JPWO2019207725A1 - Hot water storage system - Google Patents

Abstract

Provided is a hot water storage type hot water supply system that forms a hot water route from a water source to a hot water supply terminal by a plurality of hot water storage type water heaters connected in series without impairing energy saving. In the hot water storage type hot water supply system, each hot water storage type water heater (10) has a water supply pipe (31) for guiding hot water from a water source to a hot water supply heat exchanger (21) and a hot water supply terminal from the hot water supply heat exchanger (21). Hot water supply that circulates hot water between the hot water supply pipe (34) that guides hot water to the hot water, the water supply thermista (33) provided in the water supply pipe (31), the hot water storage tank (11), and the hot water supply heat exchanger (21). A heat source pump (24) is provided, and the hot water supply pipe (34) of the hot water storage type water heater (10) on the upstream side is connected to the water supply pipe (31) of the hot water storage type water heater (10) on the downstream side. (50) stops the operation of the hot water supply heat source pump (24) when the water supply temperature detected by the water supply thermistor (33) is equal to or higher than the temperature threshold value during the hot water supply operation.

Description

The present invention relates to a hot water storage type hot water supply system.

Patent Document 1 describes a hot water storage type water heater. This hot water storage type water heater is a so-called indirect hot water supply type water heater that exchanges heat between hot water supplied from a hot water storage tank and hot water supplied from a water source.

Japanese Patent No. 6119672

If one hot water storage type water heater cannot meet the demand for hot water supply, a plurality of hot water storage type water heaters can be used in a connected state. However, when a plurality of hot water storage type water heaters described in Patent Document 1 are connected in series, when the hot water supply terminal is opened, the heat source circulation operation is started in each water heater. In this case, even if the hot water supplied from the water source is sufficiently heated by the water heater on the upstream side, the heat source circulation operation of the water heater on the downstream side is performed. For this reason, heat dissipation loss occurs, and the energy saving performance of the hot water storage type water heater is impaired.

The present invention has been made to solve the above problems. An object of the present invention is to provide a hot water storage type hot water supply system that forms a hot water route from a water source to a hot water supply terminal by a plurality of hot water storage type water heaters connected in series without impairing energy saving.

The hot water storage type hot water supply system according to the present invention is a system in which a plurality of hot water storage type water heaters connected in series form a hot water path from a water source to a hot water supply terminal, and each hot water storage type water heater is heated by a heat source. A hot water storage tank that stores hot water to be stored, a hot water supply heat exchanger that exchanges heat between the hot water supplied from the hot water storage tank and the hot water supplied from the water source, and a hot water supply heat exchanger that exchanges hot water from the water source. A hot water supply pipe that guides hot water from the hot water supply heat exchanger to the hot water supply terminal, a water supply thermista provided in the water supply pipe, and a hot water supply heat source that circulates hot water between the hot water storage tank and the hot water supply heat exchanger. It is equipped with a pump and a control unit that controls the hot water supply heat source pump. The hot water supply pipe of the hot water storage type water heater on the upstream side is connected to the water supply pipe of the hot water storage type water heater on the downstream side, and the control unit is connected during hot water supply operation. When the water supply temperature detected by the water supply thermista is equal to or higher than the temperature threshold, the operation of the hot water supply heat source pump is stopped.

According to the present invention, it is possible to form a hot water route from a water source to a hot water supply terminal by a plurality of hot water storage type water heaters connected in series without impairing energy saving.

It is a block diagram of the hot water storage type water heater in Embodiment 1. FIG. It is a block diagram which shows the state at the time of the hot water supply operation of the hot water storage type water heater in Embodiment 1. FIG. It is a block diagram of the hot water storage type hot water supply system in Embodiment 1. FIG. It is a part of the flowchart which shows the hot water supply control by the hot water storage type hot water supply system in Embodiment 1. It is the rest of the flowchart which shows the hot water supply control by the hot water storage type hot water supply system in Embodiment 1.

Hereinafter, embodiments will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are designated by the same reference numerals. Overlapping description will be simplified or omitted as appropriate.

