Chemical looping combustion boiler with automatic feeding

Abstract

The application provides an automatic feeding chemical looping combustion boiler, which comprises an oxygen carrier bin, an air reaction furnace, a raw coal bin and a fuel reaction furnace, oxygen in the oxygen carrier in the oxygen carrier bin is provided to the fuel reaction furnace after being oxidized by the air reaction furnace, and the raw coal bin is used for providing fuel to the combustion furnace; the oxygen carrier bin and the raw coal bin are provided with inventory detection devices, the oxygen carrier bin and the raw coal bin are sequentially provided with a rotary valve, a screw feeder, a pre-furnace hopper and a rotary valve, and the pre-furnace hopper is provided with a pneumatic conveying device at an entrance and exit. According to the embodiment, the pneumatic conveying device is arranged, so that the pressure in the conveying pipeline is increased, and then the material can smoothly enter the fuel reaction furnace. Further, the rotary valve and the screw feeder are arranged, so that the air tightness in the material conveying process is improved, the pressure in the conveying pipeline is stable, and the gas blocking material condition is avoided.

Description

Technical Field

[0001] This invention relates to the field of chemical chain combustion boiler technology, and in particular to an automatically fed chemical chain combustion boiler. Background Technology

[0002] Chemical looping combustion (CLC) technology, as a novel combustion technology, has attracted widespread attention due to its significant advantages such as high energy conversion efficiency, low pollutant emissions, and easy carbon dioxide capture.

[0003] The basic principle of chemical looping combustion technology is to decompose the traditional combustion reaction, where fuel directly contacts air, into two gas-solid reactions using an oxygen carrier. This allows the fuel and air to be transferred from the air to the fuel without direct contact. In this process, the oxygen carrier is first oxidized by oxygen in the air in the air reactor, and then enters the fuel reactor to undergo a reduction reaction with the fuel, releasing heat and generating CO2 and H2O. Since the gas exiting the fuel reactor mainly consists of CO2 and H2O, CO2 can be efficiently captured through simple condensation and drying, significantly reducing CO2 capture costs. This unique combustion method not only improves energy efficiency but also reduces nitrogen oxides (NOx) produced at high temperatures during traditional combustion. X Emissions from this source have significant environmental and strategic energy value.

[0004] Currently, the feed hoppers of related chemical loop combustion systems use gate valves and weighing feeders to feed materials to the boiler by gravity. Due to the slight positive pressure in the air / fuel reactor (boiler), it is difficult to force the material into the boiler, resulting in gas backfilling and difficulty in conveying it into the boiler. Furthermore, because the chemical loop combustion system requires coal particles ≤4mm and oxygen carrier particles ≤0.7mm, the gate valves and weighing feeders have poor airtightness, which easily causes powder leakage. When the moisture content is high (≥10%), it is easy for the material to stick and block. The feed of coal and other fuels is sent to the dense phase zone of the fuel reactor (boiler), and there is no reliable conveying equipment in front of the furnace, which causes the feeding system to be blocked and the boiler backfire phenomenon is prone to occur. Summary of the Invention

[0005] The summary section of this invention provides a brief overview of the concepts, which will be described in detail in the detailed description section that follows. This summary section is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0006] Some embodiments of the present invention provide an automatically fed chemical looping combustion boiler to solve the technical problems mentioned in the background section above.

[0007] This automatically fed chemical loop combustion boiler includes an oxygen carrier chamber, an air reactor, a raw coal chamber, and a fuel reactor.

[0008] The oxygen carrier in the oxygen carrier chamber is oxidized in the air reactor and then supplies oxygen to the fuel reactor; the raw coal chamber is used to supply fuel to the combustion reactor.

[0009] The oxygen carrier silo and the raw coal silo are equipped with inventory detection devices. A rotary valve, a screw feeder, a furnace front hopper, and another rotary valve are sequentially installed after the oxygen carrier silo and the raw coal silo. The furnace front hopper is equipped with a pneumatic conveying device at its inlet and outlet.

[0010] Optionally, in response to the inventory detection device detecting that the inventory is lower than a preset low value, the feeding system is controlled to feed material; in response to the inventory detection device detecting that the inventory is higher than a preset high value, the feeding system is stopped to feed material.

