A carbonization incineration power generation system and process for sludge mixed with solid waste

Abstract

The present invention discloses a carbonization incineration power generation system and process for incinerating sludge mixed with solid waste. The carbonization incineration power generation system includes a solid waste pre-treatment unit, a sludge pre-treatment unit, a co-firing grate furnace carbonization unit, a heat exchange unit, a power generation unit, and a flue gas purification unit. The present invention employs a method for incinerating solid waste mixed with dry sludge, which reduces energy consumption, lowers system operating costs, and realizes resource utilization of various types of solid waste. A flue gas purification unit is used to purify the flue gas generated by incineration and carbonization, achieving "zero emissions." Furthermore, the present invention employs a DCS automatic control unit to coordinate the various components of the system, achieving automated control of the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste treatment, and in particular relates to a carbonization incineration power generation treatment system and process for mixing sludge with solid waste. Background Art

[0002] With the acceleration of urbanization in my country, people's living standards have greatly improved, and the amount of domestic sewage has also increased. Although sewage treatment has achieved remarkable results, the sludge treatment capacity of most sewage treatment plants is relatively backward, causing great harm to the environment. Sludge, as a solid waste, has become the second largest source of solid waste pollution after urban garbage pollution. Traditional sludge disposal methods, such as landfill, incineration, and composting, can reduce sludge to a certain extent, but they do not achieve stable treatment results.

[0003] Relevant data indicates that sludge carbonization technology has high application value. It can effectively treat sludge, separate and eliminate pollutants contained in sludge, and completely reduce its volume and quantity, making it a leading method for sludge treatment. However, the sludge needs to be dried and carbonized, which requires a large amount of energy, resulting in high energy consumption for the equipment. Furthermore, the waste after sludge incineration is not properly handled, causing environmental pollution. Therefore, how to use sludge carbonization technology to properly and scientifically treat sludge and fully utilize the resources contained in sludge to achieve volume reduction, stabilization, harmlessness, and resource utilization is of great practical significance. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide a carbonization incineration power generation system and process for sludge mixed with solid waste, which solves the technical problems of high energy consumption of existing sludge carbonization technology and environmental pollution caused by improper waste treatment.

[0005] To achieve the above technical objectives, in a first aspect, the present invention provides a sludge co-combustion solid waste carbonization incineration power generation system, comprising a solid waste pre-treatment unit, a sludge pre-treatment unit, a co-combustion grate furnace carbonization unit, a heat exchange unit, a power generation unit and a flue gas purification unit, wherein:

[0006] The solid waste pre-treatment unit and the sludge pre-treatment unit are respectively connected to the solid waste fuel inlet and the dry sludge inlet of the co-firing grate furnace carbonization unit;

[0007] The heat exchange unit is connected to the high-temperature flue gas outlet of the co-firing grate furnace carbonization unit, and the heat exchange unit has a flue gas outlet end for the outflow of low-temperature flue gas after heat exchange and a steam outlet end for the outflow of high-temperature steam. The power generation unit is connected to the steam outlet end and is used to transport high-temperature steam to the power generation unit to convert thermal energy into mechanical energy and then into electrical energy. The power generation unit is connected to the sludge pre-treatment unit and is used to transport the high-temperature steam remaining after power generation to the sludge pre-treatment unit to provide heat energy for sludge drying.

[0008] The flue gas purification unit is connected to the flue gas outlet end and is used to purify the flue gas generated by the incineration carbonization reaction.

[0009] Preferably, the solid waste pre-treatment unit includes a unloading device, a crushing device, a solid waste storage bin, a first loading device and a first feeding device connected in sequence, the feed port of the unloading device is connected to an external solid waste transport vehicle, and the discharge port of the first feeding device is connected to the solid waste fuel inlet.

[0010] Preferably, the sludge pre-treatment unit includes a wet sludge receiving bin, a wet sludge conveyor, a wet sludge scraper, a sludge dryer, a dry sludge scraper, a dry sludge conveyor, a second loading device and a second feeding device connected in sequence, the feed port of the wet sludge receiving bin is connected to an external wet sludge transport vehicle, and the discharge port of the second feeding device is connected to the dry sludge inlet, wherein:

[0011] The sludge dryer is also connected to the power generation unit to utilize the high-temperature steam remaining after the power generation unit generates electricity to dry the sludge.

[0012] Preferably, the carbonization unit of the blended grate furnace includes a furnace body and a cyclone separator, wherein:

[0013] A first air inlet is formed on one side of the lower portion of the furnace body, second air inlets are formed on both sides of the middle portion of the furnace body, a solid waste fuel inlet and a dry sludge inlet are formed on one side of the upper portion of the furnace body, an ash recovery inlet is formed on the other side of the upper portion of the furnace body, and a high-temperature flue gas outlet is formed on the top of the furnace body. The first air inlet is connected to the heat exchange unit and the first fan in sequence through a first pipe, and the second air inlet is connected to the heat exchange unit and the second fan in sequence through a second pipe;

[0014] The inlet of the cyclone separator is connected to the high-temperature flue gas outlet, and the outlet of the cyclone separator is connected to the heat exchange unit. An ash discharge outlet is formed at the bottom of the cyclone separator, and the ash discharge outlet is connected to the ash recovery inlet through a pipeline.

