Method and system for achieving low-load SCR of coal-fired boiler through high-temperature flue gas of internal combustion engine

Abstract

The invention discloses a method and system for achieving coal-fired boiler low-load SCR through internal combustion engine high-temperature flue gas. The method comprises the steps that the internal combustion engine high-temperature flue gas is obtained, the internal combustion engine high-temperature flue gas is fed into a boiler tail flue after being adjusted and mixed with boiler tail gas in the boiler tail flue, and the temperature of the boiler flue gas is increased through heat exchange; the SCR reaction temperature requirement is met; carrying out denitration reaction on the boiler flue gas after the temperature is increased by utilizing a catalyst, and monitoring the temperature of the boiler flue gas and the concentration of harmful substances in real time; the combination of the smoke exhaust valves of the internal combustion engine is adjusted according to monitoring data, the optimal range of the temperature and the concentration of harmful substances before SCR reaction is kept, the whole system is very simple in structure, equipment investment and maintenance are very small, the operation cost is greatly reduced, and economic benefits are remarkable.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine technology, and in particular to a method and system for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine. Background Technology

[0002] Large-scale natural gas internal combustion engine generator sets possess high power generation efficiency and rapid load-change capabilities, often serving as crucial peak-shaving and frequency-regulating power sources for the power grid. During operation, the exhaust temperature of these large internal combustion engines reaches 300–500°C, containing high concentrations of nitrogen oxides (NOx) at 500–800 mg / m³. Currently, two methods are generally used to handle the high-temperature exhaust from internal combustion engines: one is to directly discharge the high-temperature flue gas into the atmosphere, resulting in significant energy waste; the second is to add a waste heat boiler and steam turbine power generation system at the engine's tail. However, limited by the exhaust temperature, the steam temperature generated by the waste heat boiler cannot be very high, leading to low efficiency in newly constructed waste heat power generation systems, while the overall system investment is high, resulting in poor economic returns. Furthermore, the NOx concentration in the exhaust from internal combustion engines far exceeds national air pollutant emission standards and cannot be directly released into the atmosphere; it must undergo treatment. Currently, the mainstream method for treating NOx in internal combustion engine exhaust is selective catalytic reduction (SCR), which uses urea or ammonia as a reducing agent. This ultimately reduces the NOx concentration in the exhaust to within permissible emission standards. However, this requires the addition of an expensive SCR denitrification catalyst system and consumes large amounts of urea or ammonia during operation. In coal-fired boilers under deep peak-shaving conditions, the flue gas temperature in the tail-end SCR zone often fails to reach the optimal denitrification temperature, significantly impacting denitrification performance and causing catalytic poisoning damage. Therefore, it is necessary to increase the flue gas temperature to address the denitrification problem under deep peak-shaving conditions.

[0003] Therefore, further recovering waste heat from internal combustion engine exhaust, reducing high-concentration NOx in internal combustion engine exhaust, and improving the denitrification capacity of coal-fired power units under deep-conditioning conditions are important measures to improve the energy utilization efficiency of internal combustion engines, reduce pollutant emissions, protect the stable operation of the units, and reduce operating costs. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a method and system for achieving low-load SCR in coal-fired boilers using high-temperature flue gas from internal combustion engines, and utilizes the waste heat from high-temperature flue gas from internal combustion engines to solve the denitrification problem under deep regulation of coal-fired units.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine, comprising:

[0008] High-temperature flue gas from an internal combustion engine is obtained, and after adjustment, the high-temperature flue gas from the internal combustion engine is sent into the tail flue of the boiler to mix with the boiler exhaust gas in the tail flue. The temperature of the boiler flue gas is increased through heat exchange to meet the SCR reaction temperature requirements.

[0009] The boiler flue gas, after being heated, undergoes a denitrification reaction using a catalyst, and the temperature and concentration of harmful substances in the boiler flue gas are monitored in real time.

[0010] Adjust the internal combustion engine exhaust valve combination based on monitoring data to maintain the optimal range of temperature and concentration of harmful substances before the SCR reaction.

[0011] As a preferred embodiment of the method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine according to the present invention, the method includes: adjusting the internal combustion engine exhaust valve assembly based on monitoring data.