Embodiment 1.
FIG. 1 is a configuration diagram of a hot water storage type water heater according to the first embodiment. The hot water storage type water heater 10 includes a heat pump unit 1, a tank unit 2, and a remote controller 3. Piping and various parts are built in the tank unit 2. The tank unit 2 is connected to the heat pump unit 1 via the HP going pipe 12, the HP return pipe 13, and an electric wiring (not shown).

The control unit 50 is built in the tank unit 2. The control unit 50 is electrically connected to various valves, pumps, sensors, and the like included in the tank unit 2 and the heat pump unit 1. The control unit 50 controls the operation of the hot water storage type water heater 10 based on the stored operation setting information and the like.

The remote controller 3 is connected so as to be able to communicate with the control unit 50. The remote controller 3 is equipped with an operation unit and a display unit. The user operates the remote controller 3 to make settings necessary for operating the hot water storage type water heater 10, for example. The remote controller 3 accepts, for example, an operation of inputting an operation command to the hot water storage type water heater 10 and an operation of changing a set value. The remote controller 3 displays, for example, a set value and an operating state of the hot water storage type water heater 10.

The heat pump unit 1 functions as a heating means for heating the low temperature water led from the tank unit 2. The heat pump unit 1 is a heat source that utilizes a heat pump cycle. The heat pump cycle is formed by connecting a compressor, a water refrigerant heat exchanger, an expansion valve, and an air heat exchanger in an annular shape with a refrigerant pipe. The heat pump unit 1 generates high-temperature water by performing heat exchange between the refrigerant obtained from the atmosphere and the low-temperature water led from the tank unit 2 by a water-refrigerant heat exchanger.

The tank unit 2 includes a hot water storage tank 11. The hot water storage tank 11 is for storing heat energy used in hot water supply. In the hot water storage tank 11, for example, water previously derived from a water source or the like is stored as a heat medium. The lower part of the hot water storage tank 11 is connected to the heat pump unit 1 via the HP going pipe 12. The upper part of the hot water storage tank 11 is connected to the heat pump unit 1 via the HP return pipe 13. The HP going pipe 12 and the HP returning pipe 13 form an annular circulation circuit in which the heat medium moves between the heat pump unit 1 and the hot water storage tank 11.

A boiling circulation pump 14 is provided on the HP going pipe 12. By operating the boiling circulation pump 14, a boiling operation is performed in which the hot water heated by the heat pump unit 1 is stored inside the hot water storage tank 11. When the operation of the boiling circulation pump 14 is started, cold water is guided from the lower part of the hot water storage tank 11 to the heat pump unit 1 via the HP going pipe 12, and after being heated by the heat pump unit 1, the HP return pipe 13 is connected. It is returned as hot water to the upper part of the hot water storage tank 11 via the hot water storage tank 11. By the boiling operation, hot water is gradually stored in the hot water storage tank 11 from the upper part to the lower part.

A residual hot water thermistor is provided on the surface of the can body of the hot water storage tank 11. As the residual hot water thermistor, for example, an upper residual hot water thermistor 15, a lower residual hot water thermistor 16, and a central residual hot water thermistor 17 are provided. The upper residual hot water thermistor 15 is provided above the hot water storage tank 11. The lower residual hot water thermistor 16 is provided in the lower part of the hot water storage tank 11. The central residual hot water thermistor 17 is provided at a height between the upper residual hot water thermistor 15 and the lower residual hot water thermistor 16. Each residual hot water thermistor detects the residual hot water temperature at each attachment position with respect to the hot water storage tank 11.

The control unit 50 controls the start and stop of the boiling operation. The control unit 50 starts the operation of the boiling circulation pump 14 when, for example, the temperature detected by the upper residual hot water thermistor 15 falls below a preset temperature. The control unit 50 starts the operation of the boiling circulation pump 14 when, for example, a preset time is reached. The control unit 50 stops the operation of the boiling circulation pump 14 when, for example, the temperature detected by the lower residual hot water thermistor 16 becomes equal to or higher than a preset temperature. That is, when the control unit 50 determines that the amount of hot water stored has reached the required amount, the boiling operation is stopped. The residual hot water temperature information detected by the central hot water residual hot water thermistor 17 is used by the control unit 50, for example, in order to calculate how much heat energy is stored in the hot water storage tank 11.

