CN104615853A - Thermal power generating unit coal blending co-combustion effect online evaluation method - Google Patents

Abstract

The invention discloses a thermal power generating unit coal blending co-combustion effect online evaluation method. The method comprises the steps that when a load of a thermal power generating unit to be evaluated is in a steady condition, a series of operating parameters which comprise metal wall temperature and a combustion chamber draft of a boiler, temperature and pressure of main steam, temperature and pressure of reheat steam, a wind-warm syndrome of an exit of a coal mill and the like are collected, and a plurality of practical performance parameters which comprise boiler efficiency, standard coal consumption of a power generation, standard coal consumption of a power supply and the like are obtained simultaneously; a series of the obtained operating parameters are used to carry out multidirectional evaluation operation of security and combustion efficiency respectively; on the basis of an obtained security evaluation index and an evaluation index of a coal blending combustion efficiency of the thermal power generating unit, and a method of weighing and summation is adopted to obtain a final evaluation result of a coal blending combustion effect. The method can efficiently and roundly reflect the current security condition of the boiler and the coal blending combustion efficiency height, and at the same time, the method has the advantages that the operation is convenient, the practicability is strong, and the evaluation is precise.

Description

A kind of fired power generating unit coal mixing combustion effect online evaluation method

Technical field

The invention belongs to thermoelectricity electrification technique as well as association area, more specifically, relate to a kind of fired power generating unit coal mixing combustion effect online evaluation method.

Background technology

Due to the skewness of coal resources and the complicacy of coal market, most domestic coal fired power plant is all using non dipper, easily occurs slagging scorification, metal overtemperature, degradation problem under exert oneself reduction, boiler efficiency when boiler uses non dipper.The coal of variety classes, character is mixed and is joined by coal mixing combustion by a certain percentage, mutually can make up the defect of different single coal, learn from other's strong points to offset one's weaknesses, and effectively solves this series of problems brought when using non dipper.In the actual moving process of power plant especially large thermal power plant, often need to adopt mixed coal combustion technology.Mixed coal combustion technology can effectively be widened coal-burning boiler and be suitable for coal, therefore significant in the rational utilization of coal resources, the safe and highly efficient operation of station boiler etc.

But, in prior art, laboratory stage is focusing more on to the research of mixed coal combustion, more to the research of the combustion characteristics, pollutant emission characteristic etc. of mixed coal, the technique study burning effect assessment is mixed less for coal blending at power plant, especially lack and study in the key parameter such as system of boiler tube wall temperature, vapor (steam) temperature and boiler efficiency in coal mixing combustion situation, correspondingly, the solution that searching is more perfect is needed badly, to obtain more accurate, comprehensive fired power generating unit coal mixing combustion Performance Evaluation effect in association area.

Summary of the invention

For above defect or the Improvement requirement of prior art, the invention provides a kind of fired power generating unit coal mixing combustion effect online evaluation method, wherein by the application characteristic in conjunction with Large-scale fire-electricity unit self, select system of boiler tube wall temperature, the key parameter such as vapor (steam) temperature and boiler efficiency is as evaluation factor, and build specific assessment models and come boiler safety, burning efficiency is evaluated, mutually should be able to high-level efficiency, reflect the height of the safety conditions that boiler is current and Blended Coal Combustion efficiency all sidedly, possess simultaneously and be convenient to manipulation, the features such as practical and assessment is accurate, thus the application scenarios such as Large-scale fire-electricity unit coal mixing combustion recruitment evaluation are particularly useful for.

For achieving the above object, according to the present invention, provide a kind of fired power generating unit coal mixing combustion effect online evaluation method, it is characterized in that, the method comprises the following steps:

A () is under fired power generating unit load to be assessed is in steady-state conditions, gather to obtain and comprise the tube wall temperature of boiler, combustion chamber draft, the temperature and pressure of main steam, the temperature and pressure of reheated steam, a series of operational factors of coal pulverizer outlet wind-warm syndrome, obtain boiler efficiency, the multiple actual performance parameter such as generating standard coal consumption and supply standard coal consumption etc. when it is in lower state simultaneously; Wherein said tube wall temperature comprises the measuring point wall temperature value gathered respectively to multiple measuring points of drum, superheater and reheater three parts further, the multiple combustion chamber draft data before described combustion chamber draft is included in and performs collection within t;

