Phase change heat accumulator

Abstract

The utility model discloses a phase change heat accumulator which comprises a box body, a heat exchanger and a heat exchanger, the heat exchanger is arranged in the box body and comprises a heat charging heat exchanger, and the heat charging heat exchanger charges heat from an inlet of the heat charging heat exchanger; the phase-change materials are arranged in the box body and comprise a first phase-change material and a second phase-change material, the first phase-change material is located on the upper layer of the second phase-change material, the density and the phase-change temperature of the first phase-change material are lower than those of the second phase-change material, a part of the heat charging heat exchanger is located in the first phase-change material, and a part of the heat charging heat exchanger is located in the second phase-change material. And a part of the heat exchange medium is located in the second phase change material, and the heat exchange medium flowing into the heat charging heat exchanger firstly passes through the heat charging heat exchanger located in the second phase change material and then passes through the heat charging heat exchanger located in the first phase change material. According to the phase change heat accumulator, the overall heat exchange efficiency of the heat exchanger can be balanced, the heat utilization rate is improved, the heat accumulation performance of the phase change heat accumulator is guaranteed, and the energy efficiency of the phase change heat accumulator is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat accumulators, in particular to a phase change heat accumulator. Background Art

[0002] Phase change heat storage has the advantages of small size, large heat storage capacity and no water storage. It can be connected with heat pump to form household hot water heating equipment, which has great application prospects. However, in the existing technology, the energy efficiency of phase change heat storage is fixed and cannot be improved. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a phase change heat accumulator, which can balance the heat exchange efficiency of the heat exchanger, improve the heat utilization rate, ensure the heat storage performance of the phase change heat accumulator, and improve the energy efficiency of the phase change heat accumulator.

[0004] According to the embodiment of the utility model, the phase change heat accumulator includes: a box body; a heat exchanger, which is arranged in the box body and includes a heat charging heat exchanger, and the heat charging heat exchanger charges heat from the inlet of the heat charging heat exchanger; a phase change material, which is arranged in the box body, and the phase change material includes a first phase change material and a second phase change material, the first phase change material is located on the upper layer of the second phase change material, the density of the first phase change material is lower than the density of the second phase change material, the phase change temperature of the first phase change material is lower than the phase change temperature of the second phase change material, part of the heat charging heat exchanger is located in the first phase change material, and part of it is located in the second phase change material, and the heat exchange medium flowing into the heat charging heat exchanger first passes through the heat charging heat exchanger located in the second phase change material, and then passes through the heat charging heat exchanger located in the first phase change material.

[0005] According to the phase change heat storage device of the embodiment of the utility model, the phase change material includes a first phase change material and a second phase change material, the first phase change material is located on the upper layer of the second phase change material, the density and phase change temperature of the first phase change material are lower than the density and phase change temperature of the second phase change material, part of the heat charging heat exchanger is located in the first phase change material, and part of it is located in the second phase change material. The heat exchange medium flowing into the heat charging heat exchanger first passes through the heat charging heat exchanger located in the second phase change material, and then passes through the heat charging heat exchanger located in the first phase change material. The initial temperature of the heat exchange medium flowing into the heat charging heat exchanger from the inlet is higher than the phase change temperature of the second phase change material, so that The heat exchange medium in the heat charging heat exchanger first exchanges heat with the second phase change material with a relatively small temperature difference. After the temperature of the heat exchange medium in the heat charging heat exchanger drops to a certain level, it exchanges heat with the first phase change material with a relatively low phase change temperature. This allows the heat of the heat exchange medium to be fully utilized, ensuring effective heat exchange between the heat exchange medium and the phase change material during the heat exchange process, and balancing the problem of decreased heat exchange power caused by the increasingly smaller temperature difference between the heat exchange medium and the phase change material in the heat charging heat exchanger from bottom to top. This in turn balances the overall heat exchange efficiency of the heat exchanger, improves heat utilization, ensures the heat storage performance of the phase change heat accumulator, and improves the energy efficiency of the phase change heat accumulator.

[0006] In addition, the phase change heat storage device according to the utility model may also have the following additional technical features:

[0007] In some embodiments, the heat charging heat exchanger includes a first fin and a first heat exchange tube, the first heat exchange tube includes a plurality of first straight tube sections and a plurality of first curved tube sections, the plurality of first straight tube sections are spaced apart in the up and down directions, the first curved tube section connects two adjacent first straight tube sections, and there are a plurality of first fins that are spaced apart along the extension direction of the first straight tube sections.

[0008] In some embodiments, both the first phase change material and the second phase change material can change between a solid state and a liquid state. When both the first phase change material and the second phase change material are in a solid state, in the up and down directions, the first fin and the first heat exchange tube are both located below the upper surface of the first phase change material; or, at least a portion of the first heat exchange tube is exposed outside the phase change material, and a corrosion rate of the first heat exchange tube at an interface where the first phase change material contacts the air is less than a preset corrosion rate, wherein the preset corrosion rate is less than or equal to a corrosion rate of the first heat exchange tube at an interface where the second phase change material contacts the air.

[0009] In some embodiments, the heat exchanger further includes: a heat-releasing heat exchanger, which releases heat to the outside from an outlet of the heat-releasing heat exchanger, wherein part of the heat-releasing heat exchanger is located in the first phase change material and part of the heat-releasing heat exchanger is located in the second phase change material, and the heat exchange medium flowing into the heat-releasing heat exchanger first passes through the heat-releasing heat exchanger located in the first phase change material and then passes through the heat-releasing heat exchanger located in the second phase change material.

