JP2017067351A - Hot water system and operating method of hot water system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water system and an operating method of the hot water system such that even if trouble occurs to a selector valve in switching a flow passage for hot water, the trouble never harms user's health.SOLUTION: A hot water system has: a water heater 2 having a burner 23 arranged below a reheating heating heat exchanger 22; reheating circulation outward passages 221, 411 through which hot water exiting from the reheating heating heat exchanger toward a bathtub 40 flows; reheating circulation return passages 222, 412 through which hot water exiting from the bathtub toward the reheating heating heat exchanger flows; a circulation pump 220; a bath outward three-way valve 31 arranged halfway in the reheating circulation outward passages; a bath return three-way valve 32 arranged halfway in the reheating circulation return passages; a heating outward passage 511; heating return passages 512, 331; a reservoir part 33; and a water displacement part displacing water in the heating heat exchanger 51, heating outward passages, heating return passages, and reservoir part within a time shorter than a predetermined time for which clean water is considered to be safe after driving the circulation pump.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hot water supply system and a method for operating the hot water supply system.

  The inventors are developing a hot water supply system using a hot water supply heat exchanger and a reheating heating heat exchanger as disclosed in Patent Document 1. In such a system, by switching the heat exchanger to be used, or by switching the hot water flow path using a switching valve, supply of hot water to the bathtub or currant, reheating of hot water in the bathtub, heating of the bathroom, etc. And so on. The system can also heat the bathroom and reheat the bathtub at the same time. In this case, the bath water is made hot (sterilized), and hot water is used for heating. I can catch up.

  The hot water supply system of Patent Document 1 switches between a pipe line that heats (reheats) bathtub water and a pipe line that performs heating using a three-way valve. During heating, the bath water is sucked by a pump and sent to a reheating heating heat exchanger, heated and sterilized by a reheating heating heat exchanger, and then sent to a heating pipeline. Since it becomes like this, even if miscellaneous bacteria (for example, Legionella bacteria) are mixed in the bath water, since it is heated and sterilized, there is no possibility that the germs propagate in the heating pipe.

  In addition, there is also a system that only supplies hot water to a bathtub, a currant, etc., and replenishes hot water from the bathtub. In such a system, when reheating is performed during bathing, bath water containing various germs is sucked by a pump. If the device is left as it is after completion of the memorial service (for example, when the user returns home for several days), there is a possibility that various germs may grow in the memorial service channel. If the proliferated bacteria flow into the bathtub with automatic hot water filling, the user will be bathed in hot water containing various bacteria, which is not preferable. In order to prevent such a situation, as in Patent Document 2, when it is detected that the water level detected by the pressure sensor has become below a certain level and water has been drained from the bathtub (the bathing has been completed), a memorial pipeline It is conceivable to wash with hot water.

Japanese Patent No. 3620357 Japanese Patent No. 2132837

  Even in the hot water supply system of Patent Document 1, there is a case where reheating is performed in the middle of bathing after completion of heating. When reheating, the bath water containing various germs is sucked with a pump. In some cases, the hot water remaining in the heating pipe line cools after the completion of the memorial service, and the inside of the heating pipe line becomes negative pressure. In the hot water supply system of Patent Document 1, a three-way valve is disposed between the bathtub and the pump, and the closing function of the three-way valve cannot withstand the negative pressure (or if the three-way valve is broken). There is a concern that bath water containing germs in the memorial pipeline will pass through the three-way valve and enter the heating pipeline. If there is an overflow pipe, germs may enter the heating line via the overflow pipe. When germs enter the heating pipeline and then return to the home for several days and then perform automatic hot water filling, there is a problem that germs grown in the heating pipeline flow out into the bathtub.

  The present invention has been made paying attention to such conventional problems. An object of the present invention is to provide a hot water supply system and a method for operating the hot water supply system that do not impair the health of the user due to the failure even if a failure occurs in the switching valve that switches the hot water flow path.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this. Further, the configuration described with reference numerals may be appropriately replaced or improved.

  1st invention is connected to the hot water heater (2) by which the burner (23) is arrange | positioned under the reheating heating heat exchanger (22), and the reheating heating heat exchanger (22), and reheating heating A recirculation circulation path (221, 411) through which hot water flows out of the heat exchanger (22) toward the bathtub (40) and the bathtub (40) and is connected to the bathtub (40) and out of the bathtub (40). Hot water is circulated in the recirculation return path (222, 412) where hot water flows toward the heat exchanger (22), the recirculation return path (221, 411) and the recirculation return path (222, 412). A circulation pump (220), a bathing three-way valve (31) disposed in the middle of the recirculation circulation passage (221, 411), and a middle of the recirculation circulation return passage (222, 412). Ru Lu return three-way valve (32) and a heating forward passage (511) that is connected to the three-way valve (31) that goes out of the bath and through which hot water flows from the three-way valve (31) to the heating heat exchanger (51). , A heating return passage (512, 331) through which hot water flows from the heating heat exchanger (51) to the bath return three-way valve (32), connected to the heating heat exchanger (51), and the heating return passage ( 512, 331) and the circulating pump (220) after driving the storage section (33), the heating heat exchanger ( 51), a heating water supply system having a heating replacement passage (511), a heating return passage (512, 331), and a water replacement section (S18) for replacing water in the storage section (33).

  In a second aspect based on the first aspect, the storage section (33) is an air separator (33), one end of which is connected to the upper surface of the air separator (33) and the other end is the three-way bath. The hot water supply system further includes an overflow pipe (332) that joins the recirculation circulation passage (411) between the valve (31) and the bathtub (40).

  3rd invention is the hot water supply system whose said storage part (33) is an expansion tank (33) in 1st or 2nd invention.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the water replacement unit (S18) drives the circulation pump (220) and bath water is supplied to the bath return three-way valve (32). This is a hot water supply system that performs water replacement when it reaches the point.

  In a fifth aspect of the present invention based on any one of the first to third aspects, the water replacement section (S18) performs water purge by performing an air purge operation without igniting the burner (23), thereby performing water replacement. System.

