JP4247187B2 - Auxiliary water heater - Google Patents

Description

  The present invention relates to an auxiliary hot water supply apparatus interposed between a water heater and a faucet that are permanently installed in a home or the like.

  In recent homes and the like, a hot water heater is permanently installed, and hot water heated by the hot water heater is discharged from the faucet by opening the faucet operating part in a region where the hot water is discharged. Further, the water faucet can mix normal temperature water that has not been heated and hot water according to the operation state of the operation unit, and can adjust and discharge the water to a desired temperature.

However, in this water heater, when the operation part is opened to discharge hot water, it remains in the pipe connecting the water heater and the water tap, and hot water cooled to room temperature is discharged, and residual water in the pipe is discharged. After the discharge is finished, heated hot water is discharged. Specifically, the time during which the residual water continues to be discharged varies depending on the length of the pipe, but as shown by the temperature transition A in FIG. 4 , after the cold residual water is discharged for about 30 seconds, the residual water gradually And warm water are mixed and heated up, and the warm water set after about 50 seconds is discharged. And the water discharged in these 50 seconds is often drained without being used at all, and is useless.

Therefore, in recent years, an auxiliary hot water supply device that keeps a predetermined amount of water at a predetermined temperature and mixes and discharges the warm water and the residual water in the cooled pipe is provided between the water heater and the faucet. There are intervening. Thereby, as shown by the temperature transition B in FIG. 4 , it is comprised so that warm water of predetermined temperature can be discharged immediately after opening.

  Prior art document information related to this auxiliary hot water supply apparatus includes the following.

Japanese Patent Laid-Open No. 60-221631 JP-A-5-319488

  Patent Document 1 includes a hot water storage tank, a sheathed heater disposed inside the hot water storage tank, an exterior body that houses the hot water storage tank, and a heat insulating material disposed between the hot water storage tank and the exterior body. An auxiliary hot water supply apparatus provided is described.

  In Patent Document 2, a hot water storage tank having a vacuum double structure composed of an inner container and an outer container is connected in parallel between a water heater and a faucet, and is positioned between an introduction pipe and a discharge pipe of the hot water storage tank. A flow control valve is installed in the piping to be used. As a result, about half of the hot water supplied from the water heater is allowed to flow into the hot water storage tank so that other hot water passes through the flow rate control valve. It is configured to be mixed at a ratio of 1: 1 and discharged from the faucet.

  However, since the auxiliary hot water supply apparatus described in Patent Document 1 needs to be provided with a thick heat insulating material in order to insulate, there is a problem that the whole is increased in size. Further, in order to keep the water in the hot water tank at a predetermined temperature, it is necessary to use an expensive sheathed heater, and its mounting structure is complicated, resulting in a problem of high cost.

  In addition, the hot water supply apparatus described in Patent Document 2 is a heat insulation system that does not include a heating means, and since the tank has a vacuum double structure, the whole is small and inexpensive. However, when the faucet is closed in a state where hot water from the water heater does not flow into the tank, there is an inconvenience that the residual water in the cooled pipe is kept warm.

  Therefore, an auxiliary hot water supply apparatus combining these configurations, that is, a configuration in which heating means is disposed in a tank having a vacuum double structure is conceivable. However, in this case, since the heat of the heating means is applied to the tank in addition to the water pressure from the water heater, not only the material of the inner container and the outer container constituting the tank but also high processing accuracy is required. There is a problem of becoming.

  It is an object of the present invention to provide an auxiliary hot water supply apparatus that can be reduced in size and cost.

In order to solve the above problems, an auxiliary hot water supply apparatus of the present invention is an auxiliary hot water supply apparatus that is provided in a pipe connected to a hot water supply apparatus that supplies hot water heated to a predetermined temperature and at least a faucet that discharges the hot water. A hot water storage tank having an introduction part connected to the pipe and a discharge part connected to the faucet side, a heat retaining means for keeping the water stored in the hot water storage tank at a predetermined temperature, and the periphery of the hot water storage tank A heat insulating member having a vacuum double structure composed of an inner member and an outer member surrounding the inner member, and a plurality of reinforcing protrusions extending in the circumferential direction in a dimension contacting the outer peripheral surface of the hot water storage tank. It is said.

