CN85104835B

CN85104835B - Energy conversion equipment for desulphurization device

Info

Publication number: CN85104835B
Application number: CN85104835A
Authority: CN
Inventors: 克莱门斯·拉夫; 勒德韦格·苏尔; 保罗·佩克特
Original assignee: GEA Luftkuehlergesellschaft Happel GmbH and Co KG
Current assignee: GEA Luftkuehlergesellschaft Happel GmbH and Co KG
Priority date: 1984-05-26
Filing date: 1985-06-24
Publication date: 1987-08-26
Also published as: FI851948A0; AT392910B; FI75926C; JPH0459927B2; ATA128885A; CS268801B2; FR2564746B1; CS340785A2; JPS6138617A; DE3419735A1; CN85104835A; FI851948L; FR2564746A1; FI75926B; DE3419735C2; IN161338B

Abstract

As far as anyone knows, smoke gas is desulfurized through a washer. In order to obtain a required temperature of an inlet of the chimney for purifying air flows, the heat quantity of thick air flows is used. The heat quantity can be converted to purifying air flows through a heat shifting system as long as the temperature is higher than the dew point of sulfuric acid. Steel materials can be used, but when the temperature is lower than the dew point of the sulfuric acid, difficulty appears, and thus, special measures are required. The present invention provides modern gradient heat shifting systems 13 and 14. In the systems, firstly, heat exchangers 3 and 7 made of steel are mutually combined through a heat carrier in high temperature range. Then, heat exchangers 4 and 6 composed of corrosion resistant and anti-sticking plastics are used in a second heating shifting system 14 connected to the rear part.

Description

The shift energy-consuming equipment of desulfurizer

The invention relates to the shift energy-consuming equipment of desulfurizer.

The result who actively makes great efforts to cause on the environmental protection cause is, not only to newly-built power plant, and to already present power plant, must take preventive measures, and flue gas is carried out desulfurization.Mainly be wet desulfurization system in the middle of this, flue gas be cooled to about 50 ℃ by cleaning solution leave washer.

In prior art, be that a heat exchanger is installed in thick air-flow before the washer of desulfurizer, this heat exchanger by a kind of forced flow heat carrier and another purifying gas flow behind washer in the heat exchanger installed couple together according to the mode of fluid communication, heat exchanger and by-pass line with heat-exchange tube of fin are all made by pressure-resistant material such as steel.In thick air-flow between heat exchanger and washer, and a heat exchanger at low-temperature working is installed respectively between washer and heat exchanger in purifying gas flow, the heat carrier that flows through by bypass pipe is connected to each other, and all positions that contact with gas of low temperature heat exchanger all cover or coated with plastics corrosion-resistant, anti-adhesive.

Before the flue gas that makes purification enters atmosphere, it must be heated at least 72 ℃ again and be absolutely necessary.In order to heat, developed various method.Optimum on energy economy is such certain methods, is used for reheating required heat energy and is also obtained by the thick gas of the heat that does not purify in these methods.

In the thick air-flow of washer front, insert a heat exchanger that has the heat exchanger tube of fin for this purpose, and with this heat exchanger through a heat carrier that flows, for example resemble the water of anti-freeze, be connected with the heat exchanger of another heat exchanger tube of with ribbing, this heat exchanger is contained in behind washer in the air-flow of purification.Therefore by means of this equipment can be from thick air-flow heat removal, pass to clarifier through heat carrier.The pipeline and the bypass line of heat exchanger, heat carrier here generally are made of steel.But when being in the sulphuric acid dew point scope as if temperature, then its consequence is difficult to imagination.Therefore there is the people to advise,, but shows here each parts coated of heat exchanger, because coated substance belongs to macromolecular structure, along with the time progress, the molecule that oozes out below coating has constituted residue, this residue has not only destroyed basic material, and makes coating loose.Even the heat exchanger of enamel also has been used for desulfurizer.Yet the measure that all are narrated previously owing to various different reasons, can not make the professional person satisfied so far.

Basic task of the present invention is to improve the shift energy-consuming equipment of desulfurizer, makes without precious materials, can accomplish long-term trouble-free purification flue gas.

