CN115681943A - Automatic combustion control system for three kinds of coal gas power generation boiler - Google Patents
Automatic combustion control system for three kinds of coal gas power generation boiler Download PDFInfo
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Abstract
The invention provides a three-gas automatic combustion control system of a gas power generation boiler, which relates to the technical field of gas power generation boilers.A boiler drum water level automatic adjusting control module adjusts the water level of a boiler drum and controls the boiler drum to supply steam to the boiler; the first-stage desuperheating water and second-stage desuperheating water automatic regulation control module controls the output temperature information of the superheater; the constant adjustment control module for the main steam pressure of the boiler adjusts and controls the main steam pressure of the boiler so that the main steam pressure of the boiler meets the preset requirement; the gas amount distribution and adjustment control module of the coal gas as fired controls the gas amount of the coal gas as fired; the hearth negative pressure automatic adjustment control module controls the rotating speed of the induced draft fan to control the boiler hearth negative pressure, so that the boiler hearth negative pressure is within a preset threshold value. The invention utilizes the field bus control technology and the intelligent instrument decentralized control, combines the idea of fuzzy control, and ensures that the proportion of cold air and coal gas can be kept consistent in the static and dynamic processes, thereby realizing the optimized combustion of the boiler.
Description
Technical Field
The invention relates to the technical field of gas power generation boilers, in particular to an automatic combustion control system for three kinds of gas of a gas power generation boiler.
Background
In the process flow of iron and steel enterprises, three kinds of gas, namely blast furnace gas, converter gas and coke oven gas, are often surplus, and the gas is usually mixed and combusted in a boiler hearth by adopting a three-gas mixed combustion mode, so that the generated heat is recycled, and the effect of recycling economy is achieved.
The outside cold air is sent to the air preheater after being boosted by the blower, the cold air is heated by the flue gas in the air preheater, the hot air is directly sent to the hearth through the burner, and the part of the hot air is called primary air; the primary air is mixed with the ignited gas flow in the hearth and participates in the combustion reaction. The gas and the air are sent into the hearth through the burner and then are combusted in the hearth to release heat. The heat released by combustion heats water, the water is pressurized and heated to become steam, the steam does work to push a steam turbine to rotate, and the steam turbine rotates to drive a generator to work to generate electric energy which is transmitted to a power grid.
The traditional manual furnace operation has the following disadvantages:
(1) The combustion process is not economical. The economical efficiency is ensured by the optimal ratio of the fuel quantity entering the hearth to the ventilation quantity, enough wind is provided to enable the fuel to be fully combusted, and the heat loss caused by smoke discharge is reduced as much as possible. Due to the varying individual skill levels of the operators, the ratio between the amount of fuel in the furnace and the amount of ventilation is difficult to optimize.
(2) The combustion process is less stable. Factors influencing the combustion process are many, including automatic control of desuperheating water, automatic adjustment of drum water level, automatic control of furnace negative pressure, and the like. The links are adjusted only manually, so that uniform regulation and control balance are difficult to achieve, and the stability of the combustion process is difficult to grasp.
(3) Boiler control and steam turbine load change control, and manual operation reaction lags behind, can not reach energy saving and consumption reduction's purpose.
Disclosure of Invention
The invention provides an automatic combustion control system for three kinds of coal gas of a coal gas power generation boiler, aiming at overcoming the defects of coal gas combustion of a traditional manually operated boiler and ensuring the economy and stability of the combustion process.
The three kinds of gas automatic combustion control systems of the gas power generation boiler comprise: the system comprises a boiler master control module, a boiler drum water level automatic adjusting control module, a primary desuperheating water and secondary desuperheating water automatic adjusting control module, a boiler main steam pressure constant adjusting control module, a boiler coal gas quantity distribution adjusting control module and a hearth negative pressure automatic adjusting control module;
the boiler master control module is connected with the boiler drum water level automatic adjusting control module, adjusts the boiler drum water level and controls the boiler drum to supply steam to the boiler;
the boiler master control module is connected with the first-stage desuperheating water and the second-stage desuperheating water automatic regulation control module and respectively controls the output temperature information of the superheater;
the boiler main control module is connected with the boiler main steam pressure constant adjusting control module and is used for adjusting and controlling the main steam pressure of the boiler so that the main steam pressure of the boiler meets the preset requirement;
the boiler master control module is connected with the gas quantity distribution and adjustment control module of the coal gas entering the boiler to control the gas quantity of the coal gas entering the boiler;
the boiler master control module is connected with the hearth negative pressure automatic adjustment control module, controls the rotating speed of the draught fan, and controls the boiler hearth negative pressure, so that the boiler hearth negative pressure is in a preset threshold value.
