JP5322991B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system.

  The hot water supply system disclosed in Patent Document 1 includes a power generation unit, a hot water storage tank, a water supply path, a hot water path, a mixed water path, and a mixing ratio adjuster. In this hot water supply system, the power generation unit and the hot water storage tank are connected by a circulation path, and hot water heated by the heat generated by the power generation unit is stored in the hot water storage tank. The hot water path extends between the hot water tank and the hot water use point, and guides the hot water flowing out of the hot water tank to the hot water use point. The water supply path connects a water pipe and a hot water tank, and feeds tap water into the hot water tank. The mixed water path branches from the water supply path and joins the warm water path. The mixing ratio adjuster adjusts the ratio between the flow rate of the hot water path before the mixed water path merges and the flow rate of the mixed water path, and adjusts the temperature of the hot water flowing through the hot water path after the mixed water path merges. Hot water whose temperature has been adjusted is supplied to the hot water use location.

  The water supply may be cut off, and the water pipe pressure may drop. At this time, it is necessary to prevent backflow from the hot water tank to the water pipe. In addition, it is necessary to prevent backflow from the hot water path to the water pipe through the mixed water path. In order to prevent backflow from the hot water path to the water pipe, a check valve (referred to as the first check valve in this specification) is inserted in the mixed water path, and the backflow from the hot water tank to the water pipe In order to prevent this, a check valve (referred to as a second check valve in this specification) is also inserted in the water supply path after the mixed water path is branched.

JP 2009-216352 A

The first check valve inserted in the mixed water path prevents water flow from the warm water path toward the water supply path when the pressure in the hot water path is higher than the pressure in the water supply path. On the other hand, when the pressure of the water supply path is higher than the pressure of the hot water path, the valve is opened to allow the water flow from the water supply path to the hot water path (hereinafter referred to as opening in the forward direction and allowing the forward water flow. ). However, there may be a situation in which the valve is kept closed even though the pressure of the water supply path is higher than the pressure of the hot water path, and the water flow from the water supply path to the hot water path is blocked.
If the first check valve blocks the water flow from the water supply path to the hot water path, tap water that mixes with the hot water sent out from the hot water tank to lower the temperature cannot be obtained, and the temperature is unexpectedly high. Hot water may come out.

  The present invention has been made in view of such circumstances, and its purpose is to provide a first check valve when an operation failure occurs in which the first check valve blocks a water flow from the water supply path to the hot water path. An attempt is made to eliminate the malfunction of the valve.

The hot water supply system of the present invention includes a hot water storage tank, a water supply path for feeding tap water into the hot water tank, a hot water path through which hot water flowing out from the hot water tank passes, a mixed water path branched from the water supply path and joined to the hot water path And a mixing ratio adjuster that adjusts the ratio between the flow rate of the hot water path and the flow rate of the mixed water path before the mixed water path merges. A first check valve is inserted in the mixed water path. When the pressure in the water supply path is higher than the pressure in the hot water path, the first check valve causes the water flow from the water supply path to the hot water path due to the pressure difference. On the other hand, it prevents water flow from the hot water path to the water supply path. The first on-off valve is inserted in the water supply path after the mixed water path branches or the warm water path before the mixed water path joins, and the path can be closed. A water temperature sensor is arranged in the hot water path after the mixed water path merges.
In the hot water supply system of the present invention, when the detected value of the water temperature sensor exceeds a predetermined value, the first on-off valve is closed and opened, and when the detected value of the water temperature sensor detected thereafter exceeds the predetermined value, the first opening and closing is performed. Close the valve.

If a malfunction occurs in which the first check valve inserted in the mixed water path does not open even though a forward pressure difference is acting on it, the temperature is lowered by mixing with the hot water sent from the hot water tank. Tap water will not be obtained, and the temperature of the hot water flowing through the hot water path after joining will rise. It can be seen that the malfunction of the first check valve occurred when the temperature of the hot water flowing through the hot water path after the merging exceeded a predetermined value.
In this case, the water supply path after branching or the warm water path before joining is temporarily closed by the first on-off valve. The hot water flowing through the hot water path continues to flow due to its inertial energy. Therefore, if the water supply path after branching or the warm water path before merging is temporarily closed, the pressure on the warm water path side of the first check valve decreases. As a result, even if a malfunction occurs in which the first check valve does not open in the forward direction, a large pressure difference can be applied to the first check valve, and the first check valve can be opened. .
If the first check valve opens in the forward direction by temporarily closing the water supply path after branching or the hot water path before joining, then the water supply path after branching or the hot water path before joining will be opened from the hot water tank. The hot water that has started to flow out is cooled by tap water flowing in the forward direction through the first check valve, and adjusted to an appropriate temperature. The temperature of the hot water flowing through the hot water path after merging decreases. If the temperature of the hot water flowing through the hot water path after merging does not exceed a predetermined value, it is understood that the malfunction of the first check valve has been eliminated. In this case, normal hot water supply operation is continued without closing the first on-off valve.
If the first check valve does not open even if an attempt is made to open the first check valve in the forward direction by temporarily closing the water supply path after branching or the hot water path before joining, the hot water is adjusted to an appropriate temperature. Since the operation cannot be performed, the first on-off valve is closed. An attempt to open the first check valve in the forward direction by temporarily closing the first on-off valve may be performed a plurality of times. The first on-off valve may be closed when the first check valve does not open even if it is implemented a plurality of times.

