An oxycombustion system

Abstract

This utility model relates to the field of cement production technology, and in particular to an oxygen-enriched combustion system. The oxygen-enriched combustion system includes a liquid oxygen storage device for storing liquid oxygen, a liquid oxygen vaporization device for vaporizing the liquid oxygen, a mixing pipeline, a burner, and a rotary kiln; the liquid oxygen storage device, the liquid oxygen vaporization device, the burner, and the rotary kiln are arranged sequentially; the burner is used to mix and burn the vaporized liquid oxygen output from the liquid oxygen vaporization device with fuel. The oxygen-enriched combustion system provided by this utility model effectively improves fuel combustion efficiency, improves cement clinker quality, reduces fuel consumption, and reduces exhaust emissions.

Description

Technical Field

[0001] This utility model relates to the field of cement production technology, and in particular to an oxygen-enriched combustion system. Background Technology

[0002] The efficiency of fuel combustion in a rotary kiln directly affects the product quality, energy consumption, and environmental emissions of cement production, and has long been a critical issue affecting cement production. Traditional production processes directly use air as a combustion aid, but only 21% of the oxygen is effective, while the remaining 79% nitrogen is discharged as waste gas, absorbing a large amount of heat, thus reducing heat utilization efficiency.

[0003] Therefore, how to effectively improve the combustion efficiency in rotary kilns, increase the flame temperature, reduce the amount of flue gas generated during combustion, reduce energy consumption, improve fuel combustion efficiency, improve the quality of cement clinker, reduce fuel consumption, and reduce exhaust emissions are problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this utility model provides an oxygen-enriched combustion system.

[0005] This utility model provides an oxygen-enriched combustion system, which includes a liquid oxygen storage device for storing liquid oxygen, a liquid oxygen vaporization device for vaporizing liquid oxygen, a mixing pipe, a burner, and a rotary kiln; the liquid oxygen storage device, the liquid oxygen vaporization device, the burner, and the rotary kiln are arranged sequentially; the burner is used to mix and burn the vaporized liquid oxygen output from the liquid oxygen vaporization device with fuel.

[0006] Optionally, the liquid oxygen gasification device is connected to the burner via a main oxygen delivery pipeline and multiple oxygen delivery branch pipes; the burner is equipped with an oil gun pipeline, an external air pipeline, a fuel delivery pipeline, and an internal air pipeline.

[0007] Optionally, multiple oxygen delivery branches are connected to the oil gun pipe, the external air pipe, the fuel delivery pipe, and the internal air pipe, respectively; each of the multiple oxygen delivery branches is equipped with an oxygen branch regulating valve, which is used to control the amount of vaporized liquid oxygen delivered to the oil gun pipe, the external air pipe, the fuel delivery pipe, and the internal air pipe.

[0008] Optionally, the fuel delivery pipeline is equipped with a check valve.

[0009] Optionally, a mixer is provided on the main oxygen delivery pipeline. The mixer is used to mix the vaporized liquid oxygen output from the liquid oxygen vaporization device with air and then deliver it to multiple oxygen delivery branch pipes.

[0010] Optionally, the burner's input pipe is equipped with an oxygen concentration detection device.

[0011] Optionally, the output pipeline of the liquid oxygen gasification device is equipped with an oxygen regulating valve and an oxygen pressure detection device.

[0012] Optionally, the liquid oxygen storage device is provided with a liquid oxygen injection pipe and a liquid oxygen detector, the liquid oxygen injection pipe is located at the upper end of the liquid oxygen detector, and the liquid oxygen detector is a liquid oxygen level and / or pressure gauge.

[0013] Optionally, the liquid oxygen storage device is further provided with a liquid oxygen pressurization valve and a liquid oxygen pressurization pipe.

[0014] Optionally, the liquid oxygen storage device and the liquid oxygen gasification device are connected by an oxygen delivery pipeline, which is equipped with a liquid oxygen flow regulating valve and a liquid oxygen flow meter.

