Hot water supply device, and program for controlling hot water supply device

Abstract

To provide a hot water supply device improved in combustion efficiency by executing reheating without making a user feel discomfort.SOLUTION: Processing executed by a hot water supply device includes: steps (S310, S315) of starting bath combustion control in response to a request for reheating; a step (S325) of setting a target temperature for bathing to T2 degrees as a standard combustion mode when the request is an instruction for the standard combustion mode (YES in step S320); a step (S345) of setting the target temperature to T1 degrees as an immediate combustion mode when the request is an instruction for the immediate combustion mode (YES in step S340); a step (S355) of setting the target temperature to T3 degrees as a comfortable combustion mode when the request is an instruction for the comfortable combustion mode (YES in step S350); and a step (S365) of executing bath combustion under a predetermined combustion condition when the request is an instruction for an efficiency priority mode (YES in step S360), wherein T1>T2>T3 is satisfied.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to control of a water heating apparatus, and more particularly to control of a water heating apparatus having a reheating function. [Background technology]

[0002] A water heater that supplies hot water to a bath has a reheating function. For example, Japanese Patent Publication No. 2018-189305 (Patent Document 1) discloses a technology for reheating a water heater that solves the problem that "if the bath temperature has already dropped when a person enters the bath, the pump is stopped unconditionally regardless of the temperature of the hot water in the bathtub. Therefore, if the bath temperature has already dropped when a person enters the bath, the bath temperature will drop further while the person is washing their body after entering the bath, and the person will feel uncomfortable due to the lukewarm water when they actually take a bath" (see [Abstract]). In this technology, "if the entry determination means 35 determines that a person has entered the bath during reheating operation, the temperature change means 30 lowers the preset reheating target temperature, and the reheating control means 29 continues the reheating operation if the bath temperature is lower than the reheating target temperature, and ends the reheating operation if the bath temperature is higher than the reheating target temperature."

[0003] Furthermore, JP 2010-210117 A (Patent Document 2) discloses a water heater that "allows bathers to know that the water temperature in the bathtub is being maintained at a comfortable temperature without having to check by, for example, placing part of their body in the bathtub, thereby enabling them to bathe with peace of mind." This water heater is equipped with "bath heating means 6 for heating the hot water in the bathtub 5, temperature detection means 67 for detecting the temperature of the hot water circulating in the bath circulation circuit (61, 62, 63, 64) connecting the bath heating means 6 and the bathtub 5, person detection means 93 for detecting a person in the bathroom, notification means 95, and control means 94, and when the person detection means 93 detects a person, the notification means 95 notifies the person detection means 93 of the detection of a person, and the temperature detection means 67 detects the temperature of the hot water circulating in the bath circulation circuit (61, 62, 63, 64), and when the detected temperature is lower than a predetermined value, an operation is performed to raise the temperature of the hot water in the bathtub 5" (see [Summary]). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-189305 A [Patent Document 2] JP 2010-210117 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the techniques disclosed in Patent Documents 1 and 2, for example, if a user takes a bath after operating the reheating function, the reheating function continues even after the user has taken a bath, and the temperature of the hot water discharged into the bathtub is high, which may cause the user to feel uncomfortable. Therefore, there is a need for a technique that allows reheating to be performed in a way that does not cause the user to feel uncomfortable.

[0006] In addition, even during reheating to keep the water warm, the burner of the water heater is still burning at full capacity, which reduces the combustion efficiency. Therefore, there is a need for a technology to improve the combustion efficiency of water heaters.

[0007] The present disclosure has been made in view of the above-mentioned background, and an object according to one aspect is to provide a technique for performing reheating that does not cause discomfort to the user. An object according to another aspect is to provide a technique for improving the combustion efficiency of a water heater. [Means for solving the problem]

[0008] A water heater according to an embodiment includes a temperature sensor for measuring the temperature of hot water supplied from a heat exchanger to a bathtub, and a control device for controlling the operation of the water heater. The control device detects a request for reheating operation to reheat hot water in the bathtub, and sets the target temperature of the hot water to T2 degrees when the request indicates a reheating operation in a standard combustion mode corresponding to a preset combustion condition, sets the target temperature to T1 degrees when the request indicates a reheating operation in a rapid response combustion mode in which the hot water is reheated in a shorter time than the time required for the reheating operation in the standard combustion mode, and sets the target temperature to T3 degrees when the request indicates a reheating operation in a comfortable combustion mode in which the hot water is reheated when a bather is present, and executes the reheating operation by the heat exchanger at the set target temperature, where T1>T2>T3.

