CN108507387B

CN108507387B - Phase change heat storage device and water heater

Info

Publication number: CN108507387B
Application number: CN201710116462.3A
Authority: CN
Inventors: 曾云; 曲绍鹤; 申勇兵
Original assignee: Midea Group Co Ltd
Current assignee: Wuhu Midea Smart Kitchen Appliance Manufacturing Co Ltd
Priority date: 2017-02-28
Filing date: 2017-02-28
Publication date: 2019-12-13
Anticipated expiration: 2037-02-28
Also published as: CN110879016A; CN110806133A; CN108507387A; CN110806132A

Abstract

the invention discloses a phase change heat storage device and a water heater, wherein the phase change heat storage device comprises a shell, a phase change body, a heat exchange pipeline and a heat insulation piece, wherein the shell is provided with an accommodating cavity; the shell is a plastic part; the phase change body is accommodated in the accommodating cavity; the melting point of the phase change body is lower than that of the plastic part; the heat exchange pipeline is inserted in the phase change body; the heat insulation piece is aerogel; the heat insulation piece covers in the surface of casing, the thickness of heat insulation piece is not less than 3mm, the heat insulation piece cladding the area of casing surface is not less than 30% of casing surface area. The phase change heat storage device of the technical scheme of the invention can improve the heat preservation effect and lead the electric water heater to be more energy-saving.

Description

Phase change heat storage device and water heater

Technical Field

The invention relates to the field of heat energy equipment, in particular to a phase change heat storage device and a water heater.

Background

The water heater generally has a heat storage function, and the heat storage function stores heat through a heat storage device so that a user can obtain hot water in time when using the hot water. There are various types of heat storage devices, and a phase change heat storage material is highly preferred because of its high heat storage density, and the application of a phase change material as a heat storage material is becoming more and more widespread.

However, the phase change material has high latent heat, and volume expansion occurs during the endothermic liquefaction of the phase change body. Therefore, the shell of the existing phase change heat storage device generally adopts metal parts to strengthen the strength, so that the existing phase change heat storage device has poor heat insulation performance and poor heat insulation effect. The invention provides a phase change heat storage device which has a good heat preservation effect and a poor energy-saving effect of a water heater.

Disclosure of Invention

The invention mainly aims to provide a phase change heat storage device and a water heater, and aims to improve the heat preservation effect and enable the water heater to be more energy-saving.

In order to achieve the purpose, the phase change heat storage device comprises a shell, a phase change body, a heat exchange pipeline and a heat insulation piece, wherein the shell is provided with an accommodating cavity; the shell is a plastic part; the phase change body is accommodated in the accommodating cavity; the melting point of the phase change body is lower than that of the plastic part; the heat exchange pipeline is inserted in the phase change body; the heat insulation piece is aerogel; the heat insulation piece covers in the surface of casing, the thickness of heat insulation piece is not less than 3mm, just the heat insulation piece cladding the area of casing surface is not less than 30% of casing surface area.

Preferably, the heat exchange pipeline is arranged in a coil pipe mode, the heat exchange pipeline is provided with a plurality of sections of bending sections and a plurality of sections of direct current sections, the bending sections are in semicircular bending, and heat exchange gaps are arranged among the direct current sections.

Preferably, fins are arranged between the straight flow sections, and the fins are arranged at intervals along the length direction of the straight flow sections.

Preferably, the phase change bodies are two layers, and the two layers of the phase change bodies are not mutually soluble.

Preferably, the casing has the vent, the vent is located the top of casing with the holding chamber intercommunication, the heat insulating part is in vent department is equipped with the breach of stepping down.

preferably, the air vent comprises an air inlet and an air outlet, and the air inlet is provided with a filtering device.

Preferably, the air outlet is provided with an exhaust valve.

Preferably, the accommodating cavity is a closed cavity, and a negative pressure cavity communicated with the accommodating cavity is arranged in the accommodating cavity.

Preferably, the negative pressure cavity is formed by injecting the phase change body into the accommodating cavity and solidifying the phase change body.

The invention also provides a water heater, which comprises a phase change heat storage device, wherein the phase change heat storage device comprises a shell, a phase change body, a heat exchange pipeline and a heat insulation piece, and the shell is provided with an accommodating cavity; the shell is a plastic part; the phase change body is accommodated in the accommodating cavity; the melting point of the phase change body is lower than that of the plastic part; the heat exchange pipeline is inserted in the phase change body; the heat insulation piece is aerogel; the heat insulation piece covers in the surface of casing, the thickness of heat insulation piece is not less than 3mm, the heat insulation piece cladding the area of casing surface is not less than 30% of casing surface area. .

