JP2018071875A - Hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water supply system where a plurality of water heaters are connected in parallel, and which can simply switch between single hot water supply and concurrent hot water supply.SOLUTION: A hot water supply system is configured such that a first water heater 10 and a second water heater 20 are connected in parallel with a hot water supply terminal, the first water heater including a hot water storage tank 1 and a heat source 2 configured to heat hot water in the hot water storage tank 1, and the second water heater including a heat source different from that of the first water heater 10. The hot water supply system is characterized in that a decompression device 21 is provided in a water supply route of the second water heater so that with the pressure difference between a tapping route of the first water heater 10 and a tapping route of the second water heater 20, hot water is automatically supplied from both of the first and second water heaters when a flow rate exceeds a predetermined hot water supply flow rate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hot water supply system in which a plurality of water heaters are connected.

  2. Description of the Related Art A heat pump type hot water heater having a boiling function for driving a heat pump cycle using midnight power or the like and heating low temperature water to store hot water at a desired temperature in a hot water storage tank is known. In addition, a hybrid type hot water supply system is known in which a heat pump hot water heater and an auxiliary hot water heater such as a gas water heater are connected in parallel so that stable hot water can be supplied even if the heat pump hot water heater runs out. Conventionally, in a hot water supply system configured such that a plurality of hot water heaters are connected in parallel, switching of a hot water source serving as a hot water source is a switching unit such as a three-way valve provided at a junction of a hot water outlet path of each hot water heater. (For example, Patent Document 1).

Patent No. 5634147

  By the way, in a hot water supply system in which a plurality of water heaters are connected in parallel, not only a single hot water supply from each water heater but also a simultaneous hot water supply from a plurality of water heaters can increase the flow rate of hot water supply without increasing the size of the system. Can do. Even in a hybrid type hot water supply system using a conventional switching unit, simultaneous hot water supply is possible. However, it is necessary to control the switching unit while detecting the hot water supply flow rate one by one, which increases the number of components and makes the control complicated. Further, when hot water is supplied from both hot water heaters using a three-way valve or the like as the switching unit, the resistance increases due to the mechanism of the three-way valve, and the amount of hot water supplied during simultaneous hot water supply is reduced.

  An object of the present invention is to provide a hot water supply system capable of easily switching between single hot water supply and simultaneous hot water supply in a hot water supply system having a configuration in which a plurality of hot water heaters are connected in parallel.

  The present invention relates to a hot water storage tank, a first hot water heater provided with a heating source for heating hot water in the hot water storage tank, and a second hot water heater provided with a heating source different from the first hot water heater. In a hot water supply system connected in parallel, the hot water source of the hot water source is automatically switched according to the hot water flow rate by utilizing the pressure difference between the hot water discharge path of the first hot water heater and the hot water discharge path of the second hot water heater. The pressure reducing device is provided in the water supply path of the second water heater so that hot water is supplied from both the first water heater and the second water heater when the hot water flow rate is exceeded.

  ADVANTAGE OF THE INVENTION According to this invention, in the hot water supply system of the structure which connected the some hot water heater in parallel, switching of a single hot water supply and simultaneous hot water supply can be performed simply.

1 is an overall schematic diagram illustrating a hot water supply system according to a first embodiment. It is a whole schematic diagram showing the hot-water supply system concerning a 2nd embodiment. It is a whole schematic diagram showing the hot-water supply system concerning a 3rd embodiment.

[First Embodiment]
Hereinafter, an embodiment of a hot water supply system of the present invention will be described with reference to the drawings as appropriate. FIG. 1 is a configuration diagram showing an outline of a hot water supply system of the present embodiment. As shown in FIG. 1, the hot water supply system of the present embodiment is different from a hot water storage tank 1, a first water heater 10 provided with a heating source 2 for heating hot water in the hot water storage tank 1, and the first water heater 10. And a second water heater 20 provided with a heating source. A water supply pipe 31 and a hot water supply pipe 32 are respectively connected to the first water heater 10 and the second water heater 20, and each water heater is connected in parallel to the hot water supply terminal. Thus, by connecting the 1st water heater 10 and the 2nd water heater 20 in parallel with respect to a hot water supply terminal, the hot water supply used as a hot water source can be switched, and the hot water supply to a hot water supply terminal is attained.

