JPS60235940A - Electric instantaneous water heater - Google Patents

Abstract

PURPOSE:To obtain an electric instantaneous water heater, which has high thermal efficiency and gives no shock of electricity, by a method wherein the secondary winding of a step-down transformer is also turned ON in response to the turning-ON of a tap so as to apply the secondary voltage of the transformer to an electric heating pipe connected in series on the upstream side of a tap pipe. CONSTITUTION:A step-down transformer 10 to transform high commercial supply voltage to low voltage of several volts, an electric heating pipe 20, which is connected in series on the upstream side of a tap 4 pipe and at the same time to which the secondary voltage of the transformer 10 is applied, and a switch to turn ON and OFF the primary winding of the transformer 10 in response to the turning-ON and -OFF of the tap 40 are provided. In other words, an electric instantaneous water heater, which has high thermal efficiency and is simple, can be obtained, because water flows directly through the electric heating pipe 20. In addition, no fear of being given the shock of electricity exists, because the voltage applied to the electric heating pipe is only several volts. Furthermore, because the whole electric heating pipe acts as a heat generating source, no fear of disconnection occurs even when a crack or the like develops on some portion of the electric heating pipe, resulting in facilitating the maintenance and management of the titled water heater.

Description

DETAILED DESCRIPTION OF THE INVENTION 11 Ice 1 The present invention relates to an instantaneous water heater having electric heating means.

Currently, gas water heaters are the mainstream instantaneous water heaters, but gas poses risks such as fire and gas poisoning. Furthermore, recently, in order to avoid the above-mentioned disasters caused by gas, an increasing number of buildings are no longer using gas, that is, they are using electricity instead of gas.

In view of this situation, a so-called electric instantaneous water heater has recently been proposed, but this type has an electric heater installed inside the tank, and uses the electric heater to heat the water in the tank. The hot water in the tank was heated in advance and then taken out from the faucet when needed; this was what was called a hot water storage type, and was not an instantaneous water heater in the true sense of the word. Therefore, a relatively large tank was required, making the device large and not simple.

1--The present invention has been made in part in view of the above-mentioned circumstances,
In particular, the purpose of this invention is to provide a simple electric instantaneous water heater that is free from the risk of disconnection, has good thermal efficiency, and is free from the risk of electric shock.

Spring - Figure 1 is a configuration diagram for explaining one embodiment of the present invention. In the figure, 10 indicates a commercial power supply voltage of 2 to
Step-down transformer to step down the voltage to a low voltage of about 6 ■, 20
is an electric heating pipe, 30 is a water pipe, 40 is a faucet, 50 is a switch installed on the primary side of the step-down transformer 10, and 60 is a resistor for voltage adjustment M installed on the primary side of the step-down transformer 10. The electric heating pipe 20 is made of, for example, nickel or chromium alloy, and as shown in the figure, a water pipe 3 leading to a faucet 40.
0 in series, so that water flowing into the faucet 40 flows through the electric heating pipe 20.

Electrodes 21 and 22 are provided at both ends of the electric heating pipe 20 over the entire circumference of the pipe, and the secondary voltage of the step-down transformer IO is applied between the electrodes 21 and 22. This electric heating pipe 20 is made of, for example, nickel,
Since it is made of a metal such as chromium alloy that has relatively high electrical resistance and does not melt at high temperatures, a voltage of 2 to 6 V is applied to both ends of the metal.
When a moderately low voltage is applied, a short circuit occurs, a large current flows, and the water becomes red hot.
The temperature rises to the desired temperature while flowing through the air. Note that if a voltage is applied to the electric heating pipe 20 when water is not in use, the water in the electric heating pipe will boil, which is dangerous.
When the faucet 40 is opened, a switch 50 is turned on to apply voltage to the electric heating pipe 20, and when the faucet 40 is closed, the voltage applied to the electric heating pipe 20 is cut off. Furthermore, since the water temperature differs depending on the region or season, and the appropriate temperature for the outlet also varies depending on the user, a voltage adjusting means consisting of, for example, a slide resistor is provided on the primary side of the step-down transformer 10 to adjust the outlet temperature. That's what I do. In the illustrated example, a resistor is inserted on the primary side of the step-down transformer 10 to adjust the voltage applied to the step-down transformer 10, but the turns ratio of the step-down transformer may also be changed. can be easily understood. Furthermore, in the illustrated example, the electric heating pipe 20 is made of a straight pipe, but the flow path may be lengthened by turning it in a spiral shape, bending it in a lattice shape, or the outside of the electric heating pipe may be formed by, for example, It is also possible to insulate with ceramic or the like to improve thermal efficiency.

Yutaka - As is clear from the above description, according to the present invention, an electric heating pipe is used and water is allowed to flow directly into the electric heating pipe, so that an electric instantaneous water heater with good thermal efficiency and simplicity can be achieved. can be provided. Since the voltage applied to the heating pipe is only a few volts, there is no risk of electric shock. Further, since the entire electric heating pipe is a heat generation source, there is no fear of breakage even if a part of the electric heating pipe is damaged, and there are advantages such as very easy maintenance and management.

[Brief explanation of the drawing]

The figure is a configuration diagram for explaining one embodiment of the present invention. 10... Step-down transformer, 20... Electric heating pipe, 21
゜22...electrode, 30...water pipe, 40...faucet,
50...Switch, 60...Temperature adjustment resistor.

Claims (6)

[Claims] (1) A step-down transformer that steps down the commercial power supply voltage to a voltage of several volts, an electric heating pipe connected in series on the upstream side of the faucet pipe and to which the secondary voltage of the transformer is applied, and a step-down transformer that steps down the commercial power supply voltage to a voltage of several volts; An electric instantaneous water heater, comprising a switch that turns on and off the primary side of the transformer. (2) The electric instantaneous water heater according to claim (1), wherein the electric heating pipe is made of a nickel-chromium alloy. (3) The electric instantaneous water heater according to claim (1) or (2), characterized in that the electric heating pipe has a spiral shape. (4) The electric instantaneous water heater according to claim (1) or (2), characterized in that the electric heating pipe has a lattice shape. (5) The electric instant water heater according to any one of claims (1) to (4), characterized in that the outside of the electric heating pipe is heat-insulated with a ceramic material. vessel. (6) Claims (1) to (5) include a voltage adjustment means on the primary side of the transformer.
) The electric instant water heater according to any one of the items.