CN102012039B - Forced circulation air preheat system - Google Patents

Forced circulation air preheat system Download PDF

Info

Publication number
CN102012039B
CN102012039B CN201010601629.3A CN201010601629A CN102012039B CN 102012039 B CN102012039 B CN 102012039B CN 201010601629 A CN201010601629 A CN 201010601629A CN 102012039 B CN102012039 B CN 102012039B
Authority
CN
China
Prior art keywords
air
heat exchanger
exchanger tube
hypomere
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN201010601629.3A
Other languages
Chinese (zh)
Other versions
CN102012039A (en
Inventor
孙淮林
翟松森
冯友福
刘禹卉
王炎
王晓鹏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen Zhongxing Energy Conservation & Environment Protection Co Ltd
Original Assignee
Shenzhen Zhongxing Energy Conservation & Environment Protection Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenzhen Zhongxing Energy Conservation & Environment Protection Co Ltd filed Critical Shenzhen Zhongxing Energy Conservation & Environment Protection Co Ltd
Priority to CN201010601629.3A priority Critical patent/CN102012039B/en
Publication of CN102012039A publication Critical patent/CN102012039A/en
Application granted granted Critical
Publication of CN102012039B publication Critical patent/CN102012039B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00Combustion technologies with mitigation potential
    • Y02E20/34Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Abstract

The invention discloses a forced circulation air preheat system which is characterized in that a lower-section air preheater is internally provided with at least two gas ducts and at least two air flues, wherein the numbers of the gas ducts and the air flues are same; each gas duct is isolated from each air flue; the gas ducts and the air flues are arranged at intervals; a lower-section heat exchange tube is arranged between each two adjacent gas duct and air flue, and all the lower-section heat exchange tubes are communicated; and a transporter is arranged between the water inlet and water outlet of each lower-section heat exchange tube, and is connected with a circuit controller. Because the forced circulation air preheat system is subject to secondary heat exchange by means of a medium, the medium generates phase change in the lower-section heat exchange tubes so as to maintain the wall surface temperature of the lower-section heat exchange tubes to be equal to the phase change temperature of water, and the pressure in the lower-section heat exchange tubes is adjusted in the gas ducts so as to control the tube wall temperature of the lower-section heat exchange tubes to be higher than the acid dew point temperature of flue, thus avoiding the parts, which are positioned in the gas ducts, of the lower-section heat exchange tubes from acid corrosion, thereby solving the problem of low temperature corrosion caused by the smoke removal temperature reduction of the air preheater.

