Carbon-based solid waste combustion system and method

Abstract

The invention provides a carbon-based solid waste combustion system and method, and belongs to the technical field of carbon-based solid waste dehydration and decarburization, and the carbon-based solid waste combustion system comprises a pretreatment system, a carbon-based solid waste combustion device and a waste heat recycling system. Wherein the pretreatment system is suitable for drying, dehydrating and pre-activating high-water-content fire-retardant solid waste to obtain low-water-content activated solid waste; the carbon-based solid waste combustion device comprises a hearth and an outer circulation loop connected with the hearth, and the outer circulation loop is provided with a gas-solid separator upper return feeder, a preheating activator and a lower return feeder which are sequentially connected. The waste heat recycling system comprises a waste heat recycling device connected with an exhaust port used for exhausting high-temperature flue gas in the carbon-based solid waste combustion device and a flue gas pipeline connected with the pretreatment system, and the waste heat recycling system is suitable for conveying medium-temperature flue gas generated by the high-temperature flue gas through the waste heat recycling device.

Description

Technical Field

[0001] This invention belongs to the field of carbon-based solid waste dewatering and decarbonization technology, and particularly relates to a carbon-based solid waste combustion system and method. Background Technology

[0002] Entrained fluidized bed gasification is a crucial step in the efficient conversion of coal. However, the gasification reaction in entrained fluidized beds generates a large amount of gasification slag with high moisture content (30% or higher) and low volatile matter, and this amount is increasing year by year with the development of coal chemical industry. Due to its high moisture content and low volatile matter, the gasification slag has a low calorific value, is difficult to ignite and burn completely, has a fine particle size, and a large amount of carbon is encapsulated in a glassy structure. Currently, it is commonly disposed of through landfill, leading to significant environmental pollution and waste of land resources. Furthermore, traditional circulating fluidized bed reactors and pulverized coal boilers are unable to achieve stable combustion and complete decarbonization of the gasification slag. Therefore, there is an urgent need to provide new gasification equipment to handle this slag. Summary of the Invention

[0003] In view of this, the present invention provides a carbon-based solid waste combustion system and method to at least partially solve the above-mentioned technical problems. The technical solution provided by the present invention is as follows.

[0004] In one aspect, the present invention provides a carbon-based solid waste combustion system, comprising: a pretreatment system, a carbon-based solid waste combustion device, and a waste heat recovery and utilization system.

[0005] The pretreatment system is suitable for drying, dehydrating, and pre-activating high-moisture, non-flammable solid waste to obtain low-moisture activated solid waste.

[0006] The carbon-based solid waste combustion device includes a combustion furnace and an external circulation loop connected to the combustion furnace. The external circulation loop is equipped with a first gas-solid separator, an upper return feeder, a preheating activator, and a lower return feeder connected in sequence. The preheating activator is equipped with an upper return feeder inlet connected to the upper return feeder, a solid waste inlet for low-moisture activated solid waste, an activator inlet for activating gasification agent, and a solid waste outlet for flammable solid waste formed by the heating, gasification, and activation reaction of low-moisture activated solid waste and activating gasification agent. In the dense phase zone or transition zone at the bottom of the combustion furnace, there is a solid material inlet connected to the lower return feeder for flammable solid waste, a primary air inlet for combustion air, and a slag discharge port for bottom ash discharge.

[0007] The waste heat recovery system includes: a waste heat recovery device connected to the exhaust port of the carbon-based solid waste combustion device for discharging high-temperature flue gas, and a flue gas pipeline connected to the pretreatment system, suitable for conveying medium-temperature flue gas generated by the waste heat recovery device from high-temperature flue gas.

[0008] Another aspect of the present invention provides a carbon-based solid waste combustion method using the aforementioned carbon-based solid waste combustion system. The method includes: drying, dehydrating, and pre-activating high-moisture-content, difficult-to-burn solid waste using a pretreatment system to obtain low-moisture-content activated solid waste; the low-moisture-content activated solid waste entering a preheating activator where it is heated by circulating material from an upper return feeder and reacts with an activating gasifying agent introduced into the preheating activator to convert it into flammable solid waste; the flammable solid waste being returned to the combustion furnace via a lower return feeder to react with combustion air introduced into the combustion furnace to produce bottom ash and high-temperature flue gas; and utilizing a waste heat recovery device in a waste heat recovery system to recover the high-temperature flue gas, and introducing the medium-temperature flue gas generated by the waste heat recovery device into the pretreatment system via a flue gas pipeline for drying and activation.

[0009] Based on the above technical solution, the carbon-based solid waste combustion system and method provided by the present invention have at least one of the following beneficial effects:

[0010] (1) In the embodiments of the present invention, in order to solve the problems of difficult combustion and sufficient decarbonization of high water content and difficult-to-burn carbon-based solid waste such as gasification slag, the present invention provides a stable combustion device and combustion method for high water content and difficult-to-burn solid waste. A carbon-based solid waste combustion system suitable for high water content and difficult-to-burn solid waste is designed. The high water content and difficult-to-burn solid waste is dried and pre-activated by a pretreatment system to obtain low water content activated solid waste. The low water content activated solid waste obtained by the pretreatment system is transported to the preheating activator of the carbon-based solid waste combustion device and is fully mixed with the circulating material returned by the upper return feeder and preheated. The small amount of water brought in by the low water content activated solid waste and / or the activating gasification agent introduced into the preheating activator undergo a partial water vaporization activation reaction under the high temperature of the preheating activator to form a partial combustible gas. At the same time, the internal stress formed by the water vaporization reaction breaks and activates the glass body that encapsulates the carbon, converting the low water content activated solid waste into low water content flammable solid waste. After being preheated and activated by a preheater, the low-moisture flammable solid waste reaches a temperature of 600-900℃, which is the ignition temperature. After being returned to the combustion furnace by the return feeder, it can quickly undergo a combustion reaction. The combustible substances in the solid waste are burned and decarbonized through combustion, generating decarbonized bottom ash and high-temperature flue gas.

[0011] (2) In the embodiments of the present invention, in view of the contradiction that high-moisture-content refractory solid waste has low calorific value and high moisture content, but requires high temperature (above 850°C) to burn completely, the present invention adopts a strategy of temperature matching and energy cascade utilization. Specifically, the high-grade heat generated by the combustion of flammable solid waste in the combustion furnace (i.e., high-temperature flue gas, with a temperature above 850-1000°C) is used for high-grade utilization and to maintain the heat required for high-temperature combustion of flammable solid waste, so as to ensure the stability of its combustion. The high-temperature flue gas is recovered through the waste heat recovery device. At the same time, the low-grade heat (such as medium-temperature flue gas) generated by the waste heat recovery device is transported to the pretreatment system through the flue gas pipeline for dehydration and activation, so as to reduce the moisture content of high-moisture-content refractory solid waste to 10% or below and increase the calorific value of refractory solid waste. Attached Figure Description

[0012] Figure 1 This is a process flow diagram of stable combustion of high-moisture-content, flame-retardant solid waste according to the present invention;

[0013] Figure 2 This is a schematic diagram of the drying system structure of the present invention;

[0014] Figure 3 This is a schematic diagram of the carbon-based solid waste combustion device in this invention;

[0015] Figure 4 This is a schematic diagram of the preheating activator of the present invention;

[0016] Figure 5 This is a schematic diagram of the structure of the drying system of the present invention, which is a fluidized bed dryer;

[0017] Figure 6 This is a schematic diagram of another fluidized bed dryer according to the present invention;

[0018] Figure 7 This is a schematic diagram of the process coupling between the pressure filter device and the drying system in this invention;

[0019] Figure 8 This is a schematic diagram of the structure of the U-shaped reaction coupling return device of the present invention.

