CN112833545A

CN112833545A - Water heater

Info

Publication number: CN112833545A
Application number: CN201911156578.5A
Authority: CN
Inventors: 盛保敬; 孙强; 边文兵; 赵小勇
Original assignee: Qingdao Economic And Technology Development District Haier Water Heater Co ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Economic And Technology Development District Haier Water Heater Co ltd; Haier Smart Home Co Ltd
Priority date: 2019-11-22
Filing date: 2019-11-22
Publication date: 2021-05-25

Abstract

The invention belongs to the technical field of water heaters, and particularly relates to a water heater. The invention aims to solve the problem that the damage probability of an electric heating pipe is increased due to the accumulation of water scale of the existing water heater. The water heater comprises an inner container, a central tube, an outer sleeve, a plug, a base and scale removing substances, wherein the central tube is inserted on the inner container, a first end of the central tube is arranged in the inner container, a second end of the central tube extends out of the inner container, the outer sleeve is arranged in the inner container and sleeved on the central tube, a gap is formed between the outer sleeve and the central tube, a first through hole is formed in the outer sleeve, the plug and the base are sleeved on the central tube arranged in the inner container, the plug is used for plugging the first end of the gap, the base is used for plugging the second end of the gap, and the scale removing substances are. Compared with the prior art, when the water heater is heated by the electric heating pipe, the probability of damage to the electric heating pipe caused by accumulation of scale on the electric heating pipe is reduced.

Description

Water heater

Technical Field

The invention belongs to the technical field of water heaters, and particularly relates to a water heater.

Background

A household water storage type electric water heater is a common household appliance, and generally includes an inner container for storing water and an electric heating tube disposed in the inner container, and the electric heating tube is used for heating water in the inner container.

The household water storage type electric heater can generate scale in the heating and heat preservation processes because the water contains impurities such as calcium ions, magnesium ions, carbonate, bicarbonate radical, sulfate radical and the like, when the water reaches a certain temperature, the calcium ions and the carbonate radical are combined to generate calcium carbonate, the calcium ions and the sulfate radical are combined to generate calcium sulfate, the magnesium ions and the carbonate radical are combined to generate magnesium carbonate, and the calcium carbonate, the calcium sulfate, the magnesium carbonate and the like are precipitated to form the scale. The scale deposits on the electric heating tube, which can cause the temperature inside the electric heating tube to be too high, and further increase the damage probability of the electric heating tube.

Disclosure of Invention

In order to solve the problems in the prior art, namely to solve the problem that the damage probability of an electric heating pipe is increased due to the accumulation of water scale of the existing water heater, the invention provides a water heater, which comprises an inner container, a central pipe, an outer sleeve, a plug, a base and scale removing substances, wherein the inner container is provided with a water inlet and a water outlet;

the central tube is inserted on the liner wall of the liner, the first end of the central tube protrudes a set length in the liner, and the second end of the central tube extends out of the liner;

the outer sleeve is positioned in the inner container and sleeved on the central tube; a gap is formed between the outer sleeve and the central tube, and a first through hole for communicating the gap and the inner container is formed in the outer sleeve;

the plug and the base are sleeved on a central pipe positioned in the inner container and positioned at two ends of the gap, the plug is used for plugging a first end of the gap, and the base is used for plugging a second end of the gap;

the descaling substance is filled in the gap.

In the above preferred technical solution of the water heater, the first through hole is in the shape of a strip hole and/or a round hole.

In the preferable technical scheme of the water heater, the descaling substance is granular descaling agent.

In the preferred technical scheme of the water heater, the plug comprises a conical pipe section and a straight pipe section connected with the large end of the conical pipe section, and at least part of the conical pipe section is inserted into the gap.

In the preferable technical scheme of the water heater, the plug is a hollow first cylinder, a first flange is arranged at the first end of the first cylinder, the second end of the first cylinder is located in the gap, and the first flange abuts against the first end of the outer sleeve.

In the above preferred technical solution of the water heater, the outer side surface of the first cylinder is provided with a first annular groove coaxial with the first cylinder, and the first annular groove is located between the second end of the first cylinder and the first flange.

In the preferable technical scheme of the water heater, the base is a hollow second cylinder, a first end of the second cylinder is provided with a second flange, a second end of the second cylinder is located in the gap, and the second flange abuts against a second end of the outer sleeve.