  6th invention is connected to the hot water heater (2) by which the burner (23) is arrange | positioned under the reheating heating heat exchanger (22), and the reheating heating heat exchanger (22), and reheating heating A recirculation circulation path (221, 411) through which hot water flows out of the heat exchanger (22) toward the bathtub (40) and the bathtub (40) and is connected to the bathtub (40) and out of the bathtub (40). Hot water is circulated in the recirculation return path (222, 412) where hot water flows toward the heat exchanger (22), the recirculation return path (221, 411) and the recirculation return path (222, 412). A circulation pump (220), a bathing three-way valve (31) disposed in the middle of the recirculation circulation passage (221, 411), and a middle of the recirculation circulation return passage (222, 412). Ru Lu return three-way valve (32) and a heating forward passage (511) that is connected to the three-way valve (31) that goes out of the bath and through which hot water flows from the three-way valve (31) to the heating heat exchanger (51). , A heating return passage (512, 331) through which hot water flows from the heating heat exchanger (51) to the bath return three-way valve (32), connected to the heating heat exchanger (51), and the heating return passage ( 512, 331) is a method for operating a hot water supply system having a storage part (33) provided in the middle of the water pump, and after driving the circulation pump (220), the water supply is shorter than a predetermined time when it is safe. Within a period of time, a water replacement step (S18) of replacing water in the heating heat exchanger (51), the heating forward passage (511), the heating return passage (512, 331), and the storage section (33) is performed. Having a hot water supply system A rolling method.

  According to this aspect, even if the closing function of the three-way valve is lost due to a failure, or even if it cannot withstand negative pressure due to adhesion of hair or the like, the bath water containing germs caused by this passes through the three-way valve. Even if it enters the heating pipeline, it can be washed with water containing chlorine before the germs grow in the heating conduit to prevent the propagated germs from flowing into the bathtub.

FIG. 1 is a diagram illustrating a basic configuration of a hot water supply system 1 with a heating function. FIG. 2 is a diagram illustrating the air purge operation. FIG. 3 is a diagram illustrating a hot water filling operation. FIG. 4 is a diagram for explaining the chasing operation. FIG. 5 is a diagram illustrating the heating operation. FIG. 6 is a diagram illustrating simultaneous operation of heating in the bathroom and reheating of the bathtub. FIG. 7 is a diagram showing a general internal structure of the three-way valve 31 for taking out the bath and the three-way valve 32 for returning to the bath. FIG. 8 is a view showing a state in which hot water containing various bacteria stored in the bath return pipe 412 flows into the air separator 33. FIG. 9 is a diagram illustrating a state where hot water containing various bacteria stored in the bath outlet pipe 411 flows into the heating outlet pipe 511 and the overflow pipe 332. FIG. 10 is a flowchart of the control executed when the bathtub stopper is removed after the bathing is completed and the water level drop is detected by the pressure sensor 2131. FIG. 11 is a flowchart of control of the second embodiment of the hot water supply system. FIG. 12 is a diagram illustrating an application form of the hot water supply system. FIG. 13 is a diagram for explaining the chasing operation of the second embodiment. FIG. 14 is a diagram illustrating a state in which hot water containing various bacteria stored in the bath return pipe 412 flows into the expansion tank 33. FIG. 15 is a diagram illustrating a state in which hot water containing various bacteria stored in the bath outlet pipe 411 flows into the heating outlet pipe 511. FIG. 16 is a diagram illustrating an air purge operation in which the bath return three-way valve 32 and the bath going-out three-way valve 31 are set to 50% opening. FIG. 17 is a diagram for explaining an air purge operation that is performed with a 50% opening degree only for the bathing three-way valve 31.

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

(First embodiment)
FIG. 1 is a diagram illustrating a basic configuration of a hot water supply system 1 with a heating function.

  The hot water supply system 1 mainly includes a hot water heater 2 and a hot water branching unit 3.

  In the water heater 2, a hot water supply heat exchanger 21 and a reheating heating heat exchanger 22 are arranged vertically and integrated with a common fin 201. Below that, a gas burner 23 is arranged. A combustion fan for supplying combustion air is provided under the gas burner 23. The gas burner 23 burns the fuel gas supplied from the gas supply pipe 231 and heats the hot water supply heat exchanger 21 and the reheating heating heat exchanger 22.

  An inlet pipe 211 is connected to the inlet of the hot water supply heat exchanger 21. Water from the tap water flows through the inlet pipe 211. The water of the water supply is supplied to the hot water supply heat exchanger 21 through the water intake pipe 211. Note that the flow rate of water flowing through the water intake pipe 211 is detected by a flow rate sensor 2111.

  A hot water outlet pipe 212 is connected to the outlet of the hot water supply heat exchanger 21. Hot water heated by the hot water supply heat exchanger 21 flows through the hot water discharge pipe 212. Hot water heated by the hot water supply heat exchanger 21 is supplied to a hot water outlet terminal 60 such as a currant or a shower head through a hot water outlet pipe 212. A hot water dropping pipe 213 branches from the hot water pipe 212. The hot water dropping pipe 213 joins the hot water return pipe 222 connected to the inlet of the reheating heating heat exchanger 22. The hot water drop pipe 213 is provided with a pressure sensor 2131. Inside the hot water supply heat exchanger 21, a hot water temperature sensor 2121 is provided for detecting the temperature of hot water in the hot water supply heat exchanger 21 (retained hot water temperature). A temperature sensor 2122 for detecting the temperature of hot water passing through the hot water supply heat exchanger 21 is provided at the outlet of the hot water supply heat exchanger 21. A hot water temperature sensor 2123 for detecting the temperature of hot water sent to the hot water terminal 60 is provided in a hot water pipe 212 through which hot water whose temperature has dropped by mixing water from the hot water supply heat exchanger 21 with water from the bypass pipe 214 passes. Is provided.

  One end of a hot water outlet pipe 221 is connected to the outlet of the reheating heater heat exchanger 22. The other end of the hot water outlet pipe 221 is connected to the hot water branch unit 3 of the hot water branch unit 3. One end of a hot water return pipe 222 is connected to the inlet of the reheating heating heat exchanger 22. The other end of the hot water return pipe 222 is connected to the bath return three-way valve 32 of the hot water branching unit 3. A circulating pump 220 is provided in the hot water return pipe 222. The circulation pump 220 is provided at a location closer to the reheating and heating heat exchanger 22 than the joining location of the hot water dropping pipe 213. The hot water return pipe 222 is also provided with a bath water flow switch 2221 and a bath temperature sensor 2222. The bath water flow switch 2221 and the bath temperature sensor 2222 are provided at a location farther from the heating / heating heat exchanger 22 than the junction location of the hot water drop pipe 213. Bath temperature sensor 2222 is, for example, a thermistor. By using the bath temperature sensor 2222, the hot water temperature of the bathtub 40 can be detected.

  The hot water branching unit 3 includes a bath going three-way valve 31 and a bath returning three-way valve 32.

