Cascade heat storage multi-parameter stable steam supply device and control method thereof

Abstract

The invention relates to the technical field of solid heat storage, and discloses a cascade heat storage multi-parameter stable steam supply device and a control method thereof.The steam supply device comprises a solid heat storage preheating device, a solid heat storage evaporator, a solid heat storage superheater, a steam pocket, a water feeding pump, a temperature sensor and a control unit; the solid heat storage preheating device, the solid heat storage evaporator, the steam pocket and the solid heat storage superheater are sequentially connected through a circulating pipeline, a heat exchange medium passing through the water feeding pump flows into a medium inlet of the solid heat storage preheating device, and a high-parameter medium with the temperature of 500 DEG C or above flows out of a medium outlet of the solid heat storage superheater; electric heaters, heat storage materials, heat exchange tubes and temperature sensors are arranged in the solid heat storage preheating device, the solid heat storage evaporator and the solid heat storage superheater in a layered mode. By means of a modularized heat storage device structure for direct contact heat exchange, heat storage materials and heat exchange pipes of all modules are arranged in a layered mode, flow control is conducted in a layered mode, and stable control over the gas production temperature of the device is achieved.

Description

Technical Field

[0001] This invention relates to the field of solid thermal storage technology, specifically to a multi-parameter stable steam supply device for cascade thermal storage and its control method. Background Technology

[0002] Currently, commonly used thermal storage technologies mainly include solid thermal storage and molten salt thermal storage, both of which have seen successful applications in recent years. Solid thermal storage commonly uses magnesia bricks and concrete as storage media, offering advantages such as low cost and mature technology. However, because solid thermal storage utilizes sensible heat, its energy density is low, and it typically requires indirect heat exchange with water / steam systems using hot air / thermal oil, resulting in a large footprint and low heat production parameters. This limits its widespread application, as it is generally used for heating or industrial steam supply. Using a heat exchange method where the storage medium and the solid thermal storage medium are in direct contact can improve the heat production parameters of solid thermal storage. However, because commonly used solid thermal storage media have low thermal conductivity, and the temperature of the solid thermal storage material gradually decreases during the energy release process, the gas production parameters during the energy release process are difficult to control stably. Summary of the Invention

[0003] To address existing problems, this invention provides a multi-parameter stable steam supply device for cascaded thermal storage. It proposes a modular thermal storage device structure with direct contact heat exchange. The thermal storage materials and heat exchange tubes of each module are arranged in layers with layered flow control. By real-time monitoring of the temperature of the thermal storage body and the flow rate of the heat exchange tubes in each layer, the flow rate of the heat exchange tubes is dynamically adjusted, achieving stable control of the gas production temperature of the modular thermal storage device with direct contact heat exchange. The more layers, the more accurate the temperature control. Furthermore, the final gas production temperature and flow rate are finely adjusted through steam drum buffering, water spray desuperheating, and flow bypass methods, further ensuring stable steam supply from the modular thermal storage device with direct contact heat exchange. This invention expands the application scenarios of solid thermal storage devices, has a simple structure, wide applicability, and is easy to implement in engineering.

[0004] To achieve the above objectives, the present invention provides the following technical solution.

[0005] This invention provides a multi-parameter stable steam supply device for cascaded thermal storage, comprising a solid thermal storage preheating device, a solid thermal storage evaporator, a solid thermal storage superheater, a steam drum, a feedwater pump, a temperature sensor, and a control unit; the solid thermal storage preheating device, the solid thermal storage evaporator, the steam drum, and the solid thermal storage superheater are connected in sequence through a circulation pipeline, wherein the heat exchange medium flowing into the feedwater pump flows into the medium inlet of the solid thermal storage preheating device, and the high-parameter medium with a temperature of over 500°C flows out from the medium outlet of the solid thermal storage superheater; The solid thermal storage preheating device, solid thermal storage evaporator, and solid thermal storage superheater are all equipped with layered electric heaters, thermal storage materials, heat exchange tubes, and temperature sensors. The heat exchange medium in the circulation pipeline flows into the heat exchange tubes of each layer through multiple branch pipes. The heat exchange tubes are used for heat exchange with the thermal storage material. The heat exchange medium flowing through the thermal storage material in each layer flows out through multiple converging pipes. The electric heaters are installed in the thermal storage material to heat the thermal storage material in each layer. The temperature sensors are installed in the thermal storage material and electrically connected to the control unit. The temperature sensors are used to monitor the temperature of each layer.

[0006] As a further improvement of the present invention, the medium outlet of the solid heat storage superheater is connected to a branch of the circulation pipeline, the branch is connected to the inlet of the steam drum, and a flow control valve is provided on the branch to realize bypass flow regulation.

