JPS59183242A - Control device for hot water storage type electrical water heater - Google Patents

Abstract

PURPOSE:To reduce the quantity of remaining hot water and to minimize the maintenance cost by a method wherein the required power supply time calculated with respect to a predetermined quantity of hot water to be used is made to be consumed at the time of termination of the midnight power supply time. CONSTITUTION:The control device is provided with a normal hot water quantity setting means 7 for determining the quantity of hot water to be stored in a hot water storage tank 1, a provisional hot water quantity setting means 8, a temperature detecting means 6 for detecting the temperature of feed water and the heating temperature for the feed water, a power supply time operating means 10 for calculating the time required for supplying power to a heat generating body on the basis of the required calorific value of the hot water calculated by a calorific value operating means 9 from the set hot water quantity and the detected temperatures, a power supply start control means 11 for starting the supply of power to the heat generating body 2 on the midway of a midnight power supply time zone so that the required power supply time elapses at the time of termination of the midnight power supply time and a power supply cut control means 13 after cutting the power supply to the heat generating body when the heating temperature obtained by a heating temperature operating means 12 on the basis of the required calorific value of hot water is reached, whereby when the user predetermines the quantity of hot water to be used, it is possible to supply power to the water heater, during the latter half of the midnight power supply time zone to thereby reduce the maintenance cost.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a hot water storage type electric water heater that uses electricity late at night, and calculates the energization time to be applied to a heating element from the water supply temperature and the preset amount of hot water used, and The purpose is to reduce the amount of remaining water and heat loss after boiling by starting energization to the heating element in the middle of the late-night power supply time so that the power supply time can be obtained at the same time as the end of the power supply time. It is said that

FIG. 1 is a block diagram of a general hot water storage type electric water heater, and FIG. 2 shows the main electric circuit of a conventional hot water storage type electric water heater.

In the figure, 1 is a hot water storage tank, 2 is a heating element, 3 is an automatic temperature control booklet, 4 is a power supply, and 5 is a time switch for late-night power, which is generally turned on from 11:00 p.m. to 7:00 the next morning. It is 8 hours.

Next, the operation of the above conventional example will be explained. When the midnight power supply start time comes, the contact of the time switch 5 is closed and the supply of electricity to the heating element 2 is started.

When the water temperature in the hot water storage tank 1 reaches 85°C, the contact point of the automatic temperature control @S opens and generates a heating element. It's different.

Especially on days when you don't take a bath, you can end up with more than half of the hot water remaining. Additionally, depending on the season, the temperature of the water supply has a great effect on the amount of hot water that can be drawn at the appropriate temperature, and in the summer when the temperature of the water supply is high, a larger amount of hot water can be drawn at the appropriate temperature than in the winter.

On the other hand, the amount of hot water used is generally constant throughout the year, or in fact actually decreases in the summer because hot water is used at a lower temperature, and the amount of hot water remaining in the summer is larger than in the winter. .

Therefore, if the water supply temperature is high or there is residual hot water, the water will boil quickly and the hot water will be left unused for a long time.

Leaving hot water at an unnecessarily high temperature unused for a long time like this has the disadvantage of increasing heat loss due to natural heat radiation from the hot water storage tank 1 and heat radiation from hot water stagnant in the pipes. The present invention attempts to solve these drawbacks by setting the constant amount of hot water used and the provisional amount of hot water used in advance, and using the water supply temperature as a reference for the preset amount of hot water used the next day. In addition to calculating the required energization time to the heating element, energization to the heating element is started in the middle of the midnight power energization time so that the required energization time can be completed by the end time of the midnight power energization. This aims to reduce the amount of remaining hot water and eliminate as much heat loss as possible after boiling.

An embodiment of the present invention will be described below with reference to the overall configuration diagram in Fig. 3 and Fig. 4B.
This will be explained based on the control flowchart.

In FIG. 3, reference numeral 4.6 denotes a temperature sensor such as a thermistor for continuously detecting the temperature inside the hot water storage tank, and is provided at the bottom of the hot water storage tank 1.

