Anti-slagging biomass and coal coupling power generation system and method

Abstract

The invention provides an anti-slagging biomass and coal coupling power generation system and method. The system comprises a pyrolysis reactor, and a raw material inlet of the pyrolysis reactor communicates with a raw material outlet of a biomass bin; a pyrolysis gas outlet of the pyrolysis reactor is communicated with a raw material gas inlet of the high-temperature filter, a solid outlet of the high-temperature filter is communicated with a raw material inlet of the pyrolytic carbon cooling machine, and a purified gas outlet of the high-temperature filter is communicated with the coal-fired boiler; a raw material outlet of the pyrolysis reactor is communicated with a raw material inlet of the pyrolytic carbon cooling machine, a raw material outlet of the pyrolytic carbon cooling machine is communicated with a raw material inlet of the carbon storage bin, and a raw material outlet of the carbon storage bin is communicated with a raw material inlet of the pyrolytic carbon forming device, so that pyrolytic carbon, a binder and an anti-coking agent are fully mixed and formed; and the raw material outlet of the pyrolytic carbon forming device is communicated with the coal-fired boiler, so that slag-bonding corrosion of the boiler can be effectively avoided.

Description

Technical Field

[0001] The present invention belongs to the field of biomass and coal coupled power generation utilization, and particularly relates to a slagging-resistant biomass and coal coupled power generation system and method. Background Art

[0002] Against the backdrop of the global response to climate change and the accelerating progress towards achieving the "dual carbon" goals, carbon emission control has become a crucial principle that must be followed in all sectors of society. As a major source of carbon emissions, the energy production sector faces immense pressure to reduce emissions. Coal-fired power generation, a widely used power generation method worldwide, plays a vital role in the energy supply system, but it also contributes significantly to carbon emissions. Therefore, low-carbon transformation of coal-fired power generation and reducing its carbon emission intensity are crucial to achieving the global "dual carbon" goals.

[0003] At present, the industry has explored and practiced a variety of technical paths for low-carbon transformation of coal-fired power. Carbon capture, utilization and storage technology (CCUS) reduces emissions into the atmosphere by capturing carbon dioxide produced during coal combustion and utilizing or storing it. However, this technology has problems such as large equipment investment, high operating costs, and the need to improve technical maturity, which limits its large-scale promotion and application. Green ammonia blending technology uses renewable energy to produce green ammonia and blends it into coal for combustion to reduce the proportion of coal used. However, the production cost of green ammonia is high, and the combustion characteristics of ammonia are different from those of coal, which poses new challenges to combustion equipment and processes.

[0004] In contrast, biomass co-firing technology has attracted considerable attention due to its unique advantages. As a renewable energy source, biomass is zero-carbon: the carbon dioxide it absorbs during its growth is roughly equivalent to the carbon dioxide released during its combustion. From a lifecycle perspective, it generates virtually no additional carbon emissions. Therefore, using biomass to partially replace coal combustion can effectively reduce the carbon intensity of coal-fired power generation without altering existing coal-fired power generation infrastructure, making it a highly promising low-carbon transformation strategy.

[0005] However, the traditional method of directly blending biomass and coal faces many technical difficulties in practical application. There are significant differences in the combustion characteristics of biomass and coal. Coal has a relatively low volatile matter content, a high ignition temperature, and a relatively stable combustion process; while biomass generally has a high volatile matter content, a low ignition temperature, and a fast combustion rate. This difference makes it difficult to achieve synchronous combustion of biomass and coal during direct blending, affecting combustion efficiency. Some biomass contains high levels of alkali metals, chlorine, and other elements. During the combustion process, these elements easily escape in gaseous form and condense and deposit on the surface of the boiler's heating surface, forming slag. Slagging not only reduces the boiler's thermal efficiency and increases energy consumption, but can also cause local overheating of the heating surface, leading to safety accidents. At the same time, the presence of chlorine can exacerbate boiler corrosion, shorten the equipment's service life, and increase maintenance costs.