According to the invention, the shell is set to be the plastic part, and the heat insulation part is arranged on the outer surface of the shell and is integrally formed with the plastic part, so that after the phase change body in the accommodating cavity is in contact with the shell for heat exchange, the heat of the shell is blocked by the heat insulation part and is difficult to exchange heat with the outside, and the heat is kept in the shell, so that the speed of radiating the phase change body to the outside is reduced, the temperature reduction of the phase change body is further slowed down, the heat insulation effect of the phase change heat storage device is improved, and the water heater is more energy-saving.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic internal structural view of a phase change heat storage device according to a first embodiment of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1;

Fig. 3 is a schematic view of the internal structure of a phase change thermal storage device according to a second embodiment of the present invention.

The reference numbers illustrate:

Reference numerals	Name (R)	Reference numerals	name (R)
				10	Shell body	31	bending section
11	Containing cavity	32	Direct current section
				111	Negative pressure cavity	321	Fin
12	Vent port	40	Heat insulation piece
				121	Air inlet	41	Abdication gap
122	Air outlet	50	Filter device
				20	Phase change body	60	Air exhaust valve
30	Heat exchange pipeline

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The invention provides a phase change heat storage device.

In the embodiments of the present invention, as shown in fig. 1 and 2, solid lines with arrows indicate planes or spaces such as faces, cavities, holes, etc. The phase change heat storage device comprises a shell 10, a phase change body 20, a heat exchange pipeline 30 and a heat insulation piece 40, wherein the shell 10 is provided with an accommodating cavity 11; the shell 10 is a plastic part; the phase change body 20 is accommodated in the accommodating cavity 11; the melting point of the phase change body 20 is lower than that of the plastic part; heat exchange tubes 30 are interspersed within the phase-change body 20; the thermal insulation 40 is aerogel; the heat insulation piece 40 covers the outer surface of the shell 10, the thickness of the heat insulation piece is not less than 3mm, and the area of the outer surface of the shell 10, which is coated by the heat insulation piece 40, is not less than 30% of the area of the outer surface of the shell 10.

specifically, referring to fig. 1, the housing 10 of the phase change heat storage device is used for accommodating the phase change body 20, the housing 10 has an accommodating chamber 11, and the larger the capacity of the accommodating chamber 11 is, the more the phase change body 20 can be accommodated accordingly. The phase change body 20 is used for absorbing heat through heat exchange with the heat exchange pipe 30 or the housing 10, and then storing the heat in the accommodating chamber 11, and when the heat of the phase change heat storage device needs to be used, the heat of the phase change body 20 is conducted out of the phase change heat storage device through heat exchange so as to release heat to the outside. During the process of heat absorption and release of the phase change body 20, the phase change body 20 undergoes phase change, the phase change action causes the volume of the phase change body 20 in the accommodating cavity 11 to change, and when the phase change body 20 absorbs enough heat, the solid state is converted into the liquid state to undergo volume expansion; when the phase change body 20 releases sufficient heat, the volume of the liquid phase changes to a solid phase, and the liquid phase shrinks. The heat of the phase change body 20 can be conducted out of the phase change heat storage device through the casing 10, and the heat insulation material is arranged around the casing 10 to achieve the effect of heat insulation.

referring to fig. 1, in the embodiment of the present invention, the phase change body 20 is accommodated in the accommodating cavity 11 and can freely expand or contract, where the expansion or contraction refers to that the phase change body 20 does not directly press the shell 10 after being deformed, so that the shell 10 is plastically deformed. A certain space is set in the accommodating cavity 11 for the phase change body 20 to expand, when the phase change body 20 expands, the air in the accommodating cavity 11 is squeezed, the air pressure is positive pressure, the air pressure is reduced, and a mode of communicating the accommodating cavity 11 with the atmosphere or applying negative pressure can be adopted. The heat insulating material 40 is provided on the outer surface of the casing 10, and the type and material of the heat insulating material 40 are not particularly limited, but asbestos, heat insulating felt, or other material having a low thermal conductivity may be used. Those skilled in the art can obtain corresponding technical solutions through the embodiments of the present invention and the accompanying drawings, which are not described herein in detail. Of course, the thermal insulation member 40 can be made into a thermal sleeve, a thermal coating, a thermal ring or other shapes that can cover the surface of the housing 10 to achieve the purpose of sufficient heat insulation. When the phase change body 20 in the accommodating chamber 11 contacts the housing 10 for heat exchange, the heat of the housing 10 is blocked by the heat insulator 40 and is difficult to exchange heat with air. The heat of the casing 10 stays inside the casing 10, so that the temperature difference between the phase change body 20 and the casing 10 is reduced, the heat transfer speed from the phase change body 20 to the casing 10 is reduced, the temperature change of the phase change body 20 is further slowed down, the heat preservation effect of the phase change heat storage device is improved, and the water heater is more energy-saving.

