Heat storage device and system

Abstract

The utility model discloses a heat storage device and system, and relates to the technical field of power system energy storage. The heat storage device comprises a heat storage body, and the outer side of the heat storage body is coated with a heat preservation layer. The heating unit is arranged in the heat accumulator and can heat the heat accumulator after being electrified; one end of the control circuit is connected with a power supply and the other end is connected with the heating unit; the adjusting unit is connected with the control circuit and can transmit signals to the control circuit and adjust the heating power of the heating unit. According to the heat storage device and system, large-scale long-time energy storage can be achieved, and the energy storage efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of power system energy storage technology, and in particular to a heat storage device and system. Background Technology

[0002] The installed capacity of renewable energy sources such as wind and solar power is growing rapidly, and they have become an important part of the power system. However, the intermittent and random nature of renewable energy has brought new challenges, making the supply and demand balance of the power system more complex and significantly impacting the stability and economic operation of the power grid.

[0003] Energy storage technology is increasingly important as a key means of solving the aforementioned problems. It not only smooths out fluctuations in renewable energy and ensures the continuity and reliability of power supply, but also provides ancillary services such as frequency regulation and voltage support, thereby enhancing the flexibility and stability of the entire power system. Energy storage systems have a wide range of applications, covering all aspects of power production, from power smoothing on the generation side to demand response on the user side, where energy storage technology plays an indispensable role.

[0004] However, traditional energy storage technologies, such as pumped hydro storage, compressed air storage, and flywheel storage, cannot achieve large-scale, long-term energy storage and have low energy storage efficiency. Utility Model Content

[0005] The purpose of this invention is to provide a heat storage device or system to solve the problems existing in the prior art, enabling large-scale long-term energy storage and improving energy storage efficiency.

[0006] To achieve the above objectives, this utility model provides the following solution:

[0007] This invention provides a heat storage device, comprising: a heat storage body covered with an insulation layer, the insulation layer being disposed outside the heat storage body to reduce heat loss and improve heat storage efficiency; a heating unit disposed within the heat storage body, capable of heating the heat storage body when energized; a control circuit, one end of which is connected to a power source, and the other end connected to the heating unit; and an adjustment unit connected to the control circuit, capable of transmitting signals to the control circuit and adjusting the heating power of the heating unit. Thus, the adjustment unit achieves precise adjustment of the electromagnetic heating power, enabling efficient heat storage by fully utilizing low-priced electricity during off-peak hours at night. This invention utilizes electrothermal conversion technology coupled with electromagnetic induction and high-temperature radiation, and employs an IGBT-based control circuit to achieve efficient heating and temperature control of the cast iron heat storage medium, making it particularly suitable for large-scale, long-term heat storage using off-peak electricity.

[0008] This invention selects materials with high specific heat capacity and high density as the heat storage medium, such as cast iron. These materials can store a large amount of heat energy in a relatively small space. Cast iron not only has a high heat capacity but also good thermal conductivity and high-temperature resistance, making it an ideal heat storage material. Multiple cast iron bodies are closely arranged to form a heat storage module, further increasing the heat storage capacity per unit volume.

[0009] Secondly, employing efficient heating technologies, such as electromagnetic induction heating, allows for the rapid conversion of electrical energy into heat energy stored within the heat storage body. Electromagnetic induction heating is more efficient than traditional resistance heating because it generates heat directly within the heat storage body, reducing energy loss during heat conduction. Simultaneously, the control circuit and adjustment unit work together to precisely regulate the heating power as needed, ensuring the heat storage body temperature remains within the optimal range, thereby improving energy storage efficiency.

[0010] In addition, good insulation is also a key factor in ensuring heat storage capacity. Wrapping the outside of the heat storage body with a layer of high-efficiency insulation material can significantly reduce heat loss, maintain a high temperature inside the heat storage body, and extend the energy storage time. In this way, the overall system's heat storage capacity can be effectively improved without increasing the physical size of the heat storage body.

[0011] Preferably, the heat storage body is a block-shaped cast iron body with high magnetic permeability. Multiple cast iron bodies are arranged in sequence and attached together. A heating hole is opened at one end of each cast iron body, and the heating unit is disposed inside the cast iron body.

