CN219656319U - Electric water heater - Google Patents

Abstract

The utility model provides an electric water heater, which belongs to the technical field of electric appliances and comprises a first inner container, a heating assembly, a water outlet pipe, a water inlet pipe, a second inner container and a water guide assembly, wherein the heating assembly is arranged in the first inner container, the water inlet pipe is communicated with the second inner container, and the water outlet pipe is communicated with the first inner container and the second inner container, so that water in the first inner container and the water in the second inner container flows out after being mixed through the water outlet pipe; the water guide assembly is communicated with the first inner container and the second inner container, and enables water to flow from the second inner container into the first inner container in a unidirectional manner; the first inner container is further provided with an exhaust pipe, and the exhaust pipe is provided with a first control valve for controlling the on-off of the exhaust pipe, so that smooth water outlet of the electric water heater can be guaranteed when water pressure fluctuates, and water stored in the first inner container and the second inner container can be used for emergency water supply for users when water is stopped.

Description

Electric water heater

Technical Field

The utility model belongs to the technical field of electric appliances, and particularly relates to an electric water heater.

Background

The water-storage type electric water heater is a fixed type appliance capable of heating water, can store hot water for a long time or temporarily, and is an electric water heater which is more in use at present.

The existing water storage type electric water heater is generally provided with a liner with larger capacity, a heating assembly is arranged in the liner to heat water, the liner is also connected with a cold water pipe and a hot water pipe, cold water enters the liner through the cold water pipe under the action of water pressure, when hot water is used, a water outlet valve of the water heater is opened, heated water in the liner flows out through the hot water pipe under the extrusion action of the cold water, and at the moment, the inflow rate of the cold water in the liner is basically consistent with the outflow rate of the hot water.

In actual life, the condition that the water pressure of tap water fluctuates greatly or water is stopped is unavoidable. When the water pressure fluctuates, the inflow rate of cold water correspondingly fluctuates, so that the hot water outlet rate of the water storage type electric water heater changes, and the hot water used by a user is greatly influenced; when water is stopped, the water storage type electric water heater cannot discharge water, and at the moment, even if water is stored in the inner container, the water cannot be provided for a user for emergency use.

Disclosure of Invention

The utility model provides an electric water heater, which solves the problem that the existing water storage type electric water heater cannot normally discharge water when the water pressure fluctuates or water is stopped.

The technical scheme adopted by the utility model is as follows:

the utility model provides an electric water heater, which comprises a first inner container, a heating assembly, a water outlet pipe, a water inlet pipe, a second inner container and a water guide assembly, wherein the heating assembly is arranged in the first inner container;

the water guide assembly is communicated with the first inner container and the second inner container, and enables water to flow from the second inner container into the first inner container in a unidirectional manner;

the first liner is also provided with an exhaust pipe, and the exhaust pipe is provided with a first control valve for controlling the on-off of the exhaust pipe.

In one possible design, the electric water heater further comprises a controller, a pressure sensor is arranged on the water inlet pipe and used for detecting the pressure in the water inlet pipe, and the first control valve and the pressure sensor are electrically connected with the controller;

the controller controls the first control valve to be closed when the pressure in the water inlet pipe is greater than or equal to a preset pressure;

and when the pressure in the water inlet pipe is smaller than the preset pressure, the controller controls the first control valve to be opened.

In one possible design, the exhaust pipe is installed at the upper part of the first liner, a second connecting pipe is arranged between the exhaust pipe and the water inlet pipe, and the first control valve is located above the second connecting pipe.

In one possible design, the water outlet pipe includes a first water outlet pipe, a second water outlet pipe and a water mixing valve, an inlet end of the first water outlet pipe is communicated with the second liner, an inlet end of the second water outlet pipe is communicated with the first liner, and outlet ends of the first water outlet pipe and the second water outlet pipe are communicated with the water mixing valve.