[0009] According to another embodiment, a program for controlling a hot water supply device is provided. This program causes a control device of the hot water supply device to execute the steps of receiving the temperature of hot water supplied from a heat exchanger to a bathtub, detecting a request for reheating operation to reheat hot water in the bathtub, setting a target temperature of hot water to T2 degrees based on the request indicating a reheating operation in a standard combustion mode corresponding to a preset combustion condition, setting the target temperature to T1 degrees based on the request indicating a reheating operation in a rapid response combustion mode in which the hot water is reheated in a shorter time than the time required for the reheating operation in the standard combustion mode, setting the target temperature to T3 degrees based on the request indicating a reheating operation in a comfortable combustion mode in which the hot water is reheated when a bather is present, and executing the reheating operation by the heat exchanger at the set target temperature, where T1>T2>T3.

[0010] According to an embodiment, reheating is performed without causing discomfort to the user. In another aspect, the combustion efficiency of the water heater can be improved.

[0011] The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating an example of an outline of the configuration of a hot water supply system 100. FIG. [Diagram 2] FIG. 2 is a block diagram illustrating a configuration of a controller 12 according to an embodiment. [Diagram 3] 1 is a flowchart (part 1) illustrating a part of the processing executed by a controller 12. [Figure 4] 13 is a flowchart (part 2) illustrating a part of the processing executed by the controller 12. [Diagram 5] 11 is a flowchart (part 3) illustrating a part of the processing executed by the controller 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[0014] The configuration of a hot water supply system 100 according to the present embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram illustrating an example of an outline of the configuration of hot water supply system 100. Hot water supply system 100 includes a hot water supply device 110. In addition to a hot water tap (not shown) and the like, hot water supply device 110 includes a bathtub 20 installed in a bathroom 200 as a hot water supply destination.

[0015] The water heating device 110 comprises a housing 1, a burner 2, a fan 3, a heat exchanger 4, a water inlet pipe 5, a hot water supply pipe 6, a bypass valve 7, a bypass pipe 7a, a circulation path 8, temperature sensors 9, 12T, 18, 19, a circulation pump 10, a water level sensor 11, a controller 12, a bath hot water supply valve 13, electrical wiring 14, and remote controls 30, 50.

[0016] The housing 1 is provided so that the inside and outside of the housing 1 are in communication with each other, and has an exhaust port 1a for discharging combustion gas. The housing 1 is configured to accommodate a burner 2, a fan 3, a heat exchanger 4, a water inlet pipe 5, a hot water supply pipe 6, a bypass valve 7, a bypass pipe 7a, temperature sensors 9, 12T, 18, 19, a circulation pump 10, a water level sensor 11, a controller 12, and a bath hot water supply valve 13. The housing 1 also accommodates a part of a circulation path 8 for reheating operation. In this embodiment, the reheating operation refers to reheating the water in the bathtub 20.

[0017] The burner 2 is configured to perform combustion operation by receiving a supply of fuel gas from a fuel supply system (not shown). The burner 2 supplies the combustion gas to the heat exchanger 4. The burner 2 has a burner 2a for hot water supply and a burner 2b for reheating.

[0018] Fan 3 supplies air for combustion to burner 2. Fan 3 has fan 3a that supplies air for combustion to burner 2a, and fan 3b that supplies air for combustion to burner 2b. Each of fans 3a and 3b has a blade and a motor for rotating the blade. When a current is supplied to the motor, the blade rotates, and fans 3a and 3b supply air for combustion. Fans 3a and 3b are disposed below burners 2a and 2b, respectively, in the height direction of water heater 110. Note that, regarding fan 3, FIG. 1 illustrates a configuration in which burners 2a and 2b each have one fan 3a and one fan 3b, respectively, but is not limited to the configuration illustrated in FIG. 1. In another aspect, a configuration in which one fan is shared by multiple burners 2a and 2b may be adopted.

[0019] Heat exchanger 4 has heat exchanger 4a for hot water supply and heat exchanger 4b for reheating. Heat exchangers 4a and 4b are respectively arranged above burners 2a and 2b in the height direction of hot water supply device 110. Heat exchangers 4a and 4b are arranged near exhaust port 1a.

[0020] The heat exchanger 4a recovers heat from the combustion gas supplied by the burner 2a. The heat exchanger 4b recovers heat from the combustion gas supplied by the burner 2b. Each of the heat exchangers 4a and 4b may include a primary heat exchanger that heats incoming water by heat exchange with the sensible heat (combustion heat) of the combustion gas of the burner 2, and a secondary heat exchanger that heats the flowing water by heat exchange with the latent heat of the combustion exhaust gas from the burner 2.

