JP2012220143A - Mixing instantaneous hot-water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixing instantaneous hot water supply system that instantaneously supplies mixed hot water of an intermediate temperature without wastefully using hot-water/water, and supplies hot water of a set temperature or less from a mixing hot water supply opening at all times irrespective of use conditions.SOLUTION: This mixing instantaneous hot water supply system 1 includes a return pathway (arrow C) branched from the way of a mixing hot water return pathway (arrow B) for returning hot-water/water in a mixing hot water return pipe 8 to a mixing hot water supply pipe 6, and further includes a first mixing valve 91 for mixing hot water in a hot water return pipe 90 and the water of a water supply branch pipe 74 branched from a water supply pipe 71, in the return pathway. A temperature of hot-water/water flowing in the mixing valve inflow pipe 92 is kept at a prescribed temperature or less by adjusting an opening of the first mixing valve 91. Thus this mixing instantaneous hot water supply system 1 can instantaneously supply the mixed hot water of intermediate temperature, and supplying the hot water/water of the set temperature or less from the mixing hot water supply opening 60 at all times regardless of use states.

Description

  The present invention relates to a mixed hot water system that can immediately discharge hot water of medium temperature.

Conventionally, there is a hot water supply system in which water is boiled by a heat pump and hot water stored in a hot water storage tank is supplied to a hot water use terminal such as a currant or a dishwasher. In this heat pump, a high pressure is applied to a natural refrigerant such as a CO ₂ refrigerant by a pressurizing machine to raise the natural refrigerant to a high temperature, and the heat is used to boil hot water. Since atmospheric heat can be used, hot water is more efficiently used. And CO ₂ emissions can be reduced.

  And the mixing instant hot water system which can discharge hot water of medium temperature immediately without wasting hot water is known (for example, refer patent document 1). As shown in FIG. 7, in this mixed quick hot water system 100, the mixed return hot water pipe 181 is connected to the mixing valve inlet pipe 165 without being connected to the hot water storage tank 120.

  When the hot water return pump 182 is driven, a part of the hot water in the mixed hot water pipe 168 is mixed through the mixed hot water pipe 181 and the mixing valve water inlet pipe 165 along the path indicated by the arrow D in the figure. The water is returned to 166. The remaining hot water in the mixed hot water pipe 168 is returned to the lower layer of the hot water storage tank 120 through the mixed hot water pipe 181, the mixing valve water inlet pipe 165, and the water supply pipe 171 along the path indicated by arrow E in the drawing. . In addition, the hot water is returned to the mixing valve 166 through the three-way valve 163 and the mixing valve hot water inlet pipe 164 through the high temperature hot water outlet pipe 161 or the intermediate temperature hot water outlet pipe 162. The control unit 104 adjusts the mixing ratio of hot water from the mixing valve inlet pipe 164 and feed water from the mixing valve inlet pipe 165 by the mixing valve 166 so that the hot water temperature of the mixed hot water detected by the temperature sensor 169 becomes the set temperature. is doing.

  In the mixed hot water system 100 shown in FIG. 8, hot water that has not been used from the high temperature hot water supply pipe 105 and the mixed hot water supply pipe 106 is returned to the middle layer of the hot water storage tank 120 via the mixed hot water supply pipe 181. It has a structure.

Japanese Patent Application No. 2009-266957

  However, in the conventional mixed hot water system 100 described above, the temperature of the return hot water flowing through the mixed hot water pipe 181 at the time of the mixed hot water becomes high, and the temperature of the mixed valve water supply pipe 165 on the water side of the mixing valve 166 exceeds the set temperature. Hot water may be supplied. In that case, there is a possibility that hot water supply from the mixed hot water supply port 167 at a set temperature or lower cannot be performed. In addition, there is also a problem in that hot water storage tank 120 increases the amount of medium-temperature water lower than the temperature that can be used for mixed hot water, and runs out of hot water at mixed hot water supply port 167 during mixed hot water.

