CN102536345A - Method for increasing running energy efficiency of BPRT (blast furnace power recovery turbine) system - Google Patents

Abstract

The invention relates to energy efficiency analysis technology, and aims to provide a method for increasing running energy efficiency of a BPRT (blast furnace power recovery turbine) system. The method includes (1) gradually adjusting opening of a butterfly valve of an inlet of a turbomachine under the condition that coal gas flow is not changed, and selecting the opening of the butterfly valve when the current of a motor is the lowest or energy efficiency of the turbomachine is the highest as the best opening; (2) changing a coal gas flow condition, repeating the experiment, and building a mathematical model of the corresponding relation of coal gas flow and the opening of the butterfly valve; and (3) obtaining the corresponding best opening of the butterfly valve of the inlet via the mathematical model according to the coal gas flow in a running process of the BPRT system, controlling the butterfly valve of the inlet of the turbomachine according to the best opening, and accordingly realizing that the BPRT system runs in an energy efficiency optimum state. The method can be used for people to comprehensively know running conditions of the turbomachine, effectively reduces errors of energy efficiency calculation data due to noise caused by sampling, calculates the opening of the butterfly valve of the inlet in an optimizing manner, and improves the energy efficiency of the BPRT system.

Description

A kind of method that improves BPRT system operational energy efficiency

Technical field

The present invention relates to the method for the operational energy efficiency of a kind of blast furnace gas energy recovery system that improves turbine engine Driven by Coaxial blower (Blast Furnace Power Recovery Turbine is called for short BPRT).In particular, be that the BPRT system that is directed against blast furnace carries out the optimization of operational energy efficiency.

Background technique

Metallurgical process industry is the energy, various raw-material product survivor, also is the main consumer of the energy, and is energy-saving and cost-reducing most important.China's metallurgical industry comprehensive energy consumption level is far above the average level in the whole world.

Ironmaking system is the general name of operations such as coking, sintering, ironmaking.The energy that this system directly consumes accounts for about 70% of Steel Complex's total energy consumption, is the energy-conservation emphasis of Steel Complex.Blast Furnace Blower System is as the heart of ironmaking system, and its energy consumption also occupies the major component of ironmaking system.Blast furnace air consumption proportion in the ironmaking process energy consumption is bigger.The blast furnace air energy consumption accounts for ironmaking process energy consumption 10%～15%.Therefore the energy-saving and cost-reducing energy-saving and emission-reduction for metallurgy industry to Blast Furnace Blower System have great importance.

The BPRT system is the abbreviation of the blast furnace gas energy recovery system of turbine engine Driven by Coaxial blower.This device drives the turbine engine arbor and rotates, directly the Driven by Coaxial blast furnace blower through blast furnace gas is introduced turbine engine; The original bulky systems of TRT is simplified to be merged; Cancellation generator and be transported to electric system merges robot control system(RCS), lubricating oil system, power oil system etc., and the energy that reclaims is directly replenished axle as rotating mechanical energy fastens; Avoid the loss of transformation of energy, the motor that makes blower reduces electric current and energy-conservation.Therefore at China's steel industry high speed development and today of energy wretched insufficiency, for the supporting BPRT of blast furnace system becomes the main path that energy Conservation of Blast Furnace reduces discharging gradually.

The BPRT system all is the Driven by Coaxial of simply carrying out turbine engine and blower at present, and turbine engine efficiency problem also is not optimized, and often is in the low spot of efficient, has influenced the efficiency of energy utilization of BPRT system.

Summary of the invention

The technical problem that the present invention will solve is, overcomes deficiency of the prior art, and the method for a kind of BPRT of raising system operational energy efficiency is provided.

For solving its technical problem, solution of the present invention is:

The method of a kind of BPRT of raising system operational energy efficiency is provided, may further comprise the steps:

(1) keeping progressively adjusting the aperture of turbine engine inlet butterfly valve under the constant situation of gas flow; The current of electric of pairing turbine engine efficiency and blower when writing down different valve opening; Choose the butterfly valve opening (with electric current minimum serves as preferential) of the minimum or turbine engine efficiency of current of electric wherein when the highest, as the best aperture of this gas flow lower inlet butterfly valve;

(2) change the gas flow condition, repeat above-mentioned experiment; After obtaining enough data, set up the mathematical model of gas flow and butterfly valve opening corresponding relation;

(3) according to the gas flow in the BPRT system running, obtain the best aperture of corresponding inlet butterfly valve through said mathematical model, and in view of the above to the control of turbine engine inlet butterfly valve, thereby realize that BPRT operates in the efficiency the optimum state.