[0015] Preferably, the co-firing grate furnace carbonization unit further comprises a soot blowing device, which is arranged on a furnace wall inside the furnace body above the solid waste fuel inlet and the dry sludge inlet.

[0016] Preferably, the heat exchange unit includes a waste heat boiler and a plurality of air preheaters, economizers, evaporators and superheaters arranged in the waste heat boiler, wherein:

[0017] The waste heat boiler is provided with the flue gas outlet at one end and the steam outlet at the other end. The high-temperature flue gas discharged from the cyclone separator outlet passes through the superheater, evaporator, economizer and air preheater in sequence, and is cooled by heat exchange with the flue gas channel formed by the waste heat boiler furnace wall, and then is connected to the flue gas purification unit through the flue gas outlet.

[0018] The plurality of air preheaters are arranged in two parallel groups, wherein two ends of one group are respectively connected to the first air inlet and the first fan through the first pipe, and two ends of the other group are respectively connected to the second air inlet and the second fan through the second pipe;

[0019] One end of the economizer is connected to external desalted water, and the other end is connected to the evaporator and superheater in sequence. The desalted water entering the economizer flows through the evaporator and superheater in sequence to absorb the heat of the high-temperature flue gas and convert it into high-temperature steam, and then is connected to the power generation unit through the steam outlet.

[0020] Preferably, the flue gas purification unit includes a primary dust collector, a secondary dust collector and a wet deacidification tower which are connected in sequence through a flue, the primary dust collector is connected to the flue gas outlet end of the waste heat boiler through the flue, and the wet deacidification tower is connected to the chimney for external flue gas discharge through the flue.

[0021] Preferably, the power generation unit includes a condensing steam turbine generator and a deaerator, the condensing steam turbine generator is connected to the steam outlet to utilize the heat energy generated by carbonization incineration, the water inlet end of the deaerator is respectively connected to the condensing steam turbine generator and external desalted water, and the water outlet end of the deaerator is connected to the economizer.

[0022] Preferably, the carbonization incineration power generation system further includes a DCS automatic control unit, which is electrically connected to the solid waste pre-treatment unit, sludge pre-treatment unit, co-firing grate furnace carbonization unit, heat exchange unit, power generation unit and flue gas purification unit respectively.

[0023] On the other hand, the present invention also provides a carbonization incineration power generation process, which is applicable to the above-mentioned carbonization incineration power generation system for incinerating sludge mixed with solid waste, and the process comprises the following steps:

[0024] S1, start the carbonization unit of the mixed-firing grate furnace to start combustion;

[0025] S2, sending the solid waste and dry sludge treated by the solid waste pre-treatment unit and the sludge pre-treatment unit to the co-firing grate furnace carbonization unit through the solid waste fuel inlet and the dry sludge inlet in a certain proportion for incineration and carbonization;

[0026] S3, the heat exchange unit collects the high-temperature flue gas generated by incineration and carbonization, and uses it to heat the air and desalted water entering it to form preheated air that is returned to the carbonization unit of the co-firing grate furnace and to form high-temperature steam that is sent from the steam outlet of the heat exchange unit to the power generation unit to provide heat energy for power generation;

[0027] S4, transporting the remaining high-temperature steam after the power generation unit generates electricity to the sludge pre-treatment unit to provide heat energy for sludge drying;

[0028] S5, the high-temperature flue gas after heat exchange enters the flue gas purification unit from the flue gas outlet of the heat exchange unit, is purified, and then discharged into the atmosphere.

[0029] Compared with the prior art, the beneficial effects of the present invention mainly include:

[0030] The present invention adopts a process route that combines solid waste incineration with sludge carbonization, and uses the heat generated by solid waste incineration to provide energy for sludge carbonization, which makes up for the insufficient organic matter content and low calorific value in the sludge and promotes the carbonization of the sludge; at the same time, it also replaces the external energy supply required for sludge carbonization, reduces operating energy consumption, and realizes the resource utilization of solid waste; and the high-temperature flue gas generated by the mixed combustion is collected and used on the one hand for preheating the air for incineration and carbonization, which can reduce energy consumption, and on the other hand for heating desalted water to make it into high-temperature steam to provide thermal energy for power generation, and the remaining high-temperature waste heat steam from power generation provides thermal energy for sludge drying. In this way, the system's own surplus energy is fully utilized, which greatly reduces energy loss and reduces operating costs; in addition, the present invention also purifies the flue gas after carbonization and incineration through a flue gas purification unit, reduces the harm of the end product to the system equipment and the pollution to the environment, and achieves "zero emissions". BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a structural diagram of the carbonization incineration power generation system for sludge mixed with solid waste according to the present invention;

[0032] Figure 2 It is a flow chart of the carbonization incineration power generation process of the present invention.

