Solid waste disposal system coupled to a fossil fuel power unit

Abstract

The present application relates to solid waste treatment technical field and disclose a kind of solid waste disposal system coupled with thermal power generating unit, including thermal power generating unit, multiple heat exchange systems, multiple drying components and blending unit, heat exchange system is connected with thermal power generating unit, for using steam waste heat or flue gas waste heat generated by thermal power generating unit to heat air and output hot air, multiple drying components are sequentially connected in series, solid waste is sequentially dried through multiple drying components, multiple drying components are connected with multiple heat exchange systems one by one, to make each drying component utilize the hot air of corresponding heat exchange system output to dry the solid waste passing through it, blending unit is connected with thermal power generating unit and the drying component in most downstream, for receiving dried solid waste and conveying it to blend in thermal power generating unit.This application uses the steam waste heat and flue gas waste heat of thermal power generating unit in multistage cascade for drying solid waste, and the sludge after drying is blended to realize harmlessness treatment.

Description

Technical Field

[0001] This invention belongs to the field of solid waste treatment technology, specifically relating to a solid waste disposal system coupled with a thermal power unit. Background Technology

[0002] The technology for drying solid waste using thermal power units has gradually matured. For example, related technologies utilize the waste heat of flue gas from thermal power units to dry municipal sludge. However, current technologies typically employ a single heat source during sludge drying, such as directly extracting low-temperature flue gas from the tail end of a thermal power unit boiler and feeding it into a drying device for one-time drying of the sludge. This results in low waste heat utilization efficiency from thermal power units and easily leads to incomplete or over-drying of the sludge. Furthermore, these technologies often only utilize the waste heat of flue gas, neglecting the full utilization of the steam waste heat from the turbine, and the dried sludge is difficult to process. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a solid waste disposal system coupled with a thermal power unit. This system utilizes the flue gas and steam waste heat of the thermal power unit to achieve multi-stage drying of solid waste, and further, by co-firing the dried sludge, achieves harmless treatment.

[0004] The solid waste disposal system of the coupled thermal power unit according to an embodiment of the present invention includes a thermal power unit, multiple independent heat exchange systems, multiple drying components, and a co-firing unit. The heat exchange systems are connected to the thermal power unit and are used to heat air and output hot air by utilizing the waste heat of steam or flue gas generated by the thermal power unit. The multiple drying components are arranged in series, with the upstream drying component used to introduce solid waste. The solid waste is dried by passing through the multiple drying components in sequence. The multiple drying components are connected one-to-one with the multiple heat exchange systems so that each drying component uses the hot air output from the corresponding heat exchange system to dry the solid waste passing through it. The co-firing unit is connected to the thermal power unit and the downstream drying component and is used to receive the dried solid waste and transport it to the thermal power unit for co-firing.

[0005] This invention, through the establishment of multiple independent heat exchange systems, enables the tiered and efficient recovery of waste heat from steam and flue gas of varying grades generated by thermal power units, converting it into hot air. Utilizing this hot air, multiple drying components connected in series can perform multi-stage, gradual drying of solid waste, significantly improving drying efficiency and energy utilization. Finally, the dried solid waste is transported back to the thermal power unit for co-incineration, achieving the harmless treatment of solid waste.

[0006] In some embodiments, the solid waste disposal system coupled to the thermal power unit further includes a pretreatment unit, which includes a dissolving tank, a sorting machine and a crusher connected in sequence. The discharge port of the crusher is connected to the inlet of the upstream drying component. The pretreatment unit is used to introduce solid waste and dissolve, sort and crush the solid waste in sequence before conveying it to the upstream drying component.

[0007] In some embodiments, the thermal power unit includes a steam turbine and a boiler. Each heat exchange system includes a heat source input terminal and a hot air output terminal. The plurality of heat exchange systems includes a first heat exchange system, a second heat exchange system, and a third heat exchange system. The heat source input terminal of the first heat exchange system is connected to the exhaust pipe of the steam turbine for extracting the waste heat of the steam in the exhaust pipe. The heat source input terminal of the second heat exchange system is connected to a first temperature zone in the flue gas of the boiler for extracting the waste heat of the flue gas in the first temperature zone. The heat source input terminal of the third heat exchange system is connected to a second temperature zone in the flue gas of the boiler for extracting the waste heat of the flue gas in the second temperature zone. The hot air output terminals of the first, second, and third heat exchange systems are respectively connected to drying components from upstream to downstream, and the temperature of the hot air output by the first, second, and third heat exchange systems increases sequentially.

