JP2001263813A - Heat exchanger and hot water supply device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger for instantly controlling water temperature without any damage by thermal shock in a heat exchanger with a reduced heat capacity. SOLUTION: A metal layer 11, an insulation layer 12 containing a thin or thick film that is formed on the metal layer, a beat generation layer 14 that contains a thin-film or thick-film resistor being formed at a specific region on the insulation layer and generates heat by receiving power, and a plurality of power feed terminals 1 3a and 1 3b that are electrically connected to the resistor of the heat generation layer are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for heating water passing from an inlet to an outlet to obtain hot water. Furthermore, the present invention relates to a hot water supply device for supplying hot water obtained using such a heat exchanger.

[0002]

2. Description of the Related Art Generally, as a heat exchanger used in a hot water supply device (for example, a local cleaning device attached to a toilet seat and used), water accumulated in a tank is preliminarily warmed and used at the time of use. There are a hot water storage type and an instantaneous type in which warm water is used each time warm water is used. The hot water storage type can use a lot of hot water at a time, but the drawback is that the tank size is large, heat is dissipated when storing hot water, and it cannot be used continuously for a long time (for example, it cools down if used for more than 1 minute) have.

On the other hand, in the instant type heat exchanger, it is necessary to instantly raise the temperature of water to an appropriate temperature during use, and to stop heating immediately after use. Also, if the supply pressure of tap water fluctuates, the water pressure changes suddenly due to sudden drop in water pressure at other places using tap water, or when the incoming water temperature changes suddenly, You have to change the output. The same applies when the user changes the set flow rate or the set temperature. Furthermore, when used in showers, local washing devices and hand washers, since hot water is used directly on the human body, safety such as electric leakage prevention and burn prevention is taken into consideration, as well as unpleasant cold water discharge and temperature hunting etc. Must be taken into account.

Conventionally, as an instant type heat exchanger, a ceramic heater having a resistor embedded therein and a water heater passing through the outer and inner surfaces of the ceramic, a nichrome wire inserted into a pipe with one end closed, and a pipe inserted thereinto have been used. A sheathed heater has been used in which an insulating agent (for example, MgO powder) is filled between the wire and the nichrome wire to form an insulating layer and water is passed outside the pipe.

[Problems to be solved by the invention]

However, in a conventional ceramic heater having a resistor embedded therein, the heat capacity is large because the thickness of the ceramic is increased to provide strength.
Furthermore, since water flows through the outer surface and the inner surface of the ceramic, the heat capacity of the water also increases. Therefore, there is a problem that thermal responsiveness is not good. Also, if the amount of power supplied to the resistor is rapidly increased to instantly raise the temperature of the water, the resistor will become hot before the water reaches the set water temperature, and the ceramic will not be able to withstand thermal shock and will crack. There was a problem that it would. On the other hand, in the sheathed heater, the heat capacity of the insulating layer for preventing the short circuit between the pipe and the nichrome wire is large, so that there is also a problem that the thermal response is not good.

In view of the above, the first object of the present invention is to provide a heat exchanger having a small heat capacity and capable of instantaneously controlling the water temperature without being damaged by a thermal shock. The purpose of. Also, the present invention
It is a second object of the present invention to provide a heat exchanger having a reduced heat capacity and in which safety is ensured. Further, a third object of the present invention is to provide a hot water supply device including such a heat exchanger.

[0007]

In order to solve the above problems, a heat exchanger according to the present invention is a heat exchanger for heating water passing from an inlet to an outlet to obtain hot water. ,
A power supply including a cylindrical or plate-shaped metal layer, an insulating layer including a thin or thick glass formed on the metal layer, and a thin or thick film resistor formed in a predetermined region on the insulating layer And a plurality of power supply terminals electrically connected to the resistors of the heat generating layer. According to the above configuration, the metal layer resistant to thermal shock is responsible for heat conduction,
Even if the calorific value per unit area (watt density) is large, there is no risk of cracking (breakage) and the metal layer and the insulating layer can be made thin, so that the heat capacity can be significantly reduced. Therefore, the water temperature can be controlled instantaneously.

Preferably, the metal layer is cylindrical. The cylindrical heater has a constant heat transfer amount to the water in the circumferential direction (perpendicular to the flow) as compared with the plate-like heater, so that the temperature of the heating element itself can be made uniform and the temperature of the water can be reduced. There is no unevenness, and safe and efficient heat transfer is possible. In addition, the tubular heater has higher strength and a thinner metal layer than the plate-shaped heater, so that the thermal responsiveness is also improved. Further, since the cylindrical heater itself also functions as a hot water tank, it is only necessary to connect the water inlet and the water outlet, and the structure is simplified.