[0012] The high-temperature flue gas from the internal combustion engine is mixed with the flue gas from the boiler at multiple points on the same cross section. By monitoring the flue gas data in the tail flue of the boiler, the corresponding combination of exhaust valves for the internal combustion engine is adjusted.

[0013] As a preferred embodiment of the method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine according to the present invention, the optimal range for maintaining the temperature and concentration of harmful substances before the SCR reaction includes:

[0014] Construct the temperature field distribution and harmful substance concentration field distribution of the internal cross section of the boiler tail flue;

[0015] The objective functions are set as optimizing temperature uniformity and optimal uniformity of harmful substances.

[0016] The constraint is that the temperature at each measuring point on the cross section is not lower than the set temperature threshold.

[0017] As a preferred embodiment of the method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine as described in this invention, the SCR reaction temperature requirements include:

[0018] The boiler flue gas temperature is higher than the minimum temperature for SCR reaction;

[0019] The reaction temperature of SCR is obtained by measuring the flue gas temperature at a point located in front of the catalyst in the flue gas duct at the tail end of the boiler.

[0020] As a preferred embodiment of the method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine according to the present invention, the denitrification reaction includes:

[0021] By selectively catalytically reducing harmful substances, harmful substances are converted into harmless substances, thereby reducing the concentration of harmful substances.

[0022] The waste heat from the exhaust of the internal combustion engine is recovered in the tail flue of the coal-fired boiler.

[0023] As a preferred embodiment of the method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine according to the present invention, wherein: the high-temperature flue gas from the internal combustion engine is regulated and then fed into the boiler tail flue includes:

[0024] The exhaust flow rate of the internal combustion engine is regulated by a high-temperature valve at the exhaust outlet of the internal combustion engine.

[0025] As a preferred embodiment of the method for achieving low-load SCR of a coal-fired boiler using high-temperature flue gas from an internal combustion engine according to the present invention, the mixing with boiler exhaust gas in the boiler tail flue includes:

[0026] It is placed at the nozzle to mix directly with the boiler flue gas, and mixed according to the set ratio.

[0027] Secondly, the present invention provides a system for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine, comprising:

[0028] The mixing module is used to obtain high-temperature flue gas from the internal combustion engine, and after adjustment, send the high-temperature flue gas from the internal combustion engine into the tail flue of the boiler to mix with the boiler exhaust gas in the tail flue of the boiler. The temperature of the boiler flue gas is increased through heat exchange to meet the SCR reaction temperature requirements.

[0029] The monitoring module is used to perform a denitrification reaction on the boiler flue gas after the temperature is increased using a catalyst, and to monitor the temperature and concentration of harmful substances in the boiler flue gas in real time.

[0030] The combined module is used to adjust the exhaust valve combination of the internal combustion engine based on monitoring data to maintain the optimal range of temperature and concentration of harmful substances before the SCR reaction.

[0031] Thirdly, the present invention provides a computing device, comprising:

[0032] Memory and processor;

[0033] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, which, when executed by the processor, implement the steps of a method for achieving low-load SCR of a coal-fired boiler using high-temperature flue gas from an internal combustion engine.

[0034] Fourthly, the present invention provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the steps of the method for achieving low-load SCR of a coal-fired boiler using high-temperature flue gas from an internal combustion engine.

[0035] Compared with existing technologies, the advantages of this invention are as follows: This invention avoids the waste of energy and pollution of the surrounding environment caused by the direct emission of high-temperature exhaust gas from internal combustion engines, greatly improving the energy utilization efficiency of the entire system. Furthermore, by using the high-temperature exhaust gas from the internal combustion engine to heat the boiler flue gas, ensuring it meets the temperature requirements for SCR denitrification at the tail end, and by using the boiler's SCR to reduce NOx in the internal combustion engine exhaust, and by using the boiler's tail-end heating surface to recover the waste heat from the internal combustion engine exhaust, the NOx purification SCR equipment for internal combustion engine exhaust is eliminated. The entire system has a very simple structure, requires minimal equipment investment and maintenance, significantly reduces operating costs, and yields significant economic benefits. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the overall process logic of a method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine, as described in one embodiment of the present invention. Detailed Implementation

[0038] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0039] Example 1

[0040] Reference Figure 1 As an embodiment of the present invention, a method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine is provided, comprising:

[0041] S100: Obtain high-temperature flue gas from the internal combustion engine, and after adjustment, send the high-temperature flue gas from the internal combustion engine into the tail flue of the boiler, mix it with the boiler exhaust gas in the tail flue of the boiler, and increase the temperature of the boiler flue gas through heat exchange to meet the SCR reaction temperature requirements.

