A mobile sand-based thermal storage system and method

Abstract

This invention discloses a mobile sand-based thermal energy storage system and method, belonging to the field of industrial waste heat recovery and solid-medium energy storage technology. The system includes a jet-heating mechanism, comprising a lower accelerating pipe, an upper accelerating pipe, and a jet-heating bed. The upper part of the upper accelerating pipe is connected to a flue gas generating mechanism and a thermal energy storage material conveying mechanism, and its bottom end extends into the inner cavity of the jet-heating bed. The lower accelerating pipe is located in the lower part of the inner cavity of the jet-heating bed, and the lower and upper accelerating pipes are arranged opposite each other from top to bottom, with the gap between adjacent ends forming a flue gas impact convection zone. A jet-heating bed outlet is opened on the side wall of the jet-heating bed, and a heat exchange mechanism is connected to the jet-heating bed outlet and fixedly installed on a transfer mechanism. This solution optimizes the jet-heating structure, effectively improving the heating efficiency of the sand-based thermal energy storage material; simultaneously, the transfer mechanism moves the heat exchange mechanism to a designated area, solving the problem of uneven spatial distribution between heat sources and heat users.

Description

Technical Field

[0001] This invention relates to the field of industrial waste heat recovery and solid-medium energy storage technology, and more specifically, to a mobile sand-based thermal energy storage system and method. Background Technology

[0002] Driven by global energy shortages and the strategic goals of "carbon peaking and carbon neutrality," industrial energy conservation and emission reduction have become a key path to achieving a green and low-carbon transformation. High-energy-consuming industrial equipment such as metallurgical furnaces, rotary kilns, and boilers generate large amounts of high-temperature flue gas during operation, with temperatures typically reaching 300℃ to 800℃ or even higher. Currently, most of this high-temperature flue gas is directly discharged into the atmosphere, which not only causes enormous energy waste but also exacerbates environmental pollution.

[0003] Due to the influence of production processes, the generation of high-temperature flue gas often exhibits intermittent and fluctuating characteristics, making it difficult to match with downstream heat demand in time and space, resulting in low waste heat utilization efficiency. Therefore, how to efficiently and economically recover and store high-temperature waste heat is one of the key links in achieving industrial energy conservation and emission reduction, improving energy utilization efficiency, and promoting green and low-carbon transformation.

[0004] Medium- and high-temperature thermal energy storage technology serves as a crucial link between heat energy recovery and cascade utilization, currently employing storage media such as molten salt, heat transfer oil, and metals. However, molten salt storage systems suffer from drawbacks including high freezing points, susceptibility to low-temperature crystallization and pipe blockage, and strong corrosiveness. Heat transfer oil storage systems have a relatively low upper temperature limit and pose a risk of combustion and explosion. Metal storage materials are prohibitively expensive, hindering large-scale application. Against this backdrop, sand-based thermal energy storage materials have become a research hotspot in the field of medium- and high-temperature thermal energy storage due to their wide availability, low cost, chemical stability, excellent high-temperature resistance (capable of withstanding temperatures above 1000℃ for extended periods), and environmental friendliness.

[0005] However, existing sand-based thermal energy storage technologies mostly employ fluidized beds as heating devices. For example, Chinese patent application CN116989474A discloses a fluidized bed-based solid particle energy storage device, including a fluidized bed heating device, a fluidized bed heat release device, and an energy storage tank. The fluidized bed heating device keeps the solid particles in a fluidized state during the heating process, and electrodes for heating the solid particles are arranged inside the bed. The energy storage tank is located between the fluidized bed heating device and the fluidized bed heat release device. The energy storage tank is used to store the heated solid particles and is connected to an air compressor for pressurizing the energy storage tank. The fluidized bed heat release device keeps the solid particles in a fluidized state during the heat release process and heats water into steam through heat exchange tube bundles. However, this type of heating method using a fluidized bed generally suffers from the following problems: its gas-solid relative velocity is low, the heat transfer coefficient is limited, resulting in low heating efficiency. Furthermore, during long-term operation, existing sand-based thermal energy storage devices generally suffer from wear and tear of the energy storage material, which limits the equipment's service life.

[0006] Furthermore, due to the uneven geographical distribution of industrial waste heat sources and users, traditional stationary heat recovery and pipeline transportation systems struggle to effectively match heat sources with end-users. On one hand, waste heat resources are mostly concentrated in specific areas such as industrial parks and production plants, while heat users are scattered across cities, towns, remote factories, and distributed heat-using units. Conventional heating networks involve high investment, significant heat loss, and long construction periods, and are difficult to flexibly adapt to constantly changing heat usage patterns and load demands, making it impossible to achieve efficient cross-regional and long-distance heat energy allocation.

