JP2016033439A - Hot water storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water storage system which enables water stored in a hot water storage tank to be used as drinking water even when gas, electricity, and water service is interrupted.SOLUTION: A hot water storage system includes a water discharge valve 42 which switches on and off the discharge of water in a hot water storage tank 13 from a water discharge port 16 in a lower portion of the hot water storage tank 13, and a water purifier 46 which purifies the water discharged from the water discharge port 16. The water purifier 46 is of a hollow fiber membrane type. To apply water pressure equal to or more than a specific pressure to an inlet side of the water purifier 46, a pressure inlet 49 is provided in an upper portion of the hot water storage tank 13. Pressure is applied to the inside of the hot water storage tank 13 with an air pump for a bicycle, or the like.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a hot water storage system that includes a hot water storage tank for storing hot water supplied to the hot water, and raises the temperature of the hot water in the hot water storage tank with a predetermined heat source.

  Some hot water storage systems reduce adhesion of scale by purifying water supplied from a water supply source with a water purifier and then replenishing the hot water storage tank (see, for example, Patent Document 1).

Japanese Patent No. 4882731

  When water supply becomes unavailable due to a disaster, it is desirable to use hot water stored in a hot water storage tank of a hot water storage system.

  However, if electricity and gas are cut off in addition to the water shutoff, the water temperature in the hot water storage tank decreases, and sterilization by heat cannot be performed, leading to the propagation of germs. For this reason, the water in the hot water storage tank cannot be used as drinking water.

  Although the system of patent document 1 is equipped with the water purifier, it purifies the feed water replenished to the hot water storage tank, and cannot cope with the above problem.

  The present invention is intended to solve the above-described problem, and provides a hot water storage system that can use water stored in a hot water storage tank for a long time as drinking water in a situation where electricity, gas, and water are shut off during a disaster or the like. It is intended to provide.

  The gist of the present invention for achieving the object lies in the inventions of the following items.

[1] A hot water storage system that includes a hot water storage tank for storing hot water supplied to the hot water, and raises the temperature of the hot water in the hot water storage tank with a predetermined heat source device,
A drain valve for switching whether or not to drain the water in the hot water storage tank from the drain outlet at the bottom of the hot water storage tank;
A water purifier for purifying water drained from the drain;
A hot water storage system characterized by comprising:

  In the said invention, the water in a hot water storage tank can be purified and drained with a water purifier. Even when electricity, gas, and water are shut off during a disaster and the water in the hot water storage tank is contaminated with germs, the water in the hot water storage tank can be purified and used as drinking water.

[2] The hot water storage system according to [1], wherein the outlet for taking out the water that has passed through the water purifier is provided at a location that is higher than the ground contact surface of the hot water storage system by a predetermined distance or more.

  For example, when a faucet is provided as a water outlet through the water purifier, the faucet installation height is set so that a small tank or the like can be placed under the faucet to receive and collect water flowing out from the faucet.

[3] The hot water storage system according to [1] or [2], wherein the water purifier is a hollow fiber membrane type.

  In the above invention, since the hollow fiber membrane type does not propagate germs inside the water purifier even if it is left after passing water, discharge from the water purifier by trial for disaster prevention training etc. is performed before use at the time of disaster. No problem.

[4] The hot water storage system according to [3], wherein a pressure inlet for increasing the pressure in the hot water storage tank is provided.

  In the said invention, the pressure in a hot water storage tank can be raised by sending air with a pump from a pressure inlet. Hollow fiber membrane water purifiers need to send water at a certain level of water pressure, but when the drain valve is opened by increasing the pressure in the hot water storage tank, water is sent to the water purifier at a high water pressure. Can do.

[5] An activated carbon filter provided in the middle of a pressurizing path connecting the pressure inlet and the upper opening of the hot water storage tank;
A check valve provided in the pressurization path between the activated carbon filter and the opening;
The hot water storage system according to [4], characterized by comprising:

  In the said invention, smells, such as lubricating oil of the pump connected to the pressure inlet, are deodorized with an activated carbon filter. Further, the check valve prevents water in the hot water storage tank from reaching the activated carbon filter.

[6] The open / close valve provided in any one of [1] to [5] is characterized in that a water supply passage for supplying water to the hot water storage tank is provided with an open / close valve that opens when energized and closes when deenergized. Hot water storage system.

  In the above invention, the solenoid valve is closed, so that when the drain valve is opened in an apartment or the like, the water in the hot water storage tank is prevented from flowing down through the water supply pipe.

  According to the hot water storage system according to the present invention, it is possible to use, as drinking water, water that has been accumulated in the hot water storage tank for a long time in a situation where electricity, gas, and water are shut off during a disaster or the like.

