JP5083552B2 - Hot water system - Google Patents

Description

  The present invention includes, for example, a hot water supply system used to supply hot water to a kitchen, bathroom, or other desired location, and more specifically, a main heating device and an auxiliary heating device as means for heating and generating hot water. This is related to a hot water supply system.

  A specific example of this type of hot water supply system is described in Patent Document 1. The hot water supply system described in this document includes a main heating device that performs hot water heating using exhaust heat from a fuel cell, a hot water storage tank that stores hot water heated by the main heating device, and a hot water storage tank. And an auxiliary heating device capable of heating the flowing hot water. According to the hot water supply system having such a configuration, when there is no hot water above the target hot water supply temperature in the hot water storage tank, the hot water flowing out of the hot water storage tank is heated using the auxiliary heating device, and hot water at the target hot water supply temperature is supplied. Can be generated. Therefore, it is possible to supply hot water at the target hot water supply temperature to a desired hot water supply destination regardless of the amount of hot water in the hot water storage tank.

  As an auxiliary heating device for the hot water supply system as described above, a device equipped with a liquid fuel vaporization type combustion device that vaporizes and burns liquid fuel such as kerosene according to user's request and various other circumstances. There is. In this type of combustion apparatus, liquid fuel is supplied to a carburetor heated (preliminarily heated) by an electric heater, whereby vaporization of the liquid fuel is promoted and ignition is performed. After ignition of the liquid fuel, the carburetor is heated by the combustion heat of the liquid fuel. Therefore, when the combustion of the liquid fuel is started, the preheating of the carburetor ends.

  However, when the above-described liquid fuel vaporization type combustion apparatus is used for the auxiliary heating apparatus of the hot water supply system, the following problems occur.

  That is, it takes some time for the temperature of the vaporizer to rise to a temperature suitable for vaporizing the liquid fuel after energization of the heater for the vaporizer is started. Therefore, if hot water exceeding the target hot water supply temperature no longer exists in the hot water storage tank, if the energization of the heater is started to drive the combustion device, the operation of the combustion device will not be in time. In this case, a large amount of hot water that does not reach the target hot water supply temperature is supplied to the hot water supply destination. In order to prevent this, when the hot water supply system is set to be on, the vaporizer may be always preheated. However, this is not preferable from the viewpoint of energy saving because the power consumption of the heater for the vaporizer increases.

JP 2007-64526 A

  The present invention has been conceived under the circumstances as described above, and an auxiliary heating device used in combination with a main heating device or a hot water storage tank is provided with a liquid fuel vaporization type combustion device. In this case, when the hot water storage tank is in a so-called hot water condition, it is possible to eliminate the problem that a large amount of hot water that does not reach the target hot water supply temperature is supplied to the hot water supply destination, and the heater for the vaporizer An object of the present invention is to provide a hot water supply system capable of suitably suppressing power consumption.

  In order to solve the above problems, the present invention takes the following technical means.

  The hot water supply system provided by the present invention is capable of hot water heating independently of a main heating device capable of hot water heating, a hot water storage tank for storing hot water heated by the main heating device, and the main heating device. An auxiliary heating device, and the auxiliary heating device has a vaporizer for liquid fuel, and as a mode for starting the combustion of the liquid fuel, preheating by preheating the vaporizer with a heater A hot water supply system comprising a liquid fuel vaporization type combustion device in which a mode is set, wherein the remaining hot water situation in the hot water storage tank is judged, and no hot water above the target hot water supply temperature exists in the hot water storage tank And when it is determined that the amount of hot water equal to or higher than the target hot water supply temperature is less than a preset specified amount, the vaporizer is set to the preheating mode while the target water supply is When it is determined that there is more than the specified amount of hot or cold water, the heater is kept off without setting the vaporizer to the preheating mode, or the heating temperature of the heater is set to the preheating. It is characterized by comprising control means for executing control for lowering the temperature than in the mode.

