JPH09126546A - One-boiler/two-path type hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hot water supply system capable of both filling a bathtub and being used for shower at a time by controlling a rise of hot water temperature due to reheating. SOLUTION: When filling a bathtub 14 with hot water is started, a target temperature THS is set at 50 deg.C, which is the highest set temperature of bathtub set temperature TSF, in order to change the target temperature THS of a heat exchanger from 80 deg.C to 50 deg.C. A gas proportional control valve 20 and combustion of a burner 19 are controlled according to detected water flow rate value (Q) and supply water temperature TC so that temperature TH of the heat exchanger becomes equal to TFS. Hot water supplied as described above is mixed in a mixing valve 8 with a small amount of water introduced from a bypass pipe 5 side. The resulting mixture of the hot water and the water is sucked to a reheating heat exchanger 18 side through a hot water filling pipe 22 and a bathtub supply pipe 13. The mixture is slightly reheated by the heat exchanger 18 and then flows into the bathtub 14 through the bathtub supply pipe 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a hot water supply heat exchanger and a bath heating heat exchanger in one combustion chamber, and so-called one-can-two-water channel for heating both heat exchangers by the same heating unit. This is related to the improvement of the hot water heater.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned 1-can, 2-drain type water heater, in order to shorten the filling time when filling the bathtub, two bath circulation circuits are used to connect the bathtub to the bathtub. It is known to supply hot water.

[0003]

However, in this water heater, part of the hot water supplied to the bathtub when it is filled with water is reheated by the heat exchanger for bath heating, so that it is reheated by the heat exchanger. The temperature gets too high.

In particular, 1 which adopts bypass type mixing
In the can 2 water channel type water heater, the hot water discharged from the hot water heat exchanger is mixed with the water bypassing the heat exchanger to adjust the final hot water temperature by the mixing ratio. The outlet hot water temperature is the hot water supply set temperature (normally 38 ° C to 60 ° C).
Since the temperature is controlled to be considerably higher (80 ° C.) than (° C.), the temperature rise of the reheating also becomes large.

Therefore, conventionally, in the above-mentioned hot water heater, the hot water temperature is changed to a low value in anticipation that the hot water temperature rises due to the reheating of a part of the hot water while the hot water is being filled. A control method is known.

However, with this control method, the temperature at which hot water is discharged from the general hot water is lowered, so that even if it is desired to use water filling and a shower at the same time, the temperature of the hot water in the shower is too low to be used. There was a problem that it would end up. In addition, since it is necessary to lower the filling temperature by anticipating the worst case of filling temperature due to reheating, in some cases when reheating is small, filling is performed at a low temperature, and extra time is required to heat it by heating. It was hanging.

Therefore, an object of the present invention is to suppress the rise in hot water temperature due to reheating of a heat exchanger for bath heating when performing hot water filling in a bathtub, and to use hot water filling and shower at the same time. An object is to provide a 1-can, 2-channel water heater.

[0008]

DISCLOSURE OF THE INVENTION The present invention is a one-can-two-water channel for heating a heat exchanger for hot water supply to a hot water tap or a bathtub and a heat exchanger for additional heating to heat the hot water by the same heating unit. In a hot water heater, a hot and cold water mixing mechanism for mixing hot water supplied from the hot water supply heat exchanger and water supplied from a water supply source,
Hot and cold water mixed by the hot and cold water mixing mechanism, a water filling channel for filling the bathtub through the heat exchanger for additional heating, and a water flow detecting means for detecting water flow to the hot water flow channel, When the water flow detecting means detects water flow, it comprises a control means for controlling the heating unit so as to lower the temperature of the hot water supply heat exchanger, as compared to when the water flow is not detected. Characterize.

In a preferred embodiment of the present invention, the control means sets the temperature of the hot water supply heat exchanger to a temperature much higher than the hot water supply set temperature when the water flow is not detected. When water flow is detected, the heating units are controlled so that the temperature is slightly higher than the hot water supply set temperature.

According to the present invention, when the water flow detecting means detects the water flow, the heating section is controlled so as to lower the temperature of the hot water supply heat exchanger more than when the water flow is not detected. For example, in a preferred embodiment, the temperature of the hot water heat exchanger is
When the water flow is not detected, the heating unit is controlled so that the temperature is much higher than the hot water supply set temperature, and when the water flow is detected, the heating unit is controlled to be a temperature slightly higher than the hot water supply set temperature. As a result, when the hot water is being filled, the temperature of the hot water heat exchanger becomes close to the set temperature of the bath or general hot water, so the difference in temperature between the hot water heat exchanger and the heat exchanger for reheating is small. As a result, the reheating amount in the heat exchanger for additional heating becomes small, and the filling temperature can be maintained at the set temperature or a temperature value in the vicinity thereof. Further, even if general hot water such as a shower is supplied during this hot water filling, there is no need to lower the set temperature of the general hot water, so that the shower or the like can be used at the set hot water temperature.

