JP6776751B2 - Water heater and hot water supply system - Google Patents

Description

The disclosed embodiments relate to water heaters and hot water supply systems.

Conventionally, as a water heater that heats water supplied from a water source such as a water pipe to generate hot water, a so-called hot water storage type water heater having a structure equipped with a tank provided inside is widely known ( For example, see Patent Document 1). In such a water heater, the water supplied from the water source is heated by a heater until it reaches a relatively high temperature and stored in the tank, and the relatively high temperature water in the tank and the water from the water source are transferred downstream of the tank. It is mixed at the mixing part on the side to make hot water at an appropriate temperature, and it is discharged from the faucet.

Further, as another type of water heater, an instantaneous water heater that directly heats running water without providing a tank is also known (see, for example, Patent Document 2). In such a water heater, the water supplied from the water source is instantaneously heated by a heater provided in the flow path to reach a desired temperature, and the water is discharged from the faucet.

Japanese Unexamined Patent Publication No. 2012-112597 Japanese Unexamined Patent Publication No. 11-264612

However, in the hot water storage type water heater, when the amount of continuous hot water discharged from the faucet is increased, the capacity of the tank is increased, so that the water heater becomes large. In addition, in the instantaneous water heater that does not have a tank and raises the temperature of the water supplied from the water source to the appropriate temperature, the power consumption becomes large in order to achieve the same flow rate and discharge temperature as the hot water storage type. .. As described above, there is room for improvement in the prior art in that the amount of continuous hot water is increased while suppressing the power consumption.

One aspect of the embodiment is made in view of the above, and an object of the present invention is to provide a water heater and a hot water supply system capable of increasing the amount of continuous hot water output while suppressing power consumption.

The water heater according to one aspect of the embodiment includes a flow path through which water supplied from the water source flows, a tank provided in the flow path for storing water, and a water heater provided in the tank and stored in the tank. A first heating unit that raises the temperature of water, a bypass flow path that branches from the flow path on the upstream side of the tank, bypasses the tank, and joins the flow path on the downstream side of the tank, and the bypass. A second temperature raising section provided in the flow path for raising the temperature of water in the bypass flow path is provided at a confluence position between the flow path and the bypass flow path, and is supplied from the tank to raise the temperature of the first temperature. It is characterized by including a mixing section for mixing the water heated by the section and the water supplied from the bypass flow path and heated by the second heating section.

In this way, in the water heater, the first temperature rising section of the tank and the second temperature rising section of the bypass flow path are provided in parallel, and the water heated by the first and second temperature rising sections is mixed in the mixing section. I tried to make it. As a result, in the water heater, the amount of continuous hot water can be increased while suppressing the increase in size of the tank and the power consumption.

Specifically, by mixing the hot water in the tank heated in the first temperature raising section and the hot water heated in the second heating section, the hot water in the tank heated in the first heating section can be obtained. Compared with the conventional hot water storage type water heater that mixes and uses unheated water, it is possible to reduce the consumption of hot water in the tank when discharging the same temperature and the same flow rate. On the other hand, compared to an instantaneous water heater that does not have a tank and produces hot water only by heating in the second temperature riser, the heating performance of the second temperature riser may be lower, so a heater with low power consumption or the like may be used. 2 It can be used as a temperature rising unit.

Further, the second temperature raising unit is a heater that heats the water flowing in the bypass flow path to raise the temperature. As a result, the heat dissipation loss can be reduced as compared with the case where the hot water storage tank is provided in the bypass flow path, and the water in the bypass flow path can be efficiently heated.

Further, the control unit for controlling the first temperature raising unit and the second temperature rising unit is provided, and the control unit exclusively operates the first temperature rising unit and the second temperature rising unit. And. By preventing the first temperature rising unit and the second temperature rising unit from operating at the same time in this way, it is possible to suppress, for example, the maximum power consumption of the water heater.

Further, the control unit includes a control unit that controls the first temperature raising unit and the second temperature rising unit, and an on-off valve that is provided in the flow path and opens and closes the flow path. The control unit has the on-off valve. When the valve is opened, the second temperature rising section is operated. As a result, it is possible to prevent the second heating unit from empty-heating or overheating the bypass flow path.

Further, the control unit is provided with a flow detection unit that is provided in the flow path and detects whether or not water is flowing in the flow path. The control unit has the on-off valve opened and is described by the flow detection unit. When it is detected that water is flowing in the flow path, the second temperature raising unit is operated.

As a result, it is possible to reliably prevent the second heating unit from empty-heating or overheating the bypass flow path. Specifically, when the user reaches out to the faucet, the on-off valve opens, but for example, a water outage may occur and water from the water source may not be supplied to the flow path or the bypass flow path. If the second temperature riser operates in such a case, dry heating or overheating will occur, but when the flow detection unit detects that water is flowing in the flow path, the second rise By activating the hot part, it is possible to surely prevent empty heating or overheating.