In one possible design, the water outlet pipe further comprises a third water outlet pipe, and the water mixing valve is further communicated with an outlet end of the third water outlet pipe;

the inlet end of the third water outlet pipe is communicated with the bottom of the first liner, and the inlet end of the second water outlet pipe extends to the upper portion of the first liner.

In one possible design, a second control valve is arranged on the third water outlet pipe, and the second control valve is electrically connected with the controller;

the controller controls the second control valve to be closed when the pressure in the water inlet pipe is greater than or equal to a preset pressure;

and when the pressure in the water inlet pipe is smaller than the preset pressure, the controller controls the second control valve to be opened.

In one possible design, the water guide assembly includes a first connection tube, and a one-way valve disposed on the first connection tube.

In one possible design, the electric water heater further comprises a housing and a heat shield;

the shell is internally hollow to form an inner cavity, the heat insulation baffle separates the inner cavity into a first cavity and a second cavity, the second inner container is positioned in the first cavity, the first inner container is positioned in the second cavity, and the first connecting pipe penetrates through the heat insulation baffle to be communicated with the first inner container and the second inner container.

In one possible design, an insulating layer is provided between the inner wall of the second cavity and the first liner.

In one possible design, the heating assembly includes a magnesium rod and an electric heating tube.

The utility model has the beneficial effects that:

when the electric water heater is used, cold water is fed into the second inner container through the water inlet pipe, when the water in the second inner container reaches a certain amount, the water in the second inner container is fed into the first inner container through the water guide component, so that the second inner container and the first inner container can be filled with water, the heating component is arranged in the first inner container, at the moment, the water in the first inner container can be heated through the heating component, when a user uses hot water, if the water inlet pressure is normal, the first control valve on the exhaust pipe is closed, so that the first inner container is not communicated with the outside, and the water in the first inner container and the second inner container flows out through the water outlet pipe under the extrusion action of the cold water entering through the water inlet pipe and is mixed to the water temperature required by the user in the water outlet pipe; when the water pressure is low, the first control valve can be opened, so that the exhaust pipe is communicated with the outside, the water pressure in the first liner can not be excessive, and the water in the second liner can still stably flow into the first liner at the moment, so that a certain pressure stabilizing effect can be achieved, and the influence of the water pressure change on the water outlet rate is reduced; in addition, when water is stopped, both the cold water stored in the second inner container and the hot water stored in the first inner container can be used for meeting the emergency water demand of users.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model.

Fig. 1 is a schematic diagram of a first structure of an electric water heater according to an embodiment of the present utility model;

fig. 2 is a schematic diagram of a second structure of an electric water heater according to an embodiment of the present utility model;

fig. 3 is a schematic diagram of a third structure of an electric water heater according to an embodiment of the present utility model.

Reference numerals:

100-shell, 200-second inner container, 300-first inner container, 301-exhaust pipe, 302-first control valve, 400-water guide component, 401-first connecting pipe, 402-one-way valve, 500-heating component, 501-electric heating pipe, 502-magnesium rod, 601-first water outlet pipe, 602-second water outlet pipe, 603-water mixing valve, 604-third water outlet pipe, 700-water inlet pipe, 800-heat insulation baffle and 900-heat preservation.

Specific embodiments of the present utility model have been shown by way of the above drawings and will be described in more detail below. The drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but rather to illustrate the inventive concepts to those skilled in the art by reference to the specific embodiments.

Detailed Description

In order to make the objects, technical solutions and advantages of the present utility model more apparent, the technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings.

The terms "first," "second," "third," "fourth" and the like in the description and in the claims and in the above drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the utility model described herein may be implemented, for example, in sequences other than those illustrated or otherwise described herein.

