JPH0587404A - Boiling-up control device for electric water warmer - Google Patents

Abstract

PURPOSE:To provide a boiling-up control device for an electric hot water warmer which automatically changes a boiling-up temperature without effecting operation to set a daily hot water temperature, ensures a necessary hot water temperature, and enables saving of a power. CONSTITUTION:A fuzzy inference means 44 decides a current energizing time according to a fuzzy rule based on a time in which a heat generating body 2 is energized by a heat generating body control means 6 during a past specified period. A computing means 45 computes a boiling-up temperature and an energization starting time based on a current energizing time and a water temperature set by a hot water temperature setting means 3. A heat generating body control means 6 controls energization to the heat generating body 2 and automatically controls the boiling-up temperature of hot water in a hot water storage tank 1. Thus, there is no need to effect operation to set a daily hot water temperature and a boiling-up temperature is automatically changed to ensure a necessary hot water temperature. Thereby, troublesomeness to set a hot water temperature is eliminated, temperature is adjusted to a value optimum to a user, hot water is used with comfortableness, and incurring of a heat loss is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiling control device for an electric water heater that automatically controls the boiling temperature of hot water.

[0002]

2. Description of the Related Art FIG. 11 is an overall configuration diagram of a conventional boiling control device for an electric water heater. FIG. 12 is a circuit configuration diagram of a main part of the boiling control device. In the figure, reference numeral 1 is a hot water storage tank, and a heating element 2 is attached to the lower portion thereof. 3 is a hot water temperature measuring means for measuring the temperature of the supplied water and the boiling water temperature, 4 is a hot water temperature setting means for setting the hot water temperature, 5 is a computing means, and the hot water temperature is set by the hot water temperature setting means 4. The energization start time is calculated based on the hot water temperature measured by the hot water temperature measuring means 3. Reference numeral 6 denotes a heating element control means, which controls energization to the heating element 2 based on the calculation result by the calculation means 5 and the measured hot water temperature by the hot water temperature measuring means. Reference numeral 7 is a power source for late-night power, 8 is a late-night power detecting means for detecting the presence or absence of supply of late-night power, and 9 is a faucet for taking out boiled hot water.

A microcomputer 10 in the control circuit comprises a CPU 11, a clock means 12, a memory 13, an input circuit 14, an output circuit 15, an A / D converter 16 and an analog multiplexer 17. Reference numeral 18 denotes a heating element control circuit, which corresponds to the heating element control means 6 in FIG.
9, 20, a transistor 21, relays 22 and 23, and diodes 24 and 25.

The coil of the relay 22 has a positive terminal +
Connected to V and the other end via transistor 21 to GND
Is connected to the terminal, the base of the transistor 21 and the resistor 19
It is connected to the output circuit 15 via. The resistor 20 is connected between the base and the emitter of the transistor 21. One end of the normally-open contact of the relay 22 is connected to the positive electrode terminal + Va, and the other end is connected to the GND terminal via the coil of the relay 23. Diodes 24 and 25 are connected to both ends of each coil of the relay 22 and the relay 23.
The contacts of the relay 23 are connected in series to the heating element 2 and the midnight power supply 7.

The resistor 26 is connected in series with the hot water temperature setting means 4 composed of a variable resistor, and both ends of the resistor 26 are positive terminal + V and GND.
It is connected to the terminal. Further, the connection between the resistor 26 and the hot water temperature setting means 4 is connected to the analog multiplexer 17. The resistor 27 is a temperature detecting means 3 including a thermistor.
Are connected in series, and both ends thereof are connected to the positive electrode terminal + V and the GND terminal. Further, the resistor 27 and the hot water temperature detecting means 3
The connection part with is connected to the analog multiplexer 17.

Reference numeral 28 denotes a midnight power detection circuit for detecting the midnight power, which corresponds to the midnight power detection means 8 in FIG. 11, and includes resistors 29, 30, a diode 31, and a photocoupler 3.
It consists of 2. The light emitting side of the photocoupler 32 has a resistor 2
A photo diode 32 is connected in series to the power source 7 via a diode 9, and a diode 31 is connected in parallel to both ends of the photo coupler 32 on the light emitting side. One end of the photocoupler 32 on the light receiving side is connected to the positive electrode terminal + V via the resistor 30, and the other end is connected to the GND terminal.
The connection between 0 and the light receiving side of the photocoupler 32 is connected to the input circuit 14 in the micro computer 10.