Further, a control unit for controlling the first temperature raising unit and the second temperature rising unit, and a second unit provided on the upstream side of the second temperature rising unit in the bypass flow path to detect the water temperature of the bypass flow path. The control unit includes one water temperature detecting unit, and the control unit operates the second temperature raising unit based on the water temperature of the bypass flow path detected by the first water temperature detecting unit. As a result, unnecessary operation of the second temperature raising unit can be prevented, and power consumption can be suppressed.

Further, the second temperature raising unit is an electric heater that heats the water flowing in the bypass flow path to raise the temperature, and the control unit measures the amount of electricity supplied by the second temperature rising unit. It is characterized in that the water temperature of the bypass flow path detected by the first water temperature detection unit is set to increase as the water temperature decreases.

As a result, for example, even when the water temperature of the bypass flow path detected by the first water temperature detection unit is low, the amount of energization of the second temperature riser unit increases and the amount of heat generated increases, so that the bypass flow path The temperature of water can be raised to a desired temperature, and it is possible to prevent the amount of continuous hot water from decreasing.

Further, a control unit for controlling the first temperature raising unit and the second temperature rising unit, and a second unit provided on the downstream side of the second temperature rising unit in the bypass flow path to detect the water temperature of the bypass flow path. The control unit includes two water temperature detection units, and the control unit operates the second temperature riser unit based on the water temperature of the bypass flow path detected by the second water temperature detection unit. This makes it possible to suppress the power consumption in the second temperature raising unit.

Further, the second temperature raising unit is an electric heater that heats the water flowing in the bypass flow path to raise the temperature, and the control unit measures the amount of electricity supplied by the second temperature rising unit. It is characterized in that the water temperature of the bypass flow path detected by the second water temperature detection unit is set to increase as the water temperature decreases.

As a result, for example, even when the water temperature of the bypass flow path detected by the second water temperature detection unit is low, the amount of energization of the second temperature riser unit increases and the amount of heat generated increases, so that the bypass flow path The temperature of water can be raised to a desired temperature, and it is possible to prevent the amount of continuous hot water from decreasing.

Further, the hot water supply system according to one aspect of the embodiment is characterized by including any one of the above-mentioned water heaters and a faucet for discharging hot water generated by the water heater. As a result, the amount of continuous hot water output can be increased in the hot water supply system.

According to one aspect of the embodiment, the amount of continuous hot water output can be increased in the water heater and the hot water supply system.

FIG. 1 is a front view showing a hot water supply system including a water heater according to the first embodiment. FIG. 2 is a block diagram showing a configuration example of a water heater. FIG. 3 is a block diagram showing a configuration example of a water heater provided with a control device. FIG. 4 is a flowchart showing a processing procedure of heater control executed by the control device. FIG. 5 is a block diagram showing a configuration example of the water heater according to the first modification. FIG. 6 is a block diagram showing a configuration example of the water heater according to the second modification. FIG. 7 is a diagram showing energization amount information in the second embodiment. FIG. 8 is a flowchart showing a procedure for controlling the energization amount of the second heater executed by the control device according to the second embodiment. FIG. 9 is a diagram showing energization amount information in the third embodiment. FIG. 10 is a flowchart showing a procedure for controlling the energization amount of the second heater executed by the control device according to the third embodiment.

Hereinafter, embodiments of the water heater and the hot water supply system disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

(First Embodiment)
FIG. 1 is a front view showing a hot water supply system including a water heater according to the first embodiment. As shown in FIG. 1, the hot water supply system 1 includes a water supply pipe 10, a water heater 20, a hot water outlet pipe 30, a faucet 100, and a washbasin 110.

The water supply pipe 10 is connected to a water source such as a water pipe (not shown) via a water stop valve 11 provided on the wall surface W. Therefore, water from the water source flows through the water supply pipe 10. Then, the water supply pipe 10 supplies water from the water source to the water heater 20.

The water heater 20 heats the water supplied from the water supply pipe 10 to generate hot water. The water heater 20 is attached to the wall surface W, for example, but this is an example and is not limited, and the water heater 20 may be installed on the floor F. The specific configuration of the water heater 20 will be described with reference to FIGS. 2 and 2.

The hot water outlet pipe 30 is connected to the water heater 20 and the faucet 100, and supplies the hot water generated by the water heater 20 to the faucet 100.

The faucet 100 is an automatic faucet that discharges hot water when a user's hand or the like (not shown) is extended. Specifically, the faucet 100 has a built-in human body detection sensor 101. Although the human body detection sensor 101 is built in the faucet 100 here, the present invention is not limited to this, and the human body detection sensor 101 may be attached to the washbasin 110 or other places.

When the user's hand or the like is extended below the discharge port 102 of the faucet 100, the human body detection sensor 101 outputs a detection signal indicating that the hand or the like has been detected to the water heater 20. Then, while the detection signal is being output from the human body detection sensor 101, the water heater 20 supplies the generated hot water to the faucet 100 via the hot water outlet pipe 30 and discharges the generated hot water from the discharge port 102. As the human body detection sensor 101, a non-contact infrared sensor can be used, but the present invention is not limited to this.

The wash basin 110 receives the hot water discharged from the faucet 100, and drains the received hot water from the drain pipe 111.