[0006] In order to overcome the drawbacks of the traditional direct co-combustion of biomass and coal and improve the efficiency and stability of the coupled combustion of biomass and coal, it is of great practical significance to develop an efficient coupled combustion method of biomass and coal with anti-slagging. Summary of the Invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a slagging-resistant biomass and coal coupled power generation system and method. The system first pyrolyzes the biomass to obtain high-temperature pyrolysis gas and pyrolysis carbon, and purifies the high-temperature pyrolysis gas to ensure that its incineration does not produce alkali metals, chlorine elements and other substances that are prone to cause boiler slagging and corrosion; at the same time, the alkali metals, chlorine elements and other substances solidified in the pyrolysis carbon are fully mixed with an anti-coking agent to form them. When the formed particles are incinerated, the anti-coking agent captures volatile components such as alkali metals and chlorine elements therein to prevent them from escaping, thereby avoiding boiler corrosion.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a slagging-resistant biomass and coal coupled power generation system, comprising a pyrolysis reactor, wherein the raw material inlet of the pyrolysis reactor is connected to the raw material outlet of the biomass silo; the pyrolysis gas outlet of the pyrolysis reactor is connected to the raw material gas inlet of the high-temperature filter, the solid outlet of the high-temperature filter is connected to the raw material inlet of the pyrolytic carbon cooler, and the purified gas outlet of the high-temperature filter is connected to the coal-fired boiler; the raw material outlet of the pyrolytic carbon cooler is connected to the raw material inlet of the pyrolytic carbon cooler, the raw material outlet of the pyrolytic carbon cooler is connected to the raw material inlet of the carbon storage silo, the raw material outlet of the carbon storage silo is connected to the raw material inlet of the pyrolytic carbon forming device for fully mixing and molding the pyrolytic carbon with the binder and the anti-coking agent, and the raw material outlet of the pyrolytic carbon forming device is connected to the coal-fired boiler.

[0009] Furthermore, the raw material outlet of the biomass silo is communicated with the raw material inlet of the sealed feeder, and the raw material outlet of the sealed feeder is communicated with the raw material inlet of the pyrolysis reactor.

[0010] Furthermore, the pyrolytic carbon forming device includes a mixer, a forming machine, and a dryer. The raw material outlet of the carbon storage bin is connected to the raw material inlet of the mixer, the raw material outlet of the mixer is connected to the raw material inlet of the forming machine, the raw material outlet of the forming machine is connected to the raw material inlet of the dryer, and the raw material outlet of the dryer is connected to the coal-fired boiler.

[0011] Furthermore, the pyrolysis reactor is also provided with a flue gas inlet and a flue gas outlet. The flue gas inlet is connected to the coal-fired boiler, and the flue gas outlet is connected to the flue gas purification system; the flue gas outlet of the coal-fired boiler is connected to the flue gas purification system, and the steam outlet of the coal-fired boiler is connected to the steam power generation system, the steam backflush port of the high-temperature filter, and the steam inlet of the pyrolytic carbon forming device. The pyrolytic carbon forming device is also provided with a condensate outlet, which is connected to the coal-fired boiler.

[0012] The present invention also provides a method for using a slagging-resistant biomass and coal coupled power generation system, comprising the following steps:

[0013] Step 1: Biomass that meets the feeding requirements is loaded into the biomass silo and fed into the pyrolysis reactor under the action of a sealed feeder;

[0014] Step 2: The biomass is thermally decomposed in a pyrolysis reactor to produce high-temperature pyrolysis gas and pyrolysis carbon. The pyrolysis gas is sent to a high-temperature filter, and the pyrolysis carbon is sent to a pyrolysis carbon cooler. The pyrolysis carbon cooler cools the pyrolysis carbon to a certain condition and then sends it to a carbon storage bin.

[0015] Step 3: The high-temperature filter filters and purifies the high-temperature pyrolysis oil and gas to remove solid particles contained in the gas. The purified gas is sent to the coal-fired boiler for combustion, and the solid particles are sent to the pyrolytic carbon cooler for cooling and recovery along with the pyrolytic carbon.

[0016] Step 4: Take out the pyrolytic carbon from the carbon storage bin, mix it with a binder and an anti-slagging agent in a certain proportion, and then send it into a pyrolytic carbon forming device, and then send the obtained pyrolytic carbon formed particles into a coal-fired boiler for combustion.