  As described above, the hot water supply pipe 221 is connected to one connection port of the three-way valve 31 of the hot water. One end of a bath-out pipe 411 is connected to another connection port of the bath-out three-way valve 31. The other end of the bath outlet pipe 411 is connected to the circulation fitting 41 of the bathtub 40. One end of a heating forward pipe 511 is connected to the remaining connection port of the bath going three-way valve 31. The other end of the heating forward pipe 511 is connected to the inlet of the heating heat exchanger 51 of the heating unit 50, and the inlet and outlet of the heating heat exchanger 51 are bypassed. The hot water branching unit 3 including the heating heat exchanger 51 is installed in the bathroom (for example, between the bathtub and the apron of the bathtub).

  As described above, the hot water return pipe 222 is connected to one connection port of the bath return three-way valve 32. One end of a bath return pipe 412 is connected to another connection port of the bath return three-way valve 32. The other end of the bath return pipe 412 is connected to the circulation fitting 41 of the bathtub 40. One end of an air separator connection pipe 331 is connected to the remaining connection port of the bath return three-way valve 32. The other end of the air separator connection pipe 331 is connected to the bottom surface of the air separator 33. The air separator 33 has a space for storing hot water. The other end of the heating return pipe 512 connected to the outlet of the heating heat exchanger 51 is connected to the bottom surface of the air separator 33.

  Thus, the bath return three-way valve 31 is switched so that the hot water return pipe 221 and the bath return pipe 411 communicate with each other, and the bath return three-way valve 32 so that the bath return pipe 412 and the hot water return pipe 222 communicate with each other. When the circulation pump 220 is activated in a state where is switched, the hot water heated by the water heater 2 circulates in the bathtub 40.

  In the state where the bath return three-way valve 31 is switched so that the hot water return pipe 221 and the heating forward pipe 511 communicate with each other, and the bath return three-way valve 32 is switched so that the air separator connection pipe 331 and the hot water return pipe 222 communicate with each other. When the pump 220 is activated, hot water heated by the water heater 2 circulates through the heating heat exchanger 51 and the air separator 33 of the heating unit 50.

  One end of an overflow pipe 332 is connected to the upper surface of the air separator 33. The other end of the overflow pipe 332 joins the bath outlet pipe 411.

  In the figure, 200 is a controller of the hot water heater 2, 300 is a controller of the hot water branching unit 3, and 52 is a room temperature detection sensor of the heating unit 50.

  A remote controller (not shown) is connected to the water heater controller 200, and the remote controller is operated to set the hot water supply temperature and the bath temperature. When the tap of the hot water terminal 60 such as a currant or a shower head is opened, the combustion of the gas burner 23 is adjusted so that the hot water temperature detected by the hot water temperature sensor 2123 becomes the hot water supply set temperature, and the hot water supply heat exchanger 21. Is heated. Further, during the reheating combustion of the bath, the combustion of the gas burner 23 is adjusted so that the bath temperature detected by the bath temperature sensor 2222 becomes the bath set temperature, and the reheating heating heat exchanger 22 is heated. .

  Subsequently, the operation of the hot water supply system 1 along a specific operation scene will be described in more detail below.

  Taking the case where the remote control is operated and 18:00 is set as the scheduled bathing time, and the bath automatic operation switch (water filling operation, chasing operation, automatic heat insulation operation) and the bathroom heating switch are set as an example, a hot water supply system 1 will be described. The bathroom heating is also completed before the scheduled bathing time (18:00).

  In this case, the system starts operating 30 minutes before the scheduled bathing time (18:00). First, an air purge operation is performed. In the air purge operation, as shown in FIG. 2, the three-way valve 31 is switched so that the reheating heating heat exchanger 22 and the heating terminal 26 communicate with each other, and the reheating heating heat exchanger 22 and the air separator 33 are switched. The bath return three-way valve 32 is switched so as to communicate with each other. In this state, when water from the water supply is supplied, the water flows through the water inlet pipe 211 and is heated by the hot water supply heat exchanger 21, flows from the hot water outlet pipe 212 to the hot water dropping pipe 213, and then flows into two flows through the hot water return pipe 222. Divide. In the figure, the outline of the hot and cold water temperature is expressed by the density of dots. Where the dots are dark, the hot water temperature is high, and when the dots are light, the hot water temperature is low. In FIG. 2, the two flows are shaded so that they can be easily understood. However, since the heating fan is not operated during the air purge operation, the temperatures are substantially the same.

  One of the divided flows is a flow of hot water return pipe 222 → reheating heating heat exchanger 22, which is further heated by reheating heating heat exchanger 22, and has a hot water recirculation pipe 221 → a bath opening three-way valve 31 → heating. It goes to the air separator 33 through the forward pipe 511 → the heating heat exchanger 51 → the heating return pipe 512. Another flow that has been divided is a flow of hot water return pipe 222 → bath return three-way valve 32 → air separator 33. Thus, the flow divided into two by the hot water return pipe 222 is joined by the air separator 33.

  Then, the air separator 33 flows from the overflow pipe 332 to the bath outlet pipe 411 to the circulation fitting 41 to reach the bathtub 40. As the hot water flows in this way, the air in the pipe is purged. Although depending on the specifications, the air purge is completed when about 2 to 3 liters of hot water flows. If hot water flows about 2 liters per minute due to the supply water pressure, this air purge is completed in about 1 minute.

  When the air purge is completed, the hot water filling operation is performed until the bathtub 40 reaches a desired amount of hot water. In this case, as shown in FIG. 3, the bath going-out three-way valve 31 and the bath returning three-way valve 32 are switched so that the reheating heating heat exchanger 22 and the bathtub 40 communicate with each other. When water in the water supply is supplied in this state, the water flows through the inlet pipe 211 and is heated by the hot water supply heat exchanger 21 and flows from the hot water outlet pipe 212 to the hot water dropping pipe 213, and then is divided into two flows by the hot water return pipe 222. To do.

  One flow is a flow of the hot water return pipe 222 → the reheating heater heat exchanger 22, which is further heated by the reheating heater heat exchanger 22, and the hot water recirculation pipe 221 → the bathing three-way valve 31 → the bathing duct. 411 → flows with the circulation fitting 41 and reaches the bathtub 40. Another flow is a flow of hot water return pipe 222 → bath return three-way valve 32 → bath return pipe 412 → circulation fitting 41 (tub 40). Thus, the hot water heated by the hot water supply heat exchanger 21 is divided into two systems along the way and supplied to the bathtub 40. This hot water filling operation is performed until the bathtub 40 reaches a desired amount of hot water. The amount Q of hot water in the bathtub 40 is obtained by fitting the water pressure P detected by the pressure sensor 2131 to the PQ diagram.

