CN117784588A - Control method and system of cogeneration unit based on energy balance and electronic equipment - Google Patents
Control method and system of cogeneration unit based on energy balance and electronic equipment Download PDFInfo
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Abstract
The invention discloses a control method, a control system and electronic equipment of a cogeneration unit based on energy balance, and relates to the field of unit control. The invention obtains the deviation of the boiler combustion rate by determining the energy demand of the turbine and the energy released by the boiler so as to generate a fuel quantity adjusting signal, and generates a feedforward control signal based on the set value of the power generation load and the set value of the heat supply steam extraction flow so as to balance and control the pressure of main steam. The PID controller is adopted to realize the control of the opening of the steam turbine regulating valve and the opening of the heat supply steam extraction regulating butterfly valve, so that the fusion of the heat supply steam extraction quick regulating loop and the fuel quantity precise regulating loop is realized, and the load control performance of the unit is effectively improved. And the load change is overlapped on the deviation of the load instruction and the actual load so as to control the opening of the regulating valve of the steam turbine, thereby not only ensuring the conservation of energy in the regulating process, but also ensuring that the heat supply steam extraction flow can be restored to the original heat supply working condition requirement and avoiding great influence on the heat supply effect.
Description
Technical Field
The invention relates to the technical field of unit control, in particular to a cogeneration unit control method and system based on energy balance and electronic equipment.
Background
The coordination control of the pure condensing unit is conventionally implemented by using a PID controller, but the control effect is limited. The cogeneration unit has the functions of power supply and heat supply, the heat is easy to store and difficult to transmit, the power is easy to transmit and difficult to store, and the cogeneration unit and the heat supply unit have obvious coupling and complementary characteristics and can be used for coordination control. The traditional thermal power generating unit can not generate heat at the same time, namely, the thermal power generating unit which only generates electricity can only convert 30% of fuel energy into usable electric energy, and nearly 70% of energy is wasted in the form of heat energy, namely, useless heat; the cogeneration unit can convert up to 50% of useless heat into industrial energy, improves the utilization rate of fuel energy to 60%, has a very large development space, and is the most mainstream trend of the current thermal power plant development.
For the traditional coordination control strategy, although the quick action of the heating steam extraction butterfly valve can change the generating load of the unit more quickly than the change of the fuel quantity, the control method is still limited by the delay characteristic of the boiler side, and the response time of the unit is long. The thermal power generating unit generally depends on a coordination control system to realize variable load control, and the essence of the thermal power generating unit is that the load of the unit is changed through coordination and cooperation of coal feeding amount and a main valve regulating valve, but the thermal power generating unit is limited by large delay inertia of a boiler side, and the variable load rate is generally only 1% -2% of rated load per minute. For the cogeneration unit which takes both power generation and heat supply into consideration, the control strategy is more conservative when the cogeneration unit runs in a thermoelectric mode, the load-changing rate of the cogeneration unit is generally not more than 1% of rated load per minute, and some units are even directly withdrawn from coordination control to be changed into manual control, so that the automatic power generation control requirement of a power grid is difficult to be achieved. At present, research conducted around the optimization of a coordinated control system is quite hot, but the research is still limited by the large delay inertia of the boiler side, and the variable load rate of a unit is difficult to be improved fundamentally. From the aspects of stable operation of the unit, improvement of delay of the boiler side, improvement of control effect and the like, the traditional coordination control scheme needs to be optimized.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a control method, a control system and electronic equipment of a cogeneration unit based on energy balance.