[0017] Furthermore, in step 5, the pyrolysis gas, pyrolysis carbon particles and coal are burned in the coal-fired boiler to generate high-temperature flue gas, a portion of which is fed into the pyrolysis reactor to provide heat for the pyrolysis process, and the rest is used to produce steam;

[0018] The steam produced is used for back-flushing of high-temperature filters, drying of pyrolytic carbon pellets in the pyrolytic carbon forming device, and is fed into the steam power generation system for electricity production. The condensed water produced after the steam generation system and the pyrolytic carbon forming device are used is fed into the coal-fired boiler for steam production.

[0019] Step 6: The flue gas heated by the coal-fired boiler and the pyrolysis reactor is sent to the flue gas purification system for purification before being discharged.

[0020] Furthermore, in step 1, meeting the feed requirements means that the biomass particles have a particle size of ≤5 mm and a moisture content of ≤15%.

[0021] Furthermore, in step 2, cooling to a certain condition means that the temperature of the pyrolytic carbon is ≤ 60°C.

[0022] Furthermore, in step 4, the binder is one or more of dextrin, coal tar, and biomass pyrolysis tar, and the anti-slagging agent is one or more of kaolin, clay, and waste white clay. The certain proportion means that the binder dosage is 1-5%, and the anti-slagging agent dosage is 3-5%.

[0023] Furthermore, in step 5, the flue gas temperature of the high-temperature flue gas is ≥700°C.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] The present invention provides a slagging-resistant biomass and coal-coupled power generation system. The pyrolysis reactor serves as the core device, which pyrolyzes the biomass into high-temperature pyrolysis gas and pyrolysis carbon, and decomposes the biomass from the source. The high-temperature filter purifies the pyrolysis gas, effectively removing the solid particles contained therein, ensuring the purity of the pyrolysis gas entering the coal-fired boiler, and avoiding the problem of boiler slagging corrosion caused by impurities. The pyrolysis carbon cooler cools the pyrolysis carbon to a suitable temperature and then sends it into the carbon storage bin to prepare for subsequent mixing and molding with anti-coking agents and the like. The pyrolysis carbon molding device fully mixes and molds the pyrolysis carbon with the binder and the anti-coking agent, so that the anti-coking agent can be evenly distributed in the pyrolysis carbon molded particles. In the coal-fired boiler, when the molded particles are burned, the anti-coking agent can fully capture the volatile components such as alkali metals and chlorine elements therein to prevent them from escaping, thereby fundamentally avoiding the slagging corrosion of the boiler and ensuring the stable operation of the boiler.

[0026] Furthermore, a portion of the high-temperature flue gas generated by the coal-fired boiler is fed into the pyrolysis reactor, providing the heat required for the biomass pyrolysis process, ensuring that the material can be fully decomposed and achieving cascaded energy utilization. At the same time, the steam generated by the coal-fired boiler is used in multiple links, such as backflushing the high-temperature filter and drying the pyrolytic carbon forming device to form pyrolytic carbon particles. Steam backflushing the high-temperature filter not only prevents the high-temperature pyrolysis oil and gas from cooling and condensing, which could clog the filter material, but also utilizes the excellent solubility of steam to blow off particles, dust, and tar adhering to the filter material, preventing clogging the filter material and extending the service life of the filter. Using steam to dry the formed particles avoids the risk of combustion of the formed particles due to excessively high heat source temperatures, and the steam condensate can be reused in the boiler, eliminating energy waste, further improving the thermal efficiency of the system, and reducing energy consumption.

[0027] Furthermore, the arrangement of the biomass silo and the sealed feeder ensures that the biomass can enter the pyrolysis reactor stably and continuously, thus avoiding fluctuations in the pyrolysis process caused by unstable feeding.