  Furthermore, when boiling water is heated by a heating method using a heat pump cycle, the lower the temperature of the water before boiling, the lower the heating efficiency of the heat pump can be prevented, which is economical. The conventional mixed hot water system 100 also has a problem that the hot water stays in the lower part of the hot water storage tank 120 as medium-temperature water during the hot water and lowers the boiling efficiency of the heat pump 103.

  The present invention has been made in view of the above-mentioned problems, and immediately discharges hot water (instant water) without wasting hot water, regardless of the state of use. The purpose is to provide a mixed instant hot water system that can supply hot water.

  In order to achieve the above object, the present invention provides a high temperature hot water supply pipe for supplying high temperature hot water in a hot water storage tank, and a mixed hot water mixed with high temperature hot water or medium temperature hot water in the hot water storage tank and water from the water supply pipe through a mixed hot water outlet. A mixed hot water system comprising: a mixed hot water pipe for supplying hot water; and a mixed hot water system for returning hot water in the mixed hot water pipe to the hot water storage tank for immediate hot water from the mixed hot water outlet. A return path that branches off from the middle of the path and returns the hot water in the mixed hot water return pipe to the mixed hot water supply pipe, and this return path includes the hot water in the mixed hot water return pipe and the water supply pipe in the path. A first mixing valve for mixing the water of the branched water supply branch pipe is provided, and hot water of a predetermined temperature or less is supplied to the mixed hot water pipe by adjusting the opening of the first mixing valve. .

  In this mixed hot water system, the route of the mixed hot water pipe includes a high temperature hot water pipe branched from the high temperature hot water pipe, an intermediate hot water pipe for discharging hot water in the hot water storage tank, the high temperature hot water pipe and an intermediate hot water pipe, A first three-way valve that connects the two, a mixing valve inlet pipe that feeds hot water from the first three-way valve, hot water from the mixing valve inlet pipe, and water from a mixing valve inlet pipe that constitutes the return path A second mixing valve for mixing, and a mixed hot water pipe for discharging the hot water mixed by the second mixing valve from the mixed hot water supply port, and the return path is branched from the middle of the mixed hot water pipe, Corresponding to the temperature of hot water supplied from the mixing hot water supply port, having a return hot water pipe connected to the first mixing valve and the mixing valve inlet pipe connecting the first mixing valve and the second mixing valve A controller that adjusts the opening of the first mixing valve based on the signal Preferred.

  In this mixed hot water system, the mixing valve inlet pipe is provided with a temperature sensor, and the control unit adjusts the valve opening of the first mixing valve based on a detection value from the temperature sensor, and the mixing valve inlet It is preferable to set the temperature of the hot water flowing through the water pipe to a predetermined temperature or lower.

  In this mixed immediate hot water system, a second three-way valve provided in the intermediate temperature hot water pipe for branching a part of the hot water in the pipe, and a hot water in the intermediate temperature hot water pipe branched by the second three way valve It is preferable to further comprise a branched hot water intermediate temperature pipe that sends the hot water to the hot water pipe.

  According to the mixed hot water system according to the present invention, hot water at a predetermined temperature or less is supplied to the mixed hot water pipe by adjusting the opening of the mixing valve provided in the return path for returning the hot water in the mixed hot water pipe to the mixed hot water pipe. . For this reason, while mixing hot water of medium temperature immediately, hot water below preset temperature can always be supplied from a mixing hot-water supply port irrespective of a use condition.

It is a block diagram of the mixed instant hot water system which concerns on Embodiment 1 of this invention. It is a flowchart which shows the operation | movement procedure of a mixed instant hot water system same as the above. It is a block diagram of the mixed instant hot water system which concerns on the 1st modification of Embodiment 1 same as the above. It is a flowchart which shows the operation | movement procedure of a mixed instant hot water system same as the above. It is a block diagram of the mixing instant hot water system which concerns on Embodiment 2 of this invention. It is a flowchart which shows the operation | movement procedure of a mixed instant hot water system same as the above. It is a block diagram of the conventional mixed hot water system. It is a block diagram of another conventional mixed hot water system.