Next, FIG. 13 shows a microcomputer 10.
It is a flowchart of heating element control which shows the program memorize | stored in the memory 13 of this, and operation | movement of the conventional boiling control apparatus of the electric water heater is demonstrated using this figure. First, at the same time when the control power supply (not shown) is turned on, the presence or absence of the midnight power supply is detected in step 33. If power is supplied at midnight, the timer is started by the clock means 12 in step 34, the supplied water temperature is measured by the hot water temperature measuring means 3 in step 35, and the hot water temperature setting means 4 controls the temperature inside the hot water storage tank 1 in step 36. Read the setting value of boiling temperature.

Next, the calculating means 5 calculates the net energization time required to boil from the feed water temperature to the set temperature in step 37, and in step 38 the energization is started from which time in the midnight power supply time zone. Is calculated. The calculation of the net energization time and the energization start time is performed as follows. Supply water temperature is Tw (℃), boiling temperature is T
(° C) and the capacity of the heating element 2 is P (kw), the net energization time H (hr) is

[0009]

[Equation 1]

Here, V: volume of hot water storage tank 1 (liter) 860: 1 kw calorific value 0.9: efficiency is calculated. In addition, the midnight power supply time is generally 8 hours from 23:00 to 7:00 the next morning, and the energization start time Hp
Becomes Hp = 8-H.

Next, in step 39, it is judged by the clock means 12 in the microcomputer 10 whether or not the energization start time has come. When the energization start time comes, step 40
Then, the heating element control means 6 starts energizing the heating element 2. After that, in step 41, the hot water temperature in the hot water storage tank 1 is measured by the hot water temperature measuring means 3 (the measured value is Tm (° C.)), and in step 42, the boiling temperature set value T (° C.) and the hot water temperature The measured values Tm (° C.) are compared, and when Tm reaches T, the process proceeds to step 43, and the heating element control means 6 stops energizing the heating element 2. With the above, the control of energization to the heating element 2 for one day ends, and the next day starts from step 33 again,
The above control is repeated.

[0012]

The conventional boiling control device for an electric water heater is constructed as described above, and the hot water storage tank 1
The hot water inside is boiled to a high temperature state. When actually using the hot water, the hot water in the hot water storage tank 1 is mixed with water and the hot water temperature is lowered to an appropriate temperature for use. Therefore, when the boiling water is heated to an unnecessarily high temperature, the amount of remaining hot water increases, heat loss due to heat radiation increases, and heating to hot water is wasted. Therefore, in order to reduce this heat loss, it is necessary to appropriately set the hot water temperature each time according to the fluctuation of the daily hot water amount and the supply water temperature depending on the season, and there is a problem that the operation is troublesome. The present invention has been made to solve the above-mentioned problems, and automatically changes the boiling temperature without performing daily hot water temperature setting operations to secure the required hot water temperature and save electricity. It is an object of the present invention to provide a boiling control device for a water heater.

[0013]

A boiling control device for an electric water heater according to the present invention comprises a hot water storage tank for storing water, a heating element provided in the hot water storage tank, and a midnight power supply for energizing the heating element. A midnight power detection means for detecting the presence or absence, an energization means for energizing the heating element by the midnight power detection means to heat the water in the tank when a midnight power source is present, and water is supplied to the hot water storage tank. Hot water temperature measuring means for measuring the water temperature, fuzzy reasoning means for determining the current-carrying time of the day by fuzzy reasoning using a membership function from the current-carrying time of the past constant period by the current-carrying means, and current-carrying time by the fuzzy reasoning means And a calculating means for calculating the boiling temperature and the energization start time based on the water temperature by the hot water temperature measuring means, and the boiling temperature and the energization start time by the calculating means. Is obtained by a heating element control means for controlling the energization of the heating element according Hazuki said energizing means.

