CN102746857A

CN102746857A - Low-cost high-efficiency coke oven residual heat recovery system

Info

Publication number: CN102746857A
Application number: CN2012101693107A
Authority: CN
Inventors: 熊承庆; 李应锐; 黄萌; 宋喜友
Original assignee: Building Material Energy Saving Apparatus General Plant Huangshi
Current assignee: Hubei Jinlu Energy Saving Co ltd
Priority date: 2012-05-29
Filing date: 2012-05-29
Publication date: 2012-10-24
Anticipated expiration: 2032-05-29
Also published as: CN102746857B

Abstract

The invention relates to a coke oven residual heat recovery energy-saving modification technology, and discloses a low-cost high-efficiency coke oven residual heat recovery system. The system comprises a coke oven. The rear part of a combustion chamber of the coke oven is connected to a chimney through an exit flue. A regulating valve is arranged in the exit flue, and divides the exit flue into an inner flue and an outer flue. A system controlling apparatus is arranged in the inner flue. The system is characterized in that: a flue gas recovery extracting apparatus is arranged in the outer flue. The apparatus comprises an exhaust controller, and an exhauster, a pressure gauge, and a temperature gauge connected with the outer flue. The exhaust controller is simultaneously connected to input terminals of the pressure gauge and the temperature gauge. The controller is connected to the exhauster, and controls the exhauster. The exhauster is connected to a drying system outside. With an existing coke oven residual heat recovery system, an extracting point is not properly selected, the system is not easy to control, the cost is high, and flue gas extraction rate is restricted. With the system provided by the invention, the problems are overcome. The invention is mainly used in modifications of heat recovery systems of coke ovens and similar operating conditions.

Description

A kind of low-cost high-efficiency pit kiln residual neat recovering system

(1) technical field: the present invention relates to the waste heat recovering energy conserving renovation technique of pit kiln, especially a kind of low-cost high-efficiency pit kiln residual neat recovering system.

The (2) prior art: pit kiln is present widely used dry distillation of coal processing unit; Its composition is seen Fig. 1; Pit kiln has coking space 1, outside the coking space 1 mobile pushing machine 2 is housed, and the combustion chamber 3 that heat supply is used is established in the coking space bottom; Be provided with many row's burners 4 in the combustion chamber of employing heat storage technology, mobile feeder 5 is equipped with at the coking space top.During production, pushing machine is released ripe Jiao off and on one by one and is loaded new coal to be refined, combustion chamber continuous heat supply by feeder; The waste gas in combustion chamber afterburnt is through inside and

outside flue

7 and 11, variable valve 10, is communicated with chimney 12 (seeing Appendix 1) that negative pressure is stablized in maintenance to discharge out of the furnace.Because the operating mode at intermittence of coking space; Must cause the internal pressure of combustion chamber fluctuation; For fluctuating in the balance chamber, on inner flue, be provided with central controller 6 automatic controls or manual variable valve 10, tensimeter 8, TM 9, keep internal pressure of combustion chamber dynamically to guarantee stable heating.

For energy cascade utilization, waste heat fully is used to adjust the water cut into the stokehold raw coal in the waste gas that chimney is effluxed, and to guarantee coking quality and save energy, just must from former flue gas emission, extract waste gas; And it is necessary to extract waste gas: first does not influence coking when extracting normally moves, and second can switch rapidly when not taking out waste gas is discharged from former chimney, and the 3rd can extract waste gas to greatest extent and be used for production satisfying under preceding two conditions.

At present domestic mainly is introduction of foreign technology, and 7 places establish fume extraction point (see figure 2) at inner flue.Because having received the frequent irregular fluctuation influence of load in burner hearth 3 internal pressures is difficult under the equilibrated operating mode; Increase the vacuum fan load of a variation again; The mathematical model of its steering logic is a n+M equation with many unknowns, causes system unit bulky complex, and cost is high; Fault is many, and the extraction amount of waste gas is restricted; General all less than 70%, finally have influence on the efficient of total system waste heat recovery and stablizing of system.

The (3) summary of the invention: the object of the invention will solve existing pit kiln waste heat extraction recovery system configuration complicacy exactly, cost is high, the trouble spot is many, and the little problem of extraction amount of waste gas provides a kind of low-cost high-efficiency pit kiln residual neat recovering system.