[0007] The aforementioned uneven spatial distribution results in a large amount of industrial waste heat not being effectively transported to the demand side, leading to energy waste and low utilization efficiency. Therefore, there is an urgent need to develop a mobile thermal storage and heat energy transmission technology to overcome the spatial limitations of traditional fixed systems, achieve flexible connection between heat sources and heat users, and solve the problem of heat energy allocation caused by the uneven spatial distribution of heat sources and heat users. Summary of the Invention

[0008] This invention provides a mobile sand-based thermal energy storage system and method. The system employs a jet-driven bed to heat the sand-based thermal energy storage material and optimizes the structure of the jet-driven bed to improve the heating efficiency of the sand-based thermal energy storage material. Simultaneously, the system also includes a transfer mechanism and a heat exchange mechanism. The jet-driven heating mechanism delivers the heated sand-based thermal energy storage material into the heat exchange mechanism, and the transfer mechanism moves the heat exchange mechanism to a designated area, thereby solving the problem of uneven spatial distribution between the heat source and heat users.

[0009] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0010] The first aspect of this invention provides a mobile sand-based thermal energy storage system, comprising: a jet heating mechanism, the jet heating mechanism including a lower acceleration pipe, an upper acceleration pipe, and a jetting bed body; the upper part of the upper acceleration pipe is connected to a flue gas generating mechanism and a thermal energy storage material conveying mechanism, and the lower end extends into the inner cavity of the jetting bed body to introduce sand-based thermal energy storage material and flue gas into the interior of the jetting bed body; the bottom end of the jetting bed body is provided with a lower air inlet for introducing flue gas into the inner cavity of the jetting bed body; the lower acceleration pipe is disposed in the lower part of the inner cavity of the jetting bed body, and the lower acceleration pipe is connected to... The upper acceleration tubes are arranged facing each other from top to bottom, and the gap between adjacent ends forms an impact convection zone for the flue gas; the side wall of the jetting bed is provided with a jetting bed outlet, through which the flue gas and the heated sand-based thermal storage material flow out; a heat exchange mechanism is connected to the jetting bed outlet and is used to transport the heated sand-based thermal storage material into the heat exchange mechanism, where the sand-based thermal storage material exchanges heat with the heat exchange medium inside the heat exchange mechanism; and a transfer mechanism is fixedly installed on the transfer mechanism, which is used to drive the heat exchange mechanism to move.

[0011] Furthermore, the jet heating mechanism also includes a heating tube assembly, which is disposed in the inner cavity of the jet bed body. The top end of the heating tube assembly is located below the top end of the lower acceleration tube, and the bottom end is located above the bottom end of the lower acceleration tube.

[0012] Furthermore, the heating tube assembly includes multiple layers of heat pipe units spaced apart along the height direction. Adjacent layers of heat pipe units are aligned along the height direction. Each layer of heat pipe unit includes a ring tube and multiple threaded tubes. The ring tube is sleeved outside the lower acceleration tube and there is a gap between the ring tube and the lower acceleration tube. The multiple threaded tubes are radially distributed between the ring tube and the cavity of the jet bed. One end of the threaded tube is connected to the ring tube, and the other end passes through the jet bed and extends to the outside. The resistance wire passes through the multiple threaded tubes in an S-shaped routing manner.

[0013] Furthermore, the jet heating mechanism also includes a filter screen, which is sleeved on the lower part of the lower acceleration tube and located below the heating tube assembly.

[0014] Furthermore, the flue gas generating mechanism includes a first air inlet branch and a second air inlet branch. The side wall of the upper acceleration pipe located outside the jet bed is connected to the outlet of the first air inlet branch for introducing flue gas into the upper acceleration pipe. The outlet of the second air inlet branch is connected to the lower air inlet for introducing flue gas into the bottom of the lower air inlet.

[0015] Furthermore, the discharge port of the jetting bed is located on the side wall of the jetting bed body, near its top, and above the impact convection zone.

[0016] Furthermore, the heat exchange mechanism includes a heat exchanger housing, the top of which is provided with at least two media inlets spaced apart in the horizontal direction, and the heat storage material conveying mechanism includes a heat exchange mechanism feed pipe, one end of which is connected to the outlet of the spouting bed, and the other end is provided with a pipe branch corresponding to each of the media inlets.

[0017] Furthermore, the heat storage material conveying mechanism includes a heat exchange mechanism discharge pipe. One end of the heat exchange mechanism discharge pipe is connected to the medium outlet, and a branch connected to the storage silo is provided in the middle for providing sand-based heat storage material to the heat exchange mechanism discharge pipe. The other end is connected to the flue gas generating component.

[0018] Furthermore, the top of the upper acceleration tube is provided with a feed hopper connected to it; the flue gas generating component and the feed hopper are connected by a jet feed pipe for conveying sand-based thermal storage material to the upper acceleration tube.

[0019] A second aspect of the present invention provides a mobile sand-based thermal storage method, which employs any of the mobile sand-based thermal storage systems described above, comprising: sand-based thermal storage material entering the inner cavity of a jetting bed body via an upper acceleration pipe; flue gas being ejected from the upper acceleration pipe from top to bottom and from the lower acceleration pipe from bottom to top, respectively, and forming opposing impacts within the impact convection zone; the sand-based thermal storage material, heated within the inner cavity of the jetting bed body, flowing out through the jetting bed outlet and into the interior of a heat exchange mechanism; and a transfer mechanism driving the heat exchange mechanism containing the sand-based thermal storage material to a designated area.

