JPH0552413A - Device to control boiling-up in electric hot water device - Google Patents

Abstract

PURPOSE:To carry out the actions of boiling-up in night time zone and addi tional boiling-up in daytime time zone in the system of charging electric rate according to time zone of use. CONSTITUTION:A boiling-up calculator 11 calculates the temperature To1 of boiling-up in night time zone and To2 in daytime zone with priority on the temperature of boiling-up in night time zone, To1 from the set temperature of boiling up To that is set by a boiling-up temperature setting device 16 and the quantity of additional boiling-up of tomorrow that is determined by a set value Va of an additional boiling-up quantity setting device 12. An additional boiling-up controller 13 determines a specified time of electricity supply, t2 for a heater H from the quantity of additional boiling-up of today that is determined by the set value V2 and the temperature of boiling-up To2 in daytime zone. A heater controller 14 supplies electricity to the heater H according to the temperature of boiling-up To1 in night time zone and to a required time of electricity supply t2 in daytime time zone.

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 for efficiently realizing an additional boiling water function when the power charge is a time-based charge system.

[0002]

2. Description of the Related Art A conventional electric water heater is a so-called late-night power utilizing device, and is supplied with power only during a predetermined midnight power energization time period, for example, from 23:00 midnight to 7:00 the next morning. It has become. However, in this case, since other general loads are always energized,
The power demand in the daytime cannot be positively suppressed and the power demand in the nighttime cannot be raised, and the effect of leveling the power load cannot be achieved sufficiently.

Therefore, a constant-current type electric water heater has been studied. In this case, the electric water heater is always energized in the same manner as other general loads, while the electric power charge system has, for example, a nighttime time zone corresponding to the conventional midnight power energization time zone, and It is set at a lower price than the daytime hours, and such a fee system is called an hourly fee system. However, on the contrary, the charge during the daytime hours is set to be somewhat higher than the electricity charge for the conventional general load.

On the other hand, the conventional electric water heater uses late-night power to boil hot water in a tank to a preset boiling temperature and use the hot water during the daytime. Therefore, when the amount of hot water used increases or decreases depending on the day, there may occasionally occur a situation where the amount of hot water is insufficient, but even in that case, power is not supplied unless the midnight power energization period arrives, There was a serious drawback that so-called reheating was not possible and hot water could not be added at all. Under the hourly charge system, the electric water heater is always energized, so it has the advantage that it can be reheated at any time and that it can easily cope with an unexpected increase in the amount of hot water used.

[0005]

According to the prior art, since the boiling temperature in the nighttime zone is generally set manually, the set boiling temperature is low,
If additional boiling is performed each time the amount of hot water is insufficient, not only is it uneconomical because the amount of power used during the daytime is expensive, it is also uneconomical, and leveling of the power load cannot be achieved. On the contrary, if you set the boiling temperature too high,
The chances of additional boiling in the daytime will decrease,
It is uneconomical in this respect because it boils excess hot water during the night hours. Therefore, it is necessary to optimally set the boiling temperature, but there is a problem that such setting is not necessarily easy.

Therefore, in view of the problems of the prior art, the object of the present invention is to set the boiling temperature in the night time zone and give priority to the boiling temperature in the night time zone from the set boiling temperature and the additional boiling amount tomorrow. By providing the boiling temperature calculation means for automatically calculating the boiling temperature with the daytime hours, the most economical boiling operation can be performed, and the purpose of leveling the power load can be well met. It is to provide a boiling control device for an electric water heater.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the structure of the present invention has a night time zone in which the boiling temperature in the night time zone is prioritized from the set boiling temperature and the additional boiling amount tomorrow. And heating time calculation means for calculating the distribution of the heating temperature in the daytime time zone, the heating temperature in the daytime time from the heating temperature calculation means, and the additional heating amount for today, the heater required In the additional boiling control means for calculating the energization time and the night time zone, the heater is energized until the average temperature of the tank reaches the boiling temperature in the night time zone from the boiling temperature calculation means, and in the daytime zone. Is provided with heater control means for energizing the heater for the required energization time from the additional boiling control means.

In the daytime, the heater control means may energize the heater until the lower temperature of the tank reaches a predetermined temperature or higher, regardless of the required energization time from the additional boiling control means. Also, the boiling temperature calculation means can be provided with a mode changeover switch for making the additional boiling amount for tomorrow valid continuously every day after the next day or only for the next day.

Further, the boiling temperature calculation means may have a peak shift function.