It is a figure which shows schematic structure of the bath hot-water supply system to which the hot water storage system of this invention is applied. It is a figure which shows the structural example of a bath water heater. It is explanatory drawing which shows the flow of the hot water in waste heat recovery operation | movement. It is explanatory drawing which shows the flow of the hot water in the hot water supply operation | movement of a 1st mode. It is explanatory drawing which shows the flow of the hot water in the hot water supply operation | movement of a 2nd mode. It is explanatory drawing which shows the flow of the hot water in the hot water supply operation | movement of a 3rd mode. It is explanatory drawing which shows the flow of the hot water in pouring operation | movement. It is a figure which shows the flow of the water at the time of draining the water in a hot water storage tank through a water purifier in the state which stopped electricity, gas, and water supply. It is a figure which shows the structure of the bath hot-water supply system at the time of providing the faucet for water purification in the position higher than predetermined installation distance from the installation surface of a hot water storage system.

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

  FIG. 1 shows a configuration of a bath hot water supply system 10 to which a hot water storage system of the present invention is applied. The bath hot water supply system 10 includes a hot water storage tank unit 11, a heat source unit 4, an exhaust heat recovery device 50, and a bath water heater 70 as a backup heat source unit. In this example, the heat source unit 4 is a fuel cell. In the figure, piping between apparatuses and external piping are indicated by double arrows.

  The hot water storage tank unit 11 includes a hot water storage tank 13 that stores water supplied from a water supply pipe 12. The hot water storage tank 13 is a hollow, substantially cylindrical tank, with a water supply port 14 provided at the lower part and a hot water outlet 15 provided at the upper part. Further, a water intake port 16 is provided at the lower part of the hot water storage tank 13 and a return port 17 is provided at the upper part.

  The hot water storage tank 13 has, for example, a capacity of about 100 liters, and a first temperature sensor 18a for detecting the water temperature at the water level of 20 liters from the bottom has a water level of 40 liters from the bottom. A second temperature sensor 18b for detecting the water temperature at the location is located at a location where the water level is 60 liters from the bottom, and a third temperature sensor 18c for detecting the water temperature at the location is located at a location where the water level is 80 liters from the bottom. A hot water temperature sensor 18d for detecting the water temperature is further provided, and a tank upper temperature sensor 18e for detecting the water temperature at the location is provided at the uppermost part of the hot water storage tank 13, respectively.

  The exhaust heat recovery device 50 is provided in the heat source unit 4 or the like and recovers the exhaust heat of the heat source unit 4. The exhaust heat recovery device 50 includes an exhaust heat recovery heat exchanger 51 and an exhaust heat recovery pump 52. The exhaust heat recovery heat exchanger 51 of the hot water storage tank 13 and the exhaust heat recovery device 50 has a heat recovery pipe 53 (53a, 53b) so that an exhaust heat recovery circulation path for circulating the water of the hot water storage tank 13 is formed between them. ). Specifically, one end of a heat recovery pipe (low temperature) 53 a is connected to the water intake 16 of the hot water storage tank 13, and the other end of the heat recovery pipe (low temperature) 53 a is connected to the inlet side of the exhaust heat recovery heat exchanger 51. ing. The exhaust heat recovery pump 52 is inserted into a heat recovery pipe (low temperature) 53a in the vicinity of the entrance side of the exhaust heat recovery heat exchanger 51, and the exhaust heat recovery pump 52 uses the water in the heat recovery pipe (low temperature) 53a. Water is fed from the intake 16 side of the hot water storage tank 13 toward the entrance side of the exhaust heat recovery heat exchanger 51.

  A heat recovery pipe (high temperature) 53 b is connected to the outlet side of the exhaust heat recovery heat exchanger 51, and the other end of the heat recovery pipe (high temperature) 53 b is the first connection of the first three-way valve 21 in the hot water storage tank unit 11. It is connected to the mouth 21a.

  The first three-way valve 21 includes the first connection port 21a, the second connection port 21b, and the third connection port 21c, and connects the first connection port 21a and the second connection port 21b to form a third connection port. The connection state can be switched between the A direction for closing 21c and the B direction for connecting the first connection port 21a and the third connection port 21c and closing the second connection port 21b. The first three-way valve 21 is controlled by the control unit 20 so as to be in the A direction if the temperature of the water flowing in from the first connection port 21a is equal to or higher than the predetermined temperature, and to be switched to the B direction if the temperature is lower than the predetermined temperature.

  The second connection port 21 b of the first three-way valve 21 is connected to the return port 17 of the hot water storage tank 13. One end of the bypass pipe 54 is connected to the third connection port 21 c of the first three-way valve 21, and the other end of the bypass pipe 54 joins the heat recovery pipe (low temperature) 53 a in the hot water storage tank unit 11.

  A heat recovery pipe high temperature side temperature sensor 22a is provided in the heat recovery pipe (high temperature) 53b in the vicinity of the first connection port 21a of the first three-way valve 21, and a junction between the water intake 16 of the hot water storage tank 13 and the bypass pipe 54 is provided. The heat recovery pipe low temperature side sensor 22b is provided in the heat recovery pipe (low temperature) 53a until the above.