[0007] As a further improvement of the present invention, a flow sensor is installed in the circulation pipeline at a position downstream of the junction of the branches.

[0008] As a further improvement of the present invention, the heat storage material of the solid heat storage preheating device is low-parameter concrete or magnesium brick solid heat storage material; the heat storage material of the solid heat storage evaporator is medium-parameter magnesium brick solid heat storage material; and the heat storage material of the solid heat storage superheater is high-parameter graphite or alumina solid heat storage material.

[0009] As a further improvement of the present invention, the electric heater is one or more of a resistance heater, an electrode heater, and an induction heater; the resistance heater is a plate heater or an electric heating tube.

[0010] As a further improvement of the present invention, each of the branch pipes is provided with a stratified flow meter and a stratified flow control valve.

[0011] As a further improvement of the present invention, temperature sensors, pressure sensors and flow sensors are provided in the circulation pipelines between the water pump and the solid thermal storage preheating device, between the solid thermal storage preheating device and the solid thermal storage evaporator, between the solid thermal storage evaporator and the steam drum, between the steam drum and the solid thermal storage superheater, and at the medium outlet of the solid thermal storage superheater.

[0012] As a further improvement of the present invention, a water spraying desuperheating device is provided at the medium outlet of the solid heat storage superheater. The water spraying desuperheating device is used to circulate desuperheating water to cool down the medium outlet of the solid heat storage superheater.

[0013] The present invention also provides a control method for a multi-parameter stable steam supply device for cascaded thermal storage, comprising the following steps: During the heat storage process, the upper and lower limits of the heat storage temperature T1' and T1'', T2' and T2'', and T3' and T3'' of the solid heat storage preheating device, solid heat storage evaporator, and solid heat storage superheater are set respectively; the electric heater is turned on, the heat storage temperature of each layer of heat storage material is monitored and the power of the electric heater is adjusted to prevent the heat storage material from exceeding the upper and lower limits of the heat storage temperature. During the energy release process, the upper and lower limits of the solid thermal storage preheating device, the solid thermal storage evaporator, and the solid thermal storage superheater, as well as the measured temperatures T1, T2, T3, and the specific heat capacity C, are used. t 石墨 And the inlet flow rate m1, m2, m3, specific heat capacity, and saturation temperature T of the heat exchange medium. b Saturation temperature T under pressure b The difference between the medium inlet temperature T0 and the latent heat of vaporization q at that temperature and pressure. r The total masses M1, M2, and M3 of the heat storage materials for the solid heat storage preheating device, solid heat storage evaporator, and solid heat storage superheater are obtained respectively through heat balance calculations. Calculate the mass of heat storage material M1', M2' and M3' of each layer of the solid heat storage preheating device, solid heat storage evaporator and solid heat storage superheater, and obtain the required number of solid heat storage layers G1, G2 and G3; Based on the required number of solid heat storage layers G1, G2 and G3, and the medium inlet flow rates m1, m2 and m3, calculate the required flow rates m1', m2' and m3' for each layer of the distribution pipe; Based on temperature monitoring of the heat storage material in each layer of the solid heat storage preheating device, solid heat storage evaporator, and solid heat storage superheater during the heat release process, the flow rate of each layer of the distribution pipe is calculated in real time according to the heat balance calculation formula. Then, by adjusting the layer flow control valve or opening more layer flow control valves, the output steam with a temperature not less than the target temperature and a gas production flow rate that meets the requirements is controlled and switched.

[0014] As a further improvement of the present invention, when the temperature of the heat exchange medium at the medium outlet of the solid thermal storage superheater is too high, it is cooled down; when the flow rate of the heat exchange medium at the medium outlet of the solid thermal storage superheater exceeds the required flow rate, the flow rate entering the steam turbine is reduced through a steam bypass, thereby achieving precise regulation of the temperature and flow rate of the energy-releasing steam.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This device adopts a modular heat storage structure with direct contact heat exchange. The heat storage materials and heat exchange tubes of each module are arranged in layers and the flow rate is controlled in each layer. By monitoring the temperature of the heat storage body and the flow rate of the heat exchange tubes in real time, the flow rate of the heat exchange tubes is dynamically adjusted, thus achieving stable control of the gas production temperature of the modular heat storage device with direct contact heat exchange. This device can output high-parameter media with a stable temperature of over 500℃, meeting the needs of different industrial scenarios for high-parameter steam.

[0016] Preferably, the medium outlet of the solid thermal accumulator superheater is connected to a branch of the circulation pipeline, and the branch is equipped with a flow control valve to achieve bypass flow regulation. During system operation, the bypass flow can be flexibly adjusted according to actual needs, thereby better controlling the operating parameters of the entire system, improving the stability and flexibility of system operation, and adapting to steam supply requirements under different operating conditions.

