A new energy storage device and waste heat recovery system

Abstract

The application provides a novel energy storage device and a waste heat recovery system. The energy storage device comprises a main body, the main body comprises a steel structure frame, the inside of the steel structure frame is surrounded by a refractory material structure to enclose a main body inner cavity, the main body inner cavity is filled with a composite steel slag energy storage material, a porous support frame is arranged at the bottom of the composite steel slag energy storage material, a flue gas outlet and a flue gas inlet are respectively arranged at the upper part and the lower part of the main body, and an ash outlet is arranged at the bottom of the main body. The application can break through the bottleneck of the prior art, realize efficient recovery, large-scale storage and stable flue gas temperature of high-temperature flue gas waste heat in the steel industry, and promote the resource utilization of steel slag solid waste.

Description

Technical Field

[0001] This application relates to the field of industrial solid waste resource utilization and waste heat recovery and energy storage technology, specifically to a new type of energy storage device and waste heat recovery system. Background Technology

[0002] The steel industry is a typical high-energy-consuming and high-emission industry, and the large amount of high-temperature flue gas generated during its production process contains abundant high-quality waste heat resources. Effectively recovering and utilizing this waste heat is of great significance for energy conservation, emission reduction, and lowering production costs.

[0003] Currently, the recovery of waste heat from high-temperature flue gas in the steel industry mainly relies on indirect heat exchange technology. These technologies have the following shortcomings: flue gas temperature varies intermittently, lacks large-scale energy storage capacity, and makes it difficult to achieve peak utilization of waste heat; commonly used energy storage materials are expensive; heat exchangers are easily clogged by dust in the flue gas, affecting heat exchange efficiency and increasing maintenance costs. At the same time, indirect heat exchange suffers from heat transfer temperature difference loss. Utility Model Content

[0004] To address at least one of the aforementioned problems, this application provides a novel energy storage device and waste heat recovery system that combines large-scale energy storage capacity, good economic efficiency (able to utilize solid waste), and efficient and stable heat exchange (avoiding blockage and reducing heat transfer temperature difference).

[0005] In a first aspect, this application provides a novel energy storage device, comprising a main body, the main body including a steel structure frame, the inner side of which is surrounded by a refractory material structure, the inner cavity of the main body being filled with a composite steel slag energy storage material, the bottom of which is provided with a porous support frame, the upper and lower parts of the main body having a flue gas outlet and a flue gas inlet respectively, and the bottom of the main body having an ash outlet.

[0006] As an optional embodiment, the main body also includes a chassis, the porous support frame is disposed above the chassis, and the chassis has a flue gas inlet and an ash outlet.

[0007] As an optional embodiment, the flue gas inlet is a cylindrical opening located in the middle of the chassis, and the cylindrical opening is vertically oriented.

[0008] As an optional embodiment, the ash outlets are arranged in multiple ways along the flue gas inlet and are inclined.

[0009] As an optional embodiment, a dust removal trolley for receiving fallen ash is provided below the ash outlet.

[0010] As an optional embodiment, the outer side of the steel structure frame is covered with thermal insulation cotton.

[0011] As an optional embodiment, the inner cavity of the main body is provided with a temperature sensor for detecting temperature.

[0012] A second aspect of this application provides a waste heat recovery system, including a novel energy storage device of this application, wherein the energy storage device is embedded in the waste heat recovery system through a pipeline system.

[0013] As an optional embodiment, the pipeline system includes a main pipeline, a bypass, and regulating valves. The bypass is connected to the air inlet section of the main pipeline, the air inlet section of the bypass is connected to the flue gas inlet, and the flue gas outlet section is connected to the outlet section of the main pipeline via the outlet section of the bypass. Multiple regulating valves are installed on the main pipeline and the bypass.

[0014] As an optional embodiment, a fan is installed at the air inlet end of the main pipeline; thermocouples and flow meters are installed on the main pipeline and the bypass.

[0015] This application proposes a novel energy storage device and waste heat recovery system based on steel slag as an energy storage medium and employing direct contact heat exchange. This system can overcome the bottlenecks of existing technologies, achieve efficient recovery, large-scale storage, and stable flue gas temperature of waste heat from high-temperature flue gas in the steel industry, and promote the resource utilization of steel slag solid waste. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the novel energy storage device provided in the embodiments of this application;

[0018] Figure 2 This is a schematic diagram of the waste heat recovery system provided in an embodiment of this application.

