Solid energy storage device and thermal management method

Abstract

The invention relates to the technical field of solid energy storage, and discloses a solid energy storage device and a heat management method.The solid energy storage device comprises a heat exchange loop and a first bypass, and the heat exchange loop comprises an energy storage furnace, a heat exchanger and a circulating fan which are sequentially connected in the gas flow direction; one end of the first bypass is connected between the air inlet of the energy storage furnace and the air outlet of the circulating fan, the other end of the first bypass is connected between the air outlet of the energy storage furnace and the air inlet of the heat exchanger, the first bypass comprises a first adjusting valve, and the first adjusting valve is used for adjusting the opening degree of the first bypass. When the temperature of the air at the air outlet of the energy storage furnace is too high, the first bypass is opened, so that part of the air leaving the heat exchanger does not pass through the energy storage furnace but returns to the air inlet of the heat exchanger along the first bypass, the temperature of the air entering the heat exchanger is reduced, and the material cost of the heat exchanger is reduced; along with heat consumption, the opening degree of the first bypass is gradually reduced, so that the temperature of gas entering the heat exchanger is kept stable for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of solid energy storage, and in particular to a solid energy storage device and a thermal management method. Background Art

[0002] Electric thermal energy storage technology uses electric heating to convert green electricity (or valley electricity) into thermal energy and stores it in heat storage materials. When used, the heat is released to provide hot water, steam, etc. to the outside world. It has the advantages of low energy cost and reliable operation, and has been widely used in clean heating, heat storage and peak regulation.

[0003] Solid energy storage adopts the sensible heat storage technology route, uses heat storage materials that do not undergo phase change, and uses the temperature change of the heat storage material to achieve thermal energy storage. The characteristics of sensible heat storage result in a high outlet air temperature of the energy storage furnace at the initial heat release, and the outlet air temperature gradually decreases during the heat release process. When designing the system, the heat exchanger needs to be selected according to the highest air temperature, resulting in high costs and increased heat storage costs; secondly, large-scale temperature changes have a significant impact on the service life of the heat exchanger. Summary of the invention

[0004] In view of this, the present invention provides a solid energy storage device and a thermal management method to solve the problems of high cost and short life of heat exchangers in sensible heat storage.

[0005] In a first aspect, the present invention provides a solid energy storage device, comprising a heat exchange circuit and a first bypass, wherein the heat exchange circuit comprises an energy storage furnace, a heat exchanger and a circulating fan connected in sequence along a gas flow direction, one end of the first bypass is connected between an air inlet of the energy storage furnace and an air outlet of the circulating fan, and the other end of the first bypass is connected between an air outlet of the energy storage furnace and an air inlet of the heat exchanger, and the first bypass comprises a first regulating valve, which is used to adjust the opening of the first bypass.

[0006] Beneficial effects: The energy storage furnace converts electrical energy into thermal energy through electric heating and stores it. When using heat, the circulating fan causes the airflow to circulate along the heat exchange loop. The airflow absorbs thermal energy in the energy storage furnace and then transfers the thermal energy to the fluid to be heated in the heat exchanger. When the gas temperature at the air outlet of the energy storage furnace is too high, the first bypass is opened so that a part of the gas leaving the heat exchanger does not pass through the energy storage furnace, but returns to the air inlet of the heat exchanger along the first bypass, thereby reducing the gas temperature entering the heat exchanger and helping to reduce the material cost of the heat exchanger. As the heat is used, the opening of the first bypass is gradually reduced, so that the gas temperature entering the heat exchanger remains stable for a long time, which helps to extend the service life of the heat exchanger.

[0007] In an optional embodiment, the energy storage furnace is formed with a heating chamber, and the energy storage furnace further includes a heating module and a heat storage module, and the heating module and the heat storage module are alternately arranged in the heating chamber along the air flow direction.

[0008] Beneficial effects: On the one hand, the heating module converts electrical energy into thermal energy, and then transmits it to the heat storage module for storage. On the other hand, the heat storage module is arranged between the heating modules, which can also improve the insulation effect between the heating modules, making the heating modules suitable for connecting to high voltage electricity, thereby improving the heating power of the solid energy storage device.

[0009] In an optional embodiment, the heating module includes a support frame, a support rod and a resistance wire, a plurality of the support rods are arranged at intervals on the support frame, the support rods extend in a direction perpendicular to the airflow direction, the resistance wire is spirally mounted on the support rod, and the resistance wire is used to connect to a high-voltage power supply.

[0010] Beneficial effect: The resistance wire directly exchanges heat with the air during the heating process, which can effectively increase the heating rate of the air, help reduce the surface temperature of the resistance wire, and reduce the risk of the resistance wire fusing.