[0012] Preferably, the heating unit is a coil, which is fixedly disposed in the heating hole and connected to the control circuit. The heating unit uses the principle of electromagnetic induction to generate eddy currents in the cast iron body through the nonlinear changing current in the high-temperature coil, thereby converting electrical energy into heat energy.

[0013] Preferably, the control circuit includes a rectifier circuit, a choke coil, a resonant capacitor, and an IGBT chip. The input terminal of the rectifier circuit is connected to an AC power supply, and the output terminal is connected to the choke coil. The choke coil is sequentially connected to the resonant capacitor and the IGBT chip. The IGBT chip is electrically connected to the heating unit and can receive signals from the adjustment unit to adjust the output power to the heating unit. The IGBT chip, rectifier circuit, choke coil, and resonant capacitor form the main oscillation circuit for electrothermal conversion, realizing power-controllable electromagnetic eddy current heating and resistance radiation heating technology. The rectifier circuit generally consists of a bridge rectifier composed of four diodes, or a dedicated rectifier module can be used. Its main function is to convert the input AC power into unidirectional pulsating DC power, preparing for subsequent DC-AC conversion or direct power supply to the load. A square wave width control circuit is constructed. Increasing the square wave width increases the IGBT chip path time, and the output power increases accordingly; decreasing the square wave width shortens the IGBT chip path time, and the output power decreases accordingly. This control method not only avoids the risk of IGBT burnout caused by the significant decrease in ferromagnetism when the temperature of the ferromagnetic material exceeds the Curie temperature during electromagnetic eddy current heating, but also avoids the problem of burnout of weak parts such as joints or bends due to excessive current during cold start-up when resistive radiation heating is used, thus providing important basic technical support for high-temperature thermal storage.

[0014] Square wave width modulation (PWM) adjusts output power by changing the duty cycle of the signal. The controller compares the actual temperature fed back by the temperature sensor with the preset temperature, calculates the required heating power, and generates a corresponding PWM signal. This signal is sent to the IGBT chip, which rapidly switches its conduction state based on the high and low levels of the signal. The longer the high level duration, the higher the duty cycle, the greater the average current received by the heating unit, and the higher the heating power; conversely, the lower the duty cycle, the lower the heating power. The entire process forms a closed-loop control system. The temperature sensor continuously monitors and feeds back the actual temperature, and the controller continuously adjusts the duty cycle of the PWM signal accordingly to ensure that the actual temperature is close to the preset value. This control method not only achieves precise power regulation but also improves the system's response speed and control accuracy. In this way, even with a limited volume of heat storage material, its internal temperature can be efficiently managed and regulated, thereby achieving large-scale heat storage.

[0015] Preferably, the device further includes a temperature sensor disposed within the heat storage body and connected to the adjustment unit. The temperature sensor is used to detect the temperature inside the heat storage body and transmit the temperature signal to the adjustment unit, thereby adjusting the output power of the control circuit to achieve closed-loop temperature control.

[0016] This utility model also provides a heat storage system, including pipelines and the heat storage device as described above; the heat storage body has multiple parallel cavities, the pipeline enters from the first cavity at one end of the heat storage body, passes through multiple cavities in sequence, and exits from the last cavity at the other end of the heat storage body, the pipeline's entry end is connected to a water tank through an inlet pipe and a circulation pump, and the pipeline's exit end is connected to a steam turbine, the steam turbine is connected to the water tank through a return pipe; the steam turbine is connected to the user end through a power transmission line.

[0017] Preferably, the pipeline includes a first bypass and a second bypass. The second bypass passes through multiple cavity diameters in sequence. A first regulating valve and a second regulating valve are sequentially provided near the first cavity diameter of the second bypass. The first bypass is located outside the heat storage body, and one end of the first bypass is connected to the second bypass located between the first regulating valve and the second regulating valve. The other end of the first bypass is connected to the second bypass near the last cavity diameter through a first bypass valve.