[0028] The present invention proposes a biomass pyrolysis and coal coupled combustion power generation method, in which volatile components such as alkali metals and chlorine are fixed in pyrolytic carbon through biomass pyrolysis, and then mixed with the pyrolytic carbon through adhesives, anti-slagging agents, etc. to form a mixture, which can effectively ensure that the anti-slagging agent and pyrolytic carbon are fully mixed. At the same time, unlike direct combustion of biomass, pyrolytic carbon combustion is a surface combustion phenomenon, that is, combustion is carried out from the outside to the inside, and basically no volatile matter escapes, which ensures that the anti-slagging agent fully captures volatile components such as alkali metals and chlorine, thereby avoiding boiler slagging corrosion.

[0029] Furthermore, the present invention has strict requirements for biomass feed, with particle size ≤5mm and moisture content ≤15%. Such raw material conditions are conducive to the smooth progress of the pyrolysis reaction, improving the pyrolysis efficiency and product quality. In the pyrolytic carbon forming process, the types and amounts of binders and anti-slagging agents are clearly specified. The binder is one or more of dextrin, coal tar, and biomass pyrolysis tar, and the anti-slagging agent is one or more of kaolin, clay, and waste white clay. The binder dosage is 1-5%, and the anti-slagging agent dosage is 3-5%. Such a formula design can ensure that the pyrolytic carbon formed particles have good physical properties and anti-slagging properties, providing a guarantee for stable combustion in coal-fired boilers.

[0030] Furthermore, the coal-fired boiler provides high-temperature flue gas and steam for biomass pyrolysis at the same time. The high-temperature flue gas provides heat for pyrolysis to ensure the required pyrolysis temperature and ensure that the material is fully decomposed, while the steam is used for back-flushing of the high-temperature filter. Firstly, it can prevent the high-temperature pyrolysis oil and gas from cooling and condensing to clog the filter material. Secondly, the steam has good solubility and can blow off the particles, dust and tar adhering to the filter material to prevent clogging of the filter material.

[0031] Furthermore, steam is used to dry the formed particles. Firstly, the steam temperature is limited, which can completely eliminate the risk of combustion of the formed particles caused by excessively high heat source temperature. Secondly, the steam condensate can be reused in the boiler, which does not waste energy and has high thermal efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 1 is a process flow chart of the system of the present invention. DETAILED DESCRIPTION

[0033] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0036] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0037] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0038] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] The present invention aims to address the shortcomings of existing coal-fired power plants in biomass-coupled low-carbon transformation, such as easy slagging and corrosion of boilers and poor operating stability. It provides a slagging-resistant biomass and coal-coupled power generation system and method. By coupling the combustion of biomass pyrolysis products with coal, it effectively avoids the escape of volatile components such as alkali metals and chlorine elements from the boiler, thereby realizing the low-carbon transformation of coal-fired power plants.

[0040] Example 1

[0041] In order to implement the above technical solution, Figure 1 As shown, the present invention provides a slagging-resistant biomass and coal coupled power generation system, comprising a biomass silo, a sealed feeder, a pyrolysis reactor, a pyrolysis carbon cooler, a charcoal storage silo, a mixer, a molding machine, a dryer, a high-temperature filter, a coal-fired boiler, a steam power generation system, and a flue gas purification system. The biomass silo, the sealed feeder, the pyrolysis reactor, the pyrolysis carbon cooler, the charcoal storage silo, the molding machine, and the dryer are all provided with a raw material inlet and a raw material outlet. The raw material outlet of the biomass silo is connected to the raw material inlet of the sealed feeder, the raw material outlet of the sealed feeder is connected to the raw material inlet of the pyrolysis reactor, the raw material outlet of the pyrolysis reactor is connected to the raw material inlet of the pyrolysis carbon cooler, the raw material outlet of the pyrolysis carbon cooler is connected to the raw material inlet of the charcoal storage silo, the raw material outlet of the charcoal storage silo is connected to the raw material inlet of the mixer, the raw material outlet of the mixer is connected to the raw material inlet of the dryer, and the raw material outlet of the dryer is connected to the coal-fired boiler.

[0042] As a better way, the pyrolysis reactor is also provided with a pyrolysis gas outlet, the high-temperature filter is provided with a raw gas inlet, a purified gas outlet and a solid outlet, the pyrolysis gas outlet is connected to the raw gas inlet of the high-temperature filter, the solid outlet of the high-temperature filter is connected to the raw material inlet of the pyrolysis carbon cooler, and the purified gas outlet is connected to the coal-fired boiler.