In order to achieve the above object, the present invention provides the following solutions:
a cogeneration unit control method based on energy balance, comprising:
determining a turbine energy demand based on turbine regulation stage pressure, main steam given pressure, and main steam pressure;
determining the combustion release energy of the boiler based on the turbine regulation stage pressure, the drum pressure and the boiler heat storage coefficient;
determining a boiler firing rate bias based on the turbine energy demand and the boiler firing release energy;
generating a fuel quantity adjustment signal based on the boiler firing rate deviation;
generating a feedforward control signal based on the power generation load set point and the heating steam extraction flow set point;
a PID controller is adopted to control the fuel quantity based on the fuel quantity adjusting signal and the feedforward control signal;
determining a turbine regulating valve opening regulating signal based on the heat supply air extraction flow set value, the heat supply air extraction flow and the set time value;
determining a load deviation signal based on the power generation load set point and the power generation load;
the PID controller is adopted to realize the control of the opening of the turbine regulating valve based on the opening regulating signal of the turbine regulating valve and the load deviation signal;
determining a difference value between a given value of the heating steam extraction pressure and the heating steam extraction pressure;
when the difference value is smaller than zero, a PID controller is adopted to adjust the opening of a heating and steam extracting adjusting butterfly valve, and whether a load deviation signal rises is determined;
and when the load deviation signal rises, the opening of the heating and steam extracting adjusting butterfly valve is adjusted by adopting a PID controller so as to increase the power generation load.
Optionally, determining the turbine energy requirement based on the turbine tuning stage pressure, the main steam given pressure, and the main steam pressure specifically includes:
determining a ratio of the turbine tuning stage pressure to the main steam given pressure;
and determining the product of the ratio and the set value of the main steam pressure, and taking the product as the energy requirement of the steam turbine.
Optionally, determining the boiler combustion release energy based on the turbine conditioning stage pressure, the drum pressure and the boiler heat storage coefficient specifically includes:
performing differential treatment on the drum pressure to obtain differential values; the differential value is used for representing the change rate of the drum pressure;
determining a product of the differential value and the boiler heat storage coefficient;
and determining the sum of the product and the turbine regulating stage pressure, and taking the sum of the product and the turbine regulating stage pressure as the boiler combustion release energy.
Optionally, generating the feedforward control signal based on the power generation load set point and the heating extraction flow set point specifically includes:
determining a thermal load value based on the heating extraction flow set point and the set time value;
determining a sum of the thermal load value and the power generation load set point;
the feedforward control signal is generated based on a sum of the thermal load value and the power generation load setpoint.
Optionally, the set time value adopts a formulaDetermining;
wherein G is a set time value, k is an open-loop amplification factor, and T is an inertial time constant.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention adopts a control loop for controlling fuel quantity by a direct energy balance control system, on one hand, the boiler combustion rate deviation is obtained by determining the energy demand of a turbine and the combustion release energy of a boiler, a fuel quantity adjusting signal is generated based on the boiler combustion rate deviation, and on the other hand, a feedforward control signal is generated based on a power generation load given value and a heat supply steam extraction flow given value so as to balance and control the main steam pressure. On the basis, the PID controller is adopted to realize the control of the opening of the steam turbine regulating valve and the opening of the heat supply and steam extraction regulating butterfly valve based on the opening regulating signal of the steam turbine regulating valve and the load deviation signal, so that the fusion of the heat supply and steam extraction quick regulating loop and the fuel quantity precise regulating loop is realized, the load control performance of the unit can be effectively improved, in addition, the load change caused by the deviation of a load instruction and an actual load and the heat supply and steam extraction flow change is overlapped to control the opening of the steam turbine regulating valve, the energy conservation in the regulating process is ensured, the heat supply and steam extraction flow can be restored to the original heat supply working condition requirement, and the great influence on the heat supply effect is avoided.
