Hot water supply device and hot water supply system

Abstract

The present invention provides a hot water supply device and a hot water supply system, which can suppress the temperature drop of the hot water in the hot water storage tank even when a signal corresponding to the detected hot water temperature in the hot water storage tank cannot be obtained. The hot water supply device includes: a pump that circulates hot water between the hot water storage tank and the water heater; a centralized control unit that performs a circulating heating operation, that is, when a heating request signal is obtained based on the temperature of the hot water in the hot water storage tank being below a first heating temperature, the hot water in the hot water storage tank is circulated by the pump and heated by the water heater; and a temperature sensor that detects the inlet water temperature in the water heater. After a first reference time has elapsed in a state where no heating request signal is input, the centralized control unit circulates the hot water in the hot water storage tank by the pump, detects the inlet water temperature using the temperature sensor, and when the inlet water temperature is below a second heating temperature, heats the hot water by the circulating heating operation.

Description

Technical Field

[0001] The present invention relates to a hot water supply device that heats hot water circulating between a hot water storage tank. In addition, the present invention relates to a hot water supply system including these hot water storage tanks and hot water supply devices. Background Art

[0002] Conventionally, a hot water storage type hot water supply system is known. The hot water supply system connects a hot water storage tank and a water heater through a circulation pipe, stores hot water that circulates between the water heater and is heated in the hot water storage tank in advance, and supplies hot water from the hot water storage tank to a faucet (for example, refer to Patent Document 1).

[0003] In such a hot water supply system, the temperature of the hot water in the hot water storage tank is detected by a temperature sensor disposed in the hot water storage tank, and a temperature signal corresponding to the temperature of the hot water is input to a control unit. If the temperature of the hot water is lower than a preset temperature, the control unit drives a circulation pump to cause the hot water in the hot water storage tank to flow to the water heater, and causes the water heater to burn to heat the hot water, and the heated hot water returns to the hot water storage tank. As a result, the temperature of the hot water in the hot water storage tank rises to an appropriate temperature.

[0004] In addition, according to the hot water supply system, a structure may be adopted in which the temperature signal from the temperature sensor is not directly input to the control unit but input to a temperature regulator. In this case, if the temperature of the hot water is lower than a preset temperature, a signal (heating request signal) requesting heating is output from the temperature regulator to the control unit, and the control unit drives the circulation pump based on this.

[0005] [Prior Art Documents]

[0006] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent No. 3611396 Summary of the Invention

[0008] [Problems to be Solved by the Invention]

[0009] In the hot water supply system, in the case of an abnormality such as a failure of the temperature sensor or the temperature regulator, a temperature signal or a heating request signal cannot be obtained. Therefore, the hot water in the hot water storage tank cannot be circulated between the water heater and heated, and there is a risk that the hot water in the hot water storage tank becomes cold.

[0010] Therefore, an object of the present invention is to provide a hot water supply device and a hot water supply system that can suppress a decrease in the temperature of the hot water in the hot water storage tank even when a signal corresponding to the temperature of the hot water in the hot water storage tank cannot be obtained.

[0011] [Technical Means for Solving the Problems]

[0012] The hot water supply device according to the first embodiment of the present invention includes: a water heater connected to a hot water storage tank through a circulation path; a pump for circulating hot water between the hot water storage tank and the water heater; an operation control unit for performing a circulation heating operation, that is, when obtaining a specific signal output from a signal output unit based on the temperature of the hot water in the hot water storage tank being below a first reference temperature, circulating the hot water in the hot water storage tank by the pump and heating it using the water heater; and a temperature detection unit for detecting the temperature of the hot water flowing into the water heater as the incoming water temperature. Here, after a first reference time has elapsed in a state where the specific signal is not input, or after an abnormal signal is obtained from the signal output unit, the operation control unit circulates the hot water in the hot water storage tank by the pump, detects the incoming water temperature using the temperature detection unit, and when the incoming water temperature is below a second reference temperature, heats the hot water through the circulation heating operation, and when the incoming water temperature is higher than the second reference temperature, stops the pump.

[0013] For example, the water heater may be configured to include a flow rate detection unit for detecting the flow rate of the incoming hot water. In this case, during the circulation heating operation, if the detected flow rate of the flow rate detection unit exceeds a specific flow rate due to the hot water circulation performed by the pump, the water heater starts heating the hot water.

[0014] Here, in Technical Solution 1, the sentence "after a first reference time has elapsed in a state where the specific signal is not input, or after an abnormal signal is obtained from the signal output unit" includes: only determining whether the first reference time has elapsed in a state where the specific signal is not input, and the result is that the first reference time has elapsed in a state where the specific signal is not input; only determining whether an abnormal signal is obtained from the signal output unit, and the result is that an abnormal signal is obtained from the signal output unit; determining whether the first reference time has elapsed in a state where the specific signal is not input, and determining whether an abnormal signal is obtained from the signal output unit, and the result is that the first reference time has elapsed in a state where the specific signal is not input, or an abnormal signal is obtained from the signal output unit. That is, it means that the condition is at least one of the first reference time having elapsed in a state where the specific signal is not input and an abnormal signal being obtained from the signal output unit.

[0015] According to the hot water supply device of this form, even when an abnormality occurs in the signal output unit and a specific signal cannot be obtained, when the temperature of the hot water in the hot water storage tank decreases, the hot water can be heated using the water heater, and the hot water in the hot water storage tank can be kept warm.

[0016] In the hot water supply device of this embodiment, the operation control unit causes the reporting unit to report an abnormality based on the fact that the circulation heating operation has been performed, and the circulation heating operation is performed based on the incoming water temperature being below the second reference temperature.

[0017] For example, the operation control unit may also cause the reporting unit to report an abnormality after the circulation heating operation based on the incoming water temperature being below the second reference temperature is performed only once. Additionally, the reporting unit may be caused to report an abnormality when the circulation heating operation is performed a specific number of times.

[0018] According to the above structure, it is possible to notify the user that an abnormality may have occurred in the signal output unit.

[0019] In the hot water supply device of this embodiment, the following structure may be adopted, that is, it includes: a plurality of water heaters; and a centralized control unit that performs combined control to cause the plurality of water heaters to operate jointly. In this case, the centralized control unit functions as the operation control unit.