  According to the present invention, the carburetor of the liquid fuel vaporization combustion apparatus is set to the preheating mode before the hot water of the hot water storage tank is over the target hot water supply temperature, that is, before the hot water runs out. Can do. Therefore, for example, unlike when the vaporizer is set to the preheating mode when the hot water tank is out of hot water, the combustion apparatus is operated at a time considerably delayed after the hot water tank is hot. Things that become possible can be solved appropriately. As a result, despite the fact that a liquid fuel vaporization type combustion device is used as the auxiliary heating device, a large amount of hot water that does not reach the target hot water temperature due to the hot water in the hot water storage tank has reached the hot water supply destination. The problem of being supplied to is preferably eliminated. On the other hand, if there is more than a certain amount of hot water above the target hot water temperature in the hot water storage tank and there is no possibility that the hot water will run out immediately, or if there is little possibility, the heater to preheat the vaporizer Since the power supply amount is set to zero, or the power supply amount is smaller than that in the preheating mode, an advantage that power saving is suitably achieved can be obtained.

  In a preferred embodiment of the present invention, it has a function of dropping hot water into a bathtub, and a bath reheating function capable of heating hot water dropped into the bathtub using the auxiliary heating device, and the control The means is set to a predetermined bath-related operation mode by operating a predetermined operation means even when it is determined that hot water having a temperature equal to or higher than a target hot water supply temperature is present in the hot water storage tank. Sometimes, the vaporizer is configured to set to the preheating mode.

  According to such a configuration, the following effects can be obtained. That is, for example, when a bath-related operation mode such as an automatic heat retention mode is set, there is a high possibility that the bath will be revoked. On the other hand, according to the above configuration, when there is a high possibility that such a bath will be retreated, the vaporizer is set to the preheating mode, and the operation of the liquid fuel vaporization type combustion apparatus can be started immediately. In order to be ready, when a bath retreat is requested, it is possible to respond quickly to this request. Unlike the above-described configuration, for example, if the vaporizer is preheated after bathing is requested, the waiting time until the chasing is started becomes long, and the comfort during bathing is inferior. According to the above configuration, such a problem is appropriately avoided.

  In a preferred embodiment of the present invention, the control means maintains the vaporizer in the preheating mode until a predetermined time has elapsed even after the predetermined bath-related operation mode is canceled. It is configured.

  According to such a configuration, the following effects can be obtained. That is, even when the predetermined bath-related operation mode is finished, the bather may be revoked for a while after that, for example, by bathers changing one after another. According to the above-described configuration, in such a case, the bath can be quickly repelled so that the operation of the liquid fuel vaporization type combustion apparatus can be started immediately, which matches the actual usage situation of the hot water supply system. Will be.

  In a preferred embodiment of the present invention, the control means may operate the auxiliary heating device after the predetermined bath-related operation mode is canceled based on the operation results of the auxiliary heating device. It has a learning function for determining a time band considered to be high and changing the predetermined time in accordance with the time band.

  According to such a configuration, the time during which the vaporizer is set to the preheating mode is determined in accordance with the actual usage situation of the hot water supply system, so that the vaporizer is not caused inconvenience to the user. It is possible to shorten the preheating time as much as possible and achieve energy saving more appropriately.

  In a preferred embodiment of the present invention, there is provided means capable of determining the presence or absence of bathing, and when it is determined that bathing is performed by this means, the control means is configured to store the remaining hot water in the hot water storage tank. Regardless of the situation, control is performed to set the vaporizer to the preheating mode.

  According to such a configuration, when there is a high possibility that a person takes a bath and performs a bath reheating operation, the vaporizer is set in a preheating mode so that the bath retreat can be immediately executed. Therefore, it can be made comfortable for the user.