[0020] [Attached image labels]

[0021] 0-Filter press device;

[0022] 1-Drying system;

[0023] 11-Hopper, 12-Screw Conveying Unit, 13-Flue Gas Outlet, 14-Rotary Kiln Shell, 15-Rotary Kiln Insulation Layer, 16-Rotary Kiln Guide Internal Components, 17-Flue Gas Inlet, 18-Screw Discharge Unit, 1-1 Dryer Furnace, 1-2 Second Gas-Solid Separator, 1-3-Air Inlet, 1-4 Solid Material Distributor, 1-5-Second Gas-Solid Outlet, 1-6-Second Gas-Solid Inlet, 1-7-Second Exhaust Port, 1-8-Second Solid Discharge Port, 1-9-Waiting Section;

[0024] 2-Activation system;

[0025] 3-Carbon-based solid waste combustion device;

[0026] 3-1 Combustion furnace, 3-2 First gas-solid separator, 3-3 Upper return feeder, 3-4 Preheating activator, 3-5 Lower return feeder, 3-11 Primary air inlet, 3-12 Slag discharge port, 3-13 Secondary air inlet, 3-14 First gas-solid outlet, 3-15 Solid material inlet, 3-21 First gas-solid inlet, 3-22 First exhaust port, 3-23 First solid discharge port, 3- 31-Upper feeder inlet, 3-32-Upper feeder outlet, 3-33-Ash discharge port, 3-41-Upper feeder inlet, 3-42-Solid waste inlet, 3-43-Solid waste outlet, 3-44-Activator inlet, 3-45-Gasification gas outlet, 3-51-Lower feeder inlet, 3-52-Lower feeder outlet, 3-6-Descending section, 3-7-Rising section, 3-8-Feeder section, 3-9-Horizontal section;

[0027] 4- Waste heat recovery device;

[0028] A1-Combustion air, A2-Secondary air, A3-Activating gasification agent, SW-High moisture content refractory solid waste, C1-Low moisture content refractory solid waste, C2-Low moisture content activated solid waste, F-Bottom ash, F1-Fly ash, g1-High temperature flue gas, g2-Medium temperature flue gas, g3-Low temperature flue gas, g4-Residual heat flue gas. Detailed Implementation

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0030] Considering that the gasification slag produced by current fluidized bed gasification has high water content (generally greater than 30%, as high as 50%-60%, or even higher), low volatile matter, fine particle size, and a large amount of carbon encapsulated in glass, it is difficult to ignite, has high ignition temperature, long burnout time, short residence time in the combustion furnace, and incomplete combustion when directly burned. This makes it difficult for traditional circulating fluidized bed and pulverized coal boilers to achieve stable combustion and complete decarbonization.

[0031] In order to address the problems of difficult combustion and complete decarbonization of high-moisture-content, difficult-to-burn solid wastes such as gasification slag, this invention provides a stable combustion method and combustion device for high-moisture-content, difficult-to-burn solid wastes, namely, the present invention "Carbon-based Solid Waste Combustion System and Method".

[0032] Specifically, the carbon-based solid waste combustion system of the present invention includes: a pretreatment system, a carbon-based solid waste combustion device, and a waste heat recovery and utilization system.

[0033] The pretreatment system is suitable for drying, dehydrating, and pre-activating high-moisture, non-flammable solid waste to obtain low-moisture activated solid waste.

[0034] A carbon-based solid waste combustion device is suitable for producing low-moisture activated solid waste and high-temperature flue gas formed by the heating and gasification activation reaction of low-moisture activated solid waste and an activating gasifying agent. The carbon-based solid waste combustion device of this invention includes a combustion furnace and an external circulation loop connected to the combustion furnace. The external circulation loop is equipped with a first gas-solid separator, an upper return feeder, a preheating activator, and a lower return feeder connected in sequence. The preheating activator includes: an upper return feed inlet connected to the upper return feeder; a solid waste inlet for the low-moisture activated solid waste; an activating agent inlet for the activating gasifying agent; and a solid waste outlet for the flammable solid waste formed by the heating and gasification activation reaction of the low-moisture activated solid waste and the activating gasifying agent. In the dense phase zone or transition zone at the bottom of the combustion furnace, there is a solid material inlet connected to the lower return feeder for the flammable solid waste, a primary air inlet for the combustion air, and a ash discharge port for the bottom ash.

[0035] The waste heat recovery and utilization system includes a waste heat recovery device and a flue gas pipeline connected to the pretreatment system. It is suitable for transporting high-temperature flue gas to the waste heat recovery device for recovery and transporting the generated medium-temperature flue gas to the pretreatment system for drying, dehydration and pre-activation through the flue gas pipeline. This achieves high-quality utilization of high-temperature flue gas, ensuring the heat and combustion stability required for the combustion of easily combustible solid waste, while using the low-grade heat from the generated medium-temperature flue gas for drying, dehydration and pre-activation, thus achieving energy cascade utilization and temperature matching utilization.

[0036] The composition and function of the carbon-based solid waste combustion system of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] Figure 1This is a process flow diagram of the stable combustion of high-moisture, flame-retardant solid waste according to the present invention.

[0038] like Figure 1 As shown, the carbon-based solid waste combustion system of the present invention includes a pretreatment system, a carbon-based solid waste combustion device 3, and a waste heat recovery and utilization system connected in sequence. The pretreatment system includes a drying system 1 and an activation system 2. The drying system 1 is located upstream of the activation system 2, and the activation system 2 is connected to the carbon-based solid waste combustion device 3. The waste heat recovery and utilization system is provided with a waste heat recovery device 4 connected to the exhaust port of the carbon-based solid waste combustion device 3 for discharging high-temperature flue gas g1, and a flue gas duct connected to the pretreatment system.

[0039] The activation system 2, located upstream of the carbon-based solid waste combustion device 3, is suitable for heating, dehydrating, and pre-activating the low-moisture, difficult-to-burn solid waste C1 from the drying system 1 using medium-temperature flue gas g2, to obtain low-moisture activated solid waste C2 and low-temperature flue gas g3.

[0040] Drying system 1, located upstream of activation system 2, is suitable for drying and dehydrating high-moisture-content, flame-retardant solid waste SW using low-temperature flue gas g3 to obtain low-moisture-content, flame-retardant solid waste C1 and waste heat flue gas g4; wherein the moisture content of high-moisture-content, flame-retardant solid waste SW, low-moisture-content, flame-retardant solid waste C1, and low-moisture-content activated solid waste C2 decreases in that order.