In embodiments of the utility model, words such as "exemplary" or "such as" are used to mean examples, illustrations, or descriptions. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

The existing water storage type electric water heater is generally provided with a liner with larger capacity, a heating assembly is arranged in the liner to heat water, the liner is also connected with a cold water pipe and a hot water pipe, cold water enters the bottom of the liner through the cold water pipe, after the cold water is heated, the hot water floats upwards due to the fact that the specific gravity of the hot water is smaller than that of the cold water, when the hot water is used, a water outlet valve of the water heater can be opened, heated water in the liner flows out through the hot water pipe under the extrusion action of the cold water, and at the moment, the inflow rate of the cold water in the liner is basically consistent with the outflow rate of the hot water.

However, when the pressure in the water inlet pipe fluctuates, the cold water inlet rate of the inner container is influenced to synchronously fluctuate, so that the hot water outlet rate is also influenced, and when the user stops water, the cold water inlet rate is zero, and the water heater is not continuously discharging hot water.

In order to avoid the problems, the utility model provides an electric water heater, which is provided with a first inner container and a second inner container, and the first inner container and the second inner container are communicated through a water guide assembly, so that the second inner container can store cold water and supplement water for the first inner container, a certain pressure stabilizing effect is achieved when water pressure fluctuates, the water outlet rate is relatively stable, meanwhile, an exhaust pipe is arranged on the first inner container, when the water pressure is unstable or water is stopped, the exhaust pipe is communicated with the outside, the pressure in the first inner container can be reduced, the first inner container can smoothly outlet water, and therefore the electric water heater can be normally used under the condition of low water pressure and can also supply emergency water when water is stopped.

Fig. 1 is a schematic diagram of a first structure of an electric water heater according to an embodiment of the present utility model.

Referring to fig. 1, the present embodiment provides an electric water heater, which is substantially identical to the existing electric water heater, and includes a first liner 300, a heating assembly 500, a water outlet pipe, and a water inlet pipe 700.

The difference between this embodiment is that the second liner 200 is further included.

The heating assembly 500 is disposed in the first inner container 300 to heat the water in the first inner container 300 to a temperature set by a user. The water inlet pipe 700 is connected with the second inner container 200 to send cold water into the second inner container 200, and the water outlet pipe is connected with the second inner container 200 and the first inner container 300, and can adjust the water outlet amount of the second inner container 200 and the water outlet amount of the first inner container 300, so that the water flowing out of the second inner container 200 and the first inner container 300 can reach the temperature required by a user after being mixed in the water outlet pipe, and the water flowing out of the first inner container 300 or the water flowing out of the second inner container 200 can be controlled.

Meanwhile, the first liner 300 is provided with an exhaust pipe 301, the exhaust pipe 301 is provided with a first control valve 302, when the first control valve 302 is opened, the exhaust pipe 301 communicates the first liner 300 with the outside, and when the first control valve 302 is closed, the first liner 300 cannot communicate with the outside through the exhaust pipe 301.

Of course, a water guiding assembly 400 is further disposed between the first liner 300 and the second liner 200, and the water guiding assembly 400 is used for connecting the second liner 200 and the first liner 300, so that water in the second liner 200 can flow into the first liner 300 to supplement water to the first liner 300, and water in the first liner 300 cannot reversely flow into the second liner 200, thereby avoiding heat waste.

In the working process of the electric water heater, water enters the second inner container 200 through the water inlet pipe 700, when the water in the second inner container 200 reaches a certain amount, the water in the second inner container 200 is sent into the first inner container 300 through the water guide assembly 400, so that the second inner container 200 and the first inner container 300 can be filled with water, the heating assembly 500 is arranged in the first inner container 300, at the moment, the water in the first inner container 300 can be heated through the heating assembly 500, when a user uses hot water and opens a water outlet valve, if the water pressure is normal, the first control valve 302 is not opened, the exhaust pipe 301 is in a non-conducting state, namely, the first inner container 300 is not communicated with the outside, the water in the first inner container 300 and the second inner container 200 flows out through the water outlet pipe under the extrusion action of the cold water entering through the water inlet pipe 700, and is mixed to the water temperature required by the user in the water outlet pipe, so that the user can use the hot water normally.

