Thermal power plant electric heating steel bar heat storage and energy storage device and heat storage method thereof

Abstract

The invention discloses a thermal power plant electric heating steel bar heat and energy storage device and a heat storage method thereof, and belongs to the technical field of heat storage, a device heat preservation layer serves as a shell of a steel bar heat storage body to play a role in heat preservation and protection, and steel bars, arranged in groups, of the steel bar heat storage body are horizontally or vertically arranged in the device heat preservation layer; the heating wire or the heating plate is horizontally or vertically arranged in a space between two adjacent reinforcing steel bars of the reinforcing steel bar heat accumulator; the circulating fan feeds air into the reinforcing steel bar heat accumulator to be heated, the heated hot air exchanges heat with feed water in the air-water heat exchanger, and the feed water is heated into hot water or industrial steam to be supplied to the outside.

Description

Technical Field

[0001] The invention belongs to the technical field of heat storage, and in particular relates to a heat storage device for electrically heated steel bars in a thermal power plant and a heat storage method thereof. Background Art

[0002] Thermal storage technologies include sensible heat, latent heat (these two are thermophysical heat storage) and thermochemical heat storage. Among them, sensible heat storage uses the temperature rise of high specific heat capacity materials to store heat, and the energy storage density is 30~80kWh / m 3 The storage method is simple and the energy storage cost is low, but the system volume is too large and the heat loss is serious. Latent heat storage uses the phase change of materials to store heat, and the energy storage density is 83~140kWh / m 3 The temperature is stable during the phase change process, but the material is prone to aging, and some materials are highly corrosive and have large heat losses.

[0003] At present, the commonly used heat storage technologies in engineering include solid heat storage (sensible heat), water heat storage (sensible heat), phase change heat storage (latent heat + sensible heat), etc. Among them, water heat storage has the lowest cost, solid heat storage has the medium cost, and phase change heat storage has the higher cost. Steel, as the most widely used metal material, has the advantages of high thermal stability, high heat storage temperature, and steel can be reused. If the power consumption of the electric heating steel bar heat storage device of the electric heating thermal power plant can be increased or decreased to respond to the auxiliary service signal of the peak and frequency regulation of the power grid, low-cost and high-efficiency electric heat storage can be achieved, which has practical significance for the peak and frequency regulation of thermal power plants or new energy power plants or the peak and frequency regulation of the power grid load side. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a thermal power plant electric heating steel bar heat storage energy storage device and a heat storage method thereof in view of the deficiencies in the above-mentioned prior art, which are used to solve the technical problems of difficulty in peak and frequency regulation of thermal power units and difficulty in industrial steam supply under low load.

[0005] The present invention adopts the following technical solutions: A heat storage device for electrically heated steel bars in a thermal power plant comprises a heat storage body, a device insulation layer is arranged on the outside of the heat storage body, steel bar heat storage bodies are densely arranged inside the heat storage body, an air passage is arranged between the steel bar heat storage body and the device insulation layer, and heating wires or heating plates are arranged horizontally or vertically in the interval between two adjacent steel bars of the steel bar heat storage body; an air-water heat exchanger and a circulating fan are arranged at the bottom of the heat storage body, the circulating fan is connected to a motor arranged on the device insulation layer, and the circulating fan is used to send air into the steel bar heat storage body for heating, and the heated hot air exchanges heat with feed water in the air-water heat exchanger, and the feed water is heated to become hot water or industrial steam and then supplied to the outside.

[0006] Preferably, the steel bar heat storage body comprises a plurality of steel bars, which are arranged in groups horizontally or vertically, and a fixing device is provided at the root or top of the steel bar, and the fixing device is loosely reinforced and connected to the steel bar.

[0007] Preferably, the electric heating wire or the heating plate is electrically connected to a power supply control cabinet disposed outside the thermal insulation layer of the device, and the surplus power from the peak and frequency regulation of the thermal power unit is utilized for power supply.

[0008] Preferably, the circulating fan and the air-water heat exchanger are connected to the heat storage device via a heat-resistant and heat-insulating air supply duct.

[0009] Preferably, the circulating fan and the air-water heat exchanger are installed at the bottom, top or side of the steel bar heat storage body, and are separated from the heat storage body by a heat-resistant partition to form two spaces.

