JP2004257575A - Hot water supply device for storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize heat loss without unnecessarily heating hot water in a bathtub B. <P>SOLUTION: This hot water supply device is provided with an on-off valve 12 for supplying hot water and a circulating system 20 for circulating the hot water in the bathtub B via a pump 21 into a heat exchanger 23 in a tank T. The circulating system 20 has a bypass line 20a with a selector valve 22 for selecting the heat exchanger 23 to be used or not. The circulating system 20 can circulate the hot water in the bathtub B via the selector valve 22 and the bypass line 20a without using the heat exchanger 23 during checking the temperature of hot water as required in temperature retaining operation or during operation of preventing the freezing of the line. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hot water supply device for a hot water storage type water heater that can minimize heat loss without unnecessarily heating hot water in a bathtub.
[0002]
[Prior art]
In some cases, an electric water heater is combined with a hot water supply device having a reheating function (for example, JP-A-11-83156).
[0003]
The hot water supply device is configured by combining a mixing valve Va for filling water and a circulation system 2 having a pump P and a heat exchanger R (FIG. 9). In addition, an upper heat exchanger R is installed in the tank T of the electric water heater in addition to the upper and lower heaters H, H, and the outlet side of the mixing valve Va for hot water is supplied via an on-off valve Vb. It is connected to the outgoing side of the circulation system 2.
[0004]
Therefore, when the on-off valve Vb is opened, the hot water from the tank T and the water from the water source W can be mixed and filled in the bathtub B through the mixing valve Va. On the other hand, the circulation system 2 can operate the pump P to feed hot water in the bathtub B to the heat exchanger R, reheat the hot water in the bathtub B via the heat exchanger R, and maintain the temperature. In addition, freezing of the pipeline can be prevented. Note that, in order to determine whether or not additional heating is required during the heat retention, the pump P is operated intermittently, and the hot water in the bathtub B is circulated through the circulation system 2 to obtain the temperature detected by the temperature sensor TS.
[0005]
[Problems to be solved by the invention]
According to such a conventional technique, the circulation system operates the pump to circulate the hot water in the bathtub to the heat exchanger of the circulation system when determining whether or not additional heating is necessary. Heating may cause discomfort to the bather, and also has a problem that the use of a heat exchanger when preventing freezing of the pipeline causes a large heat loss and is extremely uneconomical.
[0006]
Accordingly, an object of the present invention is to provide a bypass pipe with a switching valve for selecting use or non-use of a heat exchanger in view of the problem of the related art, thereby unnecessarily heating hot water in a bathtub. Another object of the present invention is to provide a hot water supply device for a hot water storage type water heater that can minimize heat loss.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the configuration of the first invention according to the present application includes an on-off valve for filling hot water, and a circulation system for circulating hot water in a bathtub to a heat exchanger in the tank via a pump. The circulation system has a bypass pipe with a switching valve for selecting use or non-use of the heat exchanger, and the switching valve is connected to either the heat exchanger side or the bypass pipe side of the pump outlet side. The point is to selectively open them.
[0008]
In addition, the switching valve can be opened to both the heat exchanger side and the bypass pipe side at an early stage of the reheating operation, and can be opened to the heat exchanger side after a lapse of a predetermined time.
[0009]
The configuration of the second invention comprises an opening / closing valve for filling hot water, and a circulation system for circulating hot water in the bathtub to a heat exchanger in the tank via a pump, wherein the circulation system uses a heat exchanger. It has a bypass line with a switching valve that selects non-use, and the switching valve selectively opens the outlet side of the pump to either the heat exchanger side or the bypass line side, and in the standby state, the heat exchanger side The main point is to open to the public.
[0010]
The switching valve can be opened to the bypass pipe side when the abnormal operation of the pump is detected in the standby state.
[0011]
In the first and second inventions, the switching valve may be alternately opened on the heat exchanger side and the bypass pipe side in the cleaning operation. At this time, the switching valve is shortly opened on the heat exchanger side and the bypass valve is opened. It may be repeatedly opened long to the pipeline side, and the switching valve may be a three-way switching valve provided upstream of the heat exchanger and the bypass pipeline.
[0012]
[Action]
According to the configuration of the first invention, the heat exchanger in the tank is switched when the hot water temperature is checked in order to determine the necessity of additional heating during the warming operation or when the pipe line is prevented from freezing. It is possible to circulate hot water in the bath tub via the bypass pipe by selecting it not to be used through the valve, and selecting to use it in the reheating operation including reheating at the time of warming operation and heating the hot water in the bath tub. can do. On the other hand, the on-off valve can fill the bathtub with a suitable temperature of hot water produced by mixing hot water from a tank and water from a water source such as tap water through a mixing valve.
