Instant hot water system

Abstract

To provide an instantaneous hot water system capable of increasing a user's convenience by instantaneous hot water operation by deterring instantaneous hot water operation from stopping unnecessarily by hot water filling operation.SOLUTION: An instantaneous hot water system includes: a first heating device and a second heating device for heating water; a water supply channel for supplying water of a water supply source to the first heating device; a hot water supply line for supplying hot water generated by the first heating device to a tapping plug; an instantaneous hot water circulation line connected to the hot water supply line; and a control device for executing instantaneous hot water operation for circulating hot water within the instantaneous hot water circulation line and heating it by the second heating device. Hot water filling operation is executed so as to supply hot water in the hot water supply line to a bath through a hot water filling line that is branched from the hot water supply line in an upstream position of a connection position of the instantaneous hot water circulation line and is connected to the bath. The control device determines whether one of simultaneous use of hot water filling operation and hot water supply to the tapping plug, and individual use of hot water filling operation during instantaneous hot water operation, and prohibits instantaneous hot water operation in the case of simultaneous use of hot water filling operation and hot water supply to the tapping plug, and continues instantaneous hot water operation in the case of individual use of hot water filling operation.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an instant hot water system that quickly dispenses hot water when the hot water tap is opened. [Background technology]

[0002] The instant hot water system is designed to allow hot water to be dispensed promptly when the hot water tap is opened by connecting an instant hot water circulation path in which an instant hot water circulation pump is disposed to a hot water outlet path that supplies hot water to a hot water tap such as a faucet, and executing an instant hot water operation in which the instant hot water circulation pump is driven to circulate hot water in the instant hot water circulation path while the hot water is heated by a heating device. In a conventional instant hot water system, when a combustion signal is received from a heat source machine during instant hot water operation, hot water is supplied to the hot water tap, and the instant hot water circulation pump is stopped and the instant hot water operation is interrupted, so that the hot water tap side is not depressurized by the instant hot water circulation pump and a sufficient amount of hot water can be dispensed from the hot water tap (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-18625 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional instant hot water system, when a hot water supply path is provided that branches off from the hot water outlet path and connects to the bathtub, if the heat source unit is combusted by the hot water supply operation and a combustion signal is output, the instant hot water operation is stopped regardless of the supply of hot water to the hot water tap. When only the hot water supply operation is in progress, there is no hot water supply to the hot water tap, so there is no need to interrupt the instant hot water operation and stop the instant hot water circulation pump so that a sufficient amount of hot water can be supplied from the hot water tap. In other words, there is a problem that the instant hot water operation is stopped even when only the hot water supply operation is in progress, which should not be stopped, and the convenience of the user is lost, which allows hot water to be supplied immediately by the instant hot water operation when the hot water tap is opened. In addition, even if a hot water supply flow rate sensor is provided in the water supply path or the hot water outlet path and the operation of the instant hot water operation is determined based on the flow rate detection value of the hot water flowing through the hot water outlet path by this hot water supply flow rate sensor, as long as the hot water supply flow rate sensor detects the flow rate by the hot water supply operation, the same problem as in the case of the combustion signal occurs.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an instant hot water system that prevents the instant hot water operation from being stopped unnecessarily due to the water filling operation, thereby improving the convenience for users through the instant hot water operation. [Means for solving the problem]

[0006] The instant hot water system according to the present invention comprises: An instant hot water system including a first heating device and a second heating device for heating water to generate hot water, a water supply passage for supplying water from a water supply source to the first heating device, a hot water outlet passage for supplying the hot water generated by the first heating device to a hot water outlet valve, an instant hot water circulation passage connected to the hot water outlet passage, and a control device for enabling instant hot water operation in which hot water is circulated in the instant hot water circulation passage while being heated by the second heating device, A hot water filling path is provided which branches off from the hot water outlet path upstream of the connection position of the immediate hot water circulation path and is connected to the bathtub, and a hot water filling operation can be performed to supply hot water from the hot water outlet path to the bathtub through the hot water filling path, The control device is provided with a control configuration that determines whether, during instant hot water operation, the water filling operation and hot water supply to the hot water tap are being used simultaneously, or the water filling operation is being used alone, and prohibits instant hot water operation when the water filling operation and hot water supply to the hot water tap are being used simultaneously, and continues the instant hot water operation when the water filling operation is being used alone.

[0007] According to the above configuration, when the water filling operation is used alone, the instant hot water operation continues without being stopped. This prevents the instant hot water operation from being stopped due to the use of only the water filling operation, which should not be stopped, even if hot water is not being supplied to the hot water tap. Therefore, unnecessary stopping of the instant hot water operation due to the water filling operation can be suppressed, so that hot water can be dispensed immediately when the hot water tap is used even during the water filling operation. This improves the convenience of the instant hot water operation for the user.