It should be further noted that the boiler drum water level automatic regulation control module is provided with a boiler drum regulating valve, a plurality of boiler drum liquid level sensors and a PID control unit;
the method comprises the following steps of (1) taking a boiler drum regulating valve as controlled equipment, taking a plurality of boiler drum liquid level sensors as detection sensing liquid level information, taking 2 liquid level values as reference values at will, and adopting a PID control algorithm of a drum regulating PID control unit to carry out control program operation; adjusting according to the deviation between the set value of the liquid level of the boiler drum and the actual liquid level value; so as to achieve the balance of the liquid level of the boiler steam drum.
It should be further noted that the automatic regulating and controlling module for the first-stage desuperheating water and the second-stage desuperheating water comprises: the temperature-reducing water PID control unit is used for controlling the temperature of the water to be reduced;
controlling the temperature of an outlet of the superheater by using a first-stage desuperheating water regulating valve and a second-stage desuperheating water regulating valve as controlled equipment;
the primary desuperheating water regulating valve is controlled by a desuperheating water PID control unit according to the numerical value of the outlet temperature t1 of the primary desuperheater to obtain the opening numerical value of the primary desuperheating water regulating valve;
and the opening numerical value of the second-stage desuperheating water regulating valve is obtained by controlling the second-stage desuperheating water regulating valve through a desuperheating water PID control unit according to the numerical value of the outlet temperature t2 of the superheater.
It should be further noted that the constant adjustment control module for main steam pressure of the boiler controls the main steam pressure P2 of the boiler by adjusting the coal gas charging amount of the gas power generation boiler and the blast furnace gas charging amount to meet the operation requirement of the gas power generation boiler;
the opening degree of a gas flow regulating valve in the boiler is automatically regulated by taking the outlet pressure P1 of the boiler drum as a detection quantity and combining with the combustion temperature value in the boiler through a control program algorithm.
It should be further noted that the constant adjustment control module for the main steam pressure of the boiler takes the main steam pressure P2 of the boiler as a detection quantity, combines the value of the main steam flow of the gas power generation boiler, and automatically adjusts the opening of the gas flow adjustment valve of the blast furnace through a control program algorithm.
It should be further noted that the as-fired gas quantity distribution adjustment control module automatically adjusts the opening of the coke oven gas flow adjustment valve by taking the boiler drum outlet pressure P1 as a detection quantity and combining a combustion temperature value in the gas power generation boiler through a control program algorithm;
and the opening of the blast furnace gas flow regulating valve is automatically regulated by taking the main steam pressure P2 of the boiler as a detection quantity and combining the numerical value of the main steam flow of the boiler through a control program algorithm.
It should be further noted that the boiler entering gas distribution regulation control module is used for taking the main steam temperature T of the boiler as a detection quantity, taking the opening of the converter gas regulating valve as a controlled quantity on the basis that the flow L1 of the boiler entering cold air is kept stable, and adopting a single-loop PID to regulate so as to keep the main steam temperature T of the gas power generation boiler stable;
the boiler-entering gas quantity distribution regulation control module performs load-up or load-down control according to the control instruction of the boiler master control module, and performs PID operation in combination, wherein the PID output value regulates the opening degree of different gas valves according to a preset proportionality coefficient, so that the combustion heat of the boiler is within a preset heat threshold value.
It should be further noted that the boiler entering gas flow distribution regulation control module is also based on an output value obtained by the air supply quantity regulation system from the boiler main steam flow signal after function operation; the functional relation is the corresponding relation of load and air quantity, and the system is self-adaptive to gas quantity control according to operation test data and operation experience;
the fired gas quantity distribution regulation control module is also sent into a main regulator together with a set value for PID operation based on a measured value of the oxygen content of the flue gas and the set value, the operation result and a set value of the total air quantity regulation air quantity are subjected to function processing together and then serve as the set value of a secondary regulator, PID operation is carried out on the operation result and the measured value of the total air quantity, and the operation result serves as a control instruction of the total air quantity; the adjustment of the oxygen content to the total air volume is automatically corrected to 10-15%.