Further, the invention provides a cogeneration unit control system based on energy balance, which is used for implementing the cogeneration unit control method based on energy balance; the system comprises:
the turbine energy demand determination module is used for determining the turbine energy demand based on the turbine regulation stage pressure, the main steam given pressure and the main steam pressure;
the boiler combustion release energy determining module is used for determining the boiler combustion release energy based on the turbine regulating stage pressure, the steam drum pressure and the boiler heat storage coefficient;
a boiler combustion rate deviation determination module for determining a boiler combustion rate deviation based on the turbine energy demand and the boiler combustion release energy;
a fuel quantity adjustment signal generation module for generating a fuel quantity adjustment signal based on the boiler combustion rate deviation;
the feedforward control signal generation module is used for generating a feedforward control signal based on the power generation load given value and the heating steam extraction flow given value;
the fuel quantity control module is used for realizing control of the fuel quantity by adopting a PID controller based on the fuel quantity adjusting signal and the feedforward control signal;
the opening adjusting signal determining module is used for determining an opening adjusting signal of the adjusting valve of the steam turbine based on the set value of the heat supply and extraction flow, the heat supply and extraction flow and the set time value;
a load deviation signal determination module for determining a load deviation signal based on the power generation load given value and the power generation load;
the valve opening control module is used for controlling the opening of the turbine regulating valve by adopting a PID controller based on the turbine regulating valve opening regulating signal and the load deviation signal;
the valve opening adjusting module is used for determining the difference value between the set value of the heating steam extraction pressure and the heating steam extraction pressure; when the difference value is smaller than zero, a PID controller is adopted to adjust the opening of a heating and steam extracting adjusting butterfly valve, and whether a load deviation signal rises is determined; and when the load deviation signal rises, the opening of the heating and steam extracting adjusting butterfly valve is adjusted by adopting a PID controller so as to increase the power generation load.
Still further, the present invention also provides an electronic device including:
a memory for storing a computer program;
and the processor is connected with the memory and is used for calling and executing the computer program so as to implement the control method of the cogeneration unit based on energy balance.
Optionally, the memory is a computer readable storage medium.
The technical effects achieved by the system and the electronic equipment provided by the invention are the same as those achieved by the control method of the cogeneration unit based on energy balance, so that the description is omitted here.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a control method of a cogeneration unit based on energy balance provided by the invention;
FIG. 2 is a schematic diagram of a heat and power cogeneration unit model of a drum furnace provided by the invention;
FIG. 3 is a schematic diagram of the power generation load tracking provided by the present invention;
FIG. 4 is a schematic diagram of the heat supply pumping flow tracking condition provided by the invention;
FIG. 5 is a graph showing the comparison effect of the power generation load tracking condition provided by the invention;
fig. 6 is a diagram showing the comparison effect of the heat supply steam extraction flow tracking condition provided by the invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention aims to provide a control method, a control system and electronic equipment of a cogeneration unit based on energy balance, which fully utilize heat storage of a boiler to enable a controller to respond quickly so as to ensure that the whole system can restore balance quickly and further realize optimization of a coordinated control strategy.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
The cogeneration unit has the advantages of improving the energy utilization rate, ensuring the economy of unit operation and improving the quality level of unit operation. The direct energy balance coordination control starts from the concept of energy balance, takes a boiler and a steam turbine as an organic tightly connected whole to control, takes the energy requirement of the steam turbine as a boiler instruction based on boiler follow-up, directly compares the energy requirement with the heat signal of the boiler at the inlet of a boiler fuel regulator to form a closed loop, and adjusts the increase and decrease of fuel to lead the inlet deviation of the regulator to be zero, thereby leading the energy supply and demand relationship between the boiler and the machine to be balanced rapidly and further realizing the integrated coordination control of the machine and the furnace simply and effectively. Under the direct energy balance coordination control mode, the load quickly reaches balance through the quick response of the controller. This control process is short, and the main steam pressure will naturally and slowly recover to the set point. The heat accumulation of the boiler is fully utilized in the process, and the heat accumulation process of the boiler is like a strong high-frequency filter, so that the change of the pressure of the main steam is gentle. When there is any disturbance on the fuel system side, the unequal main steam pressure changes, the controller reacts quickly, and eliminates them automatically and timely, which is the mechanism of the main steam pressure stabilization under the direct energy balance coordination control mode. The load adaptability of the unit set is also greatly improved due to the fast reaction of the controller and the full utilization of the heat accumulation of the boiler. At present, the direct energy balance coordination control scheme is widely adopted by field engineers of coal-fired power plants, and only the direct energy balance coordination control scheme is applied to pure condensing units in academia. Based on the energy balance, the invention provides a control method of the cogeneration unit. As shown in fig. 1, the method includes:
step 100: the turbine energy demand is determined based on turbine turndown stage pressure, main steam given pressure, and main steam pressure.
