A system and method for mixed combustion and resource utilization of waste gasification products and LNG

Abstract

The present invention discloses a system and method for mixed combustion and resource utilization of garbage gasification products and LNG, belonging to the field of industrial solid waste treatment and LNG energy cascade utilization. The high-grade cold energy of LNG is used for embrittling and pulverizing garbage; the pulverized small-particle garbage generates gasification gas in a gasification manner, and at this time, the low-grade cold energy of LNG is used for the first-stage rapid cooling treatment of high-temperature gasification gas. The bottom slag of the gasification furnace is prepared into dry activated carbon after a series of treatments. The activated carbon in the bag filter can not only perform acid removal treatment on the gasification gas, but also adsorb dioxins contained in the gasification gas. The bag filter itself performs dust removal on the gasification gas. Finally, the spent activated carbon, clean gasification gas and LNG obtained through heat treatment are mixed and burned, and part of the extracted steam of the steam turbine is used as industrial steam or user heating. It solves the problem that it is relatively difficult to pulverize garbage and realizes the multi-stage utilization of LNG energy.

Description

Technical Field

[0001] The invention belongs to the fields of industrial solid waste treatment and LNG energy cascade utilization, and particularly relates to a system for mixed combustion and resource utilization of waste gasification products and LNG. Background Art

[0002] With the rapid development of the textile, garment and footwear industries, a large amount of leather, cloth scraps, plastic and rubber products are inevitably generated. Most of these organic industrial wastes are polymerized from petrochemical products, containing a relatively high C and H content, a relatively low O content, a relatively high volatile content and a relatively low ash content, and can react with a gasifying agent in a high-temperature gasifier to generate a large amount of combustible gas. In order to improve the gasification efficiency of waste in the gasifier, it is usually crushed, but the crushing effect of traditional mechanical crushers is poor. At present, a liquid nitrogen crusher uses the cold energy released by the gasification of liquid nitrogen at low temperature to embrittle and crush waste, but the crushing capacity of the liquid nitrogen crusher is small, it is difficult to achieve large-scale treatment of waste, and the cost is relatively high. Liquid nitrogen is a product liquefied under the environment of air purification, pressurization and cooling, with a relatively low boiling point (-196 °C). The cold energy released by the vaporization of liquid nitrogen can only be used for forced cooling of waste, and the form of energy utilization is relatively single. In contrast, LNG is a cryogenic fluid at -162 °C (under normal pressure), and a large amount of cold energy can be released during the vaporization process. After the vaporization of LNG is completed, the heat energy generated by its combustion can be used to generate steam, and then power generation can be achieved. Using LNG instead of liquid nitrogen can achieve the cascade utilization of LNG cold energy.

[0003] Polyvinyl chloride plastic (PVC) contained in waste contains a relatively large amount of Cl element. When decomposed in a high-temperature gasifier, a large amount of Cl-containing gas will be released, which will not only affect the reduction of the yield of gasified gas, but also directly release dioxin without treatment, which will cause serious pollution to the environment and cause relatively serious harm to human health. Since the synthesis of dioxin mainly includes the dioxin de novo synthesis reaction mechanism (200-500 °C), the dioxin precursor synthesis reaction mechanism (200-400 °C); the high-temperature gas-phase reaction synthesis mechanism (500-700 °C), and the de novo synthesis reaction mechanism is the main mechanism for dioxin synthesis. Usually, the temperature of the gasified gas is reduced by means of rapid cooling to avoid the synthesis temperature of dioxin. In addition, activated carbon with a relatively developed microporous degree and containing alkaline additives has a dual effect of deacidifying and adsorbing dioxin on the gas, and finally realizes the clean combustion of the gasified gas. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a system and method for the mixed combustion and resource utilization of garbage gasification products and LNG. The cold energy of LNG is utilized in stages, and the high-grade cold energy of LNG is used for the embrittlement and crushing of garbage; the crushed small-particle garbage produces gasification gas in the form of gasification, and at this time, the low-grade cold energy of LNG is used for the primary rapid cooling and cooling treatment of the high-temperature gasification gas. The bottom ash of the gasifier is prepared into dry activated carbon after a series of treatments. The activated carbon can not only deacidify the gasification gas in the bag filter, but also adsorb dioxins contained in the gasification gas. The bag filter itself removes dust from the gasification gas, and finally the spent activated carbon, clean gasification gas and LNG obtained after heating treatment are mixed and burned, and part of the exhaust gas from the turbine is used as industrial steam or user heating.