[0017] Preferably, a flow sensor is installed downstream of the branch junction in the circulation pipeline. The flow sensor can monitor the flow at this location in real time, and the flow control valve adjusts according to the monitored flow data, which can more accurately control the flow in the circulation pipeline, ensure the stability of the system flow, and further guarantee the stable operation of the entire steam supply unit.

[0018] Preferably, different parameters of heat storage materials are used for different components of the solid heat storage preheating device, solid heat storage evaporator, and solid heat storage superheater. Low-parameter concrete and magnesia bricks are used for the preheating device, medium-parameter magnesia bricks are used for the evaporator, and high-parameter graphite and alumina are used for the superheater. This matching method gives full play to the characteristics of different heat storage materials, enabling each component to operate efficiently within its own operating parameter range, improving the heat storage and heat exchange performance of the entire device, and achieving stable steam supply with multiple parameters.

[0019] Preferably, the electric heater is one or more of a resistance heater, an electrode heater, and an induction heater, and the resistance heater can take various forms such as a plate heater or an electric heating tube, providing a variety of heating options. The appropriate type of electric heater can be flexibly selected according to different application scenarios, cost requirements, and heating efficiency needs, improving the applicability and flexibility of the device.

[0020] Preferably, each branch pipe is equipped with a stratified flow meter and a stratified flow control valve. The stratified flow meter can monitor the flow rate of each branch pipe in real time, and the stratified flow control valve can independently adjust the flow rate of each branch pipe based on the monitoring data. This allows for precise control of the flow rate entering each layer of heat exchange tubes, ensuring uniform heat exchange in each layer, improving heat exchange efficiency, and thus enhancing the stability and quality of steam supply for the entire device.

[0021] Preferably, temperature sensors, pressure sensors, and flow sensors are installed at multiple key locations, such as between the water pump and the solid thermal storage preheating device, to comprehensively monitor the temperature, pressure, and flow parameters at each key location in the system in real time. Real-time monitoring of these parameters allows for the timely detection of abnormalities during system operation, facilitating timely adjustments and control by operators, ensuring the safe and stable operation of the system, and providing data support for optimized system operation.

[0022] Preferably, a water spray desuperheating device is installed at the medium outlet of the solid thermal storage superheater. When the temperature at the medium outlet is too high, desuperheating water can be circulated in to cool it down. This device can effectively control the medium outlet temperature, prevent damage to downstream equipment due to excessive temperature, ensure that the temperature of the output medium is stable within a suitable range, meet the steam temperature requirements of different users, and improve the reliability and safety of the device.

[0023] This control method sets upper and lower limits for the heat storage temperature of each device during the heat storage process and monitors and adjusts the power of the electric heater to prevent the heat storage material from overheating and ensure the safety and stability of the heat storage process. During the energy release process, a series of heat balance calculations are used to obtain the total mass of the required heat storage material, the mass of each layer, and the required number of solid heat storage layers. Then, the flow rate of each layer's distribution pipe is calculated, and the stratified flow control valves are adjusted or more stratified flow control valves are opened based on the temperature monitoring of each layer's heat storage material to output steam that meets the gas production flow requirements. This control method can precisely control each parameter according to the actual operating conditions of the system, achieving stable steam supply with multiple parameters in cascade heat storage, improving energy utilization efficiency and steam supply quality.

[0024] Preferably, when the medium temperature or flow rate at the outlet of the solid heat storage superheater is too high, measures such as spraying water to de-heat the heat exchange medium or steam bypassing are taken, respectively. This control method can promptly respond to abnormal temperature and flow rates during system operation, ensuring that the temperature and flow rate at the medium outlet remain stable within a suitable range, ensuring the stable operation of the entire steam supply unit, and meeting the user's requirements for steam parameters. Attached Figure Description

[0025] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and are not intended to specifically limit the shapes and proportions of the components. In the drawings: Figure 1 This is a schematic diagram of a multi-parameter stable steam supply device for cascaded thermal storage in Example 1; Figure 2 This is a schematic diagram of a multi-parameter stable steam supply device for cascaded thermal storage in Examples 2 and 3; Figure 3This is a flowchart illustrating the control method of a multi-parameter stable steam supply device for cascaded thermal storage in Example 3.