[0021] The water inlet pipe 5 is connected to a water supply pipe at the water inlet port 5a. When the hot water tap is turned on and / or the bath hot water valve 13 is opened, low-temperature water is introduced from the water inlet port 5a to the hot water supply device 110 by the supply pressure of the tap water. A temperature sensor 18 provided on the water inlet pipe 5 detects the temperature Tw of the water introduced from the water inlet port 5a.

[0022] The water inlet pipe 5 is branched into a boiler body pipe 5b and a bypass pipe 7a via a bypass valve 7. The boiler body pipe 5b is connected to one end of the heat exchanger 4a. The flow rate ratio of the bypass pipe 7a and the boiler body pipe 5b to the total flow rate of the water inlet pipe 5 is controlled by the opening degree of the bypass valve 7.

[0023] The other end of the heat exchanger 4a is connected to one end of the hot water supply pipe 6. Low-temperature water supplied from the water inlet pipe 5 to the boiler body pipe 5b is heated to a predetermined temperature by the heat exchanger 4a and output to the hot water supply pipe 6. A flow rate sensor 15 is disposed in the boiler body pipe 5b. The flow rate sensor 15 detects the flow rate of the heat exchanger 4a (boiler body flow rate).

[0024] On the other hand, the bypass pipe 7a is connected to the hot water supply pipe 6, bypassing the heat exchanger 4a. Therefore, the low-temperature water supplied from the water inlet pipe 5 to the bypass pipe 7a is output to the hot water supply pipe 6 without being heated by the heat exchanger 4a. In this way, the hot water supply device 110 can mix the high-temperature water output from the heat exchanger 4a and the low-temperature water that has passed through the bypass pipe 7a, and output hot water at an appropriate temperature according to the set temperature from the hot water supply pipe 6.

[0025] The other end of the hot water supply pipe 6 is connected to a hot water outlet 6a that is connected to a hot water tap (not shown) or the like. Therefore, when the hot water tap is opened, hot water at an appropriate temperature controlled to a set temperature is supplied from the hot water supply device 110 to the hot water tap via the hot water outlet 6a.

[0026] The hot water supply pipe 6 is further connected to a hot water supply pipe 13a leading to a bathtub 20. A bath hot water supply valve 13 is provided in the hot water supply pipe 13a. The bath hot water supply valve 13 may be configured, for example, by a solenoid valve that can be controlled to open and close. When the bath hot water supply valve 13 is opened, a path is formed for outputting hot water from the hot water supply pipe 6 to the hot water supply pipe 13a. As a result, the hot water supply device 110 can include the bathtub 20 as a hot water supply destination in addition to a hot water tap, etc.

[0027] In this specification, the supply of hot water from the water heater 110 to the bathtub 20 is referred to as "pouring hot water". This is to be distinguished from the supply of hot water to the outlet 6a (hot water tap, etc.). A flow rate sensor 16 is provided in the hot water supply pipe 13a. The flow rate sensor 16 detects the flow rate of hot water supplied from the water heater 110 to the bathtub 20. In this embodiment, the action of supplying hot water or water to the bathtub 20 via the hot water supply pipe 13a by opening the bath hot water supply valve 13, regardless of the hot water outlet temperature at the hot water supply pipe 6, is referred to as "pouring hot water". The hot water supply circuit can be composed of the burner 2a, fan 3a, heat exchanger 4a, water inlet pipe 5, boiler body pipe 5b, hot water supply pipe 6, bypass valve 7, bypass pipe 7a, and bath hot water supply valve 13, all of which are included in the water heater 110.

[0028] The circulation path 8 is a flow path that circulates hot water 21 in the bathtub 20 (hereinafter also referred to as bathtub water 21) within the water heater 110. The circulation path 8 has a return pipe 8a, a forward pipe 8b, and a circulation pump 10. One end of the return pipe 8a is connected to a circulation adapter 25 in the bathtub 20. The other end of the return pipe 8a is connected to the input side of the heat exchanger 4b. One end of the forward pipe 8b is connected to the output side of the heat exchanger 4b. The other end of the forward pipe 8b is connected to the circulation adapter 25.

[0029] By operating the circulation pump 10, a path (reheating circulation path) is formed in which bath water 21 drawn in from the circulation adapter 25 passes through the return pipe 8a, the heat exchanger 4b, and the forward pipe 8b, and is discharged from the circulation adapter 25. When the reheating circulation path is formed, the controller 12 starts the combustion operation of the burner 2b, and the heat exchanger 4b heats the bath water 21 introduced from the return pipe 8a. The heated bath water 21 is supplied to the bathtub 20 by the forward pipe 8b. In this way, a reheating operation is performed to raise the temperature of the bath water 21.