  When the hot water filling is completed, the chasing operation is executed until the hot water temperature reaches an appropriate temperature. In this case, as shown in FIG. 4, the circulation pump 220 is operated in a state in which the hot air return heat exchanger 22 and the bathtub 40 are communicated with each other by the bath going-out three-way valve 31 and the bath return three-way valve 32. Then, the hot water in the bathtub 40 becomes the circulation fitting 41 → the bath return pipe 412 → the bath return three-way valve 32 → the hot water return pipe 222 → the reheating heating heat exchanger 22 → the hot water pipe 221 → the bath forward three-way valve 31 → the bath forward pipe. It circulates in the order of 411 → circulation fitting 41 → tub 40 and is heated by the reheating heating heat exchanger 22. In this case, only hot water is supplied without supplying hot water, but since the heat of the gas burner 23 is also transmitted to the hot water supply heat exchanger 21, hot water in the hot water supply heat exchanger 21 may be boiled. If the tap of the hot water outlet terminal 60 is opened while the hot water of the hot water supply heat exchanger 21 is boiling, the hot water boiling out of the hot water terminal 60 is dangerous. Therefore, in this case, hot water is boiled in the hot water supply heat exchanger 21 by repeatedly turning on and off the gas burner 23 while observing the detection temperature of the hot water temperature sensor 2121 provided in the hot water supply heat exchanger 21 and repeating combustion and stoppage. We will catch up while preventing this. By about 15 minutes before the scheduled bathing time (18:00), the hot water will reach the proper temperature and the chasing will be completed.

  When it is about 10 minutes before the scheduled bathing time, the heating operation is started. In this case, as shown in FIG. 5, the three-way valve 31 going back to the bath is switched to connect the reheating heating heat exchanger 22 and the heating heat exchanger 51 and the three-way valve 32 returning from the bath is switched to The fired heating heat exchanger 22 and the air separator 33 are communicated. In this state, the circulation pump 220 is operated. Then, the hot water heated to about 70 ° C. by the reheating heating heat exchanger 22 flows in the order of the hot water outlet pipe 221 → the bath outlet three-way valve 31 → the heating outlet pipe 511 and reaches the heating heat exchanger 51. In the heating heat exchanger 51, the heat of the hot water is dissipated to warm the bathroom. The temperature of the hot water passing through the heating heat exchanger 51 decreases to about 60 ° C., and flows again through the heating return pipe 512 → the air separator 33 → the air separator connection pipe 331 → the bath return three-way valve 32 → the hot water return pipe 222, and again. Then, it flows through the reheating and heat exchanger 22 and is heated.

  In this heating operation, the heating pipes (the heating forward pipe 511, the heating heat exchanger 51, the heating return pipe 512, the air separator 33, and the air separator connecting pipe 331) are filled with hot water of 60 ° C. or more and heated while being sterilized. To do. By the scheduled bathing time (18:00), the bathroom is at an appropriate temperature and the heating operation is completed.

  Then, when time passes, the temperature of bathtub hot water will fall. Therefore, the three-way valve 31 for going out of the bath and the three-way valve 32 for returning to the bath are kept in a state where the reheating / heating heat exchanger 22 and the bathtub 40 are in communication (state shown in FIG. 4). Then, the circulation pump 220 is operated every predetermined time. Then, the hot water in the bathtub 40 becomes the circulation fitting 41 → the bath return pipe 412 → the bath return three-way valve 32 → the hot water return pipe 222 → the reheating heating heat exchanger 22 → the hot water pipe 221 → the bath forward three-way valve 31 → the bath forward pipe. It circulates with 411-> circulation metal fitting 41-> bathtub 40. The temperature of the circulating hot water is detected by the bath temperature sensor 2222 of the hot water return pipe 222. If the temperature is lower than the set temperature of the remote control, the reheating is performed. If the temperature is within the predetermined range of the remote control, the reheating is not performed. The circulation pump 220 is stopped. By doing in this way, the hot water of the bathtub is kept warm (automatic warming).

  When several people take turns bathing, there is a scene where the temperature of the bathroom is lowered and the bathroom is heated and the bathtub is reheated at the same time. In this case, as shown in FIG. 6, the three-way valve 31 going back to the bath is switched to connect the reheating heating heat exchanger 22 and the heating heat exchanger 51, and the three-way valve 32 returning from the bath is switched to follow The heating heating heat exchanger 22 and the bathtub 40 are communicated. In this state, the circulation pump 220 is operated. Then, the hot water in the bathtub 40 flows through the circulation fitting 41 → the bath return pipe 412 → the bath return three-way valve 32 → the hot water return pipe 222 → the reheating heating heat exchanger 22, and is heated by the reheating heating heat exchanger 22. It becomes about 70 ℃. Then, the hot water flows in the order of the hot water outlet pipe 221 → the bath outlet three-way valve 31 → the heating forward pipe 511 and reaches the heating heat exchanger 51. In the heating heat exchanger 51, the heat of the hot water is radiated to warm the bathroom. Although the temperature of the hot water that has passed through the heating heat exchanger 51 decreases to about 60 ° C., the temperature is still high. The hot water flows through the heating return pipe 512 → the air separator 33 → the overflow pipe 332 → the bath outlet pipe 411 → the circulation fitting 41 and reaches the bathtub 40 again. Thus, the hot water heated to about 70 ° C. by the reheating heating heat exchanger 22 dissipates heat in the heating heat exchanger 51 and warms the interior of the bathroom. And although the temperature falls to about 60 ° C., hot water with a still high temperature is supplied to the bathtub, it is possible to efficiently chase the bathtub.

  In addition, there is a scene in which after the heating operation is finished, the hot water temperature is lowered and the reheating is performed again. In this case, as shown in FIG. 4, the bath going-out three-way valve 31 and the bath return three-way valve 32 are in a state where the reheating and heating heat exchanger 22 and the bathtub 40 are in communication with each other. Then, the circulation pump 220 is operated.

  As described above, after the heating operation is completed, there is a scene in which bathing is performed with bathing, and bathroom heating and bathing are performed simultaneously. When the hot water remaining in the heating pipeline is cooled after completion of the memorial service and the inside of the heating pipeline becomes negative pressure, the closing function of the bath return three-way valve 32 cannot withstand the negative pressure (or due to a failure of the three-way valve). There is a risk that the bathtub water containing germs and organic matter that favors the growth of germs will pass through the three-way valve and enter the heating pipeline, causing the germs to propagate in the heating pipeline. In general, if clean water (city water, clean water) exceeds about 100 hours, the amount of germs in the heating pipeline will propagate to an undesirable level when mixed in the bathtub. Unlike the fresh water, the bath water contains a large amount of organic matter that promotes the propagation of germs. Therefore, it is preferable to take some measures for about 72 hours, for example, 100 hours or less.