[0026] in, 1. Solid thermal storage preheating device; 2. Solid regenerative evaporator; 3. Solid-state heat storage superheater; 4. Steam drum; 5. Water spray cooling device; 6. Water supply pump; 13, 23, and 33 are all electric heaters; 11, 21, and 31 are all heat storage materials; 12, 22, and 32 are all heat exchange tubes; 111-116, 211-216, and 311-316 are layered temperature sensors for solid heat storage preheating devices, solid heat storage evaporators, and solid heat storage superheaters; 117 and 217 are temperature sensors for the inlet and outlet pipelines of the solid thermal storage preheating device, respectively. 218. Temperature sensor for the outlet pipe of a solid-state thermal regenerator evaporator; 317 and 318 are temperature sensors for the inlet and outlet pipes of the solid thermal accumulator superheater, respectively. 101-106, 201-206, and 301-306 are stratified flow control valves for solid heat storage preheating devices, solid heat storage evaporators, and solid heat storage superheaters; 308. Desuperheating water flow control valve; 309. Bypass flow control valve; 132-137, 232-237, and 332-337 are stratified flow meters for solid heat storage preheating devices, solid heat storage evaporators, and solid heat storage superheaters; 121, 221, 321, and 322 are pressure sensors for the circulation pipeline between the module devices; 131, 231, 238, 331, 338, and 339 are flow sensors for the circulation pipeline between module devices. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0028] It should be noted that when an element is referred to as "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] Example 1 like Figure 1 As shown, this embodiment provides a multi-parameter stable steam supply device for cascaded thermal storage, including a solid thermal storage preheating device 1, a solid thermal storage evaporator 2, a solid thermal storage superheater 3, a steam drum 4, a feedwater pump 6, a temperature sensor, and a control unit. The solid thermal storage preheating device 1, the solid thermal storage evaporator 2, the steam drum 4, and the solid thermal storage superheater 3 are connected in sequence through a circulation pipeline. The medium inlet of the solid thermal storage preheating device 1 flows into the heat exchange medium passing through the feedwater pump 6, and the medium outlet of the solid thermal storage superheater 3 flows out a high-parameter medium with a temperature of over 500°C.

[0031] The solid heat storage preheating device 1 is arranged in six layers, including an electric heater 13, a heat storage material 11, a heat exchange tube 12, and temperature sensors 111-116.

[0032] The solid regenerative evaporator 2 is arranged in six layers, including an electric heater 23, a heat storage material 21, a heat exchange tube 22, and temperature sensors 211-216.

[0033] The solid heat storage superheater 3 is arranged in six layers, including electric heaters 33, heat storage material 31, heat exchange tubes 32, and temperature sensors 311-316.

[0034] like Figure 1As shown, firstly, the heat exchange medium in the circulating pipeline flows into the layered heat exchange tubes 12 of the solid thermal storage preheating device 1 through six branch pipes; then, the heat exchange medium in the circulating pipeline flows into the layered heat exchange tubes 22 of the solid thermal storage evaporator 2 through six branch pipes; finally, the heat exchange medium in the circulating pipeline flows into the layered heat exchange tubes 32 of the solid thermal storage superheater 3 through six branch pipes. Heat exchange tubes 12, 22, and 32 are respectively used for heat exchange between the solid thermal storage preheating device 1, the solid thermal storage evaporator 2, and the solid thermal storage superheater 3 and the heat exchange medium in the circulating pipeline. The heat exchange medium flowing through each layer of the thermal storage material converges and flows out through its respective six confluence pipes.

[0035] The electric heaters 13, 23, and 33 are respectively disposed within the heat storage materials 11, 21, and 31, and are used to heat their respective stratified layers. The temperature sensors 111-116, 211-216, and 311-316 are respectively disposed within the heat storage materials 11, 21, and 31, and are electrically connected to the control unit (not shown). The temperature sensors 111-116, 211-216, and 311-316 are used to monitor the temperature of each stratum of the heat storage materials 11, 21, and 31. The number of layers can be determined based on the actual size of the heat exchange device, the thermal properties of the materials, and the control precision; more layers result in more accurate temperature regulation.

[0036] The heat storage material 11 of the solid heat storage preheating device 1 uses low-parameter (≤250℃) concrete and magnesia brick solid heat storage materials; the heat storage material 21 of the solid heat storage evaporator 2 uses medium-parameter (250-500℃) magnesia brick solid heat storage materials; and the heat storage material 31 of the solid heat storage superheater 3 uses high-parameter (≥500℃) graphite and alumina solid heat storage materials. The required solid heat storage materials 11, 12, and 13 can be replaced according to the required gas production parameters. The heat storage materials are not limited to any type of solid heat storage material such as concrete, magnesia bricks, graphite, or alumina.

[0037] The electric heaters 13, 23, and 33 are one or more of the following: resistance heaters, electrode heaters, and induction heaters; the resistance heater is a plate heater or an electric heating tube.