Step 101: and determining the combustion release energy of the boiler based on the turbine regulation stage pressure, the drum pressure and the boiler heat storage coefficient.
Step 102: the boiler firing rate bias is determined based on the turbine energy demand and the boiler firing release energy.
Step 103: a fuel quantity adjustment signal is generated based on the boiler firing rate deviation.
Step 104: and generating a feedforward control signal based on the power generation load set value and the heating steam extraction flow set value.
Step 105: the PID controller is used for realizing the control of the fuel quantity based on the fuel quantity adjusting signal and the feedforward control signal.
Step 106: and determining a turbine regulating valve opening regulating signal based on the heat supply extraction flow set value, the heat supply extraction flow and the set time value.
Step 107: a load deviation signal is determined based on the power generation load set point and the power generation load.
Step 108: and the PID controller is adopted to realize the control of the opening of the turbine regulating valve based on the opening regulating signal of the turbine regulating valve and the load deviation signal.
Step 109: and determining the difference value between the set value of the heat supply steam extraction pressure and the heat supply steam extraction pressure.
Step 110: and when the difference value is smaller than zero, the opening of the heating and steam extraction regulating butterfly valve is regulated by adopting a PID controller, and whether the load deviation signal is increased is determined.
Step 111: when the load deviation signal rises, a PID controller is adopted to adjust the opening of a heating and steam extracting adjusting butterfly valve so as to increase the power generation load.
In this regard, the steps 100 to 105 are to control the fuel amount. In the actual application process, the original traditional control strategy is as follows: according to pressure deviation (i.e. p t -p 0 ) The fuel quantity u is regulated by a PID controller B For example, when the main steam pressure p t When descending, the controller enables the fuel quantity u to be B Increasing the main steam pressure p t The rise reaches equilibrium. The control strategy provided by the invention adopts a direct energy balance control system to control the loop, and is specific in that: on the one hand, the turbine is firstly made to regulate the stage pressure p 1 With main steam pressure p t Dividing to obtain a ratio signal which represents the opening degree u of the regulating valve of the steam turbine T . Then, the pressure is matched with the set value p of the main steam pressure 0 Multiplying to obtain an output signal asThis output signal is representative of the energy demand of the turbine, and is used as a master energy demand signal for the boiler to replace the master steam pressure setpoint p in the conventional control strategy 0 . On the other hand, to drum pressure p b Differential processing is carried out, the obtained signal shows the change rate of the drum pressure, and then the obtained signal is matched with the heat storage coefficient C of the boiler b Multiplying the signals to obtain a signal +.>The signal thus obtained is indicative of the heat stored in the boiler steam and is then coupled to the turbine regulating stage pressure p 1 Adding to obtain an output signal of +.>The obtained output signal represents the heat released by the combustion of the boiler and is used as a feedback signal of a unit to replace the main steam pressure p in the traditional control strategy t . Taking energy balance of a unit as outputHair nodulation by->And->Obtaining a fuel quantity adjusting signal by deviation, and adjusting the fuel quantity u based on the fuel quantity adjusting signal by a PID controller B 。
At the same time, in order to prevent the large reverse change of the throttle valve pressure, the set value q of the heating steam extraction flow is set mH0 Multiplying the set time value to obtain a thermal load value (load converted by heat supply air extraction flow), and then making it be matched with power generation load set value N e0 The obtained output signals are superimposed and used for controlling the fuel quantity u by a PD type controller B Is subjected to feedforward control. In detail, the flow rate q of heat supply and air extraction mH To the power generation load N e The conversion (i.e., equivalent correspondence of thermoelectric) is represented by a first order inertial transfer function model. The set time value adopts the formulaAnd (5) determining. Wherein G is a set time value, k is an open-loop amplification factor, and T is an inertial time constant. Wherein k reflects the static correspondence between input and output, and T reflects the rapidity of the response. The integral equation for determining the set time value reflects the relation between the heat supply steam extraction flow and the unit output. Because the influence of heat source flow disturbance on the loads of different units is caused, the inertia time constant T is in the range of 10-20 seconds, the invention takes the values of T=11s and k according to the formula ∈>The calculation can be as follows: k= -0.162.ΔNe is the power generation load variation value, Δq mH And s is the Laplacian operator for the change value of the heat supply and air extraction flow.
