JPH0760016B2 - Bath water heater - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bath water heater using a bypass mixing system, and more particularly to a bath water heater capable of reliably determining the use of another plug when dropping water into a bath. Is.

[0002]

2. Description of the Related Art Traditionally, a bath water heater has been designed and used as a water heater exclusively for a bathroom, which is used only for dropping a hot water supply in the bath or for heating the bath to heat the inside of the bath.

In recent years, however, there is a strong demand for general hot water supply to other taps such as the kitchen and washbasin, rather than using the bath hot water supply device only for the bathroom due to the problem of installation space and the like.

However, when the bath water heater is used together with general hot water for the kitchen, for example, when the bath hot water supply and the kitchen hot water supply are performed at different times, there is no big problem, but during the bath hot water supply. If there was a request for hot water to the kitchen, there would be a serious problem.

That is, the temperature of hot water generally required in the kitchen and the like are different from the temperature of hot water required for dropping hot water in a bath. Therefore, if there is a request for hot water supply to the kitchen while hot water is being dropped into the bath, either one of the hot water sources should be standardized to supply hot water, or one of the hot water supplies should be prioritized. It is necessary to stop temporarily.

[0006] Therefore, when the bath water heater is used together with general hot water in the kitchen or the like, a function for determining whether or not the other plug is used by opening the other plug in the kitchen while dropping the bath It is essential to have

[0007] As the simplest configuration for determining whether or not the other plug of the kitchen or the like is opened and the other plug is used during the hot water supply of the bath, the drop circuit for the bath is A water flow switch that detects the presence or absence of water flow is installed in the main waterway that is downstream of the branched portion, and it is judged that other plugs such as kitchen are used while the water flow switch is operating. is there.

FIG. 7 is a block diagram of a bath water heater of the prior art which uses the above water flow switch to determine the use of the other plug. The basic configuration except the water flow switch shown in FIG. 7 has already been disclosed by the present applicant in JP-A-4-76350.

In FIG. 7, B is a prior art bath water heater, which is roughly divided into a main water channel 1 passing through a heat exchanger 2.
And a bypass water channel 3 provided in the main water channel 1 in parallel with the heat exchanger 2, and a hot water mixing section below the main water channel 1, that is, in the conventional example, a drop water channel 4 branched from the downstream of the flow rate changing means 9. To be done. The entrance side of the main waterway 1 is branched from city water, while the branching point 30 of the drop waterway 4 of the main waterway 1 is connected to other taps such as a kitchen and a washroom.

The main water passage 1 is heated by the incoming water temperature detecting means 5 for detecting the incoming water temperature, the hot water flow rate sensor 6 for detecting the amount of water flowing through the heat exchanger 2, the heat exchanger 2, and the heat exchanger 2. hot water temperature detector 2 for detecting the water temperature T _K
2. In addition to piping 2, the mixed hot water temperature detecting means 10 for detecting the hot water temperature, a water flow switch 12 is provided after the branch point 30 of the drop water channel 4. The temperature detecting means are all thermistors.

A flow rate varying means 9 is provided at the end of the bypass water channel 3, that is, at the connection with the main water channel 1.
The flow rate varying means 9 has an actuator such as a stepping motor coupled to the main body of the mixing valve, and the opening of the mixing valve can be adjusted by adjusting the operating position of the stepping motor to flow through the bypass channel 3. The hot water flowing through the main water channel 1 and the water flowing through the bypass water channel 3 are mixed at an appropriate ratio by variably controlling the flow rate to obtain a mixed hot water at a required temperature. That is, the flow rate of the water flowing through the bypass channel is variably controlled by adjusting the opening degree of the stepping motor.

Drop-in channel 4 branched from the main channel 1.
The drop flow rate sensor 11 is connected to the pipe, and the drop flow rate sensor 11 measures the drop flow rate.

The heat exchanger 2 is a heat source device 8 composed of a gas burner.
Heated by. Further, the gas pipe of the heat source device 8 is provided with a heat quantity adjusting means 7 composed of a proportional valve, and the gas quantity is controlled by adjusting the opening degree of the heat quantity adjusting means 7.

Reference numeral 14 denotes a controller which operates by sending a signal to the above-mentioned heat amount adjusting means and the like, and a controller such as a heat source device and the controller are connected by wiring shown by a chain line in the figure. Further, the remote controller 15 is connected, and the remote controller 15 is provided with a bathtub automatic hot water filling button 16. By pushing this button 16, hot water is dropped into the bathtub.

In the prior art bath water heater, water from city water passes through the main water channel 1, is heated and mixed to be temperature-controlled, and is discharged to the drop channel 4 and other taps. And in the bath water heater of the prior art, the main water channel 1 drop channel 4
Since the water flow switch 12 is piped after the branch point 30 of the above, if there is a water flow after the branch point 30 of the drop channel 4, it is detected by the water flow switch 12.

That is, in the prior art shown in FIG. 7, it is possible to determine that the hot water is being supplied to another tap of the kitchen or the like by detecting the water flow switch 12 even while it is being dropped into the bathtub.

As another method for determining whether or not the other plug is used, the total flow rate of the hot water flowing through the heat exchanger and the water flowing through the bypass channel is measured with a flow meter, and At the same time, there is a method of measuring the flow rate of hot water flowing through a drop channel of a bath and comparing the two. That is, it is determined that the other plug is used when the total flow rate is higher than the flow rate in the drop channel.

FIG. 8 is a block diagram of a conventional bath water heater for determining whether another plug is used by using a flow meter. The bath water heater C of FIG. 8 does not use the water flow switch 12, but instead has a bypass flow rate sensor 13 for measuring the flow rate of the water flowing through the bypass water channel 3, and the other configurations are the bath water heater of FIG. 7. Same as device B. In the configuration of FIG. 8, the detected value Q _K of the high temperature hot water flow sensor 6 and the bypass flow sensor 13
The controller 14 calculates the difference between the total value (Q _K + Q _B ) of the detected values Q _B and the detected value Q _F of the drop flow rate sensor 11. If this value is less than a certain small amount of water considering the error value (for example, 3 liters / minute), it is considered that there is no other plug used in the kitchen when the bath is dropped,
On the contrary, if the amount of water exceeds a certain level, it is judged that the other plug is used.

