CN113280508B - Determining system and method for optimal air temperature entering the furnace for thermal power units equipped with air heaters - Google Patents

Abstract

The invention discloses a system and method for determining the optimum air temperature of a thermal power unit equipped with an air heater. The field operation data is used to optimize the power supply load of the thermal power unit under the conditions of a given boiler inlet coal amount and ambient temperature. The objective function is to use the single-variable comparison method to adjust the air temperature of the unit entering the furnace by means of the steam or hot water flow on the hot side of the heater, and compare the power supply load of the thermal power unit with the reference working condition. If it is smaller than the original reference working condition. As the reference working condition; if it is greater than that, the corresponding operating condition of the inlet air temperature will be used as the new comparison reference condition, and the unit will adjust the inlet air temperature and carry out the next iterative optimization. The invention takes the maximum power supply load of the thermal power unit under the conditions of fixed boiler inlet coal amount and ambient temperature as the optimization objective function, and obtains the optimal control of the boiler inlet air temperature of the thermal power unit on-line under the boundary conditions of different boiler inlet coal amount and ambient temperature. value to achieve the highest power supply load and maximize profitability.

Description

Determining system and method for optimal air temperature entering the furnace for thermal power units equipped with air heaters

technical field

The invention belongs to the technical field of energy saving and consumption reduction, and relates to a system and a method for determining the optimal air temperature of a thermal power unit equipped with an air heater.

Background technique

Coal-fired boilers in power plants are usually equipped with air heaters to avoid the harm of low-temperature corrosion on the rear heating surface. The heater is arranged in the air duct from the outlet of the primary fan (including the blower) to the inlet of the air preheater. According to the form of heat source, air heaters can be divided into steam heaters and hot water heaters. Among them, steam heaters are the standard configuration for the design and construction of coal-fired power stations. The steam source is taken from the auxiliary steam header; A flue gas-water heat exchanger is installed in the flue from the outlet of the boiler air preheater to the inlet of the dust collector, and a flue gas-water heat exchanger is installed at the outlet of the primary fan (including the blower) to the outlet of the air preheater. An air-water heat exchanger is set in the air duct at the inlet of the heater, with water as the heat carrier, and the waste heat of the flue gas at the outlet of the boiler air preheater is used to heat the cold air entering the furnace, and the excess part enters the inlet of the No. Partial extraction of steam from the cylinder, this system is called the low temperature economizer and air heater combined system, this system can effectively use the waste heat of exhaust smoke, partially replace the steam heater, reduce the coal consumption of the unit power generation, improve the efficiency of the dust collector, and improve the air quality. The inlet air temperature and outlet smoke temperature of the preheater can greatly alleviate the ash blocking of the air preheater, and can also reduce the power consumption of the induced draft fan and the water consumption of the desulfurization system.

In the actual operation of the boiler, due to various reasons such as ash, slagging or ash blocking in the heated area, changes in the type of coal used (such as increased moisture and ash content), and operation level, the exhaust gas temperature is generally higher than the design value. Based on the principle of cascade utilization of energy, the exhaust gas temperature should be reduced as much as possible in the furnace. For units that cannot reduce the exhaust gas temperature in the furnace, the flue gas waste heat recovery technology is generally used to reduce the exhaust gas temperature. The outlet of the boiler air preheater is used for dust removal. A flue gas-water heat exchanger is installed in the flue at the inlet of the air heater, and low-temperature condensed water is introduced to absorb the waste heat of the flue gas at the outlet of the air preheater.

In short, the air heater and the low temperature economizer are combined to form the waste heat recovery system of the thermal power unit.

Referring to Fig. 1, Fig. 1 is a technical representation of the combined system of the steam heater and the low temperature economizer. The steam from the superheater outlet of boiler 1 enters the high pressure cylinder 2 to do work, the exhaust steam enters the reheater of boiler 1 for secondary warming, and then enters the medium pressure cylinder 2 to do work. The condenser 5 condenses; the other way enters the steam heater 13. The high and medium pressure cylinder 2 and the low pressure cylinder 3 are coaxially connected to jointly drive the generator 4 to generate electricity. The condensed water at the outlet of condenser 5 passes through No. 8 low-pressure heater 6, No. 7 low-pressure heater 7, No. 6 low-pressure heater 8, No. 5 low-pressure heater 9, feed water pump 10 and high-pressure heater group 11. , into the boiler to complete the thermal cycle.

