JPH02263040A - Electric water heater - Google Patents

Abstract

PURPOSE:To provide high temperature hot water in a short time and to enable heating of only a necessary amount of hot water by a method wherein the inflow pipe of a feed hot water heating circuit is coupled to the bottom part of a tank and an outflow pipe to the top of the tank, and a hot water temperature detecting thermistor is mounted in a line through which a heater and a flow rate sensor are intercoupled. CONSTITUTION:When operation is started, a feed hot water circulating pump 8 and a heater 9 are energized, and feed hot water stored in a tank 1 is fed through an inflow pipe 11 to the heater 9 to increase temperature. The temperature of hot water after heating is detected by a thermistor 13 for detecting a hot water temperature and compared with a set hot water temperature by a controller 14. The number of revolutions of the circulating pump 8 is controlled and an amount of water fed to the heater 9 is controlled so that the temperature of hot water at the outlet of the heater 9 is adjusted to a value equal to a set value. In this way, feed hot water the temperature of which is increased to a set value is returned from the top part of the tank 1 to the tank 1 through a flow rate sensor 10 and an outflow pipe 12, and is stored in the tank 1. Meanwhile, an amount of boiled up hot water is controlled in a way that energization of the feed hot water circulating pump 8 and the heater 9 is shut off at a point of time when an amount of hot water preset by a control part 15 is detected by a flow rate sensor 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a household electric water heater that heats hot water using an electric heater as a heat source.

2. Description of the Related Art As shown in FIG. 2, a conventionally known electric water heater includes a tank 1 for storing hot water and having a water inlet and a hot water inlet, an electric heater 2 detachably attached to the tank 1, and It is composed of a thermostat 3 that controls the supply of electricity to the electric heater 2, a heat insulating material 4 that wraps around the tank 1, and an exterior material 5. When the heated hot water is heated to a set temperature, the thermostat 3 shuts off the electricity to the electric heater 2.

Problems to be Solved by the Invention In the above-mentioned conventional electric water heater, the entire hot water stored in the tank is heated by the electric heater, so it takes time to boil the hot water, and even when the amount of hot water used is small, the stored hot water cannot be heated. There was a problem in that the entire amount of water had to be heated, resulting in leftover water being left unused, resulting in wasted energy due to heating loss.

The present invention solves the above problems and provides an electric water heater that can obtain hot water at a relatively high temperature in a relatively short time after energizing the electric heater, and that can heat only the necessary amount of hot water.

Means for Solving the Problems The electric water heater of the present invention, in order to solve the two problems, has a tank for storing hot water and equipped with a water supply pipe and a hot water supply pipe, and an i-ring pump for heating the hot water. The inlet pipe of the hot water heating circuit is connected to the bottom of the tank, the outflow pipe is connected to the top of the tank, and a pipe line connecting the heating heater and the flow rate sensor is provided. A thermistor for detecting hot water temperature is installed, and the flow rate sensor and the thermistor for detecting hot water temperature are electrically connected to an operating section and a hot water circulation pump via a controller.

Function In the electric water heater of the present invention, in the above configuration, the boiling water temperature and the amount of hot water are set in the operating section and operation is started, that is, the heater is energized and the hot water circulation pump is driven. The stored hot water is fed from the bottom of the tank to the heater by the action of the hot water circulation pump, where it is heated and heated. A thermistor detects the hot water temperature after heating, compares it with a set hot water temperature, and controls the rotation speed of the hot water circulation pump so that the hot water temperature at the outlet of the heater becomes equal to the set value. On the other hand, the flow rate sensor measures the amount of hot water heated and heated by the heater, and when the set amount of hot water is measured, the power supply to the heater and hot water circulation pump is cut off.

Example Hereinafter, one embodiment of the present invention will be described based on FIG.