[0038] Each of the aforementioned branch pipes is equipped with a stratified flow meter and a stratified flow control valve. Specifically, each branch pipe of the solid thermal storage preheating device 1 is equipped with a stratified flow meter 132-137 and a stratified flow control valve 101-106; each branch pipe of the solid thermal storage evaporator 2 is equipped with a stratified flow meter 232-237 and a stratified flow control valve 201-206; and each branch pipe of the solid thermal storage superheater 3 is equipped with a stratified flow meter 332-337 and a stratified flow control valve 301-306.

[0039] A temperature sensor 117, a pressure sensor 121, and a flow sensor 131 are installed on the circulation pipeline between the water pump 6 and the solid heat storage preheating device 1.

[0040] A temperature sensor 217, a pressure sensor 221, and a flow sensor 231 are installed on the circulation pipeline between the solid thermal storage preheating device 1 and the solid thermal storage evaporator 2.

[0041] A temperature sensor 218, a pressure sensor 222, and a flow sensor 238 are installed on the circulation pipeline between the solid regenerative evaporator 2 and the steam drum 4.

[0042] A temperature sensor 317, a pressure sensor 321, and a flow sensor 331 are installed on the circulation pipeline between the steam drum 4 and the solid heat storage superheater 3.

[0043] A temperature sensor 318, a pressure sensor 322, and a flow sensor 338 are installed on the circulation pipeline at the medium outlet of the solid heat storage superheater 3.

[0044] A water spray desuperheating device 5 is installed at the medium outlet of the solid heat storage superheater 3. The opening degree of the desuperheating water flow control valve 308 is controlled by the desuperheating water flow control valve 308. The water spray desuperheating device 5 is used to circulate desuperheating water to the medium outlet of the solid heat storage superheater 3 for cooling. The outlet of the water spray desuperheating device 5 is connected to another inlet at the bottom of the steam drum 4 through a bypass flow control valve 309.

[0045] The high-parameter stable steam supply system for solid thermal storage based on thermal conductivity and heat transfer described in this invention adopts a direct contact heat exchange method between heat exchange tubes and solid thermal storage materials. Compared with the indirect heat exchange method of hot air / thermal oil in conventional solid thermal storage devices, this greatly reduces the heat exchange end difference and overcomes the technical limitation of low heat generation temperature parameters in solid thermal storage devices. Through modular thermal storage device structural design and graded arrangement of cascaded thermal storage, the solid thermal storage device has the ability to generate high-parameter heat. Direct contact heat exchange can lead to unstable heat generation temperature due to the temperature drop of the thermal storage material during the heat release process.

[0046] Example 2 like Figure 2 As shown, the difference between this embodiment and Embodiment 1 is that: 1) The medium outlet of the solid heat storage superheater 3 is connected to a branch of the circulation pipeline, and the branch is connected to the inlet of the steam drum 4. A flow control valve 309 is installed on the branch, which is used to achieve bypass flow regulation.

[0047] 2) A flow sensor 339 is installed in the circulation pipeline at a downstream position of the branch intersection.

[0048] This embodiment uses flow bypass, steam drum 4 buffer, and water spray desuperheating to finely regulate the final gas production temperature and flow rate, further ensuring stable steam supply from the modular heat storage device with direct contact heat exchange. This invention expands the application scenarios of solid-state heat storage devices, has a simple structure and wide applicability, and is easy to implement in engineering.

[0049] Example 3 The device structure in this embodiment is the same as that in Embodiment 2.