[0033] As shown in the figure:

[0034] 100 - solid waste pre-treatment unit, 110 - unloading device, 120 - crushing device, 130 - solid waste storage bin, 140 - first loading device, 141 - grab bucket, 142 - hopper, 150 - first feeding device;

[0035] 200 - sludge pre-treatment unit, 210 - wet sludge receiving bin, 220 - wet sludge conveyor, 230 - wet sludge scraper, 240 - sludge dryer, 250 - dry sludge scraper, 260 - dry sludge conveyor, 270 - second loading device, 280 - second feeding device, 290 - particle refiner;

[0036] 300 - carbonization unit of the mixed-fired grate furnace, 310 - furnace body, 311 - first air inlet, 312 - second air inlet, 313 - solid waste fuel inlet, 314 - dry sludge inlet, 315 - ash recovery inlet, 316 - high-temperature flue gas outlet, 317 - slag outlet, 320 - cyclone separator, 330 - first pipeline, 331 - first fan, 340 - second pipeline, 341 - second fan, 350 - ignition device, 360 - sootblower;

[0037] 400 - heat exchange unit, 410 - waste heat boiler, 420 - air preheater, 430 - economizer, 440 - evaporator, 450 - superheater;

[0038] 500 - power generation unit, 510 - condensing steam turbine generator, 520 - deaerator;

[0039] 600 - Flue gas purification unit, 610 - Primary dust collector, 620 - Secondary dust collector, 630 - Wet deacidification tower, 640 - Activated carbon injector. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0041] like Figure 1 As shown, the first aspect of the present invention provides a carbonization incineration power generation system for sludge co-combustion of solid waste, including a solid waste pretreatment unit 100, a sludge pretreatment unit 200, a co-combustion grate furnace carbonization unit 300, a heat exchange unit 400, a power generation unit 500 and a flue gas purification unit 600.

[0042] Among them, the solid waste pre-treatment unit 100 is mainly used to crush solid waste, and the sludge pre-treatment unit 200 is mainly used to dry wet sludge. The solid waste pre-treatment unit 100 and the sludge pre-treatment unit 200 are respectively connected to the solid waste fuel inlet and the dry sludge inlet of the co-firing grate furnace carbonization unit 300, so as to deliver the treated solid waste and dry sludge in a certain proportion to the co-firing grate furnace carbonization unit 300 for mixed incineration. Unlike existing sludge carbonization technologies, the present invention adopts a process that combines solid waste incineration with sludge carbonization. The heat generated by solid waste incineration provides energy for sludge carbonization, compensating for the insufficient organic matter content and low calorific value in the sludge, promoting sludge carbonization, and also replacing the external energy supply required for sludge carbonization, reducing operating energy consumption, and realizing resource utilization of solid waste.

[0043] The heat exchange unit 400 is connected to the high-temperature flue gas outlet of the co-firing grate furnace carbonization unit 300 and is used to collect and utilize the heat energy generated by the co-firing grate furnace carbonization unit 300. Specifically, the heat exchange unit 400 has a flue gas outlet for the outflow of low-temperature flue gas after heat exchange and a steam outlet for the outflow of high-temperature steam. The power generation unit 500 is connected to the steam outlet and is used to transport high-temperature steam to the power generation unit 500 to convert thermal energy into mechanical energy and then into electrical energy. The power generation unit 500 is also connected to the sludge pre-treatment unit 200. In this way, the high-temperature steam remaining after power generation is transported to the sludge pre-treatment unit 200 to provide heat energy for sludge drying, making full use of the system's own surplus energy, greatly reducing energy loss and reducing operating costs.

[0044] In addition, the flue gas purification unit 600 is connected to the flue gas outlet end of the heat exchange unit 400, and is used to purify the flue gas generated by the incineration carbonization reaction, reducing the harm of the end products to the system equipment and the pollution to the environment, and achieving "zero emissions".

[0045] The various components of the sludge-co-incineration and solid waste carbonization incineration power generation system of the present invention will be described in detail below.

[0046] like Figure 1As shown, the solid waste pre-treatment unit 100 includes a discharge device 110, a crushing device 120, a solid waste storage bin 130, a first loading device 140, and a first feeding device 150, which are connected in sequence. The feed port of the discharge device 110 is connected to an external solid waste transport vehicle, and the discharge port of the first feeding device 150 is connected to the solid waste fuel inlet. In this way, solid waste transported by the external solid waste transport vehicle first enters the crushing device 120 through the discharge device 110 for crushing. The crushed solid waste is then stored in the solid waste storage bin 130. When feeding is required, the solid waste is fed from the first feeding device 150 to the solid waste fuel inlet of the co-firing grate furnace carbonization unit 300 via the first loading device 140.

[0047] Preferably, the first loading device 140 is composed of a movable grab 141 and a hopper 142, and the first feeding device 150 is a screw conveyor. The grab 141 grabs the material from the solid waste storage bin 130, and sends it to the screw conveyor through the hopper 142, and the screw conveyor transports it to the carbonization unit 300 of the co-firing grate furnace.