  A mixed hot water system according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
The mixed hot water system according to Embodiment 1 of the present invention will be described with reference to FIG. The mixed instant hot water system 1 includes a hot water storage tank 2 that stores water and heated hot water, a heat pump 3 that heats the water in the hot water storage tank 2, and a control unit 4 that controls opening and closing operations of the heat pump 3 and valves. The piping of the mixed hot water system 1 includes a hot water supply pipe 5 for supplying hot water in the hot water storage tank 2, a mixed hot water pipe 6 for supplying mixed hot water, and a hot water storage tank for the hot water in the mixed hot water pipe 6 for the hot water. 2 and the like, and a return pipe 9 for returning the hot water from the mixed hot water pipe 8 to the mixed hot water pipe 6. In addition, high temperature hot water is about 75 degreeC or more hot water, and mixed hot water is about 35-45 degreeC hot water.

  The hot water storage tank 2 has a function of supplying water to the heat pump 3 via the pipe 72 and storing hot water heated by the heat pump 3 while keeping high temperature using a high-performance heat insulating material. The side wall of the hot water storage tank 2 has a plurality of temperature sensors 21 from the upper part to the lower part, and the temperature sensor 21a, which is one of them, detects the temperature of the middle layer part (intermediate temperature part). The lower layer portion of the hot water storage tank 2 is connected to a water supply pipe 71 that supplies water.

  The heat pump 3 has a pump 31 that sends heated hot water to the hot water storage tank 2. The heat pump 3 is connected to the upper layer portion of the hot water storage tank 2 via a pipe 73 and supplies heated hot water to the upper layer portion of the hot water storage tank 2. The lower layer portion of the hot water storage tank 2 is connected to the heat pump 3 via a pipe 72, and the lower layer water of the hot water storage tank 2 is heated by the heat pump 3.

  The control unit 4 controls the heat pump 3 and sends control signals for adjusting the valve opening based on information such as the temperature detected by the temperature sensor 21 to the first three-way valves 63 and 82 and the second mixing valve 65, The function to transmit to 91 is provided. The first three-way valves 63 and 82 and the second mixing valves 65 and 91 automatically change the valve opening based on the control signal.

  The upper layer portion of the hot water storage tank 2 is connected to a high temperature hot water supply port 50 through a high temperature hot water supply pipe 5, and the high temperature hot water supply pipe 5 is provided with a temperature sensor 52 that detects the temperature of the hot water in the pipe. Further, a high temperature hot water return pipe 53 for returning hot water in the high temperature hot water supply pipe 5 to the hot water storage tank 2 is branched from the vicinity of the high temperature hot water supply opening 50 of the high temperature hot water supply pipe 5. Connected to the three-way valve 82.

  Next, the main route of the piping in the mixed hot water system 1 will be described with reference to the drawings. The mixed hot water system 1 includes a mixed hot water supply path including the mixed hot water supply pipe 6 (corresponding to arrow A), a mixed hot water path including the mixed hot water pipe 8 for immediate hot water (arrow B), and a return pipe 9. A return path (arrow C) is provided.

  The mixed hot water supply path (arrow A) is a path for supplying hot water from the mixed hot water inlet 60 by mixing hot water or hot water in the hot water storage tank 2 and hot water from the mixing valve inlet pipe 92. Specifically, the mixed hot water supply path includes a high temperature hot water discharge pipe 61 for discharging hot water in the hot water storage tank 2, an intermediate temperature hot water discharge pipe 62 for discharging hot water in the hot water storage tank 2, a high temperature hot water discharge pipe 61 and an intermediate temperature hot water discharge pipe 61. A first three-way valve 63 that connects the two, a mixing valve inlet pipe 64 that is connected to the first three-way valve 63 and supplies hot water, a hot water from the mixing valve hot water pipe 64 and a water that mixes the water from the mixing valve water inlet pipe 92. 2 has a mixing valve 65 and a mixed hot water pipe 66 for discharging hot water mixed by the second mixing valve 65 from the mixed hot water supply port 60.

