Coal gasification fine slag boiler system and combustion method of coal gasification fine slag

Abstract

This application discloses a coal gasification fine ash boiler system and a method for incinerating coal gasification fine ash. The coal gasification fine ash boiler system includes: a furnace, a flue, an air preheater, a preheater, a mixing tube, a mixing chamber, and a burner. The air preheater is used to heat cold primary air with flue gas to obtain hot primary air. The preheater is used to heat hot primary air with flue gas to obtain high-temperature primary air. The mixing tube is used to mix high-temperature primary air and hot primary air to obtain mixed primary air, with a temperature of 30℃≤t0~t1≤50℃, where t0 is the ignition temperature of the coal gasification fine ash and t1 is the temperature of the mixed primary air. The mixing chamber is used to mix coal gasification fine ash and mixed primary air to obtain primary air-coal mixture. The primary air-coal mixture outlet of the mixing chamber is connected to the primary air-coal mixture inlet of the burner. This effectively increases the initial temperature of the coal gasification fine ash, actively stimulates its reactivity, thereby reducing the initial ignition difficulty of the coal gasification fine ash, and also improves the burnout rate of the coal gasification fine ash.

Description

Technical Field

[0001] This application relates to the field of coal gasification fine slag combustion technology, and more specifically, to a coal gasification fine slag boiler system and a method for incinerating coal gasification fine slag. Background Technology

[0002] With the rapid development of the coal chemical industry, large-scale fluidized bed coal gasification technology has been widely applied, resulting in a large amount of coal gasification slag. Coal gasification slag mainly includes coarse slag and fine slag. It has a high moisture content, high fixed carbon content, high proportion of fine particles, low volatile matter content, and is difficult to burn, making it a difficult-to-burn and difficult-to-treat industrial solid waste.

[0003] In related technologies, the dehydrated coal gasification slag can be mixed with raw coal and then fed into a circulating fluidized bed boiler or pulverized coal boiler for co-firing.

[0004] However, the volatile matter content of coal gasification slag is low, making it a difficult-to-burn fuel with problems such as difficulty in initial ignition and difficulty in complete combustion.

[0005] In addition, due to its low calorific value and short residence time in the furnace, the fine slag from coal gasification is difficult to participate in the internal circulation combustion process, resulting in a low co-firing ratio and low combustion efficiency of the fine slag; it also increases the carbon content of fly ash, leading to lower boiler thermal efficiency.

[0006] In summary, how to achieve the combustion of coal gasification fine slag in order to reduce the initial ignition difficulty of coal gasification fine slag and improve the combustion rate of coal gasification fine slag is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the purpose of this application is to provide a coal gasification fine slag boiler system and a method for incinerating coal gasification fine slag, so as to reduce the initial ignition difficulty of coal gasification fine slag and improve the combustion rate of coal gasification fine slag.

[0008] To achieve the above objectives, this application provides the following technical solution:

[0009] A coal gasification fine slag boiler system includes: a furnace, a flue, an air preheater, a preheater, a mixing tube, a mixing chamber, and a burner;

[0010] The burner, the furnace, and the flue are connected in sequence; the air preheater is installed in the flue and is used to heat the cold primary air through the flue gas to obtain hot primary air;

[0011] The preheater is installed in the flue and along the flue gas flow direction in the flue. The preheater is located upstream of the air preheater. The air inlet of the preheater is connected to the hot primary air outlet of the air preheater. The preheater is used to heat the hot primary air through the flue gas to obtain high-temperature primary air.

[0012] The hot primary air outlet and the high-temperature primary air outlet of the preheater are both connected to the inlet of the mixing pipe. The mixing pipe is used to mix the high-temperature primary air and the hot primary air to obtain mixed primary air. 30℃≤t0~t1≤50℃, where t0 is the ignition temperature of the coal gasification fine slag and t1 is the temperature of the mixed primary air.

[0013] The mixing pipe's primary air outlet is connected to the mixing chamber's air inlet. The mixing chamber is used to mix the coal gasification slag and the primary air to obtain primary air pulverizer. The mixing chamber's primary air pulverizer outlet is connected to the burner's primary air pulverizer inlet.

[0014] In some possible embodiments, the high-temperature primary air outlet and the mixing pipe inlet are connected through a high-temperature primary air duct, and a first flow regulating valve is connected in series with the high-temperature primary air duct;

[0015] The hot primary air outlet and the mixing pipe inlet are connected through a hot primary air duct, and a second flow regulating valve is connected in series with the hot primary air duct.

[0016] In some possible embodiments, the hot primary air duct includes a main pipe, a first branch pipe, and a second branch pipe. The inlet of the main pipe is connected to the outlet of the hot primary air duct. The inlets of the first branch pipe and the second branch pipe are connected to the outlet of the main pipe via a three-way valve. The outlet of the first branch pipe is connected to the air inlet of the preheater. The outlet of the second branch pipe is connected to the inlet of the mixing pipe.

[0017] In some possible embodiments, the burner includes:

[0018] A central ventilation duct, wherein an ignition oil gun is installed inside the central ventilation duct;

[0019] A primary air-powder cylinder, wherein the primary air-powder cylinder is fitted over the central air-powder cylinder;

[0020] A secondary air duct is fitted over the primary air-powder duct, and a secondary air cyclone separator is installed inside the secondary air duct.

[0021] The pre-combustion chamber is located on the air outlet side of the secondary air duct, and the air outlets of the central air duct, the primary air-powder duct, and the secondary air duct are all connected to the pre-combustion chamber.

[0022] A tertiary air duct is provided outside the pre-combustion chamber. The tertiary air duct is annular and its outlet is connected to the pre-combustion chamber. A tertiary air cyclone separator is provided inside the tertiary air duct.

[0023] In some possible embodiments, S1 / S2>0.4, where S1 is the cross-sectional area of ​​the central air duct and S2 is the area enclosed by the inner ring in the cross-section of the primary air powder duct.

[0024] And / or, the inlet of the central air duct is connected to a central air pipe, and the central air pipe is equipped with a fourth flow regulating valve;

[0025] And / or, a flame stabilizing ring is provided at the air outlet of the central air duct;

[0026] And / or, the outlet end of the primary air powder cylinder has a primary air flare, and the flare angle of the primary air flare is in the range of 25°~35°;

[0027] And / or, the outlet end of the secondary air duct is provided with an arch, the angle of which is in the range of 25°~35°.

[0028] In some possible embodiments, the flame stabilizing ring is a lobe flame stabilizing ring, the number of peaks of the lobe flame stabilizing ring is in the range of 6 to 12, and the height difference between the troughs and peaks of the lobe flame stabilizing ring is in the range of 60 mm to 120 mm.

[0029] In some possible embodiments, the coal gasification fine slag boiler system further includes:

[0030] A temperature sensor is disposed at the outlet end of the pre-combustion chamber, and the temperature sensor is used to detect the temperature t2 inside the pre-combustion chamber;

[0031] The third flow regulating valve is connected in series with the tertiary air duct, and the tertiary air duct is connected to the air inlet of the tertiary air duct.

[0032] In some possible embodiments, the temperature t2 in the pre-combustion chamber is less than or equal to the ash melting point.

[0033] In some possible embodiments, the coal gasification fine slag boiler system further includes a control module;

[0034] Both the temperature sensor and the third flow regulating valve are electrically connected to the control module. When t2 is less than or equal to t... 设1 In the case where t2 is greater than or equal to t, the control module is used to control the opening of the third flow regulating valve to decrease, when t2 is greater than or equal to t. 设2 In this case, the control module is used to control the opening degree of the third flow regulating valve to increase;

[0035] And / or, the tertiary cyclone separator is an adjustable cyclone separator, and both the temperature sensor and the tertiary cyclone separator are electrically connected to the control module, when t2 is less than or equal to t. 设1 In the case where t2 is greater than or equal to t 设2 In this case, the control module is used to control the swirl blade angle of the tertiary wind cyclone to decrease;

[0036] t 设1 and t 设2 All are set temperatures, and t 设1 <t 设2 .