[0048] The sludge pretreatment unit 200 includes a wet sludge receiving bin 210, a wet sludge conveyor 220, a wet sludge scraper 230, a sludge dryer 240, a dry sludge scraper 250, a dry sludge conveyor 260, a second loading device 270 and a second feeding device 280, which are connected in sequence. The feed port of the wet sludge receiving bin 210 is connected to an external wet sludge transport vehicle, and the discharge port of the second feeding device 280 is connected to the dry sludge inlet of the co-firing grate furnace carbonization unit 300. In this way, after the external wet sludge is transported by the external wet sludge transport vehicle, it is first stored in the wet sludge receiving bin 210. The wet sludge in the wet sludge receiving bin 210 is processed by the wet sludge conveyor 220 and the wet sludge scraper 230 and then enters the sludge dryer 240 for drying treatment. The treated dry sludge is processed by the dry sludge scraper 250 and then sent to the dry sludge pile silo for storage by the dry sludge conveyor 260. When feeding is required, the dry sludge is conveyed to the dry sludge inlet of the co-firing grate furnace carbonization unit 300 through the second feeding device 270 through the second feeding device 280.

[0049] Preferably, the sludge dryer 240 is also connected to the power generation unit 500, so as to deliver the excess high-temperature steam generated in the power generation unit 500 to the sludge dryer 240, thereby providing heat energy for sludge drying.

[0050] Preferably, the second loading device 270 also includes a grab and a hopper, and the second feeding device 280 is also a screw conveyor. Its operating principle is the same as that of the first loading device 140 and the first feeding device 150 in solid waste, and will not be repeated here.

[0051] Preferably, the sludge dryer 240 is also connected to a tail gas dust collector for purifying the tail gas generated by sludge drying.

[0052] Preferably, the sludge dryer 240 is further connected to the deaerator 520 of the power generation unit 500, so as to collect the steam generated by the sludge dryer 240 into the deaerator 520 for subsequent use.

[0053] Preferably, a particle refiner 290 is further provided between the second feeding device 280 and the dry sludge inlet to further convert the dry sludge into fine particles for easy combustion.

[0054] The carbonization unit 300 of the blended grate furnace includes a furnace body 310, a cyclone separator 320 and a pipeline, wherein:

[0055] A first air inlet 311 is formed on one side of the lower portion of the furnace body 310, second air inlets 312 are formed on both sides of the middle portion of the furnace body 310, a solid waste fuel inlet 313 and a dry sludge inlet 314 are formed on one side of the upper portion of the furnace body 310, an ash recovery inlet 315 is formed on the other side of the upper portion of the furnace body 310, and a high-temperature flue gas outlet 316 is formed on the top of the furnace body 310. The first air inlet 311 is connected to the heat exchange unit 400 and the first fan 331 in sequence through a first pipe 330, and the second air inlet 312 is connected to the heat exchange unit 400 and the second fan 331 in sequence through a second pipe 340. The fan 341 is connected, so that the air introduced by the first fan 331 enters the furnace body 310 from the first air inlet 311 after being preheated by the heat exchange unit 400, and the air introduced by the second fan 341 enters the furnace body 310 from the second air inlet 312 after being preheated by the heat exchange unit 400, and can respectively enter the lower part and the middle part of the furnace body 310, providing sufficient and multi-directional combustion-supporting gas for incineration to ensure its full combustion, and the preheated air can increase the temperature of the air entering the furnace body 310, improve the ignition conditions, increase the incineration temperature, and increase the incineration stability; it can also reduce the heat required for the combustion of the furnace body 310, which is beneficial to reducing energy consumption.

[0056] Preferably, the first fan 331 and the second fan 341 are connected to the solid waste pit area (that is, the solid waste storage bin 130) through the first pipe 330 and the second pipe 340 respectively, so as to introduce the air in the solid waste storage bin 130 into the co-firing grate furnace carbonization unit 300 for combustion.

[0057] The inlet of the cyclone separator 320 is connected to the high-temperature flue gas outlet 316, and the outlet of the cyclone separator 320 is connected to the heat exchange unit 400. That is to say, the high-temperature flue gas generated by the incineration and carbonization of the furnace body 310 enters the heat exchange unit 400 after separation through the cyclone separator 320; and an ash discharge outlet is formed at the bottom of the cyclone separator 320, and the ash discharge outlet is connected to the ash recovery inlet 315 of the furnace body 310 through a pipeline. The separated ash returns to the furnace body 310 and is mixed with dry sludge and solid waste for cyclic combustion and carbonization treatment.

[0058] Preferably, a slag outlet 317 is formed at the bottom of the furnace body 310. The ash produced by the furnace body 310 is discharged from the slag outlet 317 after cooling, and is transported to the ash bin by a pump and then transferred to a product processing factory to make road bricks.

[0059] Preferably, an ignition device 350 is further provided at the lower portion of the furnace body 310 for igniting the combustion of the furnace body 310 .

