Coal gasification system capable of controlling melting point of raw material coal ash

Abstract

The invention belongs to the technical field of coal chemical industry, and particularly relates to a coal gasification system capable of controlling the melting point of raw coal ash. The coal gasification system comprises a coal blending unit, a coal grinding and drying unit, a pressurizing unit and a gasification furnace, the coal blending unit is connected with the coal grinding and drying unit, the coal grinding and drying unit is connected with the pressurizing unit, and the pressurizing unit is connected with the gasification furnace; the coal blending unit comprises a plurality of coal bunkers, a plurality of annular coal feeders, a coal conveying belt and a plurality of belt weighers, the annular coal feeders are correspondingly arranged at the lower ends of the coal bunkers, the coal conveying belt is arranged below coal falling openings of the annular coal feeders, and the belt weighers are correspondingly installed at the coal falling openings of the coal conveying belt respectively. And the coal conveying belt is connected with the coal grinding and drying unit. According to the invention, on-line coal blending of various different coal types is realized, the ash fusion point of the blended coal after proportioning is detected in time, the ash fusion point of the blended coal after proportioning is ensured to be within an ideal range, and stable operation of a gasification furnace is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of coal chemical industry, and in particular to a coal gasification system capable of controlling the melting point of raw material coal ash. Background Art

[0002] The coal gas produced by the coal gasification system has a wide range of uses, including industrial gas, civil gas, chemical synthesis raw gas, fuel oil synthesis raw gas, metallurgical reduction gas, combined cycle power generation gas, coal gasification fuel cells, coal gasification hydrogen production and coal liquefaction gas source. In the future, the coal gasification system will develop in the direction of high efficiency, environmental protection and large-scale. Therefore, improving gasification efficiency, reducing pollutant emissions and reducing energy consumption from a technical level to meet the requirements of energy and environment is the way to promote the sustainable development of the coal chemical industry.

[0003] At present, in the process of producing coal gas, the coal gasification system has large fluctuations in the coal quality and ash melting point of a single coal, which causes the temperature of the gasifier to fluctuate, making the entire coal gasification system particularly unstable, and causing ash accumulation and overheating in the gasifier many times. Summary of the invention

[0004] The object of the present invention is to provide a coal gasification system capable of controlling the melting point of raw coal ash, so as to solve the problem that the coal quality and ash melting point of a single coal fluctuate greatly, causing the furnace temperature of the gasifier to fluctuate, resulting in the entire coal gasification system being particularly unstable, and repeatedly causing ash accumulation and furnace temperature overheating in the gasifier.

[0005] The present invention provides a coal gasification system capable of controlling the melting point of raw coal ash, the system comprising:

[0006] A coal blending unit, a coal grinding and drying unit, a pressurizing unit and a gasifier, wherein the coal blending unit is connected to the coal grinding and drying unit, the coal grinding and drying unit is connected to the pressurizing unit, and the pressurizing unit is connected to the gasifier;

[0007] The coal distribution unit includes several coal bins, several sets of annular coal feeders, coal conveyor belts and several belt scales. Several sets of annular coal feeders are correspondingly arranged at the lower ends of the several coal bins. A coal conveyor belt is arranged below the coal dropping ports of the several sets of annular coal feeders. Several belt scales for calculating the amount of coal dropped are respectively installed at the coal dropping ports of the several sets of annular coal feeders. The end of the coal conveyor belt is connected to the coal grinding and drying unit.

[0008] Furthermore, the coal distribution unit includes coal bunker No. 1, coal bunker No. 2, ring coal feeder No. 1, ring coal feeder No. 2, coal conveyor belt, belt scale No. 1 and belt scale No. 2. The ring coal feeder No. 1 is arranged below the coal bunker No. 1, the ring coal feeder No. 2 is arranged below the coal bunker No. 2, a coal conveyor belt is arranged below the coal dropping ports of the ring coal feeder No. 1 and the ring coal feeder No. 2, and the coal conveyor belt is respectively installed with belt scale No. 1 and belt scale No. 2 for calculating the amount of coal dropped at the coal dropping ports of the ring coal feeder No. 1 and the ring coal feeder No. 2, and the end of the coal conveyor belt is connected to the coal grinding and drying unit.

[0009] Furthermore, the pulverized coal drying unit includes a coal mill, a pulverized coal bag filter and a screw conveyor, the end of the coal conveyor belt is connected to the coal mill, the coal mill is connected to the pulverized coal bag filter, the pulverized coal bag filter is connected to the screw conveyor, and the screw conveyor is connected to the pressurizing unit.

[0010] Furthermore, the coal mill drying unit also includes a fan, and the coal mill is connected to the fan for conveying air.

[0011] Furthermore, the coal grinding and drying unit also includes a hot blast furnace for conveying hot air, the coal grinding machine is connected to the hot blast furnace, and the hot blast furnace is connected to an air pipeline and a natural gas pipeline.

