JP2009074719A - Hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact hot water supply system capable of supplying a large amount of hot water while using a small hot water storage tank, in an instantaneous hot water supply system in which a pipe is kept warm by circulating the hot water in the pipe. <P>SOLUTION: A circulation circuit 5 is constituted to circulate a going-pipe 2, a circulation pump 3 and a returning-pipe 4 from the hot water storage tank 1, a bypass circuit 6 is disposed between the going-pipe 2 and the returning-pipe 4, and a valve 9 is disposed on the way of the bypass circuit 6. A water supply circuit 7 is connected on the way of the circulation circuit 5 at a downstream position with respect to a connecting portion of the going-pipe 2 and the bypass circuit 6, and an upstream position with respect to a connecting portion of the returning-pipe 4 and the bypass circuit 6. Further a hot water supply valve 8 is connected on the way of the circulation circuit 5 at a downstream position with respect to a connecting portion of the circulation circuit 5 and the water supply circuit 7, and an upstream position with respect to a connecting portion of the returning-pipe 4 and the bypass circuit 6 to supply hot water from a terminal end of the hot water supply valve 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hot water supply system, and more particularly, to an instant hot water supply system for keeping hot water in a pipe by circulating hot water in a hot water tank.

A conventional hot water supply system has a circulation circuit that guides hot water in a hot water tank to a hot water supply pipe by driving a pump, returns the hot water from the end of the hot water supply pipe to the hot water tank by a return pipe, and has a hot water outlet in the middle of the circulation circuit (for example, (See Patent Document 1).
In such a hot water supply system, since the hot water from the hot water tank circulates in the circulation circuit, the temperature in the circulation circuit is kept sufficiently high even if heat is radiated from the pipe to the outside. Therefore, when the tap is opened, there is an advantage that hot water at a high temperature is immediately poured out.

Japanese Patent Laid-Open No. 63-91453 (pages 3-4, figure)

In the conventional hot water supply system, the amount of hot water that can be discharged is limited to the amount of hot water stored in the hot water storage tank. Therefore, when it is necessary to discharge a large amount of hot water, it is necessary to provide a large-capacity hot water storage tank. In general, the place where the hot water tank is installed is often a limited space such as the roof of a building. Therefore, there was a problem that a large-capacity hot water storage tank could not be installed due to the limited installation space, and a large amount of hot water could not be supplied.
The present invention has been made to solve the above-described problems, and a main object of the present invention is to obtain a compact hot water supply system capable of discharging a large amount of hot water while using a relatively small hot water storage tank.

The hot water supply system according to the present invention is:
A hot water tank,
A piping for introducing hot water inside the hot water tank,
A circulation pump that draws in hot water from the outgoing pipe and delivers it under pressure;
A return pipe for returning the hot water sent out by the circulation pump to the hot water storage tank,
Form a circulation circuit consisting of outgoing piping, circulation pump, and return piping,
A bypass circuit connecting the outgoing and return pipes;
A water supply circuit connected on the circulation circuit downstream from the connecting portion between the outgoing piping and the bypass circuit and upstream from the connecting portion between the return piping and the bypass circuit;
It has a hot water outlet connected on the circulation circuit downstream from the connection part between the circulation circuit and the water supply circuit and upstream from the connection part between the return pipe and the bypass circuit,
The bypass circuit is provided with a flow rate limiting means for limiting the amount of hot water passing through the bypass circuit,
The water supply circuit is provided with water supply restriction means for restricting the amount of water supply.

The hot water supply system of the present invention can increase the temperature of the hot water in the hot water storage tank higher than the temperature of the hot water to be discharged, so that it is possible to use a hot water storage tank having a smaller capacity than the required amount of hot water.
In addition, the temperature of the hot water circulating in the circulation circuit can be kept lower than the temperature of the hot water in the hot water tank, so that hot water is not discharged immediately after the hot water outlet is opened. be able to.

Embodiment 1 FIG.
FIG. 1 shows a piping circuit of a hot water supply system according to Embodiment 1 of the present invention.
In the figure, a going pipe 2 is connected to the hot water tank 1, an end of the going pipe 2 is connected to the suction port of the circulation pump 3, a return pipe 4 is connected to the discharge port of the circulation pump 3, and the return pipe 4 The end is connected to the hot water tank 1 and constitutes a circulation circuit 5 (not shown) including an outgoing pipe 2, a circulation pump 3 and a return pipe 4.
A bypass circuit 6 is provided between the outgoing pipe 2 and the return pipe 4, and a valve 9 serving as a flow restriction means is provided in the middle of the bypass circuit 6.
In the middle of the circulation circuit 5, a position downstream of the connection portion between the outgoing pipe 2 and the bypass circuit 6 and upstream of a connection portion between the return pipe 4 and the bypass circuit 6, that is, within the circulation circuit and the via-pass circuit The water supply circuit 7 is connected to the position closer to the circulation pump than the connection portion. The water supply circuit 7 introduces city water and has a check valve 12 and a pressure reducing valve 10 (water supply restriction means).
In the middle of the circulation circuit 5, a tap valve 8 is connected downstream of the connection between the circulation circuit 5 and the water supply circuit 7 and upstream of the connection between the return pipe 4 and the bypass circuit 6. The end is a tap.

Next, the operation will be described. Here, it will be described that when the hot water storage temperature of the hot water tank 1 is 80 ° C., the hot water temperature can be 60 ° C.
The check valve 12 of the water supply circuit 7 prevents the hot water in the hot water tank from flowing back into the city water. Further, the pressure reducing valve 10 uses a secondary side pressure smaller than that of the head of the hot water tank 1, thereby preventing water supply from entering the circulation circuit 5 when no hot water is discharged. In this example, the head of the hot water tank 1 is 10 m, and the secondary pressure (head) of the pressure reducing valve 10 is 9 m.
Hot water is stored in the hot water tank 1. The temperature of this hot water is expressed as Ta, and Ta = 80 ° C.
When the circulation pump 3 is driven, the hot water in the hot water tank 1 flows into the outgoing pipe 2 and returns to the hot water tank 1 through the circulation pump 3 and the return pipe 4. Further, part of the hot water that has entered the return pipe 4 from the circulation pump 3 flows into the outgoing pipe 2 through the bypass circuit 6.

Consider a case where the tap valve 8 is closed and there is no tap from the tap.
The ratio of the amount of hot water flowing into the outgoing pipe 2 from the hot water storage tank 1 and the amount from the bypass circuit 6 is determined by the opening of the valve 9. If the opening degree of the valve 9 is small, the flow rate from the bypass circuit 6 decreases and the hot water from the hot water tank 1 increases. On the contrary, if the opening degree of the valve 9 is large, the flow rate from the bypass circuit 6 increases and the hot water from the hot water storage tank 1 decreases. Here, the ratio of the amount (Qa) from the hot water tank 1 to the amount (Qb) from the bypass circuit 6 is
Qa: Qb = 1: 2
The opening of the valve 9 is adjusted so that

The temperature of the hot water flowing through the circulation circuit 5 decreases due to heat radiation from the pipe to the outside. The temperature of the connection portion between the return pipe 4 and the bypass circuit 6 is represented by Tb, and this temperature is assumed to decrease to Tb = 50 ° C. due to heat radiation. If heat dissipation in the bypass circuit 6 is ignored, the temperature Tc immediately after the connecting portion between the outgoing pipe 2 and the bypass circuit 6 is obtained as follows.
Tc = (Ta × Qa + Tb × Qb) ÷ (Qa + Qb)
= (80 x 1 + 50 x 2) ÷ (1 + 2)
= 60 [℃]

  The position of the circulation circuit 5 where the outlet valve 8 is connected is downstream of the connecting part of the outgoing pipe 2 and the bypass circuit 6 and upstream of the connecting part of the return pipe 4 and the bypass circuit 6. The temperature of the hot water is kept in the range of 50-60 ° C. Therefore, when the tap valve 8 is opened, hot water of 50 to 60 ° C. is immediately poured out.

Next, consider the case where the tap valve 8 is opened and the hot water is continuously discharged from the tap.
It is assumed that the amount of discharged hot water is sufficiently large, and the amount flowing into the outgoing pipe 2 from the bypass circuit 6 and the amount returning from the circulation circuit 5 to the hot water tank 1 can be ignored.
The hot water supply head from the hot water storage tank 1 has Ha = 10 m, and the supply pressure of city water is reduced by the pressure reducing valve 10 for water supply, so that Hd = 9 m. The flow resistance R1 from the hot water tank 1 to the connection between the circulation circuit 5 and the water supply circuit 7 and the flow resistance R2 from the connection between the circulation circuit 5 and the water supply circuit 7 to the hot water outlet, and the ratio of R1 and R2 R1: R2 = 1: 4
The piping is configured so that Let Qa denote the amount of hot water supplied from the hot water tank 1 and exit from the hot water outlet, and let Qd = α × Qa denote the amount of hot water supplied from the water supply circuit 7 and emitted from the hot water outlet. From the Bernoulli's theorem, the pressure and flow equations from the hot water tank 1 to the connection with the water supply circuit 7 are
Ha−Hd = R1 × Qa2
It becomes. Moreover, the expression of the pressure and the flow rate from the connection part with the water supply circuit 7 to the hot water outlet is the same,
Hd = R2 × (1 + α) 2 × Qa2
It becomes. Put the values set in these two equations and solve for α,
α = 0.5
The ratio of the flow rate from the hot water tank 1 to the flow rate from the water supply circuit 7 is
Qa: Qd = 1: α = 1: 0.5 = 2: 1
become. If the feed water temperature supplied from the feed water circuit 7 is Td = 20 ° C., the tapping temperature Te that comes out from the tapping tap is obtained as follows.
Te = (Ta × Qa + Td × Qd) ÷ (Qa + Qd)
= (80 × 2 + 20 × 1) ÷ (1 + 2)
= 60 [℃]
That is, the tapping temperature is 60 ° C.

As described above, even when the temperature of the hot water in the hot water storage tank 1 is 80 ° C., the temperature of the hot water at the time of hot water can be set to 60 ° C. As a result, compared to the case where the total amount of hot water required for hot water is stored in the hot water storage tank at 60 ° C., which is equal to the hot water temperature, a hot water storage tank with a smaller capacity can be used, and a compact hot water supply system can be constructed. It is done.
In addition, the temperature of the hot water circulating in the circulation circuit can be kept lower than the temperature of the hot water in the hot water tank, so that hot water is not discharged immediately after the hot water outlet is opened. be able to.

Embodiment 2. FIG.
In the first embodiment described above, a hot water temperature and a heat retaining temperature lower than the temperature in the hot water storage tank 1 are obtained. However, the heat radiation of the piping and the temperature of the water supply fluctuate depending on the season and weather, and the head of the hot water tank also changes depending on the amount of hot water consumed. Therefore, the tapping temperature and the heat retention temperature are not always obtained stably. Therefore, here, an embodiment in which the influence of the above-described fluctuation factors is suppressed and the hot water temperature and the heat insulation temperature are stably obtained will be described.

FIG. 2 shows a piping circuit of the hot water supply system in such a case.
Hot water at 80 ° C. is stored in the hot water tank 1. The hot water storage tank 1 is connected to the outgoing pipe 2, the end of the outgoing pipe 2 is connected to the suction port of the circulation pump 3, the return pipe 4 is connected to the discharge port of the circulation pump 3, and the end of the return pipe 4 is the hot water storage. A circulation circuit 5 which is connected to the tank 1 and includes an outgoing pipe 2, a circulation pump 3 and a return pipe 4 is constituted.

  A bypass circuit 6 is provided between the outgoing pipe 2 and the return pipe 4. The connecting part between the outgoing pipe 2 and the bypass circuit 6 is located immediately after the connecting part between the hot water tank 1 and the outgoing pipe 2. In the middle of the bypass circuit 6, a flow control valve 13 (flow rate limiting means) is provided that can be electrically changed in opening. Further, a resistance adjustment valve (resistance element) 14 is provided between a connection portion between the return pipe 4 and the bypass circuit 6 and a connection portion between the return pipe 4 and the hot water tank 1. The resistance of the resistance adjusting valve 14 can be changed by changing the opening.

In the middle of the circulation circuit 5, the water supply circuit 7 is connected downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 and upstream of the connecting portion between the return pipe 4 and the bypass circuit 6. Here, the water supply circuit 7 has an elevated water tank 15 in which the head is kept constant, and a water supply control valve 16 (water supply restriction means) whose opening degree can be changed electrically.
In the middle of the circulation circuit 5, a tap valve 8 is connected downstream of the connection between the circulation circuit 5 and the water supply circuit 7 and upstream of the connection between the return pipe 4 and the bypass circuit 6. The end is a tap.

  Between the connecting part of the outgoing pipe 2 and the bypass circuit 6 and the connecting part of the circulation circuit 5 and the water supply circuit 7, a heat retention temperature sensor 17 for measuring the water temperature in the pipe at this position is provided. Between the connection part of the circulation circuit 5 and the water supply circuit 7 and the connection part of the circulation circuit 5 and the tap water valve 8, the hot water temperature sensor 18 which measures the water temperature inside the piping of this position is provided.