[0030] The temperature sensor 9 and the water level sensor 11 are provided in the return pipe 8a. The temperature sensor 9 detects the temperature of the bathtub water 21. The water level sensor 11 is composed of, for example, a pressure sensor. The water level sensor 11 detects the water level of the bathtub water 21 in the bathtub 20 (hereinafter also simply referred to as the "bathtub water level") based on the water pressure of the bathtub water 21. The temperature sensor 9 and the water level sensor 11 are disposed in an area of ​​the return pipe 8a into which the bathtub water 21 enters even when the circulation pump 10 is stopped.

[0031] Return pipe 8a is further connected to hot water supply pipe 13a at connection point 8c. As a result, when water heater 110 pours hot water while circulation pump 10 is stopped, a first hot water supply path is formed from pouring pipe 13a to bathtub 20 via connection point 8c and return pipe 8a, and a second hot water supply path is formed from pouring pipe 13a to bathtub 20 via connection point 8c, return pipe 8a, heat exchanger 4b, and forward pipe 8b. This allows the bath to be filled by pouring hot water from hot water heater 110.

[0032] In this way, hot and cold water from water heater 110 (hot water pouring circuit) is supplied to bathtub 20 via the first and second hot water pouring paths, including circulation path 8. Bathtub 20 is provided with a drain plug 26. Drain plug 26 can be configured as either a "manual drain plug" that is opened and closed by manual operation by the user, or an "automatic drain plug" that can also be opened and closed automatically in response to an operation command from controller 12.

[0033] Controller 12 includes, for example, a microcomputer, a processor, or other arithmetic processing circuit. Controller 12 is electrically connected to burners 2a, 2b, fans 3a, 3b, temperature sensors 9, 18, 19, 80, circulation pump 10, water level sensor 11, bath hot water valve 13, and electrical wiring 14. Electrical wiring 14 is connected to a power source (not shown) to supply power to controller 12. Controller 12, as a control device, controls each operation of hot water supply device 110.

[0034] The controller 12 receives inputs of detection values ​​from the flow rate sensors 15, 16 and the temperature sensors 9, 12T, 18, 19, and 80. The flow rate sensors 15, 16 are realized, for example, by impeller-type flow meters. The temperature sensors 9, 12T, 18, 19, and 80 are realized, for example, by thermistors. The temperature sensor 12T is provided in the housing 1 which is usually placed outdoors. The temperature sensor 12T measures the atmospheric temperature (outside air temperature) which changes with the seasons.

[0035] The controller 12 obtains the inlet water temperature Tw from the detection value of the temperature sensor 18. The controller 12 obtains the outlet hot water temperature Th from the detection value of the temperature sensor 19. The controller 12 obtains the temperature of the bathtub water 21 from the detection value of the temperature sensor 9. The controller 12 obtains the outside air temperature Tar from the detection value of the temperature sensor 12T. The controller 12 calculates the amount (volume) of hot water poured into the bathtub 20 by integrating the flow rate (pouring hot water flow rate) detected by the flow rate sensor 16. The controller 12 obtains the temperature of the hot water after it has been heated by the heat exchanger 4b, based on the detection value of the temperature sensor 80.

[0036] Furthermore, the controller 12 is communicably connected to a remote control 30 and a remote control 50. Note that the communication between these devices may be in accordance with any known standard. The form of communication may be either wired or wireless.

[0037] Remote control 30 is installed on the wall of bathroom 200 and controls water heater 110 based on user operation. Remote control 30 includes display unit 31 for displaying information and operation unit 32 for accepting input setting operations from a user or installer. Display unit 31 is, for example, a liquid crystal panel, and displays the bath water level and set temperature. Operation unit 32 is, for example, realized by a push button or a touch button. Operation unit 32 is configured to be able to accept setting operations related to the bath water level and temperature. In still another aspect, remote control 30 may include a human presence sensor 35 for detecting the presence of a person in the bathroom. In this case, human presence sensor 35 may be realized by, for example, an infrared sensor.

[0038] Remote control 50 is installed outside bathroom 200. Remote control 50 controls water heating apparatus 110 in response to a user's operation. Remote control 50 is typically installed on a wall in the kitchen. Remote control 50 includes a display unit 51 for displaying information and an operation unit 52 for receiving input setting operations from a user or the like.

