reheating can be performed while continuing the hot water supply. Is determined. That is, it is determined whether or not the burner 1 has a margin enough to perform additional combustion in addition to hot water supply combustion.

If additional heating is possible, simultaneous operation control is performed in step 7, and both hot water supply and additional heating are performed simultaneously. On the other hand, if there is no room for performing additional combustion, steps S3 to S6 are repeated. That is, it waits until the hot water supply ends. When the hot water supply is completed, the frame rod is turned off, so that the determination in step 3 is negative.

When the frame rod is in the OFF state, the pump 24 is started in step S8, and the burner 1 is ignited by the ignition mechanism in step S9. Thereby, additional combustion is started and the flame rod is turned on. Of course, before execution of step 8, it is confirmed that the water flow switch FS is in the ON state, but such steps are omitted for the sake of simplicity of the flowchart. Hereinafter, description may be similarly given without showing in a flowchart.

[0029] Thereafter, in step S10, the detected temperature, i.e. the pump ON set temperature (pump operation temperature TH _Z Yu hot water pipe 11 is set in advance by the temperature sensor TH _Z provided in the bend portion of the hot water pipe 11 Temperature) T
Whether higher than P ₀ is determined. The pump ON set temperature TP ₀ is set to, for example, about 60 ° C.

If TH _Z <TP _0, it is determined in step S11 shown in FIG. 4 whether a predetermined minute leak detection time has elapsed since the determination in step 10 was performed. If the predetermined time has not elapsed, steps S9 to S11 are repeated until the time has elapsed.
Normally, since the water in the heat receiving pipe 11 is heated by the combustion heat of the burner 1, the TH _Z ≧ TP ₀ until a predetermined minute leakage detection time elapses. As a result, step 13
Proceed to.

However, when the hot water tap 14 is open to the extent that the flow sensors FL1 and FL2 cannot detect the amount of flowing water, or even when the hot water tap 14 is open, the flow sensors FL1 and FL2 There If it is not possible to detect the water flowing through the hot water piping system 10 because of the failure, since the combustion heat of the burner 1 is taken by the water flowing through the hot water pipe 11, the rate of temperature rise TH _Z is slow , not a TH _Z ≧ TP ₀ even after the lapse of a predetermined time. Therefore, when the predetermined time has elapsed, it is considered that a failure has occurred, and in step S12,
Failure processing is performed. Here, combustion OFF, pump OFF, and error display are executed as failure processing.
Then, the program ends.

In step 13, it is determined whether or not the temperature TH _HR of hot water in bathtub 6 is higher than its set temperature TB ₀ . If TH _HR <TB ₀ , go to step 14. On the other hand, if TH _HR ≧ TB _0, that is,
If the temperature of the hot water in the inside has reached the set temperature, step S
At 15, the reheating switch is turned off. Thereby, the combustion of the burner 1 is stopped, the flame rod is turned off, and the reheating is completed. Thereafter, the process proceeds to step 14.

[0033] Oite step S14, the water flowing through the hot water pipe 11 (water) or standing water whether the temperature TH _Z is higher than the pump ON set temperature TP ₀ (hereinafter, collectively referred to by that standing water.) Is determined. In this case, since TH _Z ≧ TP ₀ is determined in step S10,
Or combustion of the burner 1 is stopped in step 15, no fault that is TH _Z <TP ₀ unless occur water heater.

If TH _Z > TP ₀ , step 1
Is higher or not than the accumulated water temperature TH _Z first combustion stop temperature of the predetermined predetermined is TH ₀ (OFF) at 6, and a second combustion temperature TH _OUT of the hot water discharged from the heat receiving pipe 11 is predetermined It is determined whether or not the temperature is higher than the stop temperature TH ₀ ′ (OFF).

Here, the first combustion stop temperature TH ₀ (OF
F) is a temperature for preventing the stagnant water from boiling, and is set to, for example, about 80 ° C. As is clear from this temperature, the temperature is set higher than the pump ON set temperature. On the other hand, the second combustion stop temperature T
H ₀ ′ (OFF) indicates that a small amount of water is supplied through the heat receiving pipe 11 (flow sensor F) during reburning combustion with the gas burner 1 fully opened.
Minimum flow rate within the range that can be detected by L1 and FL2. For example, when it is assumed that only 1 l) flows, the temperature rise that increases while the supply water flows from the installation location of the temperature sensor TH _{Z to} the installation location of the temperature sensor TH _OUT is α, and TH ₀ (OFF ) + Α.

