JP5857259B2 - Hot water system - Google Patents

Description

  The present invention relates to a hybrid hot water supply system including a hot water storage type hot water heater and a gas water heater that assists the hot water storage type water heater.

  As this type of hot water supply system, there is a heat pump water heater and a system that uses a supplemental water heater of another heat source to heat up until the boiling hot water rises, such as at the start of operation of the heat pump of this heat pump water heater. (For example, refer to Patent Document 1). The configuration of this type of hot water supply system is shown in FIG. The hot water supply system 100 includes a hot water storage type water heater (heat pump water heater) 101 and a gas water heater 102 provided on the downstream side thereof, and a hot water supply terminal 103 is connected via a hot water discharge pipe 103 on the downstream side of the gas water heater 102. Take a bath in Karan. In this hot water supply system 100, when the amount of hot water from the heat pump water heater 101 becomes insufficient due to an increase in the amount of hot water, the gas water heater 102 is operated.

JP 2007-255775 A

  In such a hot water supply system, when a gas water heater is used as an auxiliary water heater, if hot water of a predetermined temperature or higher is supplied to the gas water heater, an abnormal operation such as an inability to adjust the gas burner output may occur. At that time, the operation of the auxiliary water heater may stop and it may become impossible to discharge hot water.

  The present invention has been made to solve the above-described problem, and is in a hot water supply system having an auxiliary hot water heater for additionally cooking hot water from a hot water storage type hot water heater, and the auxiliary hot water supply using high temperature hot water from the hot water storage type hot water heater It is an object of the present invention to provide a hot water supply system capable of preventing abnormal operation of a heater.

In order to achieve the above object, a hot water supply system of the present invention is a hot water supply system comprising a hot water storage type hot water supply device and an auxiliary hot water supply device that is disposed downstream of the hot water supply path of the hot water storage type hot water supply device and additionally cooks the hot water. A bypass pipe for directly discharging hot water from the hot water storage type water heater to the hot water supply terminal by bypassing the auxiliary hot water heater, and hot water from the hot water storage type water heater to the hot water supply terminal via the auxiliary hot water heater. An auxiliary pipe for discharging hot water and hot water from the hot water storage type water heater are passed through the bypass pipe when the hot water temperature is higher than a predetermined temperature, and are connected to the auxiliary pipe when the hot water temperature is lower than the predetermined temperature. switch comprising a switching valve, the said predetermined temperature and is Ri lower temperature der than the set temperature of the hot water to be tapped from the hot-water supply terminal, and the temperature of the feed water to the auxiliary water heater increases the auxiliary water heater Cause abnormal operation An abnormal operating temperature of the feeder, characterized in that.

  In this hot water supply system, a temperature sensor for detecting the temperature of hot water from the hot water storage type water heater, and switching of the switching valve and operation of the auxiliary water heater according to the hot water temperature detected by the temperature sensor, respectively. And a control unit for controlling.

  According to the hot water supply system of the present invention, when the hot water temperature from the hot water storage type hot water heater is low, the hot water can be reheated by the auxiliary hot water heater, and the hot water temperature is high enough to cause abnormal operation in the auxiliary hot water heater. In such a case, it is possible to prevent abnormal operation from occurring by bypassing the auxiliary water heater and discharging the hot water.

The lineblock diagram of the hot-water supply system concerning a 1st embodiment of the present invention. The figure explaining the hot water supply path | route when there is not enough hot water in a heat pump water heater with a system same as the above. The block diagram of the modification of the said embodiment. The block diagram of the hot-water supply system which concerns on the 2nd Embodiment of this invention. The figure explaining the hot water supply path | route when there is not enough hot water in a heat pump water heater with a system same as the above. The block diagram of the conventional hot-water supply system.

