JPH1047772A - Hot water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a hot water supply at a set temperature and keep a maximum amount of discharged hot water in order to obtain a sufficient range of capacity under a less-expensive configuration. SOLUTION: When a hot water feeding operation is started, an electricity applying amount Is corresponding to a set temperature Ts being set at present is calculated in reference to reference values Tm, Im (S1) and electricity is applied (S2). In addition, a maximum amount of feeding flow rate of water Fs where hot water can be fed at the set temperature Ts is calculated (S3). In this case, a detected flow rate F and a calculated flow rate Fs are compared with each other (S4). In the case that the detected flow rate F is higher than the calculated flow rate Fs (S4: YES), an electrical application amount I for a third SMA spring is increased (S5) and then the water feeding amount F is decreased. In addition, in the case that the detected flow rate F is smaller than the calculated flow rate Fs (S4: NO), the electrical application amount I is decreased (S6) and the water feeding flow rate F is increased. Additionally, in the case that the detected flow rate F is substantially stabled at the calculated flow rate Fs (S8: YES), the set temperature Ts and the amount of applied electricity I at that time are stored as reference values Tm, Im, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater that limits the flow rate of incoming water according to a set temperature.

[0002]

2. Description of the Related Art Conventionally, there has been known a gas water heater in which supplied water is heated by combustion heat of a burner to supply hot water.
Generally, such a water heater performs a hot water temperature control that adjusts a burner amount of a burner based on a set temperature to bring the hot water temperature close to the set temperature. However, if the temperature difference between the set temperature and the incoming water temperature is large and the incoming water flow rate is large, the maximum capacity of the appliance will be exceeded, and even when the burner burns up to the maximum, the outlet temperature will reach the set temperature. Since the hot water at the set temperature does not flow out, it is inconvenient.

For this reason, recently, a water heater has been used which limits the flow rate of incoming water according to a set temperature. FIG.
FIG. 2 is a schematic configuration diagram of a water heater provided with a circuit for limiting a flow rate of incoming water. The water heater includes a heat exchanger 30 to which the water supply path 10 and the tap water path 20 are connected, a burner 40 for heating water flowing through the heat exchanger 30, and a gas supply path 50 for supplying gas to the burner 40. And the controller 60 that controls combustion control
And The water supply passage 10 includes an incoming water temperature sensor 19 for detecting an incoming water temperature and a flow sensor 11 for detecting an incoming water flow rate.
And a water governor 12 for regulating the flow rate of incoming water. The water governor 12 includes a bypass 13, and the bypass 13
Is provided with an on-off valve 16 for opening and closing the bypass flow path.
Further, tapping path 20 includes tapping temperature sensor 22 that detects tapping temperature. The gas supply path 50 is provided with a main solenoid valve 51 for opening and closing the flow path, a main solenoid valve 52, and a proportional valve 53 for adjusting the gas amount.

In the flowing water of the water governor 12, a first SMA spring 15 which is a coil spring using a shape memory alloy (hereinafter, a coil spring using a shape memory alloy is called an SMA spring) is used.
Is provided, and the first SMA spring 15
, The maximum flow rate (hereinafter simply referred to as the maximum water flow rate), which is the upper limit of the water flow to the heat exchanger 30, is increased. When the water temperature decreases, the spring load of the first SMA spring 15 decreases and the maximum water flow rate increases. Reduce.

A remote controller 61 having a temperature setting switch for inputting a set temperature is connected to the controller 60. The set temperature input from the remote controller 61, the detected temperature of the incoming water temperature sensor 19, and the detected flow rate of the flow sensor 11 are provided. And a feedforward control for calculating and controlling a gas amount necessary for setting the tapping temperature to the set temperature, and a deviation between the detected temperature of the tapping temperature sensor 22 and the set temperature,
Using the feedback control for correcting the feedforward control amount, the opening degree of the proportional valve 53 is adjusted to perform hot water temperature control. Further, the controller 60 sets the set temperature to 50.
If the temperature exceeds 50 ° C., the on-off valve 16 is closed and the set temperature is 50 ° C.
When the temperature is lower than 0 ° C., the flow rate of incoming water is controlled by opening the on-off valve 16.

Next, the operation of the water heater will be described. The controller 60 checks whether the set temperature input by the remote controller 61 is 50 ° C. or more,
When the temperature is 0 ° C. or higher, the on-off valve 16 is opened, and when the temperature is lower than 50 ° C., the on-off valve 16 is closed. Here, a hot water tap (not shown) is opened to start water flow to the appliance, and when a flow rate equal to or more than a predetermined value is detected by the flow rate sensor 11, the main solenoid valve 51 and the original solenoid valve 52 are opened and the burner 40 is opened. Gas is supplied, ignited by an igniter (not shown), and a combustion operation is started to control hot water temperature.