  The hot water storage tank unit 11 includes a mixer 23 that mixes hot water from the hot water outlet 15 of the hot water storage tank 13, hot water from the bath water heater 70, and water supply. This mixer 23 is actually a first mixer 23 a that adjusts the amount of hot water supplied from the hot water outlet 15 of the hot water storage tank 13 and a second mixer that adjusts the amount of hot water supplied from the bath water heater 70. 23 b and a third mixer 23 c that adjusts the amount of water supplied from the water supply pipe 12.

  The inlet side of the first mixer 23a is connected to the hot water outlet 15 of the hot water storage tank 13 by piping, and a tank outlet temperature sensor 26 is provided in the middle of the piping. In addition, a check valve 47 is inserted in the middle of a pipe line (pressurization path) branched from the pipe, an activated carbon filter 48 is provided at the tip, and a pressure injection port 49 is provided at the end. The entrance side of the second mixer 23 b is connected to the hot water supply connection port of the bath water heater 70 by a connection pipe (high temperature) 61. A connecting pipe high temperature side temperature sensor 28 for detecting the water temperature in the connecting pipe (high temperature) 61 is provided at a predetermined location in the hot water storage tank unit 11 in the connecting pipe (high temperature) 61. A water supply pipe 12 is connected to the entrance side of the third mixer 23c.

  The outlet side of the first mixer 23a and the outlet side of the second mixer 23b merge, and after passing through the pipe provided with the hot water supply high temperature sensor 29, merge with the pipe from the outlet side of the third mixer 23c. It leads to the outlet of the mixer 23. A hot water supply pipe 31 is connected to the outlet of the mixer 23. A hot water supply temperature sensor 32 and a high cut temperature sensor 33 are provided in the hot water supply pipe 31 near the outlet of the mixer 23.

  The water supply pipe 12 inside the hot water storage tank unit 11 is inserted with an electromagnetic valve 44 that opens when energized and closes when a power failure occurs, and a flow rate sensor 34, a water supply temperature sensor 35, and a pressure reducing valve 36 are provided downstream thereof. The water supply pipe 12 branches into three downstream of these, one of which is connected to the inlet side of the third mixer 23c via a check valve 37a, and the other one via the check valve 37b. The other one is connected to the second connection port 38b of the second three-way valve 38 through the check valve 37c.

  The second three-way valve 38 includes a first connection port 38a, a second connection port 38b, and a third connection port 38c, connects the first connection port 38a and the second connection port 38b, and closes the third connection port 38c. The connection state can be switched between the C direction and the D direction in which the first connection port 38a and the third connection port 38c are connected and the second connection port 38b is closed. A pipe 31b branched from the hot water supply pipe 31 on the downstream side of the high cut temperature sensor 33 is connected to the third connection port 38c. A check valve 39 is provided in the middle of the pipe 31b. The first connection port 38 a of the second three-way valve 38 is connected to the water supply connection port of the bath water heater 70 through a connection pipe (low temperature) 62.

  Further, a drain pipe 41 leading to a predetermined drainage point is connected to the water intake 16 of the hot water storage tank unit 11, and a manual drain plug 42 for opening and closing this pipe line is further provided downstream of the drain pipe 41. A manual third three-way valve 45 is provided. The drain plug 42 is normally closed.

  The first connection port 45a of the third three-way valve 45 is connected to the outlet side of the drain plug 42, and the drain pipe 41 downstream of the third three-way valve 45 is connected to the second connection port 45b of the third three-way valve 45. Has been. The inlet side of the water purifier 46 is connected to the third connection port 45 c of the third three-way valve 45. The outlet side of the water purifier 46 is an outlet for emergency drinking water. The water purifier 46 is a hollow fiber membrane type.

  In the third three-way valve 45, the first connection port 45a communicates with the second connection port 45b, the E direction in which the third connection port 45c is blocked, the first connection port 45a communicates with the third connection port 45c, It is possible to manually switch to the F direction in which the second connection port 45b is blocked.

  The hot water storage tank unit 11 includes a control unit 20 that performs overall control of the operation of the hot water storage tank unit 11. The control unit 20 includes a CPU (Central Processing Unit), a flash ROM (Read Only Memory) that stores programs executed by the CPU, fixed data, and the like, and a RAM that temporarily stores various types of information when the CPU executes programs. (Random Access Memory) and an I / F (Interface) unit for inputting / outputting various signals and the like. Detection signals from various sensors of the hot water tank unit 11 are input to the control unit 20. A control signal is output from the control unit 20 to each valve and other controlled objects. The control unit 20 further exchanges various information and commands with the heat source unit 4 and the bath water heater 70.

  Next, a configuration example of the bath water heater 70 as a backup heat source device will be described. The bath water heater 70 has a function of heating and flowing out water flowing from a water supply connection port connected to a connection pipe (low temperature) 62, a function of pouring (hot water filling) the bath (tub) 2, and hot water in the bathtub. This is a gas-fired bath water heater having a function of reheating, a function of heating a heating medium fluid by flowing a heated heat medium fluid, and the like. In FIG. 2, the portion related to the heating function is omitted.