  The mixed hot water supply path (arrow B) is a path for returning the hot water in the mixed hot water supply pipe 6 to the hot water storage tank 2 in order to immediately hot water from the mixed hot water supply port 60. The mixed hot water pipe 66 is provided with a temperature sensor 69 for detecting the temperature of the hot water in the pipe. The hot water in the mixed hot water pipe 66 is returned to the hot water storage tank 2 from the vicinity of the mixed hot water supply port 60 of the mixed hot water pipe 66. The mixed hot water pipe 81 is branched. The mixed hot water path includes the mixed hot water pipe 81, a third three-way valve 82 provided in the middle of the mixed hot water pipe 81, an instant hot water pump 83 for flowing hot water in the pipe, and a reverse flow of hot water in the pipe when stopped. A check valve 84 and a branch hot water intermediate temperature pipe 85 branched in the middle of the hot water return pipe 90 and connected to the intermediate temperature layer of the hot water storage tank 2 are provided.

  The return path (arrow C) is a path that branches from the middle of the path of the mixed hot water pipe 8 and returns the hot water in the mixed hot water pipe 8 to the mixed hot water pipe 6. This return path includes a first mixing valve 91 for mixing the hot water in the mixed hot water return pipe 8 and the water in the feed water branch pipe 74 branched from the feed water pipe 71. Based on the hot water temperature detected by the temperature sensor 69, the control unit 4 adjusts the valve opening degrees of the first mixing valve 91 on the hot water return pipe 90 side and the feed water branch pipe 74 side, so that the first mixing valve The temperature of the hot water flowing through the mixing valve inlet pipe 92 connecting the 91 and the second mixing valve 65 is controlled below a predetermined temperature. As a result, hot water of a predetermined temperature or less is always supplied to the mixed hot water supply pipe 6 through the mixing valve water supply pipe 92.

  Next, the operation of the mixed hot water control of the mixed hot water system 1 according to Embodiment 1 will be described with reference to FIG.

  First, at the start of the mixed hot water, it is necessary to open the third three-way valve 82 to the mixed return hot water pipe 81 side and operate the immediate hot water pump 83 to circulate hot water. Accordingly, the control unit 4 transmits a control signal to the third three-way valve 82, switches the opening of the third three-way valve 82 to the mixed hot water pipe 8 (S21), and the hot water in the mixed hot water pipe 6 is discharged. The hot water pump 83 is operated for the amount of replacement.

  Next, the control unit 4 determines whether or not the temperature T1 of the middle layer of the hot water storage tank 2 detected by the temperature sensor 21a satisfies T1 ≧ Tmw + 5 (° C.) (S22). Here, Tmw (° C.) is a mixed set temperature (for example, 35 ° C.) used for the mixed hot water supply, and is set by the user using, for example, a remote controller. Note that +5 (° C.) in the above T1 ≧ Tmw + 5 (° C.) is a temporary value, and other numerical values may be used.

  Then, when the temperature detected by the temperature sensor 69 does not satisfy the above condition (No in S22), the control unit 4 switches the first three-way valve 63 to the high temperature tap pipe 61 side (S23). On the other hand, when satisfy | filling the said conditions (it is Yes at S22), the control part 4 switches the 1st three-way valve 63 to the intermediate temperature hot water pipe 62 side (S24). By this adjustment, when the temperature of the middle layer of the hot water storage tank 2 is higher than the mixed set temperature Tmw + 5 (° C.), the hot water of the middle layer of the hot water storage tank 2 is opened by opening the first three-way valve 63 toward the intermediate temperature hot water discharge pipe 62. It can be supplied as hot water for the mixing valve 63. When the temperature of the middle layer of the hot water storage tank 2 is lower than the set mixing temperature Tmw + 5 (° C.), the hot water of the upper layer of the hot water storage tank 2 is mixed by opening the first three-way valve 63 to the high temperature hot water discharge pipe 61 side. 63 hot water can be supplied.

