JP2008249316A - Hot water storage type electric water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low height and thin type hot water storage type electric water heater superior in installation performance, and superior in drainage performance of water in a tank, for example, to be installable on the reverse of a hand washbowl counter of a face-washing space and in a riser part of a kitchen cabinet. <P>SOLUTION: This hot water storage type electric water heater has a hot water storage tank 100, a circulating flow passage 20 circulating the water in the hot water storage tank 100, a pump 30 and a drain plug 40. The hot water storage tank 100 has a water inlet part 11 having a water inlet extension part 11a, a hot water outlet part 12 having a hot water outlet extension part 12a, and a circulating inlet part 13. The drain plug 40 is arranged on the downstream side of the pump in the circulating flow passage 20, and the circulating inlet part 13 is continuously connected at one end to the circulating flow passage 20, and also has a circulating inlet extension part 13a having a circulating inlet opening part 13b opening in the hot water storage tank 100 on the other end. The circulating inlet extension part 13a is extended toward a bottom surface in the hot water storage tank 100, and the circulating inlet opening part 13b exists under a continuously connecting part between a circulating flow passage extension part 13a and the circulating flow passage 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The object of the present invention is, for example, an excellent installation property that can be installed on the back of a hand-washing machine counter in a washroom space, a kitchen cabinet, or the like, ensuring the pressure resistance of the tank and the ability to boil water in the tank uniformly. It is an object of the present invention to provide a low-profile, thin hot water storage type electric water heater that is excellent in draining water in a tank.

  If the hot water storage type electric water heater is used for a long period of time, the hot water storage tank may become dirty with scales, so it is necessary to drain the water once every three months to keep the hot water storage tank clean. At this time, in order to remove stagnation such as scales deposited on the bottom surface, it is necessary to drain water sufficiently to the vicinity of the bottom surface. Moreover, there is a possibility that the water in the hot water storage tank may freeze if it is not used for a long period of time, and the device is damaged. Therefore, it is necessary to drain the hot water storage tank when the hot water storage type electric water heater is not used for a long period of time. The drain plug of the conventional hot water storage type electric water heater is installed at the bottom of the hot water storage tank or at the lowermost side of the hot water storage tank as viewed in the direction of gravity in order to drain water sufficiently to the bottom. (For example, see Patent Document 1)

  On the other hand, a hot water storage type electric water heater is used for supplying hot water from a faucet in a public washroom or the like. Conventional hot water storage type electric water heaters are installed in a conspicuous place such as the floor under the counter. When installed in such a manner, there is a problem that the beauty and unity of the washroom space are impaired.

  In recent years, instead of installing a hot water storage type electric water heater directly on the floor under the counter as in the past, it is possible to install it in an invisible place when using the wash space such as the back of the counter by lowering the height. A thin hot water storage type electric water heater is desired. In addition, such a thin hot water storage type electric water heater can be installed not only behind the counter in the wash space, but also in the kitchen area of the kitchen cabinet or the counter back in the rest room. Such low-profile hot water storage type electric water heaters are widely desired because they can improve the aesthetics and interior of various water spaces.

  By the way, the hot water storage type electric water heater boils the water stored in the hot water storage tank from the water using a heater such as a sheath heater installed in the hot water storage tank. The water in the hot water storage tank above the heater can be boiled up uniformly by convection with the density difference of the hot water. However, the water in the hot water storage tank below the heater cannot be sufficiently boiled and cannot be used effectively as hot water. Such an area that does not boil sufficiently is called a water area.

  Compared to a hot water storage type electric water heater, which has a low height without changing the amount of hot water storage, a thin hot water storage type electric water heater has a large cross-sectional area of the hot water storage tank parallel to the floor surface, so there are many water areas. Become.

  For this reason, the thin hot water storage type electric water heater has a problem that the amount of hot water that can be taken out is smaller than that of a high hot water storage type electric water heater.