[0042] S200: The boiler flue gas, after being heated, undergoes a denitrification reaction using a catalyst, and the temperature and concentration of harmful substances in the boiler flue gas are monitored in real time.

[0043] S300: Adjusts the internal combustion engine exhaust valve assembly based on monitoring data to maintain the optimal range of temperature and concentration of harmful substances before the SCR reaction.

[0044] It should be noted that by recovering the waste heat from the high-temperature exhaust of the internal combustion engine, energy waste caused by direct emissions is avoided, and the energy utilization efficiency of the entire system is improved. At the same time, the high-temperature exhaust of the internal combustion engine is used to heat the boiler flue gas to meet the temperature requirements of the tail-end SCR denitrification. Meanwhile, the boiler SCR is used to reduce NOx in the exhaust of the internal combustion engine, thereby reducing environmental pollution.

[0045] In this embodiment of the application, step S100 includes the following sub-steps A1-A2;

[0046] In A1: The exhaust flow rate of the internal combustion engine is regulated by the high-temperature valve at the exhaust outlet of the internal combustion engine;

[0047] In A2: It is mixed directly with the boiler flue gas by being arranged at the nozzle, and the mixture is mixed according to the set ratio.

[0048] Specifically, a matrix of temperature measuring points is arranged in the boiler tail flue to monitor the temperature at different locations in real time. The boiler flue gas monitoring module collects temperature data and transmits it to the control module. The adjustment range depends on the control module. The minimum temperature required for the SCR reaction is determined, which is usually not lower than 260℃ to ensure the effective denitrification reaction. Temperature and NOx concentration data in the boiler tail flue, as well as temperature and NOx concentration data of the internal combustion engine exhaust, are collected. Based on the size of the boiler tail flue, flue gas velocity, and target temperature, the required internal combustion engine exhaust volume is calculated to raise the boiler flue gas temperature to the target temperature. Through simulation, the adjustment range of the internal combustion engine exhaust flow rate is determined.

[0049] Specifically, the high-temperature exhaust gas from the internal combustion engine is transported through pipelines to an appropriate location in the boiler's tail flue. Inside the boiler's tail flue, a specific flue gas distribution and regulation module mixes the high-temperature exhaust gas from the internal combustion engine with the low-temperature flue gas from the boiler.

[0050] The mixing ratio depends on the boiler operating parameters, boiler flue gas flow rate, boiler flue gas temperature, internal combustion engine load, and internal combustion engine exhaust temperature.

[0051] The exhaust temperature of the internal combustion engine is as high as 370℃, while the flue gas temperature before the SCR is around 200℃ under the deep-tuning condition of the boiler. By mixing the high-temperature flue gas from the internal combustion engine with the flue gas from the boiler, the temperature before the SCR reaction is increased to above 260℃, thus meeting the safe reaction conditions for SCR.

[0052] In this embodiment of the application, after completing steps A1-A2, step S100 may further include steps A3-A4;

[0053] In A3: The boiler flue gas temperature is greater than the minimum temperature for the SCR reaction;

[0054] In A4: The reaction temperature of SCR is obtained by measuring the flue gas temperature at a point located in front of the catalyst in the flue gas duct at the tail of the boiler.

[0055] Specifically, the SCR reaction temperature is 250–400℃. If the flue gas temperature is below 250℃, ammonium sulfate will be deposited in large quantities on the surface of the SCR catalyst, leading to a serious problem of SCR catalyst poisoning.