Based on the control strategy provided by the invention, the change of load and heat supply requirements can be better adapted, and more stable main steam pressure is provided. The heat storage energy of the boiler is utilized, so that the fuel quantity can be adjusted in advance, the response speed is effectively increased, and the coordination control of the unit is realized. Moreover, because the energy required by the steam turbine and the actual combustion heat of the boiler are balanced, the heat supply loss caused by the rapid load-changing loop can be compensated.
Further, the steps 105 to 108 are to control the opening of the turbine adjusting valve. In the actual application process, the original traditional control strategy is as follows: according to the actual load deviation (i.e. N e0 -N e ) The opening degree u of the regulating valve of the steam turbine is regulated by a PID controller T So that the actual load successfully tracks the load command. For example, when the demand of electricity consumption of a user increases, the controller controls the opening degree u of the steam turbine regulating valve T And the load is increased, so that the load is increased, and the user requirement is met. The control strategy provided by the invention is based on the original traditional control strategy, on one hand, the set value q of the flow of the heating extraction steam is given mH0 And the heat supply and air extraction flow q mH Taking the difference to obtain a difference signal, and multiplying the obtained difference signal byThe obtained signal is used for controlling the opening degree u of the regulating valve of the steam turbine through a PID controller T . On the other hand, let the power generation load give the value N e0 Subtracting the power generation load N e Obtaining a load deviation signal, and controlling the opening degree u of a turbine regulating valve based on the load deviation signal through a PID controller T . The design can ensure that the load-changing instruction received by the boiler controller is not influenced by the regulation of heat supply and steam extraction, and the load change of the unit at the end stage of load change is completely provided by fuel quantity, thereby not only ensuring the conservation of energy in the dynamic regulation process, but also recovering the heat supply and steam extraction flow to the original heat supply working condition requirement and avoiding great influence on the heat supply effect.
Further, the steps 109 to 111 are to control the opening of the heating and steam extraction adjusting butterfly valve. In the actual application process, the original traditional control strategy is as follows: according to the heat supply and air extraction flow q mH Is changed byThe opening u of the hot extraction regulating butterfly valve is regulated by a PID controller H To meet the heating demand. Compared with the traditional control strategy, the control strategy provided by the invention enables the given value p of the heating steam extraction pressure on one hand H0 And the heat supply and steam extraction pressure p H Subtracting to obtain a difference model, and controlling the opening degree u of a heating and steam extracting regulating butterfly valve based on the obtained difference signal through a PID controller H . Specific: when heating and extracting pressure p H When the temperature is reduced, the opening u of the heating and steam extraction regulating butterfly valve is reduced through the PID controller H So that the heat supply and air extraction flow rate q mH Rise to supply heat and draw pressure p H Rise to equilibrium. On the other hand, for generating the load N e Can respond quickly, introduce a load deviation signal (i.e. N e0 -N e ) The opening u of the butterfly valve is regulated by controlling the heat supply and steam extraction through a PID controller H . Specific: when the load instruction is raised, the opening u of the butterfly valve is regulated by increasing the heat supply and steam extraction H To make the heat supply and air extraction flow rate q mH The working fluid flows into the low-pressure cylinder to do work, thereby increasing the power generation load N e To meet the power supply requirements of users. Wherein, the sacrificial heating energy is compensated by direct energy balance coordination control. The design enables the electric load to respond more quickly, the heat load can be recovered automatically during control, the whole regulating process is more stable, and the problems of slower load response speed, large fluctuation amplitude during load rising and overlong steady-state time of the traditional control strategy are solved.
