JPH04148112A - Retaining method for temperature of hot water in bathtab - Google Patents

Abstract

PURPOSE:To prevent an additional combustion that is made too early or useless by renewing the time distance from the finish of additional combustion to the start of next additional combustion by utilizing its history in the past and calculating the time distance everytime the additional combustion is made. CONSTITUTION:Based on the actual hot water temperature Kn-1 at the time of finish of the previous additional combustion which is one round earlier than the present round or a set temperature Ks, actual hot water temperature Kn when the time passes the time distance tn-1 in the past from the time of finish of the previous additional combustion to the start of the automatic additional combustion in this time, and the time distance tn-1 in the past, the time distance tn to the start of the next automatic additional combustion after automatic additional combustion is finished is calculated and renewed everytime the additional combustion is made. And, the time distance tn can be calculated based on various suitable calculation formulae from those three data, but basically as an estimated time of temperature drop that would be required for the actual hot water temperature Kn which is judged to be at set temperature Ks in the bath tab at the time of the finish of every automatic additional combustion to drop to the temperature Km to start additional combustion which is beforehand set as temperature to start additional combustion.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic heating method of the type that automatically reheats hot water filled in a bathtub at time intervals. This invention relates to improvements that enable optimal settings to be made in accordance with the environment.

[Prior Art] There have been attempts to keep the hot water in the bathtub warm by automatically reheating the water repeatedly at time intervals as described above, but this method has also recently been improved. It can be said that it has reached a level where it can be put to practical use by combining it with a remarkable automatic water heater.

To explain this conventional automatic heat retention method, first, the hot water supply system itself using such a recent automatic water heater will be described with reference to FIG.

The illustrated automatic water heater has two heat exchangers 11 and 21, one for dispensing hot water from a normal faucet 15 or shower 16 as needed, or for automatically filling a bathtub 23 with hot water. There is a heat exchanger 11 for hot water supply, and the other one is a heat exchanger for reheating or reheating when the hot water in the bathtub 23 does not reach the set temperature or cools down over time. It is the vessel 21.

Water from the water pipes is passed through the hot water supply heat exchanger 11, as indicated by the arrow "water" in the figure, and this water is heated by heating the heat exchanger 11 with the burner 12. Be warmed.

Naturally, fuel for combustion is supplied to the burner 12, but the illustrated water heater uses the most common gas as the fuel. However, kerosene and other fuels can be used in almost the same hot water supply system configuration, and if gas is replaced with such other fuels, the following explanations in this book can be applied as is.

After the gas from the gas pipe passes through the main solenoid valve 13, it is controlled to the optimum supply amount at each time by a dedicated gas flow rate adjustment solenoid valve (so-called proportional valve) 14 on the hot water supply side, and then the gas is supplied to the burner 1.
2, and the amount of air to the burner 12 is controlled by the fan 18.
controlled by

The instantaneous actual amount of water passing through heat exchanger 11, which is selectively heated by burner 12, is detected by flow sensor 28, and the temperature of the water before entering heat exchanger 11 is determined by feed water temperature sensor 19. Accordingly, the temperature of the hot water discharged from the heat exchanger 11 is detected by the hot water temperature sensor 20.

In addition, although not shown in the figure, for safety purposes, flames generated by a flame loft, etc. are used to detect whether or not the burner 12 has been ignited as specified, or whether or not the burner 12 is currently burning. A detection sensor and a high limit switch that detects when the temperature of hot water from the heat exchanger 11 becomes abnormally high are also provided.Furthermore, in order to further improve controllability, a fan is installed as necessary. A sensor for detecting the air flow rate or the actual rotational speed currently output by the motor 18 and performing feedback control is also incorporated.

On the other hand, this type of automatic water heater has a control device (not shown), which has recently become common to include a microcomputer, and determines the optimal hot water supply based on detection signals from the various sensors mentioned above. Measure to achieve control.

For example, the user operates switches attached to a remote unit (not shown) that is provided separately from the main body of the control device, sets the temperature at which he or she wants hot water, and then turns on the faucet 15 or shower 16. When the water flow is opened and a water flow is generated passing through the heat exchanger 11, the flow rate sensor 28, which had previously issued a water flow stop signal, first sends a signal indicating that water has started flowing (the flow rate signal is a water flow on/off signal). (which can also serve as a detection signal) is sent to the microcomputer.

Upon receiving this, the microcomputer creates the gas proportional valve 1.
4 to supply a predetermined amount of valve opening to supply the corresponding flow rate of gas to the burner 12, and also sends an air amount adjustment signal (rotation speed control signal) to the fan 18 to control combustion. While supplying an appropriate amount of air to the burner 12, an ignition mechanism (not shown) is operated.

When combustion in the burner 12 starts in this way,
The heat exchanger 11 is heated, and the water passing through the heat exchanger 11 is warmed and discharged as hot water from a faucet etc., but the actual hot water temperature is also detected by the hot water temperature sensor 20,
If there is an error between this temperature and the set temperature set by the user, the microcomputer adjusts the opening degree of the proportional valve 14, the rotation speed of the fan 18, etc. in a direction that eliminates the error. and control combustion energy.

When the user closes the faucet that was supplying hot water and stops the hot water,
The flow rate sensor 28 sends a water flow stop signal (flow rate qIi signal) to the microcomputer, and upon receiving this, the microcomputer functions to send a full close signal to the gas proportional valve 14 to quickly extinguish the burner 12. . However, depending on the case, a water flow switch may be provided that specifically detects whether or not water flow is generated in the car, in addition to the flow sensor 28 that outputs the actual flow rate in real time, or there may be cases where the flow rate is completely stopped. Even if it is not zero, if it becomes very small, combustion may be stopped to prevent abnormal heating of the hot water.

Furthermore, for safety, if a high limit switch is attached to the heat exchanger 11, when this detects overheating to an abnormal temperature and sends an overheating signal to the microcomputer, the The computer immediately enters a forced extinguishing operation of the burner 12 or limits the amount of combustion, and similarly controls the flame, rod, etc. (not shown).
Even when an appropriate combustion detection element detects a misfire in the burner 12, the microcomputer sends a forced closing signal to the gas proportional valve 14, and depending on the system, also sends a forced closing signal to the former '16i1 valve 13. to prevent the risk of raw fuel leaking outside the aircraft.

When the user selects automatic filling of hot water into the bathtub 23 by operating a remote unit (not shown), a request for filling the bathtub 23 with hot water is made to the microcomputer built in the control device, and the system responds to this request. Then, the microcomputer opens the switching solenoid valve 17 to allow hot water from the heat exchanger 11 to be directed to the bathtub 23. However, it is more convenient to explain this automatic hot water filling operation in conjunction with the automatic reheating operation for automatic heat retention, which is the focus of this book, so I will leave it later.

Next, to explain the system including the reheating heat exchanger 21, hot water in the bathtub 23 is guided from the hot water inlet to a circulation flow path, and this circulation flow path passes through the reheating heat exchanger 21. rear,
It is connected to a hot water outlet that opens again toward the inside of the bathtub 23.

The heat exchanger 21 for reheating is also selectively heated by a burner 22 like the one for hot water supply described above, but the burner 22 is also controlled by a so-called proportional valve 24 dedicated to the reheating side. Gas whose supply amount is controlled to be optimal at each time and air which is also controlled to an optimal flow rate from time to time are sent by the fan 18.

When heating the reheating heat exchanger 21 in the reheating mode, the circulation pump 25 naturally operates and the bathtub 2
The hot water in 3 is passed through a heat exchanger 21 while being circulated.

The temperature of the hot water in the bathtub that is reheated is detected by a temperature sensor 27 installed in the circulation flow path, and as explained later, the actual water temperature (actual water temperature) K11 in the bathtub 23 is detected by the user. Reheating combustion ends when the set temperature is reached.

Of course, although not shown in the drawings, it is preferable to use a flame sensor for detecting whether or not the reheating burner 22 has been ignited as specified, or whether or not the burner 22 is currently burning. A flame detection sensor such as a rod is provided, and the heat exchanger 21 is also preferably provided with a high limit switch or the like to detect when the temperature of the heat exchanger 21 becomes abnormally high.

However, using such an automatic water heater system, the bathtub 23
The conventional method of automatically keeping hot water that has been automatically filled inside the room can be explained using the chronological operation chart shown in FIG. 4 and the flow chart shown in FIG. 5. In addition, in order to point out some of the shortcomings of the conventional method later, 'fS4 diagram shows the case of winter (A in the same figure) and the case of summer (
Although the respective heat-keeping operations are shown in FIG.

When the user selects automatic filling of hot water in the bathtub 23 by operating a remote unit (not shown), a request for filling hot water in the bathtub 23 is made to the microcomputer built in the control device, and the microcomputer responds to this request. The switching solenoid valve 17 is opened to allow hot water from the heat exchanger 11 to be introduced into the bathtub 23.

However, for this automatic water filling operation, preset water level data is given to the microcomputer as a type of necessary data.

The set water level data is data that specifies the height of the bathtub 23 to which hot water should be filled according to the user's preference, but this is actually the data that specifies the height of the bathtub 23 to which hot water should be poured. It is expressed as the total amount of hot water required to reach the set water level. This is because if the set water level is expressed simply by the geometric height inside the bathtub, it will not be possible to accommodate changes in the shape of the bathtub. If you use an old float-type liquid level detector that floats in the bathtub, you can determine the water level simply by looking at the geometric height of the water in the bathtub, but this is a newer product. Not liked.

Therefore, at the beginning of use, the control device learns and stores, for each bathtub 23 in use, how much total hot water (total water volume) is required for that bathtub 23 to reach the set water level set by the user. In the case of the illustrated device system, this is due to the pressure sensor 26 installed in the circulation path around the reheating heat exchanger 21 and close to the outlet position to the bathtub 23 side. Pressure value to detect (water pressure value in the bathtub)
It is calculated using, for example, the following method.

First, pour water or water into the empty bathtub 23 at a rate of XU (
The following is a representative example of pouring hot water). In the illustrated case, the pressure sensor 26 is located at a certain height from the bottom of the bathtub 23, so even if xIt is poured at a time, the pressure value detected by the pressure sensor 26 is zero at first. It is. The amount of poured molten metal itself can be controlled based on the detection signal from the flow rate sensor 28.