Reference numeral 7 denotes a constant hot water amount setting means for presetting the amount of hot water to be used on the next day stored in the hot water storage tank 1, and 8 is a provisional hot water amount setting means for presetting the amount of hot water to be used only once. This is set using the hot water amount setting means 7, but for example, if you do not take a bath the next day or do not use hot water at all,
The usage amount is set by the provisional hot water amount setting means 8,
Two days later, it automatically returns to the value set by the steady hot water amount setting means 7.

Reference numeral 9 denotes a heat amount calculation means for calculating the amount of heat to be stored as hot water in the hot water storage tank 1 from the temperature detected by the temperature sensor 6 and the setting value set by the steady hot water amount setting means 7 or the provisional hot water amount setting means 8. be.

10 is an energization time calculation means for calculating the required energization time to the heating element 2 from the thermal calories calculated by the heat amount calculation means 9, and 11 is calculated by the energization time calculation means 10 at the end time of energization of the late night electricity. This is an energization start control means for starting energization of the heating element 2 in the middle of the late-night power energization time period so that a predetermined energization time can be obtained.

On the other hand, 12 is the thermal power calculated by the heat calculation means 9.
13 is a boiling water temperature calculation means for calculating the desired water temperature, and 13 is a heating element that is activated when the water temperature in the hot water storage tank reaches the temperature calculated by the boiling W!Js calculation means 12. This is an energization stop control means for stopping energization to 2.

Next, a concrete example of the operation of the above structure will be explained using formulas and a control chart shown in FIG.

At 23:00, the time switch turns OJ and power is supplied to the electric water heater (step 20).

Control is started upon receiving this power ON signal (step 21).

First, in step 22, it is determined whether the user has set the provisional hot water amount setting means 8 or not. If it has been set, the set value to the provisional hot water amount setting means 8 is confirmed in step 23. If the setting has not been made, the set value of the steady hot water amount setting means 7 is confirmed in step 24.

The set value of the steady hot water amount setting means 7 or temporary hot water amount setting means 8 confirmed in this way is set to v liters (water temperature 1°C).
shall be.

On the other hand, in step 25, the temperature sensor 6 provided at the bottom of the hot water tank 1 detects the temperature of the lower part of the hot water tank 1, that is, the temperature of the water supply.

23:00 is the time when most of the daily amount of hot water has been used, and the lower part of the hot water storage tank 1 contains water supplied from the water source, so it is possible to measure the water temperature at this point. . The feed water temperature detected by this temperature sensor 6 is now assumed to be t°C.

Next, in step 26, the calorific value calculation means 9 calculates the calorific value K (in cal) that should be stored as hot water by the end of the midnight power supply time.

The formula can be expressed as below.

K= (T 10t) x V (Kcal) Step 2
7, the energization time calculation means 10 calculates 60XW based on the heat amount K (Keal) calculated by the heat amount calculation means 9, and calculates the heating element necessary to obtain the amount of heat to be stored in the hot water storage tank 1. Required energization time H (hr) to 2
(IKWH=860Kcal)
. Here, W represents the rated power consumption (KW) of the heating element 2.

In step 28, it is determined whether the required energization time H (hr) calculated by the energization time calculation means 10 (step 27) can be obtained at the end of the midnight power supply time, and after the time switch is turned on. (8-H) When the time has elapsed, the process proceeds to step 29, and the energization start control means 11 starts energizing the heating element 2.

On the other hand, in step 30, the boiling water temperature calculation means 12 performs calculations based on the heat amount K calculated by the heat amount calculation means 9 (step 26), and calculates the water temperature To (℃
) is calculated.

Here, Vt represents the volume (liter) inside the hot water storage tank 1.

It is determined in step 31 whether the detected value of the temperature sensor 6 has reached 10°C, and when the water temperature reaches 10°C, the process proceeds to step 32, where the energization stop control means 13 stops energizing the heating element 2. Stop. A temperature sensor for detecting the hot water temperature may be provided separately from the temperature sensor 6 provided at the lower part of the hot water storage tank.