(First embodiment)
A hot water supply system according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, a hot water supply system 1 includes a hot water storage type hot water heater 2, an auxiliary hot water heater 3 such as a gas water heater disposed downstream thereof, and hot water from these water heaters to a hot water supply terminal 4. There are provided a hot water supply pipe 5, a switching valve 6 disposed in the hot water supply pipe 5, and a control unit 7 for controlling the system. The hot water storage type hot water heater 2 includes a heat pump water heater (referred to as HP water heater) having a heat pump (referred to as HP), and is connected to a water supply pipe 8 for supplying city water. Here, the hot water supply terminal 4 is assumed to be currant. The control unit 7 has a setting unit 9 for setting the temperature of hot water discharged from the hot water storage type water heater 2 and the auxiliary water heater 3, and controls the entire system including the water heaters 2, 3 and the switching valve 6. To do. In the hot water supply system 1, when the temperature of the hot water from the hot water storage type hot water heater 2 is not more than a predetermined temperature, the auxiliary hot water heater 3 is automatically operated to make additional hot water and take out the hot water. Moreover, when the temperature of the hot water from the hot water storage type hot water heater 2 is higher than a predetermined temperature, the auxiliary hot water heater 3 is bypassed and discharged.

  The hot water storage type water heater 2 includes a heat source device 21 made of HP for boiling water supply, a tank 22 for storing hot water boiled by the heat source device 21, and a hot water amount sensor 23 for detecting the amount of hot water stored in the tank 22. The mixing valve 24 is attached to the upper side of the tank 22. The mixing valve 24 has a three-way valve, and the water supply pipe 8 and the high temperature pipe 25 from the upper part of the tank 22 are connected to the two sides, respectively, and the remaining one is connected to the relay pipe 51 of the tap water pipe 5. Yes. Further, a temperature sensor 26 for detecting the temperature of the hot water from the hot water storage type hot water heater 2 is provided on the side close to the mixing valve 24 of the relay pipe 51. The hot water amount sensor 23 and the temperature sensor 26 send a hot water amount detection signal and a temperature detection signal to the control unit 7, respectively.

  The heat source device 21 has a feed pump (not shown), and sucks water from the bottom of the tank 22 through a connection pipe to boil it. This boiling hot water is supplied to the top of the tank 22 through another connecting pipe. In addition, the heat source device 21 is controlled by the control unit 7 to boil the feed water so that the boiling temperature set by the setting unit 9 is reached. This boiling temperature is set, for example, near 90 ° C.

  The tank 22 is connected to the water supply pipe 8 on the bottom side thereof, stores water that is injected by the supply water pressure, and stores boiling hot water from the heat source unit 21 on the top side. Here, in the tank 22, a temperature stratification of a high temperature region 22 a and a medium and low temperature region 22 b that becomes an intermediate temperature and a low temperature is formed from the top to the bottom. The layer width in these regions changes with the amount of hot water discharged from the hot water storage type hot water heater 2, and when the amount of hot water is large, the high temperature region 22a becomes narrower and the middle / low temperature region 22b becomes wider.

  The hot water sensor 23 is composed of a plurality of temperature sensors arranged from the upper part to the lower part of the tank 22, detects the hot water temperature at each position of the tank 22 by each temperature sensor, and sends it to the control unit 7 as a hot water quantity detection signal. The controller 7 detects the remaining hot water amount in the tank 22 based on the position information and temperature information from the hot water detection signal. A flow meter (not shown) may be provided in the relay pipe 51, and the amount of hot water may be detected based on the flow rate measured by the flow meter and the temperature of the hot water detected by the temperature sensor 26. Moreover, you may use a thermocouple etc. for a temperature sensor.