  Here, a possible cause of failure of the three-way valve will be described.

  FIG. 7 shows a general internal structure of the three-way valve 31 for bathing and the three-way valve 32 for returning to the bath. In the internal flow path of the bath going-out three-way valve 31 and the bath returning three-way valve 32, there is a butterfly valve V in which two rubbers are covered with an elliptical stainless steel plate. The butterfly valve V is spot welded to the shaft SFT at two locations (indicated by X in the figure). A gear G is fixed to the tip of the shaft SFT. The gear G is driven by a motor M. The rotation angle of the gear G (the opening degree of the butterfly valve V) is detected by the angular position sensor S. The angle of the butterfly valve V is changed by the motor M. The butterfly valve V selectively switches the flow path by opening and closing the flow path by pressing or releasing the rubber portion covered with the elliptical stainless steel plate against the pipe end.

  By the way, by using a stepping motor, the angular position sensor S as described above may not be used. In this case, the angle of the butterfly valve becomes the expected angle due to the stepping motor stepping out (a phenomenon in which the actual angle of the butterfly valve deviates from the angle required by the calculation because it does not rotate even when the stepping motor is energized). And may be different. Strictly speaking, it may not be a malfunction, but if heating operation is performed in a step-out state (stopped at an intermediate opening), the bath water temperature becomes too high or the heating effect of the bathroom is poor. Occurs. Even if an angular position sensor is used, the solder paste such as zinc chloride used when soldering the lead wire to the angular position sensor corrodes the copper foil on the detection surface of the angular position sensor, and the angular position sensor In some cases, the angle of the butterfly valve is erroneously detected due to poor contact at the contact portion. In the above two patterns, the original 100% opening suddenly changes like a 70% opening, causing a problem. By the way, the butterfly valve covered with two rubbers is closed by pressing the rubber part against the pipe line end to be switched. At this time, a force is applied to the spot welding portion that fixes the butterfly valve and the shaft in a direction in which the spot welding is peeled off. When the welding current at the time of spot welding is not appropriate, the welding is peeled off due to metal fatigue, the original 100% opening becomes 85% opening, and further peels off and the abnormality progresses slowly like 70% opening. There is a case. There are failures that suddenly cause an abnormality in the opening degree and failures that progress slowly. Next, the flow of hot water at the time of failure will be described.

  Next, with reference to FIG. 8, it will be described that bathtub water containing germs and organic matter that favors the propagation of germs passes through the three-way valve and enters the heating pipe.

  As described above, the air purge operation is executed 30 minutes before the scheduled bathing time (18:00). The air purge operation fills the heating pipe with fresh hot water. When the air purge is completed, the hot water filling operation is executed. When the bathtub 40 reaches a desired amount of hot water, the chasing operation is executed until the hot water temperature reaches an appropriate temperature. Then, when about 10 minutes before the scheduled bathing time, the heating operation is started. The air purge operation is filled with fresh hot water and there are no germs (eg, Legionella, Escherichia coli), but the heating pipeline is sterilized by heating. This heating operation is not indispensable because it is not performed depending on the user's selection (for example, a situation where heating is not necessary in summer).

  Thereafter, when time elapses, the circulation pump 220 is driven and the bath temperature sensor 2222 detects the hot water temperature in the bathtub. If the hot water temperature is lower than the temperature set by the remote controller, the driver will perform a chasing operation. Also, when several people take turns bathing, the bathroom may be heated at the same time. When such an operation is performed, as shown in FIG. 4, the hot water in the bathtub 40 flows from the circulation fitting 41 → the bath return pipe 412 → the bath return three-way valve 32 → the hot water return pipe 222, and from the bath return pipe 412. The hot water return pipe 222 is filled with hot water containing various bacteria. This hot water is reheated and sterilized by being heated by the heating heat exchanger 22, and flows from the hot water pipe 221 to the hot water three-way valve 31 to the hot water pipe 411, and therefore, from the hot water pipe 221 to the hot water pipe 411. Until then, it is filled with heat-sterilized hot water. In this way, from the bath return pipe 412 to the hot water return pipe 222 by the simultaneous execution of the bath reheating operation accompanying bathing or the bathroom heating operation and the bath reheating operation performed after the heating operation is completed in winter, It will be filled with hot water containing various bacteria. Although the circulating pump 220 is driven and the bath temperature sensor 2222 detects the hot water temperature in the bathtub, if the hot water temperature is within a predetermined range of the set temperature of the remote controller, the circulating pump 220 is stopped without reheating. . In this case, by driving the circulation pump 220, the hot water in the bathtub 40 is supplied from the circulation fitting 41 → the bath return pipe 412 → the bath return three-way valve 32 → the hot water return pipe 222 → the heating heat exchanger 22 → the hot water return pipe 221 → The flow goes from the bath going three-way valve 31 to the bath going pipe 411, and the circulation pump 220 is stopped, so that hot water containing various bacteria is filled in this path.

  After the bathing is completed, the bathtub stopper is removed, and when pressure drop is detected by the pressure sensor 2131, pipe cleaning is performed to wash away hot water in the pipe. This pipe cleaning is performed with the burner 23 burned. As a result, a flow similar to that at the time of hot water filling (FIG. 3) is generated, and the path of the hot water return pipe 222 → the reheating and heating heat exchanger 22 → the hot water pipe 221 → the three-way valve 31 for the hot water bath → the hot water pipe 411 The interior of the path of the hot water return pipe 222 → the bath return three-way valve 32 → the bath return pipe 412 is filled with fresh hot water, and various germs (eg, Legionella, E. coli) are eliminated.

  However, if the inside of the heating pipe is cooled before the bathtub plug is removed (especially in the winter, the inside of the heating pipe is easy to cool), the germs stored in the bath return pipe 412 are removed as shown in FIG. The contained hot water may flow into the air separator 33. That is, when the inside of the heating pipeline cools, the inside of the heating pipeline becomes negative pressure. At this time, if the bath return three-way valve 32 is not sufficiently closed, the hot water stored in the bath return pipe 412 flows into the air separator 33 due to the negative pressure in the heating pipe.