[0037] In some possible embodiments, the air outlet of the central air duct is located inside the primary air powder duct, and 50mm≤L1≤100mm, where L1 is the distance between the air outlet of the central air duct and the air outlet of the primary air powder duct.

[0038] And / or, the air velocity at the outlet of the primary air powder cylinder is in the range of 14m / s to 16m / s.

[0039] In some possible embodiments, the concentration of the primary air-powder is greater than or equal to 1.

[0040] In some possible embodiments, the preheater is located in the turning chamber of the flue.

[0041] Based on the coal gasification fine slag boiler system provided above, this application also provides a method for incinerating coal gasification fine slag. The method for incinerating coal gasification fine slag is applied to the coal gasification fine slag boiler system described in any of the above claims. The method for incinerating coal gasification fine slag includes:

[0042] A preheater is used to heat the cold primary air to obtain hot primary air;

[0043] The hot primary air is heated by a preheater to obtain high-temperature primary air;

[0044] The hot primary air and the high-temperature primary air are mixed in a mixing pipe to obtain mixed primary air, where 30℃≤t0~t1≤50℃, t0 is the ignition temperature of the coal gasification fine slag, and t1 is the temperature of the mixed primary air.

[0045] The coal gasification fine slag and the mixed primary air are mixed in a mixing chamber to obtain primary air powder;

[0046] The primary air-coal mixture is fed into the burner; the jet ejected from the burner is then fed into the furnace for combustion.

[0047] In some possible embodiments, the method for incinerating the coal gasification slag further includes: adjusting the flow rate of at least one of the hot primary air and the high-temperature primary air so that 30℃≤t0~t1≤50℃.

[0048] In some possible embodiments, the incineration method of the coal gasification fine slag further includes:

[0049] The temperature t2 of the pre-combustion chamber of the burner is detected;

[0050] When t2 is less than or equal to t 设1 In this case, reduce the tertiary air flow rate of the burner and / or increase the tertiary air swirl intensity of the burner;

[0051] When t2 is greater than or equal to t 设2 In this case, increase the tertiary air flow rate of the burner and / or decrease the tertiary air swirl intensity of the burner;

[0052] Among them, t 设1 and t 设2 All are set temperatures, and t 设1 <t 设2 .

[0053] In some possible embodiments, the method for incinerating the coal gasification slag further includes: adjusting the central air volume of the burner to adjust the central recirculation flue gas volume of the burner.

[0054] In some possible embodiments, the air velocity at the outlet of the primary air pulverizer of the burner ranges from 14 m / s to 16 m / s;

[0055] And / or, the concentration of the primary air-powder is greater than or equal to 1.

[0056] In the coal gasification fine slag boiler system provided in this application, a preheater is installed upstream of the air preheater to heat the hot primary air discharged from the air preheater, obtaining high-temperature primary air. This facilitates the mixing of the high-temperature primary air and the hot primary air, resulting in mixed primary air. The mixed primary air is then mixed with the coal gasification fine slag. Since the temperature t1 of the mixed primary air is greater than that of the hot primary air, and t1 is less than the ignition temperature t0 of the coal gasification fine slag, and 30℃≤t0~t1≤50℃, the temperature range of the mixed primary air can be set to achieve preheating of the coal gasification fine slag. This effectively increases the initial temperature of the coal gasification fine slag and actively stimulates its reactivity, thereby reducing the initial ignition difficulty. Furthermore, because the reactivity of the coal gasification fine slag can be actively stimulated, the burnout rate of the coal gasification fine slag can also be improved. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0058] Figure 1 This is a schematic diagram of the structure of a coal gasification fine slag boiler system provided in an embodiment of this application;

[0059] Figure 2 This is a schematic diagram of the burner structure in the coal gasification fine slag boiler system provided in the embodiments of this application;

[0060] Figure 3 for Figure 2 A magnified view of a portion of the structure shown;

[0061] Figure 4 A schematic diagram of airflow distribution within the burner of a coal gasification fine slag boiler system provided in an embodiment of this application;

[0062] Figure 5 A cross-sectional view of the central air duct and primary air-coal duct of the burner in the coal gasification fine slag boiler system provided in the embodiments of this application;

[0063] Figure 6 This is a schematic diagram of the structure of the flame-stabilizing ring of the burner in the coal gasification fine slag boiler system provided in the embodiments of this application.

[0064] Explanation of reference numerals in the attached figures:

[0065] 1-Furnace, 2-Flue, 201-Tuning Chamber, 3-Air Preheater, 4-Preheater, 5-Mixing Pipe, 6-Mixing Chamber, 7-Burner, 701-Central Air Duct, 702-Ignition Oil Gun, 703-Primary Air-Coal Duct, 7031-Primary Air Flange, 7032-Inner Ring, 704-Secondary Air Duct, 7041-Arch, 705-Secondary Air Cyclone, 706-Pre-combustion Chamber, 707-Tertiary Air Duct, 708 - Tertiary air cyclone separator, 709- Combustion stabilizing ring, 8- Powder bin, 9- High temperature primary air duct, 10- First flow regulating valve, 11- Hot primary air duct, 1101- First branch pipe, 1102- Second branch pipe, 1103- Main pipe, 1104- Three-way valve, 12- Second flow regulating valve, 13- Temperature sensor, 14- Third flow regulating valve, 15- Tertiary air duct, 16- Central air duct, 17- Fourth flow regulating valve;

[0066] 01-Primary air dust, 02-Secondary air, 03-Tertiary air, 04-Central recirculation flue gas. Detailed Implementation

[0067] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0068] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise. It should also be understood that in the embodiments of this application, “one or more” means one, two, or more; “and / or” describes the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character “ / ” generally indicates that the preceding and following related objects are in an “or” relationship.

[0069] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0070] The "multiple" mentioned in the embodiments of this application refers to two or more. It should be noted that in the description of the embodiments of this application, terms such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0071] Figure 1 A coal gasification fine slag boiler system is shown. Figure 1 Solid arrows indicate the direction of airflow (cold primary air, hot primary air, high-temperature primary air, and primary air dust), while dashed arrows indicate the direction of flue gas flow.

[0072] like Figure 1As shown, the coal gasification fine slag boiler system provided in this application embodiment includes: furnace 1, flue 2, air preheater 3, preheater 4, mixing tube 5, mixing chamber 6, and burner 7;

[0073] Air preheater 3 is installed inside flue 2. Air preheater 3 is used to heat cold primary air through flue gas to obtain hot primary air.

[0074] For example, the air preheater 3 includes a first flue gas passage and a primary air passage, which are configured for heat exchange. The first flue gas passage is connected in series in the flue duct 2, so that the flue gas can heat the cold primary air flowing through the primary air passage as it flows through the first flue gas passage, thus turning the cold primary air into hot primary air. The temperature of the hot primary air is higher than the temperature of the cold primary air.

[0075] In this embodiment, the primary cooling air can be air or other gases outside the coal gasification fine slag boiler system.

[0076] The preheater 4 is installed in the flue 2, along the flue gas flow direction in the flue 2, and is located upstream of the air preheater 3; the air inlet of the preheater 4 is connected to the hot primary air outlet of the air preheater 3, and the preheater 4 is used to heat the above-mentioned hot primary air through the flue gas to obtain high temperature primary air.

[0077] It should be noted that, along the flue gas flow direction in flue 2, the preheater 4 is located upstream of the air preheater 3, indicating that the temperature of the flue gas flowing through the preheater 4 is higher than the temperature of the flue gas flowing through the air preheater 3, so as to ensure that the preheater 4 heats the aforementioned hot primary air through the flue gas.

[0078] To facilitate the installation of the preheater 4, it can be installed inside the turning chamber 201 of the flue 2. This also helps to ensure the temperature of the high-temperature primary air, thereby facilitating the heating of the aforementioned hot primary air.