Further, in the fuzzy inference means, on the day corresponding to the season, by fuzzy inference using a membership function from the energization time of the past constant period by the energizing means and the water temperature different by the hot water temperature measuring means depending on the season. Determine the power distribution time of. Further, in the fuzzy inference, the energizing time of the past a certain period by the energizing means, the water temperature that differs according to the season by the hot water temperature measuring means, and the lowest boiling temperature that varies depending on the season In addition, determine the time for the current place where the minimum boiling temperature is guaranteed for the current day.

[0015]

In the boiling control device for the electric water heater according to the present invention, the fuzzy inference means determines the current-carrying time of the day according to the fuzzy rule based on the current-carrying time of the past constant period by the current-carrying means, and the calculating means conducts the current-powering of the day. The boiling temperature and energization start time are calculated based on the time and the water temperature measured by the hot water temperature measuring means, and the heating element control means controls the energization of the heating element by the energizing means to automatically adjust the boiling temperature of the hot water in the hot water storage tank. By controlling to, the boiling temperature is automatically changed without performing the daily hot water temperature setting operation, the required hot water temperature is secured, and heat loss is reduced.

Further, the fuzzy inference means determines the current-carrying time of the day according to the fuzzy rule based on the water temperature which is different according to the season by the hot water temperature measuring means,
You can set the boiling temperature including seasonality,
The heat loss can be reduced more efficiently.

Further, the fuzzy inference means determines the energization time of the day according to the fuzzy rule based on the minimum boiling temperature which varies depending on the season, thereby setting the minimum guaranteed temperature of the boiling temperature corresponding to the difference in season. In addition, heat loss can be efficiently reduced in consideration of seasonality.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a boiling control device for an electric water heater showing an embodiment of the present invention. In the figure, the same reference numerals as those in the conventional example are the same or corresponding parts, and the description thereof will be omitted. Four
Numeral 4 is a fuzzy control means for fuzzy inferring the energization time based on the energization time of a certain past period (for example, 8 days) using an ambiguous rule expressed by a fuzzy set.
Reference numeral 45 is an energization time calculated based on the energization time fuzzy inferred by the fuzzy control means 44 and the boiling water temperature from the supply water temperature measured by the hot water temperature measuring means 3, and the energization time is calculated in accordance with the end of the midnight power supply time. It is a calculation means for calculating the energization start time so as to end. The fuzzy control means 44 represents fuzzy inference means, and the heating element control means 6 represents heating element control means and energizing means.

FIG. 2 is a diagram showing the configuration of the fuzzy control means 44. In the figure, 46 is an input device for inputting the energization time, 47 is an input value storage unit, and 48 is a fuzzy inference for the energization time of the day. An arithmetic unit, 49 is a rule file that stores fuzzy rules, 50 is a membership function file that stores membership functions, and 51 is an output value storage unit that stores the output value of the energization time by the arithmetic unit 48.
An output device 52 outputs the energization time by fuzzy inference.

FIG. 3 is a block diagram for explaining the fuzzy inference contents of the fuzzy control means 44, and 53 is a membership function group for inferring the energization time.
It has a membership function of the current-carrying time and a membership function of the fluctuation of the current-carrying time in the past certain period. 5
Reference numeral 4 is an energization time variation determination rule for determining the variation of the energization time, and 55 is a fuzzy inference based on the energization time, the membership function 53 and the energization time determination rule 54 input to the fuzzy control means 44 to determine the energization time. It is an energization time fluctuation estimation unit that infers fluctuations. Reference numeral 56 is an energization time determination unit that calculates the energization time from the inferred energization time fluctuation value and the maximum energization time in the past fixed period (for example, 8 days).