In order to further improve the heat insulation performance of the phase change heat storage device housing 10, referring to fig. 1, in the present embodiment, the housing 10 is configured as a plastic part, and the plastic part has a lower thermal conductivity relative to a metal part, and the housing 10 is configured as a plastic part, so that the plastic part can further obstruct heat conduction between the phase change body 20 accommodated in the accommodating cavity 11 and the housing 10, so that more heat is retained inside the housing 10, and the heat insulation effect is improved. In consideration of securing the reliability of the housing 10, the melting point of the plastic member is higher than that of the phase change body 20, so that it is difficult for the heat in the accommodating chamber 11 to melt the housing 10. Further, in order to improve the heat insulation effect, the heat insulation member 60 is aerogel. The aerogel has the characteristic of low heat conductivity coefficient and has a better barrier effect on heat conduction. Meanwhile, the thermal insulation member 60 is made into aerogel, and the aerogel material has the characteristic of flexibility, and can be attached to the outer wall surface of the plastic shell 10 to generate certain deformation, so that the aerogel can be fully contacted with the outer wall surface, and a good thermal insulation effect is achieved. Moreover, the aerogel felt has the characteristics of light weight, fire resistance, environmental protection and the like, and is suitable for being used as a heat insulation material of a heat storage device so as to reduce the overall weight of the phase change heat storage device. In view of reducing the manufacturing cost of the phase change heat storage device, the plastic housing 10 and the heat insulating member 60 are integrally formed, and the heat insulating member 60 may be formed together with the plastic housing 10 by two-shot molding or two-shot molding, so as to improve mass productivity and simplify the installation process.

For the purpose of further improving the heat exchange efficiency, referring to fig. 1, in this embodiment, the heat exchange pipe 30 is a coil pipe, and the coil pipe has a larger heat exchange area and a fast heat exchange speed relative to the straight pipe. The heat exchange pipeline 30 is provided with a plurality of bending sections 31 and a plurality of straight flow sections 32, the bending sections 31 are bent in a semicircular shape to enable the heat exchange pipeline 30 to form a roundabout shape and play a role of fully utilizing the space of the accommodating cavity 11, heat exchange gaps are arranged among the straight flow sections 32, and the gaps can enable the contact area between the phase change body 20 and the heat exchange pipeline 30 to be larger and fully improve the heat exchange efficiency when the heat exchange pipeline is attached to and arranged relative to the straight flow sections 32. The heat exchange efficiency in the heat storage device is further improved, the fins 321 are arranged between the direct current sections 32, the fins 321 can be separately arranged sheets or plates for connecting the direct current sections 32, the fins 321 are arranged at intervals along the length direction of the direct current sections 32, so that a certain gap is formed between every two adjacent fins 321, and the phase change body 20 is filled in the gap between every two adjacent fins 321, so that the heat exchange area is further increased through contact heat exchange with the fins 321, and the heat exchange efficiency is improved.

In order to further accelerate the heat exchange efficiency, and fully utilize the characteristic that the phase change body 20 absorbs and releases a large amount of latent heat during phase change, referring to fig. 1, in this embodiment, the phase change body 20 is two layers, and the two layers of phase change bodies have two phase change temperature points relative to a single layer of phase change body, and the two phase change temperature points promote the absorption and release of latent heat of the phase change body 20, thereby accelerating the heat exchange efficiency of the phase change heat exchange device. The two layers of phase change bodies 20 are not mutually soluble, so that the phase change bodies 20 are stacked in the accommodating cavity 11. The density of the two layers of phase change bodies 20 has a positive correlation with the phase change temperature thereof, the higher the phase change temperature point between the two layers of phase change bodies 20 is, the higher the density thereof is, the lower the phase change temperature of the phase change body 20 is always placed above the phase change body 20 having the higher phase change temperature, so that the upper layer of phase change body 20 has the function of isolating external impurities.

In order to further reduce the pressure in the housing 10, referring to fig. 1 and 2, in the first embodiment, the housing 10 has a vent 12, and the vent 12 is used to communicate the accommodating chamber 11 with the atmosphere, however, a vent pipe may be provided to communicate with the accommodating chamber 11, and the vent 12 is provided in consideration of cost optimization. The vent 12 is positioned at the top of the shell 10 and communicated with the accommodating cavity 11, so that the vent 12 is always positioned above the end surface of the phase change body 20, the liquid surface of the phase change body 20 does not overflow the vent 12 when floating, and the vent 12 is kept unblocked. The vent 12 may be a through opening or a plurality of one-way through openings, and the cost can be saved by setting the vent 12 as a through opening. Meanwhile, the heat insulation piece 40 is provided with a relief notch 41, and the relief notch 41 is arranged at the vent 12, so that the vent 12 is not blocked by the heat insulation piece 40, and the accommodating cavity 11 is communicated with the atmosphere. The shape of the relief notch 41 is not particularly limited, and may be a circle, a square, a triangle, or other irregular shape.

