CN105861769A - Blast furnace cooling water system variable valve optimized operation and pump selecting method based on maximum temperature difference - Google Patents

Abstract

The invention discloses a blast furnace cooling water system variable valve optimized operation and pump selecting method based on the maximum temperature difference and belongs to the technical field of industrial energy saving and emission reduction. According to the maximum permissible temperature difference of cooling water and in-out water of a hearth, an air port, a furnace bosh, a furnace waist, a furnace body and other parts of a blast furnace of a steel mill, the minimum flow demand of the cooling water of all the parts is determined. Adjusting valves are arranged on water outlet pipes of cooling water branches of all the parts, aiming at the three schemes that the operated water pump number of a cooling water system is constant, optimization of the operated water pump number is reduced, and water pumps are optimized again, the resistance coefficient of the valves of all the branches serves as an unknown quantity, energy-balance equations of all the branches and a system water pump flow-lift performance equation are simultaneous, and thus, the resistance coefficient of the valves of all the branches, the system water pump operation parameter and the system energy consumption are solved; and compared with an original system operation scheme, on the premise that the blast furnace is safe and reliable, circulating cooling water system variable valve optimized operation and pump optimization are achieved, and the energy saving effect of the optimized water pump variable valve optimized operation scheme is the most remarkable.

Description

Blast-furnace cooled water system based on maximum temperature difference becomes valve optimization and runs and select pumping method

Technical field

The present invention relates to a kind of guarantee blast furnace each position recirculating cooling water system branch road Inlet and outlet water temperature difference and be simultaneously equal to (or close) respectively Pumping method is selected in the branch road outlet pipe control valve drag evaluation of the position maximum allowable Inlet and outlet water temperature difference and optimization, reaches to save circulation cold But the purpose of water system operating cost.Belong to industrial energy saving technical field of emission reduction.

Background technology

Along with the fast development of national economy, demand and the consumption of the energy are increasing.At present, China is not only the world Three big production of energy states, the most second-biggest-in-the-world energy resource consumption state.China's energy utilization rate is low, and energy waste is serious.

Steel and iron industry is as one of big high energy consumption industry of China six, and energy resource consumption is huge, energy-saving and emission-reduction arduous task.China's iron and steel Aggregated capacity about 11.5 hundred million tons, wherein, blast furnace annual capacity reaches 10.4 hundred million tons.Recirculating cooling water system is that steel mill's blast furnace is important Auxiliary facility, its ruuning situation is related to the safety of equipment, the quality of product and productivity and system energy consumption.Cooling water conveying and Cooling needs to consume substantial amounts of electric energy during processing.According to statistics, to account for iron and steel enterprise total for the power consumption of recirculating cooling water system The 20%～30% of power consumption.

Blast furnace crucibe, air port, bosh, furnace bosh, each position of shaft, be divided into 5 branch roads for water coolings by water main, each Cooling water in road is behind cooling position, and air is led in general water outlet.Relevant design handbook requires the recirculated cooling water branch road turnover of each position Water temperature difference is less than permissible value.Owing to each position cooling water discrepancy in elevation and pressure requirements are widely different, at recirculating cooling water system When design and operation, it is the most all that this has resulted in and has been to select pump performance parameters and the number of units of system according to least favorable branch road Each branch road of uniting can not reach the maximum allowable Inlet and outlet water temperature difference simultaneously, other positions cooling water bypass flow mistake in addition to least favorable branch road Greatly, the Inlet and outlet water temperature difference is higher than actual demand much smaller than the maximum allowable Inlet and outlet water temperature difference of corresponding site, system water supply ability, exists Sub-cooled, increases flow and the pump power of recirculating cooling water system, causes the serious waste of the energy.

Summary of the invention

It is an object of the invention to provide a kind of circulating cooling water system of blast furnace based on the maximum Inlet and outlet water temperature difference become valve optimization run with Selecting pumping method, the present invention, by analyzing the composition of circulating cooling water system of blast furnace, layout, operation and energy consumption, is ensureing that cooling is wanted On the premise of asking, system is implemented becomes valve optimization and runs, and again select pump, make recirculating cooling water system energy consumption minimum.

The mechanism of the present invention is, during steel mill's blast furnace steady-state operation, and blast furnace crucibe, air port, bosh, furnace bosh, shaft each position heat Load is certain.To a certain position, along with branch road cooling water flow reduces, the Inlet and outlet water temperature difference increases, and different parts has maximum fair Permitted the requirement of the Inlet and outlet water temperature difference.When a certain branch road Inlet and outlet water temperature difference reaches Maximum Permissible Temperature Difference, this branch road cooling water flow is Little need flow, just meet cooling requirement.First former to the circulating cooling water system of blast furnace operating scheme of the present invention, simultaneous equations Group solves each bypass flow；Circulating cooling water system of blast furnace each branch road outlet pipe arranges control valve, does not change pump for system Number of units is constant in operation, do not change pump operation number of units optimizes (minimizing) and changes pump (system water supply pump, booster pump and upper tower pump are changed) Three kinds of schemes, Simultaneous Equations, needs flow to substitute into each branch road by minimum respectively, and the outlet pipe that calculating each branch road needs is adjusted Joint valve resistance, controlling opening of valve, meet resistance, make overall plans and coordinate the flow of each branch road, ensureing that each position is for hydraulic pressure On the premise of power, make each position cooling water bypass flow reach (or close) minimum needs flow (corresponding each position branch road simultaneously The maximum allowable Inlet and outlet water temperature difference), whole recirculating cooling water system flow is minimum.Wherein, recirculating cooling water system changes pump, by each Road needs flow rate calculation each branch road minimum to need lift by minimum, needs lift to select water pump by each branch road minimum, it is desirable to water pump Run in efficient district.Circulating cooling water system of blast furnace uses centrifugal pump, and centrifugal pump shaft power reduces with flow and reduces.Therefore, When recirculating cooling water system flow is minimum, and when selecting pump to make water pump run in efficient district according to this, system energy consumption is minimum, reaches energy-conservation Purpose.The former operating scheme of comparative analysis recirculating cooling water system, do not change pump operation number of units constant change valve and optimize operating scheme, no Change pump operation number of units optimization (minimizing) become valve optimization operating scheme and change the energy consumption of pump change valve optimization four kinds of operating schemes of operating scheme Situation.

Technical scheme comprises the following steps:

A. circulating cooling water system of blast furnace former operating scheme parameter determination.

To water pump operation number of units and mode in the recirculating cooling water system determined and system, water can be cooled down with simultaneous blast furnace all sites The hydronic balancing valve of branch road and feed pump, booster pump flow-lift curve, solve the flow of each branch road, pressure and pump capacity, And then calculate the energy consumption of whole recirculating cooling water system.

