Garbage gasification system and control method thereof

Abstract

The present invention relates to a garbage gasification system and a control method thereof. The garbage gasification system comprises a rotary kiln, a hot blast furnace and a gasifier; the rotary kiln is provided with a garbage feed port, a pyrolysis ash outlet, a high-ash pyrolysis gas outlet and a jacket layer, and the jacket layer is provided with a first flue gas outlet and a first flue gas inlet; the hot blast furnace is provided with a second flue gas outlet and a hot blast furnace burner, and the hot blast furnace burner is provided with a first fuel gas feed port and a second fuel gas feed port; the gasifier is provided with a low-ash pyrolysis gas feed port, a third air feed port, a gasification gas outlet, a gasification ash outlet and a gasifier burner, and the gasifier burner is provided with a third fuel gas feed port and a second air feed port. In the present invention, the main heat source of the rotary kiln is provided by the hot blast furnace, and the fuel of the hot blast furnace is finally switched to the gasification gas; the heat source fuel of the gasifier can be gradually switched to the gasification gas, so as to realize the self-sustaining combustion and heating of the garbage gasification system, which is conducive to improving the energy utilization efficiency.

Description

Technical Field

[0001] The invention relates to a garbage gasification system and a control method thereof. Background Art

[0002] With the advancement of urbanization, the disposal of urban domestic waste has become an environmental problem that needs to be solved urgently. At present, there are two main methods for the disposal of urban domestic waste: landfill and incineration. Landfill not only occupies a large amount of land, but also brings soil problems in the long run and is prone to secondary pollution. This method does not eradicate the waste. Incineration disposal is suitable for large-scale incineration of domestic waste with a daily processing capacity of more than 300 tons, but the cost of the incinerator and the operating cost of the incineration system are high, and the incineration process is prone to produce toxic and harmful gases such as dioxins, which brings environmental pollution problems.

[0003] In view of the defects of existing landfill and incineration disposal methods, as well as the domestic waste disposal problems in small and medium-sized cities, pyrolysis gasification is a more appropriate disposal method. Through pyrolysis gasification, domestic waste can be pyrolyzed and gasified into combustible gas, and the combustible gas after purification can be used, such as power generation, to achieve harmless treatment of waste and resource utilization of waste. At the same time, there is no minimum disposal scale limit for the incineration line by the power plant turbine, and the pyrolysis gasification technology is flexible.

[0004] At present, the pyrolysis and gasification technologies applicable to garbage and other organic solid waste mainly include fluidized bed gasification technology, fixed bed gasification technology and rotary kiln gasification technology. Fluidized bed gasification technology has high requirements on the size of garbage particles, and requires pre-treatment such as crushing and grading of garbage. It needs to be equipped with corresponding bed material adding equipment or circulation equipment, and the equipment is complex, and the pyrolysis gas has high tar content and other disadvantages. Rotary kiln gasification technology has the disadvantages of high dust content in pyrolysis gas, high carbon content in pyrolysis ash, and high tar content in pyrolysis gas. Commonly used fixed bed gasifiers are mainly of two types: updraft and downdraft. Relatively speaking, the gasification gas produced by the updraft fixed bed gasifier has a higher tar content.

[0005] In patent CN 110715303 A (a system and method for pyrolysis and gasification of municipal solid waste for power generation), both pyrolysis and gasification reactions of waste are carried out in a reactor, and the reactor adopts a fluidized bed gasifier. It is necessary to add auxiliary fluidized medium quartz sand or silicon carbide particles as bed material. When the bed material is reduced, it is necessary to supplement part of the bed material, or return part of the ash to the pyrolysis gasifier as bed material. And it is necessary to be equipped with corresponding bed material adding equipment or circulation equipment, which is complex and has high requirements. The residence time of the waste material in the furnace is uneven. This leads to insufficient gasification reaction, affecting the overall efficiency of the system. It is difficult for the system to achieve continuous operation.

[0006] In patent CN 207313528 U (a garbage pyrolysis gasification system), the pyrolysis gasification system includes a pyrolysis reactor and an electromagnetic wave catalytic cracking reactor. The pyrolysis reactor adopts a spiral propulsion method, which is prone to jamming of garbage materials, affecting the progress of the pyrolysis reaction. At the same time, the burner of the heating device is directly arranged near the discharge end of the pyrolysis reactor. Although the pyrolysis gas combustion can provide heat to the pyrolysis reactor, this heating method is prone to cause the local temperature of the pyrolysis reactor to be too high, or cause local coking due to uneven reaction, and also puts high requirements on the equipment material. During the whole process, the pyrolysis of garbage is carried out in an oxygen-free state, and the obtained gas has complex components, low combustible gas content, and high tar content. On the one hand, it is easy to block the equipment and put forward high requirements on the gas cleaning system. On the other hand, the gas goes to the generator set, and the excessive tar content is difficult to burn out in the generator set, forming particulate matter such as carbon black, which causes great damage to the gasification gas power generation equipment.

[0007] In patent CN 107957069 A (a garbage pyrolysis gasification system), pyrolysis and gasification reactions are both carried out in an updraft gasifier. The tar produced by pyrolysis is directly mixed into the combustible gas (pyrolysis gas). The tar content of the generated combustible gas is very high, and it is difficult to use it as a fuel for generator sets such as internal combustion engines without purification and cooling. The feed inlet and pyrolysis gas outlet of the updraft gasifier are both arranged at the top of the gasifier. The feed inlet needs to be sealed when the gasifier is working, so it is difficult for the system to achieve continuous operation.

[0008] In patent CN 111635773 A (a system and method for pyrolysis and gasification of organic solid waste), part of the pyrolysis gas generated by organic solid waste in a rotary kiln is sent to a burner at the rear of the rotary kiln for combustion to produce high-temperature flue gas. The high-temperature flue gas directly conducts convection heat exchange with the material as a heat source for the pyrolysis reaction. The gas transported to the combustion chamber at the rear of the rotary kiln after pyrolysis is prone to carry solid particles. A high-temperature dust removal net is set near the inlet end of the pyrolysis rotary kiln. The dust removal net in a high-temperature environment is not easy to disassemble and clean. Under long-term operating conditions, the dust removal net is prone to clogging, resulting in the inability of the pyrolysis gas to be completely transported to the combustion chamber at the rear of the rotary kiln for reaction.

[0009] Therefore, in the face of the shortcomings of existing technologies, it is of great practical significance to establish a garbage pyrolysis system with high energy utilization efficiency, high resource utilization level, low operating cost, easy industrialization and scale, and stable operation. Summary of the invention

[0010] The present invention provides a garbage gasification system and a control method thereof to solve the technical problems existing in the prior art. The present invention performs anaerobic pyrolysis on domestic garbage and then gasifies it, realizing separate regulation of anaerobic pyrolysis reaction and anoxic gasification reaction, and at the same time removing tar in the gasifier to achieve harmless treatment of garbage, with high system thermal efficiency, stable system and high resource utilization rate.

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] In a first aspect, the present invention provides a garbage gasification system, which includes a rotary kiln, a hot blast stove and a gasification furnace;

[0013] The rotary kiln is provided with a garbage feed inlet, a pyrolysis ash outlet, a high-ash pyrolysis gas outlet and a jacket layer, and the jacket layer is provided with a first flue gas outlet and a first flue gas inlet; the hot blast furnace is provided with a second flue gas outlet and a hot blast furnace burner, and the hot blast furnace burner is provided with a first fuel gas feed inlet and a second fuel gas feed inlet; the gasifier is provided with a low-ash pyrolysis gas feed inlet, a third air feed inlet, a gasification gas outlet, a gasification ash outlet and a gasifier burner, and the gasifier burner is provided with a third fuel gas feed inlet and a second air feed inlet;

[0014] The high-ash pyrolysis gas outlet is connected to the atmosphere through the fifth pyrolysis gas pipeline; the high-ash pyrolysis gas outlet of the rotary kiln is connected to the first fuel gas feed port of the hot blast furnace through the pyrolysis gas pipeline; the low-ash pyrolysis gas feed port of the hot blast furnace is connected to the pyrolysis gas pipeline through the fourth pyrolysis gas pipeline at node A; the gasification gas outlet of the gasifier is connected to the atmosphere through the gasification gas pipeline; the gasification gas pipeline is connected to the pyrolysis gas pipeline at node B through the second gasification gas pipeline, and a valve is provided on the second gasification gas pipeline;

[0015] The second flue gas outlet of the hot blast furnace is connected to the first flue gas inlet of the rotary kiln through the first flue gas pipeline; the third fuel gas feed port of the gasifier is connected to the fuel gas source through the first natural gas pipeline; the gasification gas pipeline is connected to the first natural gas pipeline through the first gasification gas pipeline.

[0016] In the present invention, the garbage gasification system further comprises a feed conveying device, the garbage to be gasified enters from the inlet end of the feed conveying device, and the outlet of the feed conveying device is connected to the garbage feed port of the rotary kiln.