[0010] Preferably, the air-water heat exchanger is arranged in the pipeline between the hot air outlet after the steel bar heat storage body absorbs heat and the air supply outlet of the fan, and the interfaces at both ends of the heat exchange coil of the air-water heat exchanger are respectively provided with a steam or hot water outlet and a water supply inlet; the steam or hot water outlet pipeline and the water inlet pipeline pass through the insulation layer of the device for connecting to the outside world.

[0011] Preferably, the steel bar heat storage body is arranged in the heat storage body in a quick-disassembly manner.

[0012] Preferably, the air-water heat exchanger is connected to a water supply device to heat the feed water to generate hot water or steam of set pressure and temperature, and the feed water comes from the make-up water of the chemical water workshop of the power plant or the water supply pipeline of the thermal power unit.

[0013] Another technical solution of the present invention is a heat storage method of a heat storage device for electrically heating steel bars in a thermal power plant, comprising the following steps: According to the demand for thermal energy storage devices in the power grid, the thermal storage capacity and electric heating capacity of the electric heating steel bar thermal energy storage device in the thermal power plant are designed to enable the device to meet the peak frequency regulation or heat demand on the power supply side, grid side, load side or energy storage station in the power grid; According to the type of heat demand, design a thermal power plant electric heating steel bar heat storage device with matching capacity to generate hot water or steam to meet the needs of heat users; Design appropriate steel bar material type, size and shape according to hot water or steam temperature range; According to the temperature range of hot water or steam, several steel bars of the steel heat storage body are selected and arranged horizontally or vertically in the heat storage body; The power consumption of the electric heating steel bar heat storage device of the thermal power plant can be increased or decreased by switching on and off the electric heating wires or heating plates in series or in parallel in batches, so as to realize the heat storage of surplus power for peak load regulation and frequency modulation.

[0014] Preferably, the thermal energy storage using the surplus power of peak load and frequency regulation is as follows: According to the peak and frequency regulation load requirements of the power grid or thermal power units, the overall power consumption of the thermal power plant's electric heating steel bar heat storage device is adjusted; When the thermal power plant electric heating steel bar heat storage device is operating in the heat storage condition, the thermal power plant electric heating steel bar heat storage device is started to supply peak and frequency modulation power to the electric heating wire or heating plate, and the power supply power of the electric heating wire or heating plate in the increased group is used to increase the power consumption of the overall device; When the thermal power plant's electric heating steel bar heat storage device is operating in a heat release condition, the thermal power plant's electric heating steel bar heat storage device stops supplying power to the electric heating, and utilizes the heat storage and hot air circulation of the steel bar material in the thermal power plant's electric heating steel bar heat storage device to heat the feed water to generate hot water or steam for heating demand; When the power grid or thermal power unit uses the thermal power plant's electrically heated steel bar heat storage device to respond to the power grid's frequency regulation auxiliary service needs, the power supply of several electric heating wires or heating plates is quickly switched on or off to increase or decrease the power consumption of the thermal power plant's electrically heated steel bar heat storage device.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: Specially designed electric heating steel bar heat storage bodies are used to achieve efficient storage of electrical energy into thermal energy. The heat storage efficiency is high, the heat storage temperature is high, and the footprint is small. It is safer than conventional molten salt heat storage. The electric heating power is changed by switching on and off a number of electric heating steel bar heat storage bodies, thereby responding to the peak and frequency modulation signals of the power grid, so that the device can participate in the regulation of power auxiliary services and obtain auxiliary service benefits.

[0016] Furthermore, the steel bars will expand during the heating process, and the loose fixed connection can effectively adapt to the expansion and contraction of the steel bars, avoiding excessive internal stress caused by thermal expansion, and reducing the risk of structural damage or deformation due to temperature changes; the steel bars arranged in groups can provide a better heat conduction path, and the loose connection design does not affect the heat transfer between the steel bars, while ensuring the stability of the structure. This method can improve the thermal efficiency of the heat storage body and ensure the uniform distribution of heat energy; the loosely supported fixing device can provide a certain degree of flexibility, so that the steel bars can adapt to structural deformation or force changes during long-term use, avoiding the overall structural instability caused by overly rigid connections.