The hot flue gas at the exit of the economizer of boiler 1 enters the air preheater 12 and heats the hot air at the exit of the steam heater 13, and then flows through the low temperature economizer 14, the dust collector 15, the induced draft fan 16, the desulfurization tower 17 and the chimney 18 in turn. After desulfurization, denitrification, dust removal and cooling, it is discharged into the atmosphere.

Take water from No. 8 low-pressure heater 6 and No. 7 low-pressure heater 7 respectively, and after mixing, pressurized by the circulating booster pump 19, enter the low-temperature economizer 14 to absorb heat and heat up, and then enter the outlet water pipeline of No. 6 low-pressure heater 8 .

Referring to Fig. 2, Fig. 2 is a process schematic diagram of a combined system of a hot water heater and a low temperature economizer.

The hot flue gas at the outlet of the boiler economizer enters the air preheater 12 to heat the hot air at the outlet of the hot water heater 20, and then flows through the low temperature economizer 14, the dust collector 15, the induced draft fan 16, the desulfurization tower 17 and the chimney 18 in sequence. After desulfurization, denitrification, dust removal and cooling, it is discharged into the atmosphere.

Water is drawn from the No. 8 low-pressure heater 6 and the No. 7 low-pressure heater 7 respectively. After mixing, it is pressurized by the circulating booster pump 19 and then enters the low-temperature economizer 14 to absorb heat and heat up. The high-temperature condensed water at the outlet of the low-temperature economizer 14 is divided into two parts. Road, one way into the hot water heater 20 heating fan outlet cold air, the other way into the 6th low pressure heater 8 outlet jellyfish pipe.

The steam heater 13 is arranged in the air duct between the outlet of the hot water heater 20 and the inlet of the air preheater, as an emergency backup when the hot water heater fails. The heat source of the steam heater 13 is taken from the exhaust steam in the thermal power unit, and the drain is returned to the condenser.

The waste heat recovery system of the power station composed of the air heater and the low-temperature economizer should not only retain the original safety protection function of the air heater (that is, to avoid the harm of low-temperature corrosion on the rear heating surface), but also have the effect of energy saving and efficiency improvement.

However, the waste heat recovery system of the power station composed of the air heater and the low-temperature economizer does not operate in isolation. The adjustment of its parameters affects the thermal efficiency of the power station boiler, the distribution of the heat recovery and extraction of the steam turbine, and the change of the power consumption of the power plant, which affects a wide range and mechanism. complex. The analysis shows that the core adjustment parameter of the waste heat recovery system of the power station is the air temperature from the outlet of the heater to the air preheater. Based on the minimum air temperature that ensures no low-temperature corrosion on the heating surface of the boiler tail, raising the air temperature at the outlet of the air preheater has the following beneficial effects: 1) The higher the temperature of the air entering the boiler, it is beneficial to improve the combustion of the boiler and improve the thermal efficiency of the boiler; 2) Raise the exhaust gas at the outlet of the air preheater and increase the waste heat recovery of the low-temperature economizer. The adverse effects are: 1) Increase the consumption of heat source steam and reduce the working capacity of the steam turbine; 2) Raise the outlet exhaust gas of the air preheater smoke, reducing boiler thermal efficiency. Therefore, there is an optimal air temperature entering the furnace, taking into account the overall energy efficiency of the boiler and steam turbine, so that the overall economy of the unit is the best.

There are many related studies on the waste heat recovery system of the power station composed of the air heater and the low-temperature economizer, respectively involving the technical scheme and design of the thermal system, the anti-freezing of the air heater, the performance test and the correction method. However, there are few public reports on the research on the optimal air temperature at the outlet of the air preheater.

The paper "Parameter Optimization of Combined System of Low-Temperature Economizer and Air Heater [J]. Thermal Power Generation 2018, 47(03), Zhang Zhixiang, et al." The influence of coal saving amount, static investment and static investment payback period of the system, the change rule of the static investment payback period of the combined system is obtained, which first decreases and then increases with the increase of the outlet air temperature of the heater.