In a preferred embodiment of the above water heater, the outer side surface of the second cylinder is provided with a second annular groove coaxial with the second cylinder, and the second annular groove is located between the second end of the second cylinder and the second flange.

In the preferred technical scheme of above-mentioned water heater, the water heater still includes stay tube and spiral shell head, and the spiral shell head suit is on being located the outer center tube of inner bag, and the stay tube suit is outside the center tube, and the first end and the base butt of stay tube, the second end and the spiral shell head butt of stay tube.

In the preferred technical scheme of above-mentioned water heater, the first end cover of center tube is equipped with the extension pipe.

The water heater comprises an inner container, a central tube, an outer sleeve, a plug, a base and scale removing substances, wherein the central tube is inserted into the wall of the inner container, a first end of the central tube protrudes out of the inner container by a set length, a second end of the central tube protrudes out of the inner container, the outer sleeve is positioned in the inner container and sleeved on the central tube, a gap is formed between the outer sleeve and the central tube, a first through hole for communicating the gap and the inner container is formed in the outer sleeve, the plug and the base are sleeved on the central tube positioned in the inner container and positioned at two ends of the gap, the plug is used for plugging the first end of the gap, the base is used for plugging the second end of the gap, and the scale removing substances are filled in the gap. The outer sleeve, the base and the plug are sleeved outside the pipe wall of the central pipe, a gap is formed between the central pipe and the outer sleeve to fill scale removing substances, meanwhile, the first through hole is formed in the pipe wall of the outer sleeve to enable the gap to be communicated with the inside and the outside, the scale removing substances are diffused in water in the inner container through the first through hole and are subjected to physical or chemical reaction with the water, and therefore the phenomenon that impurities in the water generate scale in the inner container in the heating and heat preservation processes of the water heater is avoided.

Drawings

Preferred embodiments of the water heater of the present invention will be described with reference to the accompanying drawings in conjunction with the water heater. The attached drawings are as follows:

FIG. 1 is a schematic structural diagram of a water heater according to an embodiment of the present invention;

FIG. 2 is a sectional view taken along line A-A of FIG. 1;

FIG. 3 is an enlarged view at B of FIG. 2;

FIG. 4 is an enlarged view at C of FIG. 2;

FIG. 5 is a cross-sectional view of a water heater of an embodiment of the present invention;

FIG. 6 is a cross-sectional view of a plug according to an embodiment of the present invention;

FIG. 7 is another cross-sectional view of a plug according to an embodiment of the present invention;

FIG. 8 is a cross-sectional view of a base of an embodiment of the present invention;

figure 9 is another cross-sectional view of a base of an embodiment of the present invention.

Description of reference numerals:

10: a central tube;

11: lengthening a pipe;

20: an outer sleeve;

30: a plug;

31: a conical pipe section;

32: a straight pipe section;

33: a first annular groove;

34: a first flange;

40: a base;

41: a second annular groove;

42: a second flange;

50: a scale removing substance;

60: supporting a tube;

70: a screw head.

Detailed Description

First, it should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention. And can be adjusted as needed by those skilled in the art to suit particular applications.

Next, it should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "inside", "outside", and the like are based on the direction or positional relationship shown in the drawings, which are merely for convenience of description, and do not indicate or imply that a device or a member must have a specific orientation, be configured in a specific orientation, and operate, and thus, should not be construed as limiting the present invention.

Furthermore, it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "connected" and "connected" should be interpreted broadly, e.g., as being fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, and the two components can be communicated with each other. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

A household water storage type electric water heater generally includes an inner container for storing water and an electric heating tube disposed in the inner container for heating the water in the inner container. The household water storage type electric heater can generate scale in the heating and heat preservation processes. The scale deposits on the electric heating tube, which can cause the temperature inside the electric heating tube to be too high, and further increase the damage probability of the electric heating tube. And the incrustation scale deposit can breed the pollutant in the inner bag, reduces the quality of water in the inner bag, and then makes user experience not good. In addition, a large amount of incrustations are piled up in the inner bag, can make the water storage capacity of inner bag reduce, and then make the hot water volume reduce, and user experience is not good.

Therefore, the embodiment of the application provides a water heater to reduce the water spot that generates in the inner bag, and then reduce electric heating pipe's damage probability, promote quality of water, guarantee inner bag water storage capacity.

The present application provides a water heater, as shown in fig. 1, 2, 3, 4 and 5, comprising an inner container, a center tube 10, an outer sleeve 20, a plug 30, a base 40 and a scale removing material.