[0011] Optionally, the inventory detection device includes a level gauge and / or a weighing sensor.

[0012] Optionally, the oxygen carrier chamber and the raw coal chamber are equipped with unloading valves at their bottoms.

[0013] Optionally, the oxygen carrier bin, the raw coal bin, and the bottom of each furnace hopper are equipped with a bin arch breaker.

[0014] Optionally, the hopper arch-breaking machine between the oxygen carrier hopper and the air reactor introduces high-pressure air into the oxygen carrier hopper or the furnace front hopper through a pipeline, and the pipeline is also equipped with valves and regulating valves.

[0015] Optionally, the silo arch-breaking machine between the raw coal silo and the fuel reactor introduces high-pressure carbon dioxide into the raw coal silo or the furnace front hopper through a pipeline, and the pipeline is also equipped with valves and regulating valves.

[0016] Optionally, the pneumatic conveying device between the oxygen carrier chamber and the air reactor introduces high-pressure air into the furnace front hopper through a pipeline, and the pipeline is also equipped with valves and regulating valves.

[0017] Optionally, the pneumatic conveying device between the raw coal bunker and the fuel reactor introduces high-pressure carbon dioxide into the furnace front hopper through a pipeline, and the pipeline is also equipped with valves and regulating valves.

[0018] Optionally, another screw feeder may be installed between the fuel reactor and the rotary valve.

[0019] The above embodiments of the present invention have the following beneficial effects:

[0020] By installing a pneumatic conveying device, the pressure inside the conveying pipeline is increased, thereby preventing gas backfire or material overflow caused by slight positive pressure inside the fuel reactor, allowing the material to enter the fuel reactor smoothly. In addition, the pneumatic conveying device can also convey pulverized coal-like materials with a certain moisture content.

[0021] Furthermore, by installing rotary valves and screw conveyors, the airtightness of the material conveying process can be improved, the pressure inside the conveying pipeline can be stabilized, and gas blockage can be avoided.

[0022] Finally, the furnace hopper has a material storage function, and can also isolate the material feeding from the fuel reactor feeding, as well as buffer and compensate for the feeding amount of the conveying pipeline. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a structural embodiment of the automatically fed chemical looping combustion boiler of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of an embodiment of the oxygen carrier chamber of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of one embodiment of the pneumatic conveying device of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of one embodiment of the raw coal bunker of the present invention;

[0028] Figure 5 This is a schematic diagram of another embodiment of the pneumatic conveying device of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100. Oxygen carrier bin; 101. Level gauge; 102. Weighing sensor; 110. Hopper arch breaker; 111. High-pressure air; 112. Valve; 113. Control valve; 120. Discharge valve; 130. Rotary valve; 140. Screw feeder; 150. Furnace front hopper; 160. Hopper arch breaker; 170. Rotary valve; 180. Pneumatic conveying device; 181. High-pressure air; 182. Valve; 183. Control valve;

[0031] 200. Raw coal bunker; 201. Level gauge; 202. Weighing sensor; 210. Hopper arch breaker; 211. High-pressure carbon dioxide; 212. Valve; 213. Control valve; 220. Discharge valve; 230. Rotary valve; 240. Screw feeder; 250. Furnace front hopper; 260. Hopper arch breaker; 270. Rotary valve; 280. Pneumatic conveying device; 281. High-pressure carbon dioxide; 282. Valve; 283. Control valve; 290. Screw feeder;

[0032] 300. Air reactor;

[0033] 400. Fuel reactor. Detailed Implementation

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] Please see Figure 1 The automatically fed chemical loop combustion boiler of the present invention includes an oxygen carrier chamber 100, an air reactor 300, a raw coal chamber 200, and a fuel reactor 400. The oxygen carrier chamber 100 is used to supply oxygen to the air reactor 300, and the raw coal chamber 200 is used to supply fuel to the fuel reactor 400.

[0039] After the oxygen carrier enters the air reactor 300, it is oxidized by the air entering the air reactor 300 and then enters the fuel reactor 400. The oxygen-deficient air in the air reactor 300 is promptly discharged. After the fuel enters the fuel reactor 400, it undergoes a reduction reaction with the oxidized oxygen carrier, releasing heat and generating CO2 and H2O. The reduced oxygen carrier then returns to the air reactor 300.