[0041] In an embodiment of the present invention, high-moisture-content, flame-retardant solid waste SW is dried by a drying system 1 and then pre-activated in an activation system 2. It then enters a carbon-based solid waste combustion device 3 for combustion, generating completely decarbonized bottom ash F and high-temperature flue gas g1. The generated high-temperature flue gas g1 first undergoes waste heat recovery through a waste heat recovery device 4, simultaneously lowering its temperature to generate medium-temperature flue gas g2. The medium-temperature flue gas g2 enters the activation system 2 via a flue gas pipe, providing the necessary energy for drying, dehydration, and pre-activation, while simultaneously lowering its own temperature to form low-temperature flue gas g3. The low-temperature flue gas g3 exits from the outlet of the activation system 2 and enters the drying system 1 via a flue gas pipe, providing heat for the drying and dehydration of the high-moisture-content, flame-retardant solid waste SW. The heat-exchanged flue gas exits from the drying system 1 to form waste heat flue gas g4. Through the aforementioned process flow, the present invention reduces the moisture content of high-moisture-content, flame-retardant solid waste SW (30%-60% or even higher) to 15-25% through the drying system 1, forming low-moisture-content, flame-retardant solid waste C1. Then, in activation system 2, the moisture content of the low-moisture, difficult-to-burn solid waste C1 is further reduced to below 10% using medium-temperature flue gas g2. Simultaneously, the internal structure of activation system 2 is used to pre-activate it, forming low-moisture activated solid waste C2, with its temperature rising to 100-300℃. Finally, the low-moisture activated solid waste C2 is transported to the preheating activator 3-4 of the carbon-based solid waste combustion device 3 for heating and gasification activation. This process breaks down and activates the glassy structure containing carbon in the low-moisture activated solid waste C2, forming flammable solid waste. After preheating and activation in the preheating activator 3-4, the temperature of the flammable solid waste reaches 600-900℃, reaching the ignition temperature. It then returns to the combustion furnace of the carbon-based solid waste combustion device 3 for rapid combustion. Through combustion, the combustible substances in the flammable solid waste are decarbonized, generating decarbonized bottom ash F and high-temperature flue gas g1. The high-temperature flue gas g1, typically at 850-1000℃, exits the carbon-based solid waste combustion device 3 and enters the waste heat recovery device 4 for recovery. This process reduces the temperature of the high-temperature flue gas g1 to 400-750℃, forming medium-temperature flue gas g2. The medium-temperature flue gas g2 then enters the activation system 2 and is cooled to 200-300℃, forming low-temperature flue gas g3, which is then discharged. This discharged low-temperature flue gas g3 serves as a heat source and enters the drying system 1 for drying. After cooling to 100℃, it forms waste heat flue gas g4, which is discharged from the drying system 1 and then enters the downstream purification system for further purification. Thus, addressing the contradiction of high-moisture-content, difficult-to-burn solid waste having low calorific value and high moisture content, yet requiring high temperatures for complete combustion, this invention employs a temperature-matching, energy-cascade utilization strategy to achieve stable combustion and decarbonization of high-moisture-content, difficult-to-burn solid waste.

[0042] Figure 2 This is a schematic diagram of the drying system structure of the present invention.

[0043] like Figure 2As shown, the drying system 1 is a rotary kiln dryer, including: a hopper 11, a screw conveyor unit 12, a rotary kiln cylinder 14, a rotary kiln insulation layer 15, a rotary kiln guide internal component 16, a screw discharge unit 18, a flue gas inlet 17 for low-temperature flue gas g3 to enter at the top of the inlet flue, and a flue gas outlet 13 for waste heat flue gas g4 to be discharged at the top of the outlet flue. In detail, the rotary kiln dryer includes, from the outside to the inside: a rotary kiln cylinder 14, a rotary kiln insulation layer 15, and a rotary kiln guide inner component 16; wherein, the kiln head of the rotary kiln is connected to the outlet of the screw conveyor unit 12 and is embedded in the outlet flue. The inlet of the screw conveyor unit 12 is provided with a hopper 11 for high moisture content and refractory solid waste SW to enter. The kiln tail of the rotary kiln is embedded in the inlet flue and connected to the screw discharge unit 18, so that the high moisture content and refractory solid waste SW moves from the kiln head to the kiln tail and comes into countercurrent contact with the low temperature flue gas g3 entering through the flue gas inlet 17 to dry and dehydrate, thereby obtaining low moisture content and refractory solid waste C1. The residual heat flue gas g4 formed after cooling is discharged from the rotary kiln dryer through the flue gas outlet 13. In the rotary kiln dryer of this invention, high-moisture-content, flame-retardant solid waste SW moves from the kiln head to the kiln tail within the rotary kiln guide inner component 16. Through direct counter-current contact with low-temperature flue gas g3, and under the push of the rotary kiln guide inner component 16, it continuously tumbles, forming spheres of varying sizes (ranging from 1mm to 50mm). Simultaneously, it removes dust from the counter-current contacting low-temperature flue gas g3, reducing the amount of dust carried away from the rotary kiln dryer. After drying and dehydration in the rotary kiln dryer, the moisture content of low-moisture-content, flame-retardant solid waste C1 drops to 15-25%. When the moisture content drops below 15%, dust is generated from the low-moisture-content, flame-retardant solid waste C1, causing some carbonaceous solid waste to be carried away from the system by the waste heat flue gas g4.

[0044] The activation system 2 used in this invention is an indirect heating device, which includes an outer cavity for the passage of medium-temperature flue gas g2 and an inner cavity for the passage of low-moisture-content, flame-retardant solid waste C1. The outer cavity is equipped with a guiding structure and heat-conducting internal components, while the inner cavity is equipped with mechanical impact internal components and lifting plates. The medium-temperature flue gas g2 conducts heat to the low-moisture-content, flame-retardant solid waste C1 within the inner cavity through the wall of the indirect heating device and the heat-conducting internal components. The mechanical impact internal components within the inner cavity physically break the glassy structure of the low-moisture-content, flame-retardant solid waste C1, exposing the carbon encased within the glass and achieving initial activation of the low-moisture-content, flame-retardant solid waste C1. The lifting plates break the spheres formed by the low-moisture-content, flame-retardant solid waste C1 within the aforementioned rotary kiln dryer, ensuring thorough mixing and heat transfer within the cavity. Through activation system 2, the moisture content of the low-moisture, non-combustible solid waste C1 is further reduced to ≤10%, and its temperature is 100-300℃. Simultaneously, most of the carbon encased in the glass body is exposed, which is beneficial for combustion, forming low-moisture activated solid waste C2. Furthermore, the indirect heating device of this invention also plays a certain role in dust reduction for the medium-temperature flue gas g2. Utilizing the space and guiding structure of the outer cavity of the indirect heating device, gas-solid separation of the medium-temperature flue gas g2 is achieved through inertia and gravity, effectively reducing the amount of dust carried into the drying system 1 by the low-temperature flue gas g3.