Next, the configuration of the water heater 20 will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration example of the water heater 20. As shown in FIG. 2, the water heater 20 includes a water supply unit 41, a flow path 42, a check valve 43, a solenoid valve 44, a tank 45, a first heater 46, a bypass flow path 52, and a second. The two heaters 56, the mixing unit 61, the hot water outlet unit 62, the case unit 80, and the control device 90 are provided.

The water supply unit 41 can be connected to the water supply pipe 10 described above, and water from the water supply pipe 10 is supplied. One end of the flow path 42 is connected to the water supply unit 41, and the water supplied to the water supply unit 41 flows through the flow path 42. The other end of the flow path 42 is connected to the hot water outlet 62.

The check valve 43 is provided in the flow path 42 to prevent the backflow of the supplied water. The solenoid valve 44 is an on-off valve provided on the downstream side of the check valve 43 in the flow path 42 to open and close the flow path 42. Specifically, the solenoid valve 44 opens the flow path 42 while the detection signal is being output from the human body detection sensor 101, and closes the flow path when the output of the detection signal stops. Block 42.

The tank 45 is provided on the downstream side of the solenoid valve 44 in the flow path 42, and temporarily stores the water flowing in from the flow path 42.

The first heater 46 is provided inside the tank 45 and raises the temperature of the water stored in the tank 45. The water in the tank 45 is boiled by the first heater 46 until it reaches a first predetermined temperature (for example, 75 ° C.) higher than the optimum temperature (for example, 35 ° C.) when the water is discharged from the faucet 100. As a result, relatively high temperature water is stored in the tank 45.

An electric heater can be used as the first heater 46, but the present invention is not limited to this, and a gas type or petroleum type heater may be used. Further, the water temperature of the tank 45 and the water temperature discharged from the faucet 100 can be set to arbitrary values. The first heater 46 is an example of the first temperature raising unit.

The bypass flow path 52 is branched from the flow path 42 on the upstream side of the tank 45 and on the downstream side of the solenoid valve 44. Then, the bypass flow path 52 bypasses the tank 45 and joins the flow path 42 on the downstream side of the tank 45.

The second heater 56 is provided in the bypass flow path 52 and raises the temperature of the water in the bypass flow path 52. The second heater 56 is an example of a second temperature raising unit.

Specifically, the second heater 56 is an instantaneous heater that heats the water flowing in the bypass flow path 52 and raises the temperature to generate hot water. As the second heater 56, for example, an electric heater (for example, a ceramic heater) having a watt density (W / cm ² ) higher than that of the first heater 46 can be used, but the present invention is not limited to this.

Further, the second heater 56 operates so that the water in the bypass flow path 52 reaches the second predetermined temperature when the water is flowing in the bypass flow path 52. The second predetermined temperature can be set to an arbitrary value, but for example, the temperature of the water raised in the tank 45, that is, a value lower than the first predetermined temperature and the temperature of the water supplied from the water source ( It is set to a value higher than (for example, 5 ° C) (for example, 15 ° C).

When the temperature of the water supplied from the water source to the bypass flow path 52 is relatively high above the above-mentioned second predetermined temperature, it is not necessary to raise the temperature of the water in the bypass flow path 52, so that the second heater 56 Is configured to not work, which will be described later.

The mixing portion 61 is provided at a confluence position between the flow path 42 and the bypass flow path 52. The mixing unit 61 mixes the relatively high temperature water supplied from the tank 45 and heated by the first heater 46 with the water supplied from the bypass flow path 52 and heated by the second heater 56. Specifically, for example, 75 ° C., 1 l / min water from the tank 45 and 15 ° C., 2 l / min water from the bypass flow path 52 are mixed in the mixing section 61. As a result, in the mixing unit 61, hot water having an appropriate temperature of, for example, about 35 ° C. and 3 l / min is generated. A mixing valve can be used as the mixing unit 61.

The hot water outlet 62 is provided at the downstream end of the flow path 42, and the hot water discharge pipe 30 described above is connected to the hot water outlet portion 62. Therefore, the hot water having an appropriate temperature generated by the mixing unit 61 is discharged from the faucet 100 through the hot water outlet 62 and the hot water pipe 30.

As described above, in the water heater 20 according to the first embodiment, the first heater 46 of the tank 45 and the second heater 56 of the bypass flow path 52 are provided in parallel, and the first and second heaters 46, The water heated in 56 was mixed in the mixing section 61. As a result, in the water heater 20, the continuous hot water discharge amount can be increased while suppressing the increase in power consumption without enlarging the tank 45.

That is, the mixing unit 61 in the present embodiment mixes the relatively high temperature water from the tank 45 with the heated water from the bypass flow path 52 to generate hot water at an appropriate temperature. Therefore, in the present embodiment, when the amount of water supplied from the tank 45 to the mixing unit 61 is mixed with unheated (unheated) water from a water source as in the prior art, for example. It is possible to generate hot water at an appropriate temperature with a smaller amount than that of the above. Therefore, the amount of water in the tank 45 is less likely to decrease as compared with the prior art, and thus the amount of continuous hot water discharged in the water heater 20 can be increased without increasing the capacity of the tank 45 and increasing the size.