The document "Operation optimization of low and low temperature economizer combined with air heater system [J]. Thermal Power 2018, 47 (06), Lv Kai, et al.", using the technical method of on-site thermal performance test to use hot water heater and A 300MW unit of the low-temperature economizer combined system is the research object, and the optimal air temperature is obtained by measuring the thermal efficiency of the boiler, the heat consumption rate of the steam turbine and the change of the power consumption by using the minimum value of coal consumption for power supply as the optimization objective function.

The paper "Simulation of variable-parameter thermodynamic characteristics of combined system of air heater and low-temperature economizer [J]. Thermal Power Generation 2018, 47(07), Xie Tian, et al.", taking a subcritical 330MW unit as an example, the Ebsilon software was used to establish A complete model including boilers, steam turbines and generators, on the basis of this model, the thermodynamic characteristics of the conventional low-temperature economizer and the combined system of the heater and the low-temperature economizer are simulated, and the outlet air flow of the different designs of the heater is emphatically analyzed. The characteristic changes of the combined system and its influence on the heat consumption rate of steam turbine, boiler efficiency, power generation coal consumption, auxiliary power consumption and power supply coal consumption at temperature. The variation law of the coal consumption drop value for power supply with the wind temperature at the outlet of the heater is obtained: the reduction rate of coal consumption for power supply increases with the increase of wind temperature, but when the wind temperature rises to a certain level, the energy saving does not increase any more.

Based on the above analysis, the existing research has two types of field thermal test or numerical simulation. The field thermal test takes the minimum coal consumption for power supply as the objective function to test the thermal efficiency of the boiler, the heat consumption rate of the steam turbine and the power consumption rate under different wind temperature conditions. To find the best air temperature value, this method has high accuracy and follows the existing industry standards for boiler and steam turbine performance tests, which require test conditions, system isolation, measuring point installation, working condition adjustment, data sorting and subsequent correction calculations. Higher, more manpower and material resources are invested, and the operability and promotion degree are relatively weak; the theoretical calculation is based on the unit design and operation data, and the overall model of the power station including the boiler, steam turbine, thermal system, and generator is established. The air temperature at the outlet of the device is calculated, and the calculation of variable working conditions is carried out, and the lowest coal consumption for power supply is used as the optimization target to obtain the optimal air temperature value. Under load conditions, the values of boiler, steam turbine and thermal system boundary such as extraction steam pressure loss, heater end difference, pump efficiency, etc. in the theoretical modeling calculation are based on the design data of the equipment manufacturer, and there is a certain deviation from the actual operation. The calculated result deviates from the actual true value. Furthermore, the above method requires practitioners to have a certain level of data processing, calculation and correction, and theoretical modeling and calculation. Except for university scholars and professional and technical personnel of the Electric Power Academy, ordinary technical workers in the power industry do not have this requirement, which is limited to a certain extent. The promotion and application of the optimization method.

To sum up, there is an urgent need for an online determination method for the optimal inlet air temperature of thermal power units with strong operability, high accuracy, and in line with the actual operating conditions of specific units.

SUMMARY OF THE INVENTION

The purpose of the present invention is that the existing optimal method for optimizing the temperature of the incoming air temperature for thermal power units has the problems of large workload, partial working conditions deviating from actual results, and high operational requirements, and provides a kind of optimal air entering the furnace for thermal power units configured with air heaters. Temperature determination system and method, the present invention adopts the on-site DCS operation data of the thermal power unit, takes the maximum power supply load of the unit under the condition of fixed boiler coal input as the optimization objective function, adopts the single-variable comparison method, and adjusts the operating parameters to obtain the configuration temperature. The optimal control value of the air temperature entering the furnace for the thermal power unit of the fan under the boundary conditions of different ambient temperature and power supply load.

To achieve the above object, the present invention adopts the following technical solutions to realize:

A method for determining the optimal air temperature of a thermal power unit equipped with an air heater, comprising the following steps:

Step 1, establish the characterization parameter of the best inlet air temperature of the thermal power unit configured with the air heater;

Step 2, according to the boundary parameters boiler inlet coal quantity B and ambient air temperature _ta , delineate the test conditions;

Step 3: Guided by the highest value of the power supply load _Nnet of the thermal power unit, determine the optimum inlet air temperature for each test condition.