[0079] The preheater 4 can also be installed in other locations within the flue 2, as long as the preheater 4 can heat the aforementioned hot primary air.

[0080] For example, the preheater 4 includes a second flue gas passage and a hot primary air passage, which are configured for heat exchange. The flue gas passage is connected in series in the flue duct 2. Thus, as the flue gas flows through the second flue gas passage, it can heat the hot primary air flowing through the hot primary air passage, causing the hot primary air to become high-temperature primary air. The temperature of the high-temperature primary air is higher than the temperature of the hot primary air.

[0081] The preheater 4 can be a tubular preheater or other types, and this application embodiment does not limit this.

[0082] Both the hot primary air outlet and the high-temperature primary air outlet of the preheater 4 are connected to the inlet of the mixing pipe 5. The mixing pipe 5 is used to mix the high-temperature primary air and the hot primary air to obtain mixed primary air. In this way, the mixing pipe 5 can achieve the mixing of high-temperature primary air and hot primary air, which facilitates the obtaining of mixed primary air. It can be understood that the temperature of the mixed primary air is higher than the temperature of the hot primary air, and the temperature of the mixed primary air is lower than the temperature of the high-temperature primary air.

[0083] In this embodiment, 30℃≤t0~t1≤50℃, t0 is the ignition temperature of the coal gasification fine slag, and t1 is the temperature of the mixed primary air.

[0084] In this embodiment, the ignition temperature of the coal gasification fine slag can be obtained by thermogravimetric analysis (TGA). For example, the ignition characteristic curve of the coal gasification fine slag can be obtained through TGA experiments, and the ignition temperature can be determined based on the ignition characteristic curve. Alternatively, the ignition temperature of the coal gasification fine slag can also be obtained by other methods, which are not limited in this embodiment.

[0085] For example, the temperature range of the hot primary air can be 260℃~340℃, and the temperature range of the high-temperature primary air can be 450℃~600℃. For instance, the ignition temperature t0 of the coal gasification fine slag can be 550℃, the temperature of the hot primary air can be 300℃, the temperature of the high-temperature primary air can be 600℃, and the temperature t1 of the mixed primary air can be 520℃ or 500℃.

[0086] It should be noted that the coal gasification fine slag is the dried coal gasification fine slag, and the dried coal gasification fine slag is coal gasification fine slag powder. The moisture content of the dried coal gasification fine slag is set according to actual needs, and this application embodiment does not limit it.

[0087] The mixing pipe 5 is connected to the mixing primary air outlet and the mixing chamber 6 is connected to the air inlet. The mixing chamber 6 is used to mix coal gasification fine slag and primary air to obtain primary air powder 01.

[0088] To facilitate the mixing of coal gasification slag and primary air, the coal gasification slag boiler system may further include a slag silo 8 for holding the coal gasification slag. The outlet of the slag 8 is connected to the slag inlet of the mixing chamber. The outlet of the slag 8 can be connected to the slag inlet of the mixing chamber 6 via a feeder, so that the coal gasification slag in the slag 8 can be fed into the mixing chamber 6 via the feeder; alternatively, the coal gasification slag in the slag 8 can also be fed into the mixing chamber 6 by other means, which is not limited in this embodiment.

[0089] The powder hopper 8 can also be used to store other fuels, such as raw coal, but this application embodiment does not limit this.

[0090] The primary air-coal outlet of the mixing chamber 6 is connected to the primary air-coal inlet of the burner 7. The burner 7, furnace 1, and flue 2 are sequentially connected, allowing the jet ejected from the burner 7 to enter the furnace 1 for combustion, and the flue gas generated in the furnace 1 to enter the flue 2. It is understood that the nozzle of the burner 7 is connected to the furnace 1.

[0091] It should be noted that the coal gasification fine slag boiler system can achieve both co-firing of coal gasification fine slag and combustion of raw coal.

[0092] In the coal gasification fine slag boiler system provided in this application embodiment, a preheater is installed upstream of the air preheater to heat the hot primary air discharged from the air preheater, obtaining high-temperature primary air. This facilitates the mixing of the high-temperature primary air and the hot primary air, resulting in mixed primary air. The mixed primary air is then mixed with the coal gasification fine slag. Since the temperature t1 of the mixed primary air is greater than that of the hot primary air, and t1 is less than the ignition temperature t0 of the coal gasification fine slag, and 30℃≤t0~t1≤50℃, the temperature range of the mixed primary air can be set to preheat the coal gasification fine slag, effectively increasing its initial temperature and actively stimulating its reactivity, thereby reducing the initial ignition difficulty. Furthermore, the active stimulation of the reactivity of the coal gasification fine slag also improves its burnout rate. Simultaneously, the temperature of the mixed primary air prevents premature ignition or deflagration of the coal gasification fine slag, reducing the probability of coking.

[0093] It should be noted that the reactivity of coal gasification slag refers to the speed and ease with which the slag undergoes chemical reactions under specific conditions (such as combustion, gasification, or reaction with other substances). Understandably, the higher the reactivity of the coal gasification slag, the easier it is to react, the faster the combustion / reaction rate, and the lower the required reaction temperature.

[0094] The coal gasification fine slag boiler system provided in this application embodiment can reduce the initial ignition difficulty of coal gasification fine slag, improve the combustion rate of coal gasification fine slag, which is conducive to increasing the co-firing ratio of coal gasification fine slag and improving the combustion efficiency of coal gasification fine slag; it can also reduce the carbon content of fly ash, thereby improving the thermal efficiency of the boiler system.

[0095] like Figure 1As shown, in some embodiments, to ensure that the temperature t1 of the mixed primary air meets the requirement of 30℃≤t0~t1≤50℃, the high-temperature primary air outlet of the preheater 4 and the inlet of the mixing pipe 5 are connected through a high-temperature primary air duct 9, which is connected in series with a first flow regulating valve 10; the hot primary air outlet of the air preheater 3 and the inlet of the mixing pipe 5 are connected through a hot primary air duct 11, which is connected in series with a second flow regulating valve 12. Thus, the flow rate of the high-temperature primary air can be adjusted by adjusting the opening of the first flow regulating valve 10, thereby adjusting the temperature of the mixed primary air; or, the flow rate of the hot primary air can be adjusted by adjusting the opening of the second flow regulating valve 12, thereby adjusting the temperature of the mixed primary air; or, the flow rate of the high-temperature primary air can be adjusted by adjusting the opening of the first flow regulating valve 10 and the flow rate of the hot primary air can be adjusted by adjusting the opening of the second flow regulating valve 12, thereby adjusting the temperature of the mixed primary air.

[0096] In the above embodiments, the flow rates of both high-temperature primary air and hot primary air can be adjusted, which facilitates temperature adjustment of mixed primary air and improves adjustment efficiency.

[0097] In some other embodiments, the high-temperature primary air duct 9 and the hot primary air duct 11 can be connected to the mixing pipe 5 through a regulating valve. The regulating valve can be a three-way regulating valve. By adjusting the opening of the regulating valve, the flow rates of the high-temperature primary air and the hot primary air can also be adjusted, thereby ensuring the temperature of the mixed primary air.

[0098] like Figure 1 As shown, in some embodiments, the hot primary air duct 11 includes a main pipe 1103, a first branch pipe 1101, and a second branch pipe 1102. The inlet of the main pipe 1103 is connected to the hot primary air outlet. The inlets of the first branch pipe 1101 and the second branch pipe 1102 are connected to the outlet of the main pipe 1103 via a three-way valve 1104. The outlet of the first branch pipe 1101 is connected to the air inlet of the preheater 4, and the outlet of the second branch pipe 1102 is connected to the inlet of the mixing pipe 5. This facilitates the entry of hot primary air into the preheater 4 and the mixing pipe 5. Furthermore, the flow rate of hot primary air in the first branch pipe 1101 and the flow rate of hot primary air in the second branch pipe 1102 can be adjusted by the three-way valve.