Description

Forced circulation air preheating system
Technical field
The present invention relates to boiler plant heat recovery technology field, particularly a kind of air preheating system that reduces boiler exhaust gas heat loss and make full use of waste heat of realizing by forced circulation.
Background technology
Existing boiler plant, as all kinds of high pressure, super-pressure, subcritical pressure boiler, the exhaust gas temperature of its air preheater rear pass is higher, in order to improve boiler thermal output, conventionally using air preheater as flue surface, carries out air and the exchange of flue gas direct heat.
The wider product of application mainly contains tubular air preheater and regenerative air preheater at present.From former boiler design technique, conventional tubular or regenerative air preheater be for avoiding occurring cold end corrosion and stifled ash, and for example, when acid dew point is 80 ℃, exhaust gas temperature will be higher than 135 ℃ (if import wind-warm syndrome 20 ℃).As need further reduce the exhaust gas temperature of boiler and guarantee that the tube wall temperature of air preheater is not less than flue gas dew point, adopting conventional art is to accomplish.Therefore conventionally when guaranteeing safe operation of the boiler, exhaust gas temperature need to design highlyer, thereby causes boiler exhaust gas heat loss.
The import wind-warm syndrome of existing air preheater is along with can change season simultaneously, and exhaust gas temperature is also subject to the impacts such as load, burning, when the wall surface temperature of air preheater is during lower than acid dew-point temperature, will there is cold end corrosion and cause local dust stratification, SR increase, heating surface fouling etc. in air preheater end, thereby affect the thermal efficiency of boiler.
Summary of the invention
The technical problem that the present invention mainly solves is to provide a kind of forced circulation air preheating system, the cold end corrosion that this forced circulation air preheating system produces in the time of can avoiding reducing the exhaust gas temperature of air preheater, reduce the exhaust gas temperature of air preheat simultaneously, improve the utilization ratio of fume afterheat.
In order to address the above problem, the invention provides a kind of forced circulation air preheating system, this forced circulation air preheating system comprises hypomere air preheater, in this hypomere air preheater, be provided with at least two flues and at least two air channels that quantity is identical, each flue and air channel are mutually isolated, flue gas and air do not carry out direct heat transfer by tube wall, and flue is adjacent with interval, air channel, between this adjacent flue and air channel, be respectively equipped with the hypomere heat exchanger tube of connection, between the water inlet end of this hypomere heat exchanger tube and water side, be provided with conveying device, this conveying device is connected with circuit controller.
Preferably, described hypomere heat exchanger tube is in parallel distributes.
Preferably, between the water side of described hypomere heat exchanger tube and conveying device, being provided with the expansion tank of adjustable water pressure is connected with conveying device and accepts the first switch that circuit controller is controlled.
Preferably, described the first switch comprises electrically operated valve or electromagnetic valve.
Preferably, described conveying device comprises water circulating pump.
Preferably, described forced circulation air preheating system also comprises the stage casing air preheater being connected with hypomere air preheater, and wherein on this stage casing air preheater, two air channels are arranged in a crossed manner.
Preferably, described forced circulation air preheating system also comprises the epimere air preheater being connected with stage casing air preheater, this epimere air preheater is provided with the conduit being connected with water cooler with epimere heat exchanger tube in it, and this conduit is provided with the second switch that is connected and controls conduit condensing water flow with described circuit controller.
Preferably, described gate-controlled switch comprises electrically operated valve or electromagnetic valve.
Preferably, the condensing water conduit hydraulic pressure of the entrance of described epimere heat exchanger tube, outlet hydraulic pressure and introducing, the heat regenerative system of drawing is identical.
Preferably, at least two of described hypomere air preheater outlet air channels are higher than described at least two gas approach.
Forced circulation air preheating system of the present invention, in this hypomere air preheater, be provided with at least two flues and at least two air channels that quantity is identical, each flue and air channel are mutually isolated, flue gas and air do not carry out direct heat transfer by tube wall, and flue is adjacent with interval, air channel, the hypomere heat exchanger tube that is respectively equipped with connection between this adjacent flue and air channel, is provided with conveying device between the water inlet end of this hypomere heat exchanger tube and water side, and this conveying device is connected with circuit controller.During work, by the water that is positioned at the hypomere heat exchanger tube of flue, absorb heat, make water become steam, this steam is passed to heat in the hypomere heat exchanger tube in air channel, this steam makes to raise with the air themperature contacting in hypomere heat exchanger tube, simultaneously with air contact process in make steam condense into water to flow in header, this water carries out forced circulation under described conveying device is carried, and realizes Continuous Heat Transfer.
Because forced circulation air preheating system is to carry out secondary heat exchange by medium, medium undergoes phase transition in hypomere heat exchanger tube, make the wall surface temperature of hypomere heat exchanger tube maintain the phase transition temperature of water, in flue, by the pressure (being expansion tank pressure) in adjusting hypomere heat exchanger tube, hypomere heat exchanger tube wall temperature (water temperature) is controlled on flue gas acid dew point temperature all the time, avoid hypomere heat exchanger tube to be positioned at the pipeline generation acid corrosion of flue, thereby solve the problem of traditional air preheater cold end corrosion.
When the coal combustion speciogenesis of boiler changes, acid dew-point temperature also can change, and the phase transition temperature by medium in expansion tank pressure change hypomere heat exchanger tube, is controlled at the wall surface temperature of hypomere heat exchanger tube on acid dew-point temperature all the time, prevents the corrosion of acid dew.By circuit controller, control gate-controlled switch simultaneously and be greater than to regulate water cooler condensate flow, cigarette temperature after water cooler is changed, to change the flue-gas temperature after hypomere air preheater, thereby realize the object that prevents boiler flue corrosion and reduce to greatest extent exhaust gas temperature.
Accompanying drawing explanation
Fig. 1 is forced circulation air preheating system example structure schematic diagram of the present invention;
Fig. 2 is along A-A direction sectional structure schematic diagram;
Fig. 3 is another example structure schematic diagram of forced circulation air preheating system of the present invention.
Below in conjunction with embodiment, and with reference to accompanying drawing, the realization of the object of the invention, functional characteristics and advantage are described further.
The specific embodiment
As shown in Figure 1, Figure 2 and Figure 3, the invention provides a kind of forced circulation air preheating system embodiment.