A system for determining the optimal air temperature of a thermal power unit equipped with an air heater, comprising the following steps:

a characterization parameter establishment module, the parameter establishment module is used to establish the characterization parameter of the optimal inlet air temperature of the thermal power unit configured with the air heater;

_a test condition delimitation module, which is used to delineate the test condition according to the boundary parameters of the boiler inlet coal amount B and the ambient temperature ta;

An air temperature determination module, which is used for determining the optimal air temperature entering the furnace for each test condition, guided by the highest value of the power supply load _Nnet of the thermal power unit.

A determination device for the best inlet air temperature of a thermal power unit configuring an air heater, comprising a memory, a processor and a computer program stored in the memory and running on the processor, and the processor executes the The steps of the above method are implemented when the computer program is described.

A computer-readable storage medium storing a computer program, when the computer program is executed by a processor, implements the steps of the above method.

Compared with the prior art, the present invention has the following beneficial effects:

The invention adopts on-site operation data, takes the maximum power supply load of thermal power unit under the conditions of fixed boiler inlet coal and ambient temperature as the optimization objective function, adopts the single-variable comparison method, and adjusts the flow of steam or hot water on the hot side of the heater. Comparing the power supply load of the thermal power unit with the reference working condition for the temperature of the unit entering the furnace Under the working conditions, the unit adjusts the air temperature entering the furnace and performs the next iterative optimization. The invention takes the maximum power supply load of the thermal power unit under the conditions of constant boiler inlet coal amount and ambient temperature as the optimization objective function, and online obtains the optimal control of the boiler inlet air temperature of the thermal power unit under the boundary conditions of different boiler inlet coal amount and ambient temperature. value to achieve the highest power supply load and maximize profitability.

Description of drawings

In order to describe the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore do not It should be regarded as a limitation of the scope, and for those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

Figure 1 is a schematic diagram of a combined system of a steam heater and a low temperature economizer.

Figure 2 is a schematic diagram of the combined system of the hot water heater and the low temperature economizer.

Fig. 3 is the flow chart of determining the optimum air temperature entering the furnace of the thermal power unit equipped with the air heater according to the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inside", etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings , or the orientation or positional relationship that the product of the invention is usually placed in use, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed in a specific orientation and operation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are only used to differentiate the description and should not be construed to indicate or imply relative importance.

Furthermore, the presence of the term "horizontal" does not imply that the component is required to be absolutely horizontal, but rather may be tilted slightly. For example, "horizontal" only means that its direction is more horizontal than "vertical", it does not mean that the structure must be completely horizontal, but can be slightly inclined.

In the description of the embodiments of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. It can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Below in conjunction with accompanying drawing, the present invention is described in further detail:

Referring to Fig. 3, an embodiment of the present invention discloses a method for determining the optimal air temperature of a thermal power unit configured with an air heater, comprising the following steps:

Step 1, establish the characterization parameters of the optimal inlet air temperature of the thermal power unit equipped with the air heater

Considering the boiler, steam turbine, generator, related auxiliary machines and thermal system of the thermal power unit as a whole, the coal is input to the boiler side, and the output is the power supply load of the main transformer outlet.

The coal consumption for power supply is defined as the standard coal consumption of the unit under the unit power supply, g/kWh, which comprehensively reflects the thermal efficiency of the boiler, the heat consumption rate of the steam turbine, and the ratio of the total power consumption of the auxiliary machines to the output power of the generator. The thermal efficiency, the heat consumption rate of the steam turbine and the power consumption rate of the plant are respectively measured by the electrothermal test, and then calculated.

In the present invention, the calculation formula of coal consumption for power supply is slightly transformed, and the power supply load N _net under the given condition of the coal amount B entering the boiler is used as the characteristic parameter of the optimal inlet air temperature of the thermal power unit equipped with the air heater.

The definition of power supply load of thermal power unit _Nnet is the output power of generator outlet minus the total power consumption of auxiliary equipment (coal mill, fan, pump, etc.) and maintenance lighting system, etc. In the DCS system of thermal power unit, the main transformer outlet can be directly read.

The coal amount B at the boiler inlet is given, and by changing the heating steam flow of the heater, changing the outlet air temperature, and reading the power supply load _Nnet under different working conditions, the outlet air temperature of the heater corresponding to the highest value of the power supply load _Nnet is taken as The optimal air temperature control value under the coal amount.

