Hot water supply systems, methods, and programs

Abstract

In an efficient hot water supply system using both a hot water storage tank and a water heater, scheduled operation enables efficient hot water supply. [Solution] The system includes a hot water storage tank (12) that receives water in the lower section and high-temperature water in the upper section, storing low-temperature water in the lower section and high-temperature water in the upper section, a hot water storage unit (4) that dispenses hot water from the hot water storage tank for hot water supply, a water heater (6) that generates high-temperature water from low-temperature water supplied from the hot water storage unit, and a control unit (hot water supply system control unit 170) that includes an operating mode that operates according to schedule information, the schedule information including one or more of the day, day of the week, time, duration, hot water supply amount, and hot water supply set temperature, controls the water heater according to the schedule information, and dispenses low-temperature or high-temperature water from the hot water storage tank according to the hot water supply demand.

Description

Technical Field

[0001] The present disclosure relates to a hot water supply system, method, and program suitable for various hot water supplies, such as kitchen hot water supply including devices such as a noodle cooker, a food washer, and a dish washer.

Background Art

[0002] There is known a stored hot water supply device that uses hot water stored in a hot water storage tank for hot water supply according to the hot water supply demand. Regarding this stored hot water supply device, when the upper layer water temperature of the hot water storage tank is lower than the set temperature, it is known to supply the hot water heated in the heat exchange section of the heat source device to the hot water utilization destination (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a hot water supply system using a hot water storage tank, the heat radiation amount of the hot water storage tank cannot be ignored. When the hot water supply demand is low, if the entire hot water in the hot water storage tank is boiled up to high-temperature water, the hot water supply efficiency decreases due to the heat radiation amount. That is, even if the hot water in the hot water storage tank is raised to the hot water storage set temperature and maintained when there is no hot water supply demand, a temperature drop due to heat radiation occurs. When a hot water supply demand occurs, reheating must be performed to compensate for the heat radiation amount, resulting in an energy loss due to reheating of the hot water supply device.

[0005] Depending on the hot water supply system, even when there is no hot water supply demand, an operation for maintaining the high-temperature water temperature of the hot water storage tank due to heat radiation is continuously performed, and there is a disadvantage of repeating heat radiation and operation. Moreover, in a period when the water temperature drops, such as in winter, when the hot water output capacity of the hot water supply device is insufficient and the regulated flow rate decreases, a sufficient hot water output flow rate cannot be obtained.

[0006] Since the hot water supply capacity of a hot water supply system is regulated by the water heater itself, it is necessary to install a water heater with sufficient capacity to meet a large-capacity hot water demand that exceeds the system's capacity. However, if normal demand is low, selecting a water heater based on the assumption of sudden hot water demand is uneconomical.

[0007] If the hot water supply system is set to output 24 units of hot water, for example, outputting a larger volume of hot water, such as 32 units, may cause corrosion of the system piping, which is undesirable.

[0008] In light of these challenges, the inventors have found that scheduled operation, which anticipates the user's hot water needs, is effective in compensating for the heat loss from the hot water storage tank, providing diverse hot water supply configurations to meet various hot water demands, and reducing the heat loss from the hot water storage tank.

[0009] Therefore, the purpose of this disclosure is to achieve efficient hot water supply through scheduled operation in an efficient hot water storage system that uses both a hot water storage tank and a hot water heater, based on the above-mentioned problems and knowledge. [Means for solving the problem]

[0010] To achieve the above objective, according to one aspect of the hot water supply system of this disclosure, the system includes a hot water storage unit that supplies hot water by dispensing the hot water stored in the hot water storage tank, which receives water in the lower part and hot water in the upper part, stores low-temperature water on the lower part and the hot water on the upper part, and generates hot water by dispensing the hot water stored in the hot water storage tank; a water heater that generates hot water by receiving the low-temperature water from the hot water storage unit; and a control unit that includes an operating mode that operates according to schedule information, the schedule information including one or more of the day, day of the week, time, duration, amount of hot water supplied, and hot water set temperature, and controls the water heater according to the schedule information and dispenses the low-temperature water or the hot water from the hot water storage tank according to the hot water demand.

[0011] In this hot water supply system, a pump may be provided in the pipeline that carries the low-temperature water from the hot water storage tank to the water heater, and the control unit may operate the pump if the amount of hot water stored is below a lower threshold, and stop the operation of the pump if the amount of hot water stored exceeds an upper threshold.

[0012] In this hot water supply system, the system further includes a first temperature sensor for detecting the temperature of the hot water stored in the hot water storage tank, which represents a first amount of hot water stored in the hot water storage tank, and a second temperature sensor for detecting the temperature of the hot water stored in the hot water storage tank, which represents a second amount of hot water stored in the hot water storage tank, which exceeds the first amount of hot water stored. The control unit may, upon receiving a hot water supply demand, operate the pump if the temperature detected by the first temperature sensor is below the hot water storage set temperature, and stop the operation of the pump if the temperature detected by the second temperature sensor is equal to or above the hot water storage set temperature.

[0013] In this hot water supply system, the system may further include a temperature setting unit for setting the hot water supply set temperature, and the control unit may store the hot water in the hot water storage tank at a hot water storage set temperature that is a predetermined temperature difference higher than the hot water supply set temperature, and in response to a hot water demand, supply hot water adjusted to the hot water supply set temperature by mixing the hot water dispensed from the hot water storage tank with the supplied water.

[0014] In this hot water supply system, the control unit may further define a first mode for controlling hot water output based on the hot water output capacity of the water heater, and a second mode for controlling hot water output based on the hot water output capacity using both the water heater and the hot water storage tank. When a hot water demand is received, the first mode may be selected if the amount of hot water stored is less than a predetermined amount, and the second mode may be selected if the amount of hot water stored is equal to or greater than the predetermined amount.

[0015] In this hot water supply system, the control unit may further change from the second mode to the first mode when the first temperature sensor detects a hot water storage temperature below the hot water storage set temperature while the second mode is selected.

[0016] In this hot water supply system, the control unit may maintain the second mode while it is selected until the first temperature sensor detects a hot water storage temperature below the hot water storage set temperature.

[0017] In this hot water supply system, a flow control valve is further provided in the outlet passage of the hot water storage tank, and when the control unit receives a hot water demand and selects the second mode, it may control the flow rate through the flow control valve to be less than or equal to the regulated flow rate of the first mode.

[0018] In this hot water supply system, when the hot water demand is at a water flow rate that does not cause the water heater to operate, the system further includes a hot water supply mode in which at least the high-temperature water is dispensed from the hot water storage tank, and upon receiving the water demand, the control unit may supply hot water using the low-temperature water or the high-temperature water dispensed from the hot water storage tank by executing the hot water supply mode.

[0019] To achieve the above objective, according to one aspect of the hot water supply method of this disclosure, the method includes the steps of: storing low-temperature water in the lower part of a hot water storage tank and high-temperature water in the upper part; operating a pump to supply the low-temperature water from the hot water storage tank to a water heater; and operating in an operating mode that operates according to schedule information, wherein the schedule information includes one or more of the following: day, day of the week, time, duration, amount of hot water supplied, and set hot water temperature; controlling the water heater according to the day, day of the week, time, duration, amount of hot water supplied, or set hot water temperature; and dispensing the low-temperature water or high-temperature water from the hot water storage tank according to the hot water demand.

[0020] This hot water supply method may include a step of operating the pump if the amount of hot water stored is below a lower threshold, and stopping the operation of the pump if the amount of hot water stored exceeds an upper threshold.

[0021] In this hot water supply method, it may include a step of detecting the stored hot water temperature representing the first stored amount of the high-temperature water stored in the hot water storage tank by the first temperature sensor, a step of detecting the stored hot water temperature representing the second stored amount of the high-temperature water stored in the hot water storage tank exceeding the first stored amount by the second temperature sensor, and a step of operating the pump when the detected temperature of the first temperature sensor is lower than the set hot water storage temperature and stopping the operation of the pump when the detected temperature of the second temperature sensor exceeds the set hot water storage temperature.

[0022] In this hot water supply method, it may further include a step of setting the hot water supply set temperature in a temperature setting unit, and a step of receiving the setting of the hot water supply set temperature, storing the high-temperature water at a hot water storage set temperature that is higher than the hot water supply set temperature by a predetermined temperature difference, and mixing water supply with the high-temperature water discharged from the hot water storage tank to supply warm water at the hot water supply set temperature.

[0023] In this hot water supply method, it may further include a hot water supply mode of discharging at least the high-temperature water from the hot water storage tank when the water supply flow rate at which the hot water supply device does not operate, and a step of receiving a water supply demand and supplying hot water with the high-temperature water discharged from the hot water storage tank by executing the hot water supply mode.

[0024] To achieve the above object, according to one aspect of the program of the present disclosure, it is a program for causing a computer to execute, including a function of storing low-temperature water in the lower layer side of a hot water storage tank and storing high-temperature water in the upper layer side, a function of operating a pump to supply the low-temperature water from the hot water storage tank to a hot water supply device, including an operation mode of operating according to schedule information, where the schedule information includes any one or two or more of date, day of the week, time, hour, hot water supply amount, and hot water supply set temperature, controlling the hot water supply device according to the date, the day of the week, the time, the hour, the hot water supply amount, or the hot water supply set temperature, and causing the computer to execute a function of discharging the low-temperature water or the high-temperature water from the hot water storage tank according to a hot water supply demand.

Advantages of the Invention

[0025] According to the present disclosure, any of the following effects can be obtained. (1) By using a hot water storage tank with cold water stored on the lower layer side and hot water stored on the upper layer side in combination with a water heater, hot water supply can be performed according to the hot water supply demand. If an operation mode that operates according to schedule information is selected, planned hot water supply, hot water supply time, hot water supply amount, and hot water supply demand including the hot water supply set temperature can be assumed based on any one or two or more of the preset date, day of the week, time, hour, hot water supply amount, and hot water supply set temperature, and efficient hot water supply can be performed.

[0026] (2) In this operation mode, if the hot water storage amount in the hot water storage tank reaches a predetermined amount or more, the hot water discharge capacity can be improved, the reduction of the regulated flow rate can be mitigated, and the necessary hot water discharge flow rate can be obtained even when the water temperature drops in winter or the like.

[0027] (3) Since the hot water storage amount of the hot water stored in the hot water storage tank can be regulated, the heat dissipation amount of the hot water can be suppressed, and energy saving can be achieved.

[0028] (4) The hot water storage amount can be reduced with respect to the maximum hot water storage amount of the hot water storage tank, and economical hot water supply can be realized by using the hot water discharge from the hot water storage tank and the hot water supply operation of the water heater in combination.