Therefore, in order to reduce the water area dyingly, a circulation passage for circulating the water in the hot water storage tank is formed outside the hot water storage tank, and the water in the hot water storage tank is circulated with a pump in the circulation passage A mechanism for boiling water is considered. (For example, refer to Patent Document 2).
JP 2001-355920 A (FIG. 2) Japanese Patent Laid-Open No. 2002-89961 (FIG. 6)

  When a drain plug is to be provided in a thin hot water storage type electric water heater as shown in Patent Document 2, it is considered that the drain plug is installed at the bottom of the hot water storage tank or at the bottom of the side as in the prior art. It is done. However, if a drain plug is provided on the bottom surface, the hot water storage type electric water heater becomes thicker in the height direction by the amount of the drain plug, thus improving the aesthetics and interior of the thin hot water storage type electric water heater. The feature of doing is lost. Furthermore, if it becomes thicker in the height direction, it cannot be stored in the gap portion of the kitchen cabinet. In addition, although it is conceivable to provide a drain plug at the bottom of the side surface, the hot water storage type electric water heater is provided with a curvature (hereinafter referred to as a curvature portion) in consideration of pressure resistance at the corners between all surfaces. This curvature is also provided at the bottom of the side. It is difficult to weld a drain plug to a curved portion, and the reliability in terms of pressure is reduced.

  Next, as disclosed in Patent Document 2, the circulation channel and the pump provided in the hot water storage type electric water heater are used, and the water drain plug is installed in the circulation channel, so that the water is discharged by the pump. This is a method of sucking out water and draining water. However, even if a drain plug is installed in the circulation channel as it is, water remains in a place lower than the inlet to the circulation channel of the hot water storage tank, and the water in the hot water storage tank cannot be sufficiently removed.

    The object of the present invention is, for example, an excellent installation property that can be installed on the back of a hand-washing machine counter in a washroom space, a kitchen cabinet, or the like, ensuring the pressure resistance of the tank and the ability to boil water in the tank uniformly. It is an object of the present invention to provide a low-profile, thin hot water storage type electric water heater that is excellent in draining water in a tank.

In order to solve the above-described problems, a hot water storage type electric water heater according to the present invention includes a hot water storage tank,
A circulation passage for circulating water in the hot water storage tank;
A pump,
In a hot water storage type electric water heater equipped with a drain plug,
The hot water storage tank includes a water inlet,
The hot spring section,
A circulation inlet installed on the side surface and connected to the circulation channel;
Provided with a circulation outlet installed on the side surface and connected to the circulation channel,
The water inlet is a water inlet connecting portion provided on an outer side surface of the hot water storage tank,
A water inlet opening that opens in the hot water storage tank,
The tapping part is a tapping part provided on the outer side surface of the hot water storage tank,
A hot water opening opening in the hot water storage tank,
The circulation outlet portion has a circulation outlet opening portion opened in the hot water storage tank,
The pump is provided in the circulation channel;
The drain plug is provided in the circulation channel and downstream of the pump;
The circulation inlet portion further includes a circulation inlet extension having a circulation inlet opening that is connected to the circulation channel at one end and opened in the hot water storage tank at the other end,
The circulation inlet extension is extended toward the bottom surface of the hot water storage tank, and the circulation inlet opening is located below the connecting portion between the circulation passage extension and the circulation passage.

  In the hot water storage type electric water heater according to the present invention, the circulation inlet opening can be brought close to the bottom of the tank by the circulation inlet extension, so that the water in the hot water storage tank can be brought close to the bottom by draining using a pump. Can be pulled out sufficiently. For this reason, the hot water storage type electric water heater according to the present invention is thin and has an excellent installation property that can be installed on the underside of a hand-washing machine counter in a washroom space or in a kitchen cabinet. The water can be drained sufficiently. Further, since the circulation inlet portion can be provided in a portion that does not cover the curvature portion, the pressure resistance can be ensured.

The hot water storage type electric water heater according to claim 2 of the present invention is the hot water storage type electric water heater according to claim 1,
An intake plug is provided, and the intake plug is provided in at least one of the outlet hot water connection portion, the incoming water connection portion, and the circulation flow path between the drain plug and the circulation outlet portion. It is a feature.