[0008] In some embodiments, the first heat exchange system includes a steam-air heat exchanger, the steam side of which is connected to the exhaust pipe of the steam turbine, and the air outlet end of which forms the hot air output end of the first heat exchange system.

[0009] In some embodiments, the second heat exchange system includes a flue gas-air heat exchanger, the flue gas side of which is connected between the flue gas duct of the first temperature zone of the boiler and the subsequent flue gas duct of the boiler, and the air outlet end of which forms the hot air output end of the second heat exchange system.

[0010] In some embodiments, the temperature range of the first temperature zone is 150°C to 250°C.

[0011] In some embodiments, the third heat exchange system includes a first molten salt storage tank, a second molten salt storage tank, a molten salt-flue gas heat exchanger, a molten salt-air heat exchanger, and a molten salt circulation pipeline. Its flue gas side is connected between the flue of the second temperature zone of the boiler and the subsequent flue of the boiler, and its air side outlet constitutes the hot air output end of the third heat exchange system. The molten salt circulation pipeline is sequentially connected to the first molten salt storage tank, the molten salt side of the molten salt-flue gas heat exchanger, the second molten salt storage tank, the molten salt side of the molten salt-air heat exchanger, and returns to the first molten salt storage tank.

[0012] In some embodiments, the temperature range of the second temperature zone is 300°C to 400°C.

[0013] In some embodiments, the co-firing unit includes a solid waste bin, a raw coal bin, and a coal milling assembly. The inlet of the solid waste bin is connected to the outlet of the downstream drying assembly and is used to receive the dried solid waste. The raw coal bin is used to store and output raw coal. The coal milling assembly is connected to the outlets of the solid waste bin and the raw coal bin, and is also connected to the coal feed port of the boiler. The coal milling assembly is used to mix the solid waste and raw coal and then transport them to the boiler for combustion.

[0014] In some embodiments, the solid waste disposal system coupled to the thermal power unit further includes a moisture recovery unit, which is connected to at least one of the drying components and is used to recover water vapor in the moisture output by the drying component.

[0015] The solid waste treatment system for coupled thermal power units in this invention extracts waste heat from turbine exhaust, medium-temperature flue gas, and high-temperature flue gas in the thermal power unit through multiple heat exchange systems, and supplies it to a multi-stage drying assembly arranged in series, achieving adaptive tiered drying for solid waste with different moisture contents. The molten salt in the third heat exchange system and the phase change material in the second heat exchange system buffer the waste heat, adapting to fluctuations in waste heat from the thermal power unit under different operating conditions and providing a stable heat source for the drying assembly. The pretreatment unit dissolves, sorts, and crushes the solid waste, improving the efficiency and safety of subsequent drying. The co-firing unit mixes the dried solid waste with raw coal and sends it to the boiler for combustion, achieving energy recovery. The moisture recovery unit recovers the water vapor generated during the drying process, which is then treated and used as boiler feedwater, achieving water resource recycling. This system significantly improves the comprehensive utilization rate of waste heat from thermal power units and reduces energy consumption and carbon emissions in the solid waste treatment process. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of the present invention.

[0017] Figure 2 This is a schematic diagram of the drying component, co-firing unit, and moisture recovery unit of the present invention.

[0018] Figure 3 This is a schematic diagram of the first heat exchange system of the present invention.

[0019] Figure 4 This is a schematic diagram of the second and third heat exchange systems of the present invention.

[0020] Figure label:

