CN201348447Y

CN201348447Y - Anti-freezing direct air-cooled condenser

Info

Publication number: CN201348447Y
Application number: CNU200920037978XU
Authority: CN
Inventors: 王永新; 薛海君; 江瀚
Original assignee: Jiangsu Shuangliang Air Conditioning Equipment Co Ltd
Current assignee: Jiangsu Shuangliang Air Conditioning Equipment Co Ltd
Priority date: 2009-01-08
Filing date: 2009-01-08
Publication date: 2009-11-18
Anticipated expiration: 2019-01-08

Abstract

The utility model relates to an anti-freezing direct air-cooled condenser which is applicable to a heat power station in shortage of water and a turbine direct air-cooled condenser system. The direct air-cooled condenser comprises a steam distributing pipe (1), a plurality of blower units (2), a water condensing header (3), a vacuumizing system (4) and a water condensing pipeline. A cocurrent-flow heat transferring tube bundle (2.1) is arranged in the middle position of each blower unit; countercurrent-flow heat transferring tube bundles (2.2) are arranged in partition wall positions of two sides of each blower unit (2); the cocurrent-flow heat transferring tube bundle (2.1) is communicated with the steam distributing pipe (1) and the water condensing header (3); and the countercurrent-flow heat transferring tube bundles are respectively connected with the water condensing header (3) and the vacuumizing system (4). The anti-freezing direct air-cooled condenser can eliminate the root of causing the system to freeze, and the root is mainly that the unbalanced pressure between finned heat-exchanging pipes results in the vapor refluxing, the accumulation of non-condensable gases at the middle part of the heat transferring tube, and causes the condensed water at the upper part to freeze when remaining along the pipeline and passing through a non-condensable gas.

Description

Prevent the direct air cooled condenser freezed

(1) technical field

The utility model relates to a kind of direct air cooled condenser, is applicable to the heat power station and the turbine direct air cooled condenser system of water scarcity.

(2) background technology

It is made up of the direct air cooled condenser system heat-exchanging tube bundle, tube bundle support A type frame, blower fan group, steel platform, windbreak, jet chimney, condensing water conduit, vacuum lead, water ring vacuum pump (stream-jet ejector) and electric control system.Direct air cooled condenser is dried by the tube bank of blower fan heat exchanging, and the water vapour that generator/turbine is come is condensed into water in heat-exchanging tube bundle, moves in design load with the steady pressure jar that keeps generating set/turbine unit.Heating surface bank compares arranged according to certain " K/D ".

The system layout scheme of the air cooling tubes condenser concurrent-countercurrent unit of conventional art as shown in Figure 1.The heat-exchanging tube bundle system by steam-distributing pipe (steam inlet), following current unit, adverse current unit, coagulate water manifold, pumped vacuum systems and condensate line (summary) and form.The concurrent-countercurrent tube bank is centralized arrangement respectively, forms suitable, the adverse current fan unit concentrated.Water vapour enters the following current tube bank by the steam-distributing pipe distribution, most of steam condenses into water and discharges by condensate line through coagulating water manifold after heat exchange, remaining steam enters the adverse current tube bank, steam condenses after coagulate water manifold and discharge by condensate line, and incoagulable gas is discharged system by pumped vacuum systems.

But the direct air cooled condenser system is in subnormal ambient (vacuum state) owing to steam side in running, can contain a certain amount of incoagulable gas in the water vapour, this part incoagulable gas is mainly produced by the giving the water treatment chemicals of the feed water system of boiler, also has part to be produced by annex junction leak source air leakages such as turbine shaft seal place, whole steam-condensate line welding or valves.When unit operation, because each pipe row steam flow maldistribution of heating surface bank, (fan unit middle part air quantity is big for each fan unit air quantity skewness, partition wall place, both sides air quantity is little) etc. reason, make the driving force of heat transfer of each fan unit middle part heat-transfer pipe strengthen, make steam flow increase, cause velocity in pipes to increase, the outer wind speed of fit tube is big than the brattice side, and making conducts heat strengthens; And the steam flow of limit row's several tubes reduces, velocity in pipes reduces, fit tube is outer because air quantity is little, and form the eddy current that circles round in blower fan partition wall place tube bank corner, cause the energy loss of blowing, the reduction that is accompanied by wind speed makes heat-transfer effect descend, the quantity of steam that condenses in the pipe descends, and the incoagulable gas that causes being mingled with in the steam gathers, and makes the further variation of conducting heat to make the pressure of limit comb several tubes fall bigger than middle heat-transfer pipe.As shown in Figure 2, comb several tubes Lower Half has formed a low-pressure area on the limit, incoagulable gas is in this local gathering, and at condensate water header internal pressure basically identical, cause again that uncooled part steam blows back into limit comb several tubes in intervalve, incoagulable gas is mixed between two strands of steam and can't discharges like this.And at northern area, when unit is in winter operation, because environment temperature is very low, the condensate water of limit comb several tubes top condensation will be cooled to cold gradually when flowing through these cold incoagulable gas group zones that lack steam, As time goes on will freeze, finally cause circulation passage obstruction in the pipe, will cause the heat-transfer pipe bursting by freezing when serious, consequence is serious.

(3) summary of the invention

The purpose of this utility model is to overcome above-mentioned deficiency, provide a kind of can the elimination to cause the root that system freezes, be that pressure imbalance causes opposing steam flow between fin heat exchange pipe, cause incoagulable gas to accumulate in heat-transfer pipe middle part, cause top coagulate water when pipeline stays during by the incoagulability air mass cold excessively cause freezing prevent the direct air cooled condenser freezed.