When the water pressure is low, if the first control valve 302 is continuously closed, the water outlet rate of the water outlet pipe is influenced by the water pressure to generate fluctuation, so that the normal water use of a user is influenced, at the moment, the first control valve 302 can be opened, the air outlet pipe 301 is communicated with the outside, the water pressure in the first liner 300 cannot be excessive, and the second liner 200 can play a certain role in stabilizing the pressure while supplementing water for the first liner 300, so that the water in the first liner 300 can stably flow out through the water outlet pipe, and the smooth water outlet of the electric water heater is ensured.

When water is stopped, the first control valve 302 is also in an open state, and although no water enters the second liner 200 through the water inlet pipe 700, the water pressure in the second liner 200 and the first liner 300 are balanced with the external water pressure, and when the valve for water outlet of the second liner 200 and the first liner 300 is opened, water can still be normally discharged, and at this time, both the cold water stored in the second liner 200 and the hot water stored in the first liner 300 can be used for meeting the emergency water requirement of a user.

The first control valve 302 may be a manual valve, and a user may select whether to open the first control valve 302 according to the water outlet condition, so as to change the water outlet mode of the electric water heater.

For convenience, the first control valve 302 is an electrically controlled valve, such as a solenoid valve, and a controller and a pressure sensor are correspondingly disposed.

The pressure sensor is disposed on the water inlet pipe 700 and is used for detecting the water pressure of the water flow entering the water inlet pipe 700, and the first control valve 302 and the pressure sensor are electrically connected with the controller, so that the controller can control the opening and closing of the first control valve 302 according to the water pressure condition.

Specifically, the controller is preset with a preset pressure which is a normal pressure for ensuring that the water heater can normally discharge water through the cold water inlet pressure. When the pressure sensor detects that the water inlet pressure in the water inlet pipe 700 is smaller than the preset pressure, it indicates that the water inlet pressure of the cold water cannot keep the stable water outlet rate of the electric water heater, at this time, the first controller controls the first control valve 302 to be opened, and changes the water outlet mode of the electric water heater, so that the stable water outlet rate of the electric water heater can be kept. When the pressure sensor detects that the water pressure in the water inlet pipe 700 is greater than or equal to the preset pressure, the current pressure indicates that the electric water heater can stably discharge water, at this time, the controller controls the first control valve 302 to be closed, the electric water heater normally discharges water under the extrusion action of cold water inflow, and the comfort of water consumption is ensured.

The heating assembly 500 may directly use various heating devices used in the conventional electric water heater, so long as the heating device can effectively heat the water in the first inner container 300.

Illustratively, the heating assembly 500 may include a magnesium rod 502 and an electric heating tube 501.

Illustratively, the heating assembly 500 may also be a magnesium rod 502 and an electrical heater plate.

Fig. 2 is a schematic diagram of a second structure of an electric water heater according to an embodiment of the present utility model.

In one possible embodiment, referring to fig. 2, the electric water heater further includes a housing, the interior of the housing is hollow to form an inner cavity, a heat insulation baffle 800 is disposed in the inner cavity, the inner cavity is divided into a first cavity and a second cavity by the heat insulation baffle 800, the second liner 200 is installed in the first cavity, and the first liner 300 is installed in the second cavity.

Wherein, the heat insulation baffle 800 not only separates the first cavity and the second cavity, but also is made of heat insulation material, so that heat transfer between the first cavity and the second cavity can be reduced.

The first cavity and the second cavity may be vertically disposed or horizontally disposed, and may be parallel to each other or on the same straight line, so long as the second liner 200 and the first liner 300 can be communicated through the water guide assembly 400.

Illustratively, the water guiding assembly 400 includes a first connecting tube 401 and a one-way valve 402, a through hole is formed in the heat insulation baffle 800, the first connecting tube 401 passes through the through hole to communicate the second liner 200 with the first liner 300, and the one-way valve 402 is used for enabling water to flow from the second liner 200 into the first liner 300 only in one direction.