[0019] In the diagram: 1. Flue gas outlet; 2. Flue gas inlet; 3. Steel structure frame; 4. Thermal insulation cotton; 5. Refractory material structure; 6. Composite steel slag energy storage material; 7. Porous support frame; 8. Ash outlet; 9. Ash cleaning trolley; 10. Temperature sensor; 11. Fan; 12. Thermocouple and flow meter; 13. Regulating valve. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0022] This application provides a novel energy storage device, see [link to relevant documentation] Figure 1 The system includes a main body, which includes a steel structure frame 3. The inner side of the steel structure frame 3 is built with a refractory material structure 5 to surround the inner cavity of the main body. The inner cavity of the main body is filled with composite steel slag energy storage material 6. A porous support frame 7 is provided at the bottom of the composite steel slag energy storage material 6. A flue gas outlet 1 and a flue gas inlet 2 are respectively opened at the upper and lower parts of the main body. An ash outlet 8 is opened at the bottom of the main body.

[0023] The steel frame 3 constitutes the main support structure of the entire device, ensuring its stability. The refractory material structure 5 is built inside the steel frame 3, directly bearing high temperatures and enhancing the device's durability and service life in high-temperature environments. The composite steel slag energy storage material 6 is filled within the space enclosed by the refractory material structure 5. As the core energy storage medium, the composite steel slag energy storage material 6 is mainly composed of steel slag and some inorganic materials. Its main component, steel slag, comes from solid waste in the steel industry, resulting in low usage costs. The porous support frame 7 is located at the bottom of the composite steel slag energy storage material 6, serving a dual function: firstly, supporting the steel slag layer above it; and secondly, allowing the high-temperature flue gas entering the device to penetrate the steel slag layer evenly upwards, avoiding local blockages and reduced heat exchange efficiency caused by uneven airflow distribution.

[0024] The flue gas inlet 2 is located at the lower part or side of the device to introduce high-temperature flue gas; the flue gas outlet 1 is located at the upper part or side of the device to discharge the cooled flue gas, thereby ensuring that the high-temperature flue gas flows from bottom to top through the porous support frame 7 and the composite steel slag energy storage material 6 within the device.

[0025] In one embodiment of this application, the main body further includes a chassis, the porous support frame 7 is disposed above the chassis, and the chassis has a flue gas inlet 2 and an ash outlet 8.

[0026] In one embodiment of this application, the flue gas inlet 2 is a cylindrical opening located in the middle of the chassis, and the cylindrical opening is vertically oriented.

[0027] In one embodiment of this application, multiple ash outlets 8 are arranged along the flue gas inlet 2 and are inclined. The ash outlets 8 are located at the lowest point of the bottom of the device to facilitate the collection and discharge of settled dust.

[0028] In one embodiment of this application, a dust removal trolley 9 is provided below the ash outlet 8 to receive the falling ash. The dust removal trolley 9 is sealed to the ash outlet 8 and is used to collect and remove the dust that settles from the flue gas periodically or continuously.

[0029] In one embodiment of this application, the outer side of the steel structure frame 3 is covered with thermal insulation cotton 4. By tightly wrapping the steel structure frame 3 with the thermal insulation cotton 4, an effective heat insulation layer is formed, which significantly enhances the heat preservation and reduces heat loss during the operation of the device.

[0030] In one embodiment of this application, a temperature sensor 10 for detecting temperature is provided in the inner cavity of the main body. The temperature sensor 10 is installed on the side wall of the device, typically through an opening in the refractory material structure, with its probe pointing towards the composite steel slag energy storage material 6, for real-time monitoring of temperature changes in the steel slag.

[0031] This application provides a waste heat recovery system, including a novel energy storage device provided in this application. See also... Figure 2 The energy storage device is embedded in the waste heat recovery system through a pipeline system.

[0032] In one embodiment of this application, see Figure 2 The pipeline system includes a main pipeline, a bypass, and regulating valves 13. The bypass connects to the inlet section of the main pipeline, and the inlet section of the bypass connects to the flue gas inlet 2. The outlet section of the flue gas outlet 1 connects to the outlet section of the main pipeline via the outlet section of the bypass. Multiple regulating valves 13 are installed on the main pipeline and the bypass. The regulating valves 13 are installed at key pipeline nodes and control the flue gas flow rate based on temperature and flow signals, thereby controlling the charging / discharging mode of the steel slag energy storage device. The regulating valves 13 can be manually controlled or electrically controlled; their opening control principle is a common technique in this field and will not be elaborated further.