[0012] Furthermore, the pressurizing unit includes a pressurized pulverized coal storage tank and a pulverized coal feeding tank, the coal grinding and drying unit is connected to the pressurized pulverized coal storage tank, and the pressurized pulverized coal storage tank is connected to the pulverized coal feeding tank.

[0013] Furthermore, the pressurized pulverized coal storage tank is connected to a nitrogen pipeline for pressurization, and the pulverized coal feed tank is connected to a high-pressure carbon dioxide pipeline.

[0014] Furthermore, an inflation cone is provided at the lower end of the pulverized coal feeding tank for inputting high-pressure carbon dioxide.

[0015] Furthermore, the pressurizing unit is connected to the gasifier, the oxygen pipeline is connected to the oxygen preheater, and the oxygen preheater is connected to the gasifier; the gasifier is connected to a pipeline for outputting synthesis gas, and a slag discharge port is provided at the bottom of the gasifier.

[0016] Furthermore, a No. 1 ash melting point detection sampling point is set on the conveying belt before the No. 1 raw coal is transported to the No. 1 coal bunker; a No. 2 ash melting point detection sampling point is set on the conveying belt before the No. 2 raw coal is transported to the No. 2 coal bunker; and a No. 3 ash melting point detection sampling point is set on the coal conveying belt.

[0017] Positive effects of the present invention:

[0018] (1) The present invention adopts two or more sets of annular coal feeders to convey two or more kinds of raw coal to the same coal conveyor belt, and at the same time, two or more belt scales are installed at the coal drop-off ports of the coal conveyor belt respectively, so as to measure the coal drop-off amount of the two or more sets of annular coal feeders separately, and adjust the coal drop-off frequency of the two or more sets of annular coal feeders according to the ash melting point required by the gasifier by detecting the ash melting point of the mixed coal, thereby ensuring that the two or more kinds of raw coal can be accurately proportioned according to the required ash melting point.

[0019] (2) The present invention realizes online blending of two or more different types of coal, and can timely detect the ash melting point of the mixed coal after blending, ensuring that the ash melting point of the mixed coal after blending is within an ideal range, thereby ensuring the stable operation of the gasifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure.

[0021] Figure 1 The coal gasification system capable of controlling the melting point of raw coal ash according to the present invention;

[0022] Figure 2 This is a schematic diagram of a coal blending unit of a coal gasification system capable of controlling the melting point of raw coal ash according to the present invention. DETAILED DESCRIPTION

[0023] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0024] The coal gasification system capable of controlling the melting point of raw coal ash of the present invention comprises a coal blending unit, a coal grinding and drying unit, a pressurizing unit and a gasifier, wherein the coal blending unit is connected to the coal grinding and drying unit, the coal grinding and drying unit is connected to the pressurizing unit, and the pressurizing unit is connected to the gasifier; the coal blending unit comprises several coal bunkers, several sets of annular coal feeders, coal conveying belts and several belt scales, the lower ends of the several coal bunkers are correspondingly provided with several sets of annular coal feeders, a coal conveying belt is provided below the coal drop openings of the several sets of annular coal feeders, the coal conveying belts are respectively provided with several belt scales for calculating the amount of coal dropped at the coal drop openings of the several sets of annular coal feeders, and the end of the coal conveying belt is connected to the coal grinding and drying unit. The coal grinding and drying unit comprises a coal mill, a pulverized coal bag filter and a screw conveyor, the end of the coal conveying belt is connected to the coal mill, the coal mill is connected to the pulverized coal bag filter, the pulverized coal bag filter is connected to the screw conveyor, and the screw conveyor is connected to the pressurizing unit. The pulverized coal drying unit further comprises a blower, and the pulverized coal drying unit is connected to the blower for conveying air. The pulverized coal drying unit further comprises a hot blast furnace for conveying hot air, and the pulverized coal drying unit is connected to the hot blast furnace, and the hot blast furnace is connected to an air pipeline and a natural gas pipeline. The pressurizing unit comprises a pressurized pulverized coal storage tank and a pulverized coal feeding tank, and the pulverized coal drying unit is connected to the pressurized pulverized coal storage tank, and the pressurized pulverized coal storage tank is connected to the pulverized coal feeding tank. The pressurized pulverized coal storage tank is connected to a nitrogen pipeline for pressurization, and the pulverized coal feeding tank is connected to a high-pressure carbon dioxide pipeline. An inflation cone is provided at the lower end of the pulverized coal feeding tank for inputting high-pressure carbon dioxide. The pressurizing unit is connected to a gasifier, and an oxygen pipeline is connected to an oxygen preheater, and the oxygen preheater is connected to the gasifier; the gasifier is connected to a pipeline for outputting synthesis gas, and a slag discharge port is provided at the lower part of the gasifier.