[0020] When configured in the above structure, further, the plurality of water heaters may be configured as follows, that is, it includes: a machine control unit that controls the water heater according to an instruction from the centralized control unit; and a flow rate detection unit that detects the flow rate of the hot water flowing into the water heater. In this case, the machine control unit of one of the plurality of water heaters may be configured to be able to drive the pump. And if the state where the detected flow rate of the flow rate detection unit in the machine control unit of the one water heater does not exceed a specific flow rate continues for a second reference time, the hot water in the hot water storage tank is circulated by the pump, and the incoming water temperature is detected by the temperature detection unit. And when the incoming water temperature is below the second reference temperature, the hot water is heated by the circulation heating operation, and when the incoming water temperature is higher than the second reference temperature, the pump is stopped.

[0021] According to the above structure, even when the centralized control unit cannot operate normally, when the temperature of the hot water in the hot water storage tank decreases, the hot water can be heated by the water heater, and heat preservation of the hot water in the hot water storage tank can be achieved.

[0022] In the hot water supply device of this embodiment, the signal output unit may be configured as follows, that is, it includes a temperature regulator, and the temperature regulator is connected to a temperature sensor disposed in the hot water storage tank. In this case, the specific signal includes a signal requesting heating of the hot water.

[0023] According to the above structure, even when an abnormality occurs in the temperature sensor or the temperature regulator and a signal requesting heating cannot be obtained, when the temperature of the hot water in the hot water storage tank decreases, the hot water can be heated by the water heater, and heat preservation of the hot water in the hot water storage tank can be achieved.

[0024] In the hot water supply device of this embodiment, the signal output unit may be configured as follows, that is, it includes a temperature sensor, and the temperature sensor is disposed in the hot water storage tank. In this case, the specific signal includes a temperature signal indicating a temperature below the first reference temperature.

[0025] According to the above structure, even when the temperature sensor malfunctions and a temperature signal indicating a temperature below the first reference temperature cannot be obtained, when the temperature of the hot water in the hot water storage tank decreases, the hot water can be heated by the water heater, and heat preservation of the hot water in the hot water storage tank can be achieved.

[0026] The hot water supply device according to the second embodiment of the present invention includes: a water heater connected to the hot water storage tank through a circulation path; a pump for circulating hot water between the hot water storage tank and the water heater; an operation control unit for performing a circulation heating operation, that is, when a specific signal output from the signal output unit based on the temperature of the hot water in the hot water storage tank being below the first reference temperature is obtained, the hot water in the hot water storage tank is circulated by the pump and heated by the water heater; and a temperature detection unit for detecting the temperature of the hot water flowing into the water heater as the inlet water temperature. Here, after the operation control unit obtains an abnormal signal from the signal output unit, the hot water in the hot water storage tank is circulated by the pump, and the inlet water temperature is detected by the temperature detection unit. And in a state where the pump is operating, if the inlet water temperature becomes below the second reference temperature, the water heater is used for heating, and if the inlet water temperature becomes above the third reference temperature higher than the second reference temperature, the use of the water heater for heating is stopped.

[0027] The hot water supply device according to this embodiment can achieve the same effect as the first embodiment.

[0028] The hot water supply system according to the third embodiment of the present invention includes: a hot water storage tank, and the hot water supply device according to the first embodiment or the second embodiment.

[0029] The hot water supply system according to this embodiment can achieve the same effect as the hot water supply device of the first embodiment.

[0030] [Effects of the Invention]

[0031] As described above, according to the present invention, a hot water supply device and a hot water supply system can be provided that can suppress a decrease in the temperature of the hot water in the hot water storage tank even when a signal corresponding to the temperature of the hot water detected in the hot water storage tank cannot be obtained.

[0032] The effects or significance of the present invention can be further clarified according to the description of the embodiments shown below. However, the embodiments shown below are merely examples when implementing the present invention, and the present invention is not limited by any content described in the following embodiments. Description of the Drawings

[0033] Figure 1 is a schematic diagram showing the structure of the hot water supply system of the first embodiment;

[0034] Figure 2 is a flowchart showing the operation control of heat insulation of the first embodiment;

[0035] Figure 3 is a schematic diagram showing the structure of the hot water supply system of Variation 1 of the first embodiment;

[0036] Figure 4 is a schematic diagram showing the structure of the hot water supply system of Variation 2 of the first embodiment;

[0037] Figure 5 is a flowchart showing the operation control of standby heat insulation of Variation 2 of the first embodiment;

[0038] Figure 6 is a schematic diagram showing the structure of the hot water supply system of Variation 3 of the first embodiment;

[0039] Figure 7 is a flowchart showing the operation control of heat insulation of Variation 3 of the first embodiment;

[0040] Figure 8 is a schematic diagram showing the structure of the hot water supply system of the second embodiment;

[0041] Figure 9 is a schematic diagram showing the structure of the hot water supply system of a variation of the second embodiment;

[0042] Figure 10 is a flowchart showing the operation control of heat insulation of other variations.

[0043] [Description of Reference Signs]

[0044] 1, 3: Hot water supply system

[0045] 10: Hot water storage tank

[0046] 20, 20A: Hot water supply device

[0047] 30: Temperature adjustment unit

[0048] 31: Temperature sensor (signal output part)

[0049] 32: Temperature regulator (signal output part)

[0050] 100: Water heater

[0051] 160: Machine control unit (operation control unit)

[0052] 170: Temperature sensor (temperature detection unit)

[0053] 180: Flow sensor (flow rate detection unit)

[0054] 200: Primary side circulation path (circulation path)

[0055] 300: Pump

[0056] 500: Central control unit (operation control unit)

[0057] 600: Remote controller (reporting unit) Detailed implementation manners

[0058] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0059] In the first embodiment and the second embodiment, the temperature regulator 32 corresponds to the "signal output unit" recited in the claims. In addition, the primary side circulation path 200 corresponds to the "circulation path" recited in the claims. Further, the temperature sensor 170 corresponds to the "temperature detection unit" recited in the claims. Further, the first heating temperature corresponds to the "first reference temperature" recited in the claims, and the second heating temperature corresponds to the "second reference temperature" recited in the claims.