[0017] In the present invention, the garbage gasification system further comprises a spiral dust collector, and the spiral dust collector is provided with a first inlet for high-ash pyrolysis gas and an outlet for low-ash pyrolysis gas.

[0018] The high-ash pyrolysis gas discharge port of the rotary kiln is connected to the high-ash pyrolysis gas first inlet of the spiral dust collector through a first pyrolysis gas pipeline.

[0019] Among them, the low-ash pyrolysis gas outlet of the spiral dust collector is connected to the first fuel gas inlet of the hot blast furnace through the pyrolysis gas pipeline, and a fan is provided on the pyrolysis gas pipeline between the low-ash pyrolysis gas outlet of the spiral dust collector and the node A.

[0020] Wherein, a spiral component is provided inside the spiral dust collector.

[0021] Wherein, the spiral dust collector is 10-30° with the horizontal line.

[0022] In the present invention, the first flue gas outlet of the rotary kiln is connected to the atmosphere through a fifth flue gas pipeline. The fifth flue gas pipeline is provided with a thermometer, a valve, a flue gas purification device or a fan.

[0023] In the present invention, the pyrolysis ash outlet of the rotary kiln is connected to the inlet of the pyrolysis ash discharge equipment.

[0024] In the present invention, a thermometer is provided on the rotary kiln.

[0025] In the present invention, the garbage gasification system further comprises a pyrolysis gas spray tank, and the pyrolysis gas spray tank is provided with a second high-ash pyrolysis gas inlet, an exhaust port, a spray water inlet and a spray water outlet.

[0026] Wherein, the high-ash pyrolysis gas discharge port of the rotary kiln is connected to the high-ash pyrolysis gas second inlet of the pyrolysis gas spray tank.

[0027] Wherein, the exhaust port of the pyrolysis gas spray tank is connected to the atmosphere.

[0028] The spray water inlet is connected to a spray water source through a spray water inlet pipe. A valve is provided on the spray water inlet pipe.

[0029] Wherein, the spray water outlet is connected to a spray water outlet pipe. A valve is arranged on the spray water outlet pipe.

[0030] In the present invention, the second fuel gas feed port of the hot blast furnace is connected to the air source through the first air pipeline. The first air pipeline is provided with a fan, a third flow meter and a third flow regulating valve in sequence along the gas flow direction. The third flow meter and the third flow regulating valve are signal-connected.

[0031] In the present invention, the second fuel gas feed port of the hot blast furnace is connected to the natural gas source through a second natural gas pipeline. A second flow meter and a second flow regulating valve are sequentially arranged along the gas flow direction on the second natural gas pipeline. The second flow meter and the second flow regulating valve are signal-connected.

[0032] In the present invention, a thermometer is provided on the hot blast furnace.

[0033] In the present invention, an oxygen concentration analyzer and / or a thermometer is provided on the first flue gas pipeline at a position close to the second flue gas outlet.

[0034] In the present invention, two valves are provided between the node A and the node B.

[0035] In the present invention, the garbage gasification system further comprises a preheater, wherein the preheater is provided with a cold air inlet, a hot air outlet and a jacket, and the jacket is provided with a third smoke inlet and a third smoke outlet.

[0036] Wherein, the third flue gas inlet of the preheater is connected to the first flue gas pipeline through the second flue gas pipeline.

[0037] The first cold air inlet of the preheater is connected to the air source through a second air pipeline. A fan, a fourth flow meter and a fourth flow regulating valve are sequentially arranged along the gas flow direction of the second air pipeline. A second thermometer is arranged on the hot air furnace, and the fourth flow meter and the second thermometer are connected to the fourth flow regulating valve signal.

[0038] The hot blast furnace burner is also provided with a first air feed inlet, and the first hot air outlet of the preheater is connected to the first air feed inlet of the hot blast furnace through a third air pipeline. A thermometer is provided on the third air pipeline.

[0039] In certain specific embodiments of the present invention, the spiral dust collector is also provided with a jacket, and the jacket is provided with a fourth flue gas inlet and a fourth flue gas outlet. The fourth flue gas inlet of the spiral dust collector is connected to the first flue gas pipeline through a third flue gas pipeline, and the fourth flue gas outlet of the spiral dust collector is connected to the fifth flue gas pipeline through a seventh flue gas pipeline.

[0040] In the present invention, the gasifier is a downdraft gasifier.

[0041] In the present invention, the gasifier burner is arranged on the top of the gasifier.

[0042] In the present invention, the third fuel gas feed port of the gasifier is connected to a natural gas source through a first natural gas pipeline, and a valve and / or a flow meter are provided on the first natural gas pipeline.

[0043] In the present invention, the second air feed port of the gasifier is connected to the air source through a fourth air pipeline. A fan, a sixth flow meter and a sixth flow regulating valve are sequentially arranged along the gas flow direction of the fourth air pipeline. The sixth flow meter and the sixth flow regulating valve are signal-connected.

[0044] In the present invention, a grate is provided inside the gasifier, and a thermometer is provided at a position higher than the grate.

[0045] In the present invention, the gasifier is further provided with a pyrolysis ash feed port, and the pyrolysis ash outlet of the rotary kiln is connected to the pyrolysis ash feed port of the gasifier.

[0046] In the present invention, the gasifier is further provided with a second cold air inlet and a second hot air outlet, the second cold air inlet and the second hot air outlet are connected via an air pipeline, and the air pipeline is located inside the gasifier.

[0047] Wherein, the garbage gasification system further comprises a mixer, and the mixer is provided with a first air inlet, a first air outlet and a second air inlet.

[0048] Further, the second cold air inlet of the gasifier is connected to the first air outlet of the mixer through the sixth air pipeline. The sixth air pipeline is provided with a valve and / or a thermometer. The sixth air pipeline is connected to the air inlet of the drying device through the seventh air pipeline. The air outlet of the drying device is connected to the atmosphere through the tenth air pipeline. The tenth air pipeline is provided with a ninth flow meter and a ninth flow regulating valve in sequence along the gas flow direction. The ninth flow meter and the ninth flow regulating valve are signal-connected.

[0049] Furthermore, the first air inlet of the mixer is connected to the air source through a fifth air pipeline. A fan, an eighth flow meter and an eighth flow regulating valve are sequentially arranged along the gas flow direction on the fifth air pipeline. The eighth flow meter and the eighth flow regulating valve are signal-connected.

[0050] The second hot air outlet of the gasifier is connected to the third air feed inlet of the gasifier through an eighth air pipeline. A thermometer and / or a valve is arranged on the eighth air pipeline.

[0051] In some specific embodiments of the present invention, the eighth air pipeline is connected to the second air inlet of the mixer through a ninth air pipeline. A valve is provided on the ninth air pipeline.

[0052] In the present invention, a gasification gas buffer tank is provided on the gasification gas pipeline, the gasification gas outlet of the gasifier is connected to the inlet of the gasification gas buffer tank, and the outlet of the gasification gas buffer tank is connected to the atmosphere through a fourth gasification gas pipeline. A valve is provided on the fourth gasification gas pipeline near the atmospheric connection.

[0053] Wherein, a cyclone separator, a deacidification and dust removal device, a cooling and decoking device and a desulfurization device are sequentially arranged on the gasification gas pipeline between the gasification gas outlet of the gasifier and the gasification gas inlet of the gasification gas buffer tank along the gas flow direction. A fan, a hydrogen sulfide analyzer and a gas analyzer are arranged on the gasification gas pipeline between the desulfurization device and the gasification gas buffer tank.

[0054] Furthermore, the cooling and decoking equipment includes a venturi tube, a first-level cyclone heat exchanger, a second-level cyclone heat exchanger, a condenser and an electric tar precipitator; the venturi tube is provided with a gasification gas inlet, a contraction tube air inlet and an expansion tube air outlet; the first-level cyclone heat exchanger is provided with a first-level air inlet, a first-level air outlet and a first-level ash outlet; the second-level cyclone heat exchanger is provided with a second-level air inlet, a second-level first air outlet and a second-level second air outlet; the condenser is provided with a condensation air inlet and a condensation air outlet; the electric tar precipitator is provided with an electric tar precipitator air inlet and a gasification gas outlet.

[0055] The gasification gas inlet of the venturi tube is connected to the outlet of the deacidification and dust removal equipment, the contraction tube air inlet of the venturi tube is connected to the secondary first air outlet of the secondary cyclone heat exchanger, and the expansion tube air outlet of the venturi tube is connected to the primary air inlet of the primary cyclone heat exchanger; the primary air outlet of the primary cyclone heat exchanger is connected to the secondary air inlet of the secondary cyclone heat exchanger; the secondary second air outlet of the secondary cyclone heat exchanger is connected to the condensation air inlet of the condenser; the condensation air outlet of the condenser is connected to the electric tar precipitator air inlet of the electric tar precipitator; the gasification gas outlet of the electric tar precipitator is connected to the inlet of the desulfurization equipment.

[0056] In some specific embodiments of the present invention, the primary air inlet and the primary air outlet of the primary cyclone heat exchanger are located at the same end of the device. A water cooling jacket is provided on the outer side of the cylinder of the primary cyclone heat exchanger, and the water cooling jacket is provided with a cooling water inlet and a cooling water return port.