  The mixing valve 24 is a temperature adjustment valve for adjusting the hot water supply temperature from the hot water storage type water heater 2, and mixes the hot water supplied from the tank 22 through the high temperature pipe 25 and the water supply from the water supply pipe 8. The mixture ratio is varied to adjust the temperature of the mixed hot water and discharge the hot water. Here, the mixing ratio of the mixing valve 24 is adjusted based on the hot water temperature (for example, 90 ° C.) at the top of the tank 22 and the water supply temperature at the bottom, and the control unit 7 sets the hot water supply temperature Ta from the mixed water. The temperature is controlled to be the set temperature Ts set in 9. The mixing valve 24 can also be controlled based on temperature information from the temperature sensor 26. The mixing valve 24 is not limited to this as long as the hot water supply temperature Ta of the hot water from the hot water storage type water heater 2 can be set to the set temperature Ts and discharged. Further, the temperature of the water supply from the water supply pipe 8 is detected by providing a temperature sensor (not shown) on the water supply pipe 8 side.

  The auxiliary hot water heater 3 is located in the auxiliary pipe 53 of the hot water supply pipe 5 and is arranged in series with the hot water storage type hot water heater 2 on the downstream side of the hot water supply path, and cooks the hot water. The auxiliary water heater 3 includes a heating unit 31 for boiling water supply, an internal pipe 32, and a temperature sensor 33 for detecting a hot water supply temperature from the heating unit 31, and the internal pipe 32 is located in the auxiliary pipe 53. Then, it is piped in series with it and passes through the heating unit 31. The auxiliary water heater 3 is automatically stopped when water is not supplied in the internal pipe 32.

  When the auxiliary water heater 3 is a gas water heater, the heating unit 31 uses a heat exchanger having a gas burner as a heat source, and can rapidly heat the hot water in the internal pipe 32 passing through the heat exchanger. Yes. The temperature sensor 33 detects, for example, the hot water temperature Tb near the internal pipe 32 of the hot water outlet of the auxiliary water heater 3 and sends the temperature detection signal to the control unit 7. Based on this temperature detection signal, the control unit 7 controls the heating unit 31 so that the tapping temperature Tb becomes a set temperature Ts desired by the user (for example, 42 ° C.). At this time, the hot water temperature Tb from the auxiliary water heater 3 is controlled so as to always become the set temperature Ts, and the hot water is supplied to the currant 4 at a constant temperature. The internal pipe 32 may have a shut-off valve for shutting off the hot water when the auxiliary water heater 3 operates abnormally.

  The hot water supply pipe 5 includes a relay pipe 51 for relaying the hot water storage type water heater 2 and the currant 4, and a bypass pipe 52 and an auxiliary pipe 53 that are between the relay pipe 51 and the currant 4 and are branched from the relay pipe 51. The switching valve 6 connected to these pipes 52 and 53 and an output pipe 54 are provided. The output pipe 54 is a pipe connecting the switching valve 6 and the currant 4. The bypass pipe 52 is a pipe for bypassing the auxiliary water heater 3 and directly discharging the hot water from the hot water storage type water heater 2 to the currant 4. The auxiliary pipe 53 is a pipe for discharging hot water from the hot water storage type water heater 2 to the currant 4 via the auxiliary water heater 3.

  The switching valve 6 is composed of a three-way valve, and the two input ends thereof are connected to the downstream ends of the bypass pipe 52 and the auxiliary pipe 53, respectively, and the other one is connected to the output pipe 54. The switching valve 6 switches whether the hot water from the hot water storage type water heater 2 is passed through the bypass pipe 52 or the auxiliary pipe 53.

  The setting unit 9 stores input means (not shown) for setting each hot water supply temperature of the hot water storage type hot water heater 2 and the auxiliary hot water heater 3 and data of the set temperatures inputted from the input means. And each data in the storage unit is supplied to the control unit 7. The storage unit also stores a mixing ratio for obtaining a set temperature Ts adjusted by the mixing valve 24. Based on this mixing ratio, the control unit 7 controls the mixing valve 24 so that the hot water supply temperature Ta to the relay pipe 51 is the set temperature Ts.

  The control unit 7 includes a microcomputer, controls the boiling of the heat source unit 21 based on the amount of remaining hot water in the tank 22 detected by the hot water sensor 23, changes the mixing ratio of the mixing valve 24, and stores hot water. The hot water supply temperature Ta from the container 2 is controlled to be the set temperature Ts set by the setting unit 9. Further, the control unit 7 switches the switching valve 6 and controls the operation of the auxiliary water heater 3 based on the temperature detected from the temperature sensor 26.