[0050] like Figure 3 As shown, the present invention also provides a control method for a multi-parameter stable steam supply device for cascaded thermal storage, comprising the following steps: During the heat storage process, the upper and lower limits of the heat storage temperature T1' and T1'', T2' and T2'', and T3' and T3'' of the solid heat storage preheating device 1, the solid heat storage evaporator 2, and the solid heat storage superheater 3 are set respectively; the electric heater is turned on, the heat storage temperature of each layer of heat storage material is monitored and the power of the electric heater is adjusted to prevent the heat storage material from exceeding the upper and lower limits of the heat storage temperature; During the energy release process, based on the upper and lower limits of the heat storage temperature of the solid heat storage preheating device 1, the solid heat storage evaporator 2, and the solid heat storage superheater 3, the measured temperatures T1, T2, T3, and the specific heat capacity C... t 石墨 And the inlet flow rate m1, m2, m3, specific heat capacity, and saturation temperature T of the heat exchange medium. b Saturation temperature T under pressure b The difference between the medium inlet temperature T0 and the latent heat of vaporization q at that temperature and pressure. r The total masses M1, M2, and M3 of the heat storage materials for each of the solid heat storage preheating device 1, solid heat storage evaporator 2, and solid heat storage superheater 3 are obtained through heat balance calculations. Specifically: The heat balance calculation formula for solid thermal storage preheating device 1 is: M1·C t 石墨 ·(T1-T1'')=m1·C t 汽水介质 ·(T b -T0), calculate M1; after passing through the solid thermal storage preheating device 1, heat the feedwater to the saturated water T at this pressure. b ; The formula for calculating the heat balance of a solid regenerative evaporator is: M²·C t 石墨 ·(T2-T2'')=m2·q r M2 is calculated; after passing through the solid regenerative evaporator 2, the saturated water is heated to the saturated steam T at this pressure. s ; The formula for calculating the heat balance of a solid thermal storage superheater is: M3·C t 石墨 ·(T3-T3'')=m3·C s t · (TT) s M3 is calculated; after passing through a solid thermal storage superheater, the saturated steam T s Further superheating results in superheated steam at the target temperature T; Based on the external structure and graphite arrangement diagram of each module's solid thermal storage device, calculate the mass of thermal storage material M1', M2', and M3' for each layer of the solid thermal storage preheating device 1, solid thermal storage evaporator 2, and solid thermal storage superheater 3. Then, use the calculation formula G... n =M n / M n ', to obtain the required number of solid thermal storage layers G1, G2 and G3; Based on the required number of solid thermal storage layers G1, G2, and G3, and the medium inlet flow rates m1, m2, and m3, through m n '=m n / G n Calculate the required flow rates m1', m2', and m3' for each layer of the branch pipe; Based on the temperature monitoring of the heat storage material in each layer of the solid heat storage preheating device 1, solid heat storage evaporator 2, and solid heat storage superheater 3 during the heat release process, the flow rate of each layer of the distribution pipe is calculated in real time according to the heat balance calculation formula. Then, by adjusting the layer flow control valve or opening more layer flow control valves, the output steam with a temperature not less than the target temperature and a gas production flow rate that meets the requirements is controlled and switched.

[0051] As a further improvement of the present invention, when the temperature of the heat exchange medium at the medium outlet of the solid heat storage superheater 3 is higher than the target temperature T, the water spray desuperheating device 5 is used to cool it down, thereby achieving precise temperature control; when the flow rate of the heat exchange medium at the medium outlet of the solid heat storage superheater 3 is greater than the required target flow rate, the bypass flow control valve is opened, thereby achieving precise control of the temperature and flow rate of the superheated steam entering the turbine.

[0052] The specific traffic control strategy is as follows: m 减 To reduce the water spray temperature, m 旁 For the bypass superheated steam flow rate, the flow regulation and control strategy is to keep the water level in drum 4 constant. Therefore, m1 is the target superheated steam flow rate entering the turbine, and the control equation is: m1 = m2 + m 减 m3 = m2 + m 旁 m1=m3-m 旁By combining the temperature control equation and the flow control equation of the heat balance equation, the total inlet flow rate of the solid heat storage preheating device 1, the solid heat storage evaporator 2, and the solid heat storage superheater 3, as well as the flow rate of each layer, are dynamically adjusted, thereby achieving precise control of the temperature and flow rate of the high-temperature superheated steam entering the turbine inlet.

[0053] Specifically, such as Figure 1 As shown, during the heat storage process, the solid heat storage preheating device 1, the solid heat storage evaporator 2, and the solid heat storage superheater 3 all store heat through electric heating. The upper and lower limits of the heat storage temperature T1' and T1'', T2' and T2'', and T3' and T3'' of the respective heat storage materials of the solid heat storage preheating device 1, the solid heat storage evaporator 2, and the solid heat storage superheater 3 are set by electric heating. By monitoring the solid heat storage temperature of each layer of the respective heat storage material of the solid heat storage preheating device 1, the solid heat storage evaporator 2, and the solid heat storage superheater 3 by electric heating, the power of the electric heating rod is controlled to avoid the heat storage body from overheating during the heat storage process.

[0054] During the energy release process, take the demand steam parameters as m, 14MPa, 500℃ superheated steam, and the feed water parameters as 14MPa, 150℃ unsaturated water as an example.

[0055] First, open valve 107 and use water pump 6 to send 14MPa, 150℃ unsaturated water into solid heat storage preheating device 1. The inlet flow rate is controlled by the valve opening degree. The second step is to calculate the saturation temperature of water at 14MPa as 336.7℃. Based on the upper and lower limits of the heat storage temperature T1' and T1'', the specific heat capacity of the heat storage material, the difference between the saturation temperature and the feed water temperature at 14MPa pressure (186.7℃), the specific heat capacity of water at this pressure, and the total feed water flow rate m, the total mass M1 of the required solid heat storage preheating device 1 is obtained through heat balance calculation.

[0056] The third step is to calculate the mass M1' of each layer of heat storage material in the solid heat storage preheating device 1. Using M1 / M1'=G, rounding up G gives the initial required number of solid heat storage layers G1.