[0021] 1. Thermal power unit; 11. Steam turbine; 12. Boiler; 13. Cyclone separator; 14. Economizer; 15. Air preheater; 16. Condenser; 17. Flue; 2. Heat exchange system; 21. First heat exchange system; 211. Steam-air heat exchanger; 22. Second heat exchange system; 221. Flue gas-air heat exchanger; 222. Fan; 223. Control valve; 224. Shut-off valve; 23. Third heat exchange system; 231. First molten salt storage tank; 232. Second molten salt storage tank; 233. Molten salt-flue gas heat exchanger; 234. Molten salt-air heat exchanger; 235. Molten salt circulation pipeline; 236. Pump; 237. Heating device; 3. Drying assembly; 31. First drying assembly; 32. Second drying assembly; 33. Third drying assembly; 4. Blending unit; 41. Solid waste bin; 42. Raw coal bin; 43. Coal mill assembly; 5. Pretreatment unit; 51. Dissolving tank; 52. Separator; 53. Crusher; 6. Moisture recovery unit; 61. Condenser; 62. Purifier. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] like Figures 1-4 As shown in the figure, the solid waste disposal system of the coupled thermal power unit 1 of the present invention is characterized by comprising a thermal power unit 1, multiple independent heat exchange systems 2, multiple drying components 3, and a co-firing unit 4. The heat exchange systems 2 are connected to the thermal power unit 1 and are used to heat air and output hot air by utilizing the waste heat of steam or flue gas generated by the thermal power unit 1. The multiple drying components 3 are arranged in series. The upstream drying component 3 is used to introduce solid waste. The solid waste is dried by passing through the multiple drying components 3 in sequence. The multiple drying components 3 are connected one-to-one with the multiple heat exchange systems 2 so that each drying component 3 uses the hot air output from the corresponding heat exchange system 2 to dry the solid waste passing through it. The co-firing unit 4 is connected to the thermal power unit 1 and the downstream drying component 3 and is used to receive the dried solid waste and transport it to the thermal power unit 1 for co-firing.

[0024] The solid waste treatment system of the coupled thermal power unit 1 in this embodiment aims to achieve efficient synergy between the waste heat resources of the thermal power unit 1 and the multi-source solid waste treatment process. It includes the thermal power unit 1, multiple independent heat exchange systems 2, multiple drying components 3 arranged in series, and a co-firing unit 4.

[0025] Thermal power unit 1 is the energy source of the system, which typically includes core equipment such as boiler 12 and steam turbine 11. During operation, it generates a large amount of waste heat resources of different temperatures and grades, mainly including the steam waste heat carried by the exhaust steam of steam turbine 11 and the flue gas waste heat emitted from the tail flue duct 17 of boiler 12.

[0026] Multiple heat exchange systems 2 are connected to the thermal power unit 1 to extract and utilize this waste heat. Each heat exchange system 2 operates independently and is connected to different waste heat sources of the thermal power unit 1 to extract heat of a specific grade. Inside the heat exchange system 2, waste heat is transferred to the flowing medium through heat exchangers (such as steam-air heat exchanger 211, flue gas-air heat exchanger 221, etc.), such as phase change heat storage materials (e.g., sodium nitrate-potassium nitrate mixed salt), water, or air, thereby outputting a heat medium. For the convenience of the drying component 3 to directly utilize it, air will be used as the example below.

[0027] In some specific embodiments, a fan 222 may be provided on the duct for conveying hot air to provide power, and a regulating valve 223 and / or a shut-off valve 224 may be provided as needed to control the air volume or open / close it.

[0028] Multiple drying components 3 are connected in series to form a tiered drying path for solid waste. The upstream drying component 3 can be equipped with a feed inlet to introduce the solid waste to be treated (such as municipal sludge, industrial solid waste, etc.).

[0029] In some specific embodiments, solid waste is driven sequentially through each drying assembly 3 by a conveying component (e.g., a conveyor belt) built into or external to the drying assembly 3. Each drying assembly 3 is connected to a corresponding hot air output end of a heat exchange system 2, thereby using hot air at a specific temperature to dry the solid waste passing through it. The drying process can be either by directly blowing hot air onto the solid waste, or by releasing heat through heat sinks or an internal heat exchanger (so that the hot air can flow back to the corresponding heat exchange system 2), and then the blower component inside the drying assembly 3 blows the heat onto the solid waste.

[0030] The co-firing unit 4 is connected to the discharge port of the downstream drying component 3 and the thermal power unit 1. It is used to receive and temporarily store the solid waste after multi-stage drying, and transport the dried solid waste to the boiler 12 of the thermal power unit 1 for co-firing and combustion with fuels such as coal, thereby realizing the energy utilization of solid waste.