  Moreover, the control part 7 is based on the temperature detection signal from the temperature sensor 33, and the auxiliary | assistant water heater 3 is set so that the hot water supply temperature Tb of the auxiliary | assistant water heater 3 becomes the preset temperature (for example, Ts) set by the setting part 9. FIG. The heat source unit 31 is controlled. The control unit 7 may be provided in each of the hot water storage type water heater 2 and the auxiliary water heater 3.

  In this hot water storage type hot water heater 2, the setting unit 9 sets the boiling temperature of the heat source unit 21 to 90 ° C. which is close to the maximum boiling possible temperature, for example, the set temperature of the hot water supply temperature Ta from the hot water storage type water heater 2. Ts is set to the operating temperature (for example, 42 ° C.). At this time, the mixing valve 24 is set so that the mixed hot water of the high-temperature hot water and the feed water having a mixing ratio of 90 ° C. becomes the operating temperature, and supplies the mixed hot water to the relay pipe 51. In the auxiliary water heater 3, for example, the tapping temperature Tb is set to the same set temperature Ts as the hot water temperature Ta from the hot water storage type water heater 2.

  Here, control of the hot water supply system 1 by the control unit 7 will be described. The control unit 7 normally controls the hot water supply water heater 2 to keep the hot water supply temperature Ta at the set temperature Ts based on the hot water amount detection signal from the hot water sensor 23. Here, control of the switching valve 6 by the control unit 7 in this state will be described.

  As shown in FIG. 1, when the hot water storage hot water heater (HP water heater) 2 has a sufficient amount of remaining hot water, the switching valve 6 is switched so that the bypass pipe 52 and the output pipe 54 on the water supply side are connected, Hot water from the hot water storage type water heater 2 is directly discharged to the currant 4. Here, a predetermined temperature lower than the set temperature Ts is set in advance by the setting unit 9, and the control unit 7 determines the hot water supply temperature Ta of the hot water from the hot water storage type water heater 2 based on the temperature detection signal from the temperature sensor 26. If it is higher than the predetermined temperature, the switching valve 6 is controlled to be switched to the bypass pipe 52 side.

  For example, when the auxiliary water heater 3 is a gas water heater, the temperature of the water supplied to the auxiliary water heater 3 becomes high and the abnormal water heater 3 operates abnormally. When the abnormal operating temperature is set. The abnormal operation of the gas water heater is, for example, when the temperature difference between the temperature of hot water supplied to the gas water heater and the temperature of hot water discharged from the gas water heater (set temperature Ts) cannot be secured, the gas burner output adjustment For example, the gas water heater is suddenly stopped.

  Next, with reference to FIG. 2, the control by the control unit 7 when the hot water storage type hot water heater (HP water heater) 2 does not have a sufficient amount of remaining hot water will be described. In the hot water storage type water heater 2, when the amount of hot water discharged from the currant 4 suddenly increases, or when the amount of hot water stored in the tank 22 decreases due to a rapid decrease in the ambient temperature, the heat source machine 21 Heating up may not be in time, and the amount of hot water stored in the tank 22 may be insufficient. For this reason, the adjustment of the hot water supply temperature Ta by the mixing valve 24 becomes a limit, and the hot water supply temperature Ta is lowered without being maintained at the set temperature Ts.

  At this time, as described above, when the hot water storage water heater 2 does not have a sufficient amount of remaining hot water and the temperature of the hot water from the hot water storage water heater 2 is equal to or lower than a predetermined temperature, the hot water passes through the auxiliary water heater 3. Then, the switching valve 6 is switched so that the hot water is discharged from the currant 4 through the auxiliary pipe 53. That is, the control unit 7 connects the auxiliary pipe 53 and the output pipe 54 when detecting that the hot water supply temperature Ta of the hot water storage type water heater 2 has dropped below a predetermined temperature based on the temperature detection signal of the temperature sensor 26. Thus, the switching valve 6 is switched. As a result, hot water from the hot water storage type water heater 2 is supplied to the auxiliary water heater 3, and the control unit 7 operates the auxiliary water heater 3 to compensate for the shortage of hot water supply in the tank 22. Heat to Ts and pour out.