[0020] Compared with the prior art, the technical solution provided by this invention has the following advantages: (1) The present invention uses a jet bed to heat the sand-based thermal storage material and optimizes the structure of the jet bed. Specifically, an upper acceleration tube is added inside the jet bed. The upper acceleration tube introduces flue gas and the sand-based thermal storage material to be heated into the inner cavity of the jet bed. The main flow direction of the flue gas entering the inner cavity of the jet bed from the lower air inlet is from bottom to top, and the main flow direction of the flue gas entering the inner cavity of the jet bed from the upper acceleration tube is from top to bottom. The two flue gas with opposite flow directions form a relatively strong impact convection zone between the adjacent ends of the upper and lower acceleration tubes, thereby effectively improving the heating efficiency of the sand-based thermal storage material.

[0021] (2) The present invention further optimizes the design of the mobile sand-based thermal energy storage system. Specifically, the system includes a transplanting mechanism and a heat exchange mechanism. By utilizing the heat absorption and release of the energy storage material, industrial waste heat is transferred to the heat exchange mechanism. Furthermore, the transplanting mechanism drives the heat exchange mechanism containing the sand-based thermal energy storage material to a set area. The transplanting mechanism can be implemented in various ways, preferably using a non-fixed track transplanting method. This enables flexible transfer of thermal energy in space and time, breaks the geographical and temporal limitations between the heat source and the user, effectively solves the contradiction of uneven distribution of waste heat resources and supply-demand mismatch, and provides a feasible path for long-distance thermal energy transmission and on-demand energy supply.

[0022] (3) The present invention further refines the structure of the jet-driven bed. Specifically, the jet-driven heating mechanism also includes a heating tube assembly, which is disposed within the inner cavity of the jet-driven bed body. The top end of the heating tube assembly is located below the top end of the lower acceleration tube, and the bottom end is located above the bottom end of the lower acceleration tube. The heating tube assembly can continuously and appropriately increase the resistance and control the concentration of airflow particles, which is beneficial to reducing the wear of sand-based thermal storage materials. Furthermore, the jet-driven heating mechanism also includes a filter screen, which is sleeved on the lower part of the lower acceleration tube and located below the heating tube assembly. By setting the filter screen, it can continuously and appropriately increase the resistance and control the concentration of airflow particles, which is further beneficial to reducing the wear of sand-based thermal storage materials.

[0023] (4) The present invention further refines the design of the heating pipe structure in the jetting bed. Specifically, the heating pipe assembly includes multiple layers of heat pipe units spaced apart along the height direction. Adjacent layers of heat pipe units are aligned along the height direction. Each layer of heat pipe unit includes a ring pipe and multiple threaded pipes. The multiple threaded pipes are distributed in a spoke-like pattern between the ring pipe and the inner cavity of the jetting bed. The resistance wire passes through the multiple threaded pipes in an S-shaped routing manner. This structure not only helps to reduce the wear of the sand-based thermal storage material, but also allows the use of electrical energy to heat the resistance wire during off-peak hours, transferring the heat energy to the sand-based thermal storage material located in the inner cavity of the jetting bed, increasing the temperature of the sand-based energy storage material, increasing the energy density, and simultaneously taking into account the economic efficiency of the thermal storage system.

[0024] (5) This invention further optimizes the flow path of the flue gas. Specifically, one end of the discharge pipe of the heat exchange mechanism is connected to the medium outlet, and a branch connected to the storage bin is provided in the middle. The other end is connected to the flue gas generating component. The high-temperature flue gas enters the interior of the jet bed to heat the sand-based heat storage material, then enters the interior of the heat exchanger box, and then flows into the discharge pipe of the heat exchange mechanism. At this time, the temperature of the flue gas is greatly reduced compared to its initial temperature. The remaining low-temperature section heat energy of the flue gas is used to preheat the heat storage material flowing out of the storage bin. The above design makes full use of the heat energy in the high-temperature section and the medium-low temperature section, that is, to realize the cascade utilization of the energy carried by the high-temperature flue gas, thereby effectively improving the heat storage efficiency and improving the energy utilization efficiency. Attached Figure Description

[0025] Figure 1 This is a simplified structural diagram of a mobile sand-based thermal storage system according to an embodiment of the present invention.

[0026] Figure 2 This is a simplified top view of the internal structure of the heating tube assembly in an embodiment of the present invention.

