CN1873318A - Conduction through type steam generator - Google Patents

Abstract

The invention relates to a straight-through steamer, comprising straight smoke conduit formed with air-tight tube wall. The tubes of tube wall is spirally installed or screw-thread at lower part of smoke conduit where the mineral fuel burner is set and is vertically fixed at upper part of smoke conduit, the smoke conduit underpart passes through bottom of smoke conduit on lower part and upper part of smoke conduit passes through transverse wall of smoke conduit on upper part and is contracted by lateral section formed by tube wall through smoke conduit or passes through lower bound of heating surface set inside smoke conduit. The total height of smoke conduit lower part (4) is constructed according to formula of 1<=H<SUB>ges</SUB>/2 .(B+T) .tanalpha<=2.0; tube wall (3) of smoke conduit comprises a lower part and at least another tube wall section, and the inside of lower tube wall section (8) is smooth and is ribbed with tube of tube wall section (9); the relationship between height of lower tube wall section and total height is constructed according to formula of 0.25<=H<SUB>1</SUB>/H<SUB>ges</SUB><=0.6; and relationship between the height of tube wall section (9) and total height is formed according to formula of 0.25<=H<SUB>2</SUB>/H<SUB>ges</SUB><=0.75; and the tube inner lateral section for tubes (10,11,12) are constructed according to formula of 1<=A<SUB>1</SUB>/A<SUB>0</SUB><=1.25 and 1<A<SUB>2</SUB>/A<SUB>1</SUB><=1.25.

Description

Conduction through type steam generator

Technical field

The present invention relates to a kind of conduction through type steam generator (Durchlaufdampferzeuger), has the vertical gas pass that constitutes by airtight tube wall, the pipe of tube wall is provided with on fossil-fuel-fired device residing flue lower thread shape or spirality ground and in the upper vertical setting of flue, and its underpart on the bottom by flue and its top on the lower end on the upper end cross wall by flue, the cross section that constitutes by tube wall by flue shrink or the lower edge gauge of the heating surface by being arranged on flue inside.

Background technology

This or similar conduction through type steam generator has known from the 2nd edition mat woven of fine bamboo strips 4.4.2.4 chapter of KarlStrau β professor's document that the Doctor of engineering is shown " Kraftwerkstechnik (power station technology) " " Zwangdurchlauf (forcing straight-through) " (referring to the 171-174 page or leaf) of Springer publishing house publication in 1994, forces to lead directly to the burning generation electric energy that is used in the power station by for example fossil fuel.In straight-through or pressure conduction through type steam generator, the heating of the evaporation tube of formation combustion chamber or flue (with only the Natural Circulation or the forced-circulation steam generator of part evaporation water-vapor mixing body are opposite in the employing circulation) causes flow media or working media in the evaporation tube to evaporate in once leading directly to.The evaporation tube that constitutes flue in this regard can be vertically or thread-shaped or spirality and the ground setting of therefore can tilting to rise.

Thereby the flue bottom of the conduction through type steam generator that the inner light pipe with smooth surface of employing is an evaporation tube and the design of inclination piping are led directly to load by minimum pressure and are determined for the required mass flow density of enough coolings in this regard.Lead directly under the situation of minimum load at present desired pressure smaller or equal to full load 30%, must form the quite high mass flow density (in simple load area straight-through in service and the linear dependence between the mass flow density) and the pressure loss of relevant raising therewith in steam generator at full capacity the time, this pressure loss must be compensated by the operating cost that steam generator adds.Selectively design in the bottom of conduction through type steam generator flue under the situation of walling of flue of vertical piping, because for the required mass flow density of pipe cooling, adopt the straight-through minimum load design of pressure of light pipe can not be less than fully loaded 50%.For obtaining minimum load, must use internally ribbed pipe, even its spiral internal rib also can be improved the cooling of evaporation tube under the situation of lower mass flow density less than 50%.

But the shortcoming of the walling of flue of vertical piping is, the combustion chamber in or the interior local heat difference of flue can not get adequate remedy.By being that the evaporimeter of conduction through type steam generator uses additional complicated hybrid system or by the inlet restriction on the tube inlet of the evaporimeter of conduction through type steam generator, under temperature section (Temperaturprofil) situation of working medium water/steam on the evaporator outlet of considering at conduction through type steam generator, adopt spirality in this system and the walling of flue or the evaporator tube that tilts to rise is compared the influence that also obviously more is subject to heat crooked situation.