[0010] In some embodiments, the heat-releasing heat exchanger includes a second fin and a second heat exchange tube, the second heat exchange tube includes a plurality of second straight tube sections and a plurality of second curved tube sections, the plurality of second straight tube sections are spaced apart in the up and down directions, the second curved tube section connects two adjacent second straight tube sections, and there are a plurality of second fins that are spaced apart along the extension direction of the second straight tube sections.

[0011] In some embodiments, both the first phase change material and the second phase change material can change between a solid state and a liquid state. When both the first phase change material and the second phase change material are in a solid state, in the up and down directions, the second fins and the second heat exchange tubes are both located below the upper surface of the first phase change material; or, at least a portion of the second heat exchange tube is exposed outside the phase change material, and a corrosion rate of the second heat exchange tube at an interface where the first phase change material contacts the air is less than a preset corrosion rate, wherein the preset corrosion rate is less than or equal to a corrosion rate of the second heat exchange tube at an interface where the second phase change material contacts the air.

[0012] In some embodiments, the liquid height of the phase change material is h, the solid height is h', the liquid height of the first phase change material is h1, the liquid height of the second phase change material is h2, and the following conditions are satisfied: h1≤1 / 2h, h'>h2.

[0013] In some embodiments, the first phase change material is an organic hydrophobic phase change material.

[0014] In some embodiments, the second phase change material is an inorganic hydrophilic phase change material.

[0015] In some embodiments, there are multiple charging heat exchangers and multiple heat releasing heat exchangers, the number of the heat releasing heat exchangers is twice the number of the charging heat exchangers, and two heat releasing heat exchangers are arranged between any two adjacent charging heat exchangers.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 is a schematic structural diagram of a phase change heat storage device according to an embodiment of the utility model, wherein the phase change material is in liquid state, and the first phase change material and the second phase change material are respectively indicated by section lines in two different directions;

[0019] Figure 2 It is a schematic diagram of the structure of the phase change heat storage device, the heat pump external unit and the hydraulic module according to the embodiment of the utility model, wherein the first phase change material and the second phase change material are respectively indicated by the section lines in two different directions;

[0020] Figure 3 It is a schematic structural diagram of a phase change heat storage device according to an embodiment of the utility model, wherein the phase change material is solid, and the first phase change material and the second phase change material are respectively indicated by section lines in two different directions.

[0021] Reference numerals:

[0022] 100. Phase change heat storage device;

[0023] 1. Box body;

[0024] 2. heat exchanger; 21. heat charging heat exchanger; 211. first heat exchange tube; 212. first straight tube section; 213. first curved tube section; 214. first liquid inlet section; 215. first liquid outlet section; 22. heat releasing heat exchanger; 221. second heat exchange tube; 222. second straight tube section; 223. second curved tube section; 224. second liquid inlet section; 225. second liquid outlet section;

[0025] 3. Phase change material; 31. First phase change material; 32. Second phase change material;

[0026] 201. Heat pump outdoor unit; 202. Hydraulic module. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The phase change heat storage device 100 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0032] like Figure 1 and attached Figure 2 As shown, the phase change heat storage device 100 according to the embodiment of the present utility model includes a box body 1, a heat exchanger 2 and a phase change material 3.

[0033] Specifically, refer to the attached Figure 1 and attached Figure 2 As shown, the heat exchanger 2 is arranged in the box 1, and the box 1 can protect the heat exchanger 2 and ensure the reliability and stability of the phase change heat storage device 100. Figure 1 and attached Figure 2 As shown, the heat exchanger 2 includes a charging heat exchanger 21 , and the charging heat exchanger 21 is charged with heat from an inlet of the charging heat exchanger 21 .

[0034] Further, see Appendix Figure 1As shown, the phase change material 3 is arranged in the box body 1. The phase change material 3 refers to a substance that changes the state of matter (solid-liquid transition) and can provide latent heat without changing the temperature. The process of changing physical properties (solid-liquid transition) is called a phase change process. At this time, the phase change material 3 will absorb or release a large amount of latent heat.

[0035] Further, see the attached Figure 1 As shown, the phase change material 3 includes a first phase change material 31 and a second phase change material 32. The first phase change material 31 is located on the upper layer of the second phase change material 32. The density of the first phase change material 31 is lower than the density of the second phase change material 32. The phase change temperature of the first phase change material 31 is lower than the phase change temperature of the second phase change material 32. The first phase change material 31 with relatively low density and phase change temperature has good stability, will not produce a chemical reaction with the second phase change material 32, and will not dissolve each other. Under the action of gravity, the second phase change material 32 can naturally sink and the first phase change material 31 can naturally float, so that the first phase change material 31 and the second phase change material 32 are layered in the upper and lower directions, avoiding the mixing of the first phase change material 31 and the second phase change material 32 with different phase change temperatures.

[0036] It can be understood that compared with the prior art method of using dual heat exchangers and dual inner tanks to physically isolate heat exchange modules of different temperatures, the different densities of the first phase change material 31 and the second phase change material 32 and the natural physical separation by gravity can reduce the production and processing costs of the phase change heat accumulator 100 and reduce the system complexity of the phase change heat accumulator 100, thereby facilitating the production and processing of the phase change heat accumulator 100.