[0013]
In addition, the switching valve opens the outlet side of the pump to both the heat exchanger side and the bypass pipe side, for example, at the beginning of the reheating operation, so that the excessively hot water staying in the heat exchanger is discharged from the bathtub. It can be prevented from directly flowing into the inside, and giving a bather discomfort can be prevented. That is, in the initial stage of the reheating operation, the switching valve is opened on both the heat exchanger side and the bypass pipe side to allow hot water of an appropriate temperature to flow into the bathtub, and after a predetermined time has elapsed, is opened to the heat exchanger side, thereby providing a comfortable operation. It is possible to realize a reheating operation.
[0014]
According to the configuration of the second aspect of the invention, the same operation as in the first aspect of the invention can be realized except that the switching valve is opened to both the heat exchanger side and the bypass pipe side at the beginning of the reheating operation. In addition, the switching valve is opened to the heat exchanger side in the standby state, so that, for example, when there is no hot water or water in the bathtub, the pipeline leading to the heat exchanger is maintained in a state where drainage is completed, and the standby state is established. This is advantageous in preventing freezing of the pipeline. However, it is assumed that the heat exchanger is disposed higher than the switching valve, and that a pipe from the switching valve to the heat exchanger is piped so as to uniformly descend toward the switching valve. Further, the switching valve may be opened on both the heat exchanger side and the bypass pipe side, so that the operation of the first invention in the early stage of the reheating operation may be realized. Here, the standby state refers to a state in which the filling operation or the circulation operation by the pump is not performed regardless of the presence or absence of water or hot water in the bathtub.
[0015]
When an abnormal operation of the pump is detected in the standby state, the switching valve opens from the heat exchanger side to the bypass pipe side to prevent the hot water from the heat exchanger from being supplied to the bathtub carelessly. And the safety of bathers can be ensured.
[0016]
In addition, the switching valve is opened alternately on the heat exchanger side and the bypass pipe side in the cleaning operation, thereby reducing unnecessary heat loss in the cleaning operation and increasing the temperature of water or hot water in the bathtub by the cleaning operation. By doing so, the user's discomfort can be reduced. The cleaning operation is to clean the inside of the circulation system pipeline including the heat exchanger. The cleaning agent is poured into the remaining hot water in the bathtub, the start is started by manually operating the start switch, and the pump is started. , The opening direction of the switching valve is alternately switched.
[0017]
In the cleaning operation, the switching valve makes the time to open to the heat exchanger shorter than the time to open to the bypass pipe side, so that the temperature rise of water or hot water in the bathtub can be reduced, and the heat loss can be further reduced. .
[0018]
By making the switching valve a three-way switching valve, the number of parts can be minimized and the cost can be reduced. However, the switching valve may be a combination of two on-off valves.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the invention will be described with reference to the drawings.
[0020]
The hot water supply device of the hot water storage type water heater includes a mixing valve 11 for hot water filling, an on-off valve 12, and a circulation system 20 (FIG. 1).
[0021]
The hot water storage type water heater is an electric water heater, and upper and lower heaters H, H and an upper heat exchanger 23 are incorporated in a tank T for storing hot water. However, the hot water storage type water heater may be a type other than the electric water heater, in which the heaters H, H as heat sources in the tank T are heat exchangers using a heat pump, solar heat, or the like.
[0022]
A water supply pipe T1 from a water source W is connected to a lower portion of the tank T via a pressure reducing valve Vp, and a relief valve Vr and a mixing valve 11 for filling water are connected to a water supply pipe T2 at an upper portion of the tank T. , A mixing valve 31 for external hot water supply is branched and connected. The outlet side of the pressure reducing valve Vp is branched and connected to the mixing valves 11 and 31, respectively. The outlet side of the mixing valve 11 is connected to the downstream side of the heat exchanger 23, that is, the outgoing side of the circulation system 20 via the on-off valve 12 and the flow rate sensor 13. The outlet side of the mixing valve 31 is connected to an external mixing faucet (not shown) via a flow sensor 32, and a temperature sensor 33 is provided at the outlet side of the flow sensor 32.