Document EP 0 349 834 A1 disclose a kind of conduction through type steam generator, have the chamber wall or the walling of flue of the thread-shaped of flue bottom or spirality piping and have the walling of flue of the vertical piping on flue top, wherein, the walling of flue of spirality piping utilizes light pipe to constitute with the walling of flue of vertical piping and utilizes internally ribbed pipe formation.In the conduction through type steam generator that constitutes like this, only when selecting the sufficiently high mass flow density of working medium water/steam for the evaporator tube of the walling of flue in the spirality piping zone, just can reach smaller or equal to 30% the straight-through load of minimum at full capacity.This point has improved the power demand of feed pump and has therefore caused the consequence of the total device efficiency of unfavorable reduction.

Document DE 195 10 033 C2 disclose another kind of conduction through type steam generator, have the chamber wall or the walling of flue of the thread-shaped of flue bottom or spirality piping and have the walling of flue of the vertical piping on flue top.In this disclosed conduction through type steam generator, the surrounding wall of combustion chamber or flue or outer wall finding from bottom to up are divided into bottom stage, first and second interludes and upper segment, and wherein, upper segment can be divided into first and second parts again.Bottom stage, first and second interludes and when needing the first of upper segment can have spiral tube wall.For this conduction through type steam generator can be moved under weak load, propose bottom stage and utilize interior lights slip pipe, first interlude to utilize inner bull grilled tube (MLR:Multiple LeadRibbed), second interlude to utilize inner single head grilled tube (SLR:Single Lead Ribbed) and upper segment also to utilize the first of interior lights slip pipe or upper segment to utilize inner bull grilled tube to constitute once more.The shortcoming that shows in the structure of this dissimilar evaporator tubes is, compare with inner bull grilled tube (MLR), because the inner single head grilled tube of the flow resistance that improves (SLR) produces the higher pressure loss in working media aspect, the additional operating cost of this pressure loss forming device or make the overall plant efficiency variation that adopts this conduction through type steam generator.Another shortcoming is, for MLR pipe and SLR pipe being connected it once more with the MLR pipe mounting cost that produces raising when needing and having increased cost by using and reserve dissimilar evaporator tubes.

Summary of the invention

The objective of the invention is to, a kind of design of avoiding the conduction through type steam generator of above-mentioned shortcoming or proposing a kind of evaporator system is provided, burn the outer wall that hot conduction through type steam generator adopts the inclination piping of steam generator flue bottom for fossil fuel, minimum load has the pressure loss minimum in the steam generator and under uniform as far as possible working media temperature section situation in the conduction through type steam generator outlet, the interior flue outer wall of whole load area is enough cooled off for leading directly to smaller or equal to the pressure of full load 30%.

Above-mentioned purpose is achieved by the feature of the characteristic of claim 1.

The present invention has the formation of advantage and consults dependent claims.

By a kind of conduction through type steam generator of optimal design is provided according to solution of the present invention, it has following advantage:

-only in using the zone of internally ribbed pipe, use internal spiral or thread-shaped bull ribbing evaporator tube (MLR) and therefore only reserve such internally ribbed pipe,

-reduce the pressure loss aspect the medium by interior smooth and the internally ribbed evaporator tube optimal allocation in the flue lower area,

-use inner bull ribbing evaporator tube (MLR) even situation under when forcing straight-through minimum load, in whole load area, also reach enough coolings of evaporimeter tube wall,

-under the pressure loss situation of minimum, will force straight-through minimum load to drop to smaller or equal to 30% of full load or the maximum rate (BMCR) continuously of boiler,

-with best pitch of the laps quantity under the relevant positive characteristic of considering the inclination piping with the medium temperature section in conduction through type steam generator outlet during all heated conditions,

-aspect heating difference by flow direction at working media on finding flue bottom outer wall pipe free or manage stability and the sensitivity that the best hole enlargement of cross section improves evaporator system only.

A kind of formation with advantage is that tilt angle of climb α that rise or evaporator tube thread-shaped or spiral extension and that surround the flue bottom and horizontal plane are with 15 ° of-35 ° of formations.

What have advantage is that the pipe of flue bottom constitutes in interior smooth.These can be managed pressure inside loss thus remains on the not half and therefore and avoids the temperature of the working media in this zone crooked as far as possible (Temperaturschieflage).

Another formation with advantage is that the pipe of the tube wall on flue top constitutes in interior smooth.Therefore compare the pressure loss and the cost of reducing investment outlay that can reduce in these pipes with internally ribbed pipe.

