Electric heating energy storage system capable of quickly responding to electric power change

Abstract

The invention relates to an electric heating energy storage system capable of quickly responding to electric power change, which uses an electric energy indirect or direct heating mode to heat a heat storage metal body, and the heat storage metal body transfers heat to a fluid or gas medium, thereby avoiding overhigh local temperature of the medium or overlow outlet temperature caused by using an electric heater to directly heat the fluid medium, and improving the reliability of the electric heating energy storage system. And the electric power change can be quickly responded. An electric heater is used for heating a heat storage metal body or current is directly applied to the two ends of a heating body made of metal to generate Joule heat, then heat in the heat storage metal body is transferred out through a fluid medium heat exchange device, and finally the heat is stored in a fluid medium and the metal heat storage body. According to the invention, the solid is heated and then exchanges heat with the heat exchange medium, so that the electric power can be quickly adjusted.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to an electric heating energy storage system that quickly responds to changes in electric power. Background Art

[0002] The large-scale connection of renewable energy power generation to the grid is the development trend of the power grid. However, the randomness and volatility of renewable energy power generation pose major challenges to the safe and stable operation of the power grid. Therefore, the development of energy storage technology has become the current research focus. Compared with other energy storage methods, electric heating energy storage has the advantages of low cost, safety and reliability, large-scale deployment, and independence from geographical resources. Storing thermal energy through fluid heat storage media is currently a more mature electric heating energy storage system. However, in the process of directly heating the fluid medium with an electric heater, problems such as excessively high local temperatures, too low fluid medium outlet temperatures, and inability to quickly respond to power fluctuations may occur, which greatly limits its application in renewable energy source-side energy storage.

[0003] Chinese patent CN 105605653 B discloses a three-level adjustable heating power switching control method based on time-varying load, which proposes a three-level heating winding switching solid thermal storage device electrical circuit design method: the heating winding is switched by star-angle switching to achieve the switching of three different heating powers of 0.7Pn / Pn / 1.4Pn of the solid thermal storage device. It greatly improves the flexible adjustment ability of the solid thermal storage power, but it does not consider the quality of the temperature of the heated medium.

[0004] Chinese patent CN 107559529 B discloses a pipeline skin effect electric heating device, which uses the skin current generated by the enameled copper cable in the skin tube to heat the crude oil. The copper cable of the energized part is isolated from the heat-generating pipeline part by an insulating layer. The copper cable is expensive, cannot achieve high-temperature heating, and is not conducive to rapid fluctuations in electric power.

[0005] Chinese patent application CN 117955128 A discloses a power control system and control method for an auxiliary unit frequency modulation electric heater, which includes a transformer, a distribution bus, a power regulator, a molten salt electric heater, a generator and a high-voltage plant transformer, and uses different power regulators in the same electric heater to respond to the power plant AGC frequency modulation command. However, the patent still does not consider solving the problem of reduced heating quality caused by power fluctuations from the perspective of the electric heater body structure.

[0006] Therefore, the existing electric heating heat storage method mainly focuses on the adjustable range of electric power, and does not pay attention to the problem of heat storage medium temperature caused by rapid changes in electric power. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides an electric heating energy storage system that can quickly respond to changes in electric power. It uses indirect or direct heating to heat the heat storage metal body to quickly respond to changes in electric power, and then releases the heat in the metal into the fluid medium through a fluid medium heat exchange device.

[0008] In order to achieve the above object, the present invention adopts the following technical scheme:

[0009] An electric heating energy storage system that quickly responds to changes in electric power includes an electric heater heating metal structure or a direct heating metal structure; the electric heater heating metal structure includes a heat storage metal body, a fluid heat exchange channel, an electric heater, an insulating layer, a fluid medium, an external heat exchange device and a heating power supply; wherein the electric heater heating metal structure is plate-shaped or columnar; the insulating layer is insulating ceramic particles or insulating ceramic tubes; the electrical connection between the electric heaters is a single group or multiple groups of series or parallel connection; in the electric heater heating metal structure, a position for the electric heater is reserved in the heat storage metal body, and the electric heater is assembled in the reserved position of the heat storage metal body. The outside of the electric heater is wrapped with insulating heat conductive material to form an insulated insulation layer; when storing energy, electric energy enters the electric heater through the control of the heating power supply, and the electric heating element in the electric heater converts electric energy into thermal energy, and the thermal energy is transferred to the heat storage metal body through the insulating layer, and further transferred to the fluid medium; the fluid medium flows through the fluid heat exchange channel to exchange heat, and the fluid medium heat exchange and the electric heater heating are carried out simultaneously, or after the electric heater heats the heat storage metal body to complete energy storage; in the direct heating metal structure, the heat storage metal body and the electric heater are the same object; when storing energy, electric energy enters the heat storage metal body through the control of the heating power supply, and the heat storage metal body directly converts electric energy into thermal energy through the Joule effect; the thermal energy is transferred to the fluid medium through the heat storage metal body itself.

[0010] Preferably, the fluid medium may be a gas medium.