[0023]
The circulation system 20 includes a backflowable pump 21 interposed on the return side of the bath B from the circulation fitting B1, a bypass pipe 20a with a switching valve 22 provided on the outlet side of the pump 21, and a heat source in the tank T. An exchange 23 is provided. A water level sensor 24 and a temperature sensor 26 are provided on the suction side of the pump 21, and a flow switch 25 is interposed between the pump 21 and the switching valve 22. The switching valve 22 is a three-way switching valve disposed on the upstream side of the heat exchanger 23 and the bypass line 20a. The downstream side of the heat exchanger 23 is the outlet side of the mixing valve 11 and the downstream side of the bypass line 20a. And is connected to the circulation fitting B1 of the bathtub B as the outgoing side of the circulation system 20. However, the temperature sensor 14 is provided between the junction on the downstream side of the heat exchanger 23 and the outlet side of the mixing valve 11 and the junction on the downstream side of the bypass pipe 20a.
[0024]
The water level sensor 24 detects the water level in the bathtub B. In addition, the heat exchanger 23 is disposed sufficiently higher than the switching valve 22, and the pipeline on the return side of the circulation system 20 from the heat exchanger 23 to the bathtub B via the switching valve 22, and the bypass pipeline 20 a from the heat exchanger 23. It is preferable that the pipes leading to the downstream side of the circulation system 20 from the switching valve 22 including the bypass pipes 20a to the bathtub B including the bypass pipes 20a be piped so as to descend uniformly. However, when the bathtub B is arranged higher than the tank T, a drain plug is provided at the bottom of each pipeline for the circulation system 20 reaching the bathtub B.
[0025]
The switching valve 22 is configured by incorporating, for example, a valve body 22b forming an opening 22c in the peripheral surface into a housing 22a (FIG. 2). However, FIGS. 2B to 2D are operation explanatory diagrams corresponding to the arrows XX in FIG. 2A, respectively. The housing 22a has an inlet-side port 22a1 and outlet-side ports 22a2, 22a3, and the valve body 22b is rotatably incorporated at the junction of the ports 22a1, 22a2, 22a3. The valve body 22b is connected to a drive motor 22d of, for example, a DC motor type or a step motor type mounted on the housing 22a.
[0026]
The switching valve 22 can selectively open the outlet ports 22a2 and 22a3 through the opening 22c by rotating the valve body 22b in the forward and reverse directions via the drive motor 22d. That is, the valve body 22b connects one of the outlet-side ports 22a2 and 22a3 to the inlet-side port 22a1 and closes the other through the opening 22c (FIGS. (B) and (C)). Both ports 22a2 and 22a3 can be opened at the same time (FIG. 3D). Therefore, the switching valve 22 selectively opens the outlet side of the pump 21 to one of the heat exchanger 23 side and the bypass pipe 20a side and both the heat exchanger 23 side and the bypass pipe 20a side. be able to.
[0027]
The mixing valve 11, the opening / closing valve 12, the pump 21 of the circulation system 20, the switching valve 22, and the mixing valve 31 for external hot water supply are controlled by a common controller (not shown) in accordance with a designated operation mode.
[0028]
In each of the operation modes of the filling operation, the adding operation, the priming operation and the cutting operation (FIG. 3), the pump 21 is stopped, the switching valve 22 is opened to the bypass pipe 20a side, and the heat exchanger 23 is not used. Select and open / close valve 12 opens. That is, the mixing valve 11 mixes the hot water from the tank T and the water from the water source W, and fills the bathtub B with a suitable temperature hot water by using both the outgoing side and the return side of the circulation system 20 ( Arrows K1 and K1 directions in the figure). The mixing valve 11 continuously adjusts the mixing ratio of the hot water from the tank T and the water from the water source W so that the hot water supply temperature detected by the temperature sensor 14 becomes the set temperature. For example, the temperature is set to 35 to 45 ° C. for the filling operation and the adding hot water operation, and is set to, for example, 10 to 25 ° C. for the priming operation and the cutting water operation. However, the mixing valve 11 may supply the water from the water source W to the bathtub B as it is in the priming operation or the cutting water operation.
[0029]
Note that the heat exchanger 23 at this time is not used, and there is no risk of inadvertently discharging the internal high-temperature water. Therefore, an excessive heat load may be applied to the downstream equipment including the pump 21. Absent. Further, the on-off valve 12 closes when the integrated flow value from the flow sensor 13 reaches the set amount, and can automatically end the filling operation, the hot water operation, the priming operation, and the pouring water operation.