However, if the pressure sensor 26 is immersed in hot water after pouring water xlL y times and a significant detection output is output, at least in that bathtub 23, the pressure sensor 26 is exposed from the bottom of the bathtub. It can be seen that the amount of hot water required to fill the hot water up to the height is xy (IL) (some errors are within the allowable range).

Then, once a significant detection output is output from the pressure sensor 26, the actual water level increases each time xl of water is poured into the bathtub 23, and the detection pressure of the pressure sensor 26 at that time. There will be a one-to-one correspondence with the value (water pressure).

Therefore, the total amount of hot water (j2) required until the user stops pouring at the desired water level is determined by the pressure value detected by the pressure sensor 26 at that time and x-
yi), this pressure value is given to the microcomputer as set water level data, and the microcomputer, through this learning,
Thereafter, even if the user changes the set water level, the total amount of hot water required to reach the changed water level can be immediately calculated.

In this way, the microcomputer converts and stores the user's preferred set water level data into set pressure value data, so that after opening the switching solenoid valve 17 as described above, the pressure sensor When the switching solenoid valve 17 is closed again when the detected pressure value of 26 reaches this set pressure value, the bathtub 23 is filled with hot water up to the set water level.

Of course, the temperature of the hot water supplied into the bathtub during automatic hot water filling can also be set by the user.Same as when hot water is supplied to the faucet 15, etc., the flow rate sensor 28, the water supply temperature sensor 19, and the outlet hot water temperature sensor 20 are used. Combustion control in the heat exchanger 11 is performed by optimally controlling the opening degree of the proportional valve 14 and the rotation speed of the fan 18 based on each information from the above.

However, after the automatic filling of hot water started, the temperature detected by the hot water temperature sensor 20 reached the set temperature, and as a result of continuing to fill the hot water until the pressure sensor 26 detected a predetermined pressure value while controlling combustion as much as possible, the temperature detected by the hot water temperature sensor 20 reached the set temperature. , the set water level is reached at time T0, the switching solenoid valve 17 is closed, the burner 12 is extinguished, and the automatic hot water filling operation is completed.The actual water temperature in the bathtub 23 at that time (actual water temperature) Kn is Even if the temperature of hot water discharged from the hot water supply heat exchanger 11 correctly matches the set temperature 9, the temperature will generally be slightly lower than the set temperature.

Therefore, in the conventional automatic heat retention method, before entering the automatic heat retention mode, auxiliary reheating is immediately performed from the time T0 following the stop of pouring.

That is, when the switching electromagnetic valve 17 closes at time T0, the circulation pump 25 starts rotating instead, stirring the hot water in the bathtub 23 appropriately so that it has a uniform temperature, and then discharging the actual hot water in the bathtub. Warmly. is taken into the control device side via the temperature sensor 27, and the set temperature is set to S and this actual water temperature is set. If the temperature difference α between the two is greater than a predetermined value, the burner 22
is ignited, and the hot water in the bathtub 23 is heated while being circulated by the reheating heat exchanger 21.

As a result, as shown at time T in FIG. 4, as a result of repeatedly comparing the actual hot water temperature Ko detected by the temperature sensor 27 with the set temperature 5, the actual hot water temperature K r
When it is determined that + has exceeded the set temperature, the combustion of the burner 22 is stopped, and although it is not shown in the system in FIG. 3, the user is prompted to complete the automatic filling mode. In order to notify that the water level has risen to the set temperature, a notification means such as a buzzer is activated.

The conventional automatic keep-warm operation can occur from the time the auxiliary reheating, which is used as needed as part of the automatic hot water filling mode, is completed, and thereafter follows the flow chart shown in FIG.

First, from the boiling time T1 in FIG. 4, measurement of a predetermined time tC starts. Specifically, this time jc is selected to be about 30 minutes, and the fixed time t is from the first boiling time T1.

elapses and reaches time T2, a predetermined short time (
Rotate the circulation pump 25 shown in FIG. 3 for a period of 20 to 30 seconds (usually 20 to 30 seconds) to stir the hot water in the bathtub 23, and wait until the temperature of the water is approximately uniform everywhere in the bathtub.
The temperature sensor 27 measures the actual hot water temperature K11 in the bathtub at this time.

And the actual temperature of the water inside this bathtub 23. If the temperature difference is lower than the set temperature S by more than α°C, which is set at a predetermined value of, for example, 1°C to 2°C, then the flow chart shown in vS5 indicates YES at the relevant judgment step. burner 22 to heat the reheating heat exchanger 21.
combustion begins.

Naturally, during this reheating combustion, the circulation pump 25 continues to rotate, and the actual water temperature in the bathtub is measured by the temperature sensor 27. continues to be detected.

As shown at time T in FIG. 4, as a result of such reheating combustion, the actual hot water temperature Kn in the bathtub reaches the set temperature K.

While I was repeatedly comparing this, I found the actual water temperature. When it is determined that the set temperature has exceeded 5, the reheating combustion is stopped and the circulation pump 25 is also stopped, as shown in the flow chart in FIG. A timer for measuring time is set to a constant time tc.

In addition, the actual water temperature in the bathtub changes every time a certain period of time tc elapses. In the step of determining whether or not the difference between As such, reheating combustion is not performed this time, the circulation pump is stopped, and the timer is simply reset to the fixed time tc. Therefore, after a certain period of time tc has elapsed, the water temperature returns to the actual temperature. It is determined whether or not there is a difference of α°C or more between and the set temperature.

However, depending on the conventional example, in addition to the automatic repeated reheating in the automatic keep-warm mode, there are also cases in which there are differences in the countermeasures taken after the user manually, so to speak, forcibly reheats the heat.

In other words, the actual water temperature is shown by the solid line in Figure 4. The history characteristic of is such that even if the user reheats the fire, this fact is ignored when it comes to measuring the fixed time tc, and while the timer is counting the fixed time tc, as shown by the virtual line, the time Even if the user reheats the fire himself between T4 and T, this will not be taken into account in the time measurement, and a certain period of time will always be elapsed after the first boiling and after the end of each automatic reheat. Each time tc elapses, the operation according to the flow chart shown in FIG. 5 is performed. Therefore, in this case, the time T6 when a certain period of time 1c has elapsed from the automatic reheating end time T3 before the reheating operation by the user.
Automatic reheating starts again at .

On the other hand, there are also types that reset the timer when the user performs an additional heating operation, and the actual water temperature in that case
The history characteristic of n is as shown by the virtual line in FIG.

That is, while the timer is measuring a certain period of time tc, '
f%4 In Figure A, if there is reheating midway between time T4 and time T as shown by the imaginary line, the timer starts again for a certain period of time t at the end time T of the reheating. Therefore, the next automatic reheating will not be performed from this time T until time T7, when a certain period of time tc has elapsed. In other words, this latter type operates according to the flow chart shown in Figure 5 every time a certain period of time tc elapses from the time when reheating is completed, regardless of whether it is automatic or not. It is set up like this.

[Problems to be Solved by the Invention] As mentioned above, we have described in detail the conventional automatic water heating operation for hot water in a bathtub, including the automatic water heater or hot water system that is used in conjunction with it. Even if there is a difference in whether or not to reset the heat, in the conventional automatic keep-warm operation, if we consider only the automatic reheating operation, reheating will start if a predetermined period of time 1c has not passed since the previous reheating. do not.

Therefore, as shown in Figure 4, which shows both the case of winter (A) and the case of summer (B), the set temperature is
Even if the temperature is set at the same temperature in summer, a certain amount of time t will elapse after reheating is completed. The actual water temperature K in the bathtub 23 after passing. The degree of decrease in temperature varies greatly between winter and summer, and of course it is easier to cool down in winter.

Therefore, they set their sights on the winter season, and created an automatic reheating and automatic repeat cycle to avoid making the user feel uncomfortable after the water has heated up and no matter when they take a bath. If the fixed time period 1c is set short, as shown in FIG. 4B, the repetition frequency of reheating becomes somewhat wasteful in summer. Considering that the circulation pump and the like are operated every time the heating is reheated, it cannot be said that satisfactory results are necessarily obtained from the viewpoint of energy consumption and noise.

On the other hand, if the fixed time tc is set to be long, it may be good in the summer, but in the winter the hot water may become too cold, rendering the automatic heat retention function meaningless.

Also, the temperature of the actual water in the bathtub 23. The degree of decrease in the temperature varies greatly depending not only on seasonal changes or fluctuations in atmospheric temperature, but also on the shape and depth of the bathtub 23 used, the purchase of materials, differences in heat transfer coefficient, etc., and the size and direction of the bathroom. , it is greatly influenced by the degree of sunlight, etc. Strictly speaking, even changing the set water level changes the effective area that hot water is in contact with the inner wall of the bathtub, so the amount of heat radiated as seen from the hot water also changes.

Considering this, it is clear that the conventional automatic reheating repeated in units of a certain period of time tc cannot keep up with the fluctuations of these various parameters. There is no answer to the question of how best to specifically set the certain period of time tc, and a compromise must always be made.

The present invention has been developed in view of these conventional circumstances, and although it shares the concept of keeping the bath warm by automatically reheating the hot water in the bathtub at regular intervals, it It can respond well to various fluctuating parameters that affect the temperature drop characteristics of hot water over time, and it can maintain as stable a heat-retaining operation as possible even with fluctuations in these parameters, while preventing premature reheating or wasteful reheating as much as possible. The aim is to provide a heat retention method that avoids overheating.

[Means for Solving the Problems] In order to achieve the above object, the present invention automatically reheats the hot water filled in the bathtub repeatedly at time intervals, and automatically reheats the hot water each time. As a heat retention method using a heat retention control device that terminates each time the actual hot water temperature (K,), which is the actual temperature of the hot water filled in the tank, reaches a predetermined setting 1 (Ks), The above-mentioned time interval from the end of reburning to the start of the next reburning (
tn"tx) is the actual water temperature in the bathtub at the end of the previous reheating, which is one time before each time. Or the set temperature K
.

and the actual hot water temperature in the bathtub when the above-mentioned time interval tIl in the past from the end of the previous reheating to the start of each reheating is elapsed. , and the past time interval t, , we propose a method that calculates and updates each time.