[0005] The technical solution adopted by the present invention to solve the above-mentioned problem is: a system for mixed combustion and resource utilization of garbage gasification products and LNG, characterized in that it includes: an LNG storage tank, a cryogenic pump for delivering LNG to the inside of a mechanical crusher, a mechanical crusher for crushing garbage, a garbage feed baffle for controlling the feeding of garbage, a garbage discharge baffle for controlling the discharge of crushed garbage particles, and a system for raising the temperature to -10 ℃ to the low-temperature induced draft fan of the tube bundle heat exchanger, gasifier, cyclone separation drum for separating gasification gas and fly ash, tube bundle heat exchanger for exchanging heat between high-temperature gasification gas and cold LNG, flotation device for separating residual carbon and inorganic minerals in the bottom ash of the gasifier, magnetic agitator, drying device for evaporating activated carbon slurry, U-shaped heat exchanger arranged in the drying device, bag filter for dust removal, deacidification and dioxin removal of gasification gas, separator for separating spent activated carbon and fly ash, gasification gas induced draft fan for sending gasification gas without solid ash to the boiler, boiler, steam turbine;

[0006] The inlet of the cryogenic pump is connected to the outlet of the LNG storage tank. The outlet of the cryogenic pump is connected to the cold gas inlet of the mechanical pulverizer. The waste feed baffle is arranged at the waste feed inlet of the mechanical pulverizer. The waste discharge baffle is arranged at the waste discharge outlet of the mechanical pulverizer. The waste discharge outlet of the mechanical pulverizer is connected to the gasifier. The inlet of the low-temperature induced draft fan is connected to the cold gas outlet of the mechanical pulverizer. The outlet of the low-temperature induced draft fan is connected to the LNG cold gas inlet of the tube bundle heat exchanger. The gasifying agent inlet of the gasifier is connected to the extraction port of the steam turbine. The gasification fly ash and gas mixture outlet of the gasifier is connected to the inlet of the cyclone separator. The fly ash outlet of the cyclone separator is connected to the gasifier. The gas outlet of the cyclone separator is connected to the gas inlet of the tube bundle heat exchanger. After the gas-solid two-phase separation by the cyclone separator, the fly ash of the cyclone separator enters the gasifier, and the gas enters the high-temperature gas inlet of the tube bundle heat exchanger. The LNG gas outlet of the tube bundle heat exchanger is connected to the burner of the boiler. The bottom slag outlet of the gasifier is connected to the inlet of the flotation device. The refined carbon outlet of the flotation device is connected to the magnetic stirrer. The inorganic minerals at one side outlet of the flotation device are used as building materials, and the refined carbon at the other side outlet is introduced into the magnetic stirrer. At the same time, an alkaline additive and ethanol are added to the top inlet of the magnetic stirrer. The activated carbon slurry outlet of the magnetic stirrer is connected to the slurry inlet of the drying device. The gas outlet of the tube bundle heat exchanger is connected to the air inlet of the U-shaped heat exchanger. The air outlet of the U-shaped heat exchanger and the solid discharge port of the drying device are both connected to the air inlet of the bag filter. The bottom fly ash and spent activated carbon mixture outlet of the bag filter is connected to the inlet of the separator. The fly ash at one side outlet of the separator is used as building materials, and the spent activated carbon outlet at the other side of the separator is connected to the burner of the boiler. The inlet of the gas induced draft fan is connected to the clean gas outlet of the bag filter. The outlet of the gas induced draft fan is connected to the burner of the boiler. The high-temperature steam outlet of the boiler is connected to the steam inlet of the steam turbine. The high-temperature steam obtained by heating the boiler is used to drive the steam turbine to do work, and at the same time, part of the extraction steam of the steam turbine is used as industrial steam or for user heating.