[0030]
The filling operation of the water level setting type, the adding hot water operation of the water level setting type, and the adding hot water operation are also shown in FIG. That is, by opening the on-off valve 12, the mixing valve 11 can mix the hot water from the tank T and the water from the water source W and fill the bathtub B with the set temperature. For example, the temperature is set at 35 to 45 ° C. for the operation and the adding hot water operation, and is set at 60 to 80 ° C. for the adding hot water operation.
[0031]
The circulation system 20 for the filling operation and the hot water operation activates the pump 21 intermittently, and when the flow switch 25 detects that the water level in the bathtub B exceeds the circulation fitting B1, the pump 21 21 is stopped, and the water level in the bathtub B is continuously monitored via the water level sensor 24. When the water level in the bathtub B reaches the set value, the on-off valve 12 is closed to complete the filling operation or the adding hot water operation. In addition, in the operation of the hot water, the on-off valve 12 is closed when the integrated flow value from the flow sensor 13 reaches the set amount.
[0032]
In the initial stage of the reheating operation including reheating during the heat retaining operation (FIG. 4A), the switching valve 22 is opened on both the heat exchanger 23 side and the bypass pipe 20a side to use the heat exchanger 23. Then, the pump 21 is operated. That is, the circulation system 20 circulates the hot water in the bathtub B through the pump 21 to both the heat exchanger 23 and the bypass line 20a (in the directions indicated by arrows K3a and K3b in the figure), and supplies the bathtub B with an appropriate temperature hot water. The hot water in the bathtub B can be reheated while being heated. When a predetermined time required for discharging the high-temperature hot water staying in the heat exchanger 23 before the start of the reheating operation elapses, the switching valve 22 opens to the heat exchanger 23 side (FIG. 2B). ), Continue the reheating operation. During this time, the temperature sensor 26 checks the hot water temperature of the bathtub B, and when the hot water temperature of the bathtub B reaches the set temperature, stops the pump 21 and ends the reheating operation.
[0033]
In the hot water temperature check for judging the necessity of additional heating during the heat retention operation, the freeze prevention operation of the pipeline, and the circulation check operation for judging whether the water level of the bathtub B exceeds the circulation fitting B1 (FIG. 5). ), The switching valve 22 opens to the bypass pipe line 20a side, selects the heat exchanger 23 not to be used, activates the pump 21, and circulates the hot water in the bathtub B through the bypass pipe line 20a (arrow K4a in the figure). , K4b direction). Therefore, the hot water in the bathtub B is not unnecessarily heated and no unnecessary heat loss occurs at the time of checking the hot water temperature required during the heat retaining operation or during the freeze prevention operation. Further, in the circulation check operation, if it is detected via the flow switch 25 that the water level in the bathtub B exceeds the circulation fitting B1, and further reheating is required, the operation proceeds to the heat retention operation or the reheating operation as it is. Can be. The freeze prevention operation is an operation of intermittently operating the pump 21 to circulate the hot water in the bathtub B through the bypass pipeline 20a in order to mainly prevent freezing of each pipeline for the circulation system 20.
[0034]
On the other hand, when an external mixing faucet (not shown) is opened, the mixing valve 31 for external hot water supply mixes hot water from the tank T and water from the water source W and supplies hot water to the outside (FIG. 6). At this time, when the flow rate sensor 32 detects the start of hot water supply, the mixing valve 31 operates so that the hot water supply temperature from the temperature sensor 33 becomes the set temperature.
[0035]
In the cleaning operation, the switching valve 22 opens alternately to the heat exchanger 23 side and the bypass line 20a side. However, at this time, the cleaning agent is charged into the remaining hot water in the bathtub B, and the pump 21 is operated continuously. For example, when the washing operation is started, the pump 21 is started, and the switching valve 22 is opened toward the heat exchanger 23 for 30 seconds (FIG. 4B), and then opened for 4 minutes 30 seconds toward the bypass line 20a ( After that, the same operation is repeated four times, and the process ends. The rinsing operation may be performed by filling the bathtub B with water or hot water and performing the same operation without using a cleaning agent.
[0036]
In addition, it is preferable that the switching valve 22 be opened to the heat exchanger 23 side to stand by in a standby state in which the filling operation by the mixing valve 11 and the on-off valve 12 and the circulation operation by the pump 21 are not performed. That is, when the on-off valve 12 is closed and the pump 21 is stopped, the switching valve 22 opens toward the heat exchanger 23 and stands by regardless of the presence or absence of water or hot water in the bathtub B. . However, even in this case, for example, when the flow switch 25 is operated or the temperature sensor 26 detects an excessive temperature, the switching valve 22 is switched to the bypass line 20a by regarding the pump 21 as abnormal operation. Shall open.