[0057] In certain specific embodiments of the present invention, the secondary air inlet and the secondary second air outlet of the secondary cyclone heat exchanger are respectively located at two ends of the device. A water cooling jacket is provided on the outside of the cylinder of the secondary cyclone heat exchanger, and the water cooling jacket is provided with a cooling water inlet and a cooling water return port. A flow stabilizing mandrel is provided inside the secondary cyclone heat exchanger.

[0058] In some specific embodiments of the present invention, a water cooling jacket is provided on the outer side of the cylinder of the condenser, and the water cooling jacket is provided with a cooling water inlet and a cooling water return inlet. An oxygen concentration analyzer is provided on the pipeline connecting the condensation outlet of the condenser and the electric tar precipitator inlet of the electric tar precipitator.

[0059] In the present invention, the garbage gasification system further comprises an internal combustion engine, and the gasification gas pipeline is connected to the gasification gas inlet of the internal combustion engine through a third gasification gas pipeline.

[0060] The hot blast furnace is also provided with a second flue gas inlet, and the flue gas outlet of the internal combustion engine is connected to the second flue gas inlet of the hot blast furnace through a fourth flue gas pipeline. A valve is provided on the fourth flue gas pipeline.

[0061] In the present invention, conventionally, a valve is provided on the fourth pyrolysis gas pipeline.

[0062] In the present invention, conventionally, a valve is provided on the gasification gas pipeline near the atmospheric connection point.

[0063] In the present invention, conventionally, a valve is provided between the node A and the node B.

[0064] In the present invention, conventionally, a valve is provided on the first gasification gas pipeline.

[0065] In the present invention, a first flow meter and a first flow regulating valve are sequentially arranged along the gas flow direction on the second gasification gas pipeline, and the first flow meter and the first flow regulating valve are signal-connected.

[0066] In a second aspect, the present invention provides a control method for the garbage gasification system as described above, which comprises the following steps:

[0067] Step 1, closing the first fuel gas feed port of the hot blast furnace; introducing combustion-supporting gas and fuel gas into the second fuel gas feed port of the hot blast furnace, and burning them in the hot blast furnace burner of the hot blast furnace until the temperature of the rotary kiln reaches 350° C.;

[0068] Step 2: Open the first fuel gas feed port of the hot blast furnace and close the low-ash pyrolysis gas feed port of the gasifier; transport garbage through the garbage feed port of the rotary kiln until the temperature of the hot blast furnace reaches 800° C.

[0069] Step 3: close the connection between the second gasification gas pipeline and the pyrolysis gas pipeline, and close the connection between the first gasification gas pipeline and the first natural gas pipeline; introduce fuel gas into the third fuel gas feed port of the gasifier, introduce combustion-supporting gas into the second air feed port of the gasifier, and burn in the gasifier until the temperature of the gasifier reaches 600° C.

[0070] Step 4: close the connection between the pyrolysis gas pipeline and the first fuel gas feed port of the hot blast furnace, and open the low-ash pyrolysis gas feed port of the gasifier until the temperature of the gasifier reaches 900° C.

[0071] Step five, close the connection between the gasification gas pipeline and the atmosphere, open the connection between the second gasification gas pipeline and the pyrolysis gas pipeline, open the connection between the first gasification gas pipeline and the first natural gas pipeline, stop introducing fuel gas into the third fuel gas feed port of the gasifier, and stop introducing fuel gas into the second fuel gas feed port of the hot blast furnace.

[0072] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0073] The positive and progressive effects of the present invention are:

[0074] (1) In the present invention, the main heat source of the rotary kiln is provided by the hot blast furnace, and the fuel of the hot blast furnace can be gradually switched from the initial externally supplied natural gas to pyrolysis gas, and finally to gasification gas; similarly, the heat source fuel of the gasifier can be gradually switched from the initial externally supplied natural gas to gasification gas, so as to realize the self-sustaining combustion heating of the garbage gasification system, which is beneficial to improve the energy utilization efficiency;

[0075] (2) In the present invention, the heat source of the rotary kiln is rich, which can be the flue gas generated by the combustion of natural gas, pyrolysis gas or purified gasification gas in the hot blast furnace, or the flue gas generated by the internal combustion engine, so that the pyrolysis temperature of the rotary kiln is stable and controllable, and the system stability is high;

[0076] (3) In the present invention, the hot air of the gasifier can be derived from the internal air pipeline after the high-temperature furnace of the gasifier has been radiated and heat-exchanged. The high-temperature radiation heat in the gasifier can be used to heat the gasifier, which helps to improve the gasification efficiency, and to provide a heat source for the garbage drying equipment, thereby improving the overall heat utilization efficiency of the whole system.

[0077] (4) In the present invention, the pyrolysis ash can be put into the gasifier for gasification reaction, so that the heavy hydrocarbons are cracked again to produce gasification gas;

[0078] (5) In the present invention, a spiral dust collector can be provided at the pyrolysis gas outlet of the rotary kiln, which is beneficial for removing solid particles entrained in the pyrolysis gas, avoiding blockage of downstream pipelines and hot blast furnace burners, and improving system stability;

[0079] (6) In the present invention, the cooling and decoking equipment adopts a combination of a primary cyclone heat exchanger, a secondary cyclone heat exchanger, a condenser and an electric tar collector to remove the tar contained in the gasification gas without generating tar-containing wastewater. It has the advantages of environmental protection, energy saving and high selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 This is a schematic diagram of the cooling and decoking equipment in Example 1;

[0081] Figure 2 This is a schematic diagram of the garbage gasification system in Example 2;

[0082] Figure 3 This is a logic block diagram of the method for starting the garbage gasification system in Example 3;

[0083] The numbers in the figure show:

[0084] Feed conveying equipment1

[0085] Rotary kiln 2

[0086] Fuel gas first feed port 31, air first feed port 32, fuel gas second feed port 33, flue gas second outlet 34, flue gas second inlet 35, low ash pyrolysis gas feed port 36, cold air second inlet 37, hot air second outlet 38, air third feed port 39, pyrolysis ash feed port 310, air second inlet 311, air first outlet 312, air first inlet 313, gasification gas outlet 314

[0087] a first pyrolysis gas pipeline 41, a second pyrolysis gas pipeline 42, a third pyrolysis gas pipeline 43, a fourth pyrolysis gas pipeline 44, a first gasification gas pipeline 45, a second gasification gas pipeline 46, a third gasification gas pipeline 47, a fourth gasification gas pipeline 48, a first flue gas pipeline 49, a second flue gas pipeline 410, a third flue gas pipeline 411, a fourth flue gas pipeline 412, a fifth flue gas pipeline 413, a seventh flue gas pipeline 415, a first air pipeline 416, a second air pipeline 417, a third air pipeline 418, a fourth air pipeline 419, a fifth air pipeline 420, a sixth air pipeline 421, a seventh air pipeline 422, an eighth air pipeline 423, a ninth air pipeline 424, a tenth air pipeline 425, a first natural gas pipeline 426, a second natural gas pipeline 427, and a fifth pyrolysis gas pipeline 428;

[0088] The first thermometer 51, the second thermometer 52, the third thermometer 53, the fourth thermometer 54, the fifth thermometer 55, the fifth thermometer 56, and the ninth thermometer 59

[0089] A first flow meter 61 , a second flow meter 62 , a third flow meter 63 , a fourth flow meter 64 , a fifth flow meter 65 , a sixth flow meter 66 , a seventh flow meter 67 , an eighth flow meter 68 , and a ninth flow meter 69

[0090] A first air fan 71, a second air fan 72, a third air fan 73, a fourth air fan 74, a pyrolysis gas fan 75, a flue gas fan 76, and a gas fan 77

[0091] First flow control valve 81 , second flow control valve 82 , third flow control valve 83 , fourth flow control valve 84 , fifth flow control valve 85 , sixth flow control valve 86 , seventh flow control valve 87 , eighth flow control valve 88 , ninth flow control valve 89

[0092] First shutoff valve 91 , second shutoff valve 92 , third shutoff valve 93 , fifth shutoff valve 95 , sixth shutoff valve 96 , seventh shutoff valve 97 , eighth shutoff valve 98 , ninth shutoff valve 99 , tenth shutoff valve 910 , eleventh shutoff valve 911 , twelfth shutoff valve 912

[0093] Hot air stove 10

[0094] Preheater 11

[0095] Gasifier 12

[0096] Cooling and decoking equipment 15, venturi tube 1501, shrink tube air inlet 150101, primary cyclone heat exchanger 1502, secondary cyclone heat exchanger 1503, secondary first air outlet 150301, secondary second air outlet 150302, flow stabilizing core rod 150303, condenser 1504, second oxygen concentration analyzer 150401, electric tar collector 1505

[0097] Cyclone separator 13

[0098] Deacidification and dust removal equipment14

[0099] Desulfurization equipment16

[0100] Gasification gas buffer tank 17

[0101] Mixer 18

[0102] Drying equipment19

[0103] Gasification ash equipment 20

[0104] Pyrolysis ash slag removal equipment 21

[0105] Internal combustion engine 22

[0106] Flue gas purification equipment 23

[0107] Spiral dust collector 24

[0108] Gas Analyzer 25

[0109] First oxygen concentration analyzer 26

[0110] Pyrolysis gas spray tank 27

[0111] Hydrogen sulfide analyzer 28 DETAILED DESCRIPTION

[0112] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0113] Example 1

[0114] A cooling and decoking device, such as Figure 1, including: a venturi tube 1501, a primary cyclone heat exchanger 1502, a secondary cyclone heat exchanger 1503, a condenser 1504 and an electric tar collector 1505. The venturi tube 1501 is provided with a gasification gas inlet, a contraction tube air inlet 150101 and an expansion tube air outlet. The primary cyclone heat exchanger 1502 is provided with a primary air inlet, a primary air outlet and a primary ash outlet. The secondary cyclone heat exchanger 1503 is provided with a secondary air inlet, a secondary first air outlet 150301 and a secondary second air outlet 150302. The condenser 1504 is provided with a condensation air inlet and a condensation air outlet. The electric tar collector 1505 is provided with an electric tar collector air inlet and a gasification gas outlet.