[0018] Preferably, it further includes an intermediate pipeline located outside the heat storage body, and the intermediate pipeline is provided with a second bypass valve. One end of the intermediate pipeline is connected to a second bypass located between the first regulating valve and the second regulating valve, and the other end is connected to a second bypass located at any cavity diameter between the first cavity diameter and the last cavity diameter.

[0019] Preferably, a desuperheater is provided in the pipeline near the turbine.

[0020] This utility model also provides a control method for a thermal storage system, including the steps of: a temperature sensor detecting the temperature of the thermal storage body and transmitting the signal to a regulating unit;

[0021] When the temperature inside the heat storage body is lower than the preset temperature threshold, the regulating unit increases the heating power through the control circuit to increase the heat storage capacity of the heat storage body.

[0022] When the temperature inside the heat storage body is detected to be higher than the preset temperature threshold, the regulating unit reduces the heating power through the control circuit to reduce the heat storage capacity of the heat storage body.

[0023] When the temperature inside the heat storage body reaches the predetermined temperature value, the regulating unit controls the heating unit to stop working through the control circuit.

[0024] The present invention achieves the following technical advantages over the prior art:

[0025] The heat storage device provided by this utility model adopts a cast iron body with high magnetic permeability, which has a better heat storage effect. Its exterior is covered with a heat insulation layer to avoid heat loss and enable long-term energy storage. When needed, the energy stored in the heat storage device can heat the liquid to form steam, and the steam is transported to the steam turbine to generate electricity, realizing the release and utilization of energy. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the heat storage system of this utility model;

[0028] Figure 2 This is a schematic diagram of the heat storage device and regulating unit of this utility model;

[0029] Figure 3 This is a schematic diagram of the cast iron body assembly and coil arrangement of this utility model;

[0030] Figure 4 This is a schematic diagram of the cast iron body of this utility model;

[0031] Figure 5 This is a schematic diagram of the coil of this utility model;

[0032] Figure 6 This is a 5-hour average temperature distribution curve of a single cast iron body of the heat storage body of this utility model.

[0033] In the diagram: 1-Heat storage body; 11-Cast iron body; 111-Cavity diameter; 12-Insulation layer; 13-Pipeline; 131-First regulating valve; 132-Second regulating valve; 133-First bypass valve; 134-Second bypass valve; 135-First bypass; 136-Second bypass; 14-Temperature sensor; 2-Heating unit; 21-Coil; 22-Desuperheater; 3-Control circuit; 31-IGBT chip; 32-Rectifier circuit; 33-Choke coil; 34-Resonant capacitor; 4-Regulating unit; 5-Steam turbine; 6-User. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] The purpose of this invention is to provide a heat storage device or system to solve the problems existing in the prior art, enabling large-scale long-term energy storage and improving energy storage efficiency.

[0036] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Energy storage technology not only smooths out fluctuations in renewable energy and ensures the continuity and reliability of power supply, but also provides ancillary services such as frequency regulation and voltage support, thereby enhancing the flexibility and stability of the entire power system. Energy storage systems have a wide range of applications, covering all aspects of power production, from power smoothing on the generation side to demand response on the user side, where energy storage technology plays an indispensable role.

[0038] However, traditional energy storage technologies, such as pumped hydro storage, compressed air storage, and flywheel energy storage, face problems such as high cost, low efficiency, and slow response speed in large-scale, long-term energy storage. To address this issue, the first objective of this invention is to provide a thermal storage device that converts electrical energy into thermal energy for storage, enabling long-term and large-scale energy storage, such as... Figures 1-5 As shown, its structure includes a heat storage body 1, with an insulation layer 12 covering the outside of the heat storage body 1 to reduce heat loss and improve heat storage efficiency; a heating unit 2 is disposed inside the heat storage body 1, which can heat the heat storage body 1 after being powered on, realizing the energy storage function; a control circuit 3 is connected to the power supply at one end and to the heating unit 2 at the other end; an adjustment unit 4 is connected to the control circuit 3, which can send signals to the control circuit 3 and adjust the heating power of the heating unit 2, thereby the adjustment unit 4 realizes the fine adjustment of the electromagnetic heating power, which can make full use of low-priced electricity for efficient heat storage during off-peak hours at night. This utility model uses electrothermal conversion technology coupled with electromagnetic induction and high-temperature radiation, and uses an IGBT-based control circuit to realize efficient heating and temperature control of the heat storage medium of the heat storage body 1, which is particularly suitable for large-scale, long-term heat storage using off-peak electricity.