  The hot water storage type electric water heater according to the present invention eliminates the need to newly provide an intake plug in the hot water storage tank, and can reduce the manufacturing cost in mass production. In addition, since the number of welded parts to the hot water storage tank is reduced, the strength of the hot water storage tank is increased, and the reliability of the hot water storage tank with respect to the pressure resistance can be increased.

Moreover, the hot water storage type electric water heater according to claim 3 of the present invention is the hot water storage type electric water heater according to claim 1 or 2,
The opening / closing operation of the intake plug and the opening / closing operation of the drain plug are interlocked.

  The hot water storage type electric water heater according to the present invention opens the intake plug in conjunction with opening the drain plug, for example, so that it is not necessary to open both the intake plug and the drain plug individually when draining water. The operability can be improved.

Moreover, the hot water storage type electric water heater according to claim 4 of the present invention is the hot water storage type electric water heater according to any one of claims 1 to 3,
The tapping part further comprises a tapping extension part having one end connected to the tapping connection part and the tapping opening at the other end,
The hot water extension portion is extended upward in the hot water storage tank, and the hot water opening is located above the hot water connection portion.

  In the hot water storage type electric water heater, hot water with a low density is pushed upward with a high density of water. Here, it is desirable that hot water is discharged from the hot water outlet for a long time without mixing water and hot water as much as possible. This performance is called extrusion performance.

  In order to improve the extrusion performance, it is necessary to attach the tapping part as much as possible. However, there is a curvature part above the tank, and if a hot water supply part is provided here, pressure resistance will fall. Therefore, if a hot water outlet is installed on the side surface of the hot water storage tank that does not reach the curvature portion, the position of the hot water outlet becomes lower, and the extrusion performance is reduced.

  The hot water storage type electric water heater according to the present invention can bring the hot water opening close to the vicinity of the upper surface of the tank without reducing the pressure resistance of the tank by the hot water extending portion, so that it is difficult for hot water to remain on the upper side, thereby improving the extrusion performance. be able to.

Moreover, the hot water storage type electric water heater according to claim 5 of the present invention is the hot water storage type electric water heater according to claims 1 to 4,
The water inlet portion further includes a water inlet extension portion having one end connected to the water inlet connecting portion and the other end having the water inlet opening.
The water inlet extension portion extends downward in the hot water storage tank, and the water inlet opening portion is located below the water inlet connecting portion.

  In order to improve the extrusion performance, it is necessary to attach the water intake portion as downward as possible. However, there is a curved portion below the side of the tank, and if a water inlet is provided here, the pressure resistance is reduced. Then, if a water intake part is installed in the side surface of the hot water storage tank which does not cover a curvature part, since the position of a water intake part will become high, extrusion performance will fall.

  The hot water storage type electric water heater according to the present invention can bring the water inlet opening close to the bottom of the tank without reducing the pressure resistance by the water inlet extension. The extrusion can be performed uniformly, and the extrusion performance can be improved.

Moreover, the hot water storage type electric water heater according to claim 6 of the present invention is the hot water storage type electric water heater according to any one of claims 1 to 5,
Residual water detecting means for detecting the amount of residual water in the hot water storage tank; and opening / closing control means for detecting the open / closed state of the intake plug and the drain plug and controlling the open / closed state, the residual water detecting means, It has a pump control means for controlling the operation of the pump based on the detection result of the opening / closing control means.

    The hot water storage type electric water heater according to the present invention has a residual water detection means, an opening / closing control means and a pump control means, and the detected signal relates to the start and stop of the pump and the opening / closing of the drain plug. Can be controlled. Therefore, a part of the water draining operation can be automatically performed, and the water draining workability is improved. Further, since the water draining operation is automatically performed, human error can be prevented and safety can be improved.