Specifically, in order to obtain hot water having an appropriate temperature of about 35 ° C. and 3 l / min, the consumption of relatively high temperature water in the tank 45 is 1 l / min in the present embodiment. On the other hand, in the prior art, for example, when water at 5 ° C. is supplied to the mixing portion, the consumption of relatively high temperature water in the tank is increased in order to obtain hot water at an appropriate temperature of about 35 ° C. and 3 l / min. It is about 1.3 l / min, which is larger than the consumption amount of this embodiment. That is, in the prior art, a mixture of 75 ° C., 1.3 l / min hot water in a tank and 5 ° C., 1.7 l / min water from a water source gives a suitable temperature of about 35 ° C. and 3 l / min. Is obtained.

Further, in the present embodiment, the second heater 56 is only an auxiliary heat source and may have a relatively small power consumption. Specifically, in a conventional instantaneous water heater that obtains hot water at an appropriate temperature only by instantaneous heating with a heater, it is necessary to raise the temperature to 5 ° C. and 2 l / min to 35 ° C., and therefore, about 4000 to 5000 W. Heater is required. On the other hand, in the present embodiment in which the relatively high temperature water from the tank 45 is mixed with the heated water from the bypass flow path 52 to generate hot water at an appropriate temperature, the bypass flow path 52 has a temperature of 5 ° C. and 2 liters. The temperature of water at / min may be raised to 15 ° C., and the second heater 56 may be a heater of about 1200 W. As described above, the power consumption can be suppressed in the present embodiment.

Further, since the second heater 56 is an instantaneous heater that heats the water flowing in the bypass flow path 52 to raise the temperature, as compared with the case where the bypass flow path 52 is provided with, for example, a hot water storage tank. The configuration can be configured with less heat dissipation loss, and the water in the bypass flow path 52 can be efficiently heated.

The case portion 80 is, for example, a housing formed in a substantially rectangular parallelepiped shape (see FIG. 1), and houses each component such as a tank 45 and a solenoid valve 44.

The control device 90 is a microcomputer provided with a CPU, RAM, and ROM, and controls the entire water heater 20. The configuration of the control device 90 will be described later with reference to FIG.

The water heater 20 further includes a hot water storage water temperature sensor 70, an upstream water temperature sensor 71a, a downstream water temperature sensor 71b, and a flow sensor 72.

The hot water storage water temperature sensor 70 is provided in the tank 45 and detects the temperature of the water stored in the tank 45 (hereinafter, may be referred to as “hot water storage water temperature”). The hot water storage water temperature sensor 70 outputs a signal indicating the detected hot water storage temperature to the control device 90.

The upstream water temperature sensor 71a is provided on the upstream side of the second heater 56 in the bypass flow path 52, and detects the water temperature of the bypass flow path 52 (hereinafter, may be referred to as “upstream water temperature”). The upstream water temperature sensor 71a outputs a signal indicating the detected upstream water temperature to the control device 90. The upstream water temperature sensor 71a is an example of the first water temperature detection unit.

The downstream water temperature sensor 71b is provided on the downstream side of the second heater 56 in the bypass flow path 52, and detects the water temperature of the bypass flow path 52 (hereinafter, may be referred to as “downstream water temperature”). The downstream water temperature sensor 71b outputs a signal indicating the detected downstream water temperature to the control device 90. The downstream water temperature sensor 71b is an example of the second water temperature detection unit.

The flow sensor 72 is provided in the flow path 42. Specifically, the flow sensor 72 is provided on the downstream side of the mixing portion 61 in the flow path 42, but the position where the flow sensor 72 is provided is not limited to this.

Then, the flow sensor 72 detects whether or not water is flowing through the flow path 42 or the bypass flow path 52. The flow sensor 72 indicates that water is circulating when water is flowing through the flow path 42 or the like, in other words, when water is flowing through the flow path 42 or the like and hot water is discharged from the faucet 100. The indicated distribution signal is output to the control device 90. The flow sensor 72 is an example of a distribution detection unit.

Next, the control device 90 will be described with reference to FIG. FIG. 3 is a block diagram showing a configuration example of the water heater 20 provided with the control device 90. Note that, in FIG. 3, for simplification of the illustration, the components necessary for explaining the control of the first and second heaters 46 and 56 are mainly shown, and the other components are not shown.

The control device 90 includes a control unit 91 and a storage unit 92. The control unit 91 includes an open / close detection unit 91a, a distribution detection unit 91b, a water temperature detection unit 91c, and a heater control unit 91d. Further, the storage unit 92 stores the predetermined temperature information 92a. The predetermined temperature information 92a includes information indicating the first predetermined temperature and the second predetermined temperature described above.

The open / close detection unit 91a is connected to the solenoid valve 44 and detects the open / close of the solenoid valve 44. Then, the open / close detection unit 91a outputs a signal indicating the open / close of the solenoid valve 44 to the heater control unit 91d. The distribution detection unit 91b receives the distribution signal output from the flow sensor 72, and outputs the received distribution signal to the heater control unit 91d.