[0007] Further, the burner includes an LNG gas burner, a gas burner, and a spent activated carbon burner. The LNG gas outlet of the tube bundle heat exchanger is connected to the LNG gas burner. The spent activated carbon outlet at the other side of the separator is connected to the spent activated carbon burner. The outlet of the gas induced draft fan is connected to the gas burner. The LNG gas burner and the gas burner are respectively arranged at the front and rear walls of the boiler. The spent activated carbon burner is arranged above the LNG gas burner.

[0008] The present invention utilizes the high-quality cold energy of LNG to freeze and crush garbage. The temperature of LNG rises to about -10 °C, and the low-quality cold energy of LNG is used to cool the gasified gas until LNG warms up to about 300 °C and is sent into the boiler furnace for combustion. The small particle garbage discharged from the mechanical crusher undergoes a gasification reaction with the extraction steam of the steam turbine in the gasification furnace. The bottom slag of the gasification furnace enters the flotation device. The inorganic mineral components generated on one side of the flotation device are used as building materials, and the refined carbon generated on the other side of the flotation device is used to prepare activated carbon. The refined carbon is mixed with alkaline additives and ethanol and prepared into an activated carbon slurry in a magnetic stirrer. The activated carbon slurry exchanges heat with the gasified gas that has undergone a first cooling in the drying device to achieve the secondary cooling of the gasified gas, and finally dry activated carbon particles are obtained. In the bag filter, the dry activated carbon particles are used to remove acid and adsorb dioxins from the gasified gas that has undergone secondary cooling. The bag filter itself removes dust from the gasified gas. The fly ash and ineffective activated carbon obtained at the bottom of the bag filter are further separated in the separator. The fly ash is used as building materials, and the ineffective activated carbon enters the boiler furnace as a combustible material for combustion. The clean gasified gas discharged from the bag filter is sent into the burner nozzle of the boiler by the gasified gas induced draft fan. In the boiler furnace, the heat generated by the mixed combustion of the gasified gas, LNG, and ineffective activated carbon heats the feed water, and finally the feed water becomes high-temperature steam. The steam drives the steam turbine to do work, and part of the extraction steam of the steam turbine is used as industrial gas or user heating.

[0009] Under the action of the high-quality cold energy of LNG, the mechanical crusher crushes the garbage into granular form. The garbage particles enter the gasification furnace to produce gasified gas and bottom slag. The mixed gasification products of the gasified gas and fly ash are separated in the cyclone separator. The low-quality cold energy of LNG is used for heat exchange with the high-temperature gasified gas that has been separated from the fly ash. After the cold energy of LNG is utilized, it is sent into the burner of the boiler to generate heat energy and then generate electricity, solving the problem of relatively difficult garbage crushing and realizing the multi-stage utilization of LNG energy. The flotation device is used to separate the inorganic minerals and residual refined carbon contained in the gasification bottom slag. The refined carbon is prepared into granular activated carbon in the magnetic stirrer and drying device. In addition, the heat released during the cooling process of the gasified gas is used to evaporate the activated carbon slurry and prepare it into granular activated carbon for the subsequent acid removal and dioxin removal processes of the gasified gas. After a series of treatments, the gasified gas is used as the fuel gas for the boiler. The ash at the bottom of the bag filter and the ineffective activated carbon enter the separator for separation. The ineffective activated carbon obtained after separation is used as a solid fuel in the boiler, and the obtained ash and the inorganic minerals discharged from the flotation device are jointly used as building materials. The heat released by the mixed combustion of the clean gasified gas, LNG, and ineffective activated carbon in the boiler heats the feed water to make it become steam, and part of the steam is used as the gasifying agent of the gasification furnace, not only realizing the clean combustion of the gasified gas but also realizing the hierarchical utilization of resources.