[0060] In the first embodiment, the central control unit 500 corresponds to the "operation control unit" recited in the claims. In addition, the remote controller 600 corresponds to the "reporting unit" recited in the claims.

[0061] In the second embodiment, the machine control unit 160 corresponds to the "operation control unit" recited in the claims. In addition, the display unit 190 corresponds to the "reporting unit" recited in the claims.

[0062] However, the purpose of the above description is ultimately to establish a correspondence between the structure of the claims and the structure of the embodiments, and the invention recited in the claims is not limited by the structure of the embodiments through the above correspondence relationship.

[0063] 〈First embodiment〉

[0064] First, the hot water supply system 1 of the first embodiment will be described.

[0065] Figure 1 It is a schematic diagram showing the structure of the hot water supply system 1.

[0066] The hot water supply system 1 of the first embodiment includes a hot water storage tank 10, a hot water supply device 20, a temperature adjustment unit 30, and a secondary side circulation path 40.

[0067] The hot water storage tank 10 has, for example, a longitudinally long and substantially cylindrical shape. The inside of the hot water storage tank 10 is always in a state of being filled with the stored hot water. A water supply pipe 50 is connected to the bottom of the hot water storage tank 10. The water supply pipe 50 is connected to a tap water faucet. In addition, the hot water storage tank 10 may not be longitudinally long, that is, it may have a cylindrical shape with a diameter larger than the height, or it may have other shapes.

[0068] The hot water supply device 20 includes a plurality of water heaters 100, a primary side circulation path 200, a pump 300, a pump drive unit 400, a centralized control unit 500, and a remote controller 600.

[0069] In the present embodiment, the hot water supply device 20 includes four water heaters 100. Hereinafter, when differentiating the four water heaters 100, starting from the side closer to the hot water storage tank 10, they are referred to as the first unit 100a, the second unit 100b, the third unit 100c, and the fourth unit 100d. In addition, the number of water heaters 100 included in the hot water supply device 20 is not limited to four.

[0070] The water heater 100 includes a heat exchanger 110, a burner 120, and a combustion air blower 130. The heat exchanger 110 and the burner 120 are arranged in a tank body 101. An inlet pipe 140 and an outlet pipe 150 are connected to the heat exchanger 110. The burner 120 burns gas and heats the hot water flowing through the heat exchanger 110. The combustion air blower 130 sends air to the burner 120.

[0071] In addition, the water heater 100 includes a machine control unit 160, a temperature sensor 170, a flow sensor 180, and a display unit 190. The temperature sensor 170 and the flow sensor 180 are arranged in the inlet pipe 140. The temperature sensor 170 detects the temperature of the hot water flowing through the inlet pipe 140, that is, the temperature of the hot water flowing into the water heater 100 (hereinafter referred to as the inlet water temperature), and outputs a temperature signal corresponding to the inlet water temperature to the machine control unit 160. The flow sensor 180 detects the flow rate of the hot water flowing through the inlet pipe 140, that is, the flow rate of the hot water flowing into the water heater 100, and outputs a flow rate signal corresponding to the detected flow rate to the machine control unit 160. The display unit 190 includes a light emitting diode (LED) or the like and performs various reports related to the water heater 100 such as error reporting.

[0072] The machine control unit 160 includes a microcomputer or the like and drives and controls the burner 120, the combustion air blower 130, the display unit 190, etc.

[0073] When the machine control unit 160 is in a state where combustion is permitted and hot water flows through the inlet pipe 140, if the detected flow rate of the flow sensor 180 exceeds a specific flow rate, the burner 120 and the combustion air blower 130 are operated. As a result, the hot water flowing through the heat exchanger 110 is heated, and the heated hot water flows through the outlet pipe 150 and is discharged from the water heater 100. Then, if hot water no longer flows in the inlet pipe 140 and the detected flow rate of the flow sensor 180 becomes equal to or less than the specific flow rate, the machine control unit 160 stops the burner 120 and the combustion air blower 130. In addition, in the water heater 100 in which combustion permission is not set, even if hot water flows in the inlet pipe 140, the burner 120 does not burn. Therefore, the hot water is not heated and flows through the outlet pipe 150 and is discharged from the water heater 100.

[0074] In addition, the water heater 100 may also be a latent heat recovery type water heater including a primary heat exchanger and a secondary heat exchanger.

[0075] The primary side circulation path 200 includes a supply pipe 210 and a return pipe 220. The supply pipe 210 is connected to the lower part of the hot water storage tank 10 and the inlet pipe 140 of each water heater 100. The return pipe 220 is connected to the upper part of the hot water storage tank 10 and the outlet pipe 150 of each water heater 100.

[0076] The pump 300 is arranged in the supply pipe 210 of the primary side circulation path 200 to circulate hot water between the hot water storage tank 10 and multiple water heaters 100. That is, after the pump 300 operates, hot water flows out from the lower part of the hot water storage tank 10 to the supply pipe 210, and the hot water flowing through each water heater 100 and the return pipe 220 returns to the upper part of the hot water storage tank 10.

[0077] The pump drive unit 400 includes a relay for switching the supply and stop of power to the pump 300, etc., and drives the pump 300 in accordance with a control signal (drive instruction, stop instruction) from the central control unit 500.

[0078] The central control unit 500 is provided in one of the multiple water heaters 100, for example, the first unit 100a. The central control unit 500 includes a microcomputer, etc., and controls the pump drive unit 400 and the remote controller 600.

[0079] In addition, the central control unit 500 is connected to the machine control units 160 of the multiple water heaters 100 in a communicable manner. The central control unit 500 performs coordinated control to make the multiple water heaters 100 operate jointly by sending various instructions to each machine control unit 160.

[0080] For example, the centralized control unit 500 sends an allowable combustion instruction to the machine control unit 160 of one water heater 100. In the machine control unit 160 that has received the allowable combustion instruction, the setting for allowing combustion is made. The centralized control unit 500 periodically switches the water heater 100 allowed for combustion. In such a case, the centralized control unit 500 sends a cancellation instruction for cancellation of allowance to the water heater 100 that has been allowed for combustion, and sends an allowable combustion instruction to the new water heater 100. Thus, each water heater 100 is rotated regularly, and the hot water supplied to the hot water storage tank 10 is heated.