[0043] As a better way, the pyrolysis reactor is also provided with a flue gas inlet and a flue gas outlet, the high-temperature filter is also provided with a steam backflush port, the flue gas inlet is connected to the coal-fired boiler, the flue gas outlet is connected to the flue gas purification system, the flue gas outlet of the coal-fired boiler is also connected to the flue gas purification system, the steam outlet of the coal-fired boiler is connected to the steam power generation system, the steam outlet of the coal-fired boiler is also connected to the steam backflush port of the high-temperature filter, the steam outlet of the coal-fired boiler is also connected to the steam inlet of the dryer, the dryer is also provided with a condensate outlet, and the condensate outlet is connected to the coal-fired boiler.

[0044] As a better way, the pyrolysis reactor adopts a moving bed design, including a furnace body, a chain grate and a slag retaining plate. The chain grate includes a driving sprocket, a driven sprocket and a furnace chain. The furnace chain is engaged with the driving sprocket and the driven sprocket respectively. A bearing is installed in the shaft hole of the driving sprocket. The bearing is driven by the motor pulley. The furnace chain is used to transfer the dried biomass to the moving bed carbonization furnace for carbonization.

[0045] As a better approach, multiple rows of temperature sensors are installed in the furnace body of the pyrolysis reactor to monitor the temperature distribution in the furnace in real time. The signals of the temperature sensors are connected to the control system. The control system automatically adjusts the air volume and coal consumption according to the temperature data fed back by the temperature sensors to ensure that the temperature in the furnace remains within the set range.

[0046] As a better way, a spiral feeding device is provided at the feed end of the pyrolysis reactor to evenly distribute the biomass on the furnace chain. The speed of the spiral feeding device is adjustable to meet the requirements of different biomass characteristics.

[0047] As a better way, the pyrolytic carbon cooler adopts a circulating fluidized bed design, including a cooling cylinder, a circulating fan and a coolant distributor. There are multiple cooling zones in the cooling cylinder, and the circulating fan evenly distributes the cooling air to each cooling zone to achieve uniform cooling of the pyrolytic carbon.

[0048] As a better way, the mixer adopts a double-helix counterclockwise stirring method, including two opposing spiral blades, the pitch and rotation speed of the spiral blades are adjustable to achieve sufficient mixing of pyrolytic carbon and biomass pyrolysis tar.

[0049] As a better way, the molding machine adopts a mold-type extrusion molding method, including an upper mold and a lower mold, and an adjustable gap is provided between the upper mold and the lower mold to control the size and shape of the molded particles.

[0050] As a better approach, the dryer adopts an indirect contact design, including a steam tube bundle and an insulation layer surrounded by the steam tube bundle. Multiple parallel drying channels are arranged in the insulation layer surrounded by the steam tube bundle. Adjustable guide plates are provided in the drying channels to control the residence time and distribution uniformity of the material.

[0051] As a better way, the high-temperature filter adopts a vertical multi-stage filtration structure, including multiple filter layers. The pore size of the filter layer gradually decreases from top to bottom. The filter layers are connected by flanges, and sealing rings are provided between the flanges to ensure sealing.

[0052] As a better approach, coal-fired boilers adopt a circulating fluidized bed design, which includes a furnace body, a coal-burning area and an inert area. The furnace body is equipped with multiple horizontal water-cooled walls to absorb flue gas heat and generate steam.

[0053] As a better approach, the steam power generation system adopts a multi-stage steam extraction method, including high-pressure cylinders, low-pressure cylinders and medium-pressure cylinders. The exhaust port of each cylinder is connected to the generator through a steam collector. The generator is controlled by a frequency converter and the speed can be adjusted to adapt to load changes.

[0054] As a better way, the flue gas purification system includes a cyclone separator and a multi-stage bag filter. The cyclone separator is used to remove particulate impurities, and the bag filter is used to filter fine impurities. The system adopts automatic control to automatically adjust the air volume and filtering frequency according to the dust concentration.