  The circulating pump 220 is driven and the bath temperature sensor 2222 detects the hot water temperature of the bathtub. If the hot water temperature is within a predetermined range (within minus 0.5 ° C.) of the set temperature of the remote controller, no reheating is performed. The circulation pump 220 is stopped. In this case, by driving the circulation pump 220, the hot water in the bathtub 40 is supplied from the circulation fitting 41 → the bath return pipe 412 → the bath return three-way valve 32 → the hot water return pipe 222 → the heating heat exchanger 22 → the hot water return pipe 221 → The flow goes from the bath going three-way valve 31 to the bath going pipe 411, and the circulation pump 220 is stopped, so that hot water containing various bacteria is filled in this path. As shown in FIG. 9, hot water containing various bacteria stored in the bath outlet pipe 411 may flow into the heating outlet pipe 511 and the overflow pipe 332. That is, when the inside of the heating pipeline cools, the inside of the heating pipeline becomes negative pressure. At this time, if the close-up of the three-way valve 31 is insufficient, the hot water stored in the bath-out pipe 411 flows into the heating-out pipe 511 and the overflow pipe 332 due to the negative pressure in the heating pipe.

  In this way, the bathtub water containing germs and organic matter that favors the propagation of germs passes through the three-way valve and enters the heating pipeline.

  If there is no contrivance, pipe cleaning is performed to wash away hot water in the pipe when the bathtub stopper is removed and the pressure sensor 2131 detects a drop in water level. This pipe cleaning is performed with the burner 23 burned. As a result, a flow similar to that at the time of hot water filling (FIG. 3) is generated, and the path of the hot water return pipe 222 → the reheating and heating heat exchanger 22 → the hot water pipe 221 → the three-way valve 31 for the hot water bath → the hot water pipe 411 The hot water return pipe 222 → the bath return three-way valve 32 → the bath return pipe 412 is filled with fresh hot water and free of germs (eg, Legionella, Escherichia coli). It will remain. When about 72 hours have passed since the previous air purge operation, the germs remaining in the heating pipeline propagate and a situation occurs in which the germs flow into the bathtub 40 by the next air purge operation.

  Therefore, in the first embodiment, after the bathing is completed, when the bathtub stopper is removed and the pressure sensor 2131 detects a drop in the water level, the following control is executed. Hereinafter, specific contents will be described along the flowchart of FIG. This flowchart is repeatedly executed in a predetermined minute time cycle.

  In step S11, the controller skips the process until the detection signal of the pressure sensor 2131 becomes smaller than the reference value, and when it becomes smaller, the process proceeds to step S12.

  In step S12, the controller determines whether the timer is operating. If the determination result is negative, the controller proceeds to step S13, and if the determination result is positive, the controller proceeds to step S16. The timer is initially stopped.

  In step S13, the burner 23 is burned and an air purge operation is executed.

  In step S14, a timer is started.

  In step S15, a pipe cleaning operation is executed.

  In step S16, the controller skips the processes in and after step S17 until the timer elapses for 72 hours, and moves to step S17 when 72 hours elapses.

  In step S17, the air purge operation is performed without burning the burner 23.

  In step S18, the timer is reset.

  Next, the processing of the controller will be described. In the following description, step numbers of the flowcharts are described as appropriate so that the correspondence with the flowcharts can be easily understood.

  After bathing, when the bathtub tap is removed and the pressure sensor 2131 detects a drop in the water level (Yes in S11), the bath-going three-way valve 31 and the bath-returning three-way valve 32 are illustrated from the memorial state shown in FIG. 2 is switched to the air purge operation state shown in FIG. 2 to burn the burner 23 and perform the air purge operation (S13). As a result, hot water in the heating pipe including the air separator 33 is replaced. Then, the 72-hour timer is started (S14: starting point of 72-hour timer).

  After the next cycle, the timer is in operation, so steps S12 → S15 are processed. Then, the bath going-out three-way valve 31 and the bath return three-way valve 32 are set to the state when hot water is filled (FIG. 3), and the pipe cleaning is performed with the burner 23 burned (S16). As a result, the flow of hot water return pipe 222 → reheating heating heat exchanger 22 → hot water return pipe 221 → bath forward three-way valve 31 → bath forward pipe 411 and hot water return pipe 222 → bath return three-way valve 32 → bath return pipe The flow of 412 occurs, and the piping is cleaned.

  After the next cycle, since the piping has been cleaned, steps S15 → S17 are processed, and after 72 hours have passed (usually with the remote control turned off), steps S17 → S18 are processed to take a bath. The three-way valve 31 and the bath return three-way valve 32 are switched to the air purge operation state shown in FIG. 2, and the air purge operation is performed without burning the burner 23 (S18). Thus, the water in the heating pipe including the air separator 33 is replaced with cold water containing chlorine. Then, the 72-hour timer is reset (S19).

  After the next cycle, since the timer is operating and the pipe has been cleaned, the process is processed as step S12 → S15 → S17, and after 72 hours have elapsed (usually with the remote control turned off), step S17 → The process of S18 is performed, and the process of performing the air purge operation without burning the burner 23 (S18) is repeated.

  As described above, according to the present embodiment, the three-way valve is set to the remedy position in the normal state, and the bathtub draining operation performed at the end of bathing is detected by the pressure sensor 2131. Rinse the culvert pipe with hot water and wait for 72 hours. When 72 hours have passed, the three-way valve is set to the air purge position, and water is poured from the hot water dropping pipe 213 to fill the heating pipe with water containing chlorine and prevent germs from breeding. Then, after the predetermined amount of water has been flown, the three-way valve is returned to the memorial conduit position and waits, and this operation is repeated every 72 hours.

  By doing in this way, it is possible to prevent the germs that have grown in the heating pipeline during the next air purge operation or the next heating operation from entering the bathtub.

  Further, as described above, when the circulation pump 220 is driven without reheating, not only the bath return three-way valve 32 but also the bathtub side of the bath return three-way valve 31 is filled with hot water containing germs. Therefore, there is also a three-way valve 31 for taking a bath as a path for invasion of germs into the heating pipeline. In other words, regardless of whether or not the recirculation (combustion) is performed, when the circulation pump 220 is driven, bath water first reaches the bath return three-way valve 32, and then reaches the bath return three-way valve 31. Therefore, if at least the bathtub hot water reaches the bath return three-way valve 32, the bath hot water may enter the heating pipe due to the expansion and contraction of the hot water in the heating pipe, so that the bath hot water returns to the bath. On the condition that the three-way valve 32 is reached, the next air purge operation or the next time is performed by replacing the water in the heating pipeline in about 72 hours, which is shorter than the safety standard of about 100 hours in clean water. It is possible to prevent germs that have grown in the heating pipeline during heating operation from entering the bathtub.