According to invention, the solution of this task is the heat-tranferring system that has been connected to each other at two kinds of different temperatures horizontal operations.Make about 140 ℃ also awfully hot thick gas at first pass through the heat exchanger of one smooth or with ribbing thick walled steel tube, approximately be cooled to 115 ℃ here.Heat carrier has absorbed the heat of thick gas, through being connected on the heat exchanger in the purifying gas flow, gives purified gas with transfer of heat.To look after that at the heat carrier circulation time steady temperature is in 105 ℃ of-120 ℃ of scopes, the wall surface temperature of sulphuric acid dew point therefore can not occur being lower than in all places of the heat-tranferring system that constitutes by steel.When temperature was higher than 65 ℃, promptly after the liquid drop separator of washer, the drop that also contains in purified gas in fact all gasified.Therefore on the heat-exchanger surface in purified gas the scab shell does not appear yet.Because safety is certainly installed soot blower in addition.

At second section, that is to say that at lower temperature levels, the present heat-tranferring system that uses, its material are to be made of corrosion-resistant and plastics anti-adhesive.The heat carrier temperature of this regulation is to make thick gas for example be cooled to 95 ℃ from 115 ℃.The heat carrier temperature that in this plastics heat-tranferring system, circulates approximately be 75 ℃ because this temperature levels, thereby thick gas on one side the dew point of sulfuric acid be applied in the scope of heat exchanger of that connection.The acid that generates in this case, the flowing downward on flexible pipe or pipeline or drip of part perhaps partly mixed with ash content and is bonded on flexible pipe or the pipeline together.Can use washings in order to clean, washings can put together again, are sent to washer.

In plastic flexible pipe or pipeline, the heat that will absorb by means of the heat carrier (this heat carrier can be made up of the water of anti-freeze) of circulation is delivered to low temperature-heat exchanger of installing between washer and steel parallel operation in purifying gas flow, and be transferred to Purge gas through this heat exchanger.In this case, Purge gas is by about 50 ℃ of temperature that are heated above 65 ℃.Can reach (on the face that heat exchanger is hit) thus all gasifies the water droplet that still contains in air-flow.The calcium sulfate that may occur in this case being contained in the drop carries over.On material surface, may generate plaster shell by this way.But because the plastics that use have the surface property of anti-adhesive, so this can easily purify by vibration.Transformation temperature also can be used for purifying.

Thereby the present invention can and be higher than in 65 ℃ of dry scopes at purifying gas flow in thick air-flow is higher than the high scope of sulphuric acid dew point, uses habitual pressure-resistant material as raw material, for example resembles steel.

In the low temperature field,, and non-pressurized plastic tube or plastic flexible pipe in purifying gas flow, have in fact been used by contrast not only at thick air-flow.

The arrangement of two heat-tranferring systems of successively arranging by grade can be carried out in any place of thick air-flow and purifying gas flow.Even that in the system separately of thick air-flow and purifying gas flow, install and surpass 50 meters, do not shown any difficulty by the heat exchanger distance that heat carrier interlinks yet.Even the present invention can make old device extend reconstruction at an easy rate.Because purified gas can not be polluted by thick gas, so not only at the thick air-flow of drying, and at purifying gas flow an air blast to be installed be possible.The separating degree that washer reaches remains unchanged, and also is the separating degree of flue gas desulfur device.Because can use known corrosion resistant durable material, thus can reach the very long life-span, even the long time heat exchanger of running can not damaged yet.

A kind of favourable form of implementation is that low temperature heat exchanger and bypass line make with polytetrafluoroethylene (PTFE), poly-vinylidene fluoride or polypropylene, perhaps covers or coated with polytetrafluoroethylene (PTFE), poly-vinylidene fluoride or polypropylene.By the heat exchanger that such plastics make, in can only being used for, nature presses quite low situation.The material of being spoken of tends to flow when higher temperature and pressure, and therefore not only temperature but also interior pressure must all will prove safe and reliable.But in the middle of this, by being lower than the selection of 100 ℃ heat carrier temperature, and, can be calculated reliably by step-like basin in each quite low heat exchanger front of plastics intensity.Therefore can guarantee that the pressure that occurs must not surpass the numerical value that allows in heat exchanger.Rise even in flue gas, occur temperature suddenly, pressure inside is improved.