[0010] Compared with the prior art, the present invention has the following advantages and effects:

[0011] (1) The high-grade cold energy of LNG is used for embrittling and crushing garbage, and the low-grade cold energy of LNG is used for cooling the gasified gas. The LNG with a temperature raised to about 300 °C is used as the gas fuel for the boiler, ultimately achieving the purpose of cascaded utilization of LNG energy.

[0012] (2) Under the condition of LNG cold energy, compared with a liquid nitrogen crusher, a mechanical crusher can not only achieve large-scale crushing of garbage, but also reduce the crushing cost of garbage.

[0013] (3) The crushed garbage particles react with the steam from the steam turbine in the gasifier, which can not only achieve volume reduction of the garbage, but also reduce the emission of dioxins compared with traditional garbage incineration. Using the extraction steam of the steam turbine as the gasifying agent in the gasification process realizes the hierarchical utilization of energy.

[0014] (4) The mixture of gasified gas and gasified fly ash is separated into gas-solid two phases in the cyclone separator, and the obtained gasified fly ash is returned to the gasifier, improving the overall gasification efficiency of the garbage.

[0015] (5) In the flotation device, the bottom slag of the gasifier is separated into inorganic minerals and refined carbon. The inorganic minerals are used as building materials, and the refined carbon is the raw material for subsequent activated carbon, realizing the high-value utilization of the bottom slag of the gasifier.

[0016] (6) In the tube bundle heat exchanger, the cold energy of LNG is used to take cooling and quenching measures for the high-temperature gasified gas, reducing the dioxin content in the gasified gas. Then, heat exchange is carried out between the gasified gas and the activated carbon slurry, thereby realizing the secondary cooling of the gasified gas. This can not only prevent the bag filter from catching fire due to the too high temperature of the gasified gas, but also efficiently utilize the energy contained in the gasified gas.

[0017] (7) Activated carbon is added to the bag filter. The alkaline additive contained in the activated carbon is used to deacidify the gasified gas, and the porous characteristics of the activated carbon itself are used to adsorb the remaining dioxins. The bag is used to remove dust from the gasified gas with a small amount of remaining fly ash, providing the possibility for the clean combustion of the subsequent gasified gas.

[0018] (8) The spent activated carbon is used as the solid fuel for boiler combustion, and the heat energy generated by the combustion of LNG and gasified gas is used to preheat the spent activated carbon, improving the combustion efficiency of the fuel. Description of the Drawings

[0019] Figure 1 is a schematic diagram of the system structure of the present invention.

[0020] In the figure: LNG storage tank 1, cryogenic pump 2, mechanical pulverizer 3, waste feed baffle 4, waste discharge baffle 5, cold air outlet 6, cryogenic induced draft fan 7, gasifier 8, cyclone separator 9, tube bundle heat exchanger 10, flotation device 11, magnetic stirrer 12, U-shaped heat exchanger 13, drying device 14, bag filter 15, separator 16, gasified gas induced draft fan 17, boiler 18, LNG gas burner 19, gasified gas burner 20, spent activated carbon burner 21, steam turbine 22. Specific embodiments

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, and the present invention is not limited to the following embodiments.

[0022] Embodiment

[0023] See Figure 1 , in this embodiment, a system for mixing and burning gasified products of waste with LNG and resource utilization includes: an LNG storage tank 1, a cryogenic pump 2 for sending LNG into the mechanical pulverizer 3, a mechanical pulverizer 3 for pulverizing waste, a waste feed baffle 4 for controlling the waste feed, a waste discharge baffle 5 for controlling the discharge of pulverized waste particles, a cryogenic induced draft fan 7 for sending cold LNG with a temperature raised to about -10 °C to the tube bundle heat exchanger 10, a gasifier 8, a cyclone separator 9 for separating gasified gas and fly ash, a tube bundle heat exchanger 10 for exchanging heat between high-temperature gasified gas and cold LNG, a flotation device 11 for separating residual carbon and inorganic minerals in the bottom slag of the gasifier 8, a magnetic stirrer 12, a drying device 14 for evaporating the activated carbon slurry, a U-shaped heat exchanger 13 arranged in the drying device 14, a bag filter 15 for dust removal, acid removal and dioxin removal of the gasified gas, a separator 16 for separating spent activated carbon and fly ash, a gasified gas induced draft fan 17 for sending gasified gas without solid ash to the boiler 18, a boiler 18, and a steam turbine 22;