[0099] It should be noted that the three-way valve 1104 has three valve ports: one valve port is connected to the outlet of the main pipe 1103, one valve port is connected to the inlet of the second branch pipe 1102, and one valve port is connected to the inlet of the first branch pipe 1101.

[0100] In other embodiments, the hot primary air duct 11 can also have other structures, such as replacing the three-way valve 1104 with two two-way valves, and is not limited to the above embodiments.

[0101] like Figure 2 As shown, in some embodiments, the burner 7 includes: a central air duct 701, an ignition oil gun 702, a primary air-coal duct 703, a secondary air duct 704, a secondary air cyclone separator 705, a pre-combustion chamber 706, a tertiary air duct 707, and a tertiary air cyclone separator 708.

[0102] In the aforementioned burner 7, the ignition oil gun 702 is disposed inside the central air duct 701; the primary air-coal duct 703 is sleeved on the central air duct 701; the secondary air duct 704 is sleeved on the primary air-coal duct 703, and the secondary air cyclone separator 705 is disposed inside the secondary air duct 704; the pre-combustion chamber 706 is located on the air outlet side of the secondary air duct 704, and the air outlets of the central air duct 701, the primary air-coal duct 703, and the secondary air duct 704 are all connected to the pre-combustion chamber 706; the tertiary air duct 707 is disposed outside the pre-combustion chamber 706, the tertiary air duct 707 is annular, the air outlet of the tertiary air duct 707 is connected to the pre-combustion chamber 706, and the tertiary air cyclone separator 708 is disposed inside the tertiary air duct 707.

[0103] It should be noted that, Figure 1 The diagram shows the primary air-coal feed into burner 7. Figure 1 The position where the primary air and coal are fed into the burner 7 shown is exemplary; it is sufficient to ensure that the primary air and coal are fed into the inlet of the primary air and coal cylinder 703.

[0104] In the above embodiments, airflow can be introduced into the central air duct 701; for example, secondary air can be introduced into the central air duct 701. By controlling the airflow rate within the central air duct 701, central recirculation combustion can be achieved, such as... Figure 4 As shown, the primary air 01 flows from left to right, and the central return flue gas 04 flows from right to left; moreover, a secondary air cyclone separator 705 is installed inside the secondary air duct 704, and a tertiary air cyclone separator 708 is installed inside the tertiary air duct 707, as shown. Figure 4 As shown, this causes the secondary air 02 and the tertiary air 03 to swirl, thus burner 7 is a swirl burner. Therefore, under the combined effect of swirl and center recirculation combustion, burner 7 can enhance the initial ignition performance of coal gasification fine slag; it can also enhance the uniform air distribution in the later stage, thereby improving the burnout rate of coal gasification fine slag.

[0105] The aforementioned burner 7, through the combined action of swirling and central recirculation combustion, can achieve dual stable combustion, improve the combustion stability of coal gasification fine slag, and adapt to load fluctuations.

[0106] The aforementioned burner 7 is beneficial for increasing the co-firing ratio of coal gasification fine slag and improving the combustion efficiency of coal gasification fine slag; it can also reduce the carbon content of fly ash, thereby improving the thermal efficiency of the boiler system.

[0107] In the above embodiments, for the same mass of coal gasification slag and coal, the air volume required for coal gasification slag is 40% to 65% of the air volume required for coal combustion. To ensure sufficient intensity of the secondary air, a single secondary air structure is adopted.

[0108] In burner 7, both the secondary air cyclone separator 705 and the tertiary air cyclone separator 708 may include swirl blades. Both the secondary air cyclone separator 705 and the tertiary air cyclone separator 708 may be adjustable cyclones. The angle of the swirl blades of the adjustable cyclone separator can be adjusted, and the swirl intensity of the airflow can be adjusted by adjusting the angle of the swirl blades. For example, adjusting the angle of the swirl blades of the secondary air cyclone separator 705 can adjust the swirl intensity of the secondary air 02; adjusting the angle of the swirl blades of the tertiary air cyclone separator 708 can adjust the swirl intensity of the tertiary air 03.

[0109] It should be noted that the angle of the swirl blades refers to the tilt angle of the blades relative to the axis of the swirler (or the axis of the burner). The angle of the swirl blades is the geometric angle at which the swirl blades are installed.

[0110] In the secondary wind cyclone 705, the swirl blades can be axial blades or radial blades; in the tertiary wind cyclone 708, the swirl blades can be axial blades or radial blades.

[0111] In burner 7, the pre-combustion chamber 706 provides a high-temperature radiant environment and accommodates initial combustion. This pre-combustion chamber 706 is a key space for achieving initial combustion of fuel and enhancing the ignition process. The shell of burner 7 can be a metal shell, and correspondingly, the shell of pre-combustion chamber 706 is also a metal shell. The inner wall of pre-combustion chamber 706 can be lined with refractory bricks or cast with refractory castable to protect the metal shell from high-temperature burning.

[0112] In burner 7, the low-temperature flue gas drawn from the boiler tail flue can be used as tertiary air 03, with a temperature range of 100℃ to 400℃. Tertiary air 03 is introduced from the outside of the pre-combustion chamber 706 through an annular tertiary air duct 707, thereby forming a cooling air film on the inner wall of the pre-combustion chamber 706. In this way, tertiary air 03 can reduce the temperature of the inner wall of the pre-combustion chamber 706 and prevent ash and slag from melting and coking.

[0113] In a coal gasification fine slag boiler system, the size of the central air duct 701 affects the recirculation effect. To create a larger central recirculation zone, in some embodiments, S1 / S2 > 0.4, such as... Figure 5 As shown, S1 is the cross-sectional area of ​​the central air duct 701, and S2 is the area enclosed by the inner ring 7032 in the cross-section of the primary air powder duct 703.

[0114] It should be noted that the cross-sectional area S1 of the central air duct 701 is the cross-sectional area of ​​the channel through which the central air duct 701 supplies central air; S2 includes S1. S1 / S2 < 1.

[0115] In the above embodiments, by reasonably designing the size of the central recirculation zone, the probability of coking and burning of the burner 7 at the nozzle can be reduced.

[0116] In some other embodiments, the ratio of the cross-sectional area S1 of the central air duct 701 to the area S2 enclosed by the inner ring 7032 in the cross-section of the primary air powder duct 703 can be other values ​​and is not limited to the above range.

[0117] In burner 7, an independent central air duct is provided. Based on this, as... Figure 2 As shown, in some embodiments, the inlet of the central air duct 701 is connected to a central air pipe 16, and the central air pipe 16 is equipped with a fourth flow regulating valve 17. In this way, the central air volume can be adjusted, the size and shape of the central recirculation zone can be actively controlled, and combustion can be enhanced; at the same time, it can cool the center of the burner and prevent coking and burn-off.

[0118] like Figure 2 As shown, in some embodiments, a combustion stabilizing ring 709 is provided at the air outlet of the central air duct 701.

[0119] The 709 flame stabilizing ring can be called a flame stabilizing ring. The 709 flame stabilizing ring can enhance the intensity of backflow turbulence and improve combustion stability.

[0120] The combustion stabilizing ring 709 can be a bluff body combustion stabilizing ring, a lobe combustion stabilizing ring, or other combustion stabilizing rings. Among them, the lobe combustion stabilizing ring enhances mixing and combustion stabilization by inducing flow vortices through lobes, thereby improving mixing efficiency and reducing pressure loss and pollutant emissions.

[0121] like Figure 6 As shown, the flame stabilizing ring has a peak 7091 and a trough 7092, which are alternately distributed along the circumference of the flame stabilizing ring; along the radial direction of the flame stabilizing ring, the peak 7091 is farther away from the axis of the flame stabilizing ring than the trough 7092.