In the case of a hot water supply system in which the hot water path reaches the bathtub via the hot water filling path, the first on-off valve may be closed and then opened while hot water is being sent to the bathtub.
Also in this case, an attempt is made to open the first check valve in the forward direction by temporarily closing the water supply path after branching or the warm water path before joining. Even when the first check valve opens normally, the flow rate of the mixed water path is increased by temporarily closing the water supply path after branching or the warm water path before joining. The amount of water flowing in the forward direction through the first check valve increases, and the first check valve opens greatly in the forward direction. When a large amount of tap water passes through the first check valve that is wide open, foreign matter or the like adhering to the first check valve is removed. The first check valve is cleaned by temporarily closing the first on-off valve during the hot water operation. Note that hot water is not discharged by temporarily closing the first on-off valve. For this reason, the temperature of the hot water flowing through the hot water path after the mixed water path merges decreases. There is no particular problem because the temperature of the hot water temporarily decreases during the hot water operation.

A second check valve may be inserted in the water supply path after the mixed water path is branched. When the pressure of the water supply path is higher than the pressure of the hot water tank, the second check valve allows a water flow from the water supply path to the hot water tank due to the pressure difference, and on the other hand, the second check valve heads from the hot water tank to the water supply path. Block water flow.
In this case, a second opening / closing valve capable of closing the mixed water path may be inserted into the mixed water path, and a process of opening the second opening / closing valve after closing it while warm water is being sent to the bathtub may be performed.

  In this case, the hot water flowing through the hot water path continues to flow due to its inertial energy, and when the mixed water path is temporarily closed, the pressure on the hot water storage tank side of the second check valve decreases. As a result, even if a malfunction occurs in which the second check valve does not open in the forward direction, a large pressure difference can be applied to the second check valve, and the second check valve can be opened. . Even when the second check valve opens normally, the amount of water flowing in the forward direction through the second check valve increases by temporarily closing the mixed water path, and the second check valve increases in the forward direction. open. When a large amount of tap water passes through the second check valve that is wide open, foreign matter or the like adhering to the second check valve is removed. The second check valve is cleaned by temporarily closing the second on-off valve during the hot water operation. In addition, the tap water which mixes and cools with warm water by temporarily closing a 2nd on-off valve cannot be obtained. For this reason, the temperature of the warm water flowing through the warm water path after joining the mixed water path rises. There is no particular problem because the temperature of the hot water rises temporarily during the hot water operation.

According to the hot water supply system of the present invention, when a malfunction occurs in which the check valve blocks the water flow in the forward direction, an attempt is made to open the check valve in the forward direction. The possibility that the malfunction is eliminated is increased.
In addition, according to the hot water supply system of the present invention, the operation of cleaning the check valve is performed, and the probability of malfunction of the check valve is reduced.

1 is a system diagram of a hot water supply system according to Embodiment 1. FIG. The systematic diagram of the hot-water supply system of Example 2. FIG. FIG. 5 is a system diagram of a hot water supply system according to a third embodiment. The systematic diagram of the hot-water supply system of Example 4. FIG. The typical sectional view of a check valve.

The technical features of the embodiments described below will be described.
(Feature 1) The first on-off valve is an electromagnetic valve, and the second on-off valve is also an electromagnetic valve.
(Feature 2) The first on-off valve is a hot water flow rate servo, and the second on-off valve is a mixed water flow rate servo.
(Feature 3) The first on-off valve and the second on-off valve constitute a mixture ratio adjuster. (Feature 4) The distribution servo for adjusting the mixture ratio has the functions of the first on-off valve and the second on-off valve.