[0040] Please see Figures 1 to 3 The oxygen carrier chamber 100 is connected to a feeding system, which supplies oxygen to the oxygen carrier chamber 100. The oxygen carrier chamber 100 is equipped with a level detection device. The chemical loop boiler may also include a controller that is communicatively connected to the feeding system and the level detection device. This controller may be a PLC (Programmable Logic Controller).

[0041] The inventory detection device transmits the collected inventory information to the controller, which compares the inventory level indicated by this information with preset low and high values. When the inventory level is lower than the preset low value, it indicates insufficient oxygen carrier inventory, and the controller controls the feeding system to supply oxygen. When the inventory level is higher than the preset high value, it indicates sufficient oxygen carrier, and the controller stops the feeding system. This achieves automatic oxygen carrier supply. It should be noted that the preset high and low values ​​can be determined by those skilled in the art based on repeated experiments or the specifications of the oxygen carrier chamber.

[0042] The aforementioned inventory detection device can be a level gauge 101, which can be installed at the top of the oxygen carrier chamber 100 to determine the inventory level by detecting the height of the oxygen carrier. Alternatively, the aforementioned inventory detection device can be a weighing sensor 102, which is installed at the bottom of the oxygen carrier chamber 100 to determine the inventory level by detecting the weight of the oxygen carrier chamber 100.

[0043] The bottom of the oxygen carrier chamber 100 is equipped with a discharge valve 120, which can be connected to the controller. When it is necessary to supply oxygen carrier to the air reactor 300, the controller controls the discharge valve 120 to open.

[0044] Furthermore, to prevent blockage or wall adhesion in the oxygen carrier chamber 100, a silo arch breaker 110 is installed at the bottom of the oxygen carrier chamber 100. The aforementioned silo arch breaker 110 supplies high-pressure air 111 to the oxygen carrier chamber 100 via a pipeline. The pipeline is also equipped with a valve 112 and a regulating valve 113. The valve 112 is used to open and close the pipeline, and the regulating valve 113 can communicate with a controller. The controller regulates the flow rate and pressure of the high-pressure air 111 by controlling the regulating valve 113.

[0045] Following the oxygen carrier chamber 100, a rotary valve 130, a screw feeder 140, a furnace hopper 150, and another rotary valve 170 are sequentially installed. The rotary valves 130 and 170, respectively, following the oxygen carrier chamber 100 and furnace hopper 150, are used for unloading and gas locking to prevent gas from backing up material or clogging pipelines. The furnace hopper 150 has a material storage function, also serves to isolate the feeding from the oxygen carrier chamber 100 and the air reactor 300, and provides buffering and compensation for adjusting the feed rate of the conveying pipeline. Multiple corresponding pipelines are installed according to the feed ports required by the air reactor 300.

[0046] A hopper arch breaker 160 is installed at the bottom of the furnace front hopper 150. Its structure and working principle are the same as those of the aforementioned hopper arch breaker 110.

[0047] Furthermore, the inlet and outlet of the aforementioned furnace hopper 150 are also equipped with a pneumatic conveying device 180. This pneumatic conveying device 180 supplies high-pressure air 181 to the furnace hopper 150 through a pipeline. The pipeline is also equipped with a valve 182 and a regulating valve 183. The valve 182 is used to open and close the pipeline, and the regulating valve 183 can be communicated with a controller. The controller regulates the flow rate and pressure of the high-pressure air 181 by controlling the regulating valve 183.

[0048] The pneumatic conveying device 180 avoids blockage of the oxygen carrier chamber 100 by introducing high-pressure air 181, thus providing assistance for conveying the oxygen carrier.

[0049] Therefore, during the oxygen carrier transportation process, the conveying pipeline contains both oxygen carrier and air. The screw feeder 140 is used for the closed-loop conveying of powdery and granular oxygen carriers to prevent air leakage from the conveying pipeline, which would cause a pressure drop. Because the pressure inside the conveying pipeline is relatively high, it prevents gas backfire or other issues caused by a slight positive pressure inside the fuel reactor 400, allowing the oxygen carrier to smoothly enter the fuel reactor 400.