Furthermore, in the present invention, the time interval t is calculated each time the above-mentioned most basic aspect is satisfied. is the actual water temperature from the end of each automatic reheating to the temperature at which reheating should start. The present invention also discloses an invention in which a time value calculated as an expected temperature reduction time that will be required for the temperature to decrease is corrected.

In addition, in this case, we also propose an invention in which the temperature at which reheating should be started is also corrected in accordance with the value of the time interval 1n obtained by the above correction.

Generally, in this type of control method, several initial settings can be considered, but according to another aspect of the present invention, the actual hot water temperature Kn does not change to the set temperature until after the power is turned on to the heat retention control device. Only the time interval tn from when it is first determined that water in the bathtub has reached 3 until the first automatic reheating of the hot water in the bathtub is performed is not based on the above calculation, but is a predetermined constant time tc. We also propose that (1, = 1).

Furthermore, in another aspect of the present invention, the time interval t0 after the end of a certain reheating until the next automatic reheating starts.
Measures to be taken in the event that reheating occurs inside the vehicle will also be disclosed.

That is, if a reheating operation occurs during the above-mentioned time interval tI, the above-mentioned time interval t is restarted from the end of the reheating operation that occurred in the middle. We also propose a configuration in which the next automatic reheating is not started until the process has passed.

Similarly, in addition to or in place of this aspect, attention is paid to changes in the water level in the bathtub, and the heat retention control device is also provided with means for detecting changes in the water level in the bathtub, If a change in the water level is detected by then, it is determined that the water level change has subsided and the actual hot water temperature Kn has reached the set temperature Kg, and then the above-mentioned time interval t is repeated. The disclosure also discloses a configuration in which the next automatic reheating is not started until the next time the automatic reheating is completed.

Incidentally, the reheating that occurs midway in the above naturally includes reheating operations that the user himself or herself commands, and it also depends on the functions of the hot water supply system that incorporates the present invention, but it also includes the reheating operation that is highly automated. If it is a system, the actual water temperature will be set instead of the set temperature set by the user. This also includes reheating operations that the hot water supply system automatically or spontaneously starts in order to match the above conditions.

[Function] According to the present invention, the actual water temperature K at the end of the previous reheating, which is one time before each time. (For convenience of explanation, the actual hot water temperature at the past point in time is assumed to be -1) or the set temperature is S, and the time interval t in the past from the end of the previous reheating to the start of the current automatic reheating. (This is also referred to as tn-+ for convenience.) Actual hot water temperature K. , that is, the actual hot water temperature Kn at or just before the start of reheating this time, and the current temperature,
Based on the past time interval t7-1, the time interval t from the end of each automatic reheating to the start of the next automatic reheating. is calculated and updated each time.

The time interval 1n is based on three data as described above, namely, the actual hot water temperature at the past time n-1 or the set temperature, the time interval jn-1 in the past, and the time interval jn-1. If there is an actual hot water temperature Kn after passing through Kn, then based on various appropriate calculation formulas, basically the hot water determined to be at the set temperature Ks in the bathtub at the end of each automatic reheating. To the actual water temperature. can be calculated as the expected temperature drop time (tx) that will be required for the temperature to drop to the reheating start temperature, which is preset as the temperature at which reheating should be started.

Here, the temperature at which reheating should be started can be defined as, for example, a temperature lower than the set temperature Ks by a predetermined temperature difference Δ island. ! + Warm. When the temperature decreases, the user will feel that the temperature is too cold unless reheating is performed, and the specific value itself can be determined arbitrarily.

However, for the sake of understanding, the simplest case regarding the above calculation is a method that follows proportional calculation,
For example, if the set temperature Ks was 42°C and the time interval jn-1 in the past was 30 minutes, the actual hot water temperature Kn-1, which was initially 42°C as the set temperature,
The actual water temperature after 0 minutes.

If the temperature was 39°C, which is 3°C lower, then dividing this temperature difference of 3°C by 30 minutes gives a coefficient of 0.1°C/ll1n.

This is the actual water temperature K per unit time. Conversely, if you divide the time interval in-, = 30 minutes by the temperature decrease of 3°C, you get 10 m1n/ll:
The time required for the temperature to decrease per unit temperature can be determined.

Mathematically, the two are simply in a reciprocal relationship, so no matter which one is used, the expected temperature drop time 1 for the actual temperature Kn to drop from the set temperature to the reheating start temperature is 1.
．． can be easily determined, for example, as shown above, if the set temperature Ks is 42℃, or if the temperature at which reheating should start is 1,
In other words, if the temperature is set at 40℃ (this is just an example), there is no need to reheat the fire and the user will not feel too uncomfortable even if the temperature drops to that extent. , if the previously determined temperature drop characteristic is 0.1°C/min (or 10w1n/l), then the set temperature 42
The expected temperature drop time 1x, in which the actual water temperature that has reached 40 degrees Celsius is expected to drop by the temperature difference IK, = 2 degrees Celsius, can be calculated by using the simplest proportional calculation here as well. Divide the 2℃ by 0.1℃/win or temperature difference 2℃
By multiplying by 10m1n/l:, you can easily find 20 minutes. Note that these coefficients may hereinafter be collectively referred to as temperature reduction characteristic values.

In any case, in the present invention, since the past time interval jn-1 is updated each time using the time interval tIl=tX obtained using the past history, the shape of the bathtub 23 used Variable parameters related to installation conditions, such as depth, material purchase, or heat transfer coefficient, or bathroom size, direction, sunlight exposure, etc., or from a short-term perspective of -days or several days. It is possible to cope well with not only atmospheric temperature fluctuations, but also long-term seasonal changes observed over several months.

For example, if we take a general household as an example, as a result of actual measurement, the calculation result for the bathtub in a certain household has a temperature drop characteristic, and as shown in the previous value, it was l O + nin/'C, so compared to the set temperature of 42℃. If the reheating start temperature is set to 40°C, which is 2°C lower than that, the time interval 1 or expected temperature drop time 1X until the next automatic reheating starts is calculated to be 20 minutes as described above. On the other hand, if the temperature drop characteristic of a bathtub in another home is measured to be 11.8 min/l at the same time, even under similar installation conditions,
In that household, the time interval tn calculated for updating should be approximately 23 minutes and 36 seconds. However, it is a matter of arbitrary design whether to truncate or round to the nearest minute, to round to the nearest ten seconds, or to set the time interval accurately to the second.

In addition, even in the same bathtub in the same household, the temperature reduction characteristics vary greatly due to seasonal changes and changes in sunlight, but the method of the present invention can deal with this, so it is not dependent on the season and is wasteful. Without increasing the number of times of reheating, as if waiting for the time when the actual water temperature in the bathtub would have dropped to the temperature at which reheating should start.
Automatic reheating is repeated.

Further, in accordance with another aspect of the invention, the time interval t that is updated. However, if the predicted temperature drop time determined as above is further corrected, it is possible to realize, for example, a type of fuzzy control, and even if it is only once due to some disturbance, This avoids the possibility of setting different time intervals t7.

For example, as a form of correction, the time interval tn in the past
If we take the average of −1 and the time intervals t and l calculated this time, we get
As is clear, as a result of some disturbance, the previous time interval t. Even if there is a large difference between -8 and the time interval t0 calculated this time, the degree of difference can be reduced to about half, and from then on, each time automatic reheating is repeated, it will converge to the appropriate time interval value. Go. On the other hand, in view of the above, other modes of correction can be considered.

In another aspect of the present invention, the temperature at which reheating should be started is also corrected in accordance with the calculated and corrected time interval value. This is because the time interval or the value of the temperature drop characteristic that led to it has sufficient information to infer the season at that time. If the temperature drop characteristics change gradually, it can be inferred that we are heading from winter to summer, and if the opposite is true, we can judge that we are heading towards winter.

In this way, by controlling the reheating start temperature itself, it is possible to perform heat retention control that gives a more constant feeling to the human experience. People don't feel too uncomfortable even if they allow the hot water temperature to drop to a lower temperature in summer than in winter, so by actively taking advantage of this fact, the warmer it gets, the less reheating. The number of times can be further reduced and energy can be further saved.

Furthermore, in this type of control, it is generally necessary to consider initial settings, but in the present invention, as a rational aspect, the actual hot water temperature Kn does not change to the set temperature Ks until after the power is turned on to the heat retention control device. It is proposed that the time interval tn from when it is first determined that the temperature has been reached until the first automatic reheating is started is set to a certain - constant time Lc.

Here, after turning on the power to the heat retention control device, the actual temperature of the hot water in the bathtub. For example, as already mentioned in the explanation of the conventional example, the time when it is first determined that the temperature has reached the set temperature 5 is the point when the boiler has an automatic hot water filling function up to the set water level,
What's more, the actual water temperature is reached after the water has been poured to the set water level. When the present invention is applied to a hot water system of the type that also has a function of detecting the temperature Ks and performing auxiliary reheating if there is a temperature difference of more than a predetermined size with the set temperature Ks, At the actual temperature of the hot water, we decided to end the auxiliary reheating. When the detection is completed and there is no need for auxiliary reheating, or in a system that does not perform auxiliary reheating, the actual water temperature K of the hot water filled to the set water level in the bathtub. This is the point in time when it is first determined that the set temperature is 3 or more.

Of course, there is a slight tolerance range above and below the set temperature S, and the actual water temperature. When the temperature falls within this range, it can be determined that the set temperature has reached 5. Alternatively, as shown in the example below, the actual water temperature can be repeatedly detected at a predetermined period at high speed, and the previous temperature can be determined. was 5 or less than the set temperature, but in this detection, if it exceeds or equals the set temperature by 3,
At that point, it may be determined that the actual hot water temperature Kn has reached the set temperature. The latter method is common when a microcomputer is used as the control device.

As mentioned above, even if we consider the time when the power is turned on to the heat retention control device as the initial operation start point, in general, in recent water heater systems incorporating this type of heat retention control device, the power is turned off at the time of installation. Once turned on, the power is normally left on unless it is removed for some reason. Therefore, the above-mentioned initial fixed time tc usually only occurs once, when the apparatus for realizing the heat retention method first starts operating.