Need for water cooling if blast furnace has m position.All way outlets lead to air, i-th way outlet and water feeding of water pump side The cooling pond water surface discrepancy in elevation is H_{st i}M (), volume flow is Q_i(m³/ s), (i=1,2 ..., m).Such as, if blast furnace circulates Cooling water system has 2 grades of water pump series connection, and the 1st grade of feed pump lift is H₁, the 2nd grade of booster pump lift is H₂.1st grade of water pump Directly require that n relatively low position branch road supplies water to blast furnace pressure of supply water；1st grade of water pump and the 2nd grade of water pump series connection supply to blast furnace Water pressure requires that m-n higher position branch road supplies water.The each pipeline section of system and cooling water branch road resistance coefficient are it is known that each of simultaneous Road is from cooling pond, through water pump, cooled position, to an open to atmosphere energy-balance equation of way outlet (necessary head curve of the installation system equation) With pump characteristic equations group (1) m+2 equation altogether, system each bypass flow Q can be solved_i(i=1,2 ..., m) With the 1st grade with the 2nd grade of pump head, and and then calculate determine pump capacity, power and efficiency.

$\left\{\begin{array}{cc}{H}_1=H_{sti}+F_i(Q_1,Q_2,...Q_m);& i=1,2,...,n\\ H_1+H_2=H_{sti}+F_i(Q_1,Q_2,...Q_m);& i=n+1,n+2,...,m\\ H_1=H_1(\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{Q}_i/k_1);& \\ H_2=H_2(\underset{i=n+1}{\overset{m}{\mathrm{\Σ}}}{Q}_i/k_2);& \end{array}\right.---\left(1\right)$

In formula, rear two formulas are respectively feed pump and booster pump flow-lift performance curve；For system total flow, (feed pump always flows Amount)；k₁Number of units is run for feed pump；For system the (n+1)th to m-th position total flow (booster pump total flow)；k₂ Number of units is run for booster pump.

B. the determination of blast furnace each position thermic load.

Time water spray in last furnace shell surface, furnace shell dispersed heat is the least compared with the heat that recirculated cooling water is taken away, negligible not Meter, the heat flow that blast furnace each position thermic load is taken away equal to cooling water, it may be assumed that

G_i=Cm_iΔt_i (2)

In formula: subscript " i " represents that blast furnace i-th cools down position；C holds for cooling specific heat of water, J/ (kg DEG C), specific heat of water under normal pressure Hold for 4200J/ (kg DEG C)；M is the mass flow of cooling water, kg/s, and its volume flow is Q=m/ ρ, and ρ is water body density, kg/m³；Δ t is the Inlet and outlet water temperature difference of cooling water, DEG C.M and Δ t can record at scene.

C. cooling water minimum in blast furnace each position needs flow rate calculation.

According to relevant design handbook, blast furnace each position cooling water maximum allowable Inlet and outlet water temperature difference is as shown in table 1.

Table 1 blast furnace each position cooling water maximum allowable Inlet and outlet water temperature difference

Position a certain to blast furnace, when the cooling water Inlet and outlet water temperature difference reaches the maximum allowable Inlet and outlet water temperature difference, this position cooling water branch road stream Amount needs flow for minimum.Blast furnace each position cooling water branch road minimum needs the mass flow to be:

$m_{\min i}=\frac{G_i}{{\mathrm{C\Δt}}_{\max i}}---\left(3\right)$

D. control valve is set on blast furnace each position cooling water branch road outlet pipe, after control valve, directly leads to air.

Cooling water branch road outlet pipe in blast furnace each position arranges control valve, it is therefore an objective to the cooling water flow of each branch road can be regulated With system pump operating condition；Air is directly led to, it is possible to ensure that blast-furnace cooled water wall intracavity hydraulic pressure is malleation after control valve.

E. respectively cool down the operating environment requirements at position according to blast furnace, determine cooling water wall intracavity hydraulic demand.

By selecting feed pump and booster pump lift, control cooling water wall intracavity hydraulic pressure maximum and meet requirement；Cooling water wall intracavity Minimum hydraulic pressure can not be negative pressure.

By selecting feed pump and booster pump lift, control cooling water wall intracavity hydraulic pressure maximum and meet requirement；Cooling water branch road goes out Directly lead to air after mouth control valve, the minimum hydraulic demand that cooling water wall intracavity hydraulic pressure is malleation can be met.

F. the change valve that recirculating cooling water system water pump operation number of units is constant optimizes operating scheme.

Needed the requirement of flow according to each position cooling water branch road by minimum, (include that outlet pipe regulates with each branch road resistance coefficient Valve resistance coefficient) S_i' (i=1,2 ..., m) it is unknown quantity, sets up each branch road from cooling pond, through water pump, blast furnace cooling Position is to outlet pipe control valve, the energy-balance equation (necessary head curve of the installation system equation) of logical atmospheric outlet, and simultaneous pump performance is bent Line equation.To circulating cooling water system of blast furnace described in step A, Simultaneous Equations is

$\left\{\begin{array}{cc}{H}_1=H_{sti}+F_i(Q_{1\min },Q_{2\min },...Q_{m\min },S_i^{\′});& i=1,2,...,n\\ H_1+H_2=H_{sti}+F_i(Q_{1\min },Q_{2\min },...Q_{m\min },S_i^{\′});& i=n+1,n+2,...,m\\ H_1=H_1(\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{Q}_{i\min }/k_1);& \\ H_2=H_2(\underset{i=n+1}{\overset{m}{\mathrm{\Σ}}}{Q}_{i\min }/k_2);& \end{array}\right.---\left(4\right)$

In formula, Q_1min,Q_2min,…Q_{m min}It is respectively each branch road minimum and needs flow, for known quantity, m³/s。

Solving equation group (4), can try to achieve recirculating cooling water system is to obtain the resistance that when each branch road minimum needs flow, each branch road needs Force coefficient S_i' (i=1,2 ..., m).With each branch road resistance coefficient S solved_i' it is individually subtracted branch road former resistance coefficient S_i(no Including outlet pipe control valve resistance), i.e. obtain the resistance coefficient Δ S required for each branch road outlet pipe control valve_i(i=1,2 ..., m)。

Try to achieve the resistance coefficient Δ S required for each branch road outlet pipe control valve_i(i=1,2 ..., m) after, check each position cold But wall intracavity cooling water operating pressure should be in allowed band, it may be assumed that the pressure in cooling wall chamber before each branch road outlet pipe control valve Meet

$H_{Pimin}\≤{\mathrm{\ΔS}}_i{Q}_{i\min }^2\≤H_{Pimax},(i=1,2,...,m)---\left(5\right)$

If pressure requires pressure H less than minimum before kth position cooling water branch road outlet pipe control valve_{Pi min}, pressure can not be expired First foot requirement, then should determine this position cooling water outlet pipe control valve resistance coefficient, makes this upstream pressure want equal to minimum Seek pressure, it may be assumed that

${\mathrm{\ΔS}}_k=\frac{H_{Pkmin}}{Q_k^2}---\left(6\right)$

Then, kth branch road resistance coefficient is

$S_k^{\′}=S_k+{\mathrm{\ΔS}}_k=S_k+\frac{H_{Pk\min }}{Q_k^2}---\left(7\right)$

By adjusting kth branch road outlet pipe control valve resistance, changing kth branch road cooling water flow is Q_k(Q_k≥Q_{k min}), will Q in equation group (4)_{k min}Change into Q_k, regard unknown quantity as, formula (7) substituted into the kth formula in equation group (4), asks Solving equations (4), can obtain S_i' (i=1,2 ..., k-1, k+1 ..., m) and Q_k, calculate Δ S by formula (6)_k, Check other branch roads cooling water wall cavity pressure again, until all meeting requirement.Finally, calculating determines feed pump in system, supercharging The operation lift of pump, and and then try to achieve feed pump, booster pump, all operational factors of upper tower pump and system energy consumption.