[0011] Furthermore, when the electric heater heating metal structure is in the shape of a plate, the shape of the heat storage metal body is a straight plate or a U-shaped plate; when the heat storage metal body is in the shape of a straight plate, the electric heater and the fluid heat exchange channel are arranged in a left-right or up-down spacing; or the fluid heat exchange channel is located in the center of the heat storage metal body and is dispersedly arranged, and the electric heater is arranged around the fluid heat exchange channel; the plate-like structure is stacked or horizontally arranged in space, and an insulating shell layer is provided on the outside; the ceramic material is magnesium oxide or boron nitride; the heating power supply is an AC power supply or a DC power supply, and the fluid medium is heat transfer oil or molten salt; the gas medium is nitrogen or an inert gas.

[0012] Furthermore, when the heat storage metal body is in the shape of a U-shaped plate, the electric heaters are dispersedly arranged around the U-shaped corridor, and the U-shaped hollow part in the middle of the heat storage metal body is a fluid heat exchange channel.

[0013] Furthermore, when the electric heater heats a columnar metal structure, the electric heater is located at the geometric center of the heat storage metal body, and the fluid heat exchange channel is symmetrically distributed around the periphery of the electric heater; or the fluid heat exchange channel is located at the center of the columnar body, and the electric heaters are evenly arranged around the central heat exchange channel; sufficient metal bodies are left between the electric heater and the heat exchange channel or between the electric heaters for heat storage.

[0014] Furthermore, the external heat exchange device is a bundled pipeline or an external heat exchange channel device, the bundled pipeline is composed of parallel connected pipelines and is connected to the fluid or gas heat exchange channel, and the number of parallel pipelines in the bundled pipeline is the same as that of the fluid heat exchange channel; the external heat exchange channel device is the gap part between the heat storage metal body and the thermal insulation shell wrapped around it.

[0015] Furthermore, partial gaps are formed in the heat storage metal body, which, together with parts of the electric heater and the fluid heat exchange channel, are replaced by other heat storage materials, wherein the other heat storage materials are filling materials or porous structure materials, wherein the filling materials are carbon powder or ceramic particles, and the porous structure materials are heat storage magnesium bricks.

[0016] Furthermore, in the direct heating metal structure, the electric heater and the heat storage metal body are the same object, including single-tube direct heating or double-tube direct heating or three-tube direct heating or four-tube direct heating; the single-tube direct heating includes a first heating metal tube, a fluid heat exchange channel, an insulation layer, a high voltage access terminal, a low voltage access terminal, a fluid medium and a heating power supply; the first heating metal tube is a thick-walled single metal or bimetallic composite tube, and its cross-sectional shape is a closed polygon; the insulation layer covers the outside of the first heating metal tube; the high voltage access terminal and the low voltage access terminal are respectively located at both ends of the first heating metal tube and are connected to the heating power supply; the heating power supply is an AC power supply; after the power supply is supplied, the current formed by the skin effect generates Joule heat on the outer skin of the first heating metal tube, and the heat is transferred to the inside of the heating metal through the metal, and at the same time the fluid medium exchanges the heat through the fluid heat exchange channel; the fluid medium heat exchange is carried out simultaneously with the electric heating metal, or after the electric heating metal completes energy storage; the fluid medium is molten salt or nitrogen or inert gas.

[0017] Furthermore, the double-tube direct heating includes a fluid heat exchange channel, an inner heat exchange tube, an insulating layer, a first heating metal tube, a fluid medium and a heating power supply; the inner heat exchange tube and the first heating metal tube are any combination of thick-walled metal tubes or thin-walled metal tubes; the inner heat exchange tube is placed inside the first heating metal tube to form an inner tube, and the gap between the inner tube and the heating metal is filled with insulating heat-conductive material to form an insulating layer, and a fluid heat exchange channel is formed inside the inner tube; the high voltage access terminal and the low voltage access terminal are respectively located at both ends of the first heating metal tube and are connected to the heating power supply; the heating power supply is an AC power supply or a DC power supply; when the heating power supply is an AC power supply, due to the skin effect, the current generated generates Joule heat on the outer skin of the heating metal, and the heat is transferred to the inner side of the inner tube through the metal and the insulating layer, and at the same time the fluid medium exchanges the heat through the fluid heat exchange channel; the fluid medium heat exchange is carried out simultaneously with the electrically heated metal, or after the electrically heated metal completes heat storage.

[0018] Furthermore, the three-tube direct heating includes a first heating metal tube, a second heating metal tube, a third metal tube, a first fluid heat exchange channel, an insulating layer, a second fluid heat exchange channel, an insulating bracket, a high voltage access terminal, a first low voltage access terminal, a second low voltage access terminal, a connecting wire, a fluid medium and a heating power supply; the second heating metal tube is a thick-walled single metal or bimetallic composite tube; the first heating metal tube is placed inside the second heating metal tube, and is placed together inside the third metal tube; a first fluid heat exchange channel is formed inside the first heating metal tube, and a second fluid heat exchange channel is formed by the gap between the second heating metal tube and the third metal tube sleeves, and electrical insulation is formed between the sleeve gaps of the first heating metal tube and the second heating metal tube through an insulating layer; the insulating bracket is made of a ceramic insulator and is used to fix and support the second heating metal tube; the heating power supply is connected to both ends of the first heating metal tube, or to the first heating metal tube and the second heating metal tube.