[0008] In the instant hot water system, a hot water supply flow rate sensor provided in the hot water outlet passage upstream of a branch point to the water supply passage or the hot water filling passage, for detecting the flow rate of hot water flowing through the hot water outlet passage; a water filling flow rate sensor provided in the water filling path for detecting the flow rate of water flowing through the water filling path; When the flow rate difference between the detected values ​​of the hot water filling flow sensor and the hot water supply flow sensor during instant hot water operation is equal to or greater than a predetermined flow rate, the control device determines that the hot water filling operation and the hot water supply to the hot water tap are being used simultaneously, and prohibits instant hot water operation, and when the flow rate difference is less than the predetermined flow rate, it determines that the hot water filling operation is being used alone, and continues instant hot water operation.

[0009] According to the above configuration, the flow rate of hot water detected by the hot water supply flow sensor is the total flow rate of the hot water discharged from the hot water tap and the hot water filling flow rate flowing through the hot water filling passage. Therefore, not only the hot water supply flow sensor but also the flow rate difference between the hot water filling flow sensor and the hot water supply flow sensor is used to determine whether hot water has been discharged from the hot water tap, and the operation of the instant hot water operation is determined according to the result of the determination. In other words, if the flow rate difference between the detection values ​​of the hot water filling flow sensor and the hot water supply flow sensor is less than a predetermined flow rate, it can be assumed that the detection value of the hot water supply flow sensor is the detection value of the flow rate due to the hot water filling operation only, and the instant hot water operation is continued by determining that the hot water filling operation is being used alone. Therefore, when the operation of the instant hot water operation is determined by the combustion signal of the heat source machine as in the conventional case or the operation of the instant hot water operation is determined only by the detection value of the hot water supply flow sensor, the instant hot water operation is stopped even if the bathtub is only filled with hot water. However, with this configuration, it is possible to suppress unnecessary stoppage of the instant hot water operation due to the hot water filling operation only, improving the convenience of the user by the instant hot water operation. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of an instant hot water system according to an embodiment. [Diagram 2] 11 is a flowchart for explaining the basic processing operation of the instant hot water operation. [Diagram 3] 11 is a flowchart for explaining the processing operation for restarting instant hot water operation. [Figure 4] 13 is a flowchart for explaining the processing operation of the instant hot water operation during the hot water filling operation. [Diagram 5] 13 is a flowchart for explaining the processing operations after restarting instant hot water operation during hot water filling operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, the instant hot water system 1 according to the embodiment has an instant hot water function that can supply hot water quickly when the hot water tap P1 is opened, and mainly comprises a hot water supply circuit A1, a heating circuit A2, an instant hot water circuit A3, and a control device 2. Also provided is a remote control (e.g., a kitchen remote control, a bath remote control, etc.) 8 for remotely operating this instant hot water system 1. The remote control 8 is provided with various switches such as an operation switch that enables hot water supply to the hot water tap P1, a bath fill switch that causes the bathtub 23 to be filled with hot water, a reheating switch that causes the bathtub water in the bathtub 23 to be reheated, and an instant hot water switch that causes instant hot water operation in the instant hot water circuit A3.

[0012] The hot water supply circuit A1 has hot water supply side heating means 30 which serves as a first heating device, and a hot water supply side fluid flow path. As the hot water supply side heating means 30, arranged in this order from the bottom are a hot water supply side burner unit 33, a hot water supply side first heat exchanger 31, and a hot water supply side second heat exchanger 32. In addition, below the hot water supply side burner unit 33, a blower fan 70 that is also used by the heating side heating means 40 of the heating circuit A2 is arranged.

[0013] The hot water supply side fluid flow paths include a water supply path 90 that communicates with a water supply source and is connected to the upstream end of the hot water supply side second heat exchanger 32, a connection path 95 that connects the downstream end of the hot water supply side second heat exchanger 32 and the upstream end of the hot water supply side first heat exchanger 31, a hot water outlet path 100 that communicates with a hot water tap P1 such as a faucet and is connected to the downstream end of the hot water supply side first heat exchanger 31, a hot water bypass path 105 that bypasses the water supply path 90 and the hot water outlet path 100, and a hot water filling path 250 for filling the bathtub 23 with hot water. In addition, a water pipe 96 that guides water from the water supply is branched off from the water supply path 90 and connected to the hot water outlet path 100, and a hot water pipe 97 that guides hot water from the hot water outlet path 100 is branched off from the hot water outlet path 100 and connected to the hot water outlet path 100.

[0014] The water supply passage 90 is provided with, in order from the upstream side, a hot water supply flow rate sensor 91 which detects the flow rate of water flowing through the water supply passage 90 to detect the flow rate of hot water flowing through the hot water outlet passage 100, a water supply temperature sensor 92 which detects the temperature of water flowing through the water supply passage 90, a water volume servo 93 which changes the opening degree of the water supply passage 90 (including fully closing it), and a bypass servo 94 which changes the opening degree of the hot water supply bypass passage 105 which communicates between the water supply passage 90 and the hot water outlet passage 100 (including fully closing it). Note that the hot water supply flow rate sensor 91 provided in the water supply passage 90 detects the flow rate of hot water flowing through the hot water outlet passage 100, but a flow rate sensor may be provided in the hot water outlet passage 100 upstream of the branch point with the hot water filling passage 250 to detect the flow rate of hot water flowing through the hot water outlet passage 100.