FIG. 4 is an example showing a membership function of the energization time of the day in the membership function group 53. FIG. 5 is an example showing a membership function of the variation (= maximum energization time-minimum energization time) of the energization time within a certain past period (for example, 8 days). FIG. 6 is an example of an if-then type fuzzy rule table, where the horizontal direction corresponds to the antecedent variable corresponding to the energization time r of the day, and the vertical direction corresponds to the variation Δr of the energization time in the past certain period. Is a consequent part variable, and the intersection position of both r and Δr is a consequent part variable corresponding to the variation Δt of the energization time that should be output as a fuzzy inference result. NB to PB are antecedent part variables r, Δr and It is the fuzzy label name of the fuzzy set of the fuzzy set to which the consequent part variable Δt belongs.

The control rule is, for example, if (if) r is very small and Δr is small then (if) Δt is considerably small (r = NB, Δr = N, Δt = NB).
It is inferred that the predicted energization time becomes shorter as the past energization time is shorter and the fluctuation is smaller. Figure 6
The more detailed the rules are in the fuzzy rule table, the more the system can follow the changes in the actual amount of hot water used.

Further, the circuit configuration of the main part of the boiling control device is the same as that of the conventional example, but in this embodiment, the CPU 11 in the microcomputer 10 also serves as the calculation part 48, and the memory 13 has a rule. The file 49 and the membership function 50 are also stored.

Next, the operation will be described. FIG. 7 shows a memory 13 stored in the microcomputer 10.
In the flowchart showing the fuzzy inference, various calculations, and the control program for the heating element 2, the numbers shown in the drawing indicate the respective steps, and the same numbers as in the conventional example are the same or corresponding steps, and the description thereof will be omitted. First, a switch (not shown) is turned on to operate the control circuit, and step 33 is started. Thereafter, through steps 34 and 35, in step 57, the past energization time is read from the memory 13, and in step 58, the fuzzy control means 44 estimates the variation of the energization time based on the fuzzy inference shown in FIGS. ..

Next, at step 59, the energizing time and the boiling temperature are calculated by the calculating means 45 based on the estimated fluctuation of the energizing time as follows. The maximum energization time in the past fixed period is Hm, and the inferred energization time variation is ΔHm.
Then, the energization time Hi is calculated by Hi = Hm + ΔHm.

In step 60, the boiling temperature is calculated. When the energization time calculated in step 59 is Hi, the boiling temperature T is

[0027]

[Equation 2]

[0028] However, 860 is the heat generation amount per 1 KW, P (KW) is the heat generation capacity of the heating element, V (liter) is the capacity of the hot water storage tank, and Tw (° C) is the feed water temperature. The shorter the energizing time Hi, the lower the boiling temperature is calculated.

Steps 38 to 43 are the same as in the conventional example, and in step 61, the energization time of the day measured by the clock means 10 is stored in the memory 13. The stored data is for a fixed period (for example, 8 days), the oldest data is discarded, and new data is stored.

Example 2. FIG. 8 is a diagram for explaining fuzzy inference based on the energization time of the past certain period by the energizing means and the water temperature which is different according to the season by the hot water temperature measuring means, and the supply water temperature is determined by the seasonal membership function of the membership function group 53. The season is estimated from this, and the energization time variation determination rule according to the season is adopted. That is, since the rule of FIG. 6 is changed according to the season, it is possible to realize a fine change in the boiling temperature according to the season, and it is possible to perform boiling at the optimum hot water temperature according to the convenience of use. Is.

Example 3. FIG. 9 is a diagram for explaining fuzzy inference based on the energization time in the past fixed period by the energizing means, the water temperature different according to the season by the hot water temperature measuring means, and the minimum boiling temperature different depending on the season, and FIG. 10 is the feed water temperature and the boiling temperature. It is a figure which shows the relationship with a range, the water supply water temperature and the membership function 62 of a season, the minimum temperature determination rule 63, and the estimation part 64 of the minimum guarantee temperature are provided, and the minimum guarantee temperature of boiling temperature is changed according to season, The boiling temperature range is set, for example, as shown in FIG.

In the summer when the amount of hot water is not so high (the temperature of the supplied water is high), the minimum boiling temperature is lowered and the boiling temperature is not raised to a higher temperature than necessary, so that the loss due to heat radiation can be reduced and power can be saved. In winter (the water temperature is low), you can use a large amount of hot water by raising the minimum boiling temperature to a high temperature.
In addition, it is convenient to add water to the bathtub.