FIG. 7 is a diagram of the tapping capacity of this water heater. When the set temperature is 50 ° C. or higher, the on-off valve 16 is closed, so that the maximum incoming flow rate is 11 liters / minute, which does not exceed the maximum capacity of the appliance. When the set temperature is 50 ° C. or lower, the on-off valve 16 is opened, so that the maximum flow rate of incoming water is 17 liters / minute, and the tapping capacity range is widened so as not to exceed the maximum capacity. Therefore, it is possible to prevent a problem that the tapping temperature does not reach the set temperature. Note that in FIG. 7 and FIGS. 9, 2, and 4 described later, the vertical axis should accurately be the rising temperature (= hot water temperature−water input temperature). In the example, 15 ° C.).

[0008]

However, since the flow rate is switched in two steps by the on-off valve 16, for example, when the set temperature is 55 ° C., there is a capability of tapping water up to 15 liters / minute as shown at point a. Nevertheless, as shown at point b, the amount of hot water is limited to 11 liters / minute. Similarly, when the set temperature is 40 ° C., as shown in the point c, despite the ability to tap water up to 24 liters / minute, the point d
As shown in (1), the amount of hot water is limited to 17 liters / minute, and there is a problem that the original performance range of the appliance cannot be sufficiently exhibited. In order to solve this problem, there has been known an apparatus using a water amount control motor valve that continuously changes a maximum water flow rate in accordance with a difference between a set temperature and a water input temperature. FIG. 8 is a schematic configuration diagram of a water heater provided with a water amount control motor valve. The basic configuration is the same as that of the above-described water heater (FIG. 6).
The difference is that a water flow control motor valve 29 is provided in place of 2.
The other components are denoted by the same reference numerals and description thereof will be omitted.

The water amount control motor valve 29 is connected to the controller 6
The motor 29a is driven by being energized from 0 to adjust the valve opening to continuously change the maximum incoming flow rate. Therefore, by changing the maximum incoming flow rate according to the difference between the set temperature input by the remote controller 61 and the incoming water temperature detected by the incoming water temperature sensor 19, as shown in the hot water supply capacity diagram of FIG. It is possible to prevent the maximum capacity from being exceeded and to fully utilize the capability range of the device.

However, such a water amount control motor valve 29
In fact, it was expensive, so it was difficult to spread.

[0011] It is an object of the present invention to solve the above-described problems and to obtain hot water at a set temperature and to secure a maximum hot water amount for obtaining a sufficient capacity range with an inexpensive configuration.

[0012]

According to a first aspect of the present invention, there is provided a water heater which heats water supplied from a water supply channel by combustion heat of a burner and supplies the water to a hot water supply channel. A hot water supply device comprising: a temperature setting means for setting a set temperature; and a hot water temperature control means for adjusting a combustion amount of the burner such that the hot water temperature approaches the set temperature. A spring made of a shape memory alloy whose spring load changes according to the temperature, and in conjunction with a change in the spring load of the spring made of the shape memory alloy, the maximum value of the flow rate of water flowing through the appliance decreases as the tapping temperature increases. The gist of the present invention is to provide a flow control means.

According to a second aspect of the present invention, there is provided a water heater according to the first aspect of the present invention, wherein at least the temperature of the hot water near the spring made of the shape memory alloy in the appliance is set to a predetermined temperature while water is stopped. The gist of the present invention is to provide a heat retaining means for keeping heat.

According to a third aspect of the present invention, there is provided a water heater that heats water supplied from a water supply channel by a combustion heat of a burner and supplies the water to a hot water channel, and sets a set temperature. In a water heater provided with a temperature setting means for controlling the temperature of the hot water and a hot water temperature control means for controlling the combustion amount of the burner so that the hot water temperature approaches the set temperature, heat is generated by being energized, and a spring is generated in accordance with the heat quantity. A shape memory alloy spring whose load changes, an energizing means for energizing the shape memory alloy spring with an energization amount corresponding to the set temperature, and the above-mentioned interlocking with a change in the spring load of the shape memory alloy spring. The gist of the present invention is to provide a flow control means for reducing the maximum value of the flow rate of water flowing through the appliance as the set temperature increases.