The hot water storage type electric water heater according to claim 7 of the present invention is the hot water storage type electric water heater according to claim 6,
The pump control means detects that there is residual water in the hot water storage tank with the residual water detection means, and detects that the intake plug and the drain plug are in an open state with the opening and closing means, It is characterized by starting the operation of the pump.

  In the hot water storage type electric water heater according to the present invention, since the pump is started after the remaining water is detected, it is possible to prevent air from being caught in the pump and the pump from being broken, and the safety reliability is improved. In addition, since part of the draining operation is automatically performed, the draining workability is improved.

A hot water storage type electric water heater according to claim 8 of the present invention is the hot water storage type electric water heater according to claims 6 to 7,
The pump control means stops the operation of the pump when the residual water detection means detects that there is no residual water in the hot water storage tank, and the opening / closing means interlocks with the stop of the operation of the pump. And the drain plug is closed.

  The hot water storage type electric water heater according to the present invention can sufficiently drain water in the hot water storage tank because the pump is stopped when there is no remaining water. Furthermore, it is possible to prevent the pump from being broken by the air being caught in the pump. In addition, since the drain plug and the intake plug are automatically opened and closed, forgetting to close can be prevented.

  Since the hot water storage type electric water heater according to the present invention is provided with the circulation ports (inlet and outlet) on the side of the tank, the electric water heater can be made thin. In addition, since the circulation inlet opening can be brought close to the vicinity of the bottom of the tank by the circulation inlet extension, the water in the hot water storage tank can be sufficiently drawn to the vicinity of the bottom by draining water using a pump. In addition, since the drain plug is on the downstream side of the pump, the water in the hot water storage tank can be drained smoothly without air clogging.

  Hereinafter, a hot water storage type electric water heater according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 a is a schematic perspective view of a hot water storage tank 100, a circulation flow path 20, a pump 30 and a drain plug 40 provided in a hot water storage type electric water heater according to an embodiment of the present invention. FIG. 1 b is a cutaway view showing the water inlet 11 and the hot water outlet 12.

  The hot water storage type electric water heater includes a hot water storage tank 100 provided with a heater h, a circulation channel 20 for circulating water in the hot water storage tank 100, a pump 30, a drain plug 40, and a remote controller or operation panel not shown in detail here. And a controller for operating the heater h of the hot water storage tank 100 and the pump 30 by a signal from the remote control or the operation panel. And the hot water storage tank 100 has comprised the rectangular parallelepiped flat box shape, as shown in FIG. Moreover, the hot water storage tank 100 is provided with a curvature at a corner between all the planes.

  Of the two flat portions 10c and 10d formed at both ends in the longitudinal direction of the hot water storage tank 100, the flat portion 10c on one end side is provided with a water inlet 11 so as not to reach the curvature portion. The water inlet 11 includes a water inlet extension 11a, a water inlet opening 11b, and a water inlet 11c connected to the inside of the hot water storage tank 100. The water inlet 11c is provided outside the hot water tank 100 (not shown). It is connected to the water inlet flow path, and the water inlet opening portion 11 b is located at the lowest position in the water inlet portion and in the vicinity of the bottom surface of the hot water storage tank 100. Further, a hot water discharge portion 12 is provided on the flat surface portion 10d on the other end side so as not to reach the curvature portion. The tapping part 12 has a tapping extension 12a, tapping opening 12b, and tapping connection part 12c connected to the inside of the hot water storage tank 100, and the tapping connection part 12c is provided outside the hot water storage tank 100 (not shown). It is connected to the hot water flow path, and the hot water opening 12 b is at the uppermost position in the hot water portion 12 and is near the upper surface of the hot water storage tank 100. In addition, an intake plug 50 is provided on the flat portion 10c.