The above heat exchanger may further include an incoming water temperature detector for detecting the temperature of the water near the water inlet of the heat exchanger. In this case, even if the incoming water temperature changes rapidly, stable hot water can be supplied by detecting the water temperature near the inlet and controlling the amount of power supply.

[0010] The heat exchanger may further include a water temperature detector for detecting the water temperature near the water outlet of the heat exchanger. In this case, it is convenient to control for maintaining the water discharge temperature at the set water temperature. Further, it is also possible to detect the incoming water temperature by conducting water without supplying power, and it is possible to accurately control the water temperature by detecting the incoming water temperature first and then starting the power supply. In this case, the outgoing water temperature detector can also serve as the incoming water temperature detector, and cost reduction can be achieved.

The heat exchanger may further include a surface temperature detector for detecting an abnormality in the surface temperature of the heat exchanger. In this case, since water flows only inside the cylindrical heat exchanger, the surface temperature detector can be directly attached to the outside of the cylindrical heat exchanger, and heater abnormalities can be detected closest It is. In addition, even when there is no water inside the heat exchanger, empty cooking can be prevented by judging the presence or absence of water from the rising speed of the surface temperature detected by the surface temperature detector, and the safety of the equipment can be secured. . Alternatively, a leak detector for detecting a leak from the heating layer to the metal layer may be further provided. Thereby, the safety of the device can be ensured. Furthermore, if the surface temperature detector or the leakage detector is formed on the surface of the cylindrical heat exchanger with a thin-film or thick-film resistor, the heat capacity of the detector itself can be reduced and the abnormal temperature of the heat exchanger can be detected quickly. It is possible to secure more safety.

Further, the hot water supply apparatus according to the present invention comprises a heat exchanger as described above, a water temperature setting unit for setting a desired water temperature, a power supply unit for supplying power to the heat generating layer, A power supply control unit that controls a power supply amount to the heat generating layer based at least on a set water temperature set in the setting unit. According to the above configuration, the user can freely set and change the temperature of the hot water to obtain a desired water temperature in a short time. In particular, in the case of a local cleaning device, by operating a water temperature setting unit to alternately discharge hot and cold water to a local part of a human body, blood circulation can be promoted and hemorrhoids can be prevented, and the total heat consumption can be reduced. It is also possible to achieve energy saving by reducing energy consumption.

The above-mentioned hot water supply apparatus further comprises a flow rate detecting means for detecting a flow rate of the water passing through the heat exchanger, and the set water temperature set in the water temperature setting section and the flow rate detected by the flow rate detecting means. It is desirable to control the amount of power supply to the heating layer based at least on the flow rate. In this case, even if the water pressure at the water supply source changes suddenly and the flow rate fluctuates, the change in the flow rate is reliably detected, so that the power supply amount is controlled in advance before the water temperature at the outlet of the water heater changes, and stable. Hot water can be supplied. In addition, even when the set flow rate is changed, a desired water temperature can be obtained. In this case, by controlling the amount of power supply based on the signal of the set flow rate, it is possible to more quickly stabilize the tapping temperature. Further, by controlling the power supply amount based on the signal of the detected flow rate, more accurate control of the tapping temperature becomes possible. Further, when the water supply is cut off, it is safe to stop the power supply by detecting the stop of the water supply by the flow rate detecting means.

Further, the amount of power supplied to the heating layer is controlled based at least on the set water temperature set in the water temperature setting section, the water temperature detected by the incoming water temperature detector, and the flow rate detected by the flow rate detecting means. May be. In this case, even if there is a sudden change in the flow rate or the incoming water temperature, the amount of power supply can be calculated based on the set water temperature, the incoming water temperature, and the flow rate. Water temperature can be obtained.

Alternatively, based on at least the set water temperature set in the water temperature setting section, the water temperature detected by the incoming water temperature detector, the water temperature detected by the outlet water temperature detector, and the flow rate detected by the flow rate detecting means. The amount of power supply to the heat generating layer may be controlled. In this case, even if the amount of heat transfer to water changes due to the variation in the resistance value of the heating element and the variation in heat radiation due to the difference in the ambient temperature,
Correcting this on the basis of the outflow water temperature makes it possible to obtain an accurate water temperature.