It should be further noted that the furnace negative pressure automatic regulation control module is used for sending a speed instruction based on the rotation of the induced draft fan into the PID main controller, the furnace pressure is a feedforward signal of the control system, the flow L1 of cold air entering the furnace is used as a comparison quantity, and when the furnace pressure changes, the rotation speed of the induced draft fan is regulated, so that the boiler furnace negative pressure is within a preset threshold value.
It should be further noted that the boiler master control module ensures that the cold air and gas mixture ratio is kept consistent in static and dynamic processes by utilizing a field bus control mode and an intelligent instrument decentralized control mode and combining mutual influence of a fuzzy control mode and adjustment of three kinds of gas with different heat values in a combustion process; the automatic combustion control of three kinds of coal gas of the coal gas power generation boiler is realized.
According to the technical scheme, the invention has the following advantages:
when the three-gas automatic combustion control system of the gas power generation boiler provided by the invention operates in a steady state, the fuel quantity and the air supply quantity are coordinately controlled according to the requirements of a main control instruction of the boiler, and the optimal air/fuel ratio and the optimal oxygen content of smoke are kept. During dynamic state, the air is increased first and then fuel is increased during load increase, and the fuel is reduced first and then air is reduced during load reduction, so that the purpose of air/fuel cross limitation is achieved.
The three-gas automatic combustion control system of the gas power generation boiler provided by the invention simulates the learning and control capabilities of human beings by using tools such as numerical calculation, logical operation, symbolic reasoning and the like in an intelligent control theory and establishes an accurate combustion process mathematical model. Aiming at the characteristics of multivariable coupling, large delay and large inertia of a combustion control object, the control scheme of the automatic combustion system is designed by utilizing the classical control theories of multivariable decoupling, feedforward control and the like, and comprises three types of gas distribution regulation control of coal gas entering a furnace, furnace pressure regulation control, desuperheating water regulation control, steam drum liquid level regulation control, boiler main steam pressure regulation control and the like. The problem of only adopting single cascade control in the control process of boiler burning, to some complicated and control processes that contain the uncertainty, can't model at all, can't satisfy 3 kinds of different calorific value coal gas auto-combustion requirements simultaneously is solved.
The three gas automatic combustion control systems of the gas power generation boiler also utilize a field bus control technology and an intelligent instrument decentralized control technology; the method is combined with the idea of fuzzy control, the mutual influence of the adjustment of three kinds of coal gas with different heat values in the combustion process is fully considered, and the matching of cold air and the coal gas can be kept consistent in the static and dynamic processes; when the load of the unit is kept unchanged, the automatic combustion performance of the boiler gas is kept stable, and the dynamic deviation of each regulated parameter is small, so that the optimized combustion of the boiler is realized.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings required to be used in the description will be briefly introduced below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
FIG. 1 is a schematic view of three gas automatic combustion control systems of a gas power generation boiler;
FIG. 2 is a schematic diagram of an automatic regulating control module for the first-stage desuperheating water and the second-stage desuperheating water;
FIG. 3 is a schematic diagram of a boiler main steam pressure constant regulation control module;
FIG. 4 is a schematic view of a gas quantity distribution regulation control module of the as-fired gas;
FIG. 5 is a schematic diagram of a furnace chamber negative pressure automatic regulation control module;
FIG. 6 is a schematic diagram of automatic adjustment and control of three kinds of gas entering the furnace;
FIG. 7 is a graph of boiler combustion optimization.
Detailed Description
The invention provides three gas automatic combustion control systems of a gas power generation boiler, which mainly control the gas combustion process. The gas combustion process is controlled to meet the unit load requirement, and the main steam pressure is maintained to be stable. When the unit operation mode is a steam turbine following control mode, the combustion control system bears the unit output, namely, the power is adjusted; when the unit operation mode is a boiler following control mode, the combustion control system maintains the main steam pressure to be stable; when the unit operation mode is a coordination control mode, the combustion control system bears the unit output and maintains the main steam pressure to be stable. The three-gas automatic combustion control system of the gas power generation boiler can ensure the economy of the combustion process, which is an important aspect of improving the efficiency of the boiler, namely, the optimal ratio of the fuel quantity entering a hearth to the ventilation quantity is controlled to ensure that enough air can fully combust the fuel, and simultaneously, the heat loss caused by smoke discharge is reduced as much as possible. The system can also ensure the stability of the combustion process, the combustion stability influences the safety and the economy of the operation of the boiler, and factors influencing the combustion process are many, wherein the hearth pressure is one of important factors. The pressure of the hearth reflects the working medium balance relation between air supply and induced air in the combustion process, and when the air supply quantity is greater than the induced air, the pressure of the hearth is increased, so that the hearth can spray ash or fire outwards; the air supply amount is less than the air induction amount, the air induction power consumption is increased, the air leakage of a hearth is increased, the furnace temperature is reduced, and the combustion working condition in the furnace is influenced; in addition, the pressure fluctuation of the furnace chamber also influences the combustion stability of the fuel and has influence on the safe operation of the boiler. In order to ensure the stability of the combustion process, the invention controls the hearth pressure and maintains the stable boiler hearth pressure.