This forced circulation air preheating system comprises: hypomere air preheater, in this hypomere air preheater, be respectively equipped with at least two flues (exhaust gases passes) and at least two air channels (air duct) that quantity is identical, the quantity of flue is identical with the quantity in air channel.Each flue and air channel are mutually isolated, flue gas and air do not carry out direct heat transfer by tube wall, and flue is adjacent with interval, air channel, between this adjacent flue and air channel, be respectively equipped with the hypomere heat exchanger tube of connection, between the water inlet end of this hypomere heat exchanger tube and water side, be provided with conveying device, as adopting the water circulating pump of variable frequency adjustment, this conveying device is connected with circuit controller; Described hypomere heat exchanger tube can be in parallel distribution.
Between the water side of described hypomere heat exchanger tube and conveying device, be provided with the expansion tank of adjustable water pressure and be connected with conveying device and accept the first switch that circuit controller is controlled, this first switch comprises electrically operated valve or electromagnetic valve.
During work, flue gas is from top to bottom by described hypomere air preheater.By the water that is positioned at the hypomere heat exchanger tube of flue, absorbed the heat of flue gas, make water become steam, this steam is passed to heat the hypomere heat exchanger tube that is positioned at air channel, this steam raises the air themperature contacting with hypomere heat exchanger tube outer wall, simultaneously with air contact process in make steam in hypomere heat exchanger tube condense into water to flow in header, this water carries out forced circulation under described conveying device is carried, and realizes Continuous Heat Transfer.
Because forced circulation air preheating system is to carry out secondary heat exchange by medium, medium undergoes phase transition in hypomere heat exchanger tube, make the wall surface temperature of hypomere heat exchanger tube maintain the phase transition temperature of water, in flue, by the pressure (being expansion tank pressure) in adjusting hypomere heat exchanger tube, make hypomere heat exchanger tube wall temperature (water temperature) be controlled at all the time on acid dew-point temperature, avoid hypomere heat exchanger tube to be positioned at the pipeline generation acid corrosion of flue, thereby solve the problem of traditional air preheater cold end corrosion.
When the coal combustion speciogenesis of boiler changes, acid dew-point temperature also can change, can the wall surface temperature of hypomere heat exchanger tube be controlled on acid dew-point temperature all the time by the phase transition temperature of medium in expansion tank pressure change hypomere heat exchanger tube, prevent the corrosion of acid dew.
In upper embodiment, water source in described epimere heat exchanger tube comes from the condensate water of steam turbine water supply heat back system, hydraulic pressure is the pipeline pressure that attracts condensate water, and the condensing water conduit hydraulic pressure of the entrance of described epimere heat exchanger tube, outlet hydraulic pressure and introducing, the heat regenerative system of drawing is identical; At least two outlet air channels of described hypomere air preheater are higher than described at least two gas approach.
As shown in Figure 3, described forced circulation air preheating system also comprises the stage casing air preheater being connected with hypomere air preheater, wherein on this stage casing air preheater, two air channels are arranged in a crossed manner, can make the flue gas in flue fully contact with air channel outer wall, the heat exchange coefficient of flue gas in the air in raising air channel and flue.
On the air preheater of described stage casing, be provided with epimere air preheater, this epimere air preheater is provided with epimere heat exchanger tube, this epimere heat exchanger tube and water cooler connect, this conduit is provided with the second switch that is connected and controls conduit condensing water flow with described circuit controller, and this second switch comprises electrically operated valve or electromagnetic valve.
Technique effect for better explanation the present invention reaches, illustrates the course of work.
Described water cooler is the gas one water heat-exchanger rig of flue gas and condensate water, structure and economizer are similar, the high-temperature flue gas of 330-350 ℃ of left and right can be reduced to 250-270 ℃ of left and right, high-temperature flue gas and low-temperature condensate carry out heat exchange, and water-cooled source comes from the condensate water of water supply heat back system.Can control the flow of inlet water that second switch regulates water cooler by circuit controller as required, realize and control the cooldown rate of water cooler to flue gas.
Stage casing heat exchanger tube on the air preheater of stage casing adopts oblique layout, and air is along pipe to upwards flowing in the heat exchanger tube of the stage casing of this oblique layout, and flue gas flows downward outward and washes away heat exchanger tube at stage casing heat exchanger tube.This stage casing air preheater can be reduced to the high-temperature flue gas of 250-270 ℃ 160 ℃ of left and right, normal temperature air is heated to temperature required level simultaneously, supplies with boiler-burner and burns.
Hypomere air preheater can adopt four passages, and wherein two passages are flue, and two passages are air channel, and each flue and air channel are mutually isolated, and flue gas and air do not carry out direct heat transfer by tube wall, and flue is adjacent with interval, air channel.Hypomere heat exchanger tube on hypomere air preheater adopts parallel transistor to arrange and puts, according to circumstances hypomere heat exchanger tube also can adopt horizontal positioned, can vertical or oblique placement, in hypomere heat exchanger tube for aqueous medium carries out carbonated drink phase-change heat-exchange.Hypomere heat exchanger tube absorbs flue gas heat in flue, makes the water evaporation in hypomere heat exchanger tube produce steam, and heat is delivered to the hypomere heat exchanger tube that is positioned at air channel, makes the atmosphere temperature rising in air channel, exhaust gas temperature is down to lower; Make steam in hypomere heat exchanger tube condense into water flows in header and carries out next circulation simultaneously.By be connected expansion tank with described hypomere air preheater, control water lateral pressure in hypomere heat exchanger tube, by water circulating pump, forced to promote the reciprocation cycle of carbonated drink, for circulation provides power and carries out moisturizing.
In this system, by circuit controller, it is carried out to multi-faceted adjusting, can make the flue-gas temperature after air preheater can be down to alap level, reach the object that reduces heat loss due to exhaust gas.Because exhaust gas temperature is reduced, flue gas actual flow will reduce thereupon, so also corresponding reducing of the flow velocity of the heat exchanger tube in sweep of gases air preheater, heat exchanger tube will be improved by the abrasion condition of flying dust in flue gas, the stifled ash of Antidewing.
The foregoing is only the preferred embodiments of the present invention; not thereby limit the scope of the claims of the present invention; every equivalent structure or conversion of equivalent flow process that utilizes description of the present invention and accompanying drawing content to do; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present invention.