The characteristic of the steam generator of fossil fuel burning heat is the Level Change heat flow density section (W  rmestromdichteprofil) by combustion chamber or flue.For conduction through type steam generator typically forms a kind of vapor (steam) temperature that changes by combustion chamber height or flue height in the evaporation tube of tube wall.Be the heat flow density section considering in tube wall, to change and the influence of the vapor (steam) temperature by height change and the working medium pressure loss that obtains the inner substantially the same degree of tube wall equally by combustion chamber height or flue height, what have advantage is, tube wall the interface between flue bottom and the top and/or tube wall in the flue bottom bottom tube wall section and directly be connected the tube wall section on the tube wall section of bottom and other tube wall sections of existing when needing between the interface substantial horizontal constitute.

Description of drawings

Introduce embodiments of the invention in detail by accompanying drawing and the description of the drawings below.Wherein:

Fig. 1 schematically illustrates the vertical gas pass of conduction through type steam generator;

Fig. 2 schematically illustrates the expanded view of each evaporation tube that tilt to rise, pack into the bottom of conduction through type steam generator flue of this evaporation tube;

Fig. 3 schematically illustrates the part by the bottom tube wall of Fig. 1 cross section A-A;

Fig. 4 schematically illustrates the part by the bottom tube wall section of the flue bottom of Fig. 1 section B-B;

Fig. 5 schematically illustrates the part that directly is connected the tube wall section on the tube wall section of bottom by Fig. 1 section C-C;

Fig. 6 illustrates Fig. 1 identical content, but is selectable embodiment;

Fig. 7 illustrates Fig. 1 identical content, but is selectable embodiment;

Fig. 8 illustrates the cross section of internally ribbed pipe;

Fig. 9 illustrates the longitudinal section of internally ribbed pipe.

The specific embodiment

Burn in the conduction through type steam generator 1 of heat at the fossil fuel in traditional power station, the known working media that is generally water/steam basically the passage in steam turbine loop or straight-through in preheating, evaporation, overheated and divide intermediate superheating when needing after reducing pressure at the HD of steam turbine partial interior.Introduce conduction through type steam generator 1 below.

Fig. 1 schematically illustrates conduction through type steam generator 1, has the vertical gas pass 2 that is made of airtight tube wall 3.Tube wall 3 comprises the flue 2 of the rectangular cross section that preferably has width B and degree of depth T in this regard, and wherein, for example the antetheca of flue 2 and rear wall 20,21 extend on degree of depth T on the width B and the right side of flue 2 and left side wall 22,23, to this also referring to Fig. 2.

Flue 2 is divided into bottom and top 4,5.Boundary between bottom and the top 4,5 or comprise the bottom of flue 2 and the interface 14 of the tube wall 3 on top 4,5 moves towards best substantial horizontal according to pipe in this regard and extends.This point also can comprise the interface 14 that zigzag slightly constitutes simultaneously, because the pipe that rises can install and assembling to the tube bottom plate (not shown) is pre-, and can zigzag constitute on interface 14 in this regard.The bottom 4 of flue 2 utilizes tube wall 3 to constitute, its pipe 11,12 thread-shaped or spirality are around flue 2 and having a down dip rising (referring to Fig. 1 and 2 with the angled α of horizontal plane, wherein, only schematically illustrate the pipe of some a small amount of inclinations of airtight tube wall 3), and the pipe 13 of the tube wall 3 on flue 2 tops 5 vertically extends.For burning mineral fuel coal dust for example, in flue 2 bottoms 4, unshowned burner is arranged at flue or 2 inside, combustion chamber.Burnt gas that produces when fossil-fuel-fired or flue gas upwards flow in the inside of flue 2 and discharge by other unshowned flues subsequently.In this regard, the heat that is freely formed during burning outputs to the working medium water/steam of the top detailed introduction of conduction through type steam generator 1.

In the present embodiment, cross wall 7 gauges are passed through by the upper end on funnel-shaped bottom portion 6 gauges and flue 2 tops 5 in the lower end of flue 2 bottoms 4.Infundibulate and airtight bottom 6 with one or more soot emissions mouth 24 that is used to discharge the flue dust that produces when fossil-fuel-fired have local height H ₀, and constitute the evaporation tube 10 of bottom 6 and evaporation tube 11, the 12 same thread-shaped or the spiral extensions of flue 2 bottoms 4.Cross wall 7 is the such airtight tube wall of image tube wall 3 for example preferably.The top 5 of flue 2 also can shrink 25 or by a lower edge gauge that is arranged on the heating surface 26 of flue 2 inside by Fig. 7 by a cross section that is made of tube wall by the flue 2 of Fig. 6 on the upper end of flue 2.