  According to this auxiliary hot water supply device, the hot water storage tank provided in the pipe connecting the hot water supply device and the faucet is surrounded by the heat insulating member having a vacuum double structure. This can greatly improve the size and reduce the overall size. In addition, as the heat retention performance can be improved, a low-power heating means is sufficient as the heat retaining means for retaining the warm water in the hot water storage tank.

  Specifically, in this auxiliary hot water supply apparatus, the heat retaining means is composed of a heating means disposed at an outer lower portion of the hot water storage tank and a temperature detecting means for detecting the water temperature in the hot water storage tank. Thus, in the present invention, the heating means can employ an inexpensive band heater or cord heater disposed outside the hot water storage tank, not the expensive sheathed heater disposed in the hot water storage tank. As a result, the overall cost can be reduced and energy can be saved.

  The hot water storage tank preferably has a cylindrical shape in which the introduction portion is provided at one end and the discharge portion is provided at the other end. If it does in this way, it can install in a predetermined position without becoming obstructive at home, as if a pipe was interposed under a narrow sink.

  Furthermore, it is preferable to arrange a mixing pipe in the hot water storage tank that is continuous with the introduction portion and mixes the water stored inside by convection. In this way, the hot water kept in the hot water storage tank and the residual water cooled in the pipe can be mixed and reliably discharged as hot water at a predetermined temperature from the faucet.

  Furthermore, it is preferable that the heat insulating member has a cylindrical shape, and a separate heat insulating material is disposed on at least one end thereof. In this way, the heat retention performance can be further enhanced.

  And it is preferable that the said heat insulation member comprises an exterior body. In this way, further miniaturization can be achieved.

  In the auxiliary hot water supply apparatus of the present invention, the hot water storage tank interposed in the pipe connecting the hot water heater and the water faucet is surrounded by a heat insulating member having a vacuum double structure. This can greatly improve the size and reduce the overall size. In addition, as the heat retention performance can be improved, a low-power heating means is sufficient as the heat retaining means for retaining the warm water in the hot water storage tank. Specifically, as the heating means, an inexpensive band heater or cord heater disposed outside the hot water storage tank can be employed instead of an expensive sheathed heater disposed in the hot water storage tank. As a result, the overall cost can be reduced and energy can be saved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show an auxiliary hot water supply apparatus 20 according to an embodiment of the present invention. The auxiliary hot water supply device 20 is interposed in a hot water supply pipe 14 that connects a hot water heater 10 that is permanently installed outdoors and a faucet 11 that is disposed in an indoor sink, and a user operates a lever 12 of the faucet 11. As soon as it is opened, warm water can be discharged.

  Here, the water heater 10 includes a heat exchanger and a heat source inside, and continuously boiles and discharges water supplied to the heat exchanger. It consists of a water heater. A water supply pipe 13 and a hot water supply pipe 14 are connected to the water heater 10, and water from the water source is supplied to the heat exchanger via the water supply pipe 13 and the heated hot water is discharged to the hot water supply pipe 14. ing.

  The faucet 11 is a well-known one having a distribution valve disposed therein. A hot water supply pipe 14 and a water supply pipe 15 connected to the water heater 10 are connected to each other. The hot water and the room temperature water from the water supply pipe 15 are mixed and discharged.

  The auxiliary hot water supply device 20 of this embodiment is interposed in the hot water supply pipe 14. Here, the hot water supply pipe 14 includes a first hot water supply pipe 14 a from the hot water heater 10 to the inside of the indoor sink, and a second hot water supply pipe 14 b that connects the first hot water supply pipe 14 a and the faucet 11. Yes. This is done to improve the installation workability of the faucet 11 of a general household according to the purpose of changing the form of the faucet 11 according to the desire of the resident who is the user. Therefore, the auxiliary hot water supply apparatus 20 of this embodiment is installed in the sink so as to connect the existing first hot water supply pipe 14a and the second hot water supply pipe 14b without cutting any pipe.

  Specifically, as shown in FIG. 2 (A), the auxiliary hot water supply apparatus 20 roughly stores a hot water storage tank 21 that stores a predetermined amount of water from the hot water heater 10 and a predetermined amount of water in the hot water storage tank 21. A heat retaining means for retaining the temperature and a heat insulating member 29 for retaining the warm water in the hot water storage tank 21 are provided.