[0024] The inlet of the cryogenic pump 2 is connected to the outlet of the LNG storage tank 1, the outlet of the cryogenic pump 2 is connected to the cold gas inlet of the mechanical pulverizer 3, the waste feed baffle 4 is arranged at the waste feed port of the mechanical pulverizer 3, the waste discharge baffle 5 is arranged at the waste discharge port of the mechanical pulverizer 3, the waste discharge port of the mechanical pulverizer 3 is connected to the gasifier 8, the inlet of the low-temperature induced draft fan 7 is connected to the cold gas outlet 6 of the mechanical pulverizer 3, the outlet of the low-temperature induced draft fan 7 is connected to the LNG cold gas inlet of the tube bundle heat exchanger 10, the gasifying agent inlet of the gasifier 8 is connected to the extraction port of the steam turbine 22, the gasifying fly ash and gasifying gas mixture outlet of the gasifier 8 is connected to the inlet of the cyclone separator 9, the fly ash outlet of the cyclone separator 9 is connected to the gasifier 8, the gasifying gas outlet of the cyclone separator 9 is connected to the gasifying gas inlet of the tube bundle heat exchanger 10. After the gas-solid two-phase separation by the cyclone separator 9, the fly ash of the cyclone separator 9 enters the gasifier 8, and the gasifying gas enters the high-temperature gasifying gas inlet of the tube bundle heat exchanger 10. The LNG gas outlet of the tube bundle heat exchanger 10 is connected to the burner of the boiler 18; the bottom slag outlet of the gasifier 8 is connected to the inlet of the flotation device 11, the refined carbon outlet of the flotation device 11 is connected to the magnetic stirrer 12, the inorganic minerals at one side outlet of the flotation device 11 are used as building materials, the refined carbon at the other side outlet is introduced into the magnetic stirrer 12. At the same time, alkaline additives and ethanol are added to the top inlet of the magnetic stirrer 12. The activated carbon slurry outlet of the magnetic stirrer 12 is connected to the slurry inlet of the drying device 14. The gasifying gas outlet of the tube bundle heat exchanger 10 is connected to the air inlet of the U-shaped heat exchanger 13. The air outlet of the U-shaped heat exchanger 13 and the solid discharge port of the drying device 14 are both connected to the air inlet of the bag filter 15. The bottom fly ash and ineffective activated carbon mixture outlet of the bag filter 15 is connected to the inlet of the separator 16. The fly ash at one side outlet of the separator 16 is used as building materials, and the ineffective activated carbon outlet at the other side of the separator 16 is connected to the burner of the boiler 18. The inlet of the gasifying gas induced draft fan 17 is connected to the clean gasifying gas outlet of the bag filter 15, and the outlet of the gasifying gas induced draft fan 17 is connected to the burner of the boiler 18. The high-temperature steam outlet of the boiler 18 is connected to the steam inlet of the steam turbine 22. The high-temperature steam obtained by heating the boiler 18 is used to drive the steam turbine 22 to do work, and at the same time, part of the extraction steam of the steam turbine 22 is used as industrial steam or for user heating.

[0025] The burner includes an LNG gas burner 19, a gasifying gas burner 20 and an ineffective activated carbon burner 21. The LNG gas outlet of the tube bundle heat exchanger 10 is connected to the LNG gas burner 19, the ineffective activated carbon outlet at the other side of the separator 16 is connected to the ineffective activated carbon burner 21, and the outlet of the gasifying gas induced draft fan 17 is connected to the gasifying gas burner 20; the LNG gas burner 19 and the gasifying gas burner 20 are respectively arranged at the front and rear wall positions of the boiler 18, and the ineffective activated carbon burner 21 is arranged above the LNG gas burner 19.