FIG. 3 is a block diagram showing the flow of signals from the heat retention temperature sensor 17.
A signal from the heat retention temperature sensor 17 is input to a heat retention controller 19 (flow rate control means). For example, 55 ° C. is set as the set value of the heat insulation temperature in the heat insulation temperature setting device 20 by, for example, input from the operation panel or writing to the memory. The signal of the heat insulation temperature sensor 17 and the set value of the heat insulation temperature setter 20 are input to the heat insulation controller 19, and the heat insulation controller 19 outputs an output for driving the flow rate control valve 13.

FIG. 4 is a block diagram showing the flow of signals from the hot water temperature sensor 18.
The signal from the hot water temperature sensor 18 is input to the water supply controller 21 (water supply control means). In the tapping temperature setting unit 22, for example, 60 ° C. is set as a tapping temperature setting value by input from the operation panel or writing to the memory. A signal from the hot water temperature sensor 18 and a set value from the hot water temperature setting device 22 are input to the water supply controller 21, and the water supply controller 21 outputs an output for driving the water supply control valve 16.

Next, the operation will be described.
When the circulation pump 3 is driven, the hot water in the hot water tank 1 flows into the outgoing pipe 2 and returns to the hot water tank 1 through the circulation pump 3 and the return pipe 4. Further, part of the hot water that has entered the return pipe 4 from the circulation pump 3 flows into the outgoing pipe 2 through the bypass circuit 6.
The ratio of the amount of hot water flowing into the outgoing pipe 2 from the hot water storage tank 1 and the amount from the bypass circuit 6 is controlled by the heat retention controller 19 of FIG. The insulation controller 19 compares the temperature measured by the insulation temperature sensor 17 (this temperature becomes the insulation temperature of the circulation circuit 5 when there is no hot water) and the insulation temperature setting value set by the insulation temperature setting device 20. When the measured heat retention temperature is lower than the heat retention temperature set value, the opening degree of the flow rate control valve 13 is reduced to cope with this, the flow rate from the bypass circuit 6 is small, and the hot water from the hot water tank 1 is discharged. The heat retention temperature is increased so as to increase, and the heat retention temperature is controlled to be equal to the heat retention temperature set value.

  The length from the hot water tank 1 to the connecting part of the outgoing pipe 2 and the bypass circuit 6 as when the connecting part of the outgoing pipe 2 and the bypass circuit 6 is immediately after the connected part of the hot water tank 1 and the outgoing pipe 2 If the flow path resistance is very small, there may be too much hot water from the hot water storage tank 1 and it may be difficult to control the heat retention temperature. Therefore, at this time, there is not too much hot water from the hot water tank 1 by providing the resistance adjusting valve 14 between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the hot water tank 1. Adjust as follows.

  When it becomes difficult to control the heat insulation temperature within the control range of the heat insulation controller 19 and the flow rate control valve 13 due to the influence of the change in the flow resistance of the piping due to secular change and the influence of the change in the heat radiation condition due to the season. The flow rate balance is adjusted by adjusting the opening degree of the resistance adjustment valve 14 so that the heat insulation temperature can be controlled within the control range of the heat insulation controller 19 and the flow control valve 13.

  The amount of water supplied from the water supply circuit 7 to the circulation circuit 5 is controlled by the water supply controller 21 shown in FIG. The feed water controller 21 compares the temperature measured by the tapping temperature sensor 18 (when it is tapped, this temperature becomes the tapping temperature) with the tapping temperature set value set by the tapping temperature setting unit 22 to measure the temperature. When the tapping temperature is higher than the tapping temperature set value, the opening of the feed water control valve 16 is increased to cope with this, and the tapping temperature is lowered by increasing the amount of feed water flowing into the circulation circuit 5 from the feed water circuit 7. Thus, the hot water temperature is controlled to be equal to the hot water temperature set value. When the hot water temperature measured by the hot water temperature sensor 18 is lower than the hot water temperature set value, the opening of the water supply control valve 16 is fully closed to stop the water supply and prevent the hot water temperature from further decreasing.

  Consider a case where the tap valve 8 is closed and there is no tap from the tap. The temperature of the hot water downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 is controlled to 55 ° C., which is the heat insulation temperature setting value, by the action of the heat insulation controller 19 and the flow rate control valve 13 described above. Therefore, the temperature measured by the tapping temperature sensor 18 is 55 ° C. This temperature is lower than the tapping temperature set value of 60 ° C. Since the water supply controller 21 stops the water supply with the opening of the water supply control valve 16 fully closed, the water supply does not enter the circulation circuit 5 and the hot water tank 1. Accordingly, the temperature of the circulation circuit 5 and the hot water tank 1 is not lowered. The heat retention temperature of the circulation circuit 5 is maintained at 55 ° C. When the hot water outlet valve 8 is opened from this state, hot water at 55 ° C. is immediately discharged.

  When the hot water valve 8 is opened and hot water is being continuously discharged from the hot water outlet, a large amount of hot water flows from the hot water storage tank 1 into the outgoing pipe 2. The temperature measured by the heat retention temperature sensor 17 is a hot water storage temperature of 80 ° C. Since this temperature is higher than the heat retention temperature set value of 55 ° C., the heat retention controller 19 increases the opening of the flow control valve 13, but the hot water flow rate from the hot water storage tank 1 is larger than the circulation flow rate flowing through the bypass circuit 6. Therefore, the impact is small. Therefore, the temperature of the hot water is regarded as 80 ° C. even downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6. This hot water passes through the connection with the water supply circuit 7 and is mixed with the water supply. As described above, since the operation of the water supply is controlled by the water supply controller 21, the temperature of the hot water downstream from the connection portion with the water supply circuit 7 is 60 ° C., and this 60 ° C. hot water is discharged from the outlet. Is done.

As described above, even when the temperature of the hot water in the hot water storage tank 1 is 80 ° C., the temperature of the hot water at the time of hot water can be set to 60 ° C. Furthermore, since the temperature of the hot water is measured and controlled, Regardless, a stable tapping temperature can be obtained. As a result, compared to the case where the total amount of hot water required for hot water is stored in the hot water storage tank at 60 ° C., which is equal to the hot water temperature, a hot water storage tank with a smaller capacity can be used, and a compact hot water supply system can be constructed. It is done.
In addition, the heat-retaining temperature at which the hot water is circulated in the circulation circuit can be maintained at 55 ° C., and the hot water can be discharged at a temperature that is sufficiently warm and not too hot immediately after the hot water outlet is opened.
Moreover, since the hot water temperature setting value that is the control target of the water supply controller 21 is set higher than the heat retention temperature setting value that is the control target of the heat retention controller 19, water supply is not performed during the heat retention, and the circulation circuit 5 and The temperature drop of the hot water tank 1 can be prevented.
Moreover, since the connection part of the outgoing pipe 2 and the bypass circuit 6 is a position immediately after the connection part of the hot water tank 1 and the outgoing pipe 2, the hot water tank 1 is changed after the opening degree of the flow control valve 13 is changed small. Since the time difference until the hot water reaches the connecting portion between the going pipe 2 and the bypass circuit 6 is small, good temperature control can be performed.
Moreover, since the resistance adjustment valve 14 is provided between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the hot water tank 1, the connection part of the outgoing pipe 2 and the bypass circuit 6 from the hot water tank 1. Even when the length up to is short and the flow path resistance is very small, the heat insulation temperature can be controlled.
In addition, since the resistance of the resistance adjustment valve 14 can be changed, when the control of the heat insulation temperature becomes difficult due to the influence of secular change or change of the heat radiation condition, the opening of the resistance adjustment valve 14 can be adjusted. It is possible to control the heat insulation temperature.

Embodiment 3 FIG.
In Embodiment 2 described above, the temperature of the hot water is controlled by measuring the temperature of the hot water, and the temperature of the hot water is controlled by measuring the temperature of the hot water. In this case, the following problems may occur.
For example, PI control is used as a method in which the heat retention controller 19 controls the heat retention temperature. In order to improve the followability of PI control, a large control gain is set, but at this time, an overshoot occurs. Due to the occurrence of overshoot, the heat insulation temperature in the pipe may temporarily exceed the tapping temperature setting value. When hot water that exceeds this hot water temperature setting value reaches the hot water temperature sensor 18, the water supply controller 21 that has received a signal from the hot water temperature sensor 18 opens the water supply control valve 16 to deal with this, and the circulation circuit 5 To supply water. In the circulation circuit 5, high-temperature hot water exceeding the set temperature of the hot water and low-temperature hot water in which the water supplied from the water supply circuit 7 is mixed flow continuously. When a series of hot water and low temperature hot water circulates and reaches the heat insulation temperature sensor 17, a signal of rapid temperature fluctuation is sent to the heat insulation controller 19, and the control of the heat insulation controller 19 causes hunting and the heat insulation temperature. Becomes unstable.

Therefore, here, an embodiment for avoiding the above-described problems will be described. This also uses the control information of the heat retention temperature in the control of the tapping temperature.
FIG. 5 is a block diagram of a control system for controlling the heat retention temperature and the tapping temperature. The piping circuit of the hot water supply system is the same as that of the second embodiment and is shown in FIG.
A signal from the heat insulation temperature sensor 17 is input to the heat insulation controller 19. For example, 55 ° C. is set as a set value of the heat insulation temperature in the heat insulation temperature setting device 20 by, for example, input from the operation panel or writing in the memory. The signal of the heat insulation temperature sensor 17 and the set value of the heat insulation temperature setter 20 are input to the heat insulation controller 19, and the heat insulation controller 19 sets the flow rate control valve 13 so that the heat insulation temperature detected by the heat insulation temperature sensor 17 becomes the set value. Outputs driving.
The signal from the hot water temperature sensor 18 is input to the water supply controller 21. In the tapping temperature setting unit 22, for example, 60 ° C. is set as a tapping temperature setting value by input from the operation panel or writing to the memory.
The feed water controller 21 receives a signal from the hot water temperature sensor 18, a set value from the hot water temperature setter 22, and a signal from the heat retention controller 19, and the feed water controller 21 detects the hot water temperature detected by the hot water temperature sensor 18. Gives an output for driving the water supply control valve 16 so that the set value becomes 60 ° C.
The signal input from the heat retention controller 19 to the water supply controller 21 is a signal indicating whether or not an overshoot has occurred (for example, whether or not the integrator data is a value that increases the heat retention temperature).
When the water supply controller 21 receives a signal indicating the occurrence of overshoot from the heat retention controller 19, the water supply controller 21 performs control to keep the water supply control valve 16 closed in order to cope with this.

  Since the configuration and the control operation are as described above, when overshoot occurs, a signal indicating the occurrence of overshoot is input from the heat retention controller 19 to the water supply controller 21, so that the tapping temperature sensor 18 is set to 60 ° C. Even if the temperature exceeding the temperature is measured, the water supply controller 21 keeps the water supply control valve 16 closed to keep the temperature fluctuation of the circulation circuit 5 small. This prevents control hunting and enables stable control.

Embodiment 4 FIG.
Another embodiment for avoiding the overshoot defect of the second embodiment described above will be described. In this case, the control information of the tapping temperature is also used in the control of the heat retention temperature.
FIG. 6 is a block diagram of a control system that controls the heat retention temperature and the tapping temperature. The piping circuit of the hot water supply system is the same as that of the second embodiment and is shown in FIG.
A signal from the heat insulation temperature sensor 17 is input to the heat insulation controller 19. For example, 55 ° C. is set as a set value of the heat insulation temperature in the heat insulation temperature setting device 20 by, for example, input from the operation panel or writing in the memory.
The signal from the hot water temperature sensor 18 is input to the water supply controller 21. For example, 60 ° C. is set as the set value of the tapping temperature in the tapping temperature setting device 22 by, for example, input from the operation panel or writing in the memory. A signal from the hot water temperature sensor 18 and a set value from the hot water temperature setting device 22 are input to the water supply controller 21, and the water supply controller 21 outputs an output for driving the water supply control valve 16.

A signal from the heat retention temperature sensor 17, a set value from the heat retention temperature setting device 20, and a signal from the water supply controller 21 are input to the heat retention controller 19, and the heat retention controller 19 outputs an output for driving the flow control valve 13. put out.
The signal input from the water supply controller 21 to the heat retention controller 19 is a signal indicating whether or not the water supply corresponding to the overshoot occurs (for example, whether or not a short time hot water supply operation occurs).
When the heat retention controller 19 receives a signal indicating the occurrence of water supply corresponding to the overshoot from the water supply controller 21, the heat retention controller 19 performs control by reducing the control gain to cope with this.

  Since the above-described configuration and control operation are performed, when water supply from the water supply circuit 7 occurs due to the influence of overshoot, a signal indicating the occurrence of water supply is input from the water supply controller 21 to the heat retention controller 19. Even if the temperature sensor 17 measures an abrupt temperature fluctuation, the heat retention controller 19 reduces the control gain and keeps the temperature fluctuation of the circulation circuit 5 small. This prevents control hunting and enables stable control.