The hot water supply heat exchanger 21 is built in the tank unit 2. The primary side inlet of the hot water supply heat exchanger 21 is connected to the upper part of the hot water storage tank 11 via the heat source introduction pipe 22. The primary side outlet of the hot water supply heat exchanger 21 is connected to the lower part of the hot water storage tank 11 via the heat source lead-out pipe 23. The heat source introduction pipe 22 and the heat source lead-out pipe 23 form an annular circulation circuit connecting the hot water storage tank 11 and the hot water supply heat exchanger 21. A hot water supply heat source pump 24 for circulating hot water in this circulation circuit is provided on the heat source lead-out pipe 23.

A water supply pipe 31 for guiding hot water supplied from the water source is connected to the secondary side inlet of the hot water supply heat exchanger 21. A hot water supply pipe 34 for guiding hot water to the hot water supply terminal 4 is connected to the secondary side outlet of the hot water supply heat exchanger 21. A hot water supply flow rate sensor 32 and a water supply thermistor 33 are provided on the water supply pipe 31. A hot water supply thermistor 35 is provided on the hot water supply pipe 34.

The hot water supply flow rate sensor 32 detects the flow rate of hot water flowing through the water supply pipe 31. The water supply thermistor 33 detects the temperature of the hot water flowing through the water supply pipe 31. That is, the water supply thermistor 33 detects the temperature of the hot water flowing into the hot water supply heat exchanger 21. The hot water supply thermistor 35 detects the temperature of hot water flowing through the hot water supply pipe 34. That is, the hot water supply thermistor 35 detects the temperature of the hot water flowing out from the hot water supply heat exchanger 21. Hereinafter, the temperature detected by the water supply thermistor 33 is referred to as "water supply temperature", and the temperature detected by the hot water supply thermistor 35 is referred to as "hot water supply temperature".

FIG. 2 is a configuration diagram showing a state of the hot water storage type water heater in the first embodiment during hot water supply operation. The hot water supply operation is performed by operating the hot water supply heat source pump 24. When the hot water supply terminal 4 is opened, hot water is supplied from the water source to the hot water supply terminal 4 via the water supply pipe 31, the hot water supply heat exchanger 21, and the hot water supply pipe 34. When the flow rate is detected by the hot water supply flow rate sensor 32, the operation of the hot water supply heat source pump 24 can be started by the control unit 50.

When the operation of the hot water supply heat source pump 24 is started, the hot water stored in the upper part of the hot water storage tank 11 is introduced to the primary side of the hot water supply heat exchanger 21 via the heat source introduction pipe 22. The low-temperature hot water supplied from the water source is introduced to the secondary side of the hot water supply heat exchanger 21 via the water supply pipe 31. The low-temperature hot water introduced to the secondary side is heated by heat exchange with the high-temperature hot water on the primary side in the hot water supply heat exchanger 21, and is supplied to the hot water supply terminal 4 via the hot water supply pipe 34. The hot water on the primary side whose temperature has dropped due to heat exchange in the hot water supply heat exchanger 21 is returned to the lower part of the hot water storage tank 11 via the heat source lead-out pipe 23. In such a hot water supply method, hot water is supplied by indirectly transmitting the heat energy stored in the hot water storage tank 11 to the low-temperature hot water supplied from the water source via the hot water heat exchanger 21. It is called a method.

The control unit 50 controls the hot water supply temperature during the hot water supply operation. The hot water supply temperature Tk of the hot water supply water heated by the hot water supply heat exchanger 21 is detected by the hot water supply thermistor 35. If there is a difference between the target hot water supply temperature Tkt set by the user in advance with the remote control 3 and the current hot water supply temperature Tk, feedback is provided so that the hot water supply temperature Tk falls within the range between the upper limit value Tkmax and the lower limit value Tkmin. The hot water supply temperature Tk is adjusted by control. The control unit 50 adjusts the hot water supply temperature by changing the rotation speed which is the output of the hot water supply heat source pump 24. For example, when changing the hot water supply temperature to a high temperature, the control unit 50 increases the rotation speed of the hot water supply heat source pump 24 in order to increase the amount of high temperature water supplied from the hot water storage tank 11 to the hot water supply heat exchanger 21. For example, when changing the hot water supply temperature to a low temperature, the control unit 50 reduces the rotation speed of the hot water supply heat source pump 24 in order to reduce the amount of high temperature water supplied from the hot water storage tank 11 to the hot water supply heat exchanger 21.