On the other hand, when the automatic keep-warm mode is re-entered after the user intentionally interrupts the keep-warm mode using a separate switch, or when the automatic keep-warm mode is started for the first time after replacing the hot water in the bathtub, Regarding automatic reheating, the last data from the last interrupted automatic keep warm mode is stored and remains (as it has not been updated).
There is no way to use this.

As a result, there was a considerable amount of time or a deadline between when the automatic keep warm mode was interrupted and when it was restarted.
Time interval t calculated using past data that remains unupdated. may not be appropriate at first, but according to the principle of the present invention described above, it is possible to gradually converge to an appropriate time interval as the automatic reheating is repeated, and in particular, By using the correction function described above (by averaging, etc.), the convergence can be accelerated.

In accordance with yet another aspect of the present invention, additional factors that may cause undesirable temperature fluctuations are addressed.

For example, in the hot water supply system shown in FIG. 3, which has already been described in connection with the conventional example, the user can naturally command reheating. The present invention can also be realized as an improvement of the conventional hot water supply system as typified by the third diagram by using the control device or the microcomputer built therein.

Therefore, it is conceivable that the user himself issues a reheating command while the repeated automatic reheating mode according to the present invention is being executed. In such a case, in one aspect of the present invention, the measurement of the time interval 1n that has already occurred is interrupted, and when the reheating operation that occurred in the middle is finished, the measurement of the time interval t is continued after the end. re-measurement can be started.

Therefore, it is a "disturbance" for the repeated automatic reheating mode.
Even if there is a reheating operation like this, after that,
The repeated automatic reheating mode according to the present invention starts to operate effectively again, and wasteful reheating or premature reheating can be suppressed.

Just as one of the other "disturbances" is the time interval t.

According to another aspect of the present invention, if a change in the water level in the bathtub is detected before the time interval 1n has passed, the measurement of the time interval 1n that has already occurred is similarly interrupted,
Once the change in water level has subsided, and after that, the actual water temperature will be reached. The time t starts from the time when it is determined that the temperature reaches the set temperature 5. re-measurement can be started.

Therefore, by repeatedly returning to the automatic reheating mode after the change in water level subsides, wasteful reheating or premature reheating can be similarly suppressed.

Note that water level changes are caused by pouring hot water, pouring water, draining water (including when hot water in the bathtub is used for washing), and even people coming out to take a bath, but as already explained, Changes in water level due to any of these causes can be detected electrically using existing technology, such as by using a pressure sensor, so there is no difficulty in implementing the method of the present invention according to the above-mentioned aspects. .

Of course, no matter which of the various embodiments of the present invention described above is followed, it is possible to automatically cope with the situation where the temperature reduction characteristic changes due to a change in the set temperature S by the user. This is because, whether it is a change in the set temperature or something else, if the temperature drop characteristic itself changes as a result, the predicted temperature drop time that was used immediately will cause the temperature to drop to the reheating start temperature. This is because automatic reheating cannot be started at that point, but in the present invention, this is updated to an appropriate value.

[Example] Hereinafter, an example of the method of the present invention for automatically keeping hot water in a bathtub warm over time will be described. However, the automatic water heater or water supply system to which this embodiment of the present invention is applied is the one shown in FIG. 3, which has already been described in detail with respect to the conventional example. Therefore, the explanation of the automatic water heater or hot water supply system shown in the third diagram will be omitted in this section, and the explanation of the conventional example listed above will be referred to, and the reference numerals of each component will also be included. The symbols given in Fig. 3 are used.

FIG. 1 shows an example of an operation for keeping hot water in a bathtub warm over time achieved by this embodiment, and FIG. 2 shows a flow chart in this embodiment. The following will explain both together, but in particular, in this embodiment, the purpose of the automatic warming operation in the bathtub is already as follows:
@3 I explained about the t-system of the illustrated device! j It is set to be performed in series with the hot water filling mode.

First, a microcomputer (not shown), which is first installed in a bathtub facility where the system shown in Figure 3 is located, controls this system, and also constitutes a heat retention control device for realizing the method of the present invention. Commercial power supply (generally AC 100V
) is turned on, if the user instructs the empty bathtub 23 to automatically fill with hot water after the power is turned on, the microcomputer or heat retention control device will operate as shown in the second figure. The automatic hot water filling mode is entered, and here, first, it is determined whether or not the automatic warming mode is selected. However, as will be described later, at this point the heat retention flag has not yet been set, so the judgment is negative at this step and the process moves to the connector (node) ■, which is placed above the second column from the left in Figure 2. Enter the indicated subroutine.

Hereinafter, each column will be numbered from the left. In the subroutine for the second column, it is first determined whether or not reheating is in progress.

Naturally, the answer is no at this point, so next is the bathtub 2.
A determination is made as to whether or not the actual water level (actual water level) within 3 has reached the set water level. As already mentioned, this judgment
This can be done based on the pressure value (water pressure value) detected by the pressure sensor 26 in FIG. 3, and the applicant is also considering a separate highly accurate method.

Of course, since pouring has not yet started, the determination in this determination step is also negative.As a result, in the next processing step, the switching solenoid valve 17 shown in FIG. 3 is opened, and the bathtub 2
As already explained, the water supply temperature sensor 19 in FIG.
water supply temperature data detected by the user, set temperature data that is 5 to the desired hot water temperature specified by the user, and the hot water supply heat exchanger 11.
The hot water temperature sensor 20 detects the temperature of the hot water that is actually output through the hot water temperature sensor 20.
Based on the outlet hot water temperature data detected by the flow rate sensor 28, the actual flow rate data detected by the flow rate sensor 28, etc., a microcomputer built in the control device (not shown) calculates the optimum combustion amount, and the optimum combustion amount is calculated for the proportional valve 14. By providing a valve opening signal and an optimal rotational speed signal to the fan 18, combustion is performed in the burner 2 with optimal thermal energy.

When the pouring operation starts in this way, the microcomputer moves to the next routine execution via the connector [F], and every time a predetermined time interval elapses, the program according to the flow chart shown in ``@2'' is executed from the beginning. , the same flow as before is repeated.

Eventually, when the actual water level of the hot water in the bathtub 23 reaches the set water level, naturally, immediately after that, in the program execution stage according to the second illustrated flow chart, the actual water level will be changed to the set water level in the determination step regarding the water level. It is determined that the water level has exceeded the actual water level of the upper row of the row.
” is the juncture on the Yes side regarding the judgment step.

As shown in the upper part of the third column in Figure 2, the connector ■
In the subsequent processing step, the switching solenoid valve 17 is closed, and the pouring of hot water into the bathtub 23 is stopped, and combustion in the hot water heat exchanger 11 (not shown) is also stopped.

This time is a time marker in FIG. 1 showing the operation of this embodiment over time. However, in the next processing step, the circulation pump 25 in FIG. 3 is turned on, and as a result,
After the hot water in the bathtub begins to be forcibly stirred, in the subsequent processing step, when the circulation pump 25 continues to rotate for a certain period of time T0 or more, the temperature sensor 27 in FIG. The actual hot water temperature KIl, which is the actual hot water temperature in the bathtub 23 at that time, is detected and stored in the 'l register.

Note that, including this #l register, #2, which will be described later,
For each register in #3, when new data arrives, the previously stored data is updated, and until the data is updated, the stored data remains unchanged unless the power to the system or temperature control device is cut off. continue to hold.

In addition, in the above, the circulation pump 25 continues to be rotated for a certain period of time TI) and then the actual water temperature is reached. It is the bathtub 23 that detects
This is to stir the hot water inside and check the temperature and pressure when the temperature of the hot water becomes uniform everywhere, and at the time T. may be set arbitrarily, for example, from 20 seconds to 30 seconds.

However, for the sake of simplicity, hereinafter, the existence of this stirring time T0 may be ignored in the explanation; for example, in the above description, the existence of the stirring time T0 is ignored. From the relevant time T. To the actual hot water temperature detected later. teeth,
Treated as the actual hot water temperature at time T0.

After this processing step, the detected and stored actual water temperature is n(
#Contents of Lujistar) and set temperature K set by the user
s is compared in the judgment step, and if the end of thirst T. If the actual water temperature n(To) in the bathtub 23 is higher than the set temperature 5, the process moves from this judgment step to the subroutine on the right via the connector (2).

This flow will be followed later, so I will not continue here, but I will just state the results: If the actual hot water temperature Kn>set temperature? A YES determination in step 1 means, as already explained, that auxiliary reheating after automatic hot water filling is unnecessary. corresponds to the start of the repeated automatic reheating mode.

However, in this case, the actual water temperature is determined in the above judgment step. Suppose that it is determined that the set temperature is lower than 5. In fact, this is more normal. Even if hot water at a temperature equal to the set temperature is poured into the bathtub 23 from the hot water supply heat exchanger 11 while monitoring the temperature of the hot water outlet in real time using the hot water outlet temperature sensor 20, at least the tank wall of the bathtub 23 and the bathroom This is because heat radiation from the hot water side of the bathtub to the atmosphere inside the bathtub is unavoidable.

Therefore, in this case, in the processing step following the determination step, reheating combustion is started in automatic fishing. This reheating combustion itself is automatic/I!, as already explained with reference to FIG. This corresponds to the auxiliary reheating that is performed to raise the boil to the set temperature as the final step in the tension mode, but this auxiliary reheating operation is also performed by the burner by the mechanism already explained with reference to Fig. 3. Reheating heat exchanger 21 heated by 22
Naturally, at this time, the actual 4 temperature K in the previous processing step. The circulation pump 25 continues to be rotated since the time of detection and storage.

In addition, the actual water level mentioned above is the set water level? In the judgment step 1 and the judgment step ``Actual hot water temperature.〉Preset temperature Ks? In practice, this kind of judgment is often made, and there is no problem with it.As is well known, microcomputer programs generally run at extremely high speeds, so the immediately preceding judgment may be based on the actual water level, for example. If the actual water level is determined to be below or below the water level, and the next determination is made that the actual water level exceeds the set water level, the latter determination will affect the control system and prevent hot water from pouring into the bathtub even if the pouring is stopped. This is because the water level of the hot water does not need to change much from the set water level.The exact same thing can be said about temperature judgment.

