JP3947967B2 - Electric water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric water heater provided with heating means for heating water supplied to a hot water storage tank.
[0002]
[Prior art]
This type of conventional electric water heater is a hot water storage tank that uses hot cheap electricity late at night to meet the electricity tariff system set by the power company for the purpose of leveling power demand. There is something to store. The amount of hot water used for this day varies depending on the season and lifestyle. Here, if the boiling water temperature of the hot water storage tank is constant throughout the year, the water supply temperature will be higher in summer and the amount of hot water used will tend to decrease, so there will be a lot of hot water stored in the hot water storage tank. There was a thing. As a countermeasure for this, there is one that can change the boiling temperature manually or automatically, such as lowering the boiling water temperature of the hot water storage tank in summer. For example, Japanese Patent Laid-Open No. 5-280806 proposes a method of automatically setting the boiling water temperature according to the amount of remaining hot water in a hot water storage tank measured by a plurality of remaining hot water sensors and the number of reheatings in the daytime period. .
[0003]
[Problems to be solved by the invention]
However, when manually setting the boiling water temperature, the user sets a low water temperature so that there is not much water in the summer, and a high water temperature so that it does not run out in the winter. In addition, it takes time and effort, and there is no effect if settings are forgotten or incorrect. Further, when the boiling water temperature is automatically set according to the amount of hot water in the hot water storage tank measured by a plurality of remaining hot water sensors and the number of reheatings during the daytime, there is a problem in the accuracy of the setting. In other words, the amount of hot water used by the hot water sensor is not accurate, such as the amount of hot water used cannot be accurately detected when the mixed layer of hot water and water in the hot water storage tank becomes large. And the amount of heating heat do not necessarily match, and are not set according to the amount of hot water used.
[0004]
The present invention has been made in order to solve the above-mentioned problems, and the object of the present invention is to cause hot water to run out without bothering the user, and to use wasted power due to excessive hot water. An object is to provide an electric water heater that can reliably prevent consumption.
[0005]
[Means for solving the problems and their functions and effects]
In order to achieve the above object, claim 1 includes a hot water storage tank, heating means for heating water in the hot water storage tank, supply water temperature detection means for detecting a supply water temperature to the hot water storage tank, and in the hot water storage tank. Electricity provided with hot water temperature detecting means for detecting the boiling hot water temperature, heating time measuring means for measuring the heating time by the heating means, and hot water temperature adjusting means for adjusting the boiling water temperature in the hot water storage tank In the water heater, the hot water temperature detection means, the hot water temperature detection means, and a heating means for calculating a hot water temperature rise value per unit heating time based on the measurement results of the heating time measurement means, the hot water temperature adjustment means The temperature of the boiling water in the hot water storage tank is adjusted based on the calculation result of the calculation means. Therefore, it is possible to automatically and reliably adjust the boiling water temperature according to the hot water usage without bothering the user. As a result, it is possible to prevent running out of hot water or consuming wasteful power due to excessive hot water.
[0006]
According to a second aspect of the present invention, in the electric water heater according to the first aspect, the water supply path or the hot water supply path is provided with a flow rate detecting means, and the water supply temperature detecting means has an integrated flow rate detected by the flow rate detecting means reaching a predetermined value. It was decided to detect the temperature at the time as the feed water temperature. Therefore, even when the water temperature in the pipe fluctuates due to the influence of the outside air temperature, an accurate water supply temperature can be obtained by measuring the water temperature after passing a predetermined amount of water.
[0007]
According to a third aspect of the present invention, in the electric water heater according to the first aspect of the present invention, when the automatic hot water means for hot water filling a bathtub or the like is provided, the feed water temperature detecting means is finished when the hot water beam operation by the automatic hot water means is finished. The temperature of the water was detected as the feed water temperature. Usually, a large amount of hot water is used for the bathtub, so even if the water temperature in the piping fluctuated due to the outside air temperature before the hot water flow, water flow for the hot water was performed. By measuring the subsequent water temperature, an accurate water supply temperature can be obtained.