[0060] Preferably, the co-firing grate furnace carbonization unit 300 also includes a soot blowing device 360, which is arranged in the furnace body 310 and located on the furnace wall above the solid waste fuel inlet 313 and the dry sludge inlet 314, and is used to regularly blow away the fly ash enriched in the furnace wall to maintain the heat exchange efficiency of the flue gas.

[0061] Preferably, the high-temperature flue gas generated by incineration in the furnace body 310 is denitrified by nitrogen injection with the SNCR at the high-temperature flue gas outlet 316. The cyclone separator 320 separates the dust from the flue gas after denitrification. The separated ash is then returned to the furnace body 310 for mixing with dry mud and solid waste for cyclic combustion and carbonization treatment, followed by slag and ash discharge for resource reuse. At the same time, the separated high-temperature flue gas enters the heat exchange unit 400. In this process, the combustible gas and combustible liquid generated by the carbonization and pyrolysis of the sludge are directly incinerated in the furnace body 310, simplifying the processing of the carbonization and pyrolysis gas and fully utilizing the calorific value of the sludge.

[0062] The heat exchange unit 400 is a device for collecting waste heat from the system's waste gas, waste materials, and waste liquids. It includes a waste heat boiler 410 and multiple air preheaters 420, economizers 430, evaporators 440, and superheaters 450 disposed within the waste heat boiler 410.

[0063] The waste heat boiler 410 is provided with the flue gas outlet at one end and the steam outlet at the other end. There are three lines in the waste heat boiler 410: the first is a flue gas channel formed by the high-temperature flue gas discharged from the outlet of the cyclone separator 320, which passes through the outer wall of the superheater 450, the evaporator 440, the economizer 430 and the air preheater 420 and the inner furnace wall of the waste heat boiler 410 in sequence; the second line is an air channel formed by the air introduced by the first fan 331 and the second fan 341, which flows through multiple air preheaters 420 and then enters the furnace body 310; the third line is an air channel formed by the external desalted water and deoxidizer. The water flow introduced by the reactor 520 is converted into high-temperature water vapor through the economizer 430, the evaporator 440 and the superheater 450 and flows into the water flow channel of the condensing steam turbine generator 510. The air in the second line and the water in the third line exchange heat with the high-temperature flue gas in the first line. The flue gas generated by the furnace body 310 after heat exchange and cooling is connected to the flue gas purification unit 600 through the flue gas outlet end of the waste heat boiler 410 and discharged into the atmosphere after purification. The high-temperature water vapor converted in the third line is sent to the power generation unit 500 through the steam outlet end of the waste heat boiler 410 to provide energy for power generation.

[0064] Preferably, the multiple air preheaters 420 are arranged in two parallel groups, wherein the two ends of one group are connected to the first air inlet 311 and the first fan 331 through the first pipe 330, and the two ends of the other group are connected to the second air inlet 312 and the second fan 341 through the second pipe 340, that is, the second circuit mentioned above.

[0065] Preferably, one end of the economizer 430 is connected to external desalted water, and the other end is connected to the evaporator 440 and the superheater 450 in sequence. The desalted water entering the economizer 430 flows through the evaporator 440 and the superheater 450 in sequence to absorb the heat of the high-temperature flue gas and convert it into high-temperature steam, and then is connected to the power generation unit 500 through the steam outlet, which is the third circuit mentioned above.

[0066] The flue gas purification unit 600 includes a primary dust collector 610, a secondary dust collector 620 and a wet deacidification tower 630 connected in sequence through a flue. The primary dust collector 610 is connected to the flue gas outlet end of the waste heat boiler 410 through the flue, and the wet deacidification tower 630 is connected to the chimney for external flue gas discharge through the flue.

[0067] Preferably, the primary dust collector 610 can be an electrostatic precipitator, and the secondary dust collector 620 can be a bag dust collector. After heat exchange, the flue gas coming out of the waste heat boiler 410 is processed in sequence by the electrostatic precipitator, the bag dust collector and the wet deacidification tower 630 to remove dust, acidic gas and heavy metals in the flue gas. After meeting the standards, the flue gas is introduced into the chimney by the induced draft fan and discharged into the atmosphere, achieving "zero pollution" emissions.

[0068] Preferably, an activated carbon ejector 640 is arranged between the primary dust collector 610 and the secondary dust collector 620 to enhance the adsorption effect; the wet deacidification tower 630 is a commonly used device in the art, which includes auxiliary equipment such as Figure 1 As shown, no further details are given here.

