Energy-saving structure for waste incinerator

Abstract

The utility model discloses an energy -conserving structure for garbage incinerator, including the water -cooling pipe for heat conduction, be equipped with a plurality of hooks on the water -cooling pipe, the hook can connect the hanging plate to make a plurality of hanging plates form the protective surface on the water -cooling pipe surface, the protective surface surface has been coated with deformation layer and heat -preserving layer in proper order, heat -preserving layer can be in incinerator start -up stage heat preservation, deformation layer adopts the expanded ceramic matrix composite material, to be in incineration stage expansion broken heat -preserving layer of incinerator. To solve the problem that the garbage incinerator of prior art exists and consumes long time and many fuels when starting.

Description

Technical Field

[0001] This utility model relates to the field of waste incineration technology, specifically to an energy-saving structure for a waste incinerator. Background Technology

[0002] In the field of modern waste-to-energy incineration, to optimize energy efficiency, high thermal conductivity bricks are commonly used as the core heat exchange medium between the furnace and water-cooled walls for large mechanical grate incinerators with a processing capacity of up to 500 t / d. Among them, silicon carbide bricks, with their excellent thermal conductivity (typically maintained at 15–20 W / (m·K), can efficiently transfer the heat generated during waste combustion, making them the mainstream choice for heat exchange systems in this type of incinerator.

[0003] Under normal operating conditions, the heat released by the full combustion of waste in the furnace can be quickly conducted to the water-cooled wall behind through the silicon carbide hanging bricks, causing the water in the water-cooled wall to be rapidly heated and converted into water vapor, thereby providing stable power for the power generation system. In this process, the high thermal conductivity of silicon carbide hanging bricks becomes a key technical support for improving boiler thermal efficiency and power generation.

[0004] However, during the crucial start-up stage of the incinerator, the high thermal conductivity of silicon carbide bricks ironically translates into a significant disadvantage that restricts system operation. The start-up process requires gradually heating the furnace from ambient temperature to a stable combustion temperature range of 850–950°C, which is the combustion stage of the waste incinerator. During the start-up stage, because the waste has not yet reached stable combustion conditions, the incinerator relies primarily on auxiliary fuels such as natural gas for continuous heat supply. Due to the extremely high thermal conductivity of silicon carbide bricks, a large amount of heat generated by the combustion of auxiliary fuels is rapidly dissipated by the bricks and directly carried away by the cold water within the water-cooled walls through heat exchange, resulting in severe heat loss.

[0005] This heat loss directly leads to two core problems: First, the furnace heating rate is significantly reduced, and the start-up time is significantly prolonged, typically requiring 4-6 hours of combustion to reach a stable combustion temperature, severely impacting the start-up efficiency and overall operation of the incinerator. Second, auxiliary fuel consumption increases dramatically, accounting for over 70% of the total energy consumption during start-up, significantly increasing operating costs. More importantly, the prolonged low temperature and unstable thermal environment during start-up further affect the ignition stability and combustion completeness of subsequent waste, leading to a decrease in waste incineration rate. This not only reduces waste treatment efficiency but may also generate more harmful pollutants due to incomplete combustion, causing a chain reaction of negative impacts on the overall operational performance and environmental indicators of the incinerator. Utility Model Content

[0006] The purpose of this invention is to solve the problems of long start-up time and high fuel consumption in existing waste incinerators, and to provide an energy-saving structure for waste incinerators.

[0007] To address the shortcomings of the aforementioned technical problems, the present invention adopts the following technical solution: an energy-saving structure for a waste incinerator, comprising a water-cooled pipe for heat conduction, wherein the water-cooled pipe is provided with multiple hooks, which can connect to hanging plates to form a protective surface on the surface of the water-cooled pipe, wherein the protective surface is sequentially coated with a deformation layer and a heat insulation layer. The insulation layer can keep the incinerator warm during the start-up stage; The deformation layer is made of an expandable ceramic matrix composite material to expand and break the insulation layer during the incineration stage in the incinerator.

[0008] As a further optimization of the energy-saving structure for a waste incinerator according to this utility model: a gap is reserved between the plurality of hanging plates and the water cooling pipes, and the gap is filled with self-fluidizing filler.

[0009] As a further optimization of the energy-saving structure for a waste incinerator according to this utility model: the self-flowing filler is made of silicon carbide self-flowing material.

[0010] As a further optimization of the energy-saving structure for a waste incinerator according to this utility model: the insulation layer adopts a lightweight mullite insulation coating.

[0011] As a further optimization of the energy-saving structure for a waste incinerator according to this utility model, the thickness of the insulation layer is 0.5-1mm.

[0012] As a further optimization of the energy-saving structure for a waste incinerator according to this utility model, the thickness of the deformation layer is 1-2.5mm.

[0013] As a further optimization of the energy-saving structure for a waste incinerator according to this utility model: the hook is an L-shaped stainless steel hook, and multiple hooks are evenly distributed on the outer wall of the water-cooling pipe.