Further, of the two flat portions 10c and 10d formed at both ends in the longitudinal direction of the hot water storage tank 100, the circular inlet portion 13 is provided on the flat portion 10c on the one end side so as not to reach the curvature portion. In addition, the circulation outlet portion 14 is provided on the flat surface portion 10d on the other end side so as not to reach the curvature portion. The circulation inlet 13 has a circulation inlet extension 13a connected to the hot water storage tank, and a circulation inlet opening 13b. The circulation inlet opening 13b is at the lowest position in the circulation inlet 13 and the hot water storage tank. Near the bottom of 100.
A circulation channel 20 for circulating water in the hot water storage tank 100 is provided so as to communicate the circulation inlet portion 13 and the circulation outlet portion 14 of the hot water storage tank.
The pump 30 is provided in the circulation channel 20 as shown in FIG.
The drain plug 40 is provided in the circulation channel 20. If there is a drain plug 40 on the upstream side of the pump 30, air is drawn in when draining, and the pump does not operate normally. Therefore, the drain plug 40 is provided downstream of the pump 30. Further, the drain plug 40 may be a three-way valve. The drain plug 40 communicates between the pump 30 and the circulation outlet 14 during normal use, and at the same time as the pump 30 communicates with the atmosphere during drainage, the circulation outlet 14
The circulation flow path 20 leading to is closed. Moreover, it can comprise with two shut-off valves and one branch instead of making the drain plug 40 into a three-way valve. Specifically, a branch is provided in the downstream circulation path 20 of the pump 30, a closing valve is provided at the tip, and a closing valve is provided in the downstream circulation path 20 from the branch. During normal use, the closing valve at the branch end is closed and the closing valve in the circulation flow path 20 is opened. When draining water, the closing valve at the branch tip is opened, and the closing valve in the circulation flow path 20 is closed.

  This hot water storage type electric water heater is, for example, a kitchen part or a wash surface of a kitchen through a fixture such as a bracket (not shown) or a fastener such as a screw with the flat surfaces 10e and 10f lying vertically. It can be attached to the back of the counter in the space.

  In the hot water storage tank, as shown in FIG. 1, a heater h provided substantially parallel to the plane 10f is provided.

  Then, the effect | action of the hot water storage type electric water heater which has the above structure is demonstrated. First, the hot water storage type electric water heater having the above-described configuration is installed, for example, on the counter back surface of the wash space. In this case, the circulation channel and the hot water storage tank are installed substantially horizontally. By attaching the thin hot water storage type electric water heater in this way, it can be installed in an inconspicuous place such as the back of the counter of the wash space, and the beauty and interior of the wash space are not impaired. In addition, a hot water storage type electric water heater may be installed on the back of the kitchen counter or in the kitchen section of the kitchen cabinet. In this case, since the hot water storage type electric water heater is thin, the hot water storage type electric water heater can be installed with sufficient storage space for cooking utensils and foods on the lower surface of the counter. Moreover, since it is not necessary to install a hot water storage type electric water heater directly on the wall surface of the kitchen, the kitchen area can be cleaned and the interior can be improved.

  A hot water storage type electric water heater having such a configuration is installed in the predetermined place described above, a water pipe (not shown) is connected to the water inlet 11, and a pipe leading to a mixing tap (not shown) is connected to the hot water outlet 12. Then, the hot water storage type electric water heater is operated by operating a remote controller or an operation panel (not shown). Accordingly, the water stored in the hot water storage tank 100 via the water inlet 11 is heated to, for example, about 85 ° C. by the heater h while being circulated by the pump, and stored in the hot water storage tank 100. Since the portion above the heater h is likely to boil without being circulated, it may be boiled without being circulated by the pump 30. Further, circulation by the pump 30 at the time of boiling may be intermittently performed according to the use state. When hot water is used, a faucet (not shown) behind the mixing tap is opened so that water is introduced from the water inlet 11 and hot water in the vicinity of the hot water outlet 12 of the hot water storage tank 100 is pushed out from the hot water outlet 12 and a pipe (not shown) In addition, it is mixed with water supplied to the mixing plug via a pipe (not shown) branched separately from the water supply via the mixing plug, and discharged from the faucet to the user.