[0039] Display unit 51 is realized by, for example, a liquid crystal panel. Display unit 51 can display the hot water supply temperature setting, the bath temperature setting, and other information. Operation unit 52 is typically configured by push buttons or touch buttons, and is configured to be able to accept setting operations related to the operation of water heating device 110.

[0040] Based on input setting operations by a user or the like from remote controls 30, 50, controller 12 controls the operation of water heating device 110 so that water heating system 100 operates in accordance with the input instructions.

[0041] As an example of this control, the controller 12 executes a bath filling operation when it receives an instruction for automatic bath operation via the operation of the remote controls 30, 50. The bath filling operation ends when the water level in the bathtub 20 reaches the set water level due to hot water poured from the water heater 110 and the temperature of the bathtub water detected by the temperature sensor 9 reaches the set bath temperature.

[0042] After the bath filling operation is completed, the water heater 110 can be set to an automatic mode in which the temperature and water level of the bathtub water 21 are maintained. When this automatic mode is selected, if the temperature of the bathtub water 21 detected by the temperature sensor 9 falls below a reference temperature set in accordance with the bath setting temperature (for example, set 2 to 3°C lower than the bath setting temperature), a reheating operation is automatically started to control the temperature retention. Furthermore, if the water level of the bathtub water 21 detected by the water level sensor 11 falls below the set water level, a hot water top-up operation is started to supply additional hot water from the water heater 110 to the bathtub 20.

[0043] After draining bathtub 20, hot water supply system 110 according to this embodiment can perform a pipe cleaning operation by pouring hot water from hot water supply device 110 to clean the inside of the pipes, including circulation path 8. In the pipe cleaning operation according to this embodiment, the user can select a plurality of cleaning modes in which the supply amount and temperature of cleaning water are set differently.

[0044] <Controller> The configuration of the controller 12 will be described with reference to Fig. 2. Fig. 2 is a block diagram illustrating the configuration of the controller 12 according to an embodiment. The controller 12 includes a processor 210 and a memory 220.

[0045] Processor 210 executes instructions contained in a program stored in memory 220 and controls the operation of water heating apparatus 110 based on data stored in memory 220 .

[0046] Memory 220 holds a program having instructions for controlling the operation of water heating apparatus 110, and setting data input to water heating apparatus 110. The setting data includes, for example, a plurality of bath delivery target temperatures T1, T2, T3, a high-efficiency combustion setting value 224, and an installation status 226 of water heating system 100.

[0047] In one aspect, the bath entry target temperature T1 is preset to 70 degrees Celsius, the bath entry target temperature T2 is preset to 60 degrees Celsius, and the bath entry target temperature T3 is preset to 50 degrees Celsius.

[0048] The high-efficiency combustion setting value 224 is a temperature at which the bath thermal efficiency is maximized. In this case, the high-efficiency combustion setting value 224 is set to a temperature lower than the bath inlet target temperature T3.

[0049] Installation status 226 includes setting data indicating whether or not human presence sensor 35 is used in the bathroom in which water heating apparatus 100 is used. Other data indicating the installation status of water heating system 100 may also be registered in memory 220.

[0050] The temperatures preset as the plurality of bath entry target temperatures T1, T2, and T3 are not limited to the temperatures exemplified above. Each temperature is set so as to satisfy at least the following relationship. High-efficiency combustion setting value 224 <T3<T2<T1 Furthermore, the plurality of bath delivery target temperatures T1, T2, T3 and high-efficiency combustion setting value 224 can be changed by the installer of water heating apparatus 110 or the user.

[0051] <Control Structure> The control structure of water heating apparatus 110 will be described with reference to Figures 3 to 5. Figures 3 to 5 are each a flowchart showing a part of the process executed by controller 12.

[0052] In step S310, the processor 210 of the controller 12 detects a request for reheating. The request for reheating is given manually or automatically. A manual request for reheating is a user instruction given to the remote control 30 or the remote control 50. An automatic request for reheating is when a predetermined condition for starting reheating is met. The predetermined condition is, for example, when the temperature of the bathtub water 21 falls below the temperature at which reheating starts.

[0053] In step S315, processor 210 starts bath combustion control in response to detection of a request for reheating.