G. recirculating cooling water system water pump operation number of units optimizes the change valve optimization operating scheme of (minimizing).

For existing circulating cooling water system of blast furnace, generally press the design of least favorable branch road water supply requirement, do not consider to become valve optimization fortune OK, system totally water supply cooling capacity has the most more than needed.System is implemented change valve optimization based on the maximum allowable Inlet and outlet water temperature difference and is run Time, owing to blast furnace each position cooling water bypass flow and system total flow reduce, so, computational analysis can be passed through, ensureing On the premise of water supply flow and pressure, suitably reduce feed pump, booster pump and the start number of units of upper tower pump, go out reducing each branch road Resistance required for Water Pipe Valve door, reduces the purpose of energy consumption.

After using the feed pump operation number of units in rear 2 formulas of equation group (4) and booster pump operation number of units instead optimization (minimizing) respectively Operation number of units k₁', k₂', obtain equation group (8), solving equation group (8), obtain circulating cooling water system of blast furnace feed pump, supercharging After pump operation number of units optimizes, each position cools down water branch road resistance coefficient and feed pump, booster pump lift.

$\left\{\begin{array}{cc}{H}_1=H_{sti}+F_i(Q_{1\min },Q_{2\min },...Q_{m\min },S_i^{\′});& i=1,2,...,n\\ H_1+H_2=H_{sti}+F_i(Q_{1\min },Q_{2\min },...Q_{m\min },S_i^{\′});& i=n+1,n+2,...,m\\ H_1=H_1(\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{Q}_{i\min }/{k_1}^{\′});& \\ H_2=H_2(\underset{i=n+1}{\overset{m}{\mathrm{\Σ}}}{Q}_{i\min }/{k_2}^{\′});& \end{array}\right.---\left(8\right)$

Calculate each position cooling water branch road outlet pipe control valve resistance coefficient, optimize (minimizing) upper tower pump operation number of units, calculate Feed pump and the flow of booster pump, power and efficiency, flow, lift, power and the efficiency of upper tower pump and circulating cooling water system System total energy consumption, and optimize the observable index of operating scheme relatively with change valve is not carried out.

H. need flow according to blast furnace each position cooling water minimum, reselect recirculating cooling water system water pump.

It is not provided with control valve (or control valve resistance is 0) by formula (9) by each position cooling water branch road outlet pipe, is passed through Little needing flow, calculating each branch road needs lift:

H_{Need i}=H_{st i}+F_i(Q_1min,Q_2min,…Q_{m min}, S_i)；I=1,2 ..., m (9)

By the maximum demand lift MAX H in front n water supply branch road_{Need i}(i=1,2 ..., n) with all m water supply branch roads Flow sum, reselects feed pump, it is desirable to feed pump runs in efficient district；If the feed pump lift reselected is H₁, press Maximum demand lift in rear m-n water supply branch road deducts feed pump lift MAX H_{Need i}(i=n+1, n+2 ..., m)-H_1n Reselect booster pump lift H_2n, it is desirable to booster pump runs in efficient district；Flow is needed again to select by recirculating cooling water system minimum Select tower pump, it is desirable to upper tower pump runs in efficient district.

I. the change valve after recirculating cooling water system selects pump again optimizes operating scheme.

By the feed pump reselected and booster pump flow-lift performance curve and rear the 2 of design and operation number of units substitution equation group (4) Individual equation, obtains equation group (10), solving equation group (10), determines that recirculating cooling water system is to obtain each branch road after again selecting pump Each branch road resistance coefficient S when minimum needs flow_i' (i=1,2 ..., m) with feed pump, booster pump lift, with solve Each branch road resistance coefficient is individually subtracted branch road former resistance coefficient S_i, i.e. obtain required each branch road outlet pipe control valve resistance system Number Δ S_i(i=1,2 ..., m), and check adjustment, it is ensured that each position cooling water pressure meets requirement.

$\left\{\begin{array}{cc}{H}_1=H_{sti}+F_i(Q_{1\min },Q_{2\min },...Q_{m\min },S_i^{\′});& i=1,2,...,n\\ H_1+H_2=H_{sti}+F_i(Q_{1\min },Q_{2\min },...Q_{m\min },S_i^{\′});& i=n+1,n+2,...,m\\ H_1={H_1}^{\′}(\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{Q}_{i\min }/k_1);& \\ H_2={H_2}^{\′}(\underset{i=n+1}{\overset{m}{\mathrm{\Σ}}}{Q}_{i\min }/k_2);& \end{array}\right.---\left(10\right)$

Calculate and determine the feed pump after reselecting and booster pump flow, power and efficiency, upper tower pump discharge, lift, power and Efficiency, calculates the total energy consumption of the circulating cooling water system of blast furnace after again selecting pump.

J. several scheme of recirculating cooling water system energy consumption comparative analysis.

The former operating scheme of recirculating cooling water system (being not carried out becoming valve optimization to run), system become valve optimization and run (water pump operation number of units Constant), system becomes valve optimization and runs (water pump operation number of units optimize (minimizing)) and system selects the change valve optimization operation after pump again Four kinds of scheme system energy consumption comparative analysiss.

K. blast furnace each position cooling water branch road outlet pipe controlling opening of valve regulation.

Step F system becomes valve optimization and runs (water pump operation number of units is constant), step G. system change valve optimization operation (water pump operation Number of units optimizes (minimizing)) and step I system again select and become valve optimization three kinds of schemes of operation after pump, circulate cold according to each position of blast furnace But the aperture of water branch road outlet pipe control valve-resistance curve rule, adjusts the aperture of each branch road outlet pipe control valve, meets institute The resistance coefficient requirement needed, can realize circulating cooling water system of blast furnace change valve based on each position maximum allowable Inlet and outlet water temperature difference Combinatorial Optimization runs and pump is selected in optimization.

The present invention is directed to circulating cooling water system of blast furnace, calculate and determine each position cooling water branch road cooling thermic load and permit based on maximum The minimum being permitted the Inlet and outlet water temperature difference needs flow.Cooling water branch road outlet pipe in each position arranges control valve, cold to having circulated But water system, does not change pump, needs lift re-optimization to select pump two kinds by suitably reducing water pump operation number of units and each branch road of calculating Situation, simultaneous solution each position cooling water branch road necessary head curve of the installation system and feed pump, booster pump performance curve equation group, determine each Position cooling water branch road outlet pipe control valve resistance, makes overall plans and coordinate each bypass flow of distribution, makes flow system flow minimum, pump shaft Power is minimum, it is achieved change valve Combinatorial Optimization based on each position cooling water maximum allowable Inlet and outlet water temperature difference runs and pumping method is selected in optimization. The present invention does not change pump and re-optimization selects two kinds of change valves optimization operating schemes of pump to be applied to the height of 550,000 tons of steel of embodiment annual capacity Stove recirculating cooling water system, the most respectively economize on electricity 559.7 ten thousand kW h, 783.4 ten thousand kW h electricity；Whole nation blast furnace annual capacity reaches To 10.4 hundred million tons, in this ratio, application of result of the present invention in whole nation steel mill blast furnace, the 105.83 hundred million kW h that can economize on electricity respectively every year, 148.13 hundred million kW h, will produce great economic benefit.

