Combined hydrogen-mixing low-carbon combustion device and control method thereof

Abstract

This invention relates to the field of energy-saving combustion technology for furnaces and kilns in the metallurgical industry, specifically to a combined hydrogen-mixed low-carbon combustion device and its control method. The invention mainly includes a hydrogen valve assembly, a gas valve assembly, an air valve assembly, a burner, an igniter, and a baffle plate. The hydrogen valve assembly includes a hydrogen regulating valve and a hydrogen flow meter; the gas valve assembly includes a gas regulating valve, a gas flow meter, and an online gas composition analyzer, wherein the online gas composition analyzer is installed on the gas pipeline; the air valve assembly includes an air regulating valve and an air flow meter. This invention achieves hydrogen-mixed combustion by mixing hydrogen into the existing heating furnace combustion device during fuel combustion. Through the coordination between the various valve assemblies, the flow control valve controls the intake air volume, and the temperature monitoring device monitors the intake air temperature, achieving the effects of reducing pollutant emissions and increasing energy utilization.

Description

Technical Field

[0001] This invention relates to the field of energy-saving combustion technology for furnaces and kilns in the metallurgical industry, specifically to a combined hydrogen-mixed low-carbon combustion device and its control method. Background Technology

[0002] As a pillar industry of my country's economic development, the steel industry accounts for a significant proportion of the national economy. Regardless of whether the production process is long or short, steel rolling is an indispensable part of steel enterprises. The heating furnace, located between continuous casting and rolling, is one of the main energy-consuming devices in steel enterprises, typically accounting for 15-20% of total energy consumption and 70% of the rolling process's energy consumption. Furthermore, the fuel combustion process in the heating furnace usually results in significant NOx and CO2 emissions, causing serious environmental pollution. CO2 levels in the flue gas decrease as fuel consumption decreases. The most important component of the combustion system is the burner, also known as the nozzle, which provides heat and is a crucial part of the heating furnace. The burner's structural type significantly affects the combustion flow within the furnace, the furnace temperature distribution, and the formation of NOx and CO2, thus impacting thermal efficiency. Currently, engineers are increasingly researching burners, mainly focusing on energy saving and consumption reduction, waste heat recovery to improve thermal efficiency, reducing pollutant emissions, and improving burner performance.

[0003] Existing heating furnace combustion devices typically employ oxy-fuel combustion, a highly efficient and energy-saving technology. Its key characteristic is that the O2 content in the air is greater than 21%, even reaching pure oxygen. This reduces smoke losses caused by the 79% of N2 in the combustion air that does not participate in the combustion reaction. However, excessive air supply to the fuel furnace can lead to energy waste, reduced combustion temperature, increased oxidation loss, and increased NOx emissions. In addition, known publicly available technologies include ammonia combustion. The advantage of ammonia under suitable combustion conditions is that its products are only nitrogen and water, without producing greenhouse gases. Therefore, ammonia has the potential to be a clean fuel. However, in practical applications, it has been found that the water produced during ammonia combustion affects the combustion process, limiting the use of ammonia as fuel in heating furnaces.

[0004] Existing technologies have failed to improve fuel utilization, combustion temperature, and stability at the fuel level. Furthermore, excessive oxygen in the fuel furnace can lead to energy waste and increased oxidation loss. From the perspective of pollutant emissions, they have not been able to significantly reduce NOx and CO2 emissions. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a combined hydrogen-mixed low-carbon combustion device and its control method to address the shortcomings of the prior art, which can improve combustion efficiency and fuel utilization, reduce energy consumption and carbon emissions, and achieve low-carbon combustion effect of the burner.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] I. A combined hydrogen-mixing low-carbon combustion device

[0008] This invention provides a combined hydrogen-mixed low-carbon combustion device, mainly comprising a hydrogen valve assembly 1, an air valve assembly 2, a gas valve assembly 3, a combustion chamber 4, and a baffle plate 5. One end of the gas valve assembly 3 is connected to a gas pipeline, and the other end is connected to the combustion chamber 4 at the head of the furnace body. One end of the hydrogen valve assembly 1 is connected to a hydrogen pipeline, and the other end is connected to the side wall at the tail of the furnace body. One end of the air valve assembly 2 is connected to an air pipeline, and the other ends are connected to the side wall in the middle of the furnace body and the combustion chamber 4, respectively. The baffle plate 5 is provided inside the furnace body from the tail to the head.

