JP4696835B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply heat exchanger that is heated by combustion heat of a burner, and a hot water supply device that includes a latent heat recovery heat exchanger that recovers latent heat of combustion exhaust gas, and in particular, the hot water supply heat exchanger and the latent heat recovery device. The present invention relates to a hot water supply apparatus in which a use side heat exchanger is provided in a hot water supply circulation circuit for circulating hot water heated by a heat exchanger.

Conventionally, as this type of combustion apparatus, as disclosed in Patent Document 1, a hot water supply heat exchanger that heats water supplied through a water supply path by combustion of a burner to supply hot water to the hot water supply path, and heating supplied through an inlet path A hot water supply apparatus provided with a fluid heat exchanger that heats a target fluid by combustion of the burner and flows out to an outlet, and the hot water heat exchanger recovers sensible heat of combustion exhaust gas of the burner A sensible heat exchange unit for hot water supply, and a latent heat heat exchange unit for hot water supply that is disposed downstream of the sensible heat exchange unit for hot water supply in the flow direction of the combustion exhaust gas of the burner and recovers the latent heat of the combustion exhaust gas of the burner The fluid heat exchanger recovers sensible heat of the combustion exhaust gas of the burner, and the combustion exhaust gas of the burner than the fluid sensible heat exchange unit. Arranged downstream of the flow direction of And a fluid latent heat exchange part for recovering the latent heat of the combustion exhaust gas of the burner, and the sensible heat exchange part for hot water supply and the sensible heat exchange part for fluid are integrated in a state of conducting heat to each other. And a hot water supply device in which the latent heat heat exchange part for hot water supply and the latent heat heat exchange part for fluid are integrally formed in a state of conducting heat to each other are disclosed (for example, see Patent Document 1). .
JP 2002-267262 A

  However, in the conventional hot water supply apparatus, a hot water heat exchanger and a fluid heat exchanger are respectively arranged in the flow path of the combustion gas of the burner, and a sensible heat exchanger for hot water supply and a hot water supply are provided in the hot water heat exchanger. And a fluid sensible heat exchange section and a fluid latent heat exchange section are provided in the fluid heat exchanger, so that hot water is supplied to the sensible heat exchange section and the latent heat exchange section respectively. Therefore, the heat exchanger for fluid and the heat exchanger for fluid need to be formed integrally, and a very complicated configuration has been imposed as a heat exchanger for hot water supply and a heat exchanger for fluid. In particular, when the structure of the latent heat exchange section is a double pipe structure using a stainless steel pipe and a copper pipe in order to improve the corrosion resistance, there is a problem in workability.

  In addition, since two paths for hot water supply and fluid are formed as the paths heated by the burner, the piping configuration becomes complicated and the boiling of the residual water in the heat exchanger on the shutdown side during single operation It has a problem of generating.

  The present invention solves the above-mentioned conventional problems, and forms one heating path with a hot water supply heat exchanger and a latent heat recovery heat exchanger, and uses circulating water in the heating path to form a heating circuit or a bath circuit. By adopting a structure for supplying heat, it is possible to configure a use-side heat exchanger that is not related to the heat exchanger for hot water supply and the latent heat recovery heat exchanger. It is possible to provide a hot water supply device that is easy to use and prioritizes hot water supply performance by realizing a reduction in weight and weight and making the heating path mainly a hot water supply circuit. In addition, by adopting a single heating path configuration mainly composed of a hot water supply circuit, the configuration for improving the corrosion resistance of the latent heat recovery heat exchanger is solved while solving the problem of residual water boiling in the heat exchanger during single operation. It is an object of the present invention to provide a hot water supply device that is easy and has high efficiency and reduced running costs.

  In order to solve the above-mentioned conventional problems, a hot water supply apparatus of the present invention includes a hot water supply heat exchanger that heats water supplied from a water supply channel by combustion of a burner and supplies hot water to a hot water supply channel, and combustion exhaust gas of the burner A latent heat recovery heat exchanger disposed in the path for recovering the latent heat of the combustion exhaust gas, and connecting the hot water supply heat exchanger and the latent heat recovery heat exchanger in series to exchange heat for latent heat recovery from the water supply channel A hot water supply circuit that passes through the heat exchanger through the hot water supply heat exchanger to the hot water supply passage, and is branched from the hot water supply passage and supplied to the use side heat exchanger via the circulation pump, and then to the latent heat recovery heat exchanger. Return, form a hot water supply circulation circuit from the latent heat recovery heat exchanger through the hot water supply heat exchanger to the user side heat exchanger through the circulation pump, and use the hot water supply circuit or use the hot water supply circulation circuit Or hot water supply circuit and hot water circulation cycle A hot water supply circuit closing means for making the hot water supply circuit completely closed in the water supply passage, and a circulating flow rate detection for detecting a circulating flow rate in the hot water supply circuit And the control means closes the hot water supply circulation circuit closing means, drives the circulation pump under a predetermined condition, and detects the circulation flow rate in the hot water supply circulation circuit at that time by the circulation flow rate detection means. The presence or absence of water leakage due to breakage of the hot water supply circulation circuit can be detected.

  Thereby, one heating path is formed by the heat exchanger for hot water supply and the heat exchanger for latent heat recovery, and the heat amount is supplied to the heating circuit and the bath circuit using the circulating water of the heating path. Enables the configuration of the use side heat exchanger that is not related to the hot water supply heat exchanger or the latent heat recovery heat exchanger. By using a hot water supply circuit as a main route, it is possible to provide an easy-to-use hot water supply device that prioritizes hot water supply performance, and by adopting a single heating route configuration mainly consisting of a hot water supply circuit, It is possible to provide a hot water supply apparatus that solves the problem of residual water boiling in the exchanger, facilitates the structure for improving the corrosion resistance of the latent heat recovery heat exchanger, and achieves high efficiency and reduced running costs.

  Furthermore, by providing a hot water supply circuit closing means for making the hot water supply circuit completely closed in the water supply channel and driving the circulation pump, it becomes possible to detect minute leakage due to breakage of the hot water supply circuit. Can be detected at an early stage. The water supply path in this hot water supply apparatus passes through the heat exchange part for latent heat recovery, which is in contact with acidic dew condensation water and is feared to be damaged by corrosion, and the secondary side flow different from tap water in each use side heat exchanger part Because it is in contact with the road, there are factors that cause problems when water leaks due to pipe breakage, etc., compared to conventional hot water supply equipment, so it is extremely important to detect water leaks when pipe breakage from the hot water supply side circuit .

  The hot water supply apparatus of the present invention is configured to form one heating path with a hot water supply heat exchanger and a latent heat recovery heat exchanger, and to supply heat to a heating circuit or a bath circuit using circulating water in the heating path. This makes it possible to configure the heat exchanger on the use side that is not related to the heat exchanger for hot water supply or the latent heat recovery heat exchanger, and realizes downsizing and weight reduction of equipment by simplifying the main body configuration including the piping configuration. In addition, it is possible to provide an easy-to-use hot water supply apparatus that prioritizes hot water supply performance by using the hot water supply circuit as a main component of the heating path. In addition, by adopting a single heating path configuration mainly composed of a hot water supply circuit, the configuration for improving the corrosion resistance of the latent heat recovery heat exchanger is solved while solving the problem of residual water boiling in the heat exchanger during single operation. It is possible to provide a hot water supply device that is easy and highly efficient with reduced running costs.

Furthermore, by providing a hot water supply circuit closing means for making the hot water supply circuit completely closed in the water supply channel and driving the circulation pump, it becomes possible to detect minute leakage due to breakage of the hot water supply circuit. Can be detected at an early stage. The water supply path in this hot water supply apparatus passes through the heat exchange part for latent heat recovery, which is in contact with acidic dew condensation water and is feared to be damaged by corrosion, and the secondary side flow different from tap water in each use side heat exchanger part Because it is in contact with the road, there are factors that cause problems when water leaks due to pipe breakage, etc., compared to conventional hot water supply equipment, so it is extremely important to detect water leaks when pipe breakage from the hot water supply side circuit .

  A first aspect of the invention is a hot water supply heat exchanger that heats water supplied from a water supply channel by combustion of a burner and supplies hot water to a hot water supply channel, and recovers the latent heat of the combustion exhaust gas disposed in the combustion exhaust gas path of the burner. A latent heat recovery heat exchanger that connects the hot water supply heat exchanger and the latent heat recovery heat exchanger in series, passes through the latent heat recovery heat exchanger from the water supply channel, passes through the hot water supply heat exchanger, Forming a hot water supply circuit leading to the road, and after branching from the hot water supply path and supplying to the use side heat exchanger via the circulation pump, returning to the latent heat recovery heat exchanger and from the latent heat recovery heat exchanger for hot water supply A hot water supply circulation circuit that passes through the heat exchanger and reaches the user-side heat exchanger through the circulation pump is formed, the hot water supply circuit is used, the hot water supply circulation circuit is used, or the hot water supply circuit and the hot water supply circulation circuit Can be used at the same time And a hot water supply circuit closing means for making the hot water supply circuit into a completely closed circuit and a circulating flow rate detecting means for detecting a circulating flow rate in the hot water supply circuit, the control means comprising the hot water supply circuit The circulation circuit closing means is closed, the circulation pump is driven under a predetermined condition, and the circulation flow rate in the hot water supply circulation circuit at that time is detected by the circulation flow rate detection means. It is characterized by the fact that it can be detected, and a heating path is formed by a heat exchanger for hot water supply and a heat exchanger for recovering latent heat, and a heating circuit and a bath circuit using the circulating water of the heating path It is possible to configure the use-side heat exchanger not related to the hot water supply heat exchanger or the latent heat recovery heat exchanger, and to simplify the main body configuration including the piping configuration. Smaller and lighter At the same time, it is possible to provide an easy-to-use hot water supply apparatus that prioritizes hot water supply performance by using the hot water supply circuit as a main component, and by adopting a single heating path configuration mainly including the hot water supply circuit. Provides a hot water supply system that eliminates the problem of residual water boiling in the heat exchanger during stand-alone operation, facilitates the structure for improving the corrosion resistance of the heat exchanger for latent heat recovery, and reduces the running cost with high efficiency can do.