[0069] The power generation unit 500 includes a condensing steam turbine generator 510 and a deaerator 520. The condensing steam turbine generator 510 is connected to the steam outlet of the waste heat boiler 410. The high-temperature and high-pressure steam generated by the waste heat boiler 410 after heat exchange is transported to the condensing steam turbine generator 510. The steam turbine first converts the thermal energy of the high-temperature and high-pressure steam into mechanical energy, and then the generator converts the mechanical energy of the turbine rotation into electrical energy. In this way, the thermal energy generated by carbonization incineration is used to generate electricity; the water inlet end of the deaerator 520 is respectively connected to the condensing steam turbine generator 510 and external desalted water, and the water outlet end of the deaerator 520 is connected to the economizer 430. The high-temperature flue gas generated by the furnace body 310 is used to heat the desalted water in the economizer 430, and is converted into high-temperature water vapor through the evaporator 440 and the superheater 450 and sent to the condensing steam turbine generator 510 for power generation. The remaining high-temperature steam from power generation is then sent to the sludge dryer 240 to provide heat energy for sludge drying. At the same time, the cooling water generated by the condensing steam turbine generator 510 enters the deaerator 520 and flows into the economizer 430 together with the desalted water from the outside. This cycle can fully utilize the energy of the system. In addition, part of the water in the deaerator 520 comes from the steam drain generated by the sludge drying in the sludge dryer 240. In this way, not only the energy of the system itself is fully utilized, but also the discharged pollutants are reduced, which is beneficial to environmental protection.

[0070] In addition, the carbonization incineration power generation system described in the present invention also includes a DCS automatic control unit, which is electrically connected to the solid waste pre-treatment unit 100, the sludge pre-treatment unit 200, the co-firing grate furnace carbonization unit 300, the heat exchange unit 400, the power generation unit 500 and the flue gas purification unit 600, respectively, to achieve coordinated control and realize automatic control of the entire system.

[0071] like Figure 2 As shown, another aspect of the present invention provides a carbonization incineration power generation process of a carbonization incineration power generation system for incinerating sludge mixed with solid waste, comprising the following steps:

[0072] S1, start the carbonization unit 300 of the mixed-firing grate furnace to start combustion;

[0073] The DCS automatic control unit controls the start-up of the carbonization unit 300 of the blended grate furnace. With the temporary injection of external oil, the ignition device 350 of the furnace body 310 and the first and second fans 331 and 341 are started to start combustion.

[0074] S2, the solid waste and dry sludge treated by the solid waste pre-treatment unit 100 and the sludge pre-treatment unit 200 are respectively sent to the co-firing grate furnace carbonization unit 300 through the solid waste fuel inlet 313 and the dry sludge inlet 314 in a certain proportion for incineration and carbonization;

[0075] In this process, external wet sludge with a moisture content greater than 60% is generally dried to reduce its moisture content to 40% to 50%, that is, the dry sludge is sent to the furnace body 310 for incineration, and the mixing ratio of solid waste and dry sludge is 4:6 or 5:5.

[0076] S3, the heat exchange unit collects the high-temperature flue gas generated by incineration and carbonization, and uses it to heat the air and desalted water entering it to form preheated air that is returned to the carbonization unit of the co-firing grate furnace and to form high-temperature steam that is sent from the steam outlet of the heat exchange unit to the power generation unit to provide heat energy for power generation;

[0077] During this process, the primary air generated by the first fan 331 enters the bottom of the furnace body 310 through the first pipe 330, and the secondary air generated by the second fan 341 enters the middle of the furnace body 310 through the second pipe 340. The first pipe 330 and the second pipe 340 are both connected to the multiple air preheaters 420 in the waste heat boiler 410 to increase the temperature of the air entering the furnace. The dry sludge and solid waste are fluidized, mixed and burned from bottom to top in the furnace body 310 by the primary air at the bottom. The secondary air provides sufficient oxygen for combustion and ensures full combustion. At the same time, the soot blowing device 360 is used to regularly blow away the fly ash enriched in the furnace wall of the furnace body 310 to maintain the flue gas heat exchange efficiency.

[0078] The high-temperature flue gas generated by the furnace body 310 reacts with ammonia water at the high-temperature flue gas outlet to perform denitrification. The denitrified flue gas enters the cyclone separator 320; the cyclone separator 320 separates the dust in the flue gas, and the separated ash returns to the furnace body 310 and is mixed with dry sludge and solid waste for cyclic combustion and carbonization treatment. The slag and ash are cooled and then pumped to the ash silo, and then transported to the processing product factory to make road bricks.

[0079] At the same time, the flue gas separated by the cyclone separator 320 passes through the superheater 450, evaporator 440, economizer 430, and air preheater 420 for heat exchange and cooling in sequence. After cooling, it is sent to the flue gas purification unit 600 for purification. During this process, the feed water from the deaerator 520 is connected to the economizer 430. The waste heat of the flue gas is used to heat the feed water in the economizer 430. The feed water after the flue gas preheating is sent to the steam drum. At the same time, it forms a water circulation loop together with the downcomer, header, and water-cooled wall. The circulating feed water absorbs heat in the water-cooled wall to form a steam-water mixture that is collected in the steam drum. After the steam-water separation, saturated steam is delivered to the evaporator 440 and superheater 450. The superheater 450 heats the saturated steam into superheated steam of a certain temperature and delivers it to the power generation unit 500 for power generation.

[0080] S4, transporting the remaining high-temperature steam after the power generation unit generates electricity to the sludge pre-treatment unit to provide heat energy for sludge drying;

[0081] After the superheated steam is delivered to the condensing steam turbine generator 510 for power generation, the remaining waste heat steam can be sent to the sludge dryer 240 to dry the sludge, or to the low-temperature heater for auxiliary heating and temperature regulation; it can also be directly removed from the oxygenator 520; the waste heat steam can also be output externally for heating and other uses.