[0011] In an optional embodiment, the solid energy storage device also includes a second bypass, one end of which is connected between the air inlet of the circulating fan and the air outlet of the heat exchanger, and the other end of the second bypass is connected between the air outlet of the energy storage furnace and the air inlet of the heat exchanger, and the second bypass includes a second regulating valve, which is used to adjust the opening of the second bypass; the heat exchange circuit also includes a third regulating valve, which is used to adjust the opening of the heat exchange circuit.

[0012] Beneficial effects: On the one hand, by introducing the second bypass, airflow is formed in the heating chamber during heat storage, which can promote heat exchange between the resistance wire and the air through the flow of airflow, help to further reduce the surface temperature of the resistance wire and reduce the risk of the resistance wire melting. On the other hand, the airflow can produce a convective heat exchange effect, so that the heat is more concentrated in the heat storage module near the downstream, and the temperature gradient of the heat storage module is increased, which helps to better utilize the sensible heat of the heat storage module.

[0013] In an optional implementation, the heat storage capacity of the heat storage module gradually increases along the air flow direction.

[0014] Beneficial effect: By reasonably allocating the distribution of heat storage capacity, the heat is more concentrated in the heat storage modules close to the downstream, which helps to better utilize the sensible heat of the heat storage modules.

[0015] In an optional embodiment, the heating power of the heating module is configured to decrease sequentially along the air flow direction.

[0016] Beneficial effect: By increasing the heating power of the heating module close to the upstream, it helps to quickly increase the temperature during the heating process, and helps to transfer as much heat energy in the airflow as possible to the heat storage module, reducing heat loss.

[0017] In an optional embodiment, a third bypass and a fourth bypass are further included, wherein one end of the third bypass is connected between the air inlet of the circulating fan and the air outlet of the heat exchanger, and the other end of the third bypass is used to connect to the external environment, and the third bypass is provided with a fresh air valve, and one end of the fourth bypass is connected to the air outlet of the energy storage furnace, and the other end of the fourth bypass is used to connect to the external environment, and the fourth bypass is provided with an exhaust valve.

[0018] Beneficial effect: Before formal operation, open the fresh air valve and the exhaust valve, heat the heat storage module, and discharge the moisture in the heat storage module from the fourth bypass along with the air flow, thereby reducing the water content of the heat storage module, improving the insulation performance of the heat storage module, and reducing the risk of breakdown discharge during formal heat storage.

[0019] In a second aspect, the present invention further provides a thermal management method, which uses the solid energy storage device provided by the present invention, and the thermal management method includes a heat release condition, which includes: monitoring the temperature of the air outlet of the energy storage furnace to obtain a first air temperature; adjusting the opening of the first bypass in response to the first air temperature so that the temperature of the air inlet of the heat exchanger is less than or equal to the second air temperature.

[0020] Beneficial effects: The thermal management method uses the solid energy storage device provided by the present invention, and therefore has the corresponding beneficial effects brought by the solid energy storage device, which will not be elaborated here.

[0021] In an optional implementation, a heat storage condition is further included, and the heat storage condition includes: opening the second regulating valve and closing the third regulating valve; starting the circulating fan; and starting the heating module to heat the heat storage module.

[0022] Beneficial effects: On the one hand, airflow is formed in the heating chamber during heat storage, which can promote heat exchange between the resistance wire and the air through the flow of airflow, help to further reduce the surface temperature of the resistance wire and reduce the risk of the resistance wire melting. On the other hand, the airflow can produce a convective heat transfer effect, so that the heat is more concentrated in the heat storage module near the downstream, and the temperature gradient of the heat storage module is increased, which helps to better utilize the sensible heat of the heat storage module.

[0023] In an optional implementation, each of the heating modules is started in sequence according to the airflow direction.

[0024] Beneficial effect: Starting in sequence can avoid instantaneous large load on the power grid and also help the heat generated by heating to be transferred backward step by step. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 This is a schematic structural diagram of a solid energy storage device according to an embodiment of the present invention;

[0027] Figure 2 for Figure 1 Schematic diagram of the structure of the medium energy storage furnace;

[0028] Figure 3 for Figure 2 Schematic cross-sectional view of the AA section;

[0029] Figure 4 for Figure 1 Schematic diagram of the temperature gradient formed by the heat storage module;