The central tube 10 is inserted into the liner wall of the liner, a first end of the central tube 10 protrudes a set length in the liner, and a second end of the central tube 10 protrudes out of the liner. The central tube 10 may be, for example, a water inlet tube, and water from a water source enters from the second end of the central tube 10 and flows from the first end of the central tube 10 into the inner container to fill the inner container with water. The central tube 10 may also be a water outlet tube, and water in the inner container enters from the first end of the central tube 10 and flows out of the inner container from the second end of the central tube 10, so that hot water is discharged from the water heater.

In a specific example, as shown in fig. 5, when the central tube 10 is a water outlet tube, the first end of the central tube 10 is sleeved with the extension tube 11, and the extension tube 11 enables hot water in the inner container above to preferentially discharge out of the inner container, because the hot water is usually above cold water, correspondingly, the extension tube 11 is not usually arranged on the water inlet tube, so that the cold water is directly discharged below the inner container, and heat exchange between the cold water and the hot water is reduced. The extension tube 11 may be, for example, a stainless steel tube, which is sleeved outside the wall of the central tube 10.

In a specific example, when the central tube 10 is a water inlet tube or a water outlet tube, the electricity-proof wall of the water heater is integrated on the central tube 10, and the water column in the central tube 10 is used for dividing the leakage voltage so as to ensure that the voltage value of the water flowing out is the human body safety voltage when the electricity is leaked, thereby ensuring the use safety of the water heater.

The outer sleeve 20 is located in the liner and is sleeved on the central tube 10, as shown in fig. 2-5, a gap 50 is provided between the outer sleeve 20 and the central tube 10, the plug 30 and the base 40 are sleeved on the central tube 10 located in the liner and located at two ends of the gap 50, the plug 30 is used for plugging a first end of the gap 50, and the base 40 is used for plugging a second end of the gap 50. The first end of gap 50 refers to the end of gap 50 corresponding to the first end of base pipe 10 and the second end of gap 50 refers to the end of gap 50 corresponding to the second end of base pipe 10.

The outer sleeve 20 is provided with a first through hole for communicating the gap 50 with the inner container, the first through hole arranged on the outer sleeve 20 is used for water in the inner container to enter the gap 50 from the first through hole, so that the scale removing substances are dissolved in the water and generate physical and chemical reactions with the water, of course, the first through hole arranged on the outer sleeve 20 is also used for the scale removing substances in the gap 50 to diffuse into the inner container outside the gap 50 from the first through hole, biological and chemical reactions with the water are realized, and further the generation amount of scale is reduced.

In a specific embodiment, the descaling substance can be, for example, granular descaling agent, and the size of the first through hole formed in the outer sleeve 20 is smaller than that of the granular descaling agent, so that the granular descaling agent is confined in the gap 50 and cannot be scattered to any position in the liner, thereby ensuring that the granular descaling agent cannot pollute the water in the liner and cannot realize the effects of hot water bathing and the like.

In a specific embodiment, the water heater further comprises a filter screen pipe, the filter screen pipe is disposed in the outer sleeve 20 or outside the outer sleeve 20, and when the filter screen pipe is disposed in the outer sleeve 20, the descaling substances are filled between the filter screen pipe and the pipe wall of the central pipe 10, so that a gap 50 is formed between the filter screen pipe and the pipe wall of the central pipe 10.

Of course, the distance between the first end of the filter screen pipe and the plug 30 is smaller than the size of the scale removing material, or the first end of the filter screen pipe abuts against the plug 30, and the distance between the second end of the filter screen pipe and the base 40 is smaller than the size of the scale removing material, or the second end of the filter screen pipe abuts against the base 40, or the outer side of the pipe wall of the filter screen pipe abuts against the inner side of the pipe wall of the outer sleeve 20, so that the filter screen pipe can be arranged in the gap 50. When the outer side of the tube wall of the filter screen tube abuts against the inner side of the tube wall of the outer tube 20, the filter screen tube may be attached to only a partial region of the outer tube 20, that is, the filter screen tube may be changed into a filter screen sheet instead of a tubular shape.

The filter holes on the filter screen pipe are smaller than the scale removing substances, the position of the scale removing substances is limited by the filter screen pipe, the size of the first through hole on the outer sleeve 20 is not specifically limited as long as the inside and outside conduction of the gap 50 can be realized, and obviously, in the scheme, the size of the first through hole can be larger than the size of the scale removing substances.