[0037] Further, see the attached Figure 1 As shown, part of the heat exchanger 21 is located in the first phase change material 31 of the upper layer, and part of it is located in the second phase change material 32 of the lower layer. The heat exchange medium flowing into the heat exchanger 21 first passes through the heat exchanger 21 located in the second phase change material 32, and then passes through the heat exchanger 21 located in the first phase change material 31. The initial temperature of the heat exchange medium flowing into the heat exchanger 21 from the inlet is higher than the phase change temperature of the second phase change material 32, so that the heat exchange medium in the heat exchanger 21 first exchanges heat with the second phase change material 32 with a relatively small temperature difference, and then in the heat exchanger 21 After the temperature of the heat exchange medium is reduced to a certain level, it exchanges heat with the first phase change material 31 with a relatively low phase change temperature, thereby making full use of the heat of the heat exchange medium and ensuring effective heat exchange between the heat exchange medium and the phase change material 3 during the heat exchange process, balancing the problem of decreased heat exchange power caused by the increasingly smaller temperature difference between the heat exchange medium and the phase change material 3 in the heat exchanger 21 from bottom to top, thereby balancing the overall heat exchange efficiency of the heat exchanger 2, improving the heat utilization rate, ensuring the heat storage performance of the phase change heat accumulator 100, and improving the heat charging energy efficiency of the phase change heat accumulator 100.

[0038] Preferably, the phase change temperature of the first phase change material 31 is not less than 40° C., which can ensure the heat storage capacity of the phase change heat storage device 100 .

[0039] According to the phase change heat storage device 100 of the embodiment of the present invention, the phase change material 3 includes a first phase change material 31 and a second phase change material 32. The first phase change material 31 is located on the upper layer of the second phase change material 32. The density and phase change temperature of the first phase change material 31 are lower than the density and phase change temperature of the second phase change material 32. Part of the heat exchanger 21 is located in the first phase change material 31, and part of it is located in the second phase change material 32. The heat exchange medium flowing into the heat exchanger 21 first passes through the heat exchanger 21 located in the second phase change material 32, and then passes through the heat exchanger 21 located in the first phase change material 31. The initial temperature of the heat exchange medium flowing into the heat exchanger 21 from the inlet is higher than that of the second phase change material 32. The phase change temperature causes the heat exchange medium in the heat charging heat exchanger 21 to first exchange heat with the second phase change material 32 with a relatively small temperature difference. After the heat exchange medium in the heat charging heat exchanger 21 is cooled to a certain temperature, it exchanges heat with the first phase change material 31 with a relatively low phase change temperature. This allows full use of the heat of the heat exchange medium to ensure effective heat exchange between the heat exchange medium and the phase change material 3 during the heat exchange process, balances the problem of decreased heat exchange power caused by the decreasing temperature difference between the heat exchange medium and the phase change material 3 in the heat charging heat exchanger 21 from bottom to top, and further balances the overall heat exchange efficiency of the heat exchanger 2, improves heat utilization, ensures the heat storage performance of the phase change heat accumulator 100, and improves the energy efficiency of the phase change heat accumulator 100.

[0040] In some embodiments of the present invention, refer to the attached Figure 1 As shown, the heat charging heat exchanger 21 includes a first fin and a first heat exchange tube 211. The first heat exchange tube 211 includes a plurality of first straight tube segments 212 and a plurality of first curved tube segments 213. The plurality of first straight tube segments 212 are spaced apart in the up and down directions. The first curved tube segment 213 connects two adjacent first straight tube segments 212, which can increase the contact area between the first heat exchange tube 211 and the phase change material 3, and improve the heat transfer rate between the heat exchange medium in the first heat exchange tube 211 and the phase change material 3.

[0041] Furthermore, the first fins are multiple and extend along the extension direction of the first straight tube section 212 (see Appendix Figure 1 The first fins are fixedly connected to the first heat exchange tube 211, and the phase change material 3 can be filled in the space defined by the box body 1, the first fins and the first heat exchange tube 211. The arrangement of multiple first fins can further increase the contact area between the heat exchanger 2 and the phase change material 3, thereby improving the heat transfer rate between the heat exchange medium in the first heat exchange tube 211 and the phase change material 3.

[0042] It can be understood that when the heat exchange medium in the first heat exchange tube 211 is a refrigerant, the refrigerant exchanges heat with the second phase change material 32 and the first phase change material 31 in turn, and the refrigerant transfers heat to the first phase change material 31 and the second phase change material 32 to achieve heat charging of the phase change material 3.

[0043] Further, see Attachment Figure 1 As shown, the heat charging heat exchanger 21 also includes a first liquid inlet section 214 and a first liquid outlet section 215. The two ends of the first heat exchange tube 211 in the length direction are respectively connected to the first liquid inlet section 214 and the first liquid outlet section 215. After the heat exchange medium enters from the inlet of the heat charging heat exchanger 21, it flows into the first heat exchange tube 211 through the first liquid inlet section 214, and then flows to the outlet through the first liquid outlet section 215, and finally flows out of the heat charging heat exchanger 21.