[0030] Figure 5 This is a schematic diagram of electrical connections of a solid energy storage device according to an embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 101. Energy storage furnace; 1011. Shell; 1012. Heating module; 10121. Support frame; 10122. Support rod; 10123. Resistance wire; 1013. Heat storage module; 1014. Insulation foundation; 1015. Insulation layer; 10161. Guide plate; 10162. Air distribution plate; 1017. Electronic control unit; 102. Heat exchanger; 103. Circulation fan; 104. Third regulating valve; 201. First regulating valve; 301. Second regulating valve; 401. Fresh air valve; 402. Exhaust valve. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0034] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a", "an" and "an" as used herein may also be meant to include the plural forms. The terms "comprise", "include" and "have" are inclusive and therefore specify the presence of stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0035] Although the terms first, second, etc. may be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. In addition, in the description of this application, unless otherwise clearly specified and limited, the terms "set" and "connection" 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 directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0036] For ease of description, spatial relative terms can be used in the text to describe the relationship of an element or feature relative to another element or feature as shown in the figure, and these relative terms are, for example, "end", "length", "inside", "outside", etc. Such spatial relative terms are intended to include different orientations of the mechanism in use or operation except the orientation depicted in the figure. For example, if the mechanism in the figure flips, the element described as "below other elements or features" or "below other elements or features" will be subsequently oriented to "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include the orientation on and below. The mechanism can be oriented in addition (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0037] Solid energy storage adopts the sensible heat storage technology route. The characteristics of sensible heat storage cause the outlet air temperature of the energy storage furnace to be higher at the initial moment of heat release. The outlet air temperature gradually decreases during the heat release process. Therefore, the selection of the heat exchanger needs to depend on the highest air temperature, which is more expensive. And due to the large temperature difference before and after, the service life of the heat exchanger is relatively low.

[0038] Combine the following Figures 1 to 5 , describing an embodiment of the present invention.

[0039] Reference Figure 1 According to an embodiment of the present invention, on the one hand, a solid energy storage device is provided, including a heat exchange circuit and a first bypass, the heat exchange circuit including an energy storage furnace 101, a heat exchanger 102 and a circulating fan 103 connected in sequence along the gas flow direction, one end of the first bypass is connected between the air inlet of the energy storage furnace 101 and the air outlet of the circulating fan 103, and the other end of the first bypass is connected between the air outlet of the energy storage furnace 101 and the air inlet of the heat exchanger 102, and the first bypass includes a first regulating valve 201, and the first regulating valve 201 is used to adjust the opening of the first bypass.

[0040] The energy storage furnace 101 converts electrical energy into thermal energy through electric heating and stores it. When using heat, the circulating fan 103 causes the airflow to circulate along the heat exchange loop. The airflow absorbs thermal energy in the energy storage furnace 101 and then transfers the thermal energy to the fluid to be heated in the heat exchanger 102.

[0041] According to the solid energy storage device of the present invention, when the gas temperature at the air outlet of the energy storage furnace 101 is too high, the first regulating valve 201 is opened, thereby opening the first bypass. Under the action of the circulating fan 103, a part of the gas leaving the air outlet of the circulating fan 103 continues to flow to the energy storage furnace 101 along the heat exchange loop, and another part of the gas does not pass through the energy storage furnace 101, but returns to the air inlet of the heat exchanger 102 along the first bypass. The two parts of gas mix with each other, thereby reducing the temperature of the gas entering the heat exchanger 102, which helps to reduce the material cost of the heat exchanger 102.

[0042] As heat is used, the temperature of the gas at the outlet of the energy storage furnace 101 gradually decreases. At this time, the opening of the first bypass can be gradually reduced to adjust the ratio of the gas entering the energy storage furnace 101 and the gas not entering the energy storage furnace 101, so that the temperature of the gas entering the heat exchanger 102 after mixing remains stable for a long time, which helps to extend the service life of the heat exchanger 102.

[0043] It can be understood that the first bypass is connected to the heat exchange circuit through a three-way structure, and the position where the gas returns to the heat exchange circuit (that is, the setting position of the three-way structure) can be selected at any position of the pipeline between the air outlet of the energy storage furnace 101 and the air inlet of the heat exchanger 102. For example, the three-way structure can be set on the side close to the air outlet of the energy storage furnace 101. On the one hand, this extends the distance for air flow mixing, which helps to make the temperature of the gas entering the heat exchanger 102 more uniform. On the other hand, this can also reduce the gas temperature as early as possible, which helps to reduce the material cost of the pipeline.

[0044] The energy storage furnace 101 stores energy by converting electrical energy into thermal energy of solid heat storage materials. Figure 2For example, in some embodiments, the energy storage furnace 101 is formed with a heating chamber, and the energy storage furnace 101 further includes a heating module 1012 and a heat storage module 1013, and the heating module 1012 and the heat storage module 1013 are alternately arranged in the heating chamber along the air flow direction. The heat storage module 1013 is arranged between the heating modules 1012, which can improve the insulation effect between the heating modules 1012, so that the heating modules 1012 are suitable for accessing high voltage electricity (greater than or equal to 1 kV), thereby improving the heating power of the solid energy storage device.