[0015] The technical solution provided by this utility model has the following advantages compared with the prior art:

[0016] The oxygen-enriched combustion system provided by this utility model consists of a liquid oxygen storage device, a liquid oxygen vaporization device, a mixing pipe, a burner, and a rotary kiln arranged in sequence. The burner is used to mix the gasified liquid oxygen output from the liquid oxygen vaporization device with fuel and burn it into the rotary kiln, thereby increasing the oxygen ratio in the rotary kiln, improving fuel combustion efficiency, improving the quality of cement clinker, reducing fuel consumption, and reducing exhaust emissions. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0018] To more clearly illustrate the technical solutions in the embodiments or prior art, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of an oxygen-enriched combustion system provided in a specific embodiment of this utility model;

[0020] Figure 2 for Figure 1 A magnified view of a portion of the image;

[0021] Figure 3 A schematic diagram of an oxygen-enriched combustion system provided for another specific embodiment of this utility model. Detailed Implementation

[0022] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0023] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0024] This utility model embodiment provides an oxygen-enriched combustion system, such as Figure 1-3 As shown, the oxygen-enriched combustion system includes a liquid oxygen storage device for storing liquid oxygen, a liquid oxygen vaporization device for vaporizing liquid oxygen, a mixing pipeline, a burner, and a rotary kiln; the liquid oxygen storage device, the liquid oxygen vaporization device, the burner, and the rotary kiln are arranged in sequence; the burner is used to mix and burn the vaporized liquid oxygen output from the liquid oxygen vaporization device with fuel.

[0025] Two specific implementation methods are provided below. Specific Implementation Example 1

[0027] like Figure 1-2 As shown, in some embodiments, the oxygen-enriched combustion system for cement firing may include a liquid oxygen storage device 101, a liquid oxygen delivery pipeline 102, a liquid oxygen flow meter 103, a liquid oxygen regulating valve 104, a liquid oxygen gasification device 105, an oxygen main line regulating valve 106, an oxygen delivery main pipeline 1071 and an oxygen delivery branch pipeline 1072, an oxygen pressure detection device 108, an oxygen branch line regulating valve 109, a one-way regulating valve 110, a burner 111, a rotary kiln 112, an oil gun pipeline 113, an external air pipeline 114, a fuel delivery pipeline 115, an internal air pipeline 116, an oxygen concentration detection device 117, and a mixer 118.

[0028] The liquid oxygen vaporization unit 105 is connected to the burner 111 via a main oxygen delivery pipeline 1071 and multiple oxygen delivery branch pipelines 1072. The burner is equipped with an oil gun pipeline 113, an external air pipeline 114, a fuel delivery pipeline 115, and an internal air pipeline 116. The multiple oxygen delivery branch pipelines are respectively connected to the oil gun pipeline, the external air pipeline, the fuel delivery pipeline, and the internal air pipeline. The oil gun pipeline 113 is used for ignition, igniting the fuel (usually pulverized coal) that enters the burner from the fuel channel. The oil gun pipeline is located at the very center of the burner. Since fuel is delivered by air, the fuel channel contains both air and fuel, located between the external and internal air channels. The external air channel, also known as the axial flow channel, is located on the outermost side of the burner and provides direct current airflow. The internal air channel, also known as the vortex channel, has a certain angle and provides swirling airflow. The oil gun pipeline, the external air pipeline, the fuel delivery pipeline, and the internal air pipeline are the input pipelines for the burner.

[0029] In detail, the output pipeline of the liquid oxygen vaporization unit includes a main oxygen delivery pipeline 1071 and an oxygen delivery branch pipeline 1072. Liquid oxygen in the liquid oxygen storage device 101 enters the liquid oxygen vaporization unit 105 through the liquid oxygen delivery pipeline 102. The vaporized liquid oxygen, through the main oxygen delivery pipeline 1071 and the oxygen delivery branch pipeline 1072, can be directly mixed with air in the oil gun pipeline 113, external air pipeline 114, fuel delivery pipeline 115, and internal air pipeline 116, respectively, and then enters the rotary kiln 112 via the burner 111. Alternatively, it can be mixed with air first in the mixer 118 before entering the oil gun pipeline 113, external air pipeline 114, fuel delivery pipeline 115, and internal air pipeline 116, and then enters the rotary kiln 112 via the burner 111.