Brief Description of the Drawings

[0029] [Figure 1] FIG. 1 is a diagram showing a hot water storage type hot water supply system according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a hot water storage unit. [Figure 3] FIG. 3 is a diagram showing the relationship between each hot water storage amount of the hot water storage tank and each temperature sensor. [Figure 4] FIG. 4 is a diagram showing an example of a water heater. [Figure 5] A in FIG. 5 is a diagram showing a remote control device, and B in FIG. 5 is a diagram showing a second operation unit of the remote control device. [Figure 6] FIG. 6 is a block diagram showing a hot water supply system control unit. [Figure 7]Figure 7 shows the schedule database, timer, and calendar section. [Figure 8] Figure 8A is a table showing the regulated flow rate (1), and Figure 8B is a diagram showing the hot water supply operation in the second mode. [Figure 9] Figure 9A is a table showing the regulated flow rate (2), and Figure 9B is a diagram showing the hot water supply operation from the second mode to the first mode. [Figure 10] Figure 10A is a table showing the regulated flow rate (3), and Figure 10B is a diagram showing the hot water supply operation when changing from the first mode to the second mode. [Figure 11] Figure 11 is a flowchart showing the flow rate regulation process. [Figure 12] Figure 12 is a flowchart showing the process for selecting the operating mode. [Figure 13] Figure 13A shows the settings for the hot water supply mode, and Figure 13B shows the hot water supply operation. [Figure 14] Figure 14 is a flowchart showing the processing procedure for the hot water supply mode. [Figure 15] Figure 15A shows the settings for the continuous heating mode, and Figure 15B shows the hot water supply operation in continuous heating mode. [Figure 16] Figure 16 is a flowchart showing the processing procedure for the continuous heating mode. [Figure 17] Figure 17 is a flowchart showing the processing steps for scheduling. [Figure 18] Figure 18A shows the settings for the scheduled operation mode, and Figure 18B shows the hot water supply operation during scheduled operation. [Figure 19] Figure 19 is a flowchart showing the processing procedure for the scheduled operation mode. [Figure 20] Figure 20A shows the settings for the second hot water supply mode according to the second embodiment, and Figure 20B shows the hot water supply operation. [Figure 21] Figure 21 is a flowchart showing the processing procedure for the second hot water supply mode. [Figure 22] Figure 22A shows the settings for the tank hot water supply mode according to the third embodiment, and Figure 22B shows the hot water supply operation in the tank hot water supply mode. [Figure 23] Figure 23 is a flowchart showing the processing procedure for the tank hot water supply mode. [Figure 24] Figure 24 is a diagram showing the processing procedure for the tank hot water supply mode according to the fourth embodiment. [Figure 25] Figure 25 shows a kitchen hot water supply system according to the fifth embodiment. [Modes for carrying out the invention]

[0030] [First Embodiment] <Storage-type hot water supply system 2> Figure 1 shows a storage-type hot water supply system according to the first embodiment. The configuration shown in Figure 1 is an example, and this disclosure is not limited to such a configuration. This storage-type hot water supply system 2 (hereinafter simply referred to as "hot water supply system 2") comprises a storage unit 4, a water heater 6, and a remote control device 8.

[0031] In this hot water supply system 2, when a demand for hot water arises, water supply W is received at the water inlet 10 of the hot water storage unit 4, and the high-temperature water HHW stored in the hot water storage tank 12 is adjusted to the hot water HW of the set hot water temperature, and then discharged from the hot water outlet 14 to the hot water supply passage 16 and supplied to the demand location. At this time, in accordance with the water supply W due to the hot water demand, low-temperature water LHW from the hot water storage unit 4 flows from the hot water storage unit 4 to the water heater 6. The water heater 6 is a gas water heater that supplies high-temperature water HHW to the hot water storage unit 4, and is a heat source that heats the low-temperature water LHW to high-temperature water HHW by heat exchange with the low-temperature water LHW using the heat from the combustion exhaust of the fuel gas G. The outlet 18 of the hot water storage unit 4 and the water inlet 20 on the water heater 6 side are connected by a supply pipe 22, and low-temperature water LHW is supplied to the water heater 6 through the supply pipe 22.

[0032] When low-temperature water LHW flows into the water heater 6, the water heater 6 starts the combustion operation of fuel gas G, and heats the low-temperature water LHW through heat exchange between the combustion exhaust of fuel gas G and the low-temperature water LHW. As a result, high-temperature water HHW, heated to a temperature above the storage water set temperature, is supplied to the storage water unit 4. Fuel gas G is supplied to the gas supply port 24 of the water heater 6, and when water enters at the water inlet 20, the water heater 6 starts combustion. The hot water outlet 26 of the water heater 6 and the hot water return port 28 of the storage water unit 4 are connected by a return pipe 30, and high-temperature water HHW is introduced from the water heater 6 to the storage water unit 4.

[0033] The remote control device 8 is connected to the hot water storage unit 4 via signal line 32 and to the water heater 6 via signal line 34. Control signals from the remote control device 8 are input to the control systems of the hot water storage unit 4 and the water heater 6, enabling coordinated operation of the hot water storage unit 4 and the water heater 6.

[0034] <Hot water storage unit 4> As shown in Figure 2, the hot water storage unit 4 is equipped with a hot water storage tank 12, a water supply channel 36, a first pipe 38-1, a second pipe 38-2, a third pipe 38-3, a hot water outlet channel 40, a temperature control unit 42, and the like.

[0035] The hot water storage tank 12 can store, for example, 90 liters of hot water to meet the hot water demand. The hot water storage tank 12 has a water inlet 44 and a lower water outlet 46 at the bottom, and a hot water return outlet 48 and a hot water outlet 50 at the top.

[0036] The water supply channel 36 is connected between the water inlet 10 and the water supply inlet 44 of the hot water storage tank 12. The water supply channel 36 is equipped with a water supply check valve 51 to prevent backflow of the water supply W, a water flow sensor 52 to detect the amount of water passing through, a pressure reducing valve 54 to reduce the pressure in the water supply channel 36, a mixed water control valve 56 to control the amount of mixture between high-temperature water HHW and the water supply W, and a tank check valve 58 to prevent backflow from the hot water storage tank 12 side. The water flow sensor 52 detects the amount of water supply Wq, which represents the water supply demand.

[0037] Pipeline 38-1 connects the lower water outlet 46 and the supply outlet 18, and the second pipeline 38-2 connects the hot water return outlet 28 and the hot water return outlet 48. Pipeline 38-1 is equipped with a pump 60, and when this pump 60 is running, it supplies low-temperature water LHW taken from the lower side of the hot water storage tank 12 to the water heater 6.

[0038] Pipelines 38-1 and 38-2 are connected by pipeline 38-3, which branches off from pipeline 38-1, and by a water switching valve 62 installed in the middle of pipeline 38-2. Pipeline 38-3 bypasses the hot water storage tank 12 and, together with pipelines 38-1 and 38-2, forms a circulation path to the water heater 6. In the case of normal hot water supply or storage, the water switching valve 62 is closed on the pipeline 38-3 side, allowing high-temperature water HHW from the water heater 6 to flow to the hot water return port 48. During the warm-up operation or freeze prevention operation of the water heater 6, the water switching valve 62 opens on the pipeline 38-3 side, operating the water heater 6 and circulating the high-temperature water HHW to the water heater 6 and the circulation path.

[0039] The hot water outlet channel 40 is installed between the hot water outlet 50 and the hot water supply outlet 14, and a mixing water control valve 56 of the temperature adjustment unit 42 is installed in the middle of it.

[0040] The temperature control unit 42 is equipped with water control valves 64-1 and 64-2 and a bypass passage 66. Water control valve 64-1 adjusts the amount of water supply W introduced from the water inlet 10 into the water supply passage 36, and water control valve 64-2 adjusts the amount of water supply W flowing from the water supply passage 36 to the bypass passage 66, thereby adjusting the amount of high-temperature water HHW passing through the hot water outlet passage 40. As a result, the amount of mixture between the high-temperature water HHW flowing into the hot water outlet passage 40 and the water supply W is adjusted, and the high-temperature water HHW is adjusted to the hot water set to the hot water outlet temperature.

[0041] The hot water storage tank 12 is equipped with multiple temperature sensors 68-1, 68-2, 68-3, 68-4, and 68-5 to detect the temperature of the stored hot water. The water supply channel 36 is equipped with a temperature sensor 68-6 to detect the water supply temperature, and the pipe 38-2 is equipped with a temperature sensor 68-7 to detect the temperature of the high-temperature water HHW supplied from the water heater 6. The outlet channel 40 is equipped with a temperature sensor 68-8 to detect the outlet temperature of the hot water storage tank 12, and a temperature sensor 68-9 to detect the mixing temperature. The hot water storage unit 4 is equipped with a temperature sensor 68-10 to detect the outside temperature.

[0042] An overflow pipe 72 is installed between the hot water outlet 40 and the overflow port 70, and an overpressure relief valve 74 with a built-in vacuum breaker is installed in the middle of this overflow pipe 72. The water supply channel 36 is connected to the tank drain port 78 via the tank drain pipe 76.

[0043] <Relationship between the amount of hot water stored in each hot water storage tank Q and temperature sensors 68-1, 68-2, ..., 68-5> Figure 3 shows the relationship between the amount of hot water stored (heat storage amount) in the hot water storage tank 12 and each temperature sensor 68-1, 68-2, ..., 68-5. The hot water storage tank 12 has multiple temperature sensors, for example, five temperature sensors 68-1, 68-2, ..., 68-5, installed from the top to the bottom. For example, for a 90-liter hot water storage tank 12, the height positions of the temperature sensors 68-1, 68-2, ..., 68-5 are set as follows. Each height position represents the amount of heat stored by the high-temperature water HHW, corresponding to the hot water storage amounts Q1, Q2, Q3, Q4, Q5 from the top of the hot water storage tank 12. In other words, each temperature sensor 68-1, 68-2, ..., 68-5 in the hot water storage tank 12 detects the temperature of the stored hot water at the position that specifies the amount of high-temperature water HHW stored. Therefore, the amount of hot water HHW or cold water LHW stored in the hot water storage tank 12 can be determined by the temperature detected by each temperature sensor 68-1, 68-2, ..., 68-5.

[0044] The temperature sensor 68-1 is installed at a height where the storage volume Q1 = 10 liters is above the upper limit of the storage volume of the hot water storage tank 12.

[0045] Installation position (height position) of temperature sensor 68-2: It is set at a position where the hot water storage amount Q2 = 16 liters (= Q1 × 1.6 times) can be specified from the upper limit of hot water storage in the hot water storage tank 12. In this example, as an example, the hot water storage amounts Q1 and Q2 are set such that Q2 = Q1 × 1.6 times, but the present disclosure is not limited to such a setting.

[0046] Installation position (height position) of temperature sensor 68-3: It is set at a position where the hot water storage amount Q3 = 35 liters can be specified from the upper limit of hot water storage in the hot water storage tank 12. In this example, as an example, the hot water storage amounts Q1, Q2, and Q3 are set such that Q3 = Q1 × 3.5 > Q2 × 2, but the present disclosure is not limited to such a setting.

[0047] Installation position (height position) of temperature sensor 68-4: It is set at a position where the hot water storage amount Q4 = 55 liters can be specified from the upper limit of hot water storage in the hot water storage tank 12. In this example, as an example, the hot water storage amounts Q1, Q3, and Q4 are set such that Q4 = Q1 × 5.5 < Q3 × 2, but the present disclosure is not limited to such a setting.

[0048] Installation position (height position) of temperature sensor 68-5: It is set at a position where the hot water storage amount Q5 = 75 liters can be specified from the upper limit of hot water storage in the hot water storage tank 12. In this example, as an example, the hot water storage amounts Q1, Q2, Q3, Q4, and Q5 are set such that Q5 = Q1 × 7.5 > Q4 + Q2, Q1 × 7.5 > Q3 × 2, but the present disclosure is not limited to such a setting.

[0049] <Hot water supply device 6> Figure 4 shows an example of the hot water supply device 6. In this hot water supply device 6, a gas combustion unit 80, a heat exchange unit 82, a hot water adjustment unit 84, a drain treatment unit 86, etc. are installed.

[0050] The gas combustion section 80 is equipped with a burner 88 capable of multi-stage combustion, and the exhaust gas from the combustion of fuel gas G by the burner 88 is used for heat exchange with low-temperature water LHW. Gas switching valves 90-1, 90-2, 90-3, a gas proportional valve 94, and a main gas solenoid valve 96 are installed between the burner 88 and the gas supply port 24. A flame rod 98 and a spark plug 99 are installed on the combustion port side of the burner 88, and an igniter 100 is connected to the spark plug 99. An air intake fan 102 is installed below the burner 88 to supply the air necessary for combustion to the burner 88. In one example of four-stage combustion, opening only gas switching valve 90-1 enables one-stage combustion, opening gas switching valves 90-1 and 90-2 enables two-stage combustion, closing gas switching valve 90-2 and opening gas switching valves 90-1 and 90-3 enables three-stage combustion, and opening gas switching valves 90-1, 90-2, and 90-3 enables four-stage combustion.