According to a fourth aspect of the present invention, there is provided a water heater which heats water supplied from a water supply channel by combustion heat of a burner and supplies the water to a hot water channel, and sets a set temperature. A water heater comprising: a temperature setting means for detecting the flow rate of water flowing through the appliance; a flow sensor for detecting a flow rate of water flowing through the appliance; and a tapping temperature control means for controlling a combustion amount of the burner so that the tapping temperature approaches the set temperature. In the above, the heat is generated by being energized, the spring made of a shape memory alloy whose spring load changes according to the amount of heat, the valve body is positioned by the spring made of the shape memory alloy, and the maximum flow rate of water flowing through the appliance is The flow rate adjusting means for adjusting the value and the maximum flow rate at which the hot water can be discharged at the set temperature are calculated, and when the flow of water starts, or when the set temperature is changed, or the detection value of the flow sensor is calculated. When the maximum flow rate is exceeded, the set temperature The amount of current supplied to the shape memory alloy spring is controlled so as to be close to the calculated flow rate by supplying power to the shape memory alloy spring with a corresponding amount of power supply, and thereafter the detected value of the flow rate sensor approaches the calculated flow rate. And a flow control means for controlling the flow by changing the flow rate.

According to a fifth aspect of the present invention, there is provided a water heater according to the fourth aspect, wherein the amount of electricity supplied according to the set temperature is such that a detection value of the flow rate sensor corresponds to the calculated flow rate. The point is that the calculation is performed based on the set temperature and the amount of current supplied to the shape memory alloy spring when the temperature is substantially stable.

In the water heater according to the first aspect of the present invention having the above structure, the water supplied from the water supply channel is heated by the combustion heat of the burner and supplied to the hot water channel, and the hot water temperature approaches the set temperature. So as to control the burner combustion amount. In addition, the spring load of the shape memory alloy spring provided in the tapping path changes according to the temperature of the hot water, and the maximum value of the flow rate of water decreases as the temperature of the hot water increases in accordance with the change in the load. It is possible to limit the maximum capacity and not to exceed the maximum capacity.

In the water heater according to the second aspect of the present invention having the above structure, when the water in the appliance is cold at the start of tapping, the flow control means increases the maximum value of the flow through the appliance. Therefore, it is possible that the flow rate will exceed the set temperature, and the temperature rise will be slow and the flow rate adjustment will be slow, and it will take some time for the tap water temperature to reach the set temperature. By providing a heat retaining means for keeping at least the hot water near the spring made of a shape memory alloy in the appliance at the set temperature at the time of water, the maximum value of the flow rate at the start of tapping is set to a flow rate commensurate with the set temperature. It is possible to shorten the time until the hot water temperature stabilizes, and it is possible to prevent the flow rate from being reduced during hot water supply even though the set temperature is not changed.

In the water heater according to the third aspect of the present invention having the above structure, the water supplied from the water supply channel is heated by the combustion heat of the burner and supplied to the hot water channel, and the hot water temperature approaches the set temperature. So as to control the burner combustion amount. In addition, when the spring is made energized by energizing the shape memory alloy spring with an energization amount corresponding to the set temperature and the spring load is changed by the generated heat amount, the water flow rate increases as the set temperature increases in conjunction with the change in the load. In order to reduce the maximum value of the instrument, it is possible to limit the maximum capacity of the device so as not to exceed the maximum capacity, and to obtain a sufficient capacity range.

In the water heater according to the fourth aspect of the present invention having the above structure, the maximum flow rate at which the tap water can be discharged at the set temperature is calculated, and when the water supply starts, when the set temperature is changed, or when the flow rate sensor is used. When the detected value exceeds the calculated flow rate, power is supplied to the shape memory alloy spring with the amount of power supply corresponding to the set temperature, and thereafter the power is supplied to the shape memory alloy spring so that the detected value of the flow sensor approaches the calculated flow rate. The flow rate is controlled by changing the volume. Therefore, even if the ambient temperature of the spring made of the shape memory alloy fluctuates, the amount of hot water can be limited to the calculated flow rate.

In the water heater according to the fifth aspect of the present invention having the above structure, when the detected value of the flow rate sensor is substantially stable at the calculated flow rate, the set temperature and the amount of electricity supplied to the shape memory alloy spring are determined. Based on the calculated temperature, the amount of energization corresponding to the set temperature is calculated. Therefore, it is possible to obtain a more optimal energization amount according to the set temperature.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the water heater of the present invention will be described below. FIG. 1 is a schematic configuration diagram of a water heater as a first embodiment of the present invention. The basic configuration is the same as that of the conventional water heater (FIG. 6).
3 is provided with a bypass valve 14 for adjusting a bypass flow rate in place of the on-off valve 16, and a second SMA spring 21 using a shape memory alloy is provided in the tapping path 20, and the second SMA spring 21 is interlocked with a change in spring load. The second SMA spring 21 is provided with a heater 31 for electrically heating hot water in the vicinity of the second SMA spring 21. Since other configurations are the same as the conventional example,
The same reference numerals are given and the description is omitted.