[0045] In addition, since the energy storage furnace 101 is provided with a plurality of heating modules 1012, the heating power of the energy storage furnace 101 can be adjusted by independently controlling each heating module 1012 and selectively shutting down some of the heating modules 1012. When the power supply changes (for example, the power capacity of the plant where the solid energy storage device is located decreases due to production expansion, etc.), the heating power can be adjusted to ensure the normal operation of the energy storage furnace 101.

[0046] In the related art, the heating module 1012 often uses an electric heating tube, which is mainly composed of an external protective sleeve, an internal heating resistance wire 10123 and protective insulating magnesium oxide powder. The heating resistance wire 10123 does not directly contact the outside air, but indirectly heats the air through the sleeve set on the outside. The use of the sleeve and magnesium oxide powder will increase the heat transfer resistance of the resistance wire 10123. When the heating power is high and the air flow rate outside the electric heating tube is low, the large surface heat load can easily cause the resistance wire 10123 to fuse, affecting the use of the equipment. In order to avoid the resistance wire 10123 from fusing, it is necessary to control the heating power of the resistance wire 10123 in real time according to the working conditions. However, the current power regulation technology under high voltage is not mature and the cost is high, and it cannot be applied on a large scale.

[0047] Reference Figure 3 In some embodiments, the heating module 1012 includes a support frame 10121, a support rod 10122 and a resistance wire 10123. A plurality of support rods 10122 are arranged at intervals on the support frame 10121. The support rod 10122 extends in a direction perpendicular to the airflow direction. The resistance wire 10123 is spirally sleeved on the support rod 10122. The resistance wire 10123 is used to connect to a high-voltage power supply.

[0048] In other words, the solid energy storage device of the present invention abandons the outer sleeve of the resistance wire 10123. The resistance wire 10123 directly exchanges heat with the air during the heating process, which can effectively increase the heating rate of the air and transfer the heat from the resistance wire 10123 to the air as quickly as possible, which helps to reduce the surface temperature of the resistance wire 10123 and reduce the risk of the resistance wire 10123 melting.

[0049] It is understandable that the support frame 10121 and the support rod 10122 need to be made of insulating materials. For example, the material of the support frame 10121 and the support rod 10122 can be ceramic. Ceramics are commonly used insulating materials in the field of high-voltage power transmission and distribution, and have good high-voltage insulation properties. Specifically, the ceramics can be silicon carbide, silicon nitride, aluminum oxide, etc.

[0050] In some embodiments, the solid energy storage device further includes an insulating foundation 1014, the number of the insulating foundations 1014 corresponds to the heating modules 1012, and the heating modules 1012 are disposed on the insulating foundations 1014. The insulating foundations 1014 can ensure the insulation requirements of the heating modules 1012 to the ground, and by equipping each heating module 1012 with a separate insulating foundation 1014, the insulation requirements between the heating modules 1012 can be ensured, thereby improving the safety of the solid energy storage device.

[0051] The high voltage power supply is a power grid or other upstream power supply facilities. The resistor wire 10123 is not suitable for directly connecting to the high voltage power supply. Figure 5 In some embodiments, the solid energy storage device may further include an electric control unit 1017. The high voltage electricity from the upstream power supply facility first enters the electric control unit 1017 and is transmitted to the resistance wire 10123 of the heating module 1012 under the control of the electric control unit 1017. Specifically, in some embodiments, each heating module 1012 is equipped with an independent electric control unit 1017, so as to flexibly control the start and stop of each heating module 1012.

[0052] For example, refer to Figure 3 In some embodiments, the resistance wire 10123 is divided into three groups, and the three groups of resistance wires 10123 are respectively used to access the A phase, B phase, and C phase of the high-voltage power supply, and the resistance wires 10123 in the same group are connected in series. The three-phase connection method makes the heating module 1012 suitable for accessing the three-wire high-voltage alternating current, meeting the requirements of the solid energy storage device operating under high voltage. The resistance wires 10123 of the same phase are connected in series, so as to reduce the heating power of a single resistance wire 10123 and reduce the risk of the resistance wire 10123 fusing under high voltage.

[0053] Continue to refer to Figure 3 The resistance wire 10123 can be connected in a star shape, that is, the resistance wire 10123 of each phase is finally connected to the same neutral point.

[0054] Optionally, the resistance wire 10123 is made of an electrothermal alloy, and the surface of the resistance wire 10123 is coated with a high-temperature resistant, heat-conductive and anti-corrosion coating to extend the service life of the resistance wire 10123 exposed to the environment.