[0019]

The structure for determining the use of the other plug used in the bath water heater of the prior art has a simple operation principle and can accurately determine the use of the other plug.

However, in the bath hot water supply apparatus of the prior art, it is essential to provide a flow rate sensor and a special water amount detection sensor for measuring the total flow rate, and there is a problem that the number of parts increases.

Therefore, in order not to increase the number of parts,
The total flow rate is calculated by calculating from the detected amount of the hot water flow rate detecting means for measuring the flow rate of the hot water and the valve opening of the flow rate varying means 9, and the calculated value is compared with the flow rate of the hot water flowing through the drop channel of the bath. Then, when this value exceeds a certain value, it was attempted to adopt a configuration in which it was judged that the other plug was used.

However, such a configuration for determining the use of the other plug by obtaining the total flow rate from the flow rate of the high temperature hot water and the valve opening of the flow rate varying means 9 has a low determination accuracy and is not practical. It was

As another problem, the conventional bath water heater has a fact that the surface of the heat exchanger is easily rusted or punctured. That is, in the above-described conventional bath hot water supply device, no measures were taken for the temperature of the heat exchanger body. For example, when the temperature of the incoming water from city water is close to 30 ° C, such as in summer, when trying to obtain hot water of 40 ° C suitable for bathing, if the bypass flow rate ratio is decided without considering the incoming water temperature. The flow rate of the bypass channel becomes small and the flow rate of high temperature hot water becomes large. As a result, the temperature of the heat exchanger body is lowered, and water droplets such as drain adhere to the surface of the heat exchanger body, causing corrosion such as rust and perforation on the surface of the heat exchanger.

Focusing on the above-mentioned drawbacks of the prior art, the present invention does not require a water flow sensor or a special flow rate sensor for measuring the total flow rate, and only the components that a normal bath water heater has are provided. It is an object of the present invention to propose a bath water heater that can determine whether or not a plug has been used and can make an accurate determination.

Another object of the present invention is to propose a bath water heater having a long life by preventing rust or the like from being generated on the surface of the heat exchanger.

Furthermore, in addition to the above problems, safety problems that may newly arise in order to achieve the above-mentioned object are also examined to prevent the hot water from coming out unexpectedly and to be used with confidence. The purpose is to propose a bath water heater that can be used.

[0027]

As described above, the configuration for determining the use of the other plug by obtaining the total flow rate from the flow rate of the high temperature hot water and the valve opening of the flow rate varying means 9 has a low determination accuracy and is practically used. However, as a result of further investigations by the present inventors regarding this cause, it was found that the main causes are as follows.

In other words, in the bath water heater of the bypass mixing system, the temperature of the mixed hot water is dropped to match the set temperature, so that the valve opening of the flow rate changing means 9 constantly changes. For this reason, there is a large difference between the hot and cold water mixing ratio of the flow rate varying means 9 and the actual amount of hot water discharged at each moment, and as a result, the determination of the use of the other plug is erroneous.

The bath hot water supply apparatus of the present invention completed based on this finding is a main water channel having a heat exchanger, a bypass channel connected in parallel with the heat exchanger, water flowing through the bypass channel and the heat exchanger. Water mixing section for mixing high-temperature hot water discharged from the main water channel, a drop channel branched from the main channel, a flow rate changing means for adjusting the mixing ratio of water flowing through the bypass channel and the high-temperature hot water, and a heat source for heating the heat exchanger. In a bath water heater equipped with a water heater and a mixing ratio control means for controlling the flow rate varying means so that the temperature of the mixed hot water becomes equal to the desired set temperature for tapping hot water, the flow rate of high-temperature hot water or the flow rate of water flowing through the bypass channel. It has a pre-mixing flow rate detecting means for detecting the flow rate and a drop water amount detecting means for detecting the amount of water flowing through the drop water channel, and the flow rate varying means is temporarily fixed at a predetermined mixing ratio to detect the pre-mixing flow rate. The total flow rate of the mixed hot water calculated by the detection value of the stage and the mixing ratio of the flow rate varying means is compared with the detection value of the drop water amount detecting means. It is characterized in that it has another plug interrupt control means for releasing the fixation.

Although only one kind of mixing ratio is sufficient for fixing the flow rate varying means, several kinds of mixing ratios are preset in order to prevent water droplets from being generated on the surface of the heat exchanger. It is desirable that the configuration be selected according to various situations.

A feature of the present invention completed from such a point of view is that a plurality of mixing ratios of the flow rate varying means are set in advance, the temperature of incoming water entering the heat exchanger or the bypass water channel, the preset temperature of dropping, The mixing ratio of the flow rate varying means is selected on the basis of either the difference between the water temperature and the drop set temperature, and the flow rate varying means is temporarily fixed according to the selected mixing ratio. The bath water heater according to 1.

Similarly, water droplets are prevented from being generated on the surface of the heat exchanger, and a feature of the invention which is a further development of the above invention is that the temperature of the mixed hot water discharged from the hot water mixing section is detected. It has a mixed hot water temperature detecting means, a heat quantity adjusting means for adjusting the heat generation amount of the heat source device, and a high temperature hot water temperature detecting means for detecting the temperature of the high temperature hot water. If the difference between the total flow rate of the mixed hot water calculated by the mixing ratio and the detection value of the drop water amount detecting means is less than a certain amount, the temperature of the mixed hot water discharged from the hot and cold water mixing unit is made equal to the drop set temperature. If the difference between the total flow rate of the mixed hot water and the detection value of the dropped water amount detection means is a certain amount or more, the mixing ratio of the flow rate varying means is released and the temperature of the hot water is adjusted. Predetermined A bath water heater according to claim 1 or 2, wherein the control means for adjusting the heating value of the heat source unit so that the hot water set temperature.

Further, in the invention for improving the safety of the above-mentioned invention, the mixing ratio of the flow rate varying means is fixed after a lapse of a fixed time after the drop hot water supply command. The bath water heater according to any one of 3 above.