[0054] In step S320, processor 210 determines whether the request corresponds to an instruction for the standard combustion mode. In the present embodiment, the standard combustion mode refers to a combustion mode when the temperature of bath water 21 is undetermined, or when remote control 30 provided in bathroom 200 does not have human sensor 35. In other words, the standard combustion mode is a mode in which hot water in bath water 20 is reheated according to preset combustion conditions. For example, when a reheating operation is instructed on remote control 50, or when an operation is performed to increase the set temperature of bath water 21, the operation corresponds to an instruction for the standard combustion mode. When processor 210 determines that the request corresponds to an instruction for the standard combustion mode (YES in step S320), processor 210 switches control to step S325. Otherwise (NO in step S320), processor 210 switches control to step S340.

[0055] In step S325, the processor 210 sets the bath entry target temperature to T2 degrees for the standard combustion mode.

[0056] In step S330, the processor 210 executes a forced circulation operation. In the forced circulation operation, the circulation pump 10 is operated.

[0057] In step S340, processor 210 determines whether the request corresponds to an instruction for the immediate combustion mode. In the present embodiment, the immediate combustion mode refers to a combustion mode in which short-time reheating (immediate response) is required. Short-time reheating refers to reheating in a time shorter than the time required for cooking in the standard combustion mode. In the immediate combustion mode, hot water in bathtub 20 can be reheated in a time shorter than the time required for reheating in the standard combustion mode. More specifically, in the immediate combustion mode, fuel (gas, electricity, kerosene, etc.) is supplied to a combustion device (not shown) so that the heating power of water heater 110 is stronger than that in the standard combustion mode. For example, when no one is in bathroom 200 and a user instructs remote control 50 installed outside bathroom 200 to reheat, the instruction corresponds to an instruction for the immediate combustion mode. Alternatively, if the immediate combustion mode is provided as an independent menu in water heating apparatus 110, when an instruction for the immediate combustion mode is given to remote control 30 or remote control 50, processor 210 detects the instruction for the immediate combustion mode.

[0058] If processor 210 determines that the request corresponds to an instruction for the fast combustion mode (YES in step S340), processor 210 switches control to step S345. If not (NO in step S340), processor 210 switches control to step S350.

[0059] In step S345, the processor 210 sets the bath entry target temperature to T1 degrees as the rapid combustion mode.

[0060] In step S350, processor 210 determines whether the request corresponds to an instruction for the comfortable combustion mode. In this embodiment, the comfortable combustion mode refers to a combustion mode in which reheating is performed in conjunction with the detection of bathing, or a combustion mode that is performed when forced reheating based on a user's operation is performed or when entry into bathroom 200 is detected during warm reheating. Reheating in conjunction with the detection of bathing may also include reheating performed after water is added. When forced reheating based on a user's operation is performed or when the presence of a person in bathroom 200 is detected during warm reheating, it is determined that the comfortable combustion mode has been instructed if the following conditions are met. Bath water temperature 21 ≧ Bath setting temperature - A degrees (A degrees is a preset constant) If processor 210 determines that the request corresponds to an instruction for the comfortable combustion mode (YES in step S350), processor 210 switches control to step S355. If not (NO in step S350), processor 210 switches control to step S360.

[0061] In step S355, the processor 210 sets the bath entry target temperature to T3 degrees as the comfortable combustion mode.

[0062] In step S360, processor 210 determines whether the request corresponds to an instruction for the efficiency priority mode. In the present embodiment, the efficiency priority mode refers to a combustion mode in which heating is performed when a high efficiency setting is performed, or warmth retention and reheating is performed when no one is in bathroom 200. If processor 210 determines that the request corresponds to an instruction for the efficiency priority mode (YES in step S360), it switches control to step S365. If not (NO in step S360), processor 210 switches control to step S380.

[0063] In step S365, the processor 210 executes bath combustion under predetermined combustion conditions as the efficiency priority mode. In one aspect, the processor 210 may execute bath combustion based on the high-efficiency combustion setting value 224.

[0064] In step S370, the processor 210 executes a forced circulation operation. In the forced circulation operation, the circulation pump 10 is operated.

[0065] In step S380, the processor 210 operates in the heat retention reheating mode. In step S390, the processor 210 executes the forced circulation operation. In the forced circulation operation, the circulation pump 10 is operated.

[0066] 4, in step S410, processor 210 determines whether bathroom 200 is equipped with an entry sensor (for example, human presence sensor 35) and whether the entry sensor is abnormal. This determination is made based on data representing the installation status of hot water supply system 100 stored in memory 220. If processor 210 determines that bathroom 200 is equipped with an entry sensor and that the entry sensor is abnormal (YES in step S410), it switches control to step S420. Otherwise (NO in step S410), processor 210 switches control to step S430.

[0067] In step S420, processor 210 switches the operation mode of water heating apparatus 110 to the efficiency priority mode, and executes bath combustion with a predetermined combustion setting.