Embodiment 5 FIG.
In the above second to fourth embodiments, the flow rate control valve is provided in the bypass circuit, but an embodiment in which the flow rate control valve is provided in the return pipe is shown.
FIG. 7 shows a piping circuit of the hot water supply system in such a case.
Hot water at 80 ° C. is stored in the hot water tank 1. The hot water storage tank 1 is connected to the outgoing pipe 2, the end of the outgoing pipe 2 is connected to the suction port of the circulation pump 3, the return pipe 4 is connected to the discharge port of the circulation pump 3, and the end of the return pipe 4 is the hot water storage. A circulation circuit 5 which is connected to the tank 1 and includes an outgoing pipe 2, a circulation pump 3 and a return pipe 4 is constituted.

  A bypass circuit 6 is provided between the outgoing pipe 2 and the return pipe 4. The connecting part between the outgoing pipe 2 and the bypass circuit 6 is located immediately after the connecting part between the hot water tank 1 and the outgoing pipe 2. A resistance adjustment valve 14 is provided in the middle of the bypass circuit 6. The resistance of the resistance adjusting valve 14 can be changed by changing the opening. In addition, a flow rate control valve 13 whose opening degree can be changed electrically is provided between a connection portion between the return pipe 4 and the bypass circuit 6 and a connection portion between the return pipe 4 and the hot water tank 1.

In the middle of the circulation circuit 5, the water supply circuit 7 is connected downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 and upstream of the connecting portion between the return pipe 4 and the bypass circuit 6. Here, the water supply circuit 7 has an elevated water tank 15 in which the head is kept constant, and a water supply control valve 16 whose opening degree can be changed electrically.
In the middle of the circulation circuit 5, a tap valve 8 is connected downstream of the connection between the circulation circuit 5 and the water supply circuit 7 and upstream of the connection between the return pipe 4 and the bypass circuit 6. The end is a tap.

Between the connecting part of the outgoing pipe 2 and the bypass circuit 6 and the connecting part of the circulation circuit 5 and the water supply circuit 7, a heat retention temperature sensor 17 for measuring the water temperature in the pipe at this position is provided. Between the connection part of the circulation circuit 5 and the water supply circuit 7 and the connection part of the circulation circuit 5 and the tap water valve 8, the hot water temperature sensor 18 which measures the water temperature inside the piping of this position is provided.
A block diagram showing the flow of signals from the heat insulation temperature sensor 17 is the same as that of the second embodiment, and is shown in FIG.
A block diagram showing a flow of signals from the tapping temperature sensor 18 is the same as that of the second embodiment and is shown in FIG.

Next, the operation will be described.
When the circulation pump 3 is driven, the hot water in the hot water tank 1 flows into the outgoing pipe 2 and returns to the hot water tank 1 through the circulation pump 3 and the return pipe 4. Further, part of the hot water that has entered the return pipe 4 from the circulation pump 3 flows into the outgoing pipe 2 through the bypass circuit 6.
The ratio of the amount of hot water flowing into the outgoing pipe 2 from the hot water storage tank 1 and the amount from the bypass circuit 6 is controlled by a heat retention controller 19. The insulation controller 19 compares the temperature measured by the insulation temperature sensor 17 (this temperature becomes the insulation temperature of the circulation circuit 5 when there is no hot water) and the insulation temperature setting value set by the insulation temperature setting device 20. When the measured heat retention temperature is lower than the heat retention temperature set value, the opening degree of the flow control valve 13 is increased in order to cope with this, the amount of hot water from the hot water tank 1 is large, and the flow rate from the bypass circuit 6 is increased. The heat retention temperature is increased so as to decrease, and the heat retention temperature is controlled to be equal to the heat retention temperature set value. In addition, when the measured temperature is higher than the temperature setting value, the flow control valve 13 is fully closed so that circulation from the bypass circuit 6 alone is performed without using hot water from the hot water tank 1. Then, the heat insulation temperature is lowered, and the heat insulation temperature is controlled to be equal to the heat insulation temperature set value.

  When the length of the bypass circuit 6 is short and the flow path resistance of the bypass circuit 6 is very small, there is a case where there is too much hot water flowing into the outgoing pipe 2 from the bypass circuit 6 and it becomes difficult to control the heat insulation temperature. . Therefore, at this time, the resistance adjustment valve 14 is provided in the bypass circuit 6 so that the amount of hot water from the bypass circuit 6 is adjusted so as not to be excessive.

  When it becomes difficult to control the heat insulation temperature within the control range of the heat insulation controller 19 and the flow rate control valve 13 due to the influence of the change in the flow resistance of the piping due to secular change and the influence of the change in the heat radiation condition due to the season. The flow rate balance is adjusted by adjusting the opening degree of the resistance adjustment valve 14 so that the heat insulation temperature can be controlled within the control range of the heat insulation controller 19 and the flow control valve 13.

  The amount of water supplied from the water supply circuit 7 to the circulation circuit 5 is controlled by the water supply controller 21 shown in FIG. The feed water controller 21 compares the temperature measured by the tapping temperature sensor 18 (when it is tapped, this temperature becomes the tapping temperature) with the tapping temperature set value set by the tapping temperature setting unit 22 to measure the temperature. When the tapping temperature is higher than the tapping temperature set value, the opening of the feed water control valve 16 is increased to cope with this, and the tapping temperature is lowered by increasing the amount of feed water flowing into the circulation circuit 5 from the feed water circuit 7. Thus, the hot water temperature is controlled to be equal to the hot water temperature set value. When the hot water temperature measured by the hot water temperature sensor 18 is lower than the hot water temperature set value, the opening of the water supply control valve 16 is fully closed to stop the water supply and prevent the hot water temperature from further decreasing.

  Consider a case where the tap valve 8 is closed and there is no tap from the tap. The temperature of the hot water downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 is controlled to 55 ° C., which is the heat insulation temperature setting value, by the action of the heat insulation controller 19 and the flow rate control valve 13 described above. Therefore, the temperature measured by the tapping temperature sensor 18 is 55 ° C. This temperature is lower than the tapping temperature set value of 60 ° C. Since the water supply controller 21 in FIG. 4 stops the water supply with the opening of the water supply control valve 16 fully closed, the water supply does not enter the circulation circuit 5 and the hot water tank 1. Accordingly, the temperature of the circulation circuit 5 and the hot water tank 1 is not lowered. For this reason, the heat retention temperature of the circulation circuit 5 is maintained at 55 ° C. When the hot water valve 8 is opened from this state, hot water at 55 ° C. is immediately discharged.

  When the hot water valve 8 is opened and hot water is being continuously discharged from the hot water outlet, a large amount of hot water flows from the hot water storage tank 1 into the outgoing pipe 2. The temperature measured by the heat retention temperature sensor 17 is a hot water storage temperature of 80 ° C. Since this temperature is higher than the heat retention temperature set value of 55 ° C., the heat retention controller 19 reduces the opening degree of the flow control valve 13, but the hot water flow rate from the hot water tank 1 is larger than the circulation flow rate flowing through the bypass circuit 6. Therefore, the impact is small. Therefore, the temperature of the hot water is regarded as 80 ° C. even downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6. This hot water passes through the connection with the water supply circuit 7 and is mixed with the water supply. As described above, since the operation of the water supply is controlled by the water supply controller 21, the temperature of the hot water downstream from the connection portion with the water supply circuit 7 is 60 ° C., and this 60 ° C. hot water is discharged from the outlet. Is done.

As described above, even when the temperature of the hot water in the hot water storage tank 1 is 80 ° C., the temperature of the hot water at the time of hot water can be set to 60 ° C. Furthermore, since the temperature of the hot water is measured and controlled, Regardless, a stable tapping temperature can be obtained. As a result, compared to the case where the total amount of hot water required for hot water is stored in the hot water storage tank at 60 ° C., which is equal to the hot water temperature, a hot water storage tank with a smaller capacity can be used, and a compact hot water supply system can be constructed. It is done.
In addition, the heat-retaining temperature at which the hot water is circulated in the circulation circuit can be maintained at 55 ° C., and the hot water can be discharged at a temperature that is sufficiently warm and not too hot immediately after the hot water outlet is opened.

Furthermore, by providing the flow rate control valve 13 between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the hot water tank 1, the heat insulation temperature when there is no hot water is higher than the heat insulation temperature set value. If it is too high, the flow rate control valve 13 is fully closed, so that the hot water in the hot water tank 1 is not used at all, and the hot water temperature in the hot water tank 1 can be kept high.
Moreover, since the connection part of the outgoing pipe 2 and the bypass circuit 6 is a position immediately after the connection part of the hot water storage tank 1 and the outgoing pipe 2, the opening degree of the flow control valve 13 is largely changed before the hot water storage tank 1 Since the time difference until the hot water reaches the connecting portion between the going pipe 2 and the bypass circuit 6 is small, good temperature control can be performed.
Further, since the resistance adjusting valve 14 is provided in the bypass circuit 6, even when the length of the bypass circuit 6 is short and the flow path resistance is very small, the heat insulation temperature can be controlled.
In addition, since the resistance of the resistance adjustment valve 14 can be changed, when the control of the heat insulation temperature becomes difficult due to the influence of secular change or change of the heat radiation condition, the opening of the resistance adjustment valve 14 can be adjusted. It is possible to control the heat insulation temperature.

Note that the opening degree of the flow control valve 13 may be fixed as long as the variation in the heat retention temperature is allowed to some extent. Similarly, if the fluctuation of the tapping temperature is allowed to some extent, it is possible to use a check valve and a pressure reducing valve in place of the feed water control valve 16 to make the water supply amount at the time of tapping hot water constant.
As shown in FIG. 5, the feed water controller 21 receives a signal from the hot water temperature sensor 18, a set value from the hot water temperature setter 22, and a signal from the heat retention controller 19. It is good also as a structure which outputs the output which drives the water supply control valve 16. FIG. As in the third embodiment, the stability of temperature control can be improved.

  Further, as shown in FIG. 6, a signal from the heat retention temperature sensor 17, a set value from the heat retention temperature setter 20, and a signal from the water supply controller 21 are input to the heat retention controller 19. It is good also as a structure which outputs the output which drives the flow control valve 13. FIG. Similar to the fourth embodiment, the stability of temperature control can be improved.

Embodiment 6 FIG.
In Embodiments 1 to 5 described above, hot water in the hot water tank is directly flowed into the circulation circuit in order to keep the circulation circuit warm, but the heat is maintained by heat exchange between the hot water circulating in the circulation circuit and the hot water in the hot water tank. The embodiment in the case where it does is shown.
FIG. 8 shows a piping circuit of a hot water supply system in such a case.
Hot water at 80 ° C. is stored in the hot water tank 1. A heat exchanger 23 is provided inside the hot water tank 1, and the outgoing pipe 2 is connected to the outlet of the heat exchanger 23, and the end of the outgoing pipe 2 is connected to the suction port of the circulation pump 3. A return pipe 4 is connected to the discharge port, and an end of the return pipe 4 is connected to an inlet of the heat exchanger 23 to constitute a circulation circuit 5 including the outgoing pipe 2, the circulation pump 3, and the return pipe 4. .

  A bypass circuit 6 is provided between the outgoing pipe 2 and the return pipe 4. The connecting portion between the outgoing pipe 2 and the bypass circuit 6 is located immediately after the connecting portion between the heat exchanger 23 and the outgoing pipe 2. In the middle of the bypass circuit 6, a flow control valve 13 whose opening degree can be changed electrically is provided. Further, a resistance adjusting valve 14 is provided between the connection portion of the return pipe 4 and the bypass circuit 6 and the connection portion of the return pipe 4 and the heat exchanger 23. The resistance of the resistance adjusting valve 14 can be changed by changing the opening.

In the middle of the circulation circuit 5, the hot water supply circuit 24 is connected downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 and upstream of the connecting portion between the return pipe 4 and the bypass circuit 6. The hot water supply circuit 24 is connected to the hot water tank 1 via the check valve 11 and supplies hot water from the hot water tank 1 to the circulation circuit 5.
A water supply circuit 7 is connected in the middle of the hot water supply circuit 24. Here, the water supply circuit 7 has an elevated water tank 15 in which the head is kept constant, and a water supply control valve 16 whose opening degree can be changed electrically.
In the middle of the circulation circuit 5, a tap valve 8 is connected downstream of the connection portion of the circulation circuit 5 and the hot water supply circuit 24 and upstream of the connection portion of the return pipe 4 and the bypass circuit 6. The end is a tap.

Between the connecting part of the outgoing pipe 2 and the bypass circuit 6 and the connecting part of the circulation circuit 5 and the hot water supply circuit 24, a heat retaining temperature sensor 17 for measuring the water temperature in the pipe at this position is provided. Between the connection part of the hot water supply circuit 24 and the water supply circuit 7 and the connection part of the circulation circuit 5 and the hot water supply circuit 24, a hot water temperature sensor 18 for measuring the water temperature inside the pipe at this position is provided.
A block diagram showing the flow of signals from the heat insulation temperature sensor 17 is the same as that of the second embodiment, and is shown in FIG.
A block diagram showing a flow of signals from the tapping temperature sensor 18 is the same as that of the second embodiment and is shown in FIG.