[0009] The hydrogen valve group 1 is equipped with a hydrogen regulating valve and a hydrogen flow meter; the air valve group 2 is equipped with an air regulating valve and an air flow meter; and the gas valve group 3 is equipped with a gas regulating valve, a gas flow meter, and a gas temperature monitoring system. The hydrogen regulating valve, hydrogen flow meter, air regulating valve, air flow meter, gas regulating valve, gas flow meter, and gas temperature monitoring system are all electrically connected to the combustion device controller.

[0010] Preferably, the hydrogen valve group 1 has two symmetrical sets, which are respectively connected to the upper and lower side walls of the tail of the furnace body and respectively connected to the combustion chamber 4 through the upper and lower hydrogen channels inside the furnace body.

[0011] Preferably, the air valve group 2 is provided in two symmetrical groups, each group of air valve group 2 is provided with a main air channel and an auxiliary air channel, the main channel is connected to the middle side wall of the furnace body, and the auxiliary channel is connected to the combustion chamber 4.

[0012] Preferably, the gas valve assembly 3 has three gas channels in the vertical direction: upper, middle, and lower. The middle gas channel is the main gas channel, and the two symmetrical upper and lower gas channels are auxiliary gas channels.

[0013] Preferably, the hydrogen valve assembly 1 includes a hydrogen gun, which is mounted on a support tube, and the support tube is welded to the upper and lower side walls of the furnace body of the device.

[0014] Preferably, the guide plate 5 has two symmetrically arranged vertically, and the two guide plates 5 are respectively arranged along the upper and lower hydrogen channels inside the furnace body of the device.

[0015] Preferably, the combustion chamber 4 is equipped with an ignition burner.

[0016] II. A control method for a combined hydrogen-mixed low-carbon combustion device

[0017] Based on the same inventive concept, the present invention also provides a control method for the combined hydrogen-mixing low-carbon combustion device as described above, specifically including the following steps:

[0018] S1, open the regulating valves of the main gas passage and the main air passage to introduce the preset flow rate of gas and air into the combustion chamber, and ignite them through the ignition burner;

[0019] S2 monitors the gas inlet temperature in real time through the gas temperature monitoring system, and cuts off the gas pipeline in time when the inlet temperature exceeds the safety threshold.

[0020] S3, by adjusting the regulating valve of the auxiliary air passage, controls the air-fuel ratio in the combustion chamber in real time, so that the fuel gas and air reach the preset stable combustion state;

[0021] S4, open the regulating valves of the upper and lower hydrogen passages and the corresponding auxiliary gas passages, so that the hydrogen flow of the preset flow rate is premixed with the gas in the auxiliary gas passage after passing through the guide plate and then enters the combustion chamber.

[0022] S5, based on the real-time flow rate of the fuel gas and hydrogen entering the combustion chamber, performs adaptive air flow control to ensure that the fuel gas, hydrogen, and air reach the preset stable combustion state.

[0023] Preferably, the preset stable combustion state one is specifically: the air-fuel ratio A in the combustion chamber is 0.9A. 0fuel A 0fuel The theoretical air-fuel ratio of the fuel gas and air.

[0024] Preferably, the second preset stable combustion state is specifically as follows:

[0025] F air =(Q fuel ×A 0fuel ×u1)+(Q H2 ×A 0H2 ×u2)

[0026] In the formula, F air Q is the airflow rate introduced into the combustion chamber. fuel Q represents the gas flow rate entering the combustion chamber. H2 A represents the hydrogen flow rate introduced into the combustion chamber. 0fuel For the theoretical air-fuel ratio, A 0H2 U1 represents the theoretical air-to-hydrogen ratio, and u2 are both excess air correction factors.

[0027] Compared with the prior art, the present invention has the following main advantages:

[0028] 1. This invention proposes a combined hydrogen-mixing low-carbon combustion device, which achieves the effect of mixing hydrogen and fuel combustion by cooperating with hydrogen valve group, air valve group, gas valve group and guide plate. Hydrogen, with its high calorific value and pollution-free characteristics, can reduce the pollutant emissions of fuel combustion and improve energy utilization efficiency.