[0115] In this embodiment, the gasification gas inlet of the venturi tube 1501 is connected to the gasification gas source, the contraction tube air inlet 150101 of the venturi tube 1501 is connected to the secondary first air outlet 150301 of the secondary cyclone heat exchanger 1503, and the expansion tube air outlet of the venturi tube 1501 is connected to the primary air inlet of the primary cyclone heat exchanger 1502. The primary air outlet of the primary cyclone heat exchanger 1502 is connected to the secondary air inlet of the secondary cyclone heat exchanger 1503. The secondary second air outlet 150302 of the secondary cyclone heat exchanger 1503 is connected to the condensation air inlet of the condenser 1504. The condensation air outlet of the condenser 1504 is connected to the electric tar precipitator air inlet of the electric tar precipitator 1505.

[0116] In this embodiment, the first-stage cyclone heat exchanger 1502 adopts the form of "water-cooled jacket + reflux cyclone separator", that is, the first-stage air inlet and the first-stage air outlet of the first-stage cyclone heat exchanger 1502 are located at the same end position of the equipment; a water-cooled jacket is arranged on the outside of the cylinder of the first-stage cyclone heat exchanger 1502, and the water-cooled jacket is provided with a cooling water inlet and a cooling water return outlet, and the cooling water inlet temperature is 30°C.

[0117] In this embodiment, the secondary cyclone heat exchanger 1503 adopts the form of "water-cooled jacket + direct-flow cyclone separator", that is, the secondary air inlet and the secondary second air outlet 150302 of the secondary cyclone heat exchanger 1503 are respectively located at the two ends of the equipment; the outer side of the cylinder of the secondary cyclone heat exchanger 1503 is provided with a water-cooled jacket, and the water-cooled jacket is provided with a cooling water inlet and a cooling water return inlet, and the cooling water inlet temperature is 30°C. A flow stabilizing core rod 150303 is provided inside the secondary cyclone heat exchanger 1503.

[0118] In this embodiment, a water cooling jacket is provided on the outer side of the cylinder of the condenser 1504, and the water cooling jacket is provided with a cooling water inlet and a cooling water return port. A second oxygen concentration analyzer 150401 is provided on the pipeline connecting the condensation outlet of the condenser 1504 and the electric tar precipitator 1505 electric tar precipitator inlet.

[0119] Example 2

[0120] A garbage gasification system, such as Figure 2 , including: a rotary kiln 2, a spiral dust collector 24, a hot blast furnace 10, a preheater 11 and a gasifier 12. The rotary kiln 2 is provided with a garbage feed port, a pyrolysis ash outlet, a high-ash pyrolysis gas outlet and a jacket layer. The jacket layer is provided with a first flue gas outlet and a first flue gas inlet. The spiral dust collector 24 is provided with a first high-ash pyrolysis gas inlet, a low-ash pyrolysis gas outlet and a jacket, and the jacket is provided with a fourth flue gas inlet and a fourth flue gas outlet. The hot blast furnace 10 is provided with a second flue gas inlet 35, a second flue gas outlet 34 and a hot blast furnace burner, and the hot blast furnace burner is provided with a first fuel gas feed port 31, a second fuel gas feed port 33 and a first air feed port 32. The preheater 11 is provided with a cold air inlet, a hot air outlet and a jacket, and the jacket is provided with a third flue gas inlet and a third flue gas outlet. The gasifier 12 is provided with a gasifier burner, a low-ash pyrolysis gas feed inlet 36, a pyrolysis ash feed inlet 310, a third air feed inlet 39, a second cold air inlet 37, a second hot air outlet 38, a gasification gas outlet 314 and a gasification ash outlet, and the gasifier burner is provided with a third fuel gas feed inlet and a second air feed inlet.

[0121] In this embodiment, garbage enters from the inlet end of the feed conveying device 1. The outlet of the feed conveying device 1 is connected to the garbage feed port of the rotary kiln 2. The high-ash pyrolysis gas outlet of the rotary kiln 2 is connected to the first inlet of the high-ash pyrolysis gas of the spiral dust collector 24 through the first pyrolysis gas pipeline 41. A spiral component is provided inside the spiral dust collector 24. When installed, the spiral dust collector 24 is 15° to the horizontal line. The high-ash pyrolysis gas produced by the anaerobic pyrolysis of the garbage in the rotary kiln 2 contains dust. After the high-ash pyrolysis gas passes through the spiral component, the dust falls to the bottom of the spiral dust collector 24, and along the first pyrolysis gas pipeline 41, falls back into the rotary kiln 2 through the high-ash pyrolysis gas outlet. The rotary kiln 2 is provided with a first thermometer (TT101) 51.

[0122] In this embodiment, the low-ash pyrolysis gas outlet of the spiral dust collector 24 is connected to the inlet of the pyrolysis gas blower 75 through the second pyrolysis gas pipeline 42, and the outlet of the pyrolysis gas blower 75 is connected to the first fuel gas feed port 31 of the hot blast furnace burner on the hot blast furnace 10 through the third pyrolysis gas pipeline 43. The low-ash pyrolysis gas feed port 36 of the gasifier 12 is connected to the third pyrolysis gas pipeline 43 at the node A through the fourth pyrolysis gas pipeline 44. The first shut-off valve 91 and the second shut-off valve 92 are sequentially provided on the third pyrolysis gas pipeline 43 along the gas flow direction, and the first shut-off valve 91 is downstream of the node A. The fourth pyrolysis gas pipeline 44 is provided with a third shut-off valve 93.

[0123] In this embodiment, the garbage gasification system also includes a pyrolysis gas spray tank 27. The pyrolysis gas spray tank 27 is provided with a second high-ash pyrolysis gas inlet, an exhaust port, a spray water inlet and a spray water outlet. The first pyrolysis gas pipeline 41 is connected to the second high-ash pyrolysis gas inlet of the pyrolysis gas spray tank 27 through the fifth pyrolysis gas pipeline 428. The exhaust port of the pyrolysis gas spray tank 27 is connected to the atmosphere. A valve may be provided on the fifth pyrolysis gas pipeline 428. The spray water inlet is connected to the spray water source through the spray water inlet pipeline. The spray water inlet pipeline is provided with a thirteenth shut-off valve. The spray water outlet is connected to the spray water outlet pipeline, and the spray water outlet pipeline is provided with a fourteenth shut-off valve.

[0124] In this embodiment, the second flue gas outlet 34 of the hot blast furnace 10 is connected to the first flue gas inlet of the rotary kiln 2 through the first flue gas pipeline 49. A first oxygen concentration analyzer 26 and a third thermometer 53 are provided on the first flue gas pipeline 49 near the second flue gas outlet 34. The third flue gas inlet of the preheater 11 is connected to the first flue gas pipeline 49 through the second flue gas pipeline 410. The fourth flue gas inlet of the spiral dust collector 24 is connected to the first flue gas pipeline 49 through the third flue gas pipeline 411.

[0125] In this embodiment, the first flue gas outlet of the rotary kiln 2 is connected to the atmosphere through the fifth flue gas pipeline 413. The fifth flue gas pipeline 413 is provided with a ninth thermometer 59, a fifth shut-off valve 95, a flue gas purification device 23 and a flue gas fan 76 in sequence along the gas flow direction. The fourth flue gas outlet of the spiral dust collector 24 is connected to the fifth flue gas pipeline 413 through the seventh flue gas pipeline 415. The pyrolysis ash outlet of the rotary kiln 2 is connected to the inlet of the pyrolysis ash slag discharge device 21.