Flue 2 bottoms 4, just its tube wall 3 designs the part of the flue 2 of the pipe 11,12 that thread-shaped or spiral extension are arranged, its total height (H _Ges) according to formula

$1\&le;\frac{{\mathrm{<figure-callout\; id="2"\; label="H\; ges"\; filenames="A20061008987500151.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{ges}}}{2\&CenterDot;(B+T)\&CenterDot;\tan \mathrm{\&alpha;}}\&le;2.0$

Constitute, wherein, B and T represent the width and the degree of depth of flue 2, and angle α represents the lift angle of the pipe 11,12 of tube wall 3 inner each thread-shaped just that tilt to rise or spiral extension.Therefore Fig. 2 illustrates internally or from flue 2 expansion of being seen pipe 11,12 in flue 2 bottoms 4.Above-mentioned formula H _Ges, B and T size determine separately represent with unit rice.

In addition, that the tube wall 3 of flue 2 bottoms 4 is divided into a bottom and another tube wall section 8,9 at least, wherein, pipe 11 interior smooth (light pipe) of bottom tube wall section 8 and the pipe 12 that directly is connected the tube wall section 9 on the bottom tube wall section 8 are in internal spiral or thread-shaped ground bull ribbing 16, referring to Fig. 8 and 9.Wherein, bottom tube wall section 8 has overall height H _GesLocal height H ₁The tube wall section 9 that directly is connected on the bottom tube wall section 8 has overall height H _GesLocal height H ₂Direct-connected meaning, tube wall section 9 in vertical direction finding directly be in bottom tube wall section 8 above.The boundary of tube wall section 8,9 or preferably extend in a horizontal manner basically in 4 inside, bottom of flue 2 at their other unshowned interfaces 15 between the tube wall section aspect different tubular constructions or the model when needing.This point also can comprise the interface 15 of zigzag formation slightly here simultaneously, because the pipe that rises can also can zigzag constitute on interface 15 in this regard to pre-installation of tube bottom plate (not shown) and assembling.

The local height H of bottom tube wall section 8 ₁In this regard with the overall height H of flue 2 bottoms 4 _GesRelevant according to formula

$0.25\&le;\frac{H_1}{H_{\mathrm{ges}}}\&le;0.6$

Directly be connected the local height H of the tube wall section 9 on the bottom tube wall section 8 ₂Overall height H with flue 2 bottoms 4 _GesRelevant according to formula

$0.25\&le;\frac{H_2}{H_{\mathrm{ges}}}\&le;0.75$

Constitute, wherein, height is separately represented with unit rice.

The pipe 11 of bottom 6 pipe 10, bottom tube wall section 8 and the pipe 12 that directly is connected the tube wall section 9 on the tube wall section 8 have internal cross section A separately ₀(pipe 10), A ₁(pipe 11) and A ₂(pipe 12) is also referring to Fig. 3-5.Pipe internal cross section separately is in this regard according to formula

$1\&le;\frac{A_1}{A_0}\&le;1.25$

With

$1\&le;\frac{A_2}{A_1}\&le;1.25$

Constitute, wherein, internal cross section is with the m of unit ²Expression.

The pipe 10 best interior smooth ground (light pipe) of bottom 6 constitute.Relevant with mean inside diameter according to the internal cross section of Fig. 8 and 9 internally ribbed pipe 12 is the average internal cross section, and this average internal diameter is between the rib pin and ribbed back face of rib 16 of internally ribbed pipe 12.

The tube wall 3 of the pipe 11,12 that is provided with around the thread-shaped of flue 2 bottoms 4 or spirality preferably constitutes with 15 °-35 ° angle of climb α with respect to the horizontal plane.

The vertically extending pipe 13 best interior smooth ground of the tube wall 3 on flue 2 tops 5 constitute, and that is to say that its pipe internal surface constitutes (light pipe) glossily.

According to the requirement of evaporator system, other the unshowned tube wall sections in flue 2 bottoms 4 can be set on tube wall section 9 directly.The preferred interior smooth of the thread-shaped of this unshowned tube wall section or the evaporator tube of spiral extension ground constitutes.