Claims (6)

1. forced circulation air preheating system, it comprises hypomere air preheater, it is characterized in that:
In this hypomere air preheater, be provided with at least two flues and at least two air channels that quantity is identical, each flue and air channel are mutually isolated, and flue is adjacent with interval, air channel, between this adjacent flue and air channel, be respectively equipped with the hypomere heat exchanger tube of connection, between the water inlet end of this hypomere heat exchanger tube and water side, be provided with the conveying device of forced water circulation, this conveying device is connected with circuit controller, described hypomere heat exchanger tube is in parallel to distribute, in described hypomere heat exchanger tube for aqueous medium carries out carbonated drink phase-change heat-exchange, hypomere heat exchanger tube wall temperature is controlled on flue gas acid dew point temperature all the time, between the water side of described hypomere heat exchanger tube and conveying device, being provided with the expansion tank of adjustable water pressure is connected with conveying device and accepts the first switch that circuit controller is controlled, described hypomere heat exchanger tube water inlet end and water side are equipped with header, described forced circulation air preheating system also comprises the stage casing air preheater being connected with hypomere air preheater, wherein the stage casing heat exchanger tube of walking air on this stage casing air preheater is arranged in a crossed manner, this stage casing heat exchanger tube is communicated with the air channel on hypomere air preheater, described forced circulation air preheating system also comprises the epimere air preheater being connected with stage casing air preheater, this epimere air preheater is provided with epimere heat exchanger tube, this epimere heat exchanger tube is communicated with water cooler by conduit, this conduit is provided with the second switch that is connected and controls conduit condensing water flow with described circuit controller.
2. forced circulation air preheating system according to claim 1, is characterized in that:
Described the first switch comprises electrically operated valve.
3. forced circulation air preheating system according to claim 1, is characterized in that:
Described conveying device comprises water circulating pump.
4. forced circulation air preheating system according to claim 1, is characterized in that:
Described second switch comprises electrically operated valve.
5. forced circulation air preheating system according to claim 1, is characterized in that:
The condensing water conduit hydraulic pressure of the entrance of described epimere heat exchanger tube, outlet hydraulic pressure and introducing, the heat regenerative system of drawing is identical.
6. forced circulation air preheating system according to claim 1, is characterized in that:
The outlet at least two air channels of described hypomere air preheater is higher than the entrance of described at least two flues.
CN201010601629.3A 2010-12-22 2010-12-22 Forced circulation air preheat system Expired - Fee Related CN102012039B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201010601629.3A CN102012039B (en) 2010-12-22 2010-12-22 Forced circulation air preheat system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201010601629.3A CN102012039B (en) 2010-12-22 2010-12-22 Forced circulation air preheat system

Publications (2)

Publication Number Publication Date
CN102012039A CN102012039A (en) 2011-04-13
CN102012039B true CN102012039B (en) 2014-01-22