[0081] In addition, in each water heater 100, a flow rate adjustment valve (not shown) is provided in the water inlet pipe 140, and the flow rate of the hot water flowing into the water heater 100 not allowed for combustion is adjusted by the flow rate adjustment valve so that it is significantly less than the flow rate of the hot water flowing into the water heater 100 allowed for combustion.

[0082] The remote controller 600 includes an operation display unit 610 such as a touch panel, and a speaker 620.

[0083] The temperature adjustment unit 30 includes a temperature sensor 31 and a temperature regulator 32 connected to the temperature sensor 31. The temperature sensor 31 is disposed in the hot water storage tank 10, detects the temperature of the hot water in the hot water storage tank 10, and outputs a temperature signal corresponding to the detected temperature to the temperature regulator 32. In the present embodiment, the temperature sensor 31 is disposed at a position lower than the center of the hot water storage tank 10 and higher than the position of the water supply pipe 210 connecting to the primary side circulation path 200. The temperature sensor 31 may also be disposed at the central portion of the hot water storage tank 10 or a position higher than it.

[0084] When the detected temperature of the temperature sensor 31 becomes equal to or lower than a first heating temperature (for example, 65°C), the temperature regulator 32 outputs a signal (hereinafter referred to as a heating request signal) requesting heating of hot water to the centralized control unit 500 of the hot water supply device 20. In addition, after the detected temperature of the temperature sensor 31 becomes equal to or lower than the first heating temperature (for example, 65°C), if it becomes equal to or higher than a first stop temperature (for example, 70°C) higher than the first heating temperature, the temperature regulator 32 outputs a signal (hereinafter referred to as a stop request signal) requesting stop of heating to the centralized control unit 500. For example, the heating request signal is a voltage signal of several volts, and the stop request signal is a voltage signal of 0V.

[0085] The inlet 40a of the secondary side circulation path 40 is connected to the upper part of the hot water storage tank 10, and its outlet 40b is connected to the lower part of the hot water storage tank 10. A pump 41 is disposed in the secondary side circulation path 40 and is always operating. By the operation of the pump 41, hot water circulates between the hot water storage tank 10 and the secondary side circulation path 40. That is, the hot water flowing out from the upper part of the hot water storage tank 10 flows through the secondary side circulation path 40 and returns to the lower part of the hot water storage tank 10.

[0086] A plurality of faucets 2, such as bathroom faucets with showers, kitchen faucets, and washbasin faucets, are connected to the secondary side circulation path 40 via the connection path 42. Additionally, for convenience, Figure 1 only one faucet 2 is illustrated. After the faucet 2 is opened, the hot water flowing through the secondary side circulation path 40 is discharged from the faucet 2. Thus, when the hot water in the hot water storage tank 10 decreases, water from the water tap is supplied to the hot water storage tank 10 through the water supply pipe 50.

[0087] Furthermore, in the hot water supply system 1, if the faucet 2 is opened and hot water flows out from the hot water storage tank 10, water will be supplied to the hot water storage tank 10 from the water supply pipe 50. Therefore, the temperature of the hot water in the hot water storage tank 10 may decrease. Additionally, when hot water supply from the hot water storage tank 10 is not performed for a long time, such as late at night, the temperature of the hot water in the hot water storage tank 10 may also decrease.

[0088] Therefore, in the hot water supply system 1, when the temperature of the hot water in the hot water storage tank 10 decreases, the centralized control unit 500 performs heat preservation operation control, that is, circulates the hot water in the hot water storage tank 10 between the hot water supply device 20 and heats it.

[0089] Figure 2 It is a flowchart showing the heat preservation operation control.

[0090] When the hot water supply system 1 is in an operating state, the centralized control unit 500 repeatedly executes Figure 2 the heat preservation operation control.

[0091] The centralized control unit 500 monitors the input of the heating request signal from the temperature regulator 32 (S101). After the temperature of the hot water in the hot water storage tank 10 becomes below the first heating temperature, a heating request signal is sent from the temperature regulator 32 to the centralized control unit 500.

[0092] When the heating request signal is input (S101: Yes), the centralized control unit 500 drives the pump 300 by sending a driving instruction to the pump driving unit 400 (S102). The hot water circulates between the hot water storage tank 10 and the hot water supply device 20, and in the water heater 100 where combustion is permitted, the burner 120 burns. Thus, the circulated hot water is heated. In this way, the circulating heating operation is started.

[0093] By supplying heated hot water to the hot water storage tank 10, the temperature of the hot water in the hot water storage tank 10 gradually rises. In addition, when many faucets 2 are opened and a large amount of hot water flows out from the hot water storage tank 10, the amount of water supplied from the water supply pipe 50 increases. Therefore, even if only the water heater 100 that has been permitted to burn is used for heating, the temperature of the hot water in the hot water storage tank 10 may continue to decrease. In this case, the centralized control unit 500 also permits other water heaters 100 to burn, and starts heating using other water heaters 100. At this time, in other water heaters 100, the flow rate adjustment valve is adjusted to increase the flow rate.

[0094] The centralized control unit 500 monitors the input of the stop request signal from the temperature regulator 32 (S103). After the temperature of the hot water in the hot water storage tank 10 rises and becomes above the first stop temperature, a stop request signal is sent from the temperature regulator 32 to the centralized control unit 500.

[0095] When the stop request signal has been input (S103: Yes), the centralized control unit 500 stops the pump 300 by sending a stop command to the pump drive unit 400 (S104).

[0096] During the monitoring of the input of the heating request signal in S101, furthermore, the centralized control unit 500 determines whether the first reference time (for example, 1 hour) has elapsed in a state where no heating request signal is input (S105).

[0097] In general cases, before the first reference time elapses, in most cases, the temperature of the hot water in the hot water storage tank 10 is below the first heating temperature, and a heating request signal is sent from the temperature regulator 32. Therefore, when the first reference time has elapsed without the input of a heating request signal, it is suspected that there is an abnormality such as a failure of the temperature sensor 31 or the temperature regulator 32 of the temperature adjustment unit 30.