[0031] The system's workflow is briefly described as follows: Multi-source solid waste is first introduced into the upstream drying component 3 of the series drying path, flowing sequentially through each drying component 3. During this process, hot air, with a temperature gradient distribution provided by multiple heat exchange systems 2, dries the solid waste in each drying component 3 stage by stage, gradually removing moisture. Finally, the dried solid waste is transported to the co-firing unit 4 and fed into the boiler 12 of the thermal power unit 1 for co-firing. The entire system accurately utilizes the originally discarded low, medium, and high-temperature waste heat from the thermal power unit 1 to match the heat requirements of different stages of solid waste drying, significantly improving the overall energy utilization efficiency.

[0032] In some embodiments, the solid waste disposal system of the coupled thermal power unit 1 further includes a pretreatment unit 5. The pretreatment unit 5 includes a dissolving tank 51, a separator 52 and a crusher 53 connected in sequence. The discharge port of the crusher 53 is connected to the inlet of the drying component 3 located at the uppermost position. The pretreatment unit 5 is used to introduce solid waste and to dissolve, separate and crush the solid waste in sequence before conveying it to the drying component 3 located at the uppermost position.

[0033] In this embodiment, the pretreatment unit 5 of the solid waste disposal system coupled to the thermal power unit 1 includes a dissolving tank 51, a separator 52, and a crusher 53 connected in sequence. The dissolving tank 51 is used to introduce raw solid waste (such as municipal sludge) and can dissolve some soluble substances such as organic chlorine by adding water and stirring.

[0034] The separator 52 is connected downstream of the dissolving tank 51 and is used to separate the solid waste that has been dissolved, for example, by magnetic separation or air separation to remove metals or light impurities mixed in it.

[0035] The crusher 53 is connected downstream of the separator 52 and is used to crush the sorted solid waste to adjust its particle size and make it more uniform. The discharge port of the crusher 53 is connected to the feed port of the drying component 3 located at the upstream end.

[0036] Through this pretreatment unit 5, the solid waste undergoes dissolution, impurity sorting, and crushing before entering the drying process. This not only removes impurities such as metals that may damage subsequent equipment, but also makes the solid waste particle size more uniform, increasing the heat exchange area of ​​the subsequent drying process, thereby creating more favorable conditions for subsequent cascade drying.

[0037] In some embodiments, the thermal power unit 1 includes a steam turbine 11 and a boiler 12. Each heat exchange system 2 includes a heat source input end and a hot air output end. The multiple heat exchange systems 2 include a first heat exchange system 212, a second heat exchange system 222, and a third heat exchange system 232. The heat source input end of the first heat exchange system 212 is connected to the exhaust pipe of the steam turbine 11 for extracting waste heat from the steam in the exhaust pipe. The heat source input end of the second heat exchange system 222 is connected to a first temperature section in the flue 17 of the boiler 12 for... The waste heat of the flue gas in the first temperature zone is extracted. The heat source input end of the third heat exchange system 232 is connected to the second temperature zone in the flue 17 of the boiler 12 to extract the waste heat of the flue gas in the second temperature zone. The hot air output ends of the first heat exchange system 212, the second heat exchange system 222 and the third heat exchange system 232 are respectively connected to the drying components 3 from upstream to downstream, and the temperature of the hot air output by the first heat exchange system 212, the second heat exchange system 222 and the third heat exchange system 232 increases sequentially.

[0038] In this embodiment of the invention, the hot air output ends of the first heat exchange system 212, the second heat exchange system 222, and the third heat exchange system 232 in the solid waste treatment system of the coupled thermal power unit 1 are respectively connected to the drying components 3 from upstream to downstream, and the temperature of the hot air output by these three heat exchange systems 2 increases sequentially. Through this structure, the system realizes the cascade recovery and precise allocation of different grades of waste heat (low-temperature steam waste heat, medium-temperature flue gas waste heat, and high-temperature flue gas waste heat) generated by the thermal power unit 1, and uses them respectively for different stages of the solid waste drying process with different temperature requirements, thereby achieving better matching in energy utilization. This effectively solves the energy waste problem caused by the single utilization of waste heat and the use of high-grade heat sources for low-grade requirements in traditional methods, and significantly improves the overall energy utilization efficiency.

[0039] In some specific embodiments, the first heat exchange system 212 to the third heat exchange system 232 can adjust the temperature and air volume of the hot air output as needed, and can be turned on or off as needed.