[0045] Figure 3 This is a schematic diagram of the carbon-based solid waste combustion device of the present invention. Figure 4 This is a schematic diagram of the preheating activator of the present invention.

[0046] like Figure 3 As shown, the carbon-based solid waste combustion device 3 of the present invention includes: a combustion furnace 3-1 and an external circulation loop connected to the combustion furnace 3-1. The external circulation loop is provided with a first gas-solid separator 3-2, an upper return feeder 3-3, a preheating activator 3-4 and a lower return feeder 3-5 connected in sequence. The combustion furnace 3-1 includes a dense phase zone and a dilute phase zone located above the dense phase zone.

[0047] like Figure 4As shown, the preheating activator 3-4 of the present invention is a fluidized bed composed of a frustoconical section with a smaller lower part and a larger upper part and an enlarged upper part. It is provided with: an upper return material inlet 3-41 connected to the upper return material device 3-3; a solid waste inlet 3-42 located above the upper return material inlet 3-41 for low-moisture activated solid waste C2 to enter; an activator inlet 3-44 located at the bottom for activating gasification agent A3 to enter; a solid waste outlet 3-43 located below the upper return material inlet 3-41 for flammable solid waste formed by the heating and gasification activation reaction of low-moisture activated solid waste C2 and activating gasification agent A3 to be discharged; and a gasification gas outlet 3-45 located at the top of the preheating activator 3-4 for the gasification gas formed by the gasification activation reaction to be discharged. The activating gasifying agent A3 is fed into the preheating activator 3-4 through the activating agent inlet 3-44 at the bottom, with an apparent velocity of 1.5-4 m / s. This allows the circulating material returned from the upper return feeder 3-3 to be fully fluidized, mixed, and heated with the low-moisture activated solid waste C2 from activation system 2 at the bottom of the preheating activator 3-4. A small amount of water carried in by the low-moisture activated solid waste C2 itself, or water vapor from the activating gasifying agent A3, undergoes a partial water vaporization reaction under the high temperature (850℃~950℃) of the preheating activator 3-4, forming partially vaporized gas (i.e., combustible gas). Simultaneously, the internal stress generated by the activation gasification reaction of the water vapor breaks and activates the glassy shell in the low-moisture activated solid waste C2, activating the carbon in the low-moisture activated solid waste C2 into low-moisture, easily combustible solid waste (referred to as "flammable solid waste"). The carbon conversion rate of the low-moisture activated solid waste C2 reaches 0.5%-10%. The combustible gas formed by the gasification reaction is discharged from the preheating activator 3-4 through the gasification gas outlet 3-45. Furthermore, the apparent velocity of the upper enlarged section of the preheating activator 3-4 is 0.5-1.5 m / s, which is relatively low, reducing or preventing flammable solid waste from escaping from the top gasification gas outlet 3-45 of the preheating activator 3-4 due to the entrainment effect of the gasification gas. After preheating and activation in the preheating activator 3-4, the low-moisture combustible solid waste C2 reaches a temperature of 600-900℃, reaching the ignition temperature. After being returned to the combustion furnace 3-1 via the return feeder 3-5, it can be rapidly combusted. The activating gasification agent A3 used in this invention is air or air with a water vapor content ≤15%.

[0048] The combustion furnace 3-1 includes a dense phase zone and a dilute phase zone located above the dense phase zone. The dense phase zone consists of a frustum-shaped section that is smaller at the bottom and larger at the top, while the dilute phase zone consists of a cylindrical section. The location and area of ​​the water-cooled walls in the combustion furnace 3-1 are determined based on the calorific value of the flammable solid waste generated by the preheating activator 3-4. The dense phase zone or transition zone at the bottom of the combustion furnace 3-1 is equipped with: a solid material inlet 3-15 connected to the lower return feeder 3-5 for flammable solid waste to enter; a primary air inlet 3-11 at the bottom for combustion air A1 to enter; and a ash discharge port 3-12 for bottom ash F to be discharged. This allows the flammable solid waste returned from the lower return feeder 3-5 to react with the combustion air A1 entering from the primary air inlet 3-11 at the bottom of the combustion furnace 3-1. The bottom ash F after the reaction is completed is discharged through the ash discharge port 3-12. The primary air inlet 3-11 consists of an air chamber, an air distribution plate, and an air cap. The combustion air A1 can be hot air preheated to 100-300℃ by a waste heat recovery system, or it can be room temperature air. The apparent wind speed in the dense phase zone at the bottom of the combustion furnace 3-1 is 1.5-5 m / s to ensure that the combustion air A1 and the flammable solid waste are fully fluidized and undergo a gasification reaction. The solid material inlet 3-15 of the present invention is 1.3-2.8m away from the air distribution plate, located in the transition zone between the dense phase zone and the dilute phase zone of the combustion furnace 3-1, or located in the dilute phase zone.

[0049] Furthermore, a secondary air inlet 3-13 is provided above the solid material inlet 3-15 for secondary air A2 to enter. This secondary air inlet 3-13 is located in the transition zone between the dense phase and dilute phase zones of the combustion furnace 3-1, suitable for unreacted flammable solid waste to continue combustion with secondary air A2, releasing heat. The secondary air in this invention is air. Further still, in some embodiments, a gasification gas outlet 3-45 arranged at the top of the preheating activator is connected to the dilute phase zone of the combustion furnace 3-1. The connection point with the combustion furnace 3-1 is located at the same level as secondary air A2 or <1m above it, so that the gasified gas generated by the activation gasification reaction in the preheating activator 3-4 is input into the combustion furnace 3-1 for use as secondary air A2.

[0050] The upper dilute phase zone of the combustion furnace 3-1 is equipped with a first gas-solid outlet 3-14 for discharging gas-solid materials, which include unreacted flammable solid waste, high-temperature flue gas g1, fly ash F1, and bed material generated by the gasification reaction of flammable solid waste and combustion air A1. The apparent operating velocity of the upper dilute phase zone of the combustion furnace 3-1 is 2.0-5 m / s, similar to the apparent operating velocity of the lower dense phase zone, to maintain stable fluidization of the materials in the combustion furnace 3-1 and maintain a longer residence time, allowing the carbonaceous solid waste to burn as completely as possible in the combustion furnace 3-1. Furthermore, the unreacted flammable solid waste, fly ash F1, and bed material are carried out from the first gas-solid outlet 3-14 at the top of the combustion furnace 3-1 under the entrainment of the high-temperature flue gas g1 and enter the first gas-solid separator 3-2.

[0051] The first gas-solid separator 3-2 is suitable for gas-solid separation of gas and solid materials, separating high-temperature flue gas g1 and unreacted flammable solid waste and bed material. It is equipped with a first gas-solid inlet 3-21 connected to a first gas-solid outlet 3-14, a first exhaust port 3-22 for the high-temperature flue gas g1 carrying a portion of fly ash F1 to be discharged, and a first solid discharge port 3-23 for the unreacted flammable solid waste and bed material as circulating material carrying a portion of fly ash F1 to be discharged. The first gas-solid separator 3-2 used in this invention can be a cyclone separator. Further, the cyclone separator can be a volute-type cyclone separator or an inlet tangential-type cyclone separator, and can also be a high-efficiency cyclone separator with a separation efficiency ≥99%.