The setting is made for the following reason.
That is, when there is no leak in the hot water pipe 13, and outputs approximately the same temperature of the temperature sensor TH _Z and a temperature sensor TH _OUT. Therefore, when the temperature of the stagnant water in the heat receiving tube 11 rises, first, TH _Z > TH ₀ (OFF) is detected. Thereby, it turns out that there is no leak in the tapping pipe 13. If it is determined that TH _Z > TH ₀ (OFF), the combustion of the gas burner 1 is stopped as described later. Therefore, if there is no leakage, TH _OUT > TH ₀ ′ (OF
F) is not determined.

On the other hand, when there is a slight leak in the tapping pipe 13,
For example accidentally pouring plug 14 will only open a small amount, when such a heat receiving pipe 11 is below water 1l / min is flowing, the temperature feed water of the small amount from the installation location of the temperature sensor TH _Z During the flow to the installation location of the sensor TH _OUT , the temperature of the feedwater increases by β. This temperature rise β is larger than the temperature rise α when the leak rate is 1 l / min. Therefore, TH _OUT > TH ₀ ′ (OFF) is detected before TH _Z > TH ₀ (OFF) is detected. Thus, it can be seen that there is leakage to such an extent that the flow sensors FL1 and FL2 cannot detect it. Note that TH
_{If OUT} > TH ₀ ′ (OFF) is detected before TH _Z > TH ₀ (OFF), the combustion of the gas burner 1 may be immediately stopped and a failure may be displayed.

In step S16, TH _Z > TH ₀ (O
If it is determined that FF) or TH _OUT > TH ₀ ′ (OFF), the routine proceeds to step 17, where combustion of the burner 1 is stopped and the flame rod is turned off. Then, the process returns to step S13. As a result, TH _Z ≤ TH
₀ (ON), and (see step S18) TH _OUT ≦ TH ₀ until (ON), while the pump 24 of the combustion OFF
Is driven. Thus, not only can the accumulated water is prevented from boiling, it is possible to lower the temperature TH _Z quickly. Moreover, the hot water in the bathtub 6 can be heated using the heat of the heat exchange section 2 (including the heat of the stagnant water). Thereby, the time required for additional firing can be reduced. Then, again, TH _Z ≤ TH
_{If 0} (OFF) and TH _OUT ≤ TH ₀ (OFF), a negative determination is made in step S16, and the process proceeds to step S18.

In step 18, it is determined whether or not the temperature TH _Z is lower than the first combustion ON temperature (additional combustion ON temperature) TH ₀ (ON), and the temperature TH _OUT is set to the second combustion ON temperature ( Additional firing combustion ON temperature) TH ₀ ′ (ON)
It is determined whether it is lower. Here, the first combustion ON temperature TH ₀ (ON) is, of course, higher than the pump ON set temperature TP ₀ , but the first combustion stop temperature TH ₀ (OFF).
The temperature is set slightly lower (for example, about 5 ° C. lower). This is to prevent frequent burning and stopping of the gas burner 1, and to provide a kind of hysteresis. Similarly, TH ₀ ′ (ON) is set to a temperature slightly lower (for example, lower by about 5 ° C.) than the second combustion stop temperature TH ₀ ′ (OFF).

If a negative determination is made in step 18, that is, TH _Z ≧ TH ₀ (ON) and TH _OUT ≧ TH ₀ ′
If at least one of (ON) is satisfied, the process returns to step 13, and if the reburning combustion is stopped, the stop state is continued, and if the reburn combustion is being performed, the reburn combustion is continued. . On the other hand, if an affirmative determination is made in step 18, the process proceeds to step S19.

In step S19, it is determined whether or not the reheating switch has been turned off. If the OFF operation has not been performed, the process returns to step S9, where the burner 1 is ignited again, and the reheating is resumed. On the other hand, when the additional heating switch is turned off, the process proceeds to step S17, the combustion is stopped, and the flame rod is turned off.

When the combustion is stopped in step 15 or when the operation proceeds from step 19 to step 17 and the combustion is stopped, the burner 1 does not burn again, so that steps S13, S14, S16 and S18 are performed. ,
While repeating S19 and S17, the hot water in the bathtub 6 is circulated by the pump 24, so that the temperature T
H _Z is quickly cooled. If TH _Z ≤TP ₀ , a negative determination is made in step 14, and the process proceeds to step 20.

