JPS60235946A - Electric water heater - Google Patents

Abstract

PURPOSE:To reduce the energy loss due to wasteful heating by a method wherein the required heating-up temperature is calculated and controlled based upon the set hot water quantity, the feed water temperature and the energizing hours to a midnight power heater for a certain period of time in order to realize the heating-up of water fit for actual states for use. CONSTITUTION:The temperature of the water in a hot water storage tank 1 is detected by a temperature detection means 3. At the same time, the temperature of water fed to the hot water storage tank is detected by a water temperature detection means 5. In addition, the amount of hot water to use in the hot water storage tank is set in advance by a hot water amount setting means 6. Further, an energizing detection means 7 detects the energizing hours to a midnight power heater 2. At the same time, a memorizing means 8 memorizes the signals sent from the means 7 for a certain period of time. Furthermore, an arithmetic means 9 calculates the heating-up temperature based upon the signals from the means 6, 5 and 8. At the same time, an energizing controlling means 10 controls the energizing to the heater 2 by the signals from the means 9 and 3. Consequently, the heating-up fit for actual states for use is realized, resulting in reducing the energy loss due to wasteful heating.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to heater energization control of a hot water storage type electric water heater using late-night electricity.

Structure of the conventional example and its problems As shown in FIG.
and a heat amount calculation means 5 that calculates the amount of heat to be added from the set value set by the hot water amount setting means 4 that presets the amount of hot water to be used.
, a set temperature calculation means 6 for calculating the required boiling temperature from the detected value detected by the water supply temperature detection means 3' and the amount of heat calculated by the amount of heat calculation means 5, and a temperature detection means 7' for detecting the temperature of the hot water storage tank. , and an energization control means 9 that controls energization to the late-night power heater 8 based on the difference between the signal from the temperature detection means 7 and the temperature calculated by the set temperature calculation means 6.

In this configuration, the set value set by the hot water amount setting means 4 is
It is rarely changed every day, and is set to the maximum so as not to run out of hot water, so heat loss due to residual hot water is not reduced. In order to prevent this, the customer must make settings while checking the status of remaining hot water every day, which is as inconvenient as manual setting.

OBJECTS OF THE INVENTION The present invention solves these conventional problems, and aims to determine an appropriate boiling temperature and reduce energy loss.

Structure of the Invention In order to achieve this object, the present invention provides a late-night power heater installed in a hot water storage tank, a temperature detection means for detecting the temperature of the hot water storage tank, and a water temperature detection means for detecting the temperature of water supplied to the hot water storage tank. a hot water amount setting means for presetting the amount of hot water to be used in the hot water storage tank; an energization detection means for detecting the time period during which electricity is applied to the late-night heater; a storage means for storing a signal from the energization detection means for a certain period of time; a calculation means for calculating a required boiling temperature based on signals from the setting means, the storage means, and the water temperature detection means; and an energization control means for controlling energization to the heater for late-night electricity based on the signals from the calculation means and the temperature detection means. It has been established that

With this configuration, the required boiling temperature is calculated by the calculation means from the amount of hot water used set by the hot water amount setting means, the signal from the energization detection means for a certain period stored in the storage means, and the water temperature from the water temperature detection means, and the required boiling temperature is calculated in the middle of the night. The power heater works to control the temperature of the hot water storage tank to the required boiling temperature, eliminating unnecessary boiling and reducing energy loss.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

A late-night power heater 2 installed inside the hot water tank 1, a temperature detection means 3 installed above the late-night power heater 2 to detect the temperature of the hot water tank, and a water temperature of the water supply pipe 4 connected to the lower part of the hot water tank 1. a water temperature detection means 5 for detecting water temperature, a hot water amount setting means 6 for presetting the amount of hot water used in the hot water storage tank 1, an energization detection means 7 for detecting the energization time to the late-night power heater 2, and a energization detection means for detecting energization for a certain period of time. a storage means 8 for storing the signal from the means 7; a calculation means 9 for calculating the required boiling temperature based on the amount of hot water set by the amount of water setting means 6, the signal from the water temperature detection means 5, and the signal from the storage means 8; Calculating means 9 and temperature detecting means 3
energization control means 10 for controlling the energization of the heater 2 for late-night power use based on a signal from the storage means 8; It is equipped with a selection section 11 for making a selection, and a calculation section 12 for calculating a required boiling temperature based on a signal from the selection section 11, a set value of the hot water amount setting means 6, and a signal from the water temperature detection means 4. In addition, 13 is a hot water supply pipe, and 14 is a timer for late-night power.