In any case, when auxiliary reheating, which is the last step of automatic hot water refilling mode, starts as described above, the program according to the flow chart in Figure 2 determines whether automatic hot water heating mode is active or not during the main routine. After determining no in the judgment of , the judgment step at the head of the subroutine in the second column determines whether or not reheating is in progress, and this time it is judged as yes and flows to the connector ■ side, and the process is executed again. To water temperature □ vs. set temperature K
.

The process passes through the determination steps 1 and 2, and as a result of the first determination being NO, the process moves to the next routine, and the operation is repeated.

Eventually, as shown at time T1 in Figure 1, as a result of continued auxiliary reheating, when the actual hot water temperature Kn exceeds the set temperature by 8 (in fact, it is almost the same temperature for the above reason), immediately after that In the determination step regarding both temperature quantities, the determination is YES, and the process moves to the subroutine in the fourth column via the connector (2).

In such a case, the above-mentioned time point T1 substantially corresponds to the start of the repeated automatic reheating mode, but in the subroutine in the fourth row, the circulation pump 25 is first stopped, not shown. However, at this point, the auxiliary reheating combustion using the burner 22 and the reheating heat exchanger 21 also ends.

At this time, in the illustrated embodiment, the actual hot water temperature is set to K again. is detected and stored in register 12. That is, the temperature data stored in the temperature register becomes the actual hot water temperature Kn(TI) at the time T when the repeated automatic reheating mode starts.

After the actual water temperature at time TI is detected as 11 (TI), the timer enters the step of determining whether or not it is counting up.As will be described in detail later, this timer is The fixed time tc in Figure 1 that is allowed only once, and is calculated each time from the second time onwards,
Restored time Tx to update past stored values
It is a conceptual component for measuring, and is actually constructed by software processing using a microcomputer.

However, in this embodiment, the timer is the time t.

When set to a certain value, the count starts from the time of the setting.
We are considering a type that will hold the reset value "O" until it is set next time when it starts counting up and counting up, so in this judgment step, the timer will be in the same state as when it counted up. be.

Therefore, in this judgment step, YES is selected, and in the next judgment step, it is judged whether or not the automatic warming mode is currently in effect. At this point, the automatic keep-warm mode has not yet been entered, so the flow goes to "No" and the keep-warm flag is set in the following processing step. After this warming flag is set, the system is considered to be in automatic warming mode.

Next, we reach the step of determining whether or not this is the first operation after the power is turned on, and since this is the case here, we move on to soaking and change the data content of the #2 register stored above, that is, automatic hot water filling mode. The actual hot water temperature data xn (Tl) at the time of completion T1 is transferred to the 23 register. If auxiliary reheating is not required, the time is substantially at time T in FIG. and time T1 can be considered to be the same time, so in that case as well, the actual hot water temperature data transferred to register #3 will be the actual temperature at this time T+ (=To) < 1SKo (TI
).

Along with this process, the timer time t. is set to a predetermined constant time tc. This certain period of time can be set arbitrarily, for example, 15 minutes or 30 minutes.

t on the timer. When =1c is set, the timer starts counting down the specified time tc from this point, but after this processing step, the process returns to the beginning of the flow chart shown in FIG. 2 from the connector ■. This time, the determination step as to whether or not the automatic warming mode is in effect is determined to be YES, so the main routine continues directly downward.

This series of flows includes whether or not molten metal is being poured, whether or not water is being poured, whether or not it is being reheated, whether or not a molten metal pouring request has been made, and whether a water pouring request has been made. There are various steps to determine whether or not a reheating request has been made, but as will be shown later, these are all "disturbances" for the automatic reheating mode that occurs repeatedly during the automatic heat retention mode. Therefore, if YES is selected at each judgment step to take countermeasures, the optimal processing will be performed for each step. Since only modes will be explained, it is assumed that all these disturbances are absent.

Therefore, following the step of determining whether the automatic keep warm mode is present, the determination of whether the timer has counted up is repeated, as shown at the bottom of the main routine, and eventually As shown at time T2 in FIG. 1, after starting the timer, a certain period of time 1. l=1. When the timer has passed, it is determined that the timer has counted up, and the process jumps to the middle of the subroutine on the upper side of the third column via the connector (2), where the circulation pump 25 is turned on again.

This can be done for a relatively short time of about 20 to 30 seconds for the same reason as mentioned above, but it is for the purpose of forcibly stirring the hot water in the bathtub 23 for a certain period of time or more to equalize the water temperature. Thereafter, the temperature sensor 27 detects the actual temperature n(T2) at this time T2 and stores it in the #l register.

This #l register previously contains the time T immediately before the start of auxiliary reheating. Actual hot water temperature data K. (To) was stored, but at this point its contents are actual hot water temperature data K. As a result of being updated to (T2), it is substantially erased.

Following the above processing step, a determination is made again in the judgment step, ``The actual hot water temperature is l>set temperature Ks? Since the temperature K. (T2) is cold, the answer to this decision step is generally no.

The result of such judgment is the time T in Figure 1.
As shown in Figure 2 and after, the reheating combustion is started again, and then the micro combinator returns to the beginning of the flow chart shown in Figure 2, and the result of the judgment as to whether or not it is in the automatic warming mode is determined. , since it is already in the automatic keep warm mode, it is judged as yes, and then, even if there is no other disturbance, it is already in the reheating mode, so the first step is to determine whether or not it is in the reheating mode. , it is determined that reheating is in progress, the process moves to the middle of the subroutine on the upper side of the third row via the connector (2), and it is determined whether or not the actual hot water temperature Kn exceeds the set temperature by 5.

This routine is the same as described above, and of course it continues to be judged as no until the water boils, but as shown at time T3 in FIG. When the set temperature is reached, the actual water temperature in the subroutine at the top of the third row in Figure 2 above is reached. In the step of comparing and determining the set temperature Ks, the flow shifts to the YES side, and moves to the subroutine in the fourth column on the right via the connector .

Here, first, the circulation pump 25 is stopped, and after the reheating operation is completed, the actual hot water temperature Kn (T3) at this time T is detected via the temperature sensor 27, and this is stored in the #2 register. .

Next, as will be described later, in order to distinguish whether the various disturbance operations have ended or the timer has counted up, it is detected whether the timer has counted up or not. Since this is the operation after counting up, it moves to the YES side, and in the same way, it is again asked whether or not it is currently in the keep warm mode. , moves to the subroutine shown in the fifth column on the far right.

Here, first, the difference Δ between the actual hot water temperature data Kr1 ("3) stored in the #3 register and the actual hot water temperature data n ("1) stored in the 'l register is taken. .

However, at this point, the actual hot water temperature data K stored in the town register. (#3) is the actual hot water temperature data at time T1 when the auxiliary reheating ends and the repeated automatic reheating mode starts in FIG. (T1), which can be considered to be approximately equal to the set temperature of 8. On the other hand, n ('l) in the actual hot water temperature data stored in the #l register indicates the repeated automatic reheating. Actual hot water temperature data at time T2 after a certain period of time set in the timer has elapsed from mote start time T1 (T2).

Therefore, the value we are looking for here, Δ, = , (#3) - K. (#l) means Avon = (T11 - n(T2)), which means that as shown in Figure 1, the boiling temperature reaches the set temperature at time T. When the hot water in the bathtub 23 has elapsed for a predetermined period of time tc!'JT2 indicates how much the temperature has decreased.For example, if the setting 4Ks is 42℃, For example, the fixed time tIl=tc is 30 minutes, and at time T2 after 30 minutes, the hot water in the bathtub 23 is 39 minutes.
℃, AKI in the above is 3℃
is required.

Therefore, in the next processing step, the value JK obtained as described above as the temperature drop actually occurring in the hot water in the bathtub 23 and the timer time t are set. = Mmm. From this, the temperature decrease characteristic over time t. /ΔK. is calculated.

At this point, the timer time t. is a constant time tc, and if this is, for example, 30 minutes, then if the actual water temperature decrease ΔKn from time T to time T2 is determined to be, for example, 3°C as above, then the temperature The deterioration characteristic 1n/ΔKn is calculated by dividing the 30 minutes by 3℃ and calculating 10m1
It can be calculated as mouth/℃.

However, in order to know the characteristics that are in this reciprocal relationship, that is, how many degrees Celsius the actual water temperature drops per unit time,
Δ, = 3℃, timer time jn = tC = 30 (minutes)
The temperature reduction characteristic value of 0.1° C./win may be obtained by dividing the temperature by 0.1° C./win.

However, in the case of this embodiment, the temperature drop characteristic tn/Δ obtained in this processing step is, as will become clear later, the temperature drop characteristic jn-17Δ calculated and stored - times before. It is also corrected using the value of -1, and (t
It is determined as n/ΔKI+)'. The simplest case of correction is to take the average as shown in Figure 2, that is, to ttn/-. )' = [(t, /Δ to n)◆(
1, -+/Δ to n-+)]/2.

The reason why it is good to correct in this way will be explained later, but as explained here, when the power is first turned on, the past temperature drop characteristics are not stored in the storage device attached to the heat retention control device. Therefore, this judgment step is performed only the first time after the power is turned on by software processing, for example, 1-+/ΔKn-1 is changed to tn/Δ.

or do not make such amendments.
In either case, the result obtained in this judgment step for the first time after the power is turned on is as follows.
(1,/Δ to n)' ” tn/ΔKn.

After this correction step, in the example shown, the temperature drop characteristic value (tfi
/Δ, based on the value of ,)', its open number f[(t
, /ΔK11)'] is the temperature K at which reheating should start.
.

Also change the settings to the optimal setting.

The temperature at which you should start reheating is, of course, the actual temperature of the water. is within an acceptable range even if the temperature drops, and there is no need for reheating, in other words, it is a temperature at which reheating should automatically start when the temperature drops below this temperature. There is a predetermined temperature difference ΔK with respect to the set temperature 5. The temperature can be set as low as possible.

That is, wa = K5 - ΔK.

Therefore, for example, ΔK is fixed throughout the year.

It is also possible to set the temperature to be 2°C lower, etc., which is fine as long as the most basic aspect of the present invention is followed, but in this embodiment, in order to achieve even better automatic reheating control, this temperature difference ΔKc is also set. Correction is made using the temperature drop characteristic (tn/Δ)'.