[0052] The upper return feeder 3-3 is equipped with an upper return feeder inlet 3-31 connected to the first solid discharge port 3-23, an upper return feeder outlet 3-32 for discharging the circulated material, and an ash discharge port 3-33 for discharging a portion of the fly ash F1. The upper return feeder 3-3 of this invention can be a U-shaped return feeder. During gas-solid separation in the first gas-solid separator 3-2, a portion of the fly ash F1 is carried into the upper return feeder 3-3 by the circulating material and can be returned to the combustion furnace 3-1 via the preheating activator 3-4 and the lower return feeder 3-5. If a large amount of fly ash F1 returns, it will increase the fly ash concentration in the combustion furnace 3-1 and the heat transfer coefficient between the fly ash and the heating surface of the combustion furnace 3-1, leading to a decrease in temperature within the combustion furnace 3-1. This, in turn, affects the combustion efficiency of flammable solid waste in the combustion furnace 3-1 and reduces decarbonization efficiency. To address this, the present invention includes an ash discharge port 3-33 in the descending section of the upper return feeder 3-3 to discharge fly ash F1 from the first gas-solid separator 3-2. The ash discharge from the upper return feeder 3-3 accounts for 10%-50% of the total ash and slag. The upper return feeder 3-3 is connected to the upper return inlet 3-41 of the preheating activator 3-4 via the upper return feeder outlet 3-32, conveying the circulating material from the upper return feeder 3-3 to the preheating activator 3-4. There, the material mixes with the low-moisture activated solid waste C2 entering the preheating activator 3-4 via the solid waste inlet 3-42 and undergoes a heating and gasification activation reaction. The flammable solid waste and circulating material formed after preheating and activation are discharged together through the solid waste outlet 3-43 of the preheating activator 3-4 and enter the lower return feeder 3-5.

[0053] The return feeder 3-5 is equipped with a return feeder inlet 3-51 connected to the solid waste outlet 3-43 and a return feeder outlet 3-52 for discharging flammable solid waste and recycled materials. The return feeder outlet 3-52 is connected to the solid material inlet 3-15 of the combustion furnace 3-1 to return flammable solid waste and recycled materials into the combustion furnace 3-1. Since the low-moisture activated solid waste C2 has been preheated to above the ignition temperature, it begins to burn as soon as it enters the combustion furnace 3-1. Under the high heat capacity and turbulence of the dense phase zone, it burns violently, releasing heat and maintaining the temperature and height of the dense phase zone in the lower part of the combustion furnace 3-1.

[0054] As Figure 2 Alternatives to the drying system 1 shown, the drying system 1 of the present invention can also be a fluidized bed dryer, with the specific structure as follows: Figure 5 As shown.

[0055] Figure 5 This is a schematic diagram of the structure of the drying system of the present invention, which is a fluidized bed dryer.

[0056] like Figure 5 As shown, the fluidized bed dryer of the present invention includes a hopper 11, a screw conveyor unit 12, a dryer furnace 1-1, and a second gas-solid separator 1-2 connected in sequence.

[0057] The dryer furnace 1-1 includes a lower dense phase zone and an upper dilute phase zone. The dense phase zone consists of a frustum-shaped section that is smaller at the bottom and larger at the top, while the dilute phase zone consists of a cylindrical section. Alternatively, the dryer furnace 1-1 can be designed as sections of equal diameter at the top and bottom. The hopper 11 and the screw conveyor unit 12 are located in the dilute phase zone. The bottom of the dense phase zone is provided with an air inlet 1-3 for the low-temperature flue gas g3 to enter and a solid material distributor 1-4 for dispersing the high-moisture-content, flame-retardant solid waste SW. At the top of the dilute phase zone is a second gas-solid outlet 1-5 for the fluidization of the low-temperature flue gas g3 and the heat exchange between the high-moisture-content, flame-retardant solid waste SW to discharge the low-moisture-content, flame-retardant solid waste C1, the waste heat flue gas g4, and the water vapor.

[0058] The second gas-solid separator 1-2 is suitable for gas-solid separation of waste heat flue gas g4, water vapor and low water content refractory solid waste C1. It is equipped with a second gas-solid inlet 1-6 connected to the second gas-solid outlet 1-5, a second exhaust port 1-7 for waste heat flue gas g4 to be discharged with water vapor, and a second solid discharge port 1-8 for low water content refractory solid waste C1 to be discharged.

[0059] In the fluidized bed dryer of this invention, high-moisture-content, flame-retardant solid waste SW is conveyed via hopper 11 and screw conveyor unit 12 to the lower part of the dryer furnace 1-1 of the drying system 1. Under the stirring, dispersing and agitation of the bottom solid material distributor 1-4, it comes into direct contact with the low-temperature flue gas g3 entering through the bottom air inlet 1-3 and is heated. This facilitates the contact and heat transfer between the low-temperature flue gas g3 and the high-moisture-content, flame-retardant solid waste SW, forming low-moisture-content, flame-retardant solid waste C1, waste heat flue gas g4, and water vapor. The low-moisture-content, flame-retardant solid waste C1, formed by dispersion and drying dehydration, leaves from the second gas-solid outlet 1-5 at the top of the dryer furnace 1-1 under the entrainment of waste heat flue gas g4 and water vapor, and then enters the second gas-solid separator 1-2 for gas-solid separation. Most of the low-moisture, flame-retardant solid waste C1 is captured by the second gas-solid separator 1-2 and discharged through the second solid discharge port 1-8; a small amount of low-moisture, flame-retardant solid waste C1 is discharged from the second exhaust port 1-7 of the second gas-solid separator 1-2 under the entrainment of waste heat flue gas g4 and water vapor. The apparent wind speed of the fluidized bed dryer of the present invention is 10-30 m / s, preferably 10-18 m / s.

[0060] As Figure 5 An alternative to the fluidized bed dryer shown is to design the structure of the dryer furnace 1-1, for example, by adding a waiting section at the bottom of the dryer furnace 1-1, as shown in the specific structure. Figure 6 As shown.

[0061] Figure 6 This is a schematic diagram of another fluidized bed dryer according to the present invention.

[0062] like Figure 6 As shown, this fluidized bed dryer has the same characteristics as... Figure 5 The fluidized bed dryer shown has the same structure, but differs in that: the low-temperature flue gas g3 is introduced from the bottom of the dryer furnace 1-1, and a waiting section 1-9 is set in the dense phase zone. The hopper 11 and the screw conveyor unit 12 are both located above the waiting section 1-9. This waiting section 1-9 accelerates the low-temperature flue gas g3, fluidizing, agitating, dispersing, and dispersing the high-moisture-content, non-combustible solid waste SW conveyed to the lower part of the dryer furnace 1-1. Furthermore, the apparent velocity of the waiting section 1-9 is 15-40 m / s, preferably 20-30 m / s; if the velocity is too low, the agitation, dispersing, and dispersion effects cannot be achieved.