The by-pass line of low temperature heat exchanger couples together with another bypass pipe, can guarantee heat carrier temperature stabilization remain on the desired horizontal.This favorable properties also is applicable to first section heat-tranferring system that is made of steel naturally.

For its pressure is too raise, can differently survey highly installation, and always be equipped with the relay reservoir of a heat carrier in the front and back of heat exchanger with the heat exchanger of water as heat carrier.Therefore can guarantee, can only give certain hydraulic pressure of predesignating each heat exchanger.Water flows through heat exchanger because of potential difference, heat is transferred to the water of purified gas by thick gas.Backflow is finished by a pump.

At the low temperature heat exchanger of high position the control valve of a controlled pressure is installed to the by-pass line of lower position low temperature heat exchanger, is used for monitoring stream to cross the heat carrier process of the highly lower heat exchanger of survey with being contained in.

A kind of particularly advantageous form of implementation of the present invention is, low temperature heat exchanger in thick air-flow and the purifying gas flow has U-shape plastic tube or the plastic flexible pipe of hanging from the top, such flexible pipe and pipeline can be installed by bunchy, therefore the tube bank of each heat exchanger also can be installed the valve of each bundle, and can switch when operation.By the U-shaped of flexible pipe or pipeline, distributor chamber and collecting chamber can be installed in beyond the air-flow, therefore just guarantee easy to use in simple mode.

When uprush, also can substitute the plastic flexible pipe or the pipeline of U-shape with freely-suspended plastic flexible pipe of level or pipeline.

The free end of plastic flexible pipe or plastic tube can be inserted tube with hole enlargement and be fixed at the end of heat exchanger, inserts the outer end of tube and expands funneling.At first flexible pipe or pipeline are inserted tube bottom plate for this reason, then will insert tube and insert the termination, carry out bloated mouthful of pipe then.Inserting tube is advantageous by copper or brass manufacturing.

Hose end always constitutes a water inlet that is suitable for flowing, and the drag losses that this mouthful causes is very little.

The length (L) of inserting tube should fracture on tube bottom plate to prevent flexible pipe or pipeline greater than the base thickness (D) of heat exchanger.

The distributor chamber of low temperature heat exchanger and collecting chamber separate by corrosion resistant air seal face and air-flow.When producing, to each flexible pipe or pipeline flows into distributor chamber and collecting chamber is controlled, constantly can interrupt serious.This in addition measure also can be used for using high-intensity versatile material to constitute distributor chamber and collecting chamber, and uses material etch-proof but that intensity is relatively poor to be used as air seal face.

Plastic flexible pipe or plastic tube be voluntarily sealing and fixing on air seal face.The automatic sealing and fixing of plastic flexible pipe on the air seal face or plastic conduit is that hydraulic pressure that the elasticity by flexible hose conduit exists at hose inner wall when producing combines and obtains, and the pressure of water is higher than the gas pressure of regulation.

Plastic flexible pipe or plastic tube can wash with stream of cleaned water.The surface property of the flushing of stream of cleaned water and the anti-adhesive of plastics plays a kind of effect of easy purification.In the middle of this, can wash carbon black off, dust and sulfuric acid.Relevant therewith can insert a distributor pipe at each bundle, and the predetermined distance of Guan Zaiyi flows out washings from the limit thus.

Plastic flexible pipe between the long arch surface of air seal face and buckling or plastic tube pass a Board for adjusting vision distance from vertical middle fore-and-aft plane to both sides that make the roof type tendency from least, the Board for adjusting vision distance of this roof type or a plurality of such plate have guaranteed that not only the plastic flexible pipe pipeline accurately installs, and have guaranteed the sequenced flow process of washings.

The low temperature heat exchanger of installing in purifying gas flow is vibratile, and therefore the possibility that the booty of adhesion is removed by vibration is provided.Vibration also can combine with the thermal expansion of plastic substance, so that the thing of adhesion is burst apart out when temperature change.This is only required assurance does not stop flexible pipe or pipe expansion in the vertical.

The present invention is further described with the examples of implementation of describing among the following figure:

Fig. 1 shows: on stream, a cover flue gas desulfur device has two and divide the front and back heat-tranferring system that group is installed in flue gas stream.