[0122] In the lobe-shaped flame stabilizing ring, the number of peaks 7091 and troughs 7092 are the same. In some embodiments, the number of peaks 7091 in the lobe-shaped flame stabilizing ring ranges from 6 to 12, and Δh = 60 mm to 120 mm, where Δh is the height difference between the troughs 7092 and peaks 7091 in the lobe-shaped flame stabilizing ring.

[0123] It should be noted that the height difference between trough 7092 and crest 7091 refers to the distance between trough 7092 and crest 7091 along the radial direction of the flame stabilizing ring.

[0124] For example, the peaks 7091 of the lobed stabilizing ring are 6, 8, 9 or 12.

[0125] For example, Δh is 60mm, 80mm, 100mm or 120mm.

[0126] In the above embodiments, by reasonably designing the number of crests 7091 and the height difference between the troughs 7092 and crests 7091 of the lobe stabilizing ring, the stabilizing effect of the lobe stabilizing ring can be improved, the backflow turbulence intensity can be further enhanced, and the combustion stability can be further enhanced.

[0127] In some other embodiments, the number of peaks of the lobe-type flame stabilizing ring can be other values, and Δh can be other values; the lobe-type flame stabilizing ring can also be replaced by other types of flame stabilizing rings, and is not limited to the above-mentioned lobe-type flame stabilizing ring.

[0128] like Figure 2 As shown, in some embodiments, the outlet end of the primary air-coal cylinder 703 has a primary air flare 7031. In this way, the primary air flare 7031 can guide the flow of primary air-coal 01 and secondary air 02, increase the size of the central recirculation zone, and reduce the probability of coking and burning of the burner 7 at the nozzle.

[0129] like Figure 3 As shown, the flaring angle θ of the primary air flaring port 7031 ranges from 25° to 35°. This optimizes the guiding effect of the primary air flaring port 7031 on the secondary air 02 and the guiding effect of the primary air flaring port 7031 on the primary air powder 01.

[0130] The primary air flare 7031 can be a flared structure; or, as... Figure 3 As shown, the primary air flare 7031 can have two flare structures with different flare angles θ, and the flare angle θ of the two flare structures is in the range of 25°~35°.

[0131] The flaring angle of the primary air flaring 7031 can also be other values, and is not limited to the above range.

[0132] The embodiments mentioned above, such as S1 / S2>0.4, the embodiment with a fourth flow regulating valve 17 in the central air duct 16, the embodiment with a combustion stabilizing ring 709 at the air outlet of the central air duct 701, and the embodiment with a primary air vent 7031 at the outlet end of the primary air powder cylinder 703, can be implemented individually or in combination of any two.

[0133] To effectively improve the performance of burner 7, embodiments with S1 / S2>0.4, embodiments with a combustion stabilizing ring 709 at the outlet of the central air duct 701, embodiments with a primary air vent 7031 at the outlet end of the primary air duct 703, and embodiments with a secondary air cyclone separator 705 can be implemented in combination. These embodiments work together to obtain a larger, more intense, and stable central recirculation zone, which can effectively reduce the probability of coking and burn-off at the nozzle of burner 7, improve the initial ignition performance, combustion intensity, and burnout efficiency of coal gasification fine slag, increase the blending ratio of coal gasification fine slag, improve the combustion efficiency of coal gasification fine slag, and reduce the carbon content of fly ash, thereby improving the thermal efficiency of the boiler system.

[0134] like Figure 2 As shown, in some embodiments, the outlet end of the secondary air duct 704 is provided with an arch 7041, and the angle β of the arch 7041 ranges from 25° to 35°. In this way, the arch 7041 can guide the secondary air 02 and the tertiary air 03, increase the size of the central recirculation zone, and reduce the probability of coking and burning of the burner 7 at the nozzle.

[0135] For example, the angle of the arch 7041 can be 25°, 30° or 35°. The inner wall of the arch 7041 can be formed of refractory bricks or refractory castables to improve its refractory performance.

[0136] The angle β of the arch 7041 can also be other values, and is not limited to the above range.

[0137] The embodiments of having an arch 7041 at the outlet end of the secondary air duct 704, the aforementioned embodiment of S1 / S2>0.4, the embodiment of having a fourth flow regulating valve 17 in the central air duct 16, the embodiment of having a combustion stabilizing ring 709 at the air outlet of the central air duct 701, and the embodiment of having a primary air vent 7031 at the outlet end of the primary air-powder duct 703 can be implemented individually or in any combination.

[0138] like Figure 2 As shown, in some embodiments, the air outlet of the central air duct 701 is located inside the primary air-coal cylinder 703, and 50mm≤L1≤100mm, where L1 is the distance between the air outlet of the central air duct 701 and the air outlet of the primary air-coal cylinder 703. It can be understood that the air outlet of the central air duct 701 is closer to the air inlet of the primary air-coal cylinder 703 than the air outlet of the primary air-coal cylinder 703. Thus, by controlling the distance between the air outlet of the central air duct 701 and the air outlet of the primary air-coal cylinder 703, combustion can be enhanced, the initial ignition performance of the coal gasification fine slag can be improved, and the burnout rate of the coal gasification fine slag can be increased.

[0139] The distance between the air outlet of the central air duct 701 and the air outlet of the primary air powder duct 703 can also be other values, and is not limited to the above range.

[0140] In some embodiments, the outlet velocity of the primary air-coal duct 703 can range from 14 m / s to 16 m / s. While ensuring the transport of fine coal gasification slag, a lower primary air-coal velocity can prolong the residence time of the fine coal gasification slag, which is beneficial for enhancing the initial ignition of the slag.

[0141] The outlet air velocity of the primary air powder cylinder 703 can also be other values, and is not limited to the above range.

[0142] In some embodiments, a enrichment / dilutement device may be provided inside the primary air-coal cylinder 703, which forms an air-coal airflow distribution with a richer inner layer and a thinner outer layer at the nozzle of the burner 7. In this way, low nitrogen emissions can be achieved while ensuring combustion efficiency.

[0143] It should be noted that the enrichment / depletion device uses mechanical or pneumatic methods to separate the primary air-coal gas flow into burner 7 into a high-concentration pulverized coal gas flow (dense phase) and a low-concentration pulverized coal gas flow (depleted phase) before entering the furnace, and then sends these two gas flows into different areas of the furnace for combustion. In the "inner enrichment, outer depletion" configuration, "inner" refers to the area near the nozzle axis of burner 7, and "outer" refers to the area near the outer perimeter of the nozzle of burner 7.

[0144] In some embodiments, the primary air-coal concentration is greater than or equal to 1. The primary air-coal concentration is the ratio of the mass flow rate of the coal gasification fine slag to the mass flow rate of the conveying gas. In this way, the primary air-coal is a gas-solid two-phase flow with a higher concentration, which can reduce the heat of ignition per unit fuel, strengthen the basic conditions for ignition, and reduce the difficulty of initial ignition of the coal gasification fine slag.

[0145] like Figure 2 As shown, in some embodiments, the coal gasification fine slag boiler system further includes a temperature sensor 13 and a third flow regulating valve 14. The temperature sensor 13 is located at the outlet end of the pre-combustion chamber 706 and is used to detect the temperature t2 inside the pre-combustion chamber 706. The third flow regulating valve 14 is connected in series to the tertiary air duct 15, and the tertiary air duct 15 is connected to the air inlet of the tertiary air duct 707.

[0146] It should be noted that the outlet end of the pre-combustion chamber 706 is the nozzle end of the burner 7.

[0147] In the above embodiment, the opening of the third flow regulating valve 14 can be adjusted according to the temperature t2 detected by the temperature sensor 13, thereby adjusting the flow rate of the tertiary air 03. That is, by monitoring the temperature of the pre-combustion chamber 706 and feeding back the adjustment of the air volume of the tertiary air 03, the flow rate of the tertiary air 03 can adjust the temperature of the pre-combustion chamber 706, which can realize dynamic and closed-loop control of the temperature of the pre-combustion chamber 706, so as to ensure that the maximum temperature of the pre-combustion chamber 706 does not exceed the set value, and can ensure the safe, efficient and long-term stable operation of the system.