[0098] Therefore, if the first reference time has elapsed in a state where no heating request signal is input (S105: Yes), the centralized control unit 500 drives the pump 300 (S106). Then, after the centralized control unit 500 has elapsed the standby time (for example, 5 minutes), it obtains the incoming water temperature detected by the temperature sensor 170 of the water heater 100 via the machine control unit 160 of the water heater 100 that has been permitted to burn (S108). In addition, regardless of which water heater 100 is permitted to burn, the standby time is set in consideration of the time required for the hot water to reach the water heater 100 from the hot water storage tank 10 after the pump 300 is driven.

[0099] Next, the centralized control unit 500 determines whether the incoming water temperature is below the second heating temperature (S109). The second heating temperature can be set to a temperature that is a specific temperature (e.g., 10 °C) lower than the first heating temperature (e.g., 55 °C). This is considering the following situations: the position of the water supply pipe 210 connected to the hot water storage tank 10 is lower than the temperature sensor 31 disposed in the hot water storage tank 10, and the temperature of the hot water flowing out from the hot water storage tank 10 to the water supply pipe 210 is slightly lower than the detection temperature of the temperature sensor 31; during the flow through the water supply pipe 210, the temperature of the hot water will slightly decrease, etc. In addition, when the difference between the incoming water temperature (the detection temperature of the temperature sensor 170) and the detection temperature of the temperature sensor 31 is not so large, the second heating temperature can also be set to be the same as the first heating temperature.

[0100] When the temperature adjustment unit 30 (temperature sensor 31, temperature regulator 32) is normal, in most cases the incoming water temperature is higher than the second heating temperature. When the incoming water temperature is higher than the second heating temperature (S109: No), the centralized control unit 500 stops the pump 300.

[0101] On the other hand, when the temperature adjustment unit 30 is abnormal, in most cases the incoming water temperature is below the second heating temperature. When the incoming water temperature is below the second heating temperature (S109: Yes), the centralized control unit 500 continues the operation of the pump 300. If the operation of the pump 300 causes the hot water to circulate between the hot water storage tank 10 and the hot water supply device 20, then the water heater 100 that has permitted combustion performs a combustion operation, so the circulating heating operation is started to heat the circulated hot water. Thus, the temperature of the hot water in the hot water storage tank 10 rises.

[0102] In order to count the number of times of the circulating heating operation based on the incoming water temperature being below the second heating temperature, the centralized control unit 500 includes a counter (not shown). The centralized control unit 500 increments the count value of the counter by 1 (S110).

[0103] Then, the centralized control unit 500 periodically obtains the incoming water temperature (S111), and determines whether the obtained incoming water temperature is above the second stop temperature (S112). The second stop temperature is set to, for example, the same temperature as the first stop temperature. Or the second stop temperature can also be set to a temperature slightly higher or lower than the first stop temperature.

[0104] If, as the temperature of the hot water in the hot water storage tank 10 becomes higher, the incoming water temperature becomes higher and exceeds the second stop temperature (S112: Yes), then the centralized control unit 500 stops the pump 300 (S113).

[0105] Next, the centralized control unit 500 determines whether the count value of the counter has reached a reference value (for example, 10) (S114). When the count value, that is, the number of times of the circulating heating operation based on the incoming water temperature being below the second heating temperature reaches the reference value (reference number of times) (S114: Yes), the centralized control unit 500 causes the remote controller 600 to perform an abnormality report, that is, reports that an abnormality may have occurred in the temperature adjustment unit 30 (S115). For example, a message is displayed on the operation display unit 610 of the remote controller 600. Or an alarm sound or a message sound is output from the speaker 620 of the remote controller 600.

[0106] <Effect of the First Embodiment>

[0107] According to the present embodiment, the following effects can be achieved.

[0108] After the first reference time has elapsed in a state where no heating request signal is input from the temperature regulator 32, the hot water in the hot water storage tank 10 is circulated by the operation of the pump 300, and the incoming water temperature is detected by the temperature sensor 170. When the incoming water temperature is below the second heating temperature, the hot water continues to circulate, and the hot water is heated by the circulating heating operation. Thus, even when an abnormality occurs in the temperature sensor 31 or the temperature regulator 32 of the temperature adjustment unit 30 and no heating request signal can be obtained, when the temperature of the hot water in the hot water storage tank 10 decreases, the hot water can be heated by the hot water supply device 20, and heat preservation of the hot water in the hot water storage tank 10 can be achieved.

[0109] In addition, since the circulating heating operation is performed based on the incoming water temperature being below the second heating temperature and an abnormality report is made based on this, it is possible to notify the user that an abnormality may have occurred in the temperature sensor 31 or the temperature regulator 32.

[0110] <First Variation Example 1 of the First Embodiment>

[0111] Figure 3 It is a schematic diagram showing the structure of the hot water supply system 1 of Variation Example 1.

[0112] In the first embodiment, the hot water supply device 20 includes the centralized control unit 500. In contrast, in this Variation Example 1, as Figure 3 shown, the hot water supply device 20 does not include the centralized control unit 500. Instead, the machine control unit 160 of any one water heater 100, which is the first machine 100a in this Variation Example 1, is responsible for the function of the centralized control unit 500 in the first embodiment.

[0113] A heating requirement signal and a stop requirement signal are input from the temperature regulator 32 to the machine control unit 160 of the first unit 100a. In addition, the machine control unit 160 of the first unit 100a controls the pump drive unit 400 and the remote controller 600. Furthermore, the machine control unit 160 of the first unit 100a is communicably connected to the machine control units 160 of the second unit 100b, the third unit 100c, and the fourth unit 100d.

[0114] Moreover, in this first modification example 1, the operation control of heat preservation shown in Figure 2 is executed by the machine control unit 160 of the first unit 100a.

[0115] In addition, in this first modification example 1, the machine control unit 160 corresponds to the "operation control unit" recited in the claims.

[0116] <First Modification Example 2 of the First Embodiment>

[0117] Figure 4 is a schematic diagram showing the structure of the hot water supply system 1 of the second modification example.

[0118] In the first embodiment, the pump drive unit 400 is controlled by the central control unit 500 to drive and stop the pump 300. In contrast, in this second modification example, as shown in Figure 4 , not only the central control unit 500 but also the machine control unit 160 of any one water heater 100 (the second unit 100b in this second modification example) without the central control unit 500 provided can control the pump drive unit 400 to drive and stop the pump 300.

