JPH02197757A - Electric power supply control device for electric water heater - Google Patents

Abstract

PURPOSE:To simplify the contents of work required during installation time dramatically and hence reduce the whole cost by selecting the application of peak shift time control based on the presence of power failure and moreover by dividing midnight power for the supply of control power source. CONSTITUTION:A control power source is supplied from midnight power PW. At the same time it is provided with a peak shift time decision making means 11, a timer means 12, an output means 13, and a power failure detection means 14. The shift time decision making means 11 decides peak shift time based on the application of temperature in a hot water storage tank WT in the beginning of midnight power charging. The timer means 12 detects the heat shift time lapsed. The output means 13 charges electricity to a heater by the output of the timer means 12. On the other hand, this device is designed to select the application of peak shift time control based on the presence of midnight power in power supply time zone. The power failure detection means 14 is provided with a charging and discharging circuit 14a, which has discharging time longer than power supply time zone at midnight.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an energization control device for an electric water heater that utilizes late-night power, and particularly for an energization control type electric water heater that performs so-called peak shift time control.

Conventional energization control type electric water heaters operate during predetermined energization hours such as late-night electricity (hereinafter simply referred to as the energization period of late-night electricity), rather than starting from the start of energization during that energization period. A predetermined appropriate delay time (hereinafter referred to as
By energizing the heater after a delay of the peak shift time, reducing the peak load on the power transmission line, and by aligning the boiling completion time with the end of the power-on period, It is possible to reduce heat radiation loss until the hot water is consumed.

In energization control type electric water heaters, the peak shift time is generally calculated by performing complex calorific value calculations, and the results are used to control the energization of the heater.
The control device usually incorporates a microcomputer. Therefore, in conventional control devices, in addition to power wiring for late-night power to energize the heater, there is also wiring for control power to energize the microcomputer throughout the day.
Wiring for commercial electricity b”rt, which is constantly supplied, was essential.

In addition, if power wiring for the control power source is omitted and this is supplied from late-night power, late-night power will only be supplied during the predetermined energized hours of the day, and there will be no power at other times. In order to
Publication No. 52).

The reason why control power must always be maintained is that the temperature information of the hot water storage tank is constantly read by a microcomputer, and the results are used to calculate the peak shift time. It's for a reason.

The problem to be solved by the invention is that among these conventional techniques, when the former is used, the construction work at the time of installation is complicated because it is necessary to wire the commercial power supply in addition to the power wiring for the late-night power supply. ,
There was a problem in that electrical work costs tended to be excessive. In addition, if the latter is adopted, a backup battery and a switching circuit for switching the control power source between the battery and late-night power must be added, making the overall configuration complicated and requiring high-level operation for a long time. There has been a problem in that batteries that can maintain reliability are extremely expensive.

Therefore, in view of the problems of the prior art, the purpose of the present invention is to calculate the peak shift time using the temperature in the hot water storage tank at the time when the late-night power supply starts, and to calculate the peak shift time based on the presence or absence of a late-night power outage. By selecting the application of peak shift time control, the control power is supplied from late-night electricity, and the electric water heater's energization control device eliminates the need for backup batteries and commercial power wiring. It is about providing.

Means for Solving the Problems In order to achieve the object, the present invention has a configuration in which the control power source is supplied from late-night electric power, and also includes a peak shift time determining means, a timer means, an output means, and a power outage detecting means. The peak shift time determining means determines the peak shift time using the temperature in the hot water storage tank at the time when the late-night power supply starts, the timer means detects the elapse of the peak shift time, and the output means detects the elapse of the peak shift time. The gist is that while the heater is energized by the output of the means, application of peak shift time control is selected depending on whether there is a late-night power outage during the energization time period.

Note that the power outage detection means may include a charging/discharging circuit having a discharge time longer than the late-night power supply time period.

Therefore, when using this configuration, the peak shift time is
Since the temperature in the hot water tank is calculated using the temperature in the hot water storage tank at the time when late-night electricity starts being turned on, a control power source is not required at times other than the hours when late-night electricity is turned on. There is no problem in supplying it. Furthermore, it has been found that the peak shift time calculated in this way does not cause any practical problems in terms of accuracy compared to when temperature information measured throughout the day is used. There is.