In a specific embodiment, the number of the first through holes is multiple, each of the first through holes may be a strip-shaped hole or a circular hole, or may be a plurality of first through holes, some of the first through holes are strip-shaped holes, and some of the first through holes are circular holes. The arrangement mode of the first through holes can be various, the specific arrangement mode is not limited, and only the inside and the outside of the conduction gap 50 need to be realized. Specifically, the first through holes are provided on the entire wall of the outer sleeve 20 to allow the scale removing substance to sufficiently diffuse into the water outside the gap 50, thereby better achieving reduction of scale generation.

The water heater comprises an inner container, a central tube 10, an outer sleeve 20, a plug 30, a base 40 and scale removing substances, wherein the central tube 10 is inserted on the wall of the inner container, a first end of the central tube 10 protrudes out of the inner container by a set length, a second end of the central tube 10 extends out of the inner container, the outer sleeve 20 is positioned in the inner container and sleeved on the central tube 10, a gap 50 is formed between the outer sleeve 20 and the central tube 10, a first through hole for communicating the gap 50 with the inner container is formed in the outer sleeve 20, the plug 30 and the base 40 are sleeved on the central tube 10 positioned in the inner container and positioned at two ends of the gap 50, the plug 30 is used for plugging the first end of the gap 50, and the base 40 is used for plugging the second end of the gap. The outer sleeve 20, the base 40 and the plug 30 are sleeved outside the pipe wall of the central pipe 10, the gap 50 is formed between the central pipe 10 and the outer sleeve 20 to fill scale removing substances, meanwhile, the first through hole is formed in the pipe wall of the outer sleeve 20, and the inside and the outside of the gap 50 are conducted, so that the scale removing substances are diffused in water in the inner container through the first through hole and are subjected to physical or chemical reaction with the water, and the phenomenon that impurities in the water generate scale in the inner container in the heating and heat preservation processes of the water heater is avoided. In addition, the water heater of the embodiment of the invention has the advantages that the phenomenon of reducing water quality is weakened due to bacteria breeding caused by the scale, the water quality is better, the water storage capacity of the inner container is not reduced due to the scale, and the user experience is better.

It can be understood that the water heater according to the embodiment of the present invention may be filled with a mineralized material, activated carbon, or an antibacterial material, in addition to the descaling substance in the gap 50. When the gap 50 is filled with a mineralized material or activated carbon, or both, the mineralized material and activated carbon may achieve the effect of purifying water, and the mineralized material may be at least one of actinolite, tourmaline, ceramic particles, stalactite, magnesite, sepiolite, potash feldspar, zinc ore, stone needle, ochre, calcite, and talc, for example. When the gap 50 is filled with the antibacterial material, an effect of sterilizing water can be achieved.

In a specific embodiment, as shown in fig. 6, the plug 30 comprises a conical pipe section 31 and a straight pipe section 32 connected to the large end of the conical pipe section 31, the inner diameter of the conical pipe section 31 is equal to the inner diameter of the straight pipe section 32, the conical pipe section 31 and the straight pipe section 32 are sleeved on the first end of the central pipe 10, the straight pipe section 32 is closer to the first end of the central pipe 10 than the conical pipe section 31, and at least a part of the conical pipe section 31 is inserted into the gap 50 to close the first end of the gap 50. The outer side wall of the conical section 31 abuts against the first end of the outer sleeve 20, the first end of the outer sleeve 20 refers to the end of the outer sleeve 20 corresponding to the first end of the central tube 10, and at this time, line contact is formed between the conical section 31 and the first end of the outer sleeve 20.

Specifically, the outer diameter of the large end of the taper pipe section 31 is smaller than the outer diameter of the straight pipe section 32, an avoiding step is formed at the joint of the taper pipe section 31 and the straight pipe section 32, the avoiding step can avoid the wall thickness of the outer sleeve 20, and then after the first end of the outer sleeve 20 abuts against the outer side wall of the taper pipe section 31, the outer side wall surface of the outer sleeve 20 and the outer side wall surface of the straight pipe section 32 of the plug 30 are in a cylindrical surface, so that after the outer sleeve 20 and the plug 30 are assembled, the appearance is better. The first end of outer sleeve 20 abuts the outer sidewall of cone section 31, and there is line contact between cone section 31 and the first end of outer sleeve 20. Of course, the first end of the outer sleeve 20 may abut against the end wall of the small end of the conical section 31, and the conical section 31 and the first end of the outer sleeve 20 may be in surface contact.