B a series of operational factor that () utilizes step (a) to obtain and performance index, perform following safety evaluation operation to fired power generating unit:

(b1) first check whether described multiple measuring point wall temperature values of drum, superheater and reheater exist the situation exceeding alarm threshold value, and according to check result and following formula () to obtain the overtemperature assessment result a (0) of tube wall temperature:

A (0)=1-n _cwc _cw(1)

Wherein, n _cwrepresent in multiple measuring points of described drum, superheater and reheater, actual wall temperature exceedes the measuring point total quantity of alarm threshold value; C _cwrepresent penalty factor when there is overtemperature, it is predeterminable and make a (0)>=0;

(b2) based on described multiple measuring point wall temperature values of drum, superheater and reheater three parts, continue to ask for variance yields respectively to it, and adopting the wall temperature homogeneity situation of the mode of linear interpolation to these three parts to assess separately, homogeneity assessment result is expressed as a (1), a (2) and a (3) successively;

(b3) utilize the assessment result of step (b1) and (b2), calculate the comprehensive assessment result s (1) of wall temperature security according to following expression formula (two):

$s\left(1\right)=a\left(0\right)\underset{i=1}{\overset{3}{\mathrm{\Σ}}}{\mathrm{\σ}}_{i}a\left(i\right)$ (2)

Wherein, σ _ifor weight, it is predeterminable but need meet i=1,2,3;

(b4) the described combustion chamber draft data utilizing step (a) to gather, ask its sample variance, then according to the variance that this is tried to achieve, adopt the mode of linear interpolation to obtain the evaluation index s (2) of reflection flame combustion stability;

(b5) temperature and pressure of the main steam utilizing step (a) to gather and the temperature and pressure of reheated steam, and based on vapor (steam) temperature related to this and pressure alarm threshold value, adopt the mode of linear interpolation to obtain reflecting the evaluation index s (3) of vapor (steam) temperature and pressure;

(b6) the coal pulverizer outlet wind-warm syndrome utilizing step (a) to gather, and set coal pulverizer outlet wind-warm syndrome threshold value based on the volatilization of coal, the safety evaluation result s (4) of pulverized coal preparation system is then calculated based on following formula (three):

S (4)=1-n _fwc _fw(3)

Wherein, n _fwrepresent the coal pulverizer number of units exceeding described coal pulverizer outlet wind-warm syndrome threshold value, C _fwrepresent penalty factor when there is wind-warm syndrome overtemperature, it is predeterminable and make s (4)>=0;

(b7) the evaluation index s (1) utilizing step (b3) ~ (b6) to try to achieve respectively, s (2), s (3) and s (4), adopt the mode of weighted sum to obtain reflecting the comprehensive assessment index f of fired power generating unit security _safe;

Boiler efficiency, multiple actual performance parameter such as generating standard coal consumption and supply standard coal consumption etc. during what c () utilized step (a) to obtain be in lower state, adopt the mode of linear interpolation to calculate the evaluation index f of reflection Blended Coal Combustion efficiency _eff;

The comprehensive assessment index f of d reflection fired power generating unit security that () obtains based on step (b) _safe, and the evaluation index f of reflection Blended Coal Combustion efficiency that calculates of step (c) _eff, adopt the mode of weighted sum to obtain final coal mixing combustion recruitment evaluation result, complete the online evaluation process of overall fired power generating unit coal blending winding effect thus.

As further preferably, described fired power generating unit is preferably Large-scale fire-electricity unit.

In general, the above technical scheme conceived by the present invention compared with prior art, propose a kind of process for Burning Blended Coals in Thermal Power Plant resultant effect on-line evaluation first, wherein owing to having considered tube wall temperature, main steam temperature pressure, reheat steam temperature pressure, combustion chamber draft, the coal pulverizer outlet key parameter such as wind-warm syndrome also builds rational assessment models to security during Burning Blended Coals in Thermal Power Plant and evaluates, consider boiler efficiency simultaneously, generating standard coal consumption, the many-sided evaluation index of supply standard coal consumption is evaluated burning efficiency, mutually should be able to be accurate, in time with the multi-faceted information obtaining thermal power plant's coal blending burning resultant effect comprehensively, possess simultaneously and be convenient to manipulation, the features such as practical and assessment is accurate, thus the application scenarios such as Large-scale fire-electricity unit coal mixing combustion recruitment evaluation are particularly useful for.