[0119] Moreover, in this second modification example, the operation control of standby heat preservation is executed by the machine control unit 160 of the second unit 100b in case the central control unit 500 fails to operate properly due to a fault or the like.

[0120] Figure 5 is a flowchart showing the operation control of standby heat preservation of the second modification example.

[0121] When the hot water supply system 1 is in an operating state, the machine control unit 160 of the second unit 100b repeatedly executes the operation control of standby heat preservation shown in Figure 5 .

[0122] The machine control unit 160 monitors whether the hot water does not flow to the water heater 100 for a second reference time, that is, whether the detected flow rate of the flow sensor 180 does not exceed a specific flow rate (S201). The second reference time is set to a time slightly longer than the first reference time (for example, 1 hour and 10 minutes).

[0123] When the central control unit 500 operates normally and executes Figure 2When the operation control is in effect, since the pump 300 operates after the first reference time, hot water flows into the water heater 100 before the second reference time has elapsed.

[0124] On the other hand, if a failure or the like causes the centralized control unit 500 to malfunction and unable to execute Figure 2 the operation control, the second reference time will elapse while hot water does not flow into the water heater 100. In this case, the machine control unit 160 determines in S201 that the state where hot water does not flow into the water heater 100 has elapsed the second reference time (S201: Yes), and drives the pump 300 instead of the centralized control unit 500 (S202). Then, the machine control unit 160 performs the same operation control as Figure 2 from S107 to S115 of Figure 5 that is, the operation control from S203 to S212 of

[0125] However, in Figure 5 S212 of

[0126] the machine control unit 160 causes the display unit 190 of the second unit 100b to report an abnormality, that is, to report that an abnormality may have occurred in the centralized control unit 500. For example, the LED indicating an abnormality lights up in the display unit 190.

[0127] According to the structure of the second modification example, even when the centralized control unit 500 malfunctions, when the temperature of the hot water in the hot water storage tank 10 decreases, the hot water can be heated by the hot water supply device 20, and the heat preservation of the hot water in the hot water storage tank 10 can be achieved.

[0128] <First Modification Example 3 of the First Embodiment>

[0129] Figure 6 is a schematic diagram showing the structure of the hot water supply system 1 of the third modification example. Figure 7 is a flowchart showing the operation control of heat preservation of the third modification example.

[0130] In the first embodiment, based on the detected temperature of the temperature sensor 31, the temperature regulator 32 is configured to output a heating request signal or a stop request signal to the centralized control unit 500. In contrast, in this third modification example, as Figure 6As shown, a temperature signal corresponding to the detected temperature is output from the temperature sensor 31 disposed in the hot water storage tank 10 to the centralized control unit 500.

[0131] Moreover, in this third modification example, the Figure 7 heat retention operation control is executed to replace the Figure 2 heat retention operation control performed in the first embodiment.

[0132] The centralized control unit 500 periodically obtains a temperature signal corresponding to the temperature of the hot water in the hot water storage tank 10 (hereinafter referred to as the hot water temperature) from the temperature sensor 31 (S301), and determines whether the hot water temperature is equal to or lower than a first heating temperature (for example, 65°C) (S302). Then, when the hot water temperature is equal to or lower than the first heating temperature (S302: Yes), the centralized control unit 500 drives the pump 300 (S303). The hot water circulates between the hot water storage tank 10 and the hot water supply device 20 to heat the hot water.

[0133] Then, the centralized control unit 500 periodically obtains the hot water temperature from the temperature sensor 31, and obtains the incoming water temperature detected by the temperature sensor 170 of the water heater 100 via the machine control unit 160 of the water heater 100 that has been permitted to burn (S304). Then, if either the hot water temperature or the incoming water temperature becomes equal to or higher than a first stop temperature (for example, 70°C) (S305: Yes), the centralized control unit 500 stops the pump 300 (S306).

[0134] When the centralized control unit 500 determines in S302 that the hot water temperature is not equal to or lower than the first heating temperature, it determines whether the temperature signal obtained at this time represents an abnormal value (for example, a value that becomes several hundred °C), and whether a first reference time has elapsed in a state where a temperature equal to or lower than the first heating temperature (the corresponding temperature signal) has not been input (S307, S308).

[0135] In the case where the temperature signal represents an abnormal value or when a first reference time has elapsed in a state where a temperature equal to or lower than the first heating temperature has not been input, it is suspected that an abnormality such as a failure has occurred in the temperature sensor 31. Therefore, in such a case (S307: Yes, S308: Yes), the centralized control unit 500 drives the pump 300 (S309). Then, the centralized control unit 500 performs the same operation control as Figure 2 S107 to S115 of Figure 7The operation control of S310 to S318. Thus, the operation of the pump 300 circulates the hot water in the hot water storage tank 10. The inlet water temperature is detected by the temperature sensor 170. When the inlet water temperature is below the second heating temperature, the hot water continues to circulate and is heated by the circulating heating operation. In addition, the circulating heating operation is performed based on the inlet water temperature being below the second heating temperature, and an abnormality report is made based on this.

[0136] In the above example, two determinations are made: determining whether the temperature signal represents an abnormal value (S307), and determining whether the first reference time has elapsed in a state where a temperature below the first heating temperature is not input (S308). However, only one of these determinations may be made.

[0137] In addition, the structure of the first modification or the second modification can be applied to the structure of the third modification. Further, in the third modification, the temperature sensor 31 corresponds to the "signal output unit" described in the claims.

[0138] 〈Second Embodiment〉

[0139] Next, the hot water supply system 3 of the second embodiment will be described.

[0140] Figure 8 is a schematic diagram showing the structure of the hot water supply system 3. In Figure 8 the same reference numerals are given to the same structures as those in the first embodiment.

[0141] The hot water supply system 3 of the second embodiment includes a hot water storage tank 10, a hot water supply device 20A, a temperature adjustment unit 30, and a secondary side circulation path 40. That is, the structure of the hot water supply system 3 other than the hot water supply device 20A is the same as that of the hot water supply system 1 of the first embodiment.