[0051] In the heat exchange section 82, a primary heat exchanger 104 and a secondary heat exchanger 106 are installed, moving from the upstream side to the downstream side of the passage for combustion exhaust from the burner 88. A water supply channel 108 connecting the water inlet 20 and the inlet side of the secondary heat exchanger 106 is equipped with a water flow sensor 110 for detecting the amount of water entering, and a bypass valve 112 of the hot water adjustment section 84 which controls the amount of water passing through to adjust the hot water temperature, and low-temperature water LHW flows from the hot water storage tank 12 side. The primary heat exchanger 104 and the secondary heat exchanger 106 are connected in series, and a hot water outlet channel 114 connecting the outlet side of the primary heat exchanger 104 and the hot water inlet 26 is equipped with a mixed water control valve 116 of the hot water adjustment section 84 which controls the amount of water passing through.

[0052] A bypass passage 118 is installed between the bypass valve 112 and the mixed water control valve 116 of the hot water adjustment unit 84, bypassing the heat exchange unit 82. Therefore, in the hot water adjustment unit 84, the amount of mixture between the high-temperature water HHW flowing in the outlet passage 114 and the low-temperature water LHW from the bypass passage 118 is adjusted, and the high-temperature water HHW directed to the hot water storage unit 4 is adjusted to the hot water storage set temperature.

[0053] A temperature sensor 120-1 is installed at the water inlet 20 to detect the temperature of the passing low-temperature water LHW, a high-limit switch 120-2 and a temperature sensor 120-3 for detecting the hot water temperature are installed at the outlet side of the primary heat exchanger 104, and a temperature sensor 120-4 for detecting the mixed temperature of the high-temperature water HHW and low-temperature water LHW directed to the hot water storage unit 4 is installed at the hot water inlet 26.

[0054] The condensate generated in the secondary heat exchanger 106 is guided to the neutralizer 122 in the drain processing unit 86 and neutralized. The neutralizer 122 is equipped with an electrode 123 for detecting the condensate level. The neutralizer 122 and the drain outlet 124 are connected by a drain outlet pipe 125, and the condensate D neutralized in the neutralizer 122 is discharged from the drain outlet 124.

[0055] <Remote control device 8> Figure 5A shows an example of a remote control device 8. This remote control device 8 has an information display unit 128, a first operation unit 130, and an opening / closing cover 132 on the front of the remote control housing 126. The remote control housing 126 is installed on the wall of a house. The information display unit 128 is composed of an LCD (Liquid Crystal Display) display and displays various control information such as setting information, temperature information, mode information, and schedule information in characters and graphics.

[0056] The first control unit 130 includes a hot water supply button 134, a continuous heating button 136, a scheduled operation button 138, and a buzzer stop button 140. When the hot water supply button 134 is turned ON, hot water can be supplied, and the hot water supply mode is selected as the initial value. This hot water supply mode includes a hot water supply operation that primarily uses high-temperature water HHW from the hot water storage tank 12, for example, to meet the demand for intermittent hot water supply. When the hot water supply button 134 is ON, the display unit 142-1 lights up to indicate that hot water supply is in operation.

[0057] The continuous boiling button 136 allows you to select between turning it ON to activate continuous boiling mode and turning it OFF to deactivate continuous boiling mode. When the continuous boiling button 136 is ON, the display unit 142-2 lights up to indicate that continuous boiling mode is active.

[0058] The schedule operation button 138 allows you to select between entering schedule operation mode when ON and exiting schedule operation mode when OFF. When the schedule operation button 138 is ON, the display unit 142-3 lights up to indicate that schedule operation mode is active.

[0059] The buzzer stop button 140, when turned ON, can silence the buzzer sound that indicates a malfunction in the device. The display unit 142-4 of the buzzer stop button 140 is always lit and flashes when an alarm occurs.

[0060] The opening / closing cover 132 is equipped with a sound vent 144, which emits alarms and operation sounds from the speaker 148. This opening / closing cover 132 is equipped with a hinge on its lower edge, allowing it to be opened and closed downwards, and when this opening / closing cover 132 is opened, the second operating section 146 becomes operable.

[0061] <Second operating section 146 of remote control device 8> Figure 5B shows the second operating unit 146 of the remote control device 8. The second operating unit 146 should be set to be activated when the opening / closing lid 132 is in the open position, and in this case, the operation of the first operating unit 130 may be disabled.

[0062] The second control panel 146 is equipped with a speaker 148 sound outlet 144, a lock button 150, a water heating setting button 152, a service setting button 154, a pause setting button 156, an INFO button 158, a menu button 160, a hot water temperature setting button 162, a select button 164, a back button 166, and the like.

[0063] The lock button 150 is used to set or release the lock state; for example, pressing and holding it for several seconds will set or release the lock state. After pressing the water heating setting button 152, the water heating temperature can be set using the hot water temperature setting button 162, which will be described later. This water heating temperature is the remote control setting temperature and will be hereinafter referred to as the hot water setting temperature Tset.

[0064] The business setting button 154 is used to set the start time and hours of business, and the water heating will be performed according to the set start time and hours of business. The pause setting button 156 is used to set the hot water storage to pause for a certain period of time.

[0065] The menu button 160 is used to select the remote control setting menu, and the hot water temperature setting button 162 is used to raise or lower the set temperature. A short press of the up button raises the set temperature, and a short press of the down button lowers the set temperature. When setting scheduled operation, the hot water temperature setting button 162 is assigned to increase or decrease the numerical value representing the start time and business hours. The confirm button 164 is operated when confirming settings such as the set temperature and time, and is used to confirm the changes. The back button 166 is used to revert setting information, such as changing the setting content.

[0066] <Hot water supply system control unit 170> Figure 6 shows the hot water supply system control unit 170 of the hot water supply system 2. In Figure 6, the same parts as in Figures 2, 4, and 5 are denoted by the same reference numerals.

[0067] This hot water supply system control unit 170 is an example of a control unit of the present disclosure and is responsible for controlling the entire system, including the storage and supply of hot water from the hot water storage unit 4 of the hot water supply system 2, the supply of hot water from the water heater 6, and the control of the remote control device 8. This hot water supply system control unit 170 includes a hot water storage unit control unit 172, a water heater control unit 174, and a remote control control unit 176.

[0068] The hot water storage unit control unit 172 is composed of a computer equipped with a processor 178-1, memory 180-1, and input / output unit 182-1. The processor 178-1 executes the OS (Operating System) and hot water storage program stored in memory 180-1. Memory 180-1 is an example of a storage medium and includes memory elements such as ROM (Read-Only Memory) and RAM (Random-Access Memory). ROM stores the OS, hot water storage program, and schedule database 184 (Figure 7) used for scheduled operation, while RAM constitutes the work area for information processing. The input / output unit 182-1 is used for inputting and outputting information. Various sensors, including temperature sensors 68-1, 68-2, ..., 68-10, timer 186, and calendar unit 188, are connected to this input / output unit 182-1 and are used for inputting detection signals and outputting calculation results under the control of the processor 178-1.

[0069] The schedule database 184 stores schedule information for executing the scheduled operation mode. The schedule information is set by the remote control device 8 and includes one or more of the following: the day, day of the week, time, duration, hot water supply volume, and hot water supply set temperature. The day is year, month, and day information. The hot water supply volume represents the hot water demand, for example, the amount of hot water for low-temperature water LHW or high-temperature water HHW. The hot water supply set temperature is the temperature of the hot water supplied from the hot water supply system.

[0070] Timer 186 is an example of a timing means controlled by processor 178-1, and timing information is received by processor 178-1 from this timer 186. Instead of timer 186, the clock function of processor 178-1 may be used, or time information may be obtained from an external GPS (Global Positioning System).

[0071] The calendar unit 188 is a database for obtaining information such as the relationships between each year, day, and day of the week. The calendar information obtained from this calendar unit 188 includes time information such as business days (including holidays), business hours, and start times of business for the businesses using this hot water supply system 2.

[0072] The water heater control unit 174 is composed of a computer equipped with a processor 178-2, memory 180-2, and input / output unit 182-2. The processor 178-2 executes the water heating program handled by the water heater 6 from among the OS and water heating control programs stored in memory 180-2. Memory 180-2 is an example of a storage medium and includes memory elements such as ROM and RAM. ROM stores the OS, water heating program, database, etc., while RAM constitutes the work area for information processing. The input / output unit 182-2 is used for input and output of information. Various sensors, including temperature sensors 120-1, 120-2, 120-3, and 120-4, are connected to this input / output unit 182-2 and are used for acquiring detection signals and outputting control results under the control of the processor 178-2. This control includes combustion control.

[0073] The remote control unit 176 is composed of a computer equipped with a processor 178-3, memory 180-3, and input / output unit 182-3. The processor 178-3 executes the OS and the remote control program for the remote control device 8, which are stored in memory 180-3. Memory 180-3 is an example of a storage medium and includes memory elements such as ROM and RAM. The ROM stores the OS, hot water storage program, database, etc., while RAM constitutes the work area for information processing. The input / output unit 182-3 is used for inputting and outputting information. The first operation unit 130 and the second operation unit 146 are connected to this input / output unit 182-3, and are used under the control of the processor 178-3 to input input signals from the first operation unit 130 and the second operation unit 146 and output to the information presentation unit 128. This control includes combustion control.

[0074] <Relationship between hot water supply temperature Tset and storage water temperature Tref> Equation 1 expresses the relationship between the hot water supply setting temperature Tset and the storage hot water setting temperature Tref.

[0075] Tref = Tset + ΔT > Tset ... Equation 1

[0076] The temperature difference ΔT can be set to, for example, ΔT = 5℃. By setting the storage water temperature Tref higher than the hot water supply temperature Tset in this way, the effect of heat dissipation from the high-temperature water HHW can be avoided, and there is more leeway in adjusting the temperature of the high-temperature water HHW, allowing hot water HW to be supplied adjusted to the hot water supply temperature Tset.

[0077] <Schedule Operation Control Unit> Scheduled operation control includes hot water supply control that corresponds to the operating schedule of equipment such as noodle boilers.

[0078] Figure 7 shows the schedule operation control unit 190. This schedule operation control unit 190 is installed in the hot water storage unit control unit 172, and consists of a schedule database 184, a timer 186, and a calendar unit 188, and is included in the hot water supply system control unit 170.

[0079] The schedule database 184 stores schedule information set by the remote control device 8, including the set date information 184-1, day information 184-2, day of the week information 184-3, time information 184-4, hour information 184-5, business day information 184-6, holiday information 184-7, and other information such as the amount of hot water supplied and the set temperature of the hot water supply.

[0080] The setting date information 184-1 stores the setting date and date / time information set by the remote control device 8. The day information 184-2 stores day information such as business days and holidays. The day of the week information 184-3 stores day of the week information. The time information 184-4 stores time information representing the operating time. The duration information 184-5 stores duration information representing the operating time. The business day information 184-6 stores day information such as operating days. The holiday information 184-7 stores day information such as days when operations are suspended.

[0081] The timer 186 associates the stored information in the schedule database 184 with calendar information m1, m2, ... m12, and provides timing information for identification such as the day and time.

[0082] Therefore, when the scheduled operation mode is selected, the hot water supply system control unit 170 acquires timing information from the timer 186 and calendar information from the calendar unit 188, and outputs operation instruction information according to the schedule information stored in the schedule database 184. Based on this operation instruction information, the hot water supply operation of the hot water supply system 2 is performed.

[0083] The calendar unit 188 outputs month information, day information, and day of the week information for each year.

[0084] <Change in regulated flow rate (switching of flow rate number)> In this hot water supply system 2, the regulated flow rate is automatically calculated according to the amount of hot water HHW stored (heat storage amount) in the hot water storage tank 12, and the optimal maximum hot water output capacity is changed accordingly. This maximum hot water output capacity includes a first mode and a second mode. The first mode assumes the maximum hot water output capacity provided by the water heater 6 and performs proportional control from the minimum capacity up to, for example, a maximum of 24 capacity. The second mode assumes the maximum hot water output capacity when the water heater 6 is used in conjunction with hot water from the hot water storage tank 12 and performs proportional control from the minimum capacity up to, for example, a maximum of 32 capacity.