[0044] In a further embodiment of the present invention, refer to the attached Figure 1 As shown, the first phase change material 31 and the second phase change material 32 can both change between a solid state and a liquid state. When the first phase change material 31 and the second phase change material 32 are both in a solid state, in the up and down directions, the first fin and the first heat exchange tube 211 are both located below the upper surface of the first phase change material 31. The first fin and the first heat exchange tube 211 are surrounded by the phase change material, which can ensure sufficient heat exchange between the heat charging heat exchanger 21 and the first phase change material 31 and the second phase change material 32, thereby ensuring the heat storage capacity of the phase change heat accumulator 100 and meeting the user's demand for hot water.

[0045] In a further embodiment of the present invention, refer to the attached Figure 1 As shown, at least part of the first heat exchange tube 211 is exposed outside the phase change material 3. For example, when there is a certain distance between the upper surface of the first phase change material 31 and the top of the box body 1, part of the first heat exchange tube 211 leaks out of the phase change material 3, and the corrosion rate of the first heat exchange tube 211 at the interface where the first phase change material 31 contacts the air is less than the preset corrosion rate, wherein the preset corrosion rate is less than or equal to the corrosion rate of the first heat exchange tube 211 at the interface where the second phase change material 32 contacts the air. It can be understood that the corrosion rate of the first heat exchange tube 211 at the interface where the first phase change material 31 contacts the air is less than the corrosion rate of the first heat exchange tube 211 at the interface where the second phase change material 32 contacts the air.

[0046] It is understandable that if only the second phase change material is filled in the box, the corrosion rate of the first heat exchange tube at the interface where the second phase change material contacts the air is greater than or equal to the preset corrosion rate, thereby causing the first heat exchange tube to have a faster corrosion rate at the interface where the second phase change material contacts the air. In the present utility model, the corrosion rate of the first heat exchange tube 211 at the interface where the first phase change material 31 contacts the air is less than the corrosion rate of the first heat exchange tube 211 at the interface where the second phase change material 32 contacts the air. Therefore, the first phase change material 31 and the second phase change material 32 are filled in the box 1, and the first phase change material 31 is located above the second phase change material 32. Compared with only filling the second phase change material in the box, the corrosion rate at the interface where the first heat exchange tube 211 contacts the air can be reduced, thereby extending the service life of the heat exchanger 2, and further extending the service life of the phase change heat accumulator 100.

[0047] In some embodiments of the present invention, refer to the attached Figure 1 and attached Figure 2 As shown, the heat exchanger 2 further includes: a heat-releasing heat exchanger 22 , which releases heat to the outside from an outlet of the heat-releasing heat exchanger 22 .

[0048] Further, see Attachment Figure 1 As shown, part of the exothermic heat exchanger 22 is located in the first phase change material 31 of the upper layer, and part of it is located in the second phase change material 32 of the lower layer. The heat exchange medium flowing into the exothermic heat exchanger 22 first passes through the exothermic heat exchanger 22 located in the first phase change material 31, and then passes through the exothermic heat exchanger 22 located in the second phase change material 32, so that the heat exchange medium in the exothermic heat exchanger 22 first exchanges heat with the first phase change material 31 with a relatively small temperature difference. After the heat exchange medium in the exothermic heat exchanger 22 is raised to a certain temperature, it exchanges heat with the second phase change material 32, thereby ensuring effective heat exchange between the heat exchange medium and the phase change material 3 during the heat exchange process, balancing the problem of decreased heat exchange power caused by the decreasing temperature difference between the heat exchange medium in the exothermic heat exchanger 22 and the phase change material 3 in the direction from top to bottom, thereby balancing the overall heat exchange efficiency of the heat exchanger 2, improving the heat utilization rate, ensuring the effective heat output of the phase change heat accumulator 100, and improving the heat release energy efficiency of the phase change heat accumulator 100.

[0049] In a further embodiment of the present invention, refer to the attached Figure 1 As shown, the heat-releasing heat exchanger 22 includes a second fin and a second heat exchange tube 221. The second heat exchange tube 221 includes a plurality of second straight tube sections 222 and a plurality of second curved tube sections 223. The plurality of second straight tube sections 222 are spaced apart in the up and down directions. The second curved tube section 223 connects two adjacent second straight tube sections 222, which can increase the contact area between the second heat exchange tube 221 and the phase change material 3, thereby improving the heat transfer rate between the heat exchange medium in the second heat exchange tube 221 and the phase change material 3.

[0050] Furthermore, the second fins are multiple and extend along the extension direction of the second straight tube section 222 (see Appendix Figure 1 The second fins are fixedly connected to the second heat exchange tube 221, and the phase change material 3 can be filled in the space defined by the box body 1, the second fins and the second heat exchange tube 221. The arrangement of multiple second fins can further increase the contact area between the heat exchanger 2 and the phase change material 3, thereby improving the heat transfer rate between the heat exchange medium in the second heat exchange tube 221 and the phase change material 3.

[0051] It can be understood that when the heat exchange medium in the second heat exchange tube 221 is cold water, the cold water exchanges heat with the first phase change material 31 and the second phase change material 32 in turn, and the first phase change material 31 and the second phase change material 32 transfer heat to the cold water to heat the cold water and meet the user's demand for hot water.

[0052] Further, see Attachment Figure 1 As shown, the heat release heat exchanger 22 also includes a second liquid inlet section 224 and a second liquid outlet section 225. The two ends of the second heat exchange tube 221 in the length direction are respectively connected to the second liquid inlet section 224 and the second liquid outlet section 225. After the heat exchange medium enters from the inlet of the heat release heat exchanger 22, it flows into the second heat exchange tube 221 through the second liquid inlet section 224, and then flows to the outlet through the second liquid outlet section 225, and finally flows out of the heat release heat exchanger 22.