[0025] The coal blending unit preferably includes No. 1 coal bunker, No. 2 coal bunker, No. 1 annular coal feeder, No. 2 annular coal feeder, coal conveyor belt, No. 1 belt scale and No. 2 belt scale. The No. 1 annular coal feeder is arranged below the No. 1 coal bunker, the No. 2 annular coal feeder is arranged below the No. 2 coal bunker, a coal conveyor belt is arranged below the coal drop openings of the No. 1 annular coal feeder and the No. 2 annular coal feeder, and the No. 1 belt scale and the No. 2 belt scale for calculating the amount of coal are respectively installed at the coal drop openings of the No. 1 annular coal feeder and the No. 2 annular coal feeder, and the end of the coal conveyor belt is connected to the coal grinding and drying unit. A No. 1 ash melting point detection sampling point is arranged on the conveyor belt before the No. 1 raw coal is conveyed to the No. 1 coal bunker; a No. 2 ash melting point detection sampling point is arranged on the conveyor belt before the No. 2 raw coal is conveyed to the No. 2 coal bunker; and a No. 3 ash melting point detection sampling point is arranged on the coal conveyor belt.

[0026] Example 1

[0027] The coal gasification system capable of controlling the melting point of raw coal ash described in this embodiment is shown in FIG. Figure 1 and Figure 2 , including a coal blending unit, a coal grinding and drying unit, a pressurizing unit and a gasifier, wherein the coal blending unit is connected to the coal grinding and drying unit, the coal grinding and drying unit is connected to the pressurizing unit, and the pressurizing unit is connected to the gasifier;

[0028] The coal distribution unit includes No. 1 coal bunker, No. 2 coal bunker, No. 1 ring coal feeder, No. 2 ring coal feeder, coal conveyor belt, No. 1 belt scale and No. 2 belt scale. The No. 1 ring coal feeder is arranged below the No. 1 coal bunker, the No. 2 ring coal feeder is arranged below the No. 2 coal bunker, and the coal conveyor belt is arranged below the coal drop openings of the No. 1 ring coal feeder and the No. 2 ring coal feeder. The No. 1 belt scale and the No. 2 belt scale for calculating the amount of coal dropped are respectively installed at the coal drop openings of the No. 1 ring coal feeder and the No. 2 ring coal feeder. The end of the coal conveyor belt is connected to the coal grinding and drying unit. A No. 1 ash melting point detection sampling point is arranged on the conveyor belt before the No. 1 raw coal is conveyed to the No. 1 coal bunker; a No. 2 ash melting point detection sampling point is arranged on the conveyor belt before the No. 2 raw coal is conveyed to the No. 2 coal bunker; and a No. 3 ash melting point detection sampling point is arranged on the coal conveyor belt.

[0029] The pulverized coal drying unit includes a coal mill, a pulverized coal bag filter, a screw conveyor, a fan and a hot air furnace for conveying hot air. The end of the coal conveying belt is connected to the coal mill, the coal mill is connected to the fan for conveying air, the coal mill is connected to the hot air furnace, the hot air furnace is connected to an air pipeline and a natural gas pipeline, the coal mill is connected to the pulverized coal bag filter, the pulverized coal bag filter is connected to the screw conveyor, and the screw conveyor is connected to a pressurizing unit.

[0030] The pressurizing unit includes a pressurized pulverized coal storage tank and a pulverized coal feeding tank, the coal grinding and drying unit is connected to the pressurized pulverized coal storage tank, the pressurized pulverized coal storage tank is connected to a nitrogen pipeline for pressurization, the pressurized pulverized coal storage tank is connected to the pulverized coal feeding tank, an inflation cone is provided at the lower end of the pulverized coal feeding tank for inputting high-pressure carbon dioxide, and the pulverized coal feeding tank is connected to a high-pressure carbon dioxide pipeline.

[0031] The pressurizing unit is connected to the gasifier, the oxygen pipeline is connected to the oxygen preheater, and the oxygen preheater is connected to the gasifier; the gasifier is connected to a pipeline for outputting synthesis gas, and a slag discharge port is arranged at the bottom of the gasifier.

[0032] The process flow of the coal gasification system capable of controlling the melting point of raw coal ash described in this embodiment is as follows:

[0033] (1) No. 1 raw coal is transported to No. 1 coal bunker, and No. 2 raw coal is transported to No. 2 coal bunker. No. 1 ring coal feeder is installed under No. 1 coal bunker, and No. 2 ring coal feeder is installed under No. 2 coal bunker. No. 1 ring coal feeder and No. 2 ring coal feeder transport coal to the coal conveyor belt at the same time. No. 1 belt scale and No. 2 belt scale are installed at the coal drop port of the coal conveyor belt to calculate the amount of coal dropped. The mixed coal is transported to the coal grinding and drying unit.