Among the present invention, said turbine engine efficiency data obtain through following manner:

(1) gathers the BPRT system operational parameters, comprising: turbine engine inlet flow rate Q _Ti(m ³/ s), rate of discharge Q _To(m ³/ s), inlet temperature T _Ti(K), outlet temperature T _To(K), air horsepower N (kW);

(2) obtain the heat (q that turbine engine inlet coal gas is brought into through following formula _T1, kW):

${\mathrm{<figure-callout\; id="1"\; label="q\; t"\; filenames="HDA0000130884980000011.png,HDA0000130884980000031.png"\; state="\{\{state\}\}">q</figure-callout>}}_t=x_{{\mathrm{CO}}_2}{Q}_{\mathrm{<figure-callout\; id="2"\; label="ti\; c\; CO"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">ti</figure-callout>}}{c}_{{\mathrm{CO}}_{}}^{}{{}_2}_{\mathrm{ti}}^{}+x_{\mathrm{CO}}{Q}_{\mathrm{ti}}{c}_{\mathrm{CO}}^{\mathrm{ti}}+x_{H_2}{Q}_{\mathrm{ti}}{\mathrm{<figure-callout\; id="2"\; label="c\; H"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{H_{}}^{{}_2}+x_{N_2}{Q}_{\mathrm{ti}}{\mathrm{<figure-callout\; id="2"\; label="c\; N"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{N_{}}^{{}_2}+x_{{\mathrm{CH}}_4}{Q}_{\mathrm{ti}}{\mathrm{<figure-callout\; id="4"\; label="c\; CH"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{{\mathrm{CH}}_{}}^{{}_4}$

In the formula,

x _CO, Be respectively main component CO in the top gas ₂, CO, N ₂, H ₂, CH ₄Volume content (%);

Be that temperature is T _TiThe time specific enthalpy (kJ/m ³);

(3) obtain the heat (q that turbine engine outlet coal gas is brought into through following formula _T2, kW):

${\mathrm{<figure-callout\; id="2"\; label="q\; t"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">q</figure-callout>}}_t=x_{{\mathrm{CO}}_2}{Q}_{\mathrm{to}}{\mathrm{<figure-callout\; id="2"\; label="c\; CO"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{{\mathrm{CO}}_{}}^{{}_2}+x_{\mathrm{CO}}{Q}_{\mathrm{to}}{c}_{\mathrm{CO}}^{\mathrm{to}}+x_{H_2}{Q}_{\mathrm{to}}{c}_{H_2}^{\mathrm{to}}+x_{N_2}{Q}_{\mathrm{to}}{c}_{{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">N</figure-callout>}}_2}^{\mathrm{to}}+x_{{\mathrm{CH}}_4}{Q}_{\mathrm{to}}{c}_{{\mathrm{<figure-callout\; id="4"\; label="CH"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">CH</figure-callout>}}_4}^{\mathrm{to}}$

In the formula,

For temperature is T _ToThermal capacitance (kJ/m ³);

(4) obtaining the callable heat of turbine through following formula is (q _Tr, kW):

q _tr＝q _t1-q _t2

(5) obtain the efficiency of turbine engine through following formula:

${\mathrm{\&eta;}}_t=\frac{N}{q_{\mathrm{tr}}}.$

Among the present invention, after the efficiency data that obtain turbine engine, adopt the first-order lag filtering algorithm that it is carried out Shelving to remove noise according to following formula:

${\mathrm{\&eta;}}_b^{\mathrm{nf}}=(1-\mathrm{\&alpha;}){\mathrm{\&eta;}}_b^n+\mathrm{\&alpha;}{\mathrm{\&eta;}}_b^{\mathrm{nf}-1}$

In the formula; The filtered value of efficiency that

expression is the n time;

is the n time efficiency value of calculating; The filtered value of efficiency that

expression is the n-1 time, the span of α is 0～1.

Among the present invention, in the said step (1), during the aperture of adjustment inlet butterfly valve, its amplitude of accommodation is controlled at 5% to 30% aperture scope.

Compared with prior art, the invention has the beneficial effects as follows:

1, the parameter of importing and exporting through the turbine engine of sampling BPRT system; Carry out the efficiency analysis of turbine engine; Can comprehensively understand the operation conditions of turbine engine thus, thus the real time data of acquisition turbine engine efficiency, convenient operation management and Optimizing operation to turbine engine.