[0057] The fourth step is to calculate the flow rate m1' of each heat exchange tube 21 based on the known initial required number of solid heat storage layers G1 and the total feed water flow rate m.

[0058] Fifth, as the heat release process progresses, the temperature of the heat storage body gradually decreases. Real-time monitoring is achieved using thermocouples installed in each heat storage layer. To ensure a stable output temperature of saturated steam, the flow rate entering each heat exchanger tube is dynamically controlled by adjusting the opening of valves 101-106. The flow rate calculation for dynamic control of each heat exchanger tube is based on the mass M1' of each heat storage layer, the specific heat capacity of the heat storage material, the difference between the real-time feedback temperature of the heat storage body and the lower limit T1' of the heat storage temperature, the difference between the saturated temperature and the feedwater temperature at 14 MPa pressure (186.7℃), and the specific heat capacity of water at that pressure. This is calculated through heat balance to obtain the real-time flow rate entering each heat exchanger tube 21, ensuring that the outlet flow rate of each layer is saturated water at 14 MPa and 336.7℃. This is adjusted by adjusting the opening of valves 101-106 in each heat exchanger tube, which reduces the feedwater flow rate entering each layer.

[0059] Step 6: In order to ensure that the total outlet flow of the solid heat storage preheating device 1 meets the requirements, the inlet valve of the initially unused layer heat exchange tubes needs to be opened during the flow of each layer of heat exchange tubes.

[0060] If the initial required number of solid heat storage layers G1 calculated in step 3 is 3, then 101-103 is opened initially. As the heat storage material corresponding to the heat exchange tubes 101-103 continues to decrease, in step 5, the opening of valves 101-103 is dynamically reduced and adjusted, and the opening of valves 104-105 is dynamically increased step by step to ensure that the sum of the total inlet flow is m, thus meeting the gas production flow requirements.

[0061] Through the above steps, the solid thermal storage preheating device 1 stably produces saturated water at the required pressure, which then enters the solid thermal storage evaporator 2. The outlet temperature control method of steps one to five is repeated to ensure that the solid thermal storage evaporator 2 stably produces saturated steam with the required parameters. The steam enters the steam drum 4 to buffer and separate the saturated steam from the water. By controlling the water level in the steam drum 4, the steam drum 4 is guaranteed to stably output saturated steam or supersaturated steam at 14MPa, above 336.7℃, and a flow rate of m.

[0062] The saturated steam or supersaturated steam, separated from the steam drum 4 at 14 MPa and above 336.7℃, enters the solid regenerator superheater 3, where the saturated steam is further superheated to produce the required high-parameter steam. The outlet temperature control method of steps one through five is repeated to ensure that the solid regenerator superheater 3 stably outputs high-parameter superheated steam at 14 MPa and above 500℃.

[0063] The high-parameter superheated steam temperature at the outlet of the solid heat storage superheater 3 is finely adjusted by the water spray desuperheating device 5, and the gas production flow rate is finely adjusted by controlling the opening of the bypass valve 309.

[0064] Ultimately, this enables the entire multi-parameter stable steam supply system for thermal storage to stably output the required flow rate of high-parameter steam.

[0065] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A multi-parameter stable steam supply device for cascaded thermal storage, characterized in that, It includes a solid thermal storage preheating device (1), a solid thermal storage evaporator (2), a solid thermal storage superheater (3), a steam drum (4), a feed water pump (6), a temperature sensor, and a control unit; the solid thermal storage preheating device (1), the solid thermal storage evaporator (2), the steam drum (4), and the solid thermal storage superheater (3) are connected in sequence through a circulation pipeline, wherein the medium inlet of the solid thermal storage preheating device (1) flows into the heat exchange medium passing through the feed water pump (6), and the medium outlet of the solid thermal storage superheater (3) flows out a high-parameter medium with a temperature of over 500°C; The solid heat storage preheating device (1), solid heat storage evaporator (2), and solid heat storage superheater (3) are all arranged in layers with electric heaters, heat storage materials, heat exchange tubes, and temperature sensors. The heat exchange medium in the circulation pipeline flows into the heat exchange tubes of each layer through multiple branch pipes. The heat exchange tubes are used to exchange heat with the heat storage materials. The heat exchange medium flowing through the heat storage materials of each layer flows out through multiple converging pipes. The electric heater is set in the heat storage material and is used to heat the heat storage materials of each layer. The temperature sensor is set in the heat storage material and is electrically connected to the control unit. The temperature sensor is used to monitor the temperature of each layer.