Concrete scheme of the present invention is: improve to existing pit kiln residual neat recovering system, it includes pit kiln, and pit kiln top is provided with several coking spaces; Portable pushing machine is housed in the coking space, and the pit kiln bottom is the combustion chamber, is provided with many row's burners in the combustion chamber; Portable feeder is equipped with at the top of pit kiln, and the afterbody of pit kiln combustion chamber connects chimney through smoke-uptake, and variable valve is installed in the smoke-uptake; Variable valve is divided into inner flue and external flue with smoke-uptake, and tipping has tensimeter and TM in inner flue, disposes central controller; Central controller is connected with tensimeter, TM, variable valve respectively, it is characterized in that: flue gas is installed in external flue reclaims draw-out device, this device includes the exhausting unit; The vacuum fan that is connected with external flue, pressure gauge, temperature measuring gauge; Said exhausting unit is imported simultaneously with pressure gauge and temperature measuring gauge and is connected, and unit control linkage vacuum fan, the external drying system of vacuum fan.

Principle of design (see figure 3) of the present invention is: it is constant 1) to keep the former system of pit kiln; Promptly keep flue adjusted valve 10 and central controller 6 thereof, tensimeter 8, TM 9 is constant; As long as guarantee that stack draught is constant, the normal operation of pit kiln will keep former operating mode.2) extraction point with waste gas is arranged in 11 sections of external flues.The Yi Basike law, the negative pressure at this place is consistent with chimney, and can know that from annex 1 demonstration the draft of chimney is only relevant with the temperature of the column of smoke in the chimney, and is irrelevant with exhaust gas volumn.Extracting the quantity of flue gas 1. has the column of smoke to keep in the chimney as long as satisfy; 2. the heat and the chimney surface radiating amount balance that discharge of its tolerance of keeping the column of smoke keeping the temperature of chimney, can change works better rapidly over to when changing the chimney exhaust into stopping to bleed.Through measuring and calculating, keep 3% summer in south, keep 5% exhausted air quantity winter, just can guarantee normal conversion.This waste gas extraction system is by vacuum fan 13, pressure gauge 15, and temperature measuring gauge 16 is formed (see figure 3)s with exhausting unit 14.The exhausting unit is only followed the tracks of pressure gauge 15 like this, with reference to temperature measuring gauge 16, guarantees that promptly the stable negative pressure of chimney gets final product, and the digital model of its steering logic is simplified to linear equation with one unknown.This system configuration is simple, and is cheap, is easy to control, and failure rate is low, and waste gas extraction amount is greater than 95%, and the control section cost is merely 1/10 of imported technology, and this argument is correct through test.Prove as follows:

The formula of stack draught is:

S=Hyz

Figure 2012101693107100002DEST_PATH_IMAGE001

....①

In the formula: the natural draft pa of S---chimney;

--the severe 12.67N/NM of air under the-standard state ³

Figure 2012101693107100002DEST_PATH_IMAGE003

--severe 13.132 N/NM of flue gas under the-standard state ³

Tk---outside air temperature ⁰C;

The medial temperature of flue gas in the ty---chimney ⁰C;

Hyz---chimney height m;

The local normal atmosphere pa of P1---;

P---standard atmospheric pressure 101330pa

Example: as ground temperature tk=0 ^OC, height above sea level 2000m look into P ₁=79500pa. chimney height Hyz=185m.

When ty from 50-250 ^OWhen C changes with 1. formula of each item given data substitution: have

When: ty=50 ^OS=-228pa during C

Ty=100 ^OS=-444pa during C

Ty=150 ^OS=-609pa during C

Ty=200 ^OS=-739pa during C

Ty=250 ^OS=-844pa during C

Referring to Fig. 4, under the constant condition of chimney height Hyz and ambient temperature, confirm negative pressure value (being draft) by the medial temperature ty of the column of smoke in the chimney.Irrelevant with the exhaust gas volumn through chimney in the certain flow rate scope, that is to say normally in service, no matter load variations causes under the operating mode through the chimney smoke quantitative changeization that as long as flue-gas temperature is constant, its negative pressure is a certain value.According to Bath Ke Dinglv, valve external flue 11 negative pressure are certain value.