  In addition, it can grasp | ascertain that the bathtub hot water reached the bath return three-way valve 32 by the time which the circulation pump 220 was driven. For example, the distance between the bathtub and the bath return three-way valve 32 (piping capacity), the distance between the bath return three-way valve 32 and the bath temperature sensor 2222 (piping capacity), and until the circulating pump 220 is driven to detect the hot water temperature in the bathtub. Therefore, it is sufficient to use this back calculation time after the next time.

  When the distance (pipe capacity) relationship is unknown, it may be determined that the bath water has reached the bath return three-way valve 32 when the bath temperature sensor 2222 detects the hot water temperature.

  Furthermore, when the bath automatic operation switch (hot water filling operation, reheating operation, automatic heat insulation operation) is set, it is necessary to circulate in order to see the temperature of the hot water in the bathtub, whether or not it burns in the reheating operation. Bathtub hot water reaches the bath temperature sensor 2222 by driving the pump 220 (because hot water is put into the bathtub regardless of whether bathing, miscellaneous bacteria enter the bath hot water). It may be determined that the hot water reaches the bath return three-way valve 32 (the situation where the circulating pump is driven and the bath hot water reaches the bath return three-way valve).

  In the case of contamination of germs in the bathtub during heating operation, if the hot water in the heating pipeline expands due to remembrance or rise in the bathroom room temperature and does not close tightly (failure or hair is entangled and not tightly closed) This occurs because hot water containing germs leaks from the bath return three-way valve 32 and the bath return three-way valve 31 into the memorial pipeline.

  In summer, the same thing happens because the pressure in the heating pipe rises due to the heat of the bath water and the heat of the bathroom, so the above measures are necessary even in summer.

(Second Embodiment)
FIG. 11 is a flowchart of control of the second embodiment of the hot water supply system. In the following description, parts having the same functions as those described above are denoted by the same reference numerals, and redundant description is omitted as appropriate.

  Next, a second embodiment will be described. In the first embodiment, when the bathtub draining operation performed at the end of bathing is detected by the pressure sensor 2131, the burner 23 is burned and the air purge operation is performed, so that the hot water in the heating pipeline including the air separator 33 is reduced. Replaced. On the other hand, in this 2nd Embodiment, the operation | movement which replaces the hot water inside a heating pipe line is abbreviate | omitted. Other operations are the same as those in the first embodiment.

  Even if it does in this way, it can prevent that the germ which grew in the heating pipe line at the next air purge operation or the next heating operation mixes in a bathtub. This is because the germs in the air separator 33 have a small amount of growth within 72 hours and can be mixed into the bathtub without any problem. The starting point of the 72-hour timer is the previous air purge operation, for example, the air purge operation 30 minutes before the scheduled bathing time (18:00).

(Application form)
FIG. 12 is a diagram illustrating an application form of the hot water supply system.

  In the above-described system, an example in which the overflow pipe 332 is provided has been described. In such a system, when negative pressure is generated, germs may enter the heating pipeline via the overflow pipe 332. However, in a system that switches with a three-way valve even in a system that does not have an overflow pipe 332, a similar situation occurs because the bath water containing germs passes through the three-way valve and enters the heating pipeline due to the failure of the three-way valve. In this way, germs grow in the heating circuit, and if automatic hot water filling is performed after that, if the germs that have propagated in the heating pipe flow into the bathtub due to automatic hot water filling, it will be a health hazard. However, the techniques of the first and second embodiments can be applied to a system that does not have the overflow pipe 332 as shown in FIG.

  First, even in a system that does not have an overflow pipe 332 and uses an expansion tank 33 instead of the air separator 33, bathtub water containing germs and organic matter that favors the growth of germs passes through the three-way valve and enters the heating pipeline. Explain what to do.

  In the reheating operation, as shown in FIG. 13, the circulation pump 220 is operated in a state in which the reheating heating heat exchanger 22 and the bathtub 40 are in communication by the bath going-out three-way valve 31 and the bath return three-way valve 32. Then, the hot water in the bathtub 40 becomes the circulation fitting 41 → the bath return pipe 412 → the bath return three-way valve 32 → the hot water return pipe 222 → the reheating heating heat exchanger 22 → the hot water pipe 221 → the bath forward three-way valve 31 → the bath forward pipe. It circulates in the order of 411 → circulation fitting 41 → tub 40 and is heated by the reheating heating heat exchanger 22.

  When the inside of the heating pipe is cooled before the bathtub tap is pulled out (especially in the winter, the inside of the heating pipe is easy to cool), as shown in FIG. 14, it contains various germs stored in the bath return pipe 412. Hot water may flow into the air separator 33. That is, when the inside of the heating pipeline cools, the inside of the heating pipeline becomes negative pressure. At this time, if the bath return three-way valve 32 is not sufficiently closed, the hot water stored in the bath return pipe 412 flows into the expansion tank 33 due to the negative pressure in the heating pipe.

  Further, the circulating pump 220 is driven and the bath temperature sensor 2222 detects the hot water temperature in the bathtub. If the hot water temperature is within a predetermined range of the set temperature of the remote controller, the circulating pump 220 is stopped without reheating. In this case, by driving the circulation pump 220, the hot water in the bathtub 40 is supplied from the circulation fitting 41 → the bath return pipe 412 → the bath return three-way valve 32 → the hot water return pipe 222 → the heating heat exchanger 22 → the hot water return pipe 221 → The flow goes from the bath going three-way valve 31 to the bath going pipe 411, and the circulation pump 220 is stopped, so that hot water containing various bacteria is filled in this path. Then, as shown in FIG. 15, hot water containing various bacteria stored in the bath outlet pipe 411 may flow into the heating outlet pipe 511. That is, when the inside of the heating pipeline cools, the inside of the heating pipeline becomes negative pressure. At this time, if the close-up of the three-way valve 31 is insufficient, hot water stored in the hot-out pipe 411 flows into the heating-out pipe 511 due to the negative pressure in the heating pipe.

  As described above, even in a system that does not have the overflow pipe 332 and uses the expansion tank 33 instead of the air separator 33, the bathtub water containing germs and organic matter that favors the propagation of germs passes through the three-way valve and enters the heating pipeline. Intrusions.

  Even in such a system, by executing the flowcharts shown in FIG. 10 and FIG. 11, it is possible to prevent the germs that have grown in the heating pipeline during the next air purge operation or the next heating operation from entering the bathtub.