[0029] 2. The device of the present invention improves upon existing combustion devices, requires less investment, brings greater benefits, and can be applied to various types of heating furnace combustion devices, showing strong adaptability and good scalability.

[0030] 3. This invention proposes a control method for a combined hydrogen-mixed low-carbon combustion device, which can control the flow rates of hydrogen, air and fuel gas in real time, improve fuel utilization efficiency, improve combustion quality, and effectively reduce NOx and CO2 emissions, thereby reducing pollutant emissions from the fuel level. Attached Figure Description

[0031] Figure 1 This is an overall schematic diagram of the combined hydrogen-mixing low-carbon combustion device in an embodiment of the present invention;

[0032] Figure 2 This is a flowchart of the control method in an embodiment of the present invention.

[0033] In the diagram: 1-hydrogen valve assembly, 2-air valve assembly, 3-gas valve assembly, 4-combustion chamber, 5-guide plate. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0035] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0036] Example 1: This example provides a combined hydrogen-mixed low-carbon combustion device, including a hydrogen valve group 1, an air valve group 2, a gas valve group 3, a combustion chamber 4, and a baffle plate 5.

[0037] Specifically, the hydrogen valve group 1 includes a hydrogen regulating valve and a hydrogen flow meter; the air valve group 2 includes an air regulating valve and an air flow meter; and the gas valve group 3 includes a gas regulating valve, a gas flow meter, and a gas temperature monitoring system, wherein the gas temperature monitoring system is installed on the gas pipeline.

[0038] Furthermore, the hydrogen valve assembly 1 also includes an advanced hydrogen gun, which is mounted on a hydrogen gun support tube welded to the furnace body. The hydrogen gun is equipped with a shut-off valve, which has a limit switch.

[0039] Furthermore, in the combined hydrogen-mixed low-carbon combustion device, the fuel to be burned is delivered to the burner via the gas valve assembly 3 and ignited by the igniter. After combustion stabilizes, hydrogen is introduced into the combustion chamber via the hydrogen valve assembly 1 through a guide plate. The amount of gas supplied by the gas valve assembly and the amount of air supplied by the air valve assembly are adjusted accordingly to maintain a stable combustion state. The air valve assembly 2 has two inlets, which can be adjusted separately to achieve both premixed combustion and direct combustion, allowing for timely adjustment of the air-fuel ratio during combustion to achieve the optimal ideal combustion state.

[0040] Furthermore, the gas valve assembly 3 controls the gas intake volume through a gas flow control valve, so that the gas enters at a stable intake rate. The gas valve assembly has a total of three gas channels, including a central channel and two symmetrical upper and lower channels. The central gas channel is the main gas channel, and the upper and lower gas channels are auxiliary gas channels used to adjust the amount of gas and hydrogen mixed. At the same time, it can increase the gas intake volume, improve combustion efficiency, and improve combustion quality.

[0041] Furthermore, the air valve group 2 controls the air intake volume through an air flow control valve, and the air valve group has four air channels symmetrically arranged vertically. The main channel is located in the middle of the furnace body, and the auxiliary channel leads to the combustion chamber. This is used to adjust the air-fuel ratio in a timely manner so that the air intake reaches a stable state.

[0042] In practical use: Gas and air burn stably in the combustion chamber, with the intake of gas and air controlled in real time. Once the combustion is stable, the hydrogen nozzle valve is gradually opened, and the flow rate is adjusted. Hydrogen enters the combustion chamber through a guide vane, which increases turbulence and simultaneously adjusts the gas and air flow rates to achieve gas-hydrogen mixed combustion. The flow rates of hydrogen and gas are then controlled online in real time.

[0043] Example 2: This example provides a combined hydrogen-mixed low-carbon combustion device, including a hydrogen valve assembly 1, an air valve assembly 2, a gas valve assembly 3, a combustion chamber 4, and a baffle plate 5. The hydrogen valve assembly controls the flow rate of hydrogen, the air valve assembly controls the flow rate of air, the gas valve assembly controls the flow rate of gas, and the combustion chamber is equipped with a burner for fuel combustion.

[0044] Furthermore, air is supplied to the combined hydrogen-mixing low-carbon combustion device based on the conversion values ​​of the fuel flow rate of the gas valve group and the hydrogen flow rate of the hydrogen valve group.