[0056] It should be noted that by precisely controlling the mixing ratio of internal combustion engine exhaust and boiler flue gas, the SCR reaction temperature is maintained within the optimal range of 250–400℃, thereby improving denitrification efficiency. By maintaining the SCR reaction temperature within a safe range, ammonium sulfate deposition on the catalyst surface due to excessively low temperatures (below 250℃) is avoided, thus preventing SCR catalyst poisoning. The high-temperature exhaust gas from the internal combustion engine (up to 370℃) is used to raise the temperature of the flue gas before SCR under deep-tuning boiler conditions (approximately 200℃), enabling it to reach reaction conditions above 260℃, thus achieving effective energy recovery and utilization.

[0057] In this embodiment of the application, the denitrification reaction in step S200 above includes the following sub-steps B1-B2:

[0058] In B1: through selective catalytic reduction, harmful substances are converted into harmless substances, thereby reducing the concentration of harmful substances;

[0059] In B2: the waste heat from the exhaust of the internal combustion engine is recovered in the tail flue of the coal-fired boiler.

[0060] Specifically, NOx in flue gas is converted into harmless substances such as nitrogen and water;

[0061] By recovering the waste heat from the internal combustion engine exhaust through the boiler's tail heating surface, the energy utilization efficiency of the entire system is improved.

[0062] It should be noted that SCR denitrification can significantly reduce NOx emissions in flue gas, reduce environmental pollution, reduce the impact on human health, and help achieve cleaner energy production and more environmentally friendly industrial emission standards.

[0063] In this embodiment of the application, step S300 above includes the following sub-step C1;

[0064] In C1: The high-temperature flue gas from the internal combustion engine is mixed with the flue gas from the boiler at multiple points on the same cross section. By monitoring the flue gas data in the tail flue of the boiler, the corresponding combination of exhaust valves for the internal combustion engine is adjusted.

[0065] Specifically, boiler operating parameters are collected, temperature and flue gas NOx concentration are collected by a matrix of temperature and oxygen measuring points arranged in the tail flue, internal combustion engine operating parameters are collected, internal combustion engine exhaust temperature is collected, and internal combustion engine exhaust NOx concentration data are collected.

[0066] The multi-point mixing method of internal combustion engine exhaust and boiler flue gas involves mixing the internal combustion engine exhaust and boiler flue gas at multiple points on the same cross section. By monitoring the flue gas data in the boiler tail flue, the corresponding internal combustion engine exhaust valve combination is adjusted. By monitoring the temperature and NOx concentration data of the flue gas in the boiler tail flue, the opening degree of the internal combustion engine exhaust valve is adjusted to control the mixing ratio.

[0067] In this embodiment of the application, after completing step C1, step S300 may further include C2-C4;

[0068] In C2: Construct the temperature field distribution and harmful substance concentration field distribution of the cross section inside the boiler tail flue;

[0069] In C3: the objective function is set to optimize temperature uniformity and optimal uniformity of harmful substances;

[0070] In C4: The constraint is that the temperature at every measuring point on the cross section is not lower than the set temperature threshold.

[0071] Specifically, based on the data from temperature measuring points, a temperature field distribution map of the cross-section inside the boiler tail flue is constructed. Based on the data from NOx concentration measuring points, a NOx concentration field distribution map of the cross-section inside the boiler tail flue is constructed. An objective function is defined, such as minimizing the standard deviation of temperature and NOx concentration, to achieve optimal temperature uniformity and NOx uniformity, ensuring that the temperature at each measuring point on the cross-section is not lower than the temperature threshold of 260℃, in order to meet the safety requirements of the SCR denitrification reaction.

[0072] It should be noted that by precisely controlling the mixing ratio, the temperature and NOx concentration in the boiler tail flue are ensured to meet the optimal conditions for SCR denitrification reaction, thereby improving denitrification efficiency. The high-temperature exhaust waste heat of the internal combustion engine is used to raise the temperature of the boiler flue gas, thereby reducing the consumption of additional energy and improving the energy utilization efficiency of the entire system. By ensuring that the temperature at each measuring point is not lower than 260℃, thermal damage to the SCR catalyst is avoided, reducing manual intervention and lowering operating costs.