The upper limit value Tkmax and the lower limit value Tkmin of the target hot water supply temperature Tkt are automatically set by the control unit 50 when the user sets the target hot water supply temperature Tkt. The range from the upper limit value Tkmax to the lower limit value Tkmin is usually set in the range of about ± 2 [deg] in consideration of individual variations in the detection temperature of the hot water supply thermistor 35, for example.

FIG. 3 is a configuration diagram of a hot water storage type hot water supply system according to the first embodiment. In the hot water storage type hot water supply system, a plurality of hot water storage type water heaters 10 in which a water supply pipe 31 and a hot water supply pipe 34 are connected in series form a hot water route from a water source to a hot water supply terminal 4. The number of hot water storage type water heaters 10 provided in the hot water storage type hot water supply system is not limited to three, and may be two or four or more.

In the hot water storage type water heater 10 shown in FIG. 3, an integer unit number is set in order from the upstream side closest to the water source. The unit number of the hot water storage type water heater 10 located at the most upstream is set to "1". The unit number of the hot water storage type water heater 10 located at the most downstream is "N". The unit number of the hot water storage type water heater 10 located downstream of Unit 1 and upstream of Unit N is defined as "n". These connected hot water storage type water heaters 10 are equipped with the same parts. In the following description, when a plurality of hot water storage type water heaters 10 are distinguished, a machine number is added to the code of the part.

In the hot water storage type hot water supply system, the hot water supply pipe 34-1 of the first unit counting from the water source side is connected to the water supply pipe 31-2 of the second unit (not shown) which is the second unit counting from the water source. The hot water supply pipe 34-2 of Unit 2 is connected to the water supply pipe 31-3 of Unit 3 (not shown). Hereinafter, the piping is similarly connected to Unit N located at the most downstream. The hot water supply pipe 34-N of Unit N is connected to the hot water supply terminal 4.

In the hot water storage type hot water supply system, various information is stored in the control units 50-1, 50-2 ... 50-N of each hot water storage type water heater 10. The various information includes, for example, the operating status of each unit, setting information including the unit number, priority unit information, and the like. The setting information may include information input from the remote controller 3 of each unit. The priority unit information is information for identifying from which unit the hot water supply operation is preferentially performed at that time. These control units 50 are connected to each other by a communication line, and can share mutual operating states, set values, and the like. These control units 50 can change the operating state of other units by communicating with each other. These control units 50 have a function of setting priorities for a plurality of hot water storage type water heaters 10 included in the hot water storage type hot water supply system. The priority unit is the hot water storage type water heater 10 having the highest priority at that time.

FIG. 4 is a part of a flowchart showing hot water supply control by the hot water storage type hot water supply system according to the first embodiment. FIG. 5 is the rest of the flowchart showing the hot water supply control by the hot water storage type hot water supply system according to the first embodiment. 4 and 5 are a total of one flowchart. Hereinafter, an operation example of the hot water storage type hot water supply system during the hot water supply operation will be described with the priority unit as the nth unit.

In step S1, the control unit 50-n determines whether or not the detection temperature Tz of the upper residual hot water thermistor 15-n of the current priority unit is equal to or higher than the residual hot water determination temperature Tzo. The residual hot water determination temperature Tzo is a temperature threshold value for confirming whether the hot water stored in the upper part of the hot water storage tank 11-n of the priority unit can secure the residual hot water temperature sufficient for the hot water supply operation. Generally, heat transfer loss or the like occurs during heat exchange by the hot water supply heat exchanger 21, and the hot water temperature supplied to the hot water supply terminal 4 is lower than the residual hot water temperature. Therefore, a target set by the user. It is necessary to secure a residual hot water temperature higher than the hot water supply temperature Tkt.

When it is determined in step S1 that Tz <Tzo, the residual hot water temperature required for hot water supply operation is insufficient in the current priority unit. In this case, step S2 is carried out in order to change the priority unit.