  The bath water heater 70 includes a can-two-water channel heat exchanger 72 through which the first heat exchange water pipe 72 a and the second heat exchange water pipe 72 b pass, and a burner 73 that heats the heat exchanger 72. A gas supply pipe 73a is connected to the burner 73, and a gas valve for switching supply / cutoff of gas and a proportional valve for adjusting the amount of supply gas are provided in the middle of the gas supply pipe 73a.

  The inlet side of the first heat exchange water pipe 72 a is connected to a water supply connection port by a water inlet pipe 74, and the outlet side of the first heat exchange water pipe 72 a is connected to a hot water supply connection port by a hot water outlet pipe 75. Further, a bath return pipe 76 leading to the bath (tub) 2 is provided on the entry side of the second heat exchange water pipe 72b, and a bath return pipe 77 similarly leading to the bath (tub) 2 is provided on the exit side of the second heat exchange water pipe 72b. Each is connected.

  The hot water outlet pipe 75 and the bath return pipe 76 are connected by a connecting pipe 78, and a hot water electromagnetic valve 79 for switching between closing and opening of the connecting pipe 78 is provided in the middle of the connecting pipe 78. In addition, a water amount servo 81 capable of adjusting the opening degree from a substantially closed state to a fully open state is provided in the middle of the hot water discharge pipe 75 upstream from the connection point of the connecting pipe 78 to adjust the amount of hot water discharged. A tapping temperature sensor 82 for detecting tapping temperature is provided on the downstream side of the water amount servo 81.

  Furthermore, a bypass pipe 83 branched from the water intake pipe 74 and joined to and connected to the hot water discharge pipe 75 at a predetermined location on the first heat exchange water pipe 72a side from the water quantity servo 81 is provided. A bypass adjustment valve 84 whose opening degree can be adjusted until it is fully opened is provided. The bypass adjustment valve 84 is adjusted so that hot water from the first heat exchange water pipe 72a and water via the bypass pipe 83 are mixed to become hot water at a set temperature. The inlet pipe 74 upstream of the branching point of the bypass pipe 83 is provided with a flow rate sensor 85 that detects the flow rate in the inlet pipe 74 and an incoming water temperature sensor 86 that detects the incoming water temperature.

  In the middle of the bath return pipe 76, a bath circulation pump 87 for circulating the water in the bath (tub) 2 through the recirculation circulation path (bath return pipe 76, second heat exchange water pipe 72 b, bath going-out pipe 77). Is provided. A flowing water switch 88 provided in the bath return pipe 76 detects whether water is actually circulating in the recirculation circulation path when the bath circulation pump 87 is operated.

  In addition, the bath return pipe 76 and the bath return pipe 77 are provided with a bath return temperature sensor 89a and a bath return temperature sensor 89b, respectively, for detecting the temperature in the pipe.

  The control unit 91 includes a CPU, a flash ROM that stores a program executed by the CPU, fixed data, and the like, and a RAM that temporarily stores various types of information when the CPU executes the program. Has been. Various sensors, valves, a bath circulation pump 87, and the like that the bath water heater 70 has are connected to the control unit 91.

  Normally, the remote controller 92 is directly connected to the control unit 91 via wiring. Here, however, the control unit 91 is operated in order to operate the bath water heater 70 under the control of the control unit 20 on the hot water tank unit 11 side. The remote controller (a remote controller common to the hot water storage tank unit 11 side and the bath water heater 70) 92 is connected to the controller 20 via the wiring. The remote control 92 is a switch for receiving various operations from the user, such as designation of hot water supply set temperature and bath set temperature, start / end instruction of hot water filling and reheating operation, power on / off, operation state and set temperature, etc. It is comprised with the display part etc. which display.

  In the hot water supply operation in which the controller 91 of the bath water heater 70 discharges hot water from the hot water supply connection port to the connection pipe (high temperature) 61, hot water at a temperature instructed by the control unit 20 on the hot water storage tank unit 11 side is connected to the connection pipe (high temperature) 61. The amount of combustion of the burner 73, the opening degree of the bypass adjustment valve 84, and the like are controlled so that the hot water is discharged.

  In the operation of pouring (hot water) into the bath (tub) 2, the opening of the water quantity servo 81 is adjusted while the burner 73 is burned by opening the pouring solenoid valve 79, thereby flowing from the water supply connection port. The hot water is heated through the first heat exchange water pipe 72a of the heat exchanger 72, and further from the hot water pipe 75 to the bath (tub) 2 through both (or one) of the connecting pipe 78, the bath return pipe 76 and the bath outlet pipe 77. Flow in (this path is a pouring circuit). At this time, the combustion amount of the burner 73, the opening degree of the bypass adjustment valve 84, and the like are controlled so that hot water having a bath setting temperature set by the user is poured by the remote controller 92. If the hot water supplied from the hot water storage tank unit 11 through the connection pipe (low temperature) 62 has already reached the bath set temperature and no additional heating is required in the bath water heater 70, the burner 73 is not burned. Perform hot water operation. The bath water heater 70 checks the water level in the bath (tub) 2, and the hot water pouring operation ends when the set water level is reached.