The load of the second SMA spring 21 changes in the temperature range of 38 ° C. to 57 ° C.
Change the opening of 4. As the tapping temperature increases, the spring load increases, and the bypass valve 14 is moved in the valve closing direction to reduce the maximum incoming flow rate. As the tapping temperature decreases, the spring load decreases,
By moving the bypass valve 14 in the valve opening direction, the maximum flow rate of incoming water is increased. Therefore, as shown in the tapping capacity diagram of FIG. 2, as the tapping temperature rises from 38 ° C. to 57 ° C., the maximum incoming flow rate gradually decreases, and is limited to the maximum capacity of the appliance or less. It prevents the hot water from being dispensed, and can be used up to the flow rate near the maximum capacity.

When the water is stopped, the heater 31 is turned on by the second SMA spring 21.
The nearby hot water is heated, and the temperature of the hot water is detected by a tapping temperature sensor 22 provided above and near the second SMA spring 21 to keep the temperature at the set temperature. By this warming operation, the hot water flow is adjusted to the maximum flow rate corresponding to the set temperature and the apparatus stands by, and tapping at the set temperature is performed immediately after the start of tapping. Assuming that the temperature is not kept at the set temperature when the water is stopped, when the water stop state is long, the second SMA spring 21 cools down to almost the water temperature, and the opening of the bypass valve 14 is fully opened. In this state, if the set temperature is set to a high temperature and the hot water tap is opened to the maximum, the flow rate of the incoming water will be over the capacity and the temperature rise will be slow,
Since the bypass opening is narrowed in response to the slow temperature rise, it takes time for the tapping water temperature to reach the set temperature. Also, despite not changing the set temperature,
It is inconvenient to use because the flow rate of hot water is reduced during hot water.
For this reason, even when the water is stopped, the temperature is kept at the set temperature, and the incoming water flow rate is adjusted to the set temperature.

Next, the operation of the water heater of the first embodiment will be described. At the time of stopping water, the temperature of the hot water near the second SMA spring is almost kept at the set temperature by the heater 31, so that the opening degree of the bypass valve 14 is adjusted to the opening corresponding to the set temperature.
Here, a hot water tap (not shown) is opened to start water flow to the appliance, and when a flow rate equal to or more than a predetermined value is detected by the flow rate sensor 11, the main solenoid valve 51 and the original solenoid valve 52 are opened and the burner 40 is opened. Gas is supplied, ignited by an igniter (not shown), and a combustion operation is started to control hot water temperature. Start hot water temperature control. In addition, the spring load of the second SMA spring 21 changes according to the hot water temperature to adjust the opening of the bypass valve 14, and the spring load of the first SMA spring 15 changes according to the incoming water temperature to adjust the maximum incoming flow rate. I do.

When the set temperature is changed, the temperature of the hot water is changed by changing the combustion amount of the burner 40 by the hot water temperature control, and the second SMA spring 21 is operated to change the opening of the bypass valve 14 to change the maximum incoming flow rate. To change. By changing the maximum incoming flow rate according to the tapping temperature in this manner, the incoming flow rate is prevented from exceeding the maximum capacity, and the capacity range is widened.

Here, assuming that the tapping temperature is 44 ° C. and the maximum flow rate is used as shown in a point a in FIG. 2, the burner 40 has the maximum combustion amount because it is on the maximum capacity curve of the appliance. It is burning by. Here, when the set temperature is changed to, for example, 57 ° C., since the combustion amount of the burner 40 is the maximum, it is necessary to reduce the flow rate of incoming water. Therefore, the burner 40 is burned for a predetermined time at a gas supply amount equal to or more than the maximum capacity to raise the tapping temperature (b), and the second SMA
The spring load of the spring 21 is changed (c). When the second SMA spring 21 operates, the outlet water temperature rises because the maximum incoming flow rate decreases. As described above, when the set temperature is changed to a high value at the time of the combustion at the maximum combustion amount, the gas is burned at a gas supply amount equal to or more than the maximum capacity for a predetermined time, and the spring load of the second SMA spring 21 is changed. Can be changed.