  In a preferred embodiment of the present invention, the main heating device is a cogeneration system device, a heat pump, or a solar water heater. Of course, these are merely examples, and various heating devices other than those described above can be used as the main heating device of the present invention.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 and 2 show an example of a hot water supply system to which the present invention is applied. As clearly shown in FIG. 1, the hot water supply system HS of the present embodiment includes a main heating device H1, a hot water storage tank 3, an auxiliary heating device H2, and a control unit 4.

  The main heating device H1 constitutes, for example, a cogeneration system having the fuel cell 10 and also has a heat exchanger 11 that performs hot water heating using exhaust heat generated when the fuel cell 10 is driven. Yes. Many such cogeneration systems are already known, and these can be used as appropriate, so that detailed description thereof is omitted.

  The hot water storage tank 3 is for storing hot water heated using the heat exchanger 11 of the main heating device H1, and when the pump P1 is operated, the hot water in the hot water storage tank 3 is supplied from its bottom side. It is supplied to the heat exchanger 11 through the piping part 90a and heated. This heated hot water is returned to the upper part of the hot water storage tank 3 through the piping part 90b. A plurality of temperature sensors TS for detecting the internal hot water temperature are attached to the hot water storage tank 3. The control part 4 can grasp | ascertain the temperature distribution condition of the hot water in the hot water storage tank 3 based on the temperature of each part detected using these several temperature sensors TS.

  The auxiliary heating device H <b> 2 is for performing hot water heating when the amount of remaining hot water in the hot water storage tank 3 is insufficient or for reheating hot water in the bathtub 7. In the present embodiment, the auxiliary heating device H2 and the hot water storage tank 3 are accommodated in a common outer case 80, and these are unitized. Of course, they can be configured as separate units. . The auxiliary heating device H2 includes a liquid fuel vaporization type combustion device 5 and a heat exchanger 6 that performs heat recovery from the combustion gas generated by the combustion device 5 and performs hot water heating. The auxiliary heating device H2 may have a hardware configuration similar to that of a hot water supply device using a conventionally known liquid fuel vaporization type combustion device, and the contents thereof will be briefly described below.

  That is, as shown in FIG. 2, the combustion apparatus 5 includes a cup-shaped carburetor 51, a heater 52, a flame hole base 53, and the like disposed in a casing 50. Liquid fuel such as kerosene is a fuel. It can be supplied into the vaporizer 51 from the outside of the casing 50 via the pipe 54. The vaporizer 51 can be preheated by the heater 52, and the liquid fuel is supplied to the preheated vaporizer 51, thereby promoting the vaporization of the liquid fuel. The vaporized fuel travels upward above the flame hole base 53 and is mixed with combustion air. The combustion air is produced by the fan 55 driven by the motor M taking the external air into the casing 50 from the air supply port 50a. The gas mixture of the vaporized fuel and the combustion air is jetted downward from a plurality of flame holes (not shown) penetrating the flame hole base 53 and burned by being ignited by a spark plug 58. To do. After starting the combustion, the vaporizer 51 is heated by the combustion heat, so the preheating by the heater 52 is unnecessary and is stopped.

  The heat exchanger 6 includes two heat exchange units 60A and 60B that recover heat from the combustion gas generated by the combustion device 5. The heat exchange parts 60A and 60B are both provided with heat transfer tubes through which hot water flows, but as will be described later, one heat exchange part 60A is for general hot water supply, whereas the other heat exchange part The part 60B is for bathing. Connected to the heat exchanger 6 is an exhaust duct 68 having an exhaust port 68a for exhausting the combustion gas after heat recovery to the outside.