[0148] For example, when t2 is less than or equal to t 设1 In the case where the opening of the third flow regulating valve 14 is reduced, the flow rate of the tertiary air 03 is reduced, and the temperature inside the pre-combustion chamber 706 is increased; when t2 is greater than or equal to t 设2 In this case, increase the opening of the third flow regulating valve 14 to increase the flow rate of the tertiary air 03 and decrease the temperature inside the pre-combustion chamber 706. 设1 and t 设2 All are set temperatures, and t 设1 <t 设2 For t 设1 and t 设2 The specific value is selected according to the actual situation, and this application embodiment does not limit it.

[0149] In the above embodiments, the set value can be the coal ash melting point, which can be understood as: the temperature t2 inside the pre-combustion chamber 706 can be less than or equal to the coal ash melting point. This further facilitates ensuring the safe, efficient, and long-term stable operation of the system.

[0150] It should be noted that the ash melting point, also called the coal ash melting point, refers to the temperature characteristic at which the residual ash in coal begins to soften and melt into a liquid state at high temperatures after complete combustion. The coal ash melting point is a temperature range. The temperature t2 inside the pre-combustion chamber 706 can be less than or equal to the coal ash melting point, which can be understood as: the temperature t2 inside the pre-combustion chamber 706 can be less than or equal to the lower limit of the coal ash melting point.

[0151] The lower limit of the ash melting point can be 1200℃, and the temperature in the pre-combustion chamber can be less than or equal to 1200℃.

[0152] In the aforementioned coal gasification fine slag boiler system, at the front end, hot primary air and high-temperature primary air are mixed, and the hot primary air is heated to a safe and efficient preheating temperature 30℃~50℃ lower than the ignition temperature of the coal gasification fine slag. At the rear end, the temperature of the pre-combustion chamber 706 is dynamically controlled below the ash melting point by introducing tertiary air 03. This achieves a combination of efficient preheating combustion and temperature control to prevent coking, ensuring safe, efficient, and long-term stable operation of the system.

[0153] To facilitate temperature control within the pre-combustion chamber 706, the aforementioned coal gasification fine slag boiler system also includes a control module. Temperature sensor 13 and the third flow regulating valve 14 are both electrically connected to the control module. When t2 is less than or equal to t... 设1 In the case where t2 is greater than or equal to t, the control module is used to control the opening of the third flow regulating valve 14 to decrease, when t2 is greater than or equal to t. 设2 In this case, the control module is used to increase the opening degree of the third flow regulating valve 14. This allows for automatic regulation.

[0154] As mentioned above, the tertiary air cyclone separator 708 can be an adjustable cyclone separator. The swirl intensity of the tertiary air 03 can be adjusted by adjusting the angle of the swirl blades of the tertiary air cyclone separator 708, thereby adjusting the temperature inside the pre-combustion chamber 706.

[0155] It should be noted that as the angle of the swirl blades increases, the swirl intensity of Tertiary Wind 03 increases; as the angle of the swirl blades decreases, the swirl intensity of Tertiary Wind 03 decreases.

[0156] In some embodiments, the tertiary cyclone separator 708 is an adjustable cyclone separator, and both the temperature sensor 13 and the tertiary cyclone separator 708 are electrically connected to the control module. When t2 is less than or equal to t... 设1 In the case where t2 is greater than or equal to t 设2 In this case, the control module is used to control the reduction of the swirl blade angle of the tertiary cyclone separator 708. In this way, automatic adjustment can also be achieved.

[0157] The embodiments of the control module controlling the angle of the swirl blades and the embodiments of the control module controlling the opening of the third flow regulating valve 14 can be implemented individually or in combination. This application does not limit the embodiments in this regard.

[0158] The coal gasification fine slag boiler system provided in this application embodiment utilizes five complementary approaches: mixing high-temperature primary air and hot primary air to heat the hot primary air; using high-concentration primary air pulverized coal; employing a burner 7 with enhanced recirculation and swirl; having a pre-combustion chamber 706 in the burner 7; and controlling the temperature of the pre-combustion chamber 706 by adjusting the flow rate of tertiary air 03. These approaches can significantly improve the combustion performance of coal gasification fine slag; increase the co-firing ratio of coal gasification fine slag, thereby improving its combustion efficiency; and reduce the carbon content of fly ash, thus improving the thermal efficiency of the boiler system. Therefore, the coal gasification fine slag boiler system can achieve efficient, stable, and clean combustion of coal gasification fine slag.

[0159] The coal gasification fine slag boiler system provided in this application embodiment can be applied to the modification of existing equipment, such as the modification of pulverized coal boilers; or it can be applied to the construction of new equipment, such as the construction of new dedicated burners.

[0160] Based on the coal gasification fine slag boiler system provided in the above embodiments, this application embodiment also provides a method for incinerating coal gasification fine slag, which is applied to the coal gasification fine slag boiler system provided in this application embodiment.

[0161] The method for incinerating coal gasification fine slag provided in this application includes:

[0162] S1: The cold primary air is heated by the air preheater 3 to obtain hot primary air;

[0163] S2: The preheater 4 is used to heat the primary air to obtain high-temperature primary air;

[0164] S3: Mix hot primary air and high-temperature primary air in mixing pipe 5 to obtain mixed primary air, 30℃≤t0~t1≤50℃, where t0 is the ignition temperature of coal gasification fine slag and t1 is the temperature of mixed primary air;

[0165] S4: Mix the coal gasification fines and mixed primary air in the mixing chamber 6 to obtain primary air powder;

[0166] S5: The primary air and coal are fed into the burner 7, and the jet ejected from the burner 7 is sent into the furnace 1 for combustion.

[0167] For the above-mentioned incineration method, the descriptions of air preheater 3, cold primary air, preheater 4, mixing tube 5, ignition temperature, mixing chamber 6, burner 7 and furnace 1 can be found in the previous text and will not be repeated here.

[0168] In the combustion method of coal gasification fine slag provided in this application embodiment, the hot primary air discharged from the air preheater is heated by a preheater to obtain high-temperature primary air, which facilitates the mixing of high-temperature primary air and hot primary air to obtain mixed primary air. The mixed primary air is then mixed with the coal gasification fine slag. Since the temperature t1 of the mixed primary air is greater than the temperature of the hot primary air and less than the ignition temperature t0 of the coal gasification fine slag, and 30℃≤t0~t1≤50℃, the coal gasification fine slag can be preheated by setting the temperature range of the mixed primary air. This can effectively increase the initial temperature of the coal gasification fine slag and actively stimulate its reactivity, thereby reducing the difficulty of initial ignition. Because the reactivity of the coal gasification fine slag can be actively stimulated, the burnout rate of the coal gasification fine slag can also be improved. At the same time, the temperature of the mixed primary air can prevent premature ignition or deflagration of the coal gasification fine slag and reduce the probability of coking, for example, it can prevent coking.

[0169] The combustion method for coal gasification fine slag provided in this application embodiment can reduce the initial ignition difficulty of coal gasification fine slag, improve the combustion rate of coal gasification fine slag, which is conducive to increasing the co-firing ratio of coal gasification fine slag and improving the combustion efficiency of coal gasification fine slag; it can also reduce the carbon content of fly ash, thereby improving the thermal efficiency of the boiler system.

[0170] In some embodiments, the above-mentioned method for incinerating coal gasification fine slag further includes:

[0171] S3': Adjust the flow rate of at least one of the hot primary air and the high-temperature primary air to ensure that 30℃≤t0~t1≤50℃.

[0172] S3' can be located between S2 and S3; or, S3 includes S3', which can be understood as adjusting the flow rate of at least one of the hot primary air and the high-temperature primary air during the process of hot primary air and high-temperature primary air.

[0173] In the above-mentioned method for incinerating coal gasification fine slag, the temperature of the mixed primary air can be adjusted by regulating the flow rate of hot primary air, or the flow rate of high-temperature primary air, or the flow rates of both hot and high-temperature primary air, so as to ensure that 30℃≤t0~t1≤50℃.