Step 2, according to the boundary parameters boiler inlet coal quantity B and ambient air temperature _ta , delineate the test conditions.

Statistics on the operation data of thermal power units in the past year, mainly including:

Boiler inlet coal quantity B: B _min , B _max

Ambient air temperature _ta : ta _{, min} , ta _{, max}

According to the distribution of the coal amount B at the boiler inlet and the ambient temperature _ta , the test conditions are divided according to the following principles:

①B _min , B _min +(B _max -B _min )×0.2

B _min +(B _max -B _min )×0.4

B _min +(B _max -B _min )×0.6

B _min +(B _max -B _min )×0.8

B _max

②t _{a, min}

t _{a, min} + (t _{a, max} -t _{a, min} )×0.2

t _{a, min} + (t _{a, max} -t _{a, min} )×0.4

t _{a, min} + (t _{a, max} -t _{a, min} )×0.6

t _{a, min} + (t _{a, max} -t _{a, min} )×0.8

ta _{, max}

To sum up, according to the method for delineating the optimal working conditions of the present invention, the optimum furnace inlet air temperature is determined on-line for a total of 5×5=25 working conditions.

Step 3: Guided by the highest value of the power supply load _Nnet of the thermal power unit, determine the optimum inlet air temperature for each test condition.

① During the optimization test, the coal quality at the boiler inlet remains unchanged.

②The coal quantity B at the inlet of the thermal power unit boiler and the ambient air temperature _ta are given, and after the heater combined with the low temperature economizer system is put into operation, the average wall temperature of the cold end of the unit air preheater is equal to the design value as the reference condition, and the adjustment The operating parameters of the unit were stabilized for 30 minutes, and the inlet air temperature t ₀ of the air preheater and the power supply load N _net0 were recorded.

③ Based on the air heater outlet air temperature t ₀ in the benchmark operating condition, by adjusting the steam or hot water flow rate on the inlet side of the heater heat source, the outlet air temperature of the air heater is raised in increments of 2°C each time to control the boiler inlet The coal amount B remains unchanged, and the operating parameters of the unit are adjusted. After 30 minutes of stability, the power supply load N _net1 is recorded.

Compare N _net1 with N _net0 , if N _net1 ≤ N _net0 , the original reference condition is still used as the reference condition; if N _net1 <N _net0 , the operating condition corresponding to the outlet air temperature of the heater is used as the new comparison reference condition. Continue to raise the outlet air temperature of the heater by 2°C each time, and perform the next optimization iteration.

④ The operation of raising the outlet air temperature of the heater, until the outlet air temperature t _max corresponding to the maximum value of the steam or hot water flow on the hot side of the heater, and the optimization operation ends. In this process, the maximum value _Nnet of the power supply load of the thermal power unit corresponds to the optimal operating condition, and the air temperature at the outlet of the heater is the optimal control value.

_⑥Finish the determination of the best air temperature for the remaining 14 working conditions, and obtain the best air temperature for the thermal power unit under different coal amounts B and ambient air temperature ta.

Step 4, the optimization results are applied to the guidance of production energy-saving potential tapping.

Take the best inlet air temperature value of the above 25 working conditions, take the boiler inlet coal amount B and the ambient air temperature _{ta as variables, and when the ambient air temperature t a is} given, draw the optimal inlet air temperature with the boiler inlet coal amount B. ; When the coal amount B at the boiler inlet is given, draw the change curve of the best inlet air temperature with the ambient air temperature _ta .

During the production and operation, according to parameters such as the coal quantity B at the boiler inlet and the ambient temperature _ta , and according to the linear interpolation or extrapolation method, the technicians can obtain the optimal coal quantity B at the inlet of the boiler and the ambient temperature _ta for the thermal power unit. Into the furnace air temperature value, in order to achieve the highest power supply load and maximize profitability.

If the coal quality at the boiler inlet changes, the above operations need to be performed again to determine the optimal inlet air temperature value of the thermal power unit under different boiler inlet coal amounts B and different ambient air temperatures _ta .