Another invention for achieving the same object is a hot water temperature detecting means for detecting the temperature of the hot water, and a control means for adjusting the temperature of the hot water to a predetermined hot water set temperature. And a control means for fixing the mixing ratio of the flow rate varying means if the temperature detected by the high-temperature hot-water temperature detecting means and the high-temperature hot-water set temperature are compared after the drop-in hot water supply command, and the difference between them is within a certain temperature. The bath water heater according to any one of claims 1 to 4, further comprising:

[0035]

The bath water heater of the present invention basically adopts the bypass mixing system, and has a main water channel having a heat exchanger and a bypass water channel connected in parallel with the heat exchanger, The room temperature water flowing through the bypass channel and the hot water passing through the heat exchanger can be mixed in the hot water mixing section. Further, the mixing ratio control means adjusts the flow rate varying means so that the temperature of the mixed hot water becomes equal to the desired set temperature at which hot water is discharged. Therefore, similar to the bath water heater of the prior art, when the other tap of the kitchen or the like is opened, hot water of a desired set temperature is discharged.

In the bath water heater of the present invention, when the hot water is dropped into the bath, the flow rate varying means is temporarily fixed in a state of a predetermined mixing ratio. Therefore, in this state, the ratio between the flow rate of hot water and the amount of water flowing through the bypass channel does not change at all.
The specific numerical value of the mixing ratio is stored in advance in the control device. Then, the total flow rate of the mixed hot water is calculated from the mixing ratio and the flow rate of the hot water detected by the pre-mixing flow rate detection means or the amount of water flowing through the bypass water channel. Since the calculated total flow rate of the mixed hot water is based on the concrete numerical value of the mixing rate in the state where the flow rate of the high temperature hot water and the rate of the amount of water flowing through the bypass channel do not change at all as described above, the reliability is high. high.

Then, the total flow rate of the mixed hot water is compared with the detection value of the dropped water amount detecting means, and if the difference between the two is more than a certain amount, some plugs are opened in addition to the dropped hot water. Since it is certain that the tap has been tapped, it can be determined that the other tap is used. On the other hand, if the difference between the two is less than a certain amount, it can be determined that the other plug is not used because only the plug for supplying hot water to the drop channel is currently used.

When the other plug is not used, theoretically the total flow rate of the mixed hot water should be equal to the detection value of the drop water amount detecting means, but in the present invention, the total flow rate is calculated. As mentioned above, it is unavoidable that some errors occur. Therefore, if the difference between the two is more than a certain amount, it is judged that the other plug is used.

If it is found that the other plug is used,
The fixation of the mixing ratio of the flow rate varying means is released, and specific measures are taken according to the conditions of the equipment and the usage conditions. In the present invention, as the pre-mixing flow rate detecting means, a means for detecting the flow rate of high-temperature hot water is usually used, but a means for detecting the flow rate of water flowing through the bypass water channel may be used depending on the piping circuit.

Since the purpose of fixing the flow rate varying means is to stabilize the mixing ratio of hot and cold water and improve the reliability of the calculation of the total flow rate as described above, any mixing ratio is possible. Since the water is dropped into the bath at this mixing ratio at least while the flow rate is being detected, it is preferable that water drops are not generated on the surface of the heat exchanger during this period.

The generation of water droplets on the surface of the heat exchanger occurs when the temperature of the surface of the heat exchanger is low. Therefore, whether or not water drops are generated on the surface of the heat exchanger depends on the temperature of the hot water discharged from the heat exchanger. The investigation conducted by the present inventors has revealed that specifically, when the temperature of the high-temperature hot water is 50 ° C. or lower, water droplets are generated on the surface of the heat exchanger. If the temperature of the hot water exceeds 80 ° C, the hot water may boil in the heat exchanger, which is not preferable.

It has been empirically known that it is the difference between the incoming water temperature entering the bypass water channel and the drop set temperature that has the greatest effect on the temperature of the hot water. Further, it has been found that the temperature range of the high-temperature hot water can be roughly limited by simply using the inlet water temperature to enter the bypass channel or the drop setting temperature alone.

The invention of claim 2 is based on the above knowledge, and a plurality of mixing ratios when the flow rate varying means is fixed are preset. That is, the case where the proportion of high-temperature hot water is high and the case where it is low are determined. This mixing ratio is, for example, when the temperature of the hot water is 50 ° C. when the water temperature is in a certain range.
The range from 80 ° C. to 80 ° C. is obtained by experiment and stored in the control device.

In the second aspect of the invention, first, for example, the incoming water temperature is detected, and the temperature of the hot water is 50 ° C. at the incoming water temperature from a plurality of mixing ratios stored in the control device.
A ratio in the range from to 80 ° C is selected. Then, the mixing ratio of the flow rate varying means is fixed at the selected mixing ratio. While the mixing ratio of the flow rate varying means is fixed, the water is continuously dropped into the bath and the heated water passes through the heat exchanger, but at least the surface temperature of the heat exchanger is
Continue to maintain the temperature above the temperature at which water drops do not occur.

According to the third aspect of the present invention, the difference between the total flow rate of the mixed tap water calculated by the detection value of the pre-mixing flow rate detecting means and the mixing ratio of the flow rate varying means and the detection value of the drop water amount detecting means is constant. If it is less than the amount, it is judged that no other plug is used. In the invention of claim 3, when it is judged that the other plug is not used, the dropping into the bath is continued while the fixed mixing ratio of the flow rate varying means is maintained as it is.

That is, the temperature of the mixed hot water detected by the mixed hot water temperature detecting means is compared with the drop set temperature desired by the user, and the heat generation amount of the heat source device is adjusted so that both are equal. Then, the mixing ratio of the high-temperature hot water and the water flowing through the bypass channel does not change, but the temperature of the high-temperature hot water drops depending on the set temperature and the actual temperature of the mixed hot water,
Hot water at the desired dropping temperature is dropped into the bathtub.

On the contrary, if the difference between the total flow rate of the mixed hot water and the detection value of the dropped water amount detecting means is a certain amount or more, it is determined that the other plug is used. Then, subsequently, the fixation of the mixing ratio of the flow rate varying means is released. After the fixed mixing ratio is released, the mixing ratio of the flow rate varying means is automatically adjusted so that the temperature of the mixed hot water discharged from the hot water mixing unit matches the hot water temperature desired by the user.

In addition, the calorific value of the heat source device is adjusted so that the temperature of the hot water becomes a predetermined temperature, and the temperature of the hot water becomes stable. Therefore, the change in the temperature of tapping water is determined only by the mixing ratio of the flow rate varying means, and the tapping temperature after mixing is stable.