In other words, the temperature drop characteristic 1n/Δ before correction is the same as the temperature drop characteristic (t
n/ΔKn)', the specific magnitude of these values sufficiently contains information about the season or atmospheric temperature.
For example, in winter, when the atmospheric temperature is relatively low, hot water cools down easily, so the cooling time per unit degree Celsius is shorter, whereas in summer it is longer.

However, from the user's point of view, the temperature of the water is similar to that of the actual water in winter. Even if the temperature drops slightly from the set temperature, it feels too cold, but in summer, even if the actual hot water temperature Kn drops considerably from the set temperature, it still feels like there is no need to reheat it. Therefore, in this embodiment, in consideration of such circumstances, the allowable temperature drop difference ΔKc is adjusted as a function depending on the value of the temperature drop characteristic (1,/ΔKn)' (in the end, the reheating For example, in winter, ΔKe is 1°C.
However, in the summer, the temperature increases to about 3 degrees Celsius.This situation can be seen in Figure 1 A and B, where winter and summer are shown separately for each Δ. It is expressed by changing the size of. However, even with this functional operation,
It is possible to make do with a simple proportional calculation without setting a particularly complicated relational expression (although that is fine).

In any case, in this way, an appropriate allowable drop temperature difference ΔKc is determined according to the atmospheric temperature situation of the crucian carp, etc., and once the starting temperature is determined, the next step is to set the set temperature Kg ( For example, the actual water temperature reached 42℃. However, the temperature has reached the point where reheating should start.

(For example, assume that the temperature is 40° C., which is 2° C. lower than that temperature.) The expected temperature drop time 1x is calculated.

In this case as well, the simplest method is to apply proportional calculation, and for the predetermined temperature difference Δ +, calculate the temperature drop characteristic value (tn
/JK, )", so in the numerical example here, the temperature drop characteristic value (tn/-
by multiplying by n)' w 10 win/l: (or ΔKc-2°C is the temperature reduction characteristic value AKn/1l)
(by dividing by l-0.1°C/win), the expected temperature drop time 1. can be easily calculated as 20 minutes.

In this way, the expected temperature drop time 1 until time τ4 when reheating should be started next. If you calculate #3
The actual water temperature data at time T, which was in the register, is (
y+) is no longer necessary, so in the first processing step, in order to update the expected temperature drop time tx that will be required next time, the actual hot water at the first reheating end time T, which was stored in the re-register, is For temperature data. (T3) is transferred to this register, and the #2 register is left in a substantially empty state (a state in which there is no problem even if it is rewritten).
Set the timer to the timer.

As a result, a timer (not shown) starts counting down the set time 1n=1°, but as a result of the microcomputer executing the program at high speed, this start time is actually the first time in the N1 diagram. It can be considered that this time is approximately equal to the time T when the second automatic re-burning of the Buddha ended.

Next, when returning to the beginning of the flow chart shown in Figure 2 again from the connector ■, after it is determined as YES in the step of determining whether or not the automatic warming mode is in effect, the main routine continues directly below. If various disturbances are ignored in the same way as before, then from the above-mentioned time T onwards, the flow will stop and a determination will be made as to whether or not the timer has counted up.

Then, as indicated by time T4 in FIG. 1, a certain period of time t elapses after the timer is activated. When =jx is passed, it is determined that the timer has counted up, and the process moves to the middle of the third row upper subroutine via the connector (2), where the circulation pump 25 is turned on again.

Thereafter, the temperature sensor 27 detects the actual water temperature Kn (T4) in the bathtub 23 after a certain period of time TD has elapsed, and sets this to #
Store in l register. Until then, this 01 register has the actual hot water temperature K at time T2. (T2) had been stored, but this was no longer necessary, and at this point it was rewritten to I and (T4) to the actual hot water temperature at time T4, and as a result, it was essentially erased.

Following the above processing step, again in the judgment step, does the actual hot water temperature Kn>set temperature? A judgment J is made. Naturally, since the actual hot water temperature has cooled down at time T4 when the expected temperature drop time tx has elapsed after the automatic hot water filling is completed, the answer to this judgment step is generally no.

The result of such judgment is the time T in Figure 1.
As shown from 4 onwards, the reheating combustion starts again, and then the microcomputer returns to the beginning of the flow chart shown in 2nd figure and determines whether or not it is in the automatic warming mode. , since it is already in automatic warming mode, it is judged as YES, and then, even if there is no other disturbance, it is already in the reheating mode, so the step of determining whether or not reheating is in progress is performed. After determining that , the process moves to the middle of the subroutine on the upper side of the third row via the connector (■), and the actual water temperature is determined as K. It is determined whether or not the temperature exceeds the set temperature S.

This routine is the same as explained earlier, and of course it will continue to be judged as no until it boils over, but 7s1
As indicated by time T in the figure, the actual water temperature K in the bathtub 23. When the temperature reaches the set temperature, the water temperature changes to the actual water temperature in the subroutine in the upper part of the third column in Figure 2 above. The flow shifts to the yes side in the comparison judgment step 5 for the set temperature, and moves to the subroutine in the fourth column on the right via the connector .

At this point, the circulation pump 25 is stopped and after reheating is completed, the actual hot water temperature at this time T is determined via the temperature sensor 27. (
) is detected and stored in the "2 register.

Next, as will be described later, in order to distinguish whether the various disturbance operations have ended or the timer has counted up, it is detected whether the timer has counted up or not. Since this is the operation after counting up, it moves to the YES side, and in the same way, it is again asked whether or not it is currently in the keep-warm mode, and since it is YES here as well, it is passed through the connector ■ as shown in Figure 2. The process moves to the subroutine shown in the fifth column on the far right.

Here again, the actual hot water temperature data stored in register #3. (#3) and the actual hot water temperature data stored in register 6. The difference AK from (#1) is taken.

However, the actual hot water temperature data K11 (#3) stored in the #3 register at this point is the time T when the first reheating after entering the repeat automatic reheating mode is completed in Fig. 1. The actual hot water temperature data in , is 1 (Ts),
This can be considered to be approximately equal to the set temperature of 5, and on the other hand, the actual hot water temperature data KIl stored in the 'l register
('l) is the expected temperature drop time 1n=1. set in the timer from the relevant time T. Time T4 after
Actual hot water temperature data. (T4).

Therefore, the value sought here, ΔKn= n('3) −K, ('1), means Δ, = , (Ts) −K, (T4), which ultimately becomes As clearly shown in FIG. 1, the hot water in the bathtub 23, which was heated to the set temperature of 3 by the first automatic reheating at time T, continues to rise for a predetermined expected temperature drop time t8. Time T4 after
This shows how much the temperature actually dropped.

Then, check whether the predicted temperature drop time 1° obtained earlier is correct, or whether the actual drop rate of the actual hot water temperature changes with respect to the value of □ or its reciprocal value in the temperature drop characteristic 1, /Δ obtained previously. If not, according to the specific numerical example above, the expected temperature drop time t, = 2 based on the temperature drop characteristic value calculated as 10 in/l or 01°C/win.
The actual water temperature at time T4 after a time equal to 0 minutes.

(T4) is a temperature that is lower than the set temperature Ks of 42°C by a predetermined temperature difference AKe = 2°C, that is, the predetermined reheating start temperature should be 1 = 40°C (equal It is of course conceivable that a certain amount of tolerance should be established in advance as a range that can be considered as such.

Therefore, in that case, the latest temperature difference ΔKn and this temperature difference Δ in the subsequent processing steps.

The timer time 1. From 1 again, the temperature drop characteristic t. /AKn, and combine this value with the previous temperature drop characteristic value (past data 1n-+/Δ)
Even if correction processing or averaging processing is performed with -1), the resulting temperature drop characteristic value (tn/Δn)' will be the same value as before, although it has been updated. In this case, it is not necessary to change the reheating start temperature to 1, and in fact, the value of the allowable temperature difference ΔKc that determines the reheating start temperature is updated to this value in the next correction step. The value cannot be changed.

On the other hand, due to changes in atmospheric temperature and other parameters,
In the above specific numerical example, the expected temperature drop time t. =L
Until then, x is set to be 20 minutes, and when the time is counted up, it becomes the actual water temperature.

should have been 40℃, but at time T in Figure 1
At step 4, the actual water temperature is reached. (T4) is, for example, 39.5°C, and the temperature difference between them is a predetermined temperature difference ΔKe=2
If the temperature is 2.5°C, which is 0.5°C higher than the expected temperature drop time of 1. This temperature difference 2 for 20 minutes
．． By dividing by 5° C., the temperature drop characteristic value t11/ΔKn is newly determined to be approximately 8 m1n/l.

In the case of following the most basic aspect of the present invention, from then on, after each automatic reheating is completed, the (
Each time the time interval tIl of 16 hours from time T%, 16 hours from time Ta, etc.) is determined, the time interval t up to that point is determined.
You can simply calculate and update l to 1n/Δ like this, and you can still repeat the automatic reheating operation while maintaining the optimum reheating start temperature. In the example, furthermore, t, , /Δ. The past data is updated using the corrected value (shi./∆ to n)°, and especially in the case of this embodiment, this correction procedure is performed by averaging. In the case of the above numerical example, the previous 1-+/ΔKn-+= 10 mt
n/'C and the newly calculated tn/ΔKn= 8 w
From in/'C, a newly corrected temperature drop characteristic value (tn/Δ)' = 9 win/l can be obtained.

Next, based on this newly determined temperature drop characteristic value, an optimal reheating start temperature is determined as a function relationship thereof. Here, the temperature decrease rate is approximately 2 times faster than expected, so for example, the difference ΔK from S to the reheating start temperature. Slightly reduce the temperature from the previous 2°C, for example, 1.6 times smaller (in the case of proportional calculation correction).
It can be set as ℃ etc.

After this, in the next calculation step, the actual hot water temperature Krl is newly calculated from the updated ΔKe=1.6°C and the previously corrected and updated temperature drop characteristic 9m1n/l:.
Estimated time required for the temperature to drop by 6°C 1. is determined to be approximately 14.4 minutes, and this value is stored in a storage unit (not shown) in order to update the previous value.

After that, at this time, the actual hot water temperature data stored in register 2 is transferred to register #3, and the timer is set for time t.

After newly calculating and setting the updated temperature drop expected time tx, the routine moves to the next routine, and the same procedure is repeated thereafter.

