Dual-carbon-oriented steam power system full-process integrated control system and method

Abstract

According to the dual-carbon-oriented steam power system full-process integrated control system and method, steam data of a boiler, a steam turbine, a steam pipe network and a production device are fused, information islands are broken through, informatization integration and unified management are achieved, a data management unified platform is constructed, real-time monitoring of steam production, transportation and use process information is achieved, and real-time monitoring of the steam production, transportation and use process information is achieved. The comprehensive, timely and effective energy management is improved, the control characteristics of a boiler APC system, the adjustment characteristics of a steam turbine CCS and other information are combined, and the technologies of big data, expert rules, optimization control and the like are adopted, so that the boiler load and the steam turbine power target can be automatically and effectively adjusted in time when the system load is adjusted in the production process; and stable, efficient and economical operation of the steam system is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of steam power systems, and in particular relates to a full-process integrated control system and method for a dual-carbon steam power system. Background Art

[0002] In recent years, domestic and foreign research on steam power systems has been continuously carried out in many aspects, including system design analysis, process modeling optimization, system monitoring and diagnosis, and equipment operation optimization. In the design of steam power systems, in addition to the pinch point principle, waste heat power generation technology based on the organic Rankine cycle and renewable energy-driven steam power system power generation technology have attracted attention.

[0003] Steam is an important secondary energy source for process enterprises and an important medium for energy conversion such as power, electricity and heat. While consuming high-grade steam, the production process system also produces a large amount of by-product steam and low-grade waste heat resources. The process system has a strong coupling relationship with the steam power system. As the energy supply system of process enterprises, the steam power system not only plays a vital role in the production process, but also is an area that needs to be focused on to achieve carbon reduction in the enterprise process. Therefore, it is urgent to propose a full-process integrated control method for dual-carbon steam power systems to fill the gap in the integrated application of full-process control optimization of steam power systems in China. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a full-process integrated control system and method for dual-carbon steam power systems, which can improve the automation and intelligence level of enterprise steam power systems and even energy management systems, improve quality, efficiency and benefits, and reduce resource and energy consumption. It effectively fills the gap in the integrated application of full-process control optimization of steam power systems in China, provides a model and reference for the digitalization, networking and intelligence of process enterprise energy systems, and provides a new model and new method for energy-saving and optimized operation of steam power systems in related industries.

[0005] The technical solution of the present invention is as follows:

[0006] The full-process integrated control system for dual-carbon steam power systems includes:

[0007] Liquid nitrogen washing and ammonia synthesis control system, which obtains the load elasticity of liquid nitrogen washing and ammonia synthesis and the upstream and downstream load margins, and uses them to establish a dynamic model of liquid nitrogen washing and ammonia synthesis material and energy matching;

[0008] The boiler advanced control system dynamically calculates the optimal oxygen content, optimal bed temperature and optimal bed pressure setting values ​​under the current matching load, and obtains the optimal air-to-fuel ratio and primary and secondary air ratio for boiler combustion;

[0009] And the steam turbine coordinated control system establishes a steam network balance data model based on pattern recognition and big data analysis, and combines the key pressure and flow monitoring data of steam consumption in the steam pipelines at all levels to give the steam-using end load feedforward, and adjusts the compression speed and the temperature and pressure reducer according to the steam-using end load feedforward.

[0010] The full-process integrated control method for a dual-carbon steam power system includes the following steps:

[0011] Step 1: Liquid nitrogen washing and ammonia synthesis multi-unit joint optimization and carbon reduction

[0012] Obtain the load elasticity of liquid nitrogen washing and ammonia synthesis and the upstream and downstream load margins, and use them to establish a dynamic model of liquid nitrogen washing and ammonia synthesis material and energy matching; through real-time prediction, dynamic tracking, and precise control of key variables of liquid nitrogen washing and ammonia synthesis (such as liquid nitrogen washing key temperature, CO content and hydrogen-nitrogen ratio of inlet ammonia synthesis process gas, etc.), and at the same time combine with upstream devices (purification, air separation, etc.), automatically adapt to the processing load of the whole plant, establish a dynamic model of liquid nitrogen washing and ammonia synthesis material and energy matching, and realize integrated management and control of the two units;

[0013] Step 2: Advanced Control and Optimization of Circulating Fluidized Bed Boilers

[0014] Through the advanced boiler control and optimization system, the mother pipe is coordinated and controlled, and combustion self-help, performance calculation and index optimization are carried out for multiple steam turbines and multiple boilers to obtain the best air-fuel ratio and primary and secondary air ratio;

[0015] Step 3: Steam network balance and multi-stage energy optimization

[0016] Establish a steam network balance data model based on pattern recognition and big data analysis, and combine the key pressure and flow monitoring data of steam consumption at all levels of steam network to provide the steam end load feedforward quantity;

[0017] Step 4: Steam Power System Compressor Performance Control and Energy Saving Optimization

[0018] Adjust the compression speed and the temperature and pressure reducer according to the steam end load feedforward amount.