In the third aspect of the invention, the tap water temperature after the use of the other plug is found to be the above-mentioned dropping set temperature, but in general, the other plug, that is, hot water supply for kitchen etc. Since it is often prioritized, it is desirable to standardize the set temperature at which you want to tap hot water from other taps in the kitchen. At this time, it is possible to simultaneously drop hot water having a set temperature desired to be tapped into the other tap into the bathtub, but in many cases, the drop into the bathtub is temporarily suspended.

The invention of claim 4 further improves the inventions of claims 1 to 3 and enhances the safety of these inventions.

That is, according to the first to third aspects of the invention, when the signal for starting dropping into the bath is input, the flow rate varying means is fixed at a predetermined mixing ratio as described above. However, if it is assumed that another plug such as a kitchen is being used first and then the flow rate varying means is fixed after a while, hot water with an unexpected temperature will drop into the bathtub from time to time. May be

More specifically, when the other plug was previously used, the bath water heater of the present invention operates by a normal bypass mixing system, and the temperature of the hot water is usually within a certain range. Some kind of control is performed so that the temperature is reached. However, when the water flow in the heat exchanger is stopped by using the other plug, the hot water staying in the heat exchanger may be post-boiling due to the residual heat of the heat exchanger, resulting in a very high temperature. .

However, when the temperature of the hot water is considerably high as described above, a signal for starting dropping into the bath is input, the flow rate varying means is fixed at a predetermined mixing ratio, and the fixed mixing is performed. When the ratio of the high-temperature hot water is high, the high-temperature hot water is discharged at a high ratio at the beginning when it is dropped into the bathtub, and there is a risk that very hot water will come out.

According to the fourth aspect of the invention, when the drop hot water supply command is issued, first, the mixing ratio of the flow rate varying means is controlled by the normal bypass mixing method. Therefore, even if the temperature of the hot water is considerably high, the temperature of the hot water dropped by increasing the amount of water flowing through the bypass can be stabilized to some extent.

Further, while hot water is being supplied while adjusting the mixing ratio of the flow rate varying means, most of the high temperature hot water staying in the heat exchanger is replaced. Since the mixing ratio of the flow rate varying means is fixed after a certain period of time has passed after the drop hot water supply command, most of the hot water in the heat exchanger has already been replaced when the mixing ratio was fixed. There is.
Therefore, it is possible to prevent hot water from being discharged at the beginning of dropping.

According to the fifth aspect of the present invention, if there is a drop hot water supply command, the actual hot water temperature is compared with the actual hot water set temperature before opening the drop hot water supply side valve. If the difference between the two is within a certain temperature, there is no danger even if hot water is discharged at a high ratio, so the mixing ratio of the flow rate varying means is fixed and the determination of the use of the other plug is started.

[0057]

EXAMPLES Specific examples of the present invention will be described below. The same members as those of the conventional technique are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a block diagram of a bath water heater according to the present invention. FIG. 2 is a graph showing the relationship between the opening degree of the flow rate varying means and the actual mixing ratio of hot and cold water. FIG. 3 is a flowchart of the bath water heater according to the first aspect of the invention.

In FIG. 1, A indicates a bath water heater according to the present invention. The piping system of the bath water heater A of FIG. 1 is almost the same as the configuration of the bath device B of the prior art described with reference to FIG. 7. However, while the bath device B of FIG. 7 is provided with the water flow switch 12, the bath water heater A does not have a member corresponding to this water flow switch.

The controller 31 includes a heat generation amount feedforward (hereinafter referred to as FF) control unit 17, a heat generation amount feedback (hereinafter referred to as FB) control unit 18, a mixing ratio FB control unit 19, a mixing valve opening degree setting unit 20, It is composed of a hot water supply temperature setting device 21 and functions as the other plug interrupt control means as a whole.

The detected value T _C of the incoming water temperature detecting means 5 is input to the heat generation amount FF control unit 17. Then, based on the detected value T _C sent, the opening degree of the heat quantity adjusting means 7 required for the temperature of the high-temperature hot water to reach 80 ° C. is calculated, and the heat quantity adjusting means 7 is opened / closed to generate the heat source device 8 It regulates and controls the amount of gas supplied to.

The calorific value FB control unit 18 has a high temperature hot water temperature detection value T _K detected by the high temperature hot water temperature detection means 22.
When a detection value T _H of the temperature of the hot water after the hot and cold water mixing that is detected by the mixed water temperature detecting means 10, the detection value Q _F of the flow rate of darken waterway is detected by the flow sensor 11 darken are input. Then, the detected values are selectively used to adjust the opening degree of the heat amount adjusting means 7 to control the amount of gas supplied to the heat source device 8.

The mixing ratio FB control unit 19 is integrated with the heat generation amount FF control unit 17 and the heat generation amount FB control unit 18, and the respective data of the mixed hot water temperature detecting means 10 and the flow rate sensor 11 are collectively inputted. It Then, the mixing ratio FB control unit 19
Is for feeding back the signal of the mixed hot water temperature detecting means 10 to the flow rate varying means 9, the output of the mixing ratio FB control section 19 is connected to a stepping motor constituting the flow rate varying means 9, and the opening degree of the flow rate varying means 9 is θ can be adjusted. Further, the mixing ratio FB control unit 19 is connected to the hot water supply temperature setting device 21, and the signals of the temperature detecting means and the flow rate sensor are input to the hot water supply temperature setting device 21 via the mixing ratio FB control unit 19.

The hot water supply temperature setting device 21 is capable of setting the set temperature of the outlet side of the heat exchanger 2, that is, the set temperature T _{KS of} high temperature hot water and the hot water after mixing discharged from the flow rate varying means 9, and the mixing valve. It is connected to the opening degree setting unit 20. Note that the set temperature of the mixed hot water is tapped from the flow rate changing means 9 in this embodiment includes a darken the set temperature T _HS, 2 kinds of set temperature T _TS of the hot water to the desired hot water to other plug of the kitchen or the like is set To be done. Then, the two kinds of set temperatures are automatically switched in the hot water supply temperature setting device 21.

[0065] In the mixing valve opening setting unit 20, the mixing ratio FB control section 19 to the sent input temperature T _C, darken set by the hot water temperature setting unit 21 sets the temperature T _HS of the deviation by the flow rate varying means 9 The opening degree θ of is selected, and the stepping motor is adjusted so that this opening degree is obtained. The mixing valve opening degree setting unit 20 is connected to the calorific value FB control unit 18, and operates in association with each other to keep the temperature T _K of the high-temperature hot water in a certain range (for example, in the range of 50 ° C. to 80 ° C.). It is possible to control the temperature T _H of the hot water discharged from the flow rate changing means 9 while controlling the temperature.