  Further, the hot water supply circuit includes a hot water supply circuit closing means for making the hot water supply circuit completely closed, and a circulating flow rate detecting means for detecting a circulation flow rate in the hot water supply circuit, and the control means includes the hot water supply circuit. The circulation circuit closing means is closed, the circulation pump is driven under a predetermined condition, and the circulation flow rate in the hot water supply circulation circuit at that time is detected by the circulation flow rate detection means. Can be detected, and it can be detected at an early stage that water leakage has occurred.

  In the second invention, when a plurality of use-side heat exchangers are provided, the heat exchangers are connected in parallel to the hot water supply circulation circuit so that the hot water temperatures supplied from the hot water supply heat exchangers are substantially the same. A hot water supply circulation circuit by connecting a plurality of use side heat exchangers in parallel to a hot water supply circulation circuit composed of a hot water supply heat exchanger and a latent heat recovery heat exchanger. Therefore, the circulation pump can be made smaller and lighter.

  The third invention is characterized in that the branching portion from the hot water supply circulation circuit of the hot water supply passage is arranged upstream of the use side heat exchanger, and the branching portion is arranged immediately downstream of the hot water supply heat exchanger. Thus, when the hot water supply circuit is used alone, the flow pressure pressure loss of the hot water supply passage can be reduced and hot water can be supplied to the hot water supply passage quickly.

  The fourth invention is characterized in that the branch portion from the hot water supply circulation circuit of the hot water outlet is arranged downstream of the use side heat exchanger, and the branch portion is arranged downstream of the use side heat exchanger. Thus, when the hot water supply circuit and the hot water supply circulation circuit are used at the same time, a larger flow rate can be supplied by the hot water supply circulation circuit than in the third aspect of the invention, so that a larger amount of heat is supplied by the use side heat exchanger. be able to.

  According to a fifth aspect of the present invention, there is provided a hot water supply circuit closing means including a bypass passage provided in communication between the water supply passage and the hot water supply passage so as to bypass the hot water supply heat exchanger and the latent heat recovery heat exchanger in the water supply passage. It is characterized in that it is arranged downstream from the bifurcation part.When water leakage is detected due to pipe breakage in the hot water supply circulation circuit, the control means closes the hot water supply circuit close means and makes the hot water supply circulation circuit independent. In addition, the circulation pump can be driven to detect water leakage in an independent fully closed hot water supply circulation circuit.

  The sixth invention is characterized in that, as a hot water supply circulation circuit closing means, a bypass control valve having a complete closing function also serves as the function. The bypass control valve is usually disposed in a bypass passage provided by connecting the water supply passage and the hot water supply passage so as to bypass the hot water supply heat exchanger and the latent heat recovery heat exchanger, and water flowing through the bypass passage is provided. This is for controlling the flow rate. Here, the bypass control valve is not the bypass passage, but a branch portion between the water supply passage and the hot water discharge passage provided so as to bypass the hot water supply heat exchanger and the latent heat recovery heat exchanger. By arrange | positioning in the downstream, the flow volume of the water which flows through the said bypass channel can be controlled indirectly. That is, to increase the flow rate of water flowing to the bypass passage, the flow rate of water flowing to the latent heat recovery heat exchanger and the hot water supply heat exchanger is decreased by decreasing the opening degree of the bypass control valve provided on the water supply channel side. In addition, the flow rate of water flowing through the bypass passage can be increased. Conversely, if you want to reduce the flow rate of water flowing to the bypass passage, the flow rate of water flowing to the latent heat recovery heat exchanger and hot water heat exchanger is increased by increasing the opening of the bypass control valve provided on the water supply channel side. The flow rate of water flowing through the bypass passage can be increased. Further, since the bypass control valve is provided with a complete closing function, when detecting water leakage due to pipe breakage in the hot water supply circulation circuit, the control means closes the bypass control valve provided in the water supply passage and closes the hot water supply circulation circuit. It is possible to detect water leakage in the hot water supply circulation circuit of an independent fully closed circuit by driving the circulation pump after making it an independent fully closed circuit. Rather than providing a new on-off valve as the hot water supply circuit closing means, the existing bypass control valve is moved to the water supply channel side to serve as a hot water supply circuit closing means, thereby reducing costs. Can be achieved.

  According to a seventh aspect of the present invention, the hot water supply circuit closing means includes: a bypass passage provided in communication between the hot water supply passage and the hot water supply passage so as to bypass the hot water supply heat exchanger and the latent heat recovery heat exchanger. It is characterized by the fact that it is placed at the branching section. When water leakage is detected due to pipe breakage in the hot water supply circulation circuit, the control means should be closed with the hot water supply circulation circuit closing means and the hot water supply circulation circuit independent. The circulation pump can be driven to detect water leakage in an independent fully closed hot water supply circulation circuit.

  According to an eighth aspect of the present invention, in the water supply passage, hot water supply circulation is arranged at a branch portion between the water supply passage and the outlet passage that is provided so as to bypass the hot water supply heat exchanger and the latent heat recovery heat exchanger. The function of the circuit closing means is also provided by disposing a bypass control valve having a complete closing function in the branch portion. By disposing a bypass control valve at the branching section, a function of controlling a distribution ratio between the flow rate of water flowing to the latent heat recovery heat exchanger and the hot water supply heat exchanger and the flow rate of water flowing to the bypass passage, and latent heat recovery And a function of completely closing the water supply channel on the side flowing to the heat exchanger for hot water and the heat exchanger for hot water supply.

According to a ninth aspect of the present invention, the circulating pump disposed in the hot water supply circulation circuit is in particular a DC drive system, and the control means detects the presence or absence of water leakage due to the breakage of the hot water supply circulation circuit by the magnitude of the driving load of the circulation pump. It is characterized by that. For example, when detecting the presence or absence of water leakage due to breakage of the hot water supply circulation circuit, the control means closes the hot water supply circulation circuit closing means to form a complete closed circuit, and drives the DC-driven circulation pump at a predetermined rotational speed. At this time, if water leaks from the hot water supply circulation circuit, water will eventually flow out of the hot water supply circulation circuit that has become a closed circuit, and the water in the hot water supply circulation circuit will decrease. In this case, since the circulation flow rate conveyed by the circulation pump becomes small, the driving load when driving at the same rotation speed becomes small. The control means can detect this state and detect the presence or absence of water leakage due to breakage of the hot water supply circulation circuit.

  In a tenth aspect of the present invention, the controller has a function of detecting the presence or absence of water leakage due to breakage of the hot water supply circuit by closing the hot water supply circuit closing means and driving the circulation pump at an appropriate timing according to the operating state of the apparatus. It is a thing. For example, when a hot water supply operation for supplying hot water requested by a user to a hot water tap is performed, hot water cannot be supplied to the hot water tap if the hot water circulation circuit closing means is closed. Therefore, it is possible to give priority to the user's usability by detecting the presence or absence of water leakage due to breakage of the hot water supply circulation circuit at an appropriate timing according to the apparatus operating state.

  In the eleventh aspect of the invention, when there is water leakage from the hot water supply circulation circuit, the control means notifies the external notification means such as a remote control remote controller to that effect, and performs an operation to stop the operation of the apparatus. The user can be informed of the state of water leakage, and the expansion damage due to water leakage can be suppressed.

  In a twelfth aspect of the present invention, a circulation flow rate detection means for detecting a circulation flow rate of the hot water supply circulation circuit is provided upstream of a branch portion with the hot water supply path in the hot water supply circulation circuit, so that the user opens the hot water tap. In this case, the water flow can be detected by the circulating flow rate detecting means.

  In a thirteenth aspect of the invention, the control means starts combustion of the burner when the flow rate detected by the circulation flow rate detection means arranged in the hot water supply circulation circuit exceeds a predetermined value. Since burning of the burner can be started after water has been reliably passed into the water pipe, dangerous conditions such as the occurrence of airing can be avoided.

(Embodiment 1)
FIG. 1 shows a structural diagram of a hot water supply apparatus according to the first, second, fourth, fifth, ninth, tenth, eleventh, twelfth and thirteenth embodiments of the present invention.

  In FIG. 1, the water supplied from the water supply channel A <b> 1 </ b> A is branched into the water supply channel B <b> 1 </ b> B and the bypass channel 4 at the water supply channel branching section 18. The water supplied from the water supply channel B1B is heated by the combustion of the burner 26, and the heat exchange thermistor 15 is raised to a predetermined temperature and then supplied to the hot water supply channel 3. On the other hand, the water supplied from the water supply channel A1A is supplied to the hot water supply channel 3 through the bypass channel 4 having the bypass control valve 9 for adjusting the flow rate. The hot water flowing through the hot water supply passage 3 and the water flowing through the bypass passage are mixed so that the hot water temperature detected by the hot water discharge thermistor 17 becomes a desired temperature, and a hot water supply circuit discharged from the hot water tap 13 is provided. It is composed.