The water temperature detection unit 91c receives a signal indicating the hot water storage temperature from the hot water storage water temperature sensor 70, a signal indicating the upstream water temperature from the upstream water temperature sensor 71a, and a signal indicating the downstream water temperature from the downstream water temperature sensor 71b. Then, the water temperature detection unit 91c outputs each received signal to the heater control unit 91d.

The heater control unit 91d controls the first heater 46 and the second heater 56 based on each input signal. Specifically, for example, the heater control unit 91d supplies the heated water from the bypass flow path 52 to the mixing unit 61 when a signal indicating the opening of the solenoid valve 44 is input from the open / close detection unit 91a. , The second heater 56 is operated.

Further, in the heater control unit 91d according to the present embodiment, as described above, when the solenoid valve 44 is opened and water is flowing through the bypass flow path 52, the second heater 56 is operated. Therefore, it is possible to prevent the second heater 56 from burning the bypass flow path 52 in the air.

In the above, the condition for the heater control unit 91d to operate the second heater 56 is the opening of the solenoid valve 44, but the condition is not limited to this. That is, when the solenoid valve 44 is opened and the flow signal is input from the flow sensor 72 via the flow detection unit 91b, the heater control unit 91d specifically supplies water to the flow path 42 and the bypass flow path 52. When it is detected that the product is in circulation, the second heater 56 may be operated.

This makes it possible to reliably prevent the second heater 56 from burning the bypass flow path 52 in the air. That is, for example, water may be cut off and water from the water source may not be supplied to the flow path 42 or the bypass flow path 52. In such a case, when the user's hand is extended to the faucet 100, the solenoid valve 44 opens, but water does not flow into the flow path 42 or the bypass flow path 52.

Therefore, in the water heater 20 according to the present embodiment, in addition to the solenoid valve 44 being opened, the fact that the distribution signal is input from the flow sensor 72 is defined as the operating condition of the second heater 56. You may try to do so. As a result, it is possible to operate the second heater 56 in a state where water is surely flowing through the bypass flow path 52 and the like, and thus it is possible to surely prevent the bypass flow path 52 from being emptied. it can.

Further, the heater control unit 91d may operate the second heater 56 based on the detected upstream water temperature. Specifically, the heater control unit 91d compares the detected upstream water temperature of the bypass flow path 52 with the second predetermined temperature stored in the storage unit 92. Then, the heater control unit 91d may operate the second heater 56 when the upstream water temperature is lower than the second predetermined temperature, while may not operate the second heater 56 when the upstream water temperature is equal to or higher than the second predetermined temperature.

That is, in the heater control unit 91d, when the upstream water temperature, which is the temperature of the water supplied from the water source to the bypass flow path 52, is equal to or higher than the second predetermined temperature, the water in the bypass flow path 52 has already reached a desired temperature. The second heater 56 is prevented from operating. As a result, unnecessary operation of the second heater 56 can be prevented, and power consumption can be suppressed.

Further, the heater control unit 91d may operate the second heater 56 based on the detected downstream water temperature. Specifically, the heater control unit 91d compares the detected downstream water temperature of the bypass flow path 52 with the second predetermined temperature. Then, the heater control unit 91d may operate the second heater 56 when the downstream water temperature is lower than the second predetermined temperature, while may not operate the second heater 56 when the downstream water temperature is equal to or higher than the second predetermined temperature.

That is, when the downstream water temperature, which is the temperature of the water raised by the second heater 56, is equal to or higher than the second predetermined temperature, the heater control unit 91d sufficiently raises the water in the bypass flow path 52 to a desired temperature. Therefore, the second heater 56 is prevented from operating. As a result, the power consumption of the second heater 56 can be suppressed.

Further, the heater control unit 91d operates the first heater 46 based on the detected hot water storage water temperature. Specifically, the heater control unit 91d compares the detected hot water storage water temperature with the first predetermined temperature stored in the storage unit 92. Then, the heater control unit 91d operates the first heater 46 when the hot water storage water temperature is lower than the first predetermined temperature. This makes it possible to raise the temperature of the water in the tank 45 to the first predetermined temperature.

Further, in the present embodiment, the heater control unit 91d may exclusively operate the first heater 46 and the second heater 56. Specifically, the heater control unit 91d does not operate the second heater 56 when the first heater 46 is operated, and operates the first heater 46 when the second heater 56 is operated, for example. You may not let it. As described above, in the present embodiment, the maximum power consumption of the water heater 20 can be suppressed by preventing the first heater 46 and the second heater 56 from operating at the same time.

Next, a specific heater control processing procedure in the control device 90 will be described with reference to FIG. FIG. 4 is a flowchart showing a processing procedure of heater control executed by the control device 90.