[0015] The hot water outlet path 100 is provided with, from the upstream side, a heat exchanger temperature sensor 101 that detects the temperature of the hot water outlet from the hot water supply side first heat exchanger 31, and an outlet hot water temperature sensor 103 that detects the temperature of the hot water supplied downstream of the junction with the hot water bypass path 105.

[0016] With the above-described configuration of the hot water supply circuit A1, when the hot water tap P1 is opened and the hot water flow rate detected by the hot water flow rate sensor 91 becomes equal to or greater than the ignition water volume, the hot water supply side burner unit 33 ignites and burns, and the water supplied to the water supply passage 90 from the water supply is heat exchanged and heated in the hot water supply side second heat exchanger 32 and the hot water supply side first heat exchanger 31 by the combustion exhaust released from the hot water supply side burner unit 33, and the heated hot water is supplied to the hot water tap P1 through the hot water outlet passage 100, and the hot water is dispensed from the hot water tap P1.

[0017] The water filling path 250 is drawn out from the hot water outlet path 100 and is connected to a bath return path 251 that connects to the bathtub 23. In the water filling path 250, from the upstream side, there are disposed a water filling solenoid valve 261 that opens and closes the water filling path 250, a check valve 263 that prevents backflow of hot water from the water filling path 250 to the hot water outlet path 100, and a water filling flow rate sensor 262 that detects the flow rate of hot water supplied from the hot water outlet path 100 to the water filling path 250.

[0018] When the water filling operation is started by turning on the water filling switch on the remote control 8, the water filling solenoid valve 261 is opened. Then, hot water flows from the hot water outlet path 100 into the hot water filling path 250, causing the hot water supply flow rate sensor 91 to detect a flow rate equal to or greater than the ignition water amount, igniting and burning the hot water supply side burner unit 33, and supplying hot water from the hot water outlet path 100 through the hot water filling path 250 and the bath return path 251 to the bathtub 23. Then, when the cumulative amount of the hot water filling flow rate detected by the hot water filling flow rate sensor 262 reaches the set hot water amount, the water filling solenoid valve 261 is closed, and the supply of hot water from the hot water filling path 250 is stopped. Also, the flow rate detected by the hot water supply flow rate sensor 91 falls below the extinguishing water amount, and the hot water supply side burner unit 33 is extinguished. Next, the bath circulation pump 224 is driven, the bath water in the bathtub 23 is circulated through the bath return path 251 and the bath supply path 252, and heated in the bath liquid heat exchanger 221 of the heating circuit A2. When the temperature of the bath water reaches the set bath temperature, the water filling operation is completed.

[0019] The instant hot water circuit A3 is mainly composed of an instant hot water circulation path 300, an instant hot water circulation pump 311, and an instant hot water liquid-liquid heat exchanger 313 which serves as a second heating device. The instant hot water circulation path 300 is connected between the hot water outlet terminal of the hot water outlet path 100 where the hot water tap P1 is arranged, and a position downstream of the hot water filling path 250 in the hot water outlet path 100. The instant hot water circulation path 300 takes in hot water from a connection part on the hot water outlet terminal side at a downstream position of the hot water outlet path 100, and pours hot water into a connection part at a downstream position of the hot water filling path 250 to form a circulation circuit that circulates hot water. In the instant hot water circulation path 300, an instant hot water amount sensor 310, an instant hot water circulation pump 311, an instant hot water temperature sensor 312, and an instant hot water liquid-liquid heat exchanger 313 are disposed, and further, upstream of the instant hot water amount sensor 310, a check valve 317, an overpressure relief valve 316, an air-water separator 314, and an expansion tank 315 are disposed. By driving the instant hot water circulation pump 311, hot water is circulated in the instant hot water circulation path 300. Even if hot water is circulated in the instant hot water circulation path 300, no water flow is generated in the entire water supply path 90 and the hot water outlet path 100, so the hot water supply flow rate sensor 91 provided in the water supply path 90 does not detect the water flow.

[0020] The instant hot water liquid heat exchanger 313 is composed of a plate-type heat exchanger in which a planar flow path through which hot water in the instant hot water circulation path 300 flows and a planar flow path through which hot water in the heating branch circulation path 270, which is part of the heating circuit A2, flows are stacked. In the instant hot water liquid heat exchanger 313, heat exchange (liquid-liquid heat exchange) is carried out between the hot water circulating in the instant hot water circulation path 300 and the hot water flowing in the heating branch circulation path 270, and the hot water circulating in the instant hot water circulation path 300 is heated.

[0021] With the above-described configuration of the instant hot water circuit A3, when instant hot water operation is performed, the instant hot water circulation pump 311 circulates hot water in the instant hot water circulation path 300, while the hot water heated in the instant hot water liquid-liquid heat exchanger 313 is retained in the instant hot water circulation path 300. Therefore, when the hot water tap P1 is opened, hot water is dispensed from the instant hot water circulation path 300, and hot water can be dispensed immediately.