When the hot-water tap 13 is opened and the incoming flow rate sensor 5 detects an incoming flow rate of a predetermined amount (for example, 2.8 L / min) or more, the burner 26 has a gas source solenoid valve 22, a gas proportional valve 23, and a gas switching valve 24. The fuel gas is supplied from the gas supply path 21 in which is disposed, the combustion air is supplied by the combustion fan 25, and the combustion operation is performed according to a predetermined sequence. Here, as the incoming water flow rate sensor 5, for example, a configuration of a flow rate sensor that measures an actual flow rate with an output pulse corresponding to the rotation of an impeller provided in the flow path according to the flow rate of water can be considered. . The combustion gas generated by the combustion of the burner 26 passes through the combustion chamber 30, passes through the exhaust passage 31, and is discharged from the exhaust port 32 to the outside of the apparatus. A hot water supply heat exchanger 33 that recovers sensible heat of the combustion gas and a latent heat recovery heat exchanger 34 that recovers the latent heat of the combustion exhaust gas are disposed in the exhaust path of the combustion gas. Specifically, a hot water supply heat exchanger 33 is provided in the combustion chamber 30 on the downstream side of the burner 26, a latent heat recovery heat exchanger 34 is provided in the exhaust passage 31 on the downstream side, and the heat supply passage B1B is supplied. Water is first supplied to the latent heat recovery heat exchanger 34 to recover the latent heat in the combustion exhaust gas, and then supplied to the hot water supply heat exchanger 33 and heated to a predetermined high temperature water by the combustion of the burner 26, and the hot water outlet. 3
To supply. In this way, in addition to the sensible heat recovery by the conventional hot water supply heat exchanger 33, by providing the latent heat recovery heat exchanger 34 for recovering the latent heat of the combustion exhaust gas, energy saving is achieved by improving the overall thermal efficiency. It is.

  Next, in FIG. 1, high-temperature water heated by the latent heat recovery heat exchanger 34 and the hot water supply heat exchanger 33 is supplied to the use side heat exchanger via the circulation pump 7, and then the latent heat recovery heat exchange is performed. Returning to the upstream side water supply channel B1B of the heat exchanger 34, the hot water supply circulation circuit 2 from the latent heat recovery heat exchanger 34 through the hot water supply heat exchanger 33 to the use side heat exchanger via the circulation pump 7 is configured. The water supply path B1B is provided with a water supply path B on-off valve 19 that opens and closes the flow path. When the water supply passage B on-off valve 19 is closed, the hot water supply circulation circuit 2 can be separated from the water supply passage B1B to be a completely independent closed circuit. The hot water supply circulation circuit 2 can supply heat to the secondary load of the use side heat exchanger by supplying high temperature water as a primary side circuit of the use side heat exchanger. Here, as the use-side heat exchanger, a heating heat exchanger 52 having a heating circuit 41 for supplying warm water to a heating terminal that performs heating, bathroom drying, or the like as a secondary side, and the bathtub water of the bathtub 77 are heated. In this example, two bath heat exchangers 80 having the bath circuit 61 to be used as the secondary side are provided. The hot water circulation circuit 2 is branched in parallel and supplied as primary circuits of the heat exchanger 52 for heating and the heat exchanger 80 for bath, whereby the high-temperature water temperature supplied to each use-side heat exchanger Can be substantially the same. Here, a case where a bath opening / closing valve 78 for opening / closing a flow path is provided in the primary side circuit of the bath heat exchanger 80 is shown. By providing the bath opening / closing valve 78, the heating heat exchanger 52 is opened by opening the bath opening / closing valve 78 only when high temperature water is desired to be supplied to the primary circuit of the bath heat exchanger 80. It is possible to supply a large amount of high-temperature water to the primary side circuit, thereby increasing the heating output.

  In the hot water supply circulation circuit 2, the hot water supply passage 3 is branched from the downstream side of the use side heat exchanger of the heating heat exchanger 52 and the bath heat exchanger 80. In this way, by arranging the branch portion downstream of the use side heat exchanger, when the hot water supply circuit and the hot water supply circulation circuit 2 are used simultaneously, a large amount of high temperature water is supplied to the hot water supply circulation circuit 2. Therefore, a large amount of heat can be supplied to the secondary side circuit of the use side heat exchanger.

  The heating circuit 41 connects a load of a heating terminal such as a bathroom dryer to the secondary side of the heating heat exchanger 52 to form a closed circuit, and circulates the secondary side hot water by the heating circulation pump 50. Thus, in the heating heat exchanger 52, the amount of heat is supplied from the high-temperature water flowing through the hot water supply circulation circuit 2 which is the primary side.

  The bath circuit 81 is connected to the secondary side of the bath heat exchanger 80 to form a closed circuit, and the bath water is circulated by the bath circulation pump 75 so that 1 in the bath heat exchanger 80. The amount of heat is supplied from the high-temperature water flowing through the hot water supply circulation circuit 2 on the next side, and the bath is replenished. In addition, as a pouring flow path 64 for filling the bathtub 77 with a predetermined amount of hot water, a path communicating from the hot water discharge path 3 on the downstream side of the bypass path 4 to the bath circuit 61 is formed.

The neutralization circuit has a function of neutralizing the acid condensed water generated in the latent heat recovery heat exchanger 34 and discharging it to the outside of the apparatus. When the water supplied from the water supply channel B1B is heat-exchanged by the combustion exhaust gas in the latent heat recovery heat exchanger 34, the combustion exhaust gas is cooled by water, and condensed water is generated. In this condensed water, components such as CO ₂ and NOx in the combustion exhaust gas are dissolved, and usually exhibits acidity of ph2 to 3. The generated acidic dew condensation water is collected by the tray 101, passes through the acid dew condensation water channel 102, is guided to the neutralization tank 104 having a neutralizing agent 103 such as calcium carbonate inside, and neutralized, and then from the drain water channel 105. It is discharged out of the device.

  About the hot water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, during the hot water supply operation, when the hot water tap 13 is opened, the incoming water flow rate sensor 5 disposed in the water supply channel A1A detects water flow, and the combustion fan 25 is operated by this water flow signal and simultaneously the gas source solenoid valve 22 and the gas. The proportional valve 23 is opened, fuel gas and combustion air are supplied to the burner 26, ignited by spark discharge of the ignition plug 28 by the igniter 27, and combustion is started by the ignition recognition operation by the frame rod 29. The amount of combustion in the burner 26 according to the combustion load is adjusted by opening and closing the gas switching valve 24. In the process of exhausting the combustion gas, the water supplied from the water supply passage B1B is heated by the hot water supply heat exchanger 33 provided in the combustion chamber 30 and the latent heat recovery heat exchanger 34 provided in the exhaust passage 31. The

  The hot water heated by the hot water supply heat exchanger 33 passes through the water supply passage A1A and the hot water supply passage 3 so as to bypass the hot water supply heat exchanger 33 and the latent heat recovery heat exchanger 34. The bypass control valve 9 provided is mixed with water on the incoming side. The opening of the bypass control valve 9 is adjusted by a signal from the hot water thermistor 17 so that the mixed hot water has a hot water supply set temperature set by a remote controller for remote operation such as a bathroom remote controller 92 or a kitchen remote controller 93, and the hot water tap 13 More hot water is supplied.

  Thus, when selecting hot water supply independent operation, a desired temperature can be set with the remote controller for remote operation, and the hot water supply hot water set automatically can be secured by opening the hot water tap 13. .

  Next, at the time of heating operation, a heating circulation pump 50 provided in the heating circuit 41 is driven by an operation command from a controller (not shown) built in a heating terminal such as a bathroom dryer or a heating remote controller 94. A circulation pump 7 that circulates hot water in the hot water supply circulation circuit 2 is driven in conjunction with the operation command, and the circulation flow rate detected by the circulation flow rate detection means 6 provided in the hot water supply circulation circuit 2 is a predetermined amount (for example, 2. 8 L / min) or more, combustion starts by the ignition operation of the burner 26. Here, as the circulating flow rate detecting means 6, a configuration of a flow rate sensor having the same configuration as the incoming water flow rate sensor 5 can be considered. The high-temperature water heated by the hot water supply heat exchanger 33 is supplied to the primary side of the heating heat exchanger 52 by the circulation pump 7 and is heat-exchanged by the water-water heat exchange configuration and transmitted to the secondary side heating circuit 41. Be heated.

  The heating circuit 41 of FIG. 1 shows a two-temperature type configuration that can supply hot water having two different temperatures to the heating terminal. The hot water of the heating circuit 41 heated by the heating heat exchanger 52 is supplied as it is through the heating forward flow path 42 when used in a high-temperature terminal such as a bathroom dryer. When used in a low-temperature terminal such as a floor heating hot water mat, the return hot water from each heating terminal stored in the heating tank 53 through the heating return passage 44 is a low-temperature bypass having a check valve 49. It is mixed with the high temperature water flowing through the flow path 45 and supplied through the low temperature heating forward flow path 43.

  The heating tank 53 is provided with a water reducing electrode 54 that detects the amount of retained water in the heating circuit 41 that has decreased due to evaporation or the like, and a full water electrode 55 that detects the amount of retained water, and branches from the water supply channel A1A to supply water. A make-up water channel 47 having 48 is connected. When the water-reducing electrode 54 is turned off and the amount of water held in the heating tank 53 is less than the water-reducing electrode 54, the make-up water electromagnetic valve 48 is opened, and water from the make-up water channel 47 enters the heating tank 53 until the full-water electrode 55 is turned on. It is a mechanism to be supplied.

