CN104267710A - Blast-furnace gas boiler economizer boiling degree on-line monitoring device and method - Google Patents

Abstract

The invention discloses a blast-furnace gas boiler economizer boiling degree on-line monitoring device and method. The monitoring device comprises a data acquisition unit and a data processing unit. Operating data of a gas boiler are collected through a unit distributed control system, the collected operating data are stored in a real-time database server and a mirror database server, a calculation server reads the operating data from the mirror database server and processes the operating data to obtain economizer boiling degree calculation results, the calculation results are stored in the mirror database server, a WEB publishing server publishes the calculation results to a user display terminal, and a user can look up the calculation results in real time through the user display terminal and master the operating conditions of an economizer in time. If the economizer boiling degree excesses a set upper limit value, the user can lower the economizer boiling degree in time through the boiler operation adjustment, so that the economizer is in the safety state, the safety operation of the blast-furnace gas boiler is accordingly guaranteed, and the service life of the blast-furnace gas boiler economizer is accordingly prolonged.

Description

Blast furnace gas boiler economizer boiling degree on-Line Monitor Device and monitoring method

Technical field

The present invention relates to the boiler technology field of Thermal Power Engineering, particularly relate to a kind of blast furnace gas boiler economizer boiling degree on-Line Monitor Device and the monitoring method based on this monitoring device.

Background technology

Iron and steel enterprise creates a large amount of by-product gas in smelting process, comprises blast furnace gas, coal gas of converter and coke-oven gas.Wherein, blast furnace gas produces in Iron-smelting, and its quantity is maximum in three kinds of coal gas.But because blast furnace gas nitrogen content is high, the lower and poor combustion stability of thermal value, many steel plant are abundant all not to the utilization of blast furnace gas, and a large amount of blast furnace gas is directly diffused, and causes the huge waste of the energy.How to make good use of valuable blast furnace gas resource, be the problem of steel plant's person skilled general concern always.

In recent years, along with the development of low calorie fuels combustion technology, blast furnace gas boiler obtains extensive application in iron and steel enterprise, and achieves good effect.But the design and working aspect of blast furnace gas boiler does not also reach completely rationally, still there is many details needs to improve, and wherein the boiling problem of economizer is the hot issue in numerous operation problem.

For the boiler of burning blast furnace gas, its burning has relatively big difference with heat exchange characteristic and typical coal-fired boiler, be mainly reflected in following several respects: on the one hand, owing to containing a large amount of non-combustible gas (only nitrogen content is just up to 50% ~ 60%) in blast furnace gas, theoretical temperature combustion during blast furnace gas combustion is more much lower than coal dust, as the theoretical temperature combustion of bituminous coal be about 1800 DEG C ~ 2200 DEG C, even and the blast furnace gas after gas heater preheating, its theoretical temperature combustion also only has 1300 DEG C ~ 1450 DEG C, because the heat radiation power of furnace flame is directly proportional to the biquadratic of its absolute temperature of combustion, the temperature of combustion that blast furnace gas is lower must cause its Fire Radiation power on the weak side, on the other hand, from use coal and oil is different, boiler is when burning blast furnace gas, not containing carbon black and soot particle in the flue gas that burning produces, in stove, heat exchange can only rely on three atomic gas in flue gas to carry out radiation heat transmission, this just causes the radiant force of blast furnace gas boiler flue gas self more weak, is significantly less than conventional coal-burning boiler, in addition, the exhaust gas volumn of blast furnace gas boiler is comparatively large, and flue gas flow rate is higher, causes the flue gas complete heat exchange that is not also able to do in time just to flow to next stage heat-transfer surface, causes a large amount of heats to be taken to back-end surfaces.Like this, for the boiler of burning blast furnace gas, in the total caloric receptivity needed for working medium is from water to saturated vapor, in burner hearth, evaporating heating surface can only complete about 55%, remaining heat absorption must have been come by economizer, causes the vaporization of feeding water and very easily producing in economizer to a certain degree.

Economizer boiling degree to be used to characterize in economizer quantity of steam and to flow through economizer to the index parameter of water inventory number percent, and its design load is generally 10% ~ 15%, is generally no more than 20%.When economizer boiling is spent high, can threaten greatly producing the safe operation of boiler: 1) a large amount of vaporizations that height means feedwater are spent in boiling, because the specific volume of steam is more much larger than water, feed-water flashing must cause the increase of carbonated drink resistance to flow, thus causes the significantly increase of economizer pressure drop, 2) when economizer boiling degree reaches certain numerical value, potpourri in economizer changes in vapour moisture by water containing vapour, the flow state of steam water interface also can change thereupon, originally when carbonated drink flows through the bend part in pipeline, continuous uniform to washing away of elbow back inside surface, but along with the undulatory property of carbonated drink ratio changes, water droplet in steam is just as the grit in wind, under the influence of centrifugal force, impact elbow interior wall energetically discontinuously, thus define longitudinal scour channel ditch texture, along with the accumulation of time, tube wall is ceaselessly thinning, final formation is leaked, there is pipe explosion accident, 3) when boiling is spent high, very easily there is the phenomenon that film boiling occurs in the pipeline section of local in economizer, in pipe, steam steam bubble formation speed is too fast, form steam film in flakes, feedwater is separated with tube wall, causes heat transfer deterioration, and cause pipe wall temperature frequent variations along with change of external conditions, there is fatigure failure, crackle or fracture occur after certain life cycle.

As can be seen here, know the boiling degrees of data of blast furnace gas boiler economizer in real time, grasp its boiling situation, take corresponding measure to ensure the safety of economizer in time, the reliable and stable operation for blast furnace gas boiler has great importance.At present, most of blast furnace gas boiler all adopts operations staff to judge the pattern of economizer operation conditions by rule of thumb, and the relevant operational factor of operations staff's foundation economizer roughly judges the boiling degree of economizer, and carries out corresponding combustion adjustment with this.This pattern can meet the operation demand of blast furnace gas boiler to a certain extent, but this artificial empirical mode can not ensure its judged result entirely accurate, moreover the reliability of this pattern depends on the experience level of operations staff completely, and level is uneven between each operations staff, have height to have low, this can cause very large hidden danger to the safe operation of economizer.Therefore, need the boiling degree of a kind of method to blast furnace gas boiler economizer and carry out real time on-line monitoring, the number of degrees of economizer boiling accurately value is provided, for the operation adjustment of boiler operatiopn personnel provides foundation, guarantees the safe operation of boiler.