As described above, according to the water heater of the first embodiment, the maximum water flow rate is adjusted by a simple configuration using the SMA spring, so that the cost can be reduced. In addition, at the time of water stoppage, by keeping the hot water in the appliance at the set temperature and limiting it to a maximum flow rate corresponding to the set temperature or less, a flow rate exceeding the set temperature is supplied and the temperature rise is slowed down. Such inconveniences and the inconvenience that the flow rate of tapping water is reduced even though the set temperature is not changed during tapping can be prevented. A tapping temperature sensor 22 for detecting tapping temperature is connected to a second SMA spring 21.
And the temperature of the hot water heated by the heater 31 and convected upward by detecting the temperature of the hot water near the second SMA spring 21 when the water is stopped.
The temperature of the MA spring 21 can be accurately detected, and the cost can be reduced because there is no need to newly provide a temperature sensor.

In the first embodiment, when the water is stopped, the second SMA
Although the hot water near the spring 21 is kept warm, the hot water in the appliance may be entirely heated. According to such a configuration, the tapping temperature is stabilized from the start of tapping, and the heater also serves as a freezing prevention heater. Further, the temperature may be kept by the burner 40 instead of the electric heating. In addition, the temperature detection at the time of water stoppage may be performed by using a dedicated temperature sensor instead of using the tapping temperature sensor 22. Although the flow rate of the bypass 13 of the water governor 12 is changed by changing the temperature of the hot water, the flow rate may be changed in the hot water path 20 or directly in the water supply path 10.
Further, although the maximum flow rate is adjusted based on the inlet water temperature and the outlet water temperature, the flow rate control may be performed only by the outlet water temperature.

Next, a second embodiment of the present invention will be described. FIG. 3 is a schematic configuration diagram of a water heater as a second embodiment. The basic configuration is the same as that of the water heater of the first embodiment (FIG. 1), except that the water heater 20 does not have a heat retaining function, and the tapping path 20 does not include the second SMA spring 21 and the third SMA spring 3
1 in that the load is changed by passing an electric current through the circuit. The other components are denoted by the same reference numerals and description thereof will be omitted.

The controller 60 stores in advance the amount of energization corresponding to the set temperature, and energizes the third SMA spring 31 with the amount of energization. When the third SMA spring 31 is energized by the controller 60, the load changes due to Joule heat generated by the resistance of the spring itself. When the load of the third SMA spring 31 changes, the interlocking shaft 23 interlocks to change the opening of the bypass valve 14 and adjust the maximum value of the incoming water flow rate. As the set temperature increases, the amount of electricity supplied to the third SMA spring 31 is increased so that the maximum incoming water flow rate matches the set temperature, thereby preventing the capability of the appliance from being exceeded.

Next, the operation of the water heater of the second embodiment will be described. When a hot water tap (not shown) is opened to start water flow to the appliance and the flow rate sensor 11 detects a flow rate equal to or more than a predetermined value, the main solenoid valve 51 and the original solenoid valve 52 are opened to supply gas to the burner 40. Then, the fuel is ignited by an ignition device (not shown) to start the combustion operation and control the hot water temperature. Further, the third SMA spring 31 is energized with an amount of energization corresponding to the set temperature to adjust the opening of the bypass valve 14, and the spring load of the first SMA spring 15 is changed according to the incoming water temperature to adjust the incoming water flow rate. In addition, since the flow rate is limited to the maximum flow rate corresponding to the inlet water temperature and the outlet water temperature, the flow rate is limited to a range where the set temperature can be obtained even when the hot water tap is opened to the maximum.

Here, when the set temperature is changed,
The hot water temperature control is performed by adjusting the combustion amount of the burner 40, and the third SMA spring 31 is energized with the energization amount corresponding to the changed set temperature, and the opening of the bypass valve 14 is adjusted to the set temperature. Adjust the maximum incoming flow rate accordingly. Therefore, as shown in FIG. 4, it is possible to prevent the maximum capacity from being exceeded, and to fully exert the capability of the instrument.

As described above, according to the water heater of the second embodiment, the maximum incoming flow rate is adjusted by a simple configuration using the SMA spring, so that the cost can be reduced. Further, since the flow rate is continuously adjusted according to the set temperature, the range in which the original tapping capacity is sacrificed can be further reduced. Further, since the maximum flow rate can be directly controlled, even when the set temperature is changed to be high at the time of the maximum capacity, it can be dealt with by reducing the flow rate.