  In addition, when a thin hot water storage type electric water heater is installed and the water inlet 11 and the hot water outlet 12 are provided in a portion that does not affect the curvature of the side due to restrictions from pressure resistance, the water enters from a high position and takes out from a low position. Therefore, the extrusion performance is reduced. However, the hot water storage type electric water heater of the present invention has a water inlet extension portion 11 a and a water inlet opening portion 11 b connected to the water inlet portion 11 in the water inlet portion 11, and the water inlet opening portion 11 b is the lowest in the water inlet portion 11. And in the vicinity of the bottom surface of the hot water storage tank 10. Further, the hot water outlet 12 has a hot water extension 12 a and a hot water outlet 12 b connected to the hot water storage tank, the hot water outlet 12 b is at the uppermost position in the hot water hot water 12, and in the vicinity of the upper surface of the hot water tank 10. It is in. Therefore, even if it is installed in a laid state and the water inlet 11 and the hot water outlet 12 are provided on the side that does not cover the curvature portion of the hot water storage tank, the water pressure is entered and water is poured from a lower position and discharged from a higher position. Can do. Therefore, the extrusion efficiency can exhibit the same performance as that of a conventional hot water storage type electric water heater installed vertically.

  As described above, the water stored in the hot water storage tank 100 is boiled up while being circulated to the reference temperature, and then water is introduced from the water inlet 11 into the hot water storage tank 100, and the hot water boiled with the water is pushed out. Then, the hot water storage type electric water heater is operated such that when the temperature is lowered to some extent by the inflowing water, the water in the hot water storage tank 100 is boiled up to the reference temperature.

  Next, the water draining operation will be described. When draining water, turn off the heater of the hot water storage type electric water heater, open the hot water in the hot water storage tank 100 or water that has been cooled in advance, open the drain plug 40 and the intake plug 50, and then turn on the remote control or the operation panel. The water in the hot water storage tank 100 is drained from the drain plug 40 by operating and operating the pump 30 by the control unit. The hot water storage type electric water heater according to the present invention has a circulation inlet portion 13 at a portion not facing the curvature portion of the side surface, and has a circulation inlet extension portion 13a and a circulation inlet opening portion 13b connected to the hot water storage tank 100, The circulation inlet opening 13 b is at the lowest position in the circulation inlet 13. And since it draws out so that water may be sucked in with pump 30, it can drain enough water to the bottom face vicinity.

  Then, each modification of the above-mentioned embodiment is demonstrated. In addition, about the structure equivalent to the above-mentioned embodiment, a corresponding code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  Initially, the 1st modification of the above-mentioned embodiment is demonstrated. FIG. 2 is a perspective view schematically showing the hot water storage tank 101, the circulation channel 20, the pump 30, and the drain plug 40 of the hot water storage type electric water heater according to the first modification.

  In this modification, the water inlet 11 is provided with an intake plug 51 provided in a water inlet connecting part 11 c that is provided outside the hot water storage tank 101. These are branched and connected by a T-shaped pipe or the like. The intake plug 51 may be provided in the hot water connecting portion 12 c that the hot water outlet portion 12 has on the outside of the hot water storage tank 101, or in the circulation channel between the drain plug 40 and the circulation outlet portion 14.

  When the intake plug 51 is provided as in this modification, it is not necessary to newly provide an intake plug in the hot water storage tank, and the manufacturing cost in mass production can be reduced. In addition, since the number of welded parts to the hot water storage tank is reduced, the strength of the hot water storage tank is increased, and the reliability of the hot water storage tank with respect to the pressure resistance can be increased.

  Then, the 2nd modification of the above-mentioned embodiment is demonstrated. FIG. 3 is a perspective view schematically showing the hot water storage tank 102, the circulation flow path 20, the pump 30, and the drain plug 40a in the hot water storage type electric water heater according to the second modification.

  Here, the drain plug 40a that can be opened / closed electrically, the intake plug 51a that can be opened / closed electrically provided in the inlet connection portion 11c provided on the outside of the hot water storage tank 102, and the drain plug 40a and the intake plug 51a are opened / closed. A control unit (not shown) and a remote control or operation panel (not shown) for operating them are provided.