Next, the operation will be described.
The hot water in the circulation circuit 5 is sent to the heat exchanger 23 by driving the circulation pump 3. The hot water that has passed through the heat exchanger 23 and exchanged heat with the hot water tank 1 and has reached a high temperature flows into the outgoing pipe 2, passes through the circulation pump 3 and the return pipe 4, and is sent to the heat exchanger 23. Further, part of the hot water that has entered the return pipe 4 from the circulation pump 3 flows into the outgoing pipe 2 through the bypass circuit 6.
The ratio of the amount of hot water flowing into the outgoing pipe 2 from the heat exchanger 23 and the amount from the bypass circuit 6 is controlled by the heat retention controller 19. The insulation controller 19 compares the temperature measured by the insulation temperature sensor 17 (the insulation temperature of the circulation circuit 5) with the insulation temperature set value (55 ° C.) set by the insulation temperature setting device 20, and the measured insulation temperature is When the temperature is lower than the set temperature, the opening of the flow rate control valve 13 is reduced to cope with this, so that the flow rate from the bypass circuit 6 is small and hot water from the heat exchanger 23 is increased. The temperature is raised and controlled so that the temperature is equal to the temperature setting value.

  The connecting portion between the outgoing pipe 2 and the bypass circuit 6 is immediately after the connecting portion between the heat exchanger 23 and the outgoing pipe 2, from the heat exchanger 23 to the connecting portion between the outgoing pipe 2 and the bypass circuit 6. If the length is short and the flow path resistance is very small, there may be too much hot water from the heat exchanger 23, making it difficult to control the heat retention temperature. Therefore, at this time, there is too much hot water from the heat exchanger 23 by providing the resistance adjustment valve 14 between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the hot water tank 1. Adjust so that there is no.

  When it becomes difficult to control the heat insulation temperature within the control range of the heat insulation controller 19 and the flow rate control valve 13 due to the influence of the change in the flow resistance of the piping due to secular change and the influence of the change in the heat radiation condition due to the season. The flow rate balance is adjusted by adjusting the opening degree of the resistance adjustment valve 14 so that the heat insulation temperature can be controlled within the control range of the heat insulation controller 19 and the flow control valve 13.

  The amount of water supplied from the water supply circuit 7 to the hot water supply circuit 24 is controlled by the water supply controller 21. The water supply controller 21 compares the temperature measured by the tapping temperature sensor 18 (tapping temperature) with the tapping temperature setting value (60 ° C.) set by the tapping temperature setting device 22, and the measured tapping temperature is the tapping temperature setting value. If it is higher, the opening of the water supply control valve 16 is increased to cope with this, and the amount of water supplied from the water supply circuit 7 to the circulation circuit 5 is increased to lower the hot water temperature. Control to be equal to the set value.

Consider a case where the tap valve 8 is closed and there is no tap from the tap. The temperature of the hot water downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 is controlled to the heat insulation temperature set value by the functions of the heat insulation controller 19 and the flow rate control valve 13 described above. When the hot water valve 8 is opened from this state, the hot water controlled to the heat retention temperature set value is immediately discharged.
Even if the water supply control valve 16 is open, the hot water is not discharged from the circulation circuit 5 to the outside, so that the water supply does not enter the circulation circuit 5. Therefore, the temperature of the circulation circuit 5 does not decrease. Furthermore, since the check valve 11 is provided between the hot water tank 1 and the hot water supply circuit 24, water supply does not enter the hot water tank 1. Therefore, the temperature of the hot water tank 1 is not lowered.

  When the hot water valve 8 is opened and the hot water is continuously discharged from the hot water outlet, the hot water flowing from the hot water storage tank 1 into the hot water supply circuit 24 is mixed with the hot water, and the control of the hot water temperature setting unit 22 described above is performed. It becomes the tapping temperature setting value. This hot water flows into the circulation circuit 5 and is mixed with the hot water circulating through the circulation circuit 5, but since the amount of hot water from the hot water supply circuit 24 is large, the temperature of the hot water after mixing is determined by the tapping temperature setting device 22. It is considered a controlled temperature (60 ° C.). This 60 ° C. hot water is discharged from the hot water outlet.

As described above, even when the temperature of the hot water in the hot water storage tank 1 is 80 ° C., the temperature of the hot water at the time of hot water can be set to 60 ° C. Furthermore, since the temperature of the hot water is measured and controlled, Regardless, a stable tapping temperature can be obtained. As a result, compared to the case where the total amount of hot water required for hot water is stored in the hot water storage tank at 60 ° C., which is equal to the hot water temperature, a hot water storage tank with a smaller capacity can be used, and a compact hot water supply system can be constructed. It is done.
In addition, the heat-retaining temperature at which the hot water is circulated in the circulation circuit can be maintained at 55 ° C., and the hot water can be discharged at a temperature that is sufficiently warm and not too hot immediately after the hot water outlet is opened.

When there is no hot water from the hot water outlet, no hot water is discharged from the circulation circuit 5 to the outside, so that the water supply does not enter the circulation circuit 5, and the check valve 11 is interposed between the hot water tank 1 and the hot water supply circuit 24. Therefore, the water supply does not enter the hot water tank 1. For this reason, the temperature fall of the circulation circuit 5 and the hot water tank 1 can be prevented.
Moreover, since the connection part of the outgoing pipe 2 and the bypass circuit 6 is a position immediately after the connection part of the heat exchanger 23 and the outgoing pipe 2, after changing the opening degree of the flow control valve 13 small, heat exchange is carried out. Since the time difference until the hot water from the vessel 23 reaches the connecting portion between the going pipe 2 and the bypass circuit 6 is small, good temperature control can be performed.
Moreover, since the resistance adjustment valve 14 is provided between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the hot water tank 1, the connection part of the outgoing pipe 2 and the bypass circuit 6 from the hot water tank 1. Even when the length up to is short and the flow path resistance is very small, the heat insulation temperature can be controlled.
In addition, since the resistance of the resistance adjustment valve 14 can be changed, when the control of the heat insulation temperature becomes difficult due to the influence of secular change or change of the heat radiation condition, the opening of the resistance adjustment valve 14 can be adjusted. It is possible to control the heat insulation temperature.

In addition, although the heat retention temperature was demonstrated here as 55 degreeC, it does not need to be related to the setting of tapping temperature and heat retention temperature like Embodiment 2, and these two temperatures can be set independently.
Note that the opening degree of the flow control valve 13 may be fixed as long as the variation in the heat retention temperature is allowed to some extent. Similarly, if the fluctuation of the tapping temperature is allowed to some extent, it is possible to use a check valve and a pressure reducing valve in place of the feed water control valve 16 to make the water supply amount at the time of tapping hot water constant.

Embodiment 7 FIG.
In the sixth embodiment described above, the flow rate control valve is provided in the bypass circuit, but an embodiment in which the flow rate control valve is provided in the return pipe will be described.
FIG. 9 shows a piping circuit of the hot water supply system in such a case.
Hot water at 80 ° C. is stored in the hot water tank 1. A heat exchanger 23 is provided inside the hot water tank 1, and the outgoing pipe 2 is connected to the outlet of the heat exchanger 23, and the end of the outgoing pipe 2 is connected to the suction port of the circulation pump 3. A return pipe 4 is connected to the discharge port, and an end of the return pipe 4 is connected to an inlet of the heat exchanger 23 to constitute a circulation circuit 5 including the outgoing pipe 2, the circulation pump 3, and the return pipe 4. .

  A bypass circuit 6 is provided between the outgoing pipe 2 and the return pipe 4. The connecting portion between the outgoing pipe 2 and the bypass circuit 6 is located immediately after the connecting portion between the heat exchanger 23 and the outgoing pipe 2. A resistance adjustment valve 14 is provided in the middle of the bypass circuit 6. The resistance of the resistance adjusting valve 14 can be changed by changing the opening. Further, a flow rate control valve 13 whose opening degree can be changed electrically is provided between a connection portion between the return pipe 4 and the bypass circuit 6 and a connection portion between the return pipe 4 and the heat exchanger 23.

In the middle of the circulation circuit 5, the hot water supply circuit 24 is connected downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 and upstream of the connecting portion between the return pipe 4 and the bypass circuit 6. The hot water supply circuit 24 is connected to the hot water tank 1 via the check valve 11 and supplies hot water from the hot water tank 1 to the circulation circuit 5.
A water supply circuit 7 is connected in the middle of the hot water supply circuit 24. Here, the water supply circuit 7 has an elevated water tank 15 in which the head is kept constant, and a water supply control valve 16 whose opening degree can be changed electrically.
In the middle of the circulation circuit 5, a tap valve 8 is connected downstream of the connection portion of the circulation circuit 5 and the hot water supply circuit 24 and upstream of the connection portion of the return pipe 4 and the bypass circuit 6. The end is a tap.

  Between the connecting part of the outgoing pipe 2 and the bypass circuit 6 and the connecting part of the circulation circuit 5 and the hot water supply circuit 24, a heat retaining temperature sensor 17 for measuring the water temperature in the pipe at this position is provided. Between the connection part of the hot water supply circuit 24 and the water supply circuit 7 and the connection part of the circulation circuit 5 and the hot water supply circuit 24, a hot water temperature sensor 18 for measuring the water temperature inside the pipe at this position is provided.

A block diagram showing the flow of signals from the heat insulation temperature sensor 17 is the same as that of the second embodiment, and is shown in FIG.
A block diagram showing a flow of signals from the tapping temperature sensor 18 is the same as that of the second embodiment and is shown in FIG.

Next, the operation will be described.
The hot water in the circulation circuit 5 is sent to the heat exchanger 23 by driving the circulation pump 3. The hot water that has passed through the heat exchanger 23 and exchanged heat with the hot water tank 1 and has reached a high temperature flows into the outgoing pipe 2, passes through the circulation pump 3 and the return pipe 4, and is sent to the heat exchanger 23. Further, part of the hot water that has entered the return pipe 4 from the circulation pump 3 flows into the outgoing pipe 2 through the bypass circuit 6.
The ratio of the amount of hot water flowing into the outgoing pipe 2 from the heat exchanger 23 and the amount from the bypass circuit 6 is controlled by the heat retention controller 19. The insulation controller 19 compares the temperature measured by the insulation temperature sensor 17 (the insulation temperature of the circulation circuit 5) with the insulation temperature set value (55 ° C.) set by the insulation temperature setting device 20, and the measured insulation temperature is When the temperature is lower than the set temperature, the opening of the flow control valve 13 is increased in order to cope with this, so that the flow from the bypass circuit 6 is small and the hot water from the heat exchanger 23 is increased. The temperature is raised and controlled so that the temperature is equal to the temperature setting value.

  When the length of the bypass circuit 6 is short and the flow path resistance of the bypass circuit 6 is very small, there is a case where there is too much hot water flowing into the outgoing pipe 2 from the bypass circuit 6 and it becomes difficult to control the heat insulation temperature. . Therefore, at this time, the resistance adjustment valve 14 is provided in the bypass circuit 6 so that the amount of hot water from the bypass circuit 6 is adjusted so as not to be excessive.

  When it becomes difficult to control the heat insulation temperature within the control range of the heat insulation controller 19 and the flow rate control valve 13 due to the influence of the change in the flow resistance of the piping due to secular change and the influence of the change in the heat radiation condition due to the season. The flow rate balance is adjusted by adjusting the opening degree of the resistance adjustment valve 14 so that the heat insulation temperature can be controlled within the control range of the heat insulation controller 19 and the flow control valve 13.

  The amount of water supplied from the water supply circuit 7 to the hot water supply circuit 24 is controlled by the water supply controller 21. The water supply controller 21 compares the temperature measured by the tapping temperature sensor 18 (tapping temperature) with the tapping temperature setting value (60 ° C.) set by the tapping temperature setting device 22, and the measured tapping temperature is the tapping temperature setting value. If it is higher, the opening of the water supply control valve 16 is increased to cope with this, and the amount of water supplied from the water supply circuit 7 to the circulation circuit 5 is increased to lower the hot water temperature. Control to be equal to the set value.

Consider a case where the tap valve 8 is closed and there is no tap from the tap. The temperature of the hot water downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 is controlled to the heat insulation temperature set value by the functions of the heat insulation controller 19 and the flow rate control valve 13 described above. When the hot water valve 8 is opened from this state, the hot water controlled to the heat retention temperature set value is immediately discharged.
Even if the water supply control valve 16 is open, the hot water is not discharged from the circulation circuit 5 to the outside, so that the water supply does not enter the circulation circuit 5. Therefore, the temperature of the circulation circuit 5 does not decrease. Furthermore, since the check valve 11 is provided between the hot water tank 1 and the hot water supply circuit 24, water supply does not enter the hot water tank 1. Therefore, the temperature of the hot water tank 1 is not lowered.

  When the hot water valve 8 is opened and the hot water is continuously discharged from the hot water outlet, the hot water flowing from the hot water storage tank 1 into the hot water supply circuit 24 is mixed with the hot water, and the control of the hot water temperature setting unit 22 described above is performed. It becomes the tapping temperature setting value. This hot water flows into the circulation circuit 5 and is mixed with the hot water circulating through the circulation circuit 5, but since the amount of hot water from the hot water supply circuit 24 is large, the temperature of the hot water after mixing is determined by the tapping temperature setting device 22. It is considered a controlled temperature (60 ° C.). This 60 ° C. hot water is discharged from the hot water outlet.