[0019] Furthermore, when the voltage is applied to the first heating metal tube and the second heating metal tube, the high voltage access end is located on one side of the first heating metal tube, and the first low voltage access end is located on the other side of the second heating metal tube, and the first heating metal tube and the second heating metal tube are connected and conducted through a connecting wire; the heating power supply is preferably an AC power supply, and the AC current formed by the power supply generates Joule heat outside the first heating metal tube and inside the second heating metal, and the fluid medium flows through the first fluid heat exchange channel and the first fluid heat exchange channel to exchange heat.

[0020] Furthermore, when the AC voltage is only applied to the two ends of the first heating metal tube, the connecting wire is removed, the high voltage access end is located on one side of the first heating metal tube, and the second low voltage access end is located on the other side of the first heating metal tube. The fluid medium can flow through the first fluid heat exchange channel and the second fluid heat exchange channel to exchange heat, and the process can be in series or in parallel. The heating power supply is preferably an AC power supply.

[0021] Furthermore, the four-tube direct heating includes a heat exchange inner tube, a first insulating layer, a first heating metal tube, a second insulating layer, a first heat exchange outer tube, a second heat exchange outer tube, an insulating bracket, a first fluid heat exchange channel, a second fluid heat exchange channel, a high voltage access terminal, a low voltage access terminal, a fluid medium and a heating power supply; the heat exchange inner tube, the first heating metal tube, the first heat exchange outer tube and the second heat exchange outer tube are nested together from the inside to the outside in sequence to form a sleeve; wherein, a first fluid heat exchange channel is formed inside the heat exchange inner tube; the sleeve gap between the heat exchange inner tube and the first heating metal tube is electrically insulated by the insulating layer; the sleeve gap between the first heating metal tube and the first heat exchange outer tube is electrically insulated by the insulating layer; the sleeve gap between the first heat exchange outer tube and the second heat exchange outer tube forms a second fluid heat exchange channel; the insulating bracket is used to support the gap between the first heat exchange outer tube and the second heat exchange outer tube.

[0022] Furthermore, the heating power supply is connected to a high voltage access terminal and a low voltage access terminal, the high voltage access terminal is located on one side of the first heating metal tube, and the low voltage access terminal is located on the other side of the first heating metal tube; the heating power supply is a DC power supply or an AC power supply.

[0023] Furthermore, when the heating power supply is a DC power supply, the generated current generates Joule heat in the first heating metal tube, and the heat is transferred to the first fluid heat exchange channel and the second fluid heat exchange channel through the metal, the first insulating layer and the second insulating layer; the fluid medium flows through the first fluid heat exchange channel and the second fluid heat exchange channel to exchange heat, and the process is series or parallel.

[0024] Furthermore, when the heating power supply is an AC power supply, the AC current formed by the power supply generates Joule heat outside the first heating metal tube and inside the first heat exchange outer tube, and the heat is transferred to the first fluid heat exchange channel and the second fluid heat exchange channel through the metal and the first insulating layer.

[0025] Beneficial effects:

[0026] 1. The present invention uses metal as the heating medium of the fluid medium, which can increase the thermal inertia of the system and avoid local overheating of the fluid medium.

[0027] 2. The present invention can quickly respond to power fluctuations, so that the system can better adapt to the access of renewable energy and make the best possible use of renewable energy.

[0028] 3. The present invention uses metal to achieve high-temperature heat storage, can be combined with a supercritical power generation unit, and can also meet the heating needs of other industrial links.

[0029] 4. When the heating power source of the present invention is an AC power source, due to the skin effect, the current is distributed on the surface of the thick-walled metal pipe, and there is no need to consider the electrolysis problem of the fluid medium.

[0030] 5. The present invention has high economic efficiency, high metal residual value and is convenient for recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the front view of the straight plate-shaped metal structure heated by the electric heater in Example 1 of the present invention;

[0032] Figure 2 This is a schematic side view of the structure of the electric heater heating a straight plate-shaped metal structure according to Embodiment 1 of the present invention;

[0033] Figure 3 This is a schematic side view of the structure of the U-shaped metal structure of the electric heater of Example 2 of the present invention;

[0034] Figure 4 This is a schematic side view of the structure of an electric heater heating a metal column structure according to Embodiment 3 of the present invention;

[0035] Figure 5 This is a schematic side view of the structure of an electric heater heating a metal column structure according to Embodiment 4 of the present invention;

[0036] Figure 6 This is a schematic diagram of the structure in which the metal structure portion heated by the electric heater in Example 5 of the present invention is replaced by other heat storage materials;

[0037] Figure 7 This is a side structural schematic diagram of a single-tube direct heating metal device according to Example 6 of the present invention;

[0038] Figure 8 This is a front view structural schematic diagram of a single-tube direct metal heating device according to Example 6 of the present invention;