[0022] In the embodiment, the instant hot water circuit A3 is configured to form an instant hot water circulation path 300 downstream of the hot water outlet path 100, and to provide instant hot water by providing an instant hot water circulation pump 311, and to heat the hot water in the instant hot water circulation path 300 using an instant hot water liquid-liquid heat exchanger (heating device) 313 connected to the heating circuit A2 side, but it may also be configured to provide instant hot water by heating the hot water in the instant hot water circulation path 300 using an independent heating device such as a heater.

[0023] The heating circuit A2 has a heater-side heating means 40 and a heater-side fluid flow path. As the heater-side heating means 40, a heater-side burner unit 43, a heater-side first heat exchanger 41, and a heater-side second heat exchanger 42 are arranged in this order from the bottom.

[0024] The heating side fluid flow paths include a heating return path 200 connected to the upstream end of the heating side second heat exchanger 42, a heating forward path 210 connected to the downstream end of the heating side first heat exchanger 41, a communication forward path 205 and a communication return path 206 connecting the downstream end of the heating side second heat exchanger 42 and the upstream end of the heating side first heat exchanger 41 across a cistern 201, a bath branch path 240 branching off from the heating forward path 210 and connected to the heating return path 200, and a heating branch circulation path 270 branching off from the communication return path 206 and connected to the bath branch path 240.

[0025] The heating forward path 210 is connected to a high-temperature heating terminal (such as a hot air heater) P2. The communication return path 206 is provided with a heating circulation pump 211 for circulating hot water between the high-temperature heating terminal P2 and the heating-side heating means 40. A low-temperature branch path 216 branches off from the communication return path 206 at an intermediate portion downstream of the heating circulation pump 211, and is connected to a thermal valve header 212 for connecting a low-temperature heating terminal (such as a floor heater) P3. A heating branch circulation path 270 branches off from the communication return path 206 downstream of the low-temperature branch path 216, and an instant hot water flow control valve 271 for changing the opening degree of the heating branch circulation path 270 (including full closure) and an instant hot water liquid-liquid heat exchanger 313 are interposed in the heating branch circulation path 270.

[0026] A heating return path 217 that returns hot water from the low-temperature heating terminal P3 is connected to the heating return path 200. A heating high temperature sensor 213 that detects the temperature of hot water discharged from the heating-side first heat exchanger 41 is provided in the heating outgoing path 210, and a heating low temperature sensor 215 that detects the temperature of hot water supplied from the cistern 201 to the low-temperature branch path 216 is provided in the communication outgoing path 205. A bath liquid heat exchanger 221 is provided in the middle of the bath branch path 240 that branches off from the heating outgoing path 210 and is connected to the heating return path 200.

[0027] With the above-described configuration of the heating circuit A2, by operating the heating circulation pump 211 and igniting the heating side burner unit 43 to cause combustion, the hot and cold water flowing through the heating return path 200 is heat exchanged and heated in the heating side second heat exchanger 42 and the heating side first heat exchanger 41 by the combustion exhaust gas discharged from the heating side burner unit 43, and the heated hot water (heat medium) is circulated and supplied from the heating forward path 210 to each heating terminal P2, P3, the bath liquid-liquid heat exchanger 221, and the hot water liquid-liquid heat exchanger 313. Note that the heat medium for heating is not limited to hot and cold water, and antifreeze may also be used.

[0028] The bath return path 251, together with the bath supply path 252, constitutes a bath circulation path between the bathtub 23 and the bath liquid heat exchanger 221. In the bath return path 251, a bath return temperature sensor 225 that detects the temperature of the bath water flowing from the bathtub 23 into the bath return path 251, a bath circulation pump 224 for circulating the bath water in the bathtub 23 through the bath supply path 252 and the bath return path 251, a water level sensor 223 that detects the water level of the bath water in the bathtub 23, and a bath water flow switch 222 that detects whether the bath water is flowing in the bath return path 251 at a rate greater than a predetermined flow rate.

[0029] A bath outflow temperature sensor 226 is interposed in the bath outflow path 252 to detect the temperature of the bath water flowing from the bath liquid heat exchanger 221 to the bathtub 23. By operating the bath circulation pump 224, bath water circulates in the bath circulation path connecting the bathtub 23 and the bath liquid heat exchanger 221. The bath liquid heat exchanger 221 is a plate-type heat exchanger in which a planar flow path through which bath water flows from the bath return path 251 and a planar flow path through which hot water flows from the bath branch path 240 are stacked. In the bath liquid heat exchanger 221, heat exchange (liquid-liquid heat exchange) is performed between the bath water flowing in the bath outflow path 252 and the hot water flowing in the bath branch path 240, and the bath water flowing in the bath outflow path 252 is heated. The bath branch path 240 is provided with a reheating flow control valve 220 that changes the opening degree of the bath branch path 240 (including full closure).