[0027] Explanation of icon numbers: 1. Flue gas conveying mechanism; 101. First intake branch; 102. Second intake branch; 103. Flue gas regulating valve; 104. Flue gas output branch; 105. Flue gas regulating valve; 106. Exhaust fan; 2. Spray heating mechanism; 201. Upper acceleration tube; 202. Lower acceleration tube; 203. Lower air inlet; 204. Air distribution plate; 205. Spray bed body; 206. Filter screen; 207. Heating tube assembly; 271. Ring tube; 272. Conduit; 273. Resistance wire; 208. Spray bed outlet; 209. Feed bin; 3. Heat exchange mechanism; 301. Heat exchange tube; 302. Heat exchange tube inlet; 303. Heat exchange tube outlet; 304. Medium inlet; 305. Medium outlet; 306. Heat exchanger housing; 4. Transplanting mechanism; 5. Thermal storage material conveying mechanism; 501. Heat exchanger inlet pipe; 502. Heat exchanger outlet pipe; 503. Sprayed inlet pipe; 6. Storage silos; 7. Flue gas generating components. Detailed Implementation

[0028] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0029] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0030] This embodiment provides a mobile sand-based thermal storage system, referencing... Figure 1 As shown, the thermal storage system includes: a jet heating mechanism 2, a heat exchange mechanism 3, and a transplanting mechanism 4. The jet heating mechanism 2 includes a lower acceleration pipe 202, an upper acceleration pipe 201, and a jet bed 205. The upper part of the upper acceleration pipe 201 is connected to the flue gas generating mechanism 1 and the thermal storage material conveying mechanism 5, and its bottom end is located in the upper part of the inner cavity of the jet bed 205 to convey sand-based thermal storage material and flue gas into the inner cavity of the jet bed 205. The bottom end of the jet bed 205 is provided with a lower air inlet 203 for introducing flue gas into the inner cavity of the jet bed 205. The lower acceleration pipe 202 is located in the lower part of the inner cavity of the jet bed 205. The lower acceleration pipe 202 and the upper acceleration pipe 201 are arranged facing each other from top to bottom, and the gap between the adjacent ends of the upper acceleration pipe 201 and the lower acceleration pipe 202 forms a flue gas impact convection zone; the side wall of the jet bed 205 is provided with a jet bed outlet 208; the flue gas and the heated sand-based thermal storage material flow out through the jet bed outlet 208; the heat exchange mechanism 3 is connected to the jet bed outlet 208 and is used to transport the heated sand-based thermal storage material into the heat exchange mechanism 3, and the sand-based thermal storage material exchanges heat with the heat exchange medium inside the heat exchange mechanism 3; the heat exchange mechanism 3 is fixedly installed on the transfer mechanism 4, and the transfer mechanism 4 is used to drive the heat exchange mechanism 3 to move.

[0031] refer to Figure 1 As shown, the lower acceleration pipe 202 and the upper acceleration pipe 201 are spaced apart. The main flow direction of the flue gas entering the inner cavity of the jet bed 205 from the lower air inlet 203 is from bottom to top, while the main flow direction of the flue gas entering the inner cavity of the jet bed 205 from the upper acceleration pipe 201 is from top to bottom. The two form a relatively strong impact convection zone between the adjacent ends of the upper acceleration pipe 201 and the lower acceleration pipe 202.

[0032] In existing jet-heated beds, the material to be heated typically enters the inner cavity of the jet-heated bed body 205 from the side wall, and the inner cavity generally only has a lower acceleration pipe. The heating gas enters the inner cavity from the bottom end of the jet-heated bed body 205, forming a jet zone, annular gap zone, and fountain zone in the inner cavity of the jet-heated bed body 205. The heated solid particles flow out from the side wall located at the bottom of the jet-heated bed. The heating efficiency of this type of jet heating needs to be further improved.

[0033] This invention optimizes the design of the jet bed, altering the intake method of the high-temperature flue gas in the jet bed body 205. The high-temperature flue gas enters the inner cavity of the jet bed body 205 through the upper acceleration pipe 201 and the lower air inlet 203, respectively. An impact convection zone is formed between the adjacent ends of the upper acceleration pipe 201 and the lower acceleration pipe 202. The flue gas experiences relatively strong impacts in this zone, resulting in more intense disturbance of the sand-based thermal storage material, thus shortening the preheating time and improving the heating efficiency of the sand-based thermal storage material. Furthermore, because the flue gas velocity is lower around the outer wall of the lower acceleration pipe 202, the sand-based thermal storage material continues to descend there. During its descent, it undergoes convection heating with the flue gas flowing downwards from the bottom of the jet bed body 205, further enhancing the heating efficiency of the sand-based thermal storage material.

[0034] The operation process of the thermal storage system is as follows: the flue gas of the sand-based thermal storage material enters the inner cavity of the jet bed 205 through the upper acceleration pipe 201 and the lower air inlet 203. The sand-based thermal storage material in the inner cavity of the jet bed 205 is heated by the flue gas. The heated sand-based thermal storage material mixed with the flue gas flows out through the jet bed outlet 208 and into the heat exchange mechanism 3. The transfer mechanism 4 drives the heat exchange mechanism 3 containing the sand-based thermal storage material to move to the set area.

[0035] The lower acceleration pipe 202 and the upper acceleration pipe 201 are coaxially arranged and have the same diameter. The specific structure of the upper acceleration pipe 201 can be obtained by modifying the exhaust assembly at the top of the original jet bed; therefore, the specific structural design of the upper acceleration pipe 201 will not be described in detail. The main difference from the traditional jet bed lies in the way the flue gas is introduced, thus its working principle differs from that of the traditional jet bed.