2. utilize the first-order lag filtering algorithm, the efficiency data that calculate to obtain are handled, can effectively reduce because the efficiency calculated data mistake that the noise that brings of sampling causes.

3, adopt the mode of data driven, utilize laboratory data to obtain the optimum operation efficiency model of BPRT system, thereby the aperture of computation optimization import butterfly valve gets turbine engine in the raising BPRT system and has best efficiency.

Description of drawings

Fig. 1 is the BPRT system schematic;

Fig. 2 is a blast furnace blower Operational Limits instrumentation plan;

Fig. 3 is a first-order lag filtering algorithm schematic representation;

Fig. 4 is the flow chart of filtering algorithm;

Fig. 5 is a BPRT system operational energy efficiency computation optimization schematic representation.

Embodiment

At first need to prove, the present invention relates to be built in the application of the software function module in the computer, is a kind of application of computer technology in the control technique field.The claimant thinks, as read over application documents, accurately understand realization principle of the present invention and goal of the invention after, under the situation that combines existing known technology, those skilled in the art can use the software programming technical ability of its grasp to realize the present invention fully.The aforementioned software function module includes but not limited to: efficiency computing module, first-order lag filtering algorithm module etc., and this category of all genus that all application documents of the present invention are mentioned, the claimant enumerates no longer one by one.

Basic principle of the present invention is:

Parameter during at first, through the operation of collection turbine engine is also handled.Secondly, utilize the efficiency formula of turbine engine, computing is carried out in the real time data substitution of being gathered, obtain the real-time efficiency of turbine engine.When the efficient of real-time calculating is hanged down,, thereby make turbine engine efficient be improved through the butterfly valve before the import of adjustment turbine engine.

Among the present invention; Wherein the turbine engine efficiency is calculated the method that adopts energy balance; Because the loss part can't be measured and calculate, and the import and export parameter of turbine engine also can receive The noise, therefore adopt the mode of first-order filtering to proofread and correct simultaneously for last efficiency formula.

Among the present invention, the method for wherein adjusting the aperture of the preceding butterfly valve of turbine engine import mainly adopts experiment to add the data method of driving.Through to blast furnace operating period in the whole cycle, earlier butterfly valve opening is turned down a certain numerical value, the efficiency of the turbine engine in the record whole operation cycle changes.General this numerical value from 5% to 30%.After the service data of record carried out analysis modeling, just can obtain the butterfly valve opening after the interior computation optimization of next operation cycle.

With reference to figures 1 through 5, will describe the present invention below.

Fig. 1 representes the schematic representation of BPRT system.After the HTHP coal gas that blast furnace 2 produces passes through gravitational dust collection device 3 and bag-type dust collector 4 udst separations, import turbine engine 5 driving turbine arbors and rotate, the HTHP Conversion of energy that coal gas has is the mechanical kinetic energy of turbine arbor.Surpassed the rotating speed of blower 7 at its rotating speed after, clutch 6 meshes automatically, thereby mechanical kinetic energy is passed to blower, has so just reduced the power consumption of motor 9, brings hot blast into hot blast stove 1.Turbine engine breaks down when the coal gas amount changes perhaps, and its speed drop is low to moderate below blower 7 rotating speeds, and clutch 6 breaks away from automatically, is only driven through gearboxes 8 belt driven blowers 7 by motor 9, thereby has guaranteed that blower 7 can proper functioning.

Fig. 2 representes to calculate among the present invention the turbine engine efficiency and calculates the parameters needed measurment, comprising inlet pressure, the temperature of turbine engine, outlet pressure, temperature, flow and air horsepower.Here it should be noted that all measurements all need satisfy such as requirements such as sensor mounting points.

Fig. 3 representes turbine engine efficiency calculation procedure among the present invention.Wherein the summary of the invention part of key step such as this specification is said, and the formula that wherein relates to is following:

${\mathrm{<figure-callout\; id="1"\; label="q\; t"\; filenames="HDA0000130884980000011.png,HDA0000130884980000031.png"\; state="\{\{state\}\}">q</figure-callout>}}_t=x_{{\mathrm{CO}}_2}{Q}_{\mathrm{<figure-callout\; id="2"\; label="Ti\; c\; CO"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">Ti</figure-callout>}}{c}_{{\mathrm{CO}}_{}}^{}{{}_2}_{\mathrm{Ti}}^{}+x_{\mathrm{CO}}{Q}_{\mathrm{Ti}}{c}_{\mathrm{CO}}^{\mathrm{Ti}}+x_{H_2}{Q}_{\mathrm{<figure-callout\; id="2"\; label="Ti\; c\; H"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">Ti</figure-callout>}}{c}_{H_{}}^{}{{}_2}_{\mathrm{Ti}}^{}+x_{N_2}{Q}_{\mathrm{<figure-callout\; id="2"\; label="Ti\; c\; N"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">Ti</figure-callout>}}{c}_{N_{}}^{}{{}_2}_{\mathrm{Ti}}^{}+x_{{\mathrm{CH}}_4}{Q}_{\mathrm{<figure-callout\; id="4"\; label="Ti\; c\; CH"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">Ti</figure-callout>}}{c}_{{\mathrm{CH}}_{}}^{}{{}_4}_{\mathrm{Ti}}^{}$ (formula 1)

${\mathrm{<figure-callout\; id="2"\; label="q\; t"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">q</figure-callout>}}_t=x_{{\mathrm{CO}}_2}{Q}_{\mathrm{To}}{\mathrm{<figure-callout\; id="2"\; label="c\; CO"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{{\mathrm{CO}}_{}}^{{}_2}+x_{\mathrm{CO}}{Q}_{\mathrm{To}}{c}_{\mathrm{CO}}^{\mathrm{To}}+x_{H_2}{Q}_{\mathrm{To}}{c}_{H_2}^{\mathrm{To}}+x_{N_2}{Q}_{\mathrm{To}}{\mathrm{<figure-callout\; id="2"\; label="c\; N"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{N_{}}^{{}_2}+x_{{\mathrm{CH}}_4}{Q}_{\mathrm{To}}{\mathrm{<figure-callout\; id="4"\; label="c\; CH"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{{\mathrm{CH}}_{}}^{{}_4}$ (formula 2)

q _Tr=q _T1-q _T2(formula 3)

${\mathrm{\&eta;}}_t=\frac{N}{q_{\mathrm{Tr}}}$ (formula 4)

In the above-mentioned formula:

N is a generated output, and unit is kW; q _TrBe the callable heat of turbine engine, unit is kW; q _T1Be the enthalpy of turbine engine inlet coal gas, unit is kW; q _T2Be the enthalpy of turbine engine outlet coal gas, unit is kW; Main component in the top gas is: CO ₂, CO, N ₂, H ₂, CH ₄, its volume content is expressed as respectively

x _CO(%), $x_{N_2}(\%),x_{H_2}(\%),x_{{\mathrm{CH}}_4}(\%);{\mathrm{<figure-callout\; id="2"\; label="c\; CO"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{{\mathrm{CO}}_{}}^{{}_2},c_{\mathrm{CO}}^{\mathrm{Ti}},{\mathrm{<figure-callout\; id="2"\; label="c\; H"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{H_{}}^{{}_2},{\mathrm{<figure-callout\; id="2"\; label="c\; N"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{N_{}}^{{}_2},{\mathrm{<figure-callout\; id="4"\; label="c\; CH"\; filenames="HDA0000130884980000011.png"\; state="\{\{state\}\}">c</figure-callout>}}_{{\mathrm{CH}}_{}}^{{}_4}$ Be that temperature is T _TiSpecific enthalpy, unit is kJ/m ³

Be that temperature is T _ToThermal capacitance, unit is kJ/m ³Q _TiBe the turbine engine inlet flow rate, unit is m ³/ s; Q _ToBe the turbine engine rate of discharge, unit is m ³/ s;

In order to eliminate the error that noise causes, the present invention adopts the first-order lag filtering algorithm that the efficiency of calculating is carried out filtering, removes noise.Filtering algorithm is:

${\mathrm{\&eta;}}_b^{\mathrm{Nf}}=(1-\mathrm{\&alpha;}){\mathrm{\&eta;}}_b^n+\mathrm{\&alpha;}{\mathrm{\&eta;}}_b^{\mathrm{Nf}-1}$ (formula 6)

Here the filtered value of efficiency that

expression is the n time;

is the n time efficiency value of calculating, the filtered value of efficiency that

expression is the n-1 time.The value of α can be made amendment according to field condition 0 to 1.Fig. 4 is the flow chart of filtering algorithm.

Fig. 5 representes BPRT system operational energy efficiency optimization experiment schematic representation.Wherein experimental procedure mainly is through different butterfly valve openings, obtains the different motor electric current, writes down the flow that turbine engine is imported and exported simultaneously.Under the situation of same gas flow, according to above three data choose current of electric wherein minimum with turbine engine the butterfly valve opening when most effective, as the best butterfly valve opening under this flow.Through lot of data, set up the mathematical model of gas flow and butterfly valve opening.Therefore when moving next time, behind the detection gas flow, obtain best butterfly valve opening, improve the BPRT operational energy efficiency through this model.