[0055] Example 2:

[0056] The specific working process of the anti-slagging biomass and coal coupled power generation system provided by the present invention is as follows:

[0057] Step 1: biomass with a particle size of less than 5 mm and a moisture content of less than 15% is loaded into a biomass silo and fed into a pyrolysis reactor by a sealed feeder;

[0058] Step 2: The biomass is thermally decomposed in a pyrolysis reactor to produce high-temperature pyrolysis gas and pyrolysis carbon. The pyrolysis gas is sent to a high-temperature filter, and the pyrolysis carbon is sent to a pyrolysis carbon cooler. The pyrolysis carbon cooler cools the pyrolysis carbon to a temperature of less than 50°C and then sends it to a carbon storage bin.

[0059] Step 3: The high-temperature filter filters and purifies the high-temperature pyrolysis oil and gas to remove solid particles contained in the gas. The purified gas is sent to the coal-fired boiler for combustion, and the solids produced by the filtration are sent to the pyrolytic carbon cooler for cooling and recovery along with the pyrolytic carbon.

[0060] Step 4: Take out the pyrolytic carbon from the carbon storage bin, mix it with the binder and anti-slagging agent in a certain proportion and send it into a mixer. After being fully mixed in the mixer, send the mixture into a molding machine for extrusion to a certain shape. The formed particles are sent to a dryer for drying. The dried particles are sent to a coal-fired boiler for combustion;

[0061] As a preferred method, the binder is one or more of dextrin, coal tar, and biomass pyrolysis tar, and the anti-slagging agent is one or more of kaolin, clay, and waste white clay. The certain proportion means that the binder dosage is 1-5%, and the anti-slagging agent dosage is 3-5%.

[0062] Step 5: The coal-fired boiler burns the pyrolysis gas, pyrolysis carbon pellets, and coal. A portion of the high-temperature flue gas from the coal-fired boiler is fed into the pyrolysis reactor to provide heat for the pyrolysis process, and the rest is used to produce steam. Part of the generated steam is used for backflushing the high-temperature filter, part is used for drying the pellets in the dryer, and the rest is fed into the steam power generation system to generate electricity. The condensate generated after the steam generation system and the dryer steam are used is fed back into the coal-fired boiler to produce steam.

[0063] As a better way, high temperature flue gas refers to flue gas temperature ≥700℃.

[0064] Step 6: The flue gas after heating by the coal-fired boiler and the pyrolysis reactor is uniformly sent to the flue gas purification system for purification before being discharged.

[0065] In the biomass feeding stage, the method of the present invention feeds the biomass that meets the requirements into the pyrolysis reactor through a sealed feeder, thereby ensuring the stability of the feed and the quality of the raw materials. During the pyrolysis process, the high-temperature pyrolysis gas and pyrolytic carbon generated by the decomposition of the biomass are processed separately. The pyrolysis gas is purified by a high-temperature filter and then fed into a coal-fired boiler for combustion, thereby avoiding corrosion of the boiler by harmful substances. The pyrolytic carbon is cooled, mixed with a binder and an anti-slagging agent, and then fed into a coal-fired boiler for combustion. The combustion mode of the shaped particles is surface combustion, and basically no volatile matter escapes. The anti-slagging agent can fully capture volatile components such as alkali metals and chlorine elements, thereby effectively avoiding slagging corrosion of the boiler; and the high-temperature flue gas and steam generated by the coal-fired boiler are fully utilized. The high-temperature flue gas provides heat for the pyrolysis reaction, and the steam is used for backblowing of the high-temperature filter and drying of the pyrolytic carbon shaped particles, thereby realizing the cascade utilization and recycling of energy. This energy utilization method not only improves energy utilization efficiency, but also reduces the demand for external energy and reduces operating costs. At the same time, steam condensate is reused in the boiler, avoiding waste of water resources and further reducing operating costs.