[0068] In step S430, processor 210 switches the operation mode of water heating apparatus 110 to the comfort combustion mode, and sets the bath entry target temperature to T3 degrees.

[0069] In step S440, the processor 210 acquires the bath return temperature (Tx) based on the signal output from the temperature sensor 9, and measures the temperature of the bathtub water 21.

[0070] In step S450, the processor 210 determines whether or not a condition for ending the bath combustion is satisfied. Specifically, the processor 210 determines whether or not the relationship between the bath return temperature Tx and the bath set temperature Ts satisfies the following formula. Tx ≧ Ts + α (α is a constant) If processor 210 determines that the end condition of bath combustion is satisfied (Tx≧Ts+α) (YES in step S450), it switches control to step S580 (FIG. 5). If not (NO in step S450), the processor returns control to step S410.

[0071] 5, in step S510, the processor 210 acquires the bath return temperature (Tx) based on the signal output from the temperature sensor 9, and measures the temperature of the bathtub water 21.

[0072] In step S515, processor 210 determines whether or not the bath return temperature (Tx) is equal to or higher than a predetermined value. If the bath return temperature (Tx) is equal to or higher than the predetermined value (YES in step S515), processor 210 switches control to step S520. If not (NO in step S515), processor 210 switches control to step S525.

[0073] At step S520, processor 210 determines whether bathroom 200 is equipped with an entry sensor (for example, human presence sensor 35) and whether the entry sensor is abnormal. This determination is made based on data representing the installation status of hot water supply system 100 stored in memory 220. If processor 210 determines that bathroom 200 is equipped with an entry sensor and that the entry sensor is abnormal (YES at step S520), it switches control to step S530. Otherwise (NO at step S520), processor 210 switches control to step S560.

[0074] In step S530, processor 210 determines whether or not a person is present in bathroom 200. This determination is made based on the output from human presence sensor 35 included in remote control 30 provided in bathroom 200. If processor 210 determines that a person is not present in bathroom 200 (YES in step S530), it switches control to step S535. Otherwise (NO in step S530), processor 210 switches control to step S540.

[0075] In step S535, processor 210 switches the operation mode of water heating apparatus 110 to the immediate combustion mode, and sets the bath entry target temperature to T1 degrees.

[0076] In step S540, processor 210 switches the operation mode of water heating apparatus 110 to the comfort combustion mode, and sets the bath entry target temperature to T3 degrees.

[0077] In step S545, the processor 210 acquires the bath return temperature (Tx) based on the signal output from the temperature sensor 9, and detects the temperature of the bathtub water 21.

[0078] In step S550, the processor 210 determines whether or not a condition for ending the bath combustion is satisfied. Specifically, the processor 210 determines whether or not the relationship between the bath return temperature Tx and the bath set temperature Ts satisfies the following formula. Tx ≧ Ts + α (α is a constant) If processor 210 determines that the end condition of bath combustion is satisfied (Tx≧Ts+α) (YES in step S550), processor 210 switches control to step S580. If not (NO in step S550), processor 210 returns control to step S530.

[0079] In step S560, processor 210 switches the operation mode of water heating apparatus 110 to the standard combustion mode, and sets the bath entry target temperature to T2 degrees.

[0080] In step S565, the processor 210 acquires the bath return temperature (Tx) based on the signal output from the temperature sensor 9, and detects the temperature of the bathtub water 21.

[0081] In step S570, processor 210 determines whether the end condition of bath combustion (Tx≧Ts+α (α is a constant)) is satisfied. If processor 210 determines that the end condition of bath combustion is satisfied (Tx≧Ts+α) (YES in step S570), it switches control to step S580. If not (NO in step S570), processor 210 returns control to step S565.

[0082] In step S580, the processor 210 ends the bath combustion. In step S585, the processor 210 executes an operation after the end of the bath combustion. The operation includes, for example, an air purge operation by the circulation pump 10, a post purge operation in which the operation of the fan 3 is continued, and the like.

[0083] As described above, water heating apparatus 100 according to the present embodiment performs reheating operation according to the situation in which the user uses the bath, thereby improving responsiveness, comfort, and efficiency.

[0084] That is, in a certain situation, the target temperature (T1) for the bath is set higher than the target temperature (T2) in the standard combustion mode (T1>T2), so that the reheating operation time is shortened and responsiveness is improved.

[0085] In another aspect, the target temperature is set to the target temperature (T2) in the standard combustion mode, thereby preventing high-temperature hot water from being discharged from the circulation adapter 25. This allows the temperature of the bath water 21 to rise gradually, improving the comfort of the bather.