As described above, even when the temperature of the hot water in the hot water storage tank 1 is 80 ° C., the temperature of the hot water at the time of hot water can be set to 60 ° C. Furthermore, since the temperature of the hot water is measured and controlled, Regardless, a stable tapping temperature can be obtained. As a result, compared to the case where the total amount of hot water required for hot water is stored in the hot water storage tank at 60 ° C., which is equal to the hot water temperature, a hot water storage tank with a smaller capacity can be used, and a compact hot water supply system can be constructed. It is done.
In addition, the heat-retaining temperature at which the hot water is circulated in the circulation circuit can be maintained at 55 ° C., and the hot water can be discharged at a temperature that is sufficiently warm and not too hot immediately after the hot water outlet is opened.

When there is no hot water from the hot water outlet, no hot water is discharged from the circulation circuit 5 to the outside, so that the water supply does not enter the circulation circuit 5, and the check valve 11 is interposed between the hot water tank 1 and the hot water supply circuit 24. Therefore, since the water supply does not enter the hot water tank 1, the temperature reduction of the circulation circuit 5 and the hot water tank 1 can be prevented.
Furthermore, by providing the flow rate control valve 13 between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the heat exchanger 23, the heat insulation temperature when there is no hot water is the heat insulation temperature set value. When the temperature is higher, the flow rate control valve 13 is fully closed, so that heat exchange with the hot water in the hot water tank 1 is not performed at all, and the hot water temperature in the hot water tank 1 can be kept high.
Moreover, since the connection part of the outgoing pipe 2 and the bypass circuit 6 is a position immediately after the connection part of the heat exchanger 23 and the outgoing pipe 2, the hot water storage tank after changing the opening degree of the flow control valve 13 largely. Since the time difference until the hot water No. 1 reaches the connecting portion between the going pipe 2 and the bypass circuit 6 is small, good temperature control can be performed.
Further, since the resistance adjusting valve 14 is provided in the bypass circuit 6, even when the length of the bypass circuit 6 is short and the flow path resistance is very small, the heat insulation temperature can be controlled.
In addition, since the resistance of the resistance adjustment valve 14 can be changed, when the control of the heat insulation temperature becomes difficult due to the influence of secular change or change of the heat radiation condition, the opening of the resistance adjustment valve 14 can be adjusted. It is possible to control the heat insulation temperature.

In addition, although the heat retention temperature was demonstrated here as 55 degreeC, it does not need to be related to the setting of tapping temperature and heat retention temperature like Embodiment 2, and these two temperatures can be set independently.
Note that the opening degree of the flow control valve 13 may be fixed as long as the variation in the heat retention temperature is allowed to some extent. Similarly, if the fluctuation of the tapping temperature is allowed to some extent, it is possible to use a check valve and a pressure reducing valve in place of the feed water control valve 16 to make the water supply amount at the time of tapping hot water constant.

Embodiment 8 FIG.
Another embodiment is shown in which there is no fear that feed water enters the circulation circuit, and the hot water storage temperature can be higher than the hot water temperature.
FIG. 10 shows a piping circuit of a hot water supply system in such a case.
Hot water at 80 ° C. is stored in the hot water tank 1. The hot water storage tank 1 is connected to the outgoing pipe 2, the end of the outgoing pipe 2 is connected to the suction port of the circulation pump 3, the return pipe 4 is connected to the discharge port of the circulation pump 3, and the end of the return pipe 4 is the hot water storage. A circulation circuit 5 which is connected to the tank 1 and includes an outgoing pipe 2, a circulation pump 3 and a return pipe 4 is constituted.

In the middle of the circulation circuit 5, a tapping circuit 26 is connected. The hot water circuit 26 takes in hot water from the circulation circuit 5 through the check valve 11 and discharges hot water through the hot water valve 8.
The water supply circuit 7 is connected to a position downstream of the check valve 11 of the hot water circuit 26 and upstream of the hot water valve 8. Here, the water supply circuit 7 has an elevated water tank 15 in which the head is kept constant, and a water supply control valve 16 whose opening degree can be changed electrically.
The outlet of the tap valve 8 is the same as the outlet of the outlet valve 27 that drains water from the elevated water tank 15, and the outlet valve 8 and the outlet valve 27 together form a so-called mixed faucet.

Between the connecting part of the hot water circuit 26 and the water supply circuit 7 and the hot water valve 8, the hot water temperature sensor 18 which measures the water temperature inside the piping of this position is provided.
A block diagram showing a flow of signals from the tapping temperature sensor 18 is the same as that of the second embodiment and is shown in FIG.

Next, the operation will be described.
When the circulation pump 3 is driven, the hot water in the hot water tank 1 flows into the outgoing pipe 2 and returns to the hot water tank 1 through the circulation pump 3 and the return pipe 4.
The amount of water supplied from the water supply circuit 7 to the hot water circuit 26 is controlled by the water supply controller 21. The water supply controller 21 compares the temperature measured by the tapping temperature sensor 18 (tapping temperature) with the tapping temperature setting value (60 ° C.) set by the tapping temperature setting device 22, and the measured tapping temperature is the tapping temperature setting value. If it is higher, the opening of the water supply control valve 16 is increased to cope with this, and the amount of water supplied from the water supply circuit 7 to the circulation circuit 5 is increased to lower the hot water temperature. Control to be equal to the set value.

  Since the check valve 11 is provided between the circulation circuit 5 and the hot water circuit 26, even if the water supply control valve 16 is opened, the water supply does not enter the circulation circuit 5. Accordingly, the temperature of the circulation circuit 5 and the hot water tank 1 is not lowered. Further, since the water supply does not enter the circulation circuit 5, the water supply does not enter the hot water tank 1, and the temperature of the hot water tank 1 does not decrease.

Hot water from the hot water tank 1 circulates in the circulation circuit 5. When the hot water valve 8 is opened from this state, hot water flows from the circulation circuit 5 into the hot water circuit 26. The temperature measured by the tapping temperature sensor 18 rises, and water is supplied from the water supply circuit 7 by the control described above, and the hot water that has reached the tapping temperature set value (60 ° C.) is discharged through the tapping valve 8.
At this time, by operating the water outlet valve 27 to add water, the temperature of the hot water can be arbitrarily changed up to 60 ° C.

  The time from when the tap valve 8 is opened until hot water is poured out depends on the length of the tap circuit 26. Since piping such as the circulation circuit 5 can be routed relatively freely, it is possible to shorten the length of the tapping circuit 26 by piping according to the position of the tapping valve 8. In this case, the hot water valve 8 is opened, and hot water having a sufficiently high temperature is discharged in a sufficiently short time.

As described above, even when the temperature of the hot water in the hot water storage tank 1 is 80 ° C., the temperature of the hot water at the time of hot water can be set to 60 ° C., or the upper limit temperature of the hot water can be set to 60 ° C. in the case of using a mixed tap. . Furthermore, since the tapping temperature is measured and controlled, a stable tapping temperature can be obtained regardless of the season or weather. As a result, compared to the case where the total amount of hot water required for hot water is stored in the hot water storage tank at 60 ° C., which is equal to the hot water temperature, a hot water storage tank with a smaller capacity can be used, and a compact hot water supply system can be constructed. It is done.
Moreover, since hot water is taken out from a circulation circuit in which piping can be routed relatively freely, hot water having a sufficiently high temperature can be discharged in a sufficiently short time after the hot water valve is opened.

Since the check valve 11 is provided between the circulation circuit 5 and the hot water circuit 26, water supply does not enter the circulation circuit 5 and the hot water tank 1, and temperature reduction of the circulation circuit 5 and the hot water tank 1 can be prevented.
If the variation in the temperature of the hot water is allowed to some extent, it is possible to make the amount of water supplied at the time of hot water constant by using a check valve and a pressure reducing valve instead of the water supply control valve 16.

Embodiment 9 FIG.
Another embodiment is shown in which there is no fear that feed water enters the circulation circuit, and the hot water storage temperature can be higher than the hot water temperature.
FIG. 11 shows a piping circuit of a hot water supply system in such a case.
Hot water at 80 ° C. is stored in the hot water tank 1. The hot water storage tank 1 is connected to the outgoing pipe 2, the end of the outgoing pipe 2 is connected to the suction port of the circulation pump 3, the return pipe 4 is connected to the discharge port of the circulation pump 3, and the end of the return pipe 4 is the hot water storage. A circulation circuit 5 which is connected to the tank 1 and includes an outgoing pipe 2, a circulation pump 3 and a return pipe 4 is constituted.

  A bypass circuit 6 is provided between the outgoing pipe 2 and the return pipe 4. The connecting part between the outgoing pipe 2 and the bypass circuit 6 is located immediately after the connecting part between the hot water tank 1 and the outgoing pipe 2. In the middle of the bypass circuit 6, a flow control valve 13 whose opening degree can be changed electrically is provided. Further, a resistance adjusting valve 14 is provided between a connection portion between the return pipe 4 and the bypass circuit 6 and a connection portion between the return pipe 4 and the hot water tank 1. The resistance of the resistance adjusting valve 14 can be changed by changing the opening.

In the middle of the circulation circuit 5, a hot water discharge circuit 26 is connected downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 and upstream of the connecting portion between the return pipe 4 and the bypass circuit 6. The hot water circuit 26 takes in hot water from the circulation circuit 5 through the check valve 11 and discharges hot water through the hot water valve 8.
A water supply circuit 7 is connected to a position downstream of the check valve 11 of the hot water circuit 26 and upstream of the hot water valve 8. Here, the water supply circuit 7 has an elevated water tank 15 in which the head is kept constant, and a water supply control valve 16 whose opening degree can be changed electrically.
The outlet of the tap valve 8 is the same as the outlet of the outlet valve 27 that drains water from the elevated water tank 15, and the outlet valve 8 and the outlet valve 27 together form a so-called mixed faucet.

Between the connecting part of the outgoing pipe 2 and the bypass circuit 6 and the connecting part of the circulation circuit 5 and the hot water circuit 26, a heat retaining temperature sensor 17 for measuring the water temperature in the pipe at this position is provided. Between the connecting part of the hot water circuit 26 and the water supply circuit 7 and the hot water valve 8, the hot water temperature sensor 18 which measures the water temperature inside the piping of this position is provided.
A block diagram showing the flow of signals from the heat insulation temperature sensor 17 is the same as that of the second embodiment, and is shown in FIG.
A block diagram showing a flow of signals from the tapping temperature sensor 18 is the same as that of the second embodiment and is shown in FIG.
Here, the heat insulation temperature setting value set in the heat insulation temperature setting device 20 is 65 ° C., and the hot water temperature setting value set in the hot water temperature setting device 22 is 60 ° C.

Next, the operation will be described.
When the circulation pump 3 is driven, the hot water in the hot water tank 1 flows into the outgoing pipe 2 and returns to the hot water tank 1 through the circulation pump 3 and the return pipe 4. Further, part of the hot water that has entered the return pipe 4 from the circulation pump 3 flows into the outgoing pipe 2 through the bypass circuit 6.
The ratio of the amount of hot water flowing into the outgoing pipe 2 from the hot water storage tank 1 and the amount from the bypass circuit 6 is controlled by a heat retention controller 19. The insulation controller 19 compares the temperature measured by the insulation temperature sensor 17 (the insulation temperature of the circulation circuit 5) with the insulation temperature set value (65 ° C.) set by the insulation temperature setting device 20, and the measured insulation temperature is When the temperature is lower than the set temperature, the opening temperature of the flow rate control valve 13 is reduced to cope with this, so that the flow rate from the bypass circuit 6 is small and the hot water from the hot water tank 1 is increased. And the temperature is controlled so that the temperature is equal to the temperature setting value (65 ° C.).

  The length from the hot water tank 1 to the connecting part of the outgoing pipe 2 and the bypass circuit 6 as when the connecting part of the outgoing pipe 2 and the bypass circuit 6 is immediately after the connected part of the hot water tank 1 and the outgoing pipe 2 If the flow path resistance is very small, there may be too much hot water from the hot water storage tank 1 and it may be difficult to control the heat retention temperature. Therefore, at this time, there is not too much hot water from the hot water tank 1 by providing the resistance adjusting valve 14 between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the hot water tank 1. Adjust as follows.

  When it becomes difficult to control the heat insulation temperature within the control range of the heat insulation controller 19 and the flow rate control valve 13 due to the influence of the change in the flow resistance of the piping due to secular change and the influence of the change in the heat radiation condition due to the season. The flow rate balance is adjusted by adjusting the opening degree of the resistance adjustment valve 14 so that the heat insulation temperature can be controlled within the control range of the heat insulation controller 19 and the flow control valve 13.

  The amount of water supplied from the water supply circuit 7 to the hot water circuit 26 is controlled by the water supply controller 21. The water supply controller 21 compares the temperature measured by the tapping temperature sensor 18 (tapping temperature) with the tapping temperature setting value (60 ° C.) set by the tapping temperature setting device 22, and the measured tapping temperature is the tapping temperature setting value. When the temperature is higher, the opening of the water supply control valve 16 is increased to cope with this, the amount of water supplied from the water supply circuit 7 to the hot water circuit 26 is increased to lower the hot water temperature, and the hot water temperature becomes the hot water temperature. Control to be equal to the set value.