As shown in FIG. 4, the control unit 91 of the control device 90 first determines whether or not the hot water storage water temperature is lower than the first predetermined temperature (step S10). When the control unit 91 determines that the hot water storage water temperature is not lower than the first predetermined temperature (steps S10, No), that is, when the hot water storage water temperature is equal to or higher than the first predetermined temperature and the water in the tank 45 is sufficiently high. Since it is not necessary to operate the first heater 46, the process proceeds to steps S11 to S14 to determine whether or not the condition for operating the second heater 56 is satisfied.

Specifically, the control unit 91 determines whether or not the solenoid valve 44 is open (step S11). When it is determined that the solenoid valve 44 is open (step S11, Yes), the control unit 91 determines whether or not water flow in the flow path 42 or the bypass flow path 52 is detected (step S12). ), Specifically, it is determined whether or not a distribution signal has been input.

When the flow of water in the flow path 42 or the like is detected (step S12, Yes), the control unit 91 determines whether or not the upstream water temperature is lower than the second predetermined temperature (step S13). When the control unit 91 determines that the upstream water temperature is lower than the second predetermined temperature (steps S13, Yes), the control unit 91 subsequently determines whether or not the downstream water temperature is lower than the second predetermined temperature (step S14).

Then, when it is determined that the downstream water temperature is lower than the second predetermined temperature (step S14, Yes), the control unit 91 operates the second heater 56 because the condition for operating the second heater 56 is satisfied. On the other hand, the first heater 46 is not operated (step S15).

In the above, the conditions for operating the second heater 56 are the opening of the solenoid valve 44, the flow of water in the flow path 42 and the like, the upstream water temperature and the downstream water temperature, but these are examples, and among these, A part of the above may be a condition, or another condition may be added.

On the other hand, when it is determined that the solenoid valve 44 is not opened (step S11, No), the control unit 91 prevents the first and second heaters 46 and 56 from operating (step S16). Similarly, when the flow of water in the flow path 42 or the like is not detected (step S12, No), the control unit 91 determines that the upstream water temperature is not lower than the second predetermined temperature (step S13, No), the downstream When it is determined that the water temperature is not lower than the second predetermined temperature (step S14, No), the first and second heaters 46 and 56 are not operated (step S16).

Further, when it is determined that the hot water storage water temperature is lower than the first predetermined temperature (step S10, Yes), the control unit 91 determines whether or not the second heater 56 is currently operating (step S17).

When it is determined that the second heater 56 is operating (steps S17, Yes), the control unit 91 proceeds to the processes of steps S11 to S14 described above, and does the condition for operating the second heater 56 still satisfy? judge. As described above, even when the hot water storage water temperature is lower than the first predetermined temperature and the water temperature of the tank 45 is lowered, the control unit 91 is the first as long as it satisfies the condition for operating the second heater 56. 2 The heater 56 is preferentially operated.

Further, when it is determined that the second heater 56 is not operating (steps S17, No), the control unit 91 proceeds to steps S18 to S21 to satisfy the condition for newly operating the second heater 56. Judge whether it is.

Since steps S18 to S21 are the same processes as steps S11 to S14 described above, the description thereof will be omitted. When the control unit 91 is affirmed in the processes of steps S18 to S21 and newly satisfies the condition for operating the second heater 56 (steps S21, Yes), the control unit 91 operates the second heater 56 while operating the second heater 56. The first heater 46 is disabled (step S15). As described above, even if the hot water storage water temperature is lower than the first predetermined temperature, the control unit 91 operates the second heater 56 if the conditions for operating the second heater 56 are met.

On the other hand, when it is determined that the solenoid valve 44 is not opened (step S18, No), the control unit 91 operates the first heater 46 and does not operate the second heater 56 (step S22). ). Similarly, when the flow of water in the flow path 42 or the like is not detected (step S19, No), the control unit 91 determines that the upstream water temperature is not lower than the second predetermined temperature (step S20, No), the downstream When it is determined that the water temperature is not lower than the second predetermined temperature (steps S21 and No), the first heater 46 is operated and the second heater 56 is not operated (step S22).

As described above, the water heater 20 according to the first embodiment includes a flow path 42, a tank 45, a first heater 46 (an example of a first temperature rising unit), a bypass flow path 52, and a second. A heater 56 (an example of a second temperature raising unit) and a mixing unit 61 are provided. Water supplied from the water source flows through the flow path 42. The tank 45 is provided in the flow path 42 and stores water. The first heater 46 is provided in the tank 45 and raises the temperature of the water stored in the tank 45. The bypass flow path 52 is branched from the flow path 42 on the upstream side of the tank 45, bypasses the tank 45, and joins the flow path 42 on the downstream side of the tank 45. The second heater 56 is provided in the bypass flow path 52 and raises the temperature of the water in the bypass flow path 52. The mixing unit 61 is provided at the confluence position between the flow path 42 and the bypass flow path 52, and is supplied from the tank 45 and heated by the first heater 46 and supplied from the bypass flow path 52 by the second heater 56. Mix with warmed water. As a result, the amount of continuous hot water discharged can be increased in the water heater 20.

(First modification)
Next, a first modification of the first embodiment will be described. In the water heater 20 according to the first embodiment, the water in the bypass flow path 52 is heated by using the second heater 56, but the temperature is not limited to this.