[0017] Furthermore, using the surplus electricity from the peak-shaving and frequency-regulating thermal power units to supply power to electric heating wires or heating plates can improve the efficiency of electricity use, balance the grid load, reduce energy costs, promote environmental protection, and improve thermal energy utilization and economic benefits.

[0018] Furthermore, by installing a circulating fan and an air-water heat exchanger externally, combined with heat-resistant and insulated pipe connections, the thermal efficiency, safety, equipment life, flexibility and maintenance convenience of the system can be improved.

[0019] Furthermore, the air-water heat exchanger is located between the hot air outlet after the steel heat storage body absorbs heat and the fan air outlet. This position arrangement can effectively utilize the heat absorbed by the steel heat storage body and transfer the heat to steam or hot water through the heat exchange coil to achieve effective transfer of heat energy. This can improve the thermal efficiency of the system, reduce energy waste, optimize the transfer of heat energy, improve the energy utilization rate of the system, enhance flexibility, reduce energy waste, and improve the efficiency and stability of the entire heat exchange system.

[0020] Furthermore, the quick-disassembly design makes the arrangement of the steel heat storage body more efficient, flexible and easy to maintain, which helps to improve the reliability, efficiency and economy of the entire heat storage system.

[0021] Furthermore, the air-water heat exchanger heats the feed water to increase its temperature, thereby obtaining hot water or steam. This process can effectively recycle heat energy that might otherwise be wasted (such as waste heat from power plants, heat from exhaust gas emitted by thermal power units, etc.), reduce energy waste, and improve the energy efficiency of the overall system; by recovering waste heat, the energy utilization rate is improved, hot water or steam is supplied stably, and the reliability, flexibility, and environmental protection of the system are ensured, thereby achieving energy conservation and consumption reduction, reducing operating costs, and improving the efficiency and sustainability of the overall system.

[0022] The heat storage method of the electric heating steel bar heat storage device in the thermal power plant can effectively adjust the load fluctuation of the power grid and prevent the collapse of the power grid due to overload or insufficient power supply; when there is too much surplus electricity in the power grid, the electricity is stored through the heat storage device to avoid waste; it adapts to the fluctuations in the demand of heat users and ensures the stability of hot water and steam supply; during the peak period of heat demand, the heat storage device can provide a supplementary heat source, reduce the burden on the thermal power unit, and improve energy efficiency; different steel bar materials and designs can ensure more efficient storage and transmission of thermal energy, thereby improving the overall performance of the heat storage device; choosing suitable materials can ensure the stability of the heat storage body in a high temperature environment and extend the service life of the equipment; reasonable layout can ensure that the heat is evenly distributed in the heat storage body, improving the storage and release efficiency of thermal energy; through the structure The design enables the equipment to achieve higher heat storage capacity in a limited space; by controlling the power of the electric heating device, it can dynamically respond to changes in the load of the power grid, reduce the pressure on the power grid, and improve the regulation capacity of the power grid; when the power grid has excess electricity, the heat storage device can automatically adjust the working state and convert the surplus electricity into thermal energy storage to avoid electricity waste; the heat storage device can use the surplus electricity during the off-peak electricity price period for heating, effectively reducing the cost of electricity; using surplus electricity for heat storage and energy storage, balancing the load of the power grid, and releasing heat energy during peak electricity demand, can reduce the cost of electricity production; by flexibly adjusting the load, the power grid can be prevented from failing due to overload, ensuring the safety and stability of the power supply; effectively reducing the burden on thermal power units, thereby helping to reduce the use of fossil energy and reduce greenhouse gas emissions.

[0023] In summary, the present invention has the advantages of high efficiency, environmental protection, energy saving, reliability and flexibility, and can provide a stable supply of heat energy for various industries, construction and other fields, while reducing operating costs and improving system performance.

[0024] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings to be used in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a schematic diagram of the vertical arrangement structure of the heat storage tubes of the heat storage device for electrically heated steel bars in a thermal power plant according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the horizontal arrangement structure of the heat storage tubes of the heat storage device for electrically heated steel bars in a thermal power plant according to an embodiment of the present invention; Figure 3It is a schematic diagram of the cross-sectional structure of the heat storage tube for electrically heating steel bars according to an embodiment of the present invention.