Since the check valve 11 is provided between the circulation circuit 5 and the hot water circuit 26, even if the water supply control valve 16 is opened, the water supply does not enter the circulation circuit 5. Therefore, the temperature of the circulation circuit 5 does not decrease. Further, since the water supply does not enter the circulation circuit 5, the water supply does not enter the hot water tank 1, and the temperature of the hot water tank 1 does not decrease.
The circulating circuit 5 is circulated with hot water that has been controlled by the heat retention controller 19 and has reached the heat retention temperature set value (65 ° C.). When the hot water valve 8 is opened from this state, 65 ° C. hot water flows from the circulation circuit 5 into the hot water circuit 26. The temperature measured by the tapping temperature sensor 18 rises, and water is supplied from the water supply circuit 7 by the control described above, and the hot water that has reached the tapping temperature set value (60 ° C.) is discharged through the tapping valve 8.
At this time, by operating the water outlet valve 27 to add water, the temperature of the hot water can be arbitrarily changed up to 60 ° C.

  The time from when the tap valve 8 is opened until hot water is poured out depends on the length of the tap circuit 26. Since piping such as the circulation circuit 5 can be routed relatively freely, it is possible to shorten the length of the tapping circuit 26 by piping according to the position of the tapping valve 8. In this case, the hot water valve 8 is opened, and hot water having a sufficiently high temperature is discharged in a sufficiently short time.

  As described above, even when the temperature of the hot water in the hot water storage tank 1 is set to 80 ° C., the temperature of the hot water at the time of hot water can be set to 60 ° C. . Furthermore, since the tapping temperature is measured and controlled, a stable tapping temperature can be obtained regardless of the season or weather. As a result, compared to the case where the total amount of hot water required for hot water is stored in the hot water storage tank at 60 ° C., which is equal to the hot water temperature, a hot water storage tank with a smaller capacity can be used, and a compact hot water supply system can be constructed. It is done.

Moreover, the temperature of the hot water circulating through the circulation circuit 5 can be set to a temperature lower than the hot water storage temperature of the hot water tank 1, and a heat radiation loss radiating heat from the piping of the circulation circuit 5 can be reduced.
Moreover, since hot water is taken out from a circulation circuit in which piping can be routed relatively freely, hot water having a sufficiently high temperature can be discharged in a sufficiently short time after the hot water valve is opened.
Since the check valve 11 is provided between the circulation circuit 5 and the hot water circuit 26, water supply does not enter the circulation circuit 5 and the hot water tank 1, and temperature reduction of the circulation circuit 5 and the hot water tank 1 can be prevented.

Moreover, since the connection part of the outgoing pipe 2 and the bypass circuit 6 is a position immediately after the connection part of the hot water tank 1 and the outgoing pipe 2, the hot water tank 1 is changed after the opening degree of the flow control valve 13 is changed small. Since the time difference until the hot water reaches the connecting portion between the going pipe 2 and the bypass circuit 6 is small, good temperature control can be performed.
Moreover, since the resistance adjustment valve 14 is provided between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the hot water tank 1, the connection part of the outgoing pipe 2 and the bypass circuit 6 from the hot water tank 1. Even when the length up to is short and the flow path resistance is very small, the heat insulation temperature can be controlled.
In addition, since the resistance of the resistance adjustment valve 14 can be changed, when the control of the heat insulation temperature becomes difficult due to the influence of secular change or change of the heat radiation condition, the opening of the resistance adjustment valve 14 can be adjusted. It is possible to control the heat insulation temperature.

  Note that the opening degree of the flow control valve 13 may be fixed as long as the variation in the heat retention temperature is allowed to some extent. Similarly, if the fluctuation of the tapping temperature is allowed to some extent, it is possible to use a check valve and a pressure reducing valve in place of the feed water control valve 16 to make the water supply amount at the time of tapping hot water constant.

Embodiment 10 FIG.
Another embodiment is shown in which there is no fear that feed water enters the circulation circuit, and the hot water storage temperature can be higher than the hot water temperature.
FIG. 12 shows a piping circuit of a hot water supply system in such a case.
Hot water at 80 ° C. is stored in the hot water tank 1. The hot water storage tank 1 is connected to the outgoing pipe 2, the end of the outgoing pipe 2 is connected to the suction port of the circulation pump 3, the return pipe 4 is connected to the discharge port of the circulation pump 3, and the end of the return pipe 4 is the hot water storage. A circulation circuit 5 which is connected to the tank 1 and includes an outgoing pipe 2, a circulation pump 3 and a return pipe 4 is constituted.

  A bypass circuit 6 is provided between the outgoing pipe 2 and the return pipe 4. The connecting part between the outgoing pipe 2 and the bypass circuit 6 is located immediately after the connecting part between the hot water tank 1 and the outgoing pipe 2. A resistance adjustment valve 14 is provided in the middle of the bypass circuit 6. The resistance of the resistance adjusting valve 14 can be changed by changing the opening. Further, a flow rate control valve 13 whose opening degree can be changed electrically is provided between a connection portion between the return pipe 4 and the bypass circuit 6 and a connection portion between the return pipe 4 and the heat exchanger 23.

In the middle of the circulation circuit 5, a hot water discharge circuit 26 is connected downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 and upstream of the connecting portion between the return pipe 4 and the bypass circuit 6. The hot water circuit 26 takes in hot water from the circulation circuit 5 through the check valve 11 and discharges hot water through the hot water valve 8.
A water supply circuit 7 is connected to a position downstream of the check valve 11 of the hot water circuit 26 and upstream of the hot water valve 8. Here, the water supply circuit 7 has an elevated water tank 15 in which the head is kept constant, and a water supply control valve 16 whose opening degree can be changed electrically.
The outlet of the tap valve 8 is the same as the outlet of the outlet valve 27 that drains water from the elevated water tank 15, and the outlet valve 8 and the outlet valve 27 together form a so-called mixed faucet.

Between the connecting part of the outgoing pipe 2 and the bypass circuit 6 and the connecting part of the circulation circuit 5 and the hot water circuit 26, a heat retaining temperature sensor 17 for measuring the water temperature in the pipe at this position is provided. Between the connecting part of the hot water circuit 26 and the water supply circuit 7 and the hot water valve 8, the hot water temperature sensor 18 which measures the water temperature inside the piping of this position is provided.
A block diagram showing the flow of signals from the heat insulation temperature sensor 17 is the same as that of the second embodiment, and is shown in FIG.
A block diagram showing a flow of signals from the tapping temperature sensor 18 is the same as that of the second embodiment and is shown in FIG.
Here, the heat insulation temperature setting value set in the heat insulation temperature setting device 20 is 65 ° C., and the hot water temperature setting value set in the hot water temperature setting device 22 is 60 ° C.

Next, the operation will be described.
When the circulation pump 3 is driven, the hot water in the hot water tank 1 flows into the outgoing pipe 2 and returns to the hot water tank 1 through the circulation pump 3 and the return pipe 4. Further, part of the hot water that has entered the return pipe 4 from the circulation pump 3 flows into the outgoing pipe 2 through the bypass circuit 6.
The ratio of the amount of hot water flowing into the outgoing pipe 2 from the hot water storage tank 1 and the amount from the bypass circuit 6 is controlled by a heat retention controller 19. The insulation controller 19 compares the temperature measured by the insulation temperature sensor 17 (the insulation temperature of the circulation circuit 5) with the insulation temperature set value (65 ° C.) set by the insulation temperature setting device 20, and the measured insulation temperature is When the temperature is lower than the set temperature, the opening temperature of the flow control valve 13 is increased to cope with this, so that the flow rate from the bypass circuit 6 is small and the hot water from the hot water tank 1 is increased. And the temperature is controlled so that the temperature is equal to the temperature setting value (65 ° C.).

  When the length of the bypass circuit 6 is short and the flow path resistance of the bypass circuit 6 is very small, there is a case where there is too much hot water flowing into the outgoing pipe 2 from the bypass circuit 6 and it becomes difficult to control the heat insulation temperature. . Therefore, at this time, the resistance adjustment valve 14 is provided in the bypass circuit 6 so that the amount of hot water from the bypass circuit 6 is adjusted so as not to be excessive.

  When it becomes difficult to control the heat insulation temperature within the control range of the heat insulation controller 19 and the flow rate control valve 13 due to the influence of the change in the flow resistance of the piping due to secular change and the influence of the change in the heat radiation condition due to the season. The flow rate balance is adjusted by adjusting the opening degree of the resistance adjustment valve 14 so that the heat insulation temperature can be controlled within the control range of the heat insulation controller 19 and the flow control valve 13.

  The amount of water supplied from the water supply circuit 7 to the hot water circuit 26 is controlled by the water supply controller 21. The water supply controller 21 compares the temperature measured by the tapping temperature sensor 18 (tapping temperature) with the tapping temperature setting value (60 ° C.) set by the tapping temperature setting device 22, and the measured tapping temperature is the tapping temperature setting value. When the temperature is higher, the opening of the water supply control valve 16 is increased to cope with this, the amount of water supplied from the water supply circuit 7 to the hot water circuit 26 is increased to lower the hot water temperature, and the hot water temperature becomes the hot water temperature. Control to be equal to the set value.

  Since the check valve 11 is provided between the circulation circuit 5 and the hot water circuit 26, even if the water supply control valve 16 is opened, the water supply does not enter the circulation circuit 5. Therefore, the temperature of the circulation circuit 5 does not decrease. Further, since the water supply does not enter the circulation circuit 5, the water supply does not enter the hot water tank 1, and the temperature of the hot water tank 1 does not decrease.

The circulating circuit 5 is circulated with hot water that has been controlled by the heat retention controller 19 and has reached the heat retention temperature set value (65 ° C.). When the hot water valve 8 is opened from this state, 65 ° C. hot water flows from the circulation circuit 5 into the hot water circuit 26. The temperature measured by the tapping temperature sensor 18 rises, and water is supplied from the water supply circuit 7 by the control described above, and the hot water that has reached the tapping temperature set value (60 ° C.) is discharged through the tapping valve 8.
At this time, by operating the water outlet valve 27 to add water, the temperature of the hot water can be arbitrarily changed up to 60 ° C.

  The time from when the tap valve 8 is opened until hot water is poured out depends on the length of the tap circuit 26. Since piping such as the circulation circuit 5 can be routed relatively freely, it is possible to shorten the length of the tapping circuit 26 by piping according to the position of the tapping valve 8. In this case, the hot water valve 8 is opened, and hot water having a sufficiently high temperature is discharged in a sufficiently short time.

As described above, even when the temperature of the hot water in the hot water storage tank 1 is 80 ° C., the temperature of the hot water at the time of hot water can be set to 60 ° C., or the upper limit temperature of the hot water can be set to 60 ° C. in the case of using a mixed tap. . Furthermore, since the tapping temperature is measured and controlled, a stable tapping temperature can be obtained regardless of the season or weather. As a result, compared to the case where the total amount of hot water required for hot water is stored in the hot water storage tank at 60 ° C., which is equal to the hot water temperature, a hot water storage tank with a smaller capacity can be used, and a compact hot water supply system can be constructed. It is done.
Moreover, the temperature of the hot water circulating through the circulation circuit 5 can be set to a temperature lower than the hot water storage temperature of the hot water tank 1, and a heat radiation loss radiating heat from the piping of the circulation circuit 5 can be reduced.

Moreover, since hot water is taken out from a circulation circuit in which piping can be routed relatively freely, hot water having a sufficiently high temperature can be discharged in a sufficiently short time after the hot water valve is opened.
Since the check valve 11 is provided between the circulation circuit 5 and the hot water circuit 26, water supply does not enter the circulation circuit 5 and the hot water tank 1, and temperature reduction of the circulation circuit 5 and the hot water tank 1 can be prevented.
Furthermore, by providing the flow rate control valve 13 between the connection part of the return pipe 4 and the bypass circuit 6 and the connection part of the return pipe 4 and the hot water tank 1, the heat insulation temperature when there is no hot water is higher than the heat insulation temperature set value. If it is too high, the flow rate control valve 13 is fully closed, so that the hot water in the hot water tank 1 is not used at all, and the hot water temperature in the hot water tank 1 can be kept high.

Moreover, since the connection part of the outgoing pipe 2 and the bypass circuit 6 is a position immediately after the connection part of the hot water storage tank 1 and the outgoing pipe 2, the opening degree of the flow control valve 13 is largely changed before the hot water storage tank 1 Since the time difference until the hot water reaches the connecting portion between the going pipe 2 and the bypass circuit 6 is small, good temperature control can be performed.
Further, since the resistance adjusting valve 14 is provided in the bypass circuit 6, even when the length of the bypass circuit 6 is short and the flow path resistance is very small, the heat insulation temperature can be controlled.
In addition, since the resistance of the resistance adjustment valve 14 can be changed, when the control of the heat insulation temperature becomes difficult due to the influence of secular change or change of the heat radiation condition, the opening of the resistance adjustment valve 14 can be adjusted. It is possible to control the heat insulation temperature.

  Note that the opening degree of the flow control valve 13 may be fixed as long as the variation in the heat retention temperature is allowed to some extent. Similarly, if the fluctuation of the tapping temperature is allowed to some extent, it is possible to use a check valve and a pressure reducing valve in place of the feed water control valve 16 to make the water supply amount at the time of tapping hot water constant.