[0073] The above is an illustrative scheme of a method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine, according to this embodiment. It should be noted that the technical solution of this system for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine is based on the same concept as the aforementioned method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine. Details not described in detail in the technical solution of the system for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine in this embodiment can be found in the description of the aforementioned method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine.

[0074] The system for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine in this embodiment includes:

[0075] The mixing module is used to obtain high-temperature flue gas from the internal combustion engine, and after adjustment, send the high-temperature flue gas from the internal combustion engine into the tail flue of the boiler to mix with the boiler exhaust gas in the tail flue of the boiler. The temperature of the boiler flue gas is increased through heat exchange to meet the SCR reaction temperature requirements.

[0076] The monitoring module is used to perform a denitrification reaction on the boiler flue gas after the temperature is increased using a catalyst, and to monitor the temperature and concentration of harmful substances in the boiler flue gas in real time.

[0077] The combined module is used to adjust the exhaust valve combination of the internal combustion engine based on monitoring data to maintain the optimal range of temperature and concentration of harmful substances before the SCR reaction.

[0078] This embodiment also provides a computing device suitable for achieving low-load SCR in coal-fired boilers using high-temperature flue gas from internal combustion engines, including:

[0079] The system includes a memory and a processor. The memory stores computer-executable instructions, and the processor executes these instructions to implement the method proposed in the above embodiments for achieving low-load SCR of a coal-fired boiler using high-temperature flue gas from an internal combustion engine.

[0080] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the method for achieving low-load SCR of a coal-fired boiler using high-temperature flue gas from an internal combustion engine, as proposed in the above embodiments.

[0081] The storage medium proposed in this embodiment and the method for realizing low-load SCR of coal-fired boilers using high-temperature flue gas from internal combustion engines proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0082] Based on the above description of the implementation methods, those skilled in the art will clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0083] Example 2

[0084] This embodiment differs from the first embodiment, and provides a verification test of a method for achieving low-load SCR in a coal-fired boiler using high-temperature flue gas from an internal combustion engine, to verify and explain the technical effects of the method.

[0085] Take, for example, the boiler and 14 internal combustion engines coupled system of a 600MW coal-fired unit;

[0086] It is equipped with 14 18MW internal combustion engines. The exhaust temperature of each internal combustion engine is about 370℃ when running at full load. The exhaust of the internal combustion engines is collected and sent to a high-temperature exhaust pipe.

[0087] A high-temperature exhaust pipe is connected to the upper space of the SCR in the boiler tail flue to mix the high-temperature exhaust gas from the internal combustion engine with the boiler flue gas. The opening of the internal combustion engine exhaust valve is adjusted by the control module to mix the high-temperature exhaust gas from the internal combustion engine with the boiler flue gas, raising the temperature before the SCR reaction to above 260°C. A matrix of temperature measuring points is used to monitor the temperature in the boiler tail flue to ensure uniform temperature distribution and meet the safe reaction conditions of the SCR.

[0088] A heat-receiving surface is installed in the boiler tail flue to recover the waste heat from the internal combustion engine exhaust. By absorbing the heat from the internal combustion engine exhaust through the heat-receiving surface, the thermal efficiency of the boiler is improved, while the temperature of the internal combustion engine exhaust is reduced. Boiler operating parameters and internal combustion engine operating parameters, including temperature, flow rate, NOx concentration, etc., are collected. The control module adjusts the opening of the internal combustion engine exhaust valve according to the monitoring data to maintain the temperature and NOx concentration in the boiler tail flue within the optimal range.

[0089] Construct temperature field distribution and NOx concentration field distribution maps of the cross section inside the boiler tail flue, define objective functions such as minimizing the standard deviation of temperature and NOx concentration to achieve optimal temperature uniformity and NOx uniformity, and set constraints to ensure that the temperature at each measuring point is not lower than 260℃ to meet the safety requirements of SCR denitrification reaction.

[0090] By effectively utilizing the high-temperature exhaust heat of the internal combustion engine, the temperature before the SCR reaction in the boiler tail flue is increased, while the exhaust heat of the internal combustion engine is recovered, thereby improving the energy efficiency and environmental performance of the entire system.