  An embodiment embodying the hot water supply system of the present invention will be described with reference to FIG. FIG. 1 is a system diagram of a hot water supply system 68, a hot water storage tank 16, a water supply path 12 for feeding tap water into the hot water storage tank 16, a hot water path 26 through which hot water flowing out of the hot water storage tank 16 passes, and a branch from the water supply path 12. Thus, a mixed water path 20 that joins the hot water path 26 is provided. The water supply path 12 includes a pre-branch water supply path 12a before the mixed water path 20 branches, and a post-branch water supply path 12b after the mixed water path 20 branches. The hot water path 26 includes a pre-merging hot water path 26a before the mixed water path 20 merges and a post-merging hot water path 26b after the mixed water path 20 merges.

  A distribution servo 70 is provided at a branch point between the water supply path 12 and the mixed water path 20. The distribution servo 70 distributes the flow rate of the pre-branch water supply path 12a to the flow rate of the post-branch water supply path 12b (equal to the hot water outflow flow rate from the hot water storage tank 16) and the flow rate of the mixed water path 20, and the distribution ratio thereof. adjust. That is, the distribution servo 70 is in a state in which the total amount of tap water flowing through the pre-branching water supply path 12a flows from the post-branching water supply path 12b to the mixed water path 20 in which the total amount of tap water flowing through the pre-branching water supply path 12a flows through the mixed water path 20. To adjust the distribution ratio. Since the flow rate of the post-branch running water path 12b is equal to the hot water outflow rate from the hot water tank 16, the distribution ratio is the ratio of the amount of hot water flowing through the pre-merging hot water path 26a and the amount of tap water flowing through the mixed water path 20, that is, mixing. Equal to the ratio.

  The water supply path 12 connects the connection port 2 with the water pipe and the bottom of the hot water tank 16, and the pressure reducing valve 4, the tap water thermistor 6, the tap water flow sensor 8, the tap water flow rate in this order from the connection port 2 side. The servo 10, the distribution servo 70, and the second check valve 14 are inserted in this order. The pressure reducing valve 4 keeps the water pressure downstream of the water supply path 12 constant. The constant water pressure is lower than the tap water pressure and lower than the pressure resistance of the hot water tank 16. When the pressure of the water supply path 12 decreases when the pressure reducing valve 4 is discharged from the hot water tap 32 or the like, tap water is introduced into the water supply path 12 to keep the water pressure downstream of the water supply path 12 constant. The tap water thermistor 6 detects the temperature of the tap water. The tap water flow rate sensor 8 detects the flow rate of tap water passing through the pre-branch water supply path 12a. The tap water flow rate servo 10 adjusts the flow rate of tap water passing through the pre-branch water supply path 12a. The second check valve 14 prevents water flow from the hot water storage tank 16 toward the water supply path 12. On the other hand, when the pressure of the water supply path 12 is higher than the pressure of the hot water storage tank 16 and the pressure difference exceeds the reference value, The tap water is allowed to flow from the path 12 to the hot water tank 16.

  The mixed water path 20 is branched from the water supply path 12 by a distribution servo 70 disposed between the tap water flow rate servo 10 and the second check valve 14. The second check valve 14 is disposed in the post-branching water supply path 12b. The second check valve 14 cannot block the water flow from the mixed water path 20 toward the pre-branching water supply path 12a. The tap water flow rate sensor 8 is disposed in the pre-branch water supply path 12 a, and the mixing tap water flows through the mixed water path 20 with the tap water flow rate (equal to the hot water flow rate flowing out of the hot water tank 16) flowing into the hot water storage tank 16. Measure the sum of the flow rates. The tap water flow rate servo 10 is disposed in the pre-branch water supply path 12a, and the tap water flow flowing into the hot water tank 16 (equal to the hot water flow rate flowing out of the hot water tank 16) and the mixed tap water flowing through the mixed water path 20 Controls the sum of the flow rates.

  Connected to the hot water tank 16 is a circulation path 56 that sucks water from the bottom of the hot water tank 16 and returns it to the upper part of the hot water tank 16. In the circulation path 56, a circulation pump 54, a heat exchanger 58, a return thermistor 60, and an electromagnetically driven three-way valve 62 are inserted. The heat exchanger 58 is a high-temperature heat medium that flows through the heat medium path 58 b and heats water sucked from the bottom of the hot water tank 16. The heat medium flowing through the heat medium path 58b is heated by the heat generated by a power generation unit (not shown). Instead of the power generation unit, the heat medium may be heated by a heat pump unit or a solar heat utilization unit. The heated heat medium enters the heat exchanger 58 from the inlet 58c, passes through the heat medium path 58b, returns to the power generation unit or the like from the outlet 58d, and is reheated. The water sucked out from the bottom of the hot water tank 16 is heated while passing through the water path 58 a in the heat exchanger 58, and the heated hot water is returned to the upper part of the hot water tank 16. In the hot water storage tank 16, a temperature stratification is formed in which a high temperature layer is laminated on the cold water layer. When hot hot water continues to be returned to the hot water storage tank 16, the thickness (depth) of the high temperature layer gradually increases, and when the hot water is fully stored, the hot water hot water is stored in the entire hot water storage tank 16. . Even if the hot water storage tank 16 is not fully stored, by forming a temperature stratification, hot hot water stored in the upper part of the hot water storage tank 16 is sent to the hot water passage 26.