Summary of the invention

The object of the invention is for prior art Problems existing, provide a kind of and the monitoring device of on-line monitoring and the monitoring method based on this monitoring device are carried out to blast furnace gas boiler economizer boiling degree.

Technical scheme of the present invention is to provide a kind of blast furnace gas boiler economizer boiling degree on-Line Monitor Device, and its designing points is, this on-Line Monitor Device comprises:

Data acquisition unit, it comprises unit scattered control system, live database server and the first switch, and the first switch is connected with unit scattered control system, live database server respectively; Unit scattered control system gathers the service data of gas boiler, and gathered service data is stored in live database server;

Data processing unit, it comprises mirror database server, calculation server, WEB publisher server, user's display terminal and the second switch, and the second switch is connected with mirror database server, calculation server, WEB publisher server, user's display terminal respectively; Live database server to receive and the service data stored is sent to mirror database server preserves, calculation server reads service data from mirror database server, the result of calculation that computing obtains economizer boiling degree is carried out to read service data, and by result of calculation stored in mirror database server, described result of calculation is published to user's display terminal by WEB publisher server;

Described first switch is connected with the second switch.

On-Line Monitor Device of the present invention in actual applications, also has the following technical scheme improved further.

Further, uni-directional physical spacer assembly is provided with between described first switch and the second switch.

Further, described service data comprises economizer fume side inlet temperature θ _{y, in}, economizer fume side outlet temperature θ _{y, out}, economizer water side-entrance temperature t _{s, in}, economizer water side outlet temperature t _{s, out}, economizer water side-entrance pressure p _{s, in}, economizer fume side outlet dry flue gas in O ₂volume content percent φ ' (O ₂), volume content percent φ ' (CO), boiler feedwater flow G, the as-fired coal airshed B of CO in economizer fume side outlet dry flue gas _g, H in the volume content percent φ (CO) of CO, blast furnace gas in blast furnace gas ₂volume content percent φ (H ₂), N in blast furnace gas ₂volume content percent φ (N ₂), CO in blast furnace gas ₂volume content percent φ (CO ₂), blast furnace coal hydrocarbon in gas C _mh _nvolume content percent φ (C _mh _n) and blast furnace gas water capacity d _g.

Working method of the present invention is: the service data collected sends via the first switch and is stored in live database server by the unit scattered control system in on-Line Monitor Device of the present invention; Live database server by receive and the service data stored is sent to mirror database server is preserved by interconnective first switch, the second switch; Calculation server reads the service data in mirror database server, carries out to service data the result of calculation that computing obtains the boiling degree of economizer, and by result of calculation stored in mirror database server; Result of calculation is published to user's display terminal by WEB publisher server.

Technical scheme of the present invention is to provide a kind of blast furnace gas boiler economizer boiling degree on-line monitoring method, and its designing points is, comprises the following steps:

Step 1: the unit scattered control system of data acquisition unit gathers the service data of blast furnace gas boiler, and described service data is stored in live database server, live database server to receive and the service data stored is sent to mirror database server preserves;

Step 2: the calculation server of data processing unit reads service data from mirror database server;

Step 3: the data prediction service data obtained in step 2 being comprised to bad point process and data smoothing process;

Step 4: adopt the pretreated service data of step 3 to carry out computing, obtain the boiling degree of economizer, comprise following calculation procedure:

Step 4a: the theoretical dry air amount that unit of account volume blast furnace gas combustion is corresponding and theoretical dry flue gas amount:

$V_{\mathrm{gk}}^0=\frac{1}{21}[0.5\mathrm{\φ}\left(H_2\right)+0.5\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σ}(m+\frac{n}{4})\mathrm{\φ}\left(C_m{H}_n\right)]---\left(1\right)$

$V_{\mathrm{gk}}^0=\frac{1}{100}[\mathrm{\φ}\left({\mathrm{CO}}_2\right)+\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σm\φ}\left(C_m{H}_n\right)+\mathrm{\φ}\left(N_2\right)]+0.79V_{\mathrm{gk}}^0---\left(2\right)$

In formula, for the theoretical dry air amount that unit volume blast furnace gas combustion needs, m ³/ m ³(coal gas); for the theoretical dry flue gas amount that unit volume blast furnace gas combustion produces, m ³/ m ³(coal gas); φ (CO), φ (H ₂), φ (C _mh _n), φ (N ₂), φ (CO ₂) be respectively CO, H in blast furnace gas ₂, C _mh _n, N ₂, CO ₂volume content percent, %;

Step 4b: calculate CO in economizer fume side outlet dry flue gas ₂and N ₂volume content percent, comprise the following steps:

Step 4b-1: the fuel characteristic factor β calculating blast furnace gas according to analysis of blast furnace gas ingredient:

$\mathrm{\β}=\frac{0.395[\mathrm{\φ}\left(H_2\right)+\mathrm{\φ}\left({\mathrm{CO}}_2\right)]+0.79\mathrm{\Σ}\left[(m+\frac{n}{4})\mathrm{\φ}\left(C_m{H}_n\right)\right]+0.21\mathrm{\φ}\left(N_2\right)}{\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σm\φ}\left(C_m{H}_n\right)+\mathrm{\φ}\left({\mathrm{CO}}_2\right)}-0.79---\left(3\right)$

Step 4b-2: according to O in economizer fume side outlet dry flue gas ₂volume content percent φ ' (O ₂), the fuel characteristic factor β that obtains of the volume content percent φ ' (CO) of CO and step 4b-1 calculates CO in economizer fume side outlet dry flue gas ₂volume content percent φ ' (CO ₂):

${\mathrm{\φ}}^{\′}\left({\mathrm{CO}}_2\right)=\frac{21-{\mathrm{\φ}}^{\′}\left(O_2\right)-{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)(0.605+\mathrm{\β})}{1+\mathrm{\β}}---\left(4\right)$

In formula, φ ' (CO ₂), φ ' (O ₂), φ ' (CO) be respectively economizer fume side outlet dry flue gas in CO ₂, O ₂, CO volume content percent, %;

Step 4b-3: calculate N in economizer fume side outlet dry flue gas ₂volume content percent φ ' (N ₂):

φ′(N ₂)＝100-φ′(O ₂)-φ′(CO)-φ′(CO ₂) (5)

In formula, φ ' (N ₂) be N in economizer fume side outlet dry flue gas ₂volume content percent, %;

Step 4c: adopt process of iteration to calculate and solve the excess air coefficient of economizer fume side outlet correspondence and the actual dry flue gas amount of unit volume blast furnace gas combustion generation, comprise the following steps:

Step 4c-1: assuming that the actual dry flue gas amount that an initial unit volume blast furnace gas combustion produces

Step 4c-2: the actual dry flue gas amount produced according to the unit volume blast furnace gas combustion of step 4c-1 supposition calculate excess air coefficient α:

$\mathrm{\α}=\frac{21}{21-79\frac{{\mathrm{\φ}}^{\′}\left(O_2\right)-0.5{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)}{{\mathrm{\φ}}^{\′}\left(N_2\right)-\frac{\mathrm{\φ}\left(N_2\right)}{V_{\mathrm{gy}}^{\mathrm{jd}}}}}---\left(6\right)$

In formula, α is excess air coefficient; for the actual dry flue gas amount that the unit volume blast furnace gas combustion of supposition produces, m ³/ m ³(coal gas).