■ is a tank that stores hot water. A water supply port 2 and a hot water supply port 3 are fixed to the tank l, and the water supply port 2
A water supply pipe 4 is connected to the water supply pipe 4, and a pressure reducing valve 5 and a water stop valve 6 are attached to the water supply pipe 4. Further, a safety valve 7 is attached to the hot water supply port 3. 8 is a hot water circulation pump, 9 is a heater, and 10 is a flow rate sensor, which are connected in sequence to form a hot water heating circuit. The inflow pipe 11 of the hot water heating circuit is connected to the bottom of the tank 1, and the outflow pipe 12 is connected to the top of the tank 1, respectively. Reference numeral 13 denotes a thermistor for detecting the temperature of hot water, which is installed in a conduit connecting the heater 9 and the flow rate sensor 10. 14 is a controller, which includes the hot water circulation pump 8, the heater 9, and the flow rate sensor 10.
, are electrically connected to the hot water temperature detection thermistor 13 and the operating section 15. The operation unit 15 is provided with a boiling water temperature setting switch and a boiling water amount setting switch (not shown).

The electric water heater of this embodiment is controlled by the operating unit 15 based on the boiling water temperature and hot water volume setting values. That is, when the operation is started, the hot water circulation pump 8 and the heater 9 are energized, and the hot water stored in the tank 1 is heated through the inflow pipe 11 and sent to the heater 9 to raise its temperature. The hot water temperature after heating is detected by the hot water temperature detection thermistor 13, compared with the set hot water temperature by the controller 14, and the rotation speed of the hot water circulation pump 8 is adjusted so that the hot water temperature at the outlet of the heater 9 becomes equal to the set value. The amount of water fed to the heater 9 is controlled.

The hot water heated to the set temperature in this way passes through the flow rate sensor lO1 outflow pipe 12, and then flows from the top of the tank 1 into the tank 1.
It can be stored back. On the other hand, the amount of boiling water is controlled by the operation section 1.
This is done by cutting off the power to the hot water circulation pump 8 and heater 9 when the flow rate sensor IO detects the amount of hot water preset in step 5.

In the above configuration, it is also possible to prevent the heater 9 from running dry by energizing the heater 9 after the flow of hot water is detected by the flow rate sensor 10 at the start of operation.

Effects of the Invention As is clear from the description of the embodiments above, the electric water heater of the present invention comprises a hot water heating circuit in which a hot water circulation pump, a heating heater, and a flow rate sensor are connected in sequence, and the hot water heating circuit has a hot water heating circuit. By connecting the inflow pipe to the bottom of the tank that stores hot water and the outflow pipe to the top of the tank, and installing a thermistor for hot water temperature detection on the pipe connecting the heater and flow sensor, the set temperature can be adjusted from the top of the tank. Hot water can be stored and used within a short time after operation starts. In addition, since only the amount of hot water corresponding to the amount used can be heated, there is no heat radiation loss due to residual hot water, and there are advantages such as effective use of energy.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an electric water heater showing an embodiment of the present invention;
FIG. 2 is a sectional view showing a conventional electric water heater. 1...Tank, 2...Water inlet, 3...
...Hot water inlet, 4...Water supply pipe, 5...
・Pressure reducing valve, 6... Water stop valve, 7... Safety valve, 8... Hot water circulation pump, 9... Heater, 10...・Flow rate sensor, 11...
...Inflow pipe, 12...Outflow pipe, 13...
...Thermistor for water temperature detection, 14...Controller,
15...Operation unit. Name of agent: Patent attorney Shigetaka Awano N+L to one person
Q N) b is 3 ≧ white

Claims (1)

[Claims] The tank is equipped with a tank that stores hot water and has a water inlet and a hot water inlet, and a hot water heating circuit that sequentially connects a hot water circulation pump, a heater, and a flow rate sensor, and the inflow pipe of the hot water heating circuit is connected to the bottom of the tank. In this electric water heater, an outflow pipe is connected to the top of the tank, and a hot water temperature detection thermistor is installed in the pipe connecting the heater and the flow rate sensor.