[0027] Among them: 1. Heat storage body; 2. Steel heat storage body; 3. Device insulation layer; 4. Air channel; 5. Air-water heat exchanger; 6. Circulating fan; 7. Motor; 8. Power supply control cabinet; 9. Heating wire or heating plate. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "one side", "one end", "one side" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0032] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0033] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0034] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0035] The present invention provides a thermal power plant electric heating steel bar heat storage device and a heat storage method thereof, which stores energy through electric heating technology and transfers heat through hot air and an air-water heat exchanger, and finally produces hot water or industrial steam for external use; it can perform peak and frequency regulation according to the needs of the power grid, and realize flexible regulation of electricity by controlling the input of electric heating wires or heating plates, realize the storage of surplus electricity and subsequent electricity consumption regulation, thereby optimizing the load regulation and energy utilization efficiency of the power grid.

[0036] See also Figure 1 , Figure 2 and Figure 3 The present invention discloses a heat storage device for electrically heated steel bars in a thermal power plant, comprising a heat storage body 1, a densely arranged steel bar heat storage body 2, a device insulation layer 3, an air passage 4, an air-water heat exchanger 5, a circulating fan 6 and a motor 7 thereof, a power supply control cabinet 8, and a heating wire or a heating plate 9 for heating densely arranged in the middle of the steel bar heat storage body; The device insulation layer 3 serves as the outer shell of the steel heat storage body 2 to play a role of insulation and protection. The steel bars of the steel heat storage body 2 are arranged horizontally or vertically inside the device insulation layer 3, and the heating wire or heating plate 9 is arranged horizontally or vertically in the space between two adjacent steel bars of the steel heat storage body 2; the circulating fan 6 sends air into the steel heat storage body for heating, and the heated hot air exchanges heat with the feed water in the air-water heat exchanger 5, and the feed water is heated into hot water or industrial steam for external supply.

[0037] The steel bars arranged in groups of the steel bar heat storage body 2 are provided with fixing devices at the root or top, and the fixing devices are loosely connected to the steel bars to ensure compensation for the deformation and displacement of the steel bars due to thermal expansion and contraction.

[0038] Preferably, the electric heating wire or heating plate 9 is connected to the power supply control cabinet 8, and the surplus power of the peak and frequency regulation of the thermal power unit is used for power supply to heat the heat storage body.

[0039] The circulating fan and the air-water heat exchanger 5 are installed outside the heat storage device and are connected to the heat storage device through a heat-resistant and heat-insulating air supply duct to realize the heating process of the heat storage body on the feed water.

[0040] The circulating fan and the air-water heat exchanger 5 are installed in the heat storage device, specifically at the bottom, top or side of the steel heat storage body 2, and are separated from the heat storage body by a heat-resistant partition to form two spaces.

[0041] Among them, the air-water heat exchanger 5 is arranged in the pipeline between the hot air outlet after the steel bar heat storage body 2 absorbs heat and the air supply outlet of the fan. The interfaces at both ends of the heat exchange coil of the air-water heat exchanger 5 are respectively provided with a steam or hot water outlet and a water supply inlet; the steam or hot water outlet pipeline and the water inlet pipeline pass through the device insulation layer 3 for connecting to the outside world.

[0042] The function of the air-water heat exchanger is to transfer the heat of the hot air absorbed by the steel heat storage body to water or steam, and to bring the heat to other parts of the system through the flow of steam or hot water. The design of the heat exchange coil can ensure effective heat exchange between hot air and water or steam, thereby achieving higher heat exchange efficiency and improving the heating capacity of the entire system.

[0043] By setting up steam or hot water outlets and water inlets, it is more convenient to connect to external heat sources (such as boilers, heat pumps, etc.). This setting can adjust the operation mode of the system according to demand, such as using steam or hot water at different temperatures to flexibly adapt to the heat exchange requirements under different working conditions, thereby improving the energy utilization efficiency of the system and reducing energy consumption.