Fig. 2 shows: on stream in the front view, and a heat exchanger of Fig. 1 heat-tranferring system.

Fig. 3 shows: a details enlarged drawing of Fig. 2 heat exchanger.

Fig. 4 shows: the section IV enlarged drawing of Fig. 3

Fig. 5 shows: in perspective view, and partial cross section, other details of Fig. 2 heat exchanger.

Fig. 6 shows: the another kind of form of implementation of heat-tranferring system.

For example in the flow process of Fig. 1, the equipment of describing 1 has constituted a part of coal power generation factory, and is used for the flue gas desulfurization that the power plant generates.

According to the direction of arrow, the thick air-flow ROS that is come out by electric cleaner is approximately 140 ℃, at first makes it pass through a heat exchanger under this temperature, and this heat exchanger is made of steel, have one group of fin that has parallel to each other, but do not have the heat-exchanger pipeline of depicted in greater detail in the drawings.

After leaving heat exchanger 3, thick gas ROS is approximately 115 ℃ temperature in addition.Thick gas ROS under this temperature enters in another heat exchanger 4, and this heat exchanger will be further described with Fig. 2 to 6 below.

Leave this heat exchanger 4, the temperature of thick gas ROS is approximately 95 ℃, after enter in the washer 5, in washer, take off sulphur with wet method.

When the outlet of washer 5, the flue gas of purification is approximately 48 ℃, and by a heat exchanger 6, this heat exchanger is in the heat exchanger connecting state with heat exchanger 4 among the thick air-flow ROS with the purifying gas flow RES of this temperature.In this heat exchanger 6, purifying gas flow RES is heated to about 68 ℃, then is sent to another heat exchanger 7, and the heat exchanger of installing among this heat exchanger and the thick air-flow ROS 3 is in the heat exchanger connecting state.

After leaving heat exchanger 7, purifying gas flow RES is about 90 ℃, and the purifying gas flow with this temperature drains in the atmosphere through chimney 8.

In thick air-flow ROS and the heat exchanger 3,7 of the with ribbing thick walled steel tube of in purifying gas flow RES, installing, be in the connection state that liquid communicates by bypass line 9,10.Liquid is made up of antifreeze water.This water is heated to about 120 ℃ in heat exchanger 3, the pipeline 9 of flowing through then flows to the heat exchanger 7 among the purifying gas flow RES, and is cooled to about 105 ℃ at this.Pump 11 on the pipeline 10 has guaranteed the backflow of heat carrier.By the adjusting of bypass 12, the temperature of heat carrier can remain between 105 ℃ and 120 ℃, and therefore the wall temperature of sulphuric acid dew point appears being lower than in the heat-tranferring system 13 neither one places that are made of steel.

At second section of flue gas desulfurization device 1, in thick air-flow ROS, the heat exchanger of installing in purifying gas flow RES on the

other hand

4,6 also is to interlink by

bypass line

15,16 on the one hand.In this heat-tranferring system, the water of anti-freeze is to circulate between 70 ℃ and 80 ℃ in temperature range equally.In the heat exchanger 4 of this water in thick air-flow ROS, be heated to about 80 ℃, by the heat exchanger 6 that flows to purifying gas flow RES there through pipeline 15, here the heat that will emit is passed to purified gas.Heat carrier is cooled to about 70 ℃ thus.Heat carrier is with this temperature then, for example flows to heat exchanger 4 among the thick air-flow ROS again by means of pump 17.

Pipeline

15,16 interlinks by a bypass 18.

Because the temperature of the thermal cyclic carrier of second heat-tranferring system 14 is greatly about 75 ℃, so be the dew point scope of sulfuric acid entirely on one side at thick gas.All use one corrosion resistantly to cover or coated for fear of all parts that contact with gas of infringement heat-tranferring system 14, two

heat exchangers

4,6 with plastics anti-adhesive.This plastics can be polytetrafluoroethylene (PTFE), poly-vinylidene chloride or polypropylene.Even the

bypass line

15,16 between two

heat exchangers

4,6 at least also will be by a corrosion resistant plastic production.