Here, it is desirable that the flow rate detecting means is provided on the upstream side of the heating layer. This is because, at the downstream, accurate detection of the flow rate is impossible due to bubbles generated in the heat exchange section, and heat resistance is required because the temperature rises.

In the above hot water supply device, when the surface temperature detector detects an abnormality in the surface temperature of the heat exchanger, or when the leakage detector detects leakage, the power supply to the heating layer may be stopped. desirable. Alternatively, it is desirable to provide a detecting unit for detecting whether or not water exists inside the heat exchanger, and to stop supplying power to the heating layer when the detecting unit detects the absence of water. .
Both are to ensure safety.

Further, in the hot water supply device, a flow rate setting means for setting a flow rate of the water flowing through the heat exchanger, and a flow rate adjusting means for adjusting the flow rate of the water flowing through the metal pipe based on the flow rate set by the flow rate setting means. It is desirable to include flow control means. In the case of the local cleaning device, the user can freely set and change the flow rate of the water, so that the local cleaning water can be spouted to a local part of the human body with a strength that suits the taste.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. First, a heat exchanger according to an embodiment of the present invention will be described with reference to FIG. The heat exchanger 10 shown in FIG.
It is mainly configured. Since the metal pipe 11 is made of stainless steel, it is resistant to thermal shock. In addition, a ground terminal is connected to the metal pipe 11 so that the metal pipe 11
By grounding, it is possible to prevent an electric shock accident caused by water from the metal pipe 11 and to ensure safety.

On the outer surface of the metal pipe 11, an insulating layer 12 containing a thin or thick glass is formed. In the present application, a thin film refers to a relatively thin film formed by vapor deposition and equivalents thereof, and a thick film refers to a relatively thick film formed by printing and baking and equivalents thereof. By forming the insulating layer 12 in a film structure in this manner, the rate at which the insulating layer 12 contributes to the total heat capacity of the heat exchanger 10 is suppressed to a small value.

In a plurality of regions on the insulating layer 12, a conductor layer 13 including a thin or thick conductor is formed. On these conductor layers 13, power supply terminals 13a, 13b
And terminals 13c and 13d for detection are attached respectively. Further, a heating layer 14 including a thin-film or thick-film resistor is formed so as to connect between the two conductor layers to which the power supply terminals 13a and 13b are attached.
The heat generating layer 14 generates heat by being supplied with power through the terminals 13a and 13b. The metal pipe 11 has a water inlet 11a.
The heat generated by the heat generating layer 14 is uniformly and efficiently conducted to the water flowing inside the metal pipe 11.

On the other hand, a thin-film or thick-film sensing resistor 15 is formed so as to connect between the two conductor layers to which the sensing terminals 13c and 13d are attached. The detection resistor 15 may be formed mainly on the insulating film 12 or may be formed on the heat generating layer 14 via a second insulating film.
The detection resistor 15 has a PTC (positive temperature coefficient) characteristic,
By detecting the resistance value, the surface temperature of the heat exchanger can be detected. Here, the PTC characteristic is a property that the resistance value increases as the temperature increases. In addition, by detecting the potential of the detection resistor 15, the leakage can be detected.

In the above description, the conductor layer 13 is formed by, for example, transferring or screen-printing and baking a paste of silver or palladium-silver containing glass. In addition, the resistor and the detection resistor 15 of the heat generating layer 14 are formed by, for example, transfer printing or screen printing and firing a silver-palladium paste containing glass. By forming the heat generating layer 14 and the detection resistor 15 in a film structure in this manner, the ratio of the heat generation layer 14 and the detection resistor 15 contributing to the total heat capacity of the heat exchanger 10 is suppressed.

At a position near the upstream end on the insulating layer 12, a thermistor 16a for detecting the water temperature near the water inlet 11a of the metal pipe is attached. Thermistor 16
The detection unit a is immersed in water near the water inlet 11a of the metal pipe through the metal pipe 11 and the insulating layer 12. On the other hand, at a position near the downstream end on the insulating layer 12, a thermistor 16b for detecting the water temperature near the water outlet 11b of the metal pipe is provided. The detection section of the thermistor 16b penetrates the metal pipe 11 and the insulating layer 12 and is immersed in water near the water outlet 11b of the metal pipe.