[0040] In some embodiments, the first heat exchange system 212 includes a steam-air heat exchanger 211, the steam side of which is connected to the exhaust pipe of the steam turbine 11, and the air outlet end of which forms the hot air output end of the first heat exchange system 212.

[0041] In this embodiment, the steam side of the steam-air heat exchanger 211 is connected to the exhaust pipe of the steam turbine 11. Specifically, the exhaust pipe of the steam turbine 11 can be configured in parallel as two lines. One line is conventionally configured to lead to the condenser 16, and the other line is connected to the steam side inlet of the steam-air heat exchanger 211. In this way, a portion of the exhaust steam is diverted into the heat exchanger to release its contained waste heat. Furthermore, regulating valves 223 can be installed on both lines to control the steam diversion ratio.

[0042] The air side of the steam-air heat exchanger 211 is equipped with an air inlet and an air outlet. Air from the environment or circulating within the system flows through its air side and is heated by the steam inside the pipes. The air outlet on this air side constitutes the hot air output end of the first heat exchange system 212, used to output hot air heated by the waste heat of the steam. A fan 222 is typically installed on the pipes used to transport this hot air to provide power, and components such as a regulating valve 223 can be installed to control the airflow and temperature. The exhaust steam from the steam turbine 11 is 80-120℃, and the temperature of the output hot air is 60-80℃.

[0043] By installing the steam-air heat exchanger 211, the system can directly and efficiently recover the low-grade steam waste heat from the exhaust steam of the turbine 11 and convert it into hot air that can be used for the solid waste preheating stage. This avoids the energy loss caused by exhausting all of this waste heat to the condenser 16 for cooling, and realizes the effective capture and utilization of the lowest grade waste heat of the thermal power unit 1, providing a stable and controllable heat source for the initial conditioning and preheating of solid waste.

[0044] In some embodiments, the second heat exchange system 222 includes a flue gas-air heat exchanger 221, the flue gas side of which is connected between the flue 17 of the first temperature zone of the boiler 12 and the subsequent flue 17 of the boiler 12, and the air outlet end of which forms the hot air output end of the second heat exchange system 222.

[0045] In some embodiments, the temperature range of the first temperature zone is 150°C to 250°C.

[0046] In this embodiment, the second heat exchange system 222 includes a flue gas-air heat exchanger 221. The flue gas side of this heat exchanger 221 is connected between the flue duct 17 of the first temperature zone of the boiler 12 and the subsequent flue duct 17 of the boiler 12. Specifically, its flue gas side inlet is located in the section between the economizer 14 and the air preheater in the boiler 12 flue duct 17, used to extract medium-temperature flue gas with a temperature in the first temperature zone (e.g., 150°C to 250°C). The temperature of the output hot air is 120-180°C. Its flue gas side outlet is connected to the subsequent flue duct 17 located downstream of the air preheater, allowing the cooled flue gas to return to the main flue duct 17 system.

[0047] The flue gas-air heat exchanger 221 has an air inlet and an air outlet on its air side. Air from the environment or system circulation flows through its air side and is heated by the medium-temperature flue gas flowing outside the tubes or between the plates. The air outlet on this air side constitutes the hot air output end of the second heat exchange system 222, which is used to output hot air heated by the waste heat of the medium-temperature flue gas.

[0048] In some specific embodiments, the interior of the flue gas-air heat exchanger 221 in the second heat exchange system 222 is filled with a heat storage material, such as a fatty acid ester-graphene composite material, utilizing the latent heat of phase change of the fatty acid ester to achieve energy storage and release. For example, a separate area inside the heat exchanger is filled with this material.

[0049] By connecting the flue gas-air heat exchanger 221 in series in the flue duct 17 between the economizer 14 and the air preheater, this system can efficiently and directly recover the waste heat from the flue gas in this intermediate temperature range. This heat is extracted to heat air, which is then supplied as intermediate temperature hot air to the corresponding drying component 3, specifically for the intermediate stage drying of solid waste. This design avoids the waste caused by limited recovery of intermediate temperature flue gas waste heat through conventional equipment such as air preheaters or direct venting, achieving targeted utilization of waste heat of specific grades, thereby optimizing the cascade utilization process of thermal energy on the flue gas side and improving the overall heat recovery rate.

