JPS618550A - Electric water heater utilizing mid-night electric power - Google Patents

Abstract

PURPOSE:To accomplish the heating of water within a contract use time even in case of using of hot water after the starting of contract use time and subsequent to that time and of alternating a set quantity of hot water by a method wherein an energization for a heating body is started in the midway of a mid-night electricity contract use time. CONSTITUTION:A hot water temperature sensing means 1 at the lower part of a hot water storing tank, a hot water temperature setting means 2, a desired energization time calculating means 3 and the timer device for giving an energization signal for a heater body are arranged and just after the starting time of mid-night electricity contract use time, desired energization time is calculated in reference to a hot water temperature T deg.C at the lower part of the hot water storing tank A and a hot water set temperature Ts deg.C of the hot water storing tank, and then the energization for the heater body is started at the time when a desired energization period is subtracted from the finished time of a mid night electricity contract use time. Then, the calculator 3 may repeat the calculation of time up to the energization of the heating body and desired energization time. With this arrangement, the reduction of loss of heat radiation can be promoted and at the same time it is possible to complete the heating of water within a contract use time until the hot water set value is obtained even if the hot water set value subsequent to the starting time of the contract use time is varied and the variation in hot water temperature at a lower part of the hot water storing tank A is made.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric water heater that utilizes late-night electricity and is widely used in homes as a water heater.

Structure of the conventional example and its problems In the operational block diagram of a conventional electric water heater using late-night electric power, for example, as shown in FIG. Reference numeral 3 denotes a computing unit that calculates the required energization time, and 4 a timer device that sends an energization signal to the heating element. From the hot water temperature (T'C) at the bottom of the tank and Ts'C determined by the upper leg hot water temperature setting means 2, the calculator 3 determines the required energization time. Power consumption (kW) η: Heating efficiency The timer device 4 sends an energization signal to the heating element 5-\ at a time H hours prior to the end of the contract usage time.

In such a conventional example, when the contract usage time starts at 23:00, the time to start energizing the heating element is determined first. The hot water was not being used and the temperature was T = 70'C, but 30 minutes later, when the temperature changed to T = 30'C,
There was a problem with the field boiling up to Ts'C within the contract usage time.

If η=0.9 and Ts=85°C, then the problem arises that the water does not boil within the contracted usage time of 8 hours.

Purpose of the Invention The present invention solves the above-mentioned conventional problems, and includes controlling the heating element to start energizing the heating element in the middle of the contract usage time of late night electricity so that a predetermined hot water temperature is obtained within the contract usage time. The purpose is to

Structure of the Invention In order to achieve the above object, the present invention includes a computing device that calculates the required energization time from the water temperature at the bottom of the hot water storage tank and the boiling water temperature setting temperature of the hot water storage tank immediately after the start time of the late night electricity contract usage time. , a timer device that starts energizing the heating element at a time retroactive to the required energization time from the end time of the late-night electricity contract use time, and the calculation unit calculates the time until energization of the heating element and the required energization time. The structure is such that the heating element starts energizing in the middle of the contract usage time, and even if hot water is used after the contract usage time start time or the hot water temperature setting for the legs is changed, the contract usage time will continue. This has the effect of completing boiling within a few minutes.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows an operational block diagram. 1 is a water temperature detection means at the bottom of the hot water storage tank, 2 is a leg top water temperature setting means, 3 is a required energization time calculator, 4 is a timer device that gives an energization signal to the heating element, and the operations of 1 to 4 are based on the contract. The configuration is such that the process is repeated from the time when the usage time starts until the time when the heating element is energized.

FIG. 3 is a schematic cross-sectional view of the electric water heater of the present invention, in which the hot water temperature detection means 1 is installed so as to directly contact the hot water at the bottom of the tank A.

Hereinafter, the effects of the above configuration will be explained.

The operations 1 to 4 above can be repeated, so the temperature at the bottom of the tank (T'C) and the set value of the discharge hot water temperature ('r
Even if s'c) is changed by the consumer after the contract usage time start time, the calculator 3 calculates based on the new take, so the energization start signal to the heating element B can be changed freely. becomes possible.

In this way, according to this embodiment, since the power supply to the heating element B starts from the middle of the contract usage time, heat radiation loss is reduced, and at the same time, the water temperature on the legs is set after the start time of the contract usage time. Even when the water temperature at the lower part of the hot water storage tank A changes, the hot water can be heated up to the set value within the contract usage time.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Heat radiation loss can be reduced.

(2) The discharge hot water temperature setting value can be changed even after the contract usage time start time.

(3) Even if hot water is used after the start time of the contract usage time, boiling can be completed within the contract usage time.

[Brief explanation of drawings]

FIG. 1 is an operational block diagram of a conventional electric water heater control device using late-night power, FIG. 2 is an operational block diagram of an embodiment of the present invention, and FIG. 3 is a diagram of the same configuration. 1... Hot water temperature detection means at the bottom of the hot water storage tuck, 2...
. . . Upper leg hot water temperature setting means, 3 . . . Required energization time calculator, 4 . . Timer device. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] Immediately after the start time of the late-night electricity contract usage time, a calculator calculates the required energization time from the water temperature at the bottom of the hot water storage tank and the boiling water temperature setting temperature of the hot water storage tank, and calculates the required energization time from the end time of the midnight electricity contract usage time. The electric water heater using late-night electricity is provided with a timer device that starts energizing the heating element at a retroactive time, and the calculation unit repeatedly calculates the time until energization of the heating element and the required energization time.