As shown in fig. 1 to 6 for the above purposes, the drawings provided in the three-kind gas automatic combustion control system of the gas power generation boiler according to the present invention are only schematic to illustrate the basic idea of the present invention that the three-kind gas automatic combustion control system of the gas power generation boiler can acquire and process the associated data based on the artificial intelligence technology. Among them, artificial Intelligence (AI) is a theory, method, technique and application device that simulates, extends and expands human Intelligence using a digital computer or a machine controlled by a digital computer, senses the environment, acquires knowledge and uses the knowledge to obtain the best result.
The three-gas automatic combustion control system of the gas power generation boiler also simulates the learning and control capability of human beings by using tools such as numerical calculation, logical operation, symbolic reasoning and the like in an intelligent control theory, and establishes an accurate mathematical model of the automatic combustion process. The invention designs the control scheme of the automatic combustion system by using the classical control theories of multivariable decoupling, feedforward control and the like aiming at the characteristics of multivariable coupling, large delay and large inertia of a combustion control object so as to solve the problem of inaccurate traditional manual operation and further create better economic benefit.
A mobile terminal implementing various embodiments of the present invention will now be described with reference to the accompanying drawings. In the following description, suffixes such as "module", "component", or "unit" used to indicate elements are used only for facilitating the description of the embodiments of the present invention, and do not have a specific meaning per se. Thus, "module" and "component" may be used in a mixture.
The three kinds of gas automatic combustion control systems of the gas power generation boiler comprise: the system comprises a boiler master control module, a boiler drum water level automatic adjusting control module, a primary desuperheating water and secondary desuperheating water automatic adjusting control module, a boiler main steam pressure constant adjusting control module, a fired gas quantity distribution adjusting control module and a hearth negative pressure automatic adjusting control module;
the boiler master control module is a device capable of automatically performing numerical calculation and/or information processing according to a preset or stored instruction, and hardware of the boiler master control module includes, but is not limited to, a microprocessor, an Application Specific Integrated Circuit (ASIC), a Programmable Gate Array (FPGA), a Digital Signal Processor (DSP), an embedded device, and the like.
The boiler overall control module may include network devices and/or user devices. Wherein the network device includes, but is not limited to, a single network server, a server group consisting of a plurality of network servers, or a Cloud Computing (Cloud Computing) based Cloud consisting of a large number of hosts or network servers. The Network where the boiler master control module is located includes, but is not limited to, the internet, a wide area Network, a metropolitan area Network, a local area Network, a Virtual Private Network (VPN), and the like.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In three automatic gas combustion control systems of a gas power generation boiler, a boiler main control module is connected with an automatic boiler drum water level adjusting control module to adjust the boiler drum water level and control a boiler drum to supply steam to the boiler;
specifically, the boiler drum water level automatic regulation control module is provided with a boiler drum regulating valve, a plurality of boiler drum liquid level sensors and a PID control unit; the method comprises the following steps of (1) taking a boiler drum regulating valve as a controlled device, taking a plurality of boiler drum liquid level sensors as detection sensing liquid level information, taking 2 liquid level values as reference quantities at will, and adopting a PID control algorithm of a drum regulating PID control unit to carry out control program operation; adjusting according to the deviation between the set value of the liquid level of the boiler drum and the actual liquid level value; so as to achieve the balance of the liquid level of the boiler drum.