[0039] Fig. 9 This is a schematic side structural view of a double-tube direct heating metal device according to Example 7 of the present invention;

[0040] Fig.10 This is a schematic diagram of the front view of the structure of a double-tube direct heating metal device according to Example 7 of the present invention;

[0041] Fig.11 This is a schematic side view of the structure of a three-tube direct heating metal device according to Example 8 of the present invention;

[0042] Fig.12 This is a schematic diagram of the front view of the structure of a three-tube direct heating metal device according to Example 8 of the present invention;

[0043] Fig.13 This is a schematic side view of the structure of a four-tube direct heating metal device according to Example 9 of the present invention;

[0044] Fig.14This is a front view of the structure of a four-tube direct heating metal device according to Example 9 of the present invention;

[0045] Among them, the figure markings are: 11-heat storage metal body; 12-fluid heat exchange channel; 13-electric heater; 14-insulating layer; 14-1 first insulating layer; 14-2 second insulating layer; 15-other heat storage materials; 21-first heating metal tube; 23-insulating layer; 24-high voltage access terminal; 25-low voltage access terminal; 31-second heating metal tube; 32-third metal tube; 34-1-first fluid heat exchange channel; 34-3 second fluid heat exchange channel; 35-insulating bracket; 37-first low voltage access terminal; 38-connecting wire; 39-second low voltage access terminal; 41 heat exchange inner tube; 51-first heat exchange outer tube; 52 second heat exchange outer tube. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] An electric heating energy storage system that quickly responds to changes in electric power of the present invention includes an electric heater heating metal structure or a direct heating metal structure. In the electric heater heating metal structure, a position for an electric heater 13 is reserved in the heat storage metal body 11, and the electric heater 13 is assembled in the reserved position of the heat storage metal body 11. The outside of the electric heater 13 is wrapped with an insulating heat-conductive material to form an insulating layer 14. During energy storage, electric energy enters the electric heater 13 through the control of the heating power supply, and the electric heating element in the electric heater 13 converts the electric energy into thermal energy, which is transferred to the thermal storage metal body through the insulating layer 14 and can be further transferred to the fluid medium. The fluid medium flows through the fluid heat exchange channel 12 to exchange heat, and the heat exchange of the fluid medium and the heating of the electric heater 13 are carried out simultaneously, or after the electric heater 13 heats the thermal storage metal body 11 to complete energy storage. In the direct heating metal structure, the thermal storage metal body 11 and the electric heater 13 are the same object. When storing energy, the electric energy enters the heat storage metal body 11 through the control of the heating power supply, and the heat storage metal body 11 directly converts the electric energy into heat energy through the Joule effect. The heat energy is transferred to the fluid medium through the heat storage metal body 11 itself. Figure 1 and Figure 2As shown, they are schematic diagrams of the front view and side view of the straight plate-shaped electric heater heating metal structure of Example 1 of the present invention. The electric heater heating metal structure includes a heat storage metal body 11, a fluid heat exchange channel 12, an electric heater 13, an insulating layer 14, a fluid medium, an external heat exchange device and a heating power supply. The electric heater heating metal structure can be plate-shaped or columnar. When the electric heater metal structure is plate-shaped, a channel penetrating the metal body is left inside the heat storage metal body 11, and the channel constitutes the position where the electric heater 13 is placed and the fluid heat exchange channel 12, and the electric heater 13 and the fluid heat exchange channel 12 are arranged alternately, and the insulating layer 14 is arranged in the gap between the electric heater 13 and the channel penetrating the metal body. The insulating layer 14 is insulating ceramic particles or insulating ceramic tubes, and the material of the ceramic is preferably magnesium oxide or boron nitride. The electrical connection between each of the electric heaters 13 can be a single group or multiple groups-in series or parallel, and finally connected to the heating power supply. In the electric heater heating metal structure, the heat storage metal body 11 and the electric heater 13 are highly integrated into one, and the outside of the electric heater 13 is wrapped by an insulating heat-conducting material to form an insulating layer 14.

[0048] Furthermore, when the electric heater heating metal structure is in the shape of a plate, the heat storage metal body 11 may be in the shape of a straight plate or a U-shaped plate. When the heat storage metal body 11 is in the shape of a straight plate, the electric heater 13 and the fluid heat exchange channel 12 may be arranged in a left-right or up-down spacing; or the fluid heat exchange channel 12 may be located in the center of the heat storage metal body 11 and arranged in a dispersed manner, and the electric heater 13 may be arranged around the fluid heat exchange channel 12. The plate-like structure may be stacked or arranged horizontally in space, and a heat-insulating outer shell layer may be provided on the outside.

[0049] like Figure 3 The figure shows a schematic diagram of the side view of the U-shaped metal structure of the electric heater of Example 2 of the present invention. The heat storage metal body 11 is in the shape of a U-shaped plate, and the electric heater 13 is dispersedly arranged around the U-shaped corridor, and the U-shaped hollow part in the middle of the heat storage metal body 11 is the fluid heat exchange channel 12.