[0126] In this embodiment, the second fuel gas feed port 33 of the hot blast furnace burner on the hot blast furnace 10 is connected to the air source through the first air pipeline 416. The first air fan 71, the third flow meter 63 and the third flow regulating valve 83 are sequentially arranged on the first air pipeline 416 along the gas flow direction. Among them, the third flow meter 63 and the third flow regulating valve 83 are signal-connected to achieve air flow regulation of the first air pipeline 416. The second fuel gas feed port 33 of the hot blast furnace burner on the hot blast furnace 10 is connected to the natural gas source through the second natural gas pipeline 427. The second natural gas pipeline 427 is sequentially provided with a second flow meter 62 and a second flow regulating valve 82 that are signal-connected to each other along the gas flow direction to achieve natural gas flow regulation of the second natural gas pipeline 427.

[0127] In this embodiment, the first cold air inlet of the preheater 11 is connected to the air source through the second air pipeline 417. The second air fan 72, the fourth flow meter 64 and the fourth flow regulating valve 84 are arranged in sequence on the second air pipeline 417 along the gas flow direction. The first hot air outlet of the preheater 11 is connected to the first air feed port 32 of the hot blast furnace burner on the hot blast furnace 10 through the third air pipeline 418. The fourth thermometer (TT104) 54 is arranged on the third air pipeline 418. The hot blast furnace 10 is provided with a second thermometer (TT102) 52, the fourth flow meter 64 and the second thermometer (TT102) 52 are connected to the fourth flow regulating valve 84 by signal, the output of the temperature main controller TIC102 is used as the given value of the sub-controller FIC104 on the second air pipeline 417, the output of the sub-controller FIC104 is used to operate the fourth flow regulating valve 84, the air flow is controlled by the fourth flow regulating valve 84, and then the temperature in the hot blast furnace 10 is controlled.

[0128] In this embodiment, the gasifier 12 adopts a downdraft gasifier, and a gasifier burner is arranged on the top of the gasifier 12. The third fuel gas feed port of the gasifier burner on the gasifier 12 is connected to the natural gas source through the first natural gas pipeline 426. The first natural gas pipeline 426 is provided with a seventh shut-off valve 97, a seventh flow meter 67 and a seventh flow regulating valve 87 in sequence along the gas flow direction to achieve natural gas flow regulation of the first natural gas pipeline 426. The second air feed port of the gasifier burner on the gasifier 12 is connected to the air source through the fourth air pipeline 419. The third air fan 73, the sixth flow meter 66 and the sixth flow regulating valve 86 are provided in sequence along the gas flow direction on the fourth air pipeline 419, wherein the sixth flow meter 66 and the sixth flow regulating valve 86 are signal-connected to achieve air flow regulation of the fourth air pipeline 419.

[0129] In this embodiment, a grate is provided inside the gasifier 12. An internal air pipeline is provided near the grate to utilize the heat radiated from the high-temperature furnace of the gasifier 12. The air pipeline connects the second cold air inlet 37 and the second hot air outlet 38. The upper part of the gasifier 12 is a high-temperature combustion zone, and a fifth thermometer 55 is provided above the grate. In this embodiment, a slag discharge port is provided below the gasifier 12, and the slag discharge port is connected to the inlet of the gasification ash slag equipment.

[0130] In this embodiment, the garbage gasification system also includes a mixer 18. The mixer 18 is provided with a first air inlet 313, a first air outlet 312 and a second air inlet 311. The second cold air inlet 37 of the gasifier 12 is connected to the first air outlet 312 of the mixer 18 through the sixth air pipeline 421. A sixth shut-off valve 96 and a fifth thermometer 56 are sequentially provided on the sixth air pipeline 421 along the gas flow direction. The sixth air pipeline 421 is connected to the air inlet of the drying device 19 through the seventh air pipeline 422. The air outlet of the drying device 19 is connected to the atmosphere through the tenth air pipeline 425. A ninth flowmeter 69 and a ninth flow regulating valve 89, which are signal-connected to each other, are sequentially provided on the tenth air pipeline 425 along the gas flow direction to achieve air flow regulation of the tenth air pipeline 425.

[0131] In this embodiment, the first air inlet 313 of the mixer 18 is connected to the air source through the fifth air pipeline 420. The fourth air blower 74, the eighth flowmeter 68 and the eighth flow regulating valve 88 are sequentially arranged on the fifth air pipeline 420 along the gas flow direction, wherein the eighth flowmeter 68 and the eighth flow regulating valve 88 are signal-connected to realize the air flow regulation of the fifth air pipeline 420. The second hot air outlet 38 of the gasifier 12 is connected to the third air feed port 39 of the gasifier 12 through the eighth air pipeline 423. The eighth air pipeline 423 is sequentially provided with a thermometer and an eighth shut-off valve 98 along the gas flow direction. The eighth air pipeline 423 is connected to the second air inlet 311 of the mixer 18 through the ninth air pipeline 424. The ninth air pipeline 424 is provided with a ninth shut-off valve 99. According to the values ​​of the eighth flowmeter 68 and the ninth flowmeter 69, the air flow of the eighth air pipeline 423 is calculated.

[0132] In this embodiment, the gasification gas outlet 314 of the gasifier 12 is connected to the gasification gas inlet of the cooling and decoking device 15 through a gasification gas pipeline. The gasification gas outlet of the cooling and decoking device 15 is connected to the inlet of the gasification gas buffer tank 17 through a gasification gas pipeline. A cyclone separator 13 and a deacidification and dust removal device 14 are sequentially provided along the gas flow direction of the gasification gas pipeline between the gasification gas outlet 314 of the gasifier 12 and the gasification gas inlet of the cooling and decoking device 15. A desulfurization device 16, a gas blower 77, a hydrogen sulfide analyzer 28 and a gas analyzer 25 are sequentially provided along the gas flow direction of the gasification gas pipeline between the gasification gas outlet of the cooling and decoking device 15 and the inlet of the gasification gas buffer tank 17. The deacidification and dust removal equipment 14 comprises a deacidification component and a ceramic fiber filter tube dust removal component, and uses solid sodium bicarbonate as a deacidification agent to react with acidic gases such as HCl contained in the high-temperature gasification gas flowing out of the outlet of the cyclone separator 13 to remove HCl, and performs dry dust removal in the ceramic fiber filter tube dust removal component. The cooling and decoking equipment 15 is the cooling and decoking equipment 15 in Example 1. The desulfurization equipment 16 uses iron oxide as a desulfurization agent, and utilizes iron oxide and H 2 S reaction removes H contained in the gasification gas 2 S.

[0133] In this embodiment, the gasification gas flowing out of the gasification gas outlet 314 of the gasification furnace 12 contains tar, and the tar content is about 600 mg / Nm 3, among which, the mass of heavy tar accounts for 70%, the mass of light tar accounts for 30%, and the temperature of gasified gas is 600℃. After passing through the cyclone separator 13 and the deacidification and dust removal equipment 14, the temperature drops to 500℃. After the gasified gas passes through the deacidification and dust removal equipment 14 and the venturi tube 1501, it enters the primary cyclone heat exchanger 1502 along the tangent direction of the cylinder side of the primary cyclone heat exchanger 1502 at a speed of about 20 m / s. The gasified gas moves downward in a spiral form from the cylinder of the primary cyclone heat exchanger 1502 at a high speed. During the rotation process, centrifugal force is generated to throw the tar with a density greater than that of the gas to the wall of the cylinder. After the tar contacts the wall of the cylinder, it flows downward along the wall by its own gravity and inlet velocity momentum, and finally flows out from the tar outlet at the bottom of the primary cyclone heat exchanger 1502. After reaching the cone section of the primary cyclone heat exchanger 1502, the gasified gas spirals upward and flows out from the gas outlet of the primary cyclone heat exchanger 1502. After completing the primary tar removal, it then enters the secondary cyclone heat exchanger 1503 for secondary tar removal. The gasified gas after secondary purification flows directly out from the secondary second outlet 150302, and the remaining gasified gas flows out from the secondary first outlet 150301 and then is re-introduced to the inlet of the primary cyclone heat exchanger 1502 through the contraction tube inlet 150101 for recirculation. The secondary cyclone heat exchanger 1503 recycles the tar particles not captured by the primary cyclone heat exchanger 1502 into the primary cyclone heat exchanger 1502, thereby increasing the tar concentration in the gasified gas at the inlet of the primary cyclone heat exchanger 1502. At the same time, with the help of the centrifugal force in the secondary cyclone heat exchanger 1503, the probability of collision and agglomeration of tar particles is increased, and finally the tar removal efficiency of the entire system is improved. After the secondary tar removal, the gasified gas enters the condenser 1504 for the third tar removal. After the gasified gas passes through the primary cyclone heat exchanger 1502, the tar content is reduced from 600 mg / Nm 3 Reduced to 200 mg / Nm 3 The gasification gas temperature drops from 500℃ to 250℃; after passing through the secondary cyclone heat exchanger 1503, the tar decreases from 200 mg / Nm 3 Reduced to 100 mg / Nm 3 The gasification gas temperature drops from 250℃ to 80℃; after passing through the condenser 1504, the tar decreases from 100 mg / Nm 3 Reduced to 70 mg / Nm 3 The gasification gas temperature dropped from 80℃ to 40℃; after passing through the electric tar collector 1505, the tar content dropped from 70 mg / Nm 3 Reduced to 48 mg / Nm 3 The tar removal rate reaches 92%. The regularly collected tar can be used as backup fuel for the hot blast stove and gasifier baking stage.