  Specifically, for example, when the controller 7 reduces the amount of stored hot water in the tank 22 and the hot water supply temperature Ta is lower than a set temperature Ts (for example, 42 ° C.) and lower than a predetermined temperature, for example, 35 ° C. or less, The switching valve 6 is switched to the auxiliary piping 53 side, and the auxiliary water heater 3 is operated. Here, based on the temperature detected from the temperature sensor 33 of the auxiliary water heater 3, the heating unit 31 is controlled so that the tapping temperature Tb becomes the set temperature Ts. Thereby, the hot water temperature Tb from the auxiliary water heater 3 is maintained at the set temperature Ts, and hot water at the set temperature Ts is discharged from the currant 4.

  Here, in the state where the hot water is discharged from the auxiliary water heater 3, the controller 7 increases the amount of remaining hot water in the tank 22, and the temperature of the hot water supplied from the hot water storage type water heater 2 rises, and is detected by the temperature sensor 26. When the supplied hot water temperature Ta becomes higher than the predetermined temperature, the switching valve 6 is switched to the bypass pipe 52 side. At the same time, the control unit 7 stops the auxiliary water heater 3. That is, in the auxiliary water heater 3 using the gas water heater, the temperature of the water supply becomes higher while heating the water supplied from the hot water storage type water heater 2, and the temperature difference between the water supply temperature and the hot water temperature from the gas water heater is high. Before it can not be secured, the hot water piping is switched and heating is stopped. Therefore, since the operation of the auxiliary water heater 3 is stopped before hot water higher than the predetermined temperature is supplied, abnormal operations such as inability to adjust the gas burner output do not occur.

  Further, when the auxiliary water heater 3 heats the hot water supplied from the hot water storage type hot water heater 2, the hot water in the tank 22 in which the heat source device 21 is operating is higher in temperature than the water supply temperature, for example, about 30 ° C. Then, what is necessary is just to cook up from 30 degreeC hot water to preset temperature Ts (for example, 42 degreeC). Usually, the auxiliary hot water heater 3 decreases the amount of hot water that can be discharged as the temperature of the supplied water is lower, and increases the amount of hot water that is supplied as the temperature of the supplied water is higher. Here, the auxiliary water heater 3 only needs to boil from 30 ° C., so that it can supply a sufficient amount of hot water even if its discharge capacity is reduced compared to an auxiliary water heater that boils from a water temperature to 42 ° C., for example. This makes it possible to use a small water heater, saving space and reducing costs.

  According to the hot water supply system 1 of the present embodiment, when the hot water from the hot water storage type hot water heater 2 is higher than a predetermined temperature at which an abnormal operation occurs in the auxiliary hot water heater 3, the hot water can be discharged by bypassing the auxiliary hot water heater 3. Occurrence of abnormal operation in the auxiliary water heater 3 such as a gas water heater can be prevented in advance. Moreover, when the hot water supply temperature Ta of the hot water storage type hot water heater 2 is lowered to a predetermined temperature or less, the insufficient heat amount of the hot water can be directly compensated by the auxiliary hot water heater 3, and hot water shortage can be prevented.

  Further, since the auxiliary water heater 3 is continuously connected to the hot water storage type water heater 2 through the relay pipe 51 and the auxiliary pipe 53 and is always in a state where hot water can be supplied from the hot water storage type water heater 2, the switching valve 6 is connected to the auxiliary pipe 53 side. When switched to, the hot water from the hot water storage type water heater 2 can be immediately heated and discharged.