[0036] It should also be noted that in this thermal storage system, the sand-based energy storage material is heated by high-temperature flue gas through a jet bed. The sand-based energy storage material absorbs the heat energy and can be transported to the interior of the heat exchange mechanism 3 via pneumatic conveying or other conveying mechanisms. Inside the heat exchange mechanism 3, the sand-based energy storage material exchanges heat with the heated medium, releasing the energy it carries and achieving heat transfer. In summary, by using the sand-based energy storage material as a medium, the heat carried by the high-temperature flue gas is transferred to the interior of the heat exchange mechanism 3. At the same time, the transplanting mechanism 4 moves the heat exchange mechanism 3, which contains the sand-based thermal storage material, to a designated area, realizing flexible transfer of thermal energy in space and time. This breaks the geographical and temporal limitations between the heat source and the user, effectively solving the contradiction of uneven distribution of waste heat resources and supply-demand mismatch, and providing a feasible path for long-distance thermal energy transmission and on-demand energy supply. The transplanting mechanism 4 can be implemented in various specific ways, but it is preferably a non-fixed track transplanting method, such as a truck.

[0037] Specifically, the jet heating mechanism 2 also includes a heating tube assembly 207, which is disposed in the inner cavity of the jet bed body 205. The top end of the heating tube assembly 207 is located below the top end of the lower acceleration tube 202, and the bottom end of the heating tube assembly 207 is located above the bottom end of the lower acceleration tube 202.

[0038] By setting a heating tube assembly 207 in the inner cavity of the jet bed 205 and designing the relative position between the heating tube assembly 207 and the lower acceleration tube 202, the heating tube assembly 207 can continuously and appropriately increase the resistance, control the concentration of airflow particles, reduce the wear of sand-based thermal storage materials, and reduce the wear of the jet bed 205.

[0039] As a preferred embodiment of the heating tube assembly 207, refer to Figure 2 As shown, the heating pipe assembly 207 includes multiple layers of heat pipe units spaced apart along the height direction, i.e., multiple layers of heat pipe units spaced apart along the inner axis of the jetting bed body 205, with adjacent layers of heat pipe units aligned along the height direction. Each layer of heat pipe unit includes a ring pipe 271 and multiple through-tubes 272. The ring pipe 271 is sleeved on the outside of the lower acceleration pipe 202 and has a gap with it. The multiple through-tubes 272 are radially distributed between the ring pipe 271 and the inner cavity of the jetting bed body 205. One end of each through-tube 272 is connected to the ring pipe 271, and the other end passes through the jetting bed body 205 and extends to the outside. The resistance wire 273 passes through the multiple through-tubes in an S-shaped routing manner. This routing method of the resistance wire 273 is relatively simple, and each layer of heat pipe unit does not interfere with each other, thus facilitating disassembly and maintenance. The number of through-tubes 272 in each layer of heat pipe unit depends on the specific situation.

[0040] Further preferably, the multi-layer heat pipe units can share the same ring pipe 271.

[0041] The specific structural design of this heating tube assembly 207 not only helps to reduce the wear of sand-based thermal storage materials, but also allows the use of electrical energy to heat the resistance wire 273 during off-peak electricity periods, transferring the heat energy to the sand-based thermal storage material located in the inner cavity of the jet bed 205, thereby heating the sand-based thermal storage material, increasing the energy storage density, while also taking into account the economy of the thermal storage system and further reducing the subsequent heating time required for the sand-based thermal storage material.

[0042] More specifically, the jet heating mechanism 2 also includes a filter screen 206, which is fitted onto the lower part of the lower acceleration tube 202 and located below the heating tube assembly 207. By setting the filter screen 206, it can continuously and appropriately increase the resistance, control the concentration of airflow particles, reduce the wear of the sand-based thermal storage material, and reduce the wear of the jet bed body 205. The mesh size of the filter screen 206 is generally set to about 1 cm.

[0043] Generally, the bottom of the jet bed 205 is also provided with an air distribution plate 204 located in its inner cavity. The air distribution plate 204 is located above the lower air inlet 203 and below the filter screen 206, the heating tube assembly 207 and the bottom of the lower acceleration tube 202.

[0044] As an extension, the flue gas conveying mechanism 1 includes a first inlet branch 101 and a second inlet branch 102. The side wall of the upper acceleration pipe 201 located outside the jet bed 205 is connected to the outlet of the first inlet branch 101 for introducing flue gas into the upper acceleration pipe 201. The outlet of the second inlet branch 102 is connected to the lower inlet 203 for introducing flue gas into the bottom of the lower inlet 203.

[0045] The temperature of the high-temperature flue gas used in the first intake branch 101 and the second intake branch 102 is generally between 600 and 800°C, and the high-temperature flue gas used generally comes from industrial waste heat.

[0046] To facilitate the control of flue gas flow rate inside the first intake branch 101 and the second intake branch 102, a flue gas regulating valve 105 is provided on both the first intake branch 101 and the second intake branch 102 to control the flue gas flow rate in the corresponding pipeline.