[0134] In this embodiment, the outlet of the gasification gas buffer tank 17 is connected to the atmosphere through the fourth gasification gas pipeline 48. A tenth shut-off valve 910 is provided on the fourth gasification gas pipeline 48 near the atmospheric connection. The fourth gasification gas pipeline 48 is connected to the gasification gas inlet of the internal combustion engine 22 through the third gasification gas pipeline 47. The third gasification gas pipeline 47 is provided with a fifth flow meter 65 and a fifth flow regulating valve 85 which are mutually signal-connected in the direction of gas flow, so as to realize the gasification gas flow control for power generation in the internal combustion engine 22. The flue gas outlet of the internal combustion engine 22 is connected to the second flue gas inlet 35 of the hot blast furnace 10 through the fourth flue gas pipeline 412. A twelfth shut-off valve 912 is provided on the fourth flue gas pipeline 412. The fourth gasification gas pipeline 48 is connected to the first natural gas pipeline 426 through the first gasification gas pipeline 45. The first gasification gas pipeline 45 is provided with an eleventh shut-off valve 911. The point where the first gasification gas pipeline 45 is connected to the first natural gas pipeline 426 is located downstream of the seventh shut-off valve 97. The fourth gasification gas pipeline 48 is connected to the third pyrolysis gas pipeline 43 through the second gasification gas pipeline 46 at a node B. The node B is located downstream of the second shut-off valve 92. The second gasification gas pipeline 46 is provided with a first flow meter 61 and a first flow regulating valve 81 which are signal-connected to each other in sequence along the gas flow direction.

[0135] In this embodiment, before the gasification furnace 12 is started, the rotary kiln 2 can be cold-started without adding garbage, and then the hot blast furnace 10 can be started. At this time, the hot blast furnace 10 is started by relying on the flue gas generated by the combustion of external natural gas and combustion-supporting air as the heating medium of the rotary kiln 2; when the gas phase temperature of the rotary kiln 2 reaches a certain temperature, the branch flue gas of the second flue gas outlet 34 of the hot blast furnace 10 can be used to preheat the air that is about to enter the hot blast furnace 10 from the first air feed port 32; when the gas phase temperature of the rotary kiln 2 rises again, the small load garbage feeding can be started, and the pyrolysis gas generated by the rotary kiln 2 enters the hot blast furnace 10 for combustion. The pyrolysis gas is used as the combustion fuel of the hot blast furnace 10, which is beneficial to reduce Natural gas consumption; as the feed load increases, the rotary kiln 2 generates more and more pyrolysis gas that enters the hot blast furnace 10; when the rotary kiln 2 achieves full load feeding, the gasifier 12 is started; when the gasifier 12 is just started, the flue gas generated by the combustion of external natural gas and combustion air is used as a heating heat source to heat the furnace of the gasifier 12; when the furnace temperature of the gasifier 12 rises to a certain temperature, the pyrolysis gas generated by the rotary kiln 2 is changed from the hot blast furnace 10 to the gasifier 12 for combustion, and the natural gas supply to the gasifier 12 is reduced at this time; when the furnace temperature of the gasifier 12 rises again, part of the generated gasification gas enters the hot blast furnace burner for combustion as fuel, and part of it enters the gasifier burner for combustion as fuel.

[0136] Example 3

[0137] A method for starting a garbage gasification system is implemented on the garbage gasification system in Example 2, such as Figure 3 , including the following steps:

[0138] S1. Cold start of rotary kiln:

[0139] S101. In a cold state, the rotary kiln 2 initially rotates at a low speed of 0.4 r / min.

[0140] S102, after the rotary kiln 2 runs stably for 5 minutes, gradually increase the rotation speed of the rotary kiln 2 to a rated speed of 2.5 r / min.

[0141] S2, hot air furnace start:

[0142] S201, open the fifth shut-off valve 95. Close the third shut-off valve 93, the first flow regulating valve 81, the first shut-off valve 91, the second shut-off valve 92, the fourth shut-off valve 94, and the sixth shut-off valve 96. Open the thirteenth shut-off valve and the fourteenth shut-off valve of the pyrolysis gas spray tank 27. Before the pyrolysis gas blower 75 is started, the air in the rotary kiln 2 passes through the pyrolysis gas spray tank 27 and is sprayed with water before being discharged to the atmosphere.

[0143] S202, start the first air blower 71, adjust the air flow of the first air pipeline 416 through the third flow meter 63 and the third flow regulating valve 83, and adjust the natural gas flow of the second natural gas pipeline 427 through the second flow meter 62 and the second flow regulating valve 82, so that the hot blast furnace burner on the hot blast furnace 10 burns normally, and the excess air coefficient is 1.2. At the same time, start the flue gas blower 76, with a frequency of 15 Hz. The flue gas generated by the hot blast furnace 10 enters the jacket of the rotary kiln 2 through the first flue gas inlet to heat the rotary kiln 2. The excess air coefficient refers to the ratio of the actual amount of air supplied to the fuel combustion to the theoretical amount of air.

[0144] S3, load increase (combustion load increase of hot blast furnace 10, feed load increase of rotary kiln 2):

[0145] S301, gradually increase the combustion load of the hot blast stove burner on the hot blast stove 10, so that the readings of the second thermometer (TT102) 52 of the hot blast stove 10 and the first thermometer (TT101) 51 of the rotary kiln 2 are gradually increased.

[0146] S302. When the reading of the first thermometer (TT101) 51 of the rotary kiln 2 reaches 300°C, start the second air blower 72 with a frequency set to 15 Hz, and at the same time reduce the frequency of the first air blower 71, so that the readings of the second thermometer (TT102) 52 of the hot blast furnace 10 and the first thermometer (TT101) 51 of the rotary kiln 2 steadily increase.

[0147] S303, open the fourth shut-off valve 94 to 50% and the sixth shut-off valve 96 to 50%, and preheat the spiral dust collector 24, the preheater 11, the third air pipeline 418 and the seventh flue gas pipeline 415 respectively until the value of the fourth thermometer 54 reaches 350°C.

[0148] S304, when the reading of the first thermometer (TT101) 51 of the rotary kiln 2 reaches 350°C, the first shut-off valve 91 and the second shut-off valve 92 are opened, and the pyrolysis gas blower 75 is started, and the frequency is set to 15 Hz. At the same time, it is ensured that the pyrolysis gas spray tank 27 has a certain liquid seal height.

[0149] S305, start the feeding conveying device 1, and start conveying the garbage into the rotary kiln 2 at a small load of 50% for anaerobic pyrolysis reaction; at the same time, adjust the frequency of the pyrolysis gas fan 75 to 25 Hz.

[0150] S306, gradually increase the feed load of the rotary kiln 2 until the load reaches 100%. Synchronously adjust the opening of the fourth shut-off valve 94 to 100% and the opening of the sixth shut-off valve 96 to 100%; increase the frequency of the flue gas fan 76 and the frequency of the pyrolysis gas fan 75 to ensure that the pressure in the rotary kiln 2 is a slight positive pressure of 150-500 Pa; increase the frequency of the second air fan 72. The hot blast furnace 10 is provided with a second thermometer (TT102) 52, the fourth flowmeter 64 and the second thermometer (TT102) 52 are connected to the fourth flow regulating valve 84 signal, the output of the temperature main controller TIC102 is used as the given value of the sub-controller FIC104 on the second air pipeline 417, and the output of the sub-controller FIC104 is used to manipulate the fourth flow regulating valve 84, and the air flow is controlled by the fourth flow regulating valve 84, thereby controlling the temperature in the hot blast furnace 10 to maintain at 800°C.

[0151] S4, gasifier start-up:

[0152] S401, open the tenth shut-off valve 910. Close the eleventh shut-off valve 11, the fifth flow regulating valve 85, and the first flow regulating valve 81.

[0153] S402, start the grate in the gasification furnace 12.

[0154] S403, start the third air blower 73, and adjust the natural gas flow of the first natural gas pipeline 426 through the seventh flow meter 67 and the seventh flow regulating valve 87. Adjust the air flow of the fourth air pipeline 419 through the sixth flow meter 66 and the sixth flow regulating valve 86, so that the gasifier burner on the gasifier 12 burns normally, and the excess air coefficient is 1.2. At the same time, start the gas blower 77. Observe the value change of the fifth thermometer 55 in the gasifier 12, and gradually increase it to 400°C.

[0155] S404, start the fourth air blower 74, and set the frequency to 15 Hz. Open the eighth shut-off valve 98, the ninth shut-off valve 99, the sixth shut-off valve 96 and the ninth flow regulating valve 89, and start preheating the internal air pipeline. By adjusting and controlling the air flow of the fifth air pipeline 420 and the tenth air pipeline 425, the air flow of the eighth air pipeline 423 entering the gasification furnace 12 is adjusted. The difference between the values ​​of the eighth flow meter 68 and the ninth flow meter 69 is the air flow of the eighth air pipeline 423 entering the gasification furnace 12.