  Here, in the hot water supply system of the present embodiment, the pressure reducing device 21 for automatically switching the hot water supply source serving as the source of hot water according to the hot water supply flow rate is the water supply path (water supply source and second hot water supply) of the second hot water supply device 20. It is provided in a water supply pipe 31) connecting the machine 20.

  By providing the pressure reducing device 21, a pressure difference can be generated between the hot water discharge path of the first hot water supply device and the hot water supply route of the second hot water supply device. By utilizing this pressure difference, the hot water supply source of the hot water source is automatically switched between the single hot water supply and the simultaneous hot water supply according to the hot water supply flow rate, and when the predetermined hot water supply flow rate is exceeded, the first hot water supply device and the second hot water supply device are switched. It can comprise so that hot water may be supplied from both sides simultaneously. Details of the hot water supply switching will be described later.

<First water heater>
The first water heater 10 includes a hot water storage tank 1 that stores hot water and a heating source 2 that heats water to be stored in the hot water storage tank 1, and uses hot water stored in the hot water storage tank 1 to supply hot water to a hot water supply terminal. To do.

  The heating source 2 only needs to be able to heat water for storing hot water in the hot water storage tank 1, and for example, a heat pump, an electric heater, or the like can be used. Below, the case where a heat pump is used as the heating source 2 will be described as an example.

  In the 1st water heater 10, water is supplied to the hot water storage tank 1 through the water supply pipe 31 which is a water supply path. Usually, water depressurized by a pressure reducing device 3 such as a pressure reducing valve provided in a water supply path for protection of the hot water storage tank 1 is supplied to the hot water storage tank 1. The hot water in the hot water storage tank 1 is sent from the heat pump inlet pipe 34 to the heat pump, and the hot water heated by the heat pump is returned to the hot water storage tank 1 through the heat pump hot water outlet pipe 35. Then, hot water stored in the hot water storage tank 1 is used to supply hot water from the hot water supply pipe 32 serving as a hot water supply path to the hot water supply terminal.

  Here, FIG. 1 shows a configuration in which hot water stored in the hot water storage tank 1 is directly supplied to the hot water supply terminal, but a configuration in which hot water supplied from the water supply source is heated to supply hot water from the hot water in the hot water storage tank 1 as a heat source. It may be.

<Second water heater>
The second water heater 20 includes a heating source different from that of the first water heater 10, and functions as auxiliary hot water supply means for the first water heater 10. Examples thereof include a gas water heater that heats water with a gas burner (heating source) that burns combustible gas, and an oil water heater that heats water with an oil burner (heating source). In the 2nd water heater 20, the water supplied from the water supply pipe | tube 31 which is a water supply path | route is heated with a heating source, and the hot water supply to the hot water supply terminal from the piping 33 which is a hot water supply path | route, and the hot water supply pipe | tube 32 is performed. As an auxiliary hot water supply means, it is preferable to use an instantaneous water heater rather than a hot water storage type from the viewpoint of supplying a necessary amount of hot water instantly and without waste. In addition, the heating source of the second hot water heater 20 is preferably one that detects the flow of water supplied to the second hot water heater 20 and controls on / off of the heating source.

<Pressure reduction device>
The pressure reducing device 3 supplies water to the hot water storage tank 1 by reducing the pressure (primary pressure) of water supplied from the water supply source to a predetermined pressure (secondary pressure). Moreover, the decompression device 21 reduces the pressure (primary pressure) of the water supplied from the water supply source to a predetermined pressure (secondary pressure) and supplies the water to the second water heater. As the decompression device 3 and the decompression device 21, for example, a decompression valve can be used, and any device that can adjust the secondary pressure is applicable.

  The predetermined pressure (secondary pressure) set in the decompression device 3 can be appropriately set according to the strength of the hot water storage tank 10. Further, the predetermined pressure (secondary pressure) set in the pressure reducing device 21 is set in consideration of the relationship of pressure loss in the first hot water heater and the second hot water heater which will be described later.