From the perspective of improving the cleanliness of the accommodating cavity 11, referring to fig. 2, in this embodiment, the vent 12 includes an air inlet 121 and an air outlet 122, both the air inlet 121 and the air outlet 122 are one-way communication ports, the air inlet 121 is provided with a filtering device 50, the filtering device 50 may be a filter screen, an air filter element, filter cotton or other forms of air filtering materials, and the like. The filtering device 50 is used for preventing external impurities from entering the accommodating cavity 11 through the air inlet 121 to pollute the phase body 20, and the cleanliness in the accommodating cavity 11 is improved. Further, in order to prevent frequent exhaust and cause external impurities to enter the accommodating cavity 11, the gas outlet 122 is provided with the exhaust valve 60, when the phase change body 20 is liquefied and expanded, the gas pressure in the accommodating cavity 11 is increased, when the gas pressure in the accommodating cavity 11 is increased to the threshold value of the exhaust valve 60, the exhaust valve 60 is opened, the gas in the accommodating cavity 11 is discharged out of the accommodating cavity 11 through the gas outlet 122, the gas outlet 122 is converted into the normally closed state from the normally open state through the arrangement of the exhaust valve 60, and the cleanliness of the accommodating cavity 11 is further improved.

In view of sealing the housing 10 to further enhance the phase change heat storage device, referring to fig. 3, in the second embodiment, the accommodating chamber 11 is a closed chamber, a negative pressure chamber 111 communicating with the accommodating chamber 11 is provided in the accommodating chamber 11, and when the phase change body 20 is in a solid state, the air pressure in the negative pressure chamber 111 is in a negative pressure state. After the phase change body 20 absorbs heat and liquefies, the air pressure in the accommodating cavity 11 is increased due to the expansion of the phase change body 20, and the negative pressure in the negative pressure cavity 111 offsets the increase of the air pressure, so that the air pressure in the accommodating cavity 11 is in a zero pressure state, a small amount of negative pressure state or a small amount of positive pressure state. The negative pressure cavity 111 is formed by injecting the phase change body 20 into the accommodating cavity 11 and curing, so that the manufacturing cost can be saved. When the phase change body 20 injected into the accommodating chamber 11 is converted from a liquid phase to a solid phase, the volume of the phase change body 20 is shrunk in the closed accommodating chamber 11, and the air pressure in the accommodating chamber 11 is reduced from zero pressure, so that the negative pressure chamber 111 is formed.

The invention also provides a water heater, which comprises a plurality of phase change heat storage devices, the specific structure of the phase change heat storage devices refers to the above embodiments, and the water heater adopts all technical schemes of all the above embodiments, so that the water heater also has all beneficial effects brought by the technical schemes of the above embodiments, and further description is omitted.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A phase change heat storage device characterized by comprising:

A housing having an accommodating chamber; the shell is a plastic part;

The phase change body is accommodated in the accommodating cavity; the melting point of the phase change body is lower than that of the plastic part;

A heat exchange pipe inserted in the phase change body;

A thermal insulation, the thermal insulation being aerogel; the heat insulating part cover in the surface of casing, the casing with heat insulating part integrated into one piece, heat insulating part's thickness is not less than 3mm, the heat insulating part cladding the area of casing surface is not less than 30% of casing surface area.

2. The phase-change thermal storage device according to claim 1, wherein the heat exchange tube is arranged in a coil, the heat exchange tube has a plurality of bent sections and a plurality of straight sections, the plurality of bent sections are bent in a semicircular shape, and a heat exchange gap is provided between the straight sections.

3. The phase-change thermal storage device according to claim 2, wherein fins are provided between the straight flow sections, the fins being provided at intervals along the length direction of the straight flow sections.

4. The phase-change thermal storage device according to claim 3, wherein the phase-change bodies are two layers, and the two layers are immiscible with each other.

5. The phase change thermal storage device according to claim 1, wherein the case has a vent hole at a top portion thereof in communication with the housing chamber, and the heat insulator has a relief notch at the vent hole.

6. The phase-change thermal storage device according to claim 5, wherein the air vent comprises an air inlet and an air outlet, the air inlet being provided with a filtering means.

7. The phase-change thermal storage device according to claim 6, wherein the gas outlet is provided with a gas exhaust valve.

8. The phase-change heat storage device according to claim 1, wherein the housing chamber is a closed chamber, and a negative pressure chamber communicating with the housing chamber is provided in the housing chamber.

9. The phase-change thermal storage device according to claim 8, wherein the negative pressure chamber is formed by injecting the phase-change body into the accommodation chamber and solidifying the phase-change body.

10. A water heater comprising the phase change thermal storage device according to any one of claims 1 to 9.