Of course, the water guiding assembly 400 may be implemented by other structures, as long as the water can flow from the second liner 200 to the first liner 300 in one direction, for example, a ball float valve is disposed at the connection between the first connecting tube 401 and the first liner 300, and the ball float valve can automatically control the connection and disconnection between the first connecting tube 401 and the first liner 300 according to the water pressure.

In addition, in order to improve the heat insulation effect of the electric water heater and reduce heat loss, a heat insulation layer 900 may be disposed between the first inner container 300 and the inner wall of the second cavity.

Illustratively, the thermal insulation 900 may be adhered to the inner wall of the second cavity.

Illustratively, the insulating layer 900 may be adhered to the exterior of the first bladder 300.

Illustratively, the thermal insulation layer 900 may be uniformly filled between the thermal insulation layer 900 and the first liner 300, for example, the thermal insulation layer 900 may be foamed from a foaming material to directly fill a gap existing between the first liner 300 and the second cavity.

In one possible embodiment, a second connection pipe is disposed between the water inlet pipe 700 and the air outlet pipe 301, the second connection pipe communicates the water inlet pipe 700 and the air outlet pipe 301, and a connection point of the second connection pipe and the air outlet pipe 301 is located between the first control valve 302 and the first liner 300.

When the water pressure is normal, the first liner 300 can be supplemented with water synchronously through the water guide assembly 400 and the second connecting pipe, so that the water supplementing efficiency is improved.

In one possible embodiment, the water outlet pipe includes a first water outlet pipe 601, a second water outlet pipe 602, and a water mixing valve 603, where an inlet end of the first water outlet pipe 601 is communicated with the second liner 200, an inlet end of the second water outlet pipe 602 is communicated with the first liner 300, and outlet ends of the first water outlet pipe 601 and the second water outlet pipe 602 are both communicated with an inlet end of the water mixing valve 603, and the water mixing valve 603 can control water output of the first water outlet pipe 601 and the second water outlet pipe 602 and mix them, so that water flowing out from an outlet end of the water mixing valve 603 has a temperature that is in accordance with a user's requirement.

The installation mode of the electric water heater of this embodiment can effectively simplify the installation step of the water heater, specifically, when it is installed, only need to fix the electric water heater to with the inlet tube 700 with water supply devices such as water pipe or water tower intercommunication can, the outlet pipe need not to connect the cold water pipeline in user's home alone again, can adjust actual outlet water temperature through second inner bag 200 that self was equipped with and first inner bag 300, mixing valve 603.

The electric water heater is low in installation environment requirement and convenient to install, and the installation efficiency of the electric water heater can be effectively improved.

When the first inner container 300 is only connected with the second water outlet pipe 602 to discharge hot water, in order to ensure that the hot water stored in the first inner container 300 can be discharged as much as possible for emergency use when water is stopped, the water outlet end of the second water outlet pipe 602 is positioned at the lower part of the first inner container 300, and of course, the water outlet end of the first water outlet pipe 601 is also positioned at the lower part of the second inner container 200.

In the actual use process, the cold water sinks, and the hot water floats after the water temperature rises, so that the water inlet of the first liner 300 is generally arranged at the lower part, and the water outlet is arranged at the upper part.

Fig. 3 is a schematic diagram of a third structure of an electric water heater according to an embodiment of the present utility model.

Referring to fig. 3, in order to ensure that water can be discharged normally when the water pressure is insufficient or water is stopped, the present embodiment has a better hot water discharging effect when the water pressure is normal, and the water outlet pipe further includes a third water outlet pipe 604.

The outlet end of the third water outlet pipe 604 is also connected to the water mixing valve 603, and of course, in the second water outlet pipe 602 and the third water outlet pipe 604, the outlet end of one of them extends to the upper portion of the first inner container 300, and the outlet end of the other one is located at the lower portion of the first inner container 300.