  The electromagnetically driven three-way valve 62 switches whether the hot water that has passed through the heat exchanger 58 is returned to the upper part of the hot water tank 16 or returned to the inlet of the heat exchanger 58 using the bypass path 64. If the temperature of the return thermistor 60 is equal to or higher than the reference value, the hot water that has passed through the heat exchanger 58 is returned to the upper part of the hot water tank 16. If the temperature of the return thermistor 60 is less than the reference value, the hot water that has passed through the heat exchanger 58 is returned to the heat exchanger 58.

A hot water path 26 is connected to the upper part of the hot water tank 16 and extends to the hot water tap 32. The hot-water tap 32 is arranged in a bathroom, a washroom, a kitchen, etc. (in FIG. 1, the plurality of hot-water taps 32 are represented by one). A first electromagnetic valve 27 (an example of a first on-off valve), a pre-merging thermistor 28, and a post-merging thermistor 30 are attached to the hot water path 26. The mixed water path 20 joins the warm water path 26 between the thermistor 28 before joining and the thermistor 30 after joining.
The first solenoid valve 27 and the thermistor 28 before joining are arranged in the pre-merging hot water path 26a, and the after-merging thermistor 30 is arranged in the after-merging hot water path 26b. The first solenoid valve 27 switches the pre-merging hot water path 26a between a state where a water flow is allowed to flow and a state where a water flow is not allowed to flow at high speed.

  The mixed water path 20 is branched from the water supply path 12 by the distribution servo 70 and merges with the hot water path 26. A second electromagnetic valve 17 (an example of a second on-off valve) and a first check valve 22 are inserted into the mixed water path 20. The second solenoid valve 17 switches the mixed water path 20 at high speed between a state where the water flow is allowed to flow and a state where the water flow is not allowed to flow. The first check valve 22 prevents water flow from the hot water path 26 toward the water supply path 12, while the pressure of the water supply path 12 is higher than the pressure of the hot water path 26, and when the pressure difference exceeds the reference value, The tap water is allowed to flow from the path 12 to the hot water path 26. When tap water flows from the water supply path 12 to the hot water path 26, the hot hot water and the low temperature tap water flowing out of the hot water storage tank 16 are mixed and the temperature is adjusted. By adjusting the ratio of the flow rate of the pre-merging hot water path 26a and the flow rate of the mixed water path 20, the temperature of the hot water flowing through the post-merging hot water path 26b can be adjusted. The distribution servo 70 can adjust the ratio of the flow rate of the post-branching water supply path 12b (equal to the flow rate of the pre-merging hot water path 26a) and the flow rate of the mixed water path 20, and the temperature of the hot water flowing through the post-merging hot water path 26b. Can be adjusted.

  The hot water supply system includes a controller 66 and adjusts the temperature of hot water sent to the hot water tap 32 to a set temperature. The controller 66 inputs detection values from a thermistor and a flow sensor, and controls a servo, a solenoid valve, and the like. For example, the controller 66 determines the distribution servo 70 from the tap water temperature detected by the tap water thermistor 4, the hot water temperature before joining detected by the thermistor 28 before joining, and the hot water supply set temperature set in the controller 66. The distribution ratio is calculated, and the distribution ratio of the distribution servo 70 is adjusted to the calculated distribution ratio. Thereby, hot water adjusted to the hot water supply set temperature is supplied from the hot water tap 32. The controller 66 controls opening and closing of the first electromagnetic valve 27 and the second electromagnetic valve 17.

  Hot water adjusted to the required temperature can also be supplied to the bathtub 40. The hot water filling path 36 branches off from the hot water path 26b after joining. A hot water filling valve 36 and a hot water filling flow rate sensor 38 are disposed in the hot water filling path 36. The hot water filling path 36 is connected to the bathtub water circulation path 46. The bathtub water circulation path 46 extends from the bathtub 40 and returns to the bathtub 40. A bath pump 42, a water flow sensor 44, a first thermistor 48, a heat exchanger 50, and a second thermistor 52 are disposed in the bathtub water circulation path 46.