[0091] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for realizing low-load SCR of coal-fired boilers with high-temperature flue gas from internal combustion engines, characterized in that: include: Obtain high-temperature flue gas from an internal combustion engine, send the high-temperature flue gas from the internal combustion engine into the tail flue of the boiler after adjustment, mix it with the boiler tail gas in the tail flue of the boiler, and increase the temperature of the boiler flue gas through heat exchange to meet the SCR reaction temperature requirement; The boiler flue gas after the temperature is raised is denitrated using a catalyst, and the temperature and concentration of harmful substances in the boiler flue gas are monitored in real time; The exhaust valve combination of the internal combustion engine is adjusted according to the monitoring data to maintain the optimal range of temperature and harmful substance concentration before SCR reaction.

2. The method for realizing low-load SCR of coal-fired boiler with high-temperature flue gas from internal combustion engines according to claim 1, characterized in that: Adjusting the exhaust valve combination of the internal combustion engine according to the monitoring data includes: The high-temperature flue gas of the internal combustion engine is mixed with the boiler flue gas at multiple points on the same cross section, and the corresponding combination of exhaust valves of the internal combustion engine is adjusted by monitoring the flue gas data in the tail flue of the boiler.

3. The method for realizing low-load SCR of coal-fired boiler with high-temperature flue gas from internal combustion engines as claimed in claim 2, characterized in that: The optimal ranges for maintaining the temperature and concentration of harmful substances before SCR reaction include: Construct the temperature field distribution and harmful substance concentration field distribution in the cross section of the boiler tail flue; The objective function is set to the optimal temperature uniformity and the optimal uniformity of harmful substances; The constraint condition is that the temperature of each measuring point on the cross section is not lower than the set temperature threshold.

4. The method for realizing low-load SCR of coal-fired boiler with high-temperature flue gas from internal combustion engines as claimed in claim 3, characterized in that: SCR reaction temperature requirements include: The boiler flue gas temperature is greater than the minimum temperature of the SCR reaction; The reaction temperature of SCR is obtained through the flue gas temperature measuring point arranged in front of the catalyst in the tail flue of the boiler.

5. The method for realizing low-load SCR of coal-fired boiler with high-temperature flue gas from internal combustion engines as claimed in claim 4, characterized in that: Denitrification reactions include: Through selective catalytic reduction, harmful substances are converted into harmless substances, reducing the concentration of harmful substances; The waste heat from the internal combustion engine exhaust is recovered in the tail flue of the coal-fired boiler.

6. The method for realizing low-load SCR of coal-fired boiler with high-temperature flue gas from internal combustion engines as claimed in claim 1 or 5, characterized in that: The high-temperature flue gas of the internal combustion engine is sent into the tail flue of the boiler after being regulated, comprising: The exhaust flow of the internal combustion engine is regulated by a high-temperature valve at the exhaust outlet of the internal combustion engine.

7. The method for realizing low-load SCR of coal-fired boiler with high-temperature flue gas from an internal combustion engine as claimed in claim 6, characterized in that: Mixing with the boiler tail gas in the boiler tail flue comprises: It is arranged at the nozzle to mix directly with the boiler flue gas and mix according to the set ratio.

8. A system for realizing low-load SCR of coal-fired boiler by using high-temperature flue gas from an internal combustion engine as claimed in any one of claims 1 to 7, characterized in that: include: A mixing module is used to obtain high-temperature flue gas from an internal combustion engine, send the high-temperature flue gas from the internal combustion engine into the boiler tail flue after adjustment, mix it with the boiler tail gas in the boiler tail flue, and increase the temperature of the boiler flue gas through heat exchange to meet the SCR reaction temperature requirement; The monitoring module is used to use a catalyst to perform a denitration reaction on the boiler flue gas after the temperature is raised, and to monitor the temperature and harmful substance concentration of the boiler flue gas in real time; The combination module is used to adjust the exhaust valve combination of the internal combustion engine according to the monitoring data to maintain the temperature and the concentration of harmful substances before the SCR reaction in the optimal range.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the method for achieving low-load SCR of a coal-fired boiler using high-temperature flue gas from an internal combustion engine as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for achieving low-load SCR of a coal-fired boiler with high-temperature flue gas from an internal combustion engine as claimed in any one of claims 1 to 7.

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