In step S2, priorities are set for units other than the current priority units in ascending order of the amount of heat energy stored in the hot water storage tank 11 of each unit. In step S3, the unit having the smallest stored heat energy amount is set as a new priority unit. In step S4, the boiling operation of the original priority unit is permitted, and the boiling operation of the newly set current priority unit is prohibited. That is, in the current priority unit, the boiling operation is not started until the hot water is used up, so that the heat energy stored in the hot water storage tank 11-n can be effectively used without waste. Following step S4, step S5 is carried out.

When it is determined in step S1 that Tz ≧ Tzo, the current priority unit secures a sufficient residual hot water temperature for hot water supply operation. In this case, step S5 is then performed.

In step S5, it is determined whether or not the hot water supply flow rate sensor 32-n of the current priority unit detects the flow rate. If the hot water supply flow rate sensor 32-n does not detect the flow rate, it is determined that hot water supply is not necessary. In this case, step S9 is then performed. In step S9, the hot water supply operation is stopped by stopping the operation of the hot water supply heat source pumps 24 of all the units. After that, in step S10, the measured value Sk of the hot water supply start timer described later is reset to zero. On the other hand, when the hot water supply flow rate sensor 32-n detects the flow rate, it is determined that hot water is being supplied. In this case, step S6 is then performed.

In step S6, it is determined whether or not the detection temperature Tw1 of the water supply thermistor 33-n of the priority unit is lower than the first water supply temperature determination value Two1. The detection temperature Tw1 of the water supply thermistor 33-n is the water supply temperature in the priority unit. The first water supply temperature determination value Two1 is a temperature threshold value for determining whether or not to start the operation of the hot water supply heat source pump 24-n of the priority unit. The first water supply temperature determination value Two1 may be set to a temperature equal to the lower limit value Tkmin of the target hot water supply temperature Tkt or a temperature slightly smaller than the lower limit value Tkmin. The installation value of the first water supply temperature determination value Two1 may be changed from the remote controller 3 at the request of the user, for example.

When it is determined in step S6 that Tw1 ≧ Two1, the temperature of the hot water flowing into the priority unit from the upstream is high, so that the hot water supply operation by the priority unit is unnecessary. In this case, step S9 is then performed.

When it is determined in step S6 that Tw1 <Two1, the temperature of the hot water flowing into the priority unit from the upstream is low, so that the hot water supply operation by the priority unit is necessary. In this case, step S7 is then performed.

In step S7, the operation of the hot water supply heat source pump 24-n of the priority unit is started. In step S8, counting by the hot water supply start timer described later is started. Following step S8, step S11 is carried out.

In step S11, it is determined whether or not the detection temperature Tk of the hot water supply thermistor 35-n of the priority unit satisfies Tkmin ≦ Tk ≦ Tkmax. The detected temperature Tk of the hot water supply thermistor 35-n is the hot water supply temperature in the priority unit.

In step S11, when the hot water supply temperature Tk does not satisfy Tkmin ≦ Tk ≦ Tkmax, it is necessary to adjust the hot water supply temperature. In this case, step S12 is then performed. In step S12, the rotation speed of the hot water supply heat source pump 24-n is changed by feedback control or the like so that the hot water supply temperature Tk is adjusted to be within the range of Tkmin or more and Tkmax or less. Following step S12, step S13 is carried out.

In step S11, when the hot water supply temperature Tk satisfies Tkmin ≦ Tk ≦ Tkmax, it is not necessary to adjust the hot water supply temperature. In this case, the rotation speed of the hot water supply heat source pump 24-n is maintained, and step S13 is carried out.

In step S13, for each unit other than the priority unit, it is determined whether or not the unit is located downstream of the priority unit. This determination is made based on the unit number of each hot water storage type water heater 10 stored in advance in the control unit 50. If it is determined in step S13 that the unit is located upstream of the priority unit, step S14 is performed. In step S14, the hot water supply operation of the unit is stopped. If the hot water supply operation of the unit is already stopped, that state is maintained in step S14. On the other hand, if it is determined in step S13 that the unit is located downstream of the priority unit, step S15 is carried out.