In a preferred embodiment, as the slightly higher temperature, a predetermined temperature (for example, 50 ° C.) slightly higher than the upper limit value of the normal temperature range at the time of pouring is used.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a one-can / two-channel water heater using the bypass mixing according to the present invention.

In the water heater, water supplied from a water supply source (not shown) is heated by the heat exchanger 4 for hot water supply, and the heat exchanger 4 is heated.
A hot water supply system 100 for supplying hot water to a hot water faucet (including a shower) 11 and filling the bathtub 14 with the bypassed water supply, for heating and boiling the hot water in the bathtub 14 A bath circulation system 200 is provided.

The hot water supply system 100 includes a water supply pipe 1 for connecting a water supply source and an inlet of the hot water heat exchanger 4 and a burner 1 for inflowing water.
A hot water supply heat exchanger 4 for heating with heat from 9 and a hot water supply pipe 10 for supplying hot water discharged from the heat exchanger 4 to a bathtub 14 through a hot water supply faucet (including a shower nozzle) 11 and a water filling pipe 22. . The hot water supply system 100 is provided with a bypass pipe 5 that directly connects the water supply pipe 1 and the hot water supply pipe 10 and bypasses the heat exchanger 4, and a water supply amount Q provided in a portion of the water supply pipe 1 upstream of a branch portion of the bypass pipe 5. It also includes a water amount sensor 2 for detecting the water supply temperature, and a water supply temperature sensor 3 provided in the portion for detecting the water supply temperature Tc.

The hot water supply system 100 includes a heat exchanger temperature sensor 6 for detecting a heat exchanger temperature TH, which is provided in a portion of the hot water supply pipe 10 near the heat exchanger 4, and a bypass pipe 5 and a hot water supply pipe 10. A mixing valve 8 for mixing hot water from the heat exchanger 4 and water from the bypass pipe 5 at an arbitrary ratio provided in the confluence portion is also provided. The hot water supply system 100 further includes a hot water supply temperature sensor 9 for detecting the hot water supply temperature TM provided in the hot water supply pipe 10 in the vicinity of the mixing valve 8.
In addition, in the water filling pipe 22, a water filling valve 12 for disconnecting / continuing the water filling to the bathtub 14, and the bath outflow pipe 13 to the hot water supply pipe 1.
Check valves 23, 24 for preventing backflow of hot water to the 0 side
Is provided. The combustion control of the burner 19 is performed by adjusting the opening degree of the gas proportional valve 20 that adjusts the fuel gas supply amount from the supply gas source (not shown) to the burner 19.

The bath circulation system 200 includes an additional heat exchanger 18 for receiving heat from the burner 19 together with the heat exchanger 4, a bath return pipe 16 connecting the bath 14 and the heat exchanger 18, and a bath return pipe 16. And a bath circulation pump 15 for pumping the hot and cold water in the bathtub 14 into the heat exchanger 18 through the bath return pipe 16. The bath circulation system 200 forms a bath circulation circuit together with the bath return pipe 16 by connecting the return hot water temperature sensor 17 for detecting the temperature TF of hot water passing through the bath return pipe 16 and the heat exchanger 18 to the bathtub 14. Bath outflow pipe 13 for flowing hot water heated by heat exchanger 18 into bathtub 14.
Also equipped with. The above-mentioned filling pipe 22 communicates with the bath outward pipe 13.

In the above structure, the water supplied from the water supply source through the water supply pipe 1 has the water supply flow rate Q measured by the water amount sensor 2.
After the feed water temperature TC is detected by the feed water temperature sensor 3,
It is distributed and supplied to the heat exchanger 4 for hot water supply and the bypass pipe 5 side. The hot water discharged from the heat exchanger 4 flows toward the mixing valve 8 in the hot water supply pipe 10 after the temperature of the heat exchanger TH is detected by the temperature sensor 6 and flows into the mixing valve 8 from the bypass pipe 5 side. And is mixed at a predetermined ratio. The mixed hot water is heated by the hot water temperature sensor 9 (hot water temperature T
After M) is detected, hot water is supplied to the hot water supply faucet (or shower nozzle) 11 through the hot water supply pipe 10, or is filled in the bathtub 14 through the hot water pipe 22 and the bath outward pipe 13. On the other hand, the hot water in the bathtub 14 is heated by the bath circulation pump 15 from the bathtub 14 through the bath return pipe 16 until the hot water temperature TF detected by the return hot water temperature sensor 17 reaches the bath set temperature TSF. The circulation operation of reaching the exchanger 18 and flowing into the bathtub 14 from the heat exchanger 18 through the bath outward pipe 13 is repeated.