[0050] In some embodiments, the third heat exchange system 232 includes a first molten salt tank 231, a second molten salt tank 232, a molten salt-flue gas heat exchanger 233, a molten salt-air heat exchanger 234, and a molten salt circulation pipeline 235. Its flue gas side is connected between the flue duct 17 of the second temperature zone of the boiler 12 and the subsequent flue duct 17 of the boiler 12, and its air side outlet constitutes the hot air output end of the third heat exchange system 232. The molten salt circulation pipeline 235 is sequentially connected to the first molten salt tank 231, the molten salt side of the molten salt-flue gas heat exchanger 233, the second molten salt tank 232, and the molten salt side of the molten salt-air heat exchanger 234, and returns to the first molten salt tank 231.

[0051] In some embodiments, the temperature range of the second temperature zone is 300°C to 400°C.

[0052] In the solid waste disposal system of the coupled thermal power unit 1 of this embodiment, the first molten salt storage tank 231 is used to store low-temperature molten salt, and the second molten salt storage tank 232 is used to store high-temperature molten salt. The flue gas side of the molten salt-flue gas heat exchanger 233 is connected between the flue duct 17 of the second temperature zone of the boiler 12 and the subsequent flue duct 17 of the boiler 12. Specifically, its flue gas side inlet is located upstream of the economizer 14 of the boiler 12, and is used to extract high-temperature flue gas with a temperature of 300°C to 400°C; its flue gas side outlet is connected to the flue duct 17 between the economizer 14 and the air preheater. In this way, the waste heat of the high-temperature flue gas is effectively intercepted for heating the molten salt, while the cooled flue gas continues to flow through the subsequent heating surface.

[0053] The air outlet of the molten salt-air heat exchanger 234 forms the hot air output end of the third heat exchange system 232, which is used to output high-temperature hot air.

[0054] The molten salt circulation pipeline 235 sequentially connects to the first molten salt storage tank 231, the molten salt side of the molten salt-flue gas heat exchanger 233, the second molten salt storage tank 232, and the molten salt side of the molten salt-air heat exchanger 234, ultimately returning to the first molten salt storage tank 231, forming a closed-loop circulation circuit. At least one pump 236 is installed on this circuit to drive the molten salt circulation flow. For example, the molten salt pump 236 can be installed at the outlet of the first molten salt storage tank 231 or the inlet of the second molten salt storage tank 232. Furthermore, a backup electric heating device 237 is installed on the molten salt circulation pipeline 235, particularly on the pipeline between the molten salt side outlet of the molten salt-flue gas heat exchanger 233 and the second molten salt storage tank 232. This electric heating device 237 can supplement heat when the flue gas waste heat is insufficient or when the system is started, ensuring a stable molten salt temperature.

[0055] During system operation, low-temperature molten salt is pumped from the first molten salt storage tank 231 by pump 236, flows through the molten salt-flue gas heat exchanger 233, absorbs the waste heat from the high-temperature flue gas, and its temperature rises, transforming into high-temperature molten salt, which is then stored in the second molten salt storage tank 232. When high-temperature drying is required, the high-temperature molten salt flows from the second molten salt storage tank 232 through the molten salt-air heat exchanger 234, releasing its stored high-temperature heat energy to the air flowing through the air side, thereby producing high-temperature hot air; the molten salt, after releasing heat and cooling, flows back to the first molten salt storage tank 231, completing one cycle.

[0056] The above design recovers high-grade flue gas waste heat (300℃ to 400℃) from thermal power unit 1. Utilizing the high heat storage density of molten salt materials (such as nitrate mixtures) near the phase change temperature, intermittent or fluctuating flue gas waste heat is converted into stable and controllable high-temperature thermal energy for storage. This energy can then be released as needed for the deep drying stage of solid waste. The output hot air temperature is 200-250℃. This solves the problem in related technologies where high-temperature waste heat is difficult to store efficiently and use in high-energy-consuming drying processes due to the lack of suitable high-temperature heat storage methods, significantly improving the utilization rate of high-temperature waste heat and ensuring the stability of the final drying effect. Furthermore, the flow rate and volume of the molten salt can be controlled to adapt to changes in the waste heat of thermal power unit 1 under different operating conditions.