[0055] Optionally, refer to Figure 1In some embodiments, the solid energy storage device further includes a second bypass, one end of which is connected between the air inlet of the circulating fan 103 and the air outlet of the heat exchanger 102, and the other end of the second bypass is connected between the air outlet of the energy storage furnace 101 and the air inlet of the heat exchanger 102, and the second bypass includes a second regulating valve 301, which is used to adjust the opening of the second bypass; the heat exchange circuit further includes a third regulating valve 104, which is used to adjust the opening of the heat exchange circuit.

[0056] When storing heat, the third regulating valve 104 is closed and the second regulating valve 301 is opened to generate an airflow that bypasses the heat exchanger 102 through the second bypass.

[0057] On the one hand, by introducing the second bypass, airflow is formed in the heating chamber during heat storage, which can promote heat exchange between the resistor 10123 and the air through the flow of airflow, help to further reduce the surface temperature of the resistor 10123, reduce the risk of the resistor 10123 melting, and make the solid energy storage device more suitable for connection to high voltage electricity. On the other hand, by increasing the airflow during the heat storage process, the effect of convective heat transfer can be produced, so that the heat is more concentrated in the heat storage module 1013 near the downstream, and the temperature gradient of the heat storage module 1013 increases, which helps to better utilize the sensible heat of the heat storage module 1013.

[0058] Furthermore, the airflow bypasses the heat exchanger 102 , thereby preventing the heat exchanger 102 from being damaged by high-temperature gas that exceeds the bearing capacity of the heat exchanger 102 during the heat storage process.

[0059] Specific reference Figure 4 , Figure 4 The temperature zone of the heat storage module 1013 under the action of the airflow is shown, wherein the horizontal axis shows the arrangement order of each heat storage module 1013 along the airflow direction, the upper edge line of the shaded area shows the temperature reached by the heat storage module 1013 after the heat storage is completed, and the lower edge line of the shaded area shows the temperature of the heat storage module 1013 at the end of heat release, and the area between the upper edge line and the lower edge line is the heat storage temperature zone that can be used. It can be noted that since the airflow gradually heats up in the energy storage furnace 101, the heat storage module 1013 close to the air inlet of the energy storage furnace 101 can reach a lower final temperature, while the heat storage module 1013 close to the air outlet of the energy storage furnace 101 needs to be maintained at a higher temperature (higher than the target temperature of the air outlet) to ensure normal heat release of the solid energy storage device.

[0060] In the related art, circulating airflow is generally not formed in the heating chamber during heat storage, the heating module 1012 statically heats the heat storage module 1013, and the final temperature of each heat storage module 1013 is basically the same (set to T). At this time, the temperature range that can be used by the heat storage module 1013 close to the air outlet of the energy storage furnace 101 is relatively narrow, and it is difficult to fully utilize the thermal energy of the solid energy storage device.

[0061] The present invention increases the airflow during the heat storage process so that the heat is concentrated more in the heat storage module 1013 near the downstream (air outlet). The heat storage module 1013 forms a temperature gradient. The final temperature of the heat storage module 1013 near the upstream (air inlet) is lower than T, and the final temperature of the heat storage module 1013 near the downstream is higher than T, which helps to better utilize the sensible heat of the heat storage module 1013.

[0062] In addition, since the heat storage modules 1013 are arranged at intervals, there is a heat insulation layer formed by air between the heat storage modules 1013, so the generated temperature gradient can be well maintained. The fact that each heating module 1012 can be independently controlled also helps maintain the temperature gradient.

[0063] It should be noted that since the resistance wire 10123 is arranged perpendicular to the airflow direction, it helps to make the temperature of the surface of the resistance wire 10123 uniform during the heat storage process, reduce the risk of damage, and thus increase the service life of the resistance wire 10123. Optionally, in some embodiments, the support rod 10122 extends in the horizontal direction.

[0064] For the resistance wire 10123 provided in the form of an electric heating tube in the related art, the placement direction (axis direction) of the electric heating tube does not affect the electric heating performance. However, for the exposed resistance wire 10123 in the present invention, if a vertical placement is adopted, due to the lack of protection of the casing and the filling support of magnesium oxide powder, the spiral resistance wire 10123 will be deformed under the action of gravity, so that the pitch is larger at the top and smaller at the bottom, and the gas is heated unevenly. When a horizontal placement is adopted, the horizontal support rod 10122 supports the resistance wire 10123, and the gravity of the resistance wire 10123 does not generate a component force along the horizontal axis, thereby overcoming this defect and preventing the resistance wire 10123 from changing its pitch under the action of its own weight, which affects the uniformity of heating.