The boiler master control module is connected with the first-stage desuperheating water and the second-stage desuperheating water automatic regulation control module and respectively controls the output temperature information of the superheater;
in this embodiment, first order desuperheating water and second grade desuperheating water automatically regulated control module includes: the temperature-reducing water PID control unit is used for controlling the temperature of the water to be reduced; controlling the temperature of an outlet of the superheater by using a first-stage desuperheating water regulating valve and a second-stage desuperheating water regulating valve as controlled equipment; the primary desuperheating water regulating valve is controlled by a desuperheating water PID control unit according to the numerical value of the outlet temperature t1 of the primary desuperheater to obtain the opening numerical value of the primary desuperheating water regulating valve; and the opening numerical value of the second-stage desuperheating water regulating valve is obtained by controlling the second-stage desuperheating water regulating valve through a desuperheating water PID control unit according to the numerical value of the outlet temperature t2 of the superheater. The temperature of the superheater is ensured to be kept stable through the common adjustment of the primary desuperheater and the secondary desuperheater adjusting valve.
The boiler main control module is connected with the boiler main steam pressure constant adjusting control module and is used for adjusting and controlling the main steam pressure of the boiler so that the main steam pressure of the boiler meets the preset requirement;
for the constant regulating and controlling module of the main steam pressure of the boiler, the main steam pressure P2 of the boiler is controlled by regulating the coal gas charging quantity of the coal gas power generation boiler and the coal gas charging quantity of the blast furnace, so as to meet the operation requirement of the coal gas power generation boiler; the opening degree of a gas flow regulating valve in the boiler is automatically regulated by taking the outlet pressure P1 of the boiler drum as a detection quantity and combining with the combustion temperature value in the boiler through a control program algorithm.
The constant regulating and controlling module of the main steam pressure of the boiler takes the main steam pressure P2 of the boiler as a detection quantity, combines the numerical value of the main steam flow of the gas power generation boiler and automatically regulates the opening of the gas flow regulating valve of the blast furnace through a control program algorithm.
The boiler main steam pressure constant adjusting control module feeds the value after the differential function operation of the boiler drum pressure to the algorithm of the opening of the blast furnace gas flow valve in a feedforward mode so as to improve the response speed of the system, improve the sensitivity of the control algorithm and simultaneously play a role in avoiding the gas quantity overshoot.
The boiler master control module is connected with the gas quantity distribution and adjustment control module of the coal gas entering the boiler to control the gas quantity of the coal gas entering the boiler;
the distribution regulation control module of the gas amount of the coal gas entering the furnace takes the outlet pressure P1 of a boiler drum as a detection amount, combines a combustion temperature value in the boiler of the coal gas power generation boiler, and automatically regulates the opening degree of a coke oven gas flow regulation valve through a control program algorithm; and the opening of the blast furnace gas flow regulating valve is automatically regulated by taking the main boiler steam pressure P2 as a detection quantity and combining the numerical value of the main boiler steam flow through a control program algorithm.
The boiler entering gas quantity distribution regulation control module is used for taking the main steam temperature T of the boiler as a detection quantity, taking the opening of a converter gas regulating valve as a controlled quantity on the basis that the flow L1 of cold air entering the boiler is kept stable, and adopting a single-loop PID (proportion integration differentiation) to regulate so as to keep the main steam temperature T of the gas power generation boiler stable; the three gas regulating valves can be respectively put into automation or manual operation so as to carry out fine adjustment.
The boiler-entering gas quantity distribution regulation control module performs load-up or load-down control according to the control instruction of the boiler master control module, and performs PID operation in combination, wherein the PID output value regulates the opening degree of different gas valves according to a preset proportionality coefficient, so that the combustion heat of the boiler is within a preset heat threshold value.
The boiler gas quantity distribution regulation control module considers the value of the oxygen content V1 in the tail gas discharged by the boiler gas and ensures that the oxygen content V1 is kept in a certain range; when the three kinds of coal gas are burnt, the coal gas is completely and fully burnt, and the excessive coal gas entering the furnace is avoided.