[0039] Specifically, the regulating unit 4 is primarily responsible for monitoring the system status and adjusting the power of the heating unit 2 as needed to ensure that the temperature within the heat storage body 1 is maintained within the ideal range. The regulating unit 4 includes a known, existing core controller (such as a microprocessor or PLC). This controller receives data from devices such as temperature sensors and determines how to adjust the power of the heating unit 2 based on preset, well-established algorithms or control logic. The controller's signal processing module converts the analog signals sent by the sensors into digital signals so that the controller can read and process this data. Once the controller determines the required heating power, it sends instructions to the control circuit through the output drive module, which may be a pulse width modulation (PWM) controller or an interface circuit that communicates directly with the IGBT chip.

[0040] The connection between the regulating unit 4 and the control circuit 3 is typically achieved through electrical wiring. The regulating unit 4 calculates the required heating power based on real-time temperature information obtained from the temperature sensor and a preset target temperature range, and then generates a corresponding control signal which is transmitted to the IGBT chip in the control circuit 3. The IGBT chip changes its conduction time according to the received signal, thereby precisely regulating the electrical energy supplied to the heating unit 2 to control the heating process. In this way, the regulating unit 4 generates appropriate control commands by monitoring and analyzing the temperature, and executes these commands through the control circuit, forming a closed-loop control system that helps improve energy storage efficiency and ensures the safe operation of the entire system.

[0041] To improve heat storage efficiency, the heat storage body 1 in this embodiment is a block-shaped cast iron body 11 with high magnetic permeability. Multiple cast iron bodies 11 are arranged in sequence to form a complete heat storage module. A heating hole is provided at one end of the cast iron body 11. The heating unit 2 uses a coil 21, which is a high-temperature coil capable of normal operation at high temperatures. The coil 21 is fixed inside the heating hole and connected to the control circuit 3. The heating unit 2 uses the principle of electromagnetic induction to generate eddy currents in the cast iron body 11 through the nonlinear changing current in the high-temperature coil. These eddy currents encounter the cast iron body 11 and generate heat based on the resistance of the cast iron body 11 material, thereby converting electrical energy into heat energy. In this case, the coil is usually made of high-temperature resistant material and designed to withstand high-temperature working environments. By using the cast iron body 11 as the heat storage medium and combining it with efficient electromagnetic heating technology, a rapid and stable heat storage process can be achieved, improving heat storage efficiency while reducing operating costs.

[0042] After being heated to a certain temperature by electromagnetic induction, the heat storage body 1 begins to radiate heat outward in the form of thermal radiation. As the temperature rises, the surface of the heat storage body 1 emits more energy in the form of electromagnetic waves, such as infrared rays. In the heat storage device, once the cast iron body 11 is heated to a sufficiently high temperature, it becomes an effective source of thermal radiation, transferring heat to the surrounding environment or a specific target. The electromagnetic induction heating of this invention first rapidly increases the temperature of the heat storage body 1. When the heat storage body 1 reaches a certain temperature, it begins to significantly release heat through thermal radiation, heating the medium within the pipes running through the heat storage body 1 through radiative heating. This means that the heat storage body 1 not only heats water or other media through contact heat transfer but also transfers energy to the surrounding space through radiation. To effectively combine these two heating methods, this invention uses materials with high magnetic permeability and good thermal conductivity (such as cast iron), ensuring high efficiency of electromagnetic induction heating while effectively storing and releasing heat. Furthermore, the shape and layout of the heat storage body 1 also need to be optimized so that thermal radiation can uniformly cover the object to be heated. Good insulation measures reduce unnecessary heat loss, allowing more heat to be used for direct heating of the target medium or for effective heat transfer via radiation.