The hot water storage tank 21 has a cylindrical shape in which an introduction part 22 connected to the first hot water supply pipe 14a is formed at one end and a discharge part 23 connected to the second hot water supply pipe 14b on the faucet 11 side at the other end. Made of stainless steel pipe member. The connection between the introduction part 22 and the first hot water supply pipe 14a and the connection between the discharge part 23 and the second hot water supply pipe 14b are performed by a well-known joint member or joint structure (not shown). The hot water storage tank 21 has its central portion 33 bulged, and the inside thereof constitutes a water storage portion 24. A heat retaining means disposing portion 25 that is recessed inward is provided at the outer lower portion of the water storage portion 24. In addition, a mixing pipe 26 is provided in the hot water storage tank 21 for convection and mixing the warm water in the water storage unit 24 and the water introduced from the introduction unit 22. The mixing pipe 26 has a substantially inverted J shape, and its lower end is connected to the introduction portion 22.

The heat retaining means retains the water in the hot water storage tank 21 at a predetermined temperature, and detects a water temperature in the hot water storage tank 21 and a band heater 27 that is a heating means disposed in the heat retaining means disposed portion 25. And a thermostat 28 as temperature detecting means. A control circuit (not shown) controls the band heater 27 on and off based on detection data corresponding to the detected temperature input from the thermostat 28. In this embodiment, about 3 liters of water can be stored in the hot water storage tank 21 and the water is kept at about 60 ° C.

The heat insulating member 29 constitutes an exterior body of the auxiliary hot water supply device 20 of the present embodiment, and is a vacuum double-structured cylinder composed of an inner metal member 30 and an outer metal member 35 that surround the entire circumference of the hot water storage tank 21. It consists of a jacket. These inner and outer metal members 30 and 35 are formed in a cylindrical shape without a neck portion by winding a stainless steel plate and joining in the longitudinal direction. The inner metal member 30 has an upper end portion 31 and a lower end portion 32 that are larger in diameter than the central portion 33, and the central portion 33 is provided with a reinforcing protrusion 34 that extends in the circumferential direction by extending from the inner side to the outer side. It is formed at a plurality of locations in the direction. Incidentally, the projection 34 has its inner end the formed dimensions in contact with the outer peripheral surface of the hot water storage tank 21 is configured to form a role as positioning projections of the hot water storage tank 21. The outer metal member 35 has the same length as the inner metal member 30 and an inner diameter slightly larger than the outer diameters of the upper and lower end portions 31 and 32 of the inner metal member 30. The inner metal member 30 is inserted inside the outer metal member 35, and the upper and lower ends of each member are joined by seam welding.

  As shown in FIG. 2B, in this embodiment, the inner metal member 30 is provided with an exhaust hole 36 so as to be positioned below the water reservoir 24, and a tip tube 37 is provided at the periphery of the exhaust hole 36. Are joined by welding. The tip tube 37 is evacuated after the space 38 between the inner metal member 30 and the outer metal member 35 is evacuated, and then sealed, and a tip cover 39 made of silicon rubber is mounted. Further, a metal foil 40 made of copper or aluminum is disposed in the space 38 between the metal materials 30 and 35 in order to prevent radiant heat transfer. Furthermore, a getter 41 is provided for adsorbing gas generated in the sealed space 38 and maintaining a desired degree of vacuum. Furthermore, the upper end opening of the heat insulating member 29 is sealed with a heat insulating material 42 made of foamed resin. Thereby, the warm atmosphere by heating is prevented from being dissipated from the upper part, and the heat retaining performance is further improved.

  In the hot water supply system provided with the auxiliary hot water supply device 20, when the lever 12 of the water tap 11 is operated to open the region where hot water is discharged, first, in the water heater 10, room temperature is supplied from the water supply pipe 13. The water is heated to a predetermined temperature to become hot water, and discharged to the hot water supply pipe 14. Thereby, in the 1st hot water supply piping 14a, the residual water which remained inside is pushed out, and the residual water is supplied to the auxiliary hot water supply apparatus 20.