[0050] The aforementioned screw feeder 140 can be connected to a controller, which can adjust the speed of the screw feeder 140, thereby adjusting the conveying power and controlling the conveying volume.

[0051] After the oxygen carrier successfully enters the air reactor 300, it undergoes an oxidation reaction with the oxygen in the air, and finally enters the fuel reactor 400.

[0052] Please see Figure 1 , Figure 4 and Figure 5 The aforementioned raw coal bunker 200 is connected to a feeding system, which supplies fuel to the raw coal bunker 200. Similar to the oxygen carrier bunker 100, the raw coal bunker 200 is also equipped with a level detection device that communicates with the controller. The function, principle, and control process of the level detection device in the raw coal bunker 200 are the same as those in the oxygen carrier bunker 100. The level detection device in the raw coal bunker 200 can also be a level gauge 201 and / or a weighing sensor 202.

[0053] The bottom of the raw coal bunker 200 is equipped with a discharge valve 220, which can be connected to the controller. When it is necessary to supply fuel to the fuel reactor 400, the controller controls the discharge valve 220 to open.

[0054] Furthermore, to prevent blockage or wall adhesion in the raw coal bunker 200, a silo arch breaker 210 is also installed at the bottom of the raw coal bunker 200. The aforementioned silo arch breaker 210 supplies high-pressure carbon dioxide 211 to the raw coal bunker 200 through a pipeline. The pipeline is also equipped with a valve 212 and a regulating valve 213. Valve 212 is used to open and close the pipeline, and regulating valve 213 can communicate with a controller. The controller regulates the flow rate and pressure of the high-pressure carbon dioxide 211 by controlling regulating valve 213.

[0055] Since this chemical loop combustion boiler reacts fuel with oxygen carrier, in order to avoid direct contact between fuel and air, the silo arch breaker 210 uses high-pressure carbon dioxide 211 to prevent the raw coal silo 200 from becoming clogged, thus improving the reliability of the chemical loop combustion boiler.

[0056] Following the raw coal bunker 200, a rotary valve 230, a screw feeder 240, a furnace hopper 250, a rotary valve 270, and a rotary feeder 290 are sequentially installed. Rotary valves 230 and 270 are respectively installed after the raw coal bunker 200 and the furnace hopper 250 for unloading and gas locking, preventing gas from backing up material and clogging pipelines. The furnace hopper 250 has a material storage function, and also serves to isolate the feeding from the raw coal bunker 200 to the fuel reactor 400, as well as buffering and compensating for the feed rate of the conveying pipeline 240. Multiple corresponding pipelines are installed according to the feed port required by the fuel reactor 400.

[0057] The bottom of the furnace front hopper 250 is equipped with a hopper arch breaker 260, which has the same structure and working principle as the hopper arch breaker 210 mentioned above.

[0058] Furthermore, a pneumatic conveying device 280 is installed at the inlet and outlet of the furnace hopper 250. This pneumatic conveying device 280 supplies high-pressure carbon dioxide 281 to the furnace hopper 250 through a pipeline. The pipeline is also equipped with a valve 282 and a regulating valve 283. The valve 282 is used to open and close the pipeline, and the regulating valve 283 can communicate with a controller. The controller regulates the flow rate and pressure of the high-pressure carbon dioxide 281 by controlling the regulating valve 283.

[0059] Similarly, the pneumatic conveying device 280 avoids blockage of the raw coal bunker 200 by introducing high-pressure carbon dioxide 281, which helps to transport fuel and also prevents the fuel from coming into direct contact with air, thus not affecting the reaction between the fuel and the oxygen carrier and improving the reliability of the chemical looping combustion boiler.

[0060] Therefore, during fuel transportation, the conveying pipeline contains both fuel and carbon dioxide. The screw feeder 240 is used for the closed-loop conveying of powdery and granular fuel to prevent air leakage from the pipeline and thus avoid pressure drop. Because the pressure inside the conveying pipeline is relatively high, it prevents gas backfire or other issues caused by a slight positive pressure inside the fuel reactor 400, allowing the fuel to smoothly enter the fuel reactor 400.