<Water heater switching operation>
Next, the switching operation of the hot water source as the source of hot water according to the hot water supply flow rate in the hot water supply system of the present embodiment will be described.

First, the hot water pressure P ₁ to hot water path from the first water heater, so that the relationship of the pouring pressure P ₂ to the tapping path from the second water heater becomes at a predetermined hot-water flow velocity V ₀ to P _1> P ₂ The decompression device 21 is set. Here, the hot water pressure P ₁ and the hot water pressure P ₂ are expressed by the following formulas 1 and 2. From Equations 1 and ₂ , the relationship of P ₁ > P ₂ is replaced by Equation 3, and the set pressure (secondary pressure) of the decompression device may be determined so as to satisfy Equation 3.

Hot water pressure P ₁ = P ₀ −ΔP ₁ (Formula 1)
Hot water pressure P ₂ = P ₀ −ΔP ₂ −ΔP ₃ (Expression 2)
ΔP ₁ <ΔP ₂ + ΔP ₃ (Expression 3)
Here, P ₀ is the feed water pressure from the feed water source, ΔP ₁ is the pressure loss of the first water heater, ΔP ₂ is the amount of pressure reduction in the decompression device 21 (difference between the primary pressure and the secondary pressure), and ΔP ₃ is the second. It is the pressure loss of the water heater.

Hot water is preferentially supplied to the hot water supply pipe 32 from the first hot water supply device having a high hot water pressure when the relation of the hot water pressure P ₁ > the hot water pressure P ₂ is established at a predetermined hot water supply flow velocity V ₀ . Since the high pressure of the hot water supply tube 32 than pouring the pressure P ₂ of the second water heater, hot water supply pipe 32 from the second water heater hot water easily flow. For this reason, the hot water flowing through the second water heater is in a substantially stationary state, or depending on the pressure condition, a very small amount of hot water flows through the hot water flowing through the first water heater. Therefore, when there is a relationship of the hot water pressure P ₁ > the hot water pressure P ₂ , the hot water source from the hot water source is dominant in the hot water source, and hot water is supplied to the hot water terminal (hot water supply mode 1). Here, although a small amount of hot water may flow through the second water heater, water is only supplied from the second water heater to the hot water supply terminal when the flow rate is lower than the operating temperature of the second water heater. No hot water is supplied. That is, such a state is a single hot water supply from the first water heater.

Next, the case where the hot water supply flow rate to the hot water supply terminal is increased and the hot water supply flow rate is increased will be described. Pressure loss of the fluid flowing through the pipes to increase in proportion to the square of the flow velocity, pressure loss [Delta] P ₁ of the first water heater is increased with the increase of the hot water supply flow rate. On the other hand, since the amount of hot water flowing in the second water heater is small and the flow rate fluctuation is small, the pressure loss ΔP ₃ of the second water heater does not vary greatly. Further, since the amount of pressure reduction in the pressure reducing device 21 is constant, the flow rate increases from a predetermined hot water supply flow velocity V ₀ , and the pressure relationship is expressed by Equation 4 at a certain hot water supply flow velocity V ₁ . That is, hot water pressure _{P 1} and the pouring pressure _{P 2} are the same.

ΔP ₁ = ΔP ₂ + ΔP ₃ (Expression 4)
In this relationship, there is no pressure difference in the hot water supply path between the first hot water heater and the second hot water heater. For this reason, the hot water flow from the second water heater to the hot water supply pipe 32 is not suppressed as in the hot water supply mode 1, and hot water is supplied simultaneously from both the first and second water heaters (hot water supply mode 2). . Here, the timing of simultaneous hot water supply from both the first hot water heater and the second hot water heater is started before the pressure relationship of Equation 4 is satisfied. Specifically, before the hot water supply flow rate to the hot water supply terminal increases and the pressure relationship of Formula 4 is reached, the amount of hot water flowing through the second hot water supply device increases as the pressure difference decreases. Then, exceeds a predetermined flow rate when the heat source of the second water heater is a hot water supply is started from the second water heater started, hot water of the second water heater as hot water flow rate approaches the hot water flow rate V ₁ is increased To do.