Specifically, the conical pipe section 31 and the straight pipe section 32 are of an integrated structure, and the conical pipe section 31 and the straight pipe section 32 are of an integrated structure, so that the assembly procedure between the conical pipe section 31 and the straight pipe section 32 can be avoided, and the whole assembly time is shortened.

In another specific embodiment, as shown in fig. 7, the plug 30 is a hollow first cylinder, that is, the plug 30 is a tubular column, the first end of the first cylinder is provided with a first flange 34, the first end of the first cylinder refers to an end of the first cylinder corresponding to the first end of the central tube 10, the first flange 34 protrudes toward the outside of the first cylinder, the first cylinder is sleeved on the first end of the central tube 10, and the first end of the first cylinder is closer to an end surface of the first end of the central tube 10 than the second end of the first cylinder, the second end of the first cylinder is located in the gap 50, and the first flange 34 abuts against the first end of the outer sleeve 20, so that the plug 30 blocks the first end of the gap 50.

In the specific example, as shown in fig. 7, the outer lateral surface of the first cylinder is provided with a first annular groove 33 coaxial with the first cylinder, i.e. the first annular groove 33 is arranged around the axis of the first cylinder, the first annular groove 33 being located between the second end of the first cylinder and the first flange 34. The first annular groove 33 opens towards the inside of the wall of the outer sleeve 20.

In a specific embodiment, as shown in fig. 8, the base 40 is a hollow second cylinder, that is, the base 40 is a tubular column, a first end of the second cylinder is provided with a second flange 42, the first end of the second cylinder refers to an end of the second cylinder corresponding to the first end of the central tube 10, the first end of the second cylinder is opposite to the first end of the first cylinder, the second cylinder is sleeved on a second end of the central tube 10, the second end of the second cylinder is closer to the second end of the central tube 10 than the first end of the second cylinder, the second end of the second cylinder is located in the gap 50, and the second flange 42 abuts against the second end of the outer sleeve 20, so that the base 40 blocks the second end of the gap 50.

In the specific example, as shown in fig. 9, the outer lateral surface of the second cylinder is provided with a second annular groove 41 coaxial with the second cylinder, i.e. the second annular groove 41 is arranged around the axis of the second cylinder, the second annular groove 41 being located between the second end of the second cylinder and the second flange 42, the opening of the second annular groove 41 facing towards the inner side of the wall of the outer sleeve 20.

In a specific embodiment, as shown in fig. 2, 4 and 5, the water heater further includes a support tube 60 and a screw head 70, the screw head 70 is located outside the inner container, the screw head 70 is sleeved on the central tube 10 located outside the inner container, the support tube 60 is sleeved outside the central tube, a first end of the support tube 60 abuts against the base 40, and a second end of the support tube 60 abuts against the screw head 70.

In a specific example, the screw head 70 is a hollow tube, the hollow tube includes a first hole section, a second hole section and a third hole section, the inner diameter of the first hole section is sequentially increased, a first step surface is formed at a joint of the first hole section and the second hole section, a second step surface is formed at a joint of the second hole section and the third hole section, the second end of the central tube 10 abuts against the first step surface, the central tube 10 is connected with the screw head in a welding manner or a threaded manner, and a support tube sleeved outside the central tube 10 abuts against the second step surface.

In a specific embodiment, the plug 30 is provided with a blocking portion for blocking the first end opening of the central tube 10, and the wall of the central tube 10 is provided with a second through hole for communicating the inside and the outside of the wall of the central tube 10, that is, communicating the inside of the wall of the central tube 10 and the gap 50. The inner container is communicated with the gap 50 through a first through hole on the outer sleeve 20, and the gap 50 is communicated with the inner side of the tube wall of the central tube 10 through a second through hole.

When the central tube 10 is a water outlet tube, water in the inner container enters the gap 50 through the first through hole, then flows into the tube wall of the central tube 10 from the gap 50 through the second through hole, and is discharged out of the inner container, and the gap 50 is a path through which the water must pass, so that the biological and chemical reaction with water can be realized.

When the central tube 10 is a water inlet tube, water from a water source flows into the inner container from the inner wall of the central tube 10 through the second through hole channel gap 50, the water in the gap 50 flows into the inner container through the first through hole on the outer sleeve 20, and the gap 50 is a path through which water flow must pass, so that a biochemical reaction with water can be realized.