[0030] The control device 2 is composed of an electronic circuit board, software, etc., and includes a control function unit that controls each operation in the instant hot water system 1, a timer unit that measures time, a memory unit that stores data and programs, etc., and a communication unit that communicates with each sensor, each pump, each valve, and other components to be controlled. A remote control 8 that remotely controls each operation of the instant hot water system 1 and temperature settings is connected to the control device 2 so that it can communicate with the control device 2. The instant hot water operation in the instant hot water system 1 is performed by turning on the instant hot water switch of the remote control 8. The control device 2 has a control configuration that stops the instant hot water operation when it detects that the hot water tap P1 is opened and hot water is being dispensed from the hot water tap P1 (i.e., the hot water tap P1 is being used and hot water is being supplied to the hot water tap P1) during the instant hot water operation, and continues the execution of the instant hot water operation when it detects that the hot water tap P1 is not opened and hot water is not being dispensed from the hot water tap P1 (i.e., the hot water tap P1 is not being used and hot water is not being supplied to the hot water tap P1). The state in which the hot water tap P1 is opened and hot water is dispensed from the hot water tap P1 is also referred to as "hot water supply in use" (hot water supply use at the hot water tap P1), and the state in which hot water supply use at the hot water tap P1 is not being used is also referred to as "hot water supply not being used." Furthermore, in this embodiment, when a hot water filling operation is performed during an instant hot water operation, the control device 2 is configured to control the instant hot water operation to be stopped if the hot water filling operation and the hot water supply use at the hot water tap P1 are performed simultaneously, and to continue the instant hot water operation without stopping it if only the hot water filling operation is being performed.

[0031] Next, a description will be given of the basic process of the instant hot water operation by the instant hot water system 1 of the embodiment. Note that the basic process of the instant hot water operation (FIG. 2) described below shows the relationship between the use or non-use of hot water supply at the hot water tap P1. 2, when instant hot water operation is started by turning on the instant hot water switch in step S1, the control device 2 determines in step S2 whether or not hot water is not being used at the hot water tap P1. If the hot water flow rate (flow rate of water flowing through the water supply path 90) detected by the hot water flow rate sensor 91 in step S2 is less than the judgment flow rate Q1 (e.g., 1.0 L / min), it is determined that the hot water tap P1 is closed and hot water is not being used, and in step S3, the control device 2 drives the instant hot water circulation pump 311 in the instant hot water circulation path 300. Hot water is circulated within the instant hot water circulation path 300 by driving the instant hot water circulation pump 311.

[0032] Next, in step S4, the control device 2 judges whether hot water is circulating normally in the instant hot water circulation path 300. In step S4, if the instant hot water flow rate (flow rate of hot water flowing through the instant hot water circulation path 300) detected by the instant hot water amount sensor 310 is not at a predetermined flow rate (e.g., 2.0 L / min) or more and is not continued for a predetermined time (e.g., 10 seconds) or more, it is judged that hot water is not circulating normally in the instant hot water circulation path 300, and in step S5, the control device 2 controls the instant hot water circulation pump 311 to stop driving, and stops the instant hot water operation due to an error. When stopping due to an error, an error notification may be issued.

[0033] On the other hand, in step S4, if the instant hot water flow rate detected by the instant hot water water volume sensor 310 is equal to or greater than the predetermined flow rate and continues for more than a predetermined time, it is determined that the circulation of hot water in the instant hot water circulation path 300 is normal, and in step S6, the control device 2 drives the heating circulation pump 211 of the heating circuit A2 to start heating combustion in the heating side heating means 40.

[0034] From the start of heating combustion until the heating temperature (the temperature of hot water discharged from the heating-side first heat exchanger 41) detected by the heating high temperature sensor 213 reaches the instant hot water setting temperature (for example, 60°C) (if "NO" in step S7), the control device 2 determines in step S8 whether hot water has been used at the hot water tap P1. That is, if the hot water supply flow rate sensor 91 detects in step S8 that the hot water supply flow rate (the flow rate of water flowing through the water supply passage 90) is equal to or greater than the judgment flow rate Q1, it is determined that the hot water tap P1 has been opened and hot water has been used at the hot water tap P1, and in step S9, the control device 2 stops the heating combustion of the heating-side heating means 40, stops driving the instant hot water circulation pump 311, and interrupts the instant hot water operation. Then, in step S10, when the hot water flow rate sensor 91 detects that the hot water flow rate has fallen below the judgment flow rate Q1, the hot water tap P1 is closed to stop the hot water supply, it is determined that the hot water tap P1 is no longer being used to supply hot water, and the control device 2 proceeds to the process of resuming instant hot water operation (Figure 3).

[0035] On the other hand, in step S7, when the heating temperature (the temperature of hot water discharged from the heating-side first heat exchanger 41) detected by the heating high temperature sensor 213 reaches the instant hot water set temperature due to heating combustion, in step S11, the control device 2 opens the instant hot water flow control valve 271. As a result, the heat medium is circulated in the heating branch circulation path 270 to heat the instant hot water liquid-liquid heat exchanger 313, and the hot water in the instant hot water circulation path 300 is heated via the instant hot water liquid-liquid heat exchanger 313.