[0043] In one specific embodiment, the control circuit of the intelligent control system 3The circuit includes a rectifier circuit 32, a choke coil 33, a resonant capacitor 34, and an IGBT chip 31. The input of the rectifier circuit 32 is connected to an AC power source, and the output is connected to the choke coil 33. The choke coil 33 is connected in sequence to the resonant capacitor 34 and the IGBT chip 31. The IGBT chip 31 is electrically connected to the heating unit 2 and can receive signals from the regulating unit 4 to adjust the output power to the heating unit 2. The AC power is converted into DC power by the rectifier circuit 32, which is typically composed of a diode bridge. This rectifier circuit converts AC power supplied by the mains into DC power, providing a stable operating voltage for subsequent circuits. The DC power output from the rectifier circuit 32 passes through the choke coil 33. The choke coil 33 filters the current, smoothing fluctuations and limiting the rate of change of current, thus also helping to prevent electromagnetic interference. After the choke coil 33, the resonant capacitor 34 is added to the circuit. The resonant capacitor 34 and the choke coil 33 together form an LC resonant circuit, which can generate a resonant effect at a specific frequency, thereby improving the efficiency of electromagnetic heating. The specific value of the resonant capacitor needs to be selected based on the actual application requirements to achieve the best resonance effect. The intelligent control system is a mature technology used to realize the intelligent management and control of the heat storage device. Sensors, such as temperature sensors, monitor the temperature inside the heat storage body in real time. The controller (usually a microprocessor or PLC) receives this data and generates corresponding control signals according to a preset control algorithm. The control circuit includes components such as a rectifier circuit, choke coil, resonant capacitor, and IGBT chip, responsible for converting the control signals from the controller into actual power output and adjusting the operating state of the heating unit. Actuators, such as IGBT chips, adjust the power output of the heating unit according to the instructions of the control circuit.

[0044] During operation, the processed DC power is fed into the IGBT chip 31. An IGBT, or Insulated Gate Bipolar Transistor, is a power semiconductor device capable of rapid switching, enabling precise control of heating power. The IGBT's operating state (on or off) is controlled by pulse signals from the control circuit 3, thereby adjusting the power supplied to the load (such as the heating element). The regulating unit 5 performs fine-tuning of the electromagnetic heating power, typically operating during off-peak hours at night. The IGBT chip is directly connected to the regulating unit. As the core control element of the control circuit 3, the IGBT receives control signals (usually PWM signals) from the regulating unit 4 to achieve fine-tuning of the heating power. In other words, the regulating unit 4 indirectly controls the power output of the heating system by changing the duty cycle of the signal sent to the IGBT. The entire control circuit 3 is designed following the sequence from power input to final power output, with all components closely interconnected to jointly complete the power regulation task during the electromagnetic heating process.

[0045] To achieve controllable temperature of the heat storage body 1, a temperature sensor 14 is installed inside the heat storage body 1. The temperature sensor 14 is connected to the regulating unit 4. The temperature sensor 14 detects the internal temperature of the heat storage body 1 and transmits the temperature signal to the regulating unit 4, which then adjusts the output power of the control circuit 3 accordingly to achieve closed-loop temperature control. The regulating unit 4 determines how to adjust the heating power based on the temperature signal provided by the temperature sensor 14. Specifically, the temperature sensor 14 is installed inside the heat storage body 1 to monitor the temperature of the heat storage body 1 in real time and convert the temperature data into electrical signals. These signals are transmitted to the regulating unit 4, where a built-in control algorithm (such as a PID controller) processes and analyzes this data. The control algorithm is a known prior art and is not within the scope of protection of this utility model, therefore it will not be described in detail. The regulating unit 4 calculates the required heating power adjustment based on the difference between the current temperature and the preset target temperature.

[0046] The regulating unit 4 generates corresponding control signals (e.g., PWM signals) and sends these signals to the control circuit 3. The IGBT chip or other switching devices in the control circuit 3 adjust the power output of the heating unit 2 according to the received control signals. If an increase in heating power is required, the regulating unit 4 sends a PWM signal with a higher duty cycle; if a decrease in heating power is required, a PWM signal with a lower duty cycle is sent. Therefore, the entire process involves the temperature sensor 14 detecting the temperature and transmitting the signal to the regulating unit 4. The regulating unit 4 calculates the required heating power adjustment based on the temperature signal and generates control signals to send to the control circuit 3. The control circuit 3 then adjusts the power output of the heating unit 2 according to these signals, thereby achieving precise control of the temperature of the heat storage body 1. In this way, the regulating unit 4 is responsible for decision-making and generating control commands, while the control circuit 3 is responsible for executing these commands to ensure accurate adjustment of the heating power.