The purpose of this utility model is achieved in that a kind of direct air cooled condenser of freezing of preventing, comprise steam-distributing pipe, fan unit, coagulate water manifold, pumped vacuum systems and condensate line, described fan unit has several, arrange the following current heating surface bank in the centre position that each fan unit wind speed is bigger, in the less both sides partition wall location arrangements countercurrent heat-transfer tube bank of each fan unit wind speed, described following current heating surface bank is respectively with steam-distributing pipe with coagulate water manifold and be connected, the countercurrent heat-transfer tube bank respectively with coagulate water manifold and pumped vacuum systems and be connected.Water vapour is distributed the following current heating surface bank that enters each fan unit by steam-distributing pipe, most of steam condenses into water and discharges by condensate line through coagulating water manifold after heat exchange, remaining steam enters the countercurrent heat-transfer tube bank, steam condenses after coagulate water manifold and discharge by condensate line, and incoagulable gas is discharged system by pumped vacuum systems.

The utility model changes the form of arranging in former " K/D " system reverse stream pipe constriction, cancel independent countercurrent heat-transfer tube bank unit arrangement, the tube bank of air cooling adverse current on average is arranged into each fan unit, especially the countercurrent heat-transfer pipe is arranged in position near the fan unit division wall, that is to say that the adverse current tube bank with former concentrated setting is dispersed to each unit, independent adverse current unit no longer is set, the adverse current tube bank is arranged in the partition wall place, unit of each unit.The quantity of the countercurrent heat-transfer pipe that concrete each unit is arranged needs to calculate and air force calculating through heating power, to reach best equalization point.Applicable to single row of tubes, biexhaust pipe and multi coil system.

Compare with conventional art, use this arrangement form, avoided because tube bank face velocity difference is big, cause heat-transfer pipe heat exchange amount inequality, pipe internal resistance inequality, form low-pressure area in causing managing, gather incoagulable gas in a large number, and then the situation of freezing in causing managing takes place; And the countercurrent heat-transfer pipe is arranged in the relatively poor position of heat exchange effect artificially, and under the running of vaccum-pumping equipment, make that gas is flow regime in the reverse stream pipe, avoid incoagulable gas in pipe, to stay, gather, cause the generation of the phenomenon that freezes in the pipe.This system has not only improved the heat exchange uniformity that makes whole air cooling island, and has improved heat exchange efficiency and simplified system architecture.On gear-box, can not establish holdback, in the winter time, can carry out the stoppage in transit and the counter-rotating control of each blower fan according to actual environment temperature and heat exchange amount, to reach best improvements antifreezing effect.Do not need to be provided with again the branch of adverse current, following current control, make the control of each blower fan can adopt same set of control program to control, simplified design, construction, debugging, operation complexity reduce the initial cost cost, reduce time and cost that the user is spent on operation and maintenance greatly.This system has the advantage that the preventing freeze in winter ability is strong, adjusting is corresponding soon, operating cost is low.

(4) description of drawings

Fig. 1 is the system layout conceptual scheme of the air cooling tubes condenser concurrent-countercurrent unit of conventional art.

Fig. 2 is when using the arrangement of conventional art, icing schematic diagram in incoagulable gas gathers and causes managing in the pipe.

The arrangement schematic diagram of the direct air cooled condenser concurrent-countercurrent tube bank that Fig. 3 prevents to freeze for the utility model.

Fig. 4 is that the interior steam of pipe moves towards schematic diagram when using the utility model technology.

Reference numeral among the figure:

Steam-distributing pipe 1 (steam inlet), fan unit 2, coagulate water manifold 3, pumped vacuum systems 4, following current heating surface bank 2.1, countercurrent heat-transfer tube bank 2.2, fan unit line of demarcation 2.3, steam inlet 5, following current unit 6, adverse current unit 7, limit comb 8, intervalve 9, incoagulable gas group 10, condensing zone A, cross cold-zone B, fan unit partition wall 11.

(5) specific embodiment

The utility model prevents heat-exchanging tube bundle system such as Fig. 3 of the direct air cooled condenser freezed, mainly by steam-distributing pipe 1 (steam inlet), fan unit 2, coagulate water manifold 3, pumped vacuum systems 4 and condensate line (summary) and form.Described fan unit 2 has several, arrange following current heating surface bank 2.1 in the centre position that each fan unit 2 wind speed is bigger, the both sides partition wall location arrangements countercurrent heat-transfer tube bank 2.2. water vapour less at each fan unit 2 wind speed distributed the following current heating surface bank 2.1 that enters each fan unit by steam-distributing pipe, most of steam condenses into water and discharges by condensate line through coagulating water manifold 3 after heat exchange, remaining steam enters countercurrent heat-transfer tube bank 2.2, steam condenses after coagulate water manifold and discharge by condensate line, incoagulable gas is by pumped vacuum systems 4 discharge systems, as shown in Figure 4.

Claims

1, a kind of direct air cooled condenser of freezing of preventing, comprise steam-distributing pipe (1), fan unit (2), coagulate water manifold (3), pumped vacuum systems (4) and condensate line, it is characterized in that: described fan unit (2) has several, following current heating surface bank (2.1) is arranged in centre position at each fan unit (2), in the both sides of each fan unit (2) partition wall location arrangements countercurrent heat-transfer tube bank (2.2), described following current heating surface bank (2.1) is respectively with steam-distributing pipe (1) with coagulate water manifold (3) and be connected, countercurrent heat-transfer tube bank (2.2) respectively with coagulate water manifold (3) and pumped vacuum systems (4) and be connected.