[0034] A No. 1 ash melting point detection sampling point is set on the conveyor belt before the No. 1 raw coal is transported to the No. 1 coal bunker, which is used to detect the ash melting point of the No. 1 raw coal; a No. 2 ash melting point detection sampling point is set on the conveyor belt before the No. 2 raw coal is transported to the No. 2 coal bunker, which is used to detect the ash melting point of the No. 2 raw coal; a No. 3 ash melting point detection sampling point is set on the coal conveyor belt before the mixed coal is transported to the coal grinding and drying unit, which is used to detect the ash melting point of the mixed coal; by detecting the ash melting point of the mixed coal, according to the ash melting point of the required coal for the gasification furnace of the present invention (generally controlled between 1300 and 1400), the coal feeding frequency of the No. 1 ring coal feeder and the No. 2 ring coal feeder is adjusted to achieve the ash melting point of the required coal after the No. 1 coal and the No. 2 coal are proportioned, so as to ensure that the gasification furnace can stably react and produce safely, and the molten ash of the coal will not adhere to the furnace, or burn and scale in the furnace, causing shutdown or safety accidents.

[0035] (2) The mixed coal is transported to a coal mill and turned into pulverized coal by the coal mill. The coal mill transports air through a fan and hot air through a hot air furnace to dry the pulverized coal. The moisture content of the pulverized coal is controlled by adjusting the temperature of the hot air and the time of hot air. The hot air furnace is connected to an air pipeline and a natural gas pipeline for combustion and heat release. The pulverized coal is screened by a pulverized coal bag filter to select pulverized coal with a particle size (less than 90 microns) and a moisture content (less than 2%) that meet the requirements. The pulverized coal that meets the requirements is transported to a pressurizing unit by a screw conveyor.

[0036] (3) The pulverized coal that meets the requirements is conveyed to a pressurized pulverized coal storage tank through a screw conveyor. The pulverized coal at normal pressure is pressurized to a pressure higher than the reaction pressure of the gasifier by 0.8 MPa by conveying nitrogen into the pressurized pulverized coal storage tank. The pressurized pulverized coal is conveyed to a pulverized coal feeding tank. An aeration cone is provided at the lower end of the pulverized coal feeding tank. High-pressure carbon dioxide is conveyed to the high-pressure feeding tank through the aeration cone, and the pulverized coal is conveyed to the gasifier through the high-pressure carbon dioxide. At the same time, oxygen is also conveyed to the gasifier through an oxygen preheater. Under-oxygen combustion is carried out in the gasifier to mainly generate synthesis gas mainly composed of carbon monoxide, hydrogen and carbon dioxide. The synthesis gas is conveyed to the downstream for treatment, and slag (i.e., coal ash) is discharged from the lower part of the gasifier.

[0037] Coal bunker No. 1 stores thermal coal, and coal bunker No. 2 stores chemical coal. The coal blending ratio is thermal coal: chemical coal. The data during the coal gasification process are shown in Table 1 below.

[0038] Table 1 shows the coal gasification process data at different coal blending ratios

[0039]

[0040] It can be seen from Table 1 that when the coal blending ratio is different, there are obvious differences in the analysis of moisture, ash content, large calorie number, deformation temperature and softening temperature. Therefore, the coal gasification system capable of controlling the melting point of raw coal ash according to the present invention has broad application significance.

[0041] Example 2

[0042] The coal gasification system capable of controlling the melting point of raw coal ash described in this embodiment includes a coal blending unit, a coal grinding and drying unit, a pressurizing unit and a gasifier, wherein the coal blending unit is connected to the coal grinding and drying unit, the coal grinding and drying unit is connected to the pressurizing unit, and the pressurizing unit is connected to the gasifier;

[0043] Among them, the coal distribution unit includes No. 1 coal bunker, No. 2 coal bunker, No. 3 coal bunker, No. 1 ring coal feeder, No. 2 ring coal feeder, No. 3 ring coal feeder, coal conveyor belt, No. 1 belt scale, No. 2 belt scale and No. 3 belt scale. The No. 1 ring coal feeder is arranged below the No. 1 coal bunker, the No. 2 ring coal feeder is arranged below the No. 2 coal bunker, and the No. 3 ring coal feeder is arranged below the No. 3 coal bunker. A coal conveyor belt is arranged below the coal dropping ports of the No. 1 ring coal feeder, the No. 2 ring coal feeder and the No. 3 ring coal feeder. The coal conveyor belt is respectively installed with No. 1 belt scale, No. 2 belt scale and No. 3 belt scale for calculating the amount of coal dropped at the coal dropping ports of the No. 1 ring coal feeder, the No. 2 ring coal feeder and the No. 3 ring coal feeder, and the end of the coal conveyor belt is connected to the coal grinding and drying unit. A No. 1 ash melting point detection sampling point is set on the conveyor belt before the No. 1 raw coal is transported to the No. 1 coal bunker; a No. 2 ash melting point detection sampling point is set on the conveyor belt before the No. 2 raw coal is transported to the No. 2 coal bunker; a No. 3 ash melting point detection sampling point is set on the conveyor belt before the No. 3 raw coal is transported to the No. 3 coal bunker; and a No. 4 ash melting point detection sampling point is set on the coal conveyor belt.

[0044] The pulverized coal drying unit includes a coal mill, a pulverized coal bag filter, a screw conveyor, a fan and a hot air furnace for conveying hot air. The end of the coal conveying belt is connected to the coal mill, the coal mill is connected to the fan for conveying air, the coal mill is connected to the hot air furnace, the hot air furnace is connected to an air pipeline and a natural gas pipeline, the coal mill is connected to the pulverized coal bag filter, the pulverized coal bag filter is connected to the screw conveyor, and the screw conveyor is connected to a pressurizing unit.