For convenience of description, the outlet end of the second water outlet pipe 602 extends to the upper portion of the first liner 300, preferably to the upper portion of the junction between the first connecting pipe 401 and the first liner 300, and the outlet end of the third water outlet pipe 604 is located at the lower portion of the first liner 300.

When the water pressure is greater than or equal to the preset pressure, the first inner container 300 stores the hot water through the second water outlet pipe 602, and when the water pressure is less than the preset pressure, the first inner container 300 stores the hot water through the first water outlet pipe 601.

Of course, the third water outlet pipe 604 or the second water outlet pipe 602 can be controlled by the water mixing valve 603, but the structure of the water mixing valve 603 is complex, and the production and the use are inconvenient.

Therefore, a second control valve may be disposed on the third water outlet pipe 604, where when the second control valve is opened, the third water outlet pipe 604 communicates the first liner 300 with the water mixing valve 603, and when the second control valve is closed, the third water outlet pipe 604 no longer communicates the first liner 300 with the water mixing valve 603.

At this time, the water outlet ends of the third water outlet pipe 604 and the second water outlet pipe 602 may be directly communicated through a three-way pipe, and then connected to the water mixing valve 603, where the water mixing valve 603 directly uses a common cold and hot water mixing valve 603.

Of course, the second control valve can be a manual valve, which is opened or closed by the user according to the situation.

In order to improve the convenience of use, the second control valve may be an electromagnetic valve and electrically connected to the controller, and the controller may be used to automatically control the opening and closing of the second control valve according to the pressure of the water inlet pipe 700 detected by the pressure sensor.

Specifically, when the pressure of the water inlet pipe 700 detected by the pressure sensor is less than the preset pressure, the controller controls the second control valve to open, so that the water in the first liner 300 can flow out through the third water outlet pipe 604.

When the pressure of the water inlet pipe 700 detected by the pressure sensor is greater than or equal to the preset pressure, the controller controls the second control valve to be closed, so that the water in the first liner 300 can only flow out through the third water outlet pipe 604.

When the second control valve is opened, the water level in the first liner 300 may be still above the water outlet end of the second water outlet pipe 602, and at this time, the hot water may be synchronously discharged through the second water outlet pipe 602 and the third water outlet pipe 604, so that a third control valve may be disposed on the second hot water pipe and electrically connected to the controller, and when the second control valve is opened, the third control valve is closed, and when the second control valve is closed, the third electromagnetic valve is controlled to be opened.

In general, under normal water pressure, cold water enters the second liner 200 through the water inlet pipe 700, when the water pressure detected by the pressure sensor reaches a preset pressure, the controller controls the first control valve 302 on the exhaust pipe 301 to be closed, controls the second control valve on the third water outlet pipe 604 to be closed, when the cold water in the second liner 200 is stored to a certain amount, the one-way valve 402 is automatically opened, the cold water in the second liner 200 enters the first liner 300 through the first connecting pipe 401, when both the second liner 200 and the first liner 300 are full of water, the heating assembly 500 in the first liner 300 starts to work, the water in the first liner 300 is heated to a target temperature selected by a user, when the user opens the water outlet valve to use water, the hot water in the first liner 300 flows out through the second water outlet pipe 602, the cold water in the second liner 200 flows out through the first water outlet pipe 601, the water output by the first water outlet pipe 601 and the second water outlet pipe 602 is mixed in the water mixing valve 603 at the moment, and flows out after the water reaches the required water temperature, and the water heating assembly 500 is used for outputting hot water by the water depending on the water pressure of a pipeline.