  In the reheating operation, the hot water solenoid valve 79 is closed, and the burner 73 is burned with the bath circulation pump 87 activated. As a result, hot water in the bath (tub) 2 is taken into the bath water heater 70 through the bath return pipe 76 and heated while passing through the second heat exchange water pipe 72 b of the heat exchanger 72, and the heated hot water is heated to the bath outlet pipe 77. It is returned to the bath (tub) 2 through.

  Next, various operations of the bath hot water supply system 10 will be described.

<Exhaust heat recovery operation>
FIG. 3 shows the flow of hot water in the exhaust heat recovery operation, and the flow path of hot water in the exhaust heat recovery operation is indicated by a bold line. In the exhaust heat recovery operation for recovering the exhaust heat of the heat source unit 4 and heating the hot water in the hot water storage tank 13, the control unit 20 instructs the heat source unit 4 to operate the exhaust heat recovery pump 52. As a result, the hot water in the hot water storage tank 13 exits from the water intake 16 and is connected to the heat recovery pipe (low temperature) 53a, the exhaust heat recovery heat exchanger 51, the heat recovery pipe (high temperature) 53b, and the first three-way valve 21 in the A direction. It circulates in the circulation path which returns to the upper part of hot water storage tank 13 from return port 17 via. In addition, since the hot water heated by the exhaust heat recovery heat exchanger 51 and reaching a high temperature reaches the first connection port 21a of the first three-way valve 21, the control unit 20 sets the first three-way valve 21 in the A direction. .

  The hot water is supplied from the water supply port 14 at the lower part of the hot water storage tank 13 and the hot water heated by the exhaust heat recovery operation is returned to the upper part of the hot water storage tank 13, so that the lower part of the hot water storage tank 13 has a low temperature and the upper part has a high temperature. Such a temperature gradient is formed. By continuing the exhaust heat recovery operation, the amount of hot water that accumulates in the upper portion gradually increases.

<Hot-water supply operation>
The hot water storage tank unit 11 may be installed near the bath water heater 70 or may be installed far away. For example, in a house with a bath on the second floor, there is a case where the bath water heater 70 is installed on the outer wall of the second floor and the hot water storage tank unit 11 and the heat source unit 4 are installed on the first floor. The connection pipe (high temperature) 61 and the connection pipe (low temperature) 62 connecting the apparatuses become longer, resulting in an installation situation where the pressure loss is large. In the hot water supply system 10 of the present invention, even in a low water pressure area, even when the piping is long and the pressure loss is large, hot water supply is performed with suppressed increase in pressure loss so that a sufficient amount of hot water can be secured. Yes.

Hot water is supplied in one of the following three control modes.

(1) First mode (tank hot water)
The first mode is a hot water supply operation in the case where the hot water storage tank 13 has sufficiently stored heat. FIG. 4 shows the flow of hot water in the hot water supply operation in the first mode. In the figure, the path through which hot water flows is indicated by a bold line. In the first mode, hot water and hot water from the hot water storage tank 13 are mixed by the mixer 23 to make hot water at a hot water supply set temperature, and hot water is supplied. No water is sent to the bath water heater 70, no heating is performed in the bath water heater 70, and no combustion operation is performed.

  Specifically, the second mixer 23b of the mixer 23 is closed, the opening degree of the first mixer 23a and the third mixer 23c is adjusted, and the outlet side of the mixer 23 detected by the tapping temperature sensor 32 is adjusted. The hot water temperature is controlled so as to become the hot water supply set temperature. Here, for example, the detection temperature of the hot water temperature sensor 18d provided in the hot water storage tank 13 is equal to or higher than the hot water supply set temperature (actually, for example, the hot water supply set temperature + 1 ° C. in consideration of a temperature drop in the hot water supply pipe) In this case, hot water is supplied in the first mode.

(2) Second mode (hot water supply hot water mode)
The second mode is a hot water supply operation when there is no hot water available in the hot water storage tank 13. FIG. 5 shows the flow of hot water in the hot water supply operation in the second mode. In the figure, the path through which hot water flows is indicated by a bold line. In the second mode, hot water heated to a temperature higher than the hot water supply set temperature by the bath water heater 70 and hot water are mixed by the mixer 23 to supply hot water at the hot water supply set temperature.

  Specifically, the second three-way valve 38 is set in the C direction, and water is supplied to the bath water heater 70. Also, the first mixer 23a of the mixer 23 is closed, the opening degree of the second mixer 23b and the third mixer 23c is adjusted, and the hot water on the outlet side of the mixer 23 detected by the hot water temperature sensor 32 is adjusted. The temperature is controlled so as to become the hot water supply set temperature.