[0086] In still another aspect, since combustion is performed under combustion conditions that maximize bath heat efficiency, the running costs (fuel consumption) of water heating apparatus 100 are reduced and efficiency is improved.

[0087] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Industrial Applicability]

[0088] The disclosed technical features are applicable to a water heating apparatus or a controller built into the water heating apparatus. [Explanation of symbols]

[0089] 1 housing, 1a exhaust port, 2, 2a, 2b burner, 3, 3a, 3b fan, 4, 4a, 4b heat exchanger, 5 water inlet pipe, 5a water inlet, 5b boiler body pipe, 6 hot water supply pipe, 6a hot water outlet, 7 bypass valve, 7a bypass pipe, 8 circulation path, 8a pipe, 8a return pipe, 8b forward pipe, 8c connection point, 9, 12T, 18, 19, 80 temperature sensor, 10 circulation pump, 11 water level sensor, 12 controller, 13 hot water valve, 13a hot water pipe, 14 electrical wiring, 15, 16 flow rate sensor, 20 bathtub, 21 bathtub water, 25 circulation adapter, 26 drain plug, 30, 50 remote control, 31, 51 display unit, 32, 52 operation unit, 35 human presence sensor, 100 hot water supply system, 110 Water heater, 200 baths, 210 processors, 220 memory.

Claims

1. A hot water supply device, comprising: A temperature sensor that measures the temperature of hot water supplied to the bathtub from the heat exchanger; A control device for controlling the operation of the hot water supply device, The control device includes: Detecting a request for reheating operation to reheat the water in the bathtub, When the request indicates a reheating operation in a standard combustion mode corresponding to a preset combustion condition, the target temperature of the hot and cold water is set to T2 degrees, When the request indicates a reheating operation in a rapid response combustion mode in which the hot water is reheated in a time shorter than the time required for the reheating operation in the standard combustion mode, the target temperature is set to T1 degrees, If the request indicates a reheating operation in a comfortable combustion mode in which water is reheated when a bather is present, the target temperature is set to T3 degrees; A reheating operation is performed by the heat exchanger at the set target temperature, A water heating apparatus, wherein T1>T2>T3.

2. The control device includes: receiving a signal output from a human presence sensor disposed in the bathroom in which the bathtub is provided; The water heating apparatus according to claim 1, wherein when the water heating apparatus is performing reheating operation in the immediate response combustion mode, the combustion mode of the reheating operation is changed from the immediate response combustion mode to the comfortable combustion mode based on detection that a person is in the bathroom.

3. When the request is not the standard combustion mode, the rapid response combustion mode, or the comfortable combustion mode, the control device switches the combustion mode of the reheating operation to a heat retention reheating mode, The hot water supply device according to claim 1 , wherein the temperature of the hot water in the heat retention and reheating mode is lower than T3.

4. The control device includes: receiving a signal output from a human presence sensor disposed in the bathroom in which the bathtub is provided; The water heater according to claim 3, wherein when the water heater is performing re-heating operation in the heat retention re-heating mode, the combustion mode of the re-heating operation is changed from the heat retention re-heating mode to the comfortable combustion mode based on detection that a person is in the bathroom.

5. The control device includes:

5. The hot water supply device according to claim 2, wherein when it is detected that a person has left the bathroom while the reheating operation is being performed in the comfortable combustion mode, the combustion mode of the reheating operation is returned to the combustion mode before being changed to the comfortable combustion mode.

6. The hot water supply apparatus according to claim 1 , wherein the control device executes the re-heating operation in the standard combustion mode when it is unable to determine whether or not a person is present in the bathroom in which the bathtub is provided.

7. A program for controlling a hot water supply device, the program being provided to a control device of the hot water supply device, receiving a temperature of hot and cold water to be supplied to the bathtub from the heat exchanger; A step of detecting a request for a reheating operation to reheat the water in the bathtub; A step of setting the target temperature of the hot and cold water to T2 degrees based on the fact that the request indicates a reheating operation in a standard combustion mode corresponding to a preset combustion condition; A step of setting the target temperature to T1 degrees based on the fact that the request indicates a re-heating operation in a rapid response combustion mode in which the hot water is re-heated in a time shorter than the time required for the re-heating operation in the standard combustion mode; setting the target temperature to T3 degrees based on the request indicating a reheating operation in a comfortable combustion mode in which water is reheated when a bather is present; and executing a reheating operation by the heat exchanger at the set target temperature. A program in which T1>T2>T3.

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