Accompanying drawing explanation

Fig. 1 is the process chart according to fired power generating unit coal blending burning effect online evaluation method of the present invention.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.In addition, if below in described each embodiment of the present invention involved technical characteristic do not form conflict each other and just can mutually combine.

Fig. 1 is the process chart according to fired power generating unit coal blending burning effect online evaluation method of the present invention.As shown in fig. 1, the method is mainly through in conjunction with the application of fired power generating unit coal blending burning self and process characteristic, select multiple suitable key parameter as evaluation factor and assessment models studied and designs, to more accurate, comprehensive fired power generating unit coal mixing combustion Performance Evaluation effect compared with prior art can be obtained.

As the basis of general idea of the present invention, consider that metal wall superheat overtemperature easily causes the metal creep of material, reduce the serviceable life of tube wall metal material, cause boiler heating surface overtemperature tube burst, affect the normal safe operation of unit, therefore select in the present invention using tube wall temperature as important monitoring parameter, and specifically include the wall temperature of drum, superheater, reheater.Combustion chamber draft can reflect the stability of flame combustion, and when furnace pressure fluctuation is larger, combustion instability, and its parameter value also can obtain online, is selected therefore equally in the present invention as one of evaluation factor.Main steam gentle reheat steam temperature overtemperature is the bad signal of interest of unit safety, and long-time overtemperature can reduce the permissible stress of metal especially, can overtemperature tube burst time serious, therefore it can be used as an other evaluation factor in the present invention.In addition, the situation of unit operation safety is affected in order to prevent explosion of Coal Pulverizing System etc., according to the operations specification of subsidiary engine pulverized coal preparation system, according to the volatile matter setting Outlet Temperature value of coal, therefore equally coal pulverizer should be exported wind-warm syndrome as evaluation factor in the present invention.

On the other hand, also have selected the boiler efficiency of unit, many-sided evaluation index such as generating standard coal consumption, supply standard coal consumption etc. in the present invention, to evaluate burning efficiency.And then by the evaluation of this burning efficiency and the above-mentioned evaluation common combination biasing toward security performance aspect, obtain the comprehensive online evaluation result of fired power generating unit coal mixing combustion effect thus.

Specifically, first, be the step relevant a series of key parameter and performance parameter being performed to online acquisition acquisition.

Under fired power generating unit load to be assessed is in steady-state conditions, gather to obtain and comprise the tube wall temperature of boiler, combustion chamber draft, the temperature and pressure of main steam, the temperature and pressure of reheated steam, a series of operational factors of coal pulverizer outlet wind-warm syndrome, obtain boiler efficiency, the multiple actual performance parameter such as generating standard coal consumption and supply standard coal consumption etc. when it is in lower state simultaneously; Wherein said tube wall temperature comprises the measuring point wall temperature value gathered respectively to multiple measuring points of drum, superheater and reheater three parts further, and described combustion chamber draft is included in the multiple combustion chamber draft data (comprising and gather the moment itself) within t before execution gathers;

Then, a series of operational factor obtained before utilization and performance index, first perform following safety evaluation operation to fired power generating unit:

(1) check whether described multiple measuring point wall temperature values of drum, superheater and reheater exist the situation exceeding alarm threshold value, and according to check result and following formula () to obtain the overtemperature assessment result a (0) of tube wall temperature:

A (0)=1-n _cwc _cw(1)

Wherein, n _cwrepresent in multiple measuring points of described drum, superheater and reheater, actual wall temperature exceedes the measuring point total quantity of alarm threshold value; C _cwrepresent penalty factor when there is overtemperature, it is predeterminable and make a (0)>=0;

(2) based on described multiple measuring point wall temperature values of drum, superheater and reheater three parts, continue to ask for variance yields respectively to it, and adopting the wall temperature homogeneity situation of the mode of linear interpolation to these three parts to assess separately, homogeneity assessment result is expressed as a (1), a (2) and a (3) successively;