Also, if the further hot water flow rate exceeds the hot water flow rate V ₁ is increased, since the increase in both the first water heater and a second water heater pressure loss along with the flow rate increases in the same manner, both the pressure of The difference does not fluctuate greatly and the simultaneous hot water supply continues.

On the other hand, if the hot water supply demand from the hot-water supply terminal decreases the hot water supply flow rate is reduced, the pressure loss [Delta] P ₁ of the first water heater with a decrease of the hot water supply flow rate is returned to the relationship of the formula 3 by reducing switched to hot water forms 1.

In this way, the pressure reducing device is configured so that the relationship of Equation 4 is satisfied in the hot water supply flow velocity V _{1 for} simultaneous hot water supply from both the first and second water heaters, and the relationship of Equation 3 is satisfied when the hot water supply flow velocity is less than V _1. A pressure reduction amount of 21 is set. Thereby, it becomes possible to automatically switch between the hot water supply form 1 and the hot water supply form 2 in accordance with the hot water supply flow rate.

  As described above, according to the hot water supply system of the present embodiment, it is not necessary to control the switching valve for switching the hot water heater, and the first hot water supply is used when the flow rate of hot water supply is small according to the hot water supply demand with a simple system configuration. When there is a large amount of hot water supply and hot water supply flow mainly composed of a machine, it is possible to automatically switch so that simultaneous hot water supply from the first water heater and the second water heater is performed. In addition, since a switching valve for switching hot water heaters is not necessary, the amount of hot water that can be supplied by simultaneous hot water supply can be increased. Especially in applications where the amount of hot water used is greatly variable, such as in facilities that use commercial hot water, the number of times of switching of the hot water supply device increases, so the hot water supply system of this embodiment that does not require switching control is effective.

[Second Embodiment]
FIG. 2 shows an example of a hot water supply system in the case where a heat pump type hot water supply device that supplies hot water stored in a hot water storage tank to a hot water supply terminal is used as the first hot water supply device.

  As shown in FIG. 2, the hot water supply system according to this embodiment includes a hot water storage tank 1 and a first water heater 10 including a heat pump unit 12 that heats hot water in the hot water storage tank 1, as in the first embodiment. The 1st water heater 10 is provided with the 2nd water heater 20 provided with the heating source different, The 1st water heater 10 and the 2nd water heater 20 are connected in parallel with respect to the hot water supply terminal.

  In the second embodiment, the hot water supply pipe 32 is further provided with a hot water supply stop valve 6 for stopping hot water supply from the first water heater 10 to the hot water supply terminal. The hot water supply stop valve 6 is electrically connected to a control unit provided in the heat pump unit 12 (not shown), and the opening and closing of the hot water supply stop valve 6 is controlled.

Also in the present embodiment, the set pressure (secondary pressure) of the pressure reducing device 21 satisfies the relationship of Equation 4 in the hot water supply flow velocity V ₁ supplied from both the first and second hot water heaters, and the hot water supply flow velocity is V _1. Is set to satisfy the relationship of Expression 3. In the present embodiment, the pressure loss ΔP ₁ of the first water heater 10 is a pressure loss in a path from the water supply port to the hot water outlet of the first water heater 10, and specifically, in the pressure reducing valve 3 and the hot water storage tank 1. Pressure loss occurs in a path including a pipe for supplying water, a hot water storage tank 1, and a pipe connecting the hot water storage tank 1 and the hot water supply pipe 32. In some cases, the pressure reducing valve 3 is installed in a water supply pipe outside the first water heater. In this case as well, the pressure loss ΔP ₁ of the first water heater 10 including the pressure loss of the pressure reducing valve 3 is used.