  When filling the bathtub 40, the filling valve 34 is opened. Then, the hot water adjusted to the required temperature flows through the hot water filling path 36, flows through the bathtub water circulation path 46 as indicated by the dashed arrow in the figure, and the hot water is sent to the bathtub 40. When the set amount of water or water level is reached, the hot water filling valve 34 is closed.

  When the temperature of the bath water decreases, the bath pump 42 rotates. Then, the bathtub water circulates through the bathtub water circulation path 46 as shown by the solid line arrows in the figure. The circulating bath water passes through the heat exchanger 50. The heat exchanger 50 is a high-temperature heat medium that flows through the heat medium path 50 b and heats the bathtub water that circulates in the bathtub water circulation path 46. The heat medium flowing through the heat medium path 58b is heated by a heat source (not shown). As the heat source, hot water in the hot water storage layer 16, a power generation unit, a heat pump unit, a solar heat utilization unit, or a combustion heater is used. A heat medium heated by a heat source (not shown) enters the heat exchanger 50 from the inlet 50c, passes through the heat medium path 50b, returns to the heat source from the outlet 50d, and is reheated. When the temperature of the bath water drops, it is relegated and the bath water is returned to the set temperature.

  In the illustrated example, the auxiliary heat source machine is not arranged in the post-merging hot water path 26b, but an auxiliary heat source machine may be arranged in the post-merging hot water path 26b. If an auxiliary heat source such as a combustion heater is arranged in the hot water passage 26b after the joining of the hot water filling passage 36 before branching, the hot water stored in the hot water tank 16 is consumed even after the hot water is consumed. You can continue.

  In the first check valve 22 and the second check valve 14, components dissolved in water may be deposited and adhered. As a result, there is a possibility that the first check valve 22 and the second check valve 14 may not open and malfunction may occur despite the pressure difference that causes forward water flow. If a malfunction occurs in the first check valve 22, the mixing tap water stops flowing, the function of adjusting the temperature by mixing the mixing tap water is impaired, and hot water above the hot water supply set temperature is supplied from the hot water tap 32. There is a possibility of bathing.

  FIG. 5 shows a schematic cross section of the check valve, which blocks water flow from port A to port B. When the pressure on the port B side becomes higher than that on the port A side and the pressure difference exceeds the force of the spring 74, the valve 76 is displaced upward and moves away from the valve seat 78. As a result, a water flow from port B toward port A (this direction is referred to as a forward direction) begins to flow. By adjusting the force of the spring 74 and the pressure receiving area S of the valve 76, the pressure at which the check valve 72 starts to allow forward water flow can be adjusted.

  In the present embodiment, a valve having a characteristic that is easier to open than the second check valve 14 when a pressure difference in the forward direction is applied is used as the first check valve 22. That is, when the hot-water tap 32 is opened and hot water supply is started, the first check valve 22 is set to have a relationship in which the forward water flow is allowed earlier than the second check valve 14. As a result, the hot water is not discharged in a state where tap water mixed with warm water to lower the temperature cannot be obtained.

  Further, if the second check valve 14 is less likely to open in the forward direction than the first check valve 22 and does not open in the forward direction, the second check valve 14 has to be operated first. There is a high possibility of malfunction. As a result, the occurrence of a situation in which hot hot water is discharged from the hot water tap 32 due to malfunction of the first check valve 22 is prevented.

  In spite of the above measures, there is no possibility that only the first check valve 22 malfunctions. In this embodiment, since it can be determined that the function of mixing and adjusting the temperature by the thermistor 30 after merging is lost, the first electromagnetic valve 27 is closed when it is detected. In addition, the distribution servo 70 may be switched to a state in which the entire amount of tap water flowing through the pre-branching water supply path 12 a flows through the mixed water path 20. Double and triple measures are taken to prevent hot hot water from coming out of the hot water tap 32. The present technology is one measure for preventing the occurrence of a malfunction by using the first check valve 22 having the characteristic that it is easier to open in the forward direction than the second check valve 14, and it is a measure to be taken by itself. is not.

  In the present embodiment, when the hot water filling valve 34 is opened and the tap water flow sensor 8 detects the flow rate, the controller 66 opens the first electromagnetic valve 27 and adjusts the distribution ratio of the distribution servo 70. The second electromagnetic valve 17 is normally open. In the present embodiment, when the hot water adjusted to the hot water set temperature starts to be supplied to the bathtub 40, the first electromagnetic valve 27 is closed for a short time, and then the second electromagnetic valve 17 is closed for a short time. A program for executing the processing procedure is stored in the controller 66.