Step 4c-3: the excess air coefficient α obtained according to step 4c-2, and the theoretical dry air amount that the unit volume blast furnace gas combustion of step 4a acquisition needs with the theoretical dry flue gas amount that unit volume blast furnace gas combustion produces calculate the actual dry flue gas amount V that unit volume blast furnace gas combustion produces _gy:

$V_{\mathrm{gy}}=V_{\mathrm{gy}}^0+(\mathrm{\α}-1)V_{\mathrm{gk}}^0---\left(7\right)$

Step 4c-4: the actual dry flue gas amount V that the unit volume blast furnace gas combustion calculated by step 4c-3 produces _gywith the actual dry flue gas amount that the unit volume blast furnace gas combustion of step 4c-1 supposition produces compare, if the two difference exceedes the error range of setting, then by V _gywith the actual dry flue gas amount that produces as the unit volume blast furnace gas combustion of new supposition of mean value and return step 4c-1 and re-execute step 4c-1 ~ step 4c-4, until V _gywith difference meet the error range of setting;

Step 4c-5: export α as final excess air coefficient, export V _gyas the actual dry flue gas amount that final unit volume blast furnace gas combustion produces.

Step 4d: calculate the steam vapour amount that unit volume blast furnace gas combustion corresponding to economizer fume side outlet produces:

$V_{H_{2}O}=\frac{1}{100}[\mathrm{\φ}\left(H_2\right)+\mathrm{\Σ}\frac{n}{2}\mathrm{\φ}\left(C_m{H}_n\right)]+1.2(d_g+1.293\mathrm{\α}{V}_{\mathrm{gk}}^0{d}_k)---\left(8\right)$

In formula, V _h2Ofor the steam vapour amount that the unit volume blast furnace gas combustion that the outlet of economizer fume side is corresponding produces, m ³/ m ³(coal gas); d _gfor blast furnace gas water capacity, kg/m ³(coal gas); d _kfor the absolute humidity of air, kg/kg (dry air);

Step 4e: calculate the average specific heat capacity at constant pressure of dry flue gas between economizer fume side inlet temperature and outlet temperature, comprise the following steps:

Step 4e-1: according to economizer fume side inlet temperature θ _{y, in}with economizer fume side outlet temperature θ _{y, out}calculate O respectively ₂, CO ₂, CO, N ₂at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature c _{p, CO},

Step 4e-2: the result obtained according to volume content percent and the step 4e-1 of each composition in economizer fume side outlet dry flue gas, adopts calculated with weighted average method to obtain dry flue gas at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature:

$c_{p,\mathrm{gy}}=c_{p,O_2}\frac{{\mathrm{\φ}}^{\′}\left(O_2\right)}{100}+c_{p,C{O}_2}\frac{{\mathrm{\φ}}^{\′}\left(C{O}_2\right)}{100}+c_{p,\mathrm{CO}}\frac{{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)}{100}+c_{p,N_2}\frac{{\mathrm{\φ}}^{\′}\left(N_2\right)}{100}---\left(9\right)$

In formula, c _{p, gy}for economizer fume side outlet dry flue gas is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k); φ ' (O ₂), φ ' (CO ₂), φ ' (CO), φ ' (N ₂) be respectively O in economizer fume side outlet dry flue gas ₂, CO ₂, CO, N ₂volume content percent, %; c _{p, CO}, be respectively O ₂, CO ₂, CO, N ₂at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k);

Step 4f: calculate the average specific heat capacity at constant pressure of water vapor between economizer fume side inlet temperature and outlet temperature:

According to economizer fume side inlet temperature θ _{y, in}with economizer fume side outlet temperature θ _{y, out}calculate water vapor at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature

Step 4g: calculate economizer fume side thermal discharge:

$Q=B_g(V_{\mathrm{gy}}{c}_{p.\mathrm{gy}}+V_{H_{2}O}{c}_{p,H_{2}O})({\mathrm{\θ}}_{y,\mathrm{in}}-{\mathrm{\θ}}_{y,\mathrm{out}})---\left(10\right)$

In formula, Q is economizer fume side thermal discharge, kJ/h; B _gfor as-fired coal airshed, m ³/ h; θ _{y, in}for economizer fume side inlet temperature, DEG C; θ _{y, out}for economizer fume side outlet temperature, DEG C; c _{p, gy}for dry flue gas is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k); for water vapor is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k);

Step 4h: calculate economizer water side-entrance Enthalpy of Feed Water:

According to economizer water side-entrance temperature t _{s, in}, economizer water side-entrance pressure p _{s, in}, calculate economizer water side-entrance Enthalpy of Feed Water h _{s, in};

Step 4i: calculate economizer water side outlet steam water interface enthalpy:

$h_{s,\mathrm{out}}=\frac{\mathrm{\ηQ}}{G}+h_{s,\mathrm{in}}---\left(11\right)$

In formula, h _{s, out}for economizer water side outlet steam water interface enthalpy, kJ/kg; h _{s, in}for economizer water side-entrance Enthalpy of Feed Water, kJ/kg; η is economizer heat exchange efficiency; G is boiler feedwater flow, kg/h;

Step 4j: according to economizer water side outlet temperature t _{s, out}, calculate the saturation water enthalpy h that economizer water side outlet temperature is corresponding _band the saturated vapor enthalpy h that economizer water side outlet temperature is corresponding _b';

Step 4k: calculate the latent heat of vaporization that economizer water side outlet temperature is corresponding:

r＝h _b′-h _b (12)

In formula, r is the latent heat of vaporization corresponding to economizer water side outlet temperature, kJ/kg; h _bfor the saturation water enthalpy that economizer water side outlet temperature is corresponding, kJ/kg; h _b' be saturated vapor enthalpy corresponding to economizer water side outlet temperature, kJ/kg;

Step 4l: calculate economizer boiling degree:

$x=\frac{h_{s,\mathrm{out}}-h_b}{r}---\left(13\right)$

In formula, x is economizer boiling degree;

Step 5: the economizer boiling degree result of calculation obtained by step 4l is stored in mirror database server, and described result of calculation is published to user's display terminal by WEB publisher server.