By setting the set pressure (secondary pressure) of the pressure reducing device 21 in this way, when the flow rate of hot water supply is small as in the first embodiment, hot water supply (hot water supply form 1) mainly using the first water heater is performed. Is called. Further, when the hot water flow rate increases, the hot water supply automatically switches from both the first hot water heater and the second hot water heater, and simultaneous hot water supply is performed to the hot water supply terminal when the hot water supply flow rate is V ₁ or more (hot water supply mode 2).

  Next, an operation in the case where the temperature of the hot water stored in the hot water storage tank 1 is lowered and it is difficult to supply hot water from the first water heater 10 due to “hot water out” of the hot water storage tank 1 will be described.

The hot water storage tank 1 is provided with a plurality of temperature sensors 4a to 4c for detecting the temperature of the hot water at different height positions so that the temperature distribution of the hot water in the hot water storage tank 1 can be grasped.
When the temperature distribution of the hot water in the hot water storage tank 1 becomes equal to or lower than the set value based on the information of the temperature sensors 4a to 4c and it is determined that the hot water has run out, the control unit closes the hot water supply stop valve 6 and the first water heater Stop hot water supply from 10 to the hot water supply terminal. On the other hand, the control unit operates the heat pump unit 12 when the hot water runs out according to the set boiling amount or before the hot water runs out, and the hot water in the hot water storage tank 1 is boiled by the heat pump unit 12. increase. That is, the hot water storage tank 1 is sent from the lower part of the hot water storage tank 1 to the heat pump unit 12 through the heat pump inlet pipe 34 and the hot water heated by the heat pump unit 12 is returned to the upper part of the hot water storage tank 1 through the heat pump hot water outlet pipe 35. Inside, low temperature water is stored in the lower part, intermediate temperature water is stored in the middle part, and high temperature water is stored in the upper part in layers. Hot water at a predetermined temperature is stored in the hot water storage tank 1 by repeating circulation of the hot water between the hot water storage tank 1 and the heat pump unit 12.

  On the other hand, when there is a hot water supply demand from the hot water supply terminal in this state, the hot water supply stop valve 6 is closed, so that no hot water flows from the first water heater 10 to the hot water supply pipe 32. Therefore, the hot water supply from the second hot water supply device 20 to the hot water supply pipe 32 is not limited, and hot water supply from the second hot water supply device 20 to the hot water supply terminal is performed. When there is a hot water supply demand with the hot water supply stop valve 6 closed as described above, the hot water supply source of the hot water source becomes the second hot water supply device 20, and hot water supply to the hot water supply terminal is performed (hot water supply mode 3). Thus, even when the first water heater runs out of water, stable hot water can be supplied from the second water heater.

  When the boiling operation of the first hot water heater 10 is completed and the temperature distribution of the hot water in the hot water storage tank 1 becomes equal to or higher than the set value, the control unit opens the hot water supply stop valve 6 to the hot water supply terminal from the first hot water heater 10. Return to the condition where hot water can be supplied. Thereafter, the hot water supply source is automatically switched to hot water supply form 1 and hot water supply form 2 in accordance with the hot water supply flow rate, and hot water supply to the hot water supply terminal is performed.

  One of the features of this embodiment is that the hot water supply forms 1 and 2 and the hot water supply form 3 can be switched by opening and closing the hot water supply stop valve 6. In the above description, an example in which the hot water supply stop valve 6 is controlled to switch to the hot water supply mode 3 when the first hot water heater 10 runs out has been described. However, the hot water supply stop valve 6 is opened and closed based on a command from the user by operating the remote controller 5. It is also possible to control and switch to hot water supply mode 3, or to switch to hot water supply mode 3 by controlling the opening and closing of the hot water supply stop valve 6 at a timing other than hot water exhaustion.

  According to the hot water supply system of the present embodiment, the hot water supply form 1 and the hot water supply form 2 can be automatically switched according to the hot water supply flow rate as in the first embodiment, and the hot water supply stop valve 6 is controlled to switch to the hot water supply form 3. Switching can be realized with a simple system configuration.

[Third Embodiment]
FIG. 3 shows an example of a hot water supply system in the case where a heat pump type hot water supply device that uses hot water stored in a hot water storage tank as a heat source and heats water supplied from the water supply source to supply to the hot water supply terminal is used as the first water heater. is there.