  As shown in FIG. 1, the internal hot water pipes 92 a and 92 b connected to the upper part of the hot water storage tank 3 and an internal hot water pipe 92 c having a hot water outlet 920 are connected to the heat exchanging unit 60 </ b> A. For example, a hot water supply pipe (not shown) for supplying hot water to a hot water tap (not shown) such as a kitchen, a washroom, and a bathroom is connected to the hot water outlet 920. A part of this hot water supply pipe is also branched and connected to one of piping sections 94a, 94b (not shown), which will be described later, so that hot water can be dropped into the bathtub 7. An internal water supply pipe 93 having a water inlet 930 to which a water pipe or the like is connected is connected to the lower part of the hot water storage tank 3, and the water supply pressure is constantly acting in the hot water storage tank 3. For this reason, when one of the plurality of hot water taps provided in the kitchen or the like is opened, the hot water in the hot water storage tank 3 flows into the internal hot water discharge pipes 92a and 92b, and passes through the heat exchanging section 60A and the internal hot water discharge pipe 92c. The hot water outlet 920 is configured to discharge hot water. A mixing valve V1 is provided between the internal hot water discharge pipes 92a and 92b, and hot water flowing out of the hot water storage tank 3 is mixed with non-heated water from the internal water supply pipe 93 at a predetermined ratio so that the hot water at the target hot water supply temperature is obtained. Can be generated. When there is no hot water above the target hot water supply temperature in the hot water storage tank 3, the hot water flowing out of the hot water storage tank 3 is heated by the heat exchange section 60A.

  The heat exchanging section 60B is connected to piping sections 94a and 94b for reheating hot water in the bathtub 7. The hot water in the bathtub 7 is circulated so as to be returned to the bathtub 7 through the piping part 94b after being heated by being sent to the heat exchanging part 60B through the piping part 94a by driving the pump P2. .

  The control unit 4 is configured using, for example, a microcomputer, and performs various data processing and hot water supply operation control while performing data communication with one or a plurality of remote controllers 49 and the control unit 14 of the main heating device H1. To do. The remote controller 49 includes an operation switch 49a for setting on / off of the hot water supply operation (switching between a state in which the hot water supply operation is enabled and a state in which the hot water supply operation is disabled), a switch for setting a target hot water supply temperature, and automatic bath There are provided a switch for turning on / off the operation mode, a switch for turning on / off the bath automatic heat retention mode, a switch for commanding the reheating of the bath, etc. Here, the bath automatic operation mode is a mode in which hot water filling to the bathtub 7, boiling (heating) after hot water filling, and heat insulation (heating) after boiling is performed. The bath automatic heat retaining mode is a mode in which only hot water warming (refreshing) of the bathtub 7 is performed. As will be described later, the controller 4 controls the carburetor heater 52 of the combustion device 5 according to the switch operation of the remote controller 49, the hot water distribution situation in the hot water storage tank 3 (the remaining amount of hot water above a predetermined temperature), and the like. The entire combustion drive of the combustion apparatus 5 is controlled including the preheating control.

  Next, the operation of the hot water supply system HS will be described. In addition, an example of a procedure for controlling the drive of the vaporizer heater 52 by the control unit 4 will be described with reference to the flowchart shown in FIG.

  First, when the operation switch 49a is off, the controller 4 turns off the driving of the carburetor heater 52 (non-energized state) (S1: NO, S5). Next, when the operation switch 49a is turned on, it is determined whether or not hot water having a target hot water supply temperature (for example, 40 ° C.) or more exists in the hot water storage tank 3 in a predetermined amount Q or more (S1: YES, S2). Here, the prescribed amount Q is a value stored in advance in the memory of the control unit 4 or the remote controller 49, and 0 <Q <Lmax (Lmax: capacity of the hot water storage tank 3). Preferably, the specified amount Q satisfies a relationship of Q ≧ q · t, and more preferably a value that satisfies the relationship is as small as possible, that is, Q = q · t, or a value close thereto. The Here, q is the amount of hot water discharged from the hot water outlet 920 per unit time, and is a flow rate [L / min] considered to be the maximum value. t is a time required for the vaporizer 51 to reach a predetermined temperature suitable for liquid fuel ignition after the heater 52 is turned on, and the average time or the maximum time (the vaporizer 51 is in the winter season or the like). It is a time [min] considered to be a time considering a considerably low temperature in the initial stage. When the prescribed amount Q is in the relationship described above, it is possible to raise the temperature of the vaporizer 51 to a predetermined temperature suitable for igniting the liquid fuel while hot water of the prescribed amount Q is discharged from the hot water storage tank 3. Of course, the specific value of the specified amount Q is not limited to the above-described relationship, and can be arbitrarily increased or decreased by operating the remote controller 49 in accordance with the actual situation of the hot water supply system HS or the user's request. It may be.