[0014] As a further optimization of the energy-saving structure for a waste incinerator according to this utility model: the distance between two adjacent hooks is 200-250mm.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes the synergistic effect of a deformation layer and an insulation layer to reduce heat transfer to the water-cooled pipes during the start-up phase of the incinerator, thereby accelerating the furnace temperature rise and preventing thermal shock. When the temperature reaches the stable combustion range of the waste, the deformation layer expands and ruptures the insulation layer, switching to a high-efficiency heat conduction mode to ensure efficient heat exchange during operation, balancing energy saving during start-up and the heat conduction requirements of operation. This effectively reduces the long start-up time and high fuel consumption associated with waste incinerators. Attached Figure Description

[0016] Figure 1 This is a partial cross-sectional structural diagram of Embodiment 1 of the present invention; The markings in the diagram are: 1. Insulation layer; 2. Deformation layer; 3. Hanging plate; 4. Water cooling pipe; 5. Self-fluidizing filler; 6. Hook. Detailed Implementation

[0017] To better understand this utility model, the following embodiments further illustrate the content of this utility model, but the content of this utility model is not limited to the following embodiments.

[0018] An energy-saving structure for a waste incinerator is provided, consisting of a water-cooled pipe 4, a hook 6, a hanging plate 3, a deformation layer 2, and an insulation layer 1. The above structures work together to meet the insulation requirements during the start-up stage and ensure efficient heat conduction during operation.

[0019] Multiple hooks 6 are provided on the water-cooled pipe 4. These hooks 6 connect and position the mounting plate 3 onto the water-cooled pipe 4, enabling the mounting plate 3 to provide good rain protection and efficient heat exchange, thus ensuring the long-term operational stability of the waste incinerator. Multiple L-shaped stainless steel hooks 6 are uniformly welded to the outer wall of the water-cooled pipe 4, with a spacing of 200-250mm to ensure uniform stress distribution. The mounting plate 3 is a silicon carbide composite mounting plate. A 5-8mm gap is reserved between the mounting plate 3 and the water-cooled pipe 4 to fill the self-flowing filler 5, forming a stable heat conduction channel. The filler is made of silicon carbide self-flowing material, which has good fluidity and sealing properties. It can automatically fill the gaps between the hooks 6 and the mounting plate 3, and between the mounting plate 3 and the water-cooled pipe 4, preventing structural corrosion caused by high-temperature flue gas infiltration. Simultaneously, this filler ensures heat transfer efficiency, reduces local thermal stress, lowers the risk of deformation of the mounting plate 3 and the water-cooled pipe 4, further improving structural stability and reducing the system's coking rate. After multiple silicon carbide composite hanging plates are spliced ​​together, a complete low-coking protective surface is formed on the side facing the furnace, providing effective protection for the internal structure of the furnace.

[0020] The protective surface is coated with a deformation layer 2 and an insulation layer 1 sequentially from the inside out. The deformation layer 2 and insulation layer 1 work together to achieve functional switching between the start-up and operation phases. Insulation layer 1, located on the outermost layer, has a thickness of 0.5–1 mm and uses a lightweight mullite insulation coating. During the start-up phase, insulation layer 1 effectively blocks the heat generated by auxiliary fuel combustion from being transferred to the water-cooled pipe 4, reducing heat loss and significantly accelerating the furnace heating rate. Simultaneously, insulation layer 1 also prevents thermal shock caused by excessive temperature differences between the hanging plate 3 and the water-cooled pipe 4, protecting structural safety. Deformation layer 2, located between insulation layer 1 and hanging plate 3, has a thickness of 1–2.5 mm and uses an expansion-type ceramic matrix composite material. When the furnace temperature reaches 800-850℃, which is close to the stable combustion temperature of the waste, the expander in the deformation layer 2 will expand violently due to the high temperature. The expansion force generated by the deformation layer 2 will quickly burst the outer insulation layer 1. After the insulation layer 1 breaks, it will be discharged from the furnace with the flue gas. At this time, the deformation layer 2 is directly exposed to the furnace. The deformation layer 2 can also assist the silicon carbide hanging plate 3 in quickly transferring the heat of waste combustion to the water cooling pipe 4, ensuring the heat exchange efficiency during normal operation.

[0021] Silicon carbide self-flowing material uses high-purity silicon carbide as the main aggregate, forming a rigid framework. The high hardness and high melting point of silicon carbide particles determine the material's high-temperature resistance and wear resistance. Matrix bonding and high-temperature phase transformation: The matrix consists of fine silicon carbide powder, clay, alumina, etc. At room temperature, the aggregate is bonded together by binders such as clay; at high temperatures, the matrix undergoes sintering or chemical reactions, such as the formation of a mullite phase, further densifying the framework and improving structural strength and thermal shock resistance. Simultaneously, silicon carbide self-flowing material enables highly efficient heat conduction, thus ensuring overall heat exchange efficiency.