[0156] S5. Switching of combustion conditions of pyrolysis gas degasification furnace:

[0157] S501. When the fifth thermometer (TT105) 55 of the gasifier 12 is heated to 600°C, the first shut-off valve 91 and the second shut-off valve 92 are closed, the third shut-off valve 93 is opened, and the frequency of the fourth air blower 74 is adjusted to 45 Hz. The pyrolysis gas is switched to the gasifier 12 for complete combustion, so that the gasifier 12 is gradually heated. The second flow regulating valve 82 on the second natural gas pipeline 427 is opened synchronously.

[0158] S6. Gasification conditions:

[0159] S601, when the temperature of the gasifier 12 continues to rise until the throat temperature reaches 900°C, the normal temperature air enters the mixer 18 through the fourth air blower 74, and directly contacts and exchanges heat with the 500°C air in the ninth air pipeline 424. After the air at about 250°C flows out from the sixth air pipe 312 of the mixer 18, it enters the drying device 19 and the second cold air inlet 37 of the gasifier 12 through the seventh air pipeline 422 and the sixth air pipeline 421 respectively. The air entering from the second cold air inlet 37 of the gasifier 12 is heated to 500°C by the heat radiated from the high temperature furnace of the gasifier 12, and flows out from the second hot air outlet 38 of the gasifier 12; a part of the high temperature air is used to heat the gasifying agent-air of the gasifier 12, which helps to improve the gasification efficiency, and the other part provides a heat source for the drying device 19, thereby improving the overall heat utilization efficiency of the whole system. The pyrolysis ash is fed into the gasifier 12 through the pyrolysis ash feed port 310 for reaction. The air flow of the eighth air pipeline 423 is reduced by simultaneously increasing the opening of the ninth flow regulating valve 89 to ensure that the excess air coefficient is about 0.3, so that the pyrolysis gas and the pyrolysis ash undergo a strong oxidation reaction in the combustion zone of the gasifier 12, and the heavy hydrocarbon substances are cracked again. The pyrolysis ash reacts in the oxygen-deficient combustion zone of the gasifier 12, and the remaining char falls on the grate to form a charcoal layer. The cracked gas passes through the charcoal layer to obtain gasification gas and gasification ash. The gasification ash is discharged from the gasifier 12 through the gasification ash slag discharge device 20. The gasification gas generated by the gasifier 12 is successively purified by the deacidification and dust removal equipment 14, the cooling and decoking equipment 15, the desulfurization equipment 16, etc., and then transported to the gasification gas buffer tank 17 by the gas blower 77, and discharged from the fourth gasification gas pipeline 48.

[0160] S7, switch to gasification gas instead of natural gas:

[0161] S701, when the value of the second oxygen concentration analyzer (AT101) 150401 reaches 0.07 Vol%, the value of the hydrogen sulfide analyzer (AT103) 28 reaches 30 Vol ppm, and the calorific value of the gas analyzer 29 reaches 4.5 MJ / Nm 3 When the fifth flow regulating valve 85 is opened, the flow rate of the gasified gas entering the internal combustion engine 22 for power generation is controlled through the fifth flow meter 65 and the fifth flow regulating valve 85, and the tenth shut-off valve 910 is gradually closed, and the internal combustion engine 22 is started at the same time. The flue gas generated by the internal combustion engine 22 enters the second flue gas inlet 35 of the hot blast furnace 10, and enters the rotary kiln 2 together with the flue gas generated by the hot blast furnace burner on the hot blast furnace 10 to provide heat for the rotary kiln; at the same time, the temperature of the hot blast furnace 10 is adjusted and controlled by adjusting the opening of the fourth flow regulating valve 84.

[0162] S702, gradually close the tenth shut-off valve 910 again until the tenth shut-off valve 910 is completely closed, gradually open the eleventh shut-off valve 911 and the first flow regulating valve 81, and gradually reduce the openings of the seventh shut-off valve 97 on the first natural gas pipeline 426, the second flow regulating valve 82 on the second natural gas pipeline 427, and the third flow regulating valve 83 on the first air pipeline 416 until all are completely closed, so that the combustion fuel of the gasifier burner on the gasifier 12 and the hot blast furnace burner on the hot blast furnace 10 is completely switched from natural gas to gasification gas; at the same time, adjust the frequency of the second air fan 72 and the third air fan 73, and adjust the openings of the fourth flow regulating valve 84 and the sixth flow regulating valve 86 to ensure normal combustion of the hot blast furnace 10 with an excess air coefficient of about 1.2, and the gasifier burner on the gasifier 12 is oxygen-deficient combustion with an excess air coefficient of about 0.3.

Claims

1. A garbage gasification system, characterized in that: It includes a rotary kiln, a hot blast stove and a gasification furnace; The rotary kiln is provided with a garbage feed inlet, a pyrolysis ash outlet, a high-ash pyrolysis gas outlet and a jacket layer, and the jacket layer is provided with a first flue gas outlet and a first flue gas inlet; the hot blast furnace is provided with a second flue gas outlet and a hot blast furnace burner, and the hot blast furnace burner is provided with a first fuel gas feed inlet and a second fuel gas feed inlet; the gasifier is provided with a low-ash pyrolysis gas feed inlet, a third air feed inlet, a gasification gas outlet, a gasification ash outlet and a gasifier burner, and the gasifier burner is provided with a third fuel gas feed inlet and a second air feed inlet; The high-ash pyrolysis gas outlet is connected to the atmosphere through the fifth pyrolysis gas pipeline; the high-ash pyrolysis gas outlet of the rotary kiln is connected to the first fuel gas feed port of the hot blast furnace through the pyrolysis gas pipeline; the low-ash pyrolysis gas feed port of the hot blast furnace is connected to the pyrolysis gas pipeline through the fourth pyrolysis gas pipeline at node A; the gasification gas outlet of the gasifier is connected to the atmosphere through the gasification gas pipeline; the gasification gas pipeline is connected to the pyrolysis gas pipeline at node B through the second gasification gas pipeline, and a valve is provided on the second gasification gas pipeline; The second flue gas outlet of the hot blast furnace is connected to the first flue gas inlet of the rotary kiln through the first flue gas pipeline; the third fuel gas feed port of the gasifier is connected to the fuel gas source through the first natural gas pipeline; the gasification gas pipeline is connected to the first natural gas pipeline through the first gasification gas pipeline.

2. The garbage gasification system according to claim 1, characterized in that: The garbage gasification system further comprises a spiral dust collector, wherein the spiral dust collector is provided with a first inlet for high-ash pyrolysis gas and an outlet for low-ash pyrolysis gas; The high-ash pyrolysis gas outlet of the rotary kiln is connected to the high-ash pyrolysis gas first inlet of the spiral dust collector through a first pyrolysis gas pipeline; The low-ash pyrolysis gas outlet of the spiral dust collector is connected to the first fuel gas inlet of the hot blast furnace through the pyrolysis gas pipeline, and a fan is provided on the pyrolysis gas pipeline between the low-ash pyrolysis gas outlet of the spiral dust collector and the node A; The spiral dust collector is provided with a spiral component inside; The spiral dust collector is 10-30° to the horizontal line, for example, 15°; The garbage gasification system also includes a pyrolysis gas spray tank, which is provided with a second high-ash pyrolysis gas inlet, an exhaust port, a spray water inlet and a spray water outlet; The high-ash pyrolysis gas discharge port of the rotary kiln is connected to the high-ash pyrolysis gas second inlet of the pyrolysis gas spray tank; The exhaust port of the pyrolysis gas spray tank is connected to the atmosphere; The spray water inlet is connected to the spray water source through a spray water inlet pipe; a valve is provided on the spray water inlet pipe; The spray water outlet is connected to a spray water outlet pipe; a valve is arranged on the spray water outlet pipe.

3. The garbage gasification system according to claim 1, characterized in that: The garbage gasification system further comprises a feed conveying device, the garbage to be gasified enters from the inlet end of the feed conveying device, and the outlet of the feed conveying device is connected to the garbage feed port of the rotary kiln; The first flue gas outlet of the rotary kiln is connected to the atmosphere through a fifth flue gas pipeline; a thermometer, a valve, a flue gas purification device or a fan is provided on the fifth flue gas pipeline; The pyrolysis ash outlet of the rotary kiln is connected to the inlet of the pyrolysis ash discharge equipment; The rotary kiln is provided with a thermometer; The garbage gasification system further comprises an internal combustion engine, and the gasification gas pipeline is connected to the gasification gas inlet of the internal combustion engine through a third gasification gas pipeline; The hot blast furnace is also provided with a second flue gas inlet, and the flue gas outlet of the internal combustion engine is connected to the second flue gas inlet of the hot blast furnace through a fourth flue gas pipeline; a valve is provided on the fourth flue gas pipeline; The fourth pyrolysis gas pipeline is provided with a valve; A valve is provided on the gasification gas pipeline near the atmospheric connection; A valve is provided between the node A and the node B; The first gasification gas pipeline is provided with a valve; A first flow meter and a first flow regulating valve are sequentially arranged along the gas flow direction on the second gasification gas pipeline; the first flow meter and the first flow regulating valve are signal-connected; An oxygen concentration analyzer and / or a thermometer is provided on the first flue gas pipeline at a position close to the second flue gas outlet.