  As shown in FIG. 3, the hot water supply system according to this embodiment includes a hot water storage tank 1 and a first water heater 10 including a heat pump unit 12 that heats hot water in the hot water storage tank 1, as in the second embodiment. The 1st water heater 10 is provided with the 2nd water heater 20 provided with the heating source different, The 1st water heater 10 and the 2nd water heater 20 are connected in parallel with respect to the hot water supply terminal.

  The first water heater 10 of the present embodiment heats water supplied from a water supply source using hot water stored in a hot water storage tank using the hot water heat exchanger 7 as a heat medium, and supplies the heated hot water to a hot water supply terminal. It is the structure which supplies. At the time of hot water supply from the first water heater 10 to the hot water supply terminal, water is sent from the water supply source to the hot water supply heat exchanger 7 via the water supply pipe 31 and the pipe 38, and the hot water heated by the hot water supply heat exchanger 7 is supplied to the pipe 39 and Hot water is supplied through the hot water supply pipe 32. At this time, when the flow of hot water in the water supply path (pipe 38) or the hot water supply path (pipe 39) is detected by the flow rate sensor 9 or the like, the hot water supply circulation pump 8 is driven to supply hot water in the hot water storage tank 1 to the hot water supply heat exchanger forward pipe. 36 and the hot water supply heat exchanger return pipe 37 are circulated and supplied to the hot water supply heat exchanger 7, and the water supplied to the hot water supply heat exchanger 7 is heated via the pipe 38 using the hot water in the hot water storage tank 1 as a heat source. The hot water supply temperature is adjusted to the set hot water supply temperature by controlling the hot water supply circulation pump 8 based on the information on the hot water supply temperature from the hot water supply temperature sensor 11 and adjusting the amount of hot water circulating through the hot water storage tank 1 and the hot water supply heat exchanger. be able to. Other configurations are the same as those of the second embodiment.

Also in the present embodiment, the set pressure (secondary pressure) of the pressure reducing device 21 satisfies the relationship of Equation 4 in the hot water supply flow velocity V ₁ supplied from both the first and second hot water heaters, and the hot water supply flow velocity is V _1. Is set to satisfy the relationship of Expression 3. By providing the pressure reducing device 21 so as to satisfy this relationship, it is possible to automatically switch between the hot water supply form 1 and the hot water supply form 2 in accordance with the hot water supply flow rate in the configuration of this embodiment as well as in the second embodiment. Moreover, the hot water supply mode 3 can be switched by controlling the stop valve 6.

Further, in the present embodiment, the pressure loss ΔP ₁ of the first water heater 10 is a pressure loss in the path from the water supply port to the outlet port of the first water heater 10, and specifically, the pipe 38 serving as the water supply path. The pressure loss occurs in a path including the hot water supply heat exchanger 7 and the piping 39 serving as a hot water discharge path. In the first embodiment and the second embodiment, the pressure reducing valve 3 for protecting the hot water storage tank 1 is necessary, and this pressure reducing valve 3 has a large pressure loss, and the hot water outlet pressure P ₁ of the first water heater is set high. It was difficult. In contrast, in this embodiment, hot water from the water supply port without significantly lowering the supply pressure from the water supply source is not necessary to install a pressure reducing device in the path leading to the outflow position, the hot water supply terminal at a high tapping pressure P ₁ Is possible. Further, since it is possible to increase the hot water pressure P ₁ of the first water heater, set pressure of the pressure reducing device 21 (secondary pressure) also it can be increased, resulting in possible higher pouring pressure P ₂ of the second water heater. Therefore, according to the hot water supply system of this embodiment, the hot water supply pressure to the hot water supply terminal can be increased together with the effects of the first and second embodiments.

  The characteristics of the hot water supply system described in the first to third embodiments are summarized as follows.