In the embodiment of the invention, an air supply quantity adjusting system of a fired gas quantity distribution adjusting control module is taken from an output value of a boiler main steam flow signal after function operation; the functional relation is the corresponding relation between the load and the air volume, and the system self-adaptive optimization and manual correction are determined according to operation test data and operation experience; and sending the measured value of the oxygen content of the flue gas and the given value into a main air conditioner together for PID operation, performing function processing on the operation result and a setting instruction of the total air volume adjusting air volume together to obtain the given value of a secondary air conditioner, performing PID operation on the operation result and the measured value of the total air volume, and using the operation result as a control instruction of the total air volume. The adjustment of the oxygen content to the total air volume is automatically corrected by about 10-15%. Because it takes a period of time for the fuel quantity to change to the oxygen content of the smoke, the air quantity is directly processed in the air supply quantity adjusting system, and the result is used as an advance signal to be added into the control output so as to improve the quick response of the control system. The total air volume instruction and the measured value of the fuel volume are subjected to cross limitation and then are used as given values of a total air volume control system, so that the requirements of adding air and then adding fuel when the load is increased and reducing fuel and then reducing air when the load is reduced are met, and a certain excess air coefficient is guaranteed. Meanwhile, the air quantity is corrected through the oxygen quantity, the optimal air quantity is achieved, the economic efficiency of the boiler is improved, and meanwhile the boiler is guaranteed to reach the environmental protection index. The air quantity is set to be a minimum air quantity and a maximum air quantity limiting value, and the automatic adjusting range cannot exceed the air quantity limiting range so as to ensure the minimum stable combustion air quantity.
The boiler master control module is connected with the hearth negative pressure automatic adjustment control module, controls the rotating speed of the draught fan, and controls the boiler hearth negative pressure, so that the boiler hearth negative pressure is in a preset threshold value.
The hearth negative pressure automatic regulation control module can send a speed instruction of the rotation of the induced draft fan to the PID main controller, the hearth pressure is a feedforward signal of a control system, the flow L1 of cold air entering the furnace is used as a comparison quantity, and when the hearth pressure changes, the rotation speed of the induced draft fan is correspondingly regulated; meanwhile, the requirement that the induced air quantity changes along with the change of the air supply quantity in time can be met, so that the dynamic deviation of the hearth pressure can be solved; the stable control of the negative pressure of the boiler furnace is ensured.
Further, as a refinement and an extension of the embodiments of the above embodiments, in order to fully illustrate the implementation process of the present embodiment, as shown in fig. 7, in the three gas automatic combustion control systems of the gas power generation boiler, gas is used as a combustion medium and must be completely combusted and consumed, so as to achieve the balance of the gas amount. In order to achieve the best combustion efficiency of the boiler, the optimal combustion ratio must be fully considered in terms of the air intake amount and the gas flow rate in the boiler burner.
If the following occurs, the combustion characteristics of the boiler are seriously affected.
(1) The gas quantity in the boiler burner is insufficient, as shown in a point a, the gas quantity is excessive, and the gas cannot be completely combusted; the effect of the curve shown by Q3+ Q4 in the figure will occur, and the incomplete combustion curve rises, resulting in a drop in the thermal efficiency of the boiler combustion.
(2) The air quantity in the boiler burner is excessive, as shown in a point b of the figure, when the air supply quantity is large, although the coal gas is completely consumed, part of hot air is discharged outside, the heat loss Q2 of the discharged flue gas is increased, the heat loss of the discharged flue gas of the boiler burner is increased, the combustion efficiency loss of the boiler is increased, and finally the thermal efficiency of the boiler is reduced.
The above two situations, which often occur in production practice, require the optimal combustion ratio k to be found at all times through the comprehensive control of the boiler, so as to achieve the maximum boiler thermal efficiency.
The boiler combustion process flow is as follows: the heat generated by the combustion of the boiler gas is used for heating water in the steam drum, the water is heated to form steam, the steam is externally supplied to push the steam turbine to operate, and the steam turbine is coaxially connected with the generator, so that the generator is driven to generate electricity.
The heat efficiency of boiler combustion is represented by the numerical values of 2 indexes of 'main steam flow L2' and 'oxygen content V1 in flue gas'. After the coal gas with the same flow is combusted, the numerical value of the externally supplied steam flow L2 is the highest, and meanwhile, the numerical value of the oxygen content V1 in the smoke is 0.05, so that the optimal combustion effect is judged.
In FIG. 7, "boiler cold air flow L1" is the air flow in the boiler burner; its numerical value given amount is calculated by the following logical relationship.
"the air flow rate a required for theoretical combustion of the boiler", which is a calculated value. The "sum" of FT1+ FT2+ FT3 is the actual flow sum of 3 kinds of gas, i.e., the blast furnace gas combustion amount, the converter gas combustion amount, and the coke oven gas combustion amount. The air flow A required by theoretical combustion of the boiler and the sum of FT1+ FT2+ FT3 are numerically calculated to obtain a numerical value G2, namely a required combustion air flow numerical value, and the set value of the numerical value is added into a PID calculation formula.