The following establishes a model of the cogeneration unit based on direct energy balance coordination control as shown in fig. 2, and uses the established model to explain the effect of the control method of the cogeneration unit based on energy balance.
Specifically, by adjusting PID parameters of a steam drum furnace cogeneration unit model, the power generation load N in a steady state is observed e And the heat supply and air extraction flow q mH As shown in fig. 3 and 4, it can be obtained that both the load and the heat supply have a fast response speed and meet the requirement of system stability.
After the unit is in a balanced state, when t=250s, a +10MW step instruction is applied to the power generation load, the tracking condition of the power generation load and the heat supply steam extraction flow is observed, and the control effect of the control strategy provided by the invention and the control effect of the traditional coordination control strategy are obtained by comparison, as shown in fig. 5 and 6.
Based on the simulation result, the response speed of the control strategy provided by the invention is obviously superior to that of the traditional coordination control, the control process is shorter and more stable, the heat storage of the boiler is effectively utilized, the coordination control of a unit is realized, the fuel quantity is controlled through the change of the heat supply and steam extraction pressure, the heat supply and steam extraction flow can be compensated in time, and the heat supply is supplemented and balanced under the control of the heat supply and steam extraction pressure originally because of the quick load change and sacrifice.
Compared with the traditional coordination control strategy, the control strategy of the cogeneration unit based on direct energy balance coordination control has the following advantages:
(1) Compared with the traditional coordination control strategy, the novel control strategy provided by the invention has the advantages of quick response, small dynamic deviation and stronger stability.
(2) When the load change requirement exists, the invention rapidly reflects the load requirement of the steam turbine to the boiler through the transmission of the two signals. When no load change is required, the internal disturbance of each controller is eliminated by itself to reach autonomy, so that the whole system can reach balance quickly.
(3) Compared with the traditional coordination control strategy, the novel control strategy provided by the invention realizes decoupling of load, heat supply and main steam pressure, does not directly control the pressure, and controls the main steam pressure by adjusting the balance of the boiler heat signal and the energy demand of the steam turbine, so that the control of pressure correction is more stable and reliable.
(4) The invention applies the direct energy balance coordination control on the cogeneration unit, so that the energy supply and demand relationship between the unit and the furnace is balanced rapidly, and the integrated coordination control of the unit and the furnace is realized simply and effectively. Under the direct energy balance coordination control mode, the load and the heat supply reach balance quickly through the quick response of the controller. This control process is short, and the main steam pressure will naturally and slowly recover to the set point. The heat accumulation of the boiler is fully utilized in the process, and the heat accumulation process of the boiler is like a strong high-frequency filter, so that the change of the pressure of the main steam is gentle. When there is any disturbance on the fuel system side, the unequal main steam pressure changes, the controller reacts quickly, and automatically and timely eliminates them.
(5) The novel control strategy provided by the invention not only can improve the energy utilization rate, but also can ensure the economy of unit operation and improve the quality level of unit operation.
Based on the description, the novel control strategy based on direct energy balance coordination control can fully utilize heat accumulation of a boiler, the controller can quickly respond, the whole system can quickly restore balance, and the control quality of the system is effectively improved. The method has very important significance for rapid frequency modulation of the power grid and safe and stable operation of the power system under the condition of adapting to large-scale new energy access.