[0019] The controller located in the control layer is used to calculate the steam balance optimization algorithm, and controls the temperature and pressure reducers between different pressure levels. Under normal circumstances, the temperature and pressure reducers are used to control the pressure of the downstream pipeline network. At the same time, the pressure limit protection can be designed for the upstream pipeline network pressure control when necessary. In addition, for each level of steam pipeline network, a vent valve is added to monitor the pressure of the pressure pipeline network at that level. When the pressure rises, a variety of control strategies can be used to adjust the vent valve to avoid triggering the safety valve. In terms of control principle, when the pipeline network pressure fluctuates greatly, the temperature and pressure reducer, compressor and other equipment are used to quickly adjust the pipeline network pressure to ensure that the compressor inlet pressure is within a stable and reasonable range. When the pipeline network pressure fluctuates less, a load balancing strategy is adopted to gradually reduce the temperature and pressure reducer to allow the working equipment to do more work.

[0020] Preferably, in the full-process integrated control method for a dual-carbon steam power system,

[0021] In the step 1, multivariable predictive control technology is applied to achieve real-time prediction, dynamic tracking and precise control of key variables of liquid nitrogen washing ammonia synthesis, such as liquid nitrogen washing key temperature, CO content and hydrogen-nitrogen ratio of inlet ammonia synthesis process gas; multi-objective coordination technology is applied to optimize the hydrogen-nitrogen ratio of circulating gas, improve the single-pass conversion rate of ammonia synthesis, and improve the processing efficiency of the ammonia synthesis unit.

[0022] Preferably, in the full-process integrated control method for a dual-carbon steam power system,

[0023] Automatic combustion: realize multi-variable coordinated control of boiler combustion and steam-water system, and fully balance the relationship between air-coal ratio, primary and secondary air ratio, etc.

[0024] Mother pipe coordinated control: Under the premise of fully considering the dynamic characteristics, load regulation capacity, load margin and other information of each boiler, the dynamic distribution of pressure regulation load of multiple parallel boilers is realized, so as to ensure the stable control of the main steam mother pipe pressure;

[0025] Performance calculation: realize online statistical evaluation of boiler efficiency, and give the current status of key boiler efficiency indicators in real time through positive and negative balance;

[0026] Index optimization: Through online optimization and matching of air-coal ratio, primary and secondary air ratio, and optimal material layer, the comprehensive optimization of boiler efficiency and emission indicators is achieved, and the comprehensive benefits of the system (Q, C NOx ) is maximized, where J(Q,C NOx ) The specific calculation method is as follows:

[0027] J(Q,C NOx )=K Q ×Q-(1-K Q )×C NOx

[0028] Where K Q represents efficiency weight, Q represents boiler efficiency; C NOx CNOx stands for nitrogen oxide control consumption.

[0029] Preferably, in the full-process integrated control method for a dual-carbon steam power system,

[0030] In step three, a pressure control valve is added at an important pipeline network node.

[0031] Preferably, in the full-process integrated control method for a dual-carbon steam power system, in the step three;

[0032] High-temperature and high-pressure black water is introduced into the high-temperature water heater to generate high-flash steam. The high-flash steam enters the gray water heater to heat the gray water and recover part of the heat. The evaporator is used to recover the waste heat in the condensate, and the by-product steam is sent to the 0.5Mpa steam pipe network;

[0033] For the thermoelectric device, a new heat exchanger is added to use 1.3Mpa steam as a heat source to heat the desalted water, and a new recovery device is added to recover the steam after heat exchange and utilize the waste heat.

[0034] The present invention has the following beneficial effects:

[0035] 1. The present invention integrates the steam data of boilers, steam turbines, steam pipe networks and production equipment, breaks through information islands, and realizes information integration and unified management. It collects, stores, defines and analyzes the steam data of boilers, steam turbines, pipe networks and equipment in the production process, builds a unified data management platform, realizes real-time monitoring of steam production and transmission process information, and improves the comprehensiveness, timeliness and effectiveness of energy management.