The various waste heats extractions that the present invention can be applicable to similar operating mode utilize engineering.Its fume extraction amount is by bringing up to greater than 95% less than 70% originally.Application the present invention smelts the exhausted air quantity of producing coke generation per ton and is about 1266NM ³/ t, exhaust temperature are 225 ^OC-250 ^OAbout C, the heat content in producer's discharging waste gas of annual output 2200000 t/ coke scales is 2.106 * 10 ¹¹Kcal/ is used to dry material, conversion q ^yThe work of dw=5000kcal/kg, sulphur content 2%, 1200 yuan/t of valency ≈ uses coal to be 32836t/, reduces discharging CO ₂Be 76804t/, reduce discharging SO ₂Be 1313t/, energy-saving benefit is 3,940 ten thousand yuan/year.The reduction of discharging energy-saving benefit is huge.

The (4) description of drawings:

Fig. 1 is existing pit kiln system architecture synoptic diagram;

Fig. 2 is that existing pit kiln waste heat extracts the recovery system structural representation;

Fig. 3 is an overall structure synoptic diagram of the present invention;

Fig. 4 is the graph of relation of column of smoke medial temperature ty in stack draught S and the chimney.

Among the figure, 1-coking space, 2-pushing machine, 3-combustion chamber, 4-burner, 5-feeder; The 6-central controller, 7-inner flue, 8-tensimeter, 9-TM, 10-variable valve, 11-external flue; The 12-chimney, 13-vacuum fan, 14-exhausting unit, 15-pressure gauge, 16-temperature measuring gauge.

The (5) embodiment:

Referring to Fig. 3, the present invention includes pit kiln, pit kiln top is provided with several coking spaces 1; Outside the coking space 1 portable pushing machine 2 is housed, the pit kiln bottom is combustion chamber 3, is provided with many row's burners 4 in the combustion chamber 3; Portable feeder 5 is equipped with at the top of pit kiln 1, and the afterbody of pit kiln 1 combustion chamber 3 connects chimney 12 through smoke-uptake, and variable valve 10 is installed in the smoke-uptake; Variable valve 10 is divided into inner flue 7 and external flue 11 with smoke-uptake, and tipping has tensimeter 8 and TM 9 in inner flue 7, disposes central controller 6; Central controller 6 is connected with tensimeter 8, TM 9, variable valve 10 respectively, and particularly: flue gas is installed in external flue 11 reclaims draw-out device, this device includes exhausting unit 14; The vacuum fan 13 that is connected with external flue 11, pressure gauge 15, temperature measuring gauge 16; Said exhausting unit 14 is imported simultaneously with pressure gauge 15 and temperature measuring gauge 16 and is connected, and unit 14 control linkage vacuum fans 13, vacuum fan 13 external drying systems.

When the present invention works; By 13 work of exhausting unit 14 control vacuum fans; Pressure gauge 15 records the negative pressure value input exhausting unit 14 of external flue 11, and the negative pressure value in guaranteeing external flue 11 is not less than and can extracts flue gas to greatest extent under the situation of stack draught and recycle.When observing pressure gauge 15, cooperate the variation of observing temperature measuring gauge 16, normal with the operation that guarantees system, under the normal circumstances, two tables should be stablized, and change little.In case when pressure in the flue or temperature have bigger variation, unit will be adjusted vacuum fan work immediately, recover normally operation.

Claims

1. a low-cost high-efficiency pit kiln residual neat recovering system includes pit kiln, and pit kiln top is provided with several coking spaces; Coking space is equipped with portable pushing machine outward, and the pit kiln bottom is the combustion chamber, is provided with many row's burners in the combustion chamber; Portable feeder is equipped with at the top of pit kiln, and the afterbody of pit kiln combustion chamber connects chimney through smoke-uptake, and variable valve is installed in the smoke-uptake; Variable valve is divided into inner flue and external flue with smoke-uptake, and tipping has tensimeter and TM in inner flue, disposes central controller; Central controller is connected with tensimeter, TM, variable valve respectively, it is characterized in that: flue gas is installed in external flue reclaims draw-out device, this device includes the exhausting unit; The vacuum fan that is connected with external flue, pressure gauge, temperature measuring gauge; Said exhausting unit is imported simultaneously with pressure gauge and temperature measuring gauge and is connected, and exhausting unit control linkage vacuum fan, the external drying system of vacuum fan.