[0066] Example 3:

[0067] The main parameters of the anti-slagging biomass and coal coupled power generation system provided by the present invention are as follows:

[0068] The pyrolysis reactor measures 2 meters long, 2 meters wide, and 3 meters high, constructed from high-temperature-resistant stainless steel. Five rows of platinum RTD temperature sensors are installed within the furnace, with a measurement range of 0-1200°C. The control system, a Siemens S7-300 series PLC controller, automatically adjusts air volume and coal consumption based on temperature data fed back by the temperature sensors, with a control accuracy of ±5°C. The screw feeder operates at a speed of 5-20 rpm, adjustable to suit the biomass characteristics.

[0069] The cooling cylinder of the pyrolytic carbon cooler is 1.5 meters long and 1 meter in diameter and is made of high-temperature resistant stainless steel. There are 5 cooling zones in the cooling cylinder and the air volume of the circulating fan is 10,000m 3 / h, the cooling air temperature is 20-40℃. The coolant distributor adopts a uniformly distributed hole design with a hole diameter of 0.5-1mm.

[0070] The pitch of the mixer's spiral blades is 10mm, and the rotation speed is 20-30rpm. The upper and lower molds of the molding machine are made of high-strength alloy steel, and the mold gap can be adjusted within the range of 1-5mm.

[0071] The dryer's steam pipe bundle has a diameter of 20mm, and the insulation layer contains 10 drying channels, each 1.5 meters long. The guide plates in the drying channels are arranged at an angle of 30-60 degrees, with a spacing of 50-100mm.

[0072] The filter layer of the high-temperature filter is made of stainless steel wire mesh, with pore size gradually decreasing from top to bottom, ranging from 0.1-0.5mm. The flanges are connected with pressure-resistant sealing gaskets, and the sealing rings are made of graphite sealing material.

[0073] The coal-fired boiler's furnace measures 3 meters long, 3 meters wide, and 4 meters high, constructed from high-temperature, hydraulically resistant stainless steel. It features eight horizontal water-cooled walls constructed from 20mm stainless steel pipes. The coal-burning zone is 1.5 meters high, while the inert zone is 0.5 meters tall.

[0074] The steam power generation system uses a high-pressure cylinder with an exhaust pressure of 12kg / cm 2 , the exhaust steam pressure of the intermediate pressure cylinder is 2kg / cm 2 , the exhaust steam pressure of the low pressure cylinder is 0.6kg / cm 2 The steam collector is a high-pressure container with a capacity of 50L. The generator is an asynchronous machine with a rated power of 100MW and a frequency converter to adjust the speed within the range of 50-100Hz.

[0075] The cyclone separator of the flue gas purification system adopts a centrifugal separator with an exhaust volume of 100,000m 3 / h. The bag filter is made of PP material and has a filtration area of ​​1000m 2 The automatic control system automatically adjusts the air volume and filtering frequency according to the dust concentration.

[0076] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0077] In addition, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for the purpose of illustrating the technical concept of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made based on the technical solution in accordance with the technical concept proposed by the present invention fall within the scope of protection of the claims of the present invention.

Claims

1. A slagging-resistant biomass and coal coupled power generation system, characterized in that: It includes a pyrolysis reactor, the raw material inlet of the pyrolysis reactor is connected to the raw material outlet of the biomass silo; the pyrolysis gas outlet of the pyrolysis reactor is connected to the raw material gas inlet of the high-temperature filter, the solid outlet of the high-temperature filter is connected to the raw material inlet of the pyrolytic carbon cooler, and the purified gas outlet of the high-temperature filter is connected to the coal-fired boiler; the raw material outlet of the pyrolytic carbon cooler is connected to the raw material inlet of the pyrolytic carbon cooler, the raw material outlet of the pyrolytic carbon cooler is connected to the raw material inlet of the carbon storage bin, the raw material outlet of the carbon storage bin is connected to the raw material inlet of the pyrolytic carbon forming device for fully mixing and molding the pyrolytic carbon with the binder and the anti-coking agent, and the raw material outlet of the pyrolytic carbon forming device is connected to the coal-fired boiler.

2. The anti-slagging biomass and coal coupled power generation system according to claim 1, characterized in that: The raw material outlet of the biomass silo is communicated with the raw material inlet of the sealed feeder, and the raw material outlet of the sealed feeder is communicated with the raw material inlet of the pyrolysis reactor.