In this embodiment, a heat insulating hood 17 is mounted on the insulating layer 12 so as to cover the heat generating layer 14. When this heat exchanger 10 is used in a local cleaning device, the hot water comes into contact with the human body, so that safety must be sufficiently considered. Therefore, in order to provide double protection, a bimetal 18 is provided on the outer surface of the hood 17 to detect an abnormality in the temperature of the heat exchanger. In the present embodiment, the heat exchanger is configured by using the metal pipe 11, but it is also possible to configure the heat exchanger by partially using a plate-shaped metal.

Next, a hot water supply apparatus according to an embodiment of the present invention will be described with reference to FIG. Here, a local cleaning device will be described as an example of a hot water supply device, but the present invention can also be applied to a shower, an automatic faucet, and the like. The local cleaning device 20 shown in FIG. 2 is a device for cleaning by discharging hot water to a local part of a human body, and includes the heat exchanger 10 as described above. A water supply pipe 24 is connected to the heat exchanger 10, and a water stop valve 25, a flow control valve 26, and a flow sensor 27 are attached to the water supply pipe 24 in order from the upstream side. Note that the flow sensor 27 can be disposed downstream of the heat exchanger 10, but in this case, accurate detection of the flow rate of water is hindered by air bubbles generated by heating in the heat exchanger 10. There is a possibility that it will happen. Therefore, it is preferable to arrange the flow sensor 27 on the upstream side of the heat exchanger 10. The water such as tap water supplied to the water supply pipe 24 is heated in the heat exchanger 10 to become hot water for local washing, and the nozzle 23 attached to the toilet seat 22
Water is discharged from the body to a local part of the body.

The local cleaning device 20 has a control panel 21 for setting the temperature and flow rate of the local cleaning water.
Contains. The control panel 21 is provided with a plurality of buttons. These buttons include a button for pressing the local cleaning water from the nozzle 23 to the local part of the human body, a button for setting the temperature of the local cleaning water, and a flow rate of the local cleaning water. Includes buttons to press when setting.

Here, setting of the temperature and flow rate of the local cleaning water,
Power supply control to the heat generating layer 14 of the heat exchanger 10 will be described with reference to FIG. The heat generating layer 14 included in the heat exchanger is connected to the power supply circuit 3 via the terminals 13a and 13b.
1 connected. The power supply circuit 31 supplies power to the heat generation layer 14 under the control of the power supply control unit 30.
The sensing resistor 15 included in the heat exchanger has terminals 13c and 1
It is connected to the temperature / leakage detection circuit 35 via 3d. Since the detection resistor 15 changes the resistance value according to the temperature of the metal pipe or the heat generating layer, the temperature / leakage detection circuit 3
5 can detect the temperature of the metal pipe or the heat generating layer based on the resistance value. Further, the temperature / leakage detection circuit 35 can detect a leakage based on the potential of the detection resistor 15. Information on the temperature / leakage detected by the temperature detection circuit 35 is input to the power supply control unit 30.

Thermistors 16a and 1 included in the heat exchanger
6b is connected to the temperature detection circuit 36. The thermistor 16a changes the resistance value according to the water temperature near the water inlet 11a (FIG. 1) of the metal pipe.
6 can detect the water temperature near the water inlet based on the resistance value. Further, since the thermistor 16b changes the resistance value according to the water temperature near the water outlet 11b (FIG. 1) of the metal pipe, the temperature detection circuit 36 can detect the water temperature near the water outlet based on the resistance value. . The information on the temperature detected by the temperature detection circuit 36 is supplied to the power supply control unit 30.
Is input to

The bimetal 18 included in the heat exchanger is connected to a temperature detection circuit 37. Bimetal 18
If the temperature of the hood 17 (FIG. 1) rises abnormally, the contacts are separated, and the temperature detection circuit 37 can detect an abnormally high temperature of the hood based on the contact. Temperature detection circuit 37
Is input to the power supply control unit 30.

When the power of the local cleaning device 20 is turned on, the thermistors 16 a and 16 b detect the water temperature near the water inlet and the water outlet of the metal pipe, and the information is input to the power supply controller 30. The flow rate sensor 27 detects the flow rate of water flowing through the water supply pipe 24, and the information is input to the control panel 21 and the power supply control unit 30.

Next, when performing local cleaning, the flow control valve 26 is operated, and water at a set flow enters the metal pipe 11 (FIG. 1). To change the temperature and flow rate of the local cleaning water, a predetermined button on the control panel 21 is operated. With this operation, the new set temperature and set flow rate of the local cleaning water are input to the power supply control unit 30.