[0026] In this embodiment, LNG is used as a cold source to crush the waste raw materials in the mechanical crusher 3. After crushing, the waste particles generate gasified gas and a small amount of residual carbon in the gasifier 8. Finally, LNG, the gasified gas, and the activated carbon obtained by the conversion of the residual carbon are sent to the boiler 18 for mixed combustion. The chemical energy released by the fuel in the boiler 18 is converted into the kinetic energy of steam, and finally electrical energy is generated. During this process, the steam turbine 22 is bled, and the extracted steam is used as industrial steam (such as the gasifying agent in the gasifier 8) and for user heating.

[0027] Working principle: Open the waste feed baffle 4 to allow waste to enter the mechanical crusher 3. When a certain amount of waste is in the mechanical crusher 3, close the waste feed baffle 4, open the cold gas outlet 6 and the low-temperature induced draft fan 7. The cryogenic pump 2 sends LNG to the mechanical crusher 3, and the cold energy during the gasification of LNG is used to forcibly cool the waste and then crush it to a certain mesh size. After the crushing process is completed, close the cryogenic pump 2, open the waste discharge baffle 5, and the crushed waste particles enter the gasifier 8. The waste particles are gasified in the gasifier 8 by adding steam from the steam turbine 22. The gasification products enter the cyclone separator 9 to achieve gas-solid two-phase separation. The gasified gas enters the tube bundle heat exchanger 10 to exchange heat with the cold LNG gas. The gasification fly ash captured by the cyclone separator 9 returns to the gasifier 8 to be mixed with the granular waste for secondary gasification, and the gasification bottom slag is collected at the bottom of the gasifier 8. The flotation device 11 is used to separate the inorganic minerals and the remaining refined carbon in the gasification bottom slag. In the magnetic stirrer 12, the refined carbon, the alkaline additive KOH, and ethanol are made into an activated carbon slurry, and the inorganic mineral components are used as building materials. The heated LNG gas is sent to the LNG gas burner 19, and the gasified gas that has undergone primary temperature reduction is sent to the U-shaped heat exchanger 13 arranged in the drying device 14 to achieve secondary temperature reduction. The heat energy released by the gasified gas evaporates the activated carbon slurry entering the drying device 14 to make it into activated carbon particles. The gasified gas that has undergone secondary temperature reduction and the activated carbon particles are sent to the bag filter 15 at the same time. The activated carbon particles perform secondary dust removal and deacidification treatment on the gasified gas in the bag filter 15. The clean gasified gas is sent to the gasified gas burner 20 for combustion under the action of the gasified gas induced draft fan 17. The fly ash and the spent activated carbon collected at the bottom of the bag filter 15 are separated under the action of the separator 16. The spent activated carbon is sent to the spent activated carbon burner 21 for combustion, and the fly ash becomes building materials. The nozzle of the spent activated carbon burner 21 is arranged above the nozzle of the LNG gas burner 19, and the heat generated by the gas combustion is used to assist the combustion of the spent activated carbon.