[0045] The pressurizing unit includes a pressurized pulverized coal storage tank and a pulverized coal feeding tank, the coal grinding and drying unit is connected to the pressurized pulverized coal storage tank, the pressurized pulverized coal storage tank is connected to a nitrogen pipeline for pressurization, the pressurized pulverized coal storage tank is connected to the pulverized coal feeding tank, an inflation cone is provided at the lower end of the pulverized coal feeding tank for inputting high-pressure carbon dioxide, and the pulverized coal feeding tank is connected to a high-pressure carbon dioxide pipeline.

[0046] The pressurizing unit is connected to the gasifier, the oxygen pipeline is connected to the oxygen preheater, and the oxygen preheater is connected to the gasifier; the gasifier is connected to a pipeline for outputting synthesis gas, and a slag discharge port is arranged at the bottom of the gasifier.

[0047] The process flow of the coal gasification system capable of controlling the melting point of raw coal ash described in this embodiment is as follows:

[0048] (1) No. 1 raw coal is transported to No. 1 coal bunker, No. 2 raw coal is transported to No. 2 coal bunker, and No. 3 raw coal is transported to No. 3 coal bunker. No. 1 ring coal feeder is installed under No. 1 coal bunker, No. 2 ring coal feeder is installed under No. 2 coal bunker, and No. 3 ring coal feeder is installed under No. 3 coal bunker. No. 1 ring coal feeder, No. 2 ring coal feeder and No. 3 ring coal feeder are simultaneously transported to the coal conveyor belt. No. 1 belt scale, No. 2 belt scale and No. 3 belt scale are installed at the coal drop port of the coal conveyor belt to calculate the amount of coal dropped. The mixed coal is transported to the coal grinding and drying unit.

[0049] The conveyor belt before the No. 1 raw coal is transported to the No. 1 coal bunker is provided with a No. 1 ash melting point detection sampling point for detecting the ash melting point of the No. 1 raw coal; the conveyor belt before the No. 2 raw coal is transported to the No. 2 coal bunker is provided with a No. 2 ash melting point detection sampling point for detecting the ash melting point of the No. 2 raw coal; the conveyor belt before the No. 3 raw coal is transported to the No. 3 coal bunker is provided with a No. 3 ash melting point detection sampling point for detecting the ash melting point of the No. 3 raw coal; the coal conveyor belt before the mixed coal is transported to the coal grinding and drying unit is provided with a No. 4 ash melting point detection sampling point. point, which is used to detect the ash melting point of the mixed coal; by detecting the ash melting point of the mixed coal, according to the ash melting point of the required coal for the gasifier of the present invention (generally controlled between 1300 and 1400), the coal feeding frequency of No. 1 ring coal feeder, No. 2 ring coal feeder and No. 3 ring coal feeder is adjusted to achieve the ash melting point of the required coal after the proportion of No. 1 coal, No. 2 coal and No. 3 is met, so as to ensure that the gasifier can stably react and produce safe operation, and the molten ash of the coal will not adhere to the furnace, or burn out scaling in the furnace, causing shutdown or safety accidents.

[0050] (2) The mixed coal is transported to a coal mill and turned into pulverized coal by the coal mill. The coal mill transports air through a fan and hot air through a hot air furnace to dry the pulverized coal. The moisture content of the pulverized coal is controlled by adjusting the temperature of the hot air and the time of hot air. The hot air furnace is connected to an air pipeline and a natural gas pipeline for combustion and heat release. The pulverized coal is screened by a pulverized coal bag filter to select pulverized coal with a particle size (less than 90 microns) and a moisture content (less than 2%) that meet the requirements. The pulverized coal that meets the requirements is transported to a pressurizing unit by a screw conveyor.

[0051] (3) The pulverized coal that meets the requirements is conveyed to a pressurized pulverized coal storage tank through a screw conveyor. The pulverized coal at normal pressure is pressurized to a pressure higher than the reaction pressure of the gasifier by 0.8 MPa by conveying nitrogen into the pressurized pulverized coal storage tank. The pressurized pulverized coal is conveyed to a pulverized coal feeding tank. An aeration cone is provided at the lower end of the pulverized coal feeding tank. High-pressure carbon dioxide is conveyed to the high-pressure feeding tank through the aeration cone, and the pulverized coal is conveyed to the gasifier through the high-pressure carbon dioxide. At the same time, oxygen is also conveyed to the gasifier through an oxygen preheater. Under-oxygen combustion is carried out in the gasifier to mainly generate synthesis gas mainly composed of carbon monoxide, hydrogen and carbon dioxide. The synthesis gas is conveyed to the downstream for treatment, and slag (i.e., coal ash) is discharged from the lower part of the gasifier.