  The high-temperature water heat-exchanged by the heating heat exchanger 52 is returned to the upstream water supply channel B1B of the latent heat recovery heat exchanger 34 to form the hot water supply circulation circuit 2, and a heating operation command is issued from the heating terminal. During this time, the hot water circulation is continued while maintaining the predetermined temperature.

  At the time of bath rebirth operation, when a bath rebirth operation instruction is given by a remote controller for remote operation such as the bathroom remote controller 92, the bath circulation pump 75 provided in the bath circuit 61 is driven, and the water flow detector 74 circulates the bath water. Is detected, the circulation pump 7 for circulating the hot water supply circulation circuit 2 is driven by the detection signal, the bath opening / closing valve 78 is opened, and the circulation flow rate detected by the circulation flow rate detection means 6 is a predetermined amount (for example, 2. 8 L / min) or more, combustion starts by the ignition operation of the burner 26. Here, as the water flow detection unit 74, for example, a butterfly unit provided in a flow path and attached with a magnet is pushed up at a water flow rate of a predetermined (for example, 2.8 L / min) or more to be electrically connected, thereby generating a water flow. A configuration of a flow rate switch to be detected is conceivable.

  The high-temperature water heated by the hot water supply heat exchanger 33 is supplied by the circulation pump 7 to the primary side of the bath heat exchanger 80 in which the bath open / close valve 78 is opened, and heat exchange is performed by the water-water heat exchange configuration. Then, heat is transferred to the bath circuit 61 on the secondary side. The heat of the bath circuit 61 received by the bath heat exchanger 80 raises the bath water temperature of the bathtub 77 to ensure a predetermined reheating water temperature. And the high temperature water heat-exchanged with the heat exchanger 80 for baths returns to the upstream water supply path B1B of the heat exchanger 34 for latent heat recovery, forms the hot water supply circulation circuit 2, and was set with the remote controller for remote operation Circulation is continued while maintaining a predetermined hot water temperature until a predetermined reheating temperature is detected by the bath return thermistor 79.

  The circulating flow rate detection means 6 provided in the hot water supply circulation circuit 2 drives the circulation pump 7 in addition to the function of the flow rate detection means for igniting the burner 26 during the heating operation and the bath reheating operation as described above. If the configuration of the load-variable DC pump is adopted, the driving load of the circulation pump 7 depends on the secondary side load of each use-side heat exchanger during heating operation, bath reheating operation, or simultaneous operation thereof. It is possible to provide a function of supplying an optimal high-temperature water flow rate by changing.

  As described above, in the present embodiment, the hot water supply circuit and the hot water supply circulation circuit that is the primary circuit of the use side heat exchanger are configured by one heating path, thereby simplifying the main body configuration including the piping configuration. It is possible to reduce the size and weight of the device. When a plurality of use side heat exchangers are provided, the temperature of hot water supplied from the hot water supply heat exchanger can be made substantially the same by connecting each use side heat exchanger in parallel to the hot water supply circulation circuit. . Further, by improving the efficiency by recovering latent heat, it is possible to simultaneously ensure the hot water supply performance and the heating performance of the use side heat exchanger.

  Next, a method of detecting the presence or absence of water leakage due to breakage of the hot water supply circulation circuit 2 by driving the circulation pump 7 by separating the hot water supply circulation circuit 2 from the water supply path B1B and making it an independent closed circuit will be described.

  In FIG. 1, a hot water supply heat exchanger 33 and a latent heat recovery heat exchanger 34 are connected in series and branched from the hot water supply circulation circuit 2 and the hot water supply circulation circuit 2 reaching the user side heat exchanger via the circulation pump 7. In the configuration of the hot water supply apparatus having a hot water supply circuit extending to the hot water supply path 3, if water leakage occurs due to piping breakage of the hot water supply circulation circuit 2, water is wasted without the user knowing, There is a danger of sewage mixing.

  When a pipe breakage occurs in the water pipe portion of the latent heat recovery heat exchanger 34, water leakage occurs due to the water supply pressure. This water leakage is collected by the tray 101 and discharged outside the apparatus through the acidic dew condensation water channel 102, the neutralization tank 104, and the drain water channel 105. That is, when water leaks due to damage to the water pipe portion of the latent heat recovery heat exchanger 34, water is wasted without the user's knowledge.

In addition, when a pipe breakage occurs in the water pipe portion of the use side heat exchanger, there is a risk that water and sewage are mixed in addition to wasting water without the user's knowledge as described above. . In FIG. 1, the heating heat exchanger 52 and the bath heat exchanger 80 are considered as the use side heat exchangers. However, in the heating heat exchanger 52, hot water is supplied as a primary circuit. The circulation circuit 2 and the heating circuit 41 through which the circulating water for heating as sewage flows are in contact as the secondary circuit, and the hot water supply circulation circuits 2 and 2 through which the clean water flows as the primary circuit in the bath heat exchanger 80. A bath circuit 61 through which bathtub water, which is dirty water, flows is in contact with the secondary circuit. Here, when a pipe breakage of the hot water supply circulation circuit 2 of each use side heat exchanger occurs, water leakage occurs from the primary side circuit to the secondary side circuit due to the feed water pressure, and water is wasted without the user's knowledge. If the water supply pressure of the primary side circuit is reduced due to water outage or the like, the sewage of the secondary side circuit is above the primary side circuit due to the balance of the water pressure of the primary side circuit and the secondary side circuit. There is a risk that water will flow to the water side and water and sewage will be mixed.

  From the above, in this hot water supply apparatus, a function for detecting the presence or absence of water leakage due to pipe breakage of the hot water supply circulation circuit 2 which is the primary side circuit is required. Hereinafter, in this hot water supply apparatus, a specific method for detecting the presence or absence of water leakage due to pipe breakage of the hot water supply circulation circuit 2 will be described.

First, the control means 91 learns the circulation flow rate of the hot water supply circulation circuit 2 during a trial operation performed by a contractor or the like after installing the hot water supply device. The circulation flow rate learning of the hot water supply circulation circuit 2 is performed in two types, when the bath opening / closing valve 78 is opened and when it is closed. The reason why the bath opening / closing valve 78 is opened is based on the case where the bath opening / closing valve 78 is opened during the bath chasing operation. These two types of circulating flow learning values are, for example, q ₁ (0) and q ₂ (0) as described below.

q ₁ (0): Circulating flow rate learning value when the on-off valve 78 is opened (for example, 10 L / min)
q ₂ (0): Circulating flow rate learning value when bath opening / closing valve 78 is closed (for example, 7 L / min)
Next, a method for detecting the presence or absence of water leakage due to piping breakage in the hot water supply circulation circuit 2 will be described. It is necessary to detect the presence or absence of water leakage at an appropriate timing according to the operating state of the apparatus. That is, the presence / absence of water leakage is detected when the apparatus is not operating. Specifically, it is performed when the operation switches of remote controllers for remote operation such as the bathroom remote controller 92, the kitchen remote controller 93, and the heating remote controller 94 are OFF. In addition, when the operation switch of these remote control remote controllers is turned on during the leakage detection, the leakage detection operation is immediately interrupted. Similarly, when the user opens the hot water tap 13 with the operation switch of the remote controller for remote operation turned off, the water in the hot water circulation circuit 2 comes out from the hot water tap 13 through the hot water supply passage 3, so there is water leakage. The detection operation shall be interrupted. Note that the act of the user opening the hot water tap 13 at this time can be detected by the incoming water flow rate sensor 5. In addition, the controller 91 detects the presence or absence of water leakage at a maximum predetermined number of times (for example, once) within a predetermined period (for example, 10 days). If the leak detection operation is interrupted, the leak detection operation is invalid.

When performing the water leakage presence / absence detection operation of the hot water supply circulation circuit 2 at an appropriate timing according to the apparatus operating state as described above, the control unit 91 first closes the water supply channel B on / off valve 19 provided in the water supply channel B1B. . Here, as the water supply channel B on-off valve 19, a configuration of a direct-acting on-off valve that opens and closes the valve instantaneously with a load voltage can be considered. When the water supply path B on-off valve 19 is closed, the hot water supply circulation circuit 2 is disconnected from the water supply path B1B to which water is supplied, and becomes an independent closed circuit. In this state, the control means 91 drives the circulation pump 7, measures the circulation flow rate detected by the circulation flow rate detection means 6 provided in the hot water supply circulation circuit 2 at that time, and is the circulation flow rate q learned during the trial operation. _By comparing with ₁ (0) and q ₂ (0), the presence or absence of water leakage due to water pipe breakage on the hot water supply circuit 2 side of the latent heat recovery heat exchanger 34 and each use side heat exchanger is detected.

First, the method for detecting the presence or absence of water leakage due to breakage of the water pipe portion of the heat exchanger 34 for recovering latent heat will be described with the bath open / close valve 78 closed. When the water pipe of the latent heat recovery heat exchanger 34 is broken, the outside of the water pipe is open to the atmosphere. Therefore, when the circulation pump 7 is driven in this state, the hot water supply circulation circuit 2 is eventually driven by the discharge pressure of the circulation pump 7. All the water inside is drained out of the water pipe. By detecting this state with the circulating flow rate detection means 6, it is possible to detect the presence or absence of water leakage. That is, the circulating flow rate q ₂ detected by the circulating flow rate detecting unit 6 is within a predetermined maximum water leakage presence / absence detecting operation duration (for example, 30 minutes) after the control unit 91 starts the leakage detecting operation. A predetermined ratio α ₁ (for example, α ₁ = 0.6 with respect to the learning value q ₂ (0) (for example, 7 L / min) reaches q ₂ = 4.2 L / min at this time, and the circulation thereafter. When the flow rate q ₂ continues to decrease and reaches a predetermined rate α ₂ (for example, α ₂ = 0.3, at this time q ₂ = 2.1 L / min), the control means 91 performs the latent heat recovery heat exchanger. It is possible to detect the occurrence of water leakage due to pipe breakage at 34 water pipe portions.