  When the first solenoid valve 27 (first on-off valve) is closed during the hot water filling operation, the hot water flowing through the hot water filling passage 36 continues to flow due to its inertial energy, and the hot water passage 26 side of the first check valve 22 The pressure drops. As a result, even if a malfunction occurs in which the first check valve 22 does not open in the forward direction, the first check valve 22 can be opened by applying a large pressure difference to the first check valve 22. it can. When the first check valve 22 is opened, a large flow of tap water flows through the mixed water path 20 because the first electromagnetic valve 27 is closed. As a result, the first check valve 22 opens greatly in the forward direction. When a large amount of tap water passes through the first check valve 22 that is wide open, foreign matter or the like adhering to the first check valve 22 is removed. The first check valve 22 is cleaned by closing the first solenoid valve 27 during the hot water operation. When the first electromagnetic valve 27 is closed, hot water is not discharged from the hot water tank 16 and the hot water supply temperature is lowered. There is no problem even if low temperature water is temporarily supplied to the bathtub 40 during hot water filling operation. During the hot water operation, the first electromagnetic valve 27 is temporarily closed regardless of whether or not the first check valve 22 is malfunctioning. Thus, the first check valve 22 is cleaned during the hot water filling operation.

  After the first solenoid valve 27 is temporarily closed during the hot water filling operation, the second solenoid valve 17 (second on-off valve) is temporarily closed. When the second electromagnetic valve 17 is closed, the hot water flowing through the hot water filling passage 36 continues to flow due to its inertial energy, and the pressure on the hot water storage tank 16 side of the second check valve 14 decreases. As a result, even if a malfunction occurs in which the second check valve 14 does not open in the forward direction, the second check valve 14 can be opened by applying a large pressure difference to the second check valve 14. it can. When the second check valve 14 is opened, since the second electromagnetic valve 17 is closed, a large amount of tap water flows through the post-branching water supply path 12b. As a result, the second check valve 14 opens greatly in the forward direction. When a large amount of tap water passes through the second check valve 14 that is wide open, foreign matter or the like adhering to the second check valve 14 is removed. The second check valve 14 is cleaned by closing the second electromagnetic valve 17 during the hot water operation. When the second solenoid valve 17 is closed, the hot water supply temperature rises. There is no problem even if hot water is temporarily supplied to the bathtub 40 during hot water filling operation. During the hot water filling operation, the second electromagnetic valve 17 is temporarily closed regardless of whether or not the second check valve 14 is malfunctioning. As a result, the second check valve 14 is cleaned during the filling operation.

  If the first electromagnetic valve 27 is closed or the second electromagnetic valve 17 is closed, the temperature of the post-merging hot water flowing in the post-merging hot water path 26b becomes unstable. In the case of hot water filling operation, since a certain amount of bathtub water is stored in the bathtub and then heated to adjust to an appropriate temperature, the temperature of the post-merging hot water flowing through the post-merging hot water path 26b is temporarily unstable. It doesn't matter.

  In this embodiment, the first check valve 22 is cleaned by closing the first solenoid valve 27 (first on-off valve), and a valve having a characteristic that is easier to open in the forward direction than the second check valve 14 is used. The use of the first check valve 22 prevents the first check valve 22 from being opened in the forward direction.

In this embodiment, when the hot-water tap 32 is opened and the tap water flow sensor 8 detects the flow rate, the controller 66 opens the first electromagnetic valve 27 and adjusts the distribution ratio of the distribution servo 70. The second electromagnetic valve 17 is normally open. If a malfunction occurs in which the first check valve 22 does not open in the forward direction, the post-merger thermistor 30 detects a temperature higher than the set temperature. In that case, in order to prevent hot water higher than the set temperature from being supplied, the first electromagnetic valve 27 is closed for a short time. A program for executing the processing procedure is stored in the controller 66. Even when the first electromagnetic valve 27 is fully closed, the warm water in the warm water path 26 continues to flow due to its inertial energy, and the pressure on the warm water path 26 side of the first check valve 22 decreases. As a result, even if a malfunction occurs in which the first check valve 22 does not open in the forward direction, the first check valve 22 can be opened by applying a large pressure difference to the first check valve 22. it can. The first solenoid valve 27 is closed for a short time and then opened again. When the joined thermistor 30 detects the set temperature after opening again, it can be determined that the malfunction of the first check valve 22 has been eliminated, and the hot water supply operation can be continued. If the joined thermistor 30 detects a temperature equal to or higher than the set temperature after the first electromagnetic valve 27 is opened again, it can be determined that the malfunction of the first check valve 22 has not been eliminated. In this case, the first solenoid valve 27 is closed and the hot water supply operation is stopped.
In the above embodiment, the first electromagnetic valve 27 is inserted into the pre-merging hot water path 26a. Since the flow rate of the hot water path 26a before joining and the flow rate of the post-branching water supply path 12b are equal, the first electromagnetic valve 27 may be inserted into the post-branching water supply path 12b. A distribution servo 70 may be provided at the junction of the mixed water path 20 and the hot water path 26.