[0044] The heat insulation layer 3 of the device can effectively reduce heat loss, ensure that heat is not lost as much as possible during pipeline transportation, and ensure that heat is effectively transferred to the target device. This is very important for ensuring the stable operation of the system and improving heating efficiency.

[0045] Passing the steam or hot water outlet pipe and the water inlet pipe through the insulation layer of the device can prevent the water temperature in the pipe from dropping due to external temperature changes or other environmental factors, thereby ensuring heat transfer efficiency and system stability.

[0046] The steel bar heat storage body 2 is arranged in the heat storage body 1 in a quick-release manner for easy loading, unloading and replacement.

[0047] The air-water heat exchanger 5 is connected to a water supply device to heat water at a certain temperature to generate hot water or steam at a certain pressure and temperature. The water comes from the water supply of the chemical water workshop of the power plant or the water supply pipeline of the thermal power unit.

[0048] The steps of implementing heat storage and energy storage in the heat power plant electric heating steel bar heat storage and energy storage device of the present invention are as follows: According to the demand for thermal energy storage devices in the power grid, the thermal storage capacity and electric heating capacity of the electric heating steel bar thermal energy storage device in the thermal power plant are designed to enable the device to meet the peak frequency regulation or heat demand on the power supply side, grid side, load side or energy storage station in the power grid; According to the type of heat demand, design a thermal power plant electric heating steel bar heat storage device with matching capacity to generate hot water or steam to meet the needs of heat users; Design and select appropriate steel bar material type, size and shape according to the hot water or steam temperature range; According to the temperature range of hot water or steam, several steel bars of the steel bar heat storage body are selected and arranged horizontally or vertically in the heat storage body 1; The power consumption of the device can be increased or decreased by switching on and off the electric heating wires or heating plates 9 in series or in parallel in batches, thereby responding to the peak-shaving and frequency-regulating signals of the power grid or thermal power units, and realizing heat storage and energy storage using the surplus power of the peak-shaving and frequency-regulating signals.

[0049] The steps of peak and frequency regulation of the power grid based on the thermal energy storage device for electrically heated steel bars in the thermal power plant are as follows: S1. According to the peak load and frequency regulation requirements of the power grid or thermal power unit for the device, the overall power consumption of the thermal power plant's electric heating steel bar heat storage device is adjusted; S2. When the electric heating steel bar heat storage device of the thermal power plant is operating in the heat storage mode, the electric heating steel bar heat storage device starts to supply peak and frequency modulation power to the electric heating wire or the heating plate 9, and uses the power supply power of the increased group of electric heating wires or heating plates 9 to increase the power consumption of the overall device, thereby responding to the needs of the power grid or thermal power units for deep peak regulation; S3. When the electric heating steel bar heat storage device of the thermal power plant is in heat release operation, the electric heating steel bar heat storage device stops supplying power to the electric heating, and utilizes the heat storage and hot air circulation of the steel bar material in the electric heating steel bar heat storage device of the thermal power plant to heat the feed water to generate hot water or steam for heating demand, thereby responding to the demand of the power grid or the thermal power unit to increase the amount of electricity on the grid of the thermal power unit; S4. When the power grid or thermal power unit hopes to use the thermal power plant's electrically heated steel bar heat storage device to respond to the power grid's frequency regulation auxiliary service needs, the power supply of several of the electric heating wires or heating plates 9 can be quickly turned on or off to achieve a rapid increase or decrease in the power consumption of the thermal power plant's electrically heated steel bar heat storage device to respond to the power grid's frequency regulation auxiliary service needs.

[0050] It can not only efficiently store electrical energy and convert it into thermal energy, but also balance the load of the power grid through intelligent regulation and control to meet diverse thermal needs. It can meet the peak and frequency regulation needs of the power grid, improve energy utilization efficiency, reduce operating costs, and help reduce environmental burdens and promote sustainable development of energy.

[0051] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0052] Application Examples 1. Industrial heating system The electric heating steel bar heat storage device is widely used in industrial heating systems. Especially in industrial production processes that require a stable heat source supply, such as steel, fertilizer, machinery manufacturing, textiles and other fields, efficient and reliable hot water or steam supply is often required. The device can use electrical energy to heat the steel bar heat storage body, convert it into thermal energy and store it, and transfer the heat to the water or gas that needs to be heated through the air-water heat exchanger, providing a continuous and stable heat source.