[0028] Working method: Open the garbage feed baffle 4 to allow garbage to enter the mechanical crusher 3. When the amount of garbage in the mechanical crusher 3 reaches a certain level, close the garbage feed baffle 4. Then, use the cryogenic pump 2 to send LNG from the LNG storage tank 1 into the mechanical crusher 3. During the crushing process, the cryogenic induced draft fan 7 sends the LNG heated to about -10°C from the cold gas outlet 6 to the tube bundle heat exchanger 10 for secondary heating. The LNG heated to about 300°C enters the LNG gas burner 19; after the garbage crushing is completed, close the cryogenic pump 2 and open the garbage discharge baffle 5 to allow the small particle garbage to enter the gasifier 8. The small particle garbage reacts with a part of the water vapor from the steam turbine 22 in the gasifier 8 to undergo a gasification reaction. The gasification gas carrying gasification fly ash generated during the gasification process is separated in the cyclone separator 9. Most of the fly ash returns to the gasifier 8. The high-temperature gasification gas exchanges heat with the LNG cold gas in the tube bundle heat exchanger 10. The bottom slag of the gasifier 8 is separated into inorganic minerals and refined carbon under the action of the flotation device 11. The inorganic minerals are used as building materials. In the magnetic stirrer 12, the refined carbon is mixed with alkaline additives and ethanol to prepare an activated carbon slurry. The activated carbon slurry enters the drying device 14 and exchanges heat with the gasification gas inside the U-shaped heat exchanger 13 to become activated carbon particles. The activated carbon particles and the gasification gas that has undergone secondary cooling enter the bag filter 15. The porous activated carbon particles containing alkaline additives deacidify the gasification gas and adsorb dioxins. The bag filter 15 dusts the gasification gas. The clean gasification gas is sent to the gasification gas burner 20 by the gasification gas induced draft fan 17; a small amount of fly ash and ineffective activated carbon at the bottom of the bag filter 15 are separated under the action of the separator 16. The fly ash is also used as building materials. The ineffective activated carbon enters the ineffective activated carbon burner 21 and mixes with LNG and gasification gas for combustion. The heat generated by the combustion turns the boiler 18 feed water into steam. The steam enters the steam turbine 22 to do work and finally generates electricity; during this process, a part of the extraction steam from the steam turbine 22 is used as industrial steam or user heating steam.

[0029] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0030] Although the present invention has been disclosed above with embodiments, it is not intended to limit the protection scope of the present invention. Any changes and modifications made by those skilled in the art without departing from the concept and scope of the present invention shall fall within the protection scope of the present invention.

Claims

1. A system for mixed combustion and resource utilization of garbage gasification products and LNG, It is characterized in that include: LNG storage tank (1), a cryogenic pump (2) for delivering LNG to the interior of a mechanical pulverizer (3), a mechanical pulverizer (3) for pulverizing garbage, a garbage feed damper (4) for controlling the feeding of garbage, a garbage discharge damper (5) for controlling the discharge of pulverized garbage particles, a cryogenic induced draft fan (7) for delivering the cold LNG with a raised temperature to a tube bundle heat exchanger (10), a gasifier (8), a cyclone separator (9) for separating gasified gas and fly ash, a tube bundle heat exchanger (10) for exchanging heat between the high-temperature gasified gas and the cold LNG, and a gasifier (8). A flotation device (11) for separating residual carbon and inorganic minerals from the bottom ash of a gasification furnace (8), a magnetic stirrer (12), a drying device (14) for evaporating activated carbon slurry, a U-shaped heat exchanger (13) arranged in the drying device (14), a bag filter (15) for removing dust, acid and dioxins from gasification gas, a separator (16) for separating spent activated carbon from fly ash, a gasification gas induced draft fan (17) for sending gasification gas without solid ash to a boiler (18), a boiler (18), and a steam turbine (22); The inlet of the cryogenic pump (2) is connected to the outlet of the LNG storage tank (1), the outlet of the cryogenic pump (2) is connected to the cold air inlet of the mechanical pulverizer (3), the waste feed baffle (4) is arranged at the waste feed port of the mechanical pulverizer (3), the waste discharge baffle (5) is arranged at the waste discharge port of the mechanical pulverizer (3), the waste discharge port of the mechanical pulverizer (3) is connected to the gasifier (8), the inlet of the low-temperature induced draft fan (7) is connected to the cold air outlet (6) of the mechanical pulverizer (3), the outlet of the low-temperature induced draft fan (7) is connected to the LNG cold air inlet of the tube bundle heat exchanger (10), the gasifying agent inlet of the gasifier (8) is connected to the extraction port of the steam turbine (22), the gasifying fly ash and gas mixture outlet of the gasifier (8) is connected to the inlet of the cyclone separator (9), the fly ash outlet of the cyclone separator (9) is connected to the gasifier (8), the gas outlet of the cyclone separator (9) is connected to the gas inlet of the tube bundle heat exchanger (10), the LNG gas outlet of the tube bundle heat exchanger (10) is connected to the burner of the boiler (18); the bottom slag outlet of the gasifier (8) is connected to the inlet of the flotation device (11), the fine carbon outlet of the flotation device (11) is connected to the magnetic stirrer (12), the activated carbon slurry outlet of the magnetic stirrer (12) is connected to the slurry inlet of the drying device (14), the gas outlet of the tube bundle heat exchanger (10) is connected to the air inlet of the U-shaped heat exchanger (13), the air outlet of the U-shaped heat exchanger (13) and the solid discharge port of the drying device (14) are both connected to the air inlet of the bag filter (15), the bottom fly ash and ineffective activated carbon mixture outlet of the bag filter (15) is connected to the inlet of the separator (16), the ineffective activated carbon outlet of the separator (16) is connected to the burner of the boiler (18), the inlet of the gas induced draft fan (17) is connected to the clean gas outlet of the bag filter (15), the outlet of the gas induced draft fan (17) is connected to the burner of the boiler (18), and the high-temperature steam outlet of the boiler (18) is connected to the steam inlet of the steam turbine (22).