Then, the power supply control unit 30 sets one or more of the set temperature of the local cleaning water, the detected temperature of the thermistor 16a, the detected temperature of the thermistor 16b, and the detected flow rate of the flow rate sensor 27 as parameters. The amount of power supply to the heat generating layer 14 is determined, and the power supply circuit 31 is controlled.

Here, the power supply control unit 30 determines whether or not the temperature of the metal pipe or the heat generating layer is abnormal based on the temperature information input from the temperature / leakage detection circuit 35, and determines that the temperature is abnormal. In this case, the power supply to the heat generating layer 14 is stopped. In addition, the power supply control unit 30 determines whether or not leakage has occurred from the heating layer to the metal pipe based on the leakage information input from the temperature / leak detection circuit 35, and determines that leakage has occurred. In this case, the power supply to the heat generating layer 14 is stopped. Further, the power supply control unit 30 determines whether or not the temperature of the hood is abnormal based on the temperature information input from the temperature detection circuit 37, and when it is determined that the temperature of the hood is abnormal, the power supply to the heat generating layer 14 is performed. To stop.

According to the present embodiment, the temperature of the water flowing through the metal pipe can be instantaneously controlled, and even if the temperature of the water entering the metal pipe changes abruptly, the water flowing through the metal pipe is kept at the set water temperature. Can be maintained.

Further, since the detected water temperature of the thermistor on the water outlet side is also used as a parameter for controlling the power supply to the heat generating layer, the heat generating layer may be used when the resistance of the heat generating layer varies or the heat radiation varies due to the difference from the ambient temperature. Can be corrected.

Further, the flow rate detected by the flow rate sensor is also used as a parameter for controlling the power supply to the heat generating layer. Therefore, even if the flow rate changes due to operation of the control panel, water cutoff, failure of the water shutoff valve, etc. By correcting the power supply control, the temperature of the discharged water can be maintained at the set water temperature.

Further, since double protection is applied by detecting an abnormally high temperature of the hood, even if the detection resistor or the thermistor breaks down, it is possible to prevent a burn due to the excessively heated local washing water, Safety can be ensured.

In this embodiment, a detecting means for detecting whether or not water exists inside the heat exchanger is provided, and when the power supply control unit 30 detects the absence of water, the heat generating layer is provided. If power supply to the heat exchanger is stopped, it is possible to prevent the heat exchanger from being idle, and to ensure safety. The detection of the empty cooking is, for example, that the flow rate sensor detects water input to the heat exchanger, the detection resistor or the thermistor on the water input side or the water discharge side detects the temperature, or the bimetal 18 detects abnormally high temperature. Can also be performed.

[0040]

As described above, according to the present invention,
In a heat exchanger having a reduced heat capacity, the water temperature can be instantaneously controlled without being damaged by a thermal shock, and a heat exchanger with secured safety can be provided. Further, a hot water supply device including such a heat exchanger can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a heat exchanger according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a hot water supply device according to an embodiment of the present invention.

FIG. 3 is a block diagram illustrating a circuit configuration of the hot water supply device illustrated in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heat exchanger 11 Metal pipe 12 Insulating layer 13 Conductive layer 13a, 13b, 13c, 13d Terminal 14 Heating layer 15 Detector resistor 16a, 16b Thermistor 17 Food 18 Bimetal 20 Local cleaning device 21 Control panel 22 Toilet seat 23 Nozzle 24 Water supply pipe Reference Signs List 25 water stop valve 26 flow control valve 27 flow sensor 30 power supply control unit 31 power supply circuit 35 temperature / leakage detection circuit 36, 37 temperature detection circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Hatakeyama 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture Totoki Equipment Co., Ltd. (72) Koji Mine 2, Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka No. 1-1, Toto Kiki Co., Ltd. (72) Inventor Yasuo Hamada 2-1-1, Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka F-term in Toto Kiki Co., Ltd. 2D038 JB04 JH03 JH11 KA07 KA13 KA14 KA22

Claims (18)