The decompression device 21 is provided in the water supply path of the second water heater, and the set pressure (secondary pressure) is set so as to satisfy a predetermined relationship, whereby the hot water discharge path of the first water heater and the hot water discharge path of the second water heater. It is possible to automatically switch the hot water supply source using the pressure difference without performing electrical control. Specifically, the following hot water supply form 1 and hot water supply form 2 can be automatically switched.
(1) During normal times, the first water heater mainly performs hot water supply (hot water supply form 1).
(2) When a predetermined hot-water supply flow rate is exceeded (for example, when the required instantaneous hot-water supply flow rate exceeds the instantaneous hot-water supply flow rate at which the first hot-water supply can be supplied), the first hot-water supply and the second hot-water supply are used in parallel. By supplying hot water at the same time, the required instantaneous hot water flow rate is covered (hot water supply form 2).

Moreover, by providing the hot water supply stop valve in the hot water supply pipe as in the second and third embodiments, it is possible to switch between the hot water supply modes 1 and 2 and the following hot water supply mode 3 only by opening / closing control of the hot water stop valve. .
(3) When the amount of hot water stored in the first water heater is exhausted, the hot water supply stop valve is closed to supply only hot water from the second water heater, and the first water heater performs hot water storage operation during that time (hot water supply mode 3).
(4) When the amount of hot water stored in the first water heater exceeds a predetermined amount, the hot water supply stop valve is opened, and the main hot water supply of the first water heater or the simultaneous hot water supply from the first water heater and the second water heater. Return to (hot water supply form 1 or 2)
As described above, according to the hot water supply system according to the present embodiment, it is possible to switch the hot water supply source as a hot water source without performing complicated control with a simple system configuration, and when the amount of hot water supply to the hot water supply terminal increases. In addition, simultaneous hot water supply from both the first hot water heater and the second hot water heater can be performed using a physical pressure difference.

  The first to third embodiments are merely examples, and can be appropriately changed. For example, although the pressure reducing device 21 is provided in the water supply path of the second water heater, the pressure reducing device 21 may be provided in the hot water supply path of the second water heater. In that case, it is necessary to consider the heat resistance of the decompression device 21 because hot water flows in the hot water path. Further, in a system in which hot water is directly supplied to a hot water supply terminal from a hot water storage tank, the pressure reducing device 3 is installed in a water supply pipe on the downstream side of the branch portion between the first water heater and the second water heater. However, it may be installed in the water supply pipe on the upstream side of the branch portion. Moreover, you may provide a check valve in the hot water supply path (pipe 33) of a 2nd water heater as needed. In addition, the system configuration of the first water heater and the second water heater can adopt existing configurations.

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Heating source 3 Pressure reducing device 4a-4c Temperature sensor 5 Remote control 6 Hot-water supply stop valve 7 Hot-water supply heat exchanger 8 Hot-water supply circulation pump 9 Flow rate sensor 10 First hot-water supply 11 Hot-water supply temperature sensor 12 Heat pump unit 20 2nd hot-water supply machine 21 Pressure reducing device 31 Water supply pipe 32 Hot water supply pipe 33, 38, 39 Piping 34 Heat pump inlet pipe 35 Heat pump hot water outlet pipe 36 Hot water supply heat exchanger forward pipe 37 Hot water supply heat exchanger return pipe

Claims (3)

A hot water storage tank, a first hot water heater having a heating source for heating hot water in the hot water storage tank, and a second hot water heater having a heating source different from the first hot water heater are connected in parallel to the hot water supply terminal. In the hot water supply system,
Hot water is automatically supplied from both the first hot water heater and the second hot water heater when a predetermined hot water flow rate is exceeded using the pressure difference between the hot water outlet path of the first hot water heater and the hot water outlet path of the second hot water heater. A hot water supply system characterized in that a pressure reducing device is provided in the water supply path of the second hot water supply machine. The hot water supply system according to claim 1,
A hot water supply system comprising a hot water supply stop valve provided on the upstream side of a junction with the hot water supply path of the second water heater among the hot water supply paths of the first water heater. The hot water supply system according to claim 1,
The first water heater is configured to heat the water supplied from the water supply pipe using hot water stored in the hot water storage tank as a heat medium, and to supply the hot water to the hot water supply terminal. Hot water supply system.

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