  Next, the control part 4 controls the valve opening degree of the mixing valve inlet pipe 64 and the mixing valve inlet pipe 92 so as to circulate the second mixing valve 65 at the set temperature Tmw (° C.) (S25). Further, the control unit 4 opens the first mixing valve 91 that connects the hot water flowing through the mixing valve inlet pipe 92 to the water supply branch pipe 74 and the hot water return pipe 90 so as to be Tmw-10 (° C.) that is low temperature water. The degree is adjusted (S26). That is, the hot water returned through the mixed water return pipe 8 is supplied to the mixing valve inlet pipe 92 via the feed water branch pipe 74 in the first mixing valve 91 at a temperature (Tmw-10 (° C.) lower than the set temperature Tmw (° C.). )) Is supplied. The remaining amount of hot water is returned to the middle layer (intermediate temperature portion) of the hot water storage tank 2 through the branch hot water intermediate temperature pipe 85. In addition, 10 (degreeC) in Tmw-10 (degreeC) in a flow is a temporary value, and it becomes possible to set another temperature.

  And the control part 4 drives the hot water pump 83 (S27), and replaces the hot water of the mixed hot water supply pipe 6. Further, the control unit 4 confirms whether or not the replacement of the hot water in the mixed hot water supply pipe 6 has been completed (S28), and if it has been completed (Yes in S28), stops the immediate hot water pump 83 ( S29), it is possible to start the hot water (immediate hot water) from the mixed hot water supply port 60 (S30).

  As described above, the path of the mixed hot water pipe 8 of the mixed hot water system 1 includes a return path that branches from the middle of the mixed hot water pipe 8 and returns hot water to the mixed hot water pipe 6. Is provided with a first mixing valve 91 for mixing hot water in the mixed return hot water path and water in the feed water branch pipe 74. The control part 4 can always set the return hot water temperature in the mixing valve inlet pipe 92 in the case of an instant hot water to below predetermined temperature by adjusting the opening degree of the 1st mixing valve 91. FIG. For this reason, at the time of mixing hot water, even if the return hot water temperature from the mixed return hot water pipe 8 is high, the temperature rise of the hot water in the mixing valve inlet pipe 92 is suppressed, and the hot water supply temperature from the mixed hot water supply port 60 becomes higher than the set value. It is possible to prevent the rise and improve safety.

(First modification)
A first modification of the first embodiment will be described with reference to FIGS. In this modification, as shown in FIG. 3, the mixed quick water system 1 according to the first embodiment is further provided with a temperature sensor 93 in the middle of the mixing valve inlet pipe 92.

  The operation of the mixed instant hot water system 1 according to this modification will be described with reference to FIG. In FIG. 4, the same processing flow as that in FIG. 2 is denoted by the same reference numeral, and detailed description thereof is omitted.

  In this modification, it is confirmed whether or not the hot water replacement process of the mixed hot water supply pipe 6 has been completed (S28). If the hot water replacement of the mixed hot water supply pipe 6 has not been completed (No in S28), the control unit 4 Confirms whether the temperature T2 of the temperature sensor 93 satisfies T2 ≦ Tmw−10 (° C.) (S31). If this condition is not satisfied (No in S31), the first mixing valve 91 is used to perform correction control of the temperature of hot water that enters the mixing valve inlet pipe 92 (S32). That is, the control unit 4 can feedback-control the valve opening degree of the first mixing valve 91 based on the temperature T2 detected by the temperature sensor 93 provided in the mixing valve inlet pipe 92.

  Therefore, in this modification, the feed water temperature from the mixing valve inlet pipe 92 to the second mixing valve 65 is always stabilized below the set value, and as a result, the temperature control performance in the second mixing valve 65 is improved, and the second The temperature of the hot water flowing from the mixing valve 65 through the mixed hot water pipe 66 can be stabilized.

(Embodiment 2)
Hereinafter, Embodiment 2 of the mixed instant hot water system according to the present invention will be described with reference to FIGS. 5 and 6. In addition, the same code | symbol is attached | subjected to the structure similar to the mixing instant hot water system 1 which concerns on the said Embodiment 1, and the detailed description is abbreviate | omitted.