[0085] Here, No. 1 refers to the capacity to raise the temperature of 1 liter of water by 25°C per minute. Therefore, No. 24 hot water output means the capacity to raise the water temperature by 25°C and output 24 liters of hot water HW from the water heater 6 per minute. In the hot water supply system 2, which uses both the water heater 6 and the hot water storage unit 4, this means the capacity to raise the water temperature by 25°C and output 24 liters of hot water HW per minute. Furthermore, No. 32 hot water output means that in the hot water supply system 2, which uses both the water heater 6 and the hot water storage unit 4, it is possible to raise the water temperature by 25°C and output 32 liters of hot water HW per minute. However, in order to prevent corrosion of the system piping, the regulated flow rate is limited to a maximum of 24 liters / min or less when No. 32 hot water is being output.

[0086] In this water supply system 2, automatic switching between the first mode and the second mode set to the regulated flow rate is performed, and the following regulated flow rates (1), (2), and (3) are included.

[0087] <Regulated flow rate (1)> A in FIG. 8 shows an example of the table of the regulated flow rate (1). If the detected temperature T4 of the temperature sensor 68 - 4 is equal to or higher than the stored hot water set temperature Tref (T4≧Tref), the regulated flow rate at No. 32 is calculated. According to this calculation, if the incoming water temperature = 5°C, the outgoing water temperature = 60°C, and the number = 32, the regulated flow rate = 14.55 liters / min.

[0088] B in FIG. 8 shows the hot water discharging operation in the second mode. The water heater 6 can discharge hot water at No. 24. If the detected temperature T4 of the temperature sensor 68 - 4 is equal to or higher than the stored hot water set temperature Tref, in the storage tank 12, the stored amount of high - temperature water HHW at or higher than the stored hot water set temperature Tref is Q4 = 55 liters or more, so it is possible to discharge hot water at No. 32.

[0089] When a hot water supply demand occurs and the water supply W enters the lower layer of the storage tank 12, the pump 60 is driven, and low - temperature water LHW enters the water heater 6 from the storage tank 12. The water heater 6 heats the low - temperature water LHW to high - temperature water HHW at or higher than the stored hot water set temperature Tref, and this high - temperature water HHW is returned to the upper layer of the storage tank 12. At this time, it is possible to discharge hot water at No. 32 from the storage tank 12.

[0090] <Regulated flow rate (2)> A in FIG. 9 shows an example of the table of the regulated flow rate (2). During hot water discharge at No. 32 in the second mode, if the detected temperature T1 of the temperature sensor 68 - 1 becomes lower than the stored hot water set temperature Tref (T1<Tref), the hot water discharge switches to No. 24, and the regulated flow rate at No. 24 is calculated. According to this calculation, if the incoming water temperature = 5°C, the outgoing water temperature = 60°C, and the number = 24, the regulated flow rate = 10.91 liters / min.

[0091] B in Fig. 9 shows the hot water discharging operation from the second mode to the first mode. If the detected temperature T1 of the temperature sensor 68-1 drops below the stored hot water set temperature Tref (T1 < Tref), the stored amount of high-temperature hot water HHW at or above the stored hot water set temperature Tref in the hot water storage tank 12 has decreased to a stored amount of less than Q1 = 10 liters. In this case, the hot water discharge changes from the 32nd hot water discharge in the second mode to the 24th hot water discharge in the first mode.

[0092] At this time, when hot water supply demand occurs and the water supply W enters the lower layer of the hot water storage tank 12, the pump 60 is driven, and low-temperature hot water LHW enters the water heater 6 from the hot water storage tank 12. The water heater 6 heats the low-temperature hot water LHW to high-temperature hot water HHW at or above the stored hot water set temperature Tref, and this high-temperature hot water HHW is returned to the upper layer of the hot water storage tank 12. At this time, the 24th hot water discharge from the hot water storage tank 12 becomes possible.

[0093] <Regulated flow rate (3)> A in Fig. 10 shows the table of the regulated flow rate (3). During the hot water discharge at the 24th in the first mode, when the detected temperature T4 of the temperature sensor 68-4 recovers to or above the stored hot water set temperature Tref (T4 ≥ Tref), the hot water discharge switches to the 32nd, and the calculation of the regulated flow rate is performed.

[0094] B in Fig. 10 shows the hot water discharging operation from the first mode to the second mode. If the detected temperature T1 of the temperature sensor 68-1 drops below the stored hot water set temperature Tref (T1 < Tref), the hot water discharging operation at the 24th in the first mode occurs, and at the same time, the operation of storing high-temperature hot water HHW in the hot water storage tank 12 is performed. After that, when high-temperature hot water HHW is stored in the hot water storage tank 12 and the detected temperature T4 of the temperature sensor 68-4 recovers to or above the stored hot water set temperature Tref (T4 ≥ Tref), the hot water discharge switches to the 32nd. That is, the 24th hot water discharge continues until the detected temperature T4 becomes T4 ≥ Tref.

[0095] <Processing procedure for flow rate regulation> Fig. 11 shows the processing procedure for flow rate regulation. This processing procedure shows an example of the hot water supply method or program of the present disclosure. In Fig. 11, S represents the steps of the processing procedure, and the symbols attached to S are an example of the order.

[0096] Hot water supply is required, and at the initial stage of hot water discharge, the hot water discharge is in the first mode (S101). In this first mode, proportional control is up to a maximum of 24 units = 24 liters / min. In this case, the ON / OFF control of the pump 60 (ON / OFF of the water heater 6) is based on the control described in the flowchart shown in FIG. 14.

[0097] During the hot water discharge in this first mode, the stored water unit control unit 172 acquires the detected temperature T4 of the temperature sensor 68-4 and determines whether the detected temperature T4 is less than the stored water set temperature Tref (T4<Tref) (S102). If the detected temperature T4 is T4<Tref (YES in S102), the stored water unit control unit 172 acquires the detected temperature T1 of the temperature sensor 68-1 and determines whether the detected temperature T1 is less than the stored water set temperature Tref (T1<Tref) (S103).

[0098] If the detected temperature T1 is greater than or equal to the stored water set temperature Tref (T1≧Tref) (NO in S103), it is determined whether the detected temperature T4 is less than the stored water set temperature Tref (T4<Tref) (S102). If the detected temperature T4 is T4≧Tref (NO in S102), the second mode is entered (S104). In this case, the maximum is 32 units, but the regulation is 24 liters / min. In this case, the maximum of 32 units continues regardless of the ON / OFF of the flow rate, and it returns to the maximum of 24 units only when the detected temperature T1 becomes T1<Tref (YES in S105).

[0099] During the hot water discharge in this second mode, the stored water unit control unit 172 acquires the detected temperature T1 of the temperature sensor 68-1 and determines whether the detected temperature T1 is less than the stored water set temperature Tref (T1<Tref) (S105). During the hot water discharge in the second mode, if the detected temperature T1 is not T1<Tref (NO in S105), the hot water discharge in the second mode continues. That is, when shifting from the hot water discharge in the first mode to the hot water discharge in the second mode, the hot water discharge at a maximum of 32 units continues until the detected temperature T1 becomes T1<Tref.

[0100] During hot water discharge in the first mode or during hot water discharge in the second mode, if the detected temperature T1 of the temperature sensor 68-1 drops to T1 < Tref (YES in S103 or S105), the system shifts to hot water discharge in the first mode (S106). In this case, the maximum number of hot water discharges is 24, and FB (feedback) control is performed by the water control valve 64-2.

[0101] In this case, if the detected temperature of the temperature sensor 68-9 is T9, when this detected temperature T9 < Tset, the storage tank control unit 172 determines that the heating of the water heater 6 has not reached the storage temperature setpoint Tref, and controls the opening degree of the water control valve 64-2 to increase the flow rate of the high-temperature water HHW from the hot water discharge path 40 and reduce the flow rate of the water supply W from the bypass path 66.

[0102] If the detected temperature of the temperature sensor 68-8 on the hot water discharge side of the storage tank 12 is T8, when this detected temperature T8 > Tref, it is determined that there is a margin for hot water storage (heat storage) by the high-temperature water HHW, and the opening degree of the water control valve 64-2 is controlled to reduce the flow rate of the high-temperature water HHW from the hot water discharge path 40 and increase the flow rate of the water supply W from the bypass path 66. And when both the detected temperature T9 < Tset and the detected temperature T8 > Tref are satisfied, the control to limit the opening degree of the water control valve 64-2 is prioritized.

[0103] During hot water discharge in the first mode, the storage tank control unit 172 acquires the detected temperature T4 of the temperature sensor 68-4 and determines whether the detected temperature T4 satisfies T4 ≥ Tref (S107). If the detected temperature T4 < Tref (NO in S107), the hot water discharge in the first mode continues. And if the detected temperature T4 ≥ Tref (YES in S107), the system changes to hot water discharge in the second mode (S104). That is, in the first mode, up to 32 hot water discharges are not performed until the detected temperature T4 ≥ Tref.

[0104] <Operating mode> For example, the operating modes of this hot water supply system 2 include a) a hot water supply mode, b) a constant boiling mode, c) a scheduled operation mode, etc. that include regulated flow rates (1), (2), (3), and the user can set the desired mode.

[0105] a) Hot water supply mode: This hot water supply mode is an example of the hot water storage mode of this disclosure, and reduces the amount of heat emitted from the hot water by suppressing the heat emission area of ​​the hot water HHW, such as by controlling the amount of hot water HHW stored in the hot water storage tank 12 to a predetermined amount less than the maximum hot water storage capacity of the hot water storage tank 12. In this case, by reducing the amount of heat emitted, the operating time and amount of heat used for reheating the water heater 6 during hot water supply can be reduced, and energy saving is also achieved.

[0106] b) Continuous heating mode: This continuous heating mode continuously stores, for example, the maximum amount of hot water HHW in the hot water storage tank 12 to meet the diverse hot water supply demands that frequently arise.

[0107] c) Scheduled operation mode: This scheduled operation mode is used when scheduled operation is possible to accommodate regular hot water supply demands, such as for kitchen hot water supply.

[0108] This hot water supply system 2 enables energy-saving hot water storage and supply by selecting the hot water supply mode. Furthermore, it allows users to select between hot water supply mode, continuous heating mode, or scheduled operation mode according to their hot water demand. This minimizes the amount of high-temperature water HHW stored that exceeds the set storage temperature, while also accommodating diverse hot water demands, resulting in efficient hot water storage and supply.

[0109] <Procedure for selecting the driving mode> Figure 12 shows the procedure for selecting an operating mode. This procedure is an example of the function of the water supply method or program of this disclosure.

[0110] This procedure is an example of selecting and processing the operating mode set in the remote control device 8. After the operation switch is turned on, the hot water supply system control unit 170 enters a standby state (S151) and then enters a mode selection process to switch to the selected mode (S152).

[0111] In this mode selection, it is determined whether "hot water supply" = ON (S153). If "hot water supply" = ON (YES in S153), the hot water supply mode is entered (S154). If the hot water supply mode is canceled or ended, the standby state is entered (S151).

[0112] If "hot water supply" ≠ ON (NO in S153), it is determined whether "constant boiling" = ON (S155). If "constant boiling" = ON (YES in S155), the constant boiling mode is entered (S156). If the constant boiling mode is canceled or ended, the standby state is entered (S151).

[0113] If "constant boiling" ≠ ON (NO in S155), it is determined whether "scheduled operation" = ON (S157). If "scheduled operation" = ON (YES in S157), the scheduled operation mode is entered (S158). If the scheduled operation mode is canceled or ended, the standby state is entered (S151).