(3) utilize multiple assessment results above, calculate the comprehensive assessment result s (1) of wall temperature security according to following expression formula (two):

$s\left(1\right)=a\left(0\right)\underset{i=1}{\overset{3}{\mathrm{\Σ}}}{\mathrm{\σ}}_{i}a\left(i\right)$ (2)

Wherein, σ _ifor weight, it is predeterminable but need meet i=1,2,3;

Then, the described combustion chamber draft data gathered before can utilizing, ask its sample variance, then according to the variance that this is tried to achieve, and adopt the mode of linear interpolation to obtain the evaluation index s (2) of reflection flame combustion stability;

Then, the temperature and pressure of main steam that continuation gathers before utilizing and the temperature and pressure of reheated steam, and based on vapor (steam) temperature related to this and pressure alarm threshold value, adopt the mode of linear interpolation to obtain reflecting the evaluation index s (3) of vapor (steam) temperature and pressure;

Then, continue the coal pulverizer outlet wind-warm syndrome gathered before utilizing, and set coal pulverizer outlet wind-warm syndrome threshold value based on the volatilization of coal, the safety evaluation result s (4) of pulverized coal preparation system is then calculated based on following formula (three):

S (4)=1-n _fwc _fw(3)

Wherein, n _fwrepresent the coal pulverizer number of units exceeding described coal pulverizer outlet wind-warm syndrome threshold value, C _fwrepresent penalty factor when there is wind-warm syndrome overtemperature, it is predeterminable and make s (4)>=0;

Here, the evaluation index s (1) tried to achieve respectively before comprehensive utilization, s (2), s (3) and s (4), and the mode of weighted sum for example can be adopted to obtain reflecting the comprehensive assessment index f of fired power generating unit security _safe; Its concrete form is such as:

$f_{\mathrm{safe}}=\underset{i=1}{\overset{4}{\mathrm{\Σ}}}{\mathrm{\σ}}_{i}s\left(i\right)$

Wherein, σ ⁱfor the weight of each item rating, be comprehensively 1, meet

After completing above-mentioned security comprehensive assessment, also continue in the present invention to assess its burning efficiency.

Specifically, before can utilizing equally gather obtain be in lower state time boiler efficiency, multiple actual performance parameter such as generating standard coal consumption and supply standard coal consumption etc., adopt the mode of linear interpolation to calculate the evaluation index f of reflection Blended Coal Combustion efficiency _eff.

As a preferred embodiment of the present invention, in the process, for example can with the generating standard coal consumption of boiler efficiency during boiler design, power plant design and supply standard coal consumption for the upper limit, with boiler operatiopn the poorest historical efficiency, minimum generating standard coal consumption, minimum supply standard coal consumption for lower limit, the mode of linear interpolation is adopted to calculate the evaluation index of reflection Blended Coal Combustion efficiency.Its concrete form is not limited thereto, as long as it can obtain the numerical value reflecting real Blended Coal Combustion efficiency, does not therefore repeat them here.

Finally, based on the comprehensive assessment index f of reflection fired power generating unit security obtained above _safe, and the evaluation index f of reflection Blended Coal Combustion efficiency that just now calculated _eff, adopt the mode of weighted sum to obtain final coal mixing combustion recruitment evaluation result, complete the online evaluation process of overall fired power generating unit coal blending winding effect thus.Its concrete weight distribution can set according to the concrete condition of power plant and regulate, and therefore will not enumerate at this.

To sum up, pass through the present invention, compared with prior art propose the process for Burning Blended Coals in Thermal Power Plant resultant effect on-line evaluation first, and can high-level efficiency, reflect the height of the safety conditions that boiler is current and Blended Coal Combustion efficiency all sidedly, possess simultaneously and be convenient to manipulation, practical and assess the features such as accurate, be thus particularly useful for the application scenarios such as Large-scale fire-electricity unit coal mixing combustion recruitment evaluation.