In this kind of control, if there is no remaining hot water from the previous day, the time when the boiling @ temperature To℃ obtained by the S boiling hot water temperature calculation means 12 is reached and the time when the late-night power supply ends, that is, the OFF time of the time switch 5 are determined. They will match.

However, under actual usage conditions, some residual hot water will occur every day (
(If there is no remaining hot water, it means that the hot water ran out the previous day.) Therefore, the time when the predetermined boiling water 111To°C is reached and the heating element 2 is turned off is earlier by the amount of heat of the remaining water.

Therefore, after the heating element 2 shown in step 33 is turned off, the time switch is turned off, and the series of controls ends (
Step, Pu 84).

As described above, the present invention includes a constant hot water amount setting means for presetting the constant amount of hot water used to be stored in a hot water storage tank, an interim hot water amount setting means for presetting a one-time use amount, and a hot water storage tank. Thermal calories of the hot water to be stored are calculated from the temperature detection means for detecting the water supply temperature and the boiling temperature, the set value set by the hot water amount setting means, and the detected value detected by the temperature detection means. A heat amount calculation means, an energization time calculation means that calculates the required energization time to the heating element from the heat calories calculated by the calorie calculation means, and a required energization time calculated by the energization time calculation means, the end time of the energization time for late-night electricity. energization start control means for starting the energization of the heating element in the middle of the late-night power energization time period so as to obtain the same result; It is equipped with a calculation means and an energization stop control means for stopping energization to the heating element when the boiling water temperature determined by the boiling water temperature calculation is reached, and the amount of hot water to be used and the amount of hot water set in advance by the user are provided. The temperature of the water supplied to the hot water storage tank is detected to calculate the required heat calories, and from this the required time to energize the heating element is calculated so that the energization is carried out during the latter half of the late-night electricity energization period. Since the system is configured so that the amount of hot water used can be selected and set as appropriate between regular and temporary amounts, the amount of remaining hot water is reduced, and heat radiation loss after boiling is reduced, reducing maintenance costs. It has the effect of becoming

In addition, since the device according to the present invention is mainly energized during the latter half of the late-night power supply period, if it is used in combination with conventional late-night power usage equipment whose load is concentrated in the first half, the power load during the first half of the power supply period will be reduced. It also has the effect of easing the peak and improving power transmission efficiency.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a general hot water storage type electric water heater, Figure 2 is a main electrical circuit diagram of a conventional hot water storage type electric water heater, and Figure 3 is a diagram of the main electrical circuit diagram of a conventional hot water storage type electric water heater.
The figure shows the overall configuration according to the present invention, and FIG. 4 also shows a control flowchart. 1 is a hot water storage tank, 2 is a heating element, 6 is a temperature sensor (m degree detection means), 7 is a steady hot water amount setting means, 8 is a provisional hot water amount setting means, 9 is a heat amount calculation means, 10 is an energization time calculation means, 1
1 is energization start control means; 12 is boiling water temperature calculation means;
13 is an energization stop control means. Agent Shin Kuzuno - (1 other person) Figure 1 Figure 4

Claims (1)

[Claims] A constant hot water amount setting means for presetting the regular amount of hot water stored in the hot water storage tank, a provisional hot water amount setting means for presetting the amount of hot water for one-time use, and a temperature setting and boiling point for the water supplied to the hot water storage tank. a temperature detection means for detecting temperature; a heat amount for calculating the thermal calories of the stored hot water amount from the set value set by the steady hot water amount setting means or temporary hot water amount setting means and the water supply temperature detected by the temperature detection means; a calculation means, an energization time calculation means that calculates the required energization time to the heating element from the thermal calories calculated by the heat amount calculation means, and a required energization time calculated by the energization time calculation means, which is obtained at the end time of the energization time of the late-night power. energization start control means for starting energization of the heating element in the middle of the late-night power supply time period so that the electricity is supplied to the heating element in the middle of the late-night power supply time period; A control device for a hot water storage type electric water dryer, comprising an energization stop control means for stopping energization to a heating element when the wJ temperature in the tank reaches the boiling temperature calculated by the boiling water temperature calculation means.