[0082] The condensed water of the condensing steam turbine generator 510 is pumped to the steam seal heater for heating after being stabilized by the condenser, and then transported to the low-temperature heater for heating and then sent to the deaerator 520; the feed water and make-up water of the economizer 430 can use desalinated recycled water to ensure the stability of the steam system. The water produced by the deaerator 520 is then sent to the economizer 430 for heating, forming a water-steam circulation system. After the condensing steam turbine generator 510 converts heat energy into electricity, the electricity is output for use through high-voltage frequency conversion.

[0083] S5, the high-temperature flue gas after heat exchange enters the flue gas purification unit from the flue gas outlet of the heat exchange unit, is purified, and then discharged into the atmosphere;

[0084] The cooled flue gas is sent to the electrostatic precipitator for primary dust removal. After the ash from the electrostatic precipitator is cooled, it is pumped to the ash silo and transported to the processing product factory together with the slag. The flue gas passes through the flue, and the activated carbon injector 640 is installed on the flue to spray activated carbon for mixed adsorption. It is then transferred to the bag dust collector for secondary dust removal and purification. The flue gas then enters the wet deacidification tower 630. After entering, the flue gas moves from bottom to top under the action of the induced draft fan. The flue gas is fully mixed with the alkali absorption liquid sprayed from top to bottom by the alkali liquid spraying device for secondary denitrification, absorbing SO2, NO2 and NO in the flue gas; then the flue gas continues to rise to the dehumidification water tank to remove the alkali absorption liquid particles and trace solid particles entrained in the flue gas. Finally, the flue gas that meets the emission standards is discharged into the outside atmosphere through the chimney.

[0085] In summary, the beneficial effects of the carbonization incineration power generation system and process for sludge mixed with solid waste provided by the present invention can be summarized as follows:

[0086] 1. The present invention adopts a mixed incineration method of solid waste and dry sludge, and uses the heat generated by the combustion of solid waste to provide energy for sludge carbonization, which makes up for the problems of insufficient organic matter content and low calorific value in sludge, and also realizes the resource utilization of various solid wastes and reduces energy consumption;

[0087] 2. The present invention uses a heat exchange unit to collect high-temperature flue gas generated by incineration and carbonization, and introduces air and desalted water into the heat exchange unit to exchange heat with the high-temperature flue gas. The preheated air enters the furnace body to play a role in supporting combustion and stabilizing combustion, while the heated desalted water is converted into high-temperature steam and sent to the power generation unit for power generation. This fully utilizes the energy generated by the system, reduces energy loss, and reduces operating costs.

[0088] 3. The present invention transmits the high-temperature steam remaining after power generation to the sludge dryer to provide heat energy for drying the wet sludge, making full use of the system's own surplus energy and further reducing energy loss;

[0089] 4. The present invention adopts a flue gas purification unit to purify the flue gas generated by incineration and carbonization, achieving "zero emission", reducing or even eliminating the damage of the end products to system equipment, environmental pollution and occupation of land resources;

[0090] 5. The present invention adopts a DCS automatic control unit to coordinate the various components of the control system to achieve automatic control of the system.

[0091] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A carbonization incineration power generation system for sludge mixed with solid waste, characterized in that: It includes solid waste pre-treatment unit, sludge pre-treatment unit, co-firing grate furnace carbonization unit, heat exchange unit, power generation unit and flue gas purification unit, among which: The solid waste pre-treatment unit and the sludge pre-treatment unit are respectively connected to the solid waste fuel inlet and the dry sludge inlet of the co-firing grate furnace carbonization unit; The heat exchange unit is connected to the high-temperature flue gas outlet of the co-firing grate furnace carbonization unit, and the heat exchange unit has a flue gas outlet end for the outflow of low-temperature flue gas after heat exchange and a steam outlet end for the outflow of high-temperature steam. The power generation unit is connected to the steam outlet end and is used to transport high-temperature steam to the power generation unit to convert thermal energy into mechanical energy and then into electrical energy. The power generation unit is connected to the sludge pre-treatment unit and is used to transport the high-temperature steam remaining after power generation to the sludge pre-treatment unit to provide heat energy for sludge drying. The flue gas purification unit is connected to the flue gas outlet and is used to purify the flue gas generated by the incineration carbonization reaction. The carbonization unit of the blended grate furnace includes a furnace body and a cyclone separator, wherein: A first air inlet is formed on one side of the lower portion of the furnace body, second air inlets are formed on both sides of the middle portion of the furnace body, a solid waste fuel inlet and a dry sludge inlet are formed on one side of the upper portion of the furnace body, an ash recovery inlet is formed on the other side of the upper portion of the furnace body, and a high-temperature flue gas outlet is formed on the top of the furnace body. The first air inlet is connected to the heat exchange unit and the first fan in sequence through a first pipe, and the second air inlet is connected to the heat exchange unit and the second fan in sequence through a second pipe; The inlet of the cyclone separator is connected to the high-temperature flue gas outlet, and the outlet of the cyclone separator is connected to the heat exchange unit. An ash discharge outlet is formed at the bottom of the cyclone separator, and the ash discharge outlet is connected to the ash recovery inlet through a pipeline; The heat exchange unit includes a waste heat boiler and a plurality of air preheaters, economizers, evaporators and superheaters arranged in the waste heat boiler, wherein: The waste heat boiler is provided with the flue gas outlet at one end and the steam outlet at the other end. The high-temperature flue gas discharged from the cyclone separator outlet passes through the superheater, evaporator, economizer and air preheater in sequence, and is cooled by heat exchange with the flue gas channel formed by the waste heat boiler furnace wall, and then is connected to the flue gas purification unit through the flue gas outlet. The plurality of air preheaters are arranged in two parallel groups, wherein two ends of one group are respectively connected to the first air inlet and the first fan through the first pipe, and two ends of the other group are respectively connected to the second air inlet and the second fan through the second pipe; One end of the economizer is connected to external desalted water, and the other end is connected to the evaporator and superheater in sequence. The desalted water entering the economizer flows through the evaporator and superheater in sequence to absorb the heat of the high-temperature flue gas and convert it into high-temperature steam, and then is connected to the power generation unit through the steam outlet.