FIG. 2 is a graph showing the relationship between the opening of the flow rate varying means 9 and the actual mixing ratio of hot and cold water. The horizontal axis of the graph is the opening of the flow rate varying means 9, and this opening can be accurately known by the number of steps of the stepping motor that opens and closes the mixing valve. The vertical axis represents the total flow rate of hot water discharged from the flow rate varying means 9 after mixing the high-temperature hot water and the water flowing through the bypass water channel, and is expressed as a ratio with the flow rate of the high-temperature hot water detected by the high-temperature hot water flow sensor 6 as 1. Has been done. In the case of the present invention, the opening degree θ of the flow rate varying means 9 can be between 0 ° and 315 °. At 0 °, the flow rate flowing through the bypass water channel 3 is the maximum, and at 315 °, the bypass channel 3 is opened. Flow rate is minimal.

The first position and the second position shown in FIG.
The position is a position where the opening degree of the flow rate varying means 9, that is, the mixing ratio of the high-temperature hot water and the water flowing through the bypass passage is different, and is selected according to the incoming water temperature and the set temperature.

That is, in order to discharge hot water at a constant temperature into the bathtub or the kitchen, a method of changing the mixing ratio of the high temperature hot water and the water flowing through the bypass water channel, and changing the gas amount to change the temperature itself of the high temperature hot water. There is a way to do it. In order to discharge hot water having a constant temperature, it is clear from the heat quantity conservation law that the larger the bypass flow rate, the more the heat exchanger 2 must be heated to raise the temperature of the hot water. However, if it exceeds a certain limit, there is a problem that high temperature hot water boils. On the contrary, as the bypass flow rate is lowered, the temperature at the outlet side of the heat exchanger 2 for heating, that is, the temperature T _{K of the} hot water drops, and when the temperature falls below a certain temperature, the temperature of the main body of the heat exchanger 2 drops excessively and the heat Water droplets such as drain may be attached to the exchanger 2.

In the first position and the second position, hot water of a predetermined temperature can be discharged under conditions such as a certain water inlet temperature without boiling of the high temperature hot water and excessive lowering of the temperature. It was selected. The first position has a larger bypass flow rate than the second position.

FIG. 3 is a flow chart showing the contents of control of the present invention. If there is a drop command to the bathtub in step 1, an electromagnetic valve (not shown) provided in the drop water channel 4 is opened, and hot water is poured into the drop water channel 4. Then, the process proceeds to step 2, dropped into the set temperature T _HS
And the incoming water temperature T _C detected by the incoming water temperature detecting means 5
It is determined whether or not the difference is 25 ° C or more. Here darken proceeds to set the temperature T _HS and incoming water temperature T unless the difference in _C is 25 ° C. or higher Step 3, fixed by operating the stepping motor the opening θ of the flow rate changing means 9 to the first position in FIG. 2 . That is, the mixing ratio of the flow rate changing means 9 is set to the first
Fixed to the position ratio.

On the other hand, if the difference between T _HS and T _C is 25 ° C. or more, the routine proceeds to step 11, where the opening θ of the flow rate varying means 9 is fixed at the second position in FIG. As described above, the first position has a larger bypass flow rate than the second position. The opening degree θ of the flow rate varying means 9 determined in step 3 or step 11 is the hot water temperature detecting means 2
The temperature of the hot water detected in 2 is in a certain range (eg
≦ T _K ≦ 80 ° C.).

That is, when the difference between the desired temperature for tapping hot water and the incoming water temperature is small, the bypass flow rate is increased and the amount of water passing through the heat exchanger 2 is reduced. The reason for this is that by squeezing the amount of water entering the heat exchanger 2, the temperature of the high-temperature hot water is raised and the surface temperature of the heat exchanger 2 is raised, and the aforementioned adhesion of drain etc. is avoided. Therefore, darken if the difference between the set temperature T _HS and incoming water temperature T _C is large to fix the flow rate varying means 9 opening θ to the second position in FIG.

[0073] Although securing the mixing ratio of the flow rate varying means 9 by difference between the set temperature T _HS darken the incoming water temperature T _C in the present embodiment, in order to simplify the control incoming water temperature T _C or substantially larger problem be fixed opening θ by the respective set temperature T _HS alone darken does not occur. The incoming water temperature T _C and dropped into the set temperature T difference need not be limited to 25 ° C. the _HS, further incoming water temperature T _C and dropped into the set temperature T _HS difference three or more steps instead of the opening for fixing θ in two stages by the May be set in multiple stages, and conversely there may be only one position.

That is, the temperature T _{K of the} high-temperature hot water detected by the high-temperature hot-water temperature detecting means 22 is Z as a ratio of the total flow rate after mixing to the high-temperature hot water according to the heat conservation law.

[0075] _{T K = Z × T HS -} (Z-1) × T C

[0076] than is being calculated but, T _K, for example, 5
If the mixing ratio of the flow rate varying means 9 is fixed so as to be 0 ° C. or more and 80 ° C. or less, water droplets such as drain of the heat exchanger 2 main body can be prevented.

After completion of steps 3 and 11, the process proceeds to step 4 where it is determined whether or not another plug is used.
Specifically, the total flow rate Q _T (Q _T = Q _T) calculated from the mixture ratio based on the opening degree θ of the flow rate changing means 9 and the flow rate Q _K of the hot water.
_K × Z) and the flow rate Q _F dropped into the bath (Q _T −Q _F
= Q _K × Z−Q _F ) is 3 liters / minute or more. If this value is 3 liters / minute or more, it is determined that the other plug of the kitchen or the like is in use, and the process proceeds to step 9 described later.

On the other hand, if it is not more than 3 liters / minute, it is considered that other plugs such as kitchen are not used, and the process proceeds to step 5 described later. In step 4, 3 liters / min is set, but this is due to an error due to instrumental error of the drop flow rate sensor 11 and the hot water flow rate sensor 6, and the flow rate varying means 9.
This is a flow rate that takes into consideration the error of the total hot water discharge amount calculated by the opening degree θ of the actual hot water discharge amount, and is not necessarily limited to 3 liters / minute.