A schematic diagram of a device for determining the optimum inlet air temperature of a thermal power unit equipped with an air heater provided by an embodiment of the present invention. The apparatus for determining the optimum air temperature of a thermal power unit equipped with an air heater in this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in each of the foregoing method embodiments are implemented, for example, the steps shown in FIG. 3 . Alternatively, when the processor executes the computer program, the functions of the modules/units in the foregoing device embodiments are implemented.

The computer program may be divided into one or more modules/units, which are stored in the memory and executed by the processor to accomplish the present invention.

The device for determining the optimum air temperature of the thermal power unit equipped with the air heater may be a computing device such as a desktop computer, a notebook, a palmtop computer and a cloud server. The device for determining the optimal air temperature of the thermal power unit equipped with the air heater may include, but is not limited to, a processor and a memory.

The processor may be a central processing unit (Central Processing Unit, CPU), or other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field- ProgrammableGateArray, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

The memory can be used to store the computer programs and/or modules, and the processor implements the configuration by running or executing the computer programs and/or modules stored in the memory and calling data stored in the memory Various functions of the device for determining the optimal air temperature of the thermal power unit entering the furnace.

If the integrated module/unit of the device for determining the optimal inlet air temperature of the thermal power unit configured with the air heater is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage in the medium. Based on this understanding, the present invention can implement all or part of the processes in the methods of the above embodiments, and can also be completed by instructing relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the program is executed by the processor, the steps of the foregoing method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate form, and the like. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a removable hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable media may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer-readable media Electric carrier signals and telecommunication signals are not included.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. the determination method of the best entering furnace wind temperature of the thermal power unit of configuration air heater, is characterized in that, comprises the following steps: Step 1, establish the characterization parameters of the best inlet air temperature of the thermal power unit equipped with the air heater; the details are as follows: Taking the power supply load N _net under the given condition of the coal amount B entering the boiler, as the characterization parameter of the optimal inlet air temperature of the thermal power unit equipped with the air heater; The power supply load Nnet of the _thermal power unit is the output power of the generator outlet minus the total power consumption of the auxiliary equipment of the unit and the maintenance lighting system; By changing the heating steam or hot water flow of the heater, changing the outlet air temperature, reading the power supply load _Nnet under different working conditions, and _taking the heater outlet air temperature corresponding to the highest value of the power supply load Nnet as the coal volume Optimum air temperature control value; Step 2, according to the boundary parameters boiler inlet coal amount B and ambient temperature ta , delineate the test conditions _; the details are as follows: Statistics on the operation data of thermal power units in the past year, mainly including: Boiler inlet coal quantity B : B _min , B _max Ambient air temperature ta : _{ta , min} , ta _, max According to the distribution of the coal amount B at the boiler inlet and the ambient temperature ta , the test conditions are divided according to the following principles _: ① B _min , B _min +( B _max - B _min )×0.2 B _min +( B _max - B _min )×0.4 B _min +( B _max - B _min )×0.6 B _min +( B _max - B _min )×0.8 B _max ② t _{a, min} ta _{, min} + ( ta _{, max} - ta _{, min} ) × 0.2 ta _{, min} + ( ta _{, max} - ta _{, min} ) × 0.4 ta _{, min} + ( ta _{, max} - ta _{, min} ) × 0.6 ta _{, min} + ( ta _{, max} - ta _{, min} ) × 0.8 t _{a. max} Obtain several groups of optimal air temperature entering the furnace to determine the working conditions online; Step 3: _{Guided by the highest value of the power supply load Nnet} of the thermal power unit, determine the optimum inlet air temperature for each test condition. 