FIG. 2 is a block diagram showing the controller of the water heater of FIG.

The control unit is based on the detected values (Q, TC, TH, TM, TF) from the respective sensors 2 to 17, hot water supply set temperature TSK, bath set temperature TSF, etc. from the operation unit (not shown). The controller 21 is provided which controls a mixing valve drive unit 31, a water filling valve drive unit 32, a bath circulation pump drive unit 33, and a gas proportional valve drive unit 34 by performing a predetermined calculation process.

The processing operation of the filling temperature control by the controller 21 is shown in the flow chart of FIG.

That is, when water supply is started from the water supply source, the water supply flow rate detection value Q from the water amount sensor 2 is changed to the water supply temperature sensor 3
The supplied water temperature detection value TC is output from each. Therefore, the feed water flow rate detection value Q is the minimum amount of water (2 l /
min) or more (step S1), and if it is determined that the minimum water amount is exceeded, the opening / closing of the water filling valve 12 is checked next (step S2). As a result, when it is determined to be “closed”, normal hot water supply (the bath circulation pump 15 stops driving)
And set the heat exchanger temperature target value THS to the hot water supply set temperature T
The temperature is set to 80 ° C, which is considerably higher than SK (38 ° C to 50 ° C) (step S4).

Then, the gas proportional valve drive unit 34 is driven so that the hot water temperature TH from the heat exchanger 4 detected by the temperature sensor 6 becomes 80 ° C., and the burner 19 is combustion-controlled (step S5). The reason for setting the target value THS to 80 ° C. is that the heat exchanger temperature TH is set high so that the amount of heat required to maintain the hot water outlet temperature is increased by the amount of time delay from the opening of the hot water tap to the start of combustion. This is to prevent the fluctuation (undershoot) of the temperature of the hot water from being held in the exchanger 4.

The hot water then flows in the hot water supply pipe 10 toward the mixing valve 8, and in the mixing valve 8, the bypass pipe 5
It is mixed with the water flowing from the side at a predetermined ratio. The mixing ratio is determined so that the hot water supply temperature TM becomes the final hot water supply temperature (that is, the hot water supply set temperature TSK) because the hot water filling valve 12 is closed. The hot and cold water mixed in the mixing valve 8 is detected by the hot water supply temperature sensor 9 (hot water supply temperature TM: hot water supply set temperature TSK),
Hot water supply faucet (or shower nozzle) through the hot water supply pipe 10
Hot water is supplied to 11.

On the other hand, when it is judged "open" in step S2, the filling of water is started (the bath circulation pump 15 is driven).
So that the hot water supply set temperature TSK becomes the bath set temperature TSF, that is, the heat exchanger temperature target value THS is from 5 ° C to 5 ° C.
The target value THS is set to 50 ° C. which is the maximum value of the bath set temperature TSF so as to be 0 ° C. (step S3). And
Based on the detected value Q and the feed water temperature value TC, the heat exchanger temperature TH
So that the temperature target value THS (= TSF = 50 ° C.) becomes
The opening of the gas proportional valve 20 is controlled to control the combustion of the burner 19 (step S5). The reason why the target value THS is set to 50 ° C. is that the set temperature is usually not set to 50 ° C. or higher in the case of filling with water. When hot water is used during filling, since THS is set to 50 ° C and combustion is performed, there is no large fluctuation in the hot water temperature (undershoot).

After that, the hot water flows in the hot water supply pipe 10 toward the mixing valve 8 and is mixed with the water flowing from the bypass pipe 5 side in the mixing valve 8. At this time, the temperature TM of the hot water supplied from the heat exchanger 4 is only slightly higher than the bath set temperature TSF, so that the temperature reduction range by mixing the water is very small. After that, a part of the mixed hot water flows into the bathtub 14 through the bath upstream pipe 13, and a part of the mixed hot water passes through the heating heat exchanger 18 side to return to the bath return pipe 16
Through the bathtub 14. At this time, the temperature of the hot water passing through the additional heat exchanger 18 (that is, the additional heat exchanger 18
Temperature) and the temperature of the hot water supply heat exchanger 4 are very small, so that the reheating amount in the additional heating heat exchanger 18 is very small. For this reason, the set temperature during filling with water can be made almost the bath set temperature, and even if hot water is used by opening the hot water tap, the shower at the bath set temperature can be used.