[0047] The energy storage systems known to the inventors often fall short of the requirements of modern power systems for fast response and high-precision frequency control in terms of rotational inertia and primary frequency regulation capability.

[0048] Rotational inertia is fundamental to the stable operation of a power system, buffering instantaneous power fluctuations and preventing drastic frequency changes. With the decreasing proportion of traditional synchronous generators, the total system inertia declines, posing a threat to the frequency stability and dynamic performance of the power system. Primary frequency regulation is a crucial mechanism for automatically adjusting frequency deviations in a power system. It requires energy storage systems to respond rapidly to frequency changes, promptly adjusting output power to maintain the system frequency within permissible limits.

[0049] Therefore, developing novel energy storage technologies, especially energy storage systems capable of providing rotational inertia and primary frequency regulation capabilities in large-scale, long-term energy storage, has become a pressing issue for the power industry. Based on this, the second objective of this invention is to propose an energy storage system tailored to the needs of power systems, designed to improve rotational inertia and primary frequency regulation capabilities. When grid frequency fluctuates, the regulating unit 4 in this invention can quickly detect these changes and adjust the power output of the heating unit 2 through the control circuit 3. For example, when the frequency decreases, the heating power can be reduced, thereby releasing more electrical energy to supply the grid; conversely, when the frequency increases, the heating power can be increased to absorb excess electrical energy, thus improving rotational inertia and primary frequency regulation capabilities. The thermal storage system includes pipelines and the thermal storage device described above. Multiple parallel cavities 111 are formed on the thermal storage body. The pipeline enters from the first cavity 111 at one end of the thermal storage body 1, passes through multiple cavities 111 sequentially, and exits from the last cavity 111 at the other end of the thermal storage body 1. The pipeline's entry end is connected to a water tank via an inlet pipe and a circulating pump, while its exit end is connected to a steam turbine 5. The steam turbine 5 is connected to the water tank via a return pipe. The steam turbine 5 is connected to the user 6 via a power transmission line. During off-peak hours at night, AC power is used to heat the thermal storage body 1, converting electrical energy into thermal energy and storing it. During peak hours during the day, liquid can be introduced into the pipeline. As the liquid flows through the thermal storage body, it is heated into high-temperature steam. The steam is then transported to the steam turbine 5 to generate electricity, which is then transmitted to the user 6, thus utilizing the energy stored in the thermal storage body 1.

[0050] In order to ensure that the heat storage body 1 can fully contact the pipeline, improve the heating efficiency of the medium in the pipeline, and adjust the heating degree of the medium in the pipeline as needed, the pipeline in this embodiment includes a first bypass 135 and a second bypass 136. The second bypass 136 passes through multiple cavities 111 in sequence. A first regulating valve 131 and a second regulating valve 132 are sequentially provided near the first cavity 111 of the second bypass 136. The first bypass 135 is located outside the heat storage body 1, and one end of the first bypass 135 is connected to the second bypass 136 located between the first regulating valve 131 and the second regulating valve 132. The other end of the first bypass 135 is connected to the second bypass 136 near the last cavity 111 through a first bypass valve 133. By controlling the opening of the first regulating valve 131, the steam flow rate is controlled. The circulating pump delivers the liquid to the second bypass 136 through the water inlet pipe. The first regulating valve 131 and the second regulating valve 132 are opened, and other valves are closed, so that the liquid flows completely through the second bypass 136 before being output to the steam turbine. The liquid in the pipeline can fully contact the heat storage body and absorb heat.