In the second embodiment, the flow rate of the bypass 13 of the water governor 12 is changed by changing the set temperature.
The flow rate may be changed in the hot water supply path 20, or the flow rate may be directly changed in the water supply path 10. In the second embodiment, the maximum flow rate is adjusted based on the incoming water temperature and the set temperature. However, the flow rate may be controlled only by the set temperature. Further, an incoming water temperature sensor for detecting the incoming water temperature may be provided, and the maximum flow rate may be directly adjusted according to the difference between the set temperature and the incoming water temperature. Also, the third S
The ambient temperature of the MA spring 31 may be detected, and the amount of energization may be changed according to the detected temperature.

Next, a third embodiment of the present invention will be described. The basic configuration is the same as that of the water heater of the second embodiment (FIG. 3), but only the control processing of the controller 60 is different.
The same reference numerals are given to other configurations and overlapping operations, and description thereof will be omitted.

Since the load of the third SMA spring 31 changes depending on the temperature, the load changes not only due to Joule heat due to energization but also due to a change in ambient temperature. Therefore, in a configuration in which the current is simply supplied with the amount of power supply according to the set temperature, there is a problem that the control flow rate changes due to a change in the ambient temperature even at the same set temperature. Therefore, the controller 60 calculates the maximum incoming water flow rate at which hot water can be discharged at the set temperature from the maximum capacity of the appliance and the difference between the set temperature and the incoming water temperature, and compares the calculated flow rate with the detection value of the flow rate sensor 11. Are compared, and the amount of energization is controlled so that the detection value of the flow rate sensor 11 approaches the calculated flow rate. That is, the flow sensor 1
If the detected value of the first SMA is larger than the calculated flow rate, the third SMA
Increase the amount of electricity to the spring 31 to reduce the incoming water flow,
If the value detected by the flow sensor 11 is smaller than the calculated flow rate, the amount of electricity supplied to the third SMA spring 31 is reduced to increase the flow rate of incoming water. Therefore, when the opening degree of the hot-water tap is small and the detected flow rate is smaller than the calculated flow rate, the amount of energization continues to decrease, so that the amount of energization eventually becomes zero.

By such control, the third SMA spring 3
Even if the ambient temperature fluctuates, the maximum incoming flow rate can be stabilized even if the ambient temperature fluctuates, but it takes a long time to stabilize the maximum incoming flow rate by such control alone, and the usability deteriorates. Therefore, control is performed such that power is first supplied with an amount of power corresponding to the set temperature, and then correction is performed based on the detection value of the flow sensor 11. Here, in the method of storing in advance the amount of energization corresponding to the set temperature, the third S
The control flow rate varies depending on the ambient temperature of the MA spring 31. The deviation of the flow rate due to such fluctuation is corrected by looking at the detection value of the flow rate sensor, but the longer the correction width, the longer the correction time, so in order to reduce the flow control time, It is necessary to reduce the width of correction by supplying electricity with the amount of electricity corresponding to the ambient temperature. Therefore, the following control is performed. When the detection value of the flow rate sensor 11 is substantially stable at the calculated flow rate, the current flow rate is the current flow rate for adjusting the maximum incoming flow rate at the set temperature at that time at the ambient temperature of the third SMA spring 31. Therefore, the set temperature and the energization amount at that time are stored as reference values. From these reference values and the relationship of the load change due to the temperature of the third SMA spring 31,
Calculate the amount of energization to control the maximum flow rate at the current set temperature. These reference values are used for the flow sensor 11
Is rewritten each time the detected value of is substantially stabilized at the calculated flow rate. According to such control, since the energization is performed at the energization amount corresponding to the set temperature at the immediately preceding ambient temperature at which the detected flow rate and the calculated flow rate are stable, even if the atmospheric temperature fluctuates depending on the season or time zone, Electric current can be supplied with a corresponding amount of electric current.

Next, control processing performed by the controller will be described with reference to the flowchart of FIG. In this flowchart, the current set temperature is Ts, the set temperature stored at the time of stabilization is Tm, the energization amount at that time is Im, and the set temperature Ts calculated based on the stored set temperature Tm and the energization amount Im. Is the amount of electricity supplied, Is is the detected value of the incoming water temperature sensor 19, and F is the maximum incoming flow rate at which hot water can be discharged at Ts
s, F represents the detection value of the flow sensor, and I represents the amount of current supplied to the third SMA spring 31.