FIG. 5 is a block diagram showing a configuration example of the water heater 20 according to the first modification. In the following, the same reference numerals will be given to the configurations common to the above-described embodiments, and the description thereof will be omitted.

As shown in FIG. 5, the water heater 20 according to the first modification includes a heat exchanger 156 provided in the bypass flow path 52. The heat exchanger 156 is an example of the second temperature raising unit.

The heat exchanger 156 is connected to a circulation flow path 120 extending from the tank 45 and through which relatively high temperature water stored in the tank 45 flows. A circulation pump 121 is provided in the circulation flow path 120. As a result, the relatively high temperature water in the tank 45 circulates and circulates in the circulation flow path 120.

In the first modification, by providing the heat exchanger 156 described above, the water in the bypass flow path 52 becomes the water in the circulation flow path 120 in the heat exchanger 156, that is, the relatively high temperature water in the tank 45. Heat exchange is performed to raise the temperature, and the raised water is supplied to the mixing unit 61.

As described above, in the first modification, the heat energy of the water stored in the tank 45 can be used to raise the temperature of the water in the bypass flow path 52.

(Second modification)
Next, a second modification of the first embodiment will be described. FIG. 6 is a block diagram showing a configuration example of the water heater 20 according to the second modification.

As shown in FIG. 6, the water heater 20 according to the second modification is arranged so that a part of the bypass flow path 52 is close to the tank 45. In FIG. 6, a portion of the bypass flow path 52 close to the tank 45 is surrounded by a dashed-dotted line and is designated by reference numeral 256. In the following, such a portion may be referred to as a “heating portion 256”.

As described above, relatively high temperature water is stored in the tank 45. Therefore, when the water is brought close to the tank 45 as in the temperature rising portion 256 of the bypass flow path 52, the water inside is heated by the heat radiation from the tank 45 as shown by the white arrow. Then, the water of the temperature-increasing portion 256 that has been heated is supplied to the mixing unit 61. The temperature rising portion 256 is an example of a second heating portion for raising the temperature of water in the bypass flow path 52.

As described above, in the second modification, the water in the bypass flow path 52 can be heated by utilizing the heat energy radiated from the tank 45.

(Second Embodiment)
Next, the water heater 20 according to the second embodiment will be described. In the first embodiment described above, the energization amount of the second heater 56 is constant, but in the second embodiment, it is changed according to the temperature of the water in the bypass flow path 52, for example, the upstream water temperature. I did it.

More specifically, in the second embodiment, as shown by an imaginary line in FIG. 3, the storage unit 92 stores the energization amount information 92b. FIG. 7 is a diagram showing energization amount information 92b. As shown in FIG. 7, in the energization amount information 92b, the energization amount of the second heater 56 is set to increase as the upstream water temperature of the bypass flow path 52 detected by the upstream water temperature sensor 71a decreases.

In the example shown in FIG. 7, the energization amount of the second heater 56 is changed in two stages, large and small, but the present invention is not limited to this, and may be, for example, three or more stages, and further, with respect to the upstream water temperature. It may be changed linearly.

FIG. 8 is a flowchart showing a procedure for controlling the energization amount of the second heater 56 executed by the control device 90 according to the second embodiment.

As shown in FIG. 8, the control unit 91 of the control device 90 detects the upstream water temperature based on the signal from the upstream water temperature sensor 71a (step S100). Next, the control unit 91 reads out the energization amount information 92b stored in the storage unit 92, and sets the energization amount of the second heater 56 based on the detected upstream water temperature (step S101). Then, the control unit 91 energizes the second heater 56 with the set energization amount (step S102) to raise the temperature of the water in the bypass flow path 52.

As described above, in the second embodiment, the energization amount of the second heater 56 is set to increase as the upstream water temperature of the bypass flow path 52 decreases. As a result, for example, even when the upstream water temperature is low, the second heater 56 increases the amount of energization and the amount of heat generated, so that the water in the bypass flow path 52 can be raised to a desired temperature. , It is possible to prevent the amount of continuous hot water from decreasing.

Further, for example, when the upstream water temperature is high, the water in the bypass flow path 52 can be raised to a desired temperature even if the calorific value of the second heater 56 decreases, so that the amount of electricity supplied to the second heater 56 is reduced. However, power consumption can be suppressed.

(Third Embodiment)
Next, the water heater 20 according to the third embodiment will be described. In the second embodiment described above, the energization amount of the second heater 56 is changed according to the upstream water temperature, but in the third embodiment, it is changed according to the downstream water temperature.

FIG. 9 is a diagram showing energization amount information 92b according to the third embodiment. As shown in FIG. 9, in the energization amount information 92b, the energization amount of the second heater 56 is set to increase as the downstream water temperature of the bypass flow path 52 detected by the downstream water temperature sensor 71b decreases.

In the example shown in FIG. 9, the energization amount of the second heater 56 is changed in two stages, large and small, but the present invention is not limited to this, and may be, for example, three or more stages, and further, with respect to the downstream water temperature. It may be changed linearly.