  The drain plug 40a and the intake plug 51a are electrically linked, and both the drain plug 40a and the intake plug 51a are opened by pressing one switch on the remote control or the operation panel. By electrically interlocking the drain plug 40a and the intake plug 51a in this manner, it is necessary to open both the intake plug and the drain plug at the time of draining, thereby improving the drainage workability. be able to.

  Then, the 3rd modification of the above-mentioned embodiment is demonstrated. FIG. 4 is a perspective view schematically showing the hot water storage tank 103, the circulation passage 20, the pump 30, and the four-way valve 60 in the hot water storage type electric water heater according to the third modification. 5 and 6 are schematic views schematically showing the four-way valve 60. FIG.

  In the present modification, a four-way valve 60 is installed on the downstream side of the pump 30 in the circulation channel 20 as shown in FIG. As shown in FIG. 5, the four-way valve 60 includes a channel 61 used as a drain plug, a channel 62 used as an intake plug, a pump-side channel 63 connected to the circulation channel for circulation, and a circulation outlet-side flow. A path 64 is provided. During normal use, the flow path 63 on the pump side and the flow path 64 on the circulation outlet side communicate with each other as shown in FIG. 5, and when draining, the valve 65 is twisted to A flow path 61 used as a drain plug is communicated, and a flow path 64 on the circulation outlet side and a flow path 62 used as an intake plug are communicated.

  When a four-way valve is used in this way, it is possible to open the flow channel 61 used as a drain plug and the flow channel 62 used as an intake plug by twisting one valve 65, and to move both in a mechanically interlocked manner. . As a result, it is not necessary to open and close both the intake plug and the drain plug individually, and workability at the time of draining is improved.

  Then, the 4th modification of the above-mentioned embodiment is demonstrated. FIG. 7 is a perspective view schematically showing the hot water storage tank 104, the circulation flow path 20, the pump 30, and the drain plug 40a in the hot water storage type electric water heater according to the fourth modification.

  This modification is a residual water detection means 71 for detecting the amount of residual water in the hot water storage tank 104, an open / close control means (not shown) for detecting the open / closed state of the intake port 51a and the drain plug 40a and controlling the open / closed state, and residual water detection. Means 71 and pump control means (not shown) for controlling the operation of the pump 30 based on a signal from the open / close control means are provided. Here, the remaining water detection means 71 uses a pressure sensor for detecting the pressure applied by the stored water, a float sensor, a sensor using an electrode that is energized when water is present, and the like.

  By providing these, draining operation can be performed automatically and safely. Specifically, the pump control means first detects that there is residual water in the hot water storage tank 104 by the residual water detection means 71, and after opening the intake port 51a and the drain plug 40a by the opening / closing means, the pump 30 Start driving. Thereafter, when the remaining water detecting means 71 detects that there is no remaining water in the hot water storage tank, the operation is stopped, and the intake port 51a and the drain plug 40a are closed by the opening / closing means.

  Thus, the pump control means does not operate unless the remaining water detection means 71 detects that there is residual water in the hot water storage tank 104. In this case, the hot water storage type electric water heater can notify the user that it is necessary to obtain a sufficient water level for operating the pump 30 by an alarm (not shown) or the like, and can prompt water supply.

Since the present modification can automatically drain water and operate the pump, the work is simplified, and the workability is improved because the work can be easily performed in a place such as a damaged part of the kitchen room. Furthermore, forgetting to close the drain plug 40a, the operation of the pump 30 that entrains air, and the like can be prevented, and the reliability against accidents can be increased.

Fig. 1a is a perspective view schematically showing a hot water storage type electric water heater according to an embodiment of the invention, and Fig. 1b is a schematic diagram showing a cut-away view of a water inlet portion and a hot water outlet portion. It is a perspective view which shows typically the 1st modification of the hot water storage type electric water heater shown in FIG. It is a perspective view which shows typically the 2nd modification of the hot water storage type electric water heater shown in FIG. It is a perspective view which shows typically the 3rd modification of the hot water storage type electric water heater shown in FIG. It is a figure which shows typically the four-way valve of the hot water storage type electric water heater shown in FIG. It is a figure which shows typically a state when the four-way valve shown in FIG. 5 moves. It is the perspective view which showed typically the 4th modification of the hot water storage type electric water heater shown in FIG.