Calculation server of the present invention reads service data from mirror database server, the result of calculation that computing obtains economizer boiling degree is carried out to read service data, result of calculation stored in mirror database server, described result of calculation is published to user's display terminal by WEB publisher server.User can browse economizer boiling number of degrees value by real time review by user's display terminal, the operation conditions of timely grasp economizer, if find that economizer boiling degree exceedes the higher limit of setting, operations staff can reduce economizer boiling degree by boiler operatiopn adjustment in time, make economizer in a safe condition, to guarantee the safe operation of blast furnace gas boiler, and extend the serviceable life of blast furnace gas boiler economizer.

Beneficial effect:

Achieve the on-line monitoring of gas boiler economizer boiling degree, unit scattered control system gathers the service data of blast furnace gas boiler, and service data is stored in live database server; Live database server to receive and the service data stored is sent to mirror database server preserves; Calculation server reads service data from mirror database server, carries out to read service data the result of calculation that computing obtains economizer boiling degree, and result of calculation stored in mirror database server; Described result of calculation is published to user's display terminal by WEB publisher server, and user can browse economizer boiling number of degrees value by real time review by user's display terminal, grasps the operation conditions of economizer in time.If find that economizer boiling degree exceedes the higher limit of setting, operations staff can reduce economizer boiling degree by boiler operatiopn adjustment in time, make economizer in a safe condition, to guarantee the safe operation of blast furnace gas boiler, and extend the serviceable life of blast furnace gas boiler economizer.

Accompanying drawing explanation

The schematic diagram of Fig. 1 line monitoring device of the present invention.

Embodiment

In order to illustrate technical scheme of the present invention and technical purpose, below in conjunction with the drawings and the specific embodiments, the present invention is described further.

Embodiment 1 on-Line Monitor Device:

As shown in Figure 1, a kind of blast furnace gas boiler economizer boiling degree on-Line Monitor Device of the present invention comprises data acquisition unit, uni-directional physical spacer assembly and data processing unit, connects between described data acquisition unit and data processing unit through uni-directional physical spacer assembly.

Wherein, data acquisition unit, it comprises unit scattered control system, live database server and the first switch, and the first switch is connected with unit scattered control system, live database server respectively.Unit scattered control system gathers the service data of blast furnace gas boiler, and gathered service data is left in live database server.The service data that unit scattered control system gathers comprises economizer fume side inlet temperature θ _{y, in}, economizer fume side outlet temperature θ _{y, out}, economizer water side-entrance temperature t _{s, in}, economizer water side outlet temperature t _{s, out}, economizer water side-entrance pressure p _{s, in}, economizer fume side outlet dry flue gas in O ₂volume content percent φ ' (O ₂), volume content percent φ ' (CO), boiler feedwater flow G, the as-fired coal airshed B of CO in economizer fume side outlet dry flue gas _g, H in the volume content percent φ (CO) of CO, blast furnace gas in blast furnace gas ₂volume content percent φ (H ₂), N in blast furnace gas ₂volume content percent φ (N ₂), CO in blast furnace gas ₂volume content percent φ (CO ₂), blast furnace coal hydrocarbon in gas C _mh _nvolume content percent φ (C _mh _n), and blast furnace gas water capacity d _g.

Wherein, data processing unit, it comprises mirror database server, calculation server, WEB publisher server, user's display terminal and the second switch, and the second switch is connected with mirror database server, calculation server, WEB publisher server, user's display terminal respectively; Described first switch is connected with the second switch.Live database server to receive and the service data stored is sent to mirror database server preserves, calculation server reads service data from mirror database server; Calculation server carries out to read service data the result of calculation that computing obtains economizer boiling degree, result of calculation stored in mirror database server, and by WEB publisher server, result of calculation is published to user's display terminal; User can browse economizer boiling number of degrees value by real time review by user's display terminal, grasps the operation conditions of economizer in time.

Embodiment 2 on-line monitoring method:

The invention provides a kind of blast furnace gas boiler economizer boiling degree on-line monitoring method, its designing points is, comprises the following steps:

Step 1: the unit scattered control system of data acquisition unit gathers the service data of blast furnace gas boiler, and described service data is stored in live database server, live database server to receive and the service data stored is sent to mirror database server preserves.

Step 2: the calculation server of data processing unit reads the service data of blast furnace gas boiler from mirror database server by measuring point KKS code-point number.The service data of the unit scattered control system collection read comprises economizer fume side inlet temperature θ _{y, in}, economizer fume side outlet temperature θ _{y, out}, economizer water side-entrance temperature t _{s, in}, economizer water side outlet temperature t _{s, out}, economizer water side-entrance pressure p _{s, in}, economizer fume side outlet dry flue gas in O ₂volume content percent φ ' (O ₂), volume content percent φ ' (CO), boiler feedwater flow G, the as-fired coal airshed B of CO in economizer fume side outlet dry flue gas _g, H in the volume content percent φ (CO) of CO, blast furnace gas in blast furnace gas ₂volume content percent φ (H ₂), N in blast furnace gas ₂volume content percent φ (N ₂), CO in blast furnace gas ₂volume content percent φ (CO ₂), blast furnace coal hydrocarbon in gas C _mh _nvolume content percent φ (C _mh _n), and blast furnace gas water capacity d _g.

Step 3: the data prediction various service datas obtained in step 2 being comprised to bad point process and data smoothing process.Wherein adopt polynomial expression slip approximating method to judge bad point to bad point process, and bad point is rejected; Smothing filtering method is adopted to data smoothing processing, to eliminate or to weaken the impact of data sampling interference.