[0036] 2. The present invention uses the boiler APC system to dynamically calculate the set values ​​of the optimal oxygen content, optimal bed temperature and optimal bed pressure under the current matching load, and realize the optimal air-to-material ratio and primary and secondary air ratio of boiler combustion; it uses technical means such as expert rule control and nonlinear control to divide the boiler system into several control sections, and each control section is interconnected and can be switched independently, which is convenient and flexible, and realizes automatic control of feeding and air distribution of each boiler and combustion optimization control. Under the premise of meeting the system load requirements, all indicators run smoothly and the boiler reaches its own optimal operating state.

[0037] 3. The present invention combines the control characteristics of the boiler APC system and the steam turbine CCS adjustment characteristics and other information, and adopts technologies such as big data, expert rules, and optimization control to achieve timely and effective automatic adjustment of the boiler load and steam turbine power targets when the production process system load is adjusted, thereby ensuring the smooth, efficient, and economical operation of the steam system and reducing the labor intensity of operators.

[0038] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 An advanced process control diagram of a boiler in one embodiment of the full-process integrated control method for a dual-carbon steam power system provided by the present invention;

[0040] Figure 2 A boiler combustion automatic principle diagram in one embodiment of the full-process integrated control method for a dual-carbon steam power system provided by the present invention;

[0041] Figure 3 A boiler index optimization diagram of an embodiment of the full-process integrated control method for a dual-carbon steam power system provided by the present invention;

[0042] Figure 4 A flow chart of an embodiment of the full-process integrated control method for a dual-carbon steam power system provided by the present invention. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0044] The present invention provides a full-process integrated control method for a dual-carbon steam power system, comprising the following steps:

[0045] Step 1: Liquid nitrogen washing and ammonia synthesis multi-unit joint optimization and carbon reduction

[0046] Fully evaluate the load elasticity of liquid nitrogen washing and ammonia synthesis and the upstream and downstream load margins, establish a dynamic model for liquid nitrogen washing and ammonia synthesis material and energy matching, realize integrated management and control of the two units, and automatically adapt to the processing load of the entire plant in combination with upstream devices;

[0047] Step 2: Advanced Control and Optimization of Circulating Fluidized Bed Boilers

[0048] Through the boiler APC system, the mother pipe is coordinated and controlled to carry out combustion self-help, performance calculation and index optimization for multiple steam turbines and multiple boilers;

[0049] Step 3: Steam network balance and multi-stage energy optimization

[0050] Steam network balance data model based on pattern recognition and big data analysis; Steam power system steam network steam load prediction model combines key pressure and flow monitoring of steam consumption at all levels of steam network to timely provide steam end load feedforward; Steam power system steam network dynamic hierarchical optimization control;

[0051] Step 4: Steam Power System Compressor Performance Control and Energy Saving Optimization

[0052] The compression speed is adjusted in real time to match the process fluctuations to ensure that the compressor inlet pressure is within a stable and reasonable range; the speed control adds a governor startup protection function and a limit control loop to achieve a safer and smoother startup process.

[0053] like Figure 1 , Figure 2 and Figure 3 As shown in the figure, the boiler advanced control and optimization system includes research contents such as boiler combustion automation, mother pipe coordination, performance calculation and index optimization. The specific solutions are as follows:

[0054] Automatic combustion: realize multi-variable coordinated control of boiler combustion and steam-water system, fully balance the relationship between air-coal ratio, primary and secondary air ratio, etc., to realize fully automatic and stable operation of the boiler.

[0055] Mother pipe coordinated control: Under the premise of fully considering the dynamic characteristics, load adjustment capacity, load margin and other information of each boiler, the dynamic distribution of pressure regulation load of multiple parallel boilers is realized, so as to ensure the stable control of the main steam mother pipe pressure.

[0056] Performance calculation: Realize online statistical evaluation of boiler efficiency, and provide real-time status of current key boiler efficiency indicators through positive and negative balance, so as to provide guidance for boiler indicator optimization.