[0142] The hot water supply device 20A includes a water heater 100, a primary side circulation path 200, a pump 300, and a pump drive unit 400.

[0143] The water heater 100 is arranged adjacent to the hot water storage tank 10. A heating request signal and a stop request signal are input from the temperature regulator 32 to the machine control unit 160 of the water heater 100. In addition, the machine control unit 160 controls the pump drive unit 400.

[0144] In the hot water supply system 3 of the present embodiment, the machine control unit 160 executes Figure 2Operation control of heat insulation. However, the standby time of S107 is set to a time shorter than that in the first embodiment (for example, 1 minute). Additionally, in S115, the machine control unit 160 causes the display unit 190 to perform an abnormality report, that is, to report that an abnormality may have occurred in the temperature adjustment unit 30. For example, the LED indicating an abnormality in the display unit 190 lights up.

[0145] Furthermore, the hot water supply device 20A may also include a remote controller. In such a case, the abnormality report is performed by the remote controller.

[0146] In this embodiment, the same effects as those in the first embodiment can also be achieved.

[0147] 〈Modification of the second embodiment〉

[0148] Figure 9 is a schematic diagram showing the structure of the hot water supply system 3 of the modification.

[0149] In the second embodiment, based on the detected temperature of the temperature sensor 31, the temperature regulator 32 is configured to output a heating request signal or a stop request signal to the machine control unit 160. In contrast, in this modification, as Figure 9 shown, a temperature signal corresponding to the detected temperature is output from the temperature sensor 31 disposed in the hot water storage tank 10 to the machine control unit 160.

[0150] And, in this modification, the operation control of heat insulation performed in the above-mentioned modification 3 is executed Figure 7 to replace the operation control of heat insulation performed in the first embodiment Figure 2 However, the standby time of S310 is set to a time shorter than that in the modification 3 (for example, 1 minute). Additionally, in S318, the machine control unit 160 causes the display unit 190 to perform an abnormality report, that is, to report that an abnormality may have occurred in the temperature sensor 31. For example, the LED indicating an abnormality in the display unit 190 lights up.

[0151] Furthermore, in this modification, the temperature sensor 31 corresponds to the "signal output unit" recited in the claims.

[0152] The first embodiment, the second embodiment, and the modifications of these embodiments of the present invention have been described above. However, the present invention is not limited by any of the above-mentioned embodiments or modifications, and various further changes can be made as described below.

[0153] 〈Other modifications〉

[0154] In the first embodiment, the second embodiment, and the modifications of these embodiments, in Figure 2 , Figure 7The operation control of the heat preservation shown and Figure 5 In the operation control of the standby heat preservation shown, when the water inlet temperature becomes equal to or higher than the second stop temperature in S112, S209, and S315, the pump 300 is stopped. However, instead of this, the pump 300 may be stopped after a preset operation time has elapsed. Or it may be configured such that the pump 300 is not stopped unless a specific operation is performed. However, when the pump 300 is not stopped, the hot water supply temperature set for the water heater 100 may be set to a temperature lower than the normal set temperature (for example, 95°C), for example, the same temperature as the first heating temperature.

[0155] In addition, in the first embodiment, the second embodiment, and the variations of these embodiments, in Figure 2 , Figure 7 The operation control of the heat preservation shown and Figure 5 In the operation control of the standby heat preservation shown, if the pump 300 is driven in S106, S202, and S309, hot water will flow to the water heater 100, and the water heater 100 will perform a combustion operation. That is, before obtaining the water inlet temperature after the standby time, the circulating heating operation is started. However, it may be configured such that even if the pump 300 is driven in S106, S202, and S309 and hot water flows to the water heater 100, the water heater 100 does not perform a combustion operation, and when it is determined that the water inlet temperature is equal to or lower than the second heating temperature and the operation of the pump 300 is continued, the water heater 100 performs a combustion operation and starts the circulating heating operation.

[0156] Furthermore, in the first embodiment, the second embodiment, and the variations of these embodiments, in Figure 2 , Figure 7 The operation control of the heat preservation shown and Figure 5 In the operation control of the standby heat preservation shown, when the number of circulating heating operations based on the water inlet temperature being equal to or lower than the second heating temperature in S114, S211, and S317 reaches a reference value (reference number of times), an abnormality report is made. However, an abnormality report may also be made after only one circulating heating operation based on the water inlet temperature being equal to or lower than the second heating temperature.

[0157] Furthermore, in the first embodiment and the second embodiment, the second heating temperature and the second stop temperature may be set to fixed values, but when the first heating temperature and the first stop temperature vary according to the temperature adjustment unit 30, it may be configured such that the second heating temperature and the second stop temperature can be set using the remote controller 600 according to the first heating temperature and the first stop temperature.

[0158] Furthermore, in the first embodiment and the second embodiment, it is possible to Figure 2When the pump 300 is driven in S102, the inlet water temperature is detected after the standby time, and the inlet water temperature is set as the second heating temperature. Similarly, the inlet water temperature can also be detected when the pump 300 is stopped in Figure 2 S104 of, and the inlet water temperature is set as the second stop temperature.

[0159] Furthermore, in the first embodiment and the second embodiment, as the temperature detection unit for detecting the temperature of the hot water flowing into the water heater as the inlet water temperature, the temperature sensor 170 is used. However, other temperature sensors included in the water heater can be used instead of or together with the temperature sensor 170. For example, a tank hot water temperature sensor or a hot water outlet temperature sensor (not shown) disposed in the outlet pipe 150 etc. can be used.

[0160] Furthermore, when the structure of the third variation of the first embodiment is adopted, the Figure 10 shown heat preservation operation control can also be executed to replace the Figure 7 shown heat preservation operation control. In the operation control, the processing of S401 to S407 is the same as the processing of S301 to S307 in Figure 7 , and the determination processing of S308 in Figure 7 is not performed. In addition, in this variation, the second stop temperature corresponds to the "third reference temperature" described in the claims.

[0161] In S407, if it is determined that the temperature signal represents an abnormal value (S407: Yes), then the central control unit 500 causes the remote controller 600 to perform an abnormality report (S408), and drives the pump 300 (S409). If the pump 300 operates, then accordingly, the water heater 100 that has permitted combustion performs a combustion operation.