  In addition, if the hot water supply temperature Tb does not rise even if the auxiliary water heater 3 operates for a certain period of time with the control unit 7 and the like provided with a timer and the switching valve 6 switched to the auxiliary pipe 53 side, the auxiliary hot water supply The vessel 3 may be stopped and the switching valve 6 may be forcibly switched to the bypass piping 52 side.

  Also, a second mixing valve is provided in the auxiliary pipe 53 on the outlet side of the auxiliary water heater 3, the temperature setting of the hot water of the auxiliary water heater 3 is set to a set temperature Th higher than the set temperature Ts, and the hot water and the water supply pipe You may adjust so that the mixed hot water which mixed the water supply from 8 with the 2nd mixing valve may become preset temperature Ts. Thereby, even when the water supply temperature to the auxiliary water heater 3 becomes high, the temperature difference between the hot water supply temperature to the auxiliary water heater 3 and the hot water temperature (set temperature Th) from the auxiliary water heater 3 can be maintained. The abnormal operating temperature of the gas water heater can be increased. That is, it becomes difficult for the auxiliary water heater 3 to generate an abnormal operation with high-temperature hot water, the abnormal operation temperature can be increased, and the predetermined temperature can be increased correspondingly, so that the setting of the hot water heater 2 can be set. The temperature can be brought close to Ts.

  Therefore, when the hot water of the hot water storage type hot water heater 2 is discharged through the bypass pipe 52, the amount of hot water decreases, and the hot water is discharged at a temperature up to a predetermined temperature lower than the set temperature Ts before switching to the auxiliary pipe 53. By raising the predetermined temperature, the tapping temperature can be made substantially equal to the set temperature Ts. As a result, regardless of whether the hot water from the hot water storage type hot water heater 2 passes through the bypass pipe 52 or the auxiliary pipe 53, the hot water can always be discharged from the currant 4 at a hot water supply temperature close to the set temperature Ts, and hot water shortage is suppressed. Is done.

(Modification)
FIG. 3 shows a modification of the above embodiment. In this modification, the auxiliary water heater 3 includes a temperature sensor 33 and a controller 34 that controls the operation of the auxiliary water heater 3 based on the temperature sensor 33. In this modified example, the auxiliary hot water heater 3 is not controlled from the external control unit 7 but can be controlled independently in the auxiliary hot water heater 3.

  When there is water supply, the auxiliary water heater 3 automatically operates under the control of the control unit 34 based on the information on the amount of hot water from a hot water sensor (not shown) or the like, and raises the passing hot water temperature. When a gas water heater is used as the auxiliary water heater 3, if there is a temperature difference between the temperature of the water supplied to the auxiliary water heater 3 and the temperature of the hot water discharged therefrom, the gas burner output adjustment is performed as described above. Although an abnormal operation that cannot be performed occurs, this abnormal operation can be avoided by switching the switching valve 6. In this modification, the operation can be controlled by the auxiliary water heater 3 itself, so that the configuration of the system control system is simplified. Note that the control unit 34 uses not only feedback control using a microcomputer but also a contact changeover switch that automatically switches the contact point by a physical change due to temperature using, for example, a bimetal, and the auxiliary water heater 3 is turned on and off. Control may be performed by automatically switching depending on the temperature of the feed water passing through the. In addition, the operation of the auxiliary water heater 3 may be switched at a temperature such as a hot water temperature without using a temperature sensor by using the contact switching switch or the like. Further, the contact changeover switch may be formed using a shape memory alloy that undergoes temperature deformation.

(Second Embodiment)
A hot water supply system according to a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, the hot water supply system 1 of the present embodiment has the same configuration as that of the above embodiment except that the switching valve 6 is disposed on each upstream side of the bypass pipe 52 and the auxiliary pipe 53. Perform the operation.