[0036] In step S13, the control device 2 judges whether hot water is supplied from the hot water tap P1 until the hot water temperature in the hot water circulation path 300 detected by the hot water temperature sensor 312 reaches the hot water setting temperature (if "NO" in step S12). In step S13, if the hot water supply flow rate sensor 91 detects that the hot water supply flow rate is equal to or greater than the judgment flow rate Q1, it is judged that the hot water tap P1 has been opened and hot water has been supplied from the hot water tap P1, and in step S14, the control device 2 stops the heating combustion of the heating side heating means 40, stops the driving of the hot water circulation pump 311, closes the hot water flow rate control valve 271, and interrupts the hot water operation. After that, in step S15, if the hot water supply flow rate sensor 91 detects that the hot water supply flow rate is less than the judgment flow rate Q1, it is judged that the hot water tap P1 has been closed and hot water supply has been stopped, and the control device 2 proceeds to the process of restarting the hot water operation (Fig. 3).

[0037] Also, in step S12, when the instant hot water temperature detected by the instant hot water temperature sensor 312 reaches the instant hot water set temperature, in order to suppress the rise in the hot water temperature in the instant hot water circulation path 300 and keep it at a constant temperature (for example, about 60°C), in step S16, the control device 2 stops the heating combustion of the heating side heating means 40, stops the driving of the instant hot water circulation pump 311, closes the instant hot water flow control valve 271, and interrupts the instant hot water operation. After that, the process proceeds to the instant hot water operation restart process (Figure 3).

[0038] Next, the operation of the instant hot water operation restart process will be described. Referring to FIG. 3, in the process of resuming instant hot water operation, when the process shifts to this instant hot water operation resumption process, in step S21, the control device 2 starts counting the standby time.

[0039] In step S22, if the instant hot water temperature, which is the temperature of hot water in the instant hot water circulation path 300 detected by the instant hot water temperature sensor 312, has dropped below the instant hot water start temperature (e.g., 55°C) or the standby time has elapsed a predetermined standby time (e.g., 10 minutes), in step S23, the control device 2 drives the instant hot water circulation pump 311 to circulate the hot water in the instant hot water circulation path 300.

[0040] Next, in step S24, similar to the processing of step S4 in Fig. 2, the control device 2 judges whether hot water is circulating normally in the instant hot water circulation path 300. If it is judged in step S24 that hot water is not circulating normally in the instant hot water circulation path 300, in step S25, the control device 2 controls the instant hot water circulation pump 311 to stop driving, and stops the instant hot water operation due to an error. If it is judged in step S24 that the circulation of hot water in the instant hot water circulation path 300 is normal, in step S26, hot water is circulated in the instant hot water circulation path 300 for a predetermined circulation time (e.g., one minute) after the instant hot water circulation pump 311 is started to be driven in step S23.

[0041] After circulating the hot water in the instant hot water circulation path 300 for a predetermined circulation time, if the instant hot water temperature, which is the temperature of the hot water in the instant hot water circulation path 300 detected by the instant hot water temperature sensor 312, is equal to or higher than the instant hot water start temperature in step S27, the control device 2 stops driving the instant hot water circulation pump 311 in step S28, waits for the instant hot water operation to resume, and transitions the process to step S21. If the instant hot water temperature detected by the instant hot water temperature sensor 312 has fallen below the instant hot water start temperature in step S27, the control device 2 transitions the process to step S6 in Fig. 2 and resumes the instant hot water operation.

[0042] According to the above instant hot water operation control, when the hot water tap P1 is opened, hot water can be immediately dispensed from the hot water tap P1. In addition, when the hot water tap P1 is opened and hot water supply use is detected, the instant hot water operation is interrupted and the hot water circulation pump 311 is stopped, so that the hot water tap P1 side is not depressurized by the hot water circulation pump 311, and a sufficient amount of hot water can be dispensed from the hot water tap P1. Furthermore, if the hot water circulation pump 311 is driven to circulate hot water in the hot water circulation path 300 during hot water supply use at the hot water tap P1, a pressure difference occurs between the hot water outlet path 100 and the hot water circulation path 300, causing bubbles to be generated, and the bubbles may enter the hot water circulation path 300 and eventually corrode the piping of the hot water circulation path 300. However, by stopping the hot water circulation pump 311 when hot water supply is used, the problem of bubbles entering the hot water circulation path 300 and corroding the piping can be prevented.

[0043] Next, the operation of the instant hot water operation during the hot water filling operation will be described. 4, when the control device 2 detects that the water filling operation switch has been turned ON (step S31) using the remote control 8 while the instant hot water operation is being performed, the control device 2 opens the water filling solenoid valve 261 in step S32 and starts the hot water supply / water filling determination process. Note that the hot water supply / water filling determination process is performed until the water filling operation is completed.