Accompanying drawing explanation

Fig. 1 is embodiment of the present invention circulating cooling water system of blast furnace figure.

Detailed description of the invention

Use technical scheme, below in conjunction with the accompanying drawings 1 and case the invention will be further described, but present case should It is interpreted as limitation of the present invention.

Certain metallurgy and foundry factory 450m³Circulating cooling water system of blast furnace has two cooling towers, model be respectively DFNL-1000T, DFNL-1200T, uses the self-overflow type type of cooling, and matched with blower power is 30kW, and nominal air delivery is respectively 1000m³/h、 1200m³/h.System is furnished with feed pump three, and model is SLOW350-520IB, is connected in parallel, and system is dual-purpose one standby when running, A diesel oil fire pump the most in parallel, model is XBC-SLOW350-440.Feed pump single pump designs parameter: flow 1792m³/ h, Lift 63m, rotating speed 1480r/min.Feed pump supporting YKK4506-4 type motor, rated power 400kW, rated current 28.72A, power factor (PF) 0.86, rated speed 1483r/min.Arranging air port booster pump two, model is SLOW200-410, Being connected in parallel, an operation, one standby.Air port booster pump single pump designs parameter: flow 790m³/ h, lift 34m, turn Speed 1480r/min.Air port booster pump supporting Y315-4 type motor, rated power 110kW, rated current 201A, power because of Element 0.89, rated speed 1480r/min.Upper tower pump three, model is SLOW350-380I, is connected in parallel, two operations, One standby.Upper tower pump single pump designs parameter: flow 1733m³/ h, lift 32m, rotating speed 1480r/min.Upper tower pump is supporting YKK4501-4 type motor, rated power 200kW, rated current 15.1A, power factor (PF) 0.81, rated speed 1483r/min. System support hot-tub.

The flow of system water supply pump-lift performance curve is:

H=-51.7834Q²-2.4321Q+70.4623 (9)

The flow of air port booster pump-lift performance curve is:

H=-188.0777Q²-66.8503Q+64.3978 (10)

Upper tower pump discharge-lift performance curve is:

H=-72.777Q²+9.1402Q+45.639 (11)

Tower height degree 6.4m on cooling tower backwater, water cooling pond water level-0.7m, hot-tub water level-0.7m.Feed pump outlet elevation 1.6 M, water main elevation 1.6m.Air port booster pump elevation 1.35m, upper tower pump elevation 1.55m.Furnace foundation, cupola well send water height 8m, air port send water height 11.5m, and bosh send water height 12.5m, and furnace bosh send water height 13.5m, and shaft send water height 18.5 m。

A. circulating cooling water system of blast furnace former operating scheme parameter determination.

This recirculating cooling water system started to come into operation from 2007.When system is properly functioning, feed pump opens 2^#With 3^#Pump, Need to switch to 1 by wherein 1 during exchange device^#Pump；Air port booster pump runs 2^#Pump, upper tower pump operation 2^#With 3^#Pump.Water pump is every It runs 24h, runs 360 days every year on average.Do not run the valve closing of equipment.This recirculating cooling water system does not sets frequency conversion and adjusts Speed variator.

System each pipe resistance coefficient such as Fig. 1, its value is as shown in table 2.Wherein, furnace bottom cupola well, bosh, furnace bosh, shaft, Position, air port pipe resistance coefficient is respectively S₄、S₅、S₆、S₇、S₈(not including branch road outlet pipe control valve resistance coefficient).

The each pipe resistance coefficient of table 2 circulating cooling water system of blast furnace (comparison Fig. 1) (unit: s²/m⁵)

Simultaneous system cooling water each branch energy equilibrium equation and pump capacity-lift performance curve equation group:

In formula, S₄、S₅、S₆、S₇、S₈It is respectively furnace bottom cupola well, bosh, furnace bosh, shaft, position, the air port cooling each branch road of water Outlet pipe is not provided with branch road resistance coefficient during control valve.Solving equation group (12), obtains each branch road stream during running Amount Q₄, Q₅, Q₆, Q₇, Q₈With feed pump lift H₁, booster pump lift H₂.2 feed pump parallel runnings of system, solve Going out bottom hearth of blast furnace, air port, bosh, furnace bosh, shaft each position cooling water bypass flow as shown in table 3, total flow is 1.1965 m³/ s, separate unit feed pump flow is 0.59825m³/ s, lift is 50.47m, and efficiency is 83.3%；Air port booster pump 1 fortune OK, flow is 0.1 074m³/ s, lift is 55.05m, and efficiency is 71.62%；Upper tower pump 2 operation, tower pump stream on separate unit Amount is 0.59825m³/ s, lift is 25.06m, and efficiency is 78.43%.Recirculating cooling water system runs year total power consumption 11965993kW h, the result solved is consistent with measured value.

Table 3 blast furnace each position cooling water bypass flow, the Inlet and outlet water temperature difference and heat exchange amount

B. blast furnace each position thermic load determines.

Bottom hearth of blast furnace, air port, bosh, furnace bosh, shaft each position cooling water turnover water temperature under the former operating condition of actual measurement system Difference, calculates the heat exchange amount such as table 3 at each position.

C. cooling water minimum in blast furnace each position needs flow rate calculation.

Table 4 is that circulating cooling water system of blast furnace each position the highest permission of cooling water branch road of regulation in BF Design handbook passes in and out water temperature Difference.Synopsis 3, surveys each position cooling water branch road Inlet and outlet water temperature difference less than the setting in table 4, particularly bosh, furnace bosh, The shaft position actual Inlet and outlet water temperature difference is only the 1/4～1/3 of the highest permission Inlet and outlet water temperature difference.When each position cooling water branch road turnover water temperature When difference is equal to the highest respective permission Inlet and outlet water temperature difference, calculating each position cooling water minimum according to formula (2) needs (volume) stream Amount is as shown in table 4.

The highest permission in each position of the table 4 blast furnace Inlet and outlet water temperature difference and minimum need flow

Need flow to be added each position minimum, show that this recirculating cooling water system minimum needs flow to be 0.519m³/s。

In sum, system minimum needs flow to be 0.519m³/ s, actual measurement system flow is 1.1965m³/ s, needs much larger than minimum Want flow, there is supercooling.

D. control valve is set on blast furnace each position cooling water branch road outlet pipe, after control valve, directly leads to air.

At furnace bottom cupola well, bosh, furnace bosh, shaft, air port recirculated cooling water branch road outlet pipe, control valve, control valve are set Rear directly logical air, controlling opening of valve, can ensure that the cooling of blast furnace corresponding site requires and on the premise of pressure of supply water, make each Position cooling water arm flow reaches respective minimum simultaneously needs flow, system total flow to minimize.