  Note that the control unit 20 instructs the bath water heater 70 to provide a hot water temperature so that the hot water temperature of the bath water heater 70 is sufficiently higher than the hot water supply set temperature. Thus, the amount of hot water from the bath water heater 70 necessary for mixing with the water supply to obtain the hot water supply set temperature is reduced, and passes through the connection pipe (low temperature) 62, the bath water heater 70 and the connection pipe (high temperature) 61. The pressure loss caused by this can be kept small. For example, if the hot water supply set temperature is 40 ° C., hot water at 55 ° C. is obtained from the bath water heater 70. If the hot water supply set temperature is 60 ° C., 75 ° C. hot water is obtained from the bath water heater 70.

(3) Third mode (post-mixing hot water mode)
The third mode is a hot water supply operation in the case where heat is stored in the hot water storage tank 13 but the temperature is low and the hot water in the hot water storage tank 13 is not sufficient. FIG. 6 shows the flow of hot water in the hot water supply operation in the third mode. In the figure, the path through which hot water flows is indicated by a bold line. The third mode is selected, for example, when the detected temperature of the hot water temperature sensor 18d of the hot water storage tank 13 is lower than the hot water supply set temperature but not lower than 10 ° C above the hot water supply set temperature.

  In the third mode, the hot water heated by the bath water heater 70, the hot water from the hot water storage tank 13 and the hot water are mixed to make hot water having a hot water supply set temperature. Specifically, hot water produced by heating the second three-way valve 38 in the C direction and heating the hot water in the bath water heater 70, hot water from the hot water storage tank 13 and the hot water from the hot water storage tank 13 are mixed in the hot water supply set temperature. Make hot water and supply hot water. Even if the temperature of the hot water in the hot water storage tank 13 is low, the heat stored in the hot water storage tank 13 can be used up more by mixing with the hot water received from the bath water heater 70, so the first and second Energy savings are higher than when controlling only in the mode.

  The controller 20 preferentially selects the first mode, and hot water that is not lower than the hot water set temperature by a predetermined temperature (for example, 10 ° C.) from the hot water storage tank 13 when hot water at the set temperature cannot be supplied in the first mode. When the supply is possible, the third mode is selected, and when the third mode cannot be selected, the second mode is selected.

<Pouring operation>
FIG. 7 shows the flow of hot water in the pouring operation. In the figure, the path through which hot water flows is indicated by a bold line. In the pouring operation, the hot water on the outlet side of the mixer 23 is supplied to the water supply connection port of the bath water heater 70, and hot water from the hot water storage tank 13 or hot water from the hot water storage tank 13 and hot water are mixed. The hot water at the bath set temperature is poured from the bath water heater 70 to the bath (tub) 2 by adding the heating by the bath water heater 70 to the hot water produced from the outlet side of the mixer 23 or without additional heating. To control.

  Specifically, when pouring (hot water filling) with hot water stored in the hot water storage tank 13, the second three-way valve 38 is set in the D direction, and the hot water and hot water from the hot water storage tank 13 are mixed by the mixer 23. Then, the hot water having the set temperature of the bath is sent to the bath water heater 70 and filled with the pouring circuit of the bath water heater 70. The control unit 20 of the hot water storage tank unit 11 instructs the bath water heater 70 to open the pouring electromagnetic valve 79 while the burner 73 is in the combustion off state. Hot water from the outlet side of the mixer 23 included in the hot water storage tank unit 11 is supplied from a connecting pipe (low temperature) 62 to a hot water supply circuit of the bath water heater 70, that is, a water inlet pipe 74 and a first heat exchange water pipe in the bath water heater 70. After passing through 72 a, the hot water solenoid valve 79, and the connecting pipe 78, the hot water flows out into the bath (tub) 2 through both or one of the bath outlet pipe 77 and the bath return pipe 76 and is poured.

  When the hot water storage tank 13 does not store heat, the second three-way valve 38 is set in the D direction, hot water having a temperature lower than the bath setting temperature in the hot water storage tank 13, water supply, or a bath setting temperature obtained by mixing them. The low temperature hot water is sent to the bath water heater 70, heated to the bath set temperature in the bath water heater 70, and poured through the pouring circuit in the bath water heater 70.

  It should be noted that all the functions used for the fully automatic bath such as detection of water level and reheating use the functions of the bath water heater 70 as they are.

  Thus, since the hot water from the outlet side of the mixer 23 is supplied to the bath water heater 70 by switching the second three-way valve 38 in the D direction, the hot water in the hot water storage tank can be used for pouring.

  Next, a case where hot water in the hot water storage tank 13 is used as drinking water in a state where electricity, gas, and water are cut off will be described.

  When a power failure occurs, the solenoid valve 44 provided in the water supply pipe 12 is automatically closed. In this state, when the user manually switches the third three-way valve 45 to the F direction and opens the drain plug 42, the water in the hot water storage tank 13 flows out from the water purifier 46.