  FIG. 2 shows a system diagram of the hot water supply system according to the second embodiment. The same members as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. In the second embodiment, instead of the distribution servo 70, the hot water flow rate servo 24 is inserted into the pre-merging hot water passage 26a, and the mixed water flow rate servo 18 is inserted into the mixed water passage 20. The warm water flow rate servo 24 adjusts the flow rate of warm water flowing through the pre-merging warm water path 26a. The mixed water flow rate servo 18 adjusts the flow rate of the mixing tap water flowing through the mixed water path 20. Both the hot water flow rate servo 24 and the mixed water flow rate servo 18 constitute a mixing ratio adjuster that adjusts the ratio of the flow rate of hot water flowing through the pre-merging hot water passage 26 a and the flow rate of mixing tap water flowing through the mixed water passage 20. ing.

  In the present embodiment, the first electromagnetic valve 27 and the hot water flow rate servo 24 are arranged in the pre-merging hot water path 26a. The hot water flow rate flowing out of the hot water tank 16 is equal to the tap water flow rate flowing into the hot water tank 16. Therefore, the first electromagnetic valve 27 may be inserted into the post-branching water supply path 12b. Further, instead of the hot water flow rate servo 24, a tap water flow rate servo may be inserted into the post-branching water supply path 12b. By adjusting both the tap water flow rate servo and the mixed water flow rate servo 18 inserted into the post-branching water supply path 12b, the ratio of the flow rate of the hot water flowing through the pre-merging hot water path 26a and the flow rate of mixing tap water flowing through the mixed water path 20 is adjusted. The mixing ratio adjuster can be used.

In the second embodiment, the relationship between the first check valve 22 and the second check valve 14 is the same as that in the first embodiment. In addition, when the hot water adjusted to the hot water setting temperature starts to be supplied to the bathtub 40, the first electromagnetic valve 27 is closed to block outflow of hot water from the hot water tank 16. When the outflow of warm water from the hot water tank 16 is blocked, the pressure on the warm water path side of the first check valve 22 decreases and the pressure on the water supply path side increases. The forward pressure difference acting on the first check valve 22 increases. As a result, even if the first check valve 22 malfunctions, the first check valve 22 opens greatly in the forward direction and is cleaned.
In the present embodiment, after that, the second electromagnetic valve 17 is closed to block the mixing tap water flowing through the mixed water path 20. When the flow of mixing tap water flowing through the mixed water path 20 is interrupted, the pressure on the hot water storage tank side of the second check valve 14 decreases and the pressure on the water supply path side increases. The forward pressure difference acting on the second check valve 14 increases. As a result, even if a malfunction occurs in the second check valve 14, the second check valve 14 opens greatly in the forward direction and is cleaned.
When the post-merger thermistor 30 detects a temperature higher than the set temperature, the first electromagnetic valve 27 is closed for a short time so that the entire amount of tap water flowing through the pre-branching water supply path 12a flows into the mixed water path 20. The outflow of warm water from the hot water tank 16 is blocked. As a result, the forward pressure difference acting on the first check valve 22 increases. As a result, even if the first check valve 22 malfunctions, the first check valve 22 opens greatly in the forward direction and is cleaned. If the joined thermistor 30 detects the set temperature by this process, it can be determined that the malfunction of the first check valve 22 has been eliminated, and the hot water supply operation can be continued.

  In the third embodiment, as shown in FIG. 3, the first electromagnetic valve 27 and the second electromagnetic valve 17 are removed from the first embodiment. In this embodiment, the distribution servo 70 switches the total amount of tap water flowing through the pre-branching water supply path 12 a to the mixed water path 20 to switch to the same state as when the first electromagnetic valve 27 is closed. In addition, the distribution servo 70 switches the entire amount of tap water flowing through the pre-branching water supply path 12a to the post-branching water supply path 12b and the pre-merging hot water path 26a, thereby switching to the same state as when the second electromagnetic valve 17 is closed. . The distribution servo 70 realizes a first on-off valve that closes the post-branching water supply path 12 b or the pre-merging hot water path 26 a and a second on-off valve that closes the mixed water path 20. If the operating speed of the distribution servo 70 is sufficient, it is not necessary to provide a solenoid valve separately from the distribution servo 70.