[0045] Specifically, the current airflow conversion value (Fair) is (current fuel flow value (Qfuel) × theoretical air volume (A0fuel) × excess air coefficient u1 + current hydrogen flow value (QH2) × theoretical air volume (A0H2) × excess air coefficient u2).

[0046] Furthermore, the aforementioned gas valve assembly includes:

[0047] The gas flow valve controls the gas flow rate and incorporates a feedback system to control the gas flow rate in real time and coordinate the gas intake.

[0048] The gas temperature monitoring system monitors and controls the temperature of the fuel intake air to avoid potential disasters caused by excessively high gas temperatures. It also calculates the required air volume in real time based on the fuel intake air temperature and adjusts the overall gas and air intake volume accordingly.

[0049] Furthermore, based on the aforementioned coordinated control of air and fuel gas, hydrogen is simultaneously mixed in during fuel combustion.

[0050] Furthermore, the aforementioned hydrogen valve assembly includes a hydrogen flow valve, which controls the amount of hydrogen entering the system in real time to achieve hydrogen-mixed combustion and reduce carbon emissions.

[0051] Furthermore, the hydrogen and fuel gas are ignited by the ignition burner in the combustion chamber and then burned.

[0052] Furthermore, the guide plate is arranged along the hydrogen channel inside the furnace body of the device to enhance the disturbance of hydrogen, so that the hydrogen and fuel gas are mixed more evenly and the combustion is more complete.

[0053] Example 3: Based on the same inventive concept, this example also provides a control method for the combined hydrogen-mixing low-carbon combustion device as described above, such as... Figure 2 As shown, the specific steps include the following:

[0054] S1, open the regulating valves of the main gas passage and the main air passage to introduce the preset flow rate of gas and air into the combustion chamber, and ignite them through the ignition burner;

[0055] S2 monitors the gas inlet temperature in real time through the gas temperature monitoring system, and cuts off the gas pipeline in time when the inlet temperature exceeds the safety threshold.

[0056] S3, by adjusting the regulating valve of the auxiliary air passage, controls the air-fuel ratio in the combustion chamber in real time, so that the fuel gas and air reach the preset stable combustion state;

[0057] S4, open the regulating valves of the upper and lower hydrogen passages and the corresponding auxiliary gas passages, so that the hydrogen flow of the preset flow rate is premixed with the gas in the auxiliary gas passage after passing through the guide plate and then enters the combustion chamber.

[0058] S5, based on the real-time flow rate of the fuel gas and hydrogen entering the combustion chamber, performs adaptive air flow control to ensure that the fuel gas, hydrogen, and air reach the preset stable combustion state.

[0059] Furthermore, the preset stable combustion state one specifically refers to: the air-fuel ratio A in the combustion chamber = 0.9A. 0fuel A 0fuel The theoretical air-fuel ratio of the fuel gas and air.

[0060] Furthermore, the preset stable combustion state two specifically refers to:

[0061] F air =(Q fuel ×A 0fuel ×u1)+(Q H2 ×A 0H2 ×u2)

[0062] In the formula, F air Q is the airflow rate introduced into the combustion chamber. fuel Q represents the gas flow rate entering the combustion chamber. H2 A represents the hydrogen flow rate introduced into the combustion chamber. 0fuel For the theoretical air-fuel ratio, A 0H2 U1 represents the theoretical air-to-hydrogen ratio, and u2 are both excess air correction factors.

[0063] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0064] In summary:

[0065] 1. This invention proposes a combined hydrogen-mixing low-carbon combustion device, which achieves the effect of mixing hydrogen and fuel combustion by cooperating with hydrogen valve group, air valve group, gas valve group and guide plate. Hydrogen, with its high calorific value and pollution-free characteristics, can reduce the pollutant emissions of fuel combustion and improve energy utilization efficiency.

[0066] 2. The device of the present invention improves upon existing combustion devices, requires less investment, brings greater benefits, and can be applied to various types of heating furnace combustion devices, showing strong adaptability and good scalability.

[0067] 3. This invention proposes a control method for a combined hydrogen-mixed low-carbon combustion device, which can control the flow rates of hydrogen, air and fuel gas in real time, improve fuel utilization efficiency, improve combustion quality, and effectively reduce NOx and CO2 emissions, thereby reducing pollutant emissions from the fuel level.