[0008]
According to claim 4, in the electric water heater according to claim 1, the hot water temperature detecting means is provided in a lower portion of the hot water storage tank, and the water supply temperature detecting means is supplied with water to a lower portion of the hot water storage tank. Sometimes, the temperature detected by the hot water temperature detection means is detected as the feed water temperature. Therefore, since both the feed water temperature and the boiling water temperature can be detected by one temperature detection means, the temperature detection circuit can be simplified and the number of parts can be reduced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0010]
FIG. 1 is a schematic configuration diagram of an electric water heater according to an embodiment of the present invention. The hot water storage tank 1 includes a heating means 2 for heating water and a hot water temperature detecting means 6 for detecting the temperature of the boiling water in the hot water storage tank 1. The hot water supply path from the hot water storage tank 1 to the hot water mixing means 3 is provided with a hot water temperature detection means 7, and the water supply path from a water supply source (not shown) to the hot water mixing means 3 is provided with a water supply temperature detection means 8. Is provided. Further, the hot water mixing path of the hot water mixing means 3 is provided with a mixed hot water temperature detecting means 9 and a flow rate detecting means 10, and the hot water electromagnetic wave is connected to the hot water path connected to the bathtub 5 downstream thereof. A valve 11 is provided.
[0011]
Water supplied from a water supply source (not shown) to the lower part of the hot water storage tank 1 is heated by the heating means 2. Specifically, it is heated at a specific time period power (main heating) during a specific time period such as midnight, and is heated at daytime power (auxiliary heating) when an operation such as boiling is performed outside the specific time period. ) These heating controls are performed by the heating control means 21.
[0012]
The heated hot water discharged from the upper part of the hot water storage tank 1 is mixed with water by the hot water mixing means 3 and supplied to the faucet 4 and the bathtub 5. In the hot water mixing means 3, the mixed hot water temperature is set to a temperature set by a remote controller (not shown) based on the detected temperatures of the tapping temperature detecting means 7, the feed water temperature detecting means 8, and the mixed hot water temperature detecting means 9. Be controlled. When a hot water command to the bathtub 5 is input by a remote controller or the like, the hot water electromagnetic valve 11 is controlled to open and close by the automatic hot water means 25 so that a predetermined amount of hot water is supplied to the bathtub 5. The amount of hot water supplied to the bathtub 5 is measured by the flow rate detection means 10.
[0013]
The boiling water temperature in the hot water storage tank 1 can be selected and set from a high temperature, a medium temperature, a low temperature, an automatic setting, etc. with a remote controller or the like. For example, the hot water temperature is adjusted to 90 ° C. at the time of high temperature setting, 80 ° C. at the time of medium temperature setting, 70 ° C. at the time of low temperature setting, and the hot water temperature adjusted by the hot water temperature adjusting means 24 at the automatic setting time. As described above, boiling is performed at midnight or daytime.
[0014]
Next, a method for determining the boiling water temperature adjusted by the hot water temperature adjusting means 24 will be described. First, when the integrated flow rate by one continuous water flow from the flow rate detection start to the stop of the flow rate detection unit 10 reaches a predetermined value (for example, 5 liters or more), the feed water temperature detection unit 8 immediately after detecting the flow rate stop. Is stored in the storage unit 26 as the water supply temperature Tt on the day. Even when the water temperature in the pipe fluctuates due to the influence of the outside air temperature, an accurate water supply temperature can be obtained by passing a predetermined amount of water. In normal use, there are multiple times that the integrated flow rate exceeds the predetermined value during one day, so the water supply temperature Tt on the day is updated so as to store the water supply temperature at the time when the integrated flow rate is maximum. You may make it do.
[0015]
Moreover, the heating time by the heating means 2 in the daytime time zone and the midnight time zone is measured by the heating time measuring means 22 and stored in the storage unit 26 as the heating time integrated value tw of the day. Further, the hot water temperature when the main heating in the midnight time period is finished is detected by the hot water temperature detecting means 6 and stored in the storage unit 26 as the boiling end temperature Te.
[0016]
The calculation means 23 calculates the hot water temperature rise value Ku per unit heating time from the same day water supply temperature Tt, the heating time integrated value tw, and the boiling end temperature Te stored in the storage unit 26. Ku is obtained by Ku = (Te−Tt) / tw. Then, by comparing Ku with predetermined values (a and b), the amount of hot water used on the day is determined as follows.
When Ku.gtoreq.a. When the amount of hot water used is small a>Ku> b. When the amount of hot water used is b.gtoreq.Ku .... The large amount of hot water used calculating means 23 repeatedly performs the above-described hot water amount determination every day.