[0050] like Figure 4 and Figure 5 The figure shows a schematic side view of the columnar heating metal structure of the electric heater of Embodiment 3 and Embodiment 4 of the present invention. When the heating metal structure of the electric heater 13 is columnar, the electric heater 13 can be located at the geometric center of the heat storage metal body 11, and the fluid heat exchange channel 12 is symmetrically distributed at the peripheral center of the electric heater 13; or the fluid heat exchange channel 12 is located at the center of the columnar heat storage metal body 11, and the electric heater 13 is evenly arranged around the geometric center of the heat storage metal body 11; sufficient metal bodies are left between the electric heater 13 and the fluid heat exchange channel 12 or between the electric heaters 13 for heat storage.

[0051] The external heat exchange device may be a bundled pipeline or an external heat exchange channel device, wherein the bundled pipeline is composed of parallel connected pipelines and connected to the fluid or gas heat exchange channel, and the number of parallel pipelines of the bundled pipeline is the same as that of the fluid heat exchange channel 12. The external heat exchange channel device may also be the gap between the heat storage metal body 11 and the heat insulation shell wrapped outside it.

[0052] like Figure 6 As shown, it is a schematic diagram of the structure in which the metal structure of the electric heater in Example 5 of the present invention is partially replaced by other heat storage materials. The heat storage metal body can form a partial gap, and together with the electric heater 13 and the part in the fluid heat exchange channel 12, it is replaced by other heat storage materials 15 to reduce the use of metal. The other heat storage material 15 can be a filling material or a porous structure material, wherein the filling material can be carbon powder or ceramic particles, and the porous structure material can be a heat storage magnesium brick.

[0053] like Figure 7 and Figure 8 As shown, the direct heating metal structure, the electric heater 13 and the heat storage metal body 11 are the same object, and can include a variety of structures such as single-tube direct heating or double-tube direct heating or three-tube direct heating or four-tube direct heating. The structure of the single-tube direct heating includes a first heating metal tube 21, a fluid heat exchange channel 12, an insulation layer 23, a high voltage access terminal 24, a low voltage access terminal 25, a fluid medium and a heating power supply. The first heating metal tube 21 is a thick-walled single metal or bimetallic composite tube, and its cross-sectional shape can be circular, rectangular, pentagonal and other closed polygons, preferably circular. The insulation layer 23 covers the outside of the first heating metal tube 21. The high voltage access terminal 24 and the low voltage access terminal 25 are respectively located at both ends of the first heating metal tube 21 and are connected to the heating power supply. The heating power supply is preferably an AC power supply. After the power supply is supplied, the current formed by the skin effect generates Joule heat on the outer skin of the first heating metal tube 21, and the heat is transferred to the inside of the heating metal through the metal, while the fluid medium exchanges the heat through the fluid heat exchange channel 12. The fluid medium heat exchange can be carried out simultaneously with the electrically heated metal, or after the electrically heated metal has completed energy storage. The fluid medium is preferably molten salt, nitrogen or inert gas. The double-tube direct heating, triple-tube direct heating and quadruple-tube direct heating structures are all provided with an insulation layer 23 on the outermost tube body.

[0054] like Fig. 9 and Fig.10As shown, it is a schematic diagram of the side view and front view of the double-tube direct heating metal device of Example 7 of the present invention. The double-tube direct heating includes a fluid heat exchange channel 12, a heat exchange inner tube 41, an insulating layer 14, a first heating metal tube 21, a fluid medium and a heating power supply. The heat exchange inner tube 41 and the first heating metal tube 21 can be any combination of thick-walled metal tubes or thin-walled metal tubes. The heat exchange inner tube 41 is placed inside the first heating metal tube 21 to form an inner sleeve, and the gap between the inner sleeve and the heating metal is filled with insulating heat-conductive material to form an insulating layer 14, and a fluid heat exchange channel 12 is formed inside the inner sleeve. The high voltage access terminal 24 and the low voltage access terminal 25 are respectively located at both ends of the first heating metal tube 21 and are connected to the heating power supply. The heating power supply can be an AC power supply or a DC power supply, preferably an AC power supply. When the heating power source is an AC power source, due to the skin effect, the generated current generates Joule heat on the outer skin of the heated metal, and the heat is transferred to the inner side of the inner sleeve through the metal and the insulating layer 14, while the fluid medium exchanges the heat through the fluid heat exchange channel 12. The fluid medium heat exchange can be carried out simultaneously with the electrically heated metal, or after the electrically heated metal completes the heat storage.