[0052] Example 3

[0053] The coal gasification system capable of controlling the melting point of raw coal ash described in this embodiment includes a coal blending unit, a coal grinding and drying unit, a pressurizing unit and a gasifier, wherein the coal blending unit is connected to the coal grinding and drying unit, the coal grinding and drying unit is connected to the pressurizing unit, and the pressurizing unit is connected to the gasifier;

[0054] Wherein, the coal distribution unit includes No. 1 coal bunker, No. 2 coal bunker, No. 3 coal bunker, No. 1 ring coal feeder, No. 2 ring coal feeder, No. 3 ring coal feeder, No. 4 ring coal feeder, No. 5 ring coal feeder coal conveyor belt, No. 1 belt scale, No. 2 belt scale, No. 3 belt scale, No. 4 belt scale and No. 5 belt scale. The No. 1 ring coal feeder is arranged below the No. 1 coal bunker, the No. 2 ring coal feeder is arranged below the No. 2 coal bunker, the No. 3 ring coal feeder is arranged below the No. 3 coal bunker, the No. 4 ring coal feeder is arranged below the No. 4 coal bunker, and the No. 5 coal bunker is arranged below the No. 5 coal bunker. The No. 5 ring coal feeder is provided, and a coal conveying belt is arranged below the coal dropping openings of the No. 1 ring coal feeder, the No. 2 ring coal feeder, the No. 3 ring coal feeder, the No. 4 ring coal feeder and the No. 5 ring coal feeder. The coal conveying belts are respectively installed with No. 1 belt scale, No. 2 belt scale, No. 3 belt scale, No. 4 belt scale and No. 5 belt scale for calculating the amount of coal dropped at the coal dropping openings of the No. 1 ring coal feeder, the No. 2 ring coal feeder, the No. 3 ring coal feeder, the No. 4 ring coal feeder and the No. 5 ring coal feeder, and the end of the coal conveying belt is connected to the coal grinding and drying unit. A No. 1 ash melting point detection sampling point is set on the conveying belt before No. 1 raw coal is transported to No. 1 coal bunker; a No. 2 ash melting point detection sampling point is set on the conveying belt before No. 2 raw coal is transported to No. 2 coal bunker; a No. 3 ash melting point detection sampling point is set on the conveying belt before No. 3 raw coal is transported to No. 3 coal bunker; a No. 4 ash melting point detection sampling point is set on the conveying belt before No. 4 raw coal is transported to No. 4 coal bunker; a No. 5 ash melting point detection sampling point is set on the conveying belt before No. 5 raw coal is transported to No. 5 coal bunker; and a No. 6 ash melting point detection sampling point is set on the coal conveying belt.

[0055] The pulverized coal drying unit includes a coal mill, a pulverized coal bag filter, a screw conveyor, a fan and a hot air furnace for conveying hot air. The end of the coal conveying belt is connected to the coal mill, the coal mill is connected to the fan for conveying air, the coal mill is connected to the hot air furnace, the hot air furnace is connected to an air pipeline and a natural gas pipeline, the coal mill is connected to the pulverized coal bag filter, the pulverized coal bag filter is connected to the screw conveyor, and the screw conveyor is connected to a pressurizing unit.

[0056] The pressurizing unit includes a pressurized pulverized coal storage tank and a pulverized coal feeding tank, the coal grinding and drying unit is connected to the pressurized pulverized coal storage tank, the pressurized pulverized coal storage tank is connected to a nitrogen pipeline for pressurization, the pressurized pulverized coal storage tank is connected to the pulverized coal feeding tank, an inflation cone is provided at the lower end of the pulverized coal feeding tank for inputting high-pressure carbon dioxide, and the pulverized coal feeding tank is connected to a high-pressure carbon dioxide pipeline.

[0057] The pressurizing unit is connected to the gasifier, the oxygen pipeline is connected to the oxygen preheater, and the oxygen preheater is connected to the gasifier; the gasifier is connected to a pipeline for outputting synthesis gas, and a slag discharge port is arranged at the bottom of the gasifier.

[0058] The process flow of the coal gasification system capable of controlling the melting point of raw coal ash described in this embodiment is as follows:

[0059] (1) No. 1 raw coal is transported to No. 1 coal bunker, No. 2 raw coal is transported to No. 2 coal bunker, No. 3 raw coal is transported to No. 3 coal bunker, No. 4 raw coal is transported to No. 4 coal bunker, and No. 5 raw coal is transported to No. 5 coal bunker. A No. 1 ring coal feeder is set under No. 1 coal bunker, a No. 2 ring coal feeder is set under No. 2 coal bunker, a No. 3 ring coal feeder is set under No. 3 coal bunker, a No. 4 ring coal feeder is set under No. 4 coal bunker, and a No. 5 ring coal feeder is set under No. 5 coal bunker. The No. 1 ring coal feeder, the No. 2 ring coal feeder, the No. 3 ring coal feeder, the No. 4 ring coal feeder, and the No. 5 ring coal feeder are simultaneously transported to the coal conveyor belt. The No. 1 belt scale, the No. 2 belt scale, the No. 3 belt scale, the No. 4 belt scale, and the No. 5 belt scale are respectively installed at the coal drop port of the coal conveyor belt to calculate the amount of coal dropped. The mixed coal is transported to the coal grinding and drying unit.