As described above, according to the present embodiment, the hot water supply heat exchanger temperature TH is controlled to a temperature close to the set hot water temperature (bath set temperature TSF) at the time of filling water.
The amount by which this hot water is temperature-controlled by mixing with water is very small. When the hot water whose temperature has been adjusted passes through the heat exchanger 18 for additional heating, since the temperature difference between the hot water temperature TF and the hot water supply heat exchanger temperature TH is very small, the temperature is adjusted by the mixing valve 8. The amount of hot water reheated in the heat exchanger 18 for additional heating is also very small. Therefore, it is possible to fill the water at the set bath temperature (bath set temperature TSF).

It should be noted that the above content is merely an embodiment of the present invention, and does not mean that the present invention is limited to the above content. For example, in this embodiment, the temperature target value THS of the hot water supply heat exchanger 4 is set to a constant value (80 ° C. when normal hot water supply is performed, 50 ° C. when hot water filling is performed). It may be set as a function of any one of Tc, the hot water supply set temperature TSK, and the hot water supply temperature TM, or a function of a combination of these respective values. Also in this case, according to the above-described embodiment, by changing the constant or the calculation formula necessary for obtaining the temperature target value THS of the heat exchanger 4 for hot water supply, depending on whether it is normal hot water supply or hot water filling. The same effect can be achieved.

In order to further improve the accuracy of the set bath temperature TSF, the applicant of the present application filed Japanese Patent Application Laid-Open No.
By utilizing the technology disclosed in Japanese Patent Laid-Open No. 159798 or Japanese Patent Laid-Open No. 6-201185, it is possible to add a means for changing the hot water supply set temperature TSK at the time of filling water to the present embodiment.

[0030]

As described above, according to the present invention,
When filling the bathtub with water, it is possible to suppress an increase in hot water temperature due to reheating of the heat exchanger for bath heating, and to use water filling and showering at the same time. Machine can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a one-can / two-channel water heater of the present invention.

FIG. 2 is a block diagram showing a control unit of the water heater of FIG.

3 is a flowchart showing the processing operation of the filling temperature control of the control unit of FIG.

[Explanation of symbols]

 1 Water Supply Pipe 2 Water Volume Sensor 3 Water Supply Temperature Sensor 4 Hot Water Heat Exchanger 5 Bypass Pipe 6 Hot Water Heat Exchanger Temperature Sensor 8 Mixing Valve 9 Hot Water Supply Temperature Sensor 11 Hot Water Faucet (Shower Nozzle) 12 Hot Water Valve 13 Bath Outgoing Pipe 14 Bathtub 15 Bath circulation pump 16 Bath return pipe 17 Bath return hot water temperature sensor 21 Controller 22 Water filling pipe 23, 24 Check valve 31 Mixing valve drive unit 32 Water filling valve drive unit 33 Bath circulation pump 34 Gas proportional valve drive unit 100 Hot water supply system 200 Bath circulation system

Claims (3)

[Claims] 1. A one-can-two-channel water heater for heating a heat exchanger for hot water supply to a hot water tap or a bathtub and a heat exchanger for additional heating to heat the hot water by the same heating unit, wherein A hot and cold water mixing mechanism that mixes the hot water supplied from the heat exchanger and the water supplied from the water supply source, and the hot and cold water mixed by the hot and cold water mixing mechanism is poured into the bathtub through the heat exchanger for reheating. No water filling channel, water flow detection means for detecting water flow to the water flow channel, when the water flow detection means detects water flow, than when not detecting the water flow, A one-can-two-fluid water heater, comprising: a control unit that controls the heating unit to lower the temperature of the hot water heat exchanger. 2. The one-can-two-channel water heater according to claim 1, wherein the control means sets the temperature of the heat exchanger for hot water supply far above the hot water supply set temperature when the water flow is not detected. A one-can-two-channel hot water supply device, wherein each of the heating units is controlled so as to have a high temperature and a temperature slightly higher than a hot water supply set temperature when the water flow is detected. 3. The one-can-two-fluid water heater according to claim 2, wherein the slightly higher temperature is a predetermined temperature slightly higher than an upper limit of a normal temperature range when filling water. 1 can 2 water channel type water heater.