Next, a method for detecting the presence or absence of water leakage due to breakage of the water pipe portion of the heat exchanger 52 for heating will be described with the bath opening / closing valve 78 closed. When a water pipe breakage of the heat exchanger 52 for heating occurs, the heating circuit 41 as a secondary side circuit is opened to the atmosphere in the heating tank 53. Therefore, when the circulation pump 7 is driven, The water in the hot water supply circulation circuit 2 is discharged to the heating side circuit until the internal pressure and the head difference of the heating circulation water in the heating tank 53 are balanced. At this time, the head difference with respect to the hot water supply circuit 2 of the heating tank 53 arranged in the apparatus is designed to be less than about 0.5 m at most. The circulation flow rate detected by the circulation flow rate detection means 6 when the circulation pump 7 is driven and the internal pressure of the hot water supply circulation circuit 2 and the head difference of the heating circulation water in the heating tank 53 are balanced is q ₂ (2k−1). To do. Here, k is a natural number. Next, in the state where the circulation pump 7 is driven, the heating circulation pump 50 is simultaneously driven for a predetermined time (for example, 5 minutes). Since the discharge pressure of the heating circulation pump 50 is normally about 0.1 MPa (corresponding to about 10 m as a head difference), water moves from the heating side circuit to the hot water supply circulation circuit 2 side this time. At this time, the circulating flow rate detected by the circulating flow rate detection means 6 is defined as q ₂ (2k). Here, k is a natural number.

Here, the circulation flow rate learning value q ₂ (0), the circulation flow rate q ₂ (2k−1) when only the circulation pump 7 is driven, and the heating circulation pump 50 are simultaneously driven after driving only the circulation pump 7. The circulation flow rate q ₂ (2k) is compared.

First, when there is no damage to the water pipe of the heat exchanger 52 for heating, these three values are the same value. That is,
q ₂ (0) ≈q ₂ (2k−1) ≈q ₂ (2k) (Condition 1)
Here, it is assumed that the errors of q ₂ (2k−1) and q ₂ (2k) with respect to q ₂ (0) are less than a predetermined value (for example, ± 5%).

  Next, when water leakage occurs due to a water pipe breakage of the heat exchanger 52 for heating, the following condition is satisfied.

q ₂ (2k−1) <β ₁ q ₂ (0) and q ₂ (2k−1) <β ₂ q ₂ (2k) (Condition 2)
However, in (Condition 2), β ₁ and β ₂ are set to certain predetermined values (for example, β ₁ = 0.7 and β ₂ = 0.9).

As the water leakage presence / absence detection operation performed by the control means 91, only the circulation pump 7 is driven to measure q ₂ (2k−1), and after only the circulation pump 7 is driven, the heating circulation pump 50 is simultaneously driven to q _2. The measurement of (2k) is continuously performed a predetermined number of times (for example, corresponding to the case of k = 1, 2, 3). If (Condition 1) is satisfied, it is determined that there is no water leakage, and (Condition 2) If it satisfies, it can be determined that there is water leakage.

Finally, a method for detecting the presence or absence of water leakage due to breakage of the water pipe portion of the bath heat exchanger 80 will be described with the bath opening / closing valve 78 open. First, the control means 91 drives the bath circulation pump 75 and determines whether the water flow detector 74 is on or off, thereby confirming the presence or absence of bathtub water in the bathtub 77. When the water flow detection unit 74 is ON, there is bathtub water in the bathtub 77. In this case, when the water leakage presence / absence detection operation is performed, the determination is made based on the bath piping installation conditions of the bath forward flow path 62 and the bath return flow path 63. Therefore, the water leakage presence / absence detection operation is performed only when there is no bathtub water in the bathtub 77 in which the water flow detection unit 74 is OFF. When the water pipe of the bath heat exchanger 80 is broken, the bathtub is open to the atmosphere. Therefore, when the circulation pump 7 is driven in this state, the water in the hot water supply circuit 2 is eventually discharged by the discharge pressure of the circulation pump 7. Will be discharged into the bathtub. By detecting this state with the circulating flow rate detection means 6, it is possible to detect the presence or absence of water leakage. That is, the circulating flow rate q ₁ detected by the circulating flow rate detecting unit 6 is within the predetermined maximum water leakage presence / absence detecting operation continuation time (for example, 30 minutes) after the control unit 91 starts the water leakage presence / absence detecting operation. A predetermined ratio γ ₁ (for example, γ ₁ = 0.6 with respect to the learning value q ₁ (0) (for example, 10 L / min) reaches q ₁ = 6.0 L / min), and the circulation flow rate q thereafter. ₁ continues to decrease and reaches a predetermined rate γ ₂ (for example, assuming that γ ₂ = 0.3, q ₁ = 3.0 L / min), the control means 91 controls the water pipe portion of the latent heat recovery heat exchanger 34. It is possible to detect that water leakage has occurred due to pipe breakage.

  Now, a method for detecting the presence / absence of water leakage when the DC pump system is used as the circulation pump 7 will be described. In the case of the DC-driven circulation pump 7, the control means 91 can detect a load (work amount) when the circulation pump 7 is driven at a predetermined rotational speed (for example, 3000 rpm). If water leakage occurs in the hot water supply circulation circuit 2 and the water in the hot water supply circulation circuit 2 decreases, the load for driving at a predetermined number of revolutions decreases. Detection can be performed.

First, the control means 91 closes the water supply path B on-off valve 19 provided in the water supply path B1B and makes the circulation pump 7 that is a DC drive system at a predetermined rotational speed during a test operation performed by a contractor after the hot water supply apparatus is installed. A load (work amount) when driven at (for example, 3000 rpm) is detected and learned. This load learning is performed in two types: when the bath opening / closing valve 78 is opened and when it is closed. The reason why the bath opening / closing valve 78 is opened is based on the case where the bath opening / closing valve 78 is opened during the bath chasing operation. These two types of load learning values are set to w ₁ (0) and w ₂ (0) as follows, for example.

w ₁ (0): Load learning value when bath opening / closing valve 78 is opened w ₂ (0): Load learning value when bath opening / closing valve 78 is closed Next, water leakage due to piping breakage of hot water supply circulation circuit 2 A method of presence / absence detection will be described. It is necessary to detect the presence or absence of water leakage at an appropriate timing according to the operating state of the apparatus. That is, the presence / absence of water leakage is detected when the apparatus is not operating. Specifically, it is performed when the operation switches of remote controllers for remote operation such as the bathroom remote controller 92, the kitchen remote controller 93, and the heating remote controller 94 are OFF. In addition, when the operation switch of these remote control remote controllers is turned on during the leakage detection, the leakage detection operation is immediately interrupted. Similarly, when the user opens the hot water tap 13 with the operation switch of the remote controller for remote operation turned off, the water in the hot water circulation circuit 2 comes out from the hot water tap 13 through the hot water supply passage 3, so there is water leakage. The detection operation shall be interrupted. Note that the act of the user opening the hot water tap 13 at this time can be detected by the incoming water flow rate sensor 5. In addition, the controller 91 detects the presence or absence of water leakage at a maximum predetermined number of times (for example, once) within a predetermined period (for example, 10 days). If the leak detection operation is interrupted, the leak detection operation is invalid.

When performing the water leakage presence / absence detection operation of the hot water supply circulation circuit 2 at an appropriate timing according to the apparatus operating state as described above, the control unit 91 first closes the water supply channel B on / off valve 19 provided in the water supply channel B1B. . Here, as the water supply channel B on-off valve 19, a configuration of a direct-acting on-off valve that opens and closes the valve instantaneously with a load voltage can be considered. When the water supply path B on-off valve 19 is closed, the hot water supply circulation circuit 2 is disconnected from the water supply path B to which water is supplied, and becomes an independent closed circuit. In this state, the control means 91 drives the circulation pump 7 which is a DC drive system at a predetermined rotation speed (eg, 3000 rpm), measures the load of the circulation pump 7 at that time, and learns w ₁ ( 0) and w ₂ (0), the presence or absence of water leakage due to water pipe breakage on the hot water supply circuit 2 side of each latent heat recovery heat exchanger 34 and each use side heat exchanger is detected.

First, the method for detecting the presence or absence of water leakage due to breakage of the water pipe portion of the heat exchanger 34 for recovering latent heat will be described with the bath open / close valve 78 closed. When the water pipe of the latent heat recovery heat exchanger 34 is broken, the outside of the water pipe is open to the atmosphere. Therefore, when the circulation pump 7 is driven in this state, the hot water supply circulation circuit 2 is eventually driven by the discharge pressure of the circulation pump 7. All the water inside is drained out of the water pipe. By detecting the load of the circulation pump 7 in this state, it is possible to detect the presence or absence of water leakage. That is, the load w ₂ of the circulation pump 7 is set to the circulating flow rate learning value w ₂ (0) within a predetermined maximum water leakage presence / absence detection operation duration (for example, 30 minutes) after the control unit 91 starts the water leakage presence / absence detection operation. ) Reaches a predetermined ratio a ₁ (for example, a ₁ = 0.6), and thereafter the load w ₂ continues to decrease and reaches a predetermined ratio a ₂ (for example, a ₂ = 0.3). The control means 91 can detect that water leakage has occurred due to piping breakage in the water pipe portion of the heat exchanger 34 for recovering latent heat.