[0053] In a further embodiment of the present invention, refer to the attached Figure 1 As shown, the first phase change material 31 and the second phase change material 32 can both change between a solid state and a liquid state. When the first phase change material 31 and the second phase change material 32 are both in a solid state, in the up and down directions, the second fins and the second heat exchange tubes 221 are both located below the upper surface of the first phase change material 31, and the second fins and the second heat exchange tubes 221 are surrounded by the phase change material, which can ensure sufficient heat exchange between the exothermic heat exchanger 22 and the first phase change material 31 and the second phase change material 32, thereby ensuring the effective heat output of the phase change heat accumulator 100 and meeting the user's demand for hot water.

[0054] In a further embodiment of the present invention, refer to the attached Figure 1As shown, at least part of the second heat exchange tube 221 is exposed outside the phase change material 3. For example, when there is a certain distance between the upper surface of the first phase change material 31 and the top of the box body 1, part of the second heat exchange tube 221 leaks out of the phase change material 3, and the corrosion rate of the second heat exchange tube 221 at the interface where the first phase change material 31 contacts the air is less than the preset corrosion rate, wherein the preset corrosion rate is less than or equal to the corrosion rate of the second heat exchange tube 221 at the interface where the second phase change material 32 contacts the air. It can be understood that the corrosion rate of the second heat exchange tube 221 at the interface where the first phase change material 31 contacts the air is less than the corrosion rate of the second heat exchange tube 221 at the interface where the second phase change material 32 contacts the air.

[0055] It is understandable that if only the second phase change material is filled in the box, the corrosion rate of the second heat exchange tube at the interface where the second phase change material contacts the air is greater than or equal to the preset corrosion rate, thereby causing the corrosion rate of the second heat exchange tube at the interface where the second phase change material contacts the air to be faster. In the present utility model, the corrosion rate of the second heat exchange tube 221 at the interface where the first phase change material 31 contacts the air is less than the corrosion rate of the second heat exchange tube 221 at the interface where the second phase change material 32 contacts the air. Therefore, the first phase change material 31 and the second phase change material 32 are filled in the box 1, and the first phase change material 31 is located above the second phase change material 32. Compared with only filling the second phase change material in the box, the corrosion rate at the interface where the second heat exchange tube 221 contacts the air can be reduced, thereby extending the service life of the heat exchanger 2, and further extending the service life of the phase change heat accumulator 100.

[0056] In some embodiments of the present invention, refer to the attached Figure 1 and attached Figure 3 As shown, both the first phase change material 31 and the second phase change material 32 can change between solid and liquid states. The liquid height of the phase change material 3 is h, and the solid height is h'. The liquid height of the first phase change material 31 is h1, and the liquid height of the second phase change material 32 is h2, and the following conditions are satisfied: h1≤1 / 2h, h'>h2. On the basis of ensuring the charging and discharging heat efficiency of the phase change heat accumulator 100, it is possible to avoid the second phase change material 32 being too small due to the first phase change material 31 occupying a large amount of space in the box 1, thereby ensuring the usage of the second phase change material 32, and then ensuring the heat storage capacity of the phase change heat accumulator 100, and meeting the user's demand for hot water.

[0057] It is understandable that, referring to the Figure 1 and attached Figure 3As shown, when the phase change material 3 changes from liquid to solid, the height of the phase change material 3 decreases. By limiting h'>h2, it is possible to avoid the height of the phase change material 3 in the solid state being lower than the height of the second phase change material 32 in the liquid state, thereby avoiding that when the second phase change material 32 changes from liquid to solid, part of the heat exchanger 2 originally covered by the second phase change material 32 is exposed, thereby reducing the probability of corrosion of the heat exchanger 2, extending the service life of the heat exchanger 2, and further extending the service life of the phase change heat accumulator 100.

[0058] It should be noted that when the phase change heat storage device 100 is full of heat, the phase change material 3 is in liquid state, at which time the height of the phase change material 3 is h, the height of the first phase change material 31 is h1, and the height of the second phase change material 32 is h2, where h=h1+h2. When the heat release of the phase change heat storage device 100 is completed, the phase change material 3 is in solid state, at which time the height of the phase change material is h'.

[0059] It should be noted that the reference Figure 1 and attached Figure 3 As shown, a certain gap is left between the upper surface of the phase change material 3 and the upper end of the housing 1, which can prevent the phase change material 3 from overflowing from the housing 1 or the interior of the housing 1 from swelling and deforming when the phase change material 3 undergoes a solid-liquid phase change.

[0060] In some embodiments of the utility model, the first phase change material 31 is an organic hydrophobic phase change material, which is not easy to absorb moisture, and moisture is not easy to enter the first phase change material 31, so that the first phase change material 31 can physically isolate oxygen and water vapor in the air, prevent oxygen and water vapor from contacting the heat exchanger 2, effectively prevent electrochemical corrosion, and reduce the probability of corrosion of the heat exchanger 2 on the basis of ensuring heat storage density and heat storage performance, thereby extending the service life of the heat exchanger 2, and further extending the service life of the phase change heat storage device 100. It should be noted that the first phase change material 31 with a relatively low density is provided on the second phase change material 32, which belongs to physical isolation and corrosion protection, and will not cause consumption during the use of the phase change heat storage device 100, so the anti-corrosion service life is extended.