  FIG. 8 shows a water flow path when water in the hot water storage tank 13 is discharged from the water purifier 46. The water in the hot water storage tank 13 flows out from the lower water intake 16 and is discharged from the outlet side of the water purifier 46 via the drain plug 42, the third three-way valve 45, and the water purifier 46.

  When the gas, water supply, and electricity are cut off, the water in the hot water storage tank 13 is contaminated by germs over time. However, it is purified by passing through the water purifier 46 and can be used as drinking water.

  The water purifier 46 is a hollow fiber membrane type. In addition to the hollow fiber membrane type, the water purifier includes an activated carbon type. However, in the case of the activated carbon type, chlorine is also removed. Therefore, if tap water is passed through and then left as it is for a long time, various germs will propagate inside. In the hot water storage system, it is assumed that a user or the like tries to use the water in the hot water storage tank 13 as an emergency drinking water at the time of system installation or disaster prevention day. Therefore, when an activated carbon type water purifier is used, a disaster actually occurs, and when using emergency drinking water, there is a possibility that the water purifier is already contaminated with germs and cannot be used. Therefore, in this embodiment, a hollow fiber membrane type water purifier 46 is used.

  However, in the case of the hollow fiber membrane type, it is necessary to send water to the water purifier 46 with a certain level of water pressure. Therefore, in this embodiment, before drinking water is obtained through the water purifier 46, the user is caused to perform an operation of sending air from the pressure inlet 49 into the hot water storage tank 13 with a pump such as a bicycle air pump. As a result, the pressure in the hot water storage tank 13 is increased so that the water is fed into the water purifier 46 at a predetermined or higher water pressure. The pressure inlet 49 is normally closed, and is configured to open when air is sent from the pump at a certain pressure or higher.

  Furthermore, it is convenient that the water passed through the water purifier 46 is transferred to a plastic tank or the like by the user. Therefore, as shown in FIG. 9, a faucet 56 for taking out the water that has passed through the water purifier 46 is provided in a place higher than a predetermined distance from the lower part (grounding surface) of the hot water storage tank unit 11, for example, 450 mm or higher. Under the faucet 56, it is preferable to be able to install a plastic tank 57 or the like that receives and collects purified water. However, in such a case, the water stored in the portion of the hot water storage tank 13 that is lower than the faucet 56 (the h portion in the figure) cannot normally be used. If there is pressurization, the water in the hot water storage tank 13 stored in such a low place (the h portion in the figure) can be used without any trouble. In the case of FIG. 9, the faucet 56 serves as a drain valve that switches whether or not to drain the water in the hot water storage tank 16 from the drain port 16 at the lower part of the hot water storage tank 13.

  In addition, since the pump having a structure that reciprocates the piston, such as a bicycle air pump, uses lubricating oil, it is provided downstream of the pressure inlet 49 for the purpose of preventing the smell from moving to the water in the hot water storage tank 13. An activated carbon filter 48 is provided. The check valve 47 downstream of the activated carbon filter 48 prevents the water in the hot water storage tank 13 from reaching the activated carbon filter 48 so that the activated carbon filter 48 is wet and no germs grow.

Next, the operation of the electromagnetic valve 44 will be described.

  When the bath hot water system 10 is installed in an apartment, when the faucet (faucet 58 in FIG. 9) connected to the bath hot water system 10 is opened at the time of water outage, the hot water in the hot water storage tank 13 is usually used as the bath water heater 70. However, if you open the faucet on the upper floor at the time of water outage and open the faucet on the lower floor, air enters from the faucet on the upper floor, and the water in the upper floor tank is under its own weight. After going through the lower floor faucet. In order to prevent such a backflow, there is a case where a mechanical check valve (37c in the bath hot water system 10) is provided in the water meter, but the check valve is broken. The water in the hot water storage tank 13 may flow into the hot water storage tank 13 of the bath water supply system 10 on the lower floor through the water supply pipe 12. Thus, the person on the upper floor cannot use the water stored in the hot water storage tank 13 of his / her hot water supply system 10 at the time of a disaster. Therefore, in the present embodiment, when a power failure occurs due to a disaster or the like, the electromagnetic valve 44 is closed and the water supply pipe 12 is automatically sealed. Thereby, the above inconvenience is solved.

  The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration is not limited to that shown in the embodiment, and there are changes and additions within the scope of the present invention. Are also included in the present invention.

  If the hot water storage system of the present invention includes the hot water storage tank unit 11 of the bath hot water system 10, the exhaust heat recovery device 50, the bath water heater 70, and the fuel cell 4 may or may not be included. The exhaust heat recovery device 50 may be included in the fuel cell 4, or the bath water heater 70 may be an existing one.

  The configuration of the hot water storage tank unit 11 is not limited to that illustrated in the embodiment. For example, in the embodiment, the hot water from the bath water heater 70 is returned to the mixer 23 and can be mixed. However, in the mixer 23, the hot water and hot water from the hot water storage tank 13 are mixed and bath hot water is supplied. The hot water from the bath water heater 70 may be supplied to the hot water tap as it is.