Embodiment 11 FIG.
Another embodiment is shown in which there is no fear that feed water enters the circulation circuit, and the hot water storage temperature can be higher than the hot water temperature.
FIG. 13 shows a piping circuit of a hot water supply system in such a case.
Hot water at 80 ° C. is stored in the hot water tank 1. The hot water storage tank 1 is connected to the outgoing pipe 2, the end of the outgoing pipe 2 is connected to the suction port of the circulation pump 3, the return pipe 4 is connected to the discharge port of the circulation pump 3, and the end of the return pipe 4 is the hot water storage. A circulation circuit 5 which is connected to the tank 1 and includes an outgoing pipe 2, a circulation pump 3 and a return pipe 4 is constituted.

  A bypass circuit 6 is provided between the outgoing pipe 2 and the return pipe 4. The connecting part between the outgoing pipe 2 and the bypass circuit 6 is located immediately after the connecting part between the hot water tank 1 and the outgoing pipe 2. In the middle of the bypass circuit 6, a flow control valve 13 whose opening degree can be changed electrically is provided. In addition, a resistance adjustment valve 14 is provided between a connection portion between the return pipe 4 and the bypass circuit 6 and a connection portion between the return pipe 4 and the hot water tank 1. The resistance of the resistance adjusting valve 14 can be changed by changing the opening.

In the middle of the circulation circuit 5, the first hot water circuit 28 and the second hot water are located downstream of the connecting portion between the outgoing pipe 2 and the bypass circuit 6 and upstream of the connecting portion between the return pipe 4 and the bypass circuit 6. A circuit 37 is connected.
The first hot water circuit 28 takes in hot water from the circulation circuit 5 through the first check valve 29 and discharges hot water through the first hot water valve 31.
A first water supply circuit 33 is connected to a position downstream of the first check valve 29 of the first hot water circuit 28 and upstream of the first hot water valve 31. The first water supply circuit 33 includes an elevated water tank 15 in which the head is kept constant, and a first water supply control valve 34 whose opening degree can be changed electrically.

The outlet of the first outlet valve 31 is the same as the outlet of the first outlet valve 32 that discharges water from the elevated water tank 15. The first outlet valve 31 and the first outlet valve 32 are combined. The so-called mixed faucet.
The second hot water circuit 37 takes in hot water from the circulation circuit 5 through the second check valve 38 and discharges hot water through the second hot water valve 40.
A second water supply circuit 42 is connected to a position downstream of the second check valve 38 and upstream of the second hot water valve 40 of the second hot water circuit 37. The 2nd water supply circuit 42 has the elevated water tank 15 (common with a 1st water supply circuit) with which a head is kept constant, and the 2nd water supply control valve 43 which can change an opening degree electrically.
The outlet of the second outlet valve 40 is the same as the outlet of the second outlet valve 41 that discharges water from the elevated water tank 15, and the second outlet valve 40 and the second outlet valve 41 are combined. The so-called mixed faucet.

Between the connecting part of the outgoing pipe 2 and the bypass circuit 6 and the connecting part of the circulation circuit 5 and the second hot water circuit 37, a heat retaining temperature sensor 17 for measuring the water temperature in the pipe at this position is provided. Between the connection part of the 1st hot water circuit 28 and the 1st water supply circuit 33, and the 1st hot water valve 31, the 1st hot water temperature sensor 30 which measures the water temperature inside the piping of this position is provided. ing. Between the connection part of the 2nd hot water circuit 37 and the 2nd water supply circuit 42, and the 2nd hot water valve 40, the 2nd hot water temperature sensor 39 which measures the water temperature inside the piping of this position is provided. ing.
A block diagram showing the flow of signals from the heat insulation temperature sensor 17 is the same as that of the second embodiment, and is shown in FIG. Here, the heat insulation temperature set value set in the heat insulation temperature setting device 20 is 65 ° C.

FIG. 14 is a block diagram showing the flow of signals from the first hot water temperature sensor 30 and the second hot water temperature sensor 39.
A signal from the first hot water temperature sensor 30 is input to the first water supply controller 35. In the first tapping temperature setting device 36, 60 ° C. is set as a set value of the tapping temperature of the first tapping circuit by, for example, input from the operation panel or writing to the memory. The signal of the first hot water temperature sensor 30 and the set value of the first hot water temperature setting device 36 are input to the first water supply controller 35, and the first water supply controller 35 drives the first water supply control valve 34. To output.
The signal from the second hot water temperature sensor 39 is input to the second water supply controller 44. The second tapping temperature setting unit 45 is set to 45 ° C. as a set value for the tapping temperature of the second tapping circuit by, for example, input from the operation panel or writing to the memory. The signal from the second hot water temperature sensor 39 and the set value of the second hot water temperature setting device 45 are input to the second water supply controller 44, and the first water supply controller 44 drives the first water supply control valve 43. To output.

Next, the operation will be described.
The heat retaining operation of the circulation circuit 5 is the same as that of the ninth embodiment, and the description thereof is omitted.
The amount of water supplied from the first water supply circuit 33 to the first hot water circuit 28 is controlled by the first water supply controller 35. The first feed water controller 35 has a temperature measured by the first tapping temperature sensor 30 (first tapping temperature) and a first tapping temperature setting value (60 ° C.) set by the first tapping temperature setting unit 36. ), And when the measured first tapping temperature is higher than the first tapping temperature set value, in order to cope with this, the opening of the first feed water control valve 34 is increased, The amount of water supplied from the water supply circuit 33 to the first hot water circuit 28 is increased to lower the hot water temperature, and the first hot water temperature is controlled to be equal to the first hot water temperature set value.

The circulating circuit 5 is circulated with hot water that has been controlled by the heat retention controller 19 and has reached the heat retention temperature set value (65 ° C.). When the first hot water valve 31 is opened from this state, 65 ° C. hot water flows into the first hot water circuit 28 from the circulation circuit 5. Hot water whose temperature measured by the first hot water temperature sensor 30 is increased and water is supplied from the first water supply circuit 33 by the above-described control and becomes the first hot water temperature set value (60 ° C.). Is discharged through the first outlet valve 31.
At this time, by operating the first water discharge valve 32 to add water, the temperature of the hot water can be arbitrarily changed up to 60 ° C.

  The amount of water supplied from the second water supply circuit 42 to the second hot water circuit 37 is controlled by the second water supply controller 44. The second feed water controller 44 has a temperature measured by the second tapping temperature sensor 39 (second tapping temperature) and a second tapping temperature set value (45 ° C.) set by the second tapping temperature setting unit 45. ), And when the measured second tapping temperature is higher than the second tapping temperature set value, in order to cope with this, the opening degree of the second water supply control valve 43 is increased, The amount of water supplied from the water supply circuit 42 to the second hot water circuit 37 is increased to lower the hot water temperature, and the second hot water temperature is controlled to be equal to the second hot water temperature set value.

The circulating circuit 5 is circulated with hot water that has been controlled by the heat retention controller 19 and has reached the heat retention temperature set value (65 ° C.). When the second hot water valve 40 is opened from this state, 65 ° C. hot water flows from the circulation circuit 5 into the second hot water circuit 37. The temperature measured by the second tapping temperature sensor 39 rises, and water is supplied from the second water supply circuit 42 by the control described above, and reaches the second tapping temperature setting value (45 ° C.). Is discharged through the second tap valve 40.
At this time, by operating the second water discharge valve 41 to add water, the temperature of the hot water can be arbitrarily changed up to 45 ° C.

  The hot water supply system as described above has a plurality of hot water circuits, and the hot water temperature of each hot water circuit can be set uniquely. When a mixed tap is used, the upper limit temperature of the hot water can be set uniquely. For example, it is possible to set such that the upper limit temperature is limited to 60 ° C. for the hot water in the kitchen, and the upper limit temperature is limited to 45 ° C. for the hot water in the bathroom. By limiting the temperature of the hot water at a place where high temperature hot water is not required, even if the hot water valve is erroneously operated, the influence can be reduced.

It is a piping circuit of the hot water supply system which shows Embodiment 1 of this invention. It is a piping circuit of the hot water supply system which shows Embodiment 2 of this invention. It is a block diagram which shows the flow of the signal of Embodiment 2 of this invention. It is a block diagram which shows the flow of the signal of Embodiment 2 of this invention. It is a block diagram which shows the flow of the signal of Embodiment 3 of this invention. It is a block diagram which shows the flow of the signal of Embodiment 4 of this invention. It is a piping circuit of the hot water supply system which shows Embodiment 5 of this invention. It is a piping circuit of the hot water supply system which shows Embodiment 6 of this invention. It is a piping circuit of the hot water supply system which shows Embodiment 7 of this invention. It is a piping circuit of the hot water supply system which shows Embodiment 8 of this invention. It is a piping circuit of the hot water supply system which shows Embodiment 9 of this invention. It is a piping circuit of the hot water supply system which shows Embodiment 10 of this invention. It is a piping circuit of the hot water supply system which shows Embodiment 11 of this invention. It is a block diagram which shows the flow of a signal of Embodiment 11 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Hot water storage tank, 2 way piping, 3 Circulation pump, 4 Return piping, 5 Circulation circuit, 6 Bypass circuit, 7 Water supply circuit, 8 Hot water outlet valve, 9 valve, 10 Pressure reducing valve, 11 Check valve, 12 Check valve, 13 Flow control valve, 14 resistance adjustment valve, 15 elevated water tank, 16 water supply control valve, 17 heat retention temperature sensor, 18 hot water temperature sensor, 19 heat retention controller, 20 heat retention temperature setter, 21 water supply controller, 22 hot water temperature setter, DESCRIPTION OF SYMBOLS 23 Heat exchanger, 24 Hot-water supply circuit, 26 Hot-water supply circuit, 27 Outflow valve, 28 1st hot-water supply circuit, 29 1st non-return valve, 30 1st hot-water temperature sensor, 31 1st hot-water valve, 32 1st Water outlet valve, 33 first water supply circuit, 34 first water supply control valve, 35 first water supply controller, 36 first hot water temperature setting device, 37 second hot water circuit, 38 second check valve 39 Second hot water temperature center Sensor, 40 second tapping valve, 41 second tapping valve, 42 second feeding circuit, 43 second feeding control valve, 44 second feeding controller, 45 second tapping temperature setting device.

Claims (41)