[0010]

With this configuration, the boiling temperature calculation means calculates the boiling temperature in the night time zone and the daytime time zone from the set boiling temperature and the additional boiling amount tomorrow. Give priority to the boiling temperature in the night time zone. Therefore, for example, if the total amount of hot water equivalent to the set boiling temperature and tomorrow's additional boiling amount can be boiled in the nighttime zone, the boiling temperature in the nighttime zone is set to the set boiling point. The temperature can be set equal to the sum of the boiling temperature corresponding to the additional boiling amount tomorrow, and the boiling temperature in the daytime zone can be set to zero.In this case, the total amount of hot water is in the nighttime zone. Since it is boiled, no additional boiling operation is performed during the daytime. If the total amount of hot water cannot be boiled during the night time, the boiling temperature calculation means first
The boiling temperature in the nighttime zone is set to the maximum allowable value, and then the boiling temperature in the daytime zone is determined so as to correspond to the amount of hot water corresponding to the shortage of the total amount of hot water.

The additional boiling control means calculates the required energizing time of the heater on the basis of the boiling temperature in the daytime zone thus determined and the additional boiling amount for today, and the heater control means In the night time zone, according to the boiling temperature in the night time zone from the boiling temperature calculation means,
In the daytime, the heater can be energized and the above-described boiling operation can be performed according to the required energization time from the additional boiling control means.

If the heater control means energizes the heater so that the lower temperature of the tank becomes equal to or higher than the predetermined temperature, the lower limit of the water temperature in the tank is guaranteed to be equal to or higher than the predetermined temperature. Even so, it is possible to minimize the situation where cold water is discharged from the tank.

When the boiling temperature calculation means is provided with a mode changeover switch, the mode changeover switch is set to be changed so that the additional boiling amount can be appropriately set as needed, and the additional boiling point is wasted. Can be minimized.

When the boiling temperature calculation means has a peak shift function, the boiling operation in the night time zone can be completed in accordance with the end time of the night time zone, so that the heat loss due to heat dissipation is minimized. It is possible.

[0015]

Embodiments Embodiments will be described below with reference to the drawings.

The boiling control device for an electric water heater mainly comprises a boiling temperature calculation means 11, an additional boiling amount setting device 12, an additional boiling control means 13 and a heater control means 14 (FIG. 1).

A heater H is installed in a tank T of the electric water heater, and the heater H is connected via a switching element SK.
It is connected to the commercial power supply AC. The water supply pipe Tk1 is connected to the bottom of the tank T and the hot water supply pipe Tk2 is connected to the top of the tank T. The water W supplied through the water supply pipe Tk1 is filled in the tank T and heated by the heater H. It becomes hot water and is supplied to the place of use through the hot water supply pipe Tk2. On the side wall of the tank T, a plurality of temperature sensors S1,
.. are provided, and a temperature sensor S2 for detecting the water temperature Tw is provided in the water supply pipe Tk1.

Outputs of the temperature sensors S1, S1, ..., S2 are connected to the boiling temperature calculating means 11 via the temperature detecting means 15. However, the temperature detecting means 15 reads the respective outputs of the temperature sensors S1, S1 ..., S2, the average temperature Tav of the tank T which is the average of the respective outputs of the temperature sensors S1, S1, ..., The water temperature Tw indicated by the temperature sensor S2, The lower temperature Tb of the tank T formed from the output of the lowermost temperature sensor S1
Can be calculated and output. Further, another output of the temperature detection means 15 is connected to the heater control means 14.

A boiling temperature setting device 16 is connected to the boiling temperature calculating means 11. The output of the additional boiling amount setting device 12 is connected to the boiling temperature calculation means 11 and the additional boiling control means 13 together with the mode changeover switch SW. Here, it is assumed that the mode changeover switch SW has three modes of “today”, “every day”, and “next day”.

The output of the boiling temperature calculation means 11 is individually connected to the heater control means 14 and the additional boiling control means 13, and the output of the additional boiling control means 13 is connected to the heater control means 14. ing. The output of the heater control means 14 is connected to the switching element SK, and the output of the timepiece 17 is branched and connected to the boiling temperature calculation means 11, the additional boiling control means 13, and the heater control means 14.

The operation of the boiling temperature calculation means 11 can be represented by the program flow chart of FIG.

When the program is started, first, the set boiling temperature To set in the boiling temperature setting device 16 is read (step (1) in FIG. 2, hereinafter referred to simply as (1)). Then, when the mode switch SW is "next day" or "every day" (2), the set value Va of the additional boiling amount setting device 12 is read as the additional boiling amount Va1 of tomorrow (3). Here, the set boiling temperature To indicates the target temperature when boiling the water W in the tank T in the nighttime period as the average temperature of the tank T, and the additional boiling amount Va1 tomorrow is the daytime. The amount of additional boiling in the time zone is set as the amount of hot water converted to the hot water temperature Tx used. Tomorrow's additional boiling amount Va1 is the mode switch S
When W is "every day", it is treated as valid every day after the next day, and when "next day", it is treated as valid only on the next day. The hot water temperature Tx used is, for example, Tx = 45.
Determined in (℃).