  Next, when the control unit 4 determines in the above-described determination that hot water having a temperature equal to or higher than the target hot water supply temperature does not exceed the specified amount Q (S2: NO), the controller 4 starts driving the heater 52, and the vaporizer 51 is set to the preheating mode (S6). In this preheating mode, the vaporizer 51 is maintained at a temperature at which ignition of liquid fuel such as kerosene can be easily performed. Therefore, in this preheating mode, even if the hot water is started in a state where there is not much hot water above the target hot water supply temperature in the hot water storage tank 3, even if the hot water storage tank 3 is in a so-called hot water out condition, In the apparatus 5, liquid fuel can be burned immediately, and hot water heating can be performed quickly. If the specified amount Q is set so as to satisfy the relationship of Q ≧ q · t, the carburetor 51 is preheated to a temperature suitable for ignition of liquid fuel until the hot water storage tank 3 becomes hot. Will be. Therefore, when the hot water storage tank 3 is out of hot water, the start of operation of the combustion device 5 is appropriately prevented from being delayed, and the hot water at the target hot water supply temperature is continuously discharged from the hot water outlet 920, or this A state close to can be achieved.

  On the other hand, when it is determined that the hot water having the target hot water temperature or more exists in the hot water storage tank 3 in a predetermined amount or more (S2: YES), the control unit 4 determines whether or not the predetermined bath-related operation mode is off ( S3). Here, the predetermined bath-related operation mode is stored in advance in the memory of the control unit 4 or the remote controller 49 among the operation modes involving hot water supply to the bathroom (including hot water filling in the bathtub 7), bathing, etc. For example, an automatic bath operation mode and an automatic bath warming mode. Of course, the specific contents of the predetermined bath-related operation mode can also be configured to be changed as appropriate by operating the remote controller 49 in the same manner as the prescribed amount Q described above. . For example, an operation mode different from the bath automatic operation mode and the automatic heat retention mode may be selected, and the vaporizer 51 may be in the preheating mode when this mode is set.

  When the aforementioned predetermined bath-related operation mode is set to ON (S3: NO), the control unit 4 sets the vaporizer 51 to the preheating mode (S6). When such control is performed, for example, in the bath automatic operation mode, after hot water is dropped into the bathtub 7, the hot water is sprinkled up to a desired set temperature using the auxiliary heating device H2 (this operation) The operation also corresponds to a bath chasing operation). Similarly, even in the bath automatic heat retaining mode, the hot water reheating operation in the bathtub 7 can be performed quickly.

  Unlike the above, when the predetermined bath-related operation mode is turned off (S3: YES), the control unit 4 determines whether or not a predetermined time has elapsed since the bath-related operation mode was turned off. If it is determined that the predetermined time has not elapsed, the vaporizer 51 is set to the preheating mode (S4: NO, S6). The specific value of the predetermined time can also be changed as appropriate by operating the remote controller 49 or the like. Even when the bath-related operation mode is turned off, for a while after the bath-related operation mode is turned off, the bather is still taking a bath, or the bather is replaced. There are relatively many cases of bathing. If the above-mentioned control is performed, even after the bath-related operation mode is turned off, the combustion device 5 of the auxiliary heating device H2 can be immediately burned for a predetermined time thereafter, so that the bath replenishment is performed quickly. Can be made. On the other hand, after a predetermined time has elapsed from the predetermined bath-related operation mode, the heater 52 is turned off and the preheating mode is not set (S4: YES, S5).