[0063] Furthermore, in addition to the drying system 1 and activation system 2 described above, the pretreatment system of the present invention also includes a filter press 0, which is located upstream of the drying system 1 and is suitable for reducing the moisture content of the high-moisture, non-combustible solid waste SW entering the drying system 1. The filter press 0 can be a mechanical filter press.

[0064] Figure 7 This is a schematic diagram of the process coupling between the pressure filter device and the drying system in this invention.

[0065] like Figure 7 As shown, the filter press device 0 can be coupled with the aforementioned fluidized bed dryer. First, a mechanical filter press is used to filter the high-moisture-content, flame-retardant solid waste SW, reducing its moisture content from 50-60% to 30-40%. Then, the filtered high-moisture-content, flame-retardant solid waste SW is conveyed to the lower part of the dryer furnace 1-1 via hopper 11 and screw conveyor unit 12. Low-temperature flue gas g3 entering through air inlet 1-3 is used as the drying heat source, and the filtered high-moisture-content, flame-retardant solid waste SW is dried through direct contact, further reducing its moisture content to 10% or less, to obtain low-moisture-content, flame-retardant solid waste C1 at a temperature of 100-300℃. The low-moisture, non-combustible solid waste C1 formed during drying leaves the dryer furnace 1-1 under the entrainment of preheated flue gas g4 and water vapor. After gas-solid separation by the second gas-solid separator 1-2, the low-moisture, non-combustible solid waste C1 is captured, while the waste heat flue gas g4 and water vapor are separated.

[0066] As an alternative to the indirect heating device, the activation system 2 of the present invention can also employ a fluidized bed or circulating fluidized bed gasification mode to heat, dry, dehydrate, and preheat activate the low-moisture-content, flame-retardant solid waste C1. Utilizing the higher heat transfer and reaction rates of the fluidized bed or circulating fluidized bed, rapid heating, thermal stress breaking, and carbon activation of the low-moisture-content, flame-retardant solid waste C1 are achieved. The temperature of the low-moisture-content, flame-retardant solid waste C1 is raised to 650-900℃, preferably 800-900℃, to obtain low-moisture-content activated solid waste C2. The heat for the activation process comes from the heat generated by carbon combustion or gasification. Simultaneously, 0.5%-10% of the carbon is gasified into low-calorific-value fuel gas, allowing the low-moisture-content activated solid waste C2 entering the preheating activator 3-4 to be further activated and then rapidly combusted after returning to the combustion furnace 3-1. Furthermore, the activation system 2 adopts a fluidized bed or a circulating fluidized bed, which can introduce the flammable solid waste formed by the preheating and activation of the preheating activator 3-4 into the transition zone between the dense phase zone and the dilute phase zone of the combustion furnace 3-1, or into the dilute phase zone, and the position of the material entering the combustion furnace 3-1 is 0-2.5m above the solid material inlet 3-15.

[0067] In some embodiments of the present invention, the upper return feeder 3-3, the preheating activator 3-4, and the lower return feeder 3-5 are coupled together to form a U-shaped reaction coupling return device with return capability, as shown in the specific structure. Figure 8 As shown.

[0068] Figure 8 This is a schematic diagram of the structure of the U-shaped reaction coupling return device of the present invention.

[0069] like Figure 8As shown, the U-shaped reaction coupling return material device sequentially includes a descending section 3-6, a horizontal section 3-9, an ascending section 3-7, and a return material section 3-8, forming an integrated U-shaped structure. The inlet end of the descending section 3-6 is connected to the first solid discharge port 3-23 of the first gas-solid separator 3-2. The bottom of the descending section 3-6 is provided with an ash discharge port 3-33, which is used to reduce the circulation rate of fly ash F1. Its ash discharge volume accounts for 10%-50% of the total ash and slag volume, and is adjusted according to the particle size distribution of the low-moisture activated solid waste C2 entering the U-shaped reaction coupling return material device. The solid waste inlet 3-42, which supplies the low-moisture activated solid waste C2, is located 0.5-2.0m above the top of the horizontal section 3-9 in the rising section 3-7. The outlet of the return section 3-8 is connected to the solid material inlet 3-15. The height of the rising section 3-7 is designed based on a residence time of 0.2-2s for the low-moisture activated solid waste C2, ensuring that the low-moisture activated solid waste C2 and the circulating material entering the U-shaped reaction coupling return device can be mixed evenly and rapidly heated. This achieves preheating, thermal stress breaking, and carbon activation effects on the low-moisture activated solid waste C2, resulting in a carbon conversion rate of 0.5%-10% and a temperature of 650-900℃. The cross-sectional areas of the rising section 3-7 and the descending section 3-6 in the U-shaped reaction coupling return device can be the same, or the cross-sectional area of ​​the rising section 3-7 can be larger than that of the descending section 3-6. For example, the cross-sectional area of ​​the rising section 3-7 can be 1.0-1.58 times that of the descending section 3-6. The apparent wind velocity in the descending section 3-6 is 0.1-0.5 m / s, using air as the fluidizing gas (i.e., the activating gasifying agent). The apparent wind velocity in the ascending section 3-7 is 1.8-4.0 m / s, using air or mixed air with a water vapor content ≤15% as the fluidizing gas (i.e., the activating gasifying agent). The ascending section 3-7 uses a higher air velocity to quickly mix the low-moisture activated solid waste C2 with the circulating material and heat it rapidly. At the same time, the heat generated by combustion and gasification is quickly diffused to avoid local high temperature and slagging. The addition of water vapor and the small amount of water contained in the low-moisture activated solid waste C2 participate in carbon activation, enhancing the activity of the low-moisture activated solid waste C2 and converting it into flammable solid waste. At the same time, it reduces the ignition temperature and burnout time, which is conducive to the rapid and complete combustion of the flammable solid waste after it returns to the combustion furnace 3-1 via the return section 3-8.

[0070] As another aspect of the present invention, a carbon-based solid waste combustion method is provided, employing the carbon-based solid waste combustion system as described in the above embodiments. The carbon-based solid waste combustion method includes: drying, dehydrating, and pre-activating high-moisture-content, difficult-to-burn solid waste SW using a pretreatment system to obtain low-moisture-content activated solid waste C2; ​​the low-moisture-content activated solid waste C2 enters a preheating activator 3-4 and is heated by circulating material from the upper return feeder 3-3, and undergoes a gasification activation reaction with the activating gasification agent A3 introduced into the preheating activator 3-4, converting it into flammable solid waste; the flammable solid waste is returned to the combustion furnace 3-1 via the lower return feeder 3-5, and undergoes a combustion reaction with the combustion air A1 introduced into the combustion furnace 3-1 to produce bottom ash F and high-temperature flue gas g1; and the high-temperature flue gas g1 is recovered using a waste heat recovery device 4 in a waste heat recovery system, and the medium-temperature flue gas g2 generated by the waste heat recovery device 4 is introduced into the pretreatment system via a flue gas pipeline for drying and activation.