[0162] After the standby time has elapsed (S410: Yes), the central control unit 500 obtains the inlet water temperature (S411), and determines whether the inlet water temperature is equal to or higher than the second stop temperature (for example, 70 °C) (S412).

[0163] If the inlet water temperature is equal to or higher than the second stop temperature (S412: Yes), then the central control unit 500 sends a stop command to the water heater 100 that has permitted combustion, and stops the combustion operation (S413). Additionally, if the inlet water temperature is not equal to or higher than the second stop temperature (S412: No), then the central control unit 500 waits until the inlet water temperature becomes equal to or higher than the second stop temperature, and then stops the combustion operation (S413). Thereby, the heating of the circulated hot water is stopped.

[0164] Then, the centralized control unit 500 periodically obtains the incoming water temperature (S414). After the incoming water temperature becomes equal to or lower than the second heating temperature (e.g., 67°C) (S415: Yes), a start command is sent to the water heater 100 that has been permitted to burn, and the combustion operation is started (S416). Thereby, the heating of the circulated hot water is started.

[0165] Then, before an operation for releasing the abnormality is performed by the user or the like, the processes of S411 to S416 are repeated.

[0166] As described above, in the case where the heat preservation operation control as shown in Figure 10 is performed, similar to the third modification example, heat preservation of the hot water in the hot water storage tank 10 can also be achieved when a normal temperature signal cannot be obtained.

[0167] In addition, in the case where the structure of the modification example of the second embodiment is adopted, the heat preservation operation control of Figure 10 can also be executed by the machine control unit 160.

[0168] Furthermore, in the first embodiment and the second embodiment, the hot water supply device 20 and the hot water supply device 20A may include a communication unit, and information for abnormality reporting is sent to an external terminal device (e.g., a personal computer, a smart phone) through the communication unit, thereby performing abnormality reporting in the terminal device.

[0169] In addition, the embodiments of the present invention can be appropriately modified within the scope described in the claims.

Claims

1. A hot water supply device, characterized in that, Comprising: A plurality of water heaters, connected to a hot water storage tank through a circulation path; A pump for circulating hot water between the hot water storage tank and the water heaters; An operation control unit that performs a circulating heating operation, that is, when obtaining a specific signal output from a signal output unit based on the temperature of the hot water in the hot water storage tank being below a first reference temperature, circulates the hot water in the hot water storage tank through the pump and heats it using the water heaters; A temperature detection unit that detects the temperature of the hot water flowing into the water heaters as the inlet water temperature; And A centralized control unit that performs joint control to make the plurality of water heaters operate jointly, and the centralized control unit functions as the operation control unit, After a first reference time has elapsed in a state where the specific signal is not input to the operation control unit, or after obtaining an abnormal signal from the signal output unit, the operation control unit circulates the hot water in the hot water storage tank through the pump, detects the inlet water temperature using the temperature detection unit, and When the inlet water temperature is below a second reference temperature, heats the hot water through the circulating heating operation, and When the inlet water temperature is higher than the second reference temperature, stops the pump, The plurality of water heaters include: A machine control unit that controls the water heaters according to instructions from the centralized control unit; And A flow rate detection unit that detects the flow rate of the hot water flowing into the water heaters, The machine control unit of one of the plurality of water heaters can drive the pump, If the state where the detected flow rate of the flow rate detection unit does not exceed a specific flow rate continues for a second reference time in the machine control unit of the one water heater, the hot water in the hot water storage tank is circulated through the pump, and the inlet water temperature is detected using the temperature detection unit, and When the inlet water temperature is below the second reference temperature, heats the hot water through the circulating heating operation, and When the inlet water temperature is higher than the second reference temperature, stops the pump.

2. The hot water supply device according to claim 1, wherein: The operation control unit causes a reporting unit to report an abnormality based on the fact that the circulating heating operation has been performed, and the circulating heating operation is performed based on the inlet water temperature being below the second reference temperature.

3. The hot water supply device according to claim 1 or 2, wherein: The signal output unit includes a temperature regulator, and the temperature regulator is connected to a temperature sensor disposed in the hot water storage tank, The specific signal includes a signal requesting heating of hot water.

4. The hot water supply device according to claim 1 or 2, wherein: The signal output unit includes a temperature sensor disposed in the hot water storage tank, The specific signal includes a temperature signal indicating a temperature below the first reference temperature.

5. A hot water supply device, characterized in that, Comprising: A plurality of water heaters, connected to a hot water storage tank through a circulation path; A pump for circulating hot water between the hot water storage tank and the water heaters; The operation control unit performs cyclic heating operation, that is, when obtaining a specific signal output from the signal output unit based on the temperature of the hot water in the hot water storage tank being below a first reference temperature, it circulates the hot water in the hot water storage tank through the pump and heats it using the water heater; and the temperature detection unit that detects the temperature of the hot water flowing into the water heater as the inlet water temperature; and the centralized control unit that performs joint control to make the multiple water heaters operate jointly, and the centralized control unit functions as the operation control unit, after the operation control unit obtains an abnormal signal from the signal output unit, it circulates the hot water in the hot water storage tank through the pump, and uses the temperature detection unit to detect the inlet water temperature, and when the pump is in an operating state, if the inlet water temperature becomes below a second reference temperature, it heats the water using the water heater, and if the inlet water temperature becomes above a third reference temperature higher than the second reference temperature, it stops heating the water using the water heater, the multiple water heaters include: the machine control unit that controls the water heater according to an instruction from the centralized control unit; and the flow rate detection unit that detects the flow rate of the hot water flowing into the water heater, the machine control unit of one of the multiple water heaters can drive the pump, if the state where the detected flow rate of the flow rate detection unit does not exceed a specific flow rate continues for a second reference time in the machine control unit of the one water heater, it circulates the hot water in the hot water storage tank through the pump, and uses the temperature detection unit to detect the inlet water temperature, and when the inlet water temperature is below the second reference temperature, it heats the hot water through the cyclic heating operation, and when the inlet water temperature is higher than the second reference temperature, it stops the pump.

6. A hot water supply system, characterized in that including: a hot water storage tank, and the hot water supply device according to any one of claims 1 to 5.

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