[0051] When a higher steam temperature is not required, the steam flow is controlled by closing the second regulating valve 132 and opening the first regulating valve 131 and the first bypass valve 133. This allows the liquid in the pipeline to be heated through the first cavity 111 of the heat storage body 1, then enter the first bypass 135 outside the heat storage body 1, and finally pass through the last cavity 111 of the heat storage body 1 before directly entering the steam turbine 5. This achieves precise temperature control. Specifically, at a high temperature of 700℃, by opening the first bypass valve 133 and closing the second regulating valve 132, the steam is guided to bypass the heat storage body 1, preventing overheating. When the temperature drops to 500℃, by closing the first bypass valve 133 and opening the first regulating valve 131 and the second regulating valve 132, the steam flows through the main body of the heat storage body 1, maximizing heat absorption.

[0052] To achieve further temperature control, a preferred embodiment includes an intermediate pipeline located outside the heat storage body 1. The intermediate pipeline 1 is equipped with a second bypass valve 134. One end of the intermediate pipeline is connected to a second bypass 136 located between the first regulating valve 131 and the second regulating valve 132, and the other end is connected to a second bypass 136 located at any of the cavity diameters 111 between the first and last cavity diameters 111. By opening the first regulating valve 131 and the second bypass valve 134, and closing the second regulating valve 132 and the first bypass valve 133, the liquid in the pipeline flows through the second bypass 136 in the cavity diameter 111 of the first half of the heat storage body 1 and is heated. Then, it enters the second bypass 136 in the cavity diameter 111 of the second half of the heat storage body 1 through the intermediate pipeline, bypassing the second bypass 136 in the middle cavity diameter 111 of the heat storage body 1, thus partially heating the liquid and regulating the steam temperature.

[0053] Based on the above solution, this utility model also provides a heat storage system control method, including the following steps: temperature sensor 14 detects the temperature of the heat storage body and transmits the signal to the regulating unit 4; when the temperature inside the heat storage body 1 is lower than a preset temperature threshold, the regulating unit 4 increases the heating power through the control circuit to increase the heat storage capacity of the heat storage body 1; when the temperature inside the heat storage body 1 is detected to be higher than the preset temperature threshold, the regulating unit 4 decreases the heating power through the control circuit 3 to reduce the heat storage capacity of the heat storage body 1; when the temperature inside the heat storage body 1 is detected to reach a predetermined temperature value, the regulating unit 4 controls the heating unit 2 to stop working through the control circuit 3.

[0054] Specifically, a desuperheater 22 is also provided between the second bypass 136 and the turbine 5. The structure of the desuperheater 22 is known technology and will not be described in detail. When the operating temperature of the heat storage body 1 reaches 700℃, in order to prevent the outlet steam from overheating due to the excessively high temperature of the heat storage body 1, the first bypass valve 133 is opened and the second regulating valve 131 is closed, so that the steam is introduced into the first bypass 135, avoiding the intervention of the desuperheater 22. In this way, while maintaining the steam outlet temperature at the design threshold, the excessive transfer of heat from the heat storage body 1 to the steam is effectively prevented, ensuring the safe and stable operation of the system.

[0055] When the operating temperature of the heat storage body 1 drops to 500℃, in order to ensure that the outlet steam can still reach the preset superheated state, the first bypass valve 133 is closed and the first regulating valve 131 is opened, so that the steam flows through the main body of the heat storage body 1 to absorb the heat of the heat storage body to the maximum extent. At the same time, within this temperature range, the steam flow rate is finely controlled by opening the desuperheater 22 to achieve effective control of the outlet steam temperature and ensure that it meets the design requirements.

[0056] When the operating temperature of the heat storage body 1 is between 500℃ and 700℃, the research focuses on achieving precise control of the outlet steam parameters of the heat storage body 1. In specific operation, by precisely coordinating the opening of the first bypass valve 133, the second bypass valve 134, and the first regulating valve 131, and by timely activating the desuperheater 22 to spray water, the saturated steam flowing into the heat storage body 1 is diverted and its heat absorption is precisely controlled, thereby achieving stable control of the outlet steam temperature of the heat storage body 1 and ensuring that it always meets the design standards.