E. respectively cool down the operating environment requirements at position according to blast furnace, determine cooling water wall intracavity hydraulic demand.

It is malleation before requiring furnace bottom cupola well, bosh, furnace bosh, shaft, each position, air port cooling water branch road outlet pipe control valve.

F. the change valve that recirculating cooling water system water pump operation number of units is constant optimizes operating scheme.

Feed pump, booster pump and upper tower pump type and operation number of units according to the former operating scheme of recirculating cooling water system (are separately operable 2,1,2), to implement to become valve optimization and run, each branch road needs flow by minimum, and simultaneous each branch road hydraulic energy is put down Weighing apparatus equation (necessary head curve of the installation system equation) and feed pump, booster pump performance curve equation group:

In formula, S₄′、S₅′、S₆′、S₇′、S₈' it is respectively furnace bottom cupola well, bosh, furnace bosh, shaft, position, air port for reaching each portion Position is minimum need cooling water each branch road outlet pipe controlling opening of valve during assignment of traffic to adjust after branch road resistance coefficient.

Solving equation group (13): S₄'=3787.03s²/m⁵；S₅'=27317.08s²/m⁵；S₆'=56432.38s²/m⁵； S₇'=786.94s²/m⁵；S₈'=15047.29s²/m⁵.Each position cooling water branch road resistance coefficient value added Δ S (that is branch road Outlet pipe control valve resistance coefficient) such as table 5.

Table 5 recirculating cooling water system pump-type and operation number of units constant time-varying valve optimization run branch road outlet pipe control valve resistance coefficient Δ S

Now, the flow of separate unit feed pump is 0.2595m³/ s, lift is 66.34m, and efficiency is 49.66%.Air port booster pump Flow be 0.086m³/ s, lift is 57.27m, and efficiency is 60.59%.On separate unit, the flow of tower pump is 0.2595m³/ s, raises Journey is 42.99m, and efficiency is 59.50%.

Owing to directly leading to air after the recirculated cooling water branch road outlet pipe control valve of blast furnace each position, it is ensured that the cooling water before valve Pressure is malleation, and cooling water wall intracavity average water pressure meets the requirements.

Now system year total power consumption 11590780kW h, the more former actual operating scheme used economizes on electricity 37.5 ten thousand kW h every year, Economize on electricity 3.14%, power savings is the most notable.Its reason is, owing to original recirculating cooling water system water pump is according to not becoming Valve optimization runs selection, and design discharge is big, lift is low.System uses after becoming valve optimization operation, for reducing flow system flow, subtracts Little outlet pipe controlling opening of valve, increases resistance, and pump head increases, and deviates efficient district and runs, and pump efficiency declines.

G. recirculating cooling water system water pump operation number of units optimizes the change valve optimization operating scheme of (minimizing).

System Model of pump is constant, and when each branch road needs flow by minimum, feed pump and upper tower pump only need to run 1 Meet requirement.By this simultaneous each branch road hydraulic energy equilibrium equation (necessary head curve of the installation system equation) and feed pump, booster pump performance Curvilinear equation group:

Solving equation group (14): S₄'=2977.43s²/m⁵；S₅'=21357.39s²/m⁵；S₆'=42547.99s²/m⁵； S₇'=572.10s²/m⁵；S₈'=13387.45s²/m⁵.Calculate, blast furnace each position recirculated cooling water branch road outlet pipe regulation valve Gate resistance force coefficient Δ S such as table 6.

Table 6 recirculating cooling water system does not change pump, optimizes (minimizing) operation number of units time-varying valve optimization operation branch road outlet pipe control valve resistance coefficient Δ S

Recirculating cooling water system is implemented to become valve optimization and is run, and does not change pump, optimizes (minimizing) and run number of units, and feed pump only leaves 1, Flow is 0.519m³/ s, lift is 55.25m, and efficiency is 79.80%.Air port booster pump still opens 1, and flow is 0.086m³/ s, Lift is 57.27m, and efficiency is 60.59%.Upper tower pump only opens 1, and flow is 0.519m³/ s, lift is 30.78m, effect Rate is 82.89%.Now feed pump is close to running in efficient district, and upper tower pump runs in efficient district, and booster pump deviates efficient district and runs, In system year total power consumption 6369421kW h, more former operating scheme economizes on electricity 559.7 ten thousand kW h every year, economizes on electricity 46.77%, joint Electricity effect is the most notable.

H. need flow according to blast furnace each position cooling water minimum, reselect recirculating cooling water system water pump.

Consider to need flow rate working conditions according to blast furnace each position cooling water minimum, reselect recirculating cooling water system feed pump and supercharging Pump (upper tower pump runs in efficient district, is not required to reselect).

If bottom hearth of blast furnace, bosh, furnace bosh, shaft, each position, air port recirculated cooling water branch road need lift to be respectively H_{Need 4}、 H_{Need 5}、H_{Need 6}、H_{Need 7}、H_{Need 8}.Each branch road necessary head curve of the installation system equation is (2 feed pumps run):

Each branch road minimum needs flow substitute into formula (15), and calculating each branch road minimum needs lift: H_{Need 4}=29.18m； H_{Need 5}=17.26m；H_{Need 6}=17.49m；H_{Need 7}=23.42m；H_{Need 8}=71.25m.

Considering 2m safe clearance, feed pump lift chooses 31m.Select feed pump model DFSS250-370 (I), supporting electricity Machine Y280M-4, power factor (PF) 0.89.Feed pump selects pump result as shown in table 7.

Table 7 feed pump selects pump result

Flow～the lift performance curve equation of feed pump be:

H=-1028Q³+183.7Q²-22.21Q+41.03 (16)

Flow-efficiency performance curvilinear equation is:

η=-17.13Q²+7.803Q-0.014 (17)

Considering 2m safe clearance, air port booster pump lift chooses 43m.Select air port booster pump model TS200-390A, join Set motor Y225M-4, power factor (PF) 0.88.Air port booster pump selects pump result as shown in table 8.

Table 8 air port booster pump selects pump result

Flow～the lift performance curve equation of air port booster pump be:

H=-2655.6Q²+98.639Q+53.012 (18)

Flow～efficiency performance curvilinear equation be:

η=-130.16Q²+21.072Q+0.001 (19)

I. the change valve after recirculating cooling water system selects pump again optimizes operating scheme.

Recirculating cooling water system runs after changing pump, feed pump operating flux 0.2595m³/ s, lift 29.67m, efficiency 85.73%, Compared with changing before pump, pump head significantly reduces, and pump efficiency improves the most further.Calculate two feed pump year power consumption 1708971kW·h。

Now air port booster pump flow 0.086m³/ s, lift 41.85m, efficiency 85.05%, compared with changing before pump, water pump is raised Journey has reduced, and pump efficiency increases substantially.Calculate air port booster pump year power consumption 407360kW h.