[0071] In embodiments of this invention, the principle of temperature matching and energy cascade utilization is adopted to address the problem of unstable combustion of high-moisture-content, difficult-to-burn solid waste SW. The invention proposes first using medium-temperature flue gas g2 to dry and activate the SW, reducing its moisture content and increasing its reactivity and calorific value. Then, a carbon-based solid waste combustion device is used for combustion, achieving stable and complete combustion of the SW. This solves the contradiction that high-moisture-content, difficult-to-burn solid waste has a low calorific value but requires high temperatures for complete combustion. The high-grade heat generated by the carbon-based solid waste combustion device (i.e., high-temperature flue gas g1) is used for high-grade utilization and to maintain the heat required for high-temperature combustion of the solid waste, ensuring combustion stability. Low-grade heat (such as medium-temperature flue gas g2) is used for dehydration and activation, achieving energy cascade utilization and temperature matching. Using medium-temperature flue gas g2 to directly dry the water-containing, difficult-to-burn solid waste avoids the safety risks of fire caused by high flue gas temperature and oxygen content. Furthermore, the use of low-grade heat results in low application cost and high thermal efficiency.

[0072] According to an embodiment of the present invention, the above-mentioned combustion method further includes: unreacted flammable solid waste reacting with secondary air A2 entering the dense phase zone of the combustion furnace 3-1 to form gas-solid material; the gas-solid material undergoes gas-solid separation through a first gas-solid separator 3-2, the separated high-temperature flue gas g1 carrying some fly ash F1 is discharged through a first exhaust port 3-22, and the separated unreacted flammable solid waste and semi-coke are discharged as recycled material carrying some fly ash F1 through a first solid discharge port 3-23; the recycled material, as a heating heat source, enters a preheating activator 3-4 through an upper return feeder 3-3 to preheat the low-moisture activated solid waste C2, and the excess fly ash F1 is discharged through an ash discharge port.

[0073] According to an embodiment of the present invention, the drying, dehydration and pre-activation of high moisture content refractory solid waste using a pretreatment system includes: heating, dehydrating and pre-activating low moisture content refractory solid waste C1 from drying system 1 using medium-temperature flue gas g2 to obtain low moisture content activated solid waste C2 and low-temperature flue gas g3; and drying, dehydrating high moisture content refractory solid waste SW using low-temperature flue gas g3 to obtain low moisture content refractory solid waste C1 and waste heat flue gas g4.

[0074] In an embodiment of the present invention, for refractory solid waste, the present invention sets up an activation system 2 and a preheating activator 3-4. By combining physical activation and chemical activation, the solid waste before entering the combustion furnace 3-1 is broken up, preheated and carbonized, so that the flammable solid waste entering the combustion furnace 3-1 can achieve rapid combustion and shorten the burnout time, reduce the combustion temperature of refractory solid waste, improve combustion efficiency, and indirectly reduce the original emission concentration of nitrogen oxides from solid waste combustion.

[0075] According to an embodiment of the present invention, before using low-temperature flue gas g3 to dry and dehydrate the high-moisture-content, flame-retardant solid waste SW, the method further includes: using a filter press device 0 to filter and dehydrate the high-moisture-content, flame-retardant solid waste SW, thereby reducing the moisture content of the high-moisture-content, flame-retardant solid waste SW.

[0076] In summary, addressing the contradiction of low calorific value but the requirement for high-temperature combustion in high-moisture, refractory solid waste, this invention employs temperature matching and energy cascade utilization. The high-grade heat generated during combustion (i.e., high-temperature flue gas) is used for high-grade utilization and to maintain the heat required for high-temperature combustion, ensuring combustion stability. Low-grade heat is used for dehydration, achieving cascaded energy utilization and temperature matching. The high-temperature flue gas generated by the carbon-based solid waste combustion device is used to dry the moisture-containing refractory solid waste, reducing its moisture content to ≤10% and increasing its calorific value. Simultaneously, mechanical or reactive methods are used to activate the refractory solid waste, enabling it to ignite and burn rapidly within the furnace of the carbon-containing solid waste combustion device. The carbon-based solid waste combustion device uses a circulating fluidized bed to burn the dried and activated refractory solid waste, ultimately reducing the carbon content of the carbon-containing solid waste to ≤1%.

[0077] The high-moisture, flame-retardant solid waste SW is reduced to 15-25% through drying system 1, forming low-moisture, flame-retardant solid waste C1. Then, the low-moisture, flame-retardant solid waste C1 is further reduced to <10% through activation system 2. Simultaneously, the glassy body encapsulating carbon is opened using mechanical crushing or an activating agent, activating the active sites of the carbon, forming low-moisture, activated solid waste C2, with its temperature rising to 100-300℃. Finally, the low-moisture, activated solid waste C2 is fed into a carbon-based solid waste combustion device, where the combustible substances in the solid waste are burned and decarbonized, generating decarbonized bottom ash F and high-temperature flue gas g1. Part of the high-temperature flue gas g1 provides a heat source for drying system 1 and activation system 2, while another part is used to provide a heat source for drying other materials or to generate various qualities of steam for waste heat recovery.

[0078] The high-temperature flue gas g1, with a temperature of 850℃~1000℃, leaves the carbon-based solid waste combustion device and first passes through a waste heat recovery system to generate steam of various qualities, reducing the temperature of the high-temperature flue gas g1 to 400℃~750℃, forming medium-temperature flue gas g2. This medium-temperature flue gas then passes through activation system 2 and drying system 1 sequentially. Alternatively, the high-temperature flue gas g1 can be divided into two parts: one part is used for waste heat recovery, and the other part is passed through activation system 2 and drying system 1, where the waste heat it carries is utilized in a cascade manner. Finally, it exits drying system 1 as preheated flue gas g4 and enters the downstream purification system.

[0079] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A carbon-based solid waste incineration system, characterized by, The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system.

2. The carbon-based solid waste incineration system of claim 1, wherein, The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system.

3. The carbon-based solid waste incineration system of claim 1, wherein, The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. The application relates to a carbon-based solid waste combustion device and a waste heat recovery system. 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The application relates to a carbon-based solid waste combustion device and a waste The first gas-solid separator (3-2) is provided with a first gas-solid inlet (3-21) connected to the first gas-solid outlet (3-14), a first exhaust port (3-22) for the high-temperature flue gas (g1) to carry out a portion of the fly ash (F1) and a first solid discharge port (3-23) for the unreacted flammable solid waste and the bed material to carry out a portion of the fly ash (F1) as circulating materials. The upper return feeder (3-3) is provided with an upper return feeder inlet (3-31) connected to the first discharge port (3-23), an upper return feeder outlet (3-32) for discharging the circulating material, and an ash discharge port (3-33) for discharging part of the fly ash (F1). The feeder (3-5) is provided with a feeder inlet (3-51) connected to the solid waste outlet (3-43) and a feeder outlet (3-52) for discharging the flammable solid waste and the circulating material. The feeder outlet (3-52) is connected to the solid material inlet (3-15) of the combustion furnace (3-1).