  The control unit 4 repeatedly executes the series of controls described above. According to such control, the vaporizer 51 is set to the preheating mode when NO is determined in steps S2 to S4. In other periods, the driving of the heater 52 for carburetor is turned off. Therefore, the amount of power consumed by the heater 52 can be suppressed, and energy saving can be suitably achieved. On the other hand, in the hot water supply system HS, as described above, it is preferably prevented that the hot water supply at the target hot water supply temperature becomes difficult when the hot water tank 3 runs out of water, and the hot water supply system for the bath is replaced. This operation can be performed quickly when the watering is required, and the hot water supply function and the bath reheating function can be improved.

  In the present invention, in addition to the control means described above, the control unit 4 can further execute the following control.

  That is, as shown in FIG. 4, when the predetermined bath-related operation mode is turned on and then this operation mode is turned off thereafter (S10: YES, S11: YES), the control unit 4 performs the operation described above. The presence / absence of bath rebirth after the mode is turned off and the time from when the mode is turned off until the rebirth is determined (S12). In this determination, a time band in which it is highly likely that the bath will be replenished after the operation mode is turned off is also determined. This determination may be made based on data detected over a long span of several days or longer, for example. Next, the control unit 4 determines the predetermined time of step S4 shown in FIG. 3 based on the above-described determination (S13). In this determination, the predetermined time includes a time band that is highly likely to be bathed and does not greatly exceed this time band. In this case, the predetermined time after the predetermined bath-related operation mode is turned off is set as the time during which the vaporizer 51 is always set in the preheating mode, and the bath follow-up is performed separately from the predetermined time. It is also possible to separately determine a time zone in which it is considered that there is a high possibility that a whisper will be made as the time for which the preheating mode is set.

  If the control as described above is executed, the vaporizer 51 is set to the preheating mode in a time zone where there is a high possibility that the bath is actually replenished after the bath-related operation mode is turned off. It is more preferable to immediately carry out bathing according to the request of the bather. On the other hand, in a time zone in which there is little possibility of bathing, the carburetor 51 is less likely to be set to the preheating mode wastefully, and energy saving can be ensured.

  In the control shown in FIG. 5, as a premise, the hot water supply system HS is configured to include a bathing detection means. This bathing detection means is configured using, for example, a sensor capable of detecting the water level of the bathtub 7, and in the state where hot water is filled in the bathtub 7, the water level is not supplied even though hot water is not supplied. When it rises, it is determined that bathing in the bathtub 7 has been performed. When it is determined that bathing has been performed in the state where the operation switch 49a is turned on, the vaporizer 51 is set to the preheating mode (S1: YES, S1 ': NO, S6). On the other hand, if bathing is not detected, the process proceeds to step S2 in FIG.

  According to the control described above, under the circumstances where it is considered that there is a relatively high possibility that the bathing is actually performed and the operation of retreating the bath is performed, regardless of the remaining hot water situation in the hot water storage tank 3. The vaporizer 51 is set to the preheating mode, and when the bather requests bathing, the request can be suitably met. In the above-described control, it is detected that a person has entered the bathtub 7 based on a change in the water level of the bathtub 7, but instead, for example, when a person enters the bathroom, this is detected for human body detection. You may make it detect with a sensor and may consider that bathing was started when the person approached into the bathroom.

  The present invention is not limited to the embodiment described above. The specific configuration of each part of the hot water supply system according to the present invention can be varied in design in various ways.

  In the above-described embodiment, when the vaporizer 51 is not set to the preheating mode, the power supply to the heater 52 is zero, which is optimal for thorough energy saving, but the present invention is not limited to this. . In the present invention, when the vaporizer 51 is not set to the preheating mode, the power supply amount to the heater 52 may be reduced so that the heat generation temperature of the heater 52 is lower than that in the preheating mode. This is because even in this case, energy saving can be achieved as compared with the case where the vaporizer 51 is always set to the preheating mode.