  In the hot water system 1 according to Embodiment 1 described above, when mixed hot water is used, the amount of hot water returned to the hot water storage tank 2 side from the branched hot water intermediate temperature pipe 85 increases, and the hot water storage tank 2 may increase the hot water temperature. There is. And since this intermediate temperature water becomes temperature lower than the hot water supply temperature from the mixed hot water supply port 60, it cannot be used for hot water supply at the time of immediate hot water. Moreover, when the water temperature in the hot water storage tank 2 is high, the heating efficiency (coefficient of performance) at the time of boiling by the heating method using the heat pump cycle is contrary to the disadvantage that the boiling efficiency of the heat pump 3 is lowered. In particular, when boiling in the heat pump 3 is started in a state where there is remaining hot water in the hot water storage tank 2, the remaining hot water stays in the lower part of the hot water storage tank 2 as intermediate temperature water, and there is a problem that heating efficiency is further reduced.

  In order to solve this problem, in the mixed instant hot water system 1, a second three-way valve 100 provided in the intermediate temperature hot water pipe 62 for branching a part of the hot water in the intermediate temperature hot water pipe 62, and a second three way valve 100. The hot water in the intermediate hot water hot water pipe 62 branched by the branch hot water intermediate temperature pipe 101 for sending the hot water in the hot water return pipe 90 and the check valve 102 for preventing the back flow of hot water in the branched hot water intermediate temperature pipe 101 are provided. That is, a path that bypasses to the hot water return pipe 90 side is provided in the intermediate temperature hot water supply pipe 62.

  Next, the operation of the mixed hot water control of the mixed hot water system 1 according to the second embodiment will be described with reference to FIG. First, the control unit 4 determines whether or not the temperature T1 detected by the temperature sensor 21a satisfies T1 ≧ Tmw + 5 (° C.) (S22).

  When this condition is not satisfied (No in S22), the temperature of the central portion of the hot water storage tank 2 is lower than the set mixing temperature. Therefore, the control unit 4 opens the first three-way valve 63 toward the high temperature hot water discharge pipe 61 (S23), and supplies hot water in the upper part of the hot water storage tank 2 as high temperature water for the second mixing valve 65. In addition, the control unit 4 switches the valve direction of the second three-way valve 100 to the branched hot water intermediate temperature pipe 101 side (S61). In this case, water is supplied from the water supply pipe 71 to the bottom of the hot water storage tank 2 and is returned to the high temperature side of the first mixing valve 91 via the branched hot water intermediate temperature pipe 101 provided on the side of the hot water storage tank 2. Hot water is passed through the hot water pipe 90. Then, the hot water in the return hot water pipe 90 and the water in the feed water branch pipe 74 are mixed using the first mixing valve 91, and hot water that is lower than the set mixing temperature by a certain temperature (for example, 10 ° C.) is mixed through the mixing valve water inlet pipe 92. Supply to the low temperature side of the valve 65.

  On the other hand, when the above conditions are satisfied (Yes in S22), the temperature of the central portion of the hot water storage tank 2 is higher than the set mixing temperature. Therefore, the control unit 4 opens the first three-way valve 63 toward the intermediate temperature hot water pipe 62 (S24), and supplies the hot water at the center of the hot water storage tank 2 as the high temperature water of the second mixing valve 65. The valve 100 is switched to the first three-way valve 63 side (S62).

  Next, the control unit 4 connects the hot water flowing through the mixing valve inlet pipe 92 to the water supply branch pipe 74 and the hot water return pipe 90 so as to be Tmw-10 (° C.) which is low temperature water. The opening is adjusted (S63). And the control part 4 controls the valve opening degree of the mixing valve inlet water pipe 64 and the mixing valve inlet pipe 92 so that the 2nd mixing valve 65 may be circulated by temperature Tmw (degreeC) (S64). Here, the control unit 4 determines whether there is mixed hot water supply (S65). In addition, the process of the following S31 and S32 becomes the same as that of the case of the said modification.

  As described above, in the instant mixed hot water system 1, medium-temperature water having a temperature equal to or lower than the mixed hot water temperature that cannot be used at the time of mixed hot water supply from the mixed hot water supply port 60 is connected to the first mixing valve 91 through the branch hot water intermediate temperature pipe 101. It can be used on the hot water side of the hot water return pipe 90, so that the medium hot water can be used effectively. When the second three-way valve 100 is connected to the branch hot water intermediate temperature pipe 101 side, the supply temperature to the water side through the mixing valve inlet pipe 92 of the second mixing valve 65 can be increased. The required amount of heat on the high temperature side can be reduced, and hot water can be prevented from running out.