The numerical values of 2 indexes of 'main boiler steam flow L2' and 'boiler combustion tail gas oxygen content V1' are used as feedback numerical values in a 'PID (proportion integration differentiation) operation formula' and are used for regulating and controlling numerical operation; the maximum value of the main steam flow L2 of the boiler is ensured, and the value of the oxygen content of the boiler combustion tail gas is stabilized at about 0.05.
The control model obtains a numerical value instruction of 'air supply volume' through calculation, and sends the numerical value to an air supply device to ensure that the air flow is always at the optimal combustion ratio value 'K'.
The automatic combustion control technology of three kinds of coal gas of the boiler utilizes the thinking of fuzzy control, fully considers the mutual influence of the adjustment of three kinds of coal gas with different heat values in the combustion process, and the air-coal ratio can be kept consistent in the static and dynamic processes; when the load of the unit is not changed, the boiler is stably combusted, the dynamic deviation of each regulated parameter is obviously reduced, and the optimized combustion of the boiler is realized.
The elements and algorithm steps of the various examples described in the embodiments disclosed in the three gas auto-combustion control systems of a gas power boiler provided by the present invention can be implemented in electronic hardware, computer software, or a combination of both, and in the above description the components and steps of the various examples have been generally described in terms of functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
Block diagrams in the figures of a gas power boiler three gas auto-combustion control system illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. Illustratively, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. The utility model provides a three kinds of gas automatic combustion control systems of gas power generation boiler which characterized in that includes: the system comprises a boiler master control module, a boiler drum water level automatic adjusting control module, a primary desuperheating water and secondary desuperheating water automatic adjusting control module, a boiler main steam pressure constant adjusting control module, a boiler coal gas quantity distribution adjusting control module and a hearth negative pressure automatic adjusting control module;
the boiler master control module is connected with the boiler drum water level automatic adjusting control module, adjusts the boiler drum water level and controls the boiler drum to supply steam to the boiler;
the boiler master control module is connected with the first-stage desuperheating water and the second-stage desuperheating water automatic regulation control module and respectively controls the output temperature information of the superheater;
the main boiler control module is connected with the main boiler steam pressure constant adjusting control module and is used for adjusting and controlling the main boiler steam pressure so that the main boiler steam pressure meets the preset requirement;
the boiler master control module is connected with the gas quantity distribution and regulation control module of the coal gas entering the boiler to control the gas quantity of the coal gas entering the boiler;
the boiler master control module is connected with the hearth negative pressure automatic adjustment control module, controls the rotating speed of the draught fan, and controls the boiler hearth negative pressure, so that the boiler hearth negative pressure is in a preset threshold value.
2. The three-gas automatic combustion control system of a gas power generation boiler as claimed in claim 1,
the boiler drum water level automatic regulation control module is provided with a boiler drum regulating valve, a plurality of boiler drum liquid level sensors and a PID control unit;
the method comprises the following steps of (1) taking a boiler drum regulating valve as controlled equipment, taking a plurality of boiler drum liquid level sensors as detection sensing liquid level information, taking 2 liquid level values as reference values at will, and adopting a PID control algorithm of a drum regulating PID control unit to carry out control program operation; adjusting according to the deviation between the set value of the liquid level of the boiler drum and the actual liquid level value; so as to achieve the balance of the liquid level of the boiler steam drum.
3. The three-gas automatic combustion control system of a gas power generation boiler as claimed in claim 1,
the automatic regulating and controlling module for the first-stage desuperheating water and the second-stage desuperheating water comprises: a temperature-reducing water PID control unit, a first-stage temperature-reducing water regulating valve and a second-stage temperature-reducing water regulating valve;
controlling the temperature of an outlet of the superheater by using a first-stage desuperheating water regulating valve and a second-stage desuperheating water regulating valve as controlled equipment;
the primary desuperheating water regulating valve is controlled by a desuperheating water PID control unit according to the numerical value of the outlet temperature t1 of the primary desuperheater to obtain the opening numerical value of the primary desuperheating water regulating valve;
and the opening numerical value of the second-stage desuperheating water regulating valve is obtained by controlling the desuperheating water PID control unit according to the numerical value of the superheater outlet temperature t 2.