  Next, in the auxiliary hot water supply device 20, the residual water is first introduced into the water storage unit 24 through the mixing pipe 26 connected to the first hot water supply pipe 14 a via the introduction unit 22. At this time, since the mixing pipe 26 of the present embodiment has a substantially J shape so as to bypass the water storage section 24, the temperature of the mixing pipe 26 is increased by heat exchange with the hot water in the water storage section 24 that is kept warm during the water flow. Moreover, if it flows out downward from the front-end | tip of the mixing pipe 26, it will be mixed by the convection with the warm water of the heat insulation inside, and will be discharged | emitted by the 2nd hot water supply piping 14b.

  As a result, hot water having a predetermined temperature in which residual water in the hot water supply pipe 14 and warm water in the auxiliary hot water supply device 20 are mixed is discharged from the water tap 11. Further, the normal temperature water from the water supply pipe 15 and the warm water are mixed and discharged in accordance with the operation state of the lever 12 of the faucet 11. Here, the residual water in the hot water supply pipe 14 is warm water that has not been cooled if the time has not elapsed since the previous use, and is room temperature water that has been cooled to room temperature if the time has elapsed. . However, when the auxiliary hot water supply apparatus 20 of the present invention is interposed, since normal temperature water and warm water are mixed and discharged immediately after opening, hot water at a desired temperature can be discharged quickly.

  In addition, after 50 seconds or more after the heated hot water from the water heater 10 is discharged after the faucet 11 is opened, the auxiliary water heater 20 is filled with the heated hot water from the water heater 10. Is done. In this state, when the user finishes the use and closes the plug, the hot water is kept at a predetermined temperature by the heat retaining means while being insulated by the heat insulating member 29.

  On the other hand, after the water tap 11 is opened, when the user finishes the use and closes the hot water heated from the water heater 10 in a time zone that does not reach the auxiliary water heater 20, the water storage unit 24 is placed in the first hot water supply pipe 14a. Residual water and warm water are mixed. And when the said residual water is the cold normal temperature water, the water in the water storage part 24 is lower than the set heat retention temperature. Therefore, in this case, the band heater 27 is turned on to heat the internal water to a predetermined heat retaining temperature.

Thus, in the auxiliary hot water supply apparatus 20 of the present invention, the hot water storage tank 21 interposed in the pipe 14 connecting the water heater 10 and the faucet 11 is surrounded by the heat insulating member 29 having a vacuum double structure. The heat retention performance of the hot water in the hot water storage tank 21 can be greatly improved, and the overall size can be reduced. In addition, as the heat retention performance can be improved, a low-power heating means is sufficient as the heat retaining means for retaining the warm water in the hot water storage tank 21. Specifically, as the heating means, an inexpensive band heater 27 disposed outside the hot water storage tank 21 can be employed instead of an expensive sheathed heater disposed in the hot water storage tank 21. As a result, it is not necessary to provide a complicated mounting structure, so that the overall cost can be reduced and energy saving can be achieved.

  Incidentally, since the auxiliary hot water supply apparatus of the conventional example has low heat retention performance, a sheathed heater that requires about 30 W of electric power is used to maintain the desired heat retention temperature. However, since the auxiliary hot water supply apparatus 20 of the present invention has a high heat retention performance, a low power of about 10 W is sufficient to maintain a desired heat retention temperature, and an inexpensive band heater 27 can be employed.

Moreover, in this embodiment, since the hot water storage tank 21 is formed in a cylindrical shape, the hot water storage tank 21 can be installed at a predetermined position without being disturbed in a narrow sink at home as if a pipe is interposed. And since the heat insulation member 29 for heat retention is comprised as an exterior body of an apparatus, size reduction can be achieved further.

  In addition, the auxiliary hot water supply apparatus 20 of this invention is not limited to the structure of the said embodiment, A various change is possible.

  For example, in the above-described embodiment, the discharge portion 23 has a linear pipe shape. However, as illustrated in FIG. 3, a configuration in which a curved portion 23 a having a substantially N shape is provided. If it does in this way, it can suppress that the heat retention water in the water storage part 24 is thermally radiated by heat conduction via the 2nd hot water supply piping 14b, and can further improve heat retention performance.