2. The waste gasification product and LNG hybrid combustion and resource utilization system according to claim 1, characterized in that, the burner includes an LNG gas burner (19), a gasified gas burner (20) and an ineffective activated carbon burner (21), the LNG gas outlet of the tube bundle heat exchanger (10) is connected to the LNG gas burner (19), the ineffective activated carbon outlet of the separator (16) is connected to the ineffective activated carbon burner (21), and the outlet of the gas induced draft fan (17) is connected to the gasified gas burner (20); the LNG gas burner (19) and the gasified gas burner (20) are respectively arranged at the front and rear walls of the boiler (18), and the ineffective activated carbon burner (21) is arranged above the LNG gas burner (19).

3. A working method of a system for mixing and burning waste gasification products with LNG and resource utilization as described in claim 1 or 2, characterized in that, the process is as follows: Open the waste feed baffle (4) to allow waste to enter the mechanical crusher (3). When the waste in the mechanical crusher (3) reaches a certain amount, close the waste feed baffle (4). Then, use the cryogenic pump (2) to send LNG from the LNG storage tank (1) into the mechanical crusher (3). During the crushing process, the cryogenic induced draft fan (7) sends the heated LNG from the cold air outlet (6) to the tube bundle heat exchanger (10) for secondary heating, and then enters the LNG gas burner (19). After the waste crushing is completed, close the cryogenic pump (2) and open the waste discharge baffle (5) to allow small particle waste to enter the gasifier (8). The small particle waste and part of the steam from the steam turbine (22) undergo a gasification reaction in the gasifier (8). The gasification gas carrying gasification fly ash is separated in the cyclone separator (9) during the gasification process. Most of the fly ash returns to the gasifier (8). The high-temperature gasification gas exchanges heat with the LNG cold air in the tube bundle heat exchanger (10). The bottom slag of the gasifier (8) is separated into inorganic minerals and refined carbon under the action of the flotation device (11). The inorganic minerals are used as building materials. In the magnetic stirrer (12), the refined carbon is mixed with alkaline additives and ethanol to prepare an activated carbon slurry. The activated carbon slurry enters the drying device (14) to exchange heat with the gasification gas inside the U-shaped heat exchanger (13) to become activated carbon particles. The activated carbon particles and the gasification gas that has undergone secondary cooling enter the bag filter (15). The porous activated carbon particles containing alkaline additives deacidify the gasification gas and adsorb dioxins. The bag filter (15) dusts the gasification gas. The clean gasification gas is sent to the gasification gas burner (20) by the gasification gas induced draft fan (17). A small amount of fly ash and ineffective activated carbon at the bottom of the bag filter (15) are separated under the action of the separator (16). The fly ash is also used as building materials. The ineffective activated carbon enters the ineffective activated carbon burner (21) to mix and burn with LNG and gasification gas. The heat generated by the combustion turns the feed water of the boiler (18) into steam. The steam enters the steam turbine (22) to do work and finally generates electricity. During this process, part of the extraction steam from the steam turbine (22) is used as industrial steam or user heating steam.

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