[0053] Application example: The steam system of a large fertilizer plant needs to continuously supply steam for reaction heating. The electric heating steel bar heat storage device uses electricity to heat the steel bars. When steam is needed, the device will quickly release the stored heat, and exchange the heated hot air with the feed water through the air-water heat exchanger to generate high-temperature hot water or industrial steam to meet production needs.

[0054] 2. Central heating system In the district heating system in cold regions, especially in residential areas or office buildings, a large amount of hot water and heating is often required. The device can store heat during the low electricity price period and provide heat through the heat exchange system during the peak heat demand period, thus optimizing energy use.

[0055] Application example: In a city’s centralized heating system, the electric heating steel bar heat storage device uses off-peak electricity prices to store heat and energy. During peak demand periods, the stored heat is released through an air-water heat exchanger to provide hot water and heating, ensuring residents’ heating needs in cold seasons and reducing system operating costs through energy storage.

[0056] 3. Solar thermal energy storage auxiliary system The device can also be used in conjunction with a solar water heating system. When there is no sunlight, the heat storage body is heated by electric heating to supplement the insufficient heat in the system. Especially in dark weather or at night, the electric heating steel bar heat storage device can respond quickly and provide heat energy, ensuring that the system has sufficient heat supply all day long.

[0057] Application example: A residential area has installed a solar water heating system, but in winter when the weather is cold, the solar heating is insufficient. The electric heating steel bar heat storage device is combined with the solar water heating system to store heat when the sun is sufficient during the day, and use electric heating to supplement the heat at night or on cloudy days to ensure that the residents' hot water needs are met.

[0058] Simulation experiment The simulation experiment aims to evaluate the performance and feasibility of the electric heating steel bar heat storage device in practical applications by simulating the heat energy transmission, heat storage efficiency and energy efficiency performance under different load conditions and working environments. The experimental results can provide data support for equipment optimization and provide a basis for design parameters.

[0059] 1. Simulation platform and model establishment Simulation platform: CFD (computational fluid dynamics) software such as ANSYS Fluent is used for numerical simulation to simulate airflow and heat conduction processes; MATLAB / Simulink is used for energy balance and dynamic simulation.

[0060] Model building: Steel bar thermal storage body model: A three-dimensional structural model including a steel bar thermal storage body is established. The steel bars are arranged in a specific way, and the model takes into account its heat conduction, convection and radiation characteristics.

[0061] Heating system model: simulates the electric heating characteristics of the electric heating wire or heating plate. The heat transfer model includes the processes of electric heating converting heat and heat propagation in the steel bar heat storage body.

[0062] Air-water heat exchanger model: simulates the heat exchange process between hot air and feed water, taking into account the heat capacity, flow rate and heat transfer efficiency of water.

[0063] Circulation fan and air channel model: Establish a dynamic model of the circulation fan to simulate air flow, temperature changes of hot air and flow velocity distribution.

[0064] 2. Simulation steps Step 1: Input design parameters such as steel bar size, arrangement, heating power, air flow rate, water flow, etc.

[0065] Step 2: Use CFD software to simulate fluid and heat conduction to obtain efficiency data of heating, heat storage and heat conduction.

[0066] Step 3: Compare the energy efficiency performance under different working conditions and evaluate the heat storage capacity of the steel heat storage body and the efficiency of the heat release process.

[0067] Step 4: Use MATLAB / Simulink to perform dynamic simulation to simulate the time response of the heating process, temperature fluctuations, and changes in system energy efficiency in different time periods.

[0068] 3. Analysis of simulation results Heat storage efficiency: Through simulation results, the heat storage efficiency of the electric heating steel bar thermal energy storage device can be evaluated under different heating power, air flow rate and water flow rate conditions.

[0069] Heat loss: Simulation results help identify links with large heat losses (such as insulation layers, air-water heat exchangers, etc.), providing guidance for equipment improvements.

[0070] System energy efficiency: Evaluate the overall energy efficiency of the device under different operating modes and optimize the control strategy to improve the economy and environmental friendliness of the system.