[0079] while fixing the opening degree of the flow rate varying means 9 in step 5, the temperature of the hot water after mixing to control the amount of gas to match the darken set temperature T _HS. That is, in the heat generation amount FF control unit 17, the heat amount adjusting means 7 for adjusting the temperature of the mixed hot water from the incoming water temperature T _C and the flow rate Q _K flowing through the heat exchanger 2 to match the set temperature T _HS.
Of the heat quantity adjusting means 7
Is adjusted to FF control the gas amount.

In parallel with this, at the same time, with the opening θ of the flow rate varying means 9 fixed in step 3 or step 11, the detected value T _H detected by the mixed hot water temperature detecting means 10, that is, the hot water after mixing. FB gas amount calorific value FB control unit 18 so that the temperature of the darken set temperature T _HS
Control it. In step 6, it is judged whether or not the predetermined dropping into the bathtub is completed, and if it is still less than the set water amount, the process returns to step 4 in which the other plug is used.

Therefore, the control of step 5 is continued while monitoring the usage state of the other plug until the set amount of hot water is discharged into the bathtub. When it is confirmed in step 6 that the set amount of hot water has been discharged, in step 7 the dropping into the bathtub is completed. The operation of the bath water heater may be stopped after step 7, or the procedure may be returned to step 1 to wait for the use of another plug.

During dropping into the bathtub, the total flow rate Q _T (Q _T = Q _K) calculated by the mixing ratio based on the opening degree θ of the flow rate changing means 9 and the flow rate Q _K of the hot water in step 4.
× Z) and the flow rate Q _F dropped into the bath (Q _T −Q _F =
When Q _K × Z−Q _F ) is 3 liters / minute or more, it is determined that the other plug of the kitchen or the like is in use, and the process proceeds to step 9 described later.

In this embodiment, when it is found that the other plug is being used, such as a kitchen, the use of the other plug is prioritized, and the dropping into the bathtub is stopped until the use of the other plug is completed.

That is, when it is determined in step 4 that the other plug has been used, the electromagnetic valve (not shown) in the drop channel is shut off when proceeding to step 9, and the tapping into the drop channel 4 is stopped. In step 9, the temperature of the high-temperature hot water is kept constant, and the opening degree θ of the flow rate varying means 9 is adjusted so that the hot water after mixing is matched with the desired temperature T _{TS at} which hot water is discharged to the other tap. That is, first, in the hot water supply temperature setting device 21, the set temperature of the mixed hot water is switched from the drop set temperature T _HS to the set temperature T _{TS at} which hot water is desired to be discharged to another tap.

Then, the amount of gas is controlled so that the temperature of the hot water is stabilized at a temperature of 80 ° C., for example. That is, in the heat generation amount FF control unit 17, the temperature of the high-temperature hot water is set to the high-temperature hot water set temperature T _KS from the incoming water temperature T _C and the flow rate Q _K flowing through the heat exchanger 2.
The opening amount of the heat amount adjusting means 7 is calculated so as to match with, and the heat amount adjusting means 7 is adjusted so as to reach this opening amount, and the gas amount is FF controlled.

In parallel with this, the hot water temperature detecting means 22
FB control unit 18 controls the amount of gas by the heat generation amount FB control unit 18 so that the detected value T _H detected by, ie, the temperature of the high temperature hot water, matches the high temperature hot water set temperature T _KS .

Further, in the mixing ratio FB control section 19, the fixation of the opening degree of the flow rate varying means 9 performed in step 3 or step 11 is released. And the mixed hot water temperature detecting means 10
The mixing ratio FB control section FB controls the opening degree θ of the flow rate varying means 9 so that the detected value T _{H of the above} , that is, the temperature of the hot water after mixing becomes the set temperature T _{TS at} which hot water is desired to be discharged to the other tap.

This control is continuously repeated during the use of the other stopper, and when the other stopper is no longer used, the process returns to step 1 and the dropping into the bath is restarted.

Although the bath water heater was started,
If there is no drop command, it is confirmed in step 8 whether hot water is being supplied to the other plug. For example, if it is found that there is water in the main waterway 1 and the other tap is being supplied with hot water, the process proceeds to step 8 described above, and hot water is continued to be supplied to the other tap. On the contrary, if the other plug is not used, the process returns to step 1 and waits for a drop command.

Next, an embodiment of the invention of claim 4 will be described. If there is a bathtub drop command, the bath water heater explained in FIG. 3 fixes the opening degree θ of the flow rate changing means 9 by the difference between the incoming water temperature and the drop set temperature, but before the bathtub drop command in the graph of FIG. When the fixed opening degree θ is near 315 °, the flow rate of the bypass water channel 3 is close to zero. Therefore, when hot water stays in the main body of the heat exchanger 2 due to the use of another plug in the kitchen or the like before the bath drop command is issued, the amount of bypass water is small and the hot water remains in the main body of the heat exchanger 2. Then, the high-temperature hot water boiled after that is dropped directly into the bathtub, which may be dangerous to the user. Therefore, this problem is solved by the embodiment described below.

FIG. 4 is a flow chart showing an embodiment of the present invention according to claim 4. Note that steps 4 to 10 in this embodiment are the same as those in FIG. 3 described above, and a description thereof will be omitted. Further, step 23 is a routine in which a series of steps of step 2, step 3, and step 11 in FIG. 3 are routineized, and corresponds to a portion surrounded by a broken line in FIG. If there is a drop command to the bathtub in step 20, a solenoid valve (not shown) provided in the drop water channel 4 is opened and hot water is poured into the drop water channel 4. Then immediately proceed to step 21. In step 21, the time T after the drop command in step 20 is the constant time T _O
It is determined whether or not has passed. If the predetermined time T _O has not elapsed after the command in step 20, the process proceeds to step 22.

[0092] In step 22, keeping the temperature of the hot water constant, the opening θ of the flow rate varying means 9 as hot water temperature after mixing the darken set temperature T _HS match is adjusted.

That is, in the heat generation amount FF control unit 17, the opening degree of the heat amount adjusting means 7 for making the temperature of the high temperature hot water match the high temperature hot water set temperature T _KS from the incoming water temperature T _C and the flow rate Q _K flowing through the heat exchanger 2. Is calculated, and the heat amount adjusting means 7 is adjusted so as to achieve this opening degree, and the gas amount is FF controlled.