In step S15, it is determined whether or not the detection temperature Tw1 of the water supply thermistor 33 of the unit located downstream from the priority unit is lower than the second water supply temperature determination value Two2. The detection temperature Tw1 of the water supply thermistor 33 is the water supply temperature in the unit. The second water supply temperature determination value Two2 is a temperature threshold value for determining whether or not to start the operation of the hot water supply heat source pump 24 of the unit located downstream of the priority unit. The second water supply temperature determination value Two2 is larger than the first water supply temperature determination value Two1. The second water supply temperature determination value Two2 may be set to a temperature located in a range between the lower limit value Tkmin of the target hot water supply temperature Tkt and the first water supply temperature determination value Two1. The installation value of the second water supply temperature determination value Two2 may be changed from the remote controller 3 at the request of the user, for example.

When it is determined in step S15 that Tw1 ≧ Two2, a sufficient hot water supply temperature Tk can be secured by the hot water supply operation of the priority unit, so that the hot water supply operation of the unit located downstream from the priority unit is unnecessary. In this case, step S17 is then performed. In step S17, the hot water supply operation of the unit located downstream of the priority unit is stopped. If the hot water supply operation of the unit is already stopped, that state is maintained in step S17.

When it is determined in step S15 that Tw1 <Two2, a sufficient hot water supply temperature Tk is not secured in the hot water supply operation of the priority unit, so that the hot water supply operation of the unit located downstream of the priority unit is necessary. In this case, step S16 is then performed.

In step S16, it is determined whether or not the measured value Sk of the hot water supply start timer that started counting in step S8 is equal to or greater than the set value So. The set value So of the hot water supply start timer is provided so that the hot water supply operation of the unit located downstream of the priority unit is not started until a certain time elapses from the start of the hot water supply operation of the priority unit in step S7. For example, when a long time has passed since the previous hot water supply, the temperature of the hot water remaining in the hot water supply pipe 34 from the first unit located at the uppermost stream to the hot water supply terminal 4 has dropped to a level close to the outside air temperature. When the user opens the hot water supply terminal 4 in such a state, low-temperature hot water flows into each of the units connected in series. In the system of the specification that the hot water supply operation of each unit is started immediately after the hot water supply terminal 4 is opened, when the temperature of the hot water remaining in the piping is low, the priority unit and all the units located downstream thereof supply hot water at the same time. The operation will be started. In this case, the heat energy stored in the hot water storage tank 11 of each unit is unnecessarily consumed. In order to suppress such an event, in the hot water storage type hot water supply system according to the first embodiment, the hot water supply operation of the unit located downstream of the priority unit is performed until a certain time elapses from the start of the hot water supply operation of the priority unit. Not performed. As a result, after the residual water existing in the hot water supply pipe 34 from the priority unit to the hot water supply terminal 4 is discharged, it is determined whether or not the hot water supply operation of the unit located downstream from the priority unit can be started.

The set value So of the hot water supply start timer can be set in advance by the user from the remote controller 3 based on the hot water supply pipe length of the system, the instantaneous hot water supply flow rate, and the like. If the set value So of the hot water supply start timer is set by any one of the remote controllers 3, it is shared by the control unit 50 of all the units.

If it is determined in step S16 that Sk <So, a sufficient time has not passed since the start of the hot water supply operation of the priority unit. In this case, step S17 is then performed.

When it is determined in step S16 that Sk ≧ So, a sufficient time has elapsed from the start of the hot water supply operation of the priority unit. In this case, step S18 is then performed.

In step S18, it is determined whether or not the detection temperature Tk of each of the hot water supply thermistors 35 located downstream of the priority unit satisfies Tkmin ≦ Tk ≦ Tkmax. In step S18, when the hot water supply temperature Tk in the unit located downstream from the priority unit satisfies Tkmin ≦ Tk ≦ Tkmax, it is not necessary to adjust the hot water supply temperature by the unit. In this case, step S19 is then performed. In step S19, the state of the hot water supply operation of the unit at that time is maintained.

In step S18, when the hot water supply temperature Tk in the unit located downstream from the priority unit does not satisfy Tkmin ≦ Tk ≦ Tkmax, it is necessary to adjust the hot water supply temperature by the unit. In this case, step S20 is then carried out. In step S20, the operation of the hot water supply heat source pump 24 of the unit is started. Following step S20, step S21 is carried out. In step S21, by changing the rotation speed of the hot water supply heat source pump 24 of the unit by feedback control or the like, the hot water supply temperature Tk of the unit is adjusted to be within the range of Tkmin or more and Tkmax or less.