  The auxiliary heating device referred to in the present invention may be provided with a liquid fuel vaporization type combustion device having a liquid fuel vaporizer, and for heating hot water using the combustion gas generated by the combustion device. Specific means (such as a heat exchanger structure) are not limited. The auxiliary heating device is preferably configured to be able to heat hot water flowing out of the hot water storage tank, but is not limited to this. For example, when hot water runs out in the hot water storage tank, the water sent from the water supply pipe can be heated by the auxiliary heating device and discharged. As will be understood from this, it is essential that the auxiliary heating device can be operated independently of the main heating device. In addition, as described above, the main heating device in the present invention includes various devices such as a heat pump and a solar water heater other than the cogeneration system device (regardless of the type such as the fuel cell method and the gas engine method). Can be used.

It is a figure showing typically an example of the hot-water supply system concerning the present invention. It is a schematic sectional drawing which shows the auxiliary heating apparatus used for the hot water supply system shown in FIG. It is a flowchart which shows an example of the operation processing procedure of the control part of the hot-water supply system shown in FIG. It is a flowchart which shows the other example of the operation | movement process procedure of the control part of the hot water supply system shown in FIG. It is a flowchart which shows the other example of the operation | movement process procedure of the control part of the hot water supply system shown in FIG.

Explanation of symbols

HS hot water supply system H1 main heating device H2 auxiliary heating device 3 hot water storage tank 4 control unit (control means)
5 Liquid fuel vaporization combustion system 7 Bathtub 49 Remote control (operating means)
49a Operation switch 51 Vaporizer 52 Heater

Claims (6)

A main heating device capable of hot water heating,
A hot water storage tank for storing hot water heated by the main heating device;
An auxiliary heating device capable of hot water heating independently of the main heating device,
The auxiliary heating device has a liquid fuel vaporizer, and a liquid fuel vaporization method in which a preheating mode in which the vaporizer is preheated by a heater is set as a mode for starting combustion of the liquid fuel. A hot water supply system equipped with a combustion device,
When the remaining hot water situation in the hot water storage tank is determined and there is no hot water above the target hot water temperature in the hot water storage tank, and even if hot water above the target hot water temperature exists, the amount is set in advance When it is determined that the amount is less than the predetermined temperature, the vaporizer is set to the preheating mode, and when it is determined that the amount of hot water equal to or higher than the target hot water supply temperature is greater than the specified amount, the vaporizer is set to the preheating mode. And a controller for controlling the heater to be turned off or to control the temperature of the heater to be lower than that in the preliminary heating mode. A function of dropping hot water into the bathtub, and a bath reheating function capable of heating the hot water dropped into the bathtub using the auxiliary heating device,
The control means sets a predetermined bath-related operation mode by operating the predetermined operation means even when it is determined that hot water having a temperature equal to or higher than the target hot water supply temperature is present in the hot water storage tank. The hot water supply system according to claim 1, wherein the hot water supply system is configured to set the vaporizer to the pre-heating mode when it is running.   The control means is configured to maintain the vaporizer in the preheating mode until a predetermined time has elapsed even after the predetermined bath-related operation mode is canceled. The hot water supply system described.   The control means determines, based on the operation results of the auxiliary heating device, a time zone in which the auxiliary heating device is likely to be operated after the predetermined bath-related operation mode is canceled, And the hot water supply system of Claim 3 which has a learning function which changes the said predetermined time corresponding to this time zone | band.   When it is determined that the presence or absence of bathing can be determined and it is determined that bathing has been performed by this means, the control means controls the vaporizer regardless of the remaining hot water status in the hot water storage tank. The hot water supply system according to any one of claims 2 to 4, wherein the hot water supply system is configured to execute control for setting the preliminary heating mode.   The hot water supply system according to any one of claims 1 to 5, wherein the main heating device is a cogeneration system device, a heat pump, or a solar water heater.

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