Further, the invention provides a cogeneration unit control system based on energy balance, and the system is used for implementing the cogeneration unit control method based on energy balance. The system comprises:
the turbine energy demand determination module is configured to determine a turbine energy demand based on a turbine regulation stage pressure, a main steam given pressure, and a main steam pressure.
The boiler combustion release energy determining module is used for determining the boiler combustion release energy based on the turbine regulating stage pressure, the steam drum pressure and the boiler heat storage coefficient.
The boiler combustion rate deviation determining module is used for determining the boiler combustion rate deviation based on the energy demand of the turbine and the energy released by the boiler combustion.
The fuel quantity adjusting signal generating module is used for generating a fuel quantity adjusting signal based on the boiler combustion rate deviation.
And the feedforward control signal generating module is used for generating a feedforward control signal based on the power generation load given value and the heating steam extraction flow given value.
And the fuel quantity control module is used for realizing control of the fuel quantity by adopting a PID controller based on the fuel quantity adjusting signal and the feedforward control signal.
The opening adjusting signal determining module is used for determining an opening adjusting signal of the adjusting valve of the steam turbine based on the set value of the heat supply and extraction flow, the heat supply and extraction flow and the set time value.
The load deviation signal determining module is used for determining a load deviation signal based on the power generation load given value and the power generation load.
And the valve opening control module is used for controlling the opening of the steam turbine regulating valve by adopting a PID controller based on the steam turbine regulating valve opening regulating signal and the load deviation signal.
And the valve opening adjusting module is used for determining the difference value between the set value of the heating steam extraction pressure and the heating steam extraction pressure. And when the difference value is smaller than zero, the opening of the heating and steam extraction regulating butterfly valve is regulated by adopting a PID controller, and whether the load deviation signal is increased is determined. When the load deviation signal rises, a PID controller is adopted to adjust the opening of a heating and steam extracting adjusting butterfly valve so as to increase the power generation load.
Still further, the present invention also provides an electronic device including:
and a memory for storing a computer program.
And the processor is connected with the memory and is used for retrieving and executing the computer program to implement the control method of the cogeneration unit based on energy balance.
Furthermore, the computer program in the above-described memory may be stored in a computer-readable storage medium when it is implemented in the form of a software functional unit and sold or used as a separate product. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.
The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.
Claims (8)
1. The control method of the cogeneration unit based on energy balance is characterized by comprising the following steps of:
determining a turbine energy demand based on turbine regulation stage pressure, main steam given pressure, and main steam pressure;
determining the combustion release energy of the boiler based on the turbine regulation stage pressure, the drum pressure and the boiler heat storage coefficient;
determining a boiler firing rate bias based on the turbine energy demand and the boiler firing release energy;
generating a fuel quantity adjustment signal based on the boiler firing rate deviation;
generating a feedforward control signal based on the power generation load set point and the heating steam extraction flow set point;
a PID controller is adopted to control the fuel quantity based on the fuel quantity adjusting signal and the feedforward control signal;
determining a turbine regulating valve opening regulating signal based on the heat supply air extraction flow set value, the heat supply air extraction flow and the set time value;
determining a load deviation signal based on the power generation load set point and the power generation load;
the PID controller is adopted to realize the control of the opening of the turbine regulating valve based on the opening regulating signal of the turbine regulating valve and the load deviation signal;
determining a difference value between a given value of the heating steam extraction pressure and the heating steam extraction pressure;
when the difference value is smaller than zero, a PID controller is adopted to adjust the opening of a heating and steam extracting adjusting butterfly valve, and whether a load deviation signal rises is determined;
and when the load deviation signal rises, the opening of the heating and steam extracting adjusting butterfly valve is adjusted by adopting a PID controller so as to increase the power generation load.