In step 20, the combustion of the burner 1 is stopped, and the flame rod is turned off. Next, in step S21, the pump 24 is stopped.
Thereafter, it is determined in step 22 whether or not the warm-up operation is being performed. When the warm-up operation is being performed, the program is executed again from the beginning. If not, end the program.

Here, after the reheating is completed, the hot water in the bathtub 6 is circulated by the pump 24,
Temperature TH _Z of standing water is quickly cooled to a pump ON set temperature TP _0. Therefore, after additional combustion, hot water
Even if 4 is opened, hot water can be prevented from flowing out. Moreover, the temperature TH _Z of standing water is the lower than the pump ON set temperature, the pump 24 is stopped, the temperature of the standing water is maintained in the pump ON set temperature except natural cooling. Therefore, immediately after the start of hot water supply, the flow control valve GM
By opening the GM2 and the GM2 to an appropriate opening and mixing the stagnant water and the feed water, it is possible not only to prevent undershoot, but also to set the tapping temperature to the set hot water supply temperature. In other words, the flow control valves GM1, GM
The TP0 is determined based on the upper and lower limits that can be mixed (set to the set temperature) in Step ₂ .

If the reheating switch is turned off immediately after the reburn combustion and the determination in step 18 becomes affirmative, the pump 24 is determined based on the determination in step S14.
Is stopped immediately, so that the cold water in the bathtub 6 is not circulated. Therefore, it is possible to prevent dew condensation from occurring on the fins 2a and the like of the heat exchange unit 2.

During the reburn combustion, the flow sensor FL
If the hot water tap 14 is erroneously opened to the extent that the FL1 cannot detect the amount of flowing water, combustion is stopped by TH ₀ ′ (OFF) in step S18, and then combustion is restarted in step S16. temperature TH _Z of standing water until the _{can, TH Z = TH 0 (OFF} ) - [(β-α) + {TH 0 '
Drops to _{(OFF) -TH 0 '(ON} )}]. Here, TH ₀ ′ (OFF) −TH ₀ ′ (ON) = TH ₀ (OF
F) −TH ₀ (ON), the temperature TH _Z is (β) higher than the temperature TH ₀ (ON).
−α). As a result, the temperature of the retained water TH _Z
Becomes lower than the pump ON set temperature TP ₀ (TH
₀ (ON) − (β−α) <TP ₀ <TH ₀ (ON)), the combustion of the burner 1 and the operation of the pump 24 are stopped. Therefore, it is possible to prevent the reheating from continuing without ending. Further, thereafter, the process returns to step S1, and an error is displayed through steps S11 and S12.

The present invention is not limited to the above embodiment, but can be changed as appropriate. For example, in the above embodiments, the temperature of the accumulated water immediately add焚燃sintered start is determined whether higher pump ON set temperature TP ₀ (step S10), but this determination is not necessary . Further, the stop of combustion in step 19 is for further improving safety, and need not necessarily be executed.

The setting of α is 1 l / min.
/ Min or more is detected by the detection of the flow sensors FL1 and FL2, but the minimum operating flow rate is 2.5 l / mi.
If the second combustion stop temperature TH ₀ ′ (OFF) is set based on n, TH ₀ (ON) at the time of a 1 / min leak at the upper limit that cannot be detected by the flow sensors FL1 and FL2.
A large temperature difference of −TP ₀ (2.5 l)
/ Min, assuming that the temperature difference is γ, TH ₀ ′
(OFF) = TH ₀ (OFF) + γ).

Although the example in which the hysteresis of the temperature TH _Z and the hysteresis of TH _OUT are the same has been described, TH _OUT may be larger. Also in this case, if the hysteresis of TH _OUT is increased, the temperature difference TH ₀ (ON) −TP ₀ can be increased. Further, in the case of reducing the hysteresis of TH _OUT is 'by performing plus the (OFF), i.e. TH _0' difference _{TH 0 (OFF) + [{} TH 0 (OFF) -TH 0 (O
N)} - {by _{TH 0 '(OFF) -TH 0} ' (ON)}] to the new TH ₀ '(OFF), it is possible to prevent the above setting temperature TH ₀ to (ON) .

In the above embodiment, the present invention is applied to the control at the time of additional combustion, but is also applicable at the end of hot water supply combustion. Also in that case, the temperature T of the stagnant water
H _Z is a pump 24 to the operating state when higher pump ON set temperature TP _0, the pump 24 when lower than
Should be stopped. By doing so, it is possible to prevent overshoot at the time of re-watering due to a decrease in after-boiling, and to prevent the hot water from being discharged from the hot-water tap 14 and causing pain to the user.