[0033] In one embodiment of this application, a fan 11 is installed at the air inlet of the main pipeline; thermocouples and flow meters 12 are installed on the main pipeline and the bypass. The fan 11 is located at the front end of the system, providing airflow power to drive the high-temperature flue gas into the steel slag energy storage device. The thermocouples and flow meters 12 integrate temperature and flow monitoring functions, are installed at key nodes of the flue gas pipeline, and provide real-time feedback of flue gas status parameters.

[0034] In the above embodiment, the fan 1 drives the flow of high-temperature flue gas; the intelligent regulating valve 13 controls the flue gas flow rate according to the control requirements, so that the flue gas enters the steel slag energy storage device for heat storage (cooling of high-temperature flue gas) or heat release (heating of low-temperature flue gas); the flue gas after heat exchange is output after being monitored by the temperature and flow meter 12, so as to realize the dynamic control of flue gas temperature.

[0035] The working process and principle of the steel slag energy storage device and waste heat recovery system mainly include: ① flue gas introduction and direct heat exchange; ② dynamic energy storage and regulation; ③ heat release and heat output; ④ flue gas emission and waste heat utilization; ⑤ ash and slag co-treatment.

[0036] Specifically, ① flue gas introduction and direct heat exchange refers to the high-temperature flue gas generated by the steel plant entering the bottom of the device from the flue gas inlet 2, being evenly distributed by the porous support frame 7, and then penetrating upwards through the composite steel slag energy storage material 6. During this process, the high-temperature flue gas and the steel slag particles undergo direct and sufficient contact heat exchange, the sensible heat in the flue gas is absorbed and stored by the steel slag, and the flue gas temperature decreases accordingly.

[0037] Specifically, the second step, dynamic energy storage control, refers to the temperature sensor 10 continuously monitoring the temperature of the composite steel slag energy storage material 6 and feeding the signal back to the relevant control module. Based on the target energy storage temperature or downstream demand, the heating rate of the steel slag and the final energy storage temperature can be controlled by adjusting the flue gas flow rate entering the device, thereby achieving dynamic control of the energy storage intensity.

[0038] Specifically, ③ heat release and heat energy output refers to closing the high-temperature flue gas passage and introducing low-temperature flue gas or air from the flue gas inlet 2 when heat energy needs to be released. This low-temperature flue gas or air is evenly distributed through the porous support frame 7 and then penetrates upwards through the composite steel slag energy storage material 6, where it is rapidly heated through direct contact with the high-temperature steel slag. The heated high-temperature flue gas or air is then output from the flue gas outlet 1 for user use. The temperature sensor 10 monitors the steel slag temperature in real time and precisely controls the output temperature and heat release power by adjusting the input flow rate until the steel slag temperature drops to the usable lower limit.

[0039] The fourth point, flue gas emission and waste heat utilization, refers to the discharge of flue gas from flue gas outlet 1 after its temperature decreases following heat exchange with steel slag. This cooled flue gas may still contain usable low-temperature waste heat, which can be connected to a downstream waste heat recovery system (such as preheated air or boiler feedwater) for further utilization.

[0040] The fifth step, co-treatment of ash and slag, refers to the effective filtration, interception, and settling of dust particles contained in the high-temperature flue gas as it penetrates the steel slag layer. The settled dust is discharged periodically or continuously through the ash outlet 8 at the bottom and collected and treated by the connected dust removal equipment 9. This process achieves preliminary purification of the flue gas while recovering waste heat.

[0041] The steel slag energy storage device provided in this application is suitable for intermittent high-temperature flue gas waste heat recovery systems in the steel industry. It achieves heat storage through direct contact heat exchange between the composite steel slag energy storage material and the intermittent high-temperature flue gas. During operation, high-temperature flue gas enters the device through the flue gas inlet 2, penetrates the composite steel slag energy storage material 6, and directly contacts it for heat exchange, storing the heat in the steel slag energy storage material 6. A porous support frame 7 is located at the bottom of the composite steel slag energy storage material 6 to support the steel slag layer and evenly guide airflow. A temperature sensor 10 monitors the internal temperature of the device in real time. The cooled flue gas is finally discharged through the flue gas outlet 1. An ash outlet 8 is provided at the bottom of the energy storage device, connected to a dust removal trolley 9 to collect settled dust. This application utilizes the composite steel slag energy storage material 6, whose main component is steel slag, as the energy storage medium, achieving efficient recovery and storage of high-temperature flue gas waste heat, and also has a simultaneous dust removal effect. It is suitable for large-scale waste heat recovery, stabilizing high-temperature flue gas temperature, and peak-shaving energy supply in the steel industry.