Those skilled in the art will readily understand; the foregoing is only preferred embodiment of the present invention; not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (2)

1. a fired power generating unit coal mixing combustion effect online evaluation method, it is characterized in that, the method comprises the following steps:

A () is under fired power generating unit load to be assessed is in steady-state conditions, gather a series of operational factors obtaining and comprise the tube wall temperature of boiler, combustion chamber draft, the temperature and pressure of main steam, the temperature and pressure, coal pulverizer outlet wind-warm syndrome etc. of reheated steam, obtain boiler efficiency, multiple actual performance parameter such as generating standard coal consumption and supply standard coal consumption etc. when it is in lower state simultaneously; Wherein said tube wall temperature comprises the measuring point wall temperature value gathered respectively to multiple measuring points of drum, superheater and reheater three parts further, the multiple combustion chamber draft data before described combustion chamber draft is included in and performs collection within t;

B a series of operational factor that () utilizes step (a) to obtain and performance index, perform following safety evaluation operation to fired power generating unit:

(b1) first check whether described multiple measuring point wall temperature values of drum, superheater and reheater exist the situation exceeding alarm threshold value, and according to check result and following formula () to obtain the overtemperature assessment result a (0) of tube wall temperature:

A (0)=1-n _cwc _cw(1)

Wherein, n _cwrepresent in multiple measuring points of described drum, superheater and reheater, actual wall temperature exceedes the measuring point total quantity of alarm threshold value; C _cwrepresent penalty factor when there is overtemperature, it is predeterminable and make a (0)>=0;

(b2) based on described multiple measuring point wall temperature values of drum, superheater and reheater three parts, continue to ask for variance yields respectively to it, and adopting the wall temperature homogeneity situation of the mode of linear interpolation to these three parts to assess separately, homogeneity assessment result is expressed as a (1), a (2) and a (3) successively;

(b3) utilize the assessment result of step (b1) and (b2), calculate the comprehensive assessment result s (1) of wall temperature security according to following expression formula (two):

$s\left(1\right)=a\left(0\right)\underset{i=1}{\overset{3}{\mathrm{\Σ}}}{\mathrm{\σ}}_{i}a\left(i\right)$ (2)

Wherein, σ _ifor weight, it is predeterminable but need meet i=1,2,3;

(b4) the described combustion chamber draft data utilizing step (a) to gather, ask its sample variance, then according to the variance that this is tried to achieve, adopt the mode of linear interpolation to obtain the evaluation index s (2) of reflection flame combustion stability;

(b5) temperature and pressure of the main steam utilizing step (a) to gather and the temperature and pressure of reheated steam, and based on vapor (steam) temperature related to this and pressure alarm threshold value, adopt the mode of linear interpolation to obtain reflecting the evaluation index s (3) of vapor (steam) temperature and pressure;

(b6) the coal pulverizer outlet wind-warm syndrome utilizing step (a) to gather, and set coal pulverizer outlet wind-warm syndrome threshold value based on the volatilization of coal, the safety evaluation result s (4) of pulverized coal preparation system is then calculated based on following formula (three):

S (4)=1-n _fwc _fw(3)

Wherein, n _fwrepresent the coal pulverizer number of units exceeding described coal pulverizer outlet wind-warm syndrome threshold value, C _fwrepresent penalty factor when there is wind-warm syndrome overtemperature, it is predeterminable and make s (4)>=0;

(b7) the evaluation index s (1) utilizing step (b3) ~ (b6) to try to achieve respectively, s (2), s (3) and s (4), preferably adopt the mode of weighted sum to obtain reflecting the comprehensive assessment index f of fired power generating unit security _safe;

Boiler efficiency, multiple actual performance parameter such as generating standard coal consumption and supply standard coal consumption etc. during what c () utilized step (a) to obtain be in lower state, adopt the mode of linear interpolation to calculate the evaluation index f of reflection Blended Coal Combustion efficiency _eff;

The comprehensive assessment index f of d reflection fired power generating unit security that () obtains based on step (b) _safe, and the evaluation index f of reflection Blended Coal Combustion efficiency that calculates of step (c) _eff, adopt the mode of weighted sum to obtain final coal mixing combustion recruitment evaluation result, complete the online evaluation process of overall fired power generating unit coal blending winding effect thus.

2. fired power generating unit coal mixing combustion effect online evaluation method as claimed in claim 1, it is characterized in that, described fired power generating unit is preferably Large-scale fire-electricity unit.