As shown in FIG. 4, the fourth embodiment is obtained by removing the first electromagnetic valve 27 and the second electromagnetic valve 17 from the second embodiment. In this embodiment, the hot water flow rate servo 24 obtains the same result as when the first electromagnetic valve 27 is closed. Further, the same result as when the second electromagnetic valve 17 is closed by the mixed water flow rate servo 18 is obtained. The hot water flow rate servo 24 also serves as a first on-off valve that closes the post-branching water supply path 12 b or the pre-merging hot water path 26 a, and the mixed water flow rate servo 18 also serves as a second on-off valve that closes the mixed water path 20. If the operation speeds of the hot water flow rate servo 24 and the mixed water flow rate servo 18 are sufficient, it is not necessary to provide a solenoid valve separately from the hot water flow rate servo 24 and the mixed water flow rate servo 18.
(Other examples)

  The hot water supply system of FIGS. 1-4 is not provided with the auxiliary heat source machine. You may add an auxiliary heat source machine to the hot water path | route 26b after joining. By adding an auxiliary heat source machine, hot water can be continued even after the hot water stored in the hot water runs out. The hot water supply system of FIGS. 1 to 4 supplies hot water to the hot water tap 32 and the bathtub 40. In addition to this, a hot water supply system for supplying hot water to the heating system may be used.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: Connection port 4: Pressure reducing valve 6: Tap water thermistor 8: Tap water flow rate sensor 10: Tap water flow rate servo 12: Water supply path 12a: Water supply path before branch 12b: Water supply path after branch 14: Second check valve 16: Hot water storage tank 17: 2nd solenoid valve 18: Mixed water flow rate servo 20: Mixed water flow path 22: First check valve 24: Hot water flow rate servo 26: Hot water flow path 26a: Pre-merging hot water path 26b: Post-merging hot water path 27: No. 1 Solenoid valve 28: Thermistor 30 before joining Thermistor 32 after joining 32: Hot water tap 34: Hot water filling valve 36: Hot water filling path 38: Hot water filling flow rate sensor 40: Bathtub 42: Bath pump 44: Water flow sensor 46: Bath water circulation path 48 : First thermistor 50: heat exchanger 52: second thermistor 54: circulation pump 56: circulation path 58: heat exchanger 60: return thermistor 62: electromagnetically driven three-way valve 64: bypass path 66: co Controller 68: hot water system 70: distribution Servo

Claims (3)

A hot water tank,
A water supply route for feeding tap water into the hot water tank,
A hot water path through which hot water flowing out of the hot water tank passes,
A mixed water path that branches off from the water supply path and joins the warm water path;
A mixing ratio adjuster that adjusts the ratio of the flow rate of the hot water path and the flow rate of the mixed water path before the mixed water path merges;
When the pressure of the water supply path is higher than the pressure of the hot water path, the water flow from the water supply path to the hot water path is allowed by the pressure difference, and the water flow from the hot water path to the water supply path is A first check valve to block;
A first on-off valve that is inserted into a water supply path after the mixed water path branches or a warm water path before the mixed water path merges, and can close the path;
A water temperature sensor disposed in the hot water path after the mixed water path has joined,
When the detected value of the water temperature sensor exceeds a predetermined value, the first on-off valve is closed and opened, and when the detected value of the water temperature sensor detected thereafter exceeds the predetermined value, the first on-off valve is closed. Hot water supply system characterized by A hot water tank,
A water supply route for feeding tap water into the hot water tank,
A hot water path through which hot water flowing out of the hot water tank passes,
A mixed water path that branches off from the water supply path and joins the warm water path;
A mixing ratio adjuster that adjusts the ratio of the flow rate of the hot water path and the flow rate of the mixed water path before the mixed water path merges;
When the pressure of the water supply path is higher than the pressure of the hot water path, the water flow from the water supply path to the hot water path is allowed by the pressure difference, and the water flow from the hot water path to the water supply path is A first check valve to block;
It is inserted into the water supply path after the mixed water path branches or the warm water path before the mixed water path merges, and has a first on-off valve that can close the path,
The hot water path leads to a bathtub through a hot water path,
A hot water supply system, wherein the first on-off valve is closed and then opened while warm water is being sent to the bathtub. When the mixed water path is inserted into the water supply path after branching and the pressure of the water supply path is higher than the pressure of the hot water tank, the water flow from the water supply path to the hot water tank is allowed by the pressure difference, and the hot water tank A second check valve for blocking water flow from the water to the water supply path;
A second on-off valve that is inserted in the mixed water path and can close the path is added;
The hot water supply system according to claim 2, wherein the second on-off valve is opened after being closed while hot water is being sent to the bathtub.

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