[0044] Next, in step S33, the control device 2 judges whether the flow rate difference ΔQ (absolute value) between the hot water supply flow rate detected by the hot water supply flow rate sensor 91 and the hot water filling flow rate detected by the hot water filling flow rate sensor 262 is less than a judgment flow rate Q2 (e.g., 2.0 L / min). Here, the detected value of the hot water supply flow rate detected by the hot water supply flow rate sensor 91 includes the hot water outlet flow rate from the hot water tap P1 and the hot water filling flow rate of the hot water flowing through the hot water filling path 250. Therefore, it can be assumed that the flow rate difference ΔQ (absolute value) between the hot water supply flow rate detected by the hot water supply flow rate sensor 91 and the hot water filling flow rate detected by the hot water filling flow rate sensor 262 is the hot water outlet flow rate due to hot water supply use at the hot water tap P1. In addition, the flow rate judgment value (judgment flow rate Q2) for determining whether hot water is being used or not at the hot water tap P1 during hot water filling operation is set to a value larger than the flow rate judgment value (judgment flow rate Q1) when hot water use and hot water supply stoppage are determined solely by the detection value of the hot water flow sensor 91 when there is no hot water filling operation, taking into account fluctuations in the detection values ​​of the two sensors, the hot water flow sensor 91 and the hot water filling flow sensor 262, due to the opening of the hot water filling solenoid valve 261 and the hot water tap P1.

[0045] In step S33, if the flow rate difference ΔQ is equal to or greater than the judgment flow rate Q2, in step S34, the control device 2 determines that the hot water tap P1 has been opened and hot water has been supplied from the hot water tap P1, i.e., the hot water filling operation and the hot water supply from the hot water tap P1 have been used simultaneously, and in step S35, prohibits the instant hot water operation. In step S36, the control device 2 stops the instant hot water circulation pump 311 of the instant hot water circulation path 300, stops the heating combustion of the heating side heating means 40, and controls the instant hot water flow control valve 271 of the heating branch circulation path 270 to close. This stops the instant hot water operation in which hot water is circulated and heated by the instant hot water circuit A3. Therefore, by stopping the drive of the instant hot water circulation pump 311, sufficient hot water can be supplied from the hot water tap P1, and the problem of air bubbles being mixed into the instant hot water circulation path 300 can also be prevented.

[0046] If the flow rate difference ΔQ becomes less than the judgment flow rate Q2 in step S37 while the instant hot water operation is prohibited, the control device 2 determines in step S38 that the hot water tap P1 is closed to stop hot water supply and that only the water filling operation is being performed. In this case, the control device 2 cancels the prohibition of the instant hot water operation in step S39, permits instant hot water operation, and proceeds to operation "A" (Figure 3) of the instant hot water operation restart process.

[0047] As shown in Figure 3, in the instant hot water operation restart process for restarting instant hot water operation after it has been stopped during a water filling operation, if the instant hot water temperature, which is the temperature of the hot water in the instant hot water circulation path 300 detected by the instant hot water temperature sensor 312, falls below the instant hot water start temperature in step S27, the process transitions to "C" shown in Figure 5. Note that the process procedure from "C" onwards is as shown in Figure 5, and follows the process procedure from "B" onwards (steps S6 to S16) in the basic instant hot water operation process shown in Figure 2. Therefore, the explanation of the basic instant hot water operation process described above can be referred to, and will not be repeated here. However, as for the judgment content regarding hot water use and hot water supply stoppage, in the instant hot water operation restart process during hot water filling operation shown in Figure 5, instead of the judgment content of hot water use in the basic instant hot water operation process of Figure 2 (steps S8 and S13 in Figure 2), it is judged that hot water has been used at the hot water tap P1 if the flow rate difference ΔQ (absolute value) between the hot water flow rate detected by the hot water flow rate sensor 91 and the hot water filling flow rate detected by the hot water filling flow rate sensor 262 is equal to or greater than the judgment flow rate Q2 (steps S8c and S13c in Figure 5), and also instead of the judgment content of hot water supply stopped in the basic instant hot water operation process of Figure 2 (steps S10 and S15 in Figure 2), it is judged that hot water supply has been stopped at the hot water tap P1 if the flow rate difference ΔQ (absolute value) is less than the judgment flow rate Q2 (steps S10c and S15c).

[0048] 4 again, during the water filling operation, if it is determined in step S33 that the flow rate difference ΔQ (absolute value) between the hot water supply flow rate detected by the hot water supply flow rate sensor 91 and the hot water filling flow rate detected by the hot water filling flow rate sensor 262 is less than the judgment flow rate Q2, then in step S40 the control device 2 determines that only the hot water filling operation is being used, i.e., the hot water tap P1 is closed and hot water is not being used to supply hot water from the hot water tap P1. If only the hot water filling operation is being used, then in step S41 the control device 2 continues the instant hot water operation without stopping it.