[0030] Liquid oxygen in liquid oxygen storage device 101 enters liquid oxygen vaporization device 105 through liquid oxygen delivery pipe 102. After vaporization, liquid oxygen passes through main oxygen delivery pipe 1071 and branch oxygen delivery pipe 1072 and can be mixed with air in oil gun pipe 113, external air pipe 114, fuel delivery pipe 115, and internal air pipe 116. It can also be mixed with air in one or more of these pipes.

[0031] The oxygen concentration after mixing in the oil gun pipe 113, external air pipe 114, fuel conveying pipe 115, and internal air pipe 116 is 21% to 100%. It enters the rotary kiln 112 together with the fuel in the fuel conveying pipe 115 through the burner 111, enriching the fuel with oxygen to improve the fuel combustion efficiency.

[0032] The oil gun pipe 113, external air pipe 114, fuel delivery pipe 115, and internal air pipe 116 are each equipped with an oxygen branch regulating valve 109 and an oxygen concentration detection device 117. Each oxygen branch regulating valve can be used to control the amount of vaporized liquid oxygen delivered to the oil gun pipe, external air pipe, fuel delivery pipe, and internal air pipe, thereby adjusting and detecting the oxygen concentration of each pipe. The vaporized liquid oxygen output from the liquid oxygen vaporization device can be mixed with air in the oil gun pipe, external air pipe, fuel delivery pipe, and internal air pipe, or it can be mixed with air in one or more of these pipes.

[0033] The fuel delivery pipeline 115 may be equipped with a check valve to prevent fuel from entering the main oxygen delivery pipeline 1071 and branch pipeline 1072, thus avoiding safety accidents.

[0034] The oxygen main line regulating valve 106 regulates the oxygen flow rate and oxygen delivery pressure, and the oxygen pressure detection device 108 detects the oxygen delivery pressure.

[0035] The liquid oxygen storage device 101 is equipped with a level gauge and a flow meter 102 to monitor the liquid oxygen consumption. Specific Implementation Example 2

[0037] like Figure 3 As shown, in some embodiments, the oxygen-enriched combustion system for cement firing may include a liquid oxygen storage device 201, a liquid oxygen level / pressure gauge 2011, a liquid oxygen filling pipe 2012, a liquid oxygen pressurizing pipe 2013, a liquid oxygen pressurizing valve 2014, a liquid oxygen delivery pipe 202, a liquid oxygen flow regulating valve 203, a liquid oxygen flow meter 204, a liquid oxygen gasification device 205, a circulating water pump 206, circulating water pipes 2071 and 2072, a circulating water tank 208, a circulating water release pipe 2081, a circulating water filling pipe 2082, an oxygen regulating valve 209, an oxygen pressure detection device 210, an oxygen delivery pipe 211, a primary air fan 212, a primary air check valve 213, a fuel delivery pipe 214, a burner 215, an oxygen concentration detection device 216, and a rotary kiln 217.

[0038] Liquid oxygen is injected into the liquid oxygen storage device 201 through the liquid oxygen filling pipe 2012. The liquid oxygen storage device 201 has a certain pressure, which is monitored in real time by the liquid oxygen level / pressure gauge 2011. When the pressure of the liquid oxygen storage device 201 is low after liquid oxygen is consumed during use, the liquid oxygen pressurization valve 2014 is opened. After being cooled and vaporized through the liquid oxygen pressurization pipe 2013, it enters the liquid oxygen storage device, thereby achieving pressurization.

[0039] The liquid oxygen regulating valve 203 regulates the amount of liquid oxygen entering the liquid oxygen gasification device 205, which is measured by the liquid oxygen flow meter 204.

