JP2007212057A - Electric water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric water heater with a heating means whose on/off operation frequency is restricted to save energy and achieve a longer life and with a hot water storage tank whose capacity is minimized while securing a required amount of hot water to be used in maximum temporarily in the evening. <P>SOLUTION: The electric water heater comprises the heating means for heating water in the hot water storage tank 1, wherein hot water heated up with midnight power is stored in the hot water storage tank. When the hot water in the hot water storage tank 1 is used in the daytime, a hot water run-out preventing control device 5 instructs the heating means of heating-up operation a certain time before a preset time for bath hot water filling operation so that hot water is stored in the hot water storage tank up to its almost full capacity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric water heater, and in particular, while limiting the number of times the heating means is turned on and off to save energy and prolong the life of the heating means, while ensuring the necessary amount of hot water that is temporarily used in the evening The present invention relates to an electric water heater that can minimize the capacity of a hot water storage tank.

Conventionally, an electric water heater includes a hot water storage tank, a water supply pipe provided in the hot water storage tank, a hot water supply pipe provided in an upper part of the hot water storage tank, a heat pump for heating water in the hot water storage tank, and the like.
This electric water heater stores hot water boiled by inexpensive late-night power in a hot water storage tank, and uses the stored hot water in the daytime or evening to reduce running costs.

  However, since the conventional electric water heater stores hot water used in the daytime and evening in the middle of the night, a hot water storage tank for storing a large amount (370 to 460 liters) of hot water is required, and an installation space for that purpose is also required. Have a problem.

  In view of the problems of the above-described conventional electric water heater, the present invention limits the number of times the heating means is turned on and off, thereby saving energy and extending the life of the heating means. An object is to provide an electric water heater capable of minimizing the capacity of a hot water storage tank while securing a necessary amount.

  In order to achieve the above object, an electric water heater of the present invention is provided with a heating means for heating water in a hot water storage tank, and the hot water heated by midnight power is stored in the hot water storage tank. When hot water is used in the daytime, a hot water outflow prevention control device is provided to instruct the heating means to boil up before a preset time of the bath hot water filling operation time and store hot water of almost the full capacity of the hot water storage tank. It is characterized by that.

  In this case, the amount of hot water supply is reduced after bath bathing, so the hot water prevention control device is used in a predetermined amount even during periods when the amount of hot water used from the bath bathing operation to the boiling operation with midnight power is low. The heating means can be instructed to store hot water (about 50 liters).

  Further, the hot water prevention control device can instruct the heating means to perform the boiling operation with midnight power at the end of the midnight power time zone.

  According to the electric water heater of the present invention, in the electric water heater provided with heating means for heating the water in the hot water storage tank and storing hot water boiled by midnight power in the hot water storage tank, the hot water in the hot water storage tank was used during the day. Sometimes there is a hot water prevention control device that instructs the heating means to boil up a predetermined time before the preset bath hot water operation time and stores hot water of almost the full capacity of the hot water storage tank. The amount of heat that is deficient using can be boiled up just before the hot water bathing operation to make up for it at once, thereby limiting the number of times the heating means are turned on and off, saving energy and extending the life of the heating means, and in the evening It is possible to save space by minimizing the capacity of the hot water storage tank while securing the necessary amount of hot water that is temporarily used at maximum.

  In addition, since the amount of hot water supply is reduced after bath hot water filling, the hot water outflow prevention control device operates at a predetermined amount (50) even in a time zone when the amount of hot water used from the bath hot water filling operation to the boiling operation by midnight power is low. By instructing the heating means to store hot water (about 1 liter), it is possible to prevent a wasteful amount of hot water storage in the daytime (evening) and to prevent running out of hot water.

Moreover, the heat loss prevention control device can prevent the heat radiation loss by instructing the heating means to perform the boiling operation with midnight power at the end of the midnight power time zone.
In this case, by minimizing the capacity of the hot water storage tank, the boiling time can be shortened, and the boiling operation can be shifted more in the morning, effectively preventing heat dissipation.

  Hereinafter, an embodiment of an electric water heater of the present invention will be described with reference to the drawings.