A hot water tank,
The outgoing piping that introduces hot water inside this hot water tank,
A circulation pump that draws in hot water from this outgoing pipe and sends it out under pressure;
A return pipe for returning the hot water sent out by the circulation pump to the hot water storage tank,
Forming a circulation circuit composed of the outgoing pipe, the circulation pump, and the return pipe;
A bypass circuit connecting the outgoing pipe and the return pipe;
A water supply circuit connected on the circulation circuit downstream from the connection part between the outgoing pipe and the bypass circuit and upstream from a connection part between the return pipe and the bypass circuit;
A hot water outlet connected to the circulation circuit downstream from the connection part between the circulation circuit and the water supply circuit and upstream from the connection part between the return pipe and the bypass circuit,
The bypass circuit is provided with a flow rate limiting means for limiting the amount of hot water passing through the bypass circuit,
A hot water supply system, wherein the water supply circuit is provided with water supply restriction means for restricting the amount of water supply. A heat retention temperature sensor provided at a position upstream of the connection portion of the circulation circuit with the water supply circuit and downstream of the connection portion of the outgoing pipe with the bypass circuit;
Heat insulation temperature setting means for setting a target value of the heat insulation temperature;
A flow rate control means for taking in an output of the heat insulation temperature sensor and a heat insulation temperature target value set by the heat insulation temperature setting means and controlling a flow rate restriction means of the bypass circuit;
A tapping temperature sensor provided at a position downstream from the connection portion of the circulation circuit with the water supply circuit and upstream from the tapping outlet;
Tapping temperature setting means for setting a target value of tapping temperature;
A water supply control means for taking in an output of the hot water temperature sensor and a hot water temperature target value set by the hot water temperature setting means and controlling a water supply restriction means of the water supply circuit;
The hot water supply system according to claim 1, further comprising:   The hot water supply system according to claim 2, wherein the control target value of the water supply control means of the water supply circuit is set to be higher than the control target value of the flow rate control means of the bypass circuit.   The hot water supply system according to claim 2 or 3, wherein a connection position between the outgoing pipe and the bypass circuit is set immediately after the hot water storage tank and the outgoing pipe are connected.   The hot water supply system according to any one of claims 2 to 4, wherein a resistance element for increasing flow path resistance is provided downstream of a connection portion of the return pipe with the bypass circuit.   The hot water supply system according to claim 5, wherein the resistance of the resistance element is variable.   The hot water supply system according to any one of claims 2 to 6, wherein the water supply control means takes in control information of the flow rate control means.   The hot water supply system according to any one of claims 2 to 6, wherein the flow rate control means takes in control information of the water supply control means. A hot water tank,
The outgoing piping that introduces hot water inside this hot water tank,
A circulation pump that draws in hot water from this outgoing pipe and sends it out under pressure;
A return pipe for returning the hot water sent out by the circulation pump to the hot water storage tank,
Forming a circulation circuit composed of the outgoing pipe, the circulation pump, and the return pipe;
A bypass circuit connecting the outgoing pipe and the return pipe;
A water supply circuit connected on the circulation circuit downstream from the connection part between the outgoing pipe and the bypass circuit and upstream from the connection part between the return pipe and the bypass circuit;
A hot water outlet connected to the circulation circuit downstream from the connection part between the circulation circuit and the water supply circuit and upstream from the connection part between the return pipe and the bypass circuit,
A flow rate limiting means for limiting the amount of hot water returning from the return pipe to the hot water tank is provided at a position downstream of the connection portion of the return pipe with the bypass circuit,
A hot water supply system, wherein the water supply circuit is provided with water supply restriction means for restricting the amount of water supply. A heat retention temperature sensor provided at a position upstream of the connection portion of the circulation circuit with the water supply circuit and downstream of the connection portion of the outgoing pipe with the bypass circuit;
Heat insulation temperature setting means for setting a target value of the heat insulation temperature;
A flow rate control unit that takes in an output of the heat retention temperature sensor and a heat insulation temperature target value set by the heat insulation temperature setting unit, and controls a flow rate restriction unit of the return pipe;
A tapping temperature sensor provided at a position downstream from the connection portion of the circulation circuit with the water supply circuit and upstream from the tapping outlet;
Tapping temperature setting means for setting a target value of tapping temperature;
A water supply control means for taking in the output of the hot water temperature sensor and the hot water temperature target value set by the hot water temperature setting means and controlling the water supply restriction means of the water supply circuit;
The hot water supply system according to claim 9, further comprising:   The hot water supply system according to claim 10, wherein the control target value of the water supply control means is controlled to be set higher than the control target value of the flow rate control means.   The hot water supply system according to claim 10 or 11, wherein a connection position between the outgoing pipe and the bypass circuit is set immediately after connection between the hot water storage tank and the outgoing pipe.   The hot water supply system according to any one of claims 10 to 12, wherein a resistance element that increases flow path resistance is provided in the bypass circuit.   The hot water supply system according to claim 13, wherein the resistance of the resistance element is variable.   The hot water supply system according to any one of claims 10 to 14, wherein the water supply control means takes in control information of the flow rate control means.   The hot water supply system according to any one of claims 10 to 14, wherein the flow rate control means takes in control information of the water supply control means. A hot water tank,
A heat exchanger provided in the hot water tank,
The outgoing piping that introduces the hot water of this heat exchanger,
A circulation pump that draws in hot water from this outgoing pipe and sends it out under pressure;
A return pipe for returning the hot water sent out by the circulation pump to the heat exchanger,
Forming a circulation circuit composed of the outgoing pipe, the circulation pump, and the return pipe;
A bypass circuit connecting the outgoing pipe and the return pipe;
Hot water supply for supplying hot water from the hot water storage tank to the circulation circuit, connected to the circulation circuit downstream from the connection portion between the outgoing pipe and the bypass circuit and upstream from the connection portion between the return pipe and the bypass circuit. Circuit,
A check valve that prevents backflow of the flow from the hot water tank to the hot water supply circuit;
A water supply circuit connected to the hot water supply circuit;
Having a hot water outlet connected on the circulation circuit downstream from the connection part between the circulation circuit and the hot water supply circuit and upstream from the connection part between the return pipe and the bypass circuit;
The bypass circuit is provided with a flow rate limiting means for limiting the amount of hot water passing through the bypass circuit,
A hot water supply system, wherein the water supply circuit is provided with water supply restriction means for restricting the amount of water supply. A heat retention temperature sensor provided at a position upstream of the connection portion of the circulation circuit with the hot water supply circuit and downstream of the connection portion of the outgoing pipe with the bypass circuit;
Heat insulation temperature setting means for setting a target value of the heat insulation temperature;
A flow rate control means for taking in an output of the heat insulation temperature sensor and a heat insulation temperature target value set by the heat insulation temperature setting means and controlling the flow rate restriction means;
A hot water temperature sensor at a position downstream of the hot water supply circuit connected to the water supply circuit and upstream of the hot water outlet,
Tapping temperature setting means for setting a target value of tapping temperature;
A water supply control means for taking in an output of the hot water temperature sensor and a hot water temperature target value set by the hot water temperature setting means and controlling the water supply restriction means;
The hot water supply system according to claim 17, further comprising:   The hot water supply system according to claim 18, wherein a connection position between the outgoing pipe and the bypass circuit is set immediately after the connection between the heat exchanger and the outgoing pipe.   20. The hot water supply system according to claim 18, wherein a resistance element that increases flow path resistance is provided downstream of a connection portion of the return pipe with the bypass circuit.   The hot water supply system according to claim 20, wherein the resistance of the resistance element is variable. A hot water tank,
A heat exchanger provided in the hot water tank,
The outgoing piping that introduces the hot water of this heat exchanger,
A circulation pump that draws in hot water from this outgoing pipe and sends it out under pressure;
A return pipe for returning the hot water sent out by the circulation pump to the heat exchanger,
Forming a circulation circuit composed of the outgoing pipe, the circulation pump, and the return pipe;
A bypass circuit connecting the outgoing pipe and the return pipe;
Hot water supply for supplying hot water from the hot water storage tank to the circulation circuit, connected to the circulation circuit downstream from the connection portion between the outgoing pipe and the bypass circuit and upstream from the connection portion between the return pipe and the bypass circuit. Circuit,
A check valve that prevents backflow of the flow from the hot water tank to the hot water supply circuit;
A water supply circuit connected to the hot water supply circuit;
Having a hot water outlet connected on the circulation circuit downstream from the connection part between the circulation circuit and the hot water supply circuit and upstream from the connection part between the return pipe and the bypass circuit;
A flow rate control means for limiting the amount of hot water returning from the return pipe to the hot water storage tank is provided at a position downstream of the connection portion of the return pipe with the bypass circuit,
A hot water supply system, wherein the water supply circuit is provided with water supply restriction means for restricting the amount of water supply. A heat retention temperature sensor provided at a position upstream of the connection portion of the circulation circuit with the hot water supply circuit and downstream of the connection portion of the outgoing pipe with the bypass circuit;
Heat insulation temperature setting means for setting a target value of the heat insulation temperature;
A flow rate control unit that takes in an output of the heat retention temperature sensor and a heat insulation temperature target value set by the heat insulation temperature setting unit, and controls a flow rate restriction unit of the return pipe;
A hot water temperature sensor provided downstream of the hot water supply circuit connected to the water supply circuit and upstream of the hot water outlet;
Tapping temperature setting means for setting a target value of tapping temperature;
A water supply control means for taking in an output of the hot water temperature sensor and a hot water temperature target value set by the hot water temperature setting means and controlling the water supply restriction means;
The hot water supply system according to claim 22, comprising:   The hot water supply system according to claim 23, wherein a connection position between the outgoing pipe and the bypass circuit is immediately after the connection between the heat exchanger and the outgoing pipe.   The hot water supply system according to claim 23 or 24, wherein a resistance element that increases flow path resistance is provided in the bypass circuit.   26. The hot water supply system according to claim 25, wherein the resistance of the resistance element is variable. A hot water tank,
The outgoing piping that introduces hot water inside this hot water tank,
A circulation pump that draws in hot water from this outgoing pipe and sends it out under pressure;
A return pipe for returning the hot water sent out by the circulation pump to the hot water storage tank,
Forming a circulation circuit composed of the outgoing pipe, the circulation pump, and the return pipe;
A tapping circuit connected to the circulation circuit, and leading the hot water of the circulation circuit to a tapping outlet;
A check valve that prevents backflow of the flow from the circulation circuit to the tapping circuit;
Having a water supply circuit connected to the hot water circuit,
A hot water supply system characterized in that a water supply restriction means for restricting a water supply amount is provided in the water supply circuit. A hot water temperature sensor provided at a position downstream from the connection portion of the hot water circuit with the water supply circuit and upstream from the hot water outlet;
Tapping temperature setting means for setting a target value of the tapping temperature;
A water supply control means for taking in an output of the hot water temperature sensor and a hot water temperature target value set by the hot water temperature setting means and controlling the water supply restriction means;
The hot water supply system according to claim 27, comprising: A hot water tank,
The outgoing piping that introduces hot water inside this hot water tank,
A circulation pump that draws in hot water from this outgoing pipe and sends it out under pressure;
A return pipe for returning the hot water sent out by the circulation pump to the hot water storage tank,
Forming a circulation circuit composed of the outgoing pipe, the circulation pump, and the return pipe;
A bypass circuit connecting the outgoing pipe and the return pipe;
A discharge circuit that is connected to the circulation circuit downstream from the connection portion between the outgoing pipe and the bypass circuit and upstream from the connection portion between the return pipe and the bypass circuit and guides the hot water of the circulation circuit to the outlet. When,
A check valve that prevents backflow of the flow from the circulation circuit to the tapping circuit;
Having a water supply circuit connected to the hot water circuit,
The bypass circuit is provided with a flow rate limiting means for limiting the amount of hot water passing through the bypass circuit,
A hot water supply system, wherein the water supply circuit is provided with water supply restriction means for restricting the amount of water supply. A heat retention temperature sensor provided at a position upstream of a connection portion of the circulation circuit with the hot water circuit and downstream of a connection portion of the outgoing pipe with the bypass circuit;
Heat insulation temperature setting means for setting a target value of the heat insulation temperature;
A flow rate control means for taking in an output of the heat insulation temperature sensor and a heat insulation temperature target value set by the heat insulation temperature setting means and controlling the flow rate restriction means;
A hot water temperature sensor provided at a position downstream from the connection portion of the hot water circuit with the water supply circuit and upstream from the hot water outlet;
Tapping temperature setting means for setting a target value of tapping temperature;
A water supply control means for taking in an output of the hot water temperature sensor and a hot water temperature target value set by the hot water temperature setting means and controlling the water supply restriction means;
30. The hot water supply system according to claim 29, further comprising:   The hot water supply system according to claim 30, wherein the connection position between the outgoing pipe and the bypass circuit is immediately after the hot water storage tank and the outgoing pipe are connected.   32. The hot water supply system according to claim 30 or 31, wherein a resistance element for increasing flow path resistance is provided downstream of a connection portion of the return pipe with the bypass circuit.   The hot water supply system according to claim 32, wherein the resistance of the resistance element is variable. A hot water tank,
The outgoing piping that introduces hot water inside this hot water tank,
A circulation pump that draws in hot water from this outgoing pipe and sends it out under pressure;
A return pipe for returning the hot water sent out by the circulation pump to the hot water storage tank,
Forming a circulation circuit composed of the outgoing pipe, the circulation pump, and the return pipe;
A bypass circuit connecting the outgoing pipe and the return pipe;
A discharge circuit that is connected to the circulation circuit downstream from the connection portion between the outgoing pipe and the bypass circuit and upstream from the connection portion between the return pipe and the bypass circuit and guides the hot water of the circulation circuit to the outlet. When,
A check valve that prevents backflow of the flow from the circulation circuit to the tapping circuit;
Having a water supply circuit connected to the hot water circuit,
A flow rate limiting means for limiting the amount of hot water returning from the return pipe to the hot water tank is provided at a position downstream of the connection portion of the return pipe with the bypass circuit,
A hot water supply system, wherein the water supply circuit is provided with water supply restriction means for restricting the amount of water supply. A heat retention temperature sensor provided at a position upstream of a connection portion of the circulation circuit with the hot water circuit and downstream of a connection portion of the outgoing pipe with the bypass circuit;
Heat insulation temperature setting means for setting a target value of the heat insulation temperature;
A flow rate control unit that takes in an output of the heat retention temperature sensor and a heat insulation temperature target value set by the heat insulation temperature setting unit, and controls a flow rate restriction unit of the return pipe;
A hot water temperature sensor provided at a position downstream from the connection portion of the hot water circuit with the water supply circuit and upstream from the hot water outlet;
Tapping temperature setting means for setting a target value of tapping temperature;
A water supply control means for taking in an output of the hot water temperature sensor and a hot water temperature target value set by the hot water temperature setting means and controlling the water supply restriction means;
The hot water supply system according to claim 34, comprising:   36. The hot water supply system according to claim 35, wherein the connection position between the outgoing pipe and the bypass circuit is immediately after the hot water storage tank and the outgoing pipe are connected.   37. The hot water supply system according to claim 35 or 36, wherein the bypass circuit is provided with a resistance element that increases flow path resistance.   The hot water supply system according to claim 37, wherein the resistance of the resistance element is variable. Have multiple hot water circuits,
A water supply circuit is connected to each tapping circuit,
The water supply restriction means provided in each water supply circuit is capable of restricting the amount of water supply independently of the other water supply restriction means, according to any one of claims 27, 29, and 34. The hot water supply system described. Have multiple hot water circuits,
A water supply circuit is connected to each tapping circuit,
The water supply control means provided in each water supply circuit is capable of controlling the amount of water supply with a target value independent of other water supply control means, according to any one of claims 28, 30 and 35. Hot water supply system according to crab.   41. The hot water supply system according to any one of claims 1 to 40, wherein a different water supply circuit different from the water supply circuit is provided at the hot water outlet.

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