[0065] In some embodiments, the heat storage capacity of the heat storage module 1013 gradually increases along the airflow direction. By reasonably allocating the distribution of the heat storage capacity, the heat is more concentrated in the heat storage module 1013 near the downstream, which helps to better utilize the sensible heat of the heat storage module 1013.

[0066] The change of heat storage capacity can be achieved by changing the material or volume of the heat storage module 1013. Optionally, the thickness of the heat storage module 1013 in the airflow direction gradually increases along the airflow direction. In this case, different heat storage modules 1013 can use the same material, which is convenient for production management. Exemplarily, the heat storage material can use heat storage concrete or heat storage bricks.

[0067] It should be pointed out that heat storage bricks are generally magnesia bricks, whose main crystal phase is periclase, and have poor thermal shock resistance. They are prone to problems such as pulverization after rapid cooling and heating, which affects their service life. In comparison, heat storage concrete (especially high-temperature concrete) has better thermal shock resistance, larger specific heat capacity, and lower material cost.

[0068] However, since the heat storage concrete is cast in a casting process, it contains a lot of moisture. When the temperature rises, a large amount of bound water and free water will precipitate. In the related technology, the electric heating pipe is directly inserted into the heat storage module 1013, which makes the heat storage concrete very prone to arcing, posing a major safety hazard. In addition, the insulation of the heat storage concrete decreases at high temperatures, making it very prone to breakdown. Finally, the heat resistance temperature and thermal conductivity of concrete are relatively low, and direct contact heat exchange is very prone to local overheating, causing structural failure of the heat storage module 1013.

[0069] In the present invention, since the heating module 1012 is independent of the heat storage module 1013, the two are independent of each other, and a certain interval can be left between the two. The heat storage module 1013 is only used for heat storage and is not used for the insulation of the resistance wire 10123 in the same heating module 1012, thereby avoiding arcing, breakdown and other problems that may occur when using heat storage concrete, so that the solid energy storage device is also suitable for using heat storage concrete as the material of the heat storage module 1013.

[0070] In order to further eliminate the hidden dangers when using thermal storage concrete, optionally, refer to Figure 1 In some embodiments, the solid energy storage device further includes a third bypass and a fourth bypass, wherein one end of the third bypass is connected between the air inlet of the circulating fan 103 and the air outlet of the heat exchanger 102, and the other end of the third bypass is used to connect to the external environment, and the third bypass is provided with a fresh air valve 401, and one end of the fourth bypass is connected to the air outlet of the energy storage furnace 101, and the other end of the fourth bypass is used to connect to the external environment, and the fourth bypass is provided with an exhaust valve 402.

[0071] Before formal operation, open the fresh air valve 401 and the exhaust valve 402, close the first regulating valve 201, the second regulating valve 301 and the third regulating valve 104, heat the heat storage module 1013, and discharge the moisture of the heat storage module 1013 from the fourth bypass along with the airflow, thereby reducing the water content of the heat storage module 1013, improving the insulation performance of the heat storage module 1013, and reducing the risk of breakdown discharge during formal heat storage.

[0072] It should also be noted that, referring to Figure 2The energy storage furnace 101 has a shell 1011, which forms a heating chamber. The inner wall of the shell 1011 is generally provided with an insulating layer 1015, which has a good insulation effect while providing insulation. However, in actual implementation, the heat exchange loop and the second bypass may have a long length, and the reliability of insulation is difficult to ensure.

[0073] Therefore, in some embodiments, the heating power of the heating module 1012 is configured to decrease sequentially along the airflow direction. By increasing the heating power of the heating module 1012 close to the upstream, it is helpful to quickly increase the temperature during the heating process, and it is helpful to conduct as much heat energy in the airflow as possible to the heat storage module 1013, thereby reducing the heat loss when the airflow flows through the heat exchange loop and the second bypass.

[0074] In some embodiments, the energy storage furnace 101 further includes a flow balancing module, and two flow balancing modules are respectively arranged at the air inlet and the air outlet. The flow balancing module can make the air flow more evenly flow to each resistance wire 10123 on the heating module 1012, so that the air is fully heated by the resistance wire 10123, thereby improving the heating effect of the solid energy storage device.

[0075] For example, refer to Figure 2 , the flow balancing module is arranged in a trumpet shape at the air inlet and the air outlet. The cross-sectional area of ​​the flow balancing module located at the air inlet gradually increases along the airflow direction. The flow balancing module may include a guide plate 10161 and an air distribution plate 10162, wherein the guide plate 10161 is located upstream of the air distribution plate 10162, and the guide plate 10161 extends obliquely from the air inlet to the downstream. The airflow from the air inlet is dispersed and expanded under the action of the guide plate 10161. The air distribution plate 10162 is provided with an array of holes, and the airflow passing through the air distribution plate 10162 can be uniformed under the action of the air distribution plate 10162. The cross-sectional area of ​​the flow balancing module located at the air outlet gradually decreases along the airflow direction. The flow balancing module may only include the air distribution plate 10162.