[Claims] 1. A heat exchanger for heating water passing from one opening (water inlet) to another opening (water outlet) to obtain hot water, comprising: a metal layer; and a heat exchanger formed on the metal layer. An insulating layer including thin-film or thick-film glass, a heat-generating layer including a thin-film or thick-film resistor formed in a predetermined region on the insulating layer, and generating heat when supplied with electricity; And a plurality of power supply terminals electrically connected to the resistor. 2. The heat exchanger according to claim 1, wherein the metal layer has a cylindrical shape. 3. The heat exchanger according to claim 1, further comprising a water temperature detector for detecting a water temperature near a water inlet of the heat exchanger. 4. The heat exchanger according to claim 1, further comprising a water temperature detector for detecting a water temperature near a water outlet of the heat exchanger. 5. The heat exchanger according to claim 1, further comprising a surface temperature detector for detecting a surface temperature of the heat exchanger. 6. The heat exchanger according to claim 1, further comprising a leakage detector for detecting leakage from the heating layer to the metal layer. 7. The heat exchanger according to claim 5, wherein the surface temperature detector or the leakage detector includes a thin-film or thick-film resistor. 8. A heat exchanger according to claim 1, a water temperature setting unit for setting a desired water temperature, a power supply unit for supplying power to the heating layer, and the water temperature setting. A hot water supply device, comprising: a power supply control unit that controls a power supply amount to the heating layer based at least on a set water temperature set in the unit. 9. The heat exchanger according to claim 3, a water temperature setting unit for setting a desired water temperature, a power supply unit for supplying power to the heating layer, and a setting set in the water temperature setting unit. A hot water supply device, comprising: a power supply control unit that controls a power supply amount to the heating layer based at least on a water temperature and a water temperature detected by the incoming water temperature detector. 10. The heat exchanger according to claim 4, a water temperature setting unit for setting a desired water temperature, a power supply unit for supplying power to the heat generating layer, and a setting set in the water temperature setting unit. A hot water supply device comprising: a power supply control unit that controls a power supply amount to the heat generating layer based at least on a water temperature and a water temperature detected by the water discharge temperature detector. 11. A heat exchanger according to claim 1, a water temperature setting unit for setting a desired water temperature, and a water flow setting unit for detecting a flow rate of water passing through the heat exchanger. A flow rate detection unit, a power supply unit for supplying power to the heating layer, and a power supply amount to the heating layer based at least on a set water temperature set in the water temperature setting unit and a flow rate detected by the flow detection unit. A hot water supply device, comprising: 12. The heat exchanger according to claim 3, a water temperature setting unit for setting a desired water temperature, a flow rate detecting unit for detecting a flow rate of water passing through the heat exchanger, and the heat generation. A power supply unit for supplying power to the layer, the heat generation based on at least a set water temperature set in the water temperature setting unit, a water temperature detected by the incoming water temperature detector, and a flow rate detected by the flow rate detection unit. And a power supply control unit for controlling a power supply amount to the layer. 13. The heat exchanger according to claim 4, a water temperature setting unit for setting a desired water temperature, a flow rate detecting unit for detecting a flow rate of water passing through the heat exchanger, and the heat generation. A power supply unit for supplying power to the layer, a set water temperature set in the water temperature setting unit, a water temperature detected by the incoming water temperature detector, a water temperature detected by the outlet water temperature detector, and detected by the flow rate detector. And a power supply control unit for controlling a power supply amount to the heating layer based at least on the determined flow rate. 14. The apparatus according to claim 11, wherein said flow rate detecting means is provided upstream of said heat generating layer.
The hot water supply device according to any one of claims 13 to 13. 15. The heat exchanger according to claim 5 or 7, a power supply unit for supplying power to the heat generating layer, and when the surface temperature detector detects an abnormality in the surface temperature of the heat exchanger, And a power supply control unit for stopping power supply to the heat generating layer. 16. The heat exchanger according to claim 6 or 7, a power supply unit for supplying power to the heat generating layer, and stopping the power supply to the heat generating layer when the electric leakage is detected by the electric leakage detector. And a power supply control unit. 17. The heat exchanger according to claim 1, a power supply unit for supplying power to the heat generating layer, and detecting whether water exists inside the heat exchanger. A hot water supply device, comprising: a detection unit for detecting the presence of water; and a power supply control unit that stops power supply to the heating layer when the detection unit detects the absence of water. 18. A flow rate setting means for setting a flow rate of water flowing through the heat exchanger, and a flow rate adjusting means for adjusting a flow rate of water flowing through the metal pipe based on a set flow rate of the flow rate setting means. The hot water supply device according to any one of claims 8 to 17, further comprising: