JPH05253061A - Electric water boiler - Google Patents

Abstract

PURPOSE:To remove undesired substances in water efficiently even under any heat preserving temperature condition when water is added. CONSTITUTION:When the addition of water is detected by a water addition detecting means 23 during the operating of a heat insulating means 22, operation time of a motor 13 is determined by a circulation time determining means 20 according to a drop value of the temperature of the water, the temperature thereof before the lowering of the temperature and an output value of a capacity detection mean 19 after a temperature change thereof occurs. When the water reaches a boiling state, bleaching powder components get already removed with a filter 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric water heater for heating and retaining the water contained in a container.

[0002]

2. Description of the Related Art In recent years, not only is there a demand for electric water heaters as household products that can easily heat and keep water warm, but in urban areas, there is also a demand for those that have the function of making delicious water. ing. As a function of transforming the water into delicious water, the boiling water is detected for a certain period of time and then the boiling water is maintained for a certain period of time, and then the completion of the boiling water is notified, and the chlorine component in the water is removed during the boiling time.

[0003]

However, in the above-mentioned conventional configuration, when new water is added without completely using all the water once boiled, the addition ratio cannot be grasped. If it is attempted to remove the components to such an extent that the presence of the components is not an issue, there is a problem in that the boiling state must be maintained for a long period of time equivalent to that of untreated water boiling.

The present invention solves the above-mentioned conventional problems. A first object of the present invention is to purify water by heating, circulating and purifying it for a time commensurate with the amount of new water added, without maintaining a boiling state for a long time. It is an object of the present invention to provide an electric water heater that always sufficiently removes unnecessary substances such as chlorine components.

The second purpose is to detect electricity when water is newly added without being confused with temperature change due to natural cooling, and to efficiently remove unnecessary substances when necessary. The purpose is to provide a water heater.

[0006]

In order to achieve the first object, the electric water heater of the present invention comprises a container for containing water,
A heating source that heats the water in the container, a control unit that controls the amount of electricity supplied to the heating source, a temperature detection unit that detects the temperature of the water, and a water addition detection unit that detects the addition of new water. A warming temperature setting means for selecting an arbitrary warming temperature from a plurality of warming temperature values for the water, a warming means for keeping the water at a predetermined temperature, and a capacity detecting means for detecting the capacity of the water. A circulating means for forcibly circulating the water; a filtering device for removing unnecessary substances in the water sent by the circulating means; and a water addition when the addition of new water is detected during operation of the heat retaining means. A configuration is provided that includes a circulation time determining unit that determines the operating time of the circulation unit according to the amount of temperature decrease, the temperature before the temperature decrease of the water, and the output value of the capacity detecting unit after the temperature change of the water. It was done.

Further, in order to achieve the second object, in the electric water heater of the present invention, the water addition detecting means detects the temperature of water at a constant detection time period, and the detected value is within a predetermined time. When a predetermined temperature range is lowered, it is determined that new water is added, and the first temperature detection value of the detected temperature at that time is set to the temperature before the temperature drop of water.

[0008]

With the above structure, when new water is added to the water kept at a predetermined temperature, the water temperature is rapidly lowered and the water addition detecting means detects the water temperature. The additional water amount of water is detected from the amount of temperature decrease at that time and the amount of water in the container detected by the capacity detection means, and the circulation device operation corresponding to the additional water amount is detected according to the circulation capacity of the circulation device and the filtration efficiency of the filtration device. The time can be automatically determined, and the circulation device can be operated while the water in the container is being heated so that the calcination component can be sufficiently removed when the boiling state is reached.

Furthermore, it is clear that the temperature drop when the temperature changes to a predetermined heat retention temperature after heating and boiling of water and the temperature fluctuation that fluctuates up and down due to convection of water inside the container are rapid temperature drops due to the addition of water. It is possible to distinguish it into two and to have a highly reliable additional water detection function.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an electric water heater according to an embodiment of the present invention. In FIG. 1, a container 2 having an upper surface opening is accommodated in a main body container 1, and a lid 3 that covers the upper portion of the container 2 is arranged. A heating source 4 that heats the water inside the container 2 and a temperature sensor 5 that detects the water temperature inside the container 2 are arranged below.

The container 2 is connected to the electric pump 7 from the lower discharge port 6.
A water channel communicating with the water guiding tube 8 via the water guiding tube 8 is formed, and water is sent out from the water guiding tube 8 by selecting either the external outlet 11 or the internal outlet 12 depending on the position of the valve 10 in the water channel switching device 9. The water discharged from the internal outlet 12 is returned to the original container 2 through the filtering device 16 containing activated carbon and the like.

The motor 13 drives the electric pump 7 to feed water from the water conduit 8. Also operation knob
When the switch 14 is operated, the contact of the switch 15 is switched, the valve 10 is operated by the signal, and the water conduit 8 is switched to the external outlet 11 side, and at the same time, the motor 13 is operated to guide the water in the container 2 to the outside.

The temperature detecting means 18 detects the water temperature from the signal of the temperature sensor 5, and the capacity detecting means 19 for detecting the water temperature in the container 2 by the signal, the circulation time determining means 20, and the heat retention for keeping the water at a constant temperature. Input to the means 22 and the water addition detection means 23 for detecting whether or not water is newly added.

The output of the capacity detecting means 19 is the circulation time determining means 20.
And the circulation time determining means 20 outputs a drive signal to the motor 13 in response to the input signal. Thermal insulation 22
Compares the output of the temperature detecting means 18 with the output of the heat retention temperature setting means 17, and outputs the result to the control means 21. Control means
21 determines the amount of electricity supplied to the heating source 4. Additional water detection means 23
Constantly detects the temperature change detected by the temperature detecting means 18, determines that new water is added when the water temperature rapidly decreases, and outputs the result to the circulation time determining means 20.

The operation of the electric water heater thus configured will be described with reference to FIG. FIG. 2 shows changes in the temperature detected by the temperature sensor 5 mounted in pressure contact with the container 2 against the passage of time after the heating source 4 is energized. At time t0, the heat retention means 22 detects the magnitude relationship between the temperature set by the heat retention temperature setting means 17 and the output of the temperature detection means 18, and when the output of the temperature detection means 18 is large, the amount of electricity to the heating source is changed. An output signal is sent to the control means 21 so as to decrease the output, and conversely, when the output of the temperature detection means 18 becomes small, the power supply amount to the heating source is increased to keep the water at the temperature θ0.

The temperature detecting means 18 constantly measures the water temperature. When new water (water amount W1, water temperature θ1) is added at time t1, the water temperature drops to θa as shown in FIG. Here, if the initial water amount is W0, this initial water amount W
The following relational expression holds between 0 and the additional water amount W1.

W1 / W0 = (θ0−θa) / (θa−θ1) W0 = W1 · (θa−θ1) / (θ0−θa) Next, the capacitance detection means 19 causes the temperature to fall within a predetermined temperature range (θ2 to θ).
The water amount W in the container 2 is calculated by multiplying the temperature increase gradient (Δθ / Δt) per unit time of 3) by a predetermined coefficient. The water amount W at this time is represented by the following equation.

W = C (Δθ / Δt) C is a constant determined by the cross-sectional area of the container and the heating amount per unit time. Further, the following relational expression holds between the water amount W in the container 2 and the additional water amount W1.

W = W1 + W0 = W1 {1+ (θa-θ1) / (θ0-θa)} From the above, the additional water amount W1 is expressed by the equation (1).

W1 = C · (Δθ / Δt) / {1+ (θa−θ1) / (θ0−θa)} (1) where θ0 is the heat retention temperature selected by the heat retention temperature determining means 17, that is, the water temperature decrease The previous temperature, (θ0-θa) is the amount of temperature decrease caused by the addition of water, and C · (Δθ / Δ
t) is the output value of the capacity detecting means 19.

Next, the circulation time determining means 20 determines the circulation time T defined by the characteristic curve shown in FIG. 3 based on the additional water amount W1 obtained by the equation (1). In the characteristic curve, since unnecessary substances are removed at a constant rate per unit time, the circulation time increases exponentially as the amount of additional water increases. At this time, the circulation time determining means 20 forms an n × m matrix lattice having θa as a parameter and θ (Δθ / Δt) as variables as shown in FIG. Is considered to be almost constant and the circulation time according to the additional water amount obtained from the equation (1) is determined by reading the value (Tij) recorded in advance at the matrix grid point. Needless to say, the function of the circulation time determining means 20 can be easily realized by replacing it with a microcomputer.

As the temperature approaches the boiling state, the temperature rising gradient (Δθ / Δt) approaches 0, and at time t4, the control means 21 detects the boiling of water and reduces the amount of electricity supplied to the heating source 4. Then, it changes from boiling to the set heat retention state again.

Next, the operation of the water addition detecting means in the electric water heater of the present embodiment will be described with reference to FIG. 5 and an operation flowchart shown in FIG. In FIGS. 5 and 6, the water addition detecting means 23 detects the temperature of the water at a constant detection time period Ts, and the detected value (φi−φi + n) is a predetermined time (n ·
When Ts: n is less than a predetermined temperature range (Δφs) within the range, it is not judged that new water is added, and when new water is actually added, the detected value (φj−φj + n) is predetermined. Within a time (n · Ts), the temperature falls by more than a predetermined temperature range (Δφs), at which time water addition is detected for the first time, and the first detected temperature value (φj-1) of the detected temperature at that time is lowered by the water temperature. Let it be the previous temperature (θ0).

As described above, according to this embodiment, the addition of water is detected by detecting the water temperature in the container, and the optimum shortest circulation time according to the amount of added water is detected in any heat retention temperature state. To decide. Therefore, the circulation time should be long when the amount of additional water is large, and short when it is small.
It is possible to automatically determine the circulation time at which unnecessary substances such as the minimum necessary chlorine component can be removed.

Further, it is clear that the temperature drop at the time of shifting to a predetermined heat retention temperature after heating and boiling of water and the temperature fluctuation fluctuating up and down due to convection of water in the container are a rapid temperature drop due to addition of water. They can be distinguished and can also have a highly reliable additional water detection function.

[0026]

As described above, according to the present invention, when the forced filtration device is built in, when new water is added while keeping warm, the circulation time for determining the circulation time according to the amount of additional water at that time By providing the determining means, the circulation time can be automatically lengthened when the amount of additional water in the container is large and shortened when the amount of additional water is small, and unnecessary substances such as calcination components at the minimum necessary amount can be removed. Furthermore, it is possible to provide an economical and easy-to-use electric water heater that can detect the addition of new water with a built-in temperature sensor with high accuracy and does not require any additional parts.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an electric water heater according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a water temperature fluctuation operation in the electric water heater according to the embodiment of the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the additional water amount and the circulation time in the electric water heater of the embodiment of the present invention.

FIG. 4 is a diagram illustrating a matrix grid table in the circulation time determining means of the electric water heater according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a water temperature detecting operation in the water addition detecting means of the electric water heater according to the embodiment of the present invention.

FIG. 6 is an operation flowchart of the water addition detecting means of the electric water heater according to the embodiment of the present invention.

[Explanation of symbols]

 2 container 4 heating source 13 motor (circulation device) 16 filtration device 17 heat retention temperature setting means 18 temperature detection means 19 capacity detection means 20 circulation time determination means 21 control means 22 heat retention means 23 water addition detection means

Claims (2)

[Claims] 1. A container for containing water, a heating source for heating the water in the container, a control unit for controlling the amount of electricity to the heating source, and a temperature detection unit for detecting the temperature of the water. Water addition detection means for detecting addition of new water, heat retention temperature setting means for selecting an arbitrary heat retention temperature from a plurality of heat retention temperature values for the water, and heat retention means for maintaining the water at a predetermined temperature A capacity detecting means for detecting the capacity of the water, a circulating means for forcibly circulating the water, a filtering device for removing unnecessary substances contained in the water sent by the circulating means, and the heat retaining means. When the addition of new water is detected during operation, the operating time of the circulation means is determined according to the amount of decrease in the temperature of the water, the temperature before the temperature decrease of the water, and the output value of the capacity detection means after the temperature change of the water. Electric water heater with circulation time determining means for determining . 2. The water addition detection means detects the temperature of water at a constant detection time period, and judges that new water has been added when the detected value falls within a predetermined temperature range within a predetermined time. The electric water heater according to claim 1, wherein the first detected temperature value of the detected temperature at that time is the temperature before the temperature of the water decreases.