[0114] <Hot water supply mode> A in FIG. 13 shows the setting content of the hot water supply mode. If "hot water supply" = ON by operating the hot water supply button 134 of the remote control device 8, the hot water supply mode is set. In the hot water storage operation of this hot water supply mode, the water is always heated up and stored to a storage amount Q1.

[0115] In this hot water supply mode, if the detected temperature of the temperature sensor 68-1 is T1, the detected temperature of the temperature sensor 68-2 is T2, and the hot water storage set temperature is Tref, when T1 < Tref, the pump 60 is operated, and when it changes to T2 > Tref, the operation of the pump 60 is stopped. Therefore, the high-temperature water HHW with a storage amount Q2 can be stored in the hot water storage tank 12.

[0116] In this hot water supply mode, when the hot water storage tank 12 receives the makeup water W due to the hot water supply demand and the detected temperature T1 of the temperature sensor 68-1 changes to T1 < Tref, the pump 60 is operated. When the detected temperature T2 of the temperature sensor 68-2 changes to T2 > Tref, the operation of the pump 60 is stopped. Alternatively, when the hot water storage tank 12 receives the makeup water W due to the hot water supply demand, the pump 60 can be simultaneously operated (pump 60 = ON), and when the detected temperature T2 of the temperature sensor 68-2 changes to T2 > Tref, the operation of the pump 60 can be stopped. Similarly, the hot water storage tank 12 can store the high-temperature water HHW with the stored water volume Q2.

[0117] <Hot water supply operation in the hot water supply mode> B in FIG. 13 shows the hot water supply operation in the hot water supply mode. When receiving the makeup water W, the high-temperature water HHW flows out from the hot water storage tank 12, and this high-temperature water HHW is adjusted to the hot water HW at the hot water supply set temperature by mixing with the makeup water W for hot water supply.

[0118] When the makeup water W flows into the hot water storage tank 12 and the detected temperature T1 becomes T1 < Tref, the pump 60 operates, and the low-temperature water LHW is drawn out from the lower layer side of the hot water storage tank 12 and supplied to the water heater 6. The water heater 6 shifts to the combustion operation, and the low-temperature water LHW is heated to the high-temperature water HHW above the hot water storage set temperature Tref and returned to the upper layer of the hot water storage tank 12.

[0119] <Processing procedure in the hot water supply mode> FIG. 14 shows the processing procedure in the hot water supply mode. This hot water supply operation includes an intermittent hot water supply operation using the makeup water volume Wq detected by the water volume sensor 52. This processing procedure is an example of the function of the hot water supply method or program of the present disclosure.

[0120] In this processing procedure, it is determined whether "hot water supply" = ON from the standby state (S201) (S202). If "hot water supply" ≠ ON (NO in S202), the process returns to the standby state (S201).

[0121] If "hot water supply" = ON (YES in S202), it is determined whether the detected temperature T1 is T1 < Tref (S203). If T1 ≥ Tref (NO in S203), the standby state is entered (S201). At this time, the hot water storage tank 12 stores a hot water storage amount of high-temperature water HHW equal to or higher than the hot water storage set temperature Tref by a hot water storage amount equal to or higher than the hot water storage amount Q1.

[0122] If the detected temperature T1 is T1 < Tref (YES in S203), the pump 60 is operated (S204 = heat storage start). When the pump 60 starts operating, low-temperature water LHW flows from the lower layer side of the hot water storage tank 12 into the water heater 6 through the pipeline 38-1, and the water heater 6 heats the low-temperature water LHW to high-temperature water HHW at the hot water storage set temperature Tref by the hot water supply operation. This high-temperature water HHW is returned to the upper layer side of the hot water storage tank 12 through the pipeline 38-2.

[0123] If the detected temperature T2 is T2 ≤ Tref (NO in S205), the operation of the pump 60 is continued. If T2 > Tref (YES in S205), the operation of the pump 60 is stopped (S206 = heat storage stop). At this time, the storage of high-temperature water HHW (storage amount Q2) in the hot water storage tank 12 is completed.

[0124] Regarding the hot water supply demand, if there is a hot water supply demand within a predetermined time, for example, within 3 hours (NO in S207), the standby state (S201) is returned to, and the processes of S201 to S207 are executed. Also, if there is no hot water supply demand within 3 hours (YES in S207), even if the operating conditions of the pump 60 are satisfied, it waits until a hot water supply demand occurs, that is, the operation stop of the pump 60 is continued (NO in S208). If there is a hot water supply demand (YES in S208), the standby state (S201) is returned to, and the processes of S201 to S208 are executed.

[0125] <Setting of the always-boiling mode> A in FIG. 15 shows the setting content of the always-boiling mode. If "always boiling" = ON is set by operating the always-boiling button 136 of the remote control device 8, the always-boiling mode is set. In the hot water storage operation of this always-boiling mode, hot water storage of the hot water storage amount Q5 by always boiling is performed.

[0126] In this always-boiling mode, if the detected temperature of the temperature sensor 68-4 is T4, the detected temperature of the temperature sensor 68-5 is T5, and the set temperature for storing hot water is Tref, when the detected temperature T4 of the temperature sensor 68-4 satisfies T4 < Tref, the pump 60 is operated, and when the detected temperature T5 of the temperature sensor 68-5 changes to T5 > Tref, the operation of the pump 60 is stopped. Therefore, the hot water tank 12 can store high-temperature water HHW by the amount of stored hot water Q5.

[0127] In this always-boiling mode, when the hot water tank 12 receives water supply W due to hot water supply demand and the detected temperature T4 changes to T4 < Tref, the operation of the pump 60 is started, and when the detected temperature T5 changes to T5 > Tref, the operation of the pump 60 is stopped. Alternatively, when the hot water tank 12 receives water supply W due to hot water supply demand, the pump 60 can be operated simultaneously (pump 60 = ON), and when the detected temperature T5 changes to T5 > Tref, the operation of the pump 60 can be stopped. Therefore, similarly, the high-temperature water HHW in the hot water tank 12 is controlled to the stored hot water amount Q5.

[0128] <Hot water supply operation in always-boiling mode> B in FIG. 15 shows the hot water supply operation in the always-boiling mode. When receiving water supply W, high-temperature water HHW flows out from the hot water tank 12, and this high-temperature water HHW is adjusted to the hot water HW at the set hot water supply temperature by mixing with the water supply W for hot water supply.

[0129] When the water supply W flows into the hot water tank 12 and the detected temperature T4 satisfies T4 < Tref, the pump 60 operates, and low-temperature water LHW is drawn out from the lower layer side of the hot water tank 12 and supplied to the water heater 6. The water heater 6 shifts to the combustion operation, and the low-temperature water LHW is heated to high-temperature water HHW above the set hot water temperature Tref and returned to the upper layer of the hot water tank 12.

[0130] <Processing procedure in always-boiling mode> FIG. 16 shows the processing procedure in the always-boiling mode. This processing procedure is an example of the function of the hot water supply method or program of the present disclosure.

[0131] In this processing procedure, it is determined whether "always boiling" = ON from the standby state (S301) (S302). If "always boiling" ≠ ON (NO in S302), the process returns to the standby state (S301).

[0132] If "always boiling" = ON (YES in S302), it is determined whether the detected temperature T4 is T4 < Tref (S303). If T4 ≥ Tref (NO in S303), the standby state is entered (S301). At this time, the hot water storage tank 12 stores hot water HHW at a temperature equal to or higher than the hot water storage set temperature Tref in a hot water storage amount equal to or greater than the hot water storage amount Q4.

[0133] If the detected temperature T4 is T4 < Tref (YES in S303), the pump 60 is operated (S304 = heat storage start). When this pump 60 starts operating, low-temperature water LHW flows from the lower layer side of the hot water storage tank 12 into the water heater 6 through the pipeline 38-1, and the water heater 6 heats the low-temperature water LHW to high-temperature water HHW at the hot water storage set temperature Tref by the hot water supply operation. This high-temperature water HHW is returned to the upper layer side of the hot water storage tank 12 through the pipeline 38-2.

[0134] If the detected temperature T5 is T5 ≤ Tref (NO in S305), the operation of the pump 60 is continued. If T5 > Tref (YES in S305), the operation of the pump 60 is stopped (S306 = heat storage stop). At this time, the hot water storage in the hot water storage tank 12 with a hot water storage amount Q5 is completed.

[0135] Then, it is determined whether there is a hot water supply demand. If there is a hot water supply demand within a predetermined time, for example, within 3 hours (NO in S307), the process returns to the standby state (S301), and the processes of S301 to S307 are executed. Also, if there is no hot water supply demand within 3 hours (YES in S307), even if the operating conditions of the pump 60 are satisfied, the operation stop of the pump 60 is continued, and it waits until a hot water supply demand occurs (NO in S308). The hot water supply demand is determined. If there is a hot water supply demand (YES in S308), the process returns to the standby state (S301), and the processes of S301 to S308 are executed.

[0136] <Setting a schedule> Figure 17 shows the setting of schedule information. Setting schedule information is necessary to set the scheduled operation mode.

[0137] This schedule information is set using the remote control device 8. Opening the cover 132 of the remote control device 8 and pressing the business setting button 154 switches to setting mode, and the business setting menu is displayed on the information display unit 128 (start). This business setting menu includes options such as business hours, eco-driving, and regular holiday settings, and the desired business setting menu is selected from the displayed items (S401).

[0138] Selecting the business hours setting from this business settings menu (S402) will display input fields for time and time range. In the schedule settings, increasing (up) or decreasing (down) the time or numerical value representing the time is assigned to the hot water temperature setting button 162, and the time or duration can be entered using this hot water temperature setting button 162.

[0139] After entering the time and time range and pressing the schedule operation button 138, the input information representing the business hours, including the start time of business, is confirmed (S403). The processor 178-3 of the remote control device 8 determines whether the business hours setting is complete (S404). If input such as setting or modifying business hours is to be continued (NO in S404), steps S402 to S404 are repeated. This allows for the setting of multiple business hours. Then, after a certain amount of time has elapsed since the input, the system determines whether the setting is complete, and if it is (YES in S404), this process is terminated (end).

[0140] <Setting the Scheduled Driving Mode> Figure 18A shows the settings for the scheduled operation mode. By operating the scheduled operation button 138 on the remote control device 8 to "Scheduled Operation" = ON, the scheduled operation mode is set. In the hot water storage operation of this scheduled operation mode, the business setting button 154 (Figure 5B) will be used to continuously store hot water at a storage volume Q5 of high-temperature water HHW according to the set business hours.

[0141] In this scheduled operation mode, during business hours, when the detected temperature T4 satisfies T4 < Tref, the pump 60 is operated, and when the detected temperature T5 changes to T5 > Tref, the operation of the pump 60 is stopped. Therefore, hot water HHW with a stored hot water volume Q5 is stored in the hot water storage tank 12.

[0142] In this scheduled operation mode, when the hot water storage tank 12 receives the water supply W due to the hot water supply demand and the detected temperature T4 changes to T4 < Tref, the operation of the pump 60 is started, and when the detected temperature T5 changes to T5 > Tref, the operation of the pump 60 is stopped. Alternatively, when the hot water storage tank 12 receives the water supply W due to the hot water supply demand, the pump 60 may be simultaneously operated (pump 60 = ON), and when it changes to T5 > Tref, the operation of the pump 60 may be stopped. Therefore, similarly, the hot water HHW in the hot water storage tank 12 is controlled to the stored hot water volume Q5.

[0143] <Hot water supply operation in scheduled operation mode> B in FIG. 18 shows the hot water supply operation in the scheduled operation mode. During business hours, when receiving the water supply W, hot water HHW is discharged from the hot water storage tank 12. Then, the hot water HHW discharged from the hot water storage tank 12 is mixed with the water supply W, and the hot water HHW is adjusted to the hot water supply set temperature and supplied as hot water HW.