As it was previously stated, now going up tower pump total flow is 0.519m³/ s, only need to open 1 can meet requirement.Upper tower pump discharge 0.519 m³/ s, lift 30.78m, efficiency 82.89%, run in efficient district, be not required to change.Calculate tower pump year power consumption 2015304kW·h。

Reselecting recirculating cooling water system feed pump and booster pump, feed pump runs 2, and booster pump runs 1, upper tower pump Run 1, system year total power consumption 4131635kW h.Relatively system operating scheme economizes on electricity 783.4 ten thousand kW h every year, joint Electricity 65.47%, power savings becomes apparent from.

Equation group (13) two formulas afterwards are changed to

$\begin{array}{c}{H}_1=-1028{\[\frac{1}{2}(Q_{4\min }+Q_{5\min }+Q_{6\min }+Q_{7\min }+Q_{8\min })\]}^3\\ +183.7{\[\frac{1}{2}(Q_{4\min }+Q_{5\min }+Q_{6\min }+Q_{7\min }+Q_{8\min })\]}^2\\ -22.21\[\frac{1}{2}(Q_{4\min }+Q_{5\min }+Q_{6\min }+Q_{7\min }+Q_{8\min })\]+41.03\end{array}$

$H_2=-2655.6Q_{8min}^2+98.639Q_{8min}^2+53.012$

Solve and implement after circulating cooling water system of blast furnace changes pump to become valve optimization operation each position cooling water branch road resistance coefficient, be individually subtracted The former resistance coefficient of branch road, obtains each branch road outlet pipe control valve resistance coefficient Δ S ' as shown in table 9.

Table 9 recirculating cooling water system becomes valve optimization and runs cooling water branch road outlet pipe control valve resistance coefficient Δ S ' after changing pump

J. several scheme of recirculating cooling water system observable index is relatively.

Described in comprehensive A-I, embodiment circulating cooling water system of blast furnace, although former scheme water pump runs near efficient district, but by Supercooled phenomenon is there is, so system energy consumption is maximum in some position of blast furnace；Prop up way outlet at blast furnace each position cooling water to set Put control valve, implement to need the change valve optimization of flow to run based on minimum by control valve resistance, compared with former operating scheme, When system pump-type and operation number of units are constant, although pump efficiency has declined, but owing to flow reduces, pump power reduces, and follows Ring cooling water system energy consumption still declines 3.14%；Contrast table 6 and table 5, implement to become valve optimization and run, and pump-type is constant, optimizes and (subtracts Few) feed pump operation number of units, each branch road outlet pipe control valve resistance coefficient is obviously reduced, and pump head is obviously reduced, close Efficiently district runs, and compared with former scheme, recirculating cooling water system energy consumption declines 46.77%, and energy-saving effect is the most notable；Contrast table 9 with table 6, again select pump implement become valve optimization run, all water pumps all run in efficient district, and each position cooling water branch road go out Water Pipe Valve gate resistance force coefficient significantly reduces, and substantially reduces system energy consumption, compared with former scheme, and recirculating cooling water system Energy consumption declines 65.47%, and energy-saving effect is more significantly.

J. blast furnace each position cooling water branch road outlet pipe controlling opening of valve regulation.

System becomes valve optimization and runs (water pump operation number of units is constant), system change valve optimization operation (water pump operation number of units optimizes (minimizing)) Become valve optimization after changing pump with system and run three kinds of schemes, according to the resistance coefficient each required, compare aperture-resistance curve, regulation Valve opening, reaches recirculating cooling water system and becomes the purpose that valve optimization runs and selects pump based on change valve optimization running optimizatin.

The present invention is directed to circulating cooling water system of blast furnace, calculate and determine each position cooling water branch road cooling thermic load and permit based on maximum The minimum being permitted the Inlet and outlet water temperature difference needs flow.Cooling water branch road outlet pipe in each position arranges control valve, cold to having circulated But water system, does not change pump, needs lift re-optimization to select pump two kinds by suitably reducing water pump operation number of units and each branch road of calculating Situation, simultaneous solution each position cooling water branch road necessary head curve of the installation system and feed pump, booster pump performance curve equation group, determine each Position cooling water branch road outlet pipe control valve resistance, makes overall plans and coordinate each bypass flow of distribution, makes flow system flow minimum, pump shaft Power is minimum, it is achieved change valve Combinatorial Optimization based on each position cooling water maximum allowable Inlet and outlet water temperature difference runs and pumping method is selected in optimization. The present invention does not change pump and re-optimization selects two kinds of change valves optimization operating schemes of pump to be applied to the height of 550,000 tons of steel of embodiment annual capacity Stove recirculating cooling water system, the most respectively economize on electricity 559.7 ten thousand kW h, 783.4 ten thousand kW h electricity；Whole nation blast furnace annual capacity reaches To 10.4 hundred million tons, in this ratio, application of result of the present invention in whole nation steel mill blast furnace, the 105.83 hundred million kW h that can economize on electricity respectively every year, 148.13 hundred million kW h, will produce great economic benefit.

Claims (10)

1. blast-furnace cooled water system based on maximum temperature difference becomes valve optimization operation and selects pumping method, it is characterized in that, comprises the following steps:

A. circulating cooling water system of blast furnace former operating scheme parameter determination；

Needing for water cooling if blast furnace has m position, all way outlets lead to air, i-th way outlet and water feeding of water pump side The cooling pond water surface discrepancy in elevation is H_{st i}M (), volume flow is Q_i(m³/ s), (i=1,2 ..., m), if blast furnace recirculated cooling water System has 2 grades of water pump series connection, and the 1st grade of feed pump lift is H₁, the 2nd grade of booster pump lift is H₂, the 1st grade of water pump directly to Blast furnace pressure of supply water requires that n relatively low position branch road supplies water；1st grade of water pump and the 2nd grade of water pump are connected to blast furnace pressure of supply water Require that m-n higher position branch road supplies water；

B. blast furnace each position thermic load determines；

C. cooling water minimum in blast furnace each position needs flow rate calculation；

D. control valve is set on blast furnace each position cooling water branch road outlet pipe, after control valve, directly leads to air, control valve Cooling water flow and the system pump operating condition of each branch road can be regulated, and ensure that blast-furnace cooled water wall intracavity hydraulic pressure is malleation；

E. according to the operating environment requirements at each position of blast furnace, cooling water wall intracavity hydraulic demand is determined；

F. the change valve that recirculating cooling water system water pump operation number of units is constant optimizes operating scheme；

G. the change valve that the optimization of recirculating cooling water system water pump operation number of units reduces optimizes operating scheme；

H. need flow according to blast furnace each position cooling water minimum, reselect recirculating cooling water system water pump；

I. the change valve after recirculating cooling water system re-optimization selects pump optimizes operating scheme；

J. the former operating scheme of comparative analysis recirculating cooling water system and step F, G, I recirculating cooling water system operating scheme are altogether The energy consumption of four kinds of operating schemes of meter；

K. blast furnace each position cooling water branch road outlet pipe controlling opening of valve regulation.

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, its Feature is, the former operating scheme parameter determination method of circulating cooling water system of blast furnace described in step A is:

To water pump operation number of units and mode in the recirculating cooling water system determined and system, simultaneous blast furnace all sites cooling water branch road Hydronic balancing valve and feed pump flow-lift curve, booster pump flow-lift curve, solve each cooling water branch road flow, Pressure and pump capacity, and then calculate the energy consumption of whole recirculating cooling water system；