At the start of the tapping operation, the amount of current Is at the currently set temperature Ts is calculated from the set temperature Tm and the amount of current Im stored as reference values (S1).
The energization amount Is obtained by calculating the energization amount I to the third SMA spring 31
(S2). Also, the maximum incoming flow rate Fs at which hot water can be discharged at the set temperature Ts is calculated from the maximum capacity of the appliance and the difference between the set temperature Ts and the detected temperature Tw of the incoming water temperature sensor 19 (S3). Here, the incoming water flow rate F detected by the flow rate sensor 11 and the calculated flow rate Fs are compared (S4).
If the detected flow rate F is larger than the calculated flow rate Fs (S4:
YES), the amount of electricity I to the third SMA spring 31 is increased (S5), and the flow rate F of incoming water is decreased. Also, the detected flow rate F
Is smaller than the calculated flow rate Fs (S4: NO), the energization amount I is decreased (S6) and the incoming water flow rate F is increased.
If the amount of current I continues to decrease and becomes 0 (S7: YE
S), the energization amount control ends. When the detected flow rate F is substantially stabilized at the calculated flow rate Fs (S8: YES), the set temperature Ts and the energization amount I at that time are respectively set to the reference values Tm and Tm.
It is stored as Im (S9).

When the set temperature Ts is changed (S10: Y
ES), from the set temperature Tm and the energization amount Im stored as the reference value, the energization amount Is according to the changed set temperature Ts is calculated (S1), and the energization amount I to the third SMA spring 31 is calculated. Power is supplied as the supplied power amount Is (S2). Further, the maximum incoming flow rate Fs at which the hot water can be discharged at the set temperature Ts is calculated (S3), and compared with the detected flow rate F (S4), the energization amount I is increased or increased so that the incoming water flow rate F approaches the calculated flow rate Fs. It is decreased (S5, S6).

When the hot-water tap is opened widely and the detected flow rate F exceeds the calculated flow rate Fs from the state of no power supply (I = 0) (S11: YES), the set temperature Tm stored as the reference value. And the amount of current Im, the amount of current Is corresponding to the set temperature Ts is calculated (S1), and the amount of current I to the third SMA spring 31 is supplied as the calculated amount of current Is (S2).
Also, the maximum incoming flow rate Fs at which hot water can be discharged at the set temperature Ts.
Is calculated (S3), compared with the detected flow rate F (S4), and the energization amount I is increased or decreased so that the incoming water flow rate F approaches the calculated flow rate Fs (S5, S6).

As described above, according to the water heater of the third embodiment, the stored reference value is used at the start of tapping, when the set temperature changes, and when the tapping amount exceeds the calculated flow rate. Calculates the amount of energization according to the set temperature from, and energizes at the calculated amount of energization, so that it is possible to quickly control the flow rate near the maximum incoming flow rate according to the set temperature. In addition, since the maximum incoming water flow rate at which hot water can be discharged at the set temperature is calculated and the flow rate is controlled by comparing with the detection value of the flow rate sensor 11, even if the ambient temperature of the third SMA spring 31 fluctuates, the calculated maximum incoming water flow rate is determined. It can be limited below the flow rate. In addition, since the relationship between the energization amount and the immediately preceding set temperature is stored and updated, that is, learned, the energization amount according to the set temperature is changed even when the ambient temperature of the third SMA spring 31 changes due to the season or time zone. Can be reduced, so that the time required for the flow control can be shortened. Further, when the detection value of the flow sensor 11 is less than the calculated flow rate, no electricity is supplied to the third SMA spring 31, so that the electricity bill can be saved.

In the third embodiment, the set temperature and the amount of current when the detection value of the flow rate sensor 11 is substantially stabilized at the calculated flow rate are stored as reference values, and based on the values, the amount of current corresponding to the set temperature is stored. Was calculated, but the amount of energization corresponding to the set temperature may be stored in advance as a reference value.

The embodiments of the present invention have been described above.
The present invention is not limited to these embodiments at all, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention.

[0046]

As described in detail above, claim 1 of the present invention
According to the water heater described above, the cost can be reduced by a simple configuration in which the maximum value of the flow rate of water is adjusted in conjunction with a change in the spring load of the shape memory alloy spring provided in the tap hole.

Further, according to the water heater according to the second aspect of the present invention, by keeping the temperature at the time of stopping the water supply, the maximum value of the flow rate at the start of tapping is set to a flow rate commensurate with the set temperature, and the tapping water is supplied. The usability is good because it shortens the time from the start until the tapping temperature stabilizes, and prevents the tapping flow rate from being reduced even though the set temperature is not changed during tapping.

Further, according to the water heater of the third aspect of the present invention, by applying a current to the shape memory alloy spring, the spring load is changed to adjust the maximum value of the flow rate. Cost can be reduced. Further, since the flow rate of incoming water is changed according to the set temperature, the capability range of the appliance can be used more widely.