[0040] After liquid oxygen enters the liquid oxygen vaporization device 205, it exchanges heat with circulating water to vaporize. The circulating water is injected into the liquid oxygen vaporization device 205 through the circulating water pump 206. After heat exchange, it returns to the circulating water pool 208. The circulating water pool 208 includes a circulating water discharge port 2081 and a circulating water inlet 2082 to ensure the cleanliness of the circulating water.

[0041] Oxygen regulating valve 209 regulates the oxygen concentration and oxygen delivery pressure in the oxygen-enriched oxygen system; oxygen pressure detection device 210 detects the oxygen delivery pressure; and oxygen concentration detection device 216 detects the oxygen concentration.

[0042] A one-way valve 213 is installed at the outlet of the primary air fan 212 to prevent oxygen-rich backflow into the primary air fan 212.

[0043] After being vaporized by the liquid oxygen vaporization device 205, the liquid oxygen is mixed with the air at the outlet of the primary blower 212 to form an oxygen-enriched mixture with an oxygen concentration of 21% to 100%. This mixture, along with the fuel, enters the rotary kiln 217 through the burner 215. The fuel, after being enriched with oxygen for combustion, has improved combustion efficiency, increased kiln temperature, reduced fuel costs, and improved clinker quality.

[0044] The oxygen-enriched combustion system provided by this utility model does not employ pressure swing adsorption, cryogenic air separation, membrane oxygen production, or molecular sieve oxygen production, thereby reducing investment costs, shortening construction time, reducing equipment management and maintenance costs, improving safety, and facilitating operation and maintenance. Furthermore, it can minimize oxygen production costs while simultaneously obtaining the benefits of oxygen-enriched combustion.

[0045] 1. Increase the oxygen concentration in the combustion air to improve fuel combustion efficiency, thereby increasing the temperature inside the kiln and the temperature of the clinker exiting the rotary kiln.

[0046] 2. Improve the combustion efficiency of the rotary kiln and reduce fuel consumption.

[0047] 3. Increase the clinker temperature exiting the rotary kiln and the secondary and tertiary air temperatures to further improve fuel combustion efficiency. Simultaneously, increase the exhaust air temperature for waste heat power generation to increase waste heat power generation.

[0048] 4. Optimize combustion, improve the combustion performance of inferior fuels, expand the application range of fuels, and reduce fuel costs.

[0049] 5. Increased kiln temperature improves clinker quality.

[0050] 6. Replace all or part of the external ventilation fan, fuel conveying fan and internal ventilation fan to reduce fan power consumption.

[0051] 7. No oxygen production equipment is required, resulting in a short construction cycle, low cost, and low management and maintenance costs.

[0052] 8. Flexible to use, with no equipment downtime costs. Oxygen concentration can be adjusted more widely and faster.

[0053] Based on preliminary experiments, this invention achieves the following effects:

[0054] (1) The fuel combustion efficiency increases, the temperature inside the rotary kiln increases, and the flame temperature increases by 400℃.

[0055] (2) The temperature of clinker exiting the rotary kiln increases, the temperature of secondary and tertiary air increases by 80℃ (stabilizing above 1250℃ and 1060℃ respectively), and the temperature of AQC intake air increases by 30℃ (stabilizing above 420℃).

[0056] (3) Fuel combustion efficiency increases, and standard coal consumption decreases by 3 kgce / kg.cl.

[0057] (4) Increased waste heat power generation, increased AQC air intake temperature by 30℃, increased air intake heat, and increased waste heat power generation by 2 kWh / t.cl

[0058] (5) Increased kiln temperature leads to improved clinker quality, with clinker strength increasing by 2.5 MPa after 3 days, clinker strength increasing by 2 MPa after 28 days, and average free calcium content decreasing by 0.5%.

[0059] (6) Replace all or part of the external ventilation fan, fuel conveying fan and internal ventilation fan to reduce the power consumption of the fan.