2. the determination method of the thermal power unit best entering furnace wind temperature of configuration air heater according to claim 1, is characterized in that, described step 3 is specifically as follows: 3-1) During the optimization test, the coal quality at the boiler inlet remains unchanged; 3-2 ₎ The coal quantity B at the inlet of the thermal power unit boiler and the ambient temperature ta are given, and the average wall temperature of the cold end of the unit air preheater is equal to the design value after the air heater combined with the low temperature economizer system is put into operation. Adjust the operating parameters of the unit, after 30 minutes of stabilization, record the inlet air temperature t ₀ of the air preheater and the power supply load N _net0 ; 3-3) Taking the air heater outlet air temperature t ₀ in the reference condition as the benchmark, by adjusting the steam or hot water flow on the inlet side of the air heater heat source, the air heater outlet air temperature is raised by 2°C each time. Control the coal amount B at the inlet of the boiler to remain unchanged, adjust the operating parameters of the unit, and record the power supply load N _net1 after stabilizing for 30 minutes; Compare N _net1 with N _net0 , if N _net1 ≤ N _net0 , the original reference working condition is still used as the reference working condition; if N _net1 > N _net0 , the operating condition corresponding to the air temperature at the outlet of the heater is regarded as the new comparative reference working condition. Continue to raise the outlet air temperature of the heater by 2°C each time, and perform the next optimization iteration; 3-4) The operation of raising the outlet air temperature of the heater until the outlet air temperature t _max corresponding to the maximum value of the steam or hot water flow on the hot side of the heater, the optimization operation ends; the thermal power unit has the highest power supply load during this process The value N _net corresponds to the optimal operating condition, and the air temperature at the outlet of the heater is the optimal control value; 3-5) Complete the determination of the best air temperature for the remaining working conditions, and obtain the best air temperature value for the thermal power unit under different coal amounts B and _ambient air temperature ta . 3. the determination method of the best entering furnace wind temperature of the thermal power unit of configuration air heater according to claim 1, is characterized in that, also comprises: Step 4, the optimization results are applied to the guidance of production energy-saving and potential tapping; Taking the best inlet air temperature value of each working condition, the boiler inlet coal amount B and the ambient air temperature ta as variables, and when the ambient air temperature t a _{is given} , plot the change of the best inlet air temperature with the boiler inlet coal amount B curve; when the coal amount B at the boiler inlet is given, _draw the change curve of the best air temperature entering the furnace with the ambient air temperature ta . 4. the determination system of the best entering furnace wind temperature of the thermal power unit of a configuration air heater, is characterized in that, comprises the following steps: A characterization parameter establishment module, the parameter establishment module is used to establish the characterization parameter of the optimal inlet air temperature of the thermal power unit configured with the air heater; the characterization parameter is obtained by the following method: Taking the power supply load N _net under the given condition of the coal amount B entering the boiler, as the characterization parameter of the optimal inlet air temperature of the thermal power unit equipped with the air heater; The power supply load Nnet of the _thermal power unit is the output power of the generator outlet minus the total power consumption of the auxiliary equipment of the unit and the maintenance lighting system; By changing the heating steam or hot water flow of the heater, changing the outlet air temperature, reading the power supply load _Nnet under different working conditions, and _taking the heater outlet air temperature corresponding to the highest value of the power supply load Nnet as the coal volume Optimum air temperature control value; _A test condition delimitation module, which is used to delineate the test condition according to the boundary parameters boiler inlet coal quantity B and ambient temperature ta ; the test condition is obtained by the following methods: Statistics on the operation data of thermal power units in the past year, mainly including: Boiler inlet coal quantity B : B _min , B _max Ambient air temperature ta : _{ta , min} , ta _, max According to the distribution of the coal amount B at the boiler inlet and the ambient temperature ta , the test conditions are divided according to the following principles _: ① B _min , B _min +( B _max - B _min )×0.2 B _min +( B _max - B _min )×0.4 B _min +( B _max - B _min )×0.6 B _min +( B _max - B _min )×0.8 B _max ② t _{a, min} ta _{, min} + ( ta _{, max} - ta _{, min} ) × 0.2 ta _{, min} + ( ta _{, max} - ta _{, min} ) × 0.4 ta _{, min} + ( ta _{, max} - ta _{, min} ) × 0.6 ta _{, min} + ( ta _{, max} - ta _{, min} ) × 0.8 t _{a. max} Obtain several groups of optimal air temperature entering the furnace to determine the working conditions online; An air temperature determination module, which is used for determining the optimal air temperature entering the furnace for each test condition, _{guided by the highest value of the power supply load Nnet} of the thermal power unit. 5. a determination device of the thermal power unit best entering the furnace wind temperature of configuration air heater, comprises memory, processor and the computer program that can be stored in described memory and can run on described processor, it is characterized in that, The processor implements the steps of the method according to any one of claims 1-3 when executing the computer program. 6. A computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, characterized in that, when the computer program is executed by a processor, the steps of the method according to any one of claims 1-3 are implemented .

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