Further, according to the water heater according to the fourth aspect of the present invention, the shape memory alloy spring is energized with an energizing amount corresponding to the set temperature so that the detection value of the flow sensor approaches the calculated flow. Since the flow rate is controlled by changing the amount of current supplied to the shape memory alloy spring, the amount of hot water can be quickly and accurately limited to the calculated flow rate even if the ambient temperature of the shape memory alloy spring fluctuates.

Further, according to the water heater of the fifth aspect of the present invention, based on the set temperature and the energizing amount when the detected value of the flow sensor is substantially stable at the calculated flow rate, the set temperature is determined. Since the amount of energization is calculated, a more optimal amount of energization can be obtained according to the ambient temperature of the spring made of the shape memory alloy, and the flow rate can be controlled quickly.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a water heater as a first embodiment.

FIG. 2 is a hot water supply capacity diagram of the water heater of the first embodiment.

FIG. 3 is a schematic configuration diagram of a water heater as a second embodiment.

FIG. 4 is a hot water supply capacity diagram of a water heater according to a second embodiment.

FIG. 5 is a flowchart illustrating a control process performed by a controller according to a third embodiment.

FIG. 6 is a schematic configuration diagram of a water heater as a conventional example.

FIG. 7 is a diagram of a tapping capacity of a conventional water heater.

FIG. 8 is a schematic configuration diagram of a water heater as a conventional example.

FIG. 9 is a hot water supply capacity diagram of a conventional water heater.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Water supply path, 11 ... Flow sensor, 12 ... Water governor, 13 ... Bypass path, 14 ... Bypass valve, 15
… First SMA spring, 20… tapping path, 21… second SMA
Spring, 22: tapping temperature sensor, 23: interlocking shaft, 31
... 3rd SMA spring.

Claims (5)

[Claims] 1. A heat exchanger for heating water supplied from a water supply channel by combustion heat of a burner and supplying the water to a hot water channel, temperature setting means for setting a set temperature, and a method for setting the hot water temperature to approach the set temperature. A hot water supply device provided with hot water temperature control means for adjusting the amount of combustion of the burner; a spring made of a shape memory alloy provided in the hot water path, wherein a spring load changes according to the hot water temperature; In conjunction with the change in the spring load of the spring,
A water heater characterized by comprising a flow rate adjusting means for reducing the maximum value of the flow rate of water flowing through the appliance as the tapping temperature increases. 2. The water heater according to claim 1, further comprising a heat retaining means for keeping at least a temperature of the hot water near the spring made of the shape memory alloy in the appliance at a set temperature while the water is stopped. 3. A heat exchanger for heating water supplied from a water supply channel by combustion heat of a burner and supplying the water to a hot water channel, temperature setting means for setting a set temperature, and adjusting the temperature of the hot water to approach the set temperature. A water heater provided with a tapping temperature control means for controlling the amount of combustion of the burner, wherein a heat is generated by being energized, and a spring made of a shape memory alloy whose spring load changes in accordance with the amount of heat; Energizing means for energizing the shape memory alloy spring with a corresponding energization amount, interlocking with a change in the spring load of the shape memory alloy spring,
A water heater comprising: a flow rate adjusting means for reducing a maximum value of a flow rate of water flowing through the appliance as the set temperature increases. 4. A heat exchanger for heating water supplied from a water supply channel by combustion heat of a burner and supplying the heat to a hot water channel, temperature setting means for setting a set temperature, and a flow rate of water passed through the appliance. And a flow sensor for detecting the temperature of the hot water, and a hot water temperature control means for controlling the amount of combustion of the burner so that the hot water temperature approaches the set temperature. A spring made of a shape memory alloy in which a spring load changes, a flow rate adjusting means for positioning a valve body by the spring made of the shape memory alloy and adjusting a maximum value of a flow rate of water flowing through the appliance, and a tapping at the set temperature. At the start of water flow, or when the set temperature is changed, or when the detected value of the flow sensor exceeds the calculated maximum flow, the amount of electricity supplied according to the set temperature To energize the shape memory alloy spring Flow control means for controlling the flow rate near the calculated flow rate, and thereafter controlling the flow rate by changing the amount of current supplied to the shape memory alloy spring so that the detection value of the flow rate sensor approaches the calculated flow rate. A water heater characterized in that: 5. The amount of energization according to the set temperature is determined by the set temperature and the amount of energization to the shape memory alloy spring when the detection value of the flow sensor is substantially stable at the calculated flow rate. The water heater according to claim 4, wherein the water heater is calculated based on the water heater.