  In the embodiment, an example in which a bicycle inflator is connected to the pressure inlet 49 has been shown, but other types of pumps may be used.

  In the embodiment, the drain plug 42 is provided in the middle of the drain pipe 41, but the drain plug 42 may be directly attached to the water intake 16. Further, although the water purifier 46 is provided downstream of the drain plug 42, the water purifier 46 may be provided between the water intake 16 and the drain plug 42.

2 ... Bath (tub)
3. Heating radiator 4. Heat source machine (fuel cell)
DESCRIPTION OF SYMBOLS 10 ... Bath hot water supply system 11 ... Hot water storage tank unit 12 ... Water supply pipe 13 ... Hot water storage tank 14 ... Water supply port 15 ... Outlet 16 ... Water intake 17 ... Return port 18a ... First temperature sensor 18b ... Second temperature sensor 18c ... Third Temperature sensor 18d ... Hot water temperature sensor 18e ... Tank upper temperature sensor 20 ... Control unit 21 ... First three-way valve 21a ... First connection port of the first three-way valve 21b ... Second connection port of the first three-way valve 21c ... First Third connection port of three-way valve 22a ... Heat recovery pipe high temperature side temperature sensor 22b ... Heat recovery pipe low temperature side temperature sensor 23 ... Mixer 23a ... First mixer 23b ... Second mixer 23c ... Third mixer 26 ... Tank Outlet temperature sensor 28 ... Connecting pipe high temperature side temperature sensor 29 ... Hot water supply high temperature sensor 31 ... Hot water supply pipe 31b ... Pipe 32 ... Hot water temperature sensor 33 ... High cut temperature sensor 3 4 ... Flow sensor 35 ... Feed water temperature sensor 36 ... Pressure reducing valve 37a ... Check valve 37b ... Check valve 37c ... Check valve 38 ... Second three-way valve 38a ... First connection port 38b ... Second three-way valve Second connection port of valve 38c ... Third connection port of second three-way valve 39 ... Check valve 41 ... Drain pipe 42 ... Drain plug 44 ... Solenoid valve 45 ... Third three-way valve 45a ... First connection of third three-way valve Port 45b ... Second connection port of the third three-way valve 45c ... Third connection port of the third three-way valve 46 ... Water purifier 47 ... Check valve 48 ... Activated carbon filter 49 ... Pressure inlet 50 ... Waste heat recovery device 51 ... Exhaust Heat recovery heat exchanger 52 ... exhaust heat recovery pump 53 ... heat recovery pipe 53a ... heat recovery pipe (low temperature)
53b ... Heat recovery piping (high temperature)
54 ... Bypass pipe 56 ... Faucet 57 ... Poly tank 58 ... Faucet connected to bath hot water supply system 61 ... Connection piping (high temperature)
62 ... Connection piping (low temperature)
70 ... Bath water heater 72 ... Heat exchanger 72a ... First heat exchange water pipe 72b ... Second heat exchange water pipe 73 ... Burner 73a ... Gas supply pipe 74 ... Inlet pipe 75 ... Outlet pipe 76 ... Bath return pipe 77 ... Bath return pipe 77 78 ... Connecting pipe 79 ... Pouring solenoid valve 81 ... Water volume servo 82 ... Outflow temperature sensor 83 ... Bypass pipe 84 ... Bypass adjustment valve 85 ... Flow sensor 86 ... Incoming water temperature sensor 87 ... Bath circulation pump 88 ... Flow water switch 89a ... Bath going out Temperature sensor 89b ... Bath return temperature sensor 91 ... Control unit 92 ... Remote control (common remote control)

Claims (6)

A hot water storage system comprising a hot water storage tank for storing hot water supplied to the hot water, and heating the hot water in the hot water storage tank with a predetermined heat source unit,
A drain valve for switching whether or not to drain the water in the hot water storage tank from the drain outlet at the bottom of the hot water storage tank;
A water purifier for purifying water drained from the drain;
A hot water storage system characterized by comprising: The hot water storage system according to claim 1, wherein a take-out port for taking out water that has passed through the water purifier is provided at a location that is higher than a ground surface of the hot water storage system by a predetermined distance or more. The hot water storage system according to claim 1 or 2, wherein the water purifier is a hollow fiber membrane type. The hot water storage system according to claim 3, further comprising a pressure inlet for increasing the pressure in the hot water storage tank. An activated carbon filter provided in the middle of a pressure path connecting the pressure inlet and the upper opening of the hot water storage tank;
A check valve provided in the pressurization path between the activated carbon filter and the opening;
The hot water storage system according to claim 4, comprising: The hot water storage system according to any one of claims 1 to 5, wherein a water supply path for supplying water to the hot water storage tank is provided with an open / close valve that opens when energized and closes when deenergized.

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