FIG. 10 is a flowchart showing a procedure for controlling the energization amount of the second heater 56 executed by the control device 90 according to the third embodiment.

As shown in FIG. 10, the control unit 91 of the control device 90 detects the downstream water temperature based on the signal from the downstream water temperature sensor 71b (step S200). Next, the control unit 91 reads out the energization amount information 92b stored in the storage unit 92, and sets the energization amount of the second heater 56 based on the detected downstream water temperature (step S201). Then, the control unit 91 energizes the second heater 56 with a set energizing amount (step S202) to raise the temperature of the water in the bypass flow path 52.

As described above, in the third embodiment, the energization amount of the second heater 56 is set to increase as the downstream water temperature of the bypass flow path 52 decreases. As a result, for example, even when the downstream water temperature is low, the second heater 56 increases the amount of energization and the amount of heat generated, so that the water in the bypass flow path 52 can be raised to a desired temperature. , It is possible to prevent the amount of continuous hot water from decreasing.

Further, for example, when the downstream water temperature is high, the water in the bypass flow path 52 can be raised to a desired temperature even if the calorific value of the second heater 56 decreases, so that the amount of electricity supplied to the second heater 56 is reduced. However, power consumption can be suppressed.

In the above-described embodiment, as a condition for operating the second heater 56, both the upstream water temperature and the downstream water temperature are compared with the second predetermined temperature, but may be compared with different predetermined temperatures.

Further, the energization amount of the second heater 56 is set based on the upstream water temperature in the second embodiment, and is set based on the downstream water temperature in the third embodiment, but the second and third embodiments are performed. The forms may be combined and set based on the upstream water temperature and the downstream water temperature. Further, although the automatic faucet is used as the faucet 100, the faucet is not limited to this, and a manual faucet may be used.

Further, in the above, the second heater 56, the heat exchanger 156, and the temperature rising portion 256 have been mentioned as examples of the second temperature rising unit, but any configuration can be used as long as the water in the bypass flow path 52 can be heated. It may be, for example, a tank provided with a heater.

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the spirit or scope of the general concept of the invention as defined by the appended claims and their equivalents.

1 Hot water supply system 10 Water supply piping 20 Water heater 42 Flow path 44 Solenoid valve 45 Tank 46 1st heater 52 Bypass flow path 56 2nd heater 61 Mixing part 80 Case part 90 Control device 91 Control part 92 Storage part 100 Faucet 110 Washbasin

Claims (7)

The flow path through which the water supplied from the water source flows,
A tank provided in the flow path for storing water and
A first temperature raising unit provided in the tank and raising the temperature of the water stored in the tank,
A bypass flow path that branches from the flow path on the upstream side of the tank, bypasses the tank, and joins the flow path on the downstream side of the tank.
A second temperature raising unit provided in the bypass flow path and raising the temperature of water in the bypass flow path,
It is provided at the confluence position of the flow path and the bypass flow path, and water supplied from the tank and heated by the first temperature rising section and water supplied from the bypass flow path and raised by the second temperature rising section. A mixing part that mixes with warm water ,
A control unit that controls the first temperature rising unit and the second temperature rising unit,
It is provided in the flow path and includes an on-off valve for opening and closing the flow path .
The first temperature rising section is
It is an electric heater that raises the temperature of the water stored in the tank.
The second temperature rising section is
It is an electric heater that heats the water circulating in the bypass flow path to raise the temperature.
The watt density of the second temperature rising section is
Higher than the watt density of the first temperature riser
The control unit
When the first temperature riser and the second temperature riser are exclusively operated and the on-off valve is closed, only the first temperature riser is operated and the on-off valve is opened. In this case, the water heater is characterized in that only the second temperature raising unit is operated . A flow detection unit provided in the flow path and detecting whether or not water is flowing in the flow path is provided.
The control unit
The on-off valve is opened, and the case where water in the flow path by the flow detection unit is detected to be in circulation, according to claim 1, characterized in that actuating said second heating unit Water heater. Provided before Symbol bypass passage on the upstream side of the second heating section, and a first temperature detector for detecting a temperature of the bypass passage,
The control unit
The water heater according to claim 1 or 2 , wherein the second temperature raising unit is operated based on the water temperature of the bypass flow path detected by the first water temperature detecting unit. Before Symbol control unit,
The water heater according to claim 3 , wherein the energization amount of the second temperature raising unit is set so as to increase as the water temperature of the bypass flow path detected by the first water temperature detecting unit decreases. .. Provided before Symbol bypass passage on the downstream side of the second heating section, and a second temperature detector for detecting a temperature of the bypass passage,
The control unit
The water heater according to any one of claims 1 to 4 , wherein the second temperature raising unit is operated based on the water temperature of the bypass flow path detected by the second water temperature detecting unit. Before Symbol control unit,
The water heater according to claim 5 , wherein the energization amount of the second temperature raising unit is set so as to increase as the water temperature of the bypass flow path detected by the second water temperature detecting unit decreases. .. The water heater according to any one of claims 1 to 6 and
A hot water supply system including a faucet that discharges hot water generated by the water heater.

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