On the other hand, a power outage detection means is installed, and if there is a power outage in the middle of the night during the power supply time period, the calculated peak shift time will be ignored and the heater will start energizing immediately when the power outage is restored. By treating the calculation result of the peak shift time as valid only when the predetermined late-night power supply starts, the chances of the vortex in the hot water storage tank inadvertently causing insufficient boiling can be minimized.

Further, as the power failure detection means, a charging/discharging circuit using an inexpensive capacitor can be used, and in this case, no special switching circuit is required.

It works as described above.

Example Examples will be described below with reference to the drawings.

The energization control device of the electric water heater includes a control device main body 10 supplied with control power CL from the late-night power PW, and a hot water storage tank W.
It is made up of a combination of a temperature sensor 'T' I-I arranged at T and a heater HE (Fig. 1).

The control device main body 10 includes a peak shift time determining means 11, a timer means 12, an output means 13, and a power failure detection means 1.
It consists of 4.

The output of the temperature sensor TH is determined by the peak shift time determining means 1.
1, and its output is transmitted via timer means 12 to
It is input to the output means 13.

Further, the output of the hot water temperature setting means 22 is also input to the peak shift time determining means 11 . However, the water temperature setting means 22 is located outside the control device body 1o and consists of a digital switch or the like that manually sets a predetermined set water temperature, and the set water temperature can be mechanically adjusted regardless of the presence or absence of a power supply. shall be able to be maintained.

Late-night power PW is obtained from the power line AC via a time switch TS that determines a predetermined energization time period, and the late-night power PW is connected to the heater HE via an output means 13. The late-night power PW is also branched into the control power supply circuit 21, and its output is controlled by the control power supply circuit 21. IJCI is introduced into the control device main body 10. Further, another output from the control power supply circuit 21 is input to the power failure detection means 14, and this output is input to the timer means 12.

The power failure detection means 14 includes, as a part thereof, a charging/discharging circuit 14a including a capacitor C and a resistor R (FIG. 2). That is, one end of the parallel circuit of capacitor C and resistor R is connected to control power supply C through diode D and resistor R1.
The voltage at the connection point between resistor R1 and capacitor C is set as check point voltage Vcp,
It is read into the control device main body 10.

At the start of the predetermined energization time period of the late-night power PW,
When the time switch TS is activated, the late-night power PW is supplied to the control device main body 10, and at the same time, the iJA CL for control is supplied via the control power supply circuit 21. Therefore, inside the control device main body 10, the The program starts.

The program first resets the entire control device main body 10 including the microcomputer (step (1) in FIG. 3, hereinafter simply referred to as (1)), and then:
Starting the timer forming the timer means 12 (2)
.

Subsequently, the program reads the set hot water temperature set in the hot water temperature setting means 22 (3), and then the temperature sensor TI
-Read the temperature in the hot water storage tank WT output from I (4). However, here, the temperature sensor TH obtains all the temperature information necessary for calculating the peak shift time by arranging a plurality of temperature sensors 2J vertically on the wall of the hot water storage tank WT and reading the output thereof. For example, it is assumed that the temperature of water supplied to the hot water storage tank WT, the amount of hot water remaining in the hot water storage tank WT and its temperature, etc. can be detected.

Next, the program calculates and determines the peak shift time using the temperature information from the temperature sensor TH (5)
. The peak shift time is, for example, at the end of the energization period of the late-night power PW, the time point at which the heater HE starts to be energized so that the hot water temperature in the hot water storage tank WT reaches the set water temperature, and from this point in time, the time point at which the energization starts is determined. The delay time until the peak shift time can be calculated using a well-known method as the peak shift time.

Next, the program reads the check point voltage Vcp of the charging/discharging circuit 1.4a, and determines whether the starting force of the current program is the predetermined energizing time period 'F' of the late-night power PW.
(time to in Figures 4 (A) and (B)) or at the time when the power outage is restored after power outage time 1'a within the power-on time period T (time to in Figure 4 (B)). toa) is determined (6). However, the capacitor C and the resistor R of the charge/discharge circuit 14a have a discharge time Td until the check point voltage Vcp becomes lower than the check level LV.
The constant is selected so that Td≧T. That is, in general, since 'I''a<'I''≦Td, the read check point voltage Vcp is Vcp.
When cp>L V, it is assumed that the startup is after a power outage, and the peak shift time determined in step (5) is ignored and the heater HE is started to be energized immediately.8), V
When cp≦LV, the timer started in step (2) waits for the peak shift time to elapse (7),
The heater HE is energized (8). In other words, the program can select the application of peak shift time control depending on the presence or absence of a power outage during the energizing time period 1'' of late-night power 1)W.