[0060] The conveyor belt before the No. 1 raw coal is transported to the No. 1 coal bunker is provided with a No. 1 ash melting point detection sampling point for detecting the ash melting point of the No. 1 raw coal; the conveyor belt before the No. 2 raw coal is transported to the No. 2 coal bunker is provided with a No. 2 ash melting point detection sampling point for detecting the ash melting point of the No. 2 raw coal; the conveyor belt before the No. 3 raw coal is transported to the No. 3 coal bunker is provided with a No. 3 ash melting point detection sampling point for detecting the ash melting point of the No. 3 raw coal; the conveyor belt before the No. 4 raw coal is transported to the No. 4 coal bunker is provided with a No. 4 ash melting point detection sampling point for detecting the ash melting point of the No. 4 raw coal; the conveyor belt before the No. 5 raw coal is transported to the No. 5 coal bunker is provided with a No. 5 ash melting point detection sampling point for detecting the ash melting point of the No. 5 raw coal point; a No. 6 ash melting point detection sampling point is arranged on the coal conveyor belt before the mixed coal is conveyed to the coal grinding and drying unit, which is used to detect the ash melting point of the mixed coal; by detecting the ash melting point of the mixed coal, according to the ash melting point of the required coal for the gasifier of the present invention (generally controlled between 1300 and 1400), the coal feeding frequency of No. 1 ring coal feeder, No. 2 ring coal feeder, No. 3 ring coal feeder, No. 4 ring coal feeder and No. 5 ring coal feeder is adjusted to achieve the ash melting point of the required coal after the proportion of No. 1 coal, No. 2 coal, No. 3 coal, No. 4 coal and No. 5 is met, so as to ensure that the gasifier can react and produce stably and operate safely, and the molten ash of the coal will not be adhered to the furnace, or the scale in the furnace will be burned, causing shutdown or safety accidents.

[0061] (2) The mixed coal is transported to a coal mill and turned into pulverized coal by the coal mill. The coal mill transports air through a fan and hot air through a hot air furnace to dry the pulverized coal. The moisture content of the pulverized coal is controlled by adjusting the temperature of the hot air and the time of hot air. The hot air furnace is connected to an air pipeline and a natural gas pipeline for combustion and heat release. The pulverized coal is screened by a pulverized coal bag filter to select pulverized coal with a particle size (less than 90 microns) and a moisture content (less than 2%) that meet the requirements. The pulverized coal that meets the requirements is transported to a pressurizing unit by a screw conveyor.

[0062] (3) The pulverized coal that meets the requirements is conveyed to a pressurized pulverized coal storage tank through a screw conveyor. The pulverized coal at normal pressure is pressurized to a pressure higher than the reaction pressure of the gasifier by 0.8 MPa by conveying nitrogen into the pressurized pulverized coal storage tank. The pressurized pulverized coal is conveyed to a pulverized coal feeding tank. An aeration cone is provided at the lower end of the pulverized coal feeding tank. High-pressure carbon dioxide is conveyed to the high-pressure feeding tank through the aeration cone, and the pulverized coal is conveyed to the gasifier through the high-pressure carbon dioxide. At the same time, oxygen is also conveyed to the gasifier through an oxygen preheater. Under-oxygen combustion is carried out in the gasifier to mainly generate synthesis gas mainly composed of carbon monoxide, hydrogen and carbon dioxide. The synthesis gas is conveyed to the downstream for treatment, and slag (i.e., coal ash) is discharged from the lower part of the gasifier.

[0063] Example 4

[0064] The coal gasification system capable of controlling the melting point of raw coal ash described in this embodiment includes a coal blending unit, a coal grinding and drying unit, a pressurizing unit and a gasifier, wherein the coal blending unit is connected to the coal grinding and drying unit, the coal grinding and drying unit is connected to the pressurizing unit, and the pressurizing unit is connected to the gasifier;