However, correcting the temperature drop characteristic tn/ΔK ultimately means correcting the time based on the history of the past predicted temperature drop time 1, but the good thing about this is that For example, even if the temperature reduction characteristic fluctuates greatly for some reason, including various disturbances as described below, the effect can be alleviated. This is to prevent extremely different time intervals tn from being set, even if only for - times, and is a type of fuzzy control. - Even if there is a disturbance with a large degree of facultative nature, the automatic reheating can be repeated several times and eventually converge to the optimal time interval.

In addition, even when looking at long-term changes, as shown in Figure 1 A and B, the interval between automatic reheating automatically becomes longer in the summer than in the winter, leading to unnecessary energy consumption and noise. In addition to suppressing the heating temperature, the reheating start temperature itself changes appropriately, so that comfort for the user can be guaranteed.

Although the illustrated embodiment operates as described above, a time limit may be set for such repeated automatic reheating mode from the time it starts, for example, 4 hours from the start (this is just an example). ), the system does not start a new automatic reheating operation, or sets a limit on the maximum number of times automatic reheating can be repeated, and resets without performing automatic reheating more than a predetermined number of times. This works effectively if you forget to turn off the hot water system even though everyone in your family has finished taking a bath. However, on the other hand, facilities such as golf courses, dormitories, and inns that allow you to take a bath at any time, and with the recent luxury of ordinary homes, such time or number limit functions are not available. In many cases, it is no longer necessary to provide such a restrictive function, so whether or not to add such a restrictive function can be left to the user's request.

Conversely, if you want to use the automatic reheating mode again after the automatic reheating mode has ended automatically or the automatic reheating mode has ended due to the user's switch operation, etc., each The data stored in the storage unit can be used as is.

That is, since the explanation above starts from the point where the power is first turned on to the heat retention control device (the state in which all the contents of each memory section are volatilized), the period from time t1 to t2 in FIG. First time interval t. The bamboo shoots were fixed at tC for a certain period of time, but this does not mean that the power to the heat retention control device was cut off, and when the automatic reheating mode was once terminated and restarted, the previous automatic reheating mode would be restored. or (tn/
ΔKo)', to the additional firing start temperature, to the allowable drop temperature difference Δ. etc. can be stored in each corresponding storage unit, so it is possible to use this to calculate and determine the initial time interval tn of a newly started automatic reheating mode, or the first time interval tn. Only t is the last time interval data t that was before the end of the previous automatic reheating mode and the measurement was interrupted midway. (Since the end command by the user of the automatic reheating mode is generally issued during this time interval t, the time interval 1n in which measurement is stopped remains in the storage unit as it is because it is not updated by new calculations. You can also use

Particularly in this regard, it may be effective to correct the temperature drop characteristics using past history. In other words, if the period from the end of the previous automatic reheating mode to the start of the current automatic reheating mode is extremely long, and the value of the temperature drop characteristic is significantly different between the last time and this time, the automatic reheating mode will be started again. At the beginning of time, it is conceivable to set a time value t0 that deviates considerably from the appropriate value, but if the above-described correction processing is performed, such a deviation can be suppressed to about half. Of course, averaging as a correction processing method is just one example of a car, and a more appropriate functional relationship can be set, or atmospheric temperature and other data may be taken in at the beginning of automatic reheating. ,
Appropriate correction may be made depending on the value.

By the way, the embodiment of the present invention according to the flow chart shown in the second figure shows an example that can respond to more practical demands or added value as a product for this type of automatic hot water supply system in a different sense. 6 For example, in Figure 2, the left end -
As shown in the second judgment step from the bottom in the main routine shown in the column, each time interval 1n in FIG. Suppose that a request for reheating J is issued during 1X measurement.

Then, the judgment of YES in this judgment step is transferred to the middle of the subroutine on the upper side of the third row via the connector (2), where the circulation pump 25 is turned on, and after a certain period of time TD, the temperature sensor 27 detects that The actual temperature of the water in the bathtub 23 at this time. is detected and stored in register 6.

Following the above processing step, again in the judgment step, does ractual hot water temperature Kn>s to set temperature? A judgment J is made. Naturally, since reheating is required, the result of this judgment is no, and as shown in the subsequent processing steps, the main task is to start reheating combustion. As a result of returning to the top of the chart and determining whether or not it is in automatic keep-warm mode, it is already in automatic keep-warm mode, so as a result of the judgment, yes, even if there is no other disturbance, it is already in reheating mode. Therefore, it is determined that reheating is in progress at the step of determining whether or not reheating is in progress, and the process moves to the middle of the subroutine on the upper side of the third row via connector ■, and the actual water temperature is determined. To. It is determined whether or not the temperature exceeds the set temperature.

This routine is the same as described above, and of course it will continue to be judged as no until the hot water is boiled, but eventually, as a result of this midway reheating, the actual temperature of the hot water in the bathtub 23 will be K. When the temperature reaches the set temperature, the actual water temperature in the subroutine at the top of the third row in Figure 2 above is reached. The flow shifts to the YES side in the comparison judgment step of vs. the set temperature, and moves to the subroutine in the fourth column on the right via the connector ■.

At this point, the circulation pump 25 is stopped and after reheating is completed, the actual hot water temperature at that time is determined via the temperature sensor 27.

is measured and stored in register #2.

Next, as will be described later, in order to distinguish whether the various disturbance operations have ended or the timer has counted up, it is again detected whether the timer has counted up, and here, of course, , the timer is counting down, so it goes to no through the connector,
In Figure 2, jump into the 5th column (rightmost column) and read the actual water temperature data at the end of reheating from the register #.
After being moved to register 3, a new timer time of 1.1-1K is set for the timer.

In other words, after the timer's timing operation is interrupted due to reheating during actual purchase, when it is determined that the actual water temperature has reached the set temperature after the reheating is completed, the interruption occurs. This means that a new measurement of x has been started for the same time as the timer that was counting.

After this, when we return to the beginning of the second illustrated flow chart, we are again asked whether or not we are currently in automatic keep warm mode.The answer is yes, so we proceed down through the main routine and the timer starts counting. - A question is asked as to whether it has been uploaded or not, and thereafter this judgment operation is repeated at a predetermined cycle.

Eventually, when the timer counts up, the process moves from this judgment step to the middle of the subroutine on the upper side of the third row via the connector (2), where the circulation pump 25 is turned on again, and after a certain period of time Tl1l has elapsed, the temperature is By the sensor 27,
The actual water temperature in bathtub 23 is K.

is detected and stored in the town register.

Following the above processing step, again in the judgment step, is the actual hot water temperature Krl>s to the set temperature? A judgment J is made. Naturally, the actual water temperature will have cooled down by the time the restarted timer has passed the expected temperature drop time tx, so the answer in this judgment step will generally be no, and this will cause reheating to be started again in the next processing step. After that, the microcomputer returns to the beginning of the flow chart shown in @2 and determines whether or not it is in the automatic keep-warm mode.Since it is already in the automatic keep-warm mode, the microcomputer judges yes.
Next, even if there is no other disturbance, reheating is already in progress, so in the step of determining whether reheating is in progress, it is determined that reheating is in progress, and the three rows are connected via connector ■. Moving to the middle of the upper subroutine, it is determined whether or not the actual hot water temperature exceeds the set temperature S.

This routine is the same as explained several times before, and of course it will continue to be judged as no until the water boils, but the actual temperature of the water in the bathtub 23. When the temperature reaches the set temperature 5, the flow shifts to the yes side in the step of comparing the actual hot water temperature Kn and the set temperature E5 in the subroutine at the top of the third column in Figure 2 above, and the connector ■ Then, go to the subroutine in the fourth column on the right.

After the circulation pump 25 is stopped and reheating is completed, the actual hot water temperature Kn is detected via the temperature sensor 27 and stored in the register.

Next, as will be described later, in order to distinguish whether the various disturbance operations have ended or whether the timer has counted up, it is detected whether the timer has counted up or not. Since this is the operation after the timer started in Moving on to the flow in the rightmost column of Figure 2.

After this, the process goes through a group of steps that are exactly the same as those already explained regarding the automatic reheating mode, and the sequence of operations that are exactly the same as those in the repeated automatic reheating mode when there is no disturbance are repeated.

Next, we will consider the case where, for example, the user changes the set water level and wants to pour hot water, or the case where the controller or microcomputer in the hot water supply system commands hot water pouring in a mode in which the set water level is automatically maintained. .

In this case, first, during the main routine shown in the leftmost column in Figure 2, it is determined whether or not a pouring request has been issued since the automatic warming mode was entered. , and moves to the middle of the subroutine in the upper part of the second column via the connector ■.

Here, it is determined whether the actual water level exceeds the set water level or not, and if the condition is suitable for issuing a pouring request, that is, if the actual water level has not reached the set water level, it is determined no and the state shown in Figure 1 is determined. The switching solenoid valve 1 is opened, and hot water whose outlet temperature is controlled to meet the set temperature is supplied into the bathtub 23 via the heat exchanger 11 by the hot water tapping operation described above.

When the pouring operation starts in this way, in the next execution cycle of the flowchart shown in the second figure, the determination in step r pouring 71 becomes YES, and the actual water level relative to the set water level is determined again. and this is repeated.

Eventually, when it is determined that the actual water level has exceeded the set water level, the process moves from the judgment step to the third row upper subroutine via the connector (2), and after the switching solenoid valve 17 is closed, the circulation pump 25 is turned on. It is turned on, and after the stirring time T in the bathtub, which is effective for measuring the actual water temperature as described above, has elapsed, the actual water temperature is reached. is detected and stored in the #l register.

Following this, it is determined whether or not the actual hot water temperature Kn is equal to the set temperature Ks, and if not, reheating continues according to the sequence already explained, and if there is, the fourth row from the connector ■ However, in any case, as is clear from the flowchart shown in the second figure, the operation from this point onwards is based on the timer count, which was taken up earlier as one of the disturbances. The response is exactly the same as when a reheating operation occurs during a downtime, and ultimately the sequence of operations returns to exactly the same as in the repeated automatic reheating mode when there is no disturbance.