Subsequently, the program calculates the distribution of the boiling temperatures To1 and To2 in the night time zone and the daytime time zone based on the set boiling temperature To and the additional boiling amount Va1 tomorrow (4). ..

Now, the additional boiling amount Va1 tomorrow can be converted into the average temperature rise Ta1 in the tank T by Ta1 = Va1 (Tx-Tw) / Vo. However, the water temperature Tw is read through the temperature detecting means 15, and Vo is the capacity of the tank T.

Subsequently, when Toa = To + Ta1 is calculated, Toa indicates the required total boiling temperature in the night time zone and the daytime time zone on the next day. Therefore, when Toa≤Tmax, To1 = Toa, To2 = 0 When Toa> Tmax, To1 = Tmax, To2 = Toa−T
As the max, the boiling temperature To1 in the nighttime zone and the boiling temperature To2 in the daytime zone can be determined. However, Tmax is the maximum allowable boiling temperature, and is generally about Tmax = 88 (° C.). Boiling temperature To1
Is the required total boiling temperature Toa as long as Toa ≦ Tmax
Since all of the boiling temperatures are preferentially distributed, the boiling temperature calculation means 11 can calculate the distribution of the boiling temperatures To1 and To2 by giving priority to the boiling temperature To1 in the nighttime period.

Subsequently, the program calculates the required energization time t1 in the nighttime zone by the following equation (5).
That is, t1 = (To1−Tw) · Vo / A A = 860 × KW × y where KW is the capacity of the heater H and y is the heating efficiency.

When the required energizing time t1 is calculated (5),
For example, the program calculates the boiling start time (6) so that the end time of the night time zone and the expiration of the required energization time t1 match (6), and waits for the boiling start time to arrive (7). The heater control means 14 is started with the control bit K = 1 (8).

The operation of the additional boiling control means 13 can be represented by the program flow chart of FIG.

When the program is started, for example, at the time when the start time of the daytime zone arrives, or when the additional boiling amount setting device 12 and the mode changeover switch SW are operated, the mode changeover switch SW indicates "today. "(Step (1) in FIG. 3, hereinafter simply referred to as (1))", the set value Va of the additional boiling amount setting device 12 is read as the additional boiling amount Va2 for today ( 2).

Subsequently, the program is the boiling temperature To2 calculated by the boiling temperature calculating means 11 in the daytime.
Reading (3), the required energization time t in the daytime
Calculate 2 (4). That is, t2 = (Va2 (Tx-Tw) + To2.Vo) / A The program then, for example, averages the temperature Tav <Tmax of the tank T and the lower temperature Tb <Tmax of the tank T.
The energizable condition consisting of is checked, and if it is satisfied (5), the heater control means 14 is activated with the control bit K = 0 (6).

The operation of the heater control means 14 is as shown in the program flow chart of FIG.

When the program is started by the boiling temperature calculation means 11 or the additional boiling control means 13, first, the switching element SK is made conductive to start energizing the heater H (step (1) in FIG. 4). , Hereinafter simply referred to as (1)). Subsequently, when the control bit K = 1 (2), the program uses the boiling temperature To1 from the boiling temperature calculation means 11 in the nighttime period and waits for the completion of boiling (3). That is, the program shuts off the switching element SK and terminates energization of the heater H on condition that Tav ≧ To1 (4),
The operation is completed.

When the control bit K = 0 (2), the program energizes the heater H according to the required energization time t2 in the daytime time zone from the additional boiling control means 13. That is, first, when the energization time th of the heater H is th <t2 with respect to the required energization time t2 and the energization time th has not passed the required energization time t2 (5), Tav
As long as <Tmax, the heater H is continuously energized ((6),
(7)), the heater H is shut off when Tav ≧ Tmax ((6), (8)). Further, even if the heater H is once cut off (8), as long as th <t2, if Tav <Tmax, the re-energization control of the heater H is performed ((5) to (7)).

When the energization time th has passed the required energization time t2 and th ≥t2 (5), it is checked that the lower temperature Tb of the tank T is Tb> Tb1 with respect to the predetermined temperature Tb1 ( 9) The heater H is shut off (10). Here, the predetermined temperature Tb1 refers to the lowest temperature that can be used as hot water, and is preferably set to about Tb1 = 55 (° C.), for example.

The control bit K is for the heater control means 1
4 is a boiling temperature calculation means 11 and an additional boiling control means 1
It is for determining which one of the three has activated. That is, K = 1 indicates that the former performs the boiling operation in the nighttime period, and K = 0 indicates
The latter shows that the additional boiling operation is performed during the daytime.