[0055] like Fig.11 and Fig.12 As shown, it is a schematic diagram of the side view and front view of the structure of the three-tube direct heating metal device of Example 8 of the present invention. The three-tube direct heating includes a first heating metal tube 21, a second heating metal tube 31, a third metal tube 32, a first fluid heat exchange channel 34-1, an insulating layer 14, a second fluid heat exchange channel 34-3, an insulating bracket 35, a high voltage access terminal 24, a first low voltage access terminal 37, a second low voltage access terminal 39, a connecting wire 38, a fluid medium and a heating power supply. The second heating metal tube 31 is a thick-walled single metal or bimetallic composite tube. The first heating metal tube 21 is placed inside the second heating metal tube 31, and is placed together inside the third metal tube 32. The first fluid heat exchange channel 34-1 is formed inside the first heating metal tube 21, and the second first fluid heat exchange channel 34-3 is formed in the gap between the second heating metal tube 31 and the third metal tube 32. The gap between the first heating metal tube 21 and the second heating metal tube 31 is electrically insulated by the insulating layer 14. The insulating bracket 35 is made of a ceramic insulator and is used to fix and support the second heating metal tube 31. The heating power supply can be connected to both ends of the first heating metal tube 21, or to the first heating metal tube 21 and the second heating metal tube 31.

[0056] When the voltage is applied to the first heating metal tube 21 and the second heating metal tube 31, the high voltage access terminal 24 is located on one side of the first heating metal tube 21, the first low voltage access terminal 37 is located on the other side of the second heating metal tube 31, and the first heating metal tube 21 and the second heating metal tube 31 are connected and conducted through the connecting wire 38. The heating power supply is preferably an AC power supply, and the AC current formed by the power supply generates Joule heat outside the first heating metal tube 21 and inside the second heating metal, and the fluid medium flows through the first fluid heat exchange channel 34-1 and the first fluid heat exchange channel 34-1 to exchange heat.

[0057] When the AC voltage is only applied to both ends of the first heating metal tube 21, the connecting wire 38 is removed, the high voltage access terminal 24 is located on one side of the first heating metal tube 21, and the second low voltage access terminal 39 is located on the other side of the first heating metal tube 21. The fluid medium can flow through the first fluid heat exchange channel 34-1 and the second fluid heat exchange channel 34-3 to exchange heat, and the process can be series or parallel. The heating power supply is preferably an AC power supply.

[0058] like Fig.13 and Fig.14 The figure shows the side view and front view of the structure of the four-tube direct heating metal device of Example 9 of the present invention. The four-tube direct heating includes a heat exchange inner tube 41, a first insulating layer 14-1, a first heating metal tube 21, a second insulating layer 14-2, a first heat exchange outer tube 51, a second heat exchange outer tube 52, an insulating bracket 35, a first fluid heat exchange channel 34-1, a second fluid heat exchange channel 34-3, a high voltage access terminal 24, a low voltage access terminal 25, a fluid medium and a heating power supply. The heat exchange inner tube 41, the first heating metal tube 21, the first heat exchange outer tube 51 and the second heat exchange outer tube 52 are nested together from the inside to the outside in sequence to form a sleeve. Among them, a first fluid heat exchange channel 34-1 is formed inside the heat exchange inner tube 41; the sleeve gap between the heat exchange inner tube 41 and the first heating metal tube 21 is electrically insulated by the insulating layer 14; the sleeve gap between the first heating metal tube 21 and the first heat exchange outer tube 51 is electrically insulated by the insulating layer 14; the sleeve gap between the first heat exchange outer tube 51 and the second heat exchange outer tube 52 forms a second fluid heat exchange channel 34-3; the insulating bracket 35 is used to support the gap between the first heat exchange outer tube 51 and the second heat exchange outer tube 52.

[0059] The heating power supply is connected to a high voltage access terminal 24 and a low voltage access terminal 25, the high voltage access terminal 24 is located on one side of the first heating metal tube 21, and the low voltage access terminal 25 is located on the other side of the first heating metal tube 21. The heating power supply can be a DC power supply or an AC power supply, preferably an AC power supply.

[0060] When the heating power source is a DC power source, the generated current generates Joule heat in the first heating metal tube 21, and the heat is transferred to the first fluid heat exchange channel 34-1 and the second fluid heat exchange channel 34-3 through the metal, the first insulating layer 14-1 and the second insulating layer 14-2. The fluid medium flows through the first fluid heat exchange channel 34-1 and the second fluid heat exchange channel 34-3 to exchange heat, and the process can be series or parallel.

[0061] When the heating power supply is an AC power supply, the AC current formed by the power supply generates Joule heat outside the first heating metal tube 21 and inside the first heat exchange outer tube 51, and the heat is transferred to the first fluid heat exchange channel 34-1 and the second fluid heat exchange channel 34-3 through the metal and the first insulating layer 14-1.