3. The anti-slagging biomass and coal coupled power generation system according to claim 1, characterized in that: The pyrolytic carbon forming device includes a mixer, a forming machine, and a dryer. The raw material outlet of the carbon storage bin is connected to the raw material inlet of the mixer, the raw material outlet of the mixer is connected to the raw material inlet of the forming machine, the raw material outlet of the forming machine is connected to the raw material inlet of the dryer, and the raw material outlet of the dryer is connected to the coal-fired boiler.

4. The anti-slagging biomass and coal coupled power generation system according to claim 1, characterized in that: The pyrolysis reactor is also provided with a flue gas inlet and a flue gas outlet. The flue gas inlet is connected to the coal-fired boiler, and the flue gas outlet is connected to the flue gas purification system; the flue gas outlet of the coal-fired boiler is connected to the flue gas purification system, and the steam outlet of the coal-fired boiler is connected to the steam power generation system, the steam backflush port of the high-temperature filter, and the steam inlet of the pyrolytic carbon forming device. The pyrolytic carbon forming device is also provided with a condensate outlet, which is connected to the coal-fired boiler.

5. A method for using a slagging-resistant biomass and coal coupled power generation system according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Biomass that meets the feeding requirements is loaded into the biomass silo and fed into the pyrolysis reactor under the action of a sealed feeder; Step 2: The biomass is thermally decomposed in a pyrolysis reactor to produce high-temperature pyrolysis gas and pyrolysis carbon. The pyrolysis gas is sent to a high-temperature filter, and the pyrolysis carbon is sent to a pyrolysis carbon cooler. The pyrolysis carbon cooler cools the pyrolysis carbon to a certain condition and then sends it to a carbon storage bin. Step 3: The high-temperature filter filters and purifies the high-temperature pyrolysis oil and gas to remove solid particles contained in the gas. The purified gas is sent to the coal-fired boiler for combustion, and the solid particles are sent to the pyrolytic carbon cooler for cooling and recovery along with the pyrolytic carbon. Step 4: Take out the pyrolytic carbon from the carbon storage bin, mix it with a binder and an anti-slagging agent in a certain proportion, and then send it into a pyrolytic carbon forming device, and then send the obtained pyrolytic carbon formed particles into a coal-fired boiler for combustion.

6. A method for using a slagging-resistant biomass and coal coupled power generation system according to claim 5, characterized in that: Step 5: In the coal-fired boiler, pyrolysis gas, pyrolysis carbon pellets and coal are burned to generate high-temperature flue gas, a portion of which is fed into the pyrolysis reactor to provide heat for the pyrolysis process, and the rest is used to produce steam; The steam produced is used for back-flushing of high-temperature filters, drying of pyrolytic carbon pellets in the pyrolytic carbon forming device, and is fed into the steam power generation system for electricity production. The condensed water produced after the steam generation system and the pyrolytic carbon forming device are used is fed into the coal-fired boiler for steam production. Step 6: The flue gas heated by the coal-fired boiler and the pyrolysis reactor is sent to the flue gas purification system for purification before being discharged.

7. A method for using a slagging-resistant biomass and coal coupled power generation system according to claim 5, characterized in that: In step 1, meeting the feed requirements means that the biomass particles have a particle size of ≤5 mm and a moisture content of ≤15%.

8. A method for using a slagging-resistant biomass and coal coupled power generation system according to claim 5, characterized in that: In step 2, cooling to a certain condition means that the temperature of the pyrolytic carbon is ≤ 60°C.

9. A method for using a slagging-resistant biomass and coal coupled power generation system according to claim 5, characterized in that: In step 4, the binder is one or more of dextrin, coal tar, and biomass pyrolysis tar, and the anti-slagging agent is one or more of kaolin, clay, and waste clay. The certain proportion means that the binder dosage is 1-5%, and the anti-slagging agent dosage is 3-5%.

10. A method for using a slagging-resistant biomass and coal coupled power generation system according to claim 6, characterized in that: In step 5, the flue gas temperature of the high-temperature flue gas is ≥700°C.

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