4. The carbon-based solid waste incineration system of claim 2, wherein, The activation system is a fluidized bed, a circulating fluidized bed, or an indirect heating device; The indirect heating device includes: The outer cavity is for the medium-temperature flue gas (g2) to travel through, and the inner cavity is for the low-moisture, non-combustible solid waste (C1) to travel through. The outer cavity is provided with a guide structure and a heat-conducting internal component, and the inner cavity is provided with a mechanical impact internal component and a lifting plate.

5. The carbon-based solid waste incineration system of claim 2, wherein, The drying system (1) is a rotary kiln dryer, which includes, from the outside to the inside: Rotary kiln shell (14), rotary kiln insulation layer (15), and rotary kiln guide internal components (16). The rotary kiln head is connected to the outlet of the screw conveyor unit (12) and embedded in the outlet flue. The screw conveyor unit (12) is provided with a hopper (11) for the high water content refractory solid waste (SW) to enter. The rotary kiln tail is embedded in the inlet flue and connected to the screw discharge unit (18), so that the high water content refractory solid waste (SW) moves from the kiln head to the kiln tail and comes into counter-current contact with the low temperature flue gas (g3) to dry and dehydrate, thereby obtaining the low water content refractory solid waste (C1).

6. The carbon-based solid waste incineration system of claim 2, wherein, The drying system (1) is a fluidized bed dryer, which includes a hopper (11), a screw conveyor unit (12), a dryer furnace (1-1), and a second gas-solid separator (1-2) connected in sequence. The dryer furnace (1-1) includes a lower dense phase zone and an upper dilute phase zone. The hopper (11) and the screw conveyor unit (12) are located in the dilute phase zone. The bottom of the dense phase zone is provided with an air inlet (1-3) for low-temperature flue gas (g3) to enter. The top of the dilute phase zone is provided with a second gas-solid outlet (1-5) for the fluidization of the low-temperature flue gas (g3) and the heat exchange of the high-moisture-content refractory solid waste (SW) to discharge low-moisture-content refractory solid waste (C1), waste heat flue gas (g4) and water vapor. The second gas-solid separator (1-2) is suitable for gas-solid separation of the waste heat flue gas (g4), water vapor and low water content refractory solid waste (C1), and is provided with a second gas-solid inlet (1-6) connected to the second gas-solid outlet (1-5), a second exhaust port (1-7) for the waste heat flue gas (g4) to be discharged with water vapor, and a second solid discharge port (1-8) for the low water content refractory solid waste (C1) to be discharged.

7. The carbon-based solid waste incineration system of claim 6, wherein, When the dense phase zone at the bottom of the dryer furnace (1-1) is a frustum-shaped structure with a smaller bottom and a larger top, or a structure with equal diameter sections at the top and bottom, a solid material distributor (1-4) for dispersing the high-moisture, non-combustible solid waste (SW) is also provided at the bottom of the dense phase zone; or The dense phase zone is equipped with a waiting section (1-9).

8. The carbon-based solid waste incineration system according to any one of claims 1-7, wherein, The pretreatment system further includes a filter press (0), which is located upstream of the drying system (1) and is suitable for reducing the moisture content of the high-moisture, flame-retardant solid waste (SW) entering the drying system (1).

9. The carbon-based solid waste incineration system according to claim 1 or 3, characterized by, The solid waste inlet (3-42) is located above the upper return material inlet (3-41), the solid waste outlet (3-43) is located below the upper return material inlet (3-41), and the activator inlet (3-44) is located at the bottom of the preheating activator (3-4). The top of the preheating activator (3-4) is provided with a gas outlet for discharging the gasified gas formed by the gasification activation reaction.

10. The carbon-based solid waste incineration system according to claim 1 or 3, characterized by, The upper return feeder (3-3), the preheating activator (3-4), and the lower return feeder (3-5) are coupled together to form a U-shaped reaction coupling return feeder device; The U-shaped reaction coupling return device includes a descending section (3-6), a horizontal section (3-9), an ascending section (3-7), and a return section (3-8). The inlet end of the descending section (3-6) is connected to the first solid discharge port (3-23) of the first gas-solid separator (3-2). The bottom of the descending section (3-6) is provided with an ash discharge port (3-33). The solid waste inlet (3-42) for the low-moisture activated solid waste (C2) is located in the ascending section (3-7) at a distance of 0.5-2.0m from the top of the horizontal section (3-9). The outlet end of the return section (3-8) is connected to the solid material inlet (3-15). The cross-sectional area of ​​the rising segment (3-7) is 1.0-1.58 times that of the falling segment (3-6).

11. A carbon-based solid waste combustion method, characterized by, The carbon-based solid waste combustion system as described in any one of claims 1-10, wherein the carbon-based solid waste combustion method comprises: High-moisture-content, flame-retardant solid waste (SW) was dried, dehydrated, and pre-activated using a pretreatment system to obtain low-moisture-content activated solid waste (C2). The low-moisture activated solid waste (C2) enters the preheating activator (3-4) and is heated by the circulating material from the upper return feeder (3-3), and undergoes a gasification activation reaction with the activating gasification agent (A3) introduced into the preheating activator (3-4) to be converted into flammable solid waste. The flammable solid waste is returned to the combustion furnace (3-1) via the bottom return feeder (3-5), where it reacts with the combustion air (A1) introduced into the combustion furnace (3-1) to produce bottom ash (F) and high-temperature flue gas (g1); and The high-temperature flue gas (g1) is recovered using the waste heat recovery device (4) in the waste heat recovery system, and the medium-temperature flue gas (g2) generated by the waste heat recovery device (4) is introduced into the pretreatment system through the flue gas pipeline for drying and activation.

12. The carbon-based solid waste incineration method according to claim 11, characterized in that, Also includes: The unreacted flammable solid waste reacts with the secondary air entering the dense (3-1) phase zone of the combustion furnace to form gas-solid materials; The gas-solid material is separated by the first gas-solid separator (3-2). The separated high-temperature flue gas (g1) carrying some fly ash (F1) is discharged through the first exhaust port (3-22). The separated unreacted flammable solid waste and bed material are used as circulating materials and carried by some fly ash (F1) are discharged through the first solid discharge port (3-23). The recycled material, as a heat source, enters the preheating activator (3-4) via the upper return feeder (3-3) to preheat the low-moisture activated solid waste (C2), and the excess fly ash (F1) is discharged through the ash discharge port (3-33).

13. The carbon-based solid waste incineration method according to claim 12, characterized in that, The pretreatment system for drying, dewatering, and preactivating high-moisture-content, flame-retardant solid waste (SW) includes: The low-moisture, non-flammable solid waste (C1) from the drying system (1) is heated, dehydrated, and pre-activated using the medium-temperature flue gas (g2) to obtain the low-moisture activated solid waste (C2) and low-temperature flue gas; The high-moisture-content, flame-retardant solid waste (SW) is dried and dehydrated using the low-temperature flue gas (g3) to obtain low-moisture-content, flame-retardant solid waste (C2) and waste heat flue gas (g4).

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