In parallel with this, the hot water temperature detecting means 22
The heat generation amount FB control unit 18 performs FB control of the gas amount so that the detected value T _K detected by, that is, the temperature of the high temperature hot water matches the high temperature hot water set temperature T _KS . The temperature of the hot water is 8
The amount of gas is controlled so as to stabilize at the high temperature hot water set temperature T _KS of 0 ° C.

Then, the detected value T of the mixed hot water temperature detecting means 10
_H, that is, the temperature of the hot water after mixing falls and the set temperature _THS
Therefore, the mixture ratio FB control unit 19 feeds back the detected value T _H to the opening degree θ of the flow rate changing means 9.

In the control of step 22, as described above, the heat quantity adjusting means 7 is controlled by the FF control and the FB control so that the temperature of the hot water matches the hot water set temperature T _KS , and the hot water temperature after mixing matches the set temperature. As described above, the opening degree of the flow rate changing means 9 is F
The basic configuration of B control is the same as in step 9 described above. However, the point that step 22 is different from step 9 here is that in step 9, the opening degree θ of the flow rate varying means 9 is adjusted so that the hot water temperature after mixing matches the set temperature T _TS at which hot water is desired to be discharged to the other tap. whereas, in step 22, the opening degree θ of the flow rate varying means 9 so as to darken the set temperature T _HS is adjusted.

Thus, the flow rate changing means 9 is operated for a certain period of time.
The opening degree θ of is adjusted and hot water is dropped into the bathtub. As a result, even if very hot water stays in the heat exchanger 2 due to post-boiling, the hot water in the heat exchanger 2 is replaced within a certain period of time, and the hot water set temperature T _KS is stabilized.

In step 22, the hot water is continuously dropped by the FB control of the flow rate changing means 9, and when a certain time T _O has passed, the process proceeds to step 23, and the opening degree of the flow rate changing means 9 is fixed. The following steps are exactly the same as in the embodiment of FIG.

Next, another embodiment of the present invention will be described. FIG. 5 is a flowchart of a bath water heater according to a modified embodiment of the present invention.

In this embodiment, the temperature of the hot water is temporarily checked before fixing the flow rate changing means 9, and it is confirmed that this temperature is stable at the hot water set temperature T _KS to improve the safety. It is intended to improve. That is, when the bathtub drop command is issued in step 30, the solenoid valve (not shown) provided in the drop water channel 4 is opened as in the previous embodiment, and hot water is flown into the drop water channel 4.

Then, in step 31, the actual temperature T of the hot water detected by the hot water temperature detecting means 22 is detected.
Compare _K with the hot water set temperature T _KS . The value obtained by subtracting the set temperature T _{KS of} hot water from the actual temperature T _K of hot water is 5
If the temperature is higher than 0 ° C, it is determined that the hot water staying in the heat exchanger 2 is at a high temperature, and the process proceeds to step 22 described above.
In step 22, the flow rate varying means 9 is FB controlled and dropped to replace the hot water retained in the heat exchanger 2.

Then, the FB control of the flow rate varying means 9 is repeated until the value obtained by subtracting the set temperature T _{KS of the} hot water from the actual temperature T _K of the hot water becomes smaller than 5 ° C. The difference between the two is 5 ℃
If it becomes smaller than this, the hot water staying in the heat exchanger 2 is replaced, and it is judged that the hot water set temperature T _KS has stabilized, and the routine proceeds to step 23. The following steps are exactly the same as those of the embodiment shown in FIG.

In order to secure the safety,
Of course, it is also possible to adopt a configuration in which the configuration of the embodiment of FIG. 4 and the configuration of the embodiment of FIG. 5 are combined.

FIG. 6 is a flow chart of a bath water heater when the configuration of the embodiment of FIG. 4 and the configuration of the embodiment of FIG. 5 are combined. In the bath water heater of the present embodiment, after the bathtub drop command 40, the process proceeds to step 21 described above, and in step 21, it is determined whether the time T after the command in step 40 has exceeded a certain time T _o . If the fixed time T _O has not elapsed after the command at step 40, the routine proceeds to step 22, where the FB control of the flow rate varying means 9 and the FF control and FB control of the hot water are performed.

After the FB control of the flow rate varying means 9 and the FF control and FB control of the high temperature hot water are repeated for a certain period of time, the routine proceeds to step 31, where the high temperature hot water temperature detecting means 22 detects the actual condition. The high temperature hot water temperature _TK and the high temperature hot water set temperature _TKS are compared. And the actual temperature T of the hot water
The FB control of the flow rate varying means 9 is repeated until the value obtained by subtracting the high temperature hot water set temperature T _KS from _K becomes smaller than 5 ° C. In this way, after confirming the stability of the temperature of the high-temperature hot water in the two processes, the process proceeds to step 23 for the first time. After that, the same steps as those of FIG. 3 are performed.

[0106]

In the bath water heater of the present invention, when the hot water is dropped into the bath, the flow rate varying means is temporarily fixed in a state of a predetermined mixing ratio so that the flow rate of the high temperature hot water and the rate of the amount of water flowing through the bypass channel change at all. A state where no mixing is performed is made, and the total flow rate of the mixed hot water is calculated from the mixing ratio at this time and the amount of water such as high-temperature hot water detected by the pre-mixing flow rate detecting means. Therefore, the calculated value of the total flow rate of the mixed hot water is highly reliable. Therefore, the bath water heater of the present invention has an effect of being able to accurately determine the use of the other plug.

Further, the bath water heater according to the present invention does not require any special member other than the temperature detecting means or the like provided in the usual bath water heater, and the accurate use of another plug without increasing the number of parts. There is an effect that a judgment can be made.

According to the second aspect of the present invention, a plurality of mixing ratios of the flow rate changing means are set in advance, and the mixing ratio of the flow rate changing means is selected based on the temperature of the water entering the heat exchanger and the like. By fixing, hot water does not boil,
In addition, the temperature of the high-temperature hot water can be maintained in a range where water drops are not generated on the surface of the heat exchanger. Therefore, the bath water heater according to the present invention is strong and can be used for a long time without causing rust on the surface of the heat exchanger or causing corrosion such as perforation.