[0047] refer to Figure 1 As shown, the upper acceleration pipe 201 includes a cylindrical shape arranged from bottom to top and an inverted cone shape that is larger at the top and smaller at the bottom. The cylindrical region of the upper acceleration pipe 201 located outside the jet bed body 205 is connected to the outlet of the first air intake branch 101.

[0048] As a further extension, the jet bed outlet 208 is located on the side wall of the jet bed body 205 and close to the top of the jet bed body 205, and the jet bed outlet 208 is located above the impact convection zone.

[0049] Generally, the heat exchange mechanism 3 includes a heat exchanger housing 306 and a heat exchanger tube assembly 301. The heat exchanger tube assembly 301 is located inside the heat exchanger housing 306. The outer wall of the heat exchanger housing 306 is provided with connection holes corresponding to the inlets and outlets at both ends of the heat exchanger tube assembly 301. That is, the heat exchanger tube inlet 302 and the heat exchanger tube outlet 303 in the heat exchanger tube assembly 301 both extend outside the heat exchanger housing 306. The top of the heat exchanger housing 306 is provided with at least two media inlets 304 spaced apart in the horizontal direction. The heat storage material conveying mechanism 5 includes a heat exchange mechanism feed pipe 501. One end of the heat exchange mechanism feed pipe 501 is connected to the spouting bed outlet 208, and the other end is provided with pipe branches corresponding to the media inlets 304 respectively.

[0050] Generally, the heat exchange tube assembly 301 includes multiple heat exchange tubes that are evenly spaced apart, and the outer walls of the multiple heat exchange tubes and the inner wall of the heat exchanger housing 306 form a space for accommodating the sand-based thermal storage material.

[0051] In a preferred embodiment of the heat exchange mechanism 3, the heat exchange mechanism 3 employs an energy storage steam generator. This energy storage steam generator consists of a pressure shell, sand-based thermal storage material, and a heat exchange tube bundle, which is arranged in a linear or staggered manner within the pressure shell. Unlike conventional steam generators, this energy storage steam generator does not introduce a heating medium during the thermal storage phase. After the transfer mechanism 4 transfers the heat exchange mechanism 3 to the designated area, when heat is needed at the user end, the heating medium is introduced into the heat exchange tube through the heat exchange tube inlet 302, allowing it to exchange heat with the sand-based thermal storage material through the wall, transferring the heat stored in the sand-based thermal storage material to the heating medium, thereby generating the required steam. Alternatively, other forms of energy storage components can be selected for the heat exchange mechanism 3.

[0052] The material flowing out of the spouted bed outlet 208 is a sand-based thermal storage material carrying flue gas. The sand-based thermal storage material carrying flue gas flows to the medium inlet 304 through the heat exchange mechanism feed pipe 501. It then enters the inner wall of the heat exchanger housing 306 through multiple medium inlets 304.

[0053] In some embodiments, the number of medium inlets 304 depends on the specific circumstances. Generally, by increasing the number of medium inlets 304 at the top of the heat exchanger housing 306, the uniformity of the distribution of the sand-based thermal storage material inside the heat exchanger housing 306 can be improved, thereby improving the uniformity of heat exchange between the heat exchange tube assembly 301 and the sand-based thermal storage material.

[0054] To facilitate the detachable connection between the heat exchanger feed pipe 501 and the spouting bed outlet 208 and medium inlet 304, one end of the heat exchanger feed pipe 501 can be fixed to the spouting bed outlet 208 or medium inlet 304, and only the other end needs to be detached and connected. This detachable connection can use a quick-connect coupling, thereby shortening the time required for detachment and connection.

[0055] Before heat exchange begins, the heat exchange mechanism 3 needs to be connected to the outlet 208 of the jet bed via a pipeline to achieve directional transport of flue gas and heated sand-based thermal storage material. After heat exchange is completed, the pipeline connection between the heat exchange mechanism 3 and the outlet 208 of the jet bed is disconnected, so that the transplanting mechanism 4 can drive the heat exchange mechanism 3 to move.

[0056] In a further preferred embodiment, the heat storage material conveying mechanism 5 includes a heat exchange mechanism discharge pipe 502. One end of the heat exchange mechanism discharge pipe 502 is connected to the medium outlet 305, and a branch in the middle is connected to the storage silo 6. Through this branch, the storage silo 6 conveys sand-based heat storage material to the heat exchange mechanism discharge pipe 502. The other end is connected to the flue gas generating component 7, which is used to preheat the sand-based heat storage material output from the heat exchange mechanism discharge pipe 502. The specific flow pattern of the material in this process is as follows: the material entering the inner wall of the heat exchanger housing 306 is sand-based heat storage material carrying flue gas. The sand-based heat storage material remains on the inner wall of the heat exchanger housing 306. The flue gas flows out from the medium outlet 305 and into the heat exchange mechanism discharge pipe 502. Subsequently, the flue gas flows out from the heat exchange mechanism discharge pipe 502 and into the flue gas output branch 104.