[0057] To effectively control the superheated steam temperature, enhance the ability of turbine 5 to participate in primary frequency regulation, and ensure the safety of turbine 5, two sets of hybrid desuperheaters 22 are installed, located at the front end of the steam outlet and the front end of turbine 5 respectively. These desuperheaters directly inject low-temperature feedwater into the superheated steam flow, reducing its excessively high temperature. This provides double protection for the stable operation of turbine 5.

[0058] The heat storage body is composed of multiple cast iron bodies arranged sequentially. Figure 6 The figure shows the 5-hour average temperature distribution curve of a single cast iron body 1 of the heat storage body 1. The large number of cast iron bodies 11, with multiple bodies distributed adjacent to each other, causes the temperature decrease region to gradually reach equilibrium under the influence of the temperature increase region, eventually resulting in a near-uniform temperature distribution across all cast iron bodies 11. After being heated by coil 21, the temperature of a single cast iron body 11 gradually decreases from the initial time of 0h, 1h, 2h, 3h, 4h, and 5h, decreasing from 700℃ to 419℃ after 5h. The rate of temperature decrease gradually slows down, with temperature drops of 102.57℃, 64.5℃, 47.52℃, 36.83℃, and 29.48℃ per hour, respectively. Figure 6 The figure shows the average temperature distribution curve of a single cast iron body over 5 hours.

[0059] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A heat storage device, characterized in that: include: The heat storage body is covered with an insulation layer on the outside; A heating unit is disposed within the heat storage body and can heat the heat storage body when powered on; The control circuit has one end connected to the power supply and the other end connected to the heating unit; An adjustment unit, connected to the control circuit, can send signals to the control circuit and adjust the heating power of the heating unit. The heat storage body is a block-shaped cast iron body, with multiple cast iron bodies arranged sequentially. One end of each cast iron body has a heating hole, and the heating unit is disposed within the cast iron body. The control circuit includes a rectifier circuit, a choke coil, a resonant capacitor, and an IGBT chip. The input terminal of the rectifier circuit is connected to an AC power supply, and the output terminal is connected to the choke coil. The choke coil is sequentially connected to the resonant capacitor and the IGBT chip. The IGBT chip is electrically connected to the heating unit, and the IGBT chip can receive signals from the adjustment unit and adjust the output power of the heating unit. Through electrothermal conversion technology coupled with electromagnetic induction and high-temperature radiation, and using the control circuit with the IGBT chip as the core, the heating and temperature control of the cast iron body are realized.

2. The heat storage device according to claim 1, characterized in that: The heating unit is a coil, which is fixedly installed inside the heating hole and connected to the control circuit.

3. The heat storage device according to claim 1, characterized in that: It also includes a temperature sensor, which is disposed in the heat storage body and connected to the regulating unit.

4. A heat storage system, characterized in that: The device includes pipelines and a heat storage device as described in any one of claims 1 to 3; the heat storage body has multiple parallel cavities, the pipeline enters from the first cavity at one end of the heat storage body, passes through multiple cavities in sequence, and exits from the last cavity at the other end of the heat storage body, the pipeline's entry end is connected to a water tank via an inlet pipe and a circulating pump, and the pipeline's exit end is connected to a steam turbine, the steam turbine is connected to the water tank via a return pipe; the steam turbine is connected to the user end via a power transmission line.

5. The heat storage system according to claim 4, characterized in that: The pipeline includes a first bypass and a second bypass. The second bypass passes through multiple cavity diameters in sequence. A first regulating valve and a second regulating valve are sequentially provided near the first cavity diameter of the second bypass. The first bypass is located outside the heat storage body, and one end of the first bypass is connected to the second bypass located between the first regulating valve and the second regulating valve. The other end of the first bypass is connected to the second bypass near the last cavity diameter through a first bypass valve.

6. The heat storage system according to claim 5, characterized in that: It also includes an intermediate pipeline located outside the heat storage body, and the intermediate pipeline is provided with a second bypass valve. One end of the intermediate pipeline is connected to a second bypass located between the first regulating valve and the second regulating valve, and the other end is connected to a second bypass located at any cavity diameter between the first cavity diameter and the last cavity diameter.

7. The heat storage system according to claim 5, characterized in that: A desuperheater is installed near the turbine in the pipeline.

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