[0061] For example, the first phase change material 31 can be composed of one of paraffin, n-tetradecane, n-pentadecane, n-hexadecane, polypropylene glycol 600, caprylic acid, capric acid, lauric acid, propyl palmitate, isopropyl stearate and neopentyl glycol. All of the above materials are hydrophobic materials with wide sources and are easy to obtain.

[0062] In some embodiments of the present invention, the second phase change material 32 is an inorganic hydrophilic phase change material, which has good thermal conductivity, high energy storage density, stable properties, low price and other advantages. For example, the second phase change material 32 can be composed of one of sodium acetate trihydrate, aluminum sulfate dodecahydrate, barium hydroxide octahydrate, disodium hydrogen phosphate heptahydrate, zinc nitrate tetrahydrate, iron nitrite hexahydrate, and sodium phosphate dodecahydrate. All of the above materials are hydrophilic materials, low in price, widely available, easy to obtain, and have good thermal conductivity. The above inorganic hydrophilic phase change materials are incompatible with organic hydrophobic materials and will not affect each other's energy storage performance.

[0063] In a further embodiment of the present invention, there are multiple charging heat exchangers 21 and multiple heat releasing heat exchangers 22, the number of heat releasing heat exchangers 22 is twice the number of charging heat exchangers 21, and two heat releasing heat exchangers 22 are arranged between any two adjacent charging heat exchangers 21. It can be understood that the charging heat exchanger 21 is used to charge the phase change material 3, and the heat releasing heat exchanger 22 is used to release heat from the phase change material 3, and two heat releasing heat exchangers 22 are arranged between any two adjacent charging heat exchangers 21, so that the charging heat exchanger 21 and the heat releasing heat exchanger 22 are arranged adjacent to each other, which can improve the heat transfer efficiency between the charging heat exchanger 21 and the heat releasing heat exchanger 22, reduce energy waste, and improve the heat exchange efficiency of the heat exchanger 2.

[0064] At the same time, since the heat exchanger 2 needs to release heat in time when the user uses water, it can meet the user's immediate water demand. Therefore, the number of heat-releasing heat exchangers 22 is twice the number of heat-charging heat exchangers 21, which can make the heat exchange efficiency of the phase change heat accumulator 100 higher when releasing heat than when charging, thereby meeting the user's immediate water demand.

[0065] In some embodiments of the present invention, refer to the attached Figure 2 As shown, the first heat exchange tube 211 is a refrigerant tube, which is connected to the heat pump external unit 201 and the hydraulic module 202. The heat exchange medium in the first heat exchange tube 211 is the refrigerant. The heat of the refrigerant tube can be transferred to the phase change material 3, and the phase change material 3 can store heat. Further, the second heat exchange tube 221 is a water pipe, which is connected to a cold water source. The heat exchange medium in the second heat exchange tube 221 is water. The phase change material 3 can transfer heat to the water pipe to heat the water in the water pipe.

[0066] Reference below Figure 1 to Figure 2 The phase change heat storage device 100 according to three specific embodiments of the present invention is described. It is worth noting that the following description is merely exemplary and is intended to be used to explain the present invention, but cannot be construed as a limitation on the present invention.

[0067] Embodiment 1

[0068] Specifically, Figure 1 to Figure 2 As shown, the phase change heat storage device 100 includes: a box body 1, a heat exchanger 2 and a phase change material 3.

[0069] Furthermore, the phase change material 3 is arranged in the box 1, and the phase change material 3 includes a first phase change material 31 and a second phase change material 32. The first phase change material 31 and the second phase change material 32 can change between a solid state and a liquid state. The first phase change material 31 has a phase change temperature of 45°C and a density of 0.8 g / cm 3 The second phase change material 32 is a paraffin with a phase change temperature of 50°C and a density of 1.4 g / cm 3 The first phase change material 31 is located on the upper layer of the second phase change material 32. The liquid height of the phase change material 31 is h, and the solid height is h'. The liquid height of the first phase change material 31 is h1, and the liquid height of the second phase change material 32 is h2. h1 = 1 / 2h, h'> h2.

[0070] Furthermore, the heat exchanger 2 is arranged in the box body 1, and the heat exchanger 2 includes a heat-releasing heat exchanger 22 and a heat-charging heat exchanger 21. The number of the heat-releasing heat exchanger 22 and the heat-charging heat exchanger 21 is multiple, and the number of the heat-releasing heat exchanger 22 is twice the number of the heat-charging heat exchanger 21. Two heat-releasing heat exchangers 22 are arranged between any two adjacent heat-charging heat exchangers 21. The heat-charging heat exchanger 21 is used for charging the phase change material 3, and the heat-releasing heat exchanger 22 is used for releasing heat from the phase change material 3. Two heat-releasing heat exchangers 22 are arranged between any two adjacent heat-charging heat exchangers 21, so that the heat-charging heat exchanger 21 and the heat-releasing heat exchanger 22 are arranged adjacent to each other, which can improve the heat transfer efficiency between the heat-charging heat exchanger 21 and the heat-releasing heat exchanger 22, reduce energy waste, and improve the heat exchange efficiency of the heat exchanger 2.