The each pipeline section of described circulating cooling water system of blast furnace and cooling water branch road resistance coefficient are it is known that each branch road of simultaneous is from cooling pond, warp Water pump, cooled position, bent to the open to atmosphere energy-balance equation of way outlet, i.e. necessary head curve of the installation system equation and pump performance Line equation group (1) m+2 equation altogether, the system that solves respectively cools down the flow Q of water branch road_i(i=1,2 ..., m) with the 1st Level with the 2nd grade of pump head, and and then calculate determine pump capacity, power and efficiency；

$\left\{\begin{array}{c}{H}_1=H_{sti}+F_i(Q_1,Q_2,\mathrm{...}{Q}_m);i=1,2,\mathrm{...},n\\ H_1+H_2=H_{sti}+F_i(Q_1,Q_2,\mathrm{...}{Q}_m);i=n+1,n+2,\mathrm{...},m\\ H_1=H_1(\underset{i=1}{\overset{m}{\Σ}}{Q}_i/k_1);\\ H_2=H_2(\underset{i=n+1}{\overset{m}{\Σ}}{Q}_i/k_2);\end{array}\right.---\left(1\right)$

In formula, rear two formulas are respectively feed pump flow-lift performance curve and booster pump flow-lift performance curve；Supply for system Water pump total flow；k₁Number of units is run for feed pump；For system the (n+1)th to m-th position booster pump total flow；k₂For Booster pump runs number of units.

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, its Feature is, each position of blast furnace described in step B thermic load determines that method is:

Time water spray in last furnace shell surface, furnace shell dispersed heat is the least compared with the heat that recirculated cooling water is taken away, and ignores, The heat flow that blast furnace each position thermic load is taken away equal to cooling water, it may be assumed that

G_i=Cm_iΔt_i (2)

In formula: subscript " i " represents that blast furnace i-th cools down position；C holds for cooling specific heat of water, J/ (kg DEG C), specific heat of water under normal pressure Hold for 4200J/ (kg DEG C)；M is the mass flow of cooling water, and kg/s, it is Q=m/ ρ that cooling water body amasss flow, and ρ is water body Density, kg/m³；Δ t is the Inlet and outlet water temperature difference of cooling water, DEG C, m and Δ t can record at scene.

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, its Feature is, each position of blast furnace described in step C cooling water minimum needs the method for calculating flux to be:

According to relevant design handbook, blast furnace each position cooling water maximum allowable Inlet and outlet water temperature difference is as shown in table 1:

Table 1 blast furnace each position cooling water maximum allowable Inlet and outlet water temperature difference

Position a certain to blast furnace, when the cooling water Inlet and outlet water temperature difference reaches the maximum allowable Inlet and outlet water temperature difference, this position cooling water branch road stream Amount needs flow for minimum；Blast furnace each position cooling water branch road minimum needs the flow to be:

$m_{\min i}=\frac{G_i}{{\mathrm{C\Δt}}_{\max i}}---\left(3\right).$

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, its Feature is, according to blast furnace each position operating environment requirements described in step E, determines cooling water wall intracavity hydraulic demand；By selecting Feed pump and booster pump lift, control cooling water wall intracavity hydraulic pressure maximum and meet requirement；The cooling water minimum hydraulic pressure of wall intracavity can not For negative pressure.

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, its Feature is, the constant change valve of recirculating cooling water system water pump operation number of units described in step F optimize operating scheme into:

The circulating cooling water system of blast furnace of control valve is set to cooling down each way outlet of water described in step D, cools down according to each position Water branch road needs flow Q by minimum_{i min}(m³/ s), (i=1,2 ..., requirement m), with each branch road resistance coefficient S_i' (i=1, 2 ..., m) be unknown quantity, each branch road resistance coefficient includes outlet pipe control valve resistance coefficient, set up each branch road from cooling pond, Through water pump, blast furnace cooling position to outlet pipe control valve, the energy-balance equation of logical atmospheric outlet, i.e. necessary head curve of the installation system side Journey, simultaneous pump characteristic equations:

$\left\{\begin{array}{c}{H}_1=H_{sti}+F_i(Q_{1\min },Q_{2\min },\mathrm{...}{Q}_{m\min },{S_i}^{\′});i=1,2,\mathrm{...},n\\ H_1+H_2=H_{sti}+F_i(Q_{1\min },Q_{2\min },\mathrm{...}{Q}_{m\min },{S_i}^{\′});i=n+1,n+2,\mathrm{...},m\\ H_1=H_1(\underset{i=1}{\overset{m}{\Σ}}{Q}_{i\min }/k_1);\\ H_2=H_2(\underset{i=n+1}{\overset{m}{\Σ}}{Q}_{i\min }/k_2);\end{array}\right.---\left(4\right)$

In formula, Q_1min,Q_2min,…Q_{m min}It is respectively each branch road minimum and needs flow, for known quantity, m³/ s, k₁Run for feed pump Number of units；k₂Number of units is run for booster pump；

Solving equation group (4), trying to achieve recirculating cooling water system is to obtain the resistance that when each branch road minimum needs flow, each branch road needs Coefficient S_i' (i=1,2 ..., m)；With each branch road resistance coefficient S solved_i' it is individually subtracted branch road former resistance coefficient S_i, branch road Former resistance coefficient S_iDo not include outlet pipe control valve resistance, i.e. obtain the resistance coefficient required for each branch road outlet pipe control valve ΔS_i(i=1,2 ..., m)；

Try to achieve the resistance coefficient Δ S required for each branch road outlet pipe control valve_i(i=1,2 ..., m) after, check each position cold But wall intracavity cooling water operating pressure should be in allowed band, it may be assumed that the pressure in cooling wall chamber before each branch road outlet pipe control valve Meet

$H_{Pimin}\≤{\mathrm{\ΔS}}_i{Q}_{imin}^2\≤H_{Pimax},(i=1,2,...,m)---\left(5\right)$

If pressure requires pressure H less than minimum before kth position cooling water branch road outlet pipe control valve_{Pi min}, pressure can not be expired First foot requirement, then should determine this position cooling water outlet pipe control valve resistance coefficient, makes this upstream pressure want equal to minimum Seek pressure, it may be assumed that

${\mathrm{\ΔS}}_k=\frac{H_{Pkmin}}{Q_k^2}---\left(6\right)$

Then, kth branch road resistance coefficient is

$S_k^{\′}=S_k+{\mathrm{\ΔS}}_k=S_k+\frac{H_{Pkmin}}{Q_k^2}---\left(7\right)$

By adjusting kth branch road outlet pipe control valve resistance, changing kth branch road cooling water flow is Q_k(Q_k≥Q_{k min}), Will Q in equation group (4)_{k min}Change into Q_k, regard unknown quantity as, formula (7) substituted into the kth formula in equation group (4), Solving equation group (4), can obtain S_i' (i=1,2 ..., k-1, k+1 ..., m) and Q_k, calculate Δ S by formula (6)_k, Check other branch roads cooling water wall cavity pressure again, until all meeting requirement；Finally, calculating determines feed pump in system, supercharging The operation lift of pump, and and then try to achieve feed pump, booster pump, all operational factors of upper tower pump and system energy consumption.