Reference numerals list

1 conduction through type steam generator

2 flues

3 tube walls

4 flue bottoms

5 flue tops

6 bottoms

7 cross walls

8 bottom tube wall sections

9 Zhi are connected on the tube wall section on the tube wall section of bottom in succession

The pipe of 10 bottom tube walls

The pipe of the tube wall of 11 bottom tube wall sections

12 directly are connected the pipe of the tube wall of the tube wall section on the tube wall section of bottom

The pipe of the tube wall on 13 flue tops

Interface between 14 flue bottoms and the top

15 in bottom tube wall section with directly be connected interface between the tube wall section on the tube wall section of bottom

16 ribs

17

18

19

20 antethecas

21 rear walls

22 right side walls

23 left side walls

24 soot emissions mouths

25 cross sections shrink

26 heating surfaces

Claims (6)

1. conduction through type steam generator, has the vertical gas pass that constitutes by airtight tube wall, the pipe of tube wall is in the residing flue of fossil-fuel-fired device bottom that thread-shaped or spirality ground is provided with and in the upper vertical setting of flue, and its underpart on the bottom by flue and its top on the lower end on the upper end cross wall by flue, the cross section that constitutes by tube wall by flue shrink or the lower edge gauge of the heating surface by being arranged on flue inside, it is characterized in that the total height (H of flue bottom (4) _Ges) according to formula

$1\&le;\frac{H_{\mathrm{ges}}}{2\&CenterDot;(B+T)\&CenterDot;\tan \mathrm{\&alpha;}}\&le;2.0$

Constitute, that the tube wall (3) of flue (2) bottom (4) is divided into a bottom and another tube wall section (8,9) at least, and pipe (11) interior smooth of bottom tube wall section (8) and the pipe (12) that directly is connected the tube wall section (9) on the bottom tube wall section (8) are in inner multiple thread shape ground ribbing, wherein, the height (H of bottom tube wall section (8) ₁) with the total height (H of flue (2) bottom (4) _Ges) relevant according to formula

$0.25\&le;\frac{H_1}{H_{\mathrm{ges}}}\&le;0.6$

Directly be connected the height (H of the tube wall section (9) on the bottom tube wall section (8) ₂) with the total height (H of flue (2) bottom (4) _Ges) relevant according to formula

$0.25\&le;\frac{H_2}{H_{\mathrm{ges}}}\&le;0.75$

And bottom (6), bottom tube wall section (8) and directly be connected the pipe internal cross section (A of the pipe (10,11,12) of the tube wall section (9) on the bottom tube wall section (8) ₀, A ₁, A ₂) according to formula

$1\&le;\frac{A_1}{A_0}\&le;1.25$

With

$1<\frac{A_2}{A_1}\&le;1.25$

Constitute, wherein

H _GesWith rice is the total height of the flue bottom of unit,

H ₁With rice is the height of the bottom tube wall section of unit,

H ₂With rice is the height that directly is connected the tube wall section on the tube wall section of bottom of unit,

B is the flue width of unit with rice,

T is the flue degree of depth of unit with rice,

The angle of climb of the tube wall pipe that α spirality inclination is with respect to the horizontal plane risen,

A ₀With m ²Be the pipe internal cross section of the pipe of the bottom of unit,

A ₁With m ²Be the pipe internal cross section of the pipe of the bottom tube wall section of unit, and

A ₂With m ²Pipe internal cross section for the pipe that directly is connected the tube wall section on the tube wall section of bottom of unit.

2. by the described conduction through type steam generator of claim 1, it is characterized in that the angle of climb with respect to the horizontal plane (α) is 15-35 °.

3. by one of claim 1 or 2 described conduction through type steam generator, it is characterized in that the pipe (10) of bottom (6) constitutes on interior smooth ground.

4. by aforementioned claim described conduction through type steam generator one of at least, it is characterized in that the pipe (13) of the tube wall (3) on flue (2) top (5) constitutes on interior smooth ground.

5. by aforementioned claim described conduction through type steam generator one of at least, it is characterized in that essentially horizontally the extending of tube wall (3) in the bottom of flue (2) and the interface (14) between top (4,5).

6. by aforementioned claim described conduction through type steam generator one of at least, it is characterized in that essentially horizontally the extending of tube wall (3) in bottom tube wall section (8) and the interface (15) that directly is connected between the tube wall section (9) on the bottom tube wall section (8).

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