In order to carry out heat exchange (referring to Fig. 2 and 3), under the situation of horizontal gas flow, in thick air-flow ROS and purifying gas flow RES, the U-of bunchy moulds the material flexible pipe from last side suspension.This plastic flexible pipe is made of plastics, for example resembles polytetrafluoroethylene (PTFE), poly-vinylidene chloride or polypropylene.

For example Fig. 2 shows, the heat exchanger of in thick air-flow ROS, installing 4, and the same with the heat exchanger installed in purifying gas flow RES 6 all is to be divided into A, B, three headers of C, this header is always single, and on-stream standby.At each header A, B, the U-among the C mould material hose bundle 19 all following advantage (Fig. 3): only a distributor chamber 20 and collecting chamber 21 row's examples are being on air-flow ROS or the RES horizontal plane in addition.Boundary is to realize by an air seal face 22 that is made of corresponding suitable material.Heat carrier enters distributor chamber 20 at arrow 23, and enters flexible pipe 19 whereby, leaves each header A, B, C according to arrow 24.

Show that as Fig. 4 fixing each flexible pipe 19 on the end of distributor chamber and collecting chamber is to finish by following method, flexible pipe inserted in the 25 corresponding holes 26, bottom, then be pressed into and 11 the slotting tube 27 that constitutes by copper of expanding fix.The shape of inserting tube 27 is selected like this, makes a kind of funnel shaped water inlet or delivery port 28 in the termination, and the drag losses that this import or export causes is very little.Select the length L of the slotting tube 27 of choosing in addition and be longer than the pipe thickness D at the end 25.Prevent that in this way flexible pipe 19 from fractureing at pipe at the end 25.

Fixing flexible pipe 19(Fig. 3 and 4 on air seal face 22), be to realize that by the hydraulic pressure that exists at the inwall of flexible pipe 19 in the running this hydraulic pressure is because the low gas pressure that can expect relative with it guaranteed a kind of passage of sealing.29 is a spacer, and this spacer makes distributor chamber and 20,21 pairs of air seal faces of collecting chamber 22 keep essential spacing.

Find out that from Fig. 2 and 5 vertical pipe 30 passes each header A of

heat exchanger

4,6, B, C.Pipeline 30 is on the air seal face that is supported on hermetically 22, and has outlet 31 at various height.Therefore corresponding to the direction of arrow 32, by importing washings, can be with at each header A, B, the flexible pipe of bunchy (Fig. 3) cleaning when needed among the C.These washings can be led to delivery port 34 through basin 33 then.Heat exchanger 4 or all parts that contact with flue gas of 6 all are made of plastics, and these plastics are corrosion resistant at least.These parts are tube bundle support 35, baffle plate 36, basin 33 and water out 34.

Combined as can be seen with Fig. 3 by Fig. 5 in addition, each bar flexible pipe 19 is to force to pass through differing heights.Here used by long face in the middle of vertical and made the Board for adjusting vision distance 37 that the roof sample tilts to the next door gradually.By the inclination of this roof sample washings are outwards flowed down smoothly enters in the basin 33.

Whole heat exchanger

4,6 or various piece can be vibrated when needed.This essential vibrational system does not draw in the drawings.

In Fig. 6, described a form of implementation.In this embodiment, the low temperature-

heat exchanger

4,6 of second heat-tranferring system 14 is installed on the different ground survey height.In order to make within reason the increasing of pressure in

heat exchanger

4,6, in 4,6 front and back of heat exchanger one intermediate storage tank 38,39 always is installed, can guarantee that each heat exchanger has certain regulation water pressure for these two jars.With the water of transfer of heat to purifying gas flow RES, the cause owing to water-head flows through

heat exchanger

4,6 by thick air-flow ROS.In the outflow of surveying the heat exchanger 6 on the height, can monitor by pressure controlled control valve 40 by one on the pipeline 15 than the lowland.With pump 17 heat carrier is delivered to storage tank 38 through pipeline 16 by storage tank 39.