2. The carbonization incineration power generation system for sludge mixed with solid waste according to claim 1 is characterized in that: The solid waste pre-treatment unit includes a unloading device, a crushing device, a solid waste storage bin, a first loading device and a first feeding device connected in sequence. The feed port of the unloading device is connected to an external solid waste transport vehicle, and the discharge port of the first feeding device is connected to the solid waste fuel inlet.

3. The carbonization incineration power generation system for sludge mixed with solid waste according to claim 1 is characterized in that: The sludge pre-treatment unit includes a wet sludge receiving bin, a wet sludge conveyor, a wet sludge scraper, a sludge dryer, a dry sludge scraper, a dry sludge conveyor, a second loading device and a second feeding device connected in sequence. The feed port of the wet sludge receiving bin is connected to an external wet sludge transport vehicle, and the discharge port of the second feeding device is connected to the dry sludge inlet, wherein: The sludge dryer is also connected to the power generation unit to utilize the high-temperature steam remaining after the power generation unit generates electricity to dry the sludge.

4. The carbonization incineration power generation system for sludge mixed with solid waste according to claim 1 is characterized in that: The carbonization unit of the co-firing grate furnace further comprises a soot blowing device, which is arranged on a furnace wall inside the furnace body and above the solid waste fuel inlet and the dry sludge inlet.

5. The carbonization incineration power generation system for sludge mixed with solid waste according to claim 1 is characterized in that: The flue gas purification unit includes a primary dust collector, a secondary dust collector and a wet deacidification tower which are connected in sequence through a flue. The primary dust collector is connected to the flue gas outlet of the waste heat boiler through the flue, and the wet deacidification tower is connected to the chimney for external flue gas discharge through the flue.

6. The carbonization incineration power generation system for sludge mixed with solid waste according to claim 5 is characterized in that: The power generation unit includes a condensing steam turbine generator and a deaerator. The condensing steam turbine generator is connected to the steam outlet to utilize the heat energy generated by carbonization incineration. The water inlet of the deaerator is respectively connected to the condensing steam turbine generator and external desalted water, and the water outlet of the deaerator is connected to the economizer.

7. The carbonization incineration power generation system for sludge mixed with solid waste according to claim 1 is characterized in that: The carbonization incineration power generation system also includes a DCS automatic control unit, which is electrically connected to the solid waste pre-treatment unit, sludge pre-treatment unit, co-firing grate furnace carbonization unit, heat exchange unit, power generation unit and flue gas purification unit respectively.

8. A carbonization incineration power generation process, characterized in that: The carbonization incineration power generation system for sludge mixed with solid waste according to any one of claims 1 to 7 comprises the following steps: S1, start the carbonization unit of the mixed-firing grate furnace to start combustion; S2, sending the solid waste and dry sludge treated by the solid waste pre-treatment unit and the sludge pre-treatment unit to the co-firing grate furnace carbonization unit through the solid waste fuel inlet and the dry sludge inlet in a certain proportion for incineration and carbonization; S3, the heat exchange unit collects the high-temperature flue gas generated by incineration and carbonization, and uses it to heat the air and desalted water entering it to form preheated air that is returned to the carbonization unit of the co-firing grate furnace and to form high-temperature steam that is sent from the steam outlet of the heat exchange unit to the power generation unit to provide heat energy for power generation; S4, transporting the remaining high-temperature steam after the power generation unit generates electricity to the sludge pre-treatment unit to provide heat energy for sludge drying; S5, the high-temperature flue gas after heat exchange enters the flue gas purification unit from the flue gas outlet of the heat exchange unit, is purified, and then discharged into the atmosphere.

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