[0068] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a combined hydrogen-mixing low-carbon combustion device, characterized in that, The combined hydrogen-mixed low-carbon combustion device includes a hydrogen valve group (1), an air valve group (2), a gas valve group (3), a combustion chamber (4), and a baffle plate (5). One end of the gas valve group (3) is connected to a gas pipeline, and the other end is connected to the combustion chamber (4) at the head of the device furnace. One end of the hydrogen valve group (1) is connected to a hydrogen pipeline, and the other end is connected to the side wall at the tail of the device furnace. One end of the air valve group (2) is connected to an air pipeline, and the other end is connected to the side wall at the middle of the device furnace and the combustion chamber (4) respectively. A baffle plate (5) is provided inside the device furnace from the tail to the head. The hydrogen valve group (1) is equipped with a hydrogen regulating valve and a hydrogen flow meter; the air valve group (2) is equipped with an air regulating valve and an air flow meter; the gas valve group (3) is equipped with a gas regulating valve, a gas flow meter and a gas temperature monitoring system. The hydrogen regulating valve, hydrogen flow meter, air regulating valve, air flow meter, gas regulating valve, gas flow meter and gas temperature monitoring system are all electrically connected to the combustion device controller. The hydrogen valve group (1) is provided with two symmetrical groups, and the two groups of hydrogen valve groups (1) are respectively connected to the upper and lower side walls of the tail of the furnace body of the device, and respectively connected to the combustion chamber (4) through the upper and lower hydrogen channels inside the furnace body of the device. The gas valve assembly (3) is provided with three gas channels in the vertical direction: upper, middle and lower. The gas channel in the middle is the main gas channel, and the two symmetrical gas channels at the top and bottom are auxiliary gas channels. The guide plate (5) is provided in two symmetrical positions, and the two guide plates (5) are respectively arranged along the upper and lower hydrogen channels inside the furnace body of the device; The control method includes the following steps: S1, open the regulating valves of the main gas passage and the main air passage to introduce the preset flow rate of gas and air into the combustion chamber, and ignite them through the ignition burner; S2 monitors the gas intake temperature in real time through the gas temperature monitoring system, and cuts off the gas pipeline in time when the intake temperature exceeds the safety threshold. S3, by adjusting the regulating valve of the auxiliary air passage, controls the air-fuel ratio in the combustion chamber in real time, so that the fuel gas and air reach the preset stable combustion state; The preset stable combustion state one is specifically defined as follows: the air-fuel ratio A in the combustion chamber is 0.9A. 0fuel A 0fuel The theoretical air-fuel ratio of the fuel gas and air; S4, open the regulating valves of the upper and lower hydrogen passages and the corresponding auxiliary gas passages, so that the hydrogen flow of the preset flow rate is premixed with the gas in the auxiliary gas passage after passing through the guide plate and then enters the combustion chamber. S5, based on the real-time flow rate of the fuel gas and hydrogen entering the combustion chamber, performs adaptive air flow control to ensure that the fuel gas, hydrogen and air reach the preset stable combustion state. The preset stable combustion state two is specifically as follows: F air =(Q fuel ×A 0fuel ×u1)+(Q H2 ×A 0H2 ×u2) In the formula, F air Q is the airflow rate introduced into the combustion chamber. fuel Q represents the gas flow rate entering the combustion chamber. H2 A represents the hydrogen flow rate introduced into the combustion chamber. 0fuel For the theoretical air-fuel ratio, A 0H2 U1 represents the theoretical air-to-hydrogen ratio, and u2 are both excess air correction factors.

2. The control method for a combined hydrogen-mixing low-carbon combustion device according to claim 1, characterized in that, The air valve group (2) is provided with two symmetrical groups, each air valve group (2) is provided with a main air channel and an auxiliary air channel. The main air channel is connected to the middle side wall of the furnace body of the device, and the auxiliary air channel is connected to the combustion chamber (4).

3. The control method for a combined hydrogen-mixing low-carbon combustion device according to claim 1, characterized in that, The hydrogen valve assembly (1) includes a hydrogen gun, which is mounted on a support tube and the support tube is welded to the upper and lower side walls of the furnace body of the device.

4. The control method for a combined hydrogen-mixing low-carbon combustion device according to claim 1, characterized in that, The combustion chamber (4) is equipped with an ignition burner.

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