According to the first embodiment described above, the hot water supply pipe 34 of the hot water storage type water heater 10 on the upstream side of the two adjacent hot water storage type water heaters 10 is connected to the water supply pipe 31 of the hot water storage type water heater 10 on the downstream side. Be connected. When the water supply temperature detected by the water supply thermistor 33 during the hot water supply operation is equal to or higher than the temperature threshold value, the control unit 50 stops the operation of the hot water supply heat source pump 24. Therefore, it is possible to prevent unnecessary hot water supply operation from being performed. As a result, it is possible to form a hot water route from the water source to the hot water supply terminal 4 by a plurality of hot water storage type water heaters 10 connected in series without impairing energy saving.

Further, the control units 50 provided in each of the plurality of hot water storage type water heaters 10 are connected to each other by a communication line, recognize each other's operating state and set value, and set a priority for the plurality of hot water storage type water heaters 10. Has. The control unit 50 of the hot water storage type water heater 10 having the highest priority at present is the hot water storage type water heater 10 when the water supply temperature detected by the water supply thermistor 33 of the hot water storage type water heater 10 falls below the temperature threshold. The operation of the hot water supply heat source pump 24 is started. Therefore, when the temperature of the hot water flowing into the priority unit from the upstream is low, the hot water supply operation of the priority unit can be started.

Further, the control unit 50 of the hot water storage type water heater 10 having the highest priority uses a value different from that of the other hot water storage type water heater 10 as a temperature threshold value to be compared with the water supply temperature detected by the water supply thermistor 33. Specifically, the first water supply temperature determination value Two1 and the second water supply temperature determination value Two2 are set individually. Therefore, even if the hot water is not sufficiently heated in the hot water supply operation of the priority unit, the insufficient heating can be compensated for by the hot water supply operation of the unit located downstream of the priority unit.

Further, the control unit 50 of the hot water storage type water heater 10 located upstream of the hot water storage type water heater 10 having the highest priority stops the hot water supply operation of the hot water storage type water heater 10. Therefore, it is possible to prevent unnecessary hot water supply operation from being performed.

Further, the control unit 50 of the hot water storage type water heater 10 having the highest priority is the hot water storage type water heater 10 when the temperature of the hot water stored in the hot water storage tank 11 of the hot water storage type water heater 10 falls below the temperature threshold. In addition to stopping the hot water supply operation of the hot water storage type water heater 10, the hot water supply operation of the hot water storage type water heater 10 having the second highest priority is started. Therefore, if the remaining hot water temperature required for hot water supply operation is insufficient in the current priority unit, the priority unit can be reset.

Further, the control unit 50 of the hot water storage type water heater 10 located downstream of the hot water storage type water heater 10 having the highest priority has a certain time after the hot water supply operation of the hot water storage type water heater 10 having the highest priority is started. The operation of the hot water supply heat source pump 24 is not started until the elapse has passed. Specifically, the hot water supply operation of the unit located downstream of the priority unit is not started until the measured value Sk of the hot water supply start timer becomes the set value So or more. Therefore, it is possible to prevent unnecessary consumption of the thermal energy stored in the unit located downstream of the priority unit.

In addition, a certain period of time from the start of the hot water supply operation of the hot water storage type water heater 10 having the highest priority to the start of the operation of the hot water supply heat source pump 24 of the other hot water storage type water heater 10 depends on the request of the user. Can be changed. Therefore, the set value So of the hot water supply start timer can be appropriately set according to the scale of the hot water storage type hot water supply system.

Further, the control unit 50 of the hot water storage type water heater 10 having the highest priority stops the boiling operation until the hot water storage type water heater 10 runs out of hot water. Therefore, the thermal energy stored in the current priority unit can be used without waste.

Further, the control unit 50 sets the priority of the plurality of hot water storage type water heaters 10 so that the hot water storage type water heater 10 having a smaller amount of heat energy stored in the hot water storage tank 11 has a higher priority. Therefore, the heat energy stored in each of the plurality of hot water storage type water heaters 10 is consumed in ascending order of the remaining amount. As a result, it is possible to prevent a bias in the boiling operation load among the plurality of hot water storage type water heaters 10.