Therefore, in this embodiment, when a change in the water level during pouring is detected, the timer's counting is interrupted, and after the pouring operation is completed, the actual hot water temperature is reached. The timer is restarted from the time when it is determined that the temperature has reached the set temperature of 3. This also applies to the water injection operation, which is another factor that causes water level changes and is also one of the other disturbances in the repeated automatic reheating mode of the present invention.

However, there are some differences between the pouring operation and the water pouring operation, although they are not directly related to the present invention, so I will mainly explain these parts. For example, when the user performs an operation to lower the set temperature, Since this is essentially equivalent to the action of filling the hot water with water, that is, issuing a water injection request, the microcomputer executes the program according to the main routine in the flow chart shown in M2. When executed, as a result of the step of determining whether or not the "water injection request" has been issued, the process moves to the subroutine at the bottom of the second column via the connector ■, where a series of processing steps The amount of water required to fill the water to the set temperature is calculated.

First, the actual water temperature Kn at this time is taken in, and then the actual water amount Q, which is the current total amount of hot water in the bathtub 23. is detected. As already mentioned regarding the conventional example, the detected value of the pressure sensor 26 is based not only on the actual water level data but also on the integrated flow rate based on the flow rate value obtained from the flow rate sensor 28 when learning the initial shape inside the bathtub. The amount of hot water required to be poured into the bathtub 23 up to that point can also be grasped.

On the other hand, since the set temperature of 5 is naturally known, if the user performs an operation such as lowering the set temperature by 5, the actual water temperature will change. If the set temperature is higher than 5, and it is really necessary to fill the water with water, the temperature Kc of the water that can be supplied at this time can be detected by the water supply temperature sensor 19, so the actual water temperature is determined. The additional amount of water (water injection amount) QP required to lower the set temperature to 5 can be easily determined as, for example, Qp = Qll (s to Ko-)/(C to Ks-). Setting the temperature to 8 is the actual water temperature. If it is higher, the above required water injection amount Qp will be a negative value,
Although not shown, a flow for ignoring the water injection request may of course be incorporated in that case, and if this is done, there will be no interruption of the repeated automatic reheating mode shown below.

However, in general, the water injection amount Qph is considered to be a significant positive value.
Then, the switching solenoid valve 17 in FIG. 1 is opened and the water injection operation is started. Of course, at this time, the burner 12 is not ignited, and the heat exchanger +1 becomes a mere flow path for water.

When the water injection operation starts, the answer to the step of determining whether or not water is being poured in the main routine in Fig. 2 becomes YES, and the sub-function in the third row below is sent via the connector ■.
Moving on to the routine, it is repeatedly detected whether or not the calculated set amount Qp of water has already been supplied. For this purpose, data from the flow rate sensor 28 may be integrated and used, or data regarding the pressure sensor 26 may be used.

Eventually, when the set amount of water has been poured, the judgment step moves to the subroutine on the upper side of the third row via the connector (2), and after the switching solenoid valve 17 is closed, the circulation pump 25 is turned on, and the existing After the stirring time TD in the bathtub, which is effective for detecting the actual water temperature, has elapsed, the actual water temperature K is determined. is detected and this is #
Memorized by Lujista.

Following this, it is determined whether or not the actual hot water temperature Kn is equal to the set temperature Ks, and if not, reheating continues according to the sequence already explained, and if there is, the four rows from the connector Moving on to the second subroutine, in any case, as is clear from the flow chart shown in the second figure, the operations from this point onwards will occur if the reheating mentioned above occurs as one of the disturbances, The response is exactly the same as that for the pouring operation, and ultimately the sequence of operations returns to exactly the same as in the repeated automatic reheating mode when there is no disturbance.

Therefore, in this embodiment, even if a change in the water level due to water injection is detected, the timer's counting is interrupted, and after the water injection operation ends, the actual water temperature is restored. The timer is restarted from the moment it is determined that the temperature has reached the set temperature of 3.

In exactly the same way, if necessary, changes in water level due to other causes, such as changes in water level due to a person taking a bath, or conversely, changes in water level due to a person leaving the bathtub, are also detected by the pressure sensor 26 in Fig. 1. Therefore, if we consider these as disturbances for the repeated automatic reheating mode of the present invention, when these disturbances occur, the timer measurement is interrupted, and after such disturbances end, reheating is started. If the timer is restarted from the point when it is determined that the actual water temperature has reached the set temperature as a result of the above steps, automatic warming operation that is resistant to other disturbances can be expected.

The embodiments of the present invention have been described in detail above, but various modifications can be considered. For example, at the end of each reheating operation, the actual hot water temperature Kn was taken in in the above embodiment, but the actual water temperature Kn at the end of this reheating operation is taken in. If the hot water temperature Kn is within a range that can be considered to be equal to the set temperature, the actual hot water temperature is used in each judgment step and calculation step in the flow chart in FIG. may be replaced with 8 for the set temperature, however, in the case of the second illustrated flow chart, it would be more reasonable to create a flow that detects the actual hot water temperature KIl even at the end of reheating. I can do it.

Furthermore, in the above embodiment, at the temperature at which reheating should start,
is defined as 0 for the temperature difference Δ with respect to the set temperature Ks, but 1 may also be given as an absolute value to the reheating start temperature for each specific value of the set temperature Ks. Of course, depending on the user, the allowable drop temperature difference ΔK from 1 to the temperature at which reheating should be started or 5 to the set temperature. may be settable according to preference.

As for the calculation of the expected temperature drop time, the calculation of temperature drop characteristics as an example for deriving this, and each correction calculation, in the above embodiment, proportional calculation is adopted as the simplest case as described above. However, of course, if a more appropriate or highly accurate equation relationship is required in consideration of heat convection, etc., that may be used.

Regarding changes in the water level in the bathtub, among the hot water supply systems already provided, it is preferable to use a pressure sensor as shown in FIG. I used this, but as I mentioned earlier,
In principle, a classic liquid level detector may be used, and as for the heat exchanger, as shown in Figure 3, a heat exchanger 11 for hot water supply and a heat exchanger 21 for reheating may be used. Although it is desirable to have these separately, it is not a limiting element for the present invention. It is clear that the present invention can also be applied to a type having only a single heat exchanger 11.

[Effects] According to the present invention, extremely desirable results can be obtained regarding the automatic heating operation of the hot water in the bathtub, especially regarding the repetition cycle of automatic reheating.

In other words, in the automatic heat retention mode, the predicted temperature drop time required for the hot water in the bathtub currently in use to drop to the set reheating start temperature is calculated each time using past history. Since the automatic reheating is repeated based on the latest time data, as mentioned at the beginning, not only changes in season or atmospheric temperature, but also changes in the shape and depth of the bathtub used, material purchase Or the difference in heat transfer coefficient,
Although the various factors that affect the temperature drop characteristics of the hot water in the bathtub, such as the size and direction of the bathroom, the amount of sunlight, etc., naturally vary from bathing facility to bathing facility, it is possible to determine the optimum repetition cycle for each facility. This makes it possible to reheat water, greatly increasing the degree of freedom in installing hot water systems.

Therefore, as in the conventional example, if the automatic reheating repetition cycle is optimally fixed and set according to a certain season amidst seasonal fluctuations, the actual water temperature will rise before starting reheating due to seasonal changes. You can avoid the problem of starting reheating just because the set time has arrived, even though the temperature is too cold or not yet cold enough to require reheating. . In the case of an embodiment in which the reheating start temperature itself is also appropriately corrected, the effect is further enhanced, and control that is more suitable for the user's experience can be achieved.

Not repeating premature reheating is advantageous in terms of energy consumption, resulting in so-called energy saving.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of temperature history characteristics of hot water in a bathtub under an automatic warming mode or a repeated automatic reheating mode operated according to an embodiment of the present invention. FIG. 2 is an explanatory diagram illustrating an embodiment of the present invention using a flow chart. FIG. 3 is a schematic diagram of an automatic water heater or automatic water supply system to which the method of the present invention can be applied. FIG. 4 is an explanatory diagram of the conventional automatic warming operation. FIG. 5 is an explanatory diagram illustrating a conventional automatic warming operation using a flow chart. It is. 11... Heat exchanger for hot water supply. 12...Burna. 13... Former solenoid valve. 14...Proportional valve. 15. Faucet. 16...Shower 17...Switching solenoid valve. fan. Supply water temperature sensor. Hot water temperature sensor. Heat exchanger for reheating. Burna. Bathtub. proportional valve. circulation pump. pressure sensor. temperature sensor. Flow sensor applicant Rijin Hanshin Electric Co., Ltd.

Claims (6)

[Claims] (1) The hot water filled in the bathtub is automatically reheated repeatedly at time intervals, and the automatic reheating each time is the actual temperature of the hot water, which is the actual temperature of the hot water filled in the bathtub. A method of keeping hot water in a bathtub using a heat retention control device that ends the process every time the water reaches a predetermined set temperature; The interval is the actual water temperature in the bathtub or the set temperature at the end of the previous reheating, which is one time before each time, and the above time in the past from the end of the previous reheating to the start of each reheating. A method for keeping hot water in a bathtub warm, characterized in that the temperature is calculated and updated each time based on the actual hot water temperature in the bathtub at the end of the interval and the time interval in the past. (2) The time interval calculated above is the time value calculated as the expected temperature drop time required for the actual hot water temperature to drop from the end of each reheating to the temperature at which reheating should start. The method according to claim 1, characterized in that the method has been subjected to a correction. The method according to claim 2, characterized in that: (3) the temperature at which the reheating should be started is also corrected according to the corrected time interval. (4) The first automatic reheating of the hot water in the bathtub is performed after it is first determined that the actual hot water temperature has reached the set temperature after the power is turned on to the heat retention control device. The method according to claim 1, 2 or 3, characterized in that only the above-mentioned time interval is a predetermined constant time regardless of the above-mentioned calculation. (5) If the reheating operation occurs before the above time interval has passed, restart from the end of the reheating operation that occurred in the middle.
The method according to claim 1, 2, 3 or 4, characterized in that the next automatic reheating is not started until the time interval has elapsed. (6) The heat retention control device is also provided with means for detecting a change in the water level in the bathtub; if the change in the water level is detected before the time interval elapses, it is determined that the change in the water level has subsided; Claim 1, characterized in that the next reheating is not started until the time interval has elapsed since the actual water temperature was determined to have reached the set temperature. The heat retention method described in 2, 3, 4 or 5.