Family

ID=43842308

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201010601629.3A Expired - Fee Related CN102012039B (en) 2010-12-22 2010-12-22 Forced circulation air preheat system

Country Status (1)

Country Link
CN (1) CN102012039B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102345997B (en) * 2011-09-29 2012-11-28 熊泽宇 Dew point corrosion resistant method for flue gas heat exchanger
CN103148502B (en) * 2011-12-06 2015-06-03 攀钢集团西昌钢钒有限公司 Method for alleviating corrosion of boiler preheater

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2368001Y (en) * 1999-04-23 2000-03-08 杨本洛 Integrated heat-pipe type compound phase transition heat exchanger
CN200972137Y (en) * 2006-11-15 2007-11-07 上海宁松热能环境工程有限公司 Combined water thermal media air preheater
CN201582842U (en) * 2009-11-17 2010-09-15 中国石油化工集团公司 Combined air preheater
CN202002140U (en) * 2010-12-22 2011-10-05 深圳中兴节能环保股份有限公司 Forced circulation air preheating system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0631696B2 (en) * 1985-03-22 1994-04-27 三菱重工業株式会社 Combined gas preheater
JPS62175513A (en) * 1986-01-28 1987-08-01 Babcock Hitachi Kk Method for direct igniting and energizing of fine powder coal for boiler
CN201434623Y (en) * 2009-05-18 2010-03-31 上海泽宇机电设备制造有限公司 Two-phase flow water heat medium heat exchange system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2368001Y (en) * 1999-04-23 2000-03-08 杨本洛 Integrated heat-pipe type compound phase transition heat exchanger
CN200972137Y (en) * 2006-11-15 2007-11-07 上海宁松热能环境工程有限公司 Combined water thermal media air preheater
CN201582842U (en) * 2009-11-17 2010-09-15 中国石油化工集团公司 Combined air preheater
CN202002140U (en) * 2010-12-22 2011-10-05 深圳中兴节能环保股份有限公司 Forced circulation air preheating system

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
JP昭61-217694A 1986.09.27
JP昭62-175513A 1987.08.01

Also Published As

Publication number Publication date
CN102012039A (en) 2011-04-13

Similar Documents

Publication Publication Date Title
CN201666565U (en) Complementary combustion type waste heat boiler of catalytic cracking unit
CN202092207U (en) Central heating system recovering waste heat of smoke through absorbing type heat pump
CN204739568U (en) Energy saving and emission reduction system that horizontal phase transition heat exchanger and prefix type hydrophily formula GGH unite
CN104964265A (en) Energy-saving emission reduction system and energy-saving emission reduction method of horizontal type phase change heat exchanger and front-arrangement type water medium type GGH combined
CN104006401A (en) Power station boiler smoke waste heat deep recycling and emission reducing system
CN104676622A (en) Flue gas treatment system and flue gas reheating method based on fluoroplastic heat exchanger
CN102141253A (en) Phase transition combined air preheater
CN101261008B (en) Liquid phase intermediate medium heat exchanging type heat exchanger
CN102012039B (en) Forced circulation air preheat system
CN100520268C (en) Fume-fume hot pipe heater exchanger for fume desulphurization in heat-engine plant
CN202002140U (en) Forced circulation air preheating system
CN103471084A (en) Low-pressure hot-water smoke cooling system and method for avoiding low-temperature corrosion of air pre-heater
CN201206829Y (en) Liquid phase intermediate medium heat exchanging type heat exchanger
CN201827879U (en) Horizontal natural-circulation heat exchanger
CN103134044A (en) Method and device capable of improving efficiency of thermal power unit by cascade utilization of boiler smoke waste heat
CN111981465A (en) Flue gas waste heat utilization system
CN102116483A (en) Forced circulation air preheating system
CN206973523U (en) A kind of gasification of biomass coupling coal fired power generation gasification gas utilizes system
CN205535923U (en) Cleaning type coal fired boiler discharges fume waste heat and puies forward matter and utilize system
CN201748833U (en) Horizontal phase transition heat exchanger
CN205560808U (en) Low temperature exhaust gas's SOx/NOx control clean release device
CN103557532A (en) System and method for avoiding low-temperature corrosion of air preheater by using phase-change heat exchange
CN208186316U (en) A kind of injection boiler preheating section
CN208735652U (en) The eliminating white smoke system that a kind of heat exchanger and air preheater combine
CN101907413B (en) Horizontal type phase-change heat exchanger

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20140122

Termination date: 20191222