Relevant symbol table

1. flue gas desulfur device

2. electric cleaner

3. heat exchanger

4. heat exchanger

5. washer

6. heat exchanger

7. heat exchanger

8. chimney

9. bypass line

10. bypass line

11. the pump on 10

12. bypass

13. heat-tranferring system

14. heat-tranferring system

15. bypass line

16. bypass line

17. pump

18. bypass

19. flexible pipe

20. distributor chamber

21. collecting chamber

22. air seal face

23. heating medium inlet

24. heating medium outlet

25.20 and 21 the end

26.25 on the hole

27. insert tube

28. the inlet of water or outlet

29. spacer

30. water pipe

31. outlet opening

32. the inlet of water

33. basin

34. delivery port

35. tube bundle support

36. baffle plate

37. Board for adjusting vision distance

38. intermediate storage tank

39. intermediate storage tank

40. adjuster

The thick air-flow of ROS

The RES purifying gas flow

The A header

The B header

The C header

The length of L 27

The thickness of D 25

Claims

1, in the shift energy-consuming equipment that is used for desulfurizer, this equipment thick air-flow before washer a heat exchanger has been installed, the heat carrier by forced flow is connected by the mode of fluid communication with another heat exchanger in being installed in washer after-purification air-flow; Heat exchanger and by-pass line with heat-exchange tube all are to make as steel with pressure-resistant material, between heat exchanger in thick air-flow and purifying gas flow and the washer heat exchanger in low-temperature space work has been installed respectively, they are connected to each other by the heat carrier in the bypass pipe, all parts that contact with gas of low-temperature space heat exchanger are all used corrosion-resistant, inadhesive plastics cover to be gone up or coated, it is characterized in that: hang over low-temperature switch (4 in thick air-flow (ROS) and the purifying gas flow (RES), 6) flexible pipe in (19) is to make with the plastics of corrosion-resistant anti-adhesive, low temperature heat exchanger (4,6) by-pass line (15,16) equally also should use corrosion resistant plastics manufacturing.

2, shift energy-consuming equipment according to claim 1 is characterized in that: wherein said plastics corrosion-resistant, anti-adhesive are polytetrafluoroethylene (PTFE), poly-vinylidene fluoride or polypropylene.

3, shift energy-consuming equipment according to claim 1 is characterized in that: low temperature heat exchanger (4,6) is mounted in differently to be surveyed on the height, and the front and back in low temperature heat exchanger (4,6) have been equipped with relay reservoir (38,39) to heat carrier.

4, shift energy-consuming equipment according to claim 3 is characterized in that: be positioned at the control valve (40) that the low temperature heat exchanger of eminence (4) is equipped with a controlled pressure to the by-pass line (15) of the low temperature heat exchanger that is positioned at lower (6).

5, according to the shift energy-consuming equipment of claim 1, it is characterized in that: when flow level flowed, plastic flexible pipe (19) should form U one shape, and hung thick air-flow and purifying gas flow from top.

6, according to the shift energy-consuming equipment of claim 1, it is characterized in that: if air-flow is a perpendicular flow, then plastic flexible pipe (19) but level freely hang.

7, according to claim 5 or 6 described shift energy-consuming equipments, it is characterized in that: the free end of plastic flexible pipe (19) can be inserted tube (27) with hole enlargement and be fixed at the end (25) of heat exchanger.

8, shift energy-consuming equipment according to claim 7 is characterized in that: intubate (27) is made with copper or brass.

9, shift energy-consuming equipment according to claim 7 is characterized in that: the outer end (28) of intubate (27) enlarges becomes infundibulate.

10, shift energy-consuming equipment according to claim 7 is characterized in that: the length (L) of intubate (27) should be greater than the thickness (D) of (25) at the bottom of the heat exchanger.

11, according to each described shift energy-consuming equipment among the claim 1-6, it is characterized in that: the distributor chamber (20) of low temperature heat exchanger (4,6) and collecting chamber (21) separate with corrosion resistant airtight plane (22) and air-flow (thick air-flow or purifying gas flow).

12, shift energy-consuming equipment according to claim 11 is characterized in that: plastic flexible pipe (19) be voluntarily sealing and fixing on the air seal face (22).

13, shift energy-consuming equipment according to claim 12, it is characterized in that: Board for adjusting vision distance (37) in the middle of the plastic flexible pipe (19) between the bow face of air seal face (22) and buckling passes at least, this Board for adjusting vision distance are to make roof type from the vertical vertical plane of centre to both sides to tilt.