Claims (4)

1. method that improves BPRT system operational energy efficiency may further comprise the steps:

(1) keeping progressively adjusting the aperture of turbine engine inlet butterfly valve under the constant situation of gas flow; The current of electric of pairing turbine engine efficiency and blower when writing down different valve opening; Choose the butterfly valve opening of the minimum or turbine engine efficiency of current of electric wherein when the highest, as the best aperture of this gas flow lower inlet butterfly valve;

(2) change the gas flow condition, repeat above-mentioned experiment; After obtaining enough data, set up the mathematical model of gas flow and butterfly valve opening corresponding relation;

(3) according to the gas flow in the BPRT system running, obtain the best aperture of corresponding inlet butterfly valve through said mathematical model, and in view of the above to the control of turbine engine inlet butterfly valve, thereby realize that the BPRT system operates in the efficiency the optimum state.

2. method according to claim 1 is characterized in that, said turbine engine efficiency data obtain through following manner:

(1) gathers the BPRT system operational parameters, comprising: turbine engine inlet flow rate Q _Ti(m ³/ s), rate of discharge Q _To(m ³/ s), inlet temperature T _Ti(K), outlet temperature T _To(K), air horsepower N (kW);

(2) obtain the heat (q that turbine engine inlet coal gas is brought into through following formula _T1, kW):

$q_{t1}=x_{{\mathrm{CO}}_2}{Q}_{\mathrm{ti}}{c}_{{\mathrm{CO}}_2}^{\mathrm{ti}}+x_{\mathrm{CO}}{Q}_{\mathrm{ti}}{c}_{\mathrm{CO}}^{\mathrm{ti}}+x_{H_2}{Q}_{\mathrm{ti}}{c}_{H_2}^{\mathrm{ti}}+x_{N_2}{Q}_{\mathrm{ti}}{c}_{N_2}^{\mathrm{ti}}+x_{{\mathrm{CH}}_4}{Q}_{\mathrm{ti}}{c}_{{\mathrm{CH}}_4}^{\mathrm{ti}}$

In the formula,

x _CO,

Be respectively main component CO in the top gas ₂, CO, N ₂, H ₂, CH ₄Volume content (%);

Be that temperature is T _TiThe time specific enthalpy (kJ/m ³);

(3) obtain the heat (q that turbine engine outlet coal gas is brought into through following formula _T2, kW):

$q_{t2}=x_{{\mathrm{CO}}_2}{Q}_{\mathrm{to}}{c}_{{\mathrm{CO}}_2}^{\mathrm{to}}+x_{\mathrm{CO}}{Q}_{\mathrm{to}}{c}_{\mathrm{CO}}^{\mathrm{to}}+x_{H_2}{Q}_{\mathrm{to}}{c}_{H_2}^{\mathrm{to}}+x_{N_2}{Q}_{\mathrm{to}}{c}_{N_2}^{\mathrm{to}}+x_{{\mathrm{CH}}_4}{Q}_{\mathrm{to}}{c}_{{\mathrm{CH}}_4}^{\mathrm{to}}$

In the formula, For temperature is T _ToThermal capacitance (kJ/m ³);

(4) obtaining the callable heat of turbine through following formula is (q _Tr, kW):

q _tr＝q _t1-q _t2

(5) obtain the efficiency of turbine engine through following formula:

${\mathrm{\&eta;}}_t=\frac{N}{q_{\mathrm{tr}}}.$

3. method according to claim 1 is characterized in that, after the efficiency data that obtain turbine engine, adopts the first-order lag filtering algorithm that it is carried out Shelving to remove noise according to following formula:

${\mathrm{\&eta;}}_b^{\mathrm{nf}}=(1-\mathrm{\&alpha;}){\mathrm{\&eta;}}_b^n+\mathrm{\&alpha;}{\mathrm{\&eta;}}_b^{\mathrm{nf}-1}$

In the formula; The filtered value of efficiency that

expression is the n time;

is the n time efficiency value of calculating; The filtered value of efficiency that

expression is the n-1 time, the span of α is 0～1.

4. method according to claim 1 is characterized in that, in the said step (1), during the aperture of adjustment inlet butterfly valve, its amplitude of accommodation is controlled at 5% to 30% aperture scope.

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