[0022] The key component of the deformation layer 2 is zirconia expander, which exhibits high-temperature phase transformation expansion characteristics. Below 800℃, zirconia exists in a monoclinic phase with stable volume; when the temperature reaches 800-850℃, the monoclinic phase rapidly transforms into a tetragonal phase, resulting in a volume expansion of approximately 4%. Simultaneously, this is compensated for by the high-temperature sintering shrinkage of SiC particles, ultimately achieving an overall volume expansion of 30%–50%. This phase transformation process is "irreversible," ensuring that once the insulation layer 1 cracks, it will not recover, avoiding interference with heat conduction during normal operation. Furthermore, the deformation layer 2 maintains good structural integrity after expansion, serving as a "secondary protective layer" for the hanging plate 3, reducing direct wear from waste slag on the hanging plate 3 and extending its service life.

[0023] The insulation layer 1 uses a lightweight mullite insulation coating. The insulation performance of the mullite insulation coating comes from its porous structure and low thermal conductivity. During the drying process, the organic binder will gradually volatilize, forming a large number of closed pores with a diameter of 1-10μm. These pores can effectively block the convection and radiation of heat. As the main component, mullite has excellent high-temperature stability and can maintain structural integrity at the highest temperature of 950℃ during the start-up stage, avoiding insulation failure caused by high-temperature softening.

[0024] The thicknesses of the deformation layer 2 and the insulation layer 1 can be calculated using the heat conduction formula Q=λ×A×ΔT / δ, where Q is the heat flow rate, λ is the thermal conductivity, A is the area, ΔT is the temperature difference, and δ is the thickness. This ensures that the thickness of the insulation layer 1 is sufficient to guarantee the insulation effect, even if the surface temperature of the water-cooled pipe 4 is below 100℃ in the initial stage of furnace start-up, while also preventing insufficient expansion force due to excessive thickness of the insulation layer 1, which could lead to the insulation coating bursting.

[0025] In this embodiment, the specific shape, structure, composition, and operating principle of the insulation layer 1, deformation layer 2, self-fluidizing filler 5, hook 6, hanging plate 3, and water cooling pipe 4 should all be understood as existing technology.

[0026] The expandable ceramic matrix composite material in this embodiment is prior art, as evidenced by the following: The paper "Research on SR / Frit Composites: A Novel Low-Temperature Ceramifiable Expandable Flame-Retardant Material," published in the journal Materials in May 2022, studies a novel low-temperature ceramifiable expandable flame-retardant material: silicone rubber (SR) / glass powder composites. The paper indicates that by studying the effect of low-melting-point glass powder content on the expansion properties of SR, it was found that as the glass powder content increases, the ceramization temperature decreases. The sample begins to expand at 850℃, and the expansion rate reaches 157% at 950℃, with a compressive strength of 1.99 MPa, proving the existence and related properties of expandable ceramic matrix composites. This paper is available on the National Center for Biotechnology Information website.

[0027] The mullite material used in this embodiment is existing technology, as evidenced by the following: "Research on the Preparation Process of Mullite Thermal Insulation Castables by Foaming Method," published in *China Ceramic Industry*, No. 4, 2019. This paper studied the influence of different preparation processes on the performance and pore structure of mullite foamed thermal insulation materials. By adjusting process parameters such as the amount of foaming agent added, high-performance ultra-lightweight microporous mullite foamed thermal insulation materials can be prepared.

[0028] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this utility model.

Claims

1. An energy-saving structure for a waste incinerator, comprising a water-cooled pipe (4) for heat conduction, wherein the water-cooled pipe (4) is provided with a plurality of hooks (6), the hooks (6) being able to connect to hanging plates (3) so that the plurality of hanging plates (3) form a protective surface on the surface of the water-cooled pipe (4), characterized in that: The protective surface is coated with a deformation layer (2) and a thermal insulation layer (1) in sequence. The insulation layer (1) can keep the incinerator warm during the start-up stage; The deformation layer (2) is made of an expansion-type ceramic matrix composite material to expand and break the insulation layer (1) during the incineration stage of the incinerator.

2. The energy-saving structure for a waste incinerator according to claim 1, characterized in that: A gap is reserved between the plurality of hanging plates (3) and the water cooling pipe (4), and the gap is filled with self-fluidizing filler (5).

3. The energy-saving structure for a waste incinerator according to claim 2, characterized in that: The self-flowing filler (5) is made of silicon carbide.

4. The energy-saving structure for a waste incinerator as described in claim 1, characterized in that: The insulation layer (1) is made of lightweight mullite insulation coating.

5. The energy-saving structure for a waste incinerator according to claim 1 or 4, wherein: The thickness of the insulation layer (1) is 0.5 to 1 mm.

6. The energy-saving structure for a waste incinerator as described in claim 1, characterized in that: The thickness of the deformation layer (2) is 1 to 2.5 mm.

7. The energy-saving structure for a waste incinerator according to claim 1, characterized in that: The hook (6) is an L-shaped stainless steel hook (6), and multiple hooks (6) are evenly distributed on the outer wall of the water cooling pipe (4).

8. The energy-saving structure for a waste incinerator according to claim 1, characterized in that: The distance between two adjacent hooks (6) is 200-250 mm.

Images