Next, a method for detecting the presence or absence of water leakage due to breakage of the water pipe portion of the heat exchanger 52 for heating will be described with the bath opening / closing valve 78 closed. When a water pipe breakage of the heat exchanger 52 for heating occurs, the heating circuit 41 as a secondary side circuit is opened to the atmosphere in the heating tank 53. Therefore, when the circulation pump 7 is driven, The water in the hot water supply circulation circuit 2 is discharged to the heating side circuit until the internal pressure and the head difference of the heating circulation water in the heating tank 53 are balanced. At this time, the head difference with respect to the hot water supply circuit 2 of the heating tank 53 arranged in the apparatus is designed to be less than about 0.5 m at most. The circulation pump 7 is driven, and the load of the circulation pump 7 when the internal pressure of the hot water supply circulation circuit 2 and the head difference of the heating circulating water in the heating tank 53 are balanced is defined as w ₂ (2k−1). Here, k is a natural number. Next, in the state where the circulation pump 7 is driven, the heating circulation pump 50 is simultaneously driven for a predetermined time (for example, 5 minutes). Since the discharge pressure of the heating circulation pump 50 is normally about 0.1 MPa (corresponding to about 10 m as a head difference), water moves from the heating side circuit to the hot water supply circulation circuit 2 side this time. The load of the circulation pump 7 at this time is w ₂ (2k). Here, k is a natural number.

Here, the load learning value w ₂ (0), the load w ₂ (2k−1) when only the circulation pump 7 is driven, and the heating circulation pump 50 are simultaneously driven after driving only the circulation pump 7. Compare the hourly load w ₂ (2k).

First, when there is no damage to the water pipe of the heat exchanger 52 for heating, these three values are the same value. That is,
w ₂ (0) ≈w ₂ (2k−1) ≈w ₂ (2k) (Condition 3)
Here, it is assumed that the error of w ₂ (2k−1) and w ₂ (2k) with respect to w ₂ (0) is less than a predetermined value (for example, ± 5%).

  Next, when water leakage occurs due to a water pipe breakage of the heat exchanger 52 for heating, the following condition is satisfied.

w ₂ (2k−1) <b ₁ w ₂ (0) and w ₂ (2k−1) <b ₂ w ₂ (2k) (Condition 4)
However, in (Condition 4), b ₁ and b ₂ are set to certain predetermined values (for example, b ₁ = 0.7 and b ₂ = 0.9).

As the water leakage presence / absence detection operation performed by the control means 91, only the circulation pump 7 is driven to measure w ₂ (2k−1), and only the circulation pump 7 is driven, and then the heating circulation pump 50 is simultaneously driven to w _2. The measurement of (2k) is continuously performed a predetermined number of times (for example, corresponding to the case of k = 1, 2, 3). If (Condition 3) is satisfied, it is determined that there is no water leakage, and (Condition 4) is If it satisfies, it can be determined that there is water leakage.

Finally, a method for detecting the presence or absence of water leakage due to breakage of the water pipe portion of the bath heat exchanger 80 will be described with the bath opening / closing valve 78 open. First, the control means 91 drives the bath circulation pump 75 and determines whether the water flow detector 74 is on or off, thereby confirming the presence or absence of bathtub water in the bathtub 77. When the water flow detection unit 74 is ON, there is bathtub water in the bathtub 77. In this case, when the water leakage presence / absence detection operation is performed, the determination is made based on the bath piping installation conditions of the bath forward flow path 62 and the bath return flow path 63. Therefore, the water leakage presence / absence detection operation is performed only when there is no bathtub water in the bathtub 77 in which the water flow detection unit 74 is OFF. When the water pipe of the bath heat exchanger 80 is broken, the bathtub is open to the atmosphere. Therefore, when the circulation pump 7 is driven in this state, the water in the hot water supply circuit 2 is eventually discharged by the discharge pressure of the circulation pump 7. Will be discharged into the bathtub. By detecting this state with the circulating flow rate detection means 6, it is possible to detect the presence or absence of water leakage. That is, the load w ₁ of the circulation pump 7 is set to the circulating flow rate learning value w ₁ (0) within a predetermined maximum water leakage presence / absence detection operation duration (for example, 30 minutes) after the control unit 91 starts the water leakage presence / absence detection operation. ) Reaches a predetermined ratio c ₁ (for example, c ₁ = 0.6), and thereafter the load w ₁ continues to decrease and reaches a predetermined ratio c ₂ (for example, c ₂ = 0.3). The control means 91 can detect that water leakage has occurred due to piping breakage in the water pipe portion of the heat exchanger 34 for recovering latent heat.

  As described above, each leakage in the latent heat recovery heat exchanger 34 parts, the heating heat exchanger 52 parts, and the bath heat exchanger 80 parts is a water leakage error in each heat exchanger part. An external notification means represented by a remote controller for remote operation such as a bathroom remote controller 92 or a kitchen remote controller 93 is notified to stop the operation of the apparatus.

  As described above, in the present embodiment, the control means 91 closes the water supply path B on / off valve 19 provided in the water supply path B1B and closes the hot water supply circulation circuit 2 at the appropriate timing according to the operating state of the apparatus. The water pipe portion of the hot water supply circulation circuit 2 is separated from the B1B to form a completely closed circuit, and the circulation pump 7 is driven to compare the circulation flow rate detected by the circulation flow rate detection means 6 with the circulation flow rate learning value at the time of trial operation. The presence or absence of water leakage can be detected. Alternatively, particularly when a DC drive type is adopted as the circulation pump 7, the water supply passage B on-off valve 19 provided in the water supply passage B1B is closed and the hot water supply circulation circuit 2 is separated from the water supply passage B1B to form a complete closed circuit. By comparing the load when the circulation pump 7 is rotated at a predetermined rotational speed with the load during the trial operation, it is possible to detect the presence or absence of water leakage in the water pipe portion of the hot water supply circulation circuit 2. In addition, when it is determined that there is water leakage in the water leakage presence / absence detection operation, the control unit 91 notifies the external notification unit of the fact and performs an operation to stop the operation of the apparatus, so that the user has a state of water leakage. To prevent the damage caused by water leakage.

Next, the hot water supply operation when the operation of the apparatus is resumed when the above-described leakage detection operation is canceled or when the leakage detection operation is terminated will be described. When the operation switch of the remote controller for remote control such as the bathroom remote controller 92, the kitchen remote controller 93, the heating remote controller 94, etc. is turned ON during the water leakage presence / absence detection operation, the control means 91 immediately stops the water leakage presence / absence detection operation. The B on-off valve 19 is opened. Further, even when the water leakage presence / absence detection operation is completed, the control means 91 immediately opens the water supply channel B on-off valve 19. As described above, when the water leakage presence / absence detection operation is canceled halfway or during the hot water supply operation when the water leakage presence / absence detection operation is completed, the control means 91 is in a state in which the user opens the hot water tap 13 and passes water through the apparatus. However, the ignition of the burner 26 is detected by the circulating flow rate detecting means 6 provided upstream of the hot water supply circuit 2 upstream of the branch point of the hot water supply circuit 2 with the hot water supply circuit 2. Is performed when the value becomes a predetermined value (for example, 1.0 L / min) or more. Thus, by igniting the burner 26 with the flow rate detection value in the circulating flow rate detection means 6, it can be confirmed that the water supply channel B on-off valve 19 is reliably open without failure.

  As described above, when the water leakage presence / absence detection operation is canceled in the middle, or when the water leakage presence / absence detection operation is completed, the circulating flow rate detection is performed during the ignition operation of the burner 26 in the hot water supply operation when the apparatus operation is resumed. By using the means 6, it is possible to confirm that the water supply path B on-off valve 19 is opened and water is reliably passed through the water pipe of the hot water supply heat exchanger 33. When the burner 26 is ignited in a closed state by, for example, it is possible to prevent air blow or the like.

(Embodiment 2)
FIG. 2 shows a structural diagram of a hot water supply apparatus according to the first, second, fourth, fifth, sixth, ninth, tenth, eleventh, twelfth and thirteenth embodiments of the present invention. It is.

  In FIG. 2, the difference from the structure of the hot water supply apparatus in FIG. 1 shown in the above (Embodiment 1) is that the bypass control valve 9 having a fully-closed function is not disposed in the bypass passage 4 but in the water supply channel B1B. The bypass control valve 9 serves as a function of adjusting the amount of water flowing through the water supply channel B1B and the amount of water flowing through the bypass passage 4 and the function of the hot water supply circuit closing means that makes the hot water supply circuit 2 completely closed. That's right. Since the existing bypass control valve 9 also functions as the hot water circulation circuit closing means, there is no need to provide another hot water circulation circuit closing means such as the water supply path B on-off valve 19 in FIG. If the configuration is adopted, the cost can be reduced.