[0037]
Further, the switching valve 22 selectively opens the outlet side of the pump 21 to only one of the heat exchanger 23 side and the bypass pipe line 20a side, and opens the outlet side to both the heat exchanger 23 side and the bypass pipe line 20a side. It may not be necessary (FIG. 7). However, FIGS. 2A to 2C correspond to FIGS. 2B to 2D, respectively. It is assumed that the switching valve 22 at this time opens from the beginning to the heat exchanger 23 side in the additional heating operation.
[0038]
Further, the flow switch 25 may be provided between the water level sensor 24 and the pump 21. Further, the switching valve 22 may be provided on the downstream side of the heat exchanger 23 and the bypass line 20a (FIG. 8). When the hot water in the tank T is heated to an appropriate temperature for bathing, the mixing valve 11 can be omitted, and the hot water from the tank T can be directly poured into the bath tub B via the on-off valve 12. Further, the switching valve 22 may be a combination of two on-off valves provided on the bypass pipe line 20a side and the heat exchanger 23 side instead of the three-way switching valve.
[0039]
【The invention's effect】
As described above, according to the first and second aspects of the present invention, the circulation system that circulates the hot water in the bath tub to the heat exchanger via the pump is provided with the bypass pipe with the switching valve, whereby the circulation is achieved. The system selects the heat exchanger not to be used when checking the hot water temperature required during the heat insulation operation or during the freeze prevention operation of the pipeline, and does not circulate the hot water in the bath tub through the heat exchanger. There is an excellent effect that heat loss can be minimized without unnecessary heating.
[0040]
Further, according to the first invention, in the initial stage of the reheating operation, there is no fear that unnecessarily high-temperature hot water from the heat exchanger flows into the bathtub, thereby giving a bather discomfort. According to the second invention, there is an excellent effect that a freezing accident of a pipeline can be effectively prevented, for example, when the user is out of the office for a long time.
[Brief description of the drawings]
FIG. 1 is an overall configuration piping system diagram. FIG. 2 is a configuration explanatory diagram of a switching valve. FIG. 3 is an operational explanatory diagram (1).
FIG. 4 is an operation explanatory view (2).
FIG. 5 is an operation explanatory view (3).
FIG. 6 is an operation explanatory view (4).
FIG. 7 is a diagram corresponding to FIGS. 2B to 2D showing another embodiment. FIG. 8 is a piping diagram showing another embodiment. FIG. 9 is a piping diagram showing a conventional example. Description】
B ... Bathtub T ... Tank 12 ... Open / close valve 20 ... Circulation system 20a ... Bypass line 21 ... Pump 22 ... Switching valve 23 ... Heat exchanger

Claims (7)

An on-off valve for hot water filling, and a circulation system for circulating hot water in the bathtub to a heat exchanger in the tank via a pump, wherein the circulation system selects use or non-use of the heat exchanger. A hot-water storage type having a bypass pipe with a switching valve, wherein the switching valve selectively opens the outlet side of the pump to either the heat exchanger side or the bypass pipe side or both. Water heater for water heater. 2. The hot water storage type according to claim 1, wherein the switching valve opens on both the heat exchanger side and the bypass pipe side at an early stage of the reheating operation, and opens on the heat exchanger side after a lapse of a predetermined time. 3. Water heater for water heater. An on-off valve for hot water filling, and a circulation system for circulating hot water in the bathtub to a heat exchanger in the tank via a pump, wherein the circulation system selects use or non-use of the heat exchanger. It has a bypass pipe with a switching valve, and the switching valve selectively opens the outlet side of the pump to the heat exchanger side or one of the bypass pipe sides, and in the standby state, to the heat exchanger side. A hot water supply device for a hot water storage type water heater characterized by being opened. The hot water supply device for a hot water storage type water heater according to claim 3, wherein the switching valve opens to the bypass pipe side when an abnormal operation of the pump is detected in a standby state. The hot water supply device for a hot-water storage type water heater according to any one of claims 1 to 4, wherein the switching valve is alternately opened to the heat exchanger side and the bypass pipe side in a cleaning operation. The hot-water supply device for a hot-water storage type water heater according to claim 5, wherein the switching valve repeatedly opens shortly on the heat exchanger side and long opens on the bypass pipe side. The hot water supply device for a hot water storage type water heater according to any one of claims 1 to 6, wherein the switching valve is a three-way switching valve provided upstream of the heat exchanger and a bypass pipe.

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