Step 4: adopt the pretreated service data of step 3 to carry out computing, obtain the boiling degree of economizer, comprise following calculation procedure:

Step 4a: the theoretical dry air amount that unit of account volume blast furnace gas combustion is corresponding and theoretical dry flue gas amount:

$V_{\mathrm{gk}}^0=\frac{1}{21}[0.5\mathrm{\φ}\left(H_2\right)+0.5\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σ}(m+\frac{n}{4})\mathrm{\φ}\left(C_m{H}_n\right)]---\left(1\right)$

$V_{\mathrm{gk}}^0=\frac{1}{100}[\mathrm{\φ}\left({\mathrm{CO}}_2\right)+\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σm\φ}\left(C_m{H}_n\right)+\mathrm{\φ}\left(N_2\right)]+0.79V_{\mathrm{gk}}^0---\left(2\right)$

In formula, for the theoretical dry air amount that unit volume blast furnace gas combustion needs, m ³/ m ³(coal gas); for the theoretical dry flue gas amount that unit volume blast furnace gas combustion produces, m ³/ m ³(coal gas); φ (CO), φ (H ₂), φ (C _mh _n), φ (N ₂), φ (CO ₂) be respectively CO, H in blast furnace gas ₂, C _mh _n, N ₂, CO ₂volume content percent, %;

Step 4b: obtain CO in economizer fume side outlet dry flue gas ₂and N ₂volume content percent; Dry flue gas composition comprises O ₂, CO ₂, CO and N ₂, wherein O ₂real-Time Monitoring value is adopted with the volume content percent of CO, and CO ₂and N ₂volume content percent then by calculating, specifically comprise the following steps:

Step 4b-1: the fuel characteristic factor β first calculating blast furnace gas according to analysis of blast furnace gas ingredient:

$\mathrm{\β}=\frac{0.395[\mathrm{\φ}\left(H_2\right)+\mathrm{\φ}\left({\mathrm{CO}}_2\right)]+0.79\mathrm{\Σ}\left[(m+\frac{n}{4})\mathrm{\φ}\left(C_m{H}_n\right)\right]+0.21\mathrm{\φ}\left(N_2\right)}{\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σm\φ}\left(C_m{H}_n\right)+\mathrm{\φ}\left({\mathrm{CO}}_2\right)}-0.79---\left(3\right)$

In formula, β is the greenhouse gas of blast furnace gas, one;

Step 4b-2: then according to O in economizer fume side outlet dry flue gas ₂volume content percent φ ' (O ₂), the volume content percent φ ' (CO) of CO and step 4b-1 obtains in economizer fume side outlet dry flue gas fuel characteristic factor β calculates CO in economizer fume side outlet dry flue gas ₂volume content percent φ ' (CO ₂):

${\mathrm{\φ}}^{\′}\left({\mathrm{CO}}_2\right)=\frac{21-{\mathrm{\φ}}^{\′}\left(O_2\right)-{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)(0.605+\mathrm{\β})}{1+\mathrm{\β}}---\left(4\right)$

In formula, φ ' (CO ₂), φ ' (O ₂), φ ' (CO) be respectively economizer fume side outlet dry flue gas in CO ₂, O ₂, CO volume content percent, %;

Step 4b-3: finally according to O in economizer fume side outlet dry flue gas ₂, CO and CO ₂volume content percent, calculate economizer fume side outlet dry flue gas in N ₂volume content percent φ ' (N ₂):

φ′(N ₂)＝100-φ′(O ₂)-φ′(CO)-φ′(CO ₂) (5)

In formula, φ ' (N ₂) be N in economizer fume side outlet dry flue gas ₂volume content percent, %;

Step 4c: adopt process of iteration to calculate and solve the excess air coefficient of economizer fume side outlet correspondence and the actual dry flue gas amount of unit volume blast furnace gas combustion generation, comprise the following steps:

Step 4c-1: assuming that the actual dry flue gas amount that an initial unit volume blast furnace gas combustion produces

Step 4c-2: the actual dry flue gas amount produced according to the unit volume blast furnace gas combustion of step 4c-1 supposition calculate excess air coefficient α:

$\mathrm{\α}=\frac{21}{21-79\frac{{\mathrm{\φ}}^{\′}\left(O_2\right)-0.5{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)}{{\mathrm{\φ}}^{\′}\left(N_2\right)-\frac{\mathrm{\φ}\left(N_2\right)}{V_{\mathrm{gy}}^{\mathrm{jd}}}}}---\left(6\right)$

In formula, α is excess air coefficient, one; φ ' (O ₂), φ ' (CO), φ ' (N ₂) be respectively O in economizer fume side outlet dry flue gas ₂, CO, N ₂volume content percent, %; φ (N ₂) be N in blast furnace gas ₂volume content percent, %; for the actual dry flue gas amount that the unit volume blast furnace gas combustion of supposition produces, m ³/ m ³(coal gas).

Step 4c-3: the excess air coefficient α obtained according to step 4c-2, and the theoretical dry air amount that the unit volume blast furnace gas combustion of step 4a acquisition needs with the theoretical dry flue gas amount that unit volume blast furnace gas combustion produces calculate the actual dry flue gas amount V that unit volume blast furnace gas combustion produces _gy:

$V_{\mathrm{gy}}=V_{\mathrm{gy}}^0+(\mathrm{\α}-1)V_{\mathrm{gk}}^0---\left(7\right)$

In formula, V _gyfor the actual dry flue gas amount that unit volume blast furnace gas combustion produces, m ³/ m ³(coal gas);

Step 4c-4: the actual dry flue gas amount V that the unit volume blast furnace gas combustion calculated by step 4c-3 produces _gywith the actual dry flue gas amount that the unit volume blast furnace gas combustion of step 4c-1 supposition produces compare, if the two difference exceedes the error range of setting, then by V _gywith the actual dry flue gas amount that produces as the unit volume blast furnace gas combustion of new supposition of mean value and return step 4c-1 and re-execute step 4c-1 ~ step 4c-4, until V _gywith difference meet the error range of setting;

Step 4c-5: export α as final excess air coefficient, export V _gyas the actual dry flue gas amount that final unit volume blast furnace gas combustion produces.

Step 4d: calculate the steam vapour amount that unit volume blast furnace gas combustion corresponding to economizer fume side outlet produces:

$V_{H_{2}O}=\frac{1}{100}[\mathrm{\φ}\left(H_2\right)+\mathrm{\Σ}\frac{n}{2}\mathrm{\φ}\left(C_m{H}_n\right)]+1.2(d_g+1.293\mathrm{\α}{V}_{\mathrm{gk}}^0{d}_k)---\left(8\right)$

In formula, for the steam vapour amount that the unit volume blast furnace gas combustion that the outlet of economizer fume side is corresponding produces, m ³/ m ³(coal gas); d _gfor blast furnace gas water capacity, kg/m ³(coal gas); d _kfor the absolute humidity of air, kg/kg (dry air), by value in season, can get 0.002kg/kg (dry air) in the winter time, get 0.02kg/kg (dry air) summer, get 0.01kg/kg (dry air) in spring and autumn;

Step 4e: calculate the average specific heat capacity at constant pressure of dry flue gas between economizer fume side inlet temperature and outlet temperature, comprise the following steps:

Step 4e-1: according to economizer fume side inlet temperature θ _{y, in}with economizer fume side outlet temperature θ _{y, out}calculate O respectively ₂, CO ₂, CO, N ₂at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature c _{p, CO}, below, illustrate that CO is at θ for CO _{y, in}to θ _{y, out}average specific heat capacity at constant pressure c between temperature _{p, CO}computation process: first calculate CO at 0 DEG C to θ _{y, in}average specific heat capacity at constant pressure between temperature and CO arrives θ at 0 DEG C _{y, out}average specific heat capacity at constant pressure between temperature then formula is adopted calculate CO at θ _{y, in}extremely θ _{y, out}average specific heat capacity at constant pressure c between temperature _{p, CO}, process the average specific heat capacity at constant pressure c of the CO obtained like this _{p, CO}closer to actual value.