[0065] Wherein, the coal distribution unit includes No. 1 coal bunker, No. 2 coal bunker, No. 3 coal bunker, No. 4 coal bunker, No. 1 ring coal feeder, No. 2 ring coal feeder, No. 3 ring coal feeder, No. 4 ring coal feeder, coal conveyor belt, No. 1 belt scale, No. 2 belt scale, No. 3 belt scale and No. 4 belt scale. The No. 1 ring coal feeder is arranged below the No. 1 coal bunker, the No. 2 ring coal feeder is arranged below the No. 2 coal bunker, the No. 3 ring coal feeder is arranged below the No. 3 coal bunker, and the No. 4 coal bunker is arranged below the No. 4 coal bunker. A coal conveying belt is arranged below the coal dropping openings of the No. 1 ring coal feeder, the No. 2 ring coal feeder, the No. 3 ring coal feeder and the No. 4 ring coal feeder. The coal conveying belts are respectively installed with No. 1 belt scale, No. 2 belt scale, No. 3 belt scale and No. 4 belt scale for calculating the amount of coal dropped at the coal dropping openings of the No. 1 ring coal feeder, the No. 2 ring coal feeder, the No. 3 ring coal feeder and the No. 4 ring coal feeder, and the end of the coal conveying belt is connected to the coal grinding and drying unit. A No. 1 ash melting point detection sampling point is set on the conveying belt before No. 1 raw coal is transported to No. 1 coal bunker; a No. 2 ash melting point detection sampling point is set on the conveying belt before No. 2 raw coal is transported to No. 2 coal bunker; a No. 3 ash melting point detection sampling point is set on the conveying belt before No. 3 raw coal is transported to No. 3 coal bunker; a No. 4 ash melting point detection sampling point is set on the conveying belt before No. 4 raw coal is transported to No. 4 coal bunker; and a No. 5 ash melting point detection sampling point is set on the coal conveying belt.

[0066] It should be understood that the coal gasification system capable of controlling the melting point of raw coal ash described above can be used to reorder, add or delete steps. As long as the desired results of the technical solution disclosed in the present disclosure can be achieved, this document is not limited here.

[0067] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A coal gasification system capable of controlling the melting point of raw coal ash, characterized in that: It includes a coal blending unit, a coal grinding and drying unit, a pressurizing unit and a gasifier, wherein the coal blending unit is connected to the coal grinding and drying unit, the coal grinding and drying unit is connected to the pressurizing unit, and the pressurizing unit is connected to the gasifier; The coal distribution unit includes several coal bins, several sets of annular coal feeders, coal conveyor belts and several belt scales. Several sets of annular coal feeders are correspondingly arranged at the lower ends of the several coal bins. A coal conveyor belt is arranged below the coal dropping ports of the several sets of annular coal feeders. Several belt scales for calculating the amount of coal dropped are respectively installed at the coal dropping ports of the several sets of annular coal feeders. The end of the coal conveyor belt is connected to the coal grinding and drying unit.

2. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 1, characterized in that: The coal distribution unit includes coal bunker No. 1, coal bunker No. 2, ring coal feeder No. 1, ring coal feeder No. 2, coal conveyor belt, belt scale No. 1 and belt scale No.

2. The ring coal feeder No. 1 is arranged below the coal bunker No. 1, and the ring coal feeder No. 2 is arranged below the coal bunker No.

2. A coal conveyor belt is arranged below the coal dropping ports of the ring coal feeder No. 1 and the ring coal feeder No.

2. The coal conveyor belt is respectively installed with belt scale No. 1 and belt scale No. 2 for calculating the amount of coal dropped at the coal dropping ports of the ring coal feeder No. 1 and the ring coal feeder No. 2, and the end of the coal conveyor belt is connected to the coal grinding and drying unit.

3. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 1, characterized in that: The pulverized coal drying unit includes a coal mill, a pulverized coal bag filter and a screw conveyor. The end of the coal conveying belt is connected to the coal mill, the coal mill is connected to the pulverized coal bag filter, the pulverized coal bag filter is connected to the screw conveyor, and the screw conveyor is connected to a pressurizing unit.

4. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 3, characterized in that: The coal mill drying unit further comprises a fan, and the coal mill is connected to the fan for conveying air.

5. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 3, characterized in that: The coal grinding and drying unit further comprises a hot blast furnace for conveying hot blast, the coal grinding machine is connected to the hot blast furnace, and the hot blast furnace is connected to an air pipeline and a natural gas pipeline.

6. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 1, characterized in that: The pressurizing unit comprises a pressurized pulverized coal storage tank and a pulverized coal feed tank, the coal grinding and drying unit is connected to the pressurized pulverized coal storage tank, and the pressurized pulverized coal storage tank is connected to the pulverized coal feed tank.

7. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 6, characterized in that: The pressurized pulverized coal storage tank is connected to a nitrogen pipeline for pressurization, and the pulverized coal feed tank is connected to a high-pressure carbon dioxide pipeline.

8. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 6, characterized in that: The lower end of the pulverized coal feeding tank is provided with an inflation cone for inputting high-pressure carbon dioxide.

9. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 1, characterized in that: The pressurizing unit is connected to the gasifier, the oxygen pipeline is connected to the oxygen preheater, and the oxygen preheater is connected to the gasifier; the gasifier is connected to a pipeline for outputting synthesis gas, and a slag discharge port is arranged at the bottom of the gasifier.

10. The coal gasification system capable of controlling the melting point of raw coal ash according to claim 2, characterized in that: A No. 1 ash melting point detection sampling point is set on the conveyor belt before the No. 1 raw coal is transported to the No. 1 coal bunker; a No. 2 ash melting point detection sampling point is set on the conveyor belt before the No. 2 raw coal is transported to the No. 2 coal bunker; and a No. 3 ash melting point detection sampling point is set on the coal conveyor belt.

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