[0033]

As described above, the boiling control device for an electric water heater according to the present invention uses fuzzy inference means to perform fuzzy inference from the energization time of a certain past period to determine the energization time of the day, and computing means. By automatically adjusting the boiling of the hot water in the hot water storage tank by the heating element control means, it is not necessary to perform the daily hot water temperature setting operation, and the boiling temperature automatically changes to the required hot water temperature. Since there is no need to bother setting the hot water temperature, the boiling temperature is optimal for the user, the hot water can be used comfortably, and heat loss can be reduced. ..

Further, fuzzy inference means performs fuzzy inference from different water temperatures depending on the season, and by determining the energization time of the day, it is possible to set a fine boiling temperature according to the difference in the seasonal water temperature, for example, in summer. When the water temperature is high, the amount of electricity supplied to the heating element can be reduced, heat loss can be reduced efficiently, and power saving can be further promoted.

Further, the fuzzy inference means performs fuzzy inference from the lowest boiling temperature which varies depending on the season, and the minimum guaranteed temperature of the boiling temperature is set to raise the minimum boiling temperature in the winter season when the demand for hot water is high. Because of the high temperature, a large amount of hot water can be used, and it is also convenient for adding hot water to the bathtub. In summer, the minimum boiling temperature is lowered and it does not boil to a higher temperature than necessary, so both convenience and power saving are advantages. And the usability is greatly improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a boiling control device for an electric water heater showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of fuzzy control means according to the first embodiment of the present invention.

FIG. 3 is a block diagram for explaining fuzzy inference according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a membership function of energization time on the day of Example 1 of the present invention.

FIG. 5 is a diagram showing a membership function of energization time variation according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a fuzzy rule table according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 8 is a block diagram for explaining fuzzy reasoning showing a second embodiment of the present invention.

FIG. 9 is a block diagram for explaining fuzzy reasoning showing a third embodiment of the present invention.

FIG. 10 is a diagram showing a range of boiling temperatures in Example 3 of the present invention.

FIG. 11 is a configuration diagram of a conventional boiling control device for an electric water heater.

FIG. 12 is a circuit configuration diagram of a main part of a conventional boiling control device for an electric water heater.

FIG. 13 is a flowchart showing the operation of a conventional boiling control device for an electric water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Heating element 3 Hot water temperature measuring means 6 Heating element control means 7 Power supply for midnight power 8 Midnight power detection means 44 Fuzzy control means 45 Computing means

Claims (3)

[Claims] 1. A hot water storage tank for storing water, a heating element provided in the hot water storage tank, a midnight power detection means for detecting the presence or absence of a midnight power supply for energizing the heating element, and a midnight power detection means for performing the midnight power detection. An energizing unit that energizes the heating element when there is an electric power source to heat the water in the tank,
Hot water temperature measuring means for measuring the temperature of water supplied to the hot water storage tank, and fuzzy reasoning means for determining the current-carrying time of the day by fuzzy reasoning using a membership function from the current-carrying time of the past constant period by the current-carrying means. , A calculating means for calculating a boiling temperature and an energization start time based on the energizing time by the fuzzy inference means and a water temperature by the hot water temperature measuring means, and an energizing means based on the boiling temperature and the energization start time by the calculating means A boiling control device for an electric water heater, comprising: a heating element control means for controlling energization of the heating element. 2. The fuzzy inference means uses fuzzy inference using a membership function from the energizing time of the past constant period by the energizing means and the water temperature different by the hot water temperature measuring means depending on the season, and the day depending on the season. The boiling control device for an electric water heater according to claim 1, wherein the energization time of the electric water heater is determined. 3. The membership function is used in the fuzzy inference means from the energization time of the past constant period by the energization means, the water temperature that differs according to the season by the hot water temperature setting means, and the minimum boiling temperature that varies depending on the season. 2. The boiling control device for an electric water heater according to claim 1, wherein the energization time of the day corresponding to the season and guaranteeing the minimum boiling temperature is determined by fuzzy reasoning.