[0017]
The boiling hot water temperature adjusted by the hot water temperature adjusting means 24 is determined based on the result of determining the amount of hot water used for one day or multiple days. When the boiling water temperature is set to three stages of “high temperature”, “medium temperature”, and “low temperature”, for example, when the initial setting is “medium temperature” and “small amount of hot water used” continues for 14 days, the boiling water temperature Is lowered by one step, and when the “large amount of hot water used” reaches two days in the past 14 days, the boiling water temperature may be raised by one step. In this way, the boiling water temperature is automatically and reliably adjusted according to the hot water usage conditions, without bothering the user, causing hot water to run out, and excessive hot water. And wasteful power consumption can be prevented.
[0018]
In this embodiment, the water supply temperature Tt on the day is measured by the water supply temperature detection means 8 provided in the middle of the water supply path, but this water supply temperature detection means 8 may be provided in the lower part of the hot water storage tank 1, It can also serve as the hot water temperature detection means 6 at the time of boiling. When the feed water temperature detecting means 8 is also used as the hot water temperature detecting means 6, the position where the hot water temperature detecting means 6 is attached to the hot water storage tank 1 when the integrated flow rate measured by the flow rate detecting means 10 reaches 200 liters or more. The water supply temperature Tt may be measured on the day when the water is supplied up to. Further, the flow rate detection means 10 may be attached to either the water supply path to the hot water storage tank 1 or the hot water mixing means 3 or the hot water supply path of the hot water storage tank 1 and the hot water mixing means 3.
[0019]
Further, in this embodiment, when the integrated flow rate by one continuous water flow reaches a predetermined value, the water supply temperature Tt on the day is stored, but the instantaneous flow rate detected by the flow rate detection means 10 becomes the maximum on the day. The water supply temperature at the time may be updated each time and stored as the water supply temperature Tt on the day. Moreover, in the electric water heater provided with the automatic hot water means for hot water feeding to the bathtub 5 etc., you may memorize | store the water supply temperature when hot water filling operation | movement of a predetermined amount of hot water is complete | finished as the water supply temperature Tt on the day. Normally, the hot water for the bathtub 5 uses a large amount of hot water of about 200 liters, so even if the water temperature in the piping fluctuates due to the outside air temperature before the hot water, By performing the water flow, an accurate water supply temperature Tt on the day can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an electric water heater according to an embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 ... Hot water storage tank 2 ... Heating means 3 ... Hot water mixing means 4 ... Faucet 5 ... Bathtub 6 ... Hot water temperature detection means 7 ... Hot water temperature detection means 8 ... Feed water temperature detection means 9 ... Mixed hot water temperature detection means 10 ... Flow rate detection Means 11 ... Hot water solenoid valve 21 ... Heating control means 22 ... Heating time measuring means 23 ... Calculation means 24 ... Hot water temperature adjusting means 25 ... Automatic hot water means 26 ... Storage section

Claims (4)

A hot water storage tank, a heating means for heating water in the hot water storage tank, a feed water temperature detection means for detecting a feed water temperature to the hot water storage tank, and a hot water temperature detection means for detecting the boiling water temperature in the hot water storage tank; In an electric water heater comprising heating time measuring means for measuring a heating time integrated value in a daytime zone and a midnight time zone by the heating means, and a hot water temperature adjusting means for adjusting the boiling water temperature in the hot water storage tank The hot water temperature detecting means, the hot water temperature detecting means, and a heating means for calculating a hot water temperature rise value per unit heating time based on the measurement results of the heating time measuring means, the hot water temperature adjusting means, An electric water heater characterized by adjusting a boiling water temperature in the hot water storage tank based on a calculation result of a calculation means. A flow rate detection means is provided in the water supply path or the hot water supply path, and the water supply temperature detection means detects the temperature when the integrated flow rate detected by the flow rate detection means reaches a predetermined value as the supply water temperature. Item 2. An electric water heater according to item 1. 2. An automatic hot water applying means for supplying hot water to a bathtub or the like, and the feed water temperature detecting means detects a temperature when a hot water pouring operation by the automatic hot water means is finished as a feed water temperature. Electric water heater according to. The hot water temperature detecting means is provided in a lower part of the hot water storage tank, and the water supply temperature detecting means detects a temperature detected by the hot water temperature detecting means when water is supplied to the lower part of the hot water storage tank as a water supply temperature. The electric water heater according to claim 1.

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