[0076] According to an embodiment of the present invention, on the other hand, a thermal management method is further provided. The thermal management method uses the solid energy storage device provided by the present invention. The thermal management method includes a heat release condition. The heat release condition includes:

[0077] Monitor the temperature of the air outlet of the energy storage furnace 101 to obtain a first air temperature;

[0078] The opening degree of the first regulating valve 201 is adjusted in response to the first air temperature so that the temperature of the air inlet of the heat exchanger 102 is less than or equal to the second air temperature.

[0079] It can be understood that the second air temperature is the rated maximum temperature that the heat exchanger 102 can withstand, which is determined when the heat exchanger 102 is selected and designed.

[0080] The circulating fan 103 drives the low-temperature air after heat exchange in the heat exchanger 102 to be divided into two paths. One path enters the energy storage furnace 101, absorbs the heat released by the heat storage module 1013, and the heated hot air continues to be transmitted downstream. In this process, the hot air is heated step by step by the heat storage module 1013, and finally the high-temperature air after heat extraction is discharged from the air outlet; it merges with the other low-temperature air diverted by the circulating fan 103, and after forming a relatively stable air temperature, it enters the heat exchanger 102 to transfer the heat to the cold fluid outside to supply heat to the outside, and the low-temperature air after cooling enters the circulating fan 103 again, thus forming a complete heat extraction cycle. In this process, the opening of the first bypass is adjusted by the first regulating valve 201, and the temperature of the hot air entering the heat exchanger 102 is flexibly controlled to ensure the stability of the heating load.

[0081] In some embodiments, a heat storage condition is also included, and the heat storage condition includes:

[0082] Open the second regulating valve 301 and close the third regulating valve 104;

[0083] Start the circulation fan 103;

[0084] The heating module 1012 is started to heat the heat storage module 1013 .

[0085] On the one hand, when storing heat, airflow is formed in the heating chamber, which can promote the heat exchange between the resistor wire 10123 and the air through the flow of airflow, which helps to further reduce the surface temperature of the resistor wire 10123 and reduce the risk of the resistor wire 10123 melting. On the other hand, the airflow can produce a convective heat transfer effect, so that the heat is more concentrated in the heat storage module 1013 near the downstream, and the temperature gradient of the heat storage module 1013 increases, which helps to better utilize the sensible heat of the heat storage module 1013.

[0086] Furthermore, starting the circulating fan 103 first and then starting the heating module 1012 can reduce the risk of the resistance wire 10123 fusing during startup.

[0087] It can be understood that when the surplus power capacity in the use environment (such as an industrial plant) is relatively stable, all heating modules 1012 can be put into operation during heat storage; when the surplus power capacity is reduced due to expansion, etc., some heating modules 1012 are selectively turned on during heat storage, that is, the power of the heating module 1012 is dynamically adjusted and matched with the surplus power capacity to ensure the normal operation of the heating module 1012.

[0088] Optionally, in some embodiments, each heating module 1012 is started sequentially according to the airflow direction. Starting sequentially can avoid generating a large instantaneous load on the power grid, and also helps to transfer the heat generated by heating backward step by step.

[0089] In some embodiments, a mixed working condition (i.e., storing heat while releasing heat) is also included, and the mixed working condition includes:

[0090] Close the first regulating valve 201, and open the second regulating valve 301 and the third regulating valve 104;

[0091] The openings of the second regulating valve 301 and the third regulating valve 104 are adjusted in response to the first air temperature so that the temperature of the air inlet of the heat exchanger 102 meets the heat demand of the downstream.

[0092] The circulating fan 103 drives the hot air to extract heat from the heating module 1012 and transfer it to the heat storage module 1013. The higher hot air after the heat transfer is divided into two paths, one path enters the heat exchanger 102 for heating, and the other path directly returns to the energy storage furnace 101 for heat storage circulation; in this process, the opening of the second regulating valve 301 and the third regulating valve 104 is adjusted to ensure the external heat supply.

[0093] In addition, when the user's heat load is small, only the heating module 1012 with the corresponding heating power can be turned on to store heat, avoiding overheating caused by fully opening the heating modules 1012; when a heating module 1012 fails, only the heating module 1012 needs to be turned off, and the remaining heating modules 1012 can be put into use normally, thereby ensuring continuous and stable heat supply to the outside world.