[0042] This application provides a novel energy storage device and waste heat recovery system based on steel slag as the energy storage medium and employing direct contact heat exchange. This system overcomes the bottlenecks of existing technologies, enabling efficient recovery, large-scale storage, and stable flue gas temperature control of high-temperature flue gas in the steel industry, while simultaneously promoting the resource utilization of steel slag solid waste. It can achieve:

[0043] 1. Solid waste resource utilization and low-cost energy storage: Innovatively utilize steel slag, a solid waste from the steel industry, to replace traditional expensive sensible heat energy storage materials (such as ceramics, molten salt, etc.), thereby achieving low cost of energy storage media and promoting the resource utilization of steel slag.

[0044] 2. High-efficiency direct contact heat exchange: This method abandons traditional indirect heat exchangers and adopts direct contact heat exchange between flue gas and a steel slag particle bed. This eliminates the thermal resistance and temperature difference losses associated with indirect heat transfer, theoretically achieving the minimum temperature difference between the flue gas and the energy storage medium, thus greatly improving heat exchange efficiency. Simultaneously, the steel slag bed offers relatively low resistance to flue gas flow, and its porous structure makes it less prone to severe blockage compared to tubular heat exchangers.

[0045] 3. Uniform airflow distribution and self-filtration: The coupled design of the porous support frame 7 at the bottom and the composite steel slag energy storage material 6 ensures both stable support for the steel slag layer and uniform distribution of high-temperature flue gas upon entering the energy storage layer, preventing localized airflow short-circuiting or blockage. The steel slag bed itself has excellent filtration and adsorption properties for dust in the flue gas.

[0046] 4. Integrated Energy Storage and Dust Removal: While efficiently recovering and storing the waste heat of high-temperature flue gas, this device utilizes the physical filtration effect of the steel slag bed to simultaneously remove most of the dust in the flue gas, achieving synergy between the two functions of "energy storage" and "dust removal" and simplifying the system process.

[0047] 5. Two-way operation and easy switching: The same unit can switch between two operating modes—heat storage (high-temperature flue gas) and heat release (low-temperature air)—by means of valve switching. Heat release is achieved using the existing gas channels and steel slag bed structure, eliminating the need for a separate heat exchanger, significantly reducing system complexity and investment costs.

[0048] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A novel energy storage device, characterized in that, The main body includes a steel frame (3), the inner side of which is built with a refractory material structure (5) to surround the inner cavity of the main body, the inner cavity of the main body is filled with composite steel slag energy storage material (6), the bottom of the composite steel slag energy storage material (6) is provided with a porous support frame (7), the upper and lower parts of the main body are respectively provided with a flue gas outlet (1) and a flue gas inlet (2), and the bottom of the main body is provided with an ash outlet (8).

2. The novel energy storage device as described in claim 1, characterized in that, The main body also includes a chassis, and the porous support frame (7) is disposed above the chassis. A flue gas inlet (2) and an ash outlet (8) are provided on the chassis.

3. The novel energy storage device as described in claim 2, characterized in that, The flue gas inlet (2) is a cylindrical opening located in the middle of the chassis, and the cylindrical opening is vertically positioned.

4. The novel energy storage device as described in claim 3, characterized in that, The ash outlets (8) are arranged in multiple ways along the flue gas inlet (2), and are inclined.

5. A novel energy storage device as described in claim 2, characterized in that, A dust removal trolley (9) is provided below the ash outlet (8) to receive the falling ash.

6. The novel energy storage device as described in claim 1, characterized in that, The steel frame (3) is covered with thermal insulation cotton (4) on the outside.

7. A novel energy storage device as described in claim 1, characterized in that, The main body cavity is equipped with a temperature sensor (10) for detecting temperature.

8. A waste heat recovery system, characterized in that, The invention includes a novel energy storage device as described in any one of claims 1-7, wherein the energy storage device is embedded in a waste heat recovery system via a pipeline system.

9. A waste heat recovery system as described in claim 8, characterized in that, The pipeline system includes a main pipeline, a bypass, and regulating valves (13). The bypass is connected to the air inlet section of the main pipeline, and the air inlet section of the bypass is connected to the flue gas inlet (2). The flue gas outlet (1) is connected to the air outlet section of the main pipeline via the air outlet section of the bypass. Multiple regulating valves (13) are installed on the main pipeline and the bypass.

10. A waste heat recovery system as described in claim 9, characterized in that, A fan (11) is installed at the air inlet end of the main pipeline; thermocouples and flow meters (12) are installed on the main pipeline and the bypass.

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