[0060] A cement clinker production line with an actual capacity of 3600 T / D suffers from high standard coal consumption and poor clinker quality. This invention addresses this issue by purchasing liquid oxygen, mixing the vaporized liquid oxygen with air from the external and internal air ducts to create a 40% oxygen-enriched mixture, which is then introduced into the rotary kiln for combustion. Production statistics before and after implementation are shown below:

[0061] project Before use After use Secondary air temperature (°C) 1170 1250 Tertiary air temperature (°C) 980 1060 AQC air intake temperature (°C) 400 450 Standard coal consumption (kg / t.cl) 106 103 Waste heat power generation (kWh / t.cl) 30.2 22.3 3-day strength of clinker (MPa) 35.5 38 28-day strength of clinker (MPa) 58 60

[0062] As can be seen from the table above, this utility model significantly improves clinker strength, coal consumption, and waste heat power generation. Taking coal consumption as an example, the costs of liquid oxygen and physical coal are 420 yuan / ton and 850 yuan / ton, respectively. The amount of liquid oxygen used per ton of clinker and the amount of physical coal saved are 5 kg / t.cl and 4 kg / t.cl, respectively. Calculated, the cost saving per ton of clinker is 1.3 yuan, which translates to a daily saving of 4680 yuan.

[0063] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0064] The example numbers in the above embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0065] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. An oxygen-enriched combustion system, characterized in that, The oxygen-enriched combustion system includes a liquid oxygen storage device for storing liquid oxygen, a liquid oxygen vaporization device for vaporizing liquid oxygen, a mixing pipeline, a burner, and a rotary kiln; the liquid oxygen storage device, the liquid oxygen vaporization device, the burner, and the rotary kiln are arranged in sequence; the burner is used to mix and burn the vaporized liquid oxygen output from the liquid oxygen vaporization device with fuel.

2. The oxygen-enriched combustion system according to claim 1, characterized in that, The liquid oxygen gasification device is connected to the burner through a main oxygen delivery pipeline and multiple oxygen delivery branch pipes; the burner is equipped with an oil gun pipeline, an external air pipeline, a fuel delivery pipeline, and an internal air pipeline.

3. The oxygen-enriched combustion system according to claim 2, characterized in that, Multiple oxygen delivery branch pipes are respectively connected to the oil gun pipe, the external air pipe, the fuel delivery pipe and the internal air pipe; each of the multiple oxygen delivery branch pipes is equipped with an oxygen branch regulating valve, which is used to control the amount of vaporized liquid oxygen delivered to the oil gun pipe, the external air pipe, the fuel delivery pipe and the internal air pipe.

4. The oxygen-enriched combustion system according to claim 3, characterized in that, The fuel delivery pipeline is equipped with a check valve.

5. The oxygen-enriched combustion system according to claim 2, characterized in that, The main oxygen delivery pipeline is equipped with a mixer, which is used to mix the vaporized liquid oxygen output from the liquid oxygen vaporization device with air and then deliver it to multiple oxygen delivery branch pipes.

6. The oxygen-enriched combustion system according to claim 1, characterized in that, The burner's input pipe is equipped with an oxygen concentration detection device.

7. The oxygen-enriched combustion system according to claim 1, characterized in that, The output pipeline of the liquid oxygen gasification device is equipped with an oxygen regulating valve and an oxygen pressure detection device.

8. The oxygen-enriched combustion system according to claim 1, characterized in that, The liquid oxygen storage device is equipped with a liquid oxygen injection pipe and a liquid oxygen detector. The liquid oxygen injection pipe is located at the upper end of the liquid oxygen detector, which is a liquid oxygen level and / or pressure gauge.

9. The oxygen-enriched combustion system according to claim 8, characterized in that, The liquid oxygen storage device is also equipped with a liquid oxygen pressurization valve and a liquid oxygen pressurization pipe.

10. The oxygen-enriched combustion system according to any one of claims 1-9, characterized in that, The liquid oxygen storage device and the liquid oxygen gasification device are connected by an oxygen delivery pipeline, which is equipped with a liquid oxygen flow regulating valve and a liquid oxygen flow meter.

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