[0071] Furthermore, the heat-charging heat exchanger 21 is charged with heat from the inlet of the heat-charging heat exchanger 21. Part of the heat-charging heat exchanger 21 is located in the first phase change material 31, and part of it is located in the second phase change material 32. The heat exchange medium flowing into the heat-charging heat exchanger 21 first passes through the heat-charging heat exchanger 21 located in the second phase change material 32, and then passes through the heat-charging heat exchanger 21 located in the first phase change material 31. The initial temperature of the heat exchange medium flowing into the heat-charging heat exchanger 21 from the inlet is higher than the phase change temperature of the second phase change material 32, so that the heat exchange medium in the heat-charging heat exchanger 21 first exchanges heat with the second phase change material 32 with a relatively small temperature difference. After the temperature of the heat exchange medium in the heat charging heat exchanger 21 is reduced to a certain level, it exchanges heat with the first phase change material 31 having a relatively low phase change temperature, thereby making full use of the heat of the heat exchange medium, ensuring effective heat exchange between the heat exchange medium and the phase change material 3 during the heat exchange process, and balancing the problem of decreased heat exchange power caused by the increasingly smaller temperature difference between the heat exchange medium and the phase change material 3 in the heat charging heat exchanger 21 from bottom to top, thereby balancing the overall heat exchange efficiency of the heat exchanger 2, improving heat utilization, ensuring the heat storage performance of the phase change heat accumulator 100, and improving the heat charging energy efficiency of the phase change heat accumulator 100.

[0072] Furthermore, the heat charging heat exchanger 21 includes a first fin and a first heat exchange tube 211. The first heat exchange tube 211 includes a plurality of first straight tube sections 212 and a plurality of first curved tube sections 213. The plurality of first straight tube sections 212 are spaced apart in the up and down directions. The first curved tube section 213 connects two adjacent first straight tube sections 212. There are a plurality of first fins and they are spaced apart along the extension direction of the first straight tube sections 212. This can increase the contact area between the heat exchanger 2 and the phase change material 3, thereby increasing the heat transfer rate between the heat exchange medium in the first heat exchange tube 211 and the phase change material 3. The heat exchange medium in the first heat exchange tube 211 is a refrigerant. The refrigerant sequentially exchanges heat with the second phase change material 32 and the first phase change material 31. The refrigerant transfers heat to the first phase change material 31 and the second phase change material 32, thereby realizing the heat charging of the phase change material 3.

[0073] Furthermore, the exothermic heat exchanger 22 releases heat from the outlet of the exothermic heat exchanger 22. Part of the exothermic heat exchanger 22 is located in the first phase change material 31, and part of it is located in the second phase change material 32. The heat exchange medium flowing into the exothermic heat exchanger 22 first passes through the exothermic heat exchanger 22 located in the first phase change material 31, and then passes through the exothermic heat exchanger 22 located in the second phase change material 32, so that the heat exchange medium in the exothermic heat exchanger 22 first exchanges heat with the first phase change material 31 with a relatively small temperature difference, and then passes through the exothermic heat exchanger 22 in the second phase change material 32. After the heat exchange medium in 22 is raised to a certain temperature, it exchanges heat with the second phase change material 32, thereby ensuring effective heat exchange between the heat exchange medium and the phase change material 3 during the heat exchange process, and balancing the problem of decreased heat exchange power caused by the decreasing temperature difference between the heat exchange medium and the phase change material 3 in the exothermic heat exchanger 22 from top to bottom, thereby balancing the overall heat exchange efficiency of the heat exchanger 2, improving the heat utilization rate, ensuring the effective heat output of the phase change heat accumulator 100, and improving the energy efficiency of the phase change heat accumulator 100.

[0074] Furthermore, the exothermic heat exchanger 22 includes a second fin and a second heat exchange tube 221. The second heat exchange tube 221 includes a plurality of second straight tube sections 222 and a plurality of second curved tube sections 223. The plurality of second straight tube sections 222 are spaced apart in the up and down directions. The second curved tube section 223 connects two adjacent second straight tube sections 222. There are a plurality of second fins and they are spaced apart along the extension direction of the second straight tube sections 222. This can increase the contact area between the heat exchanger 2 and the phase change material 3, thereby increasing the heat transfer rate between the heat exchange medium in the second heat exchange tube 221 and the phase change material 3. The heat exchange medium in the second heat exchange tube 221 is cold water. The cold water exchanges heat with the first phase change material 31 and the second phase change material 32 in turn. The first phase change material 31 and the second phase change material 32 transfer heat to the cold water to heat the cold water and meet the user's demand for hot water.

[0075] In addition, when the first phase change material 31 and the second phase change material 32 are both in a solid state, in the up and down directions, the first fin, the first heat exchange tube 211, the second fin and the second heat exchange tube 221 are all located below the upper surface of the first phase change material 31; when at least part of the first heat exchange tube 211 and the second heat exchange tube 221 are exposed outside the phase change material 3, the corrosion rate of the first heat exchange tube 211 and the second heat exchange tube 221 at the interface where the first phase change material 31 contacts the air is less than a preset corrosion rate, wherein the preset corrosion rate is less than or equal to the corrosion rate of the first heat exchange tube 211 and the second heat exchange tube 221 at the interface where the second phase change material 32 contacts the air.

[0076] It should be noted that the heat storage capacity of the first phase change material 31 is approximately 4.5 kWh, the heat storage capacity of the second phase change material 32 is approximately 8 kWh, and the total heat storage capacity of the phase change material 3 is approximately 12.5 kWh. During the charging operation of the phase change heat storage device 100, under standard operating conditions, the heat pump energy efficiency is improved by 30%.