In the above description, steps (5) to (7) in FIG. 2 correspond to the so-called peak shift function. Therefore, when the peak shift function is not provided,
Delete steps (5) and (6), and replace step (7) with
It is only necessary to check the arrival of the start time of the night time zone, and in this case, the boiling operation in the night time zone is always started in conformity with the start time of the night time zone.

In step (9) of FIG. 4, the heater control means 14 causes the lower temperature Tb of the tank T to become equal to or higher than the predetermined temperature Tb1 even though the energization time th of the heater H exceeds the required energization time t2. Up to continuing to energize the heater H. Since the minimum temperature in the tank T is equal to or higher than the predetermined temperature Tb1, even if the amount of hot water is insufficient, the entire amount of the water W in the tank T can be used as hot water. The step (9) may be provided if necessary and can be deleted.

The mode changeover switch SW determined in step (2) of FIG. 2 and step (1) of FIG.
It is designated whether the set value Va of the additional boiling amount setting device 12 is valid only for today, only for the next day, or continuously for the following day and thereafter. Therefore, more accurately, the set value Va of the additional boiling amount setting device 12 may be individually stored in the buffer memory 12a by selecting the mode changeover switch SW (FIG. 5).

Set value V corresponding to "next day" and "every day"
a is sent to the boiling temperature calculation means 11 as the additional boiling amount Va1 of tomorrow, and the set value Va corresponding to “today” is
Additional boiling control means 1 as today's additional boiling amount Va2
Send to 3. However, the setting value Va for the "next day" in the buffer memory 12a is deleted once it is used by the boiling temperature calculation means 11,
The set value Va for "today" is also deleted once it is used by the additional boiling control means 13. Further, for the buffer memory 12a, the additional boiling amount setting device 12
The setting value Va is written and updated each time there is an update setting of the setting value Va with respect to, or whenever the mode changeover switch SW is operated.

The temperature sensor S2 for detecting the water temperature Tw may be omitted and Tw = Tb may be set by utilizing the output of the temperature sensor S1 at the bottom of the tank T.

[0041]

As described above, according to the present invention, the boiling temperature calculating means for calculating the distribution of the boiling temperature in the night time zone and the daytime time zone by giving priority to the boiling temperature in the night time zone. By combining the additional boiling control means and the heater control means, the additional boiling operation in the daytime time zone is performed in the nighttime time zone regardless of each set value of the set boiling temperature and the additional boiling amount. Since the amount of hot water equivalent to the shortfall in which the maximum amount of boiling water is preferentially distributed can be automatically distributed, the most economical boiling operation as a whole can be realized, and the power load is leveled. It also has an excellent effect that it can positively contribute.

[Brief description of drawings]

[Figure 1] Overall block system diagram

FIG. 2 Program flow chart (1)

[Figure 3] Program flow chart (2)

FIG. 4 Program flow chart (3)

FIG. 5 is a detailed view of an essential part of FIG.

[Explanation of symbols]

 T ... Tank H ... Heater SW ... Mode change switch Tav ... Average temperature Tb ... Lower temperature To ... Set boiling temperature Va1, Va2 ... Additional boiling amount To1, To2 ... Boiling temperature t1, t2 ... Required energizing time 11 ... Boiling Raised temperature calculation means 13 ... Additional boiling control means 14 ... Heater control means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hironori Naruse 48 Higashiaraya Nu, Tsubata Town, Kawakita-gun, Ishikawa Prefecture

Claims (4)

[Claims] 1. A boiling temperature for calculating the distribution of the boiling temperature between the night time zone and the daytime time zone from the set boiling temperature and the additional boiling amount tomorrow, giving priority to the boiling temperature in the nighttime zone. Based on the calculation means, the boiling temperature in the daytime zone from the boiling temperature calculation means, and the additional boiling amount for today, the additional boiling control means for calculating the required energizing time of the heater, and the nighttime zone. Is the average temperature of the tank
A heater control means for energizing the heater until it reaches the boiling temperature in the night time zone from the boiling temperature computing means, and energizing the heater for the required energization time from the additional boiling control means in the daytime zone. A boiling control device for the electric water heater provided. 2. The heater control means energizes the heater during the daytime until the lower temperature of the tank reaches a predetermined temperature or higher, regardless of the required energization time from the additional boiling control means. The boiling control device for an electric water heater according to claim 1. 3. The boiling temperature calculation means continuously validates the additional boiling amount for tomorrow every day after the next day, or
The boiling control device for an electric water heater according to claim 1 or 2, further comprising a mode changeover switch for making the switch effective only on the next day. 4. The boiling control device for an electric water heater according to claim 1, wherein the boiling temperature calculation means has a peak shift function.