[0057] In some embodiments, the co-firing unit 4 includes a solid waste bin 41, a raw coal bin 42, and a coal milling assembly 43. The inlet of the solid waste bin 41 is connected to the outlet of the downstream drying assembly 3 and is used to receive the dried solid waste. The raw coal bin 42 is used to store and output raw coal. The coal milling assembly 43 is connected to the outlet of the solid waste bin 41 and the outlet of the raw coal bin 42, and is connected to the coal feed port of the boiler 12. The coal milling assembly 43 is used to mix the solid waste and raw coal and then transport them to the boiler 12 for combustion.

[0058] In this embodiment, the co-firing unit 4 includes a solid waste bin 41, a raw coal bin 42, and a coal milling assembly 43. The inlet of the solid waste bin 41 is connected to the outlet of the downstream drying assembly 3, and is specifically used to receive and buffer solid waste after multi-stage drying treatment. The raw coal bin 42 is used to store and output the main fuel required for combustion in the boiler 12 of the thermal power unit 1—raw coal.

[0059] The coal mill assembly 43 is connected to the outlets of both the solid waste silo 41 and the raw coal silo 42, and its discharge port is connected to the coal feed port of the boiler 12. In operation, the dried solid waste discharged from the solid waste silo 41 and the raw coal discharged from the raw coal silo 42 are continuously and stably fed into the coal mill assembly 43 (such as a coal mill) in a preset ratio for crushing and thorough mixing. The uniformly mixed solid waste-raw coal mixture is then conveyed to the coal feed port of the circulating fluidized bed boiler 12 and enters the furnace for combustion.

[0060] By setting up dedicated solid waste bins 41 and raw coal bins 42, and integrating them with coal milling components 43 for unified blending and conveying, this co-firing unit 4 achieves large-scale, stable, and homogeneous utilization of dried solid waste as alternative fuel. It not only provides an adjustable auxiliary fuel source for boiler 12, but also ensures the stability of combustion and the safety of boiler 12 operation through precise feed control. This effectively avoids problems such as equipment blockage and decreased combustion efficiency that may be caused by uneven solid waste properties or feed fluctuations, ultimately achieving the harmless treatment and energy recovery of solid waste.

[0061] In some embodiments, the solid waste disposal system of the coupled thermal power unit 1 further includes a moisture recovery unit 6, which is connected to at least one drying component 3 and is used to recover water vapor in the moisture output by the drying component 3.

[0062] In this embodiment, the moisture recovery unit 6 is connected to at least one drying component 3 via a pipe. Specifically, a housing can be installed outside the second drying component 323 and / or the third drying component 333, and the drying component 3 is connected to the housing. Its core function is to recover the high-temperature moisture (mainly water vapor) generated and discharged by the drying component 3 during the heating and drying of solid waste.

[0063] The moisture recovery unit 6 typically contains a condenser 61 and a purifier 62 arranged sequentially inside. Its working process is as follows: Moisture rich in water vapor is drawn out of the chamber by a device such as an induced draft fan 222 and first introduced into the condenser 61. In the condenser 61, the moisture is cooled, and most of the water vapor condenses into liquid water. Subsequently, the condensate, along with any trace impurities it may contain, enters the purifier 62 for further treatment to remove any dust, dissolved salts, or other contaminants it may carry. After purification, clean water is produced.

[0064] The clean water obtained from this recycling and purification can be used as a water source for the boiler 12 makeup water system, and is transported through pipelines to the boiler 12 makeup water inlet to replenish the steam and water losses during boiler 12 operation. By integrating this moisture recovery unit 6, the system achieves effective recovery and resource utilization of water vapor generated during the solid waste drying process. This not only reduces water consumption and wastewater discharge in the entire disposal process, but also reuses the recovered water resources within the thermal power unit 1 itself, forming a local closed-loop water cycle.

[0065] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0066] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0067] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0068] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0069] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0070] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A solid waste disposal system coupled with a thermal power unit, characterized in that, include: Thermal power unit (1); Multiple independent heat exchange systems (2) are connected to the thermal power unit (1) to use the waste heat of steam or flue gas generated by the thermal power unit (1) to heat air and output hot air. Multiple drying components (3) are connected in series. The upstream drying component (3) is used to introduce solid waste. The solid waste is dried by passing through multiple drying components (3) in sequence. The multiple drying components (3) are connected one-to-one with multiple heat exchange systems (2) so that each drying component (3) uses the hot air output from the corresponding heat exchange system (2) to dry the solid waste passing through it. The co-firing unit (4) is connected to the thermal power unit (1) and the downstream drying component (3) for receiving the dried solid waste and transporting it to the thermal power unit (1) for co-firing.