  In such a system, the air purge operation is performed, for example, with the bath return three-way valve 32 and the bath going-out three-way valve 31 at 50% opening. When the air purge operation is performed in this manner, the hot water sent from the hot water dropping pipe 213 to the bath return three-way valve 32 is divided into an expansion tank connection pipe 331 and a bath return pipe 412 as shown in FIG. The hot water divided into the expansion tank connection pipe 331 flows through the expansion tank 33 → the heating return pipe 512 → the heating heat exchanger 51 → the heating forward pipe 511, reaches the bath going three-way valve 31, and flows through the hot water outgoing pipe 221. To the bathtub 40. In the system that does not have the overflow pipe 332 and uses the expansion tank 33 instead of the air separator 33, the air purge operation is performed in this way. Therefore, by executing the flowchart shown in FIG. 10 or FIG. It is possible to prevent germs that have grown in the heating pipeline during heating operation from entering the bathtub.

  In a system that does not have the overflow pipe 332 and uses the expansion tank 33 instead of the air separator 33, the air purge operation may be performed as follows. In other words, both the bath return three-way valve 32 and the bath return three-way valve 31 are not set to 50% opening, but only the bath return three-way valve 31 is set to 50% opening. When the air purge operation is executed in this way, as shown in FIG. 17, the entire amount of hot water sent from the hot water dropping pipe 213 to the bath return three-way valve 32 flows to the expansion tank connection pipe 331. Then, the flow goes through the expansion tank 33 → the heating return pipe 512 → the heating heat exchanger 51 → the heating forward pipe 511, reaches the bath going three-way valve 31, merges with the hot water flowing through the hot water going pipe 221, and reaches the bathtub 40. . Even if the air purge operation is performed in this way, the flowcharts shown in FIGS. 10 and 11 are executed to prevent the germs that have grown in the heating pipeline during the next air purge operation or the next heating operation from being mixed into the bathtub. Can do.

  As described above, there are various methods for the air purge operation, but the method is not particularly limited.

  Moreover, although it demonstrated using what used the hot water supply heat exchanger 21 and the reheating heating heat exchanger 22 as one can and two water, it may be two cans and two water.

  Although the example in which the bath automatic operation switch and the bathroom heating switch are set has been described, the bathroom heating is performed automatically using the outside temperature thermistor (not shown) of the hot water supply system 1 and the room temperature detection sensor 52 of the heating unit 50. When an operation switch is selected, the operation may be automatically determined.

  The first starting point of the 72-hour timer may be the time when the room temperature detection sensor 52 detects the temperature drop and the bathing ends, or the pressure sensor 2131 lowers the final water level (the bathing for a predetermined time does not occur after the water level drops due to the bathing end). It may be at the point of time when the wastewater is caught.

  The 72-hour timer is variably set according to the temperature detected by the room temperature detection sensor 52 (the lower the temperature of the bathroom, the lower the propagation temperature of germs in the heating pipeline, and it is difficult to propagate germs even for a long time. Setting).

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  For example, the fuel sent to the burner may be oil, not gas.

  The above embodiments can be appropriately combined.

DESCRIPTION OF SYMBOLS 1 Hot-water supply system 2 Hot-water heater 21 Hot-water supply heat exchanger 22 Reheating heating heat exchanger 201 Fin 23 Burner (gas burner)
221 Hot water pipe (return circulation passage)
222 Hot water return pipe (reflecting circulation return passage)
2222 Return hot water temperature sensor 3 Hot water branching unit 31 Three-way valve going out of the bath 32 Three-way valve returning to the bath 33 Air separator / expansion tank (storage part)
331 Air separator connection pipe (heating return passage)
332 Overflow pipe 40 Bathtub 411 Bath outlet pipe
412 Bath return pipe (return circulation return passage)
51 Heating Heat Exchanger 511 Heating Outpipe (Heating Outward Passage)
512 Heating return pipe (heating return passage)
S18 Water replacement part / Water replacement process

Claims (6)

A water heater with a burner located below the reheating heater,
A recirculation circulation path that is connected to the reheating heating heat exchanger and flows hot water from the reheating heating heat exchanger to the bathtub;
A recirculation circulation return passage that is connected to the bathtub and flows through the hot water flowing out of the bathtub toward the reheating heating heat exchanger,
A circulation pump for circulating hot water in the recirculation circulation return passage and the recirculation circulation return passage;
A three-way valve for bathing, which is arranged in the middle of the recirculation circulation path,
A bath return three-way valve disposed in the middle of the recirculation circulation return passage;
A heating passage that is connected to the three-way valve, and flows from the three-way valve to the heating heat exchanger.
A heating return passage connected to the heating heat exchanger, through which hot water flowing out of the heating heat exchanger and going to the bath return three-way valve flows,
A reservoir provided in the middle of the heating return passage;
After the circulating pump is driven, water in the heating heat exchanger, the heating forward passage, the heating return passage, and the storage portion is replaced within a time shorter than a predetermined time when clean water is safe. A water replacement part;
Having a hot water system. The hot water supply system according to claim 1,
The reservoir is an air separator,
One end is connected to the upper surface of the air separator, and the other end further has an overflow pipe that joins the recirculation circulation passage between the bath three-way valve and the bathtub,
Hot water system. The hot water supply system according to claim 1,
The reservoir is an expansion tank,
Hot water system. In the hot water supply system according to any one of claims 1 to 3,
The water replacement unit drives the circulation pump to perform water replacement when the bath water reaches the bath return three-way valve.
Hot water system. In the hot water supply system according to any one of claims 1 to 4,
The water replacement unit performs water replacement by performing an air purge operation without igniting the burner.
Hot water system. A water heater with a burner located below the reheating heater,
A recirculation circulation path that is connected to the reheating heating heat exchanger and flows hot water from the reheating heating heat exchanger to the bathtub;
A recirculation circulation return passage that is connected to the bathtub and flows through the hot water flowing out of the bathtub toward the reheating heating heat exchanger,
A circulation pump for circulating hot water in the recirculation circulation return passage and the recirculation circulation return passage;
A three-way valve for bathing, which is arranged in the middle of the recirculation circulation path,
A bath return three-way valve disposed in the middle of the recirculation circulation return passage;
A heating passage that is connected to the three-way valve, and flows from the three-way valve to the heating heat exchanger.
A heating return passage connected to the heating heat exchanger, through which hot water flowing out of the heating heat exchanger and going to the bath return three-way valve flows,
A reservoir provided in the middle of the heating return passage;
A method for operating a hot water supply system comprising:
After the circulating pump is driven, water in the heating heat exchanger, the heating forward passage, the heating return passage, and the storage portion is replaced within a time shorter than a predetermined time when clean water is safe. Having a water replacement step,
How to operate the hot water system.

Images