Further, the heat source of the hot water storage type water heater 10 does not have to be a heat pump. The hot water storage type water heater 10 may be provided with, for example, an electric heater or the like as a heat source in the hot water storage tank 11. In this case as well, it is possible to prevent the hot water storage type hot water supply system from impairing energy saving.

The present invention can be used in a system for forming a hot water route from a water source to a hot water supply terminal by a plurality of hot water storage type water heaters connected in series without impairing energy saving.

1 Heat pump unit 2 Tank unit 3 Remote control 4 Hot water supply terminal 10 Hot water storage type water heater 11 Hot water storage tank 12 HP Outgoing piping 13 HP Return piping 14 Boiling circulation pump 15 Upper residual hot water thermista 16 Lower residual hot water thermista 17 Central residual hot water thermista 21 For hot water supply Heat exchanger 22 Heat source introduction pipe 23 Heat source lead-out pipe 24 Hot water supply heat source pump 31 Water supply pipe 32 Hot water supply flow sensor 33 Water supply thermistor 34 Hot water supply pipe 35 Hot water supply thermistor 50 Control unit

Claims (9)

It is a system that forms a hot water route from a water source to a hot water supply terminal with multiple hot water storage type water heaters connected in series.
Individual hot water storage type water heaters
A hot water storage tank that stores hot water heated by a heat source,
A heat exchanger for hot water supply that exchanges heat between the hot water supplied from the hot water storage tank and the hot water supplied from the water source.
A water supply pipe that guides hot water from the water source to the heat exchanger for hot water supply,
A hot water supply pipe that guides hot water from the hot water heat exchanger to the hot water terminal,
The water supply thermistor provided in the water supply pipe and
A hot water supply heat source pump that circulates hot water between the hot water storage tank and the hot water heat exchanger,
A control unit that controls the hot water supply heat source pump and
With
The hot water supply pipe of the hot water storage type water heater on the upstream side is connected to the water supply pipe of the hot water storage type water heater on the downstream side.
The control unit is a hot water storage type hot water supply system that stops the operation of the hot water supply heat source pump when the water supply temperature detected by the water supply thermistor is equal to or higher than the temperature threshold value during the hot water supply operation. The control unit provided in each of the plurality of hot water storage type water heaters has a function of being connected to each other by a communication line, recognizing each other's operating state and set value, and setting a priority for the plurality of hot water storage type water heaters.
The hot water storage type hot water supply according to claim 1, wherein the control unit of the hot water storage type water heater having the highest priority starts the operation of the hot water supply heat source pump when the water supply temperature detected by the water supply thermistor falls below the temperature threshold value. system. The control unit of the hot water storage type water heater having the highest priority uses a value different from that of other hot water storage type water heaters as a temperature threshold value to be compared with the water supply temperature detected by the water supply thermistor. Hot water storage type hot water supply system. The hot water storage type hot water supply system according to claim 2 or 3, wherein the control unit of the hot water storage type water heater located upstream of the hot water storage type water heater having the highest priority stops the hot water supply operation of the hot water storage type water heater. .. When the temperature of the hot water stored in the hot water storage tank falls below the temperature threshold, the control unit of the hot water storage type water heater having the highest priority stops the hot water supply operation of the hot water storage type water heater and gives the priority. The hot water storage type hot water supply system according to any one of claims 2 to 4, which starts the hot water supply operation of the second highest hot water storage type water heater. The control unit of the hot water storage type water heater located downstream of the hot water storage type water heater having the highest priority is described until a certain time elapses from the start of the hot water supply operation of the hot water storage type water heater having the highest priority. The hot water storage type hot water supply system according to any one of claims 2 to 5, which does not start the operation of the hot water supply heat source pump. The fixed time from the start of hot water supply operation of the hot water storage type water heater with the highest priority to the start of operation of the hot water supply heat source pump of other hot water storage type water heaters can be changed according to the request of the user. The hot water storage type hot water supply system according to claim 6. The hot water storage type hot water supply system according to any one of claims 2 to 7, wherein the control unit of the hot water storage type water heater having the highest priority stops the boiling operation until the hot water storage type water heater runs out of hot water. .. The control unit sets priorities for a plurality of hot water storage type water heaters so that a hot water storage type water heater having a smaller amount of heat energy stored in the hot water storage tank has a higher priority. The hot water storage type hot water supply system according to any one of the above.

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