The electricity menu has different electricity charges for nighttime, morning and evening, and daytime. Therefore, boiling hot water necessary for nighttime and morning and evening as cheap as possible leads to energy saving and running cost reduction.
On the other hand, in a small hot water storage tank of about 150 liters for the purpose of space saving, if the replenishment boiling is not carried out by the amount always used even in the daytime, the hot water will run out.
Therefore, in the present invention, the user sets the time used for the bath using the most hot water as the bath hot water operation time, and performs operation control to replenish hot water immediately before the use time, thereby heating means. By limiting the number of on / off times, energy saving and extending the life of the heating means are achieved.
Specifically, if you set the bath hot water operation time after 19:00, do not boil until 17:00 in the evening, boil the hot water used that day after 17:00 (150 liter boiling state) Prepare for bath use.
A person who takes a bath only at night does not boil the hot water used for the bath only at night, which further reduces the cost without operating the heating means in the daytime.
Further, by determining the amount of hot water used in advance by family configuration (including the average value of the amount used for one week) and minimizing the amount of water heated in the daytime, the cost can be further reduced.
For example, in the case of a family of two, since the amount of hot water used in the daytime is small, it can be controlled not to boil up before 17:00.
In the daytime, the heating operation is not performed as much as possible, and the heating is performed after 17:00. Therefore, there is no on / off operation of the heating means in the daytime, and for example, the life of the compressor of the heat pump as the heating means can be extended.

1 to 2 show an embodiment of the electric water heater of the present invention.
This electric water heater heats water in a cylindrical hot water storage tank 1, a water supply pipe 2 provided at the lower part of the hot water storage tank 1, a hot water supply pipe 3 provided at the upper part of the hot water storage tank 1, and the hot water storage tank 1. A heat pump 4 for controlling the hot water, and a hot water prevention control device 5 incorporated in the control device of the heat pump 4.

In this embodiment, the hot water storage tank 1 has a capacity of about 150 liters, which is about 1/3 of the conventional size. During boiling operation, water extracted from the lower part passes through the circulation pipe 6 and is a heat pump. 4 is heated by the heat exchanger 42 and returned to the upper part of the tank as hot water of about 80 ° C.
Needless to say, the capacity of the hot water storage tank 1 is not limited to about 150 liters.
The circulation pipe 6 includes a bypass pipe 7 that connects the vicinity of the return port of the hot water storage tank 1 and the upstream side of the heat exchanger 42, and the bypass pipe 7 is configured by switching the three-way valve 8 to the bypass pipe 7 side. It is possible to prevent low temperature water at the start of boiling from entering the hot water storage tank 1.
The amount of water reduced by supplying hot water from the hot water supply pipe 3 is automatically supplied to the hot water storage tank 1 via the water supply pipe 2 from a water pipe (not shown).

  The heat pump 4 includes a compressor 41 that compresses and heats the heat medium, a heat exchanger 42 that indirectly heats water in the hot water storage tank 1 with the heated heat medium, an expansion valve 43 that expands the heat medium in a compressed state, And an air heat exchanger 44 that discharges the cold heat of the heat medium that has passed through the expansion valve 43 and has become a low temperature.

On the other hand, when the hot water in the hot water storage tank 1 is used during the daytime, the hot water shortage prevention control device 5 is about a predetermined time before the bath hot water filling operation time set in advance by the user, that is, about 1 to 2 necessary for the heating operation. Prior to time, the compressor 41 serving as a heating means is instructed to perform a boiling operation, and functions to store hot water of almost the entire capacity of the hot water storage tank 1.
Here, the bath hot water operation time can be appropriately set according to the life pattern of each home.
In this case, the hot water prevention control device 5 instructs the heat pump 4 to store a predetermined amount (about 50 liters) of hot water after 21:00 after the bath hot water filling operation until the boiling operation with midnight power, The heat pump 4 is instructed to perform the boiling operation with midnight power at the end of the midnight power time zone.