[0057] The heat recovery of high-temperature flue gas needs to be matched with its production cycle. When the heat exchange mechanism 3 is not connected to the heat storage system, that is, when the connection between the heat exchange mechanism 3 and the outlet 208 of the jetting bed is disconnected, and the jetting heating mechanism 2 does not yet need to supply sand-based heat storage material to the heat exchange mechanism on the transfer mechanism 4, the outlet 208 of the jetting bed is directly connected to the inlet end of the outlet pipe 502 of the heat exchange mechanism to supply the flue gas flowing out of the outlet 208 of the jetting bed to the outlet pipe 502 of the heat exchange mechanism. During this process, the flue gas flows out from the outlet 208 of the jetting bed, and the heated sand-based heat storage material remains in the inner cavity of the jetting bed body 205. Subsequently, the flue gas flows out from the outlet pipe 502 of the heat exchange mechanism and flows into the flue gas output branch 104.

[0058] When the heat exchange mechanism 3 is not connected to the heat storage system, the flue gas flows out of the spouting bed outlet 208 and directly into the heat exchange mechanism outlet pipe 502. When the heat exchange mechanism 3 is connected to the heat storage system, i.e., when the sand-based heat storage material that has been heated to a predetermined temperature inside the spouting bed needs to be discharged, the flue gas flows out of the spouting bed outlet 208, passes through the heat exchange mechanism 3 and the medium outlet 305 in sequence, and then merges into the heat exchange mechanism outlet pipe 502. Thus, compared with the high-temperature flue gas initially entering the spouting bed 205, the temperature of the flue gas flowing through the heat exchange mechanism outlet pipe 502 is lower. At this point, the flue gas comes into contact with the heat storage material entering the pipe from the storage bin 6, using the waste heat of the flue gas to preheat the heat storage material. The above design makes full use of the thermal energy in the high-temperature and medium-low temperature sections of the flue gas, that is, to realize the cascade utilization of the energy carried by the high-temperature flue gas, thereby effectively improving the heat storage efficiency and energy utilization efficiency.

[0059] In the above process, the sand-based thermal storage material carrying the flue gas flows out from the outlet 208 of the jet bed, and the heated sand-based thermal storage material remains in the inner cavity of the jet bed body 205. The flue gas flows out from the medium outlet 305 and flows into the discharge pipeline 502 of the heat exchange mechanism. The specific implementation method of controlling the directional flow of the material adopts the existing technology, so it will not be described in detail.

[0060] In the above process, flue gas flows out from the outlet 208 of the jet bed, the heated sand-based heat storage material remains in the inner cavity of the jet bed body 205, and the flue gas flows out from the medium outlet 305 and into the discharge pipeline 502 of the heat exchange mechanism. The specific implementation method of controlling the directional flow of the material adopts the existing technology, so it will not be described in detail.

[0061] As a means of directional material conveying in flue gas output branch 104, flue gas output branch 104 is equipped with an induced draft fan 106, which realizes directional transportation of materials within the corresponding path through the induced draft fan 106.

[0062] It should be noted that the specific method by which the flue gas generating component 7 preheats the sand-based thermal storage material output from the heat exchange mechanism's discharge pipe 502 adopts existing technology; therefore, the connection relationship between the flue gas generating component 7 and the outlet of the heat exchange mechanism's discharge pipe 502 is not described in detail. Preferably, the flue gas generating component 7 is a rotary kiln.

[0063] More preferably, the top of the upper acceleration pipe 201 is provided with a feed bin 209 connected thereto, and the flue gas generating component 7 is connected to the feed bin 209 through a jet feed pipe 503, which is used to output preheated sand-based thermal storage material to the upper acceleration pipe 201.

[0064] The operation process of this part is as follows: the sand-based thermal storage material, after being preheated by the flue gas generating component 7, enters the feed hopper 209 through the jet feed pipe 503, and then falls into the upper acceleration pipe 201. Through the interior of the upper acceleration pipe 201, the sand-based thermal storage material enters the inner cavity of the jet bed body 205.

[0065] The heat storage method based on the mobile sand-based thermal storage system includes the following steps: the sand-based thermal storage material enters the inner cavity of the jet bed 205 through the upper acceleration pipe 201; flue gas is ejected from the upper acceleration pipe 201 from top to bottom and the lower acceleration pipe 202 from bottom to top, forming opposing impacts in the impact convection zone; the sand-based thermal storage material heated in the inner cavity of the jet bed 205 flows out through the jet bed outlet 208 and flows into the interior of the heat exchange mechanism 3; and the transfer mechanism 4 drives the heat exchange mechanism 3 containing the sand-based thermal storage material to move to a set area.

[0066] During the return journey, the transplanting mechanism 4 brings back the cooled sand-based thermal storage material and unloads it to await the next heating, thus realizing the circulation of the sand-based thermal storage material.