  The switching valve 6 has a downstream end of the relay pipe 51 at one input end of the switching valve 6 and an upstream end of each of the bypass pipe 52 and the auxiliary pipe 53 at two output ends thereof. Arranged to connect. When the hot water from the hot water storage type hot water heater 2 is higher than a predetermined temperature, the switching valve 6 is switched to connect the relay pipe 51 and the bypass pipe 52 so that the hot water from the hot water storage type hot water heater 2 is below the predetermined temperature. At times, the relay pipe 51 and the auxiliary pipe 53 are switched to be connected.

  The hot water supply pipe 5 has a three-branch pipe 55 for connecting the downstream end of each of the bypass pipe 52 and the auxiliary pipe 53 and the output pipe 54. Each of the bypass pipe 52 and the auxiliary pipe 53 has a check valve (not shown) in the vicinity of the three-branch pipe 55 so that only one direction of the output pipe 54 discharges hot water from these pipes. The three-branch pipe 55 may be a switching valve including a three-way valve that switches and connects either the bypass pipe 52 or the auxiliary pipe 53 to the output pipe 54.

  In this hot water supply system 1, the hot water from the hot water storage type hot water heater 2 is switched to pass through the bypass pipe 52 by the switching valve 6 when the amount of hot water remaining in the tank 22 is sufficient and the temperature is higher than a predetermined temperature. The hot water is discharged from the three-branch pipe 55 through the output pipe 54 to the currant 4.

  Further, as shown in FIG. 5, when the hot water from the hot water storage type water heater 2 does not have a sufficient amount of remaining hot water in the tank 22 and its temperature falls below a predetermined temperature, the auxiliary valve 53 is connected by the switching valve 6. It is switched to pass, heated by the auxiliary water heater 3 and discharged from the three-branch pipe 55 to the currant 4.

  In the present embodiment, when the hot water from the hot water storage type hot water heater 2 is higher than a predetermined temperature, the upstream end of the auxiliary pipe 53 is disconnected from the relay pipe 51, so no hot water is supplied to the auxiliary water heater 3. Therefore, even if the auxiliary water heater 3 malfunctions, no hot water is discharged.

  In addition, this invention is not restricted to the structure of said embodiment, A various deformation | transformation is possible in the range which does not change the summary of invention. For example, in each of the above embodiments, the auxiliary water heater may be an electric water heater or a water heater using other heat sources such as kerosene, petroleum, solar heat, and a fuel cell in addition to the gas water heater. The auxiliary water heater may be provided with a plurality of gas water heaters and the like, and these may be arranged in series with each other.

DESCRIPTION OF SYMBOLS 1 Hot water supply system 2 Hot water storage type water heater 26 Temperature sensor 3 Auxiliary hot water heater 4 Karan (hot spring terminal)
5 Hot water piping (bypass piping, auxiliary piping)
52 Bypass piping 53 Auxiliary piping 6 Switching valve 7 Control unit

Claims (2)

In a hot water supply system comprising a hot water storage type hot water heater and an auxiliary hot water heater that is arranged downstream of the hot water supply path of the hot water storage type hot water heater and cooks the hot water,
By-pass piping that bypasses the auxiliary water heater and directly discharges hot water from the hot water heater,
Auxiliary piping for discharging hot water from the hot water storage type water heater to the hot water supply terminal via the auxiliary water heater,
A switching valve that switches the flow path so that hot water from the hot water storage type water heater passes through the bypass pipe when the hot water temperature is higher than a predetermined temperature, and passes through the auxiliary pipe when the hot water temperature is lower than a predetermined temperature; Prepared ,
Wherein the predetermined temperature, Ri lower temperature der than the set temperature of the hot water to be tapped from the hot-water supply terminal, when and the auxiliary water heater abnormal operation at a temperature of the feed water is higher becomes the auxiliary water heater to occur A hot water supply system characterized by an abnormal operating temperature . A temperature sensor for detecting the temperature of hot water from the hot water storage type water heater;
The hot water supply system according to claim 1, further comprising: a control unit that controls switching of the switching valve and operation of the auxiliary water heater in accordance with the hot water temperature detected by the temperature sensor. .

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