FIG. 2 shows a specific operation example of this electric water heater.
It is assumed that 22 liters of hot water boiled to the full capacity of the hot water storage tank 1 by midnight power (23:00 to 7:00 on the next day) is used at 7 o'clock and then 100 liters in total is used by 19:00.
In this case, since the bath hot water operation time is set to 20:00, the hot water prevention control device 5 instructs the heat pump 4 to perform boiling operation at 19:00, 1 hour before that, and the hot water storage tank 1 has a total capacity of 150 liters. Boil up until

If 93 liters is used from 20:00 to 21:00 in the bathing, showering, and kitchen operation at the same time, a predetermined amount (50 hours after the bathing operation after 21:00 until the boiling operation by midnight power) In order to store hot water, the hot water prevention control device 5 instructs the heat pump 4 to boil up.
Thereafter, when hot water is used over 23:00, the hot water prevention control device 5 instructs the heat pump 4 to perform boiling operation in order to store a predetermined amount (about 50 liters) of hot water.

  And since the boiling operation by midnight electric power has a predetermined amount (about 50 liters) of hot water storage, if the water is heated to about 100 liters, the hot water heated up to the full capacity of the hot water storage tank 1 can be stored. The boiling operation is shifted to the morning as much as possible, and energization is performed from 3:00 to 7:00.

Thus, the electric water heater of the present embodiment includes the compressor 41 that heats the water in the hot water storage tank 1, and the hot water boiled by midnight power is stored in the hot water storage tank 1. When hot water is used in the daytime, the controller 41 instructs the compressor 41 to perform a boiling operation a predetermined time before the preset bath hot water operation time, and stores hot water of almost the full capacity of the hot water storage tank 1. Therefore, the amount of heat that is deficient by using hot water during the daytime can be heated up immediately before the bath hot water operation, thereby making up for the heat at a stretch. As a result, it is possible to save space by minimizing the capacity of the hot water storage tank 1 while ensuring the necessary amount of hot water that is temporarily used in the evening.

In addition, since the amount of hot water supply decreases after bath bathing, the hot water prevention control device 5 performs a predetermined amount (e.g., even during a period of time during which the amount of hot water used from the bath bathing operation to the boiling operation by midnight power is low. By instructing the heat pump 4 to store hot water (about 50 liters), it is possible to prevent wasteful storage of hot water and to prevent hot water from running out.
Furthermore, the hot water shortage prevention control device 5 instructs the heat pump 4 to perform the boiling operation by the late-night power at the end of the late-night power time zone, and minimizes the capacity of the hot water storage tank 1 to increase the boiling time. Can be shortened and the heating operation can be shifted toward the morning to prevent heat loss more effectively.

  As mentioned above, although the electric water heater of the present invention has been described based on the embodiments thereof, the present invention is not limited to the configurations described in the above embodiments. For example, a heating means other than the heat pump is used. The configuration can be changed as appropriate without departing from the spirit of the invention.

  The electric water heater of the present invention uses the hot water in the daytime to boil up the shortage of heat just before the bath hot water operation and compensates at once, thereby limiting the number of times the heating means is turned on and off, saving energy and exceeding the length of the heating means. The capacity of the hot water storage tank can be minimized while ensuring the required amount of hot water, which is the maximum amount of water used temporarily in the evening, and for example, an electric water heater for the purpose of drastically saving space. It can use suitably for a use.

It is a circuit diagram which shows one Example of the electric water heater of this invention. It is a graph which shows the boiling operation of the electric water heater and the conventional electric water heater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Water supply pipe 3 Hot water supply pipe 4 Heat pump 41 Compressor 42 Heat exchanger 43 Expansion valve 44 Air heat exchanger 5 Hot water prevention controller 6 Circulation pipe 7 Bypass pipe 8 Three-way valve

Claims (3)

  An electric water heater equipped with heating means that heats the water in the hot water storage tank and stores hot water boiled by midnight power in the hot water storage tank. An electric water heater provided with a hot water prevention control device for instructing a heating operation to a heating means a predetermined time before a time and storing hot water of almost the full capacity of a hot water storage tank.   The hot water prevention control device is characterized in that the heating means is instructed to store a predetermined amount of hot water even in a time zone in which the amount of hot water used is small after the bath hot water operation until the boiling operation by midnight power. The electric water heater according to claim 1.   3. The electric water heater according to claim 1, wherein the hot water prevention control device instructs the heating means to perform a boiling operation by midnight power at the end of the midnight power time zone.

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