  About the hot water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, during the hot water supply operation, when the hot water tap 13 is opened, the incoming water flow rate sensor 5 disposed in the water supply channel A1A detects water flow. Normally, the bypass control valve 9 provided in the water supply channel B1B maintains a certain predetermined opening (for example, an intermediate opening), and the water supplied from the water supply channel 1B is a latent heat recovery heat exchanger 34, hot water supply Water flow is detected by the circulating flow rate detection means 6 through the heat exchanger 33. Here, the circulating flow rate detecting means 6 has the same configuration as the incoming water flow rate sensor 5. When a water flow signal of a predetermined value (for example, 1 L / min) or more is detected from the circulating flow rate detection means 6, the combustion fan 25 operates and at the same time, the gas source solenoid valve 22 and the gas proportional valve 23 are opened and fuel is supplied to the burner 26. Gas and combustion air are supplied, ignition is performed by spark discharge of the spark plug 28 by the igniter 27, and combustion is started by an ignition recognition operation by the frame rod 29. In (Embodiment 1), the combustion operation is started by the water flow signal of the incoming water flow rate sensor 5, but in this embodiment, the combustion operation is started by the water flow signal of the circulating flow rate detection means 6. Since the bypass control valve 9 is provided in the water supply channel B <b> 1 </ b> B, when the bypass control valve 9 is in a fully closed state and fails, water is not supplied to the hot water supply heat exchanger 33. If the combustion operation is started in this state, airing occurs and it is dangerous, and the purpose is to prevent this. When the water flow detection in the circulating flow rate detection means 6 is not obtained within a predetermined time (for example, 1 second) from the water flow detection of the incoming water flow rate sensor 5, the control means 91 determines the failure of the bypass control valve 9 and performs the combustion operation. Do not do.

The amount of combustion in the burner 26 according to the combustion load is adjusted by opening and closing the gas switching valve 24. In the process of exhausting the combustion gas, the water supplied from the water supply passage B1B is heated by the hot water supply heat exchanger 33 provided in the combustion chamber 30 and the latent heat recovery heat exchanger 34 provided in the exhaust passage 31. The

  The hot water heated by the hot water supply heat exchanger 33 is mixed with the water on the incoming side passing through the bypass passage 4 that is indirectly adjusted by adjusting the opening of the bypass control valve 9 provided in the water supply passage B1B. The opening of the bypass control valve 9 is adjusted by a signal from the hot water thermistor 17 so that the mixed hot water has a hot water supply set temperature set by a remote controller for remote operation such as a bathroom remote controller 92 or a kitchen remote controller 93, and the hot water tap 13 More hot water is supplied.

  Thus, when selecting hot water supply independent operation, a desired temperature can be set with the remote controller for remote operation, and the hot water supply hot water set automatically can be secured by opening the hot water tap 13. .

  In addition, about the apparatus operation | movement at the time of each operation | movement at the time of heating operation and a bath chase operation, it is the same as that of the above (Embodiment 1), and abbreviate | omits. Further, the hot water supply operation, the heating operation, and the bath reheating operation can be performed simultaneously in each combination. In addition, the hot water supply circuit and the hot water supply circulation circuit, which is the primary circuit of the use side heat exchanger, are configured by a single heating path, so that the apparatus configuration can be reduced in size and weight by simplifying the main body configuration including the piping configuration. In addition, when a plurality of use side heat exchangers are provided, the temperature of hot water supplied from the hot water supply heat exchanger may be substantially the same by connecting each use side heat exchanger in parallel to the hot water supply circulation circuit. This is also the same as the above (Embodiment 1) in the effect that the hot water supply performance and the heating performance of the use side heat exchanger can be secured at the same time by improving the efficiency by recovering latent heat.

  Next, a method of detecting the presence or absence of water leakage due to breakage of the hot water supply circulation circuit 2 by driving the circulation pump 7 by separating the hot water supply circulation circuit 2 from the water supply path B1B and making it an independent closed circuit will be described.

  When performing the water leakage presence / absence detection operation of the hot water supply circulation circuit 2 at an appropriate timing according to the apparatus operating state as described in (Embodiment 1), the control means 91 is a bypass control valve 9 provided in the water supply channel B1B. Is closed. Then, as in the first embodiment, the control means 91 detects the presence or absence of water leakage due to breakage of the water pipe portion of the latent heat recovery heat exchanger 34, the presence or absence of water leakage due to breakage of the water pipe portion of the heating heat exchanger 52, the bath Detecting the presence or absence of water leakage by detecting the presence or absence of water leakage due to damage to the water pipe part of the heat exchanger 80. If it is detected that there is water leakage, it is represented by a remote controller for remote operation such as the bathroom remote control 92 or the kitchen remote control 93. To the external notification means to stop the operation of the apparatus.

  As described above, in the present embodiment, the control means 91 closes the bypass control valve 9 provided in the water supply path B1B and closes the hot water supply circulation circuit 2 from the water supply path B1B at an appropriate timing according to the apparatus operating state. It can be separated to form a complete closed circuit, and the circulation pump 7 can be driven to detect the presence or absence of water leakage in the water pipe portion of the hot water supply circulation circuit 2. In addition, when it is determined that there is water leakage in the water leakage presence / absence detection operation, the control unit 91 notifies the external notification unit of the fact and performs an operation to stop the operation of the apparatus, so that the user has a state of water leakage. To prevent the damage caused by water leakage.

  When the water leakage presence / absence detection operation is canceled halfway or when the water leakage presence / absence detection operation is completed, the hot water supply operation method in the present embodiment shown in FIG. In order to start combustion by detecting the flow of water in the circulating flow rate detecting means 6 even during a normal hot water supply operation, the idling of the burner 26 when the bypass control valve 9 provided in the water supply channel B1B is closed is ignited. Etc. can be prevented.

(Embodiment 3)
FIG. 3 shows a structural diagram of a hot water supply apparatus according to the first, second, third, seventh, eighth, ninth, tenth, eleventh, twelfth and thirteenth embodiments of the present invention. It is.

  In FIG. 3, the difference from the structure of the hot water supply apparatus in FIG. Disposed upstream of the water heater 52 and the heat exchanger 80 for bath, a function of adjusting the amount of water flowing through the water supply passage B1B and the amount of water flowing through the bypass passage 4, and a hot water supply circulation circuit having the hot water supply circulation circuit 2 as a completely closed circuit The bypass control valve 9 having the function of the closing means is disposed in the water supply branch 18.

  In FIG. 3, the bypass control valve 9 disposed in the water supply branch 18 can adjust the amount of water flowing through the water supply passage B <b> 1 </ b> B and the amount of water flowing through the bypass passage 4 by adjusting the drive angle of the valve body. Yes. 4A shows a state in which the valve body of the bypass control valve 9 completely closes the water supply channel B1B, and all the water supplied from the water supply channel A1A flows to the bypass channel 4. FIG. FIG. 4B shows a state in which the valve element of the bypass control valve 9 completely closes the bypass passage 4 and all the water supplied from the water supply channel A1A flows to the water supply channel B1B. The valve body position of the bypass control valve 9 can be changed between the state shown in FIG. 4A and the state shown in FIG. 4B by, for example, drive pulse control. By changing the valve element position of the bypass control valve 9 in this way, it is possible to distribute the water supplied from the water supply passage A1A to the water supply passage B1B side and the bypass passage 4 side. FIG. 4C shows the valve body position of the bypass control valve 9 in a normal operation standby state, and maintains a predetermined opening (for example, an intermediate opening). When the ratio of the amount of water flowing through the water supply channel B1B and the amount of water flowing through the bypass passage 4 is changed during the hot water supply operation, the control means 91 has a predetermined opening shown in FIG. The amount of water flowing through the water supply channel B1B and the bypass passage 4 is adjusted by finely adjusting the valve body position from the degree.

  About the hot water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, during the hot water supply operation, when the hot water tap 13 is opened, the incoming water flow rate sensor 5 disposed in the water supply channel A1A detects water flow. Normally, as shown in FIG. 4C, the bypass control valve 9 provided in the water supply branching section 18 maintains a predetermined opening (for example, an intermediate opening) and is supplied from the water supply 1B. The water passing through the latent heat recovery heat exchanger 34 and the hot water supply heat exchanger 33 is detected by the circulating flow rate detecting means 6. Here, the circulating flow rate detecting means 6 has the same configuration as the incoming water flow rate sensor 5. When a water flow signal of a predetermined value (for example, 1 L / min) or more is detected from the circulating flow rate detection means 6, the combustion fan 25 operates and at the same time, the gas source solenoid valve 22 and the gas proportional valve 23 are opened and fuel is supplied to the burner 26. Gas and combustion air are supplied, ignition is performed by spark discharge of the spark plug 28 by the igniter 27, and combustion is started by an ignition recognition operation by the frame rod 29. In (Embodiment 1), the combustion operation is started by the water flow signal of the incoming water flow rate sensor 5, but in this embodiment, the water flow rate of the circulating flow rate detection means 6 is the same as (Embodiment 2). The combustion operation is started by the signal. Since the bypass control valve 9 is provided in the water supply branch 18, when the valve body of the bypass control valve 9 has failed in a position where the water supply path B 1 B is fully closed, the bypass is not passed through the hot water supply heat exchanger 33. There is no water. If the combustion operation is started in this state, airing occurs and it is dangerous, and the purpose is to prevent this. When the water flow detection in the circulating flow rate detection means 6 is not obtained within a predetermined time (for example, 1 second) from the water flow detection of the incoming water flow rate sensor 5, the control means 91 determines the failure of the bypass control valve 9 and performs the combustion operation. Do not do.

  In the present embodiment, the branch portion from the hot water supply circulation circuit 2 of the hot water supply passage 3 is arranged upstream of the heating heat exchanger 52 and the bath heat exchanger 80 which are use side heat exchangers. When the hot water supply circuit is used alone, the flow pressure pressure loss of the hot water supply passage 3 can be reduced, and hot water can be supplied to the hot water supply passage 3 quickly.