When the water pressure in the pipeline is insufficient or the water is stopped, the pressure detected by the pressure sensor is smaller than the preset pressure, at this time, the controller automatically controls the first control valve 302 to be opened, and controls the second control valve to be opened, so that cold water in the second liner 200 is communicated with hot water in the first liner 300 and atmospheric pressure, when a user opens the water outlet valve to use water, hot water in the first liner 300 flows out through the second water outlet pipe 602, or when the water in the first liner 300 is still at a certain water level, the water can flow out through the second water outlet pipe 602 and the third water outlet pipe 604 together, when the water level in the first liner 300 is reduced to be below the outlet end of the second water outlet pipe 602, the water in the second liner 200 can flow out through the third water outlet pipe 604, and therefore the normal water outlet of the electric water heater is ensured, and of course, the cold water in the second liner 200 and the hot water stored in the first liner 300 can be used for meeting the emergency needs of the user, namely the hot water can be selected to be stored directly out of the cold water in the second liner 200.

While the present utility model has been described with reference to the preferred embodiments shown in the drawings, it will be readily understood by those skilled in the art that the scope of the utility model is not limited to those specific embodiments, and the above examples are only for illustrating the technical solution of the utility model, not for limiting it; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (10)

1. The electric water heater comprises a heating assembly, a water outlet pipe and a water inlet pipe, and is characterized by further comprising a first inner container, a second inner container and a water guide assembly, wherein the heating assembly is arranged in the first inner container, the water inlet pipe is communicated with the second inner container, and the water outlet pipe is communicated with the first inner container and the second inner container, so that water in the first inner container and the second inner container flows out after being mixed through the water outlet pipe;

the water guide assembly is communicated with the first inner container and the second inner container, and enables water to flow from the second inner container into the first inner container in a unidirectional manner;

the first liner is also provided with an exhaust pipe, and the exhaust pipe is provided with a first control valve for controlling the on-off of the exhaust pipe.

2. The electric water heater of claim 1, further comprising a controller, wherein the water inlet pipe is provided with a pressure sensor for detecting pressure in the water inlet pipe, and wherein the first control valve and the pressure sensor are both electrically connected with the controller;

the controller controls the first control valve to be closed when the pressure in the water inlet pipe is greater than or equal to a preset pressure;

and when the pressure in the water inlet pipe is smaller than the preset pressure, the controller controls the first control valve to be opened.

3. The electric water heater according to claim 2, wherein the exhaust pipe is installed at an upper portion of the first liner, and a second connection pipe is provided between the exhaust pipe and the water inlet pipe, and the first control valve is located above the second connection pipe.

4. The electric water heater of claim 2, wherein the water outlet pipe comprises a first water outlet pipe, a second water outlet pipe and a water mixing valve, wherein an inlet end of the first water outlet pipe is communicated with the second liner, an inlet end of the second water outlet pipe is communicated with the first liner, and outlet ends of the first water outlet pipe and the second water outlet pipe are communicated with the water mixing valve.

5. The electric water heater according to claim 4, wherein the water outlet pipe further comprises a third water outlet pipe, the water mixing valve further communicating with an outlet end of the third water outlet pipe;

the inlet end of the third water outlet pipe is communicated with the bottom of the first liner, and the inlet end of the second water outlet pipe extends to the upper portion of the first liner.

6. The electric water heater according to claim 5, wherein a second control valve is arranged on the third water outlet pipe, and the second control valve is electrically connected with the controller;

the controller controls the second control valve to be closed when the pressure in the water inlet pipe is greater than or equal to a preset pressure;

and when the pressure in the water inlet pipe is smaller than the preset pressure, the controller controls the second control valve to be opened.

7. The electric water heater as claimed in any one of claims 1-6, wherein the water guide assembly includes a first connection tube and a one-way valve disposed on the first connection tube.

8. The electric water heater of claim 7, further comprising a housing and a thermal shield;

the shell is internally hollow to form an inner cavity, the heat insulation baffle separates the inner cavity into a first cavity and a second cavity, the second inner container is positioned in the first cavity, the first inner container is positioned in the second cavity, and the first connecting pipe penetrates through the heat insulation baffle to be communicated with the first inner container and the second inner container.

9. The electric water heater of claim 8, wherein an insulating layer is disposed between the inner wall of the second cavity and the first liner.

10. The electric water heater of claim 7, wherein the heating assembly comprises a magnesium rod and an electric heating tube.