[0144] When the water supply W flows into the hot water storage tank 12 and the detected temperature T4 becomes T4 < Tref, the pump 60 operates, and low-temperature water LHW is drawn out from the lower layer side of the hot water storage tank 12 and supplied to the water heater 6. The water heater 6 shifts to the combustion operation, and the low-temperature water LHW is heated to hot water HHW at or above the hot water storage set temperature Tref and returned to the upper layer of the hot water storage tank 12.

[0145] <Processing procedure in scheduled operation mode> FIG. 19 shows the processing procedure in the scheduled operation mode. This processing procedure is an example of the function of the hot water supply method or program of the present disclosure.

[0146] In this processing procedure, it is determined whether "Scheduled Operation" is ON from the standby state (S501) (S502). If "Scheduled Operation" is not ON (NO in S502), it returns to the standby state (S501).

[0147] If "Scheduled Operation" is ON (YES in S502), the system switches to scheduled operation mode, and the hot water supply system control unit 170 acquires schedule information and performs a schedule determination for scheduled operation control (S503).

[0148] When the system switches to scheduled operation mode, the hot water supply system control unit 170 refers to the schedule information and obtains the schedule information for scheduled operation control (S503). In obtaining this schedule information (S503), the system refers to the schedule information in the schedule DB 184 (S504) and determines whether it corresponds to the day, weekday, time, or hour for scheduled operation. Specifically, it obtains schedule information from the schedule DB 184, timing information from the timer 186, and calendar information from the calendar unit 188, and determines whether it corresponds to the day, weekday, time, or hour for which hot water should be supplied as set in the schedule DB 184. In this case, if it does not correspond to the day, weekday, time, or hour for which hot water should be supplied, or if it is a holiday, the hot water supply operation is stopped and the system enters standby mode (S501).

[0149] The hot water supply system control unit 170 receives instruction information (S504) representing the result of the schedule determination (S503), and determines whether or not there is an operation instruction (S505). If there is no operation instruction (NO in S505), it continues in standby mode. If there is an operation instruction (YES in S505), it switches to hot water supply control.

[0150] If the detected temperature T4 is T4 < Tref (YES in S506), the pump 60 is operated (S507 = heat storage start). When this pump 60 starts operating, the low-temperature water LHW flows from the lower layer side of the hot water storage tank 12 into the water heater 6 through the pipeline 38-1, and the water heater 6 heats the low-temperature water LHW into the high-temperature water HHW at the hot water storage set temperature Tref by the hot water supply operation. This high-temperature water HHW is returned to the upper layer side of the hot water storage tank 12 through the pipeline 38-2.

[0151] If the detected temperature T5 is T5 ≤ Tref (NO in S508), the operation of the pump 60 is continued, and if T5 > Tref (YES in S508), the operation of the pump 60 is stopped (S509 = heat storage stop). At this time, the storage of the high-temperature water HHW (hot water storage amount Q5) in the hot water storage tank 12 is completed.

[0152] Then, the hot water supply demand is determined (S510). If there is a hot water supply demand within a predetermined elapsed time, for example, within 3 hours (NO in S510), it returns to the schedule determination (S503), and the processes of S503 to S510 are executed. Also, if there is no hot water supply demand within 3 hours (YES in S510), even if the operating conditions of the pump 60 are satisfied, it waits until a hot water supply demand occurs (that is, continues to stop the operation of the pump 60), and determines the presence or absence of a hot water supply demand (S511).

[0153] If there is no hot water supply demand (NO in S511), it determines the end of the schedule operation (S512). If it is not the end of the schedule operation (NO in S512), it returns to the schedule determination (S503), and the processes of S501 to S512 are executed. Also, if it is the end of the schedule operation (YES in S512), it ends the schedule operation mode and returns to the standby state (S501).

[0154] <Boiling suppression control (S207 in FIG. 14, S307 in FIG. 16, S510 in FIG. 19)> If the remote control device 8 remains ON for a long period, for example 3 hours, and no hot water is supplied, the amount of heat stored in the hot water storage tank 12 decreases due to heat loss, which may cause unnecessary heating. Therefore, heating suppression control is implemented to prevent this unnecessary heating. For example, if, after heating is complete, no hot water demand has been made for 3 hours, even if the ON condition for the pump 60 is met, the pump 60 will stop operating, and the heating operation of the water heater 6 will be suspended. When the next hot water demand occurs, the pump 60 will start operating, and the heating operation of the water heater 6 will begin.

[0155] <Effects of the First Embodiment> According to this first embodiment, one of the following effects can be obtained. (1) Depending on the amount of hot water HHW stored in the hot water storage tank 12, either the first mode or the second mode can be executed, enabling efficient hot water supply in accordance with the hot water demand and the amount of hot water stored. In the second mode, the flow rate of the first mode is maintained, thereby preventing corrosion of the system pipeline.

[0156] (2) Depending on the hot water demand, the user can select one of the following operating modes: hot water supply mode, continuous heating mode, or scheduled operation mode.

[0157] (3) By selecting the hot water supply mode, the amount of hot water HHW stored in the hot water storage tank 12 can be reduced relative to its maximum storage capacity, reducing the amount of heat released by the heat dissipation surface area of ​​the hot water HHW, and reducing the number of times the water heater 6 heats the low-temperature water LHW to high-temperature water HHW, thereby achieving energy-saving hot water supply.

[0158] (4) Regardless of which mode is selected—hot water supply mode, continuous heating mode, or scheduled operation mode—the reduction in the amount of stored heat due to heat dissipation from the hot water storage tank 12 over a long period of time of 3 hours or more can be suppressed without requiring any additional settings to be made on the remote control device 8, and unnecessary heating operations can be prevented.

[0159] (5) After a predetermined amount of high-temperature water HHW is stored in the hot water storage tank 12 in hot water supply mode, continuous heating mode, or scheduled operation mode, if, for example, 3 hours have elapsed without any hot water demand occurring, the pump 60 will remain shut off even if the operating conditions for the pump 60 are met, and will only start heating the low-temperature water LHW to high-temperature water HHW when a hot water demand occurs, thereby reducing the number of times the water heater 6 operates.

[0160] (6) By reducing or controlling the amount of hot water HHW stored in the hot water storage tank 12, it is possible to meet a wide range of hot water supply needs, from small amounts to large amounts of hot water HHW or hot water HW, without constantly storing (storing heat) the maximum amount of hot water HHW in the hot water storage tank 12.

[0161] (7) By setting the first lower limit water supply Wref1 and the second lower limit water supply Wref2 to less than the operating flow rate of the water heater 6, when a demand for hot water is received at a flow rate that does not allow the water heater 6 to operate, the demand can be supplemented with hot water from the hot water storage tank 12, thereby enabling diverse hot water supply to meet the demand.

[0162] (8) According to the scheduled operation mode, the operating mode can be executed in accordance with the pre-set schedule information, and hot water supply operation including hot water storage operation can be executed based on one or more settings of the day, day of the week, time, and duration in the schedule information, and hot water supply demand can be met.

[0163] [Second Embodiment] In the first embodiment, the hot water supply control is performed from the hot water storage tank 12 according to the water supply amount Wq, and when a hot water demand is received that does not allow the water heater 6 to operate, the control is disclosed in which the supply of hot water from the hot water storage tank 12 is used to supplement the demand. In contrast, the second embodiment discloses a hot water supply control (= second hot water supply mode) in which the hot water supply of hot water HHW is supplied from the hot water storage tank 12 according to the amount of hot water HHW stored in the hot water storage tank 12 without operating the water heater 6. For this hot water supply control, the hot water supply system 2 shown in Figure 1 and the hot water storage unit 4 shown in Figure 2 can be used.

[0164] <Settings for the second hot water supply mode> Figure 20A shows the settings for the second hot water supply mode according to the second embodiment. The previously described remote control device 8 can be used to set this hot water storage tank / hot water supply mode. The hot water storage tank / hot water supply mode can be set by operating the hot water supply button 134 to which the hot water storage tank / hot water supply mode setting is assigned, setting it to "Second Hot Water Supply" = ON. In this hot water storage tank / hot water supply mode, the hot water storage operation is performed along with the hot water supply operation, and the hot water storage amount Q2 is heated and stored at all times.

[0165] In this second hot water supply mode, for example, the temperature Ti detected by the temperature sensor 68-i (where i=1, 2, ..., 5) is Ti≧Tref.

[0166] <Hot water supply operation in second hot water supply mode> Figure 20B shows the hot water supply operation in the second hot water supply mode. When water supply W is received, high-temperature water HHW is discharged from the hot water storage tank 12. This high-temperature water HHW is mixed with the water supply W and the temperature adjustment unit 42 adjusts the hot water HW to the set hot water temperature, which is then supplied.

[0167] <Processing procedure for the second hot water supply mode> Figure 21 shows the processing procedure for the second hot water supply mode. This processing procedure is an example of a hot water supply method or program of the present disclosure.

[0168] In this process, when the second hot water supply mode is selected, the system returns to the standby state (S601) and determines whether the "Hot Water Supply" function in the second hot water supply mode is ON (S602). If "Hot Water Supply" is not ON (NO in S602), the system returns to the standby state.

[0169] When hot water supply is required, the hot water storage unit control section 172 acquires the hot water storage amount information of the high-temperature water HHW based on the detected temperature Ti of the temperature sensors 68-i (i = 1, 2, ···, 5), and determines whether the detected temperature Ti satisfies Ti ≥ Tref (S603). If the detected temperature Ti satisfies Ti ≥ Tref (YES in S603), hot water discharge control for discharging high-temperature water HHW from the hot water storage tank 12 is executed (S604). If the detected temperature Ti does not satisfy Ti ≥ Tref (NO in S603), S604 is skipped and the hot water discharge control of S604 is not performed.

[0170] During hot water discharge control or when S604 is skipped, the hot water storage unit control section 172 monitors the detected temperature T1 of the temperature sensor 68-1, and determines whether the detected temperature T1 satisfies T1 < Tref (S605). If the detected temperature T1 does not satisfy T1 < Tref (NO in S605), the process returns to S601.

[0171] If the detected temperature T1 satisfies T1 < Tref (YES in S605), the process shifts to the normal hot water supply mode and the pump 60 is operated (S606 = heat storage start). When the pump 60 starts operating, low-temperature water LHW flows from the lower layer side of the hot water storage tank 12 through the pipeline 38-1 into the water heater 6, and the water heater 6 heats the low-temperature water LHW to high-temperature water HHW at the hot water storage set temperature Tref by the hot water supply operation. This high-temperature water HHW is returned to the lower layer side of the hot water storage tank 12 through the pipeline 38-2.

[0172] During the operation of the pump 60, it is determined whether the detected temperature T2 satisfies T2 > Tref (S607). If the detected temperature T2 satisfies T2 ≤ Tref (NO in S607), the operation of the pump 60 continues, and if T2 > Tref (YES in S607), the operation of the pump 60 is stopped (S608, heat storage stop). At this time, the storage of high-temperature water HHW (storage amount Q2) in the hot water storage tank 12 is completed.

[0173] Then, it is determined whether or not there is a demand for hot water within a predetermined time, for example, within 3 hours (S609). If there is a demand for hot water within 3 hours (NO in S609), it returns to the standby state (S601) and executes the processes in S601 to S609. If there is no demand for hot water within 3 hours (YES in S609), even if the operating conditions for the pump 60 are met, it remains on standby until a demand for hot water arises, i.e., the pump 60 continues to be stopped. It is then determined whether or not there is a demand for hot water (S610), and if there is a demand for hot water (YES in S610), it returns to the standby state (S601) and executes the processes in S601 to S610.

[0174] <Effects of the second embodiment> According to this second embodiment, one of the following effects can be obtained. (1) The same effects as the first embodiment can be obtained with this second embodiment as well.

[0175] (2) The hot water HHW stored in the hot water storage tank 12 can be used according to the hot water supply demand.