[0174] In the above embodiments, the temperature of the mixed primary air is adjusted by regulating the flow rates of hot primary air and high-temperature primary air, which facilitates the temperature adjustment of the mixed primary air and improves the adjustment efficiency.

[0175] In the above embodiments, adjusting the flow rate of the high-temperature primary air specifically includes adjusting the opening degree of the first flow regulating valve 10; adjusting the flow rate of the hot primary air specifically includes adjusting the opening degree of the second flow regulating valve 12.

[0176] The descriptions of the first flow regulating valve 10 and the second flow regulating valve 12 can be found above and will not be repeated here. In some embodiments, the above-described method for incinerating coal gasification fine slag further includes:

[0177] S51': Detects the temperature t2 of the pre-combustion chamber 706 of the burner 7;

[0178] S52': When t2 is less than or equal to t1, decrease the flow rate of the tertiary air 03 in burner 7 and / or increase the swirl intensity of the tertiary air 03 in burner 7; when t2 is greater than or equal to t1, reduce the flow rate of the tertiary air 03 in burner 7 and / or increase the swirl intensity of the tertiary air 03 in burner 7. 设2 In the case of increasing the flow rate of the tertiary air 03 in burner 7 and / or decreasing the swirl intensity of the tertiary air 03 in burner 7; wherein, t 设1 and t 设2 All are set temperatures, and t 设1 <t 设2 .

[0179] In S51' above, the temperature t2 of the pre-combustion chamber 706 can be detected by temperature sensor 13. For a description of temperature sensor 13, please refer to the preceding text; it will not be repeated here.

[0180] In S52' above, reducing the flow rate of tertiary air 03 specifically includes: reducing the opening degree of the third flow regulating valve 14; increasing the flow rate of tertiary air 03 specifically includes: increasing the opening degree of the third flow regulating valve 14. For a description of the third flow regulating valve 14, please refer to the preceding text; it will not be repeated here.

[0181] In S52' above, increasing the swirl intensity of the tertiary wind 03 specifically includes: increasing the swirl blade angle of the tertiary wind cyclone separator 708; decreasing the swirl intensity of the tertiary wind 03 specifically includes: decreasing the swirl blade angle of the tertiary wind cyclone separator 708. For a description of the tertiary wind cyclone separator 708, please refer to the preceding text; it will not be repeated here.

[0182] S51' and S52' can be executed before the primary air-coal is fed into the burner 7 to ensure that the maximum temperature of the pre-combustion chamber 706 does not exceed the set value. S51' and S52' can also be executed after the primary air-coal is fed into the burner 7 to ensure that the maximum temperature of the pre-combustion chamber 706 does not exceed the set value.

[0183] In the above embodiments, the opening degree of the third flow regulating valve 14 and / or the swirl intensity of the tertiary air 03 can be adjusted according to the temperature of the pre-combustion chamber 706, thereby adjusting the flow rate of the tertiary air 03. The flow rate of the tertiary air 03 can adjust the temperature of the pre-combustion chamber 706, which can realize dynamic and closed-loop control of the temperature of the pre-combustion chamber 706, ensuring that the maximum temperature of the pre-combustion chamber 706 does not exceed the set value, and ensuring the safe, efficient and long-term stable operation of the system.

[0184] In the above embodiments, the set value can be the coal ash melting point, which can be understood as: the temperature t2 inside the pre-combustion chamber 706 can be less than or equal to the coal ash melting point. This further facilitates ensuring the safe, efficient, and long-term stable operation of the system. For an explanation of the coal ash melting point, please refer to the preceding text; it will not be repeated here.

[0185] In the aforementioned method for incinerating fine coal gasification slag, at the front end, hot primary air and high-temperature primary air are mixed, and the hot primary air is heated to a safe and efficient preheating temperature 30°C to 50°C lower than the ignition temperature of the fine coal gasification slag. At the rear end, tertiary air 03 is introduced to dynamically control the temperature of the pre-combustion chamber 706 below the ash melting point. This achieves a combination of efficient preheating combustion ("preheating-efficient combustion-anti-coking") and temperature control to prevent coking. This temperature setting and regulation at both the beginning and end ensures the safe, efficient, and long-term stable operation of the system.

[0186] In some embodiments, the method for incinerating coal gasification slag further includes:

[0187] S53': Adjust the center air volume of burner 7 to adjust the center return flue gas volume of burner 7.

[0188] It should be noted that S53' is executed after the initial air and coal are fed into burner 7.

[0189] In the above embodiments, adjusting the central air volume can actively control the size and shape of the central recirculation zone, thereby enhancing combustion; at the same time, it can cool the center of the burner and prevent coking and burn-off.

[0190] In S53', adjusting the center airflow of burner 7 specifically includes adjusting the center airflow by adjusting the opening of the fourth flow regulating valve 17. For an explanation of the fourth flow regulating valve 17, please refer to the previous text; it will not be repeated here.

[0191] In some embodiments, the outlet velocity of the primary air-coal duct 703 of the burner 7 ranges from 14 m / s to 16 m / s. This ensures the transport of fine coal gasification slag while maintaining a lower primary air-coal velocity, which extends the residence time of the fine coal gasification slag and is beneficial for enhancing the initial ignition of the slag.

[0192] For an explanation of the primary air powder duct 703, please refer to the previous text; it will not be repeated here. The outlet air velocity of the primary air powder duct 703 can also be other values, and is not limited to the range mentioned above.

[0193] In some embodiments, the primary air-coal mixture concentration (01) is greater than or equal to 1. The air-coal mixture concentration is the ratio of the mass flow rate of the coal gasification fine slag to the mass flow rate of the conveying gas. Thus, the primary air-coal mixture (01) is a gas-solid two-phase flow with a higher concentration, which can reduce the ignition heat per unit fuel, strengthen the basic conditions for ignition, and reduce the initial ignition difficulty of the coal gasification fine slag.

[0194] The embodiment in which the outlet wind speed of the primary air powder cylinder 703 is in the range of 14m / s to 16m / s, and the embodiment in which the air powder concentration of the primary air powder 01 is greater than or equal to 1, can be implemented alone or in combination. This application does not limit this embodiment.

[0195] The coal gasification fine slag incineration method provided in this application embodiment utilizes five complementary approaches: mixing high-temperature primary air and hot primary air to heat the hot primary air; using high-concentration primary air pulverized coal; employing a burner 7 with enhanced recirculation and swirl; having a pre-combustion chamber 706 in the burner 7; and controlling the temperature of the pre-combustion chamber 706 by adjusting the flow rate of tertiary air 03. These approaches can significantly improve the combustion performance of coal gasification fine slag; increase the co-combustion ratio of coal gasification fine slag, thereby improving its combustion efficiency; and reduce the carbon content of fly ash, thereby improving the thermal efficiency of the boiler system. Therefore, the coal gasification fine slag incineration method can achieve efficient, stable, and clean combustion of coal gasification fine slag.

[0196] The technical features mentioned above, as well as those shown individually in the accompanying drawings, can be combined arbitrarily, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features.

[0197] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coal gasification fine slag boiler system, characterized in that, include: Furnace (1), flue (2), air preheater (3), preheater (4), mixing tube (5), mixing chamber (6) and burner (7); The burner (7), the furnace (1) and the flue (2) are connected in sequence; the air preheater (3) is installed in the flue (2) and is used to heat the cold primary air through the flue gas to obtain hot primary air; The preheater (4) is installed in the flue (2) along the flue gas flow direction in the flue (2), and the preheater (4) is located upstream of the air preheater (3); the air inlet of the preheater (4) is connected to the hot primary air outlet of the air preheater (3), and the preheater (4) is used to heat the hot primary air through the flue gas to obtain high temperature primary air. The hot primary air outlet and the high-temperature primary air outlet of the preheater (4) are both connected to the inlet of the mixing pipe (5). The mixing pipe (5) is used to mix the high-temperature primary air and the hot primary air to obtain mixed primary air. 30℃≤t0~t1≤50℃, t0 is the ignition temperature of the coal gasification fine slag, and t1 is the temperature of the mixed primary air. The mixing pipe (5) is connected to the mixing primary air outlet and the mixing chamber (6) air inlet. The mixing chamber (6) is used to mix the coal gasification fine slag and the mixing primary air to obtain primary air pulverizer (01). The primary air pulverizer outlet of the mixing chamber (6) is connected to the primary air pulverizer inlet of the burner (7).