[0071] 4. Experimental Verification The accuracy of the simulation model was verified through experiments. The experimental device was actually built to measure the temperature, energy consumption and heat transfer efficiency during heating, heat storage and heat exchange, and compared with the simulation results to further verify its reliability and feasibility.

[0072] In summary, the thermal power plant electrically heated steel bar heat storage device and heat storage method thereof of the present invention have the following advantages: 1. Since the steel heat storage body has a high heat capacity and good thermal conductivity, it can effectively store heat energy and maintain high temperature for a long time. This allows the entire device to provide a stable heat source during peak demand and avoid excessive energy consumption. Through intelligent regulation, the heating device can adjust its operation according to actual needs to avoid energy waste.

[0073] 2. The heating wire or heating plate is arranged between the steel bars, which can effectively heat the air and evenly distribute the hot air to the entire thermal storage body through the circulating fan. The heating process is fast and efficient, and can respond quickly according to actual needs to meet the thermal energy needs of industry or construction.

[0074] 3. The air-water heat exchanger realizes efficient heat exchange between hot air and feed water, and can fully transfer the heat in the air to water or steam, ensuring the effective use of thermal energy and the supply of hot water or steam. The configuration of the air-water heat exchanger improves the thermal efficiency of the overall system and minimizes heat loss.

[0075] 4. Through the reasonable design of densely arranged steel bar heat storage bodies and heating wires / heating plates, heat can be effectively transferred and accumulated between steel bars. At the same time, the design of the insulation layer can effectively prevent heat loss, thereby improving the thermal energy utilization efficiency of the entire system.

[0076] 5. The design of the power supply control cabinet allows the entire system to be adjusted according to different usage requirements. For example, according to different seasons, working conditions or environmental requirements, the control cabinet can flexibly adjust the electric heating power to ensure the stability and economy of the system operation.

[0077] 6. As the steel bar as a heat storage body has strong high temperature resistance and corrosion resistance, the device has high durability and can operate stably for a long time. The design of the heating wire or heating plate is simple and efficient, and the maintenance cost is low. At the same time, the dense arrangement and the protection of the insulation layer further increase the service life of the device.

[0078] 7. Compared with traditional gas heating devices, electric heating steel bar heat storage devices do not emit harmful gases and have better environmental adaptability. Driven by electricity and combined with the use of renewable energy (such as solar energy, wind energy, etc.), the device can provide heat energy for industry and construction without generating pollution, which meets modern environmental protection requirements.

[0079] 8. It is not only suitable for industrial heating, steam production, building heating and other fields, but also can be used in regional heating systems, large-scale hot water supply and other scenarios. Its flexibility and scalability enable the device to meet a variety of needs and has a high market application prospect.

[0080] 9. Through heat storage and air-water heat exchange design, the system can reduce heat loss and improve energy efficiency. The system can store heat during off-peak hours and release heat during peak hours, optimize energy production and consumption, and improve the overall economic benefits of the system.

[0081] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A thermal power plant electric heating steel bar heat storage device, characterized in that: The invention comprises a heat storage body (1), the heat storage body (1) is provided with a device heat insulation layer (3) on the outside, a steel heat storage body (2) is densely arranged inside the heat storage body (1), an air passage (4) is provided between the steel heat storage body (2) and the device heat insulation layer (3), and a heating wire or a heating plate (9) is arranged horizontally or vertically in the space between two adjacent steel bars of the steel heat storage body (2); an air-water heat exchanger (5) and a circulating fan (6) are provided at the bottom of the heat storage body (1), the circulating fan (6) is connected to a motor (7) provided on the device heat insulation layer (3), and the circulating fan (6) is used to send air into the steel heat storage body (2) for heating, and the heated hot air exchanges heat with the feed water in the air-water heat exchanger (5), and the feed water is heated to become hot water or industrial steam and then supplied to the outside.

2. The thermal power plant electrically heated steel bar heat storage device according to claim 1, characterized in that: The steel bar heat storage body (2) comprises a plurality of steel bars, which are arranged in groups horizontally or vertically. A fixing device is provided at the root or top of the steel bars, and the fixing device is loosely connected to the steel bars.