[0176] [Third Embodiment] In the first embodiment, the hot water supply control is performed according to the water supply amount Wq, and when a hot water supply demand is received that does not allow the water heater 6 to operate, the control is performed to supplement with hot water supplied from the hot water supply tank 12. In contrast, the hot water supply system 2 according to the third embodiment is a hot water supply control (tank hot water supply mode) in which hot water is supplied from the hot water supply tank 12 according to the amount of hot water HHW or cold water LHW stored in the hot water supply tank 12, without operating the water heater 6. For this hot water supply control, the hot water supply system 2 shown in Figure 1 and the hot water supply unit 4 shown in Figure 2 can be used.

[0177] <Tank Hot Water Dispensing Mode Settings> A in Fig. 22 shows the tank water supply mode setting according to the third embodiment. If "tank water supply" is assigned to the water supply button 134 of the remote control device 8 and "tank water supply = ON", the tank water supply mode is set. In this tank water supply mode, the pump 60 is controlled to be OFF, and hot water HHW or cold water LHW is discharged from the hot water storage tank 12 according to the makeup water W. When discharging hot water HHW, temperature adjustment is performed by the temperature adjustment unit 42, and hot water HHW is supplied as hot water HW adjusted to the set hot water temperature Tset.

[0178] In this tank water supply mode, for example, if the detected temperature Ti (i = 1, 2, ···, 5) of the temperature sensors 68-i (i = 1, 2, ···, 5) satisfies Ti ≧ Tref, the temperature is adjusted to the set hot water temperature Tset by the temperature adjustment unit 42. Also, if the detected temperature T1 satisfies T1 < Tref, the temperature adjustment to the set hot water temperature Tset by the temperature adjustment unit 42 is cancelled.

[0179] <Hot water supply operation in the tank water supply mode> B in Fig. 22 shows the discharge of cold water LHW during the hot water supply operation in the tank water supply mode. When receiving the makeup water W, hot water HHW is discharged from the hot water storage tank 12, and this hot water HHW is supplied as hot water HW adjusted to the set hot water temperature Tset by the temperature adjustment unit 42 through mixing with the makeup water W. When the hot water storage tank 12 transitions to cold water LHW due to the discharge of this hot water HHW, cold water LHW is discharged from the hot water storage tank 12 according to the hot water supply demand. Since the detected temperature of the cold water LHW is usually expected to be lower than the set hot water temperature Tset, no temperature adjustment is performed by the temperature adjustment unit 42.

[0180] <Processing procedure in the tank water supply mode> Fig. 23 shows the processing procedure in the tank water supply mode. This processing procedure is an example of the function of the hot water supply method or program of the present disclosure.

[0181] In this processing procedure, it is determined whether "tank hot water supply" = ON or not from the standby state (S701) (S702). If "tank hot water supply" is not ON (NO in S702), it returns to the standby state (S701). If "tank hot water supply" is ON (YES in S702), it shifts to tank hot water supply.

[0182] When hot water supply demand occurs, in this mode, the stored hot water unit control section 172 controls the pump 60 = OFF (S703). The stored hot water unit control section 172 acquires the stored hot water amount information of the high-temperature hot water HHW based on the detected temperatures Ti (i = 1, 2, ···, 5) of the temperature sensors 68-i (i = 1, 2, ···, 5), and determines whether the detected temperature Ti satisfies Ti ≧ Tref (S704). If the detected temperature Ti satisfies Ti ≧ Tref (YES in S704), hot water discharge control for discharging high-temperature hot water HHW from the hot water storage tank 12 is executed (S705), and it proceeds to S706. Also, if the detected temperature Ti does not satisfy Ti ≧ Tref (NO in S704), S705 is skipped and it proceeds to S706.

[0183] During hot water discharge control, the stored hot water unit control section 172 monitors the detected temperatures Ti of the temperature sensors 68-1 to 68-5, and determines whether the detected temperature T1 satisfies T1 < Tref (S706). If T1 does not satisfy T1 < Tref (NO in S706), it returns to S704 and executes the processing from S704 to S706.

[0184] If the detected temperature T1 satisfies T1 < Tref (YES in S706), the temperature adjustment by the temperature adjustment section 42 is cancelled (S707), hot water supply of low-temperature hot water LHW is performed in the tank hot water supply mode, it returns to S701, and the processing from S701 to S707 is executed.

[0185] <Effect of the Third Embodiment> According to this third embodiment, any of the following effects can be obtained. (1) Hot water supply based on discharging high-temperature hot water HHW or low-temperature hot water LHW from the hot water storage tank 12 can be performed.

[0186] (2) When hot water HHW is dispensed from the hot water storage tank 12, hot water HW can be supplied that has been adjusted to the hot water supply set temperature Tset by mixing the hot water HHW with the water supply W.

[0187] [Fourth Embodiment] The fourth embodiment is an alternative tank-based hot water supply mode in which the hot water stored in the storage tank 12 (high-temperature water HHW or low-temperature water LHW) is used for hot water supply when the hot water demand is low, that is, when the water supply flow rate is low enough that the water heater 6 does not operate.

[0188] Figure 24 shows the processing procedure for another tank hot water supply mode according to the fourth embodiment. When the hot water supply system 2 is in standby mode (S801), the hot water supply system control unit 170 monitors the hot water demand and obtains the water supply amount Wq detected by the water volume sensor 52.

[0189] Let Wref1 be the first lower limit water supply and Wref2 be the second lower limit water supply (>Wref1). For example, let Wref1 = 1 to 1.5 liters / min and Wref2 = 1.6 to 2 liters / min.

[0190] The system determines whether the water supply amount Wq is Wq ≥ Wref2 (S802). If Wq ≥ Wref2 (YES in S802), it executes a hot water supply control to dispense high-temperature water from the hot water storage unit 4 (S803). This hot water supply control stops the pump 60 and applies, for example, the upper water pressure of the water supply W to the hot water storage tank 12, causing high-temperature water HHW to be dispensed from the hot water storage tank 12 according to the upper water pressure. In this case, the temperature adjustment unit 42 mixes the water supply W with the high-temperature water HHW from the hot water storage tank 12 to supply hot water adjusted to the hot water supply set temperature Tset.

[0191] During hot water supply, it is determined whether the water supply amount Wq is Wq ≤ Wref1 (S804). If Wq ≤ Wref1 is not met (NO in S804), the hot water supply control (S803) is continued. This hot water supply control is performed regardless of the temperature detected by temperature sensors 68-1 to 68-5, and instead of supplying high-temperature water HHW, low-temperature water LHW may be supplied from the hot water storage tank 12.

[0192] If Wq ≤ Wref1 (YES in S804), the hot water supply is stopped and the system returns to standby mode (S801).

[0193] <Effects of the fourth embodiment> According to this fourth embodiment, one of the following effects can be obtained. (1) The desired hot water supply can be achieved by dispensing hot water HHW or cold water LHW stored in the hot water storage tank 12 without operating the hot water heater 6.

[0194] (2) When hot water HHW is dispensed from the hot water storage tank 12, hot water HW can be supplied that has been adjusted to the hot water supply set temperature Tset by mixing the hot water HHW with the water supply W.

[0195] [Fifth Embodiment] Figure 25 shows a kitchen system according to the fifth embodiment. In Figure 25, the same reference numerals are used for parts that are the same as in Figure 1, and their descriptions are omitted.

[0196] This kitchen system 200 is equipped with a noodle boiler 202 along with the hot water supply system 2 described above, which consists of a hot water storage unit 4, a water heater 6, and a remote control device 8.

[0197] The noodle boiler 202 is an example of kitchen equipment and is installed in a kitchen not shown. The remote control device 8 is located near the noodle boiler 202.

[0198] The noodle boiler 202 is an example of equipment such as a cooking appliance that generates a water supply demand that includes one of the following water supply methods: high-flow hot water supply, low-flow hot water supply, intermittent hot water supply, or continuous hot water supply. High-flow hot water supply, low-flow hot water supply, intermittent hot water supply, and continuous hot water supply include the hot water supply demand for hot water such as high-temperature water HHW and low-temperature water LHW. High-flow hot water supply is an example of high-flow hot water supply using high-temperature water HHW, low-flow hot water supply is an example of low-flow hot water supply using high-temperature water HHW or low-temperature water LHW, intermittent hot water supply is an example of intermittent hot water supply using high-temperature water HHW or low-temperature water LHW, and continuous hot water supply is an example of continuous hot water supply using high-temperature water HHW.

[0199] The noodle boiler 202 is equipped with a tank 206 on the main unit 204. A heater 208 is installed in the tank 206, and a water inlet 210 and a drain outlet 212 are installed at the bottom, and a water supply nozzle 214 is installed at the top. A water supply control valve 216 is installed in the pipeline from the water inlet 210 to the water supply nozzle 214. The heat output of the heater 208 and the opening degree of the water supply control valve 216 are controlled by the noodle boiler control unit 218.

[0200] In response to the hot water demand generated by the noodle boiler 202, hot water HW adjusted to the set temperature is supplied to the tank 206 from the hot water storage unit 4. The heater 208 heats the hot water HW using electric heating or combustion heat, and the hot water HW in the tank 206 is heated to the set cooking temperature. As a result, ingredients such as noodles are cooked in the tank 206. Used hot water HW in the tank 206 is discharged from the drain port 212.

[0201] The hot water supply demand for the noodle boiler 202 changes depending on the store's operating style, season, and busy periods, and also varies throughout the day's business hours, including the supply of hot water HW to the tank 206 at the start of business, replacement of hot water HW during business hours, and intermittent hot water supply. A variety of hot water demands arise, ranging from small to large amounts of hot water, from continuous to intermittent, and even from the tank 206 to large amounts of hot water, intermittent hot water supply during cooking, and changes in the amount of hot water supplied depending on the frequency of use. Therefore, this kitchen system 200 is required to meet the diverse hot water supply demands from the noodle boiler 202.

[0202] In this kitchen system 200, in response to the hot water demand from the noodle boiler 202, water W is supplied to the hot water storage unit 4 from the water inlet 10. The high-temperature water HHW dispensed from the hot water storage tank 12 is adjusted to the hot water set temperature HW and then supplied to the tank 206 via the hot water inlet 14 and the hot water supply passage 16. At this time, the low-temperature water LHW from the hot water storage unit 4 flows from the outlet 18 to the supply pipe 22 and enters the water heater 6 from the water inlet 20. The supply pipe 22 is an example of a first pipeline that supplies the low-temperature water LHW from the hot water storage tank 12 to the water heater 6. The water heater 6 heats the low-temperature water LHW by exchanging heat from combustion with the low-temperature water LHW to generate high-temperature water HHW. The water heater 6 uses a gas water heater that exchanges heat from the combustion exhaust of fuel gas G with the low-temperature water LHW.

[0203] When low-temperature water LHW enters the water heater 6, combustion of fuel gas G begins, and the combustion exhaust heats up the low-temperature water LHW to above the hot water storage set temperature through heat exchange, generating high-temperature water HHW. This high-temperature water HHW flows from the hot water outlet 26 to the return pipe 30 and enters the hot water storage unit 4 from the hot water storage return outlet 28. The return pipe 30 is an example of a second pipeline that supplies high-temperature water HHW to the hot water storage tank 12.

[0204] The remote control device 8 is connected to the noodle boiler 202 via signal line 220, to the hot water storage unit 4 via signal line 32, and to the water heater 6 via signal lines 32 and 34. Therefore, coordinated control of the noodle boiler 202, the hot water storage unit 4, the water heater 6, and the remote control device 8 is performed. Alternatively, the noodle boiler 202 and the hot water storage system 2 may be operated independently.

[0205] <Patterns of hot water supply demand for noodle boiler 202> The noodle boiling machine 202 generates diverse hot water supply needs depending on the store where it is installed and its business model.