[0049] As described above, according to this embodiment, when the hot water filling operation is used alone, the instant hot water operation continues without being stopped, so that the instant hot water operation is not stopped by using only the hot water filling operation, which should not be stopped, even if the hot water supply is not used at the hot water tap P1. Therefore, since unnecessary stopping of the instant hot water operation due to the hot water filling operation can be suppressed, hot water can be immediately dispensed when the hot water supply is used even during the hot water filling operation. Therefore, the convenience of the user is improved by the instant hot water operation. In addition, the instant hot water circulation pump 311 is stopped when the hot water filling operation is performed, and the instant hot water circulation pump 311 is started when the hot water filling operation is completed, and the durability of the instant hot water circulation pump 311 is improved because the repeated stopping and starting of the instant hot water circulation pump 311 can be suppressed.

[0050] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims. For example, in the embodiment, the hot water supply / filling judgment process is executed from the time when the ON operation of the hot water filling operation switch is detected until the hot water filling operation is completed, but it may also be executed while the hot water filling solenoid valve 261 is open (i.e., from the time when the open signal of the hot water filling solenoid valve 261 is output to the time when the close signal of the hot water filling solenoid valve 261 is output), etc. In addition, in the embodiment, as the flow rate judgment value for hot water supply use and hot water supply stop, the judgment flow rate Q2 (Figures 4 and 5) during water filling operation is set to a value greater than the judgment flow rate Q1 (Figure 2) when water filling operation is not in progress, but the judgment flow rate Q2 may be set to the same value as the judgment flow rate Q1, or may be set to a value smaller than the judgment flow rate Q1. In the embodiment, in the basic processing operation of the instant hot water operation (FIG. 2), the same value of the judgment flow rate Q1 is used as the judgment value for judging whether hot water supply is in use or not, but different values ​​may be used for each judgment value for hot water supply in use and not in use. For example, the judgment value for hot water supply in use and not in use may be the ignition water amount and the extinguishing water amount, which are the amounts of water used by the hot water supply side burner unit 33 for ignition and extinguishing. In this case, in FIG. 2, the ignition water amount is used as the judgment value for whether hot water supply is in use or not in steps S2, S8, and S13, and the extinguishing water amount is used as the judgment value for whether hot water supply has been stopped from the hot water supply in use state in steps S10 and S15. The extinguishing water amount can be set to a value smaller than the ignition water amount. [Explanation of symbols]

[0051] 1. Instant hot water system 2. Control device 8. Remote Control 30 Hot water supply side heating means (first heating device) 31 Hot water side first heat exchanger 32 Hot water side second heat exchanger 33 Hot water supply burner unit 40 Heating means on the heating side 41 Heating side first heat exchanger 42 Heating side second heat exchanger 43 Heating side burner unit 90 Water supply channel 91 Hot water flow sensor 100 Hot water outlet 200 Heating return passage 205 Connecting Route 206 Return Route 210 Heating Route 211 Heating Circulation Pump 261 Water filling solenoid valve 262 Water filling flow rate sensor 270 Heating branch circuit 271 Instant hot water flow control valve 300 Instant hot water circulation path 310 Instant hot water sensor 311 Instant hot water circulation pump 312 Instant hot water temperature sensor 313 Instant hot water liquid-liquid heat exchanger (second heating device) P1 Hot water tap P2 High temperature heating terminal P3 Low temperature heating terminal A1 Hot water circuit A2 Heating circuit A3 Instant hot water circuit

Claims

1. An instant hot water system including a first heating device and a second heating device for heating water to generate hot water, a water supply passage for supplying water from a water supply source to the first heating device, a hot water outlet passage for supplying the hot water generated by the first heating device to a hot water outlet valve, an instant hot water circulation passage connected to the hot water outlet passage, and a control device for enabling instant hot water operation in which hot water is circulated in the instant hot water circulation passage while being heated by the second heating device, A hot water filling path is provided which branches off from the hot water outlet path upstream of the connection position of the immediate hot water circulation path and is connected to the bathtub, and a hot water filling operation can be performed to supply hot water from the hot water outlet path to the bathtub through the hot water filling path, The control device is an instant hot water system having a control configuration that determines whether the instant hot water operation and hot water supply to the hot water tap are being used simultaneously or the instant hot water operation is being used alone during instant hot water operation, and prohibits instant hot water operation when the instant hot water operation and hot water supply to the hot water tap are being used simultaneously, and continues instant hot water operation when the instant hot water operation is being used alone.

2. In the instant hot water system according to claim 1, a hot water supply flow rate sensor provided in the hot water outlet passage upstream of a branch point to the water supply passage or the hot water filling passage, for detecting the flow rate of hot water flowing through the hot water outlet passage; a water filling flow rate sensor provided in the water filling path for detecting the flow rate of water flowing through the water filling path; This instant hot water system has a control device that, when the flow rate difference between the detected values ​​of the hot water filling flow sensor and the hot water supply flow sensor during instant hot water operation is equal to or greater than a predetermined flow rate, determines that the hot water filling operation and the hot water supply to the hot water tap are being used simultaneously and prohibits instant hot water operation, and, when the flow rate difference is less than the predetermined flow rate, determines that the hot water filling operation is being used alone and continues the instant hot water operation.

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