4. The automatic three-gas combustion control system for a gas power boiler as claimed in claim 1,
the boiler main steam pressure constant adjusting control module controls the boiler main steam pressure P2 by adjusting the coal gas charging amount of the coal gas power generation boiler and the blast furnace coal gas charging amount so as to meet the operation requirement of the coal gas power generation boiler;
the opening degree of a gas flow regulating valve in the boiler is automatically regulated by taking the outlet pressure P1 of the boiler drum as a detection quantity and combining a combustion temperature value in the boiler through a control program algorithm.
5. The three-gas automatic combustion control system of a gas power generation boiler as claimed in claim 4,
the constant regulating and controlling module of the main steam pressure of the boiler takes the main steam pressure P2 of the boiler as a detection quantity, combines the numerical value of the main steam flow of the gas power generation boiler, and automatically regulates the opening of the gas flow regulating valve of the blast furnace through a control program algorithm.
6. The automatic three-gas combustion control system for a gas power boiler as claimed in claim 1,
the boiler entering gas quantity distribution adjustment control module automatically adjusts the opening degree of a coke oven gas flow adjusting valve by taking the outlet pressure P1 of a boiler drum as a detection quantity and combining a combustion temperature value in a gas power generation boiler through a control program algorithm;
and the opening of the blast furnace gas flow regulating valve is automatically regulated by taking the main steam pressure P2 of the boiler as a detection quantity and combining the numerical value of the main steam flow of the boiler through a control program algorithm.
7. The three-gas automatic combustion control system of a gas power generation boiler as claimed in claim 6,
the boiler entering gas quantity distribution regulation control module is used for taking the main steam temperature T of the boiler as a detection quantity, taking the opening of a converter gas regulating valve as a controlled quantity on the basis of keeping the flow L1 of cold air entering the boiler stable, and adopting a single-loop PID (proportion integration differentiation) to regulate so as to maintain the main steam temperature T of the gas power generation boiler stable;
the boiler-entering gas quantity distribution regulation control module performs load-up or load-down control according to the control instruction of the boiler master control module, and performs PID operation in combination, wherein the PID output value regulates the opening degree of different gas valves according to a preset proportionality coefficient, so that the combustion heat of the boiler is within a preset heat threshold value.
8. The three-gas automatic combustion control system of a gas power generation boiler as claimed in claim 1,
the boiler gas quantity distribution regulation control module is also based on an output value of an air supply quantity regulation system, which is obtained from a main steam flow signal of the boiler after function operation; the functional relation is the corresponding relation of load and air quantity, and the system is self-adaptive to gas quantity control according to operation test data and operation experience;
the fired gas quantity distribution regulation control module is also sent into a main regulator together with a set value for PID operation based on a measured value of the oxygen content of the flue gas and the set value, the operation result and a set value of the total air quantity regulation air quantity are subjected to function processing together and then serve as the set value of a secondary regulator, PID operation is carried out on the operation result and the measured value of the total air quantity, and the operation result serves as a control instruction of the total air quantity; the adjustment proportion of the oxygen content to the total air volume is 10-15 percent, and automatic correction is carried out.
9. The three-gas automatic combustion control system of a gas power generation boiler as claimed in claim 1,
the furnace negative pressure automatic regulation control module is used for sending a speed instruction into the PID main controller based on the rotation of the induced draft fan, the furnace pressure is a feedforward signal of the control system, the flow L1 of cold air entering the furnace is taken as a comparison quantity, and when the furnace pressure changes, the rotation speed of the induced draft fan is regulated, so that the boiler furnace negative pressure is in a preset threshold value.
10. The three-gas automatic combustion control system of a gas power generation boiler as claimed in claim 1 or 2,
the boiler master control module ensures that the proportion of cold air and coal gas is kept consistent in static and dynamic processes by utilizing a field bus control mode and an intelligent instrument decentralized control mode and combining a fuzzy control mode and mutual influence of adjustment of three kinds of coal gas with different heat values in a combustion process; the automatic combustion control of three kinds of coal gas of the coal gas power generation boiler is realized.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211340403.1A CN115681943A (en) | 2022-10-28 | 2022-10-28 | Automatic combustion control system for three kinds of coal gas power generation boiler |
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| CN202211340403.1A CN115681943A (en) | 2022-10-28 | 2022-10-28 | Automatic combustion control system for three kinds of coal gas power generation boiler |
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- 2022-10-28 CN CN202211340403.1A patent/CN115681943A/en active Pending
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