[0061] For the feeding of fuels such as coal, since they are sent to the dense phase section of the fuel reactor, a double screw feeder is arranged, that is, an additional screw feeder 290 is added in front of the fuel reactor 400. Since the screw feeder 290 is close to the side wall of the fuel reactor 400, it can be cooled by circulating water.

[0062] Screw feeders 240 and 290 can communicate with a controller, which can adjust the rotational speed of screw feeders 240 and 290, thereby adjusting the conveying power.

[0063] Finally, the fuel and the oxidized oxygen carrier undergo a reduction reaction in the fuel reactor 400, releasing heat and generating CO2 and H2O. The reduced oxygen carrier is then returned to the air reactor 300. Since air cannot be introduced into the fuel reactor 400 during normal operation, the recirculated flue gas can provide fluidizing air. The fluidizing air in the circulating fluidized bed is used for the circulating fluidization of materials within the bed, which can be used to maintain parameters such as temperature and pressure of the materials within the fuel reactor 400, promoting combustion and conversion.

[0064] The automatic feeding chemical loop combustion boiler of the present invention can control the unloading valve, rotary valve and screw conveyor to operate automatically through the controller, so as to achieve timed or quantitative feeding.

[0065] By installing a pneumatic conveying device, the pressure inside the conveying pipeline is increased, thereby preventing gas backfire or material overflow caused by slight positive pressure inside the fuel reactor, allowing the material to enter the fuel reactor smoothly. In addition, the pneumatic conveying device can also convey pulverized coal-like materials with a certain moisture content.

[0066] Furthermore, by installing rotary valves and screw conveyors, the airtightness of the material conveying process can be improved, the pressure inside the conveying pipeline can be stabilized, and gas blockage can be avoided.

[0067] By controlling the feeding system and adjusting the power of the screw conveyor, the automatic supply of materials and the control of the conveying volume are realized, thereby improving the automation performance of the chemical loop combustion boiler.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatically fed chemical looping combustion boiler, characterized in that, It includes an oxygen carrier chamber, an air reactor, a raw coal bunker, and a fuel reactor, among which, The oxygen carrier in the oxygen carrier chamber is oxidized in the air reactor and then supplies oxygen to the fuel reactor; the raw coal chamber is used to supply fuel to the fuel reactor. The oxygen carrier silo and the raw coal silo are equipped with inventory detection devices. A rotary valve, a screw feeder, a furnace front hopper and a rotary valve are sequentially arranged after the oxygen carrier silo and the raw coal silo. The furnace front hopper is equipped with a pneumatic conveying device at its inlet and outlet. When the inventory detection device detects that the inventory level is lower than a preset low value, the feeding system is controlled to feed material; when the inventory detection device detects that the inventory level is higher than a preset high value, the feeding system is stopped to feed material. The oxygen carrier silo, raw coal silo, and the bottom of each furnace front hopper are equipped with silo arch breakers; The hopper arch-breaking machine between the oxygen carrier hopper and the air reactor introduces high-pressure air into the oxygen carrier hopper or the furnace front hopper through a pipeline. Valves and regulating valves are also installed on the pipeline. The silo arch-breaking machine between the raw coal silo and the fuel reactor introduces high-pressure carbon dioxide into the raw coal silo or the furnace front hopper through pipelines. Valves and regulating valves are also installed on the pipelines.

2. The automatically fed chemical looping combustion boiler according to claim 1, characterized in that, The inventory detection device includes a level gauge and / or a weighing sensor.

3. The automatically fed chemical looping combustion boiler according to claim 1, characterized in that, The oxygen carrier chamber and the raw coal chamber are equipped with unloading valves at the bottom.

4. The automatically fed chemical looping combustion boiler according to claim 1, characterized in that, The pneumatic conveying device between the oxygen carrier chamber and the air reactor introduces high-pressure air into the furnace front hopper through a pipeline, which is also equipped with valves and regulating valves.

5. The automatically fed chemical looping combustion boiler according to claim 1, characterized in that, The pneumatic conveying device between the raw coal bunker and the fuel reactor introduces high-pressure carbon dioxide into the furnace hopper through a pipeline, which is also equipped with valves and regulating valves.

6. The automatically fed chemical looping combustion boiler according to claim 1, characterized in that, Another screw feeder is installed between the fuel reactor and the rotary valve.

Images