[0077] Embodiment 2

[0078] The structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are labeled the same, and the only difference is that h1=1 / 3h, the heat storage capacity of the first phase change material 31 is approximately 2.7 kWh, the heat storage capacity of the second phase change material 32 is approximately 12 kWh, and the total heat storage capacity of the phase change material 3 is approximately 14.7 kWh. Under standard operating conditions, the energy efficiency of the heat pump is improved by 20%.

[0079] Embodiment 3

[0080] The structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, and the only difference is that the first phase change material 31 has a phase change temperature of 40° C. and a density of 0.8 g / cm 3 paraffin, h1=1 / 3h, the heat storage capacity of the first phase change material 31 is about 4.5kWh, the heat storage capacity of the second phase change material 32 is about 8kWh, and the total heat storage capacity of the phase change material 3 is about 12.5kWh. Under standard working conditions, the energy efficiency of the heat pump is improved by 40%.

[0081] Other structures and operations of the phase change heat storage device 100 according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0082] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0083] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A phase change heat storage device, characterized in that: include: Box; a heat exchanger, the heat exchanger being disposed in the housing and comprising a heat charging heat exchanger, the heat charging heat exchanger charging heat from an inlet of the heat charging heat exchanger; Phase change material, the phase change material is arranged in the box, the phase change material includes a first phase change material and a second phase change material, the first phase change material is located on the upper layer of the second phase change material, the density of the first phase change material is lower than the density of the second phase change material, the phase change temperature of the first phase change material is lower than the phase change temperature of the second phase change material, part of the heat charging heat exchanger is located in the first phase change material, and part of it is located in the second phase change material, and the heat exchange medium flowing into the heat charging heat exchanger first passes through the heat charging heat exchanger located in the second phase change material, and then passes through the heat charging heat exchanger located in the first phase change material.

2. The phase change heat storage device according to claim 1, characterized in that: The heat charging heat exchanger includes a first fin and a first heat exchange tube, the first heat exchange tube includes a plurality of first straight tube sections and a plurality of first curved tube sections, the plurality of first straight tube sections are spaced apart in the up and down directions, the first curved tube section connects two adjacent first straight tube sections, and there are a plurality of first fins which are spaced apart along the extension direction of the first straight tube sections.

3. The phase change heat storage device according to claim 2, characterized in that: The first phase change material and the second phase change material are both capable of changing between a solid state and a liquid state. When the first phase change material and the second phase change material are both in a solid state, in the up and down direction, the first fin and the first heat exchange tube are both located below the upper surface of the first phase change material; Or, at least a portion of the first heat exchange tube is exposed outside the phase change material, and a corrosion rate of the first heat exchange tube at an interface where the first phase change material contacts air is less than a preset corrosion rate, wherein the preset corrosion rate is less than or equal to a corrosion rate of the first heat exchange tube at an interface where the second phase change material contacts air.

4. The phase change heat storage device according to claim 1, characterized in that: The heat exchanger also includes: a heat release heat exchanger, which releases heat to the outside from the outlet of the heat release heat exchanger, wherein part of the heat release heat exchanger is located in the first phase change material and part of the heat release heat exchanger is located in the second phase change material, and the heat exchange medium flowing into the heat release heat exchanger first passes through the heat release heat exchanger located in the first phase change material and then passes through the heat release heat exchanger located in the second phase change material.

5. The phase change heat storage device according to claim 4, characterized in that: The exothermic heat exchanger includes a second fin and a second heat exchange tube, the second heat exchange tube includes a plurality of second straight tube sections and a plurality of second curved tube sections, the plurality of second straight tube sections are arranged at intervals in the up and down directions, the second curved tube section connects two adjacent second straight tube sections, and there are a plurality of second fins which are arranged at intervals along the extension direction of the second straight tube sections.

6. The phase change heat storage device according to claim 5, characterized in that: The first phase change material and the second phase change material are both capable of changing between a solid state and a liquid state. When the first phase change material and the second phase change material are both in a solid state, in the vertical direction, the second fin and the second heat exchange tube are both located below the upper surface of the first phase change material; Or, at least a portion of the second heat exchange tube is exposed outside the phase change material, and a corrosion rate of the second heat exchange tube at the interface where the first phase change material contacts the air is less than a preset corrosion rate, wherein the preset corrosion rate is less than or equal to a corrosion rate of the second heat exchange tube at the interface where the second phase change material contacts the air.

7. The phase change heat storage device according to claim 1, characterized in that: The liquid height of the phase change material is h, the solid height is h', the liquid height of the first phase change material is h1, the liquid height of the second phase change material is h2, and the following conditions are satisfied: h1≤1 / 2h, h'>h2.

8. The phase change heat storage device according to claim 1, characterized in that: The first phase change material is an organic hydrophobic phase change material.

9. The phase change heat storage device according to claim 1, characterized in that: The second phase change material is an inorganic hydrophilic phase change material.

10. The phase change heat storage device according to claim 4, characterized in that: There are multiple charging heat exchangers and multiple heat releasing heat exchangers, the number of the heat releasing heat exchangers is twice the number of the charging heat exchangers, and two heat releasing heat exchangers are arranged between any two adjacent charging heat exchangers.

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