  Furthermore, by using the intermediate temperature water in the hot water storage tank 2 via the intermediate temperature hot water discharge pipe 62 or the branch return hot water intermediate temperature pipe 101, the rise in the water temperature of the hot water storage tank 2 during boiling can be suppressed. Reduction in efficiency can be suppressed. The present invention is not limited to the configuration of the embodiment described above, and various modifications can be made without departing from the spirit of the invention. For example, in the first embodiment, the hot water temperature detected by the temperature sensor 69 or the like provided in the mixed hot water pipe 66 is used for adjusting the opening degree of the first mixing valve 91 by the control unit 4. Not limited. For example, a detection signal from a temperature sensor provided at an arbitrary position can be used.

DESCRIPTION OF SYMBOLS 1 Mixed instant hot water system 2 Hot water storage tank 3 Heat pump 4 Control part 5 High temperature hot water pipe 6 Mixed hot water pipe 8 Mixed hot water pipe 9 Return pipe 61 High temperature hot water pipe 62 Medium hot hot water pipe 63 1st three-way valve 65 2nd mixed valve 66 Mixed hot water Pipe 71 Water supply pipe 74 Water supply branch pipe 81 Mixed hot water return pipe 82 Third three-way valve 83 Immediate hot water pump 84 Check valve 85 Branch hot water medium temperature pipe 90 Hot water return pipe 91 First mixing valve 92 Mixing valve water inlet pipe 93 Temperature sensor 100 Second three-way valve 101 Branch hot water medium temperature tube 102 Check valve A Mixed hot water supply route B Mixed hot water route C Return route

Claims (4)

A hot water supply pipe for supplying hot water in the hot water storage tank, a mixed hot water pipe for supplying hot water from the hot water storage tank mixed with hot water or medium hot water in the hot water storage tank and water from the water supply pipe, and the mixed hot water outlet In the mixed hot water system comprising a mixed hot water return pipe for returning hot water in the mixed hot water supply pipe to the hot water storage tank in order to immediately hot water from
A return path for branching from the middle of the path of the mixed hot water pipe and returning the hot water in the mixed hot water pipe to the mixed hot water pipe;
The return path includes a first mixing valve that mixes the hot water in the mixed hot water pipe and the water of the water supply branch pipe branched from the water supply pipe, and adjusts the opening of the first mixing valve. A hot water system having a predetermined temperature or less is supplied to the mixed hot water supply pipe by the above. The route of the mixed hot water supply pipe includes a high temperature hot water pipe branched from the high temperature hot water supply pipe, a medium temperature hot water pipe for discharging hot water in the hot water storage tank, and a first three-way valve connecting the high temperature hot water pipe and the intermediate temperature hot water pipe. And a second mixing valve for mixing hot water from the mixing valve hot water pipe and water from the mixing valve water inlet pipe constituting the return path, and a mixing valve hot water pipe for sending hot water from the first three-way valve A mixed hot water pipe for discharging the hot water mixed by the second mixing valve from the mixed hot water outlet,
The return path branches from the middle of the mixed hot water pipe and is connected to the first mixed valve, and the mixed valve water pipe connecting the first mixed valve and the second mixed valve. And
The mixed hot water system according to claim 1, further comprising a control unit that adjusts a valve opening degree of the first mixing valve based on a signal corresponding to a hot water temperature supplied from the mixed hot water supply port. The mixing valve inlet pipe is provided with a temperature sensor,
The control unit adjusts a valve opening degree of the first mixing valve based on a detection value from the temperature sensor, and sets a temperature of hot water flowing through the mixing valve inlet pipe to a predetermined temperature or less. The mixed hot water system according to claim 2. A second three-way valve provided in the intermediate temperature hot water pipe for branching a part of the hot water in the pipe;
The branch return hot water intermediate temperature pipe which sends the hot water in the intermediate temperature hot water pipe branched by the second three-way valve to the return hot water pipe, 4. Mixed instant hot water system.

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