4. The garbage gasification system according to claim 1, characterized in that: The second fuel gas feed port of the hot blast furnace is connected to the air source through the first air pipeline; a fan, a third flow meter and a third flow regulating valve are arranged in sequence along the gas flow direction of the first air pipeline; the third flow meter and the third flow regulating valve are connected by signal; The second fuel gas feed port of the hot blast furnace is connected to the natural gas source through a second natural gas pipeline; a second flow meter and a second flow regulating valve are arranged in sequence along the gas flow direction of the second natural gas pipeline; the second flow meter and the second flow regulating valve are signal-connected; The hot blast stove is provided with a thermometer.

5. The garbage gasification system according to claim 1, characterized in that: The garbage gasification system further comprises a preheater, wherein the preheater is provided with a cold air inlet, a hot air outlet and a jacket, and the jacket is provided with a third smoke inlet and a third smoke outlet; The third flue gas inlet of the preheater is connected to the first flue gas pipeline through a second flue gas pipeline; The first cold air inlet of the preheater is connected to the air source through a second air pipeline; a fan, a fourth flow meter and a fourth flow regulating valve are arranged in sequence along the gas flow direction on the second air pipeline; a second thermometer is arranged on the hot air furnace, and the fourth flow meter and the second thermometer are connected to the fourth flow regulating valve signal; The hot blast furnace burner is also provided with a first air feed inlet, and the first hot air outlet of the preheater is connected to the first air feed inlet of the hot blast furnace through a third air pipeline; a thermometer is arranged on the third air pipeline.

6. The garbage gasification system according to claim 1, characterized in that: The gasifier is a downdraft gasifier; The gasifier burner is arranged on the top of the gasifier; The third fuel gas feed port of the gasifier is connected to the natural gas source through a first natural gas pipeline; a valve and / or a flow meter is provided on the first natural gas pipeline; The second air feed port of the gasifier is connected to the air source through a fourth air pipeline; a fan, a sixth flow meter and a sixth flow regulating valve are sequentially arranged along the gas flow direction of the fourth air pipeline; the sixth flow meter and the sixth flow regulating valve are signal-connected; A grate is provided inside the gasifier; a thermometer is provided at a position higher than the grate; The gasifier is also provided with a pyrolysis ash feed port, and the pyrolysis ash outlet of the rotary kiln is connected to the pyrolysis ash feed port of the gasifier; The gasifier is also provided with a second cold air inlet and a second hot air outlet, the second cold air inlet and the second hot air outlet are connected via an air pipeline, and the air pipeline is located inside the gasifier; The garbage gasification system further comprises a mixer, wherein the mixer is provided with a first air inlet, a first air outlet and a second air inlet; The second cold air inlet of the gasifier is connected to the first air outlet of the mixer through the sixth air pipeline; a valve and / or a thermometer is provided on the sixth air pipeline; the sixth air pipeline is connected to the air inlet of the drying device through the seventh air pipeline; the air outlet of the drying device is connected to the atmosphere through the tenth air pipeline; a ninth flow meter and a ninth flow regulating valve are sequentially provided on the tenth air pipeline along the gas flow direction; the ninth flow meter and the ninth flow regulating valve are signal-connected; The first air inlet of the mixer is connected to the air source through the fifth air pipeline; a fan, an eighth flow meter and an eighth flow regulating valve are arranged in sequence along the gas flow direction on the fifth air pipeline; the eighth flow meter and the eighth flow regulating valve are signal-connected; The second hot air outlet of the gasifier is connected to the third air feed inlet of the gasifier through an eighth air pipeline; a thermometer and / or a valve is provided on the eighth air pipeline; Preferably, the eighth air pipeline is connected to the second air inlet of the mixer through a ninth air pipeline; and a valve is provided on the ninth air pipeline.

7. The garbage gasification system according to claim 1, characterized in that: A gasification gas buffer tank is provided on the gasification gas pipeline, the gasification gas outlet of the gasifier is connected to the inlet of the gasification gas buffer tank, and the outlet of the gasification gas buffer tank is connected to the atmosphere through a fourth gasification gas pipeline; a valve is provided on the fourth gasification gas pipeline near the atmospheric connection; A cyclone separator, a deacidification and dust removal device, a cooling and decoking device and a desulfurization device are sequentially arranged along the gas flow direction on the gasification gas pipeline between the gasification gas outlet of the gasification furnace and the gasification gas inlet of the gasification gas buffer tank; a fan, a hydrogen sulfide analyzer and a fuel gas analyzer are arranged on the gasification gas pipeline between the desulfurization equipment and the gasification gas buffer tank.

8. The garbage gasification system according to claim 7, characterized in that: The cooling and decoking equipment includes a venturi tube, a primary cyclone heat exchanger, a secondary cyclone heat exchanger, a condenser and an electric tar collector; the venturi tube is provided with a gasification gas inlet, a contraction tube air inlet and an expansion tube air outlet; the primary cyclone heat exchanger is provided with a primary air inlet, a primary air outlet and a primary ash outlet; the secondary cyclone heat exchanger is provided with a secondary air inlet, a secondary first air outlet and a secondary second air outlet; the condenser is provided with a condensation air inlet and a condensation air outlet; the electric tar collector is provided with an electric tar precipitator air inlet and a gasification gas outlet; The gasification gas inlet of the venturi tube is connected to the outlet of the deacidification and dust removal equipment, the contraction tube air inlet of the venturi tube is connected to the secondary first air outlet of the secondary cyclone heat exchanger, and the expansion tube air outlet of the venturi tube is connected to the primary air inlet of the primary cyclone heat exchanger; the primary air outlet of the primary cyclone heat exchanger is connected to the secondary air inlet of the secondary cyclone heat exchanger; the secondary second air outlet of the secondary cyclone heat exchanger is connected to the condensation air inlet of the condenser; the condensation air outlet of the condenser is connected to the electric tar precipitator air inlet of the electric tar precipitator; the gasification gas outlet of the electric tar precipitator is connected to the inlet of the desulfurization equipment.

9. The garbage gasification system according to claim 8, characterized in that: The first-stage air inlet and the first-stage air outlet of the first-stage cyclone heat exchanger are located at the same end of the equipment; a water cooling jacket is provided on the outer side of the cylinder of the first-stage cyclone heat exchanger, and the water cooling jacket is provided with a cooling water inlet and a cooling water return port; The secondary air inlet and the secondary second air outlet of the secondary cyclone heat exchanger are respectively located at two ends of the equipment; a water cooling jacket is arranged outside the cylinder of the secondary cyclone heat exchanger, and the water cooling jacket is provided with a cooling water inlet and a cooling water return port; a flow stabilizing core rod is arranged inside the secondary cyclone heat exchanger; A water cooling jacket is arranged outside the cylinder of the condenser, and the water cooling jacket is provided with a cooling water inlet and a cooling water return port; an oxygen concentration analyzer is arranged on the pipeline connecting the condensation outlet of the condenser and the electric tar precipitator air inlet of the electric tar precipitator.

10. A control method for a garbage gasification system, characterized in that: The waste gasification system according to any one of claims 1 to 9 comprises the following steps: Step 1, closing the first fuel gas feed port of the hot blast furnace; introducing combustion-supporting gas and fuel gas into the second fuel gas feed port of the hot blast furnace, and burning them in the hot blast furnace burner of the hot blast furnace until the temperature of the rotary kiln reaches 350° C.; Step 2: Open the first fuel gas feed port of the hot blast furnace and close the low-ash pyrolysis gas feed port of the gasifier; transport garbage through the garbage feed port of the rotary kiln until the temperature of the hot blast furnace reaches 800° C. Step 3: close the connection between the second gasification gas pipeline and the pyrolysis gas pipeline, and close the connection between the first gasification gas pipeline and the first natural gas pipeline; introduce fuel gas into the third fuel gas feed port of the gasifier, introduce combustion-supporting gas into the second air feed port of the gasifier, and burn in the gasifier until the temperature of the gasifier reaches 600° C. Step 4: close the connection between the pyrolysis gas pipeline and the first fuel gas feed port of the hot blast furnace, and open the low-ash pyrolysis gas feed port of the gasifier until the temperature of the gasifier reaches 900° C. Step five, close the connection between the gasification gas pipeline and the atmosphere, open the connection between the second gasification gas pipeline and the pyrolysis gas pipeline, open the connection between the first gasification gas pipeline and the first natural gas pipeline, stop introducing fuel gas into the third fuel gas feed port of the gasifier, and stop introducing fuel gas into the second fuel gas feed port of the hot blast furnace.

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