[0062] So far, the technical route of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An electric heating energy storage system that quickly responds to changes in electric power, characterized in that: It includes an electric heater heating metal structure or a direct heating metal structure; the electric heater heating metal structure includes a heat storage metal body, a fluid heat exchange channel, an electric heater, an insulating layer, a fluid medium, an external heat exchange device and a heating power supply; wherein the electric heater heating metal structure is plate-shaped or columnar; the insulating layer is insulating ceramic particles or insulating ceramic tubes; the electrical connection between the electric heaters is a single group or multiple groups of series or parallel connection; in the electric heater heating metal structure, a position for the electric heater is reserved in the heat storage metal body, and the electric heater is assembled in the position reserved in the heat storage metal body. The outside of the electric heater is wrapped with insulating heat-conductive material to form an insulating layer; when storing energy, the electric energy is passed The control of the overheating power supply enters the electric heater, and the electric heating element in the electric heater converts electrical energy into thermal energy. The thermal energy is transferred to the heat storage metal body through the insulating layer and further transferred to the fluid medium; the fluid medium flows through the fluid heat exchange channel to exchange heat, and the fluid medium heat exchange and the electric heater heating are carried out simultaneously, or after the electric heater heats the heat storage metal body to complete energy storage; in the direct heating metal structure, the heat storage metal body and the electric heater are the same object; when storing energy, electrical energy enters the heat storage metal body through the control of the heating power supply, and the heat storage metal body directly converts electrical energy into thermal energy through the Joule effect; the thermal energy is transferred to the fluid medium through the heat storage metal body itself.

2. The electric heating energy storage system that quickly responds to electric power changes according to claim 1 is characterized in that: When the electric heater heating metal structure is in the shape of a plate, the shape of the heat storage metal body is a straight plate or a U-shaped plate; when the heat storage metal body is in the shape of a straight plate, the electric heater and the fluid heat exchange channel are arranged in a left-right or up-down spacing; or the fluid heat exchange channel is located in the center of the heat storage metal body and is dispersedly arranged, and the electric heater is arranged around the fluid heat exchange channel; the plate-like structure is stacked or horizontally arranged in space, and an insulating shell layer is provided on the outside; the ceramic material is magnesium oxide or boron nitride; the heating power supply is an AC power supply or a DC power supply, and the fluid medium is heat transfer oil or molten salt; the gas medium is nitrogen or an inert gas.

3. The electric heating energy storage system that quickly responds to electric power changes according to claim 1 is characterized in that: When the heat storage metal body is in the shape of a U-shaped plate, the electric heaters are dispersedly arranged around the U-shaped corridor, and the U-shaped hollow part in the middle of the heat storage metal body is a fluid heat exchange channel.

4. The electric heating energy storage system that quickly responds to electric power changes according to claim 1 is characterized in that: When the electric heater heating metal structure is columnar, the electric heater is located at the geometric center of the heat storage metal body, and the fluid heat exchange channel is symmetrically distributed around the outer center of the electric heater; or the fluid heat exchange channel is located at the center of the columnar body, and the electric heaters are evenly arranged around the central heat exchange channel; sufficient metal body is left between the electric heater and the heat exchange channel or between the electric heaters for heat storage.

5. The electric heating energy storage system that quickly responds to electric power changes according to claim 1, characterized in that: The external heat exchange device is a bundled pipeline or an external heat exchange channel device. The bundled pipeline is composed of parallel connected pipelines and is connected to the fluid or gas heat exchange channel. The number of parallel pipelines in the bundled pipeline is the same as that of the fluid heat exchange channel; the external heat exchange channel device is the gap part between the heat storage metal body and the insulation shell wrapped outside it.

6. The electric heating energy storage system that quickly responds to electric power changes according to claim 1, characterized in that: The heat storage metal body forms partial gaps, which are replaced together with parts of the electric heater and the fluid heat exchange channel by other heat storage materials. The other heat storage materials are filling materials or porous structure materials, wherein the filling materials are carbon powder or ceramic particles, and the porous structure materials are heat storage magnesium bricks.

7. The electric heating energy storage system that quickly responds to electric power changes according to claim 1, characterized in that: In the direct heating metal structure, the electric heater and the heat storage metal body are the same object, including single-tube direct heating or double-tube direct heating or three-tube direct heating or four-tube direct heating; the single-tube direct heating includes a first heating metal tube, a fluid heat exchange channel, an insulation layer, a high voltage access terminal, a low voltage access terminal, a fluid medium and a heating power supply; the first heating metal tube is a thick-walled single metal or bimetal composite tube, and its cross-sectional shape is a closed polygon; the insulation layer covers the outside of the first heating metal tube; the high voltage access terminal and the low voltage access terminal are respectively located at both ends of the first heating metal tube, and are connected to the heating power supply; the heating power supply is an AC power supply; After the power is supplied, the electric current formed by the skin effect generates Joule heat on the outer skin of the first heating metal tube, and the heat is transferred to the inside of the heating metal through the metal. At the same time, the fluid medium exchanges the heat through the fluid heat exchange channel; the fluid medium heat exchange is carried out simultaneously with the electrically heated metal, or after the electrically heated metal completes energy storage; the fluid medium is molten salt or nitrogen or inert gas.