[0206] (1) When operating the noodle boiler 202, after cleaning the tank 206, a large volume of hot water is required to fill the empty tank 206 with high-temperature water HHW. (2) After the tank 206 is full, intermittent low-flow hot water supply during noodle boiling operation. (3) Efficient hot water supply to prevent excessive heat storage in the hot water storage tank 12 when hot water demand decreases. (4) Scheduled hot water supply tailored to business operations and hot water demand (5) Hot water supply demands including high-flow water supply, low-flow water supply, intermittent water supply, continuous water supply, and other combinations thereof.

[0207] <Effects of the Fifth Embodiment> According to this fifth embodiment, one of the following effects can be obtained. (1) The same effects as those of the first embodiment can be obtained with this fifth embodiment as well.

[0208] (2) Diverse hot water supply needs from kitchen equipment such as noodle boilers 202, for example, hot water supply at opening time, large-volume hot water supply for changing the hot water in the hot water tank, and intermittent hot water supply to meet the demand for boiled noodles can be met by appropriately selecting the hot water supply mode, continuous boiling mode, or scheduled operation mode described above.

[0209] (3) In hot water supply mode, as described above, the amount of hot water HHW stored is reduced relative to the maximum storage capacity of the hot water storage tank 12, thereby reducing the amount of heat released and suppressing excessive operating time of the water heater 6, thus achieving energy-saving hot water supply.

[0210] (4) The hot water supply system 2 can be constructed according to the amount of hot water required from the kitchen equipment, thereby realizing an economical kitchen hot water supply system.

[0211] [Other embodiments] Embodiments of this disclosure include the following variations: (1) In the above embodiment, temperature sensors 68-1, 68-2, ..., 68-5 are installed at positions that specify the hot water storage amounts Q1, Q2, ..., Q5 of the hot water storage tank. However, temperature sensors may also be installed at positions other than those that specify each hot water storage amount to detect the hot water storage temperature at the corresponding specific position for the hot water storage amounts Q1, Q2, ..., Q5. Temperature sensors 68-1, 68-2, ..., 68-5 may be temperature sensors such as infrared sensors that detect the temperature inside the tank from outside the hot water storage tank 12.

[0212] (2) In the above embodiment, the hot water storage unit control unit 172 and the water heater control unit 174 are connected to the remote control control unit 176 and can be operated with a single remote control device 8. However, the hot water storage unit control unit 172 and the water heater control unit 174 may be controlled separately by independent remote control devices.

[0213] (3) The water heater 6 may be a heat source that uses a heat source other than the combustion heat of fuel gas G.

[0214] (4) The water heater 6 may be set to a single unit, or it may be set to a multiple unit including multiple water heaters 6.

[0215] (5) In the above embodiment, a maximum of 24 units of hot water output is achieved in the first mode and a maximum of 32 units in the second mode. However, in the first mode, the maximum number of hot water output units of the water heater 6 may be selected as, for example, 16, 20, 22, or 26 units, and in the second mode, a maximum number of units of 24, 28, 30, or 34 units may be achieved by adding the number of units that can be achieved in the hot water storage tank 12, for example, 8 units.

[0216] As described above, the most preferred embodiments and examples of this disclosure have been explained. The technology of this disclosure is not limited to those described above. Various modifications and changes are possible for those skilled in the art based on the gist of the invention as described in the claims or disclosed in the forms for carrying out the invention. It goes without saying that such modifications and changes are within the scope of this disclosure. [Industrial applicability]

[0217] According to the hot water supply system, method, and program of this disclosure, in an efficient storage-type hot water supply system using a hot water storage tank and a water heater in combination, efficient hot water supply can be obtained by scheduling operation that takes into account hot water demand, including hot water supply time, hot water supply amount, and hot water supply set temperature, and is beneficial in that it can respond to diverse hot water demands. [Explanation of Symbols]

[0218] 2. Hot water supply system 4. Hot water storage unit 6. Water heater 8 Remote control device 10, 20 Water inlet 12 Hot water storage tanks 14, 26 Hot water outlet 16 Hot water supply line 18 Entrance 22 Outgoing pipe 28 Return 30 Return tube 36 Water supply channel 38-1 First pipeline 38-2 Second pipeline 38-3 Third pipeline 40 Hot spring road 42, 84 Temperature adjustment section 44 Water inlet 46 Lower water outlet 48 Hot water return port 50 Hot water outlet 51 Water supply check valve 52 Water volume sensor 56 Mixing water control valve 58 Tank check valve 60 pumps 62 Water switching valve 64-1, 64-2 Water control valves Route 66 Bypass 68-1, 68-2, 68-3, 68-4, 68-5, 68-6, 68-7, 68-8, 68-9, 68-10, 120-1, 120-3, 120-4 Temperature Sensor 76 Tank drain pipe 78 Tank drain outlet 80 Gas combustion section 82 Heat exchange section 88 burners 104 Primary heat exchanger 106 Secondary heat exchanger 108 Water supply channel 110 Water volume sensor 112 Bypass valve 114 Hot Spring Route 116 Mixing water control valve 118 Bypass Road 128 Information Presentation Department 130 First operation section 132 Opening and closing lid 134 Hot water button 136 Always-on armpit lift button 138 Scheduled Operation Button 142-1, 142-2, 142-3, 142-4 Display section 146 Second operation section 150 Lock Button 152. Power-up setting button 154 Business Settings Button 156 Pause setting button 160 Menu button 162 Hot water temperature setting button 164 Select button 166 Back button 170 Hot water supply system control unit 172 Hot water storage unit control unit 174 Water heater control unit 176 Remote Control Unit 178-1, 178-2, 178-3 processors 180-1, 180-2, 180-3 memory 182-1, 182-2, 182-3 Input / output section 184 Schedule Database 200 Kitchen Systems 202 Noodle boiler 204 Main unit 206 Tank 208 Heater 210 Water inlet 212 Drain 214 Water supply nozzle 216 Water supply control valve 218 Noodle boiling machine control unit 220 signal line

Claims

1. A hot water storage unit is provided with a lower section for water supply, an upper section for receiving high-temperature water, a storage tank that stores low-temperature water on the lower section side and the aforementioned high-temperature water on the upper section side, and a hot water storage unit that dispenses the hot water stored in the storage tank for hot water supply. A water heater that receives the low-temperature water from the hot water storage unit and generates the high-temperature water, A control unit that includes an operating mode that operates according to schedule information, wherein the schedule information includes one or more of the following: day, day of the week, time, duration, amount of hot water supplied, and set temperature of the hot water supply, and controls the water heater according to the schedule information and dispenses the low-temperature water or high-temperature water from the hot water storage tank according to the hot water supply demand, A hot water supply system, including a hot water supply system.

2. Furthermore, the hot water supply system according to claim 1, wherein a pump is provided in the pipeline that carries the low-temperature water from the hot water storage tank to the hot water heater, and the control unit operates the pump if the amount of hot water stored is less than a lower threshold, and stops operating the pump if the amount of hot water stored exceeds an upper threshold.

3. Furthermore, a first temperature sensor detects the temperature of the hot water stored in the hot water storage tank, which represents the first amount of hot water stored in the hot water storage tank. A second temperature sensor detects the temperature of the hot water stored in the hot water storage tank, which represents a second amount of hot water stored in the hot water storage tank that exceeds the first amount of hot water stored, The hot water supply system according to claim 2, further comprising: the control unit, upon receiving a hot water supply demand, operates the pump if the temperature detected by the first temperature sensor is below the hot water storage set temperature, and stops the operation of the pump if the temperature detected by the second temperature sensor is equal to or greater than the hot water storage set temperature.

4. Furthermore, the hot water supply system according to claim 1, further comprising a temperature setting unit for setting the hot water supply set temperature, wherein the control unit stores the hot water storage tank at a hot water storage set temperature that is a predetermined temperature difference higher than the hot water supply set temperature, and in response to a hot water supply demand, supplies hot water adjusted to the hot water supply set temperature by mixing the hot water storage tank with the hot water supply to the hot water supply tank.

5. Furthermore, the control unit has a first mode for controlling hot water output based on the hot water output capacity of the water heater, and a second mode for controlling hot water output based on the hot water output capacity using both the water heater and the hot water storage tank, and when a hot water demand is received, the first mode is selected if the amount of hot water stored is less than a predetermined amount, and the second mode is selected if the amount of hot water stored is equal to or greater than a predetermined amount, according to claim 3.

6. Furthermore, the hot water supply system according to claim 5, wherein the control unit changes from the second mode to the first mode when the first temperature sensor detects a hot water storage temperature below the hot water storage set temperature while the second mode is selected.

7. The hot water supply system according to claim 5, wherein the control unit maintains the second mode while the second mode is selected until the first temperature sensor detects a hot water storage temperature below the hot water storage set temperature.

8. Furthermore, the hot water supply system according to claim 5, further comprising a flow control valve installed in the hot water outlet passage of the hot water storage tank, wherein when the control unit receives a hot water supply demand and selects the second mode, it controls the flow rate through the flow control valve to be less than or equal to the regulated flow rate of the first mode.

9. Furthermore, the hot water supply system according to claim 1, which includes a hot water supply mode in which at least the high-temperature water is dispensed from the hot water storage tank when the hot water supply demand is such that the hot water supply unit does not operate, and in response to the water supply demand, the control unit supplies hot water using the low-temperature water or the high-temperature water dispensed from the hot water storage tank by executing the hot water supply mode.

10. The process involves storing low-temperature water in the lower layer of the hot water storage tank and high-temperature water in the upper layer, The process involves operating a pump to supply the low-temperature water from the hot water storage tank to the water heater, The process includes an operating mode that operates according to schedule information, wherein the schedule information includes one or more of the following: day, day of the week, time, duration, hot water supply amount, and hot water supply set temperature, and controls the water heater according to the day, day of the week, time, duration, hot water supply amount, or hot water supply set temperature, and dispenses the low-temperature water or high-temperature water from the hot water storage tank according to the hot water supply demand. A method of supplying hot water, including the method of supplying hot water.

11. The hot water supply method according to claim 10, further comprising the step of operating the pump if the amount of hot water stored is less than a lower threshold, and stopping the operation of the pump if the amount of hot water stored exceeds an upper threshold.

12. A first temperature sensor detects the temperature of the hot water stored in the hot water storage tank, which represents a first amount of hot water stored. A second temperature sensor detects the temperature of the hot water stored in the hot water storage tank, which represents the second amount of hot water stored in the hot water storage tank, exceeding the first amount of hot water stored. The process includes operating the pump when the temperature detected by the first temperature sensor is lower than the hot water storage set temperature, and stopping the operation of the pump when the temperature detected by the second temperature sensor exceeds the hot water storage set temperature, The hot water supply method according to claim 11, including the method described in claim 11.

13. Furthermore, the process involves setting the hot water supply set temperature in the temperature setting unit, The process involves receiving the setting of the hot water supply set temperature, storing the high-temperature water at a storage set temperature that is a predetermined temperature difference higher than the hot water supply set temperature, mixing the high-temperature water dispensed from the storage tank with supplied water to supply hot water at the hot water supply set temperature, The hot water supply method according to claim 10, including the method described in claim 10.

14. Furthermore, the hot water supply method according to claim 10, which includes a hot water supply mode in which at least the hot water is dispensed from the hot water storage tank when the water supply flow rate is such that the hot water heater does not operate, and includes a step of receiving a water supply demand and supplying hot water using the hot water dispensed from the hot water storage tank by executing the hot water supply mode.

15. A program that is executed by a computer, The hot water storage tank has a function that stores low-temperature water in the lower layer and high-temperature water in the upper layer, The function of operating the pump to supply the low-temperature water from the hot water storage tank to the water heater, The system includes an operating mode that operates according to schedule information, the schedule information including one or more of the following: day, day of the week, time, duration, hot water supply amount, and hot water supply set temperature, and controls the water heater according to the day, day of the week, time, duration, hot water supply amount, or hot water supply set temperature, and dispenses the low-temperature water or high-temperature water from the hot water storage tank according to the hot water demand. A program to cause the aforementioned computer to execute.

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