Step 4e-2: the result obtained according to volume content percent and the step 4e-1 of each composition in economizer fume side outlet dry flue gas, adopts calculated with weighted average method to obtain economizer fume side outlet dry flue gas at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature:

$c_{p,\mathrm{gy}}=c_{p,O_2}\frac{{\mathrm{\φ}}^{\′}\left(O_2\right)}{100}+c_{p,C{O}_2}\frac{{\mathrm{\φ}}^{\′}\left(C{O}_2\right)}{100}+c_{p,\mathrm{CO}}\frac{{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)}{100}+c_{p,N_2}\frac{{\mathrm{\φ}}^{\′}\left(N_2\right)}{100}---\left(9\right)$

In formula, c _{p, gy}for dry flue gas is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k); φ ' (O ₂), φ ' (CO ₂), φ ' (CO), φ ' (N ₂) be respectively O in economizer fume side outlet dry flue gas ₂, CO ₂, CO, N ₂volume content percent, %; c _{p, CO}, be respectively O ₂, CO ₂, CO, N ₂at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k);

Step 4f: calculate the average specific heat capacity at constant pressure of water vapor between economizer fume side inlet temperature and outlet temperature:

According to economizer fume side inlet temperature θ _{y, in}with economizer fume side outlet temperature θ _{y, out}obtain water vapor at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature water vapor is at θ _{y, in}to θ _{y, out}the processing procedure of the average specific heat capacity at constant pressure between temperature, with step 4e-1, is not described in detail in this.

Step 4g: calculate economizer fume side thermal discharge:

$Q=B_g(V_{\mathrm{gy}}{c}_{p,\mathrm{gy}}+V_{H_{2}O}{c}_{p,H_{2}O})({\mathrm{\θ}}_{y,\mathrm{in}}-{\mathrm{\θ}}_{y,\mathrm{out}})---\left(10\right)$

In formula, Q is economizer fume side thermal discharge, kJ/h; B _gfor as-fired coal airshed, m ³/ h; θ _{y, in}for economizer fume side inlet temperature, DEG C; θ _{y, out}for economizer fume side outlet temperature, DEG C; c _{p, gy}for dry flue gas is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k); for water vapor is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k);

Step 4h: calculate economizer water side-entrance Enthalpy of Feed Water:

According to economizer water side-entrance temperature t _{s, in}, economizer water side-entrance pressure p _{s, in}adopt the industrial properties of water and steam model of classical 1997 international water and steam character associations proposition, be called for short IAPWS-IF97 (Association for the Properties of Water and Steam), calculate economizer water side-entrance Enthalpy of Feed Water h _{s, in}.

Step 4i: calculate economizer exit steam water interface enthalpy:

$h_{s,\mathrm{out}}=\frac{\mathrm{\ηQ}}{G}+h_{s,\mathrm{in}}---\left(11\right)$

In formula, h _{s, out}for economizer water side outlet steam water interface enthalpy, kJ/kg; h _{s, in}for economizer water side-entrance Enthalpy of Feed Water, kJ/kg; η is economizer heat exchange efficiency, can be taken as design load; G is boiler feedwater flow, kg/h;

Step 4j: according to economizer water side outlet temperature t _{s, out}, adopt classical IAPWS-IF97 model, calculate the saturation water enthalpy h that economizer water side outlet temperature is corresponding _band the saturated vapor enthalpy h that economizer water side outlet temperature is corresponding _b'.

Step 4k: calculate the latent heat of vaporization that economizer water side outlet temperature is corresponding:

r＝h _b′-h _b (12)

In formula, r is the latent heat of vaporization corresponding to economizer water side outlet temperature, kJ/kg; h _bfor the saturation water enthalpy that economizer water side outlet temperature is corresponding, kJ/kg; h _b' be saturated vapor enthalpy corresponding to economizer water side outlet temperature, kJ/kg;

Step 4l: calculate economizer boiling degree:

$x=\frac{h_{s,\mathrm{out}}-h_b}{r}---\left(13\right)$

In formula, x is economizer boiling degree, one;

Step 5: the result of calculation obtained by step 4l sends and stored in mirror database server, described result of calculation is published to user's display terminal by WEB publisher server, and user browses economizer boiling degree monitoring result in time by user terminal.

Calculation server of the present invention reads service data from mirror database server, the result of calculation that computing obtains economizer boiling degree is carried out to read service data, again result of calculation stored in mirror database server, described result of calculation is published to user's display terminal by WEB publisher server.User can browse economizer boiling number of degrees value by real time review by user's display terminal, the operation conditions of timely grasp economizer, if economizer boiling degree exceedes the higher limit of setting, operations staff can reduce economizer boiling degree by boiler operatiopn adjustment in time, make economizer in a safe condition, to guarantee the safe operation of blast furnace gas boiler, and extend the serviceable life of blast furnace gas boiler economizer.

In terms of existing technologies, the present invention has following progressive:

Achieve the on-line monitoring of gas boiler economizer boiling degree, the unit scattered control system be arranged on gas boiler gathers the service data of gas boiler, and institute's service data is stored in live database server; Live database server to receive and the service data stored is sent to mirror database server preserves; Calculation server reads service data from mirror database server, carries out to read service data the result of calculation that computing obtains economizer boiling degree, and result of calculation stored in mirror database server; Described result of calculation is published to user's display terminal by WEB publisher server, and user can browse economizer boiling number of degrees value by real time review by user's display terminal, grasps the operation conditions of economizer in time.If economizer boiling degree exceedes the higher limit of setting, operations staff can reduce economizer boiling degree by boiler operatiopn adjustment in time, to guarantee the safe operation of blast furnace gas boiler, and make economizer in a safe condition, extend the serviceable life of blast furnace gas boiler economizer.