2. The coal gasification fine slag boiler system according to claim 1, characterized in that, The high-temperature primary air outlet and the inlet of the mixing pipe (5) are connected through the high-temperature primary air pipe (9), and the high-temperature primary air pipe (9) is connected in series with a first flow regulating valve (10). The hot primary air outlet and the inlet of the mixing pipe (5) are connected through the hot primary air pipe (11), and the hot primary air pipe (11) is connected in series with a second flow regulating valve (12).

3. The coal gasification fine slag boiler system according to claim 2, characterized in that, The hot primary air duct (11) includes a main pipe (1103), a first branch pipe (1101), and a second branch pipe (1102). The inlet of the main pipe (1103) is connected to the outlet of the hot primary air. The inlets of the first branch pipe (1101) and the second branch pipe (1102) are connected to the outlet of the main pipe (1103) through a three-way valve (1104). The outlet of the first branch pipe (1101) is connected to the air inlet of the preheater (4), and the outlet of the second branch pipe (1102) is connected to the inlet of the mixing pipe (5).

4. The coal gasification fine slag boiler system according to claim 1, characterized in that, The burner (7) includes: A central ventilation duct (701) is provided with an ignition oil gun (702) inside the central ventilation duct (701). A primary air powder cylinder (703) is fitted over the central air cylinder (701); A secondary air duct (704) is fitted over the primary air powder duct (703), and a secondary air cyclone separator (705) is provided inside the secondary air duct (704). The pre-combustion chamber (706) is located on the air outlet side of the secondary air duct (704). The air outlet of the central air duct (701), the air outlet of the primary air-powder duct (703), and the air outlet of the secondary air duct (704) are all connected to the pre-combustion chamber (706). A tertiary air duct (707) is provided outside the pre-combustion chamber (706). The tertiary air duct (707) is annular, and the air outlet of the tertiary air duct (707) is connected to the pre-combustion chamber (706). A tertiary air cyclone separator (708) is provided inside the tertiary air duct (707).

5. The coal gasification fine slag boiler system according to claim 4, characterized in that, S1 / S2>0.4, where S1 is the cross-sectional area of ​​the central air duct (701) and S2 is the area enclosed by the inner ring (7032) in the cross-section of the primary air powder duct (703). And / or, the inlet of the central air duct (701) is connected to a central air pipe (16), and the central air pipe (16) is provided with a fourth flow regulating valve (17). And / or, a combustion stabilizing ring (709) is provided at the air outlet of the central air duct (701). And / or, the outlet end of the primary air powder cylinder (703) has a primary air flare (7031), and the flare angle of the primary air flare (7031) is in the range of 25°~35°; And / or, the outlet end of the secondary air duct (704) is provided with an arch (7041), and the angle of the arch (7041) is in the range of 25°~35°.

6. The coal gasification fine slag boiler system according to claim 5, characterized in that, The flame stabilizing ring (709) is a lobe flame stabilizing ring. The number of peaks (7091) of the lobe flame stabilizing ring ranges from 6 to 12. The height difference between the troughs (7092) and peaks (7091) of the lobe flame stabilizing ring ranges from 60 mm to 120 mm.

7. The coal gasification fine slag boiler system according to claim 4, characterized in that, Also includes: Temperature sensor (13), the temperature sensor (13) is disposed at the outlet end of the pre-combustion chamber (706), the temperature sensor (13) is used to detect the temperature t2 inside the pre-combustion chamber (706); The third flow regulating valve (14) is connected in series with the tertiary air duct (15), and the tertiary air duct (15) is connected to the air inlet of the tertiary air duct (707).

8. The coal gasification fine slag boiler system according to claim 7, characterized in that, The temperature t2 inside the pre-combustion chamber (706) is less than or equal to the coal ash melting point.

9. The coal gasification fine slag boiler system according to claim 7, characterized in that, It also includes a control module; The temperature sensor (13) and the third flow regulating valve (14) are both electrically connected to the control module. When t2 is less than or equal to t... 设1 In the case where t2 is greater than or equal to t 设2 In this case, the control module is used to control the opening degree of the third flow regulating valve (14) to increase; And / or, the tertiary cyclone separator (708) is an adjustable cyclone separator, and both the temperature sensor (13) and the tertiary cyclone separator (708) are electrically connected to the control module, when t2 is less than or equal to t 设1 In the case where t2 is greater than or equal to t 设2 In this case, the control module is used to control the swirl blade angle of the tertiary wind cyclone separator (708) to decrease; t 设1 and t 设2 All are set temperatures, and t 设1 <t 设2 .

10. The coal gasification fine slag boiler system according to claim 4, characterized in that, The air outlet of the central air duct (701) is located inside the primary air powder duct (703), and 50mm≤L1≤100mm, where L1 is the distance between the air outlet of the central air duct (701) and the air outlet of the primary air powder duct (703). And / or, the air outlet velocity of the primary air powder cylinder (703) is in the range of 14m / s to 16m / s.

11. The coal gasification fine slag boiler system according to claim 1, characterized in that, The concentration of the primary air powder (01) is greater than or equal to 1.

12. The coal gasification fine slag boiler system according to any one of claims 1-11, characterized in that, The preheater (4) is located in the turning chamber (201) of the flue (2).

13. A method for incinerating fine coal gasification slag, characterized in that, Applied to any one of the coal gasification fine slag boiler systems as described in claims 1-12, the method for incinerating the coal gasification fine slag includes: The cold primary air is heated by an air preheater (3) to obtain hot primary air; The hot primary air is heated by a preheater (4) to obtain high-temperature primary air; The hot primary air and the high-temperature primary air are mixed in the mixing pipe (5) to obtain mixed primary air, 30℃≤t0~t1≤50℃, where t0 is the ignition temperature of the coal gasification fine slag and t1 is the temperature of the mixed primary air; The coal gasification fine slag and the mixed primary air are mixed in the mixing chamber (6) to obtain primary air powder (01). The primary air powder (01) is fed into the burner (7); the jet ejected from the burner (7) is fed into the furnace (1) for combustion.

14. The method for incinerating coal gasification fine slag according to claim 13, characterized in that, Also includes: Adjust the flow rate of at least one of the hot primary air and the high-temperature primary air so that 30℃≤t0~t1≤50℃.

15. The method for incinerating coal gasification fine slag according to claim 13, characterized in that, Also includes: The temperature t2 of the pre-combustion chamber (706) of the burner (7) is detected; When t2 is less than or equal to t 设1 In the case of reducing the tertiary airflow of the burner (7) and / or increasing the tertiary airflow swirl intensity of the burner (7); When t2 is greater than or equal to t 设2 In the case of increasing the tertiary airflow of the burner (7) and / or decreasing the tertiary air swirl intensity of the burner (7); Among them, t 设1 and t 设2 All are set temperatures, and t 设1 <t 设2 .

16. The method for incinerating coal gasification fine slag according to claim 13, characterized in that, Also includes: Adjust the central air volume of the burner (7) to adjust the central return flue gas volume of the burner (7).

17. The method for incinerating coal gasification fine slag according to any one of claims 13-16, characterized in that, The air velocity at the outlet of the primary air condenser (703) of the burner (7) ranges from 14 m / s to 16 m / s. And / or, the concentration of the primary air powder (01) is greater than or equal to 1.

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