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, its Feature is, described in step G the number of units optimization of recirculating cooling water system water pump operation reduce change valve optimize operating scheme into:

Circulating cooling water system of blast furnace presses the design of least favorable branch road water supply requirement, does not considers that becoming valve optimization runs, and system totally supplies water Cooling capacity has the most more than needed；If system cooling each way outlet of water arranges control valve, then by computational analysis, system is real Execute change valve optimization based on the maximum allowable Inlet and outlet water temperature difference to run, due to blast furnace each position cooling water bypass flow and system total flow Reduce, on the premise of duty water and pressure, optimize and reduce feed pump, booster pump and the start number of units of upper tower pump, subtract Resistance required for little each branch road outlet pipe control valve, reduces the purpose of energy consumption；

To cooling down each way outlet of water described in step D, the circulating cooling water system of blast furnace of control valve is set, cold according to each position But water branch road needs flow Q by minimum_{i min}(m³/ s), (i=1,2 ..., requirement m), with each branch road resistance coefficient S_i′ (i=1,2 ..., m) be unknown quantity, each branch road resistance coefficient includes outlet pipe control valve resistance coefficient, set up each branch road from Cooling pond, through water pump, blast furnace cooling position to outlet pipe control valve, lead to atmospheric outlet energy-balance equation, i.e. need to raise Journey curvilinear equation, simultaneous pump characteristic equations, obtain equation group (8), wherein, feed pump runs number of units and booster pump runs Number of units is respectively adopted operation number of units k optimized after reducing₁', k₂′；

$\left\{\begin{array}{c}{H}_1=H_{sti}+F_i(Q_{1\min },Q_{2\min },\mathrm{...}{Q}_{m\min },{S_i}^{\′});i=1,2,\mathrm{...},n\\ H_1+H_2=H_{sti}+F_i(Q_{1\min },Q_{2\min },\mathrm{...}{Q}_{m\min },{S_i}^{\′});i=n+1,n+2,\mathrm{...},m\\ H_1=H_1(\underset{i=1}{\overset{m}{\Σ}}{Q}_{i\min }/{k_1}^{\′});\\ H_2=H_2(\underset{i=n+1}{\overset{m}{\Σ}}{Q}_{i\min }/{k_2}^{\′});\end{array}\right.---\left(8\right)$

Solving equation group (8), obtains cooling water in each position after circulating cooling water system of blast furnace feed pump, booster pump operation number of units optimization Branch road resistance coefficient and feed pump, booster pump lift；Calculate each position cooling water branch road outlet pipe control valve resistance coefficient, excellent Change and reduce upper tower pump operation number of units, calculate feed pump and the flow of booster pump, power and efficiency, the flow of upper tower pump, lift, Power and efficiency and recirculating cooling water system total energy consumption, and operating scheme former with recirculating cooling water system be i.e. not carried out becoming valve optimization The observable index of operating scheme is relatively.

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, its Feature is, needs flow according to blast furnace each position cooling water minimum described in step H, and re-optimization selects recirculating cooling water system water The method of pump is:

It is not provided with control valve by formula (9) by each position cooling water branch road outlet pipe or control valve resistance is 0, is needed by minimum Wanting flow, calculating each branch road needs lift:

H_{Need i}=H_{st i}+F_i(Q_1min,Q_2min,…Q_{m min}, S_i)；I=1,2 ..., m (9)

By the maximum demand lift MAX H in front n water supply branch road_{Need i}(i=1,2 ..., n) with all m water supply branch roads Flow sum, re-optimization selects feed pump, it is desirable to feed pump runs in efficient district；If the feed pump lift reselected is H₁； Feed pump lift MAX H is deducted by the maximum demand lift in rear m-n water supply branch road_{Need i}(i=n+1, n+2 ..., m) -H_1nReselect booster pump lift H_2n, it is desirable to booster pump runs in efficient district；Flow is needed by recirculating cooling water system minimum Reselect tower pump, it is desirable to upper tower pump runs in efficient district.

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, its Feature is, recirculating cooling water system described in step I again select the change valve after pump optimize operating scheme into:

The circulating cooling water system of blast furnace of control valve is set to cooling down each way outlet of water described in step D, cools down according to each position Water branch road needs flow Q by minimum_{i min}(m³/ s), (i=1,2 ..., requirement m), with each branch road resistance coefficient S_i' (i=1, 2 ..., m) be unknown quantity, each branch road resistance coefficient includes outlet pipe control valve resistance coefficient, set up each branch road from cooling pond, Through water pump, blast furnace cooling position to outlet pipe control valve, the energy-balance equation of logical atmospheric outlet, i.e. necessary head curve of the installation system side Journey, simultaneous pump characteristic equations, obtain equation group (10), wherein, use the feed pump reselected and booster pump flow- Lift performance curve and design and operation number of units, solving equation group (10), determine that recirculating cooling water system is each for obtaining after again selecting pump Each branch road resistance coefficient S when branch road minimum needs flow_i' (i=1,2 ..., m) with feed pump, booster pump lift, with solving The each branch road resistance coefficient gone out is individually subtracted branch road former resistance coefficient S_i, i.e. obtain required each branch road outlet pipe control valve resistance Force coefficient Δ S_i(i=1,2 ..., m), and check adjustment, it is ensured that each position cooling water pressure meets requirement；

$\{\begin{array}{c}{H}_1=H_{sti}+F_i(Q_{1\min },Q_{2\min },\mathrm{...}{Q}_{m\min },{S_i}^{\′});i=1,2,\mathrm{...},n\\ H_1+H_2=H_{sti}+F_i(Q_{1\min },Q_{2\min },\mathrm{...}{Q}_{m\min },{S_i}^{\′});i=n+1,n+2,\mathrm{...},m\\ H_1={H_1}^{\′}(\underset{i=1}{\overset{m}{\Σ}}{Q}_{i\min }/k_1);\\ H_2={H_2}^{\′}(\underset{i=n+1}{\overset{m}{\Σ}}{Q}_{i\min }/k_2);\end{array}---\left(10\right)$

Calculate and determine the feed pump after reselecting and booster pump flow, power and efficiency, upper tower pump discharge, lift, power and Efficiency, calculates the energy consumption of the circulating cooling water system of blast furnace after again selecting pump.

Blast-furnace cooled water system based on maximum temperature difference the most according to claim 1 becomes valve optimization and runs and select pumping method, It is characterized in that, each position of blast furnace described in step K cooling water branch road outlet pipe controlling opening of valve control method is:

What original system water pump operation number of units was constant becomes the change valve optimization fortune of valve optimization operation, original system water pump operation number of units optimization minimizing Row and system re-optimization select the change valve optimization after pump to run three kinds of schemes, according to the valve resistance coefficient each required, compare valve Door aperture-resistance curve, controlling opening of valve, reach recirculating cooling water system and become valve optimization operation and run excellent based on becoming valve optimization Change the purpose selecting pump.