2. The multi-parameter stable steam supply device for cascaded thermal storage according to claim 1, characterized in that, The medium outlet of the solid heat storage superheater (3) is connected to a branch of the circulation pipeline, and the branch is connected to the inlet of the steam drum (4). A flow control valve is installed on the branch, which is used to achieve bypass flow regulation.

3. The multi-parameter stable steam supply device for cascaded thermal storage according to claim 2, characterized in that, The circulation pipeline is equipped with a flow sensor located downstream of the junction of the branches.

4. The multi-parameter stable steam supply device for cascaded thermal storage according to claim 1, characterized in that, The heat storage material of the solid heat storage preheating device (1) is low-parameter concrete and magnesium brick solid heat storage material; the heat storage material of the solid heat storage evaporator (2) is medium-parameter magnesium brick solid heat storage material; and the heat storage material of the solid heat storage superheater (3) is high-parameter graphite and alumina solid heat storage material.

5. A multi-parameter stable steam supply device for cascaded thermal storage according to claim 1, characterized in that, The electric heater is one or more of a resistance heater, an electrode heater, and an induction heater; the resistance heater is a plate heater or an electric heating tube.

6. The multi-parameter stable steam supply device for cascaded thermal storage according to claim 1, characterized in that, Each of the aforementioned branch pipes is equipped with a stratified flow meter and a stratified flow control valve.

7. A multi-parameter stable steam supply device for cascaded thermal storage according to claim 1, characterized in that, Temperature sensors, pressure sensors, and flow sensors are installed in the circulation pipelines between the water pump (6) and the solid thermal storage preheating device (1), between the solid thermal storage preheating device (1) and the solid thermal storage evaporator (2), between the solid thermal storage evaporator (2) and the steam drum (4), between the steam drum (4) and the solid thermal storage superheater (3), and at the medium outlet of the solid thermal storage superheater (3).

8. A multi-parameter stable steam supply device for cascaded thermal storage according to claim 1, characterized in that, A water spray de-cooling device (5) is provided at the medium outlet of the solid heat storage superheater (3). The water spray de-cooling device (5) is used to circulate de-cooling water to the medium outlet of the solid heat storage superheater (3) to cool it down.

9. The control method for the multi-parameter stable steam supply device with cascade thermal storage as described in any one of claims 1 to 8, characterized in that, Includes the following steps: During the heat storage process, the upper and lower limits of the heat storage temperature T1' and T1'', T2' and T2'', and T3' and T3'' are set for the solid heat storage preheating device (1), solid heat storage evaporator (2), and solid heat storage superheater (3), respectively; the electric heater is turned on, the heat storage temperature of each layer of heat storage material is monitored and the power of the electric heater is adjusted to prevent the heat storage material from exceeding the upper and lower limits of the heat storage temperature; During the energy release process, the upper and lower limits of the heat storage temperature, the measured temperatures T1, T2, T3, and the specific heat capacity C of the solid heat storage preheating device (1), the solid heat storage evaporator (2), and the solid heat storage superheater (3) are used. t 石墨 And the inlet flow rate m1, m2, m3, specific heat capacity, and saturation temperature T of the heat exchange medium. b Saturation temperature T under pressure b The difference between the medium inlet temperature T0 and the latent heat of vaporization q at that temperature and pressure. r The total mass M1, M2, and M3 of the heat storage materials for the solid heat storage preheating device (1), solid heat storage evaporator (2), and solid heat storage superheater (3) are obtained through heat balance calculations. Calculate the mass of heat storage material M1', M2' and M3' of each layer of the solid heat storage preheating device (1), solid heat storage evaporator (2), and solid heat storage superheater (3) to obtain the required number of solid heat storage layers G1, G2 and G3; Based on the required number of solid heat storage layers G1, G2 and G3, and the medium inlet flow rates m1, m2 and m3, calculate the required flow rates m1', m2' and m3' for each layer of the distribution pipe; Based on the temperature monitoring of the heat storage material of each layer of the solid heat storage preheating device (1), solid heat storage evaporator (2), and solid heat storage superheater (3) during the heat release process, the flow rate of each layer of the branch pipe is calculated in real time according to the heat balance calculation formula. Then, by adjusting the layer flow control valve or opening more layer flow control valves, the output steam with a temperature not less than the target temperature and a gas production flow rate that meets the requirements is controlled and switched.

10. The control method for a multi-parameter stable steam supply device with cascaded thermal storage according to claim 9, characterized in that, Includes the following steps: When the temperature of the heat exchange medium at the medium outlet of the solid heat storage superheater (3) is too high, it is cooled down; when the flow rate of the heat exchange medium at the medium outlet of the solid heat storage superheater (3) exceeds the required flow rate, the flow rate entering the steam turbine is reduced through the steam bypass, thereby achieving precise regulation of the temperature and flow rate of the energy-releasing steam.

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