In the above configuration, hot water in the hot water storage tank 1 is supplied to the energization control means 1 at a time limited by the late-night power timer 14.
Based on the difference between the signal from the temperature detection means 3 and the required boiling temperature signal calculated by the calculation means 9, the late-night power heater 2 is energized and heated, and hot water is discharged from the hot water pipe 13 as necessary. At the same time, water is supplied from the water supply pipe 4 to the hot water tank 1. This required boiling temperature is set as shown below.

The energization detection means 7 detects the energization time of the late-night power heater 2 every day, and the energization time for a certain period (for example, -weekly hand) up to the previous day is stored in the storage means 8, and the selection section 11 stores The maximum value is selected from among the certain period of energization time obtained by the means 8, and the required boiling temperature is calculated by the calculation section 12 based on the maximum value as shown in the formula. Vs shown here is the actual usage amount of the hot water storage tank 1 set by the hot water amount setting means 6, that is, (capacity of the hot water storage tank 1) -Vs is the remaining hot water amount. Therefore, if Vs is set to a small value, hot water can be used with sufficient margin, and Vs
Increasing the value will result in economical hot water supply.

ηX q The control operation will be explained using the flowchart shown in FIG.

In the figure, control starts at the same time as the late-night power timer 14 starts supplying late-night power at 1S.
At 6, the water temperature Tw detected by the water temperature detection means 5 is taken in, and at 17, the set value Vs of the hot water amount setting means 6 is read. At step 18, the energizing time H for several days stored in the storage means 8 is read from 19 and the maximum value of the energizing time H Hm a x
is selected, and the required boiling temperature Ts is calculated at 20 based on this Hmax. At 21, the hot water temperature Th detected by the temperature detection means 3 is taken in, and at 22, the water temperature Th detected by the temperature detection means 3 is taken in.
Compare s and Th, and if Th does not reach Ts, power is applied to the late-night power heater 2 at 23, and if Th reaches Ts, power is turned on at 23.
Turn off the power at step 4. 25 detects the energization time H when the late-night power heater 2 is energized, and sends the detection result to the storage means 8.

The heater on/off control from 22 to 2S from the intake of the hot water temperature Th in step 21 is repeated until the midnight power timer 14 stops the power supply in the middle of the night.

As described above, since the required boiling temperature is determined based on the amount of hot water set by the user using the hot water amount setting means and the maximum value selected from the energization time for a certain period of time, the temperature varies depending on the season. Appropriate boiling is possible for hot water supply loads that fluctuate due to changes in water supply temperature, etc., and differences in site usage conditions, reducing residual hot water and reducing energy loss.

Effects of the Invention As described above, the electric water heater of the present invention provides the following effects.

(1) The required boiling temperature is calculated and controlled from the set amount of hot water, the water supply temperature, and the energization time for the late-night power heater for a certain period of time, so the boiling temperature matches the actual usage conditions, resulting in energy loss due to unnecessary heating. This has the effect of reducing

(2) The amount of heat to be added is determined from the energization time for a certain period of time.
Since the water temperature is known, there is no uncertainty as determined by daily control means, and the optimum water temperature can be automatically set, which is convenient.

(3) Since the amount of hot water used in the hot water tank can be set arbitrarily, users can freely choose between hot water supply with plenty of water or economical hot water supply, which is highly convenient.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional electric water heater, FIG. 2 is a block diagram of an electric water heater according to an embodiment of the present invention, and FIG. 3 is a control flowchart of the electric water heater. 1...Hot water storage tank, 2...Heater for late-night electricity, 3...Temperature detection means, 5-...Water temperature detection means, 6...Hot water amount setting means, 7... ... Energization detection means, 8 ... Memory means, 9 ... Calculation means, 1o.
...Electrification control means.

Claims (2)

[Claims] (1) A heater for late-night electricity installed in a hot water storage tank, a temperature detection means for detecting the temperature of the hot water storage tank, a water temperature detection means for detecting the temperature of water supplied to the hot water storage tank, and a predetermined amount of hot water to be used in the hot water storage tank. a hot water amount setting means to be set; an energization detection means for detecting the time period during which the late-night power heater is energized; a storage means for storing a signal from the energization detection means for a certain period; the hot water amount setting means and the water temperature detection means. and a calculation means for calculating the boiling temperature based on signals from the calculation means and the temperature detection means, and energization control means for controlling energization to the late-night power heater based on signals from the calculation means and the temperature detection means. Water heater. (2) The calculation means includes a selection section that selects the maximum value from the energization time of a certain period obtained by the signal from the storage means, and a signal output from the selection section, the hot water amount setting means, and the water temperature detection means. 2. The electric water heater according to claim 1, further comprising a calculation section that calculates the boiling temperature based on the following.