2. The energy balance-based cogeneration unit control method of claim 1, wherein determining turbine energy demand based on turbine regulation stage pressure, main steam given pressure, and main steam pressure, specifically comprises:
determining a ratio of the turbine tuning stage pressure to the main steam given pressure;
and determining the product of the ratio and the set value of the main steam pressure, and taking the product as the energy requirement of the steam turbine.
3. The energy balance-based cogeneration unit control method of claim 1, wherein determining the boiler combustion release energy based on turbine regulation stage pressure, drum pressure, and boiler heat storage coefficient, specifically comprises:
performing differential treatment on the drum pressure to obtain differential values; the differential value is used for representing the change rate of the drum pressure;
determining a product of the differential value and the boiler heat storage coefficient;
and determining the sum of the product and the turbine regulating stage pressure, and taking the sum of the product and the turbine regulating stage pressure as the boiler combustion release energy.
4. The energy balance-based cogeneration unit control method of claim 1, wherein generating the feedforward control signal based on the power generation load setpoint and the heating extraction flow setpoint comprises:
determining a thermal load value based on the heating extraction flow set point and the set time value;
determining a sum of the thermal load value and the power generation load set point;
the feedforward control signal is generated based on a sum of the thermal load value and the power generation load setpoint.
5. The energy balance-based cogeneration unit control method of claim 4, wherein the set time value uses a formulaDetermining;
wherein G is a set time value, k is an open-loop amplification factor, and T is an inertial time constant.
6. A cogeneration unit control system based on energy balance, wherein the system is configured to implement the cogeneration unit control method based on energy balance of any one of claims 1-5; the system comprises:
the turbine energy demand determination module is used for determining the turbine energy demand based on the turbine regulation stage pressure, the main steam given pressure and the main steam pressure;
the boiler combustion release energy determining module is used for determining the boiler combustion release energy based on the turbine regulating stage pressure, the steam drum pressure and the boiler heat storage coefficient;
a boiler combustion rate deviation determination module for determining a boiler combustion rate deviation based on the turbine energy demand and the boiler combustion release energy;
a fuel quantity adjustment signal generation module for generating a fuel quantity adjustment signal based on the boiler combustion rate deviation;
the feedforward control signal generation module is used for generating a feedforward control signal based on the power generation load given value and the heating steam extraction flow given value;
the fuel quantity control module is used for realizing control of the fuel quantity by adopting a PID controller based on the fuel quantity adjusting signal and the feedforward control signal;
the opening adjusting signal determining module is used for determining an opening adjusting signal of the adjusting valve of the steam turbine based on the set value of the heat supply and extraction flow, the heat supply and extraction flow and the set time value;
a load deviation signal determination module for determining a load deviation signal based on the power generation load given value and the power generation load;
the valve opening control module is used for controlling the opening of the turbine regulating valve by adopting a PID controller based on the turbine regulating valve opening regulating signal and the load deviation signal;
the valve opening adjusting module is used for determining the difference value between the set value of the heating steam extraction pressure and the heating steam extraction pressure; when the difference value is smaller than zero, a PID controller is adopted to adjust the opening of a heating and steam extracting adjusting butterfly valve, and whether a load deviation signal rises is determined; and when the load deviation signal rises, the opening of the heating and steam extracting adjusting butterfly valve is adjusted by adopting a PID controller so as to increase the power generation load.
7. An electronic device, comprising:
a memory for storing a computer program;
a processor, connected to the memory, for retrieving and executing the computer program to implement the energy balance-based cogeneration unit control method according to any one of claims 1-5.
8. The electronic device of claim 7, wherein the memory is a computer-readable storage medium.
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| CN202311811382.1A CN117784588A (en) | 2023-12-27 | 2023-12-27 | Control method and system of cogeneration unit based on energy balance and electronic equipment |
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| CN202311811382.1A CN117784588A (en) | 2023-12-27 | 2023-12-27 | Control method and system of cogeneration unit based on energy balance and electronic equipment |
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