2. The solid waste disposal system for coupled thermal power units according to claim 1, characterized in that, It also includes a pretreatment unit (5), which includes a dissolving tank (51), a sorting machine (52) and a crusher (53) connected in sequence. The discharge port of the crusher (53) is connected to the inlet of the drying component (3) located at the upstream end. The pretreatment unit (5) is used to introduce solid waste and dissolve, sort and crush the solid waste in sequence before conveying it to the drying component (3) located at the upstream end.

3. The solid waste disposal system for coupled thermal power units according to claim 1, characterized in that, The thermal power unit (1) includes a steam turbine (11) and a boiler (12), and each of the heat exchange systems (2) includes a heat source input end and a hot air output end, wherein the plurality of heat exchange systems (2) includes: The first heat exchange system (21) has its heat source input end connected to the exhaust pipe of the steam turbine (11) for extracting the waste heat of the steam in the exhaust pipe. The second heat exchange system (22) has its heat source input end connected to the first temperature section in the flue (17) of the boiler (12) for extracting the waste heat of the flue gas in the first temperature section. The third heat exchange system (23) is connected to the second temperature zone in the flue (17) of the boiler (12) at its heat source input end, and is used to extract the waste heat of the flue gas in the second temperature zone. The hot air output ends of the first heat exchange system (21), the second heat exchange system (22) and the third heat exchange system (23) are respectively connected to the drying components (3) from upstream to downstream, and the temperature of the hot air output by the first heat exchange system (21), the second heat exchange system (22) and the third heat exchange system (23) increases sequentially.

4. The solid waste disposal system for coupled thermal power units according to claim 3, characterized in that, The first heat exchange system (21) includes a steam-air heat exchanger (211), whose steam side is connected to the exhaust pipe of the steam turbine (11), and whose air side outlet end forms the hot air output end of the first heat exchange system (21).

5. The solid waste disposal system for coupled thermal power units according to claim 3, characterized in that, The second heat exchange system (22) includes a flue gas-air heat exchanger (221), the flue gas side of which is connected between the flue of the first temperature section of the boiler (12) and the subsequent flue of the boiler (12), and the air outlet end of which forms the hot air output end of the second heat exchange system (22).

6. The solid waste disposal system for coupled thermal power units according to claim 5, characterized in that, The temperature range of the first temperature zone is 150℃ to 250℃.

7. The solid waste disposal system for coupled thermal power units according to claim 3, characterized in that, The third heat exchange system (23) includes: First molten salt storage tank (231) and second molten salt storage tank (232); Molten salt-flue gas heat exchanger (233), the flue gas side of which is connected between the flue of the second temperature zone of the boiler (12) and the subsequent flue of the boiler (12); The molten salt-air heat exchanger (234) has an air outlet on its air side that forms the hot air output end of the third heat exchange system (23); Molten salt circulation pipeline (235) is connected in sequence to the first molten salt storage tank (231), the molten salt side of the molten salt-flue gas heat exchanger (233), the second molten salt storage tank (232), the molten salt side of the molten salt-air heat exchanger (234), and returns to the first molten salt storage tank (231).

8. The solid waste disposal system for coupled thermal power units according to claim 7, characterized in that, The temperature range of the second temperature zone is 300℃ to 400℃.

9. The solid waste disposal system for coupled thermal power units according to claim 1, characterized in that, The calcination unit (4) includes: Solid waste bin (41), the inlet of which is connected to the outlet of the downstream drying component (3) and is used to receive the dried solid waste; Raw coal bunker (42), which is used to store and output raw coal; The coal grinding assembly (43) is connected to the outlet of the solid waste silo (41) and the outlet of the raw coal silo (42), and is connected to the coal feed port of the boiler (12). The coal grinding assembly (43) is used to mix the solid waste and raw coal and then transport them to the boiler (12) for combustion.

10. The solid waste disposal system for coupled thermal power units according to any one of claims 1-9, characterized in that, It also includes a moisture recovery unit (6), which is connected to at least one of the drying components (3) and is used to recover water vapor in the moisture output by the drying component (3).

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