According to the third aspect of the present invention, it is determined whether the other plug is used, and when it is determined that the other plug is not used, the calorific value of the heat source device is adjusted, and hot water having a predetermined temperature is tapped out and dropped. When it is determined that the other plug is used, the temperature of the hot water is stabilized at a predetermined hot water set temperature and the mixing ratio of the flow rate varying means is changed. In this way, there is an effect that the control means can be switched to an appropriate one according to the usage status of the other plug, and hot water of the temperature desired by the user can be immediately discharged at any time.

In addition, the temperature of the high-temperature hot water is appropriately controlled, and there is an effect that it does not cause rust on the surface of the heat exchanger and does not cause corrosion such as perforation, and is durable and can be used for a long time. .

According to the fourth aspect of the present invention, the mixing ratio of the flow rate varying means is fixed after a lapse of a certain time after the drop hot water supply command. Therefore, the high temperature hot water staying in the heat exchanger during this time is fixed. Many of them are replaced, and the temperature of the hot water stabilizes. Therefore, hot water is prevented from coming out in the early stage of dropping, and there is an effect of high safety.

According to the fifth aspect of the invention, the hot water set temperatures of the actual hot water are compared before opening the valve on the hot water supply side.
When the difference between the two is within a certain temperature, the mixing ratio of the flow rate varying means is fixed. That is, after confirming that the temperature of the high-temperature hot water is stable, the mixing ratio of the flow rate varying means is fixed, so that high-temperature hot water is not discharged due to post-boiling, and there is a high safety effect. .

[Brief description of drawings]

FIG. 1 is a configuration diagram of a bath water heater according to the present invention.

FIG. 2 is a graph showing the relationship between the opening degree of the flow rate varying means and the actual mixing ratio of hot and cold water.

FIG. 3 is a flow chart of a bath water heater showing an embodiment of the invention according to claim 1.

FIG. 4 is a flowchart of a bath water heater showing an embodiment of the invention according to claim 4;

FIG. 5 is a flowchart of a bath water heater showing a modified embodiment of the invention according to claim 5;

6 is a flowchart of a bath water heater when the configuration of the embodiment of FIG. 4 and the configuration of the embodiment of FIG. 5 are combined.

FIG. 7 is a configuration diagram of a conventional bath hot water supply device that determines whether or not another plug is used by the water flow switch described above.

FIG. 8 is a configuration diagram of a bath water heater according to the related art which uses a flow meter to determine whether another plug is used.

[Explanation of symbols]

 1 Main Water Channel 2 Heat Exchanger 3 Bypass Water Channel 4 Drop Water Channel 5 Inlet Water Temperature Detection Means 6 High Temperature Hot Water Flow Sensor 7 Heat Quantity Adjusting Means 8 Heat Source 9 Flow Rate Changing Means 10 Mixed Hot Water Temperature Detection Means 11 Drop Water Flow Sensor 17 Heat Generation Feedforward Control Part 18 Heat generation amount feedback control part 19 Mixing ratio feedback control part 20 Mixing valve opening setting part 21 Hot water supply temperature setting device 22 High temperature hot water temperature detecting means 31 Controller

Claims (5)

[Claims] 1. A main water channel provided with a heat exchanger, a bypass water channel connected in parallel with the heat exchanger, and a hot and cold water mixing section for mixing water flowing through the bypass water channel with high-temperature hot water discharged from the heat exchanger. , Drop-in water channel branched from the main water channel, flow rate variable means for adjusting the mixing ratio of hot water and hot water flowing in the bypass water channel, heat source device for heating the heat exchanger, and the temperature of the mixed hot water is set to the desired hot water output. In a bath water heater provided with a mixing ratio control means for controlling the flow rate varying means so as to be equal to the temperature, a pre-mixing flow rate detecting means for detecting the flow rate of high-temperature hot water or the flow rate of water flowing in the bypass water channel, and a drop water channel are provided. It has drop water amount detecting means for detecting the amount of flowing water, temporarily fixes the flow rate varying means at a predetermined mixing ratio, and calculates it based on the detection value of the pre-mixing flow rate detecting means and the mixing ratio of the flow rate varying means. Comparing the total flow rate of the mixed hot water with the detection value of the dropped water amount detection means, and if the difference between the two is equal to or more than a certain amount, the other plug interrupt control means for releasing the fixation of the mixing ratio of the flow rate changing means is provided. Characteristic bath water heater. 2. A plurality of mixing ratios of the flow rate varying means are set in advance, and the mixing ratio is set to any one of the incoming water temperature entering the heat exchanger or the bypass water channel, the drop set temperature, and the difference between the incoming water temperature and the drop set temperature. 2. The bath water heater according to claim 1, further comprising control means for selecting a mixing ratio of the flow rate changing means based on the selected mixing ratio and temporarily fixing the flow rate changing means according to the selected mixing ratio. 3. A mixed hot water temperature detecting means for detecting the temperature of the mixed hot water discharged from the hot and cold water mixing portion, a heat quantity adjusting means for adjusting the heat generation amount of the heat source device, and a high temperature hot water temperature detecting for detecting the temperature of the high temperature hot water. If the difference between the total flow rate of the mixed hot water calculated by the detection value of the pre-mixing flow rate detection means and the mixing ratio of the flow rate varying means and the detection value of the drop water amount detection means is less than a certain amount, The heating value of the heat source device is adjusted so that the temperature of the mixed hot water discharged from the mixing section becomes equal to the drop set temperature, and the difference between the total flow rate of the mixed hot water and the detected value of the dropped water amount detection means is a certain amount or more. In this case, there is provided control means for releasing the fixation of the mixing ratio of the flow rate varying means and adjusting the heat generation amount of the heat source device so that the temperature of the hot water reaches a predetermined hot water set temperature.
Alternatively, the bath water heater according to any one of 2 and 3. 4. The bath water heater according to claim 1, wherein the mixing ratio of the flow rate varying means is fixed after a lapse of a fixed time after the drop hot water supply command. 5. A hot-water temperature detecting means for detecting the temperature of the hot-water, and a control means for adjusting the temperature of the hot-water to a predetermined hot-water set temperature, and after the drop-in hot-water supply command,
The control means for comparing the temperature detected by the high-temperature hot water temperature detecting means with the high-temperature hot water set temperature, and fixing the mixing ratio of the flow rate varying means if the difference between them is within a certain temperature. 5. A bath water heater according to any one of 4 to 4.