When the central tube 10 is a water inlet tube, specifically, the second through hole is disposed at the first end of the central tube 10, and the first through hole is disposed at the second end of the outer sleeve 20, so that cold water enters the bottom of the inner container. The size of the first through hole is smaller than that of the scale removing substances, certainly, the size of the first through hole is larger than that of the scale removing substances, at this time, a filter screen needs to be arranged in the pipe wall of the outer sleeve 20 or outside the pipe wall of the outer sleeve 20, the filter holes in the filter screen are smaller than the size of the scale removing substances, when the filter screen is arranged on the inner side of the pipe wall of the outer sleeve 20, the scale removing substances need to be ensured to be located between the outer sleeve 20 and the central pipe 10, and the scale removing substances can only enter the inner container through the first through hole.

In a particular embodiment, the descaling substance is formed into a sleeve, for example by bonding with a polymer forming material, the sleeve is fitted over the outside of the base pipe 10, and the descaling substance used to form the sleeve may be, for example, a powdery solid. Of course, when the mineralized material, the activated carbon, the antibacterial material, or the like is solid, the mineralized material, the activated carbon, the antibacterial material, or the like may be bonded to the polymer material to form the sleeve.

In the water heater of the embodiment of the invention, the outer sleeve 20, the base 40 and the plug 30 are sleeved outside the pipe wall of the central pipe 10, the gap 50 is formed between the central pipe 10 and the outer sleeve 20 to fill the scale removing substances, meanwhile, the pipe wall of the outer sleeve 20 is provided with the first through hole, and the inside and the outside of the gap 50 are conducted, so that the scale removing substances are diffused in water in the liner through the first through hole and are subjected to physical or chemical reaction with the water, and the phenomenon that impurities in the water generate scale in the liner in the heating and heat preservation processes of the water heater is avoided. In addition, the water heater of the embodiment of the invention has the advantages that the phenomenon of reducing water quality is weakened due to bacteria breeding caused by the scale, the water quality is better, the water storage capacity of the inner container is not reduced due to the scale, and the user experience is better.

The water heater provided by the embodiment of the invention has the advantages of simple structure, convenience in installation, disassembly and replacement, low cost, good descaling substance release effect and good descaling effect.

So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.

Claims

1. A water heater is characterized by comprising an inner container, a central pipe, an outer sleeve, a plug, a base and scale removing substances;

the central tube is inserted into the inner container wall of the inner container, the first end of the central tube protrudes a set length in the inner container, and the second end of the central tube extends out of the inner container;

the plug and the base are sleeved on the central pipe in the inner container and positioned at two ends of the gap, the plug is used for plugging a first end of the gap, and the base is used for plugging a second end of the gap;

the descaling substance is filled in the gap.

2. The water heater according to claim 1, wherein the first through hole is shaped as a bar hole and/or a round hole.

3. The water heater of claim 1, wherein the scale removal substance is a granular scale remover.

4. The water heater according to claim 1, wherein the plug comprises a tapered section and a straight section connected to a large end of the tapered section, and at least a portion of the tapered section is inserted into the gap.

5. The water heater according to claim 1, wherein the plug is a hollow first cylinder, a first end of the first cylinder is provided with a first flange, a second end of the first cylinder is located in the gap, and the first flange abuts against the first end of the outer sleeve.

6. The water heater according to claim 5, wherein the outer side of the first cylinder is provided with a first annular groove coaxial with the first cylinder, the first annular groove being located between the second end of the first cylinder and the first flange.

7. The water heater according to claim 1, wherein the base is a second hollow cylinder, a first end of the second cylinder is provided with a second flange, a second end of the second cylinder is located in the gap, and the second flange abuts against a second end of the outer sleeve.

8. The water heater according to claim 7, wherein the outer side of the second cylinder is provided with a second annular groove coaxial with the second cylinder, the second annular groove being located between the second end of the second cylinder and the second flange.

9. The water heater according to any one of claims 1-8, further comprising a support tube and a screw head, wherein the screw head is sleeved on the central tube outside the inner container, the support tube is sleeved outside the central tube, a first end of the support tube abuts against the base, and a second end of the support tube abuts against the screw head.

10. The water heater according to any one of claims 1-8, wherein the first end of the center tube is sleeved with an extension tube.