Explanation of symbols

10c-10f tank wall
DESCRIPTION OF SYMBOLS 11 Inlet part 11a Inlet extension part 11b Inlet opening part 11c Incoming water connection part 12 Outlet part 12a Outlet extension part 12b Outlet opening part 12c Outlet connection part 13 Circulation inlet part 13a Circulation inlet extension part 13b Circulation inlet opening part 14 Circulation outlet part 20 Circulation Flow path 30 Pump 40 40a Drain plug 50 51 51a Intake plug 60 Four-way valve 71 Remaining water detection means 100-104 Hot water storage tank

Claims (8)

A hot water storage tank,
A circulation passage for circulating water in the hot water storage tank;
A pump,
In a hot water storage type electric water heater equipped with a drain plug,
The hot water storage tank includes a water inlet,
The hot spring section,
A circulation inlet installed on the side surface and connected to the circulation channel;
Provided with a circulation outlet installed on the side surface and connected to the circulation channel,
The water inlet is a water inlet connecting portion provided on an outer side surface of the hot water storage tank,
A water inlet opening that opens in the hot water storage tank,
The tapping part is a tapping part provided on the outer side surface of the hot water storage tank,
A hot water opening opening in the hot water storage tank,
The circulation outlet portion has a circulation outlet opening portion opened in the hot water storage tank,
The pump is provided in the circulation channel;
The drain plug is provided in the circulation channel and downstream of the pump;
The circulation inlet portion further includes a circulation inlet extension having a circulation inlet opening that is connected to the circulation channel at one end and opened in the hot water storage tank at the other end,
The hot water storage type, wherein the circulation inlet extension is extended toward the bottom surface of the hot water storage tank, and the circulation inlet opening is below a connecting portion between the circulation flow channel extension and the circulation flow channel. Electric water heater.   An intake plug is provided, and the intake plug is provided in at least one of the outlet hot water connection portion, the incoming water connection portion, and the circulation flow path between the drain plug and the circulation outlet portion. The hot water storage type electric water heater according to claim 1, wherein The hot water storage type electric water heater according to claim 1 or 2, wherein the opening / closing operation of the intake plug and the opening / closing operation of the drain plug are interlocked. The tapping part further comprises a tapping extension part having one end connected to the tapping connection part and the tapping opening at the other end,
4. The hot water extension portion is extended upward in the hot water storage tank, and the hot water opening portion is located above the hot water connection portion. Hot water storage type electric water heater.
The water inlet portion further includes a water inlet extension portion having one end connected to the water inlet connecting portion and the other end having the water inlet opening.
5. The water supply extension part according to claim 1, wherein the water supply extension part extends downward in the hot water storage tank, and the water supply opening part is below the water supply connection part. Hot water storage type electric water heater described in 1.   Residual water detecting means for detecting the amount of residual water in the hot water storage tank; and opening / closing control means for detecting the open / closed state of the intake plug and the drain plug and controlling the open / closed state, the residual water detecting means, The hot water storage type electric water heater according to any one of claims 1 to 5, further comprising pump control means for controlling operation of the pump based on a detection result of the opening / closing control means.   The pump control means detects that there is residual water in the hot water storage tank with the residual water detection means, and detects that the intake plug and the drain plug are in an open state with the opening and closing means, The hot water storage type electric water heater according to claim 6, wherein operation of the pump is started.   The pump control means stops the operation of the pump when the residual water detection means detects that there is no residual water in the hot water storage tank, and the opening / closing means interlocks with the stop of the operation of the pump. The hot water storage type electric water heater according to any one of claims 6 to 7, wherein the drain plug is closed.

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