[0094] In some embodiments, a baking furnace condition is also included, and the baking furnace condition includes:

[0095] Open the fresh air valve 401 and the exhaust valve 402, and close the first regulating valve 201, the second regulating valve 301 and the third regulating valve 104;

[0096] Start the circulation fan 103;

[0097] The first heating module 1012 (that is, the heating module 1012 closest to the air inlet of the energy storage furnace 101 ) is started to heat the heat storage module 1013 .

[0098] The oven-baking condition is executed before the heat storage condition, and is used to reduce the water content of the heat storage module 1013 before heat storage. Specifically, in the oven-baking condition, the airflow in the energy storage furnace 101 is an open cycle, and the gas is sent into the energy storage furnace 101 through the third bypass. With the heat transfer effect of the airflow, the heat generated by the first heating module 1012 is used to heat up each heat storage module 1013, and the free water and bound water of each heat storage module 1013 are discharged from the energy storage furnace 101 through the fourth bypass with the wind. In this process, since the remaining heating modules 1012 are not started, the water vapor in the hot air will not affect them.

[0099] After all the heat storage modules 1013 are dried and there is no moisture in the hot air, the fresh air valve 401 and the exhaust valve 402 can be closed, switching to a closed cycle and switching to other working conditions normally.

[0100] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A solid energy storage device, characterized in that: include: A heat exchange circuit, the heat exchange circuit comprising an energy storage furnace (101), a heat exchanger (102) and a circulation fan (103) connected in sequence along a gas flow direction; A first bypass, wherein one end of the first bypass is connected between an air inlet of the energy storage furnace (101) and an air outlet of the circulating fan (103), and the other end of the first bypass is connected between the air outlet of the energy storage furnace (101) and an air inlet of the heat exchanger (102), and the first bypass comprises a first regulating valve (201), and the first regulating valve (201) is used to adjust the opening of the first bypass.

2. The solid energy storage device according to claim 1, characterized in that: The energy storage furnace (101) is formed with a heating chamber, and the energy storage furnace (101) further comprises a heating module (1012) and a heat storage module (1013), wherein the heating module (1012) and the heat storage module (1013) are alternately arranged in the heating chamber along an air flow direction.

3. The solid energy storage device according to claim 2, characterized in that: The heating module (1012) comprises a support frame (10121), a support rod (10122) and a resistance wire (10123); a plurality of the support rods (10122) are arranged on the support frame (10121) at intervals; the support rods (10122) extend in a direction perpendicular to the airflow direction; the resistance wire (10123) is spirally sleeved on the support rod (10122); and the resistance wire (10123) is used to connect to a high-voltage power supply.

4. The solid energy storage device according to claim 3, characterized in that: The heat exchange circuit further comprises a second bypass, one end of the second bypass being connected between the air inlet of the circulating fan (103) and the air outlet of the heat exchanger (102), and the other end of the second bypass being connected between the air outlet of the energy storage furnace (101) and the air inlet of the heat exchanger (102), the second bypass comprising a second regulating valve (301), the second regulating valve (301) being used to adjust the opening of the second bypass; the heat exchange circuit further comprises a third regulating valve (104), the third regulating valve (104) being used to adjust the opening of the heat exchange circuit.

5. The solid energy storage device according to claim 4, characterized in that: The heat storage capacity of the heat storage module (1013) gradually increases along the air flow direction.

6. The solid energy storage device according to claim 4, characterized in that: The heating power of the heating module (1012) is configured to decrease sequentially along the air flow direction.

7. The solid energy storage device according to claim 2, characterized in that: (10122) also includes a third bypass and a fourth bypass, One end of the third bypass is connected between the air inlet of the circulation fan (103) and the air outlet of the heat exchanger (102), and the other end of the third bypass is used to communicate with the external environment. The third bypass is provided with a fresh air valve (401). One end of the fourth bypass is connected to the air outlet of the energy storage furnace (101), and the other end of the fourth bypass is used to communicate with the external environment. The fourth bypass is provided with a drain valve (402).

8. A thermal management method, characterized in that: The thermal management method uses the solid energy storage device according to any one of claims 1 to 7, and the thermal management method includes a heat release condition, and the heat release condition includes: Monitoring the temperature of an air outlet of the energy storage furnace (101) to obtain a first air temperature; The opening degree of the first bypass is adjusted in response to the first air temperature so that the temperature of the air inlet of the heat exchanger (102) is less than or equal to the second air temperature.

9. The thermal management method according to claim 8, characterized in that: It also includes a heat storage condition, which includes: Open the second regulating valve (301) and close the third regulating valve (104); Start the circulation fan (103); The heating module (1012) is started to heat the heat storage module (1013).

10. The thermal management method according to claim 9, characterized in that: The heating modules (1012) are started in sequence according to the direction of air flow.

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