More than show and describe ultimate principle of the present invention, principal character and advantage of the present invention.The technician of the industry should understand; the present invention is not restricted to the described embodiments; what describe in above-described embodiment and instructions just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and application claims protection domain is defined by appending claims, instructions and equivalent thereof.

Claims (4)

1. a blast furnace gas boiler economizer boiling degree on-Line Monitor Device, is characterized in that, comprising:

Data acquisition unit, it comprises unit scattered control system, live database server and the first switch, and the first switch is connected with unit scattered control system, live database server respectively; Unit scattered control system gathers the service data of blast furnace gas boiler, and gathered service data is stored in live database server;

Data processing unit, it comprises mirror database server, calculation server, WEB publisher server, user's display terminal and the second switch, and the second switch is connected with mirror database server, calculation server, WEB publisher server, user's display terminal respectively; Live database server to receive and the service data stored is sent to mirror database server preserves; Calculation server reads service data from mirror database server, to read service data carry out computing obtain economizer boiling degree result of calculation and by result of calculation stored in mirror database server; Described result of calculation is published to user's display terminal by WEB publisher server;

Described first switch is connected with the second switch.

2. a kind of blast furnace gas boiler economizer boiling degree on-Line Monitor Device according to claim 1, is characterized in that: be provided with uni-directional physical spacer assembly between described first switch and the second switch.

3. a kind of blast furnace gas boiler economizer boiling degree on-Line Monitor Device according to claim 2, is characterized in that: described service data comprises economizer fume side inlet temperature θ _{y, in}, economizer fume side outlet temperature θ _{y, uot}, economizer water side-entrance temperature t _{s, in}, economizer water side outlet temperature t _{s, out}, economizer water side-entrance pressure p _{s, in}, economizer fume side outlet dry flue gas in O ₂volume content percent φ ' (O ₂), volume content percent φ ' (CO), boiler feedwater flow G, the as-fired coal airshed B of CO in economizer fume side outlet dry flue gas _g, H in the volume content percent φ (CO) of CO, blast furnace gas in blast furnace gas ₂volume content percent φ (H ₂), N in blast furnace gas ₂volume content percent φ (N ₂), CO in blast furnace gas ₂volume content percent φ (CO ₂), blast furnace coal hydrocarbon in gas C _mh _nvolume content percent φ (C _mh _n) and blast furnace gas water capacity d _g.

4. a blast furnace gas boiler economizer boiling degree on-line monitoring method, is characterized in that, comprise the following steps:

Step 1: the unit scattered control system of data acquisition unit gathers the service data of blast furnace gas boiler, and described service data is stored in live database server, live database server to receive and the service data stored is sent to mirror database server preserves;

Step 2: the calculation server of data processing unit reads service data from mirror database server;

Step 3: the data prediction service data obtained in step 2 being comprised to bad point process and data smoothing process;

Step 4: adopt the pretreated service data of step 3 to carry out computing, obtain the boiling degree of economizer, comprise following calculation procedure:

Step 4a: the theoretical dry air amount that unit of account volume blast furnace gas combustion is corresponding and theoretical dry flue gas amount:

$V_{\mathrm{gk}}^0=\frac{1}{21}[0.5\mathrm{\φ}\left(H_2\right)+0.5\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σ}(m+\frac{n}{4})\mathrm{\φ}\left(C_m{H}_n\right)]---\left(1\right)$

$V_{\mathrm{gy}}^0=\frac{1}{100}[\mathrm{\φ}\left({\mathrm{CO}}_2\right)+\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σm\φ}\left(C_m{H}_n\right)+\mathrm{\φ}\left(N_2\right)]+0.79V_{\mathrm{gk}}^0---\left(2\right)$

In formula, for the theoretical dry air amount that unit volume blast furnace gas combustion needs, m ³/ m ³(coal gas); for the theoretical dry flue gas amount that unit volume blast furnace gas combustion produces, m ³/ m ³(coal gas); φ (CO), φ (H ₂), φ (C _mh _n), φ (N ₂), φ (CO ₂) be respectively CO, H in blast furnace gas ₂, C _mh _n, N ₂, CO ₂volume content percent, %;

Step 4b: calculate CO in economizer fume side outlet dry flue gas ₂and N ₂volume content percent, comprise the following steps:

Step 4b-1: the fuel characteristic factor β calculating blast furnace gas according to analysis of blast furnace gas ingredient:

$\mathrm{\β}=\frac{0.395[\mathrm{\φ}\left(H_2\right)+\mathrm{\φ}\left({\mathrm{CO}}_2\right)]+0.79\mathrm{\Σ}\left[(m+\frac{n}{4})\mathrm{\φ}\left(C_m{H}_n\right)\right]+0.21\mathrm{\φ}\left(N_2\right)}{\mathrm{\φ}\left(\mathrm{CO}\right)+\mathrm{\Σm\φ}\left(C_m{H}_m\right)+\mathrm{\φ}\left({\mathrm{CO}}_2\right)}-0.79---\left(3\right)$

Step 4b-2: according to O in economizer fume side outlet dry flue gas ₂volume content percent φ ' (O ₂), the fuel characteristic factor β that obtains of the volume content percent φ ' (CO) of CO and step 4b-1 calculates CO in economizer fume side outlet dry flue gas ₂volume content percent φ ' (CO ₂):

${\mathrm{\φ}}^{\′}\left({\mathrm{CO}}_2\right)=\frac{21-{\mathrm{\φ}}^{\′}\left(O_2\right)-{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)(0.605+\mathrm{\β})}{1+\mathrm{\β}}---\left(4\right)$

In formula, φ ' (CO ₂), φ ' (O ₂), φ ' (CO) be respectively economizer fume side outlet dry flue gas in CO ₂, O ₂, CO volume content percent, %;

Step 4b-3: calculate N in economizer fume side outlet dry flue gas ₂volume content percent φ ' (N ₂):

φ′(N ₂)＝100-φ′(O ₂)-φ′(CO)-φ′(CO ₂) (5)

In formula, φ ' (N ₂) be N in economizer fume side outlet dry flue gas ₂volume content percent, %;

Step 4c: adopt process of iteration to calculate the actual dry flue gas amount of excess air coefficient corresponding to economizer fume side outlet and the generation of unit volume blast furnace gas combustion, comprise the following steps:

Step 4c-1: assuming that the actual dry flue gas amount that an initial unit volume blast furnace gas combustion produces

Step 4c-2: the actual dry flue gas amount produced according to the unit volume blast furnace gas combustion of step 4c-1 supposition calculate excess air coefficient α:

$\mathrm{\α}=\frac{21}{21-79\frac{{\mathrm{\φ}}^{\′}\left(O_2\right)-0.5{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)}{{\mathrm{\φ}}^{\′}\left(N_2\right)-\frac{\mathrm{\φ}\left(N_2\right)}{V_{\mathrm{gy}}^{\mathrm{jd}}}}}---\left(6\right)$

In formula, α is excess air coefficient; for the actual dry flue gas amount that the unit volume blast furnace gas combustion of supposition produces, m ³/ m ³(coal gas);

Step 4c-3: the excess air coefficient α obtained according to step 4c-2, and the theoretical dry air amount that the unit volume blast furnace gas combustion of step 4a acquisition needs with the theoretical dry flue gas amount that unit volume blast furnace gas combustion produces calculate the actual dry flue gas amount V that unit volume blast furnace gas combustion produces _gy:

$V_{\mathrm{gy}}=V_{\mathrm{gy}}^0+(\mathrm{\α}-1)V_{\mathrm{gk}}^0---\left(7\right)$

Step 4c-4: the actual dry flue gas amount V that the unit volume blast furnace gas combustion calculated by step 4c-3 produces _gywith the actual dry flue gas amount that the unit volume blast furnace gas combustion of step 4c-1 supposition produces compare, if the two difference exceedes the error range of setting, then by V _gywith the actual dry flue gas amount that produces as the unit volume blast furnace gas combustion of new supposition of mean value and return step 4c-1 and re-execute step 4c-1 ~ step 4c-4, until V _gywith difference meet the error range of setting;

Step 4c-5: export α as final excess air coefficient, export V _gyas the actual dry flue gas amount that final unit volume blast furnace gas combustion produces.

Step 4d: calculate the steam vapour amount that unit volume blast furnace gas combustion corresponding to economizer fume side outlet produces:

$V_{H_{2}O}=\frac{1}{100}[\mathrm{\φ}\left(H_2\right)+\mathrm{\Σ}\frac{n}{2}\mathrm{\φ}\left(C_m{H}_n\right)]+1.2(d_g+1.293\mathrm{\α}{V}_{\mathrm{gk}}^0{d}_k)---\left(8\right)$

In formula, for the steam vapour amount that the unit volume blast furnace gas combustion that the outlet of economizer fume side is corresponding produces, m ³/ m ³(coal gas); d _gfor blast furnace gas water capacity, kg/m ³(coal gas); d _kfor the absolute humidity of air, kg/kg (dry air);

Step 4e: calculate the average specific heat capacity at constant pressure of dry flue gas between economizer fume side inlet temperature and outlet temperature, comprise the following steps:

Step 4e-1: according to economizer fume side inlet temperature θ _{y, in}with economizer fume side outlet temperature θ _{y, out}calculate O respectively ₂, CO ₂, CO, N ₂at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature c _{p, CO},

Step 4e-2: the result obtained according to volume content percent and the step 4e-1 of each composition in economizer fume side outlet dry flue gas, adopts calculated with weighted average method to obtain dry flue gas at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature:

$c_{p,\mathrm{gy}}=c_{p,O_2}\frac{{\mathrm{\φ}}^{\′}\left(O_2\right)}{100}+c_{p,C{O}_2}\frac{{\mathrm{\φ}}^{\′}\left({\mathrm{CO}}_2\right)}{100}+c_{p,\mathrm{CO}}\frac{{\mathrm{\φ}}^{\′}\left(\mathrm{CO}\right)}{100}+c_{p,N_2}\frac{{\mathrm{\φ}}^{\′}\left(N_2\right)}{100}---\left(9\right)$

In formula, c _{p, gy}for dry flue gas is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k); be respectively O ₂, CO ₂, CO, N ₂at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k);

Step 4f: calculate the average specific heat capacity at constant pressure of water vapor between economizer fume side inlet temperature and outlet temperature:

According to economizer fume side inlet temperature θ _{y, in}with economizer fume side outlet temperature θ _{y, out}calculate water vapor at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature

Step 4g: calculate economizer fume side thermal discharge:

$Q=B_g(V_{\mathrm{gy}}{c}_{p.\mathrm{gy}}+V_{H_{2}O}{c}_{p,H_{2}O})({\mathrm{\θ}}_{y,\mathrm{in}}-{\mathrm{\θ}}_{y,\mathrm{out}})---\left(10\right)$

In formula, Q is economizer fume side thermal discharge, kJ/h; B _gfor as-fired coal airshed, m ³/ h; θ _{y, in}for economizer fume side inlet temperature, DEG C; θ _{y, out}for economizer fume side outlet temperature, DEG C; c _{p, gy}for dry flue gas is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k); for water vapor is at θ _{y, in}to θ _{y, out}average specific heat capacity at constant pressure between temperature, kJ/ (m ³k);

Step 4h: calculate economizer water side-entrance Enthalpy of Feed Water:

According to economizer water side-entrance temperature t _{s, in}, economizer water side-entrance pressure p _{s, in}, calculate economizer water side-entrance Enthalpy of Feed Water h _{s, in};

Step 4i: calculate economizer water side outlet steam water interface enthalpy:

$h_{s,\mathrm{out}}=\frac{\mathrm{\ηQ}}{G}+h_{s,\mathrm{in}}---\left(11\right)$

In formula, h _{s, out}for economizer water side outlet steam water interface enthalpy, kJ/kg; h _{s, in}for economizer water side-entrance Enthalpy of Feed Water, kJ/kg; η is economizer heat exchange efficiency; G is boiler feedwater flow, kg/h;

Step 4j: according to economizer water side outlet temperature t _{s, out}, calculate the saturation water enthalpy h that economizer water side outlet temperature is corresponding _band the saturated vapor enthalpy h that economizer water side outlet temperature is corresponding _b';

Step 4k: calculate the latent heat of vaporization that economizer water side outlet temperature is corresponding:

r＝h _b′-h _b (12)

In formula, r is the latent heat of vaporization corresponding to economizer water side outlet temperature, kJ/kg; h _bfor the saturation water enthalpy that economizer water side outlet temperature is corresponding, kJ/kg; h _b' be saturated vapor enthalpy corresponding to economizer water side outlet temperature, kJ/kg;

Step 4l: calculate economizer boiling degree:

$x=\frac{h_{s,\mathrm{out}}-h_b}{r}---\left(13\right)$

In formula, x is economizer boiling degree;

Step 5: the economizer boiling degree result of calculation obtained by step 4l is stored in mirror database server, and described result of calculation is published to user's display terminal by WEB publisher server.