8. The electric heating energy storage system that quickly responds to electric power changes according to claim 7, characterized in that: The double-tube direct heating includes a fluid heat exchange channel, an inner heat exchange tube, an insulating layer, a first heating metal tube, a fluid medium and a heating power supply; the inner heat exchange tube and the first heating metal tube are any combination of thick-walled metal tubes or thin-walled metal tubes; the inner heat exchange tube is placed inside the first heating metal tube to form an inner tube, and the gap between the inner tube and the heating metal is filled with insulating heat-conductive material to form an insulating layer, and a fluid heat exchange channel is formed inside the inner tube; the high voltage access terminal and the low voltage access terminal are respectively located at both ends of the first heating metal tube and are connected to the heating power supply; the heating power supply is an AC power supply or a DC power supply; when the heating power supply is an AC power supply, due to the skin effect, the generated current generates Joule heat on the outer skin of the heating metal, and the heat is transferred to the inner side of the inner tube through the metal and the insulating layer, and at the same time the fluid medium exchanges the heat through the fluid heat exchange channel; the fluid medium heat exchange is carried out simultaneously with the electrically heated metal, or after the electrically heated metal completes heat storage.

9. The electric heating energy storage system that quickly responds to electric power changes according to claim 7, characterized in that: The three-tube direct heating includes a first heating metal tube, a second heating metal tube, a third metal tube, a first fluid heat exchange channel, an insulating layer, a second fluid heat exchange channel, an insulating bracket, a high voltage access terminal, a first low voltage access terminal, a second low voltage access terminal, a connecting wire, a fluid medium and a heating power supply; the second heating metal tube is a thick-walled single metal or bimetallic composite tube; the first heating metal tube is placed inside the second heating metal tube, and is placed together inside the third metal tube; a first fluid heat exchange channel is formed inside the first heating metal tube, and a second fluid heat exchange channel is formed between the sleeve gaps of the second heating metal tube and the third metal tube, and electrical insulation is formed between the sleeve gaps of the first heating metal tube and the second heating metal tube through an insulating layer; the insulating bracket is made of a ceramic insulator and is used to fix and support the second heating metal tube; the heating power supply is connected to both ends of the first heating metal tube, or to the first heating metal tube and the second heating metal tube.

10. The electric heating energy storage system that quickly responds to electric power changes according to claim 9, characterized in that: When the voltage is applied to the first heating metal tube and the second heating metal tube, the high voltage access end is located on one side of the first heating metal tube, and the first low voltage access end is located on the other side of the second heating metal tube, and the first heating metal tube and the second heating metal tube are connected and conducted through a connecting wire; the heating power supply is preferably an AC power supply, and the AC current formed by the power supply generates Joule heat outside the first heating metal tube and inside the second heating metal, and the fluid medium flows through the first fluid heat exchange channel and the first fluid heat exchange channel to exchange heat.

11. The electric heating energy storage system that quickly responds to electric power changes according to claim 9, characterized in that: When the AC voltage is only applied to the two ends of the first heating metal tube, the connecting wire is removed, the high voltage access end is located on one side of the first heating metal tube, and the second low voltage access end is located on the other side of the first heating metal tube. The fluid medium can flow through the first fluid heat exchange channel and the second fluid heat exchange channel respectively to exchange heat. The process can be series or parallel, and the heating power supply is preferably an AC power supply.

12. The electric heating energy storage system that quickly responds to electric power changes according to claim 7, characterized in that: The four-tube direct heating includes a heat exchange inner tube, a first insulating layer, a first heating metal tube, a second insulating layer, a first heat exchange outer tube, a second heat exchange outer tube, an insulating bracket, a first fluid heat exchange channel, a second fluid heat exchange channel, a high voltage access terminal, a low voltage access terminal, a fluid medium and a heating power supply; the heat exchange inner tube, the first heating metal tube, the first heat exchange outer tube and the second heat exchange outer tube are nested together from the inside to the outside in sequence to form a sleeve; wherein a first fluid heat exchange channel is formed inside the heat exchange inner tube; the sleeve gap between the heat exchange inner tube and the first heating metal tube is electrically insulated by the insulating layer; the sleeve gap between the first heating metal tube and the first heat exchange outer tube is electrically insulated by the insulating layer; the sleeve gap between the first heat exchange outer tube and the second heat exchange outer tube forms a second fluid heat exchange channel; the insulating bracket is used to support the gap between the first heat exchange outer tube and the second heat exchange outer tube.

13. The electric heating energy storage system that quickly responds to electric power changes according to claim 12, characterized in that: The heating power supply is connected to a high voltage access terminal and a low voltage access terminal, the high voltage access terminal is located on one side of the first heating metal tube, and the low voltage access terminal is located on the other side of the first heating metal tube; the heating power supply is a DC power supply or an AC power supply.

14. The electric heating energy storage system that quickly responds to electric power changes according to claim 13, characterized in that: When the heating power supply is a DC power supply, the generated current generates Joule heat in the first heating metal tube, and the heat is transferred to the first fluid heat exchange channel and the second fluid heat exchange channel through the metal, the first insulating layer and the second insulating layer; the fluid medium flows through the first fluid heat exchange channel and the second fluid heat exchange channel to exchange heat, and the process is series or parallel.

15. The electric heating energy storage system that quickly responds to electric power changes according to claim 13, characterized in that: When the heating power supply is an AC power supply, the AC current formed by the power supply generates Joule heat outside the first heating metal tube and inside the first heat exchange outer tube, and the heat is transferred to the first fluid heat exchange channel and the second fluid heat exchange channel through the metal and the first insulating layer.

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