[0051]

As described above, according to the first and second aspects of the present invention, it is possible not only to prevent hot water from being discharged at the start of tapping but to cause pain to the user. It is possible to prevent the occurrence of undershoot and to shorten the time required for additional firing. According to the third aspect of the invention, it is possible to prevent the occurrence of dew condensation on the heat exchanger. According to the invention of claim 4, an effect is obtained that a situation in which the reburning combustion does not end can be prevented beforehand.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a one-can, two-channel hot water supply apparatus to which the present invention is applied.

FIG. 2 is a diagram showing the first half of a flowchart for explaining a control method according to the present invention.

FIG. 3 is a diagram showing a main part in the latter half of the flowchart.

FIG. 4 is a diagram showing a part of the latter half of the flowchart.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas burner (heat generation part) 2 Heat exchanger (heat exchange part) 6 Bathtub 10 Hot-water supply piping system 11 Heat-receiving pipe of hot-water supply piping system 20 Additional heating piping system 21 Heat-receiving pipe of additional heating piping system 24 Pump

Continued on the front page (72) Inventor Yoshihiko Tanaka 3-4 Fukamidai, Yamato City, Kanagawa Prefecture Inside Gaster Co., Ltd.

Claims (8)

[Claims] 1. A heat exchange unit commonly used for a hot water supply piping system and a reheating piping system, and provided with a heat receiving pipe of the hot water supply piping system and a heat receiving tube of the reheating heating piping system. In a one-can, two-channel hot water supply apparatus, comprising: a heat generation unit for heating; and a control unit for controlling operation of a pump for circulating water in a bathtub connected to the reheating pipe system, wherein the control unit includes: A one-can, two-channel hot water supply apparatus characterized in that when the temperature of hot water in a heat receiving pipe of a piping system is higher than a predetermined pump operating temperature, the pump is kept operating. 2. The can according to claim 1, wherein the pump operating temperature is set to a temperature lower than a reheating combustion ON temperature set for reheating the heat generating portion. Two channel water heater. 3. The controller, when the temperature of the hot water in the heat receiving pipe of the hot water supply pipe system is higher than a predetermined pump operating temperature during the reheating combustion, causes the pump to operate, and the temperature of the hot water is reduced by the pump. 3. The one-can, two-channel hot water supply apparatus according to claim 1, wherein the pump is stopped when the temperature is equal to or lower than the operating temperature. 4. The apparatus according to claim 1, further comprising a second control unit for controlling the heat generation unit, wherein the second control unit controls the temperature of the hot water in the heat receiving pipe of the hot water supply piping system during the reheating combustion. The one-tank two-channel hot water supply apparatus according to claim 3, wherein the reburning combustion is stopped when the temperature does not reach the temperature even after the lapse of a predetermined time, or when the temperature falls below the pump operating temperature. 5. A heat exchange unit commonly used for a hot water supply piping system and a reheating piping system, wherein a heat exchange unit provided with a heat receiving pipe of the hot water supply piping system and a heat receiving tube of the reheating piping system is provided. In a one-can, two-channel hot water supply apparatus comprising a heat generating portion for heating and a pump for circulating water in a bathtub in the reheating pipe system, a temperature of hot water in a heat receiving pipe of the hot water supply pipe system is predetermined. A method for controlling a one-can, two-channel hot water supply apparatus, wherein the pump is kept operating when the temperature is higher than the pump operating temperature. 6. The can according to claim 5, wherein the operating temperature of the pump is set to a temperature lower than an on-combustion combustion ON temperature set for additionally burning the heat generating portion. A control method for a two-channel water heater. 7. When the temperature of the hot water in the heat receiving pipe of the hot water supply piping system is higher than a predetermined pump operating temperature during the reheating combustion, the pump is set to the operating state, and the temperature of the hot water is equal to or lower than the pump operating temperature. The method according to claim 5 or 6, wherein the pump is sometimes stopped. 8. When the temperature of the hot water in the heat receiving pipe of the hot water supply piping system does not reach the pump operating temperature for a predetermined time during the reheating combustion, or when the temperature of the hot water drops to the pump operating temperature or lower, the additional heating is performed. The method according to claim 7, wherein the combustion is stopped.