  The amount of combustion in the burner 26 according to the combustion load is adjusted by opening and closing the gas switching valve 24. In the process of exhausting the combustion gas, the water supplied from the water supply passage B1B is heated by the hot water supply heat exchanger 33 provided in the combustion chamber 30 and the latent heat recovery heat exchanger 34 provided in the exhaust passage 31. The

  The hot water heated by the hot water supply heat exchanger 33 is mixed with the water on the incoming side passing through the bypass passage 4 adjusted by the valve body position of the bypass control valve 9 provided in the water supply passage branching section 18. The opening of the bypass control valve 9 is adjusted by a signal from the hot water thermistor 17 so that the mixed hot water has a hot water supply set temperature set by a remote controller for remote operation such as a bathroom remote controller 92 or a kitchen remote controller 93, and the hot water tap 13 More hot water is supplied.

  Thus, when selecting hot water supply independent operation, a desired temperature can be set with the remote controller for remote operation, and the hot water supply hot water set automatically can be secured by opening the hot water tap 13. .

  In addition, about the apparatus operation | movement at the time of each operation | movement at the time of heating operation and a bath chase operation, it is the same as that of the above (Embodiment 1), and abbreviate | omits. Further, the hot water supply operation, the heating operation, and the bath reheating operation can be performed simultaneously in each combination. In addition, the hot water supply circuit and the hot water supply circulation circuit, which is the primary circuit of the use side heat exchanger, are configured by a single heating path, so that the apparatus configuration can be reduced in size and weight by simplifying the main body configuration including the piping configuration. In addition, when a plurality of use side heat exchangers are provided, the temperature of hot water supplied from the hot water supply heat exchanger may be substantially the same by connecting each use side heat exchanger in parallel to the hot water supply circulation circuit. This is also the same as the above (Embodiment 1) in the effect that the hot water supply performance and the heating performance of the use side heat exchanger can be secured at the same time by improving the efficiency by recovering latent heat.

  Next, a method of detecting the presence or absence of water leakage due to breakage of the hot water supply circulation circuit 2 by driving the circulation pump 7 by separating the hot water supply circulation circuit 2 from the water supply path B1B and making it an independent closed circuit will be described.

  When performing the water leakage presence / absence detection operation of the hot water supply circulation circuit 2 at an appropriate timing according to the apparatus operating state as described in the first embodiment, the control means 91 is a bypass control provided in the water supply branch 18. As shown in FIG. 4A, the opening of the valve 9 is closed to close the water supply channel B1B. Then, as in the first embodiment, the control means 91 detects the presence or absence of water leakage due to breakage of the water pipe portion of the latent heat recovery heat exchanger 34, the presence or absence of water leakage due to breakage of the water pipe portion of the heating heat exchanger 52, the bath Detecting the presence or absence of water leakage by detecting the presence or absence of water leakage due to damage to the water pipe part of the heat exchanger 80. If it is detected that there is water leakage, it is represented by a remote controller for remote operation such as the bathroom remote control 92 or the kitchen remote control 93. To the external notification means to stop the operation of the apparatus.

  As described above, in the present embodiment, the control unit 91 determines the valve body position of the bypass control valve 9 provided in the water supply branching section 18 at an appropriate timing according to the apparatus operating state as shown in FIG. As shown in Fig. 4, the hot water supply circuit B2B is closed so that the hot water supply circuit 2 is disconnected from the water supply line B1B to form a complete closed circuit, and the circulation pump 7 is driven to detect the presence or absence of water leakage in the water pipe portion of the hot water supply circuit 2 can do. In addition, when it is determined that there is water leakage in the water leakage presence / absence detection operation, the control unit 91 notifies the external notification unit of the fact and performs an operation to stop the operation of the apparatus, so that the user has a state of water leakage. To prevent the damage caused by water leakage.

When the water leakage presence / absence detection operation is canceled halfway or when the water leakage presence / absence detection operation is completed, the hot water supply operation method in the present embodiment shown in FIG. In order to start combustion by detecting water flow in the circulating flow rate detecting means 6 even during normal hot water supply operation, the valve body position of the bypass control valve 9 provided in the water supply path B1B is in a state where the water supply path B1B is closed. When the burner 26 is ignited as it is, it is possible to prevent air blow or the like.

  As described above, the hot water supply apparatus according to the present invention has a hot water supply and heating system, a hot water supply and a bath, or a hot water supply and a heating and a bath as a single heat source. Since it is possible to reduce the weight, the installation space is secured, the workability is improved, and the latent heat recovery heat exchanger is provided, so it is possible to achieve high efficiency and save energy by reducing running costs. It can also be applied to uses such as petroleum hot water bath equipment and hot water heaters.

Structure diagram of hot water supply apparatus in Embodiment 1 of the present invention Structure diagram of hot water supply apparatus in Embodiment 2 of the present invention Structure diagram of hot water supply apparatus in Embodiment 3 of the present invention (A) Valve body position diagram of bypass control valve 9 in Embodiment 3 of the present invention (B) Valve body position diagram of bypass control valve 9 in Embodiment 3 of the present invention (C) Embodiment 3 of the present invention Of valve body position of bypass control valve 9

Explanation of symbols

1A Water supply channel A
1B Water supply channel B
DESCRIPTION OF SYMBOLS 2 Hot water supply circulation circuit 3 Hot water supply path 4 Bypass path 7 Circulation pump 9 Bypass control valve 18 Water supply path branch part 26 Burner 33 Heat exchanger for hot water supply 34 Heat exchanger for latent heat recovery 91 Control means

Claims (13)

A hot water supply heat exchanger that heats the water supplied from the water supply passage by combustion of the burner and supplies hot water to the hot water supply passage, and heat exchange for latent heat recovery that is arranged in the combustion exhaust gas passage of the burner and recovers the latent heat of the combustion exhaust gas A hot water supply heat exchanger and a latent heat recovery heat exchanger connected in series, from the latent heat recovery heat exchanger through the hot water supply heat exchanger to the user side heat exchanger via a circulation pump Forming a hot water supply circulation circuit, forming a hot water supply circuit branching from the hot water supply circulation circuit to a hot water supply path, and using either the hot water supply circulation circuit or the hot water supply circuit, or a hot water supply circulation circuit and a hot water supply circuit A hot water supply circuit closing means for making the hot water supply circuit completely closed in the water supply passage, and a circulating flow rate detection for detecting a circulating flow rate in the hot water supply circuit Means The control means closes the hot water supply circulation circuit closing means, drives the circulation pump under a predetermined condition, and detects the circulation flow rate in the hot water supply circulation circuit at that time by the circulation flow rate detection means. A water heater that can detect the presence or absence of water leakage due to circuit damage. In the case where a plurality of use side heat exchangers are provided, the use side heat exchangers are connected in parallel to the hot water supply circulation circuit so that the hot water temperatures supplied from the hot water supply heat exchangers are substantially the same. 1. A hot water supply apparatus according to item 1. The hot water supply apparatus according to claim 1 or 2, wherein the branch portion from the hot water supply circulation circuit of the hot water supply passage is arranged on the upstream side of the use side heat exchanger. The hot water supply apparatus according to claim 1 or 2, wherein a branch portion from the hot water supply circulation circuit of the hot water supply passage is disposed on the downstream side of the use side heat exchanger. The hot water supply circuit closing means is disposed downstream of the branch portion of the water supply passage and the bypass passage provided by connecting the water supply passage and the hot water supply passage so as to bypass the hot water supply heat exchanger and the latent heat recovery heat exchanger. The hot-water supply apparatus of any one of Claims 1-4 arrange | positioned. 6. The hot water supply apparatus according to claim 5, wherein the hot water supply circulation circuit closing means has a closing function, and is a bypass control valve for controlling the flow rate of the bypass passage, and also has a function of making the hot water supply circulation circuit completely closed. The hot water supply circuit closing means is disposed in the water supply passage at a branch portion between the hot water supply heat exchanger and the bypass passage provided to communicate the hot water supply passage so as to bypass the latent heat recovery heat exchanger. The hot-water supply apparatus of any one of Claims 1-4. The hot water supply circuit closing means has a water supply channel side closing function, and is a bypass control valve for controlling the flow rate of the bypass passage, and also serves as a function to make the hot water supply circuit completely closed. apparatus. The circulation pump is a DC drive system, the control means closes the hot water supply circulation circuit closing means, the control means drives the circulation pump under predetermined conditions, and the hot water supply circulation circuit is damaged due to the driving load of the circulation pump. The hot-water supply apparatus of any one of Claims 1-8 which enabled it to detect the presence or absence of the water leak by. The control means has a function of detecting the presence or absence of water leakage due to breakage of the hot water supply circulation circuit by closing the hot water supply circulation circuit closing means and driving the circulation pump at an appropriate timing according to the apparatus operating state. The hot water supply apparatus according to any one of 9. 11. The hot water supply apparatus according to claim 10, wherein the control means has a function of notifying the external notification means to that effect and stopping the operation of the apparatus when it is determined that there is water leakage from the hot water supply circulation circuit. The hot water supply apparatus according to any one of claims 1 to 4, wherein the circulation flow rate detecting means is arranged upstream of a branching portion with the hot water supply path in the hot water supply circulation circuit. 13. The hot water supply apparatus according to claim 12, wherein the control means has a function of starting combustion of the burner when the flow rate detected by the circulating flow rate detection means exceeds a predetermined value.

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