3. The thermal power plant electrically heated steel bar heat storage device according to claim 1, characterized in that: The electric heating wire or heating plate (9) is electrically connected to a power supply control cabinet (8) arranged outside the thermal insulation layer (3) of the device, and the surplus power of the peak and frequency regulation of the thermal power unit is used for power supply.

4. The thermal power plant electrically heated steel bar heat storage device according to claim 1, characterized in that: The circulating fan (6) and the air-water heat exchanger (5) are connected to the heat storage device via a heat-resistant and heat-insulating air supply duct.

5. The thermal power plant electrically heated steel bar heat storage device according to claim 1, characterized in that: The circulating fan (6) and the air-water heat exchanger (5) are installed at the bottom, top or side of the steel bar heat storage body (2), and are separated from the heat storage body by a heat-resistant partition to form two spaces.

6. The thermal power plant electrically heated steel bar heat storage device according to claim 4 or 5, characterized in that: The air-water heat exchanger (5) is arranged in a pipeline between the hot air outlet after the steel bar heat storage body (2) absorbs heat and the air supply outlet of the fan. The interfaces at both ends of the heat exchange coil of the air-water heat exchanger (5) are respectively provided with a steam or hot water outlet and a water supply inlet; the steam or hot water outlet pipeline and the water inlet pipeline pass through the device insulation layer (3) for connection to the outside world.

7. The thermal power plant electrically heated steel bar heat storage device according to claim 1, characterized in that: The steel bar heat storage body (2) is arranged in the heat storage body (1) in a quick-disassembly manner.

8. The thermal power plant electrically heated steel bar heat storage device according to claim 1, characterized in that: The air-water heat exchanger (5) is connected to a water supply device to heat the water to generate hot water or steam of set pressure and temperature. The water comes from the chemical water workshop of the power plant or the water supply pipeline of the thermal power unit.

9. The heat storage method of the heat storage device for electrically heated steel bars in a thermal power plant according to claim 1, characterized in that: The following steps are involved: According to the demand for thermal energy storage devices in the power grid, the thermal storage capacity and electric heating capacity of the electric heating steel bar thermal energy storage device in the thermal power plant are designed to enable the device to meet the peak frequency regulation or heat demand on the power supply side, grid side, load side or energy storage station in the power grid; According to the type of heat demand, design a thermal power plant electric heating steel bar heat storage device with matching capacity to generate hot water or steam to meet the needs of heat users; Design appropriate steel bar material type, size and shape according to hot water or steam temperature range; According to the temperature range of hot water or steam, several steel bars of the steel heat storage body are selected and arranged horizontally or vertically in the heat storage body; The power consumption of the electric heating steel bar heat storage device of the thermal power plant can be increased or decreased by switching on and off the electric heating wires or heating plates in series or in parallel in batches, so as to realize the heat storage of surplus power for peak load regulation and frequency modulation.

10. The heat storage method of the heat storage device for electrically heated steel bars in a thermal power plant according to claim 9, characterized in that: The details of thermal energy storage using surplus power for peak load and frequency regulation are as follows: According to the peak and frequency regulation load requirements of the power grid or thermal power units, the overall power consumption of the thermal power plant's electric heating steel bar heat storage device is adjusted; When the thermal power plant electric heating steel bar heat storage device is operating in the heat storage condition, the thermal power plant electric heating steel bar heat storage device is started to supply peak and frequency modulation power to the electric heating wire or heating plate, and the power supply power of the electric heating wire or heating plate in the increased group is used to increase the power consumption of the overall device; When the thermal power plant's electric heating steel bar heat storage device is operating in a heat release condition, the thermal power plant's electric heating steel bar heat storage device stops supplying power to the electric heating, and utilizes the heat storage and hot air circulation of the steel bar material in the thermal power plant's electric heating steel bar heat storage device to heat the feed water to generate hot water or steam for heating demand; When the power grid or thermal power unit uses the thermal power plant's electrically heated steel bar heat storage device to respond to the power grid's frequency regulation auxiliary service needs, the power supply of several electric heating wires or heating plates is quickly switched on or off to increase or decrease the power consumption of the thermal power plant's electrically heated steel bar heat storage device.

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