  The mixing pipe 26 is not limited to an inverted J shape, and may be a straight straight pipe. In this case, the drainage port 26a is provided so as to be positioned below the water storage unit 24, and water is supplied into the water storage unit 24 from the drainage port 26a and the upper end opening so that convection and mixing with the warm water in the water storage unit 24 can be performed. It is preferable to plan.

Furthermore, in the embodiment, the exhaust hole 36 and the tip tube 37 are provided on the inner metal material 30 side, but may be provided on the outer metal material 35 . In this way, since the directionality when the hot water storage tank 21 is mounted inside the cylindrical heat insulating member 29 can be eliminated, the assembling workability can be improved. However, the sealing of the metal heat insulating member 29 having a vacuum double structure is not limited to the method using the tip tube 37 and can be changed as desired.

  Further, the heating means constituting the heat retaining means is not limited to the inexpensive and low power band heater 27, and the same operation and effect as described above can be obtained even if a cord heater is used. However, this heating means is preferably changed according to the amount of water stored in the water storage unit 24, and a sheathed heater similar to the conventional one may be used in some cases.

Furthermore, the hot water storage tank 21 is not limited to the cylindrical shape in which the introduction portion 22 is provided at one end and the discharge portion 23 is provided at the other end, and may be in a shape in which the introduction portion 22 and the discharge portion 23 are provided at one end. In this case, the heat insulating member 29 is not limited to a cylindrical shape, and may have a bottomed cylindrical shape.

  Furthermore, in the above-described embodiment, the separate heat insulating material 42 is disposed only at the upper end of the heat insulating member 29, but the heat insulating materials 42 may be disposed at the openings at both ends.

It is the schematic which shows the hot water supply system which uses the auxiliary hot water supply apparatus of this invention. (A) is a fragmentary sectional view which shows the auxiliary hot water supply apparatus of this embodiment, (B) is a principal part expanded sectional view of (A). It is a fragmentary sectional view showing a modification of an auxiliary hot water supply device. It is a graph which shows the transition of the water temperature discharged when not using the case where the auxiliary hot water supply apparatus is installed.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Water heater, 11 ... Water tap, 12 ... Lever, 13 ... Water supply piping, 14 ... Hot water supply piping, 15 ... Water supply piping, 20 ... Auxiliary hot water supply device, 21 ... Hot water storage tank, 22 ... Introduction part, 23 ... Discharge part, 26 ... Mixing pipe, 27 ... Band heater (thermal insulation means), 28 ... Thermostat (thermal insulation means), 29 ... Thermal insulation member, 30 ... Inner metal material, 35 ... Outer metal material, 42 ... Thermal insulation material.

Claims (6)

In an auxiliary hot water supply apparatus provided in a pipe connected to a hot water supply apparatus that supplies hot water heated to a predetermined temperature and at least a faucet that discharges the hot water,
A hot water storage tank having an introduction part connected to the pipe and a discharge part connected to the faucet side;
Heat retaining means for retaining water stored in the hot water storage tank at a predetermined temperature;
A vacuum double structure heat insulating member comprising an inner member and an outer member surrounding the hot water storage tank ;
An auxiliary hot water supply apparatus , wherein the inner member is provided with a plurality of reinforcing protrusions extending in the circumferential direction so as to contact the outer peripheral surface of the hot water storage tank .   2. The auxiliary hot water supply apparatus according to claim 1, wherein the heat retaining unit includes a heating unit disposed at an outer lower portion of the hot water storage tank and a temperature detecting unit for detecting a water temperature in the hot water storage tank.   The auxiliary hot water supply apparatus according to claim 1 or 2, wherein the hot water storage tank has a cylindrical shape in which the introduction portion is provided at one end and the discharge portion is provided at the other end.   4. The mixing pipe according to claim 1, wherein a mixing pipe is provided in the hot water storage tank, the mixing pipe being continuous with the introduction portion and mixing the water stored in the inside by convection. 5. Auxiliary water heater.   The auxiliary hot water supply device according to any one of claims 1 to 4, wherein the heat insulating member has a cylindrical shape, and a separate heat insulating material is disposed at at least one end thereof.   The auxiliary hot water supply device according to any one of claims 1 to 5, wherein the heat insulating member constitutes an exterior body.

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