Thereafter, the program confirms that the hot water in the hot water storage tank WT has been boiled to the set water temperature (9), and then stops energizing the heater HE (10).

Here, if we compare FIG. 1 and FIG. 3, the peak shift time determining means 11 in the former corresponds to steps (3) to 5) in the latter, and the timer means 12 corresponds to step (3) to (5) in the latter.
2) and (7), the output means 13 performs steps (8) and (1).
It is clear that the power outage detection means 14 corresponds to step (6). However, the power failure detection means 14 also includes the charging/discharging circuit 14a shown in FIG. 2 as a part thereof.

Note that the microcomputer in the control device main body 10 is
Every time the late-night power PW starts energizing, it can be reset in its entirety (step (1) in Figure 3), so even if there is a temporary malfunction, the , its control functions are not affected.

Other Embodiments The order of steps (5) to 7) in FIG. 3 may be partially changed (FIG. 5). In other words, late night power PW
During normal startup at the beginning of the power-on period,
Calculate the peak shift time (step (6) in the same figure)
, (5)), When starting up after a power outage, the calculation of the peak shift time itself may be omitted and this may be forcibly set to zero (steps (6) and (5a) in the same figure). ).

Power outage detection means] 4 may change the charging/discharging circuit 14a and may partially change the program contents (Fig. 6,
Figure 7). That is, the capacitor C is connected to the control device main body 1
Charging is carried out via the transistor Q which is controlled to open and close by the charging start command S1 from 0, while the check point voltage Vcp is read into the control device main body 10 via the photocoupler PC consisting of the light emitting diode PCI and the phototransistor PC2. Make it. However, resistance R2, R
3 is a resistor for determining the base voltage of the transistor Q, and a resistor R4 is a high resistor for limiting current during reading.

The program at this time, after calculating the peak shift time (step (5) in FIG. 7), first reads the check point voltage Vcp (step (5b) in the same figure),
Next, transistor Q is made conductive, and capacitor C
(step (5c) in the figure).

Since the check point voltage Vcp can be read before charging of the capacitor C is started after the power is restored, the accuracy of reading the check point voltage Vcp can be greatly improved.

As described in detail, according to the present invention, the application of peak shift time control is selected depending on the presence or absence of a late-night power outage within the power supply time period, and furthermore, the application of peak shift time control is selected from the late-night power outage. By branching and supplying power, there is no need to constantly energize the control device itself, so there is no need for commercial power wiring or backup batteries, which greatly simplifies the installation work as a whole. This has the excellent effect of being able to keep the overall cost low.

[Brief explanation of the drawing]

Figures 1 to 4 show examples, with Figure 1 being an overall system diagram, Figure 2 being a detailed view of the main parts of Figure 1, Figure 3 being a program flowchart, and Figures 4 (A) and (B). ) is an operation diagram of the charging/discharging circuit. FIG. 5 is a main part flowchart showing another embodiment. 6 and 7 show another embodiment, with FIG. 6 being a diagram corresponding to FIG. 2, and FIG. 7 being a diagram corresponding to FIG. 5. PW...Late night power WT...Hot water storage tank HE...Heater T...Electricity time period Td...Discharge time 11...Peak shift time determining means

Claims (1)

[Scope of Claims] 1) Peak shift time determining means for determining the peak shift time using the temperature in the hot water storage tank at the start of electricity supply at night, and timer means for detecting the elapse of the peak shift time; It is equipped with an output means that energizes the heater according to the output of the timer means, and a power outage detection means that detects the presence or absence of a power outage during the energized hours of the late-night electric power, and supplies control power from the late-night electric power, and also prevents the late-night electric power during the energized hours. An energization control device for an electric water heater that selects the application of peak shift time control depending on the presence or absence of a power outage. 2) The power supply control device for an electric water heater according to claim 1, wherein the power failure detection means includes a charging/discharging circuit having a discharge time longer than a late-night power supply time period.