[0067] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A mobile sand-based thermal storage system, characterized in that, The thermal storage system includes: The jet heating mechanism (2) includes a lower acceleration pipe (202), an upper acceleration pipe (201) and a jet bed body (205). The upper part of the upper acceleration pipe (201) is connected to the flue gas generating mechanism (1) and the heat storage material conveying mechanism (5), and the bottom end extends into the inner cavity of the jet bed body (205) to introduce sand-based heat storage material and flue gas into the interior of the jet bed body (205). The bottom end of the jet bed body (205) is provided with a lower air inlet (203) for introducing flue gas into the inner cavity of the jet bed body (205); the lower acceleration pipe (202) is located in the lower part of the inner cavity of the jet bed body (205), and the lower acceleration pipe (202) and the upper acceleration pipe (201) are arranged opposite each other from top to bottom, and the gap between adjacent ends forms a flue gas impact convection zone; The side wall of the jet bed (205) is provided with a jet bed outlet (208), through which flue gas and heated sand-based thermal storage material flow out; The heat exchange mechanism (3) is connected to the outlet (208) of the jet bed and is used to transport heated sand-based thermal storage material into the heat exchange mechanism (3). The sand-based thermal storage material exchanges heat with the heat exchange medium inside the heat exchange mechanism (3). The heat exchange mechanism (3) is fixedly installed on the transplanting mechanism (4), and the transfer mechanism (4) is used to drive the heat exchange mechanism (3) to move.

2. The mobile sand-based thermal storage system according to claim 1, characterized in that, The jet heating mechanism (2) further includes a heating tube assembly (207), which is disposed in the inner cavity of the jet bed body (205). The top end of the heating tube assembly (207) is located below the top end of the lower acceleration tube (202), and the bottom end is located above the bottom end of the lower acceleration tube (202).

3. The mobile sand-based thermal storage system according to claim 1, characterized in that, The heating tube assembly (207) includes multiple layers of heat pipe units spaced apart along the height direction. Adjacent heat pipe units are aligned along the height direction. Each heat pipe unit includes a ring tube (271) and multiple threaded tubes (272). The ring tube (271) is sleeved outside the lower acceleration tube (202) and there is a gap between the ring tube (202) and the lower acceleration tube (202). The multiple threaded tubes (272) are radially distributed between the ring tube (271) and the inner cavity of the jet bed body (205). One end of the threaded tube (272) is connected to the ring tube (271), and the other end passes through the jet bed body (205) and extends to the outside. The resistance wire (273) passes through the multiple threaded tubes in an S-shaped routing manner.

4. The mobile sand-based thermal storage system according to claim 2, characterized in that, The jet heating mechanism (2) also includes a filter screen (206), which is sleeved on the lower part of the lower acceleration tube (202) and located below the heating tube assembly (207).

5. The mobile sand-based thermal storage system according to any one of claims 1-4, characterized in that, The flue gas generating mechanism (1) includes a first intake branch (101) and a second intake branch (102). The side wall of the upper acceleration pipe (201) located outside the jet bed body (205) is connected to the outlet of the first intake branch (101) for introducing flue gas into the upper acceleration pipe (201). The outlet of the second intake branch (102) is connected to the lower intake port (203) for introducing flue gas into the bottom of the lower intake port (203).

6. The mobile sand-based thermal storage system according to claim 5, characterized in that, The discharge port (208) of the jet bed is located on the side wall of the jet bed body (205), near its top, and above the impact convection zone.

7. The mobile sand-based thermal storage system according to claim 5, characterized in that, The heat exchange mechanism (3) includes a heat exchanger housing (306) and a heat exchange tube assembly (301). The heat exchange tube assembly (301) is located inside the heat exchanger housing (306). The top of the heat exchanger housing (306) is provided with at least two medium inlets (304) spaced apart in the horizontal direction. The heat storage material conveying mechanism (5) includes a heat exchange mechanism feed pipe (501). One end of the heat exchange mechanism feed pipe (501) is connected to the outlet (208) of the spouting bed, and the other end is provided with pipe branches corresponding to the at least two medium inlets (304).

8. The mobile sand-based thermal storage system according to claim 7, characterized in that, The heat storage material conveying mechanism (5) includes a heat exchange mechanism discharge pipe (502), one end of which is connected to the medium outlet (305), and a branch connected to the storage bin (6) in the middle, which is used to provide sand-based heat storage material to the heat exchange mechanism discharge pipe (502), and the other end is connected to the flue gas generating component (7).

9. The mobile sand-based thermal storage system according to claim 8, characterized in that, The top of the upper acceleration tube (201) is provided with a feed hopper (209) connected to it; the flue gas generating component (7) is connected to the feed hopper (209) through a jet feed pipe (503) for conveying sand-based thermal storage material to the upper acceleration tube (201).

10. A mobile sand-based thermal storage method, characterized in that, The thermal storage method employs a mobile sand-based thermal storage system as described in any one of claims 1-9, comprising: Sand-based thermal storage material enters the inner cavity of the jet bed body (205) through the upper acceleration pipe (201); The flue gas is ejected from the upper acceleration tube (201) from top to bottom and from the lower acceleration tube (202) from bottom to top, and forms opposing impacts in the impact convection zone; The sand-based thermal storage material, after being heated in the inner cavity of the jet bed (205), flows out through the jet bed outlet (208) and into the interior of the heat exchange mechanism (3); The transplanting mechanism (4) drives the heat exchange mechanism (3) containing sand-based thermal storage material to move to the designated area.

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