[0057] Index optimization: To optimize the optimization index of boiler system, through online optimization matching of air-coal ratio, primary and secondary air ratio, optimal material layer and other indicators, to achieve the comprehensive optimization of boiler efficiency and emission indicators, and through the index optimization algorithm to make the system comprehensive benefit J (Q, C NOx ) is maximized, where J(Q,C NOx ) The specific calculation method is as follows:

[0058] J(Q,C NOx )=K Q ×Q-(1-K Q )×C NOx

[0059] Where K Q represents efficiency weight, Q represents boiler efficiency; C NOx CNOx stands for nitrogen oxide control consumption.

[0060] like Figure 4As shown in the figure, in order to realize the dynamic balance optimization and automatic coordination control of the enterprise's multi-level steam network, it is necessary to add pressure control valves at important network nodes, and realize the complex dynamic balance optimization system of multi-pressure level steam, multi-steam network, multi-furnace, and multi-turbine compressor units in accordance with the integration of basic automation DCS system + turbine unit performance optimization control system + boiler main pipe optimization APC system + steam network equipment dynamic classification optimization APC system + network optimization scheme dynamic simulation system. Realize real-time monitoring of steam power system, and study the steam network balance data model based on pattern recognition and big data analysis; the steam load prediction model of steam network of steam power system combines the key pressure and flow monitoring of steam consumption of steam network at all levels to timely give the load feedforward of steam end; the dynamic classification optimization control of steam network of steam power system can realize network pressure control, load distribution compensation and rapid load following of boiler APC system.

[0061] In this embodiment, for the gasification unit, high-temperature and high-pressure black water is introduced into the high-temperature water heater to generate high-flash steam, and the high-flash steam enters the gray water heater to heat the gray water to recover part of the heat. The evaporator is further used to recover the waste heat in the condensate, and the by-product steam is sent to the 0.5Mpa steam network; for the thermoelectric device, a new heat exchanger is added, and 1.3Mpa steam is used as a heat source to heat the desalted water, increase the make-up water temperature, and ensure the safe and stable operation of the thermal deoxygenation system. A new recovery device is added to recover the steam after heat exchange and utilize the waste heat.

[0062] In summary, this full-process integrated control method for dual-carbon steam power systems integrates the steam data of boilers, steam turbines, steam pipe networks and production equipment, breaks through information islands, and realizes information integration and unified management. Collect, store, define and analyze the steam data of boilers, steam turbines, pipe networks and equipment in the production process, build a unified data management platform, realize real-time monitoring of steam production and transmission process information, and improve the comprehensiveness, timeliness and effectiveness of energy management.

[0063] Through the boiler APC system, the optimal oxygen content, optimal bed temperature and optimal bed pressure setting values ​​under the current matching load are dynamically calculated to achieve the optimal air-to-material ratio and primary and secondary air ratio for boiler combustion; the boiler system is divided into several control sections by expert rule control, nonlinear control and other technical means. Each control section is interconnected and can be switched independently, which is convenient and flexible, and realizes automatic control of feeding and air distribution of each boiler and combustion optimization control. Under the premise of meeting the system load requirements, all indicators run smoothly and the boiler reaches its best operating state.

[0064] Through the steam turbine CCS system, stable control is achieved under large process disturbances to ensure process and unit operation; the working point pressure line (surge control line) is automatically operated when the device is under low load; the compression speed is adjusted in real time to match the process fluctuations to ensure that the compressor inlet pressure is within a stable and reasonable range, thereby achieving energy saving and consumption reduction; fully automatic control and unmanned operation.

[0065] Combining the control characteristics of the boiler APC system and the steam turbine CCS regulation characteristics and other information, big data, expert rules, optimization control and other technologies are used to achieve timely and effective automatic adjustment of boiler load and steam turbine power targets when the production process system load is adjusted, ensuring the smooth, efficient and economical operation of the steam system and reducing the labor intensity of operators.

[0066] The present invention relates to a full-process integrated control method for a dual-carbon steam power system, including the steps of liquid nitrogen washing synthetic ammonia multi-unit joint optimization and carbon reduction, advanced control and optimization of circulating fluidized bed boilers, steam network balance and multi-stage energy optimization, and steam power system compressor performance control and energy-saving optimization. The present invention integrates the steam data of boilers, steam turbines, steam pipe networks and production equipment, breaks through information islands, realizes information integration and unified management, builds a unified data management platform, realizes real-time monitoring of steam production and transmission process information, improves the comprehensiveness, timeliness and effectiveness of energy management, combines the control characteristics of the boiler APC system and the CCS regulation characteristics of the steam turbine and other information, and adopts big data, expert rules, optimization control and other technologies to achieve timely and effective automatic adjustment of boiler load and steam turbine power targets when the production process system load is adjusted, ensuring the smooth, efficient and economical operation of the steam system.

[0067] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. Full-process integrated control system for dual-carbon steam power system, characterized by: include: Liquid nitrogen washing and ammonia synthesis control system, which obtains the load elasticity of liquid nitrogen washing and ammonia synthesis and the upstream and downstream load margins, and uses them to establish a dynamic model of liquid nitrogen washing and ammonia synthesis material and energy matching; The boiler advanced control system dynamically calculates the optimal oxygen content, optimal bed temperature and optimal bed pressure setting values ​​under the current matching load, and obtains the optimal air-to-fuel ratio and primary and secondary air ratio for boiler combustion; And the steam turbine coordinated control system establishes a steam network balance data model based on pattern recognition and big data analysis, and combines the key pressure and flow monitoring data of steam consumption in the steam pipelines at all levels to give the steam-using end load feedforward, and adjusts the compression speed and the temperature and pressure reducer according to the steam-using end load feedforward.

2. A full-process integrated control method for a dual-carbon steam power system, characterized in that: The following steps are involved: Step 1: Liquid nitrogen washing and ammonia synthesis multi-unit joint optimization and carbon reduction Obtain the load elasticity and upstream and downstream load margins of liquid nitrogen washing and ammonia synthesis, and use them to establish a dynamic model of liquid nitrogen washing and ammonia synthesis material and energy matching; Step 2: Advanced Control and Optimization of Circulating Fluidized Bed Boilers Through the advanced boiler control and optimization system, the mother pipe is coordinated and controlled, and combustion self-help, performance calculation and index optimization are carried out for multiple steam turbines and multiple boilers to obtain the best air-fuel ratio and primary and secondary air ratio; Step 3: Steam network balance and multi-stage energy optimization Establish a steam network balance data model based on pattern recognition and big data analysis, and combine the key pressure and flow monitoring data of steam consumption at all levels of steam network to provide the steam end load feedforward quantity; Step 4: Steam Power System Compressor Performance Control and Energy Saving Optimization Adjust the steam engine compression speed according to the steam end load feedforward amount.

3. The full-process integrated control method for a dual-carbon steam power system according to claim 1, characterized in that: In the step 1, multivariable predictive control technology is applied to achieve real-time prediction, dynamic tracking and precise control of key variables in liquid nitrogen washing ammonia synthesis; multi-objective coordination technology is applied to optimize the circulating gas hydrogen-nitrogen ratio.

4. The full-process integrated control method for a dual-carbon steam power system according to claim 1, characterized in that: Automatic combustion: realize multi-variable coordinated control of boiler combustion and steam-water system, and fully balance the relationship between air-coal ratio and primary and secondary air ratio; Mother pipe coordinated control: Under the premise of fully considering the dynamic characteristics, load regulation capacity and load margin information of each boiler, the dynamic distribution of pressure regulation load of multiple parallel boilers is realized, thereby ensuring the stable control of the main steam mother pipe pressure; Performance calculation: realize online statistical evaluation of boiler efficiency, and give the current status of key boiler efficiency indicators in real time through positive and negative balance; Index optimization: Through online optimization and matching of air-coal ratio, primary and secondary air ratio, and optimal material layer, the comprehensive optimization of boiler efficiency and emission indicators is achieved, and the comprehensive benefits of the system (Q, C NOx ) is maximized, where J(Q,C NOx ) The specific calculation method is as follows: J(Q,C NOx )=K Q ×Q-(1-K Q )×C NOx Where K Q represents efficiency weight, Q represents boiler efficiency; C NOx CNOx stands for nitrogen oxide control consumption.

5. The full-process integrated control method for a dual-carbon steam power system according to claim 3 is characterized in that: In step three, a pressure control valve is added at an important pipeline network node.

6. The full-process integrated control method for a dual-carbon steam power system according to claim 4 is characterized in that: In the step three; High-temperature and high-pressure black water is introduced into the high-temperature water heater to generate high-flash steam. The high-flash steam enters the gray water heater to heat the gray water and recover part of the heat. The evaporator is used to recover the waste heat in the condensate, and the by-product steam is sent to the 0.5Mpa steam pipe network; For the thermoelectric device